The overall efficiency of the dynamic DEA models

2021 ◽  
Author(s):  
Petra Zýková
Keyword(s):  
Dea Models ◽  
Overall Efficiency

Measuring Performance of a Three-Stage Network Structure Using Data Envelopment Analysis and Nash Bargaining Game: A Supply Chain Application

2018 ◽  
Vol 17 (05) ◽  
pp. 1429-1467 ◽  
Author(s):  
Mohammad Amirkhan ◽  
Hosein Didehkhani ◽  
Kaveh Khalili-Damghani ◽  
Ashkan Hafezalkotob
Keyword(s):  
Supply Chain ◽  
Data Envelopment Analysis ◽  
Nash Bargaining ◽  
Data Envelopment ◽  
Second Stage ◽  
Proposed Model ◽  
Nash Bargaining Game ◽  
Dea Models ◽  
Overall Efficiency

The issue of efficiency analysis of network and multi-stage systems, as one of the most interesting fields in data envelopment analysis (DEA), has attracted much attention in recent years. A pure serial three-stage (PSTS) process is a specific kind of network in which all the outputs of the first stage are used as the only inputs in the second stage and in addition, all the outputs of the second stage are applied as the only inputs in the third stage. In this paper, a new three-stage DEA model is developed using the concept of three-player Nash bargaining game for PSTS processes. In this model, all of the stages cooperate together to improve the overall efficiency of main decision-making unit (DMU). In contrast to the centralized DEA models, the proposed model of this study provides a unique and fair decomposition of the overall efficiency among all three stages and eliminates probable confusion of centralized models for decomposing the overall efficiency score. Some theoretical aspects of proposed model, including convexity and compactness of feasible region, are discussed. Since the proposed bargaining model is a nonlinear mathematical programming, a heuristic linearization approach is also provided. A numerical example and a real-life case study in supply chain are provided to check the efficacy and applicability of the proposed model. The results of proposed model on both numerical example and real case study are compared with those of existing centralized DEA models in the literature. The comparison reveals the efficacy and suitability of proposed model while the pitfalls of centralized DEA model are also resolved. A comprehensive sensitivity analysis is also conducted on the breakdown point associated with each stage.

scholarly journals A Revised Inverse Data Envelopment Analysis Model Based on Radial Models

Mathematics ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 803
Author(s):  
Xiaoyin Hu ◽  
Jianshu Li ◽  
Xiaoya Li ◽  
Jinchuan Cui
Keyword(s):  
Data Envelopment Analysis ◽  
Efficiency Index ◽  
Data Envelopment Analysis Model ◽  
Data Envelopment ◽  
Analysis Model ◽  
Numerical Examples ◽  
Wide Range ◽  
Dea Models ◽  
Overall Efficiency ◽  
Decision Making Units

In recent years, there has been an increasing interest in applying inverse data envelopment analysis (DEA) to a wide range of disciplines, and most applications have adopted radial-based inverse DEA models. However, results given by existing radial based inverse DEA models can be unreliable as they neglect slacks while evaluating decision-making units’ (DMUs) overall efficiency level, whereas classic radial DEA models measure the efficiency level through not only radial efficiency index but also slacks. This paper points out these disadvantages with a counterexample, where current inverse DEA models give results that outputs shall increase when inputs decrease. We show that these unreasonable results are the consequence of existing inverse DEA models’ failure in preserving DMU’s efficiency level. To rectify this problem, we propose a revised model for the situation where the investigated DMU has no slacks. Compared to existing radial inverse DEA models, our revised model can preserve radial efficiency index as well as eliminating all slacks, thus fulfilling the requirement of efficiency level invariant. Numerical examples are provided to illustrate the validity and limitations of the revised model.

Study on Improving Overall Efficiency of Front-end Power Supplies by Employing Method of Surge Energy Recycling

2012 ◽  
Vol 132 (7) ◽  
pp. 684-690 ◽  
Author(s):  
Toshikazu Okubo ◽  
Hiroyuki Shoji ◽  
Hideho Yamamura ◽  
Shinobu Irikura ◽  
Naoki Maru
Keyword(s):  
Power Supplies ◽  
Front End ◽  
Overall Efficiency

Detection of giardia and cryptosporidium in marine waters

1995 ◽  
Vol 31 (5-6) ◽  
pp. 439-442 ◽  
Author(s):  
D. C. Johnson ◽  
K. A. Reynolds ◽  
C. P. Gerba ◽  
I. L. Pepper ◽  
J. B. Rose
Keyword(s):  
Health Risk ◽  
Tap Water ◽  
Polypropylene Fiber ◽  
Marine Waters ◽  
Sewage Discharge ◽  
Antibody Staining ◽  
Parasite Detection ◽  
Cartridge Filter ◽  
Overall Efficiency ◽  
Immunofluorescence Antibody

Raw sewage disposal in marine waters is a common practice in many countries. This practice raises health risk concerns of possible transmission of Giardia and Cryptosporidium. Both of these protozoa have been shown to be transmitted by recreational swimming. To date no studies have determined the efficiency of their detection and concentration in marine waters. This study evaluated the efficiency of their detection in tap water and from marine waters in Hawaii with two different filter types. This study compared a polypropylene fiber cartridge filter, DPPPY (1.0 μm nominal porosity) (Cuno, Meriden, CT) which is typically used for parasite detection and the Filterite negatively charged filter (0.45μm) (Filtemp Sales, Inc., Phoenix, AZ). The latter would allow for both viruses and parasites to be concentrated simultaneously. The organisms were removed from the filter by passing the eluent through the filters in the opposite direction of collection and detected by indirect immunofluorescence antibody staining specific for Giardia and Cryptosporidium. Processing was simpler and faster with the Filterite filter and the overall efficiency for both Giardia and Cryptosporidium detection was greater. These methods are currently being used for the detection of the oocysts and cysts at bathing beaches in Hawaii impacted by marine sewage discharge.

Optimising the Efficiency of Storm Water Settling Basins by Means of Bypassing

1993 ◽  
Vol 27 (5-6) ◽  
pp. 105-110 ◽  
Author(s):  
F. H. L. R. Clemens ◽  
H. J. van Mameren ◽  
J. Kollen
Keyword(s):  
Boundary Conditions ◽  
Dynamic Behaviour ◽  
Storm Water ◽  
Mixed System ◽  
Research Needs ◽  
Settling Basin ◽  
Potential Increase ◽  
Overall Efficiency ◽  
Further Development

The reduction in pollutional load realised by storm water settling basins is potentially reduced due to the occurrence of a partially mixed situation in the basin or due to resuspension of settled material. The decrease in efficiency can theoretically be avoided by means of partially bypassing the basin. In order to quantify the potential increase in efficiency a settling basin in Amersfoort is taken as an example. This basin seems to behave like an almost completely mixed system, bypassing would increase the overall efficiency from ca. 34 % to ca 39 % for three overflows. The dynamic behaviour of settling basins, scouring conditions and the boundary conditions for which settling basins are to be designed are the research needs for further development in the field of storm water settling basins.

scholarly journals 222 Partitioning of retained energy between protein and fat gain, and heat of product formation and support metabolism in growing beef cattle

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 158-158
Author(s):  
Phillip A Lancaster
Keyword(s):  
Linear Regression ◽  
Mixed Models ◽  
Multivariate Regression ◽  
Literature Search ◽  
Energy Use ◽  
Random Variable ◽  
Product Formation ◽  
Metabolizable Energy ◽  
Overall Efficiency ◽  
Metabolizable Energy Intake

Abstract Multiple linear regression inaccurately computes the efficiency of energy use for protein and fat gain. The objective was to quantify efficiency of metabolizable energy use for protein and fat gain along with heats of product formation and support metabolism. A literature search was performed to compile data (31 studies, 214 treatment means) on metabolizable energy intake (MEI) and composition of empty body gain in growing steers and heifers. Data analyses were performed using R statistical package for mixed models with study as random variable. Linear regression of MEI on energy gain (EG; P < 0.001; R2 = 0.627) resulted in an estimate of metabolizable energy for maintenance (MEm) of 156 kcal/kg.75 and efficiency of ME use for gain of 0.518. Linear regression of MEI on EG as protein and fat (P < 0.001; R2 = 0.623) resulted in an estimate of MEm of 149 kcal/kg.75, and efficiency of protein (kp) and fat (kf) gain of 0.274 and 0.585, respectively, resulting in an overall efficiency of EG of 0.520. Nonlinear regression model (EG = kg*(MEI-MEm)) resulted in an estimate of MEm of 103 kcal/kg.75 and efficiency of EG of 0.342. The heat of product formation was assumed to be 0.48 (1 – 0.52) and the heat of support metabolism (HiEv) 0.18 (0.52 – 0.34). Multivariate regression was used to fit simultaneous models for EG as protein (EGp = (kp+HiEvp)*k*MEA) and fat (EGf = (kf+(0.18-HiEvp))*(1-k)*MEA). Estimates (P < 0.001) of kp and kf were 0.12 ± 0.01 and 0.63 ± 0.02, and HiEvp and proportion of ME available for protein gain (k) were 0.11 ± 0.01 and 0.75 ± 0.01, respectively. The heat of product formation and support metabolism for protein were 0.77 and 0.11, and fat were 0.30 and 0.07, respectively. In conclusion, efficiency of ME use for protein was lesser than for fat gain, and heat of support metabolism was greater for protein than fat gain.

scholarly journals The impact of gross domestic product on the financing and investment efficiency of China’s commercial banks

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Zhen Shi ◽  
Shijiong Qin ◽  
Yung-ho Chiu ◽  
Xiaoying Tan ◽  
Xiaoli Miao
Keyword(s):  
Gross Domestic Product ◽  
Commercial Banks ◽  
Domestic Product ◽  
Investment Efficiency ◽  
Internal Factors ◽  
Slowing Down ◽  
Return On Capital ◽  
Overall Efficiency ◽  
Financing And Investment ◽  
The Impact

AbstractChina’s commercial banks have developed at a very rapid speed in recent decades. However, with global economic development slowing down, the impact of gross domestic product growth as an exogenous factor cannot be ignored. Most existing studies only consider the internal factors of banks, and neglect their external economic factors. This study thus adopts an undesirable dynamic slacks-based measure under an exogenous model in combination with the Kernel density curve to explore the efficiency of state-owned commercial banks (SOCBs), joint-stock commercial banks (JSCBs), and urban commercial banks (UCBs) in China from 2012 to 2018. The results show that SOCBs have the highest overall efficiency, followed by JSCBs, then UCBs. The efficiencies of SOCBs, JSCBs, and UCBs in the financing stage are greater than those in the investment stage, indicating that the latter stage brings down overall efficiency. Thus, all commercial banks need to focus on the efficiency of non-performing loans and return on capital. Finally, SOCBs need to strengthen internal controls, reduce non-performing loans and improve return on capital. JSCBs should actively expand its business while controlling costs, and UCBs should optimize its management.

Correlation Between Gestures’ Qualitative Properties and Usa- bility metrics

2020 ◽  
Vol 64 (1) ◽  
pp. 726-730
Author(s):  
Daniela Chanci ◽  
Naveen Madapana ◽  
Glebys Gonzalez ◽  
Juan Wachs
Keyword(s):  
Linear Regression ◽  
User Satisfaction ◽  
Completion Time ◽  
User Study ◽  
Task Completion ◽  
Time Error ◽  
Qualitative Properties ◽  
Regression Techniques ◽  
Overall Efficiency ◽  
Usability Metrics

The choice of best gestures and commands for touchless interfaces is a critical step that determines the user- satisfaction and overall efficiency of surgeon computer interaction. In this regard, usability metrics such as task completion time, error rate, and memorability have a long-standing as potential entities in determining the best gesture vocabulary. In addition, some previous works concerned with this problem have utilized qualitative measures to identify the best gesture. In this work, we hypothesize that there is a correlation between the qualitative properties of gestures (v) and their usability metrics (u). Therefore, we conducted an experiment with linguists to quantify the properties of the gestures. Next, a user study was conducted with surgeons, and the usability metrics were measured. Lastly, linear and non-linear regression techniques were used to find the correlations between u and v. Results show that usability metrics are correlated with the gestures’ qualitative properties ( R2 = 0.4).

scholarly journals Performance analysis of a novel integrated photovoltaic–thermal system by top-surface forced circulation of water

Clean Energy ◽  
2020 ◽  
Author(s):  
Md Arman Arefin ◽  
Mohammad Towhidul Islam ◽  
Mohammad Zunaed ◽  
Khodadad Mostakim
Keyword(s):  
No Value ◽  
Forced Circulation ◽  
Pv Panel ◽  
Photovoltaic Thermal System ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Mass Flow Rates ◽  
Overall Efficiency ◽  
The Individual ◽  
Over The Top

Abstract Almost 80–90% of energy is wasted as heat (provides no value) in a photovoltaic (PV) panel. An integrated photovoltaic–thermal (PVT) system can utilize this energy and produce electricity simultaneously. In this research, through energy and exergy analysis, a novel design and methodology of a PVT system are studied and validated. Unlike the common methods, here the collector is located outside the PV panel and connected with pipes. Water passes over the top of the panel and then is forced to the collector by a pump. The effects of different water-mass flow rates on the PV panel and collector, individual and overall efficiency, mass loss, exergetic efficiency are examined experimentally. Results show that the overall efficiency of the system is around five times higher than the individual PV-panel efficiency. The forced circulation of water dropped the panel temperature and increased the panel efficiency by 0.8–1% and exergy by 0.6–1%, where the overall energy efficiency was ~81%.

scholarly journals Active Clamp Boost Converter with Blanking Time Tuning Considered

2021 ◽  
Vol 11 (2) ◽  
pp. 860
Author(s):  
Yeu-Torng Yau ◽  
Kuo-Ing Hwu ◽  
Yu-Kun Tai
Keyword(s):  
Boost Converter ◽  
Zero Current Switching ◽  
Active Clamp ◽  
Overall Efficiency ◽  
Auto Tuning ◽  
Voltage Spike ◽  
Resonant Inductor ◽  
Off Time ◽  
Conduction Mode ◽  
Time Point

An active clamp boost converter with blanking time auto-tuned is presented herein, and this is implemented by an additional auxiliary switch, an additional resonant inductor, and an additional active clamp capacitor as compared with the conventional boost converter. In this structure, both the main and auxiliary switches have zero voltage switching (ZVS) turn-on as well as the output diode has zero current switching (ZCS) turn-off, causing the overall efficiency of the converter to be upgraded. Moreover, as the active clamp circuit is adopted, the voltage spike on the main switch can be suppressed to some extent whereas, because of this structure, although the input inductor is designed in the continuous conduction mode (CCM), the output diode can operate with ZCS turn-off, leading to the resonant inductor operating in the discontinuous conduction mode (DCM), hence there is no reverse recovery current during the turn-off period of the output diode. Furthermore, unlike the existing soft switching circuits, the auto-tuning technique based on a given look-up table is added to adjust the cut-off time point of the auxiliary switch to reduce the current flowing through the output diode, so that the overall efficiency is upgraded further. In this paper, basic operating principles, mathematic deductions, potential designs, and some experimental results are given. To sum up, the novelty of this paper is ZCS turn-off of the output diode, DCM operation of the resonant inductor, and auto-tuning of cut-off time point of the auxiliary switch. In addition, the efficiency of the proposed converter can be up to 96.9%.

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