Critical Contingencies Ranking for Dynamic Security Assessment Using Neural Networks

A number of contingencies simulated during dynamic security assessment do not generate unacceptable values of power system state variables, due to their small influence on system operation. Their exclusion from the set of contingencies to be simulated in the security assessment would achieve a significant reduction in computation time. This paper defines a critical contingencies selection method for on-line dynamic security assessment. The selection method results from an off-line dynamical analysis, which covers typical scenarios and also covers various related aspects like frequency, voltage, and angle analyses among others. Indexes measured over these typical scenarios are used to train neural networks, capable of performing on-line estimation of a critical contingencies list according to the system state.

Integrated coordination scheduling framework of electricity-natural gas systems considering electricity transmission N—1 contingencies and gas dynamics

This paper discusses a security-constrained integrated coordination scheduling framework for an integrated electricity-natural gas system(IEGS),in which both tight interdependence between electricity and natural gas transmission networks and their distinct dynamic characteristics at different timescales are fully considered.The proposed framework includes two linear programming models.The first one focuses on hour-based steady-state coordinated economic scheduling on power outputs of electricity generators and mass flow rates of natural gas sources while considering electricity transmission N-1 contingencies.Using the steady-state mass flow rate solutions of gas sources as the initial value,the second one studies second-based slow gas dynamics and optimizes pressures of gas sources to ensure that inlet gas pressure of gas-fired generator is within the required pressure range at any time between two consecutive steady-state scheduling.The proposed framework is validated via an IEGS consisting of an IEEE 24-bus electricity network and a15-node 14-pipeline natural gas network coupled by gasfired generators.Numerical results illustrate the effectiveness of the proposed framework in coordinating electricity and natural gas systems as well as achieving economic and reliable operation of IEGS.

Allocation of a Variable Series Reactor Considering AC Constraints and Contingencies

The Variable Series Reactors(VSRs)can efficiently control the power flow through the adjustment of the line reactance.When they are appropriately allocated in the power network,the transmission congestion and generation cost can be reduced.This paper proposes a planning model to optimally allocate VSRs considering AC constraints and multi-scenarios including base case and contingencies.The planning model is originally a non-convex large scale mixed integer nonlinear program(MINLP),which is generally intractable.The proposed Benders approach decomposes the MINLP model into a mixed integer linear program(MILP)master problem and a number of nonlinear subproblems.Numerical case studies based on IEEE 118-bus demonstrate the high performance of the proposed approach.

Self-Compassion Moderates the Effect of Contingent Self-Esteem on Well-Being:Evidence from Cross-Sectional Survey and Experiment

Contingent self-esteem captures the fragile nature of self-esteem and is often regarded as suboptimal to psychological functioning.Self-compassion is another important self-related concept assumed to promote mental health and well-being.However,research on the relation of self-compassion to contingent self-esteem is lacking.Two studies were conducted to explore the role of selfcompassion,either as a personal characteristic or an induced mindset,in influencing the effects of contingent self-esteem on well-being.Study 1 recruited 256 Chinese college students(30.4%male,mean age=21.72 years)who filled out measures of contingent self-esteem,self-compassion,and well-being.The results found that self-compassion moderated the effect of contingent self-esteem on well-being.In Study 2,a sample of 90 Chinese college students(34%male,mean age=18.39 years)were randomly assigned to either a control or self-compassion group.They completed baseline trait measures of contingent self-esteem,self-compassion,and self-esteem.Then,they were led to have a 12-min break(control group)or listen to a 12-min self-compassion audio(self-compassion group),followed by a social stress task and outcome measures.The results demonstrated the effectiveness of the brief self-compassion training and its moderating role in influencing the effects of contingent self-esteem on negative affects after the social stress task.This research provides implications that to equip with a self-compassionate mindset could lower the risk of the impairment of well-being associated with elements of contingent selfesteem,which involves a fragile sense of self-worth.It may also provide insights into the development of an“optimal selfesteem”and the improvement of well-being.

Preserving environmental quality of ecotourism sites through community participation in Purulia District of West Bengal,India

The importance of valuing environmental resources,especially in ecotourism sites,has become increasingly important over the last two decades.Ecotourism is now considered as an important source of livelihood of local stakeholders in backward regions.Therefore,the preservation of ecotourism sites through community participation seems very important to maintain continued flow of tourists.This study aimed at recognizing the importance of community participation for the preservation of ecotourism sites.For this,this study executed a survey based on non-probability sampling in two ecotourism sites(Garpanchkot and Baranti)covering 100 respondents in Purulia District,West Bengal of India.The central issue of this study was to assess the tendency of community participation for the conservation of ecotourism sites and find the optimum condition for offering participatory labour time.This study showed that the participation of young people is high,and the majority of respondents are aware of the importance in protecting ecotourism sites.Because respondents were too poor to offer money,the contingent valuation method(CVM)was used to elicit their willingness to pay(WTP)participatory labour time for the conservation of ecotourism sites.Respondents’age,income,education level,caste,and their perceived environmental quality had significant relationship with their WTP participatory labour time by applying the ordinary least square(OLS)model.It was found that the mean WTP participatory labour time of each respondent in a month is approximately 3.64 h.The significance of this study is that community participation can improve the sense of belonging,trust,and credibility of ecotourism sites,making them more appreciative of the value and protection of these sites.

Estimating the value of a statistical life in China: A contingent valuation study in six representative cities

The value of a statistical life(VSL)is a crucial tool for monetizing health impacts.To explore the VSL in China,this study examines people’s willingness to pay(WTP)to reduce death risk from air pollution in six representative cities in China based on face-to-face contingent valuation interviews(n=3936)from March 7,2019 to September 30,2019.The results reveal that the WTP varied from CNY 455 to 763 in 2019(USD 66-111),corresponding to a VSL range of CNY 3.79-6.36 million(USD 549395-921940).The VSL in China in 2019 is estimated to be CNY 4.76 million(USD 689659).The statistics indicate that monthly expenditure levels,environmental concerns,risk attitudes,and assumed market acceptance,which have seldom been dis‐cussed in previous studies,significantly impact WTP and VSL.These findings will serve as a reference for ana‐lyzing mortality risk reduction benefits in future research and for policymaking.

Machine Learning for Hybrid Line Stability Ranking Index in Polynomial Load Modeling under Contingency Conditions

In the conventional technique,in the evaluation of the severity index,clustering and loading suffer from more iteration leading to more com-putational delay.Hence this research article identifies,a novel progression for fast predicting the severity of the line and clustering by incorporating machine learning aspects.The polynomial load modelling or ZIP(constant impedances(Z),Constant Current(I)and Constant active power(P))is developed in the IEEE-14 and Indian 118 bus systems considered for analysis of power system security.The process of finding the severity of the line using a Hybrid Line Stability Ranking Index(HLSRI)is used for assisting the concepts of machine learning with J48 algorithm,infers the superior affected lines by adopting the IEEE standards in concern to be compensated in maintaining the power system stability.The simulation is performed in the WEKA environment and deals with the supervisor learning in order based on severity to ensure the safety of power system.The Unified Power Flow Controller(UPFC),facts devices for the purpose of compensating the losses by maintaining the voltage characteristics.The finite element analysis findings are compared with the existing procedures and numerical equations for authentications.

Contribution to Asymmetrical Compensation through Parallel Controllers of FACTS (STATCOM)—IPC 240 Dual for a Power Transmission Line

This work is part of the resolution of problems encountered on a 225 KV MANGOMBE-OYOMABANG line. This line is characterized by important technical losses, so that the voltage injected in the busbar is always lower than 200kV. The main objective of this work is to show the new solutions that can provide a combined FACTS-STATCOM and IPC 240 dual system on this line. Then to show the limitation of STATCOM compared to RPI 240. The results obtained allowed us to observe that in symmetrical operation the STATCOM improves the voltage profile on the busbar and in asymmetrical operation we found that it continues to regulate the voltage of each phase despite the unbalance. But the system remains too unbalanced because of the sequence current flow. The IPC 240 corrects this limitation, allowing asymmetrical operation of the line in an emergency while providing continuous service to the load.

Operations Improvement Function and Organisational Adaptability of Petroleum Tank Farms in South-South, Nigeria

The study examined the nexus between operations improvement function (dimensioned by contingency planning, benchmarking and continuous improvement processes) and organisational adaptability of Petroleum tank farms in South-South, Nigeria. The contingency theory and the theory of routine dynamics underpinned the study, and positivism was the underlying philosophy. The study adopted the cross-sectional survey through the use of questionnaire. 820 middle and top-level managers constituted the elements of the population, and the Krejcie & Morgan’s formula was used to determine the sample size of 262 respondents. Structural Equation Modeling was deployed to test the hypotheses at a 0.05 significance level. The results showed that contingency planning;benchmarking and continuous improvement processes all have a significant positive relationship with organisational adaptability of Petroleum tank farms in South-South, Nigeria. The study concludes that Petroleum tank farms’ operations should focus on the adoption of contingency planning, benchmarking and continuous improvement processes to enhance organisational adaptability. Therefore, it is recommended that the management of Petroleum tank farms should put in place mechanisms to advance continuous improvement processes by allocating the necessary amount of resources, such as energy, time and money, in order to promote the continuous development of the continuous improvement systems. Furthermore, managers of Petroleum tank farms should make better the adoption of contingency planning, ensuring that there is as much necessary training and information for employees on how to act during a crises situation, in order to evaluate safety and prepare in advance for recovery from disasters.

向量集值优化超有效解的对偶问题

借助于Contingent切锥和集值映射的上图而引入的有关集值映射的Contingent切导数, 对约束集值优化问题的超有效解建立了最优性Kuhn-Tucker必要及充分性条件,借此建立了 向量集值优化超有效解的Wolfe型和Mond-Weir型对偶定理.

集值映射的超有效广义梯度

在Hausdorff局部凸拓扑线性空间中,对于集值优化问题(SOP),利用contingent上图切导数,引进了集值映射超有效意义下的广义梯度,在目标函数为锥类凸的集值映射并且具有连通性条件下,利用凸集分离定理和contingent上图切导数,证明了集值映射超有效广义梯度的存在性,得到了集值映射超有效广义梯度的等价刻画等定理。

两期交换经济Contingent资产市场的指标公式

给出了均衡流形的定向，推导出了两期交换经济Contingent资产市场的指标公式，并证明了该资产市场的均衡存在．从而证实了M．Magill“当均衡流形可定向，且Incometransfers矩阵V（p,s）是满秩阵时，可以得到定向映射度的指标公式”的推测．

弱有效意义下向量集值优化的Kuhn-Tucker条件与对偶

借助于由广义Contingent切锥并用上图而引入有关集值映射的Contingent切导数,对约束集值优化问题的弱有效解建立了Kuhn-Tucker必要及充分性条件,由此建立了向量集值优化弱有效解的Welfe型和Mond-Weir型对偶的弱定理、正定理及逆定理。

Banach空间中优化问题的最优性条件

首先在 Contingent切锥意义下界定了 Banach空间中非空集合的伪切锥和伪凸性的概念 ,并讨论了相应的性质 ;然后针对可微优化问题 ,在广义凸性假设下 。

Evaluation on Non-use Value of Dianchi Lake Wetland Using CVM

[Objective] This study was to analyze the personal Willingness to Pay （WI-P） on the non-use value of Dianchi lake wetland and the influential factors. [Method] Questionnaire was designed according to the Contingent Valuation Method （CVM） to investigate people of different occupations at different ages, based on which the evaluation on non-use value of Dianchi lake wetland was carried out. And the relationship between WTP and social characteristics were analyzed by using non- parametric estimation. [Result] The average WTP on Dianchi lake wetland is 150.03- 217.66 yuan per person every year, and the total WTP is 626-909 million yuan ev- ery year. Age, education and residence of the respondents have remarkable influ- ence on the VVTP. The influence of education level and residence on option value is significant; bequest value is significantly correlated with age; while there is no significant relationship between existence value and social characteristics. [Conclusion] The evaluation on the non-use value of Dianchi lake wetland is important for the scientific development and utilization of wetland resources.

广义梯度和ε-严有效解的最优性条件

在锥序Banach空间中引入了集值映射ε-严有效意义下的广义梯度.在连通性条件下,利用凸集分离定理证明了该广义梯度的存在性.作为应用,给出了用广义梯度刻画集值优化问题ε-严有效解的充分和必要条件.

向量集值函数松弛型弱有效鞍点元的存在性

借助于向量集值函数的 Contingent切导数建立了松弛型弱有效鞍点元存在的必要及充分性条件。

Hospitalization Can Correct Behavioral Feeding Disorders in Children by Resetting the Pedagogic Climate

Background: Behavioral feeding disorders are common among children, which sometimes become progressive, and consequently, children may refuse to eat anything. Parents have lots of difficulties to reset such a disturbed eating pattern. The aim of this study was to perform an analysis of clinical intervention in behavioral feeding disorders in young children. Methods: We conducted a retrospective analysis of data of 28 children aged 1 - 9 years with behavioral feeding disorders. A pediatrician and pediatric social worker conducted the training in two groups: outpatient or inpatient setting. Both groups were treated with parental education and guidance. The inpatient group also had a temporarily (2 weeks) resetting of the pedagogic climate in a pediatric ward of a general hospital under guidance of a pediatric social worker. Results: Almost all parents were inconsistent in applying appropriate behavioral contingencies during meals. Eleven patients followed 8 months of outpatient treatment and 25 patients followed 2 weeks of inpatient treatment. The overall success rate of outpatient treatment after 2 weeks was 18%, and that of inpatient treatment after 8 months was 88%. The corrected relapse rates are 18% and 56% respectively after 6 months. Conclusion: Short clinical intervention in a structured pedagogic environment is a successful treatment in behavioral feeding disorders. Herewith, pediatricians have a powerful tool for treating behavioral feeding disorders by temporarily resetting and changing the pedagogic climate.

Demand and Response in Smart Grids for Modern Power System

Micro-grid plays a vital role in fulfilling the increasing demand by using distributed renewable energy resources. Demand and response technique can be broadly classified under the setup DR deployed (e.g. ISO’s/RTO’s). Demand response program can be implemented to improve power system quality, reliability and increasing demand. In modern power industry, strategic player can take more benefit from more emphasized DR study in terms of social benefit (uninterrupted power supply to consumers) and economy. This paper proposes the distributed micro-grid control and implemented control setup implemented demand response algorithm, which provides better power system reliability. This paper presents contingencies control demand and response for micro-grid. The main advantage of implementation of demand and response algorithms in Micro-grids provides reliable power supplies to consumers. The proposed micro-grid TCP/IP setup provides a chance to respond the contingencies to recover the shed to active condition. Micro-grid controller implements demand and response algorithm reasonable for managing the demand of the load and intelligent load scheme in case of blackout.

向量集值优弱有效解的Kuhn-Tucker条件(英文)

借助于 Contingent切导数建立了向量集值优化弱有效解的 Kuhn- Tucker条件 ,而且在某些凸性的要求下证明这一条件还为充分的 .