A study of the operation efficiency and cost performance indices of power-supply companies in China based on a dynamic network slacks-based measure model

Omega ◽  
2016 ◽  
Vol 60 ◽  
pp. 85-97 ◽  
Author(s):  
Yan Q. You ◽  
Tao Jie
Keyword(s):  
Power Supply ◽  
Dynamic Network ◽  
Performance Indices ◽  
Cost Performance ◽  
Operation Efficiency ◽  
Measure Model

Does a Rubber Baseline Guarantee Cost Overruns on Defense Acquisition Contracts?

1998 ◽  
Vol 29 (3) ◽  
pp. 43-51 ◽  
Author(s):  
David S. Christensen ◽  
James A. Gordon
Keyword(s):  
Department Of Defense ◽  
Defense Acquisition ◽  
Performance Indices ◽  
Cost Performance ◽  
Cost Overruns ◽  
Significant Relationships ◽  
Defense Contract ◽  
Official Policy ◽  
Contract Type ◽  
The Stability

A common assertion in defense literature is that an unstable budget baseline contributes to cost overruns on defense acquisition contracts. Using cost performance data from over 400 defense acquisition contracts, we tested this assertion. The stability of the baseline was characterized by the number of significant changes to the budget, and by a statistical measure of the baseline's variability, the coefficient of variation. Cost performance was characterized by cost and schedule performance indices. Using 2 statistical methods, we found no significant relationships between baseline instability and cost overruns. Further, these results were insensitive to the managing service, the buying activity, and the contract type. Changes on a defense contract are not compelling rationale for cost overruns. Other possible causal factors should be more closely examined. The views expressed in this paper are those of the authors and do not reflect the official policy or position of the Department of Defense of the U.S. government.

scholarly journals Energy Efficiency and Cost Performance of Direct-Current Power Supply Systems in Residential Buildings by 2030s and 2050s

2019 ◽  
Vol 111 ◽  
pp. 04010
Author(s):  
Gyuyoung Yoon ◽  
Kyoko Sugiyama ◽  
Saya Yoshioka ◽  
Shinji Sakai
Keyword(s):  
Direct Current ◽  
Power Supply ◽  
Residential Buildings ◽  
Energy Price ◽  
Cost Performance ◽  
Dc Power ◽  
Study Results ◽  
Cost Reductions ◽  
Technological Developments ◽  
Supply Systems

In an effort to clarify the potential use and effectiveness of direct current (DC) power supply systems and further promote their usage, this study investigates the energy saving and cost performance characteristics of such a system for a detached house equipped with roof-mounted solar photovoltaic (PV) panels. Our evaluation considered different DC-powered appliances under different energy price conditions and made projections based on present, 2030s, and 2050s scenarios. Initial cost reductions were also considered based on assumed near-future technological developments. Our case study results show that the simple payback period is likely to be shortest in cases where DC power is only used for low-voltage appliances under present price conditions, when supplying DC power to cover interior space heating under the 2030s energy price scenario, and when covering all DC-powered appliances (including water heating) under the 2050s scenario. Taken together, these results indicate that it is desirable to set the introductory targets while projecting future energy price fluctuations and anticipating the cost reductions that will result from ongoing technological developments.

scholarly journals The Effects of Nonperforming Loans on Dynamic Network Bank Performance

2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Day-Yang Liu ◽  
Ya-Chiang Wu ◽  
Cheng-Hsien Lin ◽  
Wen-Min Lu
Keyword(s):  
Risk Management ◽  
Production Process ◽  
Banking Sector ◽  
Influencing Factor ◽  
Dynamic Network ◽  
Holding Companies ◽  
Nonperforming Loans ◽  
Measure Model ◽  
Financial Holding ◽  
Financial Holding Companies

This paper is to explore the relationship between banks’ performance and their nonperforming loans (NPLs). The banks’ performance through a network production process structure with NPLs is developed. With increasing NPLs in recent years, the quality of lending assets is a key significant and influencing factor for banks’ operational risk. The research methodology is to integrate the radial and nonradial measures of efficiency into the network production process framework with NPLs; this study utilizes network epsilon-based measure model to evaluate the banking industry performance. In addition, the key characteristics of the bank industry including those of financial holding companies and privatized government banks are needed to be figured out and to provide insight into what causes imperfectly competitive conditions for some banks. The results demonstrate that the banking sector grew consistently in three aspects of operation: operating performance, profitability performance, and risk management in the last five years of the subject period. These results showed that the overall banking sector was capable of pursuing growth in both operations and profits while accounting for risk management. The potential applications and strengths of network data envelopment analysis in assessing financial organizations are also highlighted.

scholarly journals Analysis of Photovoltaic & Battery Energy Storage System Impacts on Electric Distribution System Efficacy

2020 ◽  
Vol 12 (4) ◽  
pp. 1001-1015
Author(s):  
Kumari Kasturi ◽  
◽  
Chinmay Kumar Nayak ◽  
Ranjan Nayak ◽  
◽  
...  
Keyword(s):  
Power Supply ◽  
Distribution System ◽  
Power Loss ◽  
Power Flow ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Performance Indices ◽  
Battery Energy Storage ◽  
Technical Performance ◽  
Battery Energy

Uncertain nature of renewable energy sources like solar irradiation poses a serious concern of loss of power supply reliability. Battery energy storage (BES) system helps in improving system reliability by storing surplus energy generated and supplying the load in case of energy deficit. Thus BES allows improvement of microgrid performance and reduces operational cost by increasing the utilization of renewable energy sources. This paper presents an energy management strategy (EMS) to dictate the power flow among photovoltaic (PV) panels, BES and the load considering a proposed time-of-use (TOU) pricing as the control factor. Its efficacy in improving power supply reliability as well as power quality issues of a 69-bus radial distribution system (RDS) is evaluated from technical performance indices like power loss, voltage deviation index and security margin and economic performance considering costs of power import from the grid and active power loss and financial benefit from battery discharge. Grasshopper Optimization Algorithm (GOA), is used to optimize the sizes and placements of three PV-BES units to minimize an objective function aptly formulated combining the technical performance indices using weighted sum method. The results are contrasted against another two cases of with only PV and without PV and BES integration. Finally, the proposed system is analysed from economic perspective and the benefits obtained are compared. The results are evident of both technical and economic advantages of integrating both PV and BES units at optimal locations (load bus). The optimization results obtained from GOA have been compared with that from Genetic Algorithm (GA). GOA proves to be fast, effective and reliable in resolving power flow optimization problem.

Reliability as a Figure of Merit

2016 ◽  
pp. 231-261
Keyword(s):  
Electric Power ◽  
Design Process ◽  
Power Supply ◽  
System Performance ◽  
Figure Of Merit ◽  
High Efficiency ◽  
Power Converter ◽  
Good Choice ◽  
Performance Indices ◽  
Reliability Based Design

An electric power converter is specified by its system performance indices. Many system performance indices like efficiency are important in design process of system. However, that doesn't mean the converter performance is necessarily adequate for a practical application. At the end of design process of a converter, some desired specifications may not be achieved. In this chapter, reliability as a figure of merit in design of a system is presented and compared with other indices. We want to highlight the effect of reliability considerations on the design methodology of a power converter. The most important specification of a power supply or power converter is its robustness. Because any failure in power supply leads to failure of the whole of the system. A power converter may have poor performance but operate reliably and vice versa. In fact, this is a reliability based design approach to achieve a long useful life. It is shown that in many systems, high efficiency is not a good choice for selection of system operating point. A system can be inefficient but very reliable. Two complex examples are presented to show undesired results of neglecting reliability in design process. Methods for more reliable operation of electric power converters than high performance operation are proposed. A discussion about correct and intelligent optimization of a system parameters and operating set point is presented.

scholarly journals Instrumental monitoring of the vehicle charging balance

2020 ◽  
Vol 17 (5) ◽  
pp. 199-205
Author(s):  
A. V. Puzakov ◽  
Keyword(s):  
Power Supply ◽  
Power Supply System ◽  
Engine Speed ◽  
Technical Condition ◽  
Efficiency Factor ◽  
Supply System ◽  
Data Logger ◽  
Operation Efficiency ◽  
Automotive Alternator ◽  
Instrumental Control

The instrumental control of the charging balance makes it possible to quickly assess the efficiency and technical condition of the components of the vehicle power supply system. Factors have been developed that allow assessing the technical condition of the automobile alternator (efficiency factor) and its operation efficiency at the current combination of load and engine speed. The main parameters of the power supply system were measured using a four-channel analog data logger. Further research will be aimed at identifying the changes in the charging balance of the vehicle in case of failures of the automotive alternator and accumulator starting battery.

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