Commitment Model Research Articles

Unveiling the Dynamics of Organizational Commitment: Exploring Organizational Commitment and Demographic Factors among Teachers in Technical Secondary Schools

This study examines organizational commitment among schoolteachers, aiming to determine its extent and explore variations across different teacher groups. The research involved 217 participants from all Technical Secondary Schools in the country. Data were collected through a questionnaire adapted from the Three-Component Model of Occupational Commitment and analyzed using Statistical Package for the Social Sciences (SPSS version 26). Results indicated a notably high level of organizational commitment among the teachers. No significant differences were observed in relation to age and experience in connection to organizational commitment. However, a noteworthy gender difference emerged, revealing that female teachers exhibited higher levels of commitment compared to their male counterparts.

Explaining the Model of Marital Commitment Based on Object Relations with the Mediating Role of Ego Strength

Marriage is the greatest and most significant event in an individual's life, and a healthy marriage requires several elements, including intimacy, commitment, and satisfaction. This study aimed to explain a model predicting marital commitment based on object relations with the mediating role of ego strength. The statistical population of the present study included all married couples residing in the city of Qom in 2023, totaling 7,634 individuals. Of these, 258 individuals (148 women and 110 men) were selected through purposive sampling. This study used a descriptive-correlational research design and structural equation modeling. Participants completed the Marital Commitment Inventory (DCI) by Adams and Jones (1997), the Object Relations Inventory by Bell et al. (1995), and the Ego Strength Inventory by Markstrom et al. (1997). Data were analyzed descriptively and inferentially using SPSS-28 and AMOS-24 software. The relationships among variables were examined using Pearson correlation and path analysis, and the mediating role was tested using the Sobel method. The findings of this study confirmed the mediating role of ego strength in the relationship between object relations and marital commitment (p < .05). The indirect effect of object relations on marital commitment was -0.062. The results indicate that considering the complex interplay of issues that arise in couples' interactions and experiences, as well as the role of ego strength, can provide valuable insights into the factors that contribute to the success and longevity of relationships.

Transient Stability-Constrained Unit Commitment Using Input Convex Neural Network.

This article proposes a transient stability-constrained unit commitment (TSC-UC) model using input convex neural networks (ICNNs). An ICNN is trained to learn the transient function that maps prefault operation conditions (e.g., generator power output) to the transient stability index (TSI), which can be further utilized to identify the transient status (e.g., stable or unstable). Transient stability evaluation is conducted using the learned ICNN, without discretizing differential-algebraic equations (DAEs) or interacting with the time-domain simulation tools. Based on the convexity of ICNNs, the trained ICNN is exactly encoded as a linear programming (LP) model and integrated into conventional UC models to form a TSC-UC model. To impose transient stability constraints and expedite the solution process, the proposed TSC-UC model is decomposed into a UC master problem and two subproblems (i.e., network feasibility check subproblems and transient stability check subproblems). The decomposed problem is then iteratively solved using the Benders decomposition. Simulation tests are conducted in the New England 39-bus test system and IEEE 118-bus test system to verify the validity of the proposed approach.

Two-Stage Robust Unit Commitment Problem With Complex Temperature and Demand Uncertainties

In this paper, we present and study a robust unit commitment model and some variants that consider complex temperature and demand uncertainties. Since there is a strong relationship among the efficiency of gas generators, demand, and temperature in practical systems, our robust models have both left- and right-hand-side (LHS and RHS, respectively) uncertainties. Unlike many existing robust models with RHS uncertainty only, the introduction of LHS uncertainty imposes a huge challenge in computing robust solutions. For those complex formulations, we analyze their structures, derive important properties, and design exact and fast approximation solution strategies under the column-and-constraint generation framework. Numerical experiments are conducted on typical IEEE test systems, which showcase the great performance of our solution methods and demonstrate a clear impact of complex and correlated uncertainties in system operations.

A Fuzzy Unit Commitment Model for Enhancing Power System Reliability and Carbon Reduction with Renewable Energy, EV Charging, and Energy Storage Integration

A Fuzzy Unit Commitment Model for Enhancing Power System Reliability and Carbon Reduction with Renewable Energy, EV Charging, and Energy Storage Integration

Better to Have Played Than Not Played? Childhood Sport Participation, Dropout Frequencies and Reasons, and Mental Health in Adulthood

This study considers the long-term mental health implications of organized youth sport participation, informed by an accumulation model of health, the Sport Commitment Model, and a life course perspective. Using data from the National Sports and Society Survey (N = 3,931) and multiple regression analyses, results indicate that adults who continually played organized youth sport had fewer depressive and anxiety symptoms compared with those who played and dropped out and those who never played. Dropouts had worse mental health than those who never played. Furthermore, among dropouts, reported interpersonal reasons for dropping out of organized sport were consistently associated with subsequent mental health but some structural factors also mattered. These findings point to a need to improve the interpersonal and structural environments of organized youth sport.

A Unit Commitment Model Considering the Flexibility Retrofit of Combined Heat and Power Units for Wind Integration

A Unit Commitment Model Considering the Flexibility Retrofit of Combined Heat and Power Units for Wind Integration

Retrofit Planning and Flexible Operation of Coal-Fired Units Using Stochastic Dual Dynamic Integer Programming

The continuous growth of wind power requires greater power system operational flexibility owing to the variability and uncertainty of wind power generation. Retrofitting existing coal-fired units is a demonstrated cost-effective method for improving system flexibility. This study proposes a decision support tool that provides optimal investment decisions to enhance power system operational flexibility. A novel flexibility retrofit planning (FRP) model is proposed in which the embedded operational problem is a stochastic mixed-integer nonlinear programming (SMINLP) unit commitment problem. In the operational unit commitment model, novel mixed-integer nonlinear formulations are proposed to represent the coal-fired unit attribute (minimum power output, startup and shutdown times, and maximum ramp rate) modifications after retrofitting. A new solution method based on the Benders decomposition (BD) and stochastic dual dynamic integer programming (SDDIP) algorithms is proposed to solve the proposed FRP model. The modified IEEE 39-bus, 57-bus, and 118-bus test systems were used to verify the effectiveness of the proposed model and solution method. The results demonstrate that the proposed FRP model can balance the retrofitting and operational costs to minimize the total cost and accommodate more wind generation. The proposed solution method is computationally efficient for solving FRP models.

RoCoF Constrained Unit Commitment Considering Spatial Difference in Frequency Dynamics

The post-disturbance rate of change of frequency (RoCoF) is a critical index for low-inertia power system frequency stability. This paper proposes a RoCoF constrained unit commitment model so as to enhance the frequency stability in operation time-scale, where the spatial difference in frequency dynamics is considered and the RoCoF constraint is enforced for each node. The maximum of node RoCoF is approximated by two terms, i.e., the initial post-disturbance node RoCoF and the maximum of the center of inertia (COI) RoCoF. Analytical expressions of the node initial RoCoF under typical disturbances are derived. Then, a tractable relationship between the node initial RoCoF and the working status of generators is obtained by the piecewise linearization approach. Simulation results carried out on the IEEE 39-bus system demonstrate the proposed model can limit the node RoCoF in an economic and accurate manner. The adaptability to renewable power generation and online application are also discussed.

Operation of Energy and Regulation Reserve Markets in the presence of Virtual Power Plant Including Storage System and Distributed Generation based on Unit Commitment Model

Operation of Energy and Regulation Reserve Markets in the presence of Virtual Power Plant Including Storage System and Distributed Generation based on Unit Commitment Model

Formulating a quadratic frequency nadir constraint in unit commitment based on energy conservation law

This paper proposes a quadratic formulation for the frequency nadir constraint (FNC) based on the energy conservation law. Incorporating the formulation into the unit commitment (UC) model, a mixed-integer quadratically constrained programming (MIQCP) model for frequency nadir constrained UC can be obtained, which can be solved efficiently by the MIQCP solver. The distinct feature of the formulation is that it considers the inertia difference among generators, which has a significant effect on the on/off schedule of generators. Besides, the formulation has a clear physical meaning and does not have to be linearized. The test on the WSCC 3-machine 9-bus benchmark system validates the accuracy of the formulation, and the case studies on a New England 10-machine 39-bus system confirm the effectiveness of the proposed formulation.

Regional temperature extremes and vulnerability under net zero CO2 emissions

Signatories to the Paris Agreement have pledged to keep global warming to well below 2 °C above pre-industrial levels and preferably below 1.5 °C above pre-industrial levels. Beyond over-shooting Paris Agreement warming levels followed by net negative emissions, achieving a state of net zero carbon dioxide emissions is required to satisfy Paris Agreement warming goals. Research on climate changes under net zero CO2 emissions is very limited to date with no comprehensive analysis of changes in extremes. In this study, we use results from Earth System Models in the zero emissions commitment model intercomparison project to understand regional mean-state climate change patterns during a 100 year period following carbon dioxide emissions cessation. We also perform an initial study of the evolution of hot and cold monthly temperature extremes after net zero CO2 emissions, including an assessment of how the change in frequency of temperature extremes affects areas of different levels of socioeconomic development based on regional Human Development Index (HDI). The results show that most land regions experience a fast and continuous cooling response following emissions cessation, with large areas of significant model agreement. In contrast, the Southern Ocean continues warming over the century after emissions cessation. The frequency of land-based local monthly high temperature extremes generally stays constant or decreases during the century after emissions cessation, however, decreases in heat extreme frequencies are generally less for locations with lower modern HDI than areas with higher HDI which suggests that inequality of climate change will remain an issue even after net zero CO2 emissions. There is an evident emergence of local monthly cold extremes following emissions cessation with most significant impact over high HDI mid- and high-latitude land regions.

Profit-based unit commitment models with price-responsive decision-dependent uncertainty

Highlighting the increasing importance of demand elasticity in electricity markets and its impact on the revenues of power generating companies, this paper proposes new profit-based unit commitment models that effectively capture the uncertainty in the willingness-to-pay the price set for the elastic demand. To develop a new revenue scheme for power generating companies, we use a coupling function to model the willingness-to-pay response of the elastic demand as a decision-dependent source of uncertainty. The coupling function reflects how power generating companies’ pricing decisions may influence the market appeal (i.e., the buyer’s willingness-to-pay) and how it affects their revenues. The optimization models are stochastic mixed-integer nonlinear problems with nonconvex continuous relaxations and are not amenable to a numerical solution in their original forms. We devise a convexification reformulation method and derive valid inequalities to strengthen the formulation. We propose a learning framework to parameterize the willingness-to-pay functions and the concept of the value of the decision-dependent solution to quantify the value of the uncertainty modeling approach. Numerical tests on power systems of various sizes, demand portfolios, and price elasticity levels show (i) how the valid inequalities speed up the solution process, (ii) the benefits of properly modeling decision-dependent uncertainty and demand elasticity, and (iii) how the incorporation of decision-dependent uncertainty in demand elasticity can change the power generating companies’ decisions and revenue estimation.

Analyzing the low carbon and pro-environment behavior of agricultural enterprises based on organizational commitment and role models’ guidance

Analyzing the low carbon and pro-environment behavior of agricultural enterprises based on organizational commitment and role models’ guidance

A Bi-level optimization strategy for electric vehicle retailers based on robust pricing and hybrid demand response

The high penetration of electric vehicles (EVs) poses both opportunities and challenges for power systems. EV retailers, playing a critical role in the demand response mechanism, face market risks caused by uncertainties in electricity consumption and prices. To address the operational issues of large-scale EVs and tap the potential of EV retailers, a temporal and spatial domain-based optimization strategy is proposed, which is implemented on bi-level (referring to transmission and distribution grid networks). First, a physical scheduling model of the grid is established, consisting of a novel hybrid demand response mechanism considering the incentives of EV retailers and the retail electricity price of EV users, and a new robust retail electricity pricing strategy handling the uncertainties of EV behavior and the electric market. Then, a bi-level optimization strategy is presented: at the upper level, in the transmission network, based on the robust pricing strategy, a unit commitment model that coordinates the hybrid demand response with other distributed energy resources is designed to optimize load periods of EVs in the time domain; at the lower level, in the distribution network, an optimal power flow model is proposed to spatially dispatch the location of EV loads. The impacts of retail price profile, EV penetration, hybrid demand response mechanism, and EV load location are analyzed in ten tests using the IEEE 33 distribution network. Simulation results indicate that the robust pricing strategy can effectively handle uncertainties, the integration of the hybrid demand response mechanism into scheduling can ensure the benefits of all participants, and the bi-level optimization strategy can accommodate distributed energy resources temporally and spatially.

Unit Commitment Considering Long-term Supply Risk of Natural Gas Pipeline Network

As the coupling degree of the natural gas pipeline network (NGPN) and the power system increase, unreliable gas supply risk related to random failures in NGPN has threatened the operation security of the power system. However, present studies seldom discuss the effect of natural gas supply reliability on power system operation. In this manner, a stochastic unit commitment model is presented with the consideration of long-term gas supply risk in NGPN. Firstly, with the combination of the Monte Carlo simulation (MCS) technique and the maximum-flow algorithm, the failure scenario set corresponding to gas supply risk can be obtained. Then, a two-stage model for unit commitment is established considering gas supply uncertainty based on the stochastic optimization model. Finally, case studies have shown that the power operation reliability has been improved with the increased reliability indices.

Committed to staying single: Adapting the investment model of commitment processes to study singlehood

AbstractIn the current work, we adapt the investment model of commitment processes for single adults. Across two cross‐sectional studies using undergraduate and internet samples (total N = 647), we tested whether the same factors that predict relationship commitment (investment, satisfaction, and quality of alternatives) also predict commitment to singlehood. In line with this theoretical model, we found that singlehood satisfaction and investment in singlehood were each positively associated with commitment to singlehood, whereas the quality of alternatives to singlehood was negatively associated with commitment to singlehood. We also found that a person's expected satisfaction and planned investment were each associated with commitment to singlehood, whereas subjective norms were not associated with commitment to singlehood. In addition, we tested whether commitment to singlehood was positively associated with well‐being, but these associations were nonsignificant. Our findings provide initial evidence for the appropriateness of the investment model for understanding commitment to being single.

Operation of interconnected power and freshwater networks

As freshwater demand continues to rise and conventional freshwater resources decline, the interaction between the freshwater and power sectors is becoming increasingly relevant. Coordinating both systems entail minimizing the operation costs of the power and freshwater system while supplying the demands of electricity and freshwater and complying with operational constraints. This is particularly relevant in Middle Eastern regions, which have limited availability of freshwater resources. Careful coordination of electricity generation and freshwater production is beneficial for both the power and the freshwater systems. For example, producing excess freshwater at hours of low electricity production cost and storing it for usage at hours of high electricity production cost is economically advantageous. We use detailed models for the operation of the power and freshwater systems. That is, the power system operation is represented through a network-constrained unit commitment model, while the freshwater system model includes nonlinear representations of the freshwater production and transportation. The resulting problem is computationally intractable for large-scale systems. To achieve tractability, nonlinearities in the freshwater model are linearized. The final model is a tractable mixed-integer linear optimization problem that is solved using a state-of-the-art branch-and-cut solver. Simulation results demonstrate that a coordinated scheduling results in lower cost and lower peak as compared with uncoordinated scheduling.

The Rationality of Oaths in Armed Struggle: A Dynamic Model of Commitment and the Mau Mau Insurgency (1952–1956)

In this paper, we develop the rationality of oath giving and the socially functional role that oaths can play in securing the commitment of members of conflict groups. Oaths are a reoccurring feature of insurgencies, armed struggles, and revolutionary movements. Oaths grow out of a general set of cultural practices that leverage superstitious beliefs to perform socially valuable functions and to produce normative conformity within groups. Applied to insurgencies, we argue that swearing oaths can motivate and sustain commitment to a cause. We apply our theory to the case of the Mau Mau rebellion in which oaths played a conspicuous role. Originally carrying religious meaning among Kenyan tribes, Mau Mau leaders repurpose oathings to enhance commitment. In its repurposed form, oathing incentives relied less on supernatural sanctions and more on credibly threatening defectors with physical in-group and out-group punishment. The Mau Mau highlights how an old cultural form can be used to ground innovations and how superstition-based practices that confer group benefits might continue to do so by permitting the creation of worldly incentives even after (or when) the superstition is stripped from them.

Intrinsic and extrinsic religious orientation as a moderator of key predictors of romantic relationship commitment

Religious individuals often assume that their beliefs promote strong romantic relationships. Yet the empirical evidence is mixed. To better understand this association, this study examined religious orientation as a moderator within the investment model of commitment. A community sample of 84 couples completed measures on religious orientation and commitment as part of a larger study on romantic relationships. The findings indicate that although both religious motivations promote commitment, they do so differently. Specifically, intrinsic religious orientation buffered the negative effects of dissatisfaction in a relationship; whereas an extrinsic religious orientation attenuated the extent to which alternatives to the relationship influenced commitment. Future research in this area should consider religious orientation, rather than overall religiosity, and examine specific predictors of relationship commitment to provide greater clarity on how religiosity influences romantic relationships. Implications for counseling individuals with religious beliefs are also discussed.