Public and Private Hospital Nurses' Perceptions of the Ethical Climate in Their Work Settings, Sari City, 2011

Background: Nurses’ perceptions of ethical climate patterns have certain undeniable effects on hospitals. There is little evidence of possible differences in this element between public and private hospitals and contributing factors. Objectives: This study investigated whether the perceptions of the ethical climate in nurses’ working in public hospitals differ from that of nurses in private hospitals, and which factors may affect nurses’ perceptions. Materials and Methods: A cross-sectional study of randomly selected registered nurses (n = 235), working in four public hospitals affiliated to Mazandaran University of Medical Sciences, and three private hospitals, was conducted in Sari City, Iran. A self-administered questionnaire, containing demographic characteristics and the Hospital Ethical Climate Survey (HECS), were used to assess registered nurses’ perceptions of public and private hospitals ethical climate. An independent t-test and one-way ANOVA were used to analyze the data. Results: Across the five factors of HECS, the highest and lowest mean scores pertained to managers and physicians, respectively, in both public and private hospitals. Nurses who had a conditional employment situation and those working in pediatric intensive care units showed significantly more positive perceptions of the ethical work climate when compared to their peers (P < 0.05). Although the mean score of ethical work climate in private hospitals (3.82 ± 0.61) was higher than that in public hospitals (3.76 ± 0.54), no significant difference was found (P = 0.44). Conclusions: Hospital managers need to discover better ways to promote safety and health programs for their staff according to nurses’ area of work and their type of units. They should also encourage greater levels of participation in safety-enhancing initiatives in the hospital’s ethical climate, especially in the areas of nurses’ perceptions of their physician colleagues, and for nurses with a conditional employment situation

A Novel Hybrid Optimization Procedure for Distribution Capacitor Placement with Varying Load Condition

ABSTRACT A combination of fuzzy logic, genetic algorithm and dynamic programming has been applied to optimize the problem of capacitor placement on distribution feeders. The cost function consists of three terms: the total cost of energy loss, the total cost of capacitors, including the purchase and installation costs, and one constant term related to total cost of produced power in peak load condition. A multi-objective and non-differentiable optimization problem is formulated. The proposed method of this article uses fuzzy reasoning for siting of capacitors, optimized by genetic algorithm, which finds the optimum weighting factors of fuzzy membership functions. Dynamic programming is used for sizing of the capacitors. Varying load condition of the distribution system has been considered in the optimization problem. The proposed method has been implemented in a software package and its effectiveness has been verified on a 34-bus radial distribution feeder, as a practical case study. A comparison has been made between the proposed method of this paper and similar methods in other research works, which shows the effectiveness of the proposed method of this paper for solving optimum capacitor planning problem

A novel modeling approach for exploring the effects of UPFC on restructured electricity market

Abstract— A new steady state modeling of unified power flow controller (UPFC) is proposed in this paper. Using this model, factors that affect the objective function of electricity market as a result of UPFC installation in power grid has been decomposed into four components, including line series impedance increase, shunt reactive power compensation, in-phase component of series voltage and quadrature component of series voltage. A UPFC has been placed in different points of a test system and impact of each component on objective function of electricity market has been measured by simulation and compared with results from analytical method. Both active and reactive power spot prices are calculated and their relation with settings of UPFC series part has been studied. Also, numerical results shows that the necessary cost to improve security of electricity market decreases by UPFC installation

A New Approach for Solving Linear Bilevel Programs Based on Parameter-Free Disjunctive Decomposition

Several engineering problems are modeled as linear bilevel programs (linear BLPs) where one problem (upper-level problem) has constrained variables which are optimal solutions of another problem (lower-level problem). The well-known single-level reformulation approach replaces the lower-level linear program with its Karush-Kuhn-Tucker optimality conditions and then linearizes the complementary slackness conditions employing the big-M technique. Although this approach is relatively simple and upstanding, it requires finding the disjunctive parameters (big-M). Regularly heuristic techniques are used to tune the big-M parameters. It is well-known that these techniques could fail, even though they are common. Finding the correct big-M parameters is computational challenging and it is recently shown to be NP-hard in several applications. This research presents a new parameter-free disjunctive decomposition algorithm tailored for the linear BLPs which (1) does not need finding the big-M parameters, (2) guarantees that the obtained solution is optimal to the given linear BLP, and (3) it is computationally advantageous. Our experience shows promising performance of the proposed algorithm in solving several linear BLPs.QC 20210629</p

An optimal load shedding approach for distribution networks with DGs considering capacity deficiency modeling of bulked power supply

This paper discusses a genetic algorithm (GA) based optimal load shedding that can apply for electrical distribution networks with and without dispersed generators (DG). Also, the proposed method has the ability for considering constant and variable capacity deficiency caused by unscheduled outages in the bulked generation and transmission system of bulked power supply. The genetic algorithm (GA) is employed to search for the optimal load shedding strategy in distribution networks considering DGs in two cases of constant and variable modelling of bulked power supply of distribution networks. Electrical power distribution systems have a radial network and unidirectional power flows. With the advent of dispersed generations, the electrical distribution system has a locally looped network and bidirectional power flows. Therefore, installed DG in the electrical distribution systems can cause operational problems and impact on existing operational schemes. Introduction of DGs in electrical distribution systems has introduced many new issues in operational and planning level. Load shedding as one of operational issue has no exempt. The objective is to minimize the sum of curtailed load and also system losses within the frame-work of system operational and security constraints. The proposed method is tested on a radial distribution system with 33 load points for more practical applications

Application of a new hybrid optimization method for optimum distribution capacitor planning

Abstract--This work presents a new algorithm based on a combination of fuzzy (FUZ), Dynamic Programming (DP), and Genetic Algorithm (GA) approach for capacitor allocation in distribution feeders. The problem formulation considers two distinct objectives related to total cost of power loss and total cost of capacitors including the purchase and installation costs. The novel formulation is a multi-objective and non-differentiable optimization problem. The proposed method of this article uses fuzzy reasoning for sitting of capacitors in radial distribution feeders, DP for sizing and finally GA for finding the optimum shape of membership functions which are used in fuzzy reasoning stage. The proposed method has been implemented in a software package and its effectiveness has been verified through a 9-bus radial distribution feeder for the sake of conclusions supports. A comparison has been done among the proposed method of this paper and similar methods in other research works that shows the effectiveness of the proposed method of this paper for solving optimum capacitor planning problem

A novel modeling approach for exploring the effects of UPFC on restructured electricity market

Abstract— A new steady state modeling of unified power flow controller (UPFC) is proposed in this paper. Using this model, factors that affect the objective function of electricity market as a result of UPFC installation in power grid has been decomposed into four components, including line series impedance increase, shunt reactive power compensation, in-phase component of series voltage and quadrature component of series voltage. A UPFC has been placed in different points of a test system and impact of each component on objective function of electricity market has been measured by simulation and compared with results from analytical method. Both active and reactive power spot prices are calculated and their relation with settings of UPFC series part has been studied. Also, numerical results shows that the necessary cost to improve security of electricity market decreases by UPFC installation