Improved Unit Commitment with Accurate Dynamic Scenarios Clustering Based on Multi-Parametric Programming and Benders Decomposition

Stochastic unit commitment is one of the most powerful methods to address uncertainty. However, the existingscenario clustering technique for stochastic unit commitment cannot accurately select representative scenarios,which threatens the robustness of stochastic unit commitment and hinders its application. This paper providesa stochastic unit commitment with dynamic scenario clustering based on multi-parametric programming andBenders decomposition. The stochastic unit commitment is solved via the Benders decomposition, which decouplesthe primal problem into the master problem and two types of subproblems. In the master problem, the committedgenerator is determined, while the feasibility and optimality of generator output are checked in these twosubproblems. Scenarios are dynamically clustered during the subproblem solution process through the multiparametric programming with respect to the solution of the master problem. In other words, multiple scenariosare clustered into several representative scenarios after the subproblem is solved, and the Benders cut obtainedby the representative scenario is generated for the master problem. Different from the conventional stochasticunit commitment, the proposed approach integrates scenario clustering into the Benders decomposition solutionprocess. Such a clustering approach could accurately cluster representative scenarios that have impacts on theunit commitment. The proposed method is tested on a 6-bus system and the modified IEEE 118-bus system.Numerical results illustrate the effectiveness of the proposed method in clustering scenarios. Compared withthe conventional clustering method, the proposed method can accurately select representative scenarios whilemitigating computational burden, thus guaranteeing the robustness of unit commitment.

Management Practices:Shaping Employee Satisfaction and Commitment in Large German Companies

The rapid evolution of the political,economic,and social landscape has generated increased interest in understanding the contextual application of management styles and behaviours toward employees.In this context,organizations must comprehend and assess employee satisfaction to enhance productivity and realize their strategic and economic goals.Therefore,this study aims to investigate the prevailing and significant management behaviours toward employees in large German companies and their impact on employee satisfaction and job commitment.To achieve the research objective,the study will employ a qualitative method to explore management behaviours toward employees.Data were collected through interviews with randomly selected managers from different companies and departments.The study aims to uncover discrepancies or variations in employee expectations regarding management behaviour.The findings will provide a better understanding of the most prevalent and significant management behaviours toward employees in large German companies and their impact on employee satisfaction and job commitment.The results will be valuable to management in adopting suitable leadership styles and improving employee satisfaction,leading to increased productivity and organizational performance.The research will contribute to the existing body of knowledge in the field of management and human resource management by providing insights into the impact of management behaviours on employees.It will also offer recommendations to management on how to enhance employee satisfaction and job commitment,leading to improved organizational performance.In conclusion,this study will investigate the prevailing management behaviours toward employees in large German companies and their impact on employee satisfaction and job commitment.

Nurses'critical thinking disposition and professional commitment:a cross-sectional study

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.

A study on the current situation and factors influencing the professional commitment of private kindergarten teachers

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.

Effects of Internet-Based Acceptance and Commitment Therapy (IACT) on Adolescents: A Systematic Review and Meta-Analysis

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.

The impact of nurses’organizational commitment on their perceptions of the work environment:Strong mediating effect of the psychological contract

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.

A Study on Organizational Commitment,Work Motivation,and Job Performance After the COVID-19 Epidemic in Taiwan-The Mediating Effects of Work Motivation and Organizational Communication

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.

Watermelon Soup-commitment

因为对于一位日本艺术家Hirohiko Araki1987年开始创作的作品深有感触,从他的画面中提取了最具个人特色的元素:性感的嘴唇及其中坚定不移地蕴含着的人类之美。

CLARITY-TIMI 28和COMMIT/CCS-2研究简介

动脉粥样硬化血栓栓塞所导致的疾病是世界上最大的致命性杀手.由赛诺菲-安万特集团出资,在全球开展了两项研究CLARITY-TIMI 28(CLopidogrel as Adjunctive ReperfusIon Therapy-Thrombolysis In Myocardial Infarction Study 28)和COMMIT/CCS-2(C1Opidogrel and Metoprolol in Myocardial Infarction Trial),这项两项重要临床研究结果在2005年3月第54届美国心脏病学会(ACC)年会上公布.应法国赛诺菲-安万特集团中国公司的邀请,著名心血管专家胡大一教授和Braunwald博士2005年3月25日在北京对有关媒体通报ACC年会上发表的CLARITY-TIMI28和COMMIT/CCS-2重要临床研究结果进行通报,结果显示:抗血小板药物氯吡格雷(75mg每日1次)联合标准治疗对于急性心肌梗死(AMI)[(ST段抬高AMI(STE-AMI)]的患者显著有益.两项重大临床研究共包括了近50000名患者.

The mediating role of organizational commitment between calling and work engagement of nurses: A cross-sectional study

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.

Organizational commitment and turnover intention among rural nurses in the Philippines: Implications for nursing management

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.

Supply Chain Commitment Contract Model Based on Uncertainty Theory under Uncertain Market Information

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.

A Quick Method for Judging the Feasibility of Security-Constrained Unit Commitment Problems within Lagrangian Relaxation Framework

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.

开源社区中开发者的commit提交行为挖掘分析

以Github开源社区为研究对象,分析社区中开发者在commit提交过程中的行为,探索开发者之间的交互关系.研究内容包括分析影响开发者提交行为的因素,探析commit的提交者与创作者关系,进一步分析commit的评论者的行为.研究结果发现:1)构建项目团队的成员组织数不宜超过10,但开发者规模可以适当扩大;2)项目commit的提交90%以上都以核心成员为主,未充分调动开源社区中广大爱好者参与的积极性;3)参与一个commit评论的开发者数大多在5人以内,且参与同一个commit评论的开发者多来自不同的项目或组织.

On units combination and commitment optimization for electric power production

Electric power system is one of the most important and complex engineering in modern society, supplying main and general power for social production and social life. Meanwhile, since it is a productive system with both high input and output, it has an obvious economic significance to improve its operating efficiency. For an example, an unit is 10 GW scale, if its standard coal consumption can be decreased with 1 g/kW·h, it can save about 5 000 tons standard coal per year. It will be discussed mainly that how to establish optimization model and its numerical algorithm for operating management of the electric power system. The idea on establishing optimization model is how to dispatch work state of units or power plants, so that total cost of fuel consumption for generation is reduced to the minimum. Here the dispatch is to decide which unit or plant to operate, which unit or plant to stop running, how much power should be generated for those operating units or plants at each given time interval.

Non-Invasive Vibration-Stress of the Cirrhotic Liver of Patients Waiting for Transplantation Induces of Circulating CD133+ Stem Lymphocytes Committed Phenotypically toward the Liver

Background: Numerous studies of tissues’ regeneration have confessed the recovery of damaged liver by hematopoietic stem cells. The cells act not only by cell replacement in the target organ but also by delivering trophic factors that support endogenous liver regeneration. A little is known of how organ-derived signals recruit such committed cells into circulation. Objective: We investigated the roles of noninvasive mechanical percutaneous stress of cirrhotic human liver in numbers fluctuation of trophic, liver-specific alpha-fetoprotein-positive fraction of CD133-positive hematopoietic stem cells in lymphocytes of patients waiting for liver transplantation. Methods: To promote in blood the number of the alpha-fetoprotein-positive fraction of CD133-positive hematopoietic stem cells, committed to liver’ tissue, we activated mechanically the cirrhotic liver of patient by transcutaneous micro vibration received from skin-contacted electro-magnetic vibraphones generated mechanical pulses with amplitude 10 μm and smoothly changing frequency from 0.03 kHz to 18 kHz and back forth during one cycle duration 1 minute. The number of the alpha-fetoprotein-positive fraction of CD133-positive hematopoietic stem cells in lymphocytes of potential recipients was controlled by flow cytometry before and during daily sonication of skin area, which corresponds to liver projection on it. The 15 minutes cyclic sonication of the liver area performed daily for three weeks. Results: The sonication increased significantly averaged number of liver-specific alpha-fetoprotein-positive CD133-positive blood lymphocytes in 2 - 3 times compared to a base lane. The second similar sonication, the same zone after three weeks break showed differences with baseline, but it was statistically insignificant. The result was specifically related to the liver as it showed the control sonication of the backbone’s projection on the skin of a separate group of patients with cirrhotic liver from the waiting list. Conclusion: The stem cells committed to the liver recruit from the bone marrow into circulation, when organ mechanically stresses and secretes specific humoral signals to provoke of lymphopoiesis on host liver repair.

Unit Commitment under the Environment of Wind Power and Large-Scale Bilateral Transactions

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.

Lagrangian Relaxation-Based Unit Commitment Considering Fast Response Reserve Constraints

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.

A Hybrid Unit Commitment Approach Incorporating Modified Priority List with Charged System Search Methods

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.

The Linear Formulation of Thermal Unit Commitment Problem with Uncertainties through a Computational Mixed Integer

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.