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.

The Effect of Procrastination on Physical Exercise among College Students—The Chain Effect of Exercise Commitment and Action Control

Background:Exercise procrastination is prevalent among college students,causing decline in physical fitness.It is imperative to investigate the mechanism affecting college students’physical activity behaviors.This study was aimed at investigating the effect of procrastination on college students’physical exercise behavior,and the chain mediation effects of exercise commitment and action control(AC),to provide a theoretical basis for interventions targeting physical exercise behavior among college students.Methods:A questionnaire survey was conducted using convenience sampling.The General Procrastination Scale,Exercise Commitment Scale,Action Control Scale,and Physical Activity Rating Scale-3 questionnaires were used.Participants were 581 college students(age 19.27±0.94 years;243 males and 338 females).Statistical methods of regression analysis and structural equation modeling(SEM)were applied.Results:Procrastination,exercise commitment,and action control were found to be significant predictors of physical exercise behavior.Among these predictors,exercise commitment and action control showed full mediation effects in the relationship between procrastination and physical exercise behavior,and explained 25.48%and 30.77%of the total variance,respectively.The chain mediation effect of exercise commitment-action control was significant,accounting for 22.60%of the total variance,and the total indirect effect was 79.33%.Conclusion:Therefore,higher procrastination was associated with less participation in physical exercise behavior among college students.Improvements in exercise commitment and volitional decision-making ability for physical exercise behavior promoted physical exercise behavior,and increased exercise commitment promoted volitional decision-making ability among the students.The chain reaction effect of exercise commitment and action control also buffered the negative effects of procrastination on physical exercise behavior,thereby increasing physical exercise behavior among college students.

The Impact of Transformational Leadership on Commitment to Change Among Jordanian Government Accountant Toward IPSAS Implementation

IPSAS was accepted by Jordan’s government in accordance with worldwide trends.The Jordanian Ministry of Finance launched cash-basis IPSAS in 2015 and planned to implement accrual accounting by January 1,2021.However,the commitment to change remains uneven,hindering the full shift.Moving from old accounting processes to new ones is tough.Even then,it hasn’t been implemented,creating a gap due to the difficulty in committing to new accounting standards throughout implementation due to obstacles.Thus,knowing government accountants’issues is essential to applying IPSAS in government accounting.This study examines how transformational leadership affects government accountants’commitment to IPSAS adoption in Jordan’s public sector.This study used a quantitative approach to survey Jordanian Ministry of Finance accountants.The 384-person study had a 78%response rate.Additionally,PLS-SEM was used to confirm variable relationships.Transformational leadership positively predicted IPSAS implementation,according to the study.

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.

Trust and relationship commitment on cooperative performance of supply chain

Creating and sustaining trust in cooperative performances of the supply chain constitute critical strategic components.To study the influences of organizational and individual trust on the quality of commitment and cooperative performance,the relationships among organizational trust,individual trust,commitment and cooperative performances of the supply chain are discussed by case analysis.Questionnaire investigation is used to study the trust and relationship commitment among supply chain partnerships on cooperative performance.Results show that both organizational and individual trust are positively correlated with cooperative performance.The indirect effects of organizational trust on cooperative performance through relationship commitment is significantly greater than its direct effects.However,the indirect effects of individual trust on cooperative performance through relationship commitment is significantly less than its direct effects.It provides all essential basis for enterprises to establish and develop stable supply chain partnerships and to enhance competitive advantages.

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.

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.

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.

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.

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.

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.

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.

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.

The Braid-Based Bit Commitment Protocol

With recent advances of quantum computanon, new threats key cryptosystems. In order to build more secure bit commitment schemes, this paper gave a survey of the new coming braid-based cryptography and then brought forward the first braid-based bit commitment protocol. The security proof manifests that the proposed protocol is computationally binding and information-theoretically hiding. Furthermore, the proposed protocol is also invulnerable to currently known quantum attacks.

The Optimal Depletion of Exhaustible Resource under Different Commitment

There are few papers in the literature focusing on the issue of the optimal depletion of exhaustible resources in the framework of variable time preference. This paper attempts to analyze the pure consumption of exhaustible resource under hy- perbolic time preference, and to discuss the optimal depletion rate and the effect of the protection of the exhaustible resource under different commitment abilities. The results of model show that the case of the hyperbolic discount with the full commitment of the govemment is equivalent to the case of constant discount of the social planner problem. In that case, the optimal depletion rate and the initial consumption of exhaustible resource are the slowest. On the contrary, they are the highest and the myopic behaviors lead to excessive consumption of exhaustible resources inevitably without commitment. Otherwise, in the case of partial commit- ment, the results are between the cases of full commitment and of no commitment. Therefore, with the hyperbolic time preference, the optimal depletion rate of resource depends on the commitment ability. Higher commitment ability leads to lower effective rate of time preference, and consequently, lower depletion rate and lower initial depletion value. The improvement of commitment ability can decrease the impatience and myopia behaviors, and contribute to the protection of the exhaustible resources.

Mediating effect of undergraduate nursing students’ professional commitment on positive psychological capital and learning burnout

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.

Optimization of unit commitment based on genetic algorithms

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.

Optimizing Combination of Units Commitment Based on Improved Genetic Algorithms

GAs are general purpose optimization techniques based on principles inspired from the biological evolution using metaphors of mechanisms, such as natural selection, genetic recombination and survival of the fittest. By use of coding betterment, the dynamic changes of the mutation rate and the crossover probability, the dynamic choice of subsistence, the reservation of the optimal fitness value, a modified genetic algorithm for optimizing combination of units in thermal power plants is proposed. And through taking examples, test result are analyzed and compared with results of some different algorithms. Numerical results show available value for the unit commitment problem with examples.