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Wyszukujesz frazę "Guo, Zheng" wg kryterium: Autor


Wyświetlanie 1-8 z 8
Tytuł:
Evaluating the association between effort-reward imbalance and suboptimal health status among hospital nurses: a cross-sectional study
Autorzy:
Yu, Leilei
Liu, Weiting
Wang, Jingzheng
Jin, Ziyao
Meng, Ruoyu
Wu, Zhiyuan
Zheng, Yuanyuan
Guo, Zheng
Powiązania:
https://bibliotekanauki.pl/articles/31341044.pdf
Data publikacji:
2024-05-20
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
stress
nurses
occupational health
hospital
effort-reward imbalance
suboptimal health status
Opis:
Objectives Occupational stress is a common complaint in nurses, who perceived more sense of effort-reward imbalance (ERI). Suboptimal health status (SHS) is a state between health and disease. However, the correlation between ERI and SHS is unclear. Therefore, the aim of this study was to examine the prevalence of SHS and ERI and evaluate the relationship between ERI and SHS in clinical nurses by a cross-sectional study. Material and Methods The current cross-sectional study was conducted through an online survey at Dongping People’s Hospital in China. A total of 633 completed surveys were received. Effort-reward imbalance was measured by subscales of the ERI questionnaire. SHS was measured by the Suboptimal Health Status Questionnaire – 25 (SHSQ-25). The relationship between ERI and SHS in nurses was subsequently assessed by Spearman’s correlation coefficient and logistic regression model. Results The mean age of the optimal health status (OHS) group (M±SD 26.3±7.3 years) was younger than the SHS group (M±SD 30.3±6.9 years). The prevalence of SHS was 54.5% (345/633). Female nurses aged ≥30 years, a junior college or university graduate educational level, smokers, and nurses without regular exercise were at a higher risk of SHS. In Spearman’s correlation analysis, ERI reflected by the effort-reward ratio was correlated with SHSQ-25 score (r = 0.662, p < 0.001). In logistic regression, ERI was strongly associated with SHS after potential confounding factors adjusting (OR 27.924, 95% CI 22.845–34.132). Conclusions The prevalence of SHS was significantly high in clinical nurses. Administrators should pay more attention to health status of female nurses aged ≥30 years, with a junior college or bachelor’s degree, smoking, and without regular exercise to reduce the SHS and ERI.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2024, 37, 2; 165-175
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved upper bounds for nearly antipodal chromatic number of paths
Autorzy:
Shen, Yu-Fa
Zheng, Guo-Ping
He, Wen-Jie
Powiązania:
https://bibliotekanauki.pl/articles/743717.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
radio colorings
nearly antipodal chromatic number
paths
Opis:
For paths Pₙ, G. Chartrand, L. Nebeský and P. Zhang showed that $ac'(Pₙ) ≤ \binom{n-2}{2} + 2$ for every positive integer n, where ac'(Pₙ) denotes the nearly antipodal chromatic number of Pₙ. In this paper we show that $ac'(Pₙ) ≤ \binom{n-2}{2} - n/2 - ⎣10/n⎦ + 7$ if n is even positive integer and n ≥ 10, and $ac'(Pₙ) ≤ \binom{n-2}{2} - (n-1)/2 - ⎣13/n⎦ + 8$ if n is odd positive integer and n ≥ 13. For all even positive integers n ≥ 10 and all odd positive integers n ≥ 13, these results improve the upper bounds for nearly antipodal chromatic number of Pₙ.
Źródło:
Discussiones Mathematicae Graph Theory; 2007, 27, 1; 159-174
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Y2O3 on Microstructure and Corrosion Properties of Laser Cladding Composite Coatings on 304 Stainless Steel Substrate
Autorzy:
Yu, Jinling
Zhentai, Zheng
Li, Shuai
Guo, Donghui
Chang, Liang
Powiązania:
https://bibliotekanauki.pl/articles/27313865.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
laser cladding
Ni-based coatings
electrochemical corrosion
Opis:
Ni625/WC composite coatings added with different amounts of Y2O3 were prepared on the surface of 304 stainless steels by laser cladding. This study focused on the microstructure characteristics, microhardness, and corrosion performances of Ni625/WC composite coatings. The results showed that Y2O3 can effectively improve the corrosion resistance of the composite coatings. The microstructure from the bottom to the surface of composite coatings consists of plane crystal, cellular crystal, columnar crystal and equiaxed crystal. The Y2O3 content of optimum composite coating was 1.0%. Its microhardness was three times that of matrix material. In addition, the corrosion current density of the composite coating was only 2% of Ni625/WC coating, which was attributed to the good properties of Y2O3 and appropriate Y2O3 refined microstructure.
Źródło:
Archives of Metallurgy and Materials; 2023, 68, 2; 447--453
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A model-free direct predictive grid-current control strategy for grid-connected converter with an inductance-capacitance-inductance filter
Autorzy:
Guo, Leilei
Zheng, Mingzhe
Yu, Changzhou
Xu, Haizhen
Li, Yanyan
Powiązania:
https://bibliotekanauki.pl/articles/2202543.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
grid-connected converter
GCC
model-free predictive current control
MFPCC
parameter mismatch
robustness
Opis:
The disadvantages of the conventional model predictive current control method for the grid-connected converter (GCC) with an inductance-capacitance-inductance (LCL) filter are a large amount of calculation and poor parameter robustness. Once parameters of the model are mismatched, the control accuracy of model predictive control (MPC) will be reduced, which will seriously affect the power quality of the GCC. The article intuitively analyzes the sensitivity of parameter mismatch on the current predictive control of the conventional LCL-filtered GCC. In order to solve these issues, a model-free predictive current control (MFPCC) method for the LCL-filtered GCC is proposed in this paper. The contribution of this work is that a novel current predictive robust controller for the LCL-filtered GCC is designed based on the principle of the ultra-local model of a single input single output system. The proposed control method does not require using any model parameters in the controller, which can effectively suppress the disturbances of the uncertain parameter variations. Compared with conventional MPC, the proposed MFPCC has smaller current total harmonic distortion (THD). When the filter parameters are mismatched, the control error of the proposed method is smaller. Finally, a comparative experimental study is carried out on the platform of Typhoon and PE-Expert4 to verify the superiority and effectiveness of the proposed MFPCC method for the LCL-filtered GCC.
Źródło:
Archives of Electrical Engineering; 2023, 72, 1; 23--42
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On choosability of complete multipartite graphs $K_{4,3*t,2*(k-2t-2),1*(t+1)}$
Autorzy:
Zheng, Guo-Ping
Shen, Yu-Fa
Chen, Zuo-Li
Lv, Jin-Feng
Powiązania:
https://bibliotekanauki.pl/articles/744583.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
list coloring
complete multipartite graphs
chromatic-choosable graphs
Ohba's conjecture
Opis:
A graph G is said to be chromatic-choosable if ch(G) = χ(G). Ohba has conjectured that every graph G with 2χ(G)+1 or fewer vertices is chromatic-choosable. It is clear that Ohba's conjecture is true if and only if it is true for complete multipartite graphs. In this paper we show that Ohba's conjecture is true for complete multipartite graphs $K_{4,3*t,2*(k-2t-2),1*(t+1)}$ for all integers t ≥ 1 and k ≥ 2t+2, that is, $ch(K_{4,3*t,2*(k-2t-2),1*(t+1)}) = k$, which extends the results $ch(K_{4,3,2*(k-4),1*2}) = k$ given by Shen et al. (Discrete Math. 308 (2008) 136-143), and $ch(K_{4,3*2,2*(k-6),1*3}) = k$ given by He et al. (Discrete Math. 308 (2008) 5871-5877).
Źródło:
Discussiones Mathematicae Graph Theory; 2010, 30, 2; 237-244
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of bonding condition on mechanical performance of synthetic sports surfaces by FEM
Autorzy:
Wang, Hong
Zheng, Weitao
Liu, Gan
Guo, Zhihao
Han, Rui
Li, Duo
Powiązania:
https://bibliotekanauki.pl/articles/2200836.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
bonding condition
synthetic sports surface
finite element method
Opis:
The purpose of the study was to evaluate the effect of interlayer bonding conditions on the mechanical performance of a synthetic sports track with time. A two-dimensional finite element model of the synthetic sports track was developed in order to calculate the track temperature stress and strain in thermal environmental conditions. Thermal and structural responses of the multi-layer sports ground were simulated using a transient thermal and structural analysis in one day. Based on that, different physical parameters of the interlayer were considered to analyze the influence of the bonding layer status on the potential damage of the surface layer in the sports track. The results indicated that different bonding conditions would affect the strain difference between the top and bottom of the synthetic sports layer, which might cause a weak mechanical performance of the synthetic sports layer. Finally, 2D finite element analysis was regarded to be a proper tool to simulate the transient thermal and mechanical behavior of the synthetic sports track. The suggested simulation model can predict the influence of bonding conditions on damage of the synthetic sports track, which can provide some guidance for engineers and technicians working on constructions of synthetic sports tracks.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 4; 637--647
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electronic System Fault Diagnosis with Optimized Multi-kernel SVM by Improved CPSO
Diagnoza uszkodzeń układu elektronicznego z wykorzystaniem Wielojądrowej Maszyny Wektorów Nośnych (SVM) zoptymalizowanej przy pomocy poprawionego algorytmu CPSO
Autorzy:
Guo, Y. M.
Wang, X. T.
Liu, C.
Zheng, Y. F.
Cai, X. B.
Powiązania:
https://bibliotekanauki.pl/articles/300922.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
układ elektroniczny
diagnoza uszkodzeń
maszyna wektorów nośnych
optymalizacja metodą chaosu-roju cząstek
funkcja wielojądrowa
electronic system
fault diagnosis
support vector machine (SVM)
chaos particles swarm optimization
multi-kernel
Opis:
Bezpieczeństwo pracy układów elektronicznych stało się kluczowym zagadnieniem w odniesieniu do złożonych układów o wysokiej niezawodności. Obecnie coraz większy nacisk kładzie się na trafność diagnozy uszkodzeń układów elektronicznych. Na podstawie charakterystyki diagnozy uszkodzeń układów elektronicznych, opracowaliśmy model wielokryterialnej klasyfikacji SVM pozwalający osiągnąć lepszą trafność diagnozy uszkodzeń. Model wykorzystuje funkcję wielojądrową składającą się z kilku bazowych funkcji jądrowych pozwalającą na zwiększenie interpretowalności modelu klasyfikacyjnego. Aby zoptymalizować działanie modelu wielokryterialnej klasyfikacji SVM wykorzystującego funkcję wielojądrową, udoskonaliliśmy algorytm Optymalizacji Metodą Chaosu-Roju Cząstek (CPSO), co pozwoliło osiągnąć optymalne parametry SVM i funkcji wielojądrowej. W poprawionym algorytmie CPSO wzmocniono różnorodność wyszukiwania poprzez wykorzystanie chaotycznej sekwencji generowanej przez zmodyfikowaną mapę tent, a także włączono do standardowego algorytmu PSO efektywną metodę pozwalającą uniknąć przedwczesnej stagnacji oraz uzyskać globalne wartości optymalizacji. Wyniki symulacji diagnozy uszkodzeń systemu elektronicznego pokazują, że proponowany system optymalizacji może być wykorzystywany jako skuteczna metoda umożliwiająca znaczne zwiększenie trafności diagnozy uszkodzeń z wykorzystaniem wielojądrowej SVM.
Electronic systems’ safety operation has become a key issue to complex and high reliability systems. Now more emphasis has been laid on the accuracy of electronic system fault diagnosis. Based on the characteristics of the electronic system fault diagnosis, we design a multi-classification SVMs model to attain better fault diagnosis accuracy, which utilizes multi-kernel function consisting of several basis kernel functions to enhance the interpretability of the classification model. In order to optimize the performance of multi-classification SVMs with multi-kernel, we improve the Chaos Particles swarm Optimization (CPSO) algorithm to achieve the optimum parameters of SVMs and the multi-kernel function. For the improved CPSO algorithm, a modified Tent Map chaotic sequence is used to strengthen the search diversity, and an effective method is embedded to the stander PSO algorithm which can ensure to avoid premature stagnation and obtain the global optimization values. The fault diagnosis simulation results of an electronic system show the proposed optimization scheme is a feasible and effective method and it can significantly improve the fault diagnosis accuracy of the multi-kernel SVM.
Źródło:
Eksploatacja i Niezawodność; 2014, 16, 1; 85-91
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of progressive collapse of a super-long span latticed steel arch structure
Autorzy:
Guo, Shuangchao
Xu, Delin
Shang, Kaiguang
Yang, Shuo
Wang, Di
Li, Gen
Zheng, Bing
Jiao, Yong
Powiązania:
https://bibliotekanauki.pl/articles/2200875.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
progressive collapse
steel arch truss structure
compression instability
Opis:
The progressive collapse of a space grid structure which has a large number of members and a large span is the focus of current research. Before the progressive collapse of the structure, there is a problem of instability of the members. In this paper, dynamic nonlinear analysis of a super-long span latticed steel arch structure is carried out to study its progressive collapse process using a Kinematic Hardening Plasticity constitutive model compiled by Vumat material subprogram in Abaqus, which takes into account instability of the members. Differences in the dynamic response process of the structure at the collapse moment and the failure sequence of the members using the member stability model and the material failure constitutive model are compared. Compared with the material failure constitutive model, when the member stability constitutive model is used, the proportion of compressive buckling members in the structural failure is higher, and the bearing capacity of the structure is lower when the initial failure occurs. The structure suffers from localized member compressive failure rather than material yielding, which leads to the progressive collapse of the structure.
Źródło:
Journal of Theoretical and Applied Mechanics; 2023, 61, 1; 103--117
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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