Objective:High-quality and successful nursing care delivery in a variety of situations requires critical thinking training and professional commitment.The present study aimed to investigate critical thinking dispositi...Objective:High-quality and successful nursing care delivery in a variety of situations requires critical thinking training and professional commitment.The present study aimed to investigate critical thinking disposition,professional commitment,and the relationship between these 2 variables among nurses.Methods:As a result of stratified random sampling,201 nurses were enrolled in the present cross-sectional study.Data were gathered using a socio-demographic form,the Critical Thinking Disposition Inventory(CTDI),and the Nurses'Professional Commitment Scale(NPCS).Results:Although the critical thinking disposition scores were at a moderate level(115.70±13.55),the mean score for professional commitment was high(91.37±11.77).A positive correlation was found between critical thinking disposition and professional commitment(r=0.67,P=0.001).Conclusions:Nursing managers are urged to employ strategies to enhance nurses'critical thinking disposition and professional commitment.展开更多
This study investigated the professional commitment of kindergarten teachers in a private kindergarten located in Jinan,Shandong Province,China.The research employed a questionnaire and utilized correlation analysis t...This study investigated the professional commitment of kindergarten teachers in a private kindergarten located in Jinan,Shandong Province,China.The research employed a questionnaire and utilized correlation analysis to examine the factors influencing the professional commitment of private kindergarten teachers.The findings revealed that the overall level of career commitment among private kindergarten teachers was moderately low.Among the three dimensions of professional commitment,namely,continuance commitment,affective commitment,and normative commitment,the affective commitment dimension exhibited a relatively high level,whereas the continuance commitment and normative commitment dimensions showed relatively low levels.Significant differences in professional commitment levels were observed based on teacher age,education level,age of children,salary,and class size.However,no significant differences were found based on teacher specialty,position,and teaching experience.展开更多
Objectives:This study reviewed published randomized controlled trials(RCTs)and evaluated the efficacy of internet-based acceptance and commitment therapy(IACT)on adolescent mental health.Methods:Searches were conducte...Objectives:This study reviewed published randomized controlled trials(RCTs)and evaluated the efficacy of internet-based acceptance and commitment therapy(IACT)on adolescent mental health.Methods:Searches were conducted in PubMed,ProQuest,APA(PsycNET/PsycINFO),and Web of Science from inception to Jan-uary 2022 to identify RCTs evaluating the effects of IACT on adolescents.The included studies were assessed for quality and risk of bias.This study was performed using the standard mean difference and associated 95%confidence interval of effective measures.Review Manager 5.4 software was adopted to calculate the effect size.Results:Compared to adolescents in control groups,those in the IACT groups showed some improvement in the efficacy of depression symptoms(SMD=−0.24,95%CI=[−0.44,−0.05],p=0.01)and had a small but sig-nificant effect on reducing experiential avoidance(SMD=−0.24,95%CI=[−0.46,−0.01],p=0.04).However,the effect size on anxiety did not reach the threshold(SMD=−0.18,95%CI=[−0.27,−0.09],p<0.0001).In addition,there were no significant differences in stress and well-being compared to those of the control group.Compared with universal adolescents,IACT was found to have a more significant therapeutic effect on targeted adolescents.Conclusions:IACT is effective in adolescent mental health interventions,but its clinical reliability and significant efficacy are limited,and more rigorous RCTs are needed in future studies.展开更多
Objective:The objective is to assess the direct and indirect effects of nurses’organizational commitment(OC)on their work environment perceptions(WEP)and the role of the psychological contr act(PC).Methods:A cross‑se...Objective:The objective is to assess the direct and indirect effects of nurses’organizational commitment(OC)on their work environment perceptions(WEP)and the role of the psychological contr act(PC).Methods:A cross‑sectional quantitative study of 3047 registered nurses in four Chinese hospitals was conducted.The Essentials of Magnetism II(Chinese version),OC,and PC scales were used in the study,and the structural equation modeling was used to assess the connections among variables.Results:The results showed that OC was positively correlated with WEP(r=0.561,P<0.001),and PC was negatively correlated with the WEP(r=−0.717,P<0.001),and OC(r=−0.739,P<0.001).Nurses’PC played a strong mediating role between OC and WEP,accounting for 87.64%of the total effect.Besides,PC played an important role in creating a healthy work environment.Conclusions:The exploration of the relationships among WEP,PC,and OC provides new insights for hospital managers to build a better work environment for nurses,which is conducive to maintaining a stable nurse team and providing high‑quality nursing services for patients.展开更多
The purpose of this study is to explore the correlation between organizational commitment and job performance among employees in Taiwan Residents companies after the COVID-19 epidemic,and to use work motivation and or...The purpose of this study is to explore the correlation between organizational commitment and job performance among employees in Taiwan Residents companies after the COVID-19 epidemic,and to use work motivation and organizational communication as intermediary variables to further understand the interaction between them.Using hierarchical multiple regression analysis and bootstrap method to analyze,the research results show that organizational commitment has a significant positive impact on work motivation and work performance,and work motivation also has a significant positive impact on work performance.In addition,organizational communication has a mediating effect on organizational commitment and work motivation,and work motivation also has a mediating effect on organizational commitment and work machine performance.The results of this study hope to understand the working conditions of organizations and employees after the COVID-19 epidemic,and provide relevant business operators with follow-up references for their operations.展开更多
Objective: Nurse shortage is a critical problem for global healthcare services.It impacts the quality of clinical care.Work engagement is the core competence of hospitals,which indicates employee's positive attitu...Objective: Nurse shortage is a critical problem for global healthcare services.It impacts the quality of clinical care.Work engagement is the core competence of hospitals,which indicates employee's positive attitude toward organization and work.This study aimed to explore the relationships among calling,organizational commitment,and work engagement.Methods: A cross-sectional study was designed,and 320 nurses from tertiary hospitals in China completed the questionnaires that included demographic information,calling scale,employee engagement scale,and organizational commitment scale.Pearson correlation was performed to test the correlations among calling,organizational commitment,and work engagement.Stepwise regression analyses were performed to explore the mediating role of organizational commitment.The bootstrap method was employed to confirm the mediating effect.Results: Nurses' work engagement score was at the medium degree,whereas calling and organizational commitment were in the medium to high level.The results revealed that calling,organizational commitment,work engagement,and each dimension were positively correlated with one another (r=0.145-0.922,P < 0.01).The organizational commitment plays a partially mediating effect between calling and work engagement (β =0.603 to 0.333,P < 0.01).Conclusions: The mediation effect of organizational commitment was verified,which provided a comprehensive understanding of how calling impacted work engagement.Moreover,administrators should not only promote interventions to increase work engagement but also pay attention to calling and organizational commitment so as to improve their work engagement.Taken together,increased level of work engagement is required in the current nursing field.展开更多
Based on the uncertainty theory, market demand information updating as the background, we study the coordination and optimization problem of three-stage supply chain in this paper. In half a asymmetric market informat...Based on the uncertainty theory, market demand information updating as the background, we study the coordination and optimization problem of three-stage supply chain in this paper. In half a asymmetric market information, participants are risk neutral;under the situation of the manufacturers and wholesalers having twice pre-season decision-making opportunity, wholesalers can be replenished in the season;manufacturers join the lowest supply contract of commitment: manufacturers for exchanging the information that they cannot get directly from the market will promise wholesalers to have a season lowest supply in pre-season. According to this contract, we establish optimization models of manufacturers and wholesalers respectively, and get the optimal strategy of supply chain members by analyzing the supply chain system. Finally, by giving a numerical example and comparing the results with that under random circumstances, the result is reasonable.展开更多
Generally, the procedure for Solving Security constrained unit commitment (SCUC) problems within Lagrangian Relaxation framework is partitioned into two stages: one is to obtain feasible SCUC states;the other is to so...Generally, the procedure for Solving Security constrained unit commitment (SCUC) problems within Lagrangian Relaxation framework is partitioned into two stages: one is to obtain feasible SCUC states;the other is to solve the economic dispatch of generation power among all the generating units. The core of the two stages is how to determine the feasibility of SCUC states. The existence of ramp rate constraints and security constraints increases the difficulty of obtaining an analytical necessary and sufficient condition for determining the quasi-feasibility of SCUC states at each scheduling time. However, a numerical necessary and sufficient numerical condition is proposed and proven rigorously based on Benders Decomposition Theorem. Testing numerical example shows the effectiveness and efficiency of the condition.展开更多
Objectives:The unrelenting migration trend of Filipino nurses to other countries has threatened the quality of patient care services in the country.This study explored the extent of nurses'organizational commitmen...Objectives:The unrelenting migration trend of Filipino nurses to other countries has threatened the quality of patient care services in the country.This study explored the extent of nurses'organizational commitment and turnover intention in the Philippines.Furthermore,predictors of nurses'organizational commitment and turnover intention were identified.Methods:A cross-sectional research design was adopted for this study.Two hundred nurses from nine rural hospitals in the Central Philippines were asked to participate in the study and 166 nurses responded(an 83%response rate).Two standardized instruments were used:the Organizational Commitment Questionnaire and the Six-item Turnover Intention Inventory Scale.Results:Findings revealed that Philippine nurses were moderately committed(3.13±0.24)to and were undecided(2.42±0.67)whether or not to leave their organization.Nurses'age(P=0.006),gender,(t=-2.25,P=0.026),education(t=2.38,P<0.001),rank(t=4.38,P<0.001),and work experience(t=2.18,P=0.031)correlated significantly with organizational commitment,while nurses'age(P=0.028)and education(t=1.99,P=0.048)correlated significantly with turnover intention.An inverse relationship was identified between the organizational commitment and turnover intention(r=-0.22,P=0.005).Conclusion:The findings of this study highlight the need for formulation and implementation of interventions to promote life-long commitment in nurses and to reduce turnover rates.展开更多
Unit commitment (UC) is to determine the optimal unit status and generation level during each time interval of the scheduled period. The purpose of UC is to minimize the total generation cost while satisfying system d...Unit commitment (UC) is to determine the optimal unit status and generation level during each time interval of the scheduled period. The purpose of UC is to minimize the total generation cost while satisfying system demand, reserve requirements, and unit constraints. Among the UC constraints, an adequate provision of reserve is important to ensure the security of power system and the fast-response reserve is essential to bring system frequency back to acceptable level following the loss of an online unit within a few seconds. In this paper, the authors present and solve a UC problem including the frequency-based reserve constraints to determine the optimal FRR requirements and unit MW schedules. The UC problem is solved by using Lagrangian Relaxation-based approach and compared with the actual system schedules. It is observed that favorable reserve and unit MW schedules are obtained by the proposed method while the system security is maintained.展开更多
Bilateral electric power contract is settled based on contract output curve. This paper considered the bilateral transactions execution, new energy accommodation, power grid security and generation economy, considerin...Bilateral electric power contract is settled based on contract output curve. This paper considered the bilateral transactions execution, new energy accommodation, power grid security and generation economy, considering the executive priority of different power components to establish a multi-objective coordination unit commitment model. Through an example to verify the effectiveness of the model in promoting wind power consumption, guaranteeing trade execution, and improving power generation efficiency, and analyzed the interactions to each other among the factors of wind power, trading and blocking. According to the results, when wind power causes reverse power flow in the congestion line, it will promote the implementation of contracts, the influence of wind power accommodation to trade execution should be analyzed combined with the grid block, the results can provide reference for wind power planning.展开更多
This paper presents a new hybrid approach that combines Modified Priority List (MPL) with Charged System Search (CSS), termed MPL-CSS, to solve one of the most crucial power system’s operational optimization problems...This paper presents a new hybrid approach that combines Modified Priority List (MPL) with Charged System Search (CSS), termed MPL-CSS, to solve one of the most crucial power system’s operational optimization problems, known as unit commitment (UC) scheduling. The UC scheduling problem is a mixed-integer nonlinear problem, highly-dimensional and extremely constrained. Existing meta-heuristic UC solution methods have the problems of stopping at a local optimum and slow convergence when applied to large-scale, heavily-constrained UC applications. In the first step of the proposed method, initial hourly optimum solutions of UC are obtained by Modified Priority List (MPL);however, the obtained UC solution may still be possible to be further improved. Therefore, in the second step, the CSS is utilized to achieve higher quality solutions. The UC is formulated as mixed integer linear programming to ensure the tractability of the results. The proposed method is successfully applied to a popular test system up to 100 units generators for both 24-hr and 168-hr system. Computational results show that both solution cost and execution time are superior to those of published methods.展开更多
The solar and wind renewable energy is developing very rapidly to fulfill the energy gap. This specific increasing share of renewable energy is a reaction to the ecological trepidations to conciliate economics with se...The solar and wind renewable energy is developing very rapidly to fulfill the energy gap. This specific increasing share of renewable energy is a reaction to the ecological trepidations to conciliate economics with security due to the new challenges in power system supply. In solar and wind renewable energy, the only partially predictable is the output with very low controllability which creates unit commitment problems in thermal units. In this research paper, a different linear formulation via mixed integer is presented that only requires “binary variables” and restraints concerning earlier stated models. The framework of this model allows precisely the costs of time-dependent startup & intertemporal limitations, for example, minimum up & down times and a ramping limit. To solve the unit commitment problem efficiently, a commercially available linear programming of mixed-integer is applied for sizeable practical scale. The results of the simulation are shown in conclusions.展开更多
Objective:The objective of this study is to explore the mediating role of professional commitment of undergraduate nursing students between positive psychological capital(PsyCap)and learning burnout.Materials and Meth...Objective:The objective of this study is to explore the mediating role of professional commitment of undergraduate nursing students between positive psychological capital(PsyCap)and learning burnout.Materials and Methods:A cluster sampling method was used to survey 442 students of a bachelor’s degree in freshman to the junior in a medical college in Shaanxi Province.Results:Professional commitment was positively related to positive PsyCap(=0.487,P<0.01),while positive PsyCap and professional commitment were negatively related to learning burnout(r=−0.456,r=−0.411,P all<0.01).There are certain mediating effects of professional commitment in the relationship between positive PsyCap and learning burnout.The mediating effect value of professional commitment is−0.065,accounting for 16.08%of the total effect.Conclusion:Nursing educators in medical colleges and universities should focus on developing and training the positive PsyCap of undergraduate nursing students,thereby enhancing and stabilizing their professional commitment level and reducing the risk of learning burnout.展开更多
Participants in the Uruguay Hound have been enabled to take on specific commitments with respect to financial services under the General Agreement on Trade in Services (hereinafter referred to as the "Agreement&q...Participants in the Uruguay Hound have been enabled to take on specific commitments with respect to financial services under the General Agreement on Trade in Services (hereinafter referred to as the "Agreement") on the basis of an alternative approach to that covered by the provisions of Part Ⅲ of the Agreement. It was agreed that this approach could be applied subject to the following understanding: (i) it does not conflict with the provisions of the Agreement; (ii) it does not prejudice the right of ...展开更多
How to solve unit commitment and load dispatch of power system by genetic algorithms is discussed in this paper. A combination encoding scheme of binary encoding and floating number encoding and corresponding genetic ...How to solve unit commitment and load dispatch of power system by genetic algorithms is discussed in this paper. A combination encoding scheme of binary encoding and floating number encoding and corresponding genetic operators are developed. Meanwhile a contract mapping genetic algorithm is used to enhance traditional GA’s convergence. The result of a practical example shows that this algorithm is effective.展开更多
Grid integration of wind power is essential to reduce fossil fuel usage but challenging in view of the intermittent nature of wind.Recently,we developed a hybrid Markovian and interval approach for the unit commitment...Grid integration of wind power is essential to reduce fossil fuel usage but challenging in view of the intermittent nature of wind.Recently,we developed a hybrid Markovian and interval approach for the unit commitment and economic dispatch problem where power generation of conventional units is linked to local wind states to dampen the effects of wind uncertainties.Also,to reduce complexity,extreme and expected states are considered as interval modeling.Although this approach is effective,the fact that major wind farms are often located in remote locations and not accompanied by conventional units leads to conservative results.Furthermore,weights of extreme and expected states in the objective function are difficult to tune,resulting in significant differences between optimization and simulation costs.In this paper,each remote wind farm is paired with a conventional unit to dampen the effects of wind uncertainties without using expensive utility-scaled battery storage,and extra constraints are innovatively established to model pairing.Additionally,proper weights are derived through a novel quadratic fit of cost functions.The problem is solved by using a creative integration of our recent surrogate Lagrangian relaxation and branch-and-cut.Results demonstrate modeling accuracy,computational efficiency,and significant reduction of conservativeness of the previous approach.展开更多
Recently, many bit commitment schemes have been presented. This paper presents a new practical bit commitment scheme based on Schnorr's one-time knowledge proof scheme,where the use of cut-and-choose method and ma...Recently, many bit commitment schemes have been presented. This paper presents a new practical bit commitment scheme based on Schnorr's one-time knowledge proof scheme,where the use of cut-and-choose method and many random exam candidates in the protocols are replaced by a single challenge number. Therefore the proposed bit commitment scheme is more efficient and practical than the previous schemes In addition, the security of the proposed scheme under factoring assumption is proved, thus the cryptographic basis of the proposed scheme is clarified.展开更多
This paper presents two practical message commitment schemes: one is suitable for committing many bits, and another is useful for committing any bit-long message. They are provably secure based on pseudo-random synthe...This paper presents two practical message commitment schemes: one is suitable for committing many bits, and another is useful for committing any bit-long message. They are provably secure based on pseudo-random synthesizers. In these schemes, the sender may be unbounded to polynomial time and the receiver is bounded. The advantage of these schemes is that the secure parameter may be small.展开更多
文摘Objective:High-quality and successful nursing care delivery in a variety of situations requires critical thinking training and professional commitment.The present study aimed to investigate critical thinking disposition,professional commitment,and the relationship between these 2 variables among nurses.Methods:As a result of stratified random sampling,201 nurses were enrolled in the present cross-sectional study.Data were gathered using a socio-demographic form,the Critical Thinking Disposition Inventory(CTDI),and the Nurses'Professional Commitment Scale(NPCS).Results:Although the critical thinking disposition scores were at a moderate level(115.70±13.55),the mean score for professional commitment was high(91.37±11.77).A positive correlation was found between critical thinking disposition and professional commitment(r=0.67,P=0.001).Conclusions:Nursing managers are urged to employ strategies to enhance nurses'critical thinking disposition and professional commitment.
文摘This study investigated the professional commitment of kindergarten teachers in a private kindergarten located in Jinan,Shandong Province,China.The research employed a questionnaire and utilized correlation analysis to examine the factors influencing the professional commitment of private kindergarten teachers.The findings revealed that the overall level of career commitment among private kindergarten teachers was moderately low.Among the three dimensions of professional commitment,namely,continuance commitment,affective commitment,and normative commitment,the affective commitment dimension exhibited a relatively high level,whereas the continuance commitment and normative commitment dimensions showed relatively low levels.Significant differences in professional commitment levels were observed based on teacher age,education level,age of children,salary,and class size.However,no significant differences were found based on teacher specialty,position,and teaching experience.
基金the Humanities and Social Sciences Key Research Base Project of Anhui Province(SK2017A0278).
文摘Objectives:This study reviewed published randomized controlled trials(RCTs)and evaluated the efficacy of internet-based acceptance and commitment therapy(IACT)on adolescent mental health.Methods:Searches were conducted in PubMed,ProQuest,APA(PsycNET/PsycINFO),and Web of Science from inception to Jan-uary 2022 to identify RCTs evaluating the effects of IACT on adolescents.The included studies were assessed for quality and risk of bias.This study was performed using the standard mean difference and associated 95%confidence interval of effective measures.Review Manager 5.4 software was adopted to calculate the effect size.Results:Compared to adolescents in control groups,those in the IACT groups showed some improvement in the efficacy of depression symptoms(SMD=−0.24,95%CI=[−0.44,−0.05],p=0.01)and had a small but sig-nificant effect on reducing experiential avoidance(SMD=−0.24,95%CI=[−0.46,−0.01],p=0.04).However,the effect size on anxiety did not reach the threshold(SMD=−0.18,95%CI=[−0.27,−0.09],p<0.0001).In addition,there were no significant differences in stress and well-being compared to those of the control group.Compared with universal adolescents,IACT was found to have a more significant therapeutic effect on targeted adolescents.Conclusions:IACT is effective in adolescent mental health interventions,but its clinical reliability and significant efficacy are limited,and more rigorous RCTs are needed in future studies.
文摘Objective:The objective is to assess the direct and indirect effects of nurses’organizational commitment(OC)on their work environment perceptions(WEP)and the role of the psychological contr act(PC).Methods:A cross‑sectional quantitative study of 3047 registered nurses in four Chinese hospitals was conducted.The Essentials of Magnetism II(Chinese version),OC,and PC scales were used in the study,and the structural equation modeling was used to assess the connections among variables.Results:The results showed that OC was positively correlated with WEP(r=0.561,P<0.001),and PC was negatively correlated with the WEP(r=−0.717,P<0.001),and OC(r=−0.739,P<0.001).Nurses’PC played a strong mediating role between OC and WEP,accounting for 87.64%of the total effect.Besides,PC played an important role in creating a healthy work environment.Conclusions:The exploration of the relationships among WEP,PC,and OC provides new insights for hospital managers to build a better work environment for nurses,which is conducive to maintaining a stable nurse team and providing high‑quality nursing services for patients.
文摘The purpose of this study is to explore the correlation between organizational commitment and job performance among employees in Taiwan Residents companies after the COVID-19 epidemic,and to use work motivation and organizational communication as intermediary variables to further understand the interaction between them.Using hierarchical multiple regression analysis and bootstrap method to analyze,the research results show that organizational commitment has a significant positive impact on work motivation and work performance,and work motivation also has a significant positive impact on work performance.In addition,organizational communication has a mediating effect on organizational commitment and work motivation,and work motivation also has a mediating effect on organizational commitment and work machine performance.The results of this study hope to understand the working conditions of organizations and employees after the COVID-19 epidemic,and provide relevant business operators with follow-up references for their operations.
基金Financial support for this research was received from the National Natural Science Foundation of China (71704132)
文摘Objective: Nurse shortage is a critical problem for global healthcare services.It impacts the quality of clinical care.Work engagement is the core competence of hospitals,which indicates employee's positive attitude toward organization and work.This study aimed to explore the relationships among calling,organizational commitment,and work engagement.Methods: A cross-sectional study was designed,and 320 nurses from tertiary hospitals in China completed the questionnaires that included demographic information,calling scale,employee engagement scale,and organizational commitment scale.Pearson correlation was performed to test the correlations among calling,organizational commitment,and work engagement.Stepwise regression analyses were performed to explore the mediating role of organizational commitment.The bootstrap method was employed to confirm the mediating effect.Results: Nurses' work engagement score was at the medium degree,whereas calling and organizational commitment were in the medium to high level.The results revealed that calling,organizational commitment,work engagement,and each dimension were positively correlated with one another (r=0.145-0.922,P < 0.01).The organizational commitment plays a partially mediating effect between calling and work engagement (β =0.603 to 0.333,P < 0.01).Conclusions: The mediation effect of organizational commitment was verified,which provided a comprehensive understanding of how calling impacted work engagement.Moreover,administrators should not only promote interventions to increase work engagement but also pay attention to calling and organizational commitment so as to improve their work engagement.Taken together,increased level of work engagement is required in the current nursing field.
文摘Based on the uncertainty theory, market demand information updating as the background, we study the coordination and optimization problem of three-stage supply chain in this paper. In half a asymmetric market information, participants are risk neutral;under the situation of the manufacturers and wholesalers having twice pre-season decision-making opportunity, wholesalers can be replenished in the season;manufacturers join the lowest supply contract of commitment: manufacturers for exchanging the information that they cannot get directly from the market will promise wholesalers to have a season lowest supply in pre-season. According to this contract, we establish optimization models of manufacturers and wholesalers respectively, and get the optimal strategy of supply chain members by analyzing the supply chain system. Finally, by giving a numerical example and comparing the results with that under random circumstances, the result is reasonable.
文摘Generally, the procedure for Solving Security constrained unit commitment (SCUC) problems within Lagrangian Relaxation framework is partitioned into two stages: one is to obtain feasible SCUC states;the other is to solve the economic dispatch of generation power among all the generating units. The core of the two stages is how to determine the feasibility of SCUC states. The existence of ramp rate constraints and security constraints increases the difficulty of obtaining an analytical necessary and sufficient condition for determining the quasi-feasibility of SCUC states at each scheduling time. However, a numerical necessary and sufficient numerical condition is proposed and proven rigorously based on Benders Decomposition Theorem. Testing numerical example shows the effectiveness and efficiency of the condition.
文摘Objectives:The unrelenting migration trend of Filipino nurses to other countries has threatened the quality of patient care services in the country.This study explored the extent of nurses'organizational commitment and turnover intention in the Philippines.Furthermore,predictors of nurses'organizational commitment and turnover intention were identified.Methods:A cross-sectional research design was adopted for this study.Two hundred nurses from nine rural hospitals in the Central Philippines were asked to participate in the study and 166 nurses responded(an 83%response rate).Two standardized instruments were used:the Organizational Commitment Questionnaire and the Six-item Turnover Intention Inventory Scale.Results:Findings revealed that Philippine nurses were moderately committed(3.13±0.24)to and were undecided(2.42±0.67)whether or not to leave their organization.Nurses'age(P=0.006),gender,(t=-2.25,P=0.026),education(t=2.38,P<0.001),rank(t=4.38,P<0.001),and work experience(t=2.18,P=0.031)correlated significantly with organizational commitment,while nurses'age(P=0.028)and education(t=1.99,P=0.048)correlated significantly with turnover intention.An inverse relationship was identified between the organizational commitment and turnover intention(r=-0.22,P=0.005).Conclusion:The findings of this study highlight the need for formulation and implementation of interventions to promote life-long commitment in nurses and to reduce turnover rates.
文摘Unit commitment (UC) is to determine the optimal unit status and generation level during each time interval of the scheduled period. The purpose of UC is to minimize the total generation cost while satisfying system demand, reserve requirements, and unit constraints. Among the UC constraints, an adequate provision of reserve is important to ensure the security of power system and the fast-response reserve is essential to bring system frequency back to acceptable level following the loss of an online unit within a few seconds. In this paper, the authors present and solve a UC problem including the frequency-based reserve constraints to determine the optimal FRR requirements and unit MW schedules. The UC problem is solved by using Lagrangian Relaxation-based approach and compared with the actual system schedules. It is observed that favorable reserve and unit MW schedules are obtained by the proposed method while the system security is maintained.
文摘Bilateral electric power contract is settled based on contract output curve. This paper considered the bilateral transactions execution, new energy accommodation, power grid security and generation economy, considering the executive priority of different power components to establish a multi-objective coordination unit commitment model. Through an example to verify the effectiveness of the model in promoting wind power consumption, guaranteeing trade execution, and improving power generation efficiency, and analyzed the interactions to each other among the factors of wind power, trading and blocking. According to the results, when wind power causes reverse power flow in the congestion line, it will promote the implementation of contracts, the influence of wind power accommodation to trade execution should be analyzed combined with the grid block, the results can provide reference for wind power planning.
文摘This paper presents a new hybrid approach that combines Modified Priority List (MPL) with Charged System Search (CSS), termed MPL-CSS, to solve one of the most crucial power system’s operational optimization problems, known as unit commitment (UC) scheduling. The UC scheduling problem is a mixed-integer nonlinear problem, highly-dimensional and extremely constrained. Existing meta-heuristic UC solution methods have the problems of stopping at a local optimum and slow convergence when applied to large-scale, heavily-constrained UC applications. In the first step of the proposed method, initial hourly optimum solutions of UC are obtained by Modified Priority List (MPL);however, the obtained UC solution may still be possible to be further improved. Therefore, in the second step, the CSS is utilized to achieve higher quality solutions. The UC is formulated as mixed integer linear programming to ensure the tractability of the results. The proposed method is successfully applied to a popular test system up to 100 units generators for both 24-hr and 168-hr system. Computational results show that both solution cost and execution time are superior to those of published methods.
文摘The solar and wind renewable energy is developing very rapidly to fulfill the energy gap. This specific increasing share of renewable energy is a reaction to the ecological trepidations to conciliate economics with security due to the new challenges in power system supply. In solar and wind renewable energy, the only partially predictable is the output with very low controllability which creates unit commitment problems in thermal units. In this research paper, a different linear formulation via mixed integer is presented that only requires “binary variables” and restraints concerning earlier stated models. The framework of this model allows precisely the costs of time-dependent startup & intertemporal limitations, for example, minimum up & down times and a ramping limit. To solve the unit commitment problem efficiently, a commercially available linear programming of mixed-integer is applied for sizeable practical scale. The results of the simulation are shown in conclusions.
基金the Shaanxi Provincial Administration of Traditional Chinese Medicine Fund(No.:2019‑ZZ‑ZC010).
文摘Objective:The objective of this study is to explore the mediating role of professional commitment of undergraduate nursing students between positive psychological capital(PsyCap)and learning burnout.Materials and Methods:A cluster sampling method was used to survey 442 students of a bachelor’s degree in freshman to the junior in a medical college in Shaanxi Province.Results:Professional commitment was positively related to positive PsyCap(=0.487,P<0.01),while positive PsyCap and professional commitment were negatively related to learning burnout(r=−0.456,r=−0.411,P all<0.01).There are certain mediating effects of professional commitment in the relationship between positive PsyCap and learning burnout.The mediating effect value of professional commitment is−0.065,accounting for 16.08%of the total effect.Conclusion:Nursing educators in medical colleges and universities should focus on developing and training the positive PsyCap of undergraduate nursing students,thereby enhancing and stabilizing their professional commitment level and reducing the risk of learning burnout.
文摘Participants in the Uruguay Hound have been enabled to take on specific commitments with respect to financial services under the General Agreement on Trade in Services (hereinafter referred to as the "Agreement") on the basis of an alternative approach to that covered by the provisions of Part Ⅲ of the Agreement. It was agreed that this approach could be applied subject to the following understanding: (i) it does not conflict with the provisions of the Agreement; (ii) it does not prejudice the right of ...
文摘How to solve unit commitment and load dispatch of power system by genetic algorithms is discussed in this paper. A combination encoding scheme of binary encoding and floating number encoding and corresponding genetic operators are developed. Meanwhile a contract mapping genetic algorithm is used to enhance traditional GA’s convergence. The result of a practical example shows that this algorithm is effective.
基金supported in part by the Project Funded by ABB and U.S.National Science Foundation(ECCS-1509666)
文摘Grid integration of wind power is essential to reduce fossil fuel usage but challenging in view of the intermittent nature of wind.Recently,we developed a hybrid Markovian and interval approach for the unit commitment and economic dispatch problem where power generation of conventional units is linked to local wind states to dampen the effects of wind uncertainties.Also,to reduce complexity,extreme and expected states are considered as interval modeling.Although this approach is effective,the fact that major wind farms are often located in remote locations and not accompanied by conventional units leads to conservative results.Furthermore,weights of extreme and expected states in the objective function are difficult to tune,resulting in significant differences between optimization and simulation costs.In this paper,each remote wind farm is paired with a conventional unit to dampen the effects of wind uncertainties without using expensive utility-scaled battery storage,and extra constraints are innovatively established to model pairing.Additionally,proper weights are derived through a novel quadratic fit of cost functions.The problem is solved by using a creative integration of our recent surrogate Lagrangian relaxation and branch-and-cut.Results demonstrate modeling accuracy,computational efficiency,and significant reduction of conservativeness of the previous approach.
基金Supported by the National Natural Science Foundation of China(No.69772035,69882002) and "863" Programme
文摘Recently, many bit commitment schemes have been presented. This paper presents a new practical bit commitment scheme based on Schnorr's one-time knowledge proof scheme,where the use of cut-and-choose method and many random exam candidates in the protocols are replaced by a single challenge number. Therefore the proposed bit commitment scheme is more efficient and practical than the previous schemes In addition, the security of the proposed scheme under factoring assumption is proved, thus the cryptographic basis of the proposed scheme is clarified.
文摘This paper presents two practical message commitment schemes: one is suitable for committing many bits, and another is useful for committing any bit-long message. They are provably secure based on pseudo-random synthesizers. In these schemes, the sender may be unbounded to polynomial time and the receiver is bounded. The advantage of these schemes is that the secure parameter may be small.
