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Tytuł:
Triple-goal Estimation of Unemployment Rates for U.S. States Using the U.S. Current Population Survey Data
Autorzy:
Bonnéry, Daniel
Cheng, Yang
Ha, Neung Soo
Lahiri, Partha
Powiązania:
https://bibliotekanauki.pl/articles/465991.pdf
Data publikacji:
2015
Wydawca:
Główny Urząd Statystyczny
Tematy:
complex survey data
empirical distribution function
Monte Carlo Markov Chain
rank
risk
small area estimation
Opis:
In this paper, we first develop a triple-goal small area estimation methodology for simultaneous estimation of unemployment rates for U.S. states using the Current Population Survey (CPS) data and a two-level random sampling variance normal model. The main goal of this paper is to illustrate the utility of the triple-goal methodology in generating a single series of unemployment rate estimates for three separate purposes: developing estimates for individual small area means, producing empirical distribution function (EDF) of true small area means, and the ranking of the small areas by true small area means. We achieve our goal using a Monte Carlo simulation experiment and a real data analysis.
Źródło:
Statistics in Transition new series; 2015, 16, 4; 511-522
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of triaxial compression mechanical properties and pore-fracture characteristics of coal rocks in the Yili Basin, Xinjiang
Autorzy:
Shen, Cheng
Yue, Ling
Liu, Yang
Powiązania:
https://bibliotekanauki.pl/articles/2200886.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
triaxial compression
mechanical properties
mercury injection
pore-fissure characteristics
Opis:
Compressive mechanical properties and pore-fissure characteristics of coal rock specimens from three stably developed coal seams M1, M8 and M12 in the Xinjiang Yili Basin were investigated in detail by a series of tests. The results show that the compressive mechanical properties of coal rocks in the Yili Basin are significantly affected by the confining pressure. The peak axial stress increases and the peak modulus of elasticity decreases as the confining pressure increases. The peak axial strain increases and then remains constant, while the peak circumferential strain and peak volumetric strain increase and then decrease. The confining pressure has almost no effect on Poisson’s ratio of the coal rock specimens. In addition, electron microscopy tests show that the microscopic fraction of the coal rock specimens is predominantly vitrinite, accounting for 83.1%-89.2%, while the percentage of the inertinite group is relatively small, at 10.3%-16.1%. The throat radius of the coal rock is mainly concentrated around 1-2μm, while the pore radius of the coal rock is between 150-200μm. The coal rock has an overall fine throat and low permeability, and the coal rock in the Yili Basin of Xinjiang is a typical low-permeability coal rock.
Źródło:
Journal of Theoretical and Applied Mechanics; 2023, 61, 2; 207--218
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of PM2.5 hourly concentrations in Beijing based on machine learning algorithm and ground-based LiDAR
Autorzy:
Fang, Zhiyuan
Yang, Hao
Li, Cheng
Cheng, Liangliang
Zhao, Ming
Xie, Chenbo
Powiązania:
https://bibliotekanauki.pl/articles/2073773.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PM2.5
LiDAR
machine learning
air pollution monitoring
Opis:
The prediction of PM2.5 is important for environmental forecasting and air pollution control. In this study, four machine learning methods, ground-based LiDAR data and meteorological data were used to predict the ground-level PM2.5 concentrations in Beijing. Among the four methods, the random forest (RF) method was the most effective in predicting ground-level PM2.5 concentrations. Compared with BP neural network, support vector machine (SVM), and various linear fitting methods, the accuracy of the RF method was superior by 10%. The method can describe the spatial and temporal variation in PM2.5 concentrations under different meteorological conditions, with low root mean square error (RMSE) and mean square deviation (MD), and the consistency index (IA) reached 99.69%. Under different weather conditions, the hourly variation in PM2.5 concentrations has a good descriptive ability. In this paper, we analyzed the weights of input variables in the RF method, constructed a pollution case to correspond to the relationship between input variables and PM2.5, and analyzed the sources of pollutants via HYSPLIT backward trajectory. This method can study the interaction between PM2.5 and air pollution variables, and provide new ideas for preventing and forecasting air pollution.
Źródło:
Archives of Environmental Protection; 2021, 47, 3; 98--107
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integrated decision on spare parts ordering and equipment maintenance under condition based maintenance strategy
Zintegrowany system decyzyjny dotyczący zamawiania części zamiennych i utrzymania ruchu urządzeń w ramach strategii utrzymania zależnej od bieżącego stanu technicznego
Autorzy:
Wang, Y.
Zhao, J.
Cheng, Z.
Yang, Z.
Powiązania:
https://bibliotekanauki.pl/articles/301823.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
spare parts
inventory control
ordering
condition based maintenance
Monte Carlo simulation
części zamienne
kontrola zapasów
zamówienia
utrzymanie zależne od bieżącego stanu technicznego
symulacja Monte Carlo
Opis:
Aiming to optimize the equipment maintenance and the spare parts ordering management jointly, a comprehensive decision model under condition based maintenance (CBM) policy is presented for a single equipment system with continuous and random deterioration. In this model, the equipment deterioration is a continuous Gamma process under a continuous condition monitoring, and the spare parts inventory is controlled by spare parts support probability. Firstly, a spare part support probability model was developed to determine the optimal spare parts stock level S, which is set to meet the requirement of a predetermined stockout probability. Secondly, the equipment replacement and spare parts ordering decision is made to optimize the equipment replacement and spare parts ordering jointly, which is based on the equipment deterioration leveland total operating cost of the system. Thirdly, an integrated decision simulation model is presented for evaluating cost rate, availability and stockout probability. Finally, a numerical example is given to illustrate the performance of this model. The results show that the optimal preventive maintenance threshold obtained from the proposed decision model can satisfy the spare parts support requirements under (S-1, S) inventory control strategy.
Dążąc do jednoczesnej optymalizacji utrzymania ruchu urządzeń i zarządzania zamówieniami części zamiennych, zaproponowano kompleksowy model decyzyjny w ramach strategii utrzymania zależnej od bieżącego stanu technicznego (CBM) przeznaczony dla systemów z pojedynczym urządzeniem i ciągłym oraz losowym zużyciem. W niniejszym modelu, zużycie urządzenia jest ciągłym procesem Gamma z ciągłym monitorowaniem stanu, podczas gdy zapasy części zamiennych są kontrolowane poprzez prawdopodobieństwo wsparcia w zakresie części zamiennych. Po pierwsze, opracowano model prawdopodobieństwa wsparcia w zakresie części zamiennych w celu określenia optymalnego poziomu zapasów części zamiennych S, ustalonej aby spełnić wymogi określonego prawdopodobieństwa braku dostępności. Po drugie, przeprowadzono proces decyzyjny dotyczący wymiany urządzenia i zamawiania części zamiennych w celu jednoczesnej optymalizacji wymiany urządzenia i zamawiania części zamiennych, w oparciu o poziom zużycia urządzenia i całkowity koszt działania systemu. Po trzecie, zaprezentowano zintegrowany symulacyjny model decyzyjny dla oceny poziomu kosztów, dostępności i prawdopodobieństwa jej braku. Zasady niniejszego modelu zilustrowano przykładem numerycznym. Wyniki pokazują, że optymalny próg konserwacji zapobiegawczej uzyskany za pomocą proponowanego modelu decyzyjnego może spełnić wymagania dotyczące części zamiennych w ramach (S-1, S) strategii kontroli zapasów.
Źródło:
Eksploatacja i Niezawodność; 2015, 17, 4; 591-599
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Planned Route Based Negotiation for Collision Avoidance Between Vessels
Autorzy:
Hu, Q.
Yang, C.
Cheng, H.
Xiao, B.
Powiązania:
https://bibliotekanauki.pl/articles/116234.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
anticollision
Collision Situation
COLREGs
Collision Avoidance System
Collision Avoidance Decision Making
route planning
Computer Simulation
Negotiation
Opis:
Automatic vessel collision-avoidance systems have been studied in the fields of artificial intelligence and navigation for decades. And to facilitate automatic collision-avoidance decision-making in two-vessel-encounter situation, several expert and fuzzy expert systems have been developed. However, none of them can negotiate with each other as seafarers usually do when they intend to make a harmonious and more economic overall plan of collision avoidance in the COLREGS-COST-HIGH situations where collision avoidance following the International Regulations for Preventing Collisions at Sea(COLREGS) costs too much. A negotiation framework was put forward in our previous research to enable vessels to negotiate for optimizing collision avoidance in the COLREGS-COST-HIGH situations at open sea. In this paper, the negotiation framework is improved by considering the planned route of both vessels. The simulation results show that more economic overall plan of collision avoidance may be achieved by the improved framework when one or both parties deviate from their planed route or are approaching their next way points.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2008, 2, 4; 363-368
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A nanoparticle cationic polystyrene-co-poly(n-butylacrylate) collector to eliminate the negative effect of lizardite slimes in pyrite flotation
Autorzy:
Ai, Guanghua
Liu, Cheng
Zhu, Guangli
Yang, Siyuan
Powiązania:
https://bibliotekanauki.pl/articles/24085927.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
nanoparticle collector
pyrite
lizardite slimes
flotation separation
Opis:
Lizardite slime coating is one of significant factors in the deterioration of the floatability of sulphide minerals. In this study, a nanoparticle cationic polystyrene-co-poly(n-butylacrylate)(PS-PBNH) collector was introduced to eliminate the negative impact of lizardite slimes in pyrite flotation. Microflotation results demonstrated that lizardite slims did not affect the recovery of pyrite in the presence of PS-PBNH. Good flotation separation of pyrite from lizardite was achieved when the nanoparticle PS-PBNH collector was used. The results from adsorption study indicated that PS-PBNH exhibited a significant adsorption on the pyrite surface in the presence of lizardite slimes. Sedimentation tests showed that hetero-aggregation occurred between lizardite slimes and pyrite, whereas the introduction of PS-PBNH collector resulted in a heterogeneous dispersion between them. Zeta potential measurements suggested that PS-PBNH collector interacted with pyrite surface, and the PS-PBNH adsorption changed the surface charge of pyrite from negative to be positive. As a result, the interaction of pyrite with lizardite shifted from electrostatic attraction to electrostatic repulsion, as supported by the DLVO calculations. These results indicated PS-PBNH can be used as a potential collector for pyrite flotation in pyrite/lizardite slimes system without the need for a depressant.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 3; art. no. 170899
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the influence of the transducer and its coupling layer on round window stimulation
Autorzy:
Liu, H.
Xu, D.
Yang, J.
Yang, S.
Cheng, G.
Huang, X.
Powiązania:
https://bibliotekanauki.pl/articles/306655.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
słuch
stymulacja
przetwornik
RW
FEM
implantable middle ear hearing device
round window stimulation
transducer
coupling layer
finite element analysis
Opis:
Purpose: In this work, a finite element study is proposed to evaluate the effects of the transducer and its coupling layer on the performance of round window (RW) stimulation. Methods: Based on a set of micro-computer tomography images of a healthy adult’s right ear and reverse engineering technique, a coupled finite-element model of the human ear and the transducer was constructed and verified. Then, the effect of the cross-section of the transducer, the elastic modulus of the coupling layer, the mass of the transducer, and the preload of the transducer were studied. Results: The increase of the transducer’s cross-section area deteriorates the RW stimulation, especially at the lower frequencies. This adverse effect of the cross-section area’s increase of the transducer can be reduced by adding a coupling layer between the transducer and the RW. However, the coupling layer’s improvement on the RW stimulation is reduced with the increase of its elastic modulus. Moreover, the mass loading of the transducer decreases the RW stimulation’s performance mainly at higher frequencies and applying a static preload on the transducer enhances its hearing compensating performance at higher frequencies. Conclusions: The influence of the transducer’s mass, the mass of the transducer, the applied static preload and the properties of the coupling layer must be taken into account in the design of the RW stimulation type implantable middle ear hearing device.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 2; 103-111
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamical modeling and coupling characteristic analysis of the multistage gears system in a continuous miner
Autorzy:
Lu, Wenjia
Zhang, Yimin
Cheng, Hongchuan
Yang, Zhou
Powiązania:
https://bibliotekanauki.pl/articles/279213.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
planets
multistage gear
continuous miner
acceleration
Opis:
The lumped parameter method is adopted to establish a dynamic model of two stage planets and multistage fixed-shaft gears in which the effect of coupling shaft section radius on the system in a continuous miner is considered. The acceleration test of the system proves the accuracy of the proposed model. With the increase of cross section size of the coupled shaft, the influence of the first stage meshing frequency on the second stage planetary system is enhanced. The acceleration decreases gradually with the increase of the size of coupled carrier. It is shown that the modeling by considering the coupled size contributes to reduction of the vibration level.
Źródło:
Journal of Theoretical and Applied Mechanics; 2020, 58, 1; 45-58
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Validation of School Core Competence Scale for Undergraduates: Empirical Findings of Taiwan Case
Autorzy:
Wu, Shwu Ming
Yang, Cheng Hong
Hsu, Wan Chen
Powiązania:
https://bibliotekanauki.pl/articles/2031728.pdf
Data publikacji:
2014-09-30
Wydawca:
Wydawnictwo Adam Marszałek
Tematy:
School Core Competence Scale
validation studies
Taiwanese undergraduates
Opis:
This study aimed to validate the 25-item School Core Competence Scale (SCCS) of the National Kaohsiung University of Applied Sciences. Item analysis and exploratory factor analysis were utilized with 368 undergraduates and confirmatory factor analysis with another 384 undergraduates. The SCSS had eight subscales, including Communication and Expression, International Perspective, Humanity, Civics and Morals, Professional Knowledge and Skills, Integrative Learning, Passion and Anti-stress, and Self-discipline. Results indicated that the SCCS is a valid and reliable instrument among undergraduates. Particularly, women scored higher on Communication and Expression, Civics and Morals, Self-discipline as well as the total scale.
Źródło:
The New Educational Review; 2014, 37; 95-105
1732-6729
Pojawia się w:
The New Educational Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamic and Electronic Properties of $OsB_2$ from First-Principles Calculations
Autorzy:
Cheng, Y.
Yang, J.
Wang, Y.
Ji, G.
Chen, X.
Powiązania:
https://bibliotekanauki.pl/articles/1365243.pdf
Data publikacji:
2014-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.15.Mb
61.50.Ks
67.25.de
71.20.-b
Opis:
The pressure induced phase transitions of $OsB_2$ from the orthorhombic structure (Orth) to the hexagonal structure (Hex) is investigated by using ab initio plane-wave pseudopotential density functional theory, together with quasi-harmonic Debye model. We find that the pressure-induced phase transition occurs at 2.8 GPa and 12.5 GPa by local density approximation and general gradient approximation, respectively. It is predicted that $OsB_2$ has no phase transition temperature from the Orth structure to the Hex structure. Moreover, the dependences of the relative volume V/$V_0$ on the pressure, thermal expansion coefficient α on the pressure and temperature are also successfully obtained. The electronic properties including energy band, total and partial density of states and electron density difference for two structures are also analyzed. The Mulliken charges and Bond populations for both Orth and Hex structures are also obtained.
Źródło:
Acta Physica Polonica A; 2014, 125, 5; 1186-1190
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of lizardite on talc flotation using carboxymethyl cellulose as a depressant
Autorzy:
Deng, Jie
Yang, Siyuan
Zhang, Wencai
Liu, Cheng
Li, Hongqiang
Powiązania:
https://bibliotekanauki.pl/articles/1449414.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
talc
lizardite
flotation
CMC
magnesium ion
Opis:
The effect of lizardite on talc flotation when using carboxymethyl cellulose (CMC) as a depressant was studied by micro-flotation experiments and adsorption measurements, zeta-potential measurements, magnesium ion dissolution analysis, and solution chemistry calculation. The results for the micro-flotation experiments showed that the addition of lizardite further decreased the floatability of talc at pH 8.5 when using CMC as the depressant. The mechanism was that magnesium ions dissolved from lizardite lattice, then formed hydrolyzed species of magnesium cations and interacted with talc surfaces, which promoted CMC adsorption, and thus decreasing talc floatability.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 4; 702-709
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of benzo(a)pyrene exposure on the ATPase activity and calcium concentration in the hippocampus of neonatal rats
Autorzy:
Yang, Kai
Chen, Chengzhi
Cheng, Shuqun
Cao, Xianqing
Tu, Baijie
Powiązania:
https://bibliotekanauki.pl/articles/2161850.pdf
Data publikacji:
2017-03-30
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
hippocampus
neurodevelopment
ATPase activity
Ca2+ concentration
neonatal rats
Benzo(a)pyrene
Opis:
Objectives To investigate whether postnatal benzo(a)pyrene (B(a)P) exposure caused the impairments on the process of neurodevelopment and the alteration in the calcium medium in the neonatal rats. Material and Methods Eighty neonatal Sprague Dawley (SD) rats were randomly divided into 5 groups (untreated control group, vehicle group, 0.02 mg/kg, 0.2 mg/kg and 2 mg/kg B(a)P-exposed group). Rats were treated with B(a)P by the intragastric administration from postnatal day (PND) 4 to 25. Morris water maze (MWM) was employed to observe the spatial memory of rats. The activity of calcium adenosine triphosphatase (Ca2+-ATPase), sodium-potassium adenosine triphosphatase (Na+-K+-ATPase) and calcium-magnesium adenosine triphosphatase (Ca2+-Mg2+-ATPase) in the hippocampus were detected by commercial kits. Fura-2 pentakis(acetoxymethyl) (Fura-2/AM) probe and reactive oxygen species (ROS) reagent kit were used for measuring the concentration of Ca2+ and ROS in the hippocampus synapse, respectively. Results Rats exposed to B(a)P resulted in the deficits in the spatial memory manifested by the increased escape latency and decreased number of crossing platform and time spent in target quadrant in comparison with the control groups. Benzo(a)pyrene exposure caused the significant decrease in the ATPase activity in the hippocampus and caused Ca2+ overload in the synaptic, besides, the ROS concentration increased significantly which may further induce neurobehavioral impairment of the neonatal rats. Conclusions Our findings suggest that postnatal B(a)P exposure may cause the neurobehavioral impairments in the neonatal rats, which were mediated by the decreased ATPase activity and elevated Ca2+ concentration. Int J Occup Med Environ Health 2017;30(2):203–211
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2017, 30, 2; 203-211
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on one-dimensional ubiquitiformal constitutive relations for a bimaterial bar
Autorzy:
Yang, Min
Ou, Zhuo-Cheng
Duan, Zhuo-Ping
Huang, Feng-Lei
Powiązania:
https://bibliotekanauki.pl/articles/282073.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
ubiquitiform
fractal
composite
displacement distribution
elasticity modulus
Opis:
A one-dimensional ubiquitiformal constitutive model for a bimaterial bar is proposed in this paper. An explicit analytical expression for the effective Young modulus is then obtained, which, unlike the fractal one, leads to a continuous displacement distribution along the bar. Moreover, numerical results for concretes are calculated and found to be in agreement with previous experimental data. In addition, some previous empirical and semi-empirical constitutive models are also examined, which shows that each of these models can correspond well to a ubiquitiformal one under a certain complexity.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 2; 291-301
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A unified calculation of the optical and EPR spectral data for the trigonal Cr³⁺ center in Cr³⁺-doped α-RbAl(SO₄)₂·12H₂O alum crystal
Autorzy:
Li, Xiao-Wu
Mei, Yang
Wei, Cheng-Fu
Zheng, Wen-Chen
Powiązania:
https://bibliotekanauki.pl/articles/1070555.pdf
Data publikacji:
2016-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ch
76.30.Fc
78.40.Ha
78.55.Hx
Opis:
The optical band positions and the spin-Hamiltonian parameters (g factors g_{∥}, g_{⊥}, and zero-field splitting parameter D) of alum α-RbAl(SO₄)₂·12H₂O:Cr³⁺ are calculated by diagonalizing the 120× 120 complete energy matrix based on the two-spin-orbit-coupling-parameter model. The model takes into account not only the contributions due to the spin-orbit-coupling parameter of central d^{n} ion in the conventional crystal field theory, but also those due to ligands via covalence effect. The calculation indicates that the fourteen observed spectral data (eleven optical band positions and three spin-Hamiltonian parameters) can be reasonably and uniformly explained with four adjustable parameters (the Racah parameters B, C, intrinsic parameter A̅₄(R) in the superposition model, and the trigonal distortion angle β). The calculations also suggest that contrary to the previous findings, the trigonal distortion of Cr³⁺ (entering the Al³⁺ site in the host crystal) center in α-RbAl(SO₄)₂·12H₂O is induced mainly by the oxygen (or water) octahedron around the Cr³⁺ ion rather than the more distant neighbors.
Źródło:
Acta Physica Polonica A; 2016, 129, 3; 340-343
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
2-Spanning Cyclability Problems of Some Generalized Petersen Graphs
Autorzy:
Yang, Meng-Chien
Hsu, Lih-Hsing
Hung, Chun-Nan
Cheng, Eddie
Powiązania:
https://bibliotekanauki.pl/articles/31348327.pdf
Data publikacji:
2020-08-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
Petersen graph
spanning cyclable
Opis:
A graph G is called r-spanning cyclable if for every r distinct vertices v1, v2, . . ., vr of G, there exists r cycles C1, C2, . . ., Cr in G such that vi is on Ci for every i, and every vertex of G is on exactly one cycle Ci. In this paper, we consider the 2-spanning cyclable problem for the generalized Petersen graph GP (n, k). We solved the problem for k ≤ 4. In addition, we provide an additional observation for general k as well as stating a conjecture.
Źródło:
Discussiones Mathematicae Graph Theory; 2020, 40, 3; 713-731
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Examining the success factors of smart watch : a behavioral perspective on consumers
Badanie czynników sukcesu inteligentnego zegarka : behawioralna perspektywa konsumentów
Autorzy:
Lin, Chih Wei
Yang, Chin-Cheng
Sia, Wei Yeng
Tang, Kai-Yu
Powiązania:
https://bibliotekanauki.pl/articles/404795.pdf
Data publikacji:
2019
Wydawca:
Politechnika Częstochowska
Tematy:
perceived playfulness
compatibility
technology acceptance model
innovation diffusion theory
postrzegana użyteczność
kompatybilność
model akceptacji technologii
teoria dyfuzji innowacji
Opis:
The purpose of this study was to investigate factors influencing consumers’ intention to use Apple Watch by applying Decomposed Theory of Planned Behavior (DTPB). The subject of the study was the Apple Watch users in Taiwan. The researcher used purposive and snowball sampling as the sampling method, a total of 350 surveys were issued, 327 valid surveys were collected and the effective response rate was 93.43%. The collected data were analyzed by confirmatory factor analysis and structural equation model. The results are illustrated as follow. First, the overall behavior model of Apple Watch users constructed by Decomposed Theory of Planned Behavior in this study fitted well. Second, the research model has well explanatory power to wearable device users, which is R² of attitudes, subjective norms and perceived behavioral control on behavior intentions have reached 63%. Third, perceived usefulness and perceived playfulness are the most two important influencing factors on attitudes. Interpersonal influence is the most important influencing factor to subjective norm. The most influencing factor of perceived behavioral control is facilitating condition.
Celem tego badania było zbadanie czynników wpływających na zamiar korzystania przez Apple z zegarka przez zastosowanie dekompozycji teorii planowanego zachowania (DTPB). Przedmiotem badania byli użytkownicy Apple Watch na Tajwanie. Badacz zastosował celowe i śnieżkowe pobieranie próbek jako metodę pobierania próbek, wykonano w sumie 350 badań, zebrano 327 ważnych badań, a efektywny odsetek odpowiedzi wyniósł 93,43%. Zebrane dane przeanalizowano za pomocą potwierdzającej analizy czynnikowej i modelu równań strukturalnych. Wyniki zostały zilustrowane w następujący sposób. Po pierwsze, ogólny model zachowania użytkowników Apple Watch skonstruowany przez Dekomponowaną Teorię Planowanego Zachowania (DTPB) w tym badaniu dobrze skonstruowany. Po drugie, model badawczy wyjaśnia użytkownikom tych urządzeń, subiektywnych norm i postrzeganej kontroli behawioralnej nad zamiarami zachowań osiągnął 63%. Po trzecie, postrzegana użyteczność i postrzegana zabawa to dwa najważniejsze czynniki wpływające na postawy użytkowników.
Źródło:
Polish Journal of Management Studies; 2019, 20, 2; 368-378
2081-7452
Pojawia się w:
Polish Journal of Management Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Empirical investigation of sports management, behavior growth and usage of sports APP : new learning perspective
Empiryczne badanie zarządzania sportem, wzrostu zainteresowania i wykorzystania aplikacji sportowych : nowa perspektywa uczenia się
Autorzy:
Lin, Ching-Te
Shen, Chih-Chien
Mao, Tso-Yen
Yang, Chin-Cheng
Powiązania:
https://bibliotekanauki.pl/articles/405895.pdf
Data publikacji:
2019
Wydawca:
Politechnika Częstochowska
Tematy:
sports APP
use motivation
target orientation
sports behavior
aplikacja sportowa
wykorzystanie motywacji
orientacja na cel
zachowanie sportowe
Opis:
The purpose of this study was to investigate the use of sports app and the influence of target orientation on sports behavior. Sports app users are research object, 510 questionnaires were sent by online questionnaire survey, effective questionnaires were 441, and the effective recovery rate was 64.50%. Data processing with descriptive statistics, independent sample t-test, single-factor variance analysis, correlation analysis and multiple stepwise regression analysis. It is observed that usage of sports applications are playing their significant role for the target orientation and target orientation. In addition, impact of sports management on behavior of the students is also examined through a 2nd sample of 329. It is found that key factors to contribute for behavioral growth are weekly hours for the sports activities, and participation in physical activities. For the motivation, key contributors from sports management are joining a local club for sports activities, weekly hours and physical activities are found to be significant determinants.
Celem artykułu było zbadanie zastosowania aplikacji sportowej i wpływu orientacji na cel w zachowaniach sportowych. Obiektem badań są użytkownicy aplikacji sportowych, zbadani za pomocą ankiety internetowej w liczbie 510 kwestionariuszy, gdzie uzyskano 441, efektywny wskaźnik pozyskania danyc wyniósł 64,50%. Uzyskane dane przetworzono z wykorzystaniem narzędzi statystyki opisowej, niezależnego testu t-próby, jednoczynnikowej analizy wariancji, analizy korelacji i wielokrotnej analizy regresji krokowej. Zaobserwowano, że wykorzystanie aplikacji sportowych odgrywa znaczącą rolę w orientacji na cel. Ponadto wpływ zarządzania sportem na zachowanie uczniów jest również badany w drugiej próbie o liczebności 329. Stwierdzono, że kluczowymi czynnikami przyczyniającymi się do wzrostu zachowań są cotygodniowe godziny zajęć sportowych i udział w aktywności fizycznej. W celu motywacji kluczowi współpracownicy z kierownictwa sportowego dołączają do lokalnego klubu w celu uprawiania sportu, cotygodniowych zajęć i aktywności fizycznych.
Źródło:
Polish Journal of Management Studies; 2019, 19, 1; 225-234
2081-7452
Pojawia się w:
Polish Journal of Management Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficient solidification of Pb2+ by activated tungsten tailings and cement
Autorzy:
Cheng, Hao
Kuang, Jingzhong
Zhu, Luping
Yuan, Weiquan
Huang, Zheyu
Yang, Yiqiang
Powiązania:
https://bibliotekanauki.pl/articles/24085840.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
tungsten tailings
activation
Pb2+
Solidification
C-S-H gel
Opis:
The preparation of cementing admixture from tailings and co-solidification of Pb2+ with cement is a green way to realize the resource utilization of tailings and treatment of the lead-containing wastewater. In this paper, the tungsten tailings were activated in different ways, and the mechanical properties of the tungsten tailings-cement solidified body with different activation systems and the solidification behavior of Pb2+ were studied. The phase and microstructure of the hydrated product were characterized by XRD, FT-IR, SEM and EDS. The results showed that the curing effect of Pb2+ was obviously different of different activation systems, and the curing effect of the solidified body of the ternary composite activation system (TCAS) was the best, second only to the pure cement system (PCS). Different activation methods have a significant impact on the mechanical properties of the solidified body. With the increase of the Pb2+ content, the compressive strength of the solidified body gradually decreased, the Pb2+ leaching concentration gradually increased; with the extension of the curing age, the compressive strength gradually increased, and the Pb2+ leaching concentration gradually decreased. In particular, the compressive strength of the 28d solidified body was 31.43 MPa and the leaching concentration of Pb2+ was only 0.38 mg/L when the Pb2+ content was 5%. The phase, microstructure and EDS results of the hydration products showed that Pb2+ was mainly solidified in the C-S-H gel.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 2; art. no. 162618
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study on SHPB cyclic impact of rubber-cement composite with different confine modes
Autorzy:
Yang, Rongzhou
Xu, Ying
Chen, Peiyuan
Cheng, Lin
Ding, Jinfu
Fu, Hongxin
Powiązania:
https://bibliotekanauki.pl/articles/27312124.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
dzielony pręt Hopkinsona
polimer wzmocniony włóknem węglowym
kompozyt gumowo-cementowy
oddziaływanie cykliczne
energia pękania
uszkodzenie
odporność na uderzenia
split Hopkinson pressure bar
carbon fibre reinforced polymer
rubber-cement composite
cyclic impact
damage
fracture energy
impact resistance
Opis:
To promote the application of rubber-cement composites as the main bearing structure and key components in practical engineering under frequent dynamic disturbances, in this work, the split Hopkinson pressure bar (SHPB) cyclic impact tests of rubber-cement composite specimens with four different confine modes were carried out in which the impact load increased sequentially. The relationship between average strain rate, ultimate strain and impact times and the relationship between peak stress, damage energy, ultimate strain and incident energy were analyzed. The results showed that the appropriate confine reinforcement treatment can make rubber-cement composite give full play to its deformation ability when it was completely damaged. Carbon fiber-reinforced polymer (CFRP) sheet and steel cylinder can work together with the rubber-cement composite matrix to resist impact load, which effectively improves the structural strength, damage fracture energy, and cyclic impact resistance of the rubber-cement composite. Finally, based on the effect difference of confine modes, the simplified plane force models of rubber-cement composite specimens with four different confine modes were established, which clearly revealed the completely different impact resistance mechanism of the rubber-cement composites with different constraints under cyclic impact loading.
Źródło:
Archives of Civil Engineering; 2023, 69, 2; 517--534
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of Square-shaped Bolted Joints Based on Improved Particle Swarm Optimization Algorithm
Autorzy:
Chen, Kui
Yang, Cheng
Zhao, Yongsheng
Niu, Peng
Niu, NaNa
Hongchao, Wu
Powiązania:
https://bibliotekanauki.pl/articles/27312779.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
particle swarm optimization algorithm
bolt connection
bolted joint
fractal theory
Opis:
The bolted joint is widely used in heavy-duty CNC machine tools, which has huge influence on working precision and overall stiffness of CNC machine. The process parameters of group bolt assembly directly affect the stiffness of the connected parts. The dynamic model of bolted joints is established based on the fractal theory, and the overall stiffness of joint surface is calculated. In order to improve the total stiffness of bolted assembly, an improved particle swarm optimization algorithm with combination of time-varying weights and contraction factor is proposed. The input parameters are preloading of bolts, fractal dimension, roughness, and object thickness. The main goal is to maximize the global rigidity. The optimization results show that improved algorithm has better convergence, faster calculation speed, preferable results, and higher optimization performance than standard particle swarm optimization algorithm. Moreover, the global rigidity optimization is achieved.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 3; art. no. 168487
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of multi-objective fruit fly optimisation algorithm based on population Manhattan distance in distribution network reconfiguration
Autorzy:
Tang, Minan
Zhang, Kaiyue
Wang, Qianqian
Cheng, Haipeng
Yang, Shangmei
Du, Hanxiao
Powiązania:
https://bibliotekanauki.pl/articles/1841286.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Chebyshev chaotic mapping
distributed generation
distribution network reconfiguration
fuzzy decision method
Pareto optimal
pmdMOFOA
population Manhattan distance
Opis:
In order to optimise the operation state of the distribution network in the presence of distributed generation (DG), to reduce network loss, balance load and improve power quality in the distribution system, a multi-objective fruit fly optimisation algorithm based on population Manhattan distance (pmdMOFOA) is presented. Firstly, the global and local exploration abilities of a fruit fly optimisation algorithm (FOA) are balanced by combining population Manhattan distance (PMD) and the dynamic step adjustment strategy to solve the problems of its weak local exploration ability and proneness to premature convergence. At the same time, Chebyshev chaotic mapping is introduced during position update of the fruit fly population to improve ability of fruit flies to escape the local optimum and avoid premature convergence. In addition, the external archive selection strategy is introduced to select the best individual in history to save in external archives according to the dominant relationship amongst individuals. The leader selection strategy, external archive update and maintenance strategy are proposed to generate a Pareto optimal solution set iteratively. Lastly, an optimal reconstruction scheme is determined by the fuzzy decision method. Compared with the standard FOA, the average convergence algebra of a pmdMOFOA is reduced by 44.58%. The distribution performance of non-dominated solutions of a pmdMOFOA, MOFOA, NSGA-III and MOPSO on the Pareto front is tested, and the results show that the pmdMOFOA has better diversity. Through the simulation and analysis of a typical IEEE 33-bus system with DG, load balance and voltage offset after reconfiguration are increased by 23.77% and 40.58%, respectively, and network loss is reduced by 57.22%, which verifies the effectiveness and efficiency of the proposed method.
Źródło:
Archives of Electrical Engineering; 2021, 70, 2; 307-323
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and kinetic study of zinc leaching from metallurgical slag by 5-sulfosalicylic acid
Autorzy:
Wang, Long
Gao, Hanyu
Song, Shimin
Xue, Na
Zhang, Jinxia
Yang, Siyuan
Liu, Cheng
Powiązania:
https://bibliotekanauki.pl/articles/1447397.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
zinc metallurgical slag
5-sulfosalicylic acid
leaching kinetics
resource recover
Opis:
As an organic acid with the characters of low corrosivity and extensive source, 5-sulfosalicylic acid (5-SSA) was firstly utilized as a potential leaching reagent for the recovery of zinc from metallurgical slag. Effects of stirring speed, leaching temperature, 5-SSA concentrations and size fraction on the leaching zinc leaching rate were investigated. A zinc leaching efficiency of 94.2% was achieved under the appropriate operating conditions (450 rpm of stirring speed, 50 ℃ of leaching temperature, 0.3 mol/L of 5-SSA concentration and d90=65 µm of size fraction), indicating that 5-SSA was an excellent leaching reagent of zinc oxide. SEM-EDS and specific surface aperture analyzer further reveal the well-developed micropores and cracks from zinc metallurgical slag, which could be assigned to the removal of zinc oxide encapsulated in the sample. In addition, the leaching kinetics of zinc metallurgical slag in the 5-SSA was studied. It was found that the surface chemical reaction model satisfactorily predicted the zinc leaching rate. A reaction kinetic equation was finally established for the zinc leaching rate.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 3; 8-20
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preventive maintenance strategy optimizing model under two-dimensional warranty policy
Model optymalizacji strategii konserwacji zapobiegawczej w warunkach dwuwymiarowej polityki gwarancyjnej
Autorzy:
Cheng, Z. H.
Yang, Z. Y.
Zhao, J. M.
Wang, Y. B.
Li, Z. W.
Powiązania:
https://bibliotekanauki.pl/articles/302023.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
two-dimensional warranty
imperfect preventive maintenance
availability
gwarancja dwuwymiarowa
niepełna konserwacja zapobiegawcza
dyspozycyjność
Opis:
An effective warranty servicing strategy should be made considering both warranty cost and product availability. Based on the two-dimensional free repair warranty, a strategy combining the imperfect preventive maintenance and minimal repair is proposed where the imperfect preventive maintenances are implemented in a special subregion of the warranty and all other failures are repaired minimally. By modeling the warranty cost and product availability, we derive the optimum warranty servicing strategy and corresponding parameters to minimize the cost-effective of unit time. Finally, we provide a numerical illustration and a comparison with some other strategies.
Efektywna strategia obsługi gwarancyjnej powinna uwzględniać zarówno koszty gwarancji jak i dyspozycyjność produktu. W oparciu o pojęcie dwuwymiarowej gwarancji bezpłatnej naprawy, zaproponowano strategię łączącą niepełną konserwację zapobiegawczą z naprawą minimalną, gdzie działania obsługowe w ramach niepełnej konserwacji zapobiegawczej przeprowadza się w ramach specjalnego podobszaru gwarancji, a wszelkie inne uszkodzenia naprawia się w ramach naprawy minimalnej. Modelując koszty naprawy oraz dyspozycyjność produktu, wyprowadzono optymalną strategię obsługi gwarancyjnej oraz odpowiadające jej parametry w celu zminimalizowania kosztów na jednostkę czasu. Na koniec, proponowane rozwiązanie zilustrowano na przykładzie numerycznym oraz porównano z innymi strategiami
Źródło:
Eksploatacja i Niezawodność; 2015, 17, 3; 365-373
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reconstruction of oviraptorid clutches illuminates their unique nesting biology
Autorzy:
Yang, T.-R.
Wiemann, J.
Xu, L.
Cheng, Y.-N.
Wu, X.-C.
Sander, P.M.
Powiązania:
https://bibliotekanauki.pl/articles/19933.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
Oviraptorosaurs, a group of non-avian theropod dinosaurs from the Cretaceous of Asia and North America, left behind the most abundant and informative fossil evidence of dinosaur reproductive biology. Previous studies had suggested that oviraptorosaur reproductive biology represents an intermediate stage and exhibited unique modern avian traits. For instance, the adult-associated clutches were predominantly considered as evidence for brooding/thermoregulatory contact incubation (TCI) behaviors, whereas the hypotheses of laying or protection were neglected. Despite numerous oviraptorid egg clutches uncovered from China and Mongolia, their nest architecture and clutch arrangement were rarely investigated in detail. Here we present a comprehensive reconstruction of an oviraptorid clutch based on five new oviraptorid clutches from Jiangxi Province, China. A detailed examination of the new clutches reveals a partially-open oviraptorid nest that contains 3–4 rings of paired eggs (more than 15 pairs total) whose blunt end points toward the center devoid of eggs at an angle of 35–40°. Our detailed three-dimensional reconstruction indicates that the oviraptorid clutch has a unique architecture unknown from extant bird clutches, implying an apomorphic nesting mode. Such a unique nest architecture further contradicts the TCI hypothesis in oviraptorids, hindering sufficient heat transfer to the inner (lower) ring(s) of eggs. Moreover, the size of the new oviraptorid clutches (>30 eggs) is significantly larger than that of the adult-associated clutches (<22 eggs), raising the alternative hypothesis that the adult-associated clutches were uncompleted. This clue thus supports the hypothesis that the clutch-associated oviraptorid adults possibly represent females after an oviposition before a catastrophic sandstorm/flooding burial.
Źródło:
Acta Palaeontologica Polonica; 2019, 64, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the Mechanical and Thermal Properties, and Impact Sensitivity of Pressed HMX-based PBX
Autorzy:
Li, Yuxiang
Wu, Peng
Hua, Cheng
Wang, Jun
Huang, Bing
Chen, Jin
Qiao, Zhiqiang
Yang, Guangcheng
Powiązania:
https://bibliotekanauki.pl/articles/358006.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
nanoexplosives
impact sensitivity
particle size
hot spot
Opis:
Submicron- and nano-explosives have attracted growing attention, while the mechanism of how particle size influences the impact sensitivity is not completely understood. In the present work, HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) based PBXs (plastic bonded explosives) of three particle size distributions (1-2 and 10-20 μm, and 100-300 nm) and two pressed densities (91%TMD and 79%TMD) were characterized and tested with a range of techniques to determine their mechanical and thermal properties and impact sensitivities. The results demonstrated that with decreased particle size, the mechanical strength as well as the thermal conductivity were dramatically improved, and the impact sensitivity was significant decreased. The structure of impacted samples suggested that the ignition mechanism is dependant on the particle size. Samples with higher density were more sensitive to impact, as the impact force acting on these samples was higher. The correlation between particle size and impact sensitivity is discussed in detail.
Źródło:
Central European Journal of Energetic Materials; 2019, 16, 2; 295-315
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł

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