Skocz do pozycji: 1.

Tytuł:

Stochastic algorithms in discrete optimization with noisy values for the function

Autorzy:

Wieczorkowski, Robert

Powiązania:

https://bibliotekanauki.pl/articles/747459.pdf

Data publikacji:

1995

Wydawca:

Polskie Towarzystwo Matematyczne

Tematy:

Stochastic programming
Mathematical programming methods
Integer programming

Opis:

.
The paper deals with stochastic methods for searching approximately global minimum of function defined on discrete set. A measure of quality of solution is defined to compare different algorithms. Simple Monte Carlo method is analysed as main algorithm for which formulas dealing with the measure of quality are derived(two cases: exact values and noisy values of function). This Monte Carlo method is used as a base in simulation experiments for comparing other stochastic algorithms. The second part of the paper analyses asymptotic properties of the generalised simulated annealing algorithms. Theory of Markov chains is used in modelling this class of algorithms. Theorems about convergence of the records of algorithms to set of optima with probability one are presented in the case of function having random noisy values. The paper also reviews known results in the field of simulated annealing type algorithms for function with randomly perturbated values.

Źródło:

Mathematica Applicanda; 1995, 24, 38
1730-2668
2299-4009

Pojawia się w:

Mathematica Applicanda

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 2.

Tytuł:

Quantitative approach to project portfolio management: proposal for Slovak companies

Autorzy:

Kral, Pavol
Valjaskova, Viera
Janoskova, Katarina

Powiązania:

https://bibliotekanauki.pl/articles/19107981.pdf

Data publikacji:

2019

Wydawca:

Instytut Badań Gospodarczych

Tematy:

mathematical model
integer programming
optimization
project portfolio

Opis:

Research background: Project portfolio optimization isa  demanding process in the case of considering a large number of project intentions and has so far been the subject of research by many authors, especially foreign authors. However, the issue of project portfolio optimization is an area that is not sufficiently addressed by Slovak authors. This was the main impulse to create a specific mathematical model of integer programming with bivalent variables to optimize the company's project portfolio with the intention to reflect the specific requirements of Slovak companies. Purpose of the article: The aim of the article is to propose a mathematical model of integer programming with bivalent variables to optimize the project portfolio with a focus on Slovak companies. Methods: In accordance with the aim of the article, a questionnaire survey was carried out with the intention of identifying the criteria that are perceived by the managers of Slovak companies as important in the optimization of the project portfolio. These criteria were subsequently reflected in the mathematical model design using the mathematical programming method. Findings & Value added: Based on a literature review aimed at the project portfolio optimization, we have found a gap in considering the compliance of project intentions and strategic objectives of the company within the optimization of the project portfolio. Based on the results of the questionnaire survey, the significance of the mutual compliance of project intentions with the strategic objectives of the company was confirmed from the point of view of Slovak companies. Given the fact that our aim was to create an innovative integer programming model with bivalent variables orientated to the conditions of Slovak companies, we included in the resulting model the criteria that were not considered within the scope of existing research in this area, and which are perceived as important by the Slovak companies.

Źródło:

Oeconomia Copernicana; 2019, 10, 4; 797-814
2083-1277

Pojawia się w:

Oeconomia Copernicana

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 3.

Tytuł:

Explicit modeling of multi-period setup times in proportional lot-sizing and scheduling problem with variable capacity

Autorzy:

Kaczmarczyk, Waldemar

Powiązania:

https://bibliotekanauki.pl/articles/2083469.pdf

Data publikacji:

2021

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

production
lot-sizing
scheduling
mixed-integer programming

Opis:

Small bucket models with many short fictitious micro-periods ensure high-quality schedules in multi-level systems, i.e., with multiple stages or dependent demand. In such models, setup times longer than a single period are, however, more likely. This paper presents new mixed-integer programming models for the proportional lot-sizing and scheduling problem (PLSP) with setup operations overlapping multiple periods with variable capacity. A new model is proposed that explicitly determines periods overlapped by each setup operation and the time spent on setup execution during each period. The model assumes that most periods have the same length; however, a few of them are shorter, and the time interval determined by two consecutive shorter periods is always longer than a single setup operation. The computational experiments show that the new model requires a significantly smaller computation effort than known models.

Źródło:

Archives of Control Sciences; 2021, 31, 4; 883-912
1230-2384

Pojawia się w:

Archives of Control Sciences

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 4.

Tytuł:

Overlay Multicast Optimization : IBM ILOG CPLEX

Autorzy:

Kucharzak, M.
Zydek, D.
Poźniak-Koszałka, I.

Powiązania:

https://bibliotekanauki.pl/articles/226362.pdf

Data publikacji:

2012

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

overlay multicast
maximum flows
linear programming
mixed-integer programming

Opis:

IBM ILOG CPLEX Optimization Studio delivers advanced and complex optimization libraries that solve linear programming (LP) and related problems, e.g., mixed integer. Moreover, the optimization tool provides users with its Academic Research Edition, which is available for teaching and noncommercial research at no-charge. This paper describes the usage of CPLEX C++ API for solving linear problems and, as an exhaustive example, optimization of network flows in overlay multicast is taken into account. Applying continuous and integral variables and implementing various constraints, including equations and inequalities, as well as setting some global parameters of the solver are presented and widely explained.

Źródło:

International Journal of Electronics and Telecommunications; 2012, 58, 4; 381-388
2300-1933

Pojawia się w:

International Journal of Electronics and Telecommunications

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 5.

Tytuł:

Optimizing modular machining line design problem with mixed activation mode of machining units

Autorzy:

Belmokhtar, S.
Dolgui, A.
Delorme, X.
Ignatenko, I.

Powiązania:

https://bibliotekanauki.pl/articles/375904.pdf

Data publikacji:

2007

Wydawca:

Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH

Tematy:

modular machining line
cost optimization
mixed-integer programming

Opis:

A modular transfer line designing problem is investigated. The problem is to find the best subset of modules (machining units) from a given set and to assign them to different stations so that technological constraints and cycle upper limit are respected and the line cost is minimal. The investigated lines have a mixed activation mode for the machining units of each station, i. e. the units of each station are arranged into a series of stages such that each stage is composed of several units activated in parallel. A mixed integer program approach is proposed to model and solve the corresponding design problem. Improvements are suggested in order to reduce the model size and speed up the computations.

Źródło:

Decision Making in Manufacturing and Services; 2007, 1, 1-2; 35-48
1896-8325
2300-7087

Pojawia się w:

Decision Making in Manufacturing and Services

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 6.

Tytuł:

Modelling multi-period set-up times in the Proportional Lot-Sizing Problem

Autorzy:

Kaczmarczyk, W.

Powiązania:

https://bibliotekanauki.pl/articles/375894.pdf

Data publikacji:

2009

Wydawca:

Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH

Tematy:

production
lot-sizing and scheduling
mixed-integer programming

Opis:

This paper presents new mixed integer programming models for the Proportional Lot-Sizing Problem (PLSP) with set-up times longer than a period. Proposed models explicitly calculate the distribution of times amongst products in periods with a changeover and determine a final period for every set-up operation. Presented results prove that the proposed models are easier to solve using standard MIP methods than already known models.

Źródło:

Decision Making in Manufacturing and Services; 2009, 3, 1-2; 15-35
1896-8325
2300-7087

Pojawia się w:

Decision Making in Manufacturing and Services

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 7.

Tytuł:

Practical tips for modelling Lot-Sizing and Scheduling Problems

Autorzy:

Kaczmarczyk, W.

Powiązania:

https://bibliotekanauki.pl/articles/375896.pdf

Data publikacji:

2009

Wydawca:

Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH

Tematy:

production
lot-sizing and scheduling
mixed-integer programming

Opis:

This paper presents some important alternatives for modelling Lot-Sizing and Scheduling Problems. First, the accuracy of models can improved by using short time buckets, which allow more detailed planning but lead to higher computational effort. Next, valid inequalities make the models tighter but increase their size. Sometimes it is possible to find a good balance between the size and tightness of a model by limiting a priori the number of valid inequalities. Finally, a special normalization of the variables simplifies the presentation of results and validation of models.

Źródło:

Decision Making in Manufacturing and Services; 2009, 3, 1-2; 37-48
1896-8325
2300-7087

Pojawia się w:

Decision Making in Manufacturing and Services

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 8.

Tytuł:

An integrated modelling approach for an optimal location of warehouses in the defence industry organisation

Autorzy:

Bayrakcı, Melda Gelibolu
Baykoç, Ömer Faruk

Powiązania:

https://bibliotekanauki.pl/articles/27315334.pdf

Data publikacji:

2023

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

warehouse location
integer programming
defence industry
analytic hierarchy process
goal programming

Opis:

Countries’ defence industries are the leading indicator of their global power. The warehouse is the place where the materials are kept until the customer order arrives so that the companies are viable and can respond appropriately to internal/external customer demands. In this regard, warehouse location plays a vital role in the defence industry in terms of storage options with increased flexibility, a simplified supply chain with cost management and optimal positioning according to deployment locations. In this study, the decision on the location of warehouses for logistic support during the warranty period of military vehicles manufactured and supplied to the armed forces by a defence company was made. It is aimed to propose the best solution to a real-life problem with high complexity, containing many data and constraints. In this context, the criteria that are thought to be most relevant to this problem have been determined by taking expert opinions. Having determined the order of importance of the requirements by the analytical hierarchy process (AHP) with the Super Decisions V 2.10, their weights were included as a coefficient of the objective function in the goal programming (GP) model. As a result of solving the GP model using GAMS (general algebraic modelling system), it was decided to select the warehouses that provided the optimal results among the alternative warehouse locations in 9 different locations. Furthermore, to see the impact of changes in criterion weights, sensitivity analysis has also been included. The significance of this research lies within the integrated usage of AHP and GP in the defence industry when determining warehouse locations by the experts’ opinions. With this study, not only a solution strategy was developed, but also a basis for the warehouse location decision in the defence industry projects already signed or to be signed was given.

Źródło:

Operations Research and Decisions; 2023, 33, 2; 35--52
2081-8858
2391-6060

Pojawia się w:

Operations Research and Decisions

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 9.

Tytuł:

Mixed Integer Programming Approaches to Planning and Scheduling in Electronics Supply Chains

Autorzy:

Sawik, T.

Powiązania:

https://bibliotekanauki.pl/articles/375874.pdf

Data publikacji:

2017

Wydawca:

Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH

Tematy:

electronics supply chains
planning and scheduling
mixed integer programming

Opis:

This paper discusses mixed-integer programming (MIP) approaches to planning and scheduling in electronics supply chains. First, the short-term detailed scheduling of wafer fabrication in semiconductor manufacturing and detailed scheduling of printed wiring board assembly in surface mount technology lines are discussed. Then, the medium-term aggregate production planning in a production/assembly facility of a consumer electronics supply chain is described; and finally, the coordinated aggregate planning and scheduling of the manufacturing and supply of parts and production of the finished products is presented. The decision variables are defined, and the MIP modeling frameworks are provided. Two decisionmaking approaches are discussed and compared: an integrated (simultaneous) approach, in which all required decisions are made simultaneously using a complex, large monolithic MIP model; and a hierarchical (sequential) approach, in which the required decisions are made successively using the hierarchies of simpler and smaller-sized MIP models. The paper also highlights the research on stochastic MIP applications to the planning and scheduling in electronics supply chains with disrupted material and information flows due to natural or man-made disasters.

Źródło:

Decision Making in Manufacturing and Services; 2017, 11, 1-2; 5-17
1896-8325
2300-7087

Pojawia się w:

Decision Making in Manufacturing and Services

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 10.

Tytuł:

Modelling Set-up Times Overlapping Two Periods in the Proportional Lot-Sizing Problem with Identical Parallel Machines

Autorzy:

Kaczmarczyk, W.

Powiązania:

https://bibliotekanauki.pl/articles/375946.pdf

Data publikacji:

2013

Wydawca:

Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH

Tematy:

production planning
lot-sizing and scheduling
mixed-integer programming

Opis:

This paper presents a new mixed integer programming model for the Proportional Lot-Sizing Problem (PLSP) with identical parallel machines and set-up times overlapping two periods. The proposed model assumes constant period length and explicitly calculates the distribution of set-up operations among periods. The presented results of computational experiments with standard mip methods prove that the untying set-ups from period borders enables the reduction of the total costs in optimal solutions.

Źródło:

Decision Making in Manufacturing and Services; 2013, 7, 1-2; 43-50
1896-8325
2300-7087

Pojawia się w:

Decision Making in Manufacturing and Services

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 11.

Tytuł:

Developing and deploying electronics assembly line optimization tools: a Motorola case study

Autorzy:

Tirpak, T. M.

Powiązania:

https://bibliotekanauki.pl/articles/375906.pdf

Data publikacji:

2008

Wydawca:

Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH

Tematy:

electronics assembly
line balancing
linear-integer programming
industrial case study

Opis:

The assignment of workloads to production equipment is one category of planning decision for an electronics assembly factory. In practice, line balancing requires not only selecting machines with sufficient placement accuracy and feeder capacity, but also addressing a host of other operational objectives and constraints. Motorola Labs led a multi-year effort to apply mathematical programming to balance a variety of production mix and volume scenarios. By representing the optimization problem as a specially structured, mixed linear-integer program, we were able to incorporate a high degree of reality in the model, simultaneously optimizing fixed setups, handling custom parts, maximizing machine uptime, and mitigating secondary bottlenecks. This paper presents the story of how we developed and deployed a software solution that significantly improved assembly cycle times, setup changeovers, and overall factory productivity, saving the company tens of millions of dollars.

Źródło:

Decision Making in Manufacturing and Services; 2008, 2, 1-2; 63-78
1896-8325
2300-7087

Pojawia się w:

Decision Making in Manufacturing and Services

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 12.

Tytuł:

Partial coordination may increase overall costs in supply chains

Autorzy:

Kaczmarczyk, W.

Powiązania:

https://bibliotekanauki.pl/articles/375910.pdf

Data publikacji:

2008

Wydawca:

Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH

Tematy:

supply chain
production
distribution
lot-sizing
coordination
mixed-integer programming

Opis:

This paper presents a computational study to evaluate the impact of coordinating production and distribution planning in a two-level industrial supply chain. Three planning methods are compared. The first emulates the traditional way of planning. The two other coordinate plans of the supplier and of all the buyers according to the Vendor Managed Inventory (VMI) approach. The monolithic method solves a single model describing the entire optimization problem. The sequential method copies the imperfect VMI practice. All three methods are implemented by means of Mixed Integer Programming models. The results presented prove that the right choice of planning method is very important for overall cost of the supply chain. In contrast to the previous research, it turned out that information sharing without full coordination may even lead to increase in the overall cost. For some companies applying the VMI approach, developing exact models and solving them almost optimally may therefore be very important.

Źródło:

Decision Making in Manufacturing and Services; 2008, 2, 1-2; 47-62
1896-8325
2300-7087

Pojawia się w:

Decision Making in Manufacturing and Services

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 13.

Tytuł:

Bi-objective routing in a dynamic network: An application to maritime logistics

Autorzy:

Maskooki, Alaleh
Nikulin, Yury

Powiązania:

https://bibliotekanauki.pl/articles/2050033.pdf

Data publikacji:

2020

Wydawca:

Polska Akademia Nauk. Instytut Badań Systemowych PAN

Tematy:

travelling salesman
time dependent network
multi-objective optimization
integer programming

Opis:

A bi-objectiveMILP model for optimal routing in a dynamic network with moving targets (nodes) is developed, where all targets are not necessarily visited. Hence, our problem extends the moving target travelling salesman problem. The two objectives aim at finding the sequence of targets visited in a given time horizon by minimizing the total travel distance and maximizing the number of targets visited. Due to a huge number of binary variables, such a problem often becomes intractable in the real life cases. To reduce the computational burden, we introduce a measure of traffic density, based on which we propose a time horizon splitting heuristics. In a real-world case study of greenhouse gas emissions control, using Automatic Identification System data related to the locations of ships navigating in the Gulf of Finland, we evaluate the performance of the proposed method. Different splitting scenarios are analysed numerically. Even in the cases of a moderate scale, the results show that near-efficient values for the two objectives can be obtained by our splitting approach with a drastic decrease in computational time compared to the exact MILP method. A linear value function is introduced to compare the Pareto solutions obtained by different splitting scenarios. Given our results, we expect that the present study is valuable in logistic applications, specifically maritime management services and autonomous navigation.

Źródło:

Control and Cybernetics; 2020, 49, 2; 211--232
0324-8569

Pojawia się w:

Control and Cybernetics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 14.

Tytuł:

Energy-saving Algorithms for the Control of Backbone Networks: A Survey

Autorzy:

Kamola, M.
Niewiadomska-Szynkiewicz, E.
Arabas, P.
Sikora, A.

Powiązania:

https://bibliotekanauki.pl/articles/307968.pdf

Data publikacji:

2016

Wydawca:

Instytut Łączności - Państwowy Instytut Badawczy

Tematy:

green routing
mixed-integer programming
OSPF heuristics
power-save networks

Opis:

The rapid growth of energy demand by wired IP networks can be mitigated on hardware and software levels. While upgrading to more efficient transmission media still brings biggest savings, we take a look here at power-saving algorithms that combine the capability of setting networking equipment in arbitrary energy states which, combined with profound knowledge of the network traffic matrix, leads to considerable complex optimization problem formulations. Alternatively, lightweighted heuristic approaches are presented, built on much simpler network model but still capable to perform energy-efficient traffic engineering.

Źródło:

Journal of Telecommunications and Information Technology; 2016, 2; 13-20
1509-4553
1899-8852

Pojawia się w:

Journal of Telecommunications and Information Technology

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 15.

Tytuł:

Hybrid Models for the OWA Optimization

Autorzy:

Olender, P.

Powiązania:

https://bibliotekanauki.pl/articles/307934.pdf

Data publikacji:

2016

Wydawca:

Instytut Łączności - Państwowy Instytut Badawczy

Tematy:

location problem
mixed-integer programming
mixed linear programming
multiple criteria
ordered weighted averaging

Opis:

When dealing with multicriteria problems, the aggregation of multiple outcomes plays an essential role in finding a solution, as it reflects the decision-maker's preference relation. The Ordered Weighted Averaging (OWA) operator provides a exible preference model that generalizes many objective functions. It also ensures the impartiality and allow to obtain equitable solutions, which is vital when the criteria represent evaluations of independent individuals. These features make the OWA operator very useful in many fields, one of which is location analysis. However, in general the OWA aggregation makes the problem nonlinear and hinder its computational complexity. Therefore, problems with the OWA operator need to be devised in an efficient way. The paper introduces new general formulations for OWA optimization and proposes for them some simple valid inequalities to improve efficiency. A hybrid structure of proposed models makes the number of binary variables problem type dependent and may reduce it signicantly. Computational results show that for certain problem types, some of which are very useful in practical applications, the hybrid models perform much better than previous general models from literature.

Źródło:

Journal of Telecommunications and Information Technology; 2016, 4; 22-30
1509-4553
1899-8852

Pojawia się w:

Journal of Telecommunications and Information Technology

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 16.

Tytuł:

The airport gate assignment problem – multi-objective optimization versus evolutionary multi-objective optimization

Autorzy:

Kaliszewski, I.
Miroforidis, J.
Stańczak, J.

Powiązania:

https://bibliotekanauki.pl/articles/305661.pdf

Data publikacji:

2017

Wydawca:

Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH

Tematy:

airport gate assignment problem
Evolutionary Multi-objective Optimization
mixed-integer programming

Opis:

In this paper, we approach the Airport Gate Assignment Problem by Multi-objective Optimization as well as Evolutionary Multi-objective Optimization. We solve a bi-criteria formulation of this problem by the commercial mixed-integer programming solver CPLEX and a dedicated Evolutionary Multi-objective Optimization algorithm. To deal with multiple objectives, we apply a methodology that we developed earlier to capture decision-maker preferences in multi-objective environments. We present the results of numerical tests for these two approaches.

Źródło:

Computer Science; 2017, 18 (1); 41-52
1508-2806
2300-7036

Pojawia się w:

Computer Science

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 17.

Tytuł:

A mixed integer program for cyclic scheduling of flexible flow lines

Autorzy:

Sawik, T.

Powiązania:

https://bibliotekanauki.pl/articles/201462.pdf

Data publikacji:

2014

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

flexible flow line
cyclic scheduling
cyclic-batch scheduling
mixed-integer programming

Opis:

A new mixed integer programming formulation is presented for cyclic scheduling in flow lines with parallel machines and finite in-process buffers, where a Minimal Part Set (MPS) in the same proportion as the overall production target is repetitively scheduled. The cycle of parts in an MPS is not determined a priori, but is obtained along with the optimal schedule for all parts. In addition to the cyclic scheduling, a cyclic-batch scheduling mode is introduced, where within the MPS the parts of one type are processed consecutively. Numerical examples are included and some results of computational experiments are reported.

Źródło:

Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 1; 121-128
0239-7528

Pojawia się w:

Bulletin of the Polish Academy of Sciences. Technical Sciences

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 18.

Tytuł:

Conflict Management in University Examination Timetabling Problem: A case study of summer school mid-terms

Autorzy:

Bayar, Mustafa Mehmet
Uzun Bayar, Irmak

Powiązania:

https://bibliotekanauki.pl/articles/14147915.pdf

Data publikacji:

2020-09-20

Wydawca:

Wyższa Szkoła Bankowa we Wrocławiu

Tematy:

examination timetabling
group decision making
lexicographic optimization
linear mixed integer programming

Opis:

Abstract: Aim: This study is on tackling Examination Timetabling Problem (ETP) of the Faculty of Economics And Administrative Sciences (FEAS) of the Ankara HBV University summer school, where the courses of fall and spring semesters are offered simultaneously and regulations on restricting enrollments in inter-department electives or in-department courses of distinct years are relaxed. Thus, the complexity of the nature of the ETP problem is exacerbated. The direct heuristics based on successive assignments that the university normally adopts was proven inadequate for assuming standard regulations hence, another approach we explain in this paper was needed. Design / Research methods: The ETP was formulated as a Linear Mixed-Integer Program (LMIP) and decomposed into three stages; timetabling exams, room assignment, student allocation. To manage the conflict between the stakeholders of the examination procedure, a lexicographic optimization process based on the priority of the parties was undertaken. Conclusions / findings: After a recursive timetabling process based on a trial-and-error method a clash-free timetable was generated and, a room assignment plan that minimizes the total number of proctoring duties, usage of higher floor rooms and total crowdedness of rooms respectively was put into action. Therefore no student group experienced any clashing exams, the faculty members saved time that can be spent on research instead, since the room usage was better planned the costs (elevator usage, lighting, air conditioning, the labor of the janitors) were assumed to be decreased. Originality / value of the article: Each examination period bares a different ETP due to its problem-specific nature (number of courses offered, structure of student enrollments, availability of rooms, etc.). Summer schools provide a more irregular structure that demands special attention, a trial-and-error reformulation of the ETP in our case. In addition, the traditional formulations of the ETP, to the extent we have been able to scan, do not include the minimization of the crowdedness of the rooms. Thus, in creating a more comfortable environment, easier to monitor exams and, ability in handling unexpected dysfunctionalities (broken classroom equipment, etc.) this study is novel. Limitations of the research: The algorithms to solve an ETP formulated as an LMIP are of high complexity therefore, we are not able to assert the optimality of our suggested solutions acquired within time limitations. Keywords: examination timetabling, group decision making, lexicographic optimization, linear mixed-integer programming JEL: C44, C61, M12

Źródło:

Central European Review of Economics and Management; 2020, 4, 3; 67-87
2543-9472

Pojawia się w:

Central European Review of Economics and Management

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 19.

Tytuł:

An integer optimization model and algorithms to support the cost-revenue study and provisory designing warehouses or other storage objects

Autorzy:

Miatselski, M.
Staruch, B.

Powiązania:

https://bibliotekanauki.pl/articles/298439.pdf

Data publikacji:

2018

Wydawca:

Uniwersytet Warmińsko-Mazurski w Olsztynie

Tematy:

warehouse design
cost-revenue recognition
state space
model
algorithm
nonlinear programming
integer programming

Opis:

An optimization model for the cost–revenue study at the stage of system analysis and preliminary designs of storage objects such as warehouses, containers, packs and similar objects are developed. Our assumptions motivated by warehouses design lead us to a nonlinear integer optimization problem with the only basic constraint. We present algorithmic methods for obtaining the exact solution to the general problem with emphasizing the special case when both the objective and the constraint functions are increasing. The results of the paper may be used in developing software tools intended for supporting designers.

Źródło:

Technical Sciences / University of Warmia and Mazury in Olsztyn; 2018, 21(4); 257-269
1505-4675
2083-4527

Pojawia się w:

Technical Sciences / University of Warmia and Mazury in Olsztyn

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 20.

Tytuł:

A new Integer Linear Programming and Quadratically Constrained Quadratic Programming Formulation for Vertex Bisection Minimization Problem

Autorzy:

Jain, P.
Saran, G.
Srivastava, K.

Powiązania:

https://bibliotekanauki.pl/articles/384223.pdf

Data publikacji:

2016

Wydawca:

Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów

Tematy:

Vertex Bisection Minimization
Integer Linear Programming
quadratic programming

Opis:

Vertex Bisection Minimization problem (VBMP) consists of partitioning a vertex set V of graph G = (V, E) into two sets B and B′ where ∣B∣ = [\v|/2] such that vertex width (VW) is minimized where vertex width is defined as the number of vertices in B which are adjacent to at least one vertex in B′. It is an NP-complete problem in general. VBMP has applications in fault tolerance and is related to the complexity of sending messages to processors in interconnection networks via vertex disjoint paths. In this paper, we have proposed a new integer linear programming (ILP) and quadratically constrained quadratic programming (QCQP) formulation for VBMP. Both of them require number of variables and constraints lesser than existing ILPs and QCQP. We have also implemented ILP and obtained optimal results for various classes of graphs. The result of the experiments with the benchmark graphs shows that the proposed model outperforms the state of the art. Moreover, proposed model obtains optimal result for all the benchmark graphs.

Źródło:

Journal of Automation Mobile Robotics and Intelligent Systems; 2016, 10, 1; 69-73
1897-8649
2080-2145

Pojawia się w:

Journal of Automation Mobile Robotics and Intelligent Systems

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 21.

Tytuł:

A New Mathematical Model for Multisession Exams-Building Assignment

Autorzy:

Ergul, Z.
Kamisli Ozturk, Z.

Powiązania:

https://bibliotekanauki.pl/articles/1031701.pdf

Data publikacji:

2017-09

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

Educational timetabling
Examination-building assignment
Multi objective nonlinear optimization
Mixed Integer Programming

Opis:

The educational timetabling problem has been extensively investigated in timetabling literature. However, the problem of assigning exams to examination buildings has not been studied intensively by researchers. We were inspired by Open and Distance Education System exams of Anadolu University. Anadolu University Open and Distance Education System, which is used by approximately two millions of students and has more than two millions of graduates, is a well-known institution in Turkey. In this study, we propose a multi-objective mathematical model for multisession exam-building assignment problem. Objective functions of this model are to minimize the distance between consecutive session buildings for a given student, to maximize the number of occupants of buildings in every session and to minimize the variety of booklets for building in every session. Mathematical model has been found inadequate because students-examination building assignment in the Anadolu University Open Education system is a large size real life problem. Starting from this point of view, an order-based multi-objective heuristic algorithm is developed to solve this problem. The solutions obtained by the proposed algorithm are compared with the solution obtained by the mathematical modelling and the current state of the existing system.

Źródło:

Acta Physica Polonica A; 2017, 132, 3; 1207-1210
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 22.

Tytuł:

An incremental approach for storage and delivery planning problems

Autorzy:

Sakakibara, K.
Tian, Y.
Nishikawa, I.

Powiązania:

https://bibliotekanauki.pl/articles/375942.pdf

Data publikacji:

2012

Wydawca:

Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH

Tematy:

simultaneous optimization
logistic terminal
consolidate shipment
mixed-integer programming
relax-and-fix

Opis:

We consider a logistic planning problem for simultaneous optimization of the storage and the delivery. This problem arises in the consolidate shipment using an intermediate storage in a supply chain, which is typically found in the automobile industry. The vehicles deliver the items from the origin to the destination, while the items can be stored at some warehousing facilities as the intermediate storage during the delivery. The delivery plan is made for each day separately, but the storage at a warehouse may last for more than one day. Therefore, the entire logistic plan should be considered over a certain period for the total optimization. We formulate the storage and delivery problem as a mixed integer programming. Then, we propose a relax-and-fix type heuristic method, which incrementally fixes decision variables until all the variables are fixed to obtain a complete solution. Moreover, a semiapproximate model is introduced to effectively fix the variables. Based on the formulation, the delivery plan can be solved for each day separately. This has the advantage especially in the dynamic situation, where the delivery request is modified from the original request before the actual delivery day. Numerical experiments show that the simultaneous optimization gives the effective storage plan to reduce the total logistic cost, and the proposed heuristics efficiently reduce the computational time and are robust against the dynamic situation.

Źródło:

Decision Making in Manufacturing and Services; 2012, 6, 1-2; 5-23
1896-8325
2300-7087

Pojawia się w:

Decision Making in Manufacturing and Services

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 23.

Tytuł:

Methods of planning deliveries of food products to a trade network with the selection of suppliers and transport companies

Autorzy:

Magiera, M.

Powiązania:

https://bibliotekanauki.pl/articles/229719.pdf

Data publikacji:

2018

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

supply network
supply chain management
logistics
integer programming
transportation
scheduling
hierarchical planning

Opis:

The paper refers to planning deliveries of food products (especially those available in certain seasons) to the recipients: supermarket networks. The paper presents two approaches to solving problems of simultaneous selection of suppliers and transportation modes and construction of product flow schedules with these transportation modes. Linear mathematical models have been built for the presented solution approaches. The cost criterion has been taken into consideration in them. The following costs have been taken into account: purchase of products by individual recipients, transport services, storing of products supplied before the planned deadlines and penalties for delays in supply of products. Two solution approaches (used for transportation planning and selection of suppliers and selection of transportation modes) have been compared. The monolithic approach calls for simultaneous solutions for the problems of supplier selection and selection of transportation modes. In the alternative (hierarchical) solution approach, suppliers are selected first, and then transportation companies and their relevant transportation modes are selected. The results of computational experiments are used for comparison of the hierarchical and monolithic solution approaches.

Źródło:

Archives of Control Sciences; 2018, 28, 3; 419-442
1230-2384

Pojawia się w:

Archives of Control Sciences

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 24.

Tytuł:

Combinatorial approaches to the capital-budgeting problem

Autorzy:

Pichugina, O.

Powiązania:

https://bibliotekanauki.pl/articles/411221.pdf

Data publikacji:

2016

Wydawca:

Polska Akademia Nauk. Oddział w Lublinie PAN

Tematy:

capital-budgeting problem
integer programming
knapsack problem
combinatorial optimization
Branch and Bound

Opis:

Optimization approaches, combinatorial and continuous, to a capital-budgeting problem (CBP) are presented. This NP-hard problem, traditionally modelled as a linear binary problem, is represented as a biquadratic over an intersection of a sphere and a supersphere. This allows applying nonlinear optimization to it. Also, the method of combinatorial and surface cuttings (MCSC) is adopted to (CBP). For the single constrained version (1CBP), new combinatorial models are introduced based on joint analysis of the constraint, objective function, and feasible region. Equivalence of (1CBP) to the multichoice knapsack problem (MCKP) is shown. Peculiarities of Branch&Bound techniques to (1CBP) are described.

Źródło:

ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2016, 5, 4; 29-36
2084-5715

Pojawia się w:

ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 25.

Tytuł:

Flexible measure in the presence of the partial input to output impacts process

Autorzy:

Shakouri, Rita
Salahi, Maziar
Kordrostami, Sohrab
Wu, Jie

Powiązania:

https://bibliotekanauki.pl/articles/406427.pdf

Data publikacji:

2019

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

data envelopment analysis
flexible measure
efficiency
integer programming
partial impact
bank industry

Opis:

Precise recognition of the nonparametric measurement approach in the production process and proper application of accurate techniques to categorise the variables play a key role in the process of improving performance of decision-making units (DMUs). The classical data envelopment analysis (DEA) models require that the status of all inputs and outputs measures be precisely specified in advance. However, there are situations where a performance measure can play input role for some DMUs and output role for the others. This paper introduces an approach to determine the situation of such flexibility where in the presence of resource sharing among subunits, the partial input will impact output in DEA. As a result, DMUs have a fair evaluation when compared to each other. Likewise, the maximum improvement is obtained in aggregate efficiency due to partial input to output impacts. The proposed approach is applied to a set of real data collected from 30 branches of an Iranian bank.

Źródło:

Operations Research and Decisions; 2019, 29, 3; 77-98
2081-8858
2391-6060

Pojawia się w:

Operations Research and Decisions

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 26.

Tytuł:

Application of the polyblock method to special integer chance constrained problem

Autorzy:

Bellahcene, Fatima

Powiązania:

https://bibliotekanauki.pl/articles/406257.pdf

Data publikacji:

2019

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

stochastic programming
integer nonlinear programming
monotone optimization
polyblock method

Opis:

The focus in this paper is on a special integer stochastic program with a chance constraint in which, with a given probability, a sum of independent and normally distributed random variables is bounded below. The objective is to maximize the expectation of a linear function of the random variables. The stochastic program is first reduced to an equivalent deterministic integer nonlinear program with monotonic objective and constraints functions. The resulting deterministic problem is solved using the discrete polyblock method which exploits its special structure. A numerical example is included for illustration and comparisons with LINGO, COUENNE, BONMIN and BARON solvers are performed.

Źródło:

Operations Research and Decisions; 2019, 29, 4; 23-40
2081-8858
2391-6060

Pojawia się w:

Operations Research and Decisions

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 27.

Tytuł:

A mixed integer nonlinear programming formulation for the problem of fitting positive exponential sums to empirical data

Autorzy:

Alvarez, A.
Lara, H.

Powiązania:

https://bibliotekanauki.pl/articles/254845.pdf

Data publikacji:

2011

Wydawca:

Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH

Tematy:

mixed integer nonlinear programming
regularization
nonlinear least squares

Opis:

In this work we deal with exponential sum models coming from data acquisition in the empirical sciences. We present a two step approach based on Tikhonov regularization and combinatorial optimization, to obtain stable parameter estimations, which fit the data. We develop properties of the solutions, based on their optimality conditions. Some numerical experiments are shown to illustrate our approach.

Źródło:

Opuscula Mathematica; 2011, 31, 4; 481-499
1232-9274
2300-6919

Pojawia się w:

Opuscula Mathematica

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 28.

Tytuł:

A reference point method to triple-objective assignment of supporting services in a healthcare institution

Autorzy:

Sawik, B.

Powiązania:

https://bibliotekanauki.pl/articles/375985.pdf

Data publikacji:

2010

Wydawca:

Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH

Tematy:

reference point method
assignment problem
mixed-integer programming
services operations management
healthcare planning

Opis:

This paper presents an application of mixed integer programming model for optimal allocation of workers among supporting services in a hospital. The services include logistics, inventory management, financial management, operations management, medical analysis, etc. The optimality criterion of the problem is to minimize operational costs of supporting services subject to some specific constraints. The constraints represent specific conditions for resource allocation in a hospital. The overall problem is formulated as a triple-objective assignment model, where the decision variables represent the assignment of people to various jobs. A reference point approach with the Chebyshev metric is applied for the problem solution. The results of computational experiments modeled on a real data from a hospital in Lesser Poland are reported.

Źródło:

Decision Making in Manufacturing and Services; 2010, 4, 1-2; 37-46
1896-8325
2300-7087

Pojawia się w:

Decision Making in Manufacturing and Services

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 29.

Tytuł:

A novel approach to optimize the maintenance strategies: a case in the hydroelectric power plant

Autorzy:

Özcan, Evrencan
Yumuşak, Rabia
Eren, Tamer

Powiązania:

https://bibliotekanauki.pl/articles/1841740.pdf

Data publikacji:

2021

Wydawca:

Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN

Tematy:

maintenance management
maintenance strategy optimization
multi-criteria decision making
AHP
COPRAS
integer programming

Opis:

Countries need to develop sustainable energy policies based on the principles of environmental sensitivity, reliability, efficiency, economy and uninterrupted service and to maintain their energy supply in order to increase their global competitiveness. In addition to this impact of sustainable energy supply on the global world, maintenance processes in power plants require high costs due to allocated time, materials and labor, and generation loss. Thus, the maintenance needs to be managed within a system. This makes analytical and feasible maintenance planning a necessity in power plants. In this context, this study focuses on maintenance strategy optimization which is the first phase of maintenance planning for one of the large-scale hydroelectric power plants with a direct effect on Turkey's energy supply security with its one fifth share in total generation. In this study, a new model is proposed for the maintenance strategy optimization problem considering the multi-objective and multicriteria structure of hydroelectric power plants with hundreds of complex equipment and the direct effect of these equipment on uninterrupted and cost-effective electricity generation. In the model, two multi-criteria decision-making methods, AHP and COPRAS methods, are integrated with integer programming method and optimal maintenance strategies are obtained for 571 equipment.

Źródło:

Eksploatacja i Niezawodność; 2021, 23, 2; 324-337
1507-2711

Pojawia się w:

Eksploatacja i Niezawodność

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 30.

Tytuł:

Extended model formulation of the Proportional Lot-sizing and Scheduling Problem with lost demand costs

Autorzy:

Kaczmarczyk, W.

Powiązania:

https://bibliotekanauki.pl/articles/375882.pdf

Data publikacji:

2011

Wydawca:

Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH

Tematy:

production
lot-sizing
scheduling
mixed integer linear programming

Opis:

We consider mixed-integer linear programming (MIP) models of production planning problems known as the small bucket lot-sizing and scheduling problems. We present an application of a class of valid inequalities to the case with lost demand (stock-out) costs. Presented results of numerical experiments made for the the Proportional Lot-sizing and Scheduling Problem (PLSP) confirm benefits of such extended model formulation.

Źródło:

Decision Making in Manufacturing and Services; 2011, 5, 1-2; 49-56
1896-8325
2300-7087

Pojawia się w:

Decision Making in Manufacturing and Services

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 31.

Tytuł:

An optimum scheduling method for multi-option product flows through production lineswithout intermediate buffers

Autorzy:

Magiera, Marek

Powiązania:

https://bibliotekanauki.pl/articles/406718.pdf

Data publikacji:

2020

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

Flexible Manufacturing Systems
integer programming
linear programming
no-wait scheduling
hybrid flow shop
makespan
decision making

Opis:

The presented method is constructed for optimum scheduling in production lines with parallel machines and without intermediate buffers. The production system simultaneously performs operations on various types of products. Multi-option products were taken into account – products of a given type may differ in terms of details. This allows providing for individual requirements of the customers. The one-level approach to scheduling for multioption products is presented. The integer programming is used in the method – optimum solutions are determined: the shortest schedules for multi-option products. Due to the lack of the intermediate buffers, two possibilities are taken into account: no-wait scheduling, possibility of the machines being blocked by products awaiting further operations. These two types of organizing the flow through the production line were compared using computational experiments, the results of which are presented in the paper.

Źródło:

Management and Production Engineering Review; 2020, 11, 1; 86-94
2080-8208
2082-1344

Pojawia się w:

Management and Production Engineering Review

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 32.

Tytuł:

An optimal path planning problem for heterogeneous multi-vehicle systems

Autorzy:

Klaučo, M.
Blažek, S.
Kvasnica, M.

Powiązania:

https://bibliotekanauki.pl/articles/330754.pdf

Data publikacji:

2016

Wydawca:

Uniwersytet Zielonogórski. Oficyna Wydawnicza

Tematy:

path planning
multi vehicle system
mixed-integer programming
planowanie ruchu
system wielopojazdowy
programowanie całkowitoliczbowe

Opis:

A path planning problem for a heterogeneous vehicle is considered. Such a vehicle consists of two parts which have the ability to move individually, but one of them has a shorter range and is therefore required to keep in a close distance to the main vehicle. The objective is to devise an optimal path of minimal length under the condition that at least one part of the heterogeneous system visits all desired waypoints exactly once. Two versions of the problem are considered. One assumes that the order in which the waypoints are visited is known a priori. In such a case we show that the optimal path can be found by solving a mixed-integer second-order cone problem. The second version assumes that the order in which the waypoints are visited is not known a priori, but can be optimized so as to shorten the length of the path. Two approaches to solve this problem are presented and evaluated with respect to computational complexity.

Źródło:

International Journal of Applied Mathematics and Computer Science; 2016, 26, 2; 297-308
1641-876X
2083-8492

Pojawia się w:

International Journal of Applied Mathematics and Computer Science

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 33.

Tytuł:

A reference point approach to bi-objective dynamic portfolio optimization

Autorzy:

Sawik, B.

Powiązania:

https://bibliotekanauki.pl/articles/375931.pdf

Data publikacji:

2009

Wydawca:

Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH

Tematy:

dynamic portfolio
mixed-integer programming
reference point method
bi-objective optimization
value-at-risk

Opis:

The portfolio selection problem presented in this paper is formulated as a bi-objective mixed integer program. The portfolio selection problem considered is based on a dynamic model of investment, in which the investor buys and sells securities in successive investment periods. The problem objective is to dynamically allocate the wealth on different securities to optimize by reference point method the portfolio expected return and the probability that the return is not less than a required level. In computational experiments the dataset of daily quotations from the Warsaw Stock Exchange were used.

Źródło:

Decision Making in Manufacturing and Services; 2009, 3, 1-2; 73-85
1896-8325
2300-7087

Pojawia się w:

Decision Making in Manufacturing and Services

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 34.

Tytuł:

Computational complexity of problems of combinatorics and graph theory

Autorzy:

Sysło, M. M.

Powiązania:

https://bibliotekanauki.pl/articles/748066.pdf

Data publikacji:

1980

Wydawca:

Polskie Towarzystwo Matematyczne

Tematy:

Computational complexity and efficiency of algorithms
Exact categories, abelian categories
Network models, deterministic
Integer programming

Opis:

.
From the introduction: "The present article does not pretend to be a complete survey of all or even of the most important algorithms in combinatorics and graph theory. The algorithms presented illustrate only general considerations involving the computational complexity of problems of combinatorics. It is assumed that the reader is acquainted with the fundamental algorithms of combinatorics and graph theory. The first part of the paper is an outline of basic computation models used in the analysis of combinatorial algorithms. In subsequent parts, problems for which optimal or `good' algorithms exist are discussed. Here problems connected with the class P are presented, i.e. the class of problems that can be solved by algorithms with polynomial complexity. A formal definition is given of the class P and the class NP, to which, with minor exceptions, all difficult problems-the knapsack problem, the scheduling problem, the problem of Hamiltonian circuits in graphs and networks, etc.-belong. The question whether P=NP is a fundamental problem in the analysis of the computational complexity of combinatorial algorithms. Contents: (1) Introduction; (2) Computational complexity of algorithms; (3) Computation models; (4) Ways of representing graphs, and the efficiency of algorithms; (5) Lower bounds of computational complexity; (6) Examples of optimal and `good' algorithms; (7) Problems with polynomial complexity; (8) Problems for which the existence of algorithms with polynomial complexity is not possible; (9) NP-complete problems; (10) Conclusion; Bibliography.

Źródło:

Mathematica Applicanda; 1980, 8, 16
1730-2668
2299-4009

Pojawia się w:

Mathematica Applicanda

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 35.

Tytuł:

Mixed-integer programming formulations for the truck scheduling problem with fixed outbound departures
Rozwiązywanie problemu harmonogramowania przewozów przy ustalonych załadunkach

Autorzy:

Wolff, Pascal
Huo, Jiazhen
Pfohl, Hans-Christian

Powiązania:

https://bibliotekanauki.pl/articles/1835497.pdf

Data publikacji:

2021

Wydawca:

Wyższa Szkoła Logistyki

Tematy:

cross-docking
truck scheduling
mixed-integer programming
logistics
optimization
harmonogramowanie przewozów
programowanie różnych zmiennych
logistyka
optymalizacja

Opis:

Truck scheduling at cross-docking terminals has received much academic attention over the last three decades. A vast number of mixed-integer programming models have been proposed to assign trucks to dock-doors and time slots. Surprisingly, only a few models assume fixed outbound truck departures that are often applied in the less-than-truckload or small parcel and express delivery industry. To the best of our knowledge, none of these papers explore whether a discrete-time or continuous-time model formulation has a better computational performance. This paper attempts to close this research gap and tries to shed light on which type of formulation is advantageous. Therefore, a variant of the truck scheduling problem with fixed outbound departures is considered. This problem's objective is to find a feasible truck schedule that minimizes the number of delayed freight units. Methods: We propose two model formulations for the described variant of the truck scheduling problem with fixed outbound departures. Specifically, the problem is formulated as a discrete-time and a continuous-time mixed-integer programming model. Results: A computational experiment is conducted in order to assess the computational performance of the presented model formulations. We compare the discrete-time and continuous-time formulation in terms of both the solution quality and computational time. Conclusions: The computational results show that the proposed discrete-time model formulation can solve problem instances of medium size to proven optimality within less than one minute. The continuous-time model formulation, on the other hand, can solve small instances to optimality. However, it requires longer solution times than the discrete-time formulation. Furthermore, it is unable to solve medium-sized instances within a 5-minute time limit. Thus, it can be summarized that the proposed discrete-time model formulation is clearly superior to the continuous-time model formulation.
Harmonogramowanie przewozów oraz cross-dockingu leży w zasięgu zainteresowania uczonych już od ponad 30 lat. W tym okresie zaproponowało wiele różnych modeli programistycznych tablic awizacyjnych. Jednak zaledwie kilka modeli bierze pod uwagę stałe załadunki, które często są stosowane w przewozach niepełno samochodowych oraz kurierskich. Według naszego rozeznania, żaden z dostępnych modeli nie stosuje modelowania czasem w sposób dyskretny lub ciągły dla uzyskania lepszego wyniku. Celem pracy jest uzupełnienie tej luki w badaniach. Dlatego też rozważono wariant problemu harmonogramowania przewozów ze stałymi załadunkami z celem nadrzędnym znalezienia takiego sposobu harmonogramowania aby minimalizował on liczbę opóźnionych przewozów. Metody: Zaproponowano dwa modele, opisujące harmonogramowanie przewozów ze stałymi załadunkami. Problem ten został sformułowany poprzez model programistyczny ze zmienną czasu w ujęciu dyskretnym i ciągłym. Wyniki: Przeprowadzono symulację komputerową w celu określenie działania opracowanych modeli. Porównano wyniki pod względem jakości uzyskanego wyniku oraz niezbędnego czasu dla obliczeń. Wnioski: Na podstawie uzyskanych wyników można stwierdzić, że proponowany model dyskretny może rozwiązywać problem średniej wielkości w czasie niższej niż minuta. Model oparty na czasie ciągłym uzyskał z kolei optymalizację przy małych przypadkach. Wymagało to jednak dłuższego czasu obliczeniowego. Dodatkowo nie uzyskano dla rozwiązań średniej wielkości czasu niższego od 5 minut. Dlatego też wysunięto wniosek, że model dyskretny jest lepszym w porównaniu z modelem ciągłym.

Źródło:

LogForum; 2021, 17, 2; 243--251
1734-459X

Pojawia się w:

LogForum

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 36.

Tytuł:

Rozwiązywanie problemu komiwojażera za pomocą LP/Quadratic Solver z Analytic Solver Platform v12.5
Solving the travelling salesman problem using LP/Quadratic Solver from the Analytic Solver Platform v12.5

Autorzy:

Węgrzyn, J.

Powiązania:

https://bibliotekanauki.pl/articles/1377944.pdf

Data publikacji:

2014

Wydawca:

Polskie Wydawnictwo Ekonomiczne

Tematy:

arkusz kalkulacyjny
problem komiwojażera
oprogramowanie optymalizacyjne
programowanie całkowitoliczbowe
spreadsheet
travelling salesperson problem
optimisation software
integer programming

Opis:

The solutions of results of Traveling Salesperson Problem (TSP) samples are presented in this article. Their were received using LP/Quadratic Solver included in Analytic Solver Platform V12.5. LP/Quadratic Solver designed for solutions of LP/MIP problems allow to solve TSP as integer programming model. Solutions were received based on Assignment Problem with Miller, Tucker, Zemlin subtour eliminating constraints model introduced to Excel 2010. Solved times of symmetric and asymmetric TSP samples from TSPLIB with small size of problems, limited by max integer variables of LP/Quadratic Solver are presented.

Źródło:

Gospodarka Materiałowa i Logistyka; 2014, 10; 11-19
1231-2037

Pojawia się w:

Gospodarka Materiałowa i Logistyka

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 37.

Tytuł:

A multi-level method of support for management of product flow through supply chains

Autorzy:

Magiera, M.

Powiązania:

https://bibliotekanauki.pl/articles/201930.pdf

Data publikacji:

2015

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

supply network
supply chain
scheduling
logistic
integer programming
decision making
zasilanie
łańcuch dostaw
harmonogramowanie
logistyka
podejmowanie decyzji

Opis:

The paper presents a three-level method used to support the management of product flow through supply chain links (e.g. production lines) and between these links: suppliers and recipients of products of various types.The supply chain includes both producers of components (suppliers) and recipients of these components, which are used for the production of complex goods. The method is dedicated to the development of schedules of product flows through particular production plants (links in supply chains) and between individual plants. Each module of the developed system refers to a separate production plant. The organization of product flow through production lines covers different types of production routes and different configurations of production systems. At the first level of the method, preliminary production schedules are developed for each plant within the supply chain. The second level of the method is dedicated to the development of delivery schedules of components and semi-finished products to these plants. The determined delivery times of components to the individual production plants constitute data for the third level of the method. At this lowest level, detailed schedules of product flow through production lines with the producers of complex goods are developed. Linear mathematical models have been built for each level of the method. In the developed method, optimization take place in the developed method in the scale of the entire supply chain (cost reduction), as well as in the scale of its links (production lines for which manufacturing schedules are built with various criteria taken into consideration). The computational experiments used for verification of the method have been included.

Źródło:

Bulletin of the Polish Academy of Sciences. Technical Sciences; 2015, 63, 4; 933-946
0239-7528

Pojawia się w:

Bulletin of the Polish Academy of Sciences. Technical Sciences

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 38.

Tytuł:

Post-optimal analysis for multicriteria integer linear programming problem of finding extreme solutions

Autorzy:

Emelichev, V. A.
Nikulin, Y.

Powiązania:

https://bibliotekanauki.pl/articles/206614.pdf

Data publikacji:

2018

Wydawca:

Polska Akademia Nauk. Instytut Badań Systemowych PAN

Tematy:

sensitivity analysis
multiple criteria
extreme solutions
stability radius
integer linear programming

Opis:

We consider a multicriteria problem of integer linear programming and study the set of all individual criterion minimizers (extreme solutions) playing an important role in determining the range of Pareto optimal set. In this work, the lower and upper attainable bounds on the stability radius of the set of extreme solutions are obtained in the situation where solution and criterion spaces are endowed with various H¨older’s norms. In addition, the case of the Boolean problem is analyzed. Some computational challenges are also discussed.

Źródło:

Control and Cybernetics; 2018, 47, 3; 225-238
0324-8569

Pojawia się w:

Control and Cybernetics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 39.

Tytuł:

On MILP Models for the OWA Optimization

Autorzy:

Ogryczak, W.
Olender, P.

Powiązania:

https://bibliotekanauki.pl/articles/309199.pdf

Data publikacji:

2012

Wydawca:

Instytut Łączności - Państwowy Instytut Badawczy

Tematy:

location problem
mixed integer linear programming
multiple criteria
ordered weighted averaging (OWA)

Opis:

The problem of aggregating multiple outcomes to form overall objective functions is of considerable importance in many applications. The ordered weighted averaging (OWA) aggregation uses the weights assigned to the ordered values (i.e., to the largest value, the second largest and so on) rather than to the specific coordinates. It allows to evaluate solutions impartially, when distribution of outcomes is more important than assignments these outcomes to the specific criteria. This applies to systems with multiple independent users or agents, whose objectives correspond to the criteria. The ordering operator causes that the OWA optimization problem is nonlinear. Several MILP models have been developed for the OWA optimization. They are built with different numbers of binary variables and auxiliary constraints. In this paper we analyze and compare computational performances of the different MILP model formulations.

Źródło:

Journal of Telecommunications and Information Technology; 2012, 2; 5-12
1509-4553
1899-8852

Pojawia się w:

Journal of Telecommunications and Information Technology

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 40.

Tytuł:

Optymalizacja kosztów w łańcuchu dostaw - implementacja modelu matematycznego
Optimization of costs in supply chain - mathematical model implementation

Autorzy:

Sitek, P.
Wikarek, J.

Powiązania:

https://bibliotekanauki.pl/articles/276921.pdf

Data publikacji:

2012

Wydawca:

Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów

Tematy:

łańcuch dostaw
programowanie całkowitoliczbowe
optymalizacja
optimization
supply chain
mixed integer linear programming

Opis:

W artykule przedstawiono implementację autorskiego modelu optymalizacji kosztów w łańcuchu dostaw. Model został sformułowany w postaci zagadnienia programowania liniowego całkowitoliczbowego z funkcją celu określającą koszty dystrybutora, producenta oraz transportu. Implementacji dokonano w środowisku pakietu optymalizacji LINGO firmy LINDO Systems Inc. Po dokonaniu implementacji zostały przeprowadzone eksperymenty obliczeniowe dla przykładowych zbiorów danych.
The paper presents the implementation of the supply chain cost optimization model. The model was formulated as a linear integer programming problem with objective function specifies the cost of distribution, manufacturing and transportation. Implementation took place in an environment optimization package "LINGO". After the implementation the computational experiments were carried out for sample data sets.

Źródło:

Pomiary Automatyka Robotyka; 2012, 16, 2; 141-146
1427-9126

Pojawia się w:

Pomiary Automatyka Robotyka

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 41.

Tytuł:

Cyclic delivery-scheduling problem with synchronization of vehicles arrivals at logistic centers
Problem harmonogramowania dostaw cyklicznych z warunkiem synchronizacji przyjazdów do centrów przeładunkowych

Autorzy:

Gdowska, K. Z.
Książek, R.

Powiązania:

https://bibliotekanauki.pl/articles/361727.pdf

Data publikacji:

2015

Wydawca:

Wyższa Szkoła Logistyki

Tematy:

cyclic delivery scheduling problem
mixed-integer programming
optimization
synchronization
logistics
harmonogramowanie dostaw cyklicznych
optymalizacja
synchronizacja
programowanie całkowitoliczbowe mieszane

Opis:

Background: In this paper a cyclic delivery-scheduling problem with vehicles serving fixed routes is presented. Each vehicle is assigned to one route to which some manufacturers' warehouses and logistics centers belong. A vehicle is to be loaded at a manufacturer's warehouse, then to deliver goods to a logistics center and may be also loaded there with other goods and to transport them to the next node along the route. One logistic center belongs to several routes, so the goods delivered by one vehicle may continue their journey by another truck. For every route the frequency of the vehicle is fixed and known. The objective here is to obtain such synchronization of vehicles arrivals in logistics centers, so that it is possible to organize their arrivals in repeatable blocks. Methods: In the paper the cyclic delivery-scheduling problem with vehicles serving fixed routes is formulated as a MIP model. Due to the fixed routes and desirable synchronization of vehicles arrivals in shared points this problem seems to be similar to the public transit network timetabling problem. Because of that the model presented here was based on a model dedicated to the public transit network timetabling problem, where optimization criterion was to maximize synchronization of vehicles' arrivals at the shared nodes. Results: Mixed integer programming model was employed for solving several cases of cyclic delivery-scheduling problem with vehicles serving fixed routes. Computational experiments are reported and obtained results are presented. Conclusions: The mixed integer programming model for the cyclic delivery-scheduling problem with synchronization of vehicles arrivals at logistic centers presented in this paper can be utilized for generating schedules for a group of vehicles serving fixed long routes. It may result in reducing total operational cost related to this group of vehicles as well as in reducing the goods travel time from the place of origin to their destination.
Wstęp: W pracy przedstawiono problem harmonogramowania dostaw cyklicznych wykonywanych przez pojazdy obsługujące ustalone i niezmienne trasy. Każdy pojazd obsługuje inną trasę, gdzie ma za zadanie dostarczyć towar do centrum logistycznego, a także załadować tam inny towar i przewieźć go do kolejnego punktu trasy lub wykonać pusty przejazd do kolejnego punktu załadunku. Wspólnymi punktami tras pojazdów są centra logistyczne, w których niejednokrotnie towar przywieziony przez jeden pojazd, wyrusza w dalszą drogę następnym pojazdem z rozpatrywanej grupy. Przejazdy po każdej trasie realizowane są ze stałą częstotliwością. Celem dla wspomnianego problemu harmonogramowania dostaw cyklicznych jest uzyskanie synchronizacji przyjazdów i pobytu pojazdów w centrach logistycznych tak, aby możliwe było grupowanie ich obsługi w bloki. Metody: Ze względu na sztywno wyznaczone trasy oraz pożądaną synchronizację przyjazdów do punktów wspólnych tras problem ten wykazuje podobieństwo do problemów układania rozkładów jazdy komunikacji miejskiej. Dlatego przy konstruowaniu modelu matematycznego dla tego problemu wykorzystano model przygotowany pierwotnie dla zadania układania rozkładów jazdy komunikacji miejskiej z kryterium optymalizacji związanym z synchronizacją przyjazdów na przystanki wspólne. Wyniki: Eksperyment obliczeniowy polegał na rozwiązaniu i porównaniu uzyskanych wyników dla zbioru zadań programowania całkowitoliczbowego mieszanego dla problemu harmonogramowania cyklicznych dostaw z warunkiem synchronizacji przyjazdów do centrów przeładunkowych. Wnioski: Przedstawiony model MIP dla zadania harmonogramowania cyklicznych dostaw z warunkiem synchronizacji przyjazdów do centrów przeładunkowych może być wykorzystywany do tworzenia harmonogramów do planowania kursów cyklicznych wykonywanych przez grupę pojazdów obsługujących ustalone długie trasy. Pozwoli to na racjonalne planowanie pracy centrum logistycznego i pośrednio wpłynie na obniżenie kosztów, a także skrócenie czasu podróży towaru z punktu wysyłki do odbiorcy.

Źródło:

LogForum; 2015, 11, 4; 341-350
1734-459X

Pojawia się w:

LogForum

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 42.

Tytuł:

New models and algorithms for RNA pseudoknot order assignment

Autorzy:

Zok, Tomasz
Badura, Jan
Swat, Sylwester
Figurski, Kacper
Popenda, Mariusz
Antczak, Maciej

Powiązania:

https://bibliotekanauki.pl/articles/911230.pdf

Data publikacji:

2020

Wydawca:

Uniwersytet Zielonogórski. Oficyna Wydawnicza

Tematy:

RNA pseudoknot order
conflict graph
vertex coloring
maximum independent set
integer programming
kolorowanie grafu
zbiór niezależny
programowanie całkowitoliczbowe

Opis:

The pseudoknot is a specific motif of the RNA structure that highly influences the overall shape and stability of a molecule. It occurs when nucleotides of two disjoint single-stranded fragments of the same chain, separated by a helical fragment, interact with each other and form base pairs. Pseudoknots are characterized by great topological diversity, and their systematic description is still a challenge. In our previous work, we have introduced the pseudoknot order: a new coefficient representing the topological complexity of the pseudoknotted RNA structure. It is defined as the minimum number of base pair set decompositions, aimed to obtain the unknotted RNA structure. We have suggested how it can be useful in the interpretation and understanding of a hierarchy of RNA folding. However, it is not trivial to unambiguously identify pseudoknots and determine their orders in an RNA structure. Therefore, since the introduction of this coefficient, we have worked on the method to reliably assign pseudoknot orders in correspondence to the mechanisms that control the biological process leading to their formation in the molecule. Here, we introduce a novel graph coloring-based model for the problem of pseudoknot order assignment. We show a specialized heuristic operating on the proposed model and an alternative integer programming algorithm. The performance of both approaches is compared with that of state-of-the-art algorithms which so far have been most efficient in solving the problem in question. We summarize the results of computational experiments that evaluate our new methods in terms of classification quality on a representative data set originating from the non-redundant RNA 3D structure repository.

Źródło:

International Journal of Applied Mathematics and Computer Science; 2020, 30, 2; 315-324
1641-876X
2083-8492

Pojawia się w:

International Journal of Applied Mathematics and Computer Science

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 43.

Tytuł:

Post-optimal analysis for multicriteria integer linear programming problem with parametric optimality

Autorzy:

Emelichev, Vladimir
Nikulin, Yury

Powiązania:

https://bibliotekanauki.pl/articles/2049980.pdf

Data publikacji:

2020

Wydawca:

Polska Akademia Nauk. Instytut Badań Systemowych PAN

Tematy:

post-optimal analysis
multiple criteria
quasistability radius
integer linear programming
parametric optimality

Opis:

This paper addresses a multicriteria problem of integer linear programming with parametric optimality. Parameterizations is introduced by dividing a set of objectives into a family of disjoint subsets, within each Pareto optimality is used to establish dominance between alternatives. The introduction of this principle allows us to connect such classical optimality sets as Pareto and extreme. The parameter space of admissible perturbations in such problem is formed by a set of additive matrices, with arbitrary Hölder’s norms specified in the solution and criterion spaces. The attainable lower and upper bounds for the radii of quasistability are obtained.

Źródło:

Control and Cybernetics; 2020, 49, 2; 163-178
0324-8569

Pojawia się w:

Control and Cybernetics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 44.

Tytuł:

Model matematyczny optymalizacji kosztów w łańcuchu dostaw
Mathematical model of optimization in supply chain

Autorzy:

Sitek, P.
Wikarek, J.

Powiązania:

https://bibliotekanauki.pl/articles/276855.pdf

Data publikacji:

2012

Wydawca:

Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów

Tematy:

łańcuch dostaw
programowanie całkowitoliczbowe
optymalizacja
optimization
supply chain
mixed integer linear programming

Opis:

W artykule przedstawiono autorski model optymalizacji łańcucha dostaw z punktu widzenia operatora logistycznego. Model został sformułowany w postaci zagadnienia programowania liniowego całkowitoliczbowego z funkcją celu określającą koszty dystrybutora, producenta oraz transportu. Przeprowadzono szczegółową dyskusję modelu z omówieniem ograniczeń, parametrów i zmiennych decyzyjnych. Dodatkowo w artykule zaprezentowano aktualny stan outsourcingu usług logistycznych.
The article presents the author’s model of supply chain optimization in terms of logistics operator. The model was formulated as an integer linear programming problem with objective function specifies the cost of a distributor, manufacturer, and transportation. A detailed discussion of the discussion of model constraints, parameters and decision variables. In addition, the article presents the current state of logistics outsourcing.

Źródło:

Pomiary Automatyka Robotyka; 2012, 16, 2; 137-140
1427-9126

Pojawia się w:

Pomiary Automatyka Robotyka

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 45.

Tytuł:

Właściwości programowej realizacji zadania programowania całkowitoliczbowego
Look-and-feel realization of integer programming problems

Autorzy:

Ostanin, A.
Wasiluk, J.

Powiązania:

https://bibliotekanauki.pl/articles/341141.pdf

Data publikacji:

2008

Wydawca:

Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej

Tematy:

programowanie całkowitoliczbowe
metoda gałęzi i granic
decyzja o rozgałęzieniu
integer programming
branch-and-bound method
deciding whether to branch

Opis:

Praca poświęcona jest problemom realizacji nowej optymalizacyjnej funkcji bintprog jako nieodłącznej części Optimization Toolbox 3.0 programowego pakietu MATLAB 7. Wprowadzenie nowej funkcji istotnie poszerza skalę rozwiązywanych optymalizacyjnych zadań, ponieważ potwierdza fakt realizowania metody gałęzi i granic. Badanie tej metody wchodzi w skład programu wielu uczelnianych kursów i daje podstawędo rozwiązywania większości zadań programowania całkowitoliczbowego. Na zakończenie podano przykłady niektórych reprezentatywnych wyników uzyskanych w badaniach.
The paper is dedicated to the problems of realization a new optimization function bintprog as inseparable part of Optimization Toolbox 3.0, pack MATLAB 7. Introduction of the new function essentially extends the scale of optimization assignments that should be solved, because it confirms the fact of realizing the branch-and-bound method. Investigation of this methods is included in many of educational courses and gives base to solving most of integer programming problems. Some representative results of tests are given at the end of the paper.

Źródło:

Zeszyty Naukowe Politechniki Białostockiej. Informatyka; 2008, 3; 97-110
1644-0331

Pojawia się w:

Zeszyty Naukowe Politechniki Białostockiej. Informatyka

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 46.

Tytuł:

Heuristic energy-saving virtual network embedding algorithm based on Katz centrality

Autorzy:

Zhu, Qiang
Wang, Qing-Jun
Zang, Mu-Jun
Wang, Zhen-Dong
Xiao, Chang

Powiązania:

https://bibliotekanauki.pl/articles/141679.pdf

Data publikacji:

2020

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

energy-saving virtual network
integer linear programming
Katz centrality
network virtualization embedding
virtualization

Opis:

Current networks are designed for peak loads leading to low utilization of power resources. In order to solve this problem, a heuristic energy-saving virtual network embedding algorithm based on the Katz centrality (Katz-VNE) is proposed. For solving an energy-saving virtual network embedding problem, we introduce the Katz centrality to represent the node influence. In order to minimize the energy consumption of the substrate network, the energy-saving virtual network embedding problem is formulated as an integer linear program, and the Katz-VNE is used to solve this problem. The Katz-VNE tries to embed the virtual nodes onto the substrate nodes with high Katz centrality, which is effective, and uses the shortest paths offering the best factor of bandwidths to avoid the hot nodes. The simulation results demonstrate that the long-term average energy consumption of the substrate network is reduced significantly, and the long-term revenue/cost ratio, the acceptance rate of virtual network requests, and the hibernation rate of substrate nodes as well as links are improved significantly.

Źródło:

Archives of Electrical Engineering; 2020, 69, 3; 595-608
1427-4221
2300-2506

Pojawia się w:

Archives of Electrical Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 47.

Tytuł:

An optimization approach to the intermodal transportation network in fruit cold chain, considering cost, quality degradation and carbon dioxide footprint

Autorzy:

Ma, Q.
Wang, W.
Peng, Y.
Song, X.

Powiązania:

https://bibliotekanauki.pl/articles/260179.pdf

Data publikacji:

2018

Wydawca:

Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa

Tematy:

intermodal transport network
quality model
refrigerated container
fruit cold chain
integer linear programming

Opis:

This model optimizes port hinterland intermodal refrigerated container flows , considering both cost and quality degradation, which is distinctive from the previous literature content in a way that it quantifies the influence of carbon dioxide (CO2) emission in different setting temperature on intermodal network planning. The primary contribution of this paper is that the model is beneficial not only to shippers and customers for the novel service design, but also offer , for policy-makers of the government, insights to develop inland transport infrastructures in consideration of intermodal transportation. The majority of models of multimodal system have been established with an objective of cost minimization for normal commodities. As the food quality is possible to be influenced by varying duration time required for the storage and transportation, and transportation accompanied with refrigeration producing more CO2 emission, this paper aims to address cost minimization and quality degradation minimization within the constraint of CO2 footprint. To achieve this aim, we put the quality degradation model in a mixed-integer linear programming model used for intermodal network planning for cold chain. The example of Dalian Port and Yingkou Port offer insight into trade-offs between transportation temperature and transport mode considering CO2 footprint. Furthermore, the model can offer a useful reference for other regions with the demand for different imported food, which requires an uninterrupted cold chain during the transportation and storage.

Źródło:

Polish Maritime Research; 2018, 1; 61-69
1233-2585

Pojawia się w:

Polish Maritime Research

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 48.

Tytuł:

Real – time dispatching modelling for trucks with different capacities in open pit mines
Modelowanie w czasie rzeczywistym przewozów ciężarówek o różnej ładowności w kopalni odkrywkowej

Autorzy:

Ahangaran, D. K.
Yasrebi, A. B.
Wetherelt, A.
Foster, P.

Powiązania:

https://bibliotekanauki.pl/articles/218736.pdf

Data publikacji:

2012

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

transportation
truck dispatching and allocation
optimisation of mines’ transportationtion
integer programming
transport
dysponowanie przewozami
optymalizacja transportu w kopalni
programowanie binarne

Opis:

Application of fully automated systems for truck dispatching plays a major role in decreasing the transportation costs which often represent the majority of costs spent on open pit mining. Consequently, the application of a truck dispatching system has become fundamentally important in most of the world’s open pit mines. Recent experiences indicate that by decreasing a truck’s travelling time and the associated waiting time of its associated shovel then due to the application of a truck dispatching system the rate of production will be considerably improved. Computer-based truck dispatching systems using algorithms, advanced and accurate software are examples of these innovations. Developing an algorithm of a computer-based program appropriated to a specific mine’s conditions is considered as one of the most important activities in connection with computer-based dispatching in open pit mines. In this paper the changing trend of programming and dispatching control algorithms and automation conditions will be discussed. Furthermore, since the transportation fleet of most mines use trucks with different capacities, innovative methods, operational optimisation techniques and the best possible methods for developing the required algorithm for real-time dispatching are selected by conducting research on mathematical-based planning methods. Finally, a real-time dispatching model compatible with the requirement of trucks with different capacities is developed by using two techniques of flow networks and integer programming.
Zastosowanie w pełni zautomatyzowanych systemów dysponowania przewozami ciężarówek w poważny sposób przyczynia się do zmniejszenia kosztów transportu, które częstokroć mają poważny udział w kosztach funkcjonowania kopalni odkrywkowych. Dlatego też zastosowanie systemu dysponowania transportem ma kluczowe znaczenie w kopalniach odkrywkowych na świecie. Niedawne doświadczenia wskazują, że poprzez zmniejszenie czasu przejazdu ciężarówek oraz zmniejszenie czasu oczekiwania dzięki zastosowaniu systemu dysponowania przewozami możliwe jest znaczne podniesienie poziomu produkcji. Wspomagany komputerowo system dysponowania przewozami wykorzystujący odpowiednie algorytmy a także zaawansowane oprogramowanie stanowią przykłady nowoczesnych rozwiązań w tej dziedzinie. Opracowanie algorytmu komputerowego dostosowanego do konkretnych warunków panujących w danej kopalni odkrywkowej jest jedną z kluczowych czynności dla uruchomienia komputerowego systemu dysponowania przewozami ciężarówek w kopalni. W artykule przedstawiono zmieniające się trendy w zakresie programowania, algorytmów sterowania przewozami i automatyzacji. Ponadto, ponieważ większość kopalni odkrywkowych wykorzystuje ciężarówki o różnej ładowności, wybrano najlepsze i najnowocześniejsze metody i techniki optymalizacji oraz najskuteczniejsze metody opracowywania algorytmów wspomagających systemy dysponowania przejazdami ciężarówek w czasie rzeczywistym, wybrano je w oparciu o metody planowania wykorzystujące aparat matematyczny. W części końcowej zaprezentowano model dysponowania przewozami w czasie rzeczywistym kompatybilny z wymogiem zastosowania ciężarówek o różnej ładowności, opracowany w oparciu o metody sieci przepływowych i programowania binarnego.

Źródło:

Archives of Mining Sciences; 2012, 57, 1; 39-52
0860-7001

Pojawia się w:

Archives of Mining Sciences

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 49.

Tytuł:

Minimum Bend Shortest Rectilinear Route Discovery for a Moving Sink in a Grid Based Wireless Sensor Network

Autorzy:

Thomas, Sanu
Mathew, Thomaskutty

Powiązania:

https://bibliotekanauki.pl/articles/226096.pdf

Data publikacji:

2019

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

minimum bend shortest paths
travelling salesman problem
binary integer programming
edge orientation index
Vertex Bend Index
Vertex-Edge Incident Matrix

Opis:

In a rectilinear route, a moving sink is restricted to travel either horizontally or vertically along the connecting edges. We present a new algorithm that finds the shortest round trip rectilinear route covering the specified nodes in a grid based Wireless Sensor Network. The proposed algorithm determines the shortest round trip travelling salesman path in a two-dimensional grid graph. A special additional feature of the new path discovery technique is that it selects that path which has the least number of corners (bends) when more than one equal length shortest round trip paths are available. This feature makes the path more suitable for moving objects like Robots, drones and other types of vehicles which carry the moving sink. In the prosed scheme, the grid points are the vertices of the graph and the lines joining the grid points are the edges of the graph. The optimal edge set that forms the target path is determined using the binary integer programming.

Źródło:

International Journal of Electronics and Telecommunications; 2019, 65, 2; 267-276
2300-1933

Pojawia się w:

International Journal of Electronics and Telecommunications

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 50.

Tytuł:

Optimization of underground mine access layout and production scheduling
Optymalizacja układu dostępu do kopalni podziemnej i harmonogramu produkcji

Autorzy:

Hou, Jie
Li, Guoqing
Hu, Nailian

Powiązania:

https://bibliotekanauki.pl/articles/217032.pdf

Data publikacji:

2020

Wydawca:

Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN

Tematy:

access layout optimization
production schedule optimization
underground mine
integer programming
optymalizacja układu dostępu
optymalizacja harmonogramu produkcji
kopalnia podziemna
programowanie zintegrowane

Opis:

Optimization in mine planning could improve the economic benefit for mining companies. The main optimization contents in an underground mine includes stope layout, access layout and production scheduling. It is common to optimize each part sequentially, where optimal results from one phase are treated as the input for the next phase. The production schedule is based on the mining design. Access layout plays an important role in determining the connection relationships between stopes. This paper proposes a shortest-path search algorithm to design a network that automatically connects each stope. Access layout optimization is treated as a network flow problem. Stopes are viewed as nodes, and the roads between the stopes are regarded as edges. Moreover, the decline location influences the ore transport paths and haul distances. Tree diagrams of the ore transportation path are analyzed when each stope location is treated as an alternative decline location. The optimal decline location is chosen by an enumeration method. Then, Integer Programming (IP) is used to optimize the production scheduling process and maximize the Net Present Value (NPV). The extension sequence of access excavation and stope extraction is taken into account in the optimization model to balance access development and stope mining. These optimization models are validated in an application involving a hypothetical gold deposit, and the results demonstrate that the new approach can provide a more realistic solution compared with those of traditional approaches.
Optymalizacja w planowaniu kopalni może poprawić korzyści gospodarcze dla przedsiębiorstw górniczych. Główna część optymalizacji w kopalni podziemnej obejmuje układ wyrobisk eksploatacyjnych, schemat udostepnienia i harmonogram wydobycia. Zazwyczaj każdy etap optymalizowany jest sekwencyjnie, gdzie optymalne wyniki z jednej fazy są traktowane jako dane wejściowe do następnej fazy. Harmonogram produkcji opiera się na projekcie górniczym. Struktura udostępnienia odgrywa ważną rolę w określaniu połączeń pomiędzy przodkami eksploatacyjnymi. Ten artykuł proponuje algorytm wyszukiwania najkrótszej ścieżki, aby zaprojektować sieć, która automatycznie łączy każdy przodek. Optymalizacja struktury udostępnienia jest traktowana jako problem przepływu w sieci. Przodki są traktowane jako węzły, a drogi pomiędzy nimi jako krawędzie. Ponadto lokalizacja upadowej udostępniającej wpływa na drogi transportu rudy i odległości odstawy. Analiza ścieżek drzew zdarzeń odbywa się przy założeniu alternatywnych lokalizacji upadowych. Optymalna lokalizacja upadowej jest wybierana metodą wyliczania. Następnie, za pomocą programowania zintegrowanego (Integer Programming – IP) optymalizuje się proces planowania produkcji i maksymalizacji wartości bieżącej netto (NPV).Rozwinięty układ wyrobisk udostępniających i eksploatacyjnych jest uwzględniany w modelu optymalizacji do zbilansowania udostępnienia i eksploatacji złoża. Te modele optymalizacji są walidowane w aplikacji uwzględniającej hipotetyczne złoże rud złota, której wyniki pokazują, że nowe podejście może dostarczyć bardziej realistyczne rozwiązanie w porównaniu z tradycyjnymi metodami.

Źródło:

Gospodarka Surowcami Mineralnymi; 2020, 36, 2; 87-108
0860-0953

Pojawia się w:

Gospodarka Surowcami Mineralnymi

Dostawca treści:

Biblioteka Nauki

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