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Wyszukujesz frazę "optimum" wg kryterium: Temat


Tytuł:
Advances in estimation by the item sum technique in two move successive sampling
Autorzy:
Priyanka, Kumari
Trisandhya, Pidugu
Powiązania:
https://bibliotekanauki.pl/articles/19900669.pdf
Data publikacji:
2023-09-08
Wydawca:
Główny Urząd Statystyczny
Tematy:
Sensitive variable
Successive moves
Population mean
Variance
Mean squared error
Optimum matching fraction
Opis:
The present article proposes an estimator using the Item Sum Technique (IST) for the estimation of dynamic sensitive population mean using non-sensitive auxiliary information in the two-move successive sampling. Properties of the proposed IST estimator have been analysed. Possible allocation designs for allocating long-list and short-list samples pertaining to the IST have been elaborated. The comparison between various allocation designs has been carried out. Theoretical considerations have been integrated with numerical as well as simulation studies to show the working version of the proposed IST estimators in the two-move successive sampling.
Źródło:
Statistics in Transition new series; 2023, 24, 4; 123-138
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanism and optimum pressure for sliding-mode nanogenerator
Autorzy:
Yun, Hang
He, Ren
Powiązania:
https://bibliotekanauki.pl/articles/2204139.pdf
Data publikacji:
2023
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
triboelectric nanogenerator
ab initio calculation
optimum pressure
recovered energy
Opis:
Triboelectric nanogenerator has extensive applicability because of its capability of harvesting mechanical energy and flexible working modes. To research the optimum pressure and improve the recovered energy of the sliding-mode triboelectric nanogenerator, a contact model of the Al/PTFE tribo-pair is studied by ab initio calculation and finite element simulation. The F-atom of PTFE is proved to be the electron accepter and the charges transferred can be predicted by Bader charge analysis. The mathematical relation between interfacial distance, charges transferred and contact pressure can be fitted. By Gauss’s law, the electric field is simulated and the regeneration energy of the sliding-mode triboelectric nanogenerator can be evaluated by the total electric energy and friction loss. Finally, an optimum pressure can be set to the upper or lower limit of working pressure corresponding to larger recovered energy. And less friction coefficient and larger contact area are also effective methods for recovering energy.
Źródło:
Polish Journal of Chemical Technology; 2023, 25, 1; 35--39
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Obliczenie optymalnej średnicy otworu strzałowego z uwzględnieniem właściwości wytrzymałościowych i akustycznych urabianej skały oraz energii zastosowanego materiału wybuchowego (MW)
Calculation of the optimum blast hole diameter, taking into account the strength and acoustic properties of the excavated rock and the energy of the BM used
Autorzy:
Chrzan, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/31342951.pdf
Data publikacji:
2023
Wydawca:
Poltegor-Instytut Instytut Górnictwa Odkrywkowego
Tematy:
średnica optymalna
otwór strzałowy
obliczenia
optimum diameter
blast-hole
calculations
Opis:
Artykuł dotyczy nowego sposobu obliczenia optymalnej średnicy otworu strzałowego. Sposób ten uwzględnia właściwości wytrzymałościowe i akustyczne urabianej skały oraz energię zastosowanego MW. Przedstawiono stan obecny doboru średnicy otworów strzałowych. Na podstawie przykładów, które odzwierciadlają rzeczywiste warunki wytrzymałościowe i akustyczne urabianej w złożu bazaltu i dolomitu skały przeprowadzono obliczenia. Obliczenia te wykazały, że błąd względny określenia stosowanej średnicy w stosunku do optymalnej wynosi od -2% do+6,6%. Tak duża dokładność określenia średnicy optymalnej potwierdza prawidłowość zastosowanej zależności, która może być stosowana w praktyce.
The article deals with a new method of calculating the optimum diameter of a blast hole. This method takes into account the strength and acoustic properties of the rock being excavated and the energy of the BM used. The current status of the selection of blasthole diameters is presented. Calculations were carried out using examples that reflect the actual strength and acoustic conditions of the rock being excavated in basalt and dolomite deposits. These calculations showed that the relative error in the determination of the diameter used in relation to the optimum diameter ranges from -2% to+6.6%. This high accuracy in determining the optimum diameter confirms the validity of the relationship used, which can be applied in practice.
Źródło:
Górnictwo Odkrywkowe; 2023, 64, 1; 13-17
0043-2075
Pojawia się w:
Górnictwo Odkrywkowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Operational risk assessment model for city buses
Autorzy:
Niewczas, Andrzej
Mórawski, Łukasz
Rymarz, Joanna
Dębicka, Ewa
Hołyszko, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/24200810.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
sustainable public transport
operational risk
reliability
optimum bus life cycle
Opis:
The development of public transport systems presently focuses on sustainability. In this situation, the issue of user (passenger) migration has become important to the transport company as a service provider. This paper presents an integrated model of the operational risk of vehicle incapacity, including the following: costs of incidental repairs, costs of unplanned downtime and costs resulting from potential user migration. The paper presents the results of operational research on buses of two makes over a period of 6 years, in the mileage range of 0-420 000 km. The authors have determined the risk as a regression function of operational mileage to estimate the optimum life cycle. The quality of the vehicle was assessed using the criterion of the maximum cost of the operational incapacity risk being equal to the current residual value of the vehicle. The research results confirmed the suitability of the integrated risk model for a comparison of vehicle makes and assessment of their reasonably foreseeable life cycle in a balanced carrier-vehicle-user system.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 1; art. no. 14
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on optimum design method of cushion thickness in composite foundation under rigid base
Autorzy:
Xiao, Yaoting
Wang, Jing
Powiązania:
https://bibliotekanauki.pl/articles/27312123.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
fundament kompozytowy
grubość
konstrukcja optymalna
rozkład naprężeń
composite foundation
cushion thickness
optimum design
stress diffusion
Opis:
At present, the cushion thickness of composite foundation under rigid base is mostly selected by the experience of the engineer, which is of great arbitrariness. In order to improve this problem, the optimum design method of cushion thickness is proposed by theoretical research. First, the stress diffusion line in the cushion is assumed to be a quadratic curve, and the critical diffusion thickness of the pile top stress is obtained. Then, by analyzing the relative deformation between soil and pile, pile top penetration into the critical cushion thickness is proposed. Finally, based on the relationship between stress ratio of pile to soil and cushion thickness, the calculation method of optimum cushion thickness is put forward. The application of engineering cases shows that the proposed method has better calculation results, which attests to the correctness of the method. The method can be used for the optimal design of cushion thickness of single-type-pile or multi-type-pile composite foundation.
Źródło:
Archives of Civil Engineering; 2023, 69, 2; 471--482
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Under military war weapon support the economic bond level estimation using generalized Petersen graph with imputation
Autorzy:
Rajoriya, Deepika
Shukla, Diwakar
Powiązania:
https://bibliotekanauki.pl/articles/10583093.pdf
Data publikacji:
2023-02-24
Wydawca:
Główny Urząd Statystyczny
Tematy:
Graph
Petersen Graph
Estimator
Bias
Mean Squared Error (MSE)
Optimum Choice
Confidence intervals (CI)
Nodes (vertices)
Pattern Imputation
CI-Imputation (LLimputation and UL-imputation)
Economic Bonds
Military War
Weapon Support
Źródło:
Statistics in Transition new series; 2023, 24, 1; 295-320
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The magnitude optimum design of the PI controller for plants with complex roots and dead time
Autorzy:
Cvejn, Jan
Powiązania:
https://bibliotekanauki.pl/articles/2106500.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dead time
frequency response
magnitude optimum
PID controller
process control
stability margin
Opis:
Analytical design of the PID-type controllers for linear plants based on the magnitude optimum criterion usually results in very good control quality and can be applied directly for high-order linear models with dead time, without need of any model reduction. This paper brings an analysis of properties of this tuning method in the case of the PI controller, which shows that it guarantees closed-loop stability and a large stability margin for stable linear plants without zeros, although there are limitations in the case of oscillating plants. In spite of the fact that the magnitude optimum criterion prescribes the closed-loop response only for low frequencies and the stability margin requirements are not explicitly included in the design objective, it reveals that proper open-loop behavior in the middle and high frequency ranges, decisive for the closed-loop stability and robustness, is ensured automatically for the considered class of linear systems if all damping ratios corresponding to poles of the plant transfer function without the dead-time term are sufficiently high.
Źródło:
Archives of Control Sciences; 2022, 32, 1; 5--35
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of optimum truck number at open coal quarry
Autorzy:
Tosun, Abdurrahman
Powiązania:
https://bibliotekanauki.pl/articles/1853878.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
samochód ciężarowy
koparka
górotwór
optimum truck number
excavator
rock mass characteristics
Opis:
Optimum truck numbers of an enterprise can be found by dividing the period of time passed between a departing truck after loading, the arrival at the dumping location, the arrival at the point of loading again and the average loading time parameters of a truck. The average loading time of the truck is directly associated with the bucket fill factor and cycle time of the excavator. While the bucket fill factor depends on the mechanical strength and the discontinuity characteristics of the rock, the cycle time is related to bucket volume, the strength and the discontinuity characteristics of the rock. In this study, two relations predicting the average cycle time of the bucket fill factor for both hydraulic and electric excavators is done by seven excavators with different bucket volumes, and mass characteristics of eight different rocks from a coal open pit mine. According to the above, the optimum truck number was developed.
Źródło:
Archives of Mining Sciences; 2021, 66, 2; 213-225
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integer factor based SVPWM approach for multilevel inverters with continuous and discontinuous switching sequences
Autorzy:
Suresh, Kumar Anisetty
Sri, Gowri Kolli
Nagaraja, Rao Sulake
Manjunatha, Budagavi Matam
Sesi, Kiran Ponnapati
Niteesh, Kumar K.
Powiązania:
https://bibliotekanauki.pl/articles/1955193.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
integer factor approach
inverters
multilevel inverters
optimum switching sequence
space vector modulation
SVPWM
metoda współczynnika całkowego
inwertery
inwertery wielopoziomowe
optymalna sekwencja przełączania
modulacja wektora przestrzeni
Opis:
The most extensively employed strategy to control the AC output of power electronic inverters is the pulse width modulation (PWM) strategy. Since three decades modulation hypothesis continues to draw considerable attention and interest of researchers with the aim to reduce harmonic distortion and increased output magnitude for a given switching frequency. Among different PWM techniques space vector modulation (SVM) is very popular. However, as the number of output levels of the multilevel inverter (MLI) increases, the implementation of SVM becomes more difficult, because as the number of levels increases the total number of switches in the inverter increases which will increase the total number of switching states, which will result in increased computational complexity and increased storage requirements of switching states and switching pulse durations. The present work aims at reducing the complexity of implementing the space vector pulse width modulation (SVPWM) technique in multilevel inverters by using a generalized integer factor approach (IFA). The performance of the IFA is tested on a three-level inverter-fed induction motor for conventional PWM (CPWM) which is a continuous SVPWM method employing a 0127 sequence and discontinuous PWM (DPWM) methods viz, DPWMMIN using 012 sequences and DPWMMAX using a 721 sequence.
Źródło:
Archives of Electrical Engineering; 2021, 70, 4; 859-872
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization model the pipe diameter in the drinking water distribution network using multi-objective genetic algorithm
Autorzy:
Sulianto, -
Setiono, Ernawan
Yasa, I. Wayan
Powiązania:
https://bibliotekanauki.pl/articles/1844381.pdf
Data publikacji:
2021
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
diameter
genetic algorithm
network
Newton Raphson method
optimum
pipe
Opis:
Under conditions of gravity flow, the performance of a distribution pipe network for drinking water supply can be measured by investment cost and the difference in real and target pressures at each node to ensure fairness of the service. Therefore, the objective function for the optimization in the design of a complex gravity flow pipe network is a multi-purpose equation system set up to minimize the above-mentioned two parameters. This article presents a new model as an alternative solution to solving the optimization equation system by combining the Newton–Raphson and genetic algorithm (GA) methods into a single unit so that the resulting model can work effectively. The Newton–Raphson method is used to solve the hydraulic equation system in pipelines and the GA is used to find the optimal pipe diameter combination in a network. Among application models in a complex pipe network consisting of 12 elements and 10 nodes, this model is able to show satisfactory performance. Considering variations in the value of the weighting factor in the objective function, opti-mal conditions can be achieved at the investment cost factor (ω1) = 0.75 and the relative energy equalization factor at the service node (ω2) = 0.25. With relevant GA input parameters, optimal conditions are achieved at the best fitness value of 1.016 which is equivalent to the investment cost of USD 56.67 thous. with an average relative energy deviation of 1.925 m.
Źródło:
Journal of Water and Land Development; 2021, 48; 55-64
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Construction of constrained experimental designs on finite spaces for a modified Ek-optimality criterion
Autorzy:
Uciński, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/1838172.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
constrained optimum experimental design
minimal sum of largest eigenvalues
generalized simplicial decomposition
optimal measurement selection
Opis:
A simple computational algorithm is proposed for minimizing sums of largest eigenvalues of the matrix inverse over the set of all convex combinations of a finite number of nonnegative definite matrices subject to additional box constraints on the weights of those combinations. Such problems arise when experimental designs aiming at minimizing sums of largest asymptotic variances of the least-squares estimators are sought and the design region consists of finitely many support points, subject to the additional constraints that the corresponding design weights are to remain within certain limits. The underlying idea is to apply the method of outer approximations for solving the associated convex semi-infinite programming problem, which reduces to solving a sequence of finite min-max problems. A key novelty here is that solutions to the latter are found using generalized simplicial decomposition, which is a recent extension of the classical simplicial decomposition to nondifferentiable optimization. Thereby, the dimensionality of the design problem is drastically reduced. The use of the algorithm is illustrated by an example involving optimal sensor node activation in a large sensor network collecting measurements for parameter estimation of a spatiotemporal process.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2020, 30, 4; 659-677
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of optimum temperatures and activationenergies of inulin hydrolysis by endo-inulinase Aspergillus Niger
Autorzy:
Miłek, Justyna
Powiązania:
https://bibliotekanauki.pl/articles/185420.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
endo-inulinase Aspergillus niger
optimum temperature
activation energy
deactivation energy
endo-inulinaza Aspergillus niger
optymalna temperatura
energia aktywacji
energia dezaktywacji
Opis:
The paper presents a comparative analysis to determine the optimal temperatures and the activationenergies for various origin endo-inulinases fromAspergillus niger. The parameters were estimatedbased on the literature of the activity curves vs. temperature for hydrolysis of inulin. It was assumedthat both the hydrolysis reaction process and the deactivation process of endo-inulinase were first-orderreactions by the enzyme concentration. A mathematical model describing the effect of temperature onendo-inulinases fromAspergillus nigeractivity was used. Based on the comparison analysis, valuesof the activation energies Ea were in the range from23:53+/-3:20kJ/mol to50:66+/-3:61kJ/mol, thedeactivation energies Ed were in the range from88:42+/-5:03kJ/mol to142:87+/-2:75kJ/mol andthe optimum temperatures Topt were obtained in the range from317:12+/-0:83K to332:55+/-0:72forendo-inulinase A. niger.
Źródło:
Chemical and Process Engineering; 2020, 41, 3; 229--236
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Waste Glass Powder on Subgrade Soil Improvement
Autorzy:
Javed, Syed Aaqib
Chakraborty, Sudipta
Powiązania:
https://bibliotekanauki.pl/articles/1030256.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
California Bearing Ratio (CBR)
Liquid Limit (LL)
Maximum Dry Density (MDD)
Optimum Moisture Content (OMC)
Plastic Limit (PL)
Soil Stabilization
Unconfined Compression Strength (UCS)
Waste Glass Powder
Opis:
The weak soil is largely distributed worldwide and creates problems in constructing pavements, roadways, structures, irrigation systems and foundation works due to low shear strength and bearing capacity. The ways of improving soil is known as soil stabilization. Various soil stabilization techniques are using but none of them are cost effective and environmentally friendly way. The present study aims to effect of soil stabilization with waste glass powder which will reduce the cost and is environmentally friendly. To investigate the effect of glass powder in cohesive soil different types of index and geotechnical engineering tests are conducted and compared with the virgin soil. Glass powder was mixed with the soil samples by 2%, 4%, 6%, 8% and 10% of dry weight of soil to conduct the tests and to determine the optimum percentage of glass powder. The Liquid Limit (LL), Plastic Limit (PL) and Plasticity Index (PI) continuously decreased and found 33.9%, 18.4% and 15.5% respectively at 10% of glass powder. Maximum dry density (MDD) was increasing and found constant and Optimum Moisture Content (OMC) was decreasing when added glass powder. The both Unsoaked and Soaked California Bearing Ratio (CBR) was increasing with the addition of glass powder and found maximum value 22.5% and 10.4% respectively. Unconfined compressive strength (UCS) was increasing up to 8% of glass powder and found to 133.5 KN/m2 and then decreased to 119.7 KN/m2 when added 10% of glass powder. Shear strength parameter also increases with the increase of glass powder. The study found that the optimum percentage of glass powder is 8% of dry weight of soil.
Źródło:
World Scientific News; 2020, 144; 30-42
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New linear model for optimal cluster size in cluster sampling
Autorzy:
Shukla, Alok Kumar
Yadav, Subhash Kumar
Powiązania:
https://bibliotekanauki.pl/articles/1363544.pdf
Data publikacji:
2020-06-05
Wydawca:
Główny Urząd Statystyczny
Tematy:
Non-linear models
optimum cluster size
four-parameter model
variance function
Opis:
In this paper, a nonlinear model is proposed for improving the relationship between the size of a cluster and the variance within the cluster. This model describes the most appropriate functional relation between the within-cluster variance and the cluster size. Through this model, we can obtain the optimum size of a cluster and an estimate of the variance between clusters. The proposed model leads to further improvement in the estimation of the optimum size of a cluster, and the formula for the determination of optimum cluster size leads to explicit solution of models.
Źródło:
Statistics in Transition new series; 2020, 21, 2; 189-200
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selection of viscous damping coefficients using the continuous wavelet transform method for a gear system
Autorzy:
Yousfi, Nourhaine
Zghal, Bacem
Akrout, Ali
Walha, Lassaad
Haddar, Mohamed
Powiązania:
https://bibliotekanauki.pl/articles/2055029.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
viscous damping formulation
optimum frequencies
continuous wavelet transform
dominant frequency
Opis:
Viscous damping is frequently used in the equation of motion to present the dissipation mechanism of a mechanical system. The orders of frequencies can be easily selected to determine viscous damping coefficients (VDCs) when the degree of freedom of the structure is low. For complex structures, difficulties in selecting the orders of reference frequencies to obtain reasonable VSCs are encountered. This paper mainly discusses the capability of the CWT method to select optimum frequencies of viscous damping formulation. The proposed procedure considers both the classical Rayleigh, modal and the proposed full model modal damping. The method is validated using a numerical time domain response of a two-stage gear system.
Źródło:
Journal of Theoretical and Applied Mechanics; 2020, 58, 3; 585--598
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł

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