49 research outputs found

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

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    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

    The Nodal Market Power Index (NMP Index) for Modelling and Visualising Market Power

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    This paper deals with a systematic way for modelling and visualising market power in liberalised electricitymarkets. The paper first introduces a new index termed the “Nodal Market Power” index, the NMP index. The NMP index is calculated based on the concept of “social welfare” in economics and the game theory in applied mathematics. The oligopoly electricity market is modelled through a non-cooperative game and the solution concept of the Nash equilibrium. The solution concept of Nash equilibrium is reformulated as an optimisation problem. To tackle the multiple Nash equilibria problem, the worst Nash equilibrium in terms of the social cost to the society is selected. Then after, the NMP index is calculated for each node of power system. A colour contour map is used for visualising the market power using the NMP index

    Economic assessment of transmission expansion projects in competitive electricity markets - an analytical review

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    Restructuring of the electricity market has changed many aspects of the transmission system operation and planning. Reliability-Driven and Economic-Driven transmission expansion planning by regulated and private utilities are the substitutes of the traditional Cost-Driven transmission expansion planning. Reliability-based criteria for assessment of the transmission projects are almost well-developed while there exists a lack of a comprehensive framework for the economic evaluation of the transmission projects. Definition of a quantitative and monetary framework for economic evaluation of future transmission projects demands a detailed market analysis. In addition, specific characteristics and responsibilities of the transmission system in the open access structure must be understood comprehensively. To reaching the aforementioned goal, an analytical review on the existing economic assessment methodologies would be highly beneficial for the researchers in this area. Moreover, most of the review literatures on transmission investment in competitive electricity markets are general. These review literatures have tried to address all aspects of this challenging issue with devoting only few paragraphs to economic assessment of transmission projects. Given the aforementioned shortcomings, this article would bridge the gap by the following contributions: Firstly, reviewing available approaches for economic assessment of transmission projects based on research papers and industrial reports, Secondly, analysing the reviewed criteria critically by applying them to a modified Wood and Wollenberg 6-bus case study and Finally, summarizing the key components of a successful Economic Assessment Framework for transmission expansion or upgrade projects. Practical experiences of California Electricity Market, New England Electricity Market, Pennsylvania, New Jersey, and Maryland (PJM) and National Electricity Market, Australia have been accommodated in the article

    Transmission Augmentation in an Oligopoly Electricity Market - Part II (Numerical Studies)

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    This paper proposes a Three-Stage Model for transmission augmentation in restructured electricity markets. The mathematical formulation of the model is developed based on the game theory. Transmission Network Service Provider, TNSP, Generating Companies, GenCos, and Market Management Company, MMC, are placed in different stages of the model. These stages are linked to each other using the Leader-followers game and the concept of Nash equilibriums. An increase in transmission capacity can have two benefits for the electricity market; firstly, efficiency benefit in terms of improving the social surplus of the electricity industry, and, secondly, competition benefit which leads to increasing competition among generating companies. The introduced Three-Stage Model can capture both benefits of transmission projects in electricity markets. An effective numerical method is designed for solving the developed Three-Stage Model. A modified IEEE 14 example system is employed to show the effectiveness of the methodology. This paper has been organized in two parts. First part deals with the mathematical formulation of the algorithm and second part deals with the numerical studies. What follows is the second part of the paper

    Derivation of a mathematical structure for market-based transmission augmentation in oligopoly electricity markets using multilevel programming

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    In this paper, we derive and evaluate a new mathematical structure for market-based augmentation of the transmission system. The closed-form mathematical structure can capture both the efficiency benefit and competition benefit of the transmission capacity. The Nash solution concept is employed to model the price-quantity game among GenCos. The multiple Nash equilibria of the game are located through a characterisation of the problem in terms of minima of the R function. The worst Nash equilibrium is used in the mechanism of transmission augmentation. The worst Nash equilibrium is defined as the one which maximises the social cost, total generation cost + total value of lost load. Thorough analysis of a simple three-node network is presented to clearly highlight the mechanism of the derived mathematical structure from different perspectives

    Role of the BANYULS(BAN) Gene from Arabidopsis Thaliana in Transgenic Alfalfa Expression of Anthocyanins and Proanthocyanidins

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    Condensed tannins (CTs) are flavonoid oligomers, many of which have beneficial effects on animal (bloat safe) and human health. The BAN gene encodes anthocyanidin reductase (ANR), an enzyme proposed to convert anthocyanidins to their corresponding 2,3-cis-flavan-3-ols (Xie et al., 2003). Ectopic expression of BAN in Alfalfa transgenic foliage results in accumulation of CTs. Thus, it has been assumed that the BAN gene also acts in starter units for the condensation of tannins in Alfalfa

    Economic Transmission Augmentation With Explicit Modeling of the Competition Benefit

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    This paper derives and evaluates a mathematical structure for identifying economically-efficient transmission augmentations. The mathematical structure is based on the concepts of sequential-move and simultaneous-move games in applied mathematics. The Nash equilibrium solution concept has been reformulated as an optimization problem in the proposed structure. The problem of multiple Nash equilibria is managed by introducing the concept of the worst-case Nash equilibrium. Both the economic concepts of the "efficiency benefit" and "competition benefit" of the transmission capacity are explicitly modeled in the proposed structure. A simple three-bus example system and Garver's example system are employed and modified to suit the purpose of analysis. A thorough economic study of these example systems is presented to highlight the concept and operation of the proposed mathematical structure from different perspectives. The results demonstrate the utility of the proposed structure for measuring the total economic efficiency benefit of additional transmission capacity

    TSO-DSO Operational Coordination Using a Look-Ahead Multi-Interval Framework

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    With the rise of distributed energy resources and the increasing activation of flexibility resources by Distribution Systems Operators (DSOs), the Transmission System Operators (TSOs) need to co-ordinate their actions with those of the DSOs. This research uses a look-ahead multi-interval (LA-MI) framework for analyzing this coordination and explores two formulations. Firstly in the exogenous DSO model, a mixedinteger linear program is developed to reflect the pragmatic approach in many real situations whereby the TSO can only anticipate statistically the actions of the DSO. In the embedded DSO model, as a comparator, we propose a new organizational setup for the TSO-DSO operational coordination mechanism. In the resulting bilevel decomposition, a new method to calculate Benders cuts is developed and tested on a modified IEEE 118-bus test system as a transmission network and two modified IEEE 33-bus test systems as distribution networks. The benefits of the LAMI coordination framework are substantial in comparison with the current Look-Ahead Single-Interval (LA-SI) coordination framework widely used in Europe
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