• The Korean Journal of Ceramics
• /
• 제4권3호
• /
• pp.240-244
• /
• 1998

The analytical method was developed to calculate efficiency of densifying carbon/carbon (C/C) composites using coal tar pitch as a matrix precursor at each cyle. Three factors were defined in analyzing the densification process: impregnation efficiency, retention efficiency, and overall densification efficiency. The relationships developed were applied to the experimental results for three densification cycles of C/C composites with pitches as an impregnant to evaluate the factors which may depend on the impregnant and on the route of carbonization. The impregnation efficiency increased with the repeated process cycles whereas the retention efficiency decreased irrespective of the impregnant and carbonization route. Carbonization route P+A+G, in which pressure carbonizationl (P) and graphitization (G) were done before after atmospheric pressure carboniztion (A) respectively, using impregnant of high carbon yields was the most effective method in densifying C/C composites.

• 대한안전경영과학회지
• /
• 제15권1호
• /
• pp.249-258
• /
• 2013

Data Envelopment Analysis (DEA) is a useful tool to analyze the relative efficiency of decision making units (DMU) characterized by multiple inputs and multiple outputs. This method has been popularly used as an analytical tool to suggest some strategic improvement. To do this, the results of DEA provide decision makers with a single efficiency score, efficient frontier, return to scale, benchmarking decision making units, etc. The purpose of this paper is to evaluate research performance of 38 universities and provide an inefficient university with the way of organizational changes to be an efficient university by using DEA. Various input and output variables are used to identify technical and scale inefficiency. Additionally, we analyze how an inefficient DMU could be changed an efficient DMU based on a case university. This result will give an insight of constructive directions for increasing of research performance to university decision makers.

• 한국태양에너지학회 논문집
• /
• 제21권1호
• /
• pp.11-20
• /
• 2001

In this paper described common MPPT(Maximum Power Point Tracking) control algorithm; Constant Voltage Control, P&O(Perturbation and Observation), IncCond(Incremental Conductance), and investigated it's efficiency. Through simulation and efficiency evaluation, analyze the steady/transient states characteristics and efficiency of control algorithms respectively. Also, To high-efficiency proposed Two-mode MPPT control for improve on the existing control algorithm. Moreover, this paper suggested a topology for MPPT measuring efficiency and a method of examination.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
• /
• pp.1015-1018
• /
• 2008

Tandem organic light-emitting diodes (OLEDs) do not always improve power efficiency over their conventional OLED counterparts. When a tandem OLED utilizes optimized EL units, increased power efficiency can only be achieved if the intermediate connector in the device has excellent charge injection capability.

• 국제초고층학회논문집
• /
• 제3권3호
• /
• pp.185-190
• /
• 2014

Based on a 405m high super-tall building, the influence of outriggers, different shapes and layouts of structural plane and elevation on structural efficiency under lateral forces is studied in this paper. A calculation formula concerning the structural efficiency is given. The study shows that structural efficiency can be improved by triangulating the plane shape, using mega columns, the peripherization of the plane layout, tapering the elevation shape and setting bracing structure in the elevation. The arrangement of outriggers between the core tube and flange frame can reduce the shear lag effect in order to improve structural efficiency. The essence of improving structural efficiency of super-tall buildings is to maximize the plane bending stiffness and to make its deformation approach to plane section assumption.

• 경영과학
• /
• 제32권3호
• /
• pp.37-54
• /
• 2015

This paper suggests energy efficiency which can be the foundation on corporate profit and effective energy management following by change of global climate and of energy-related regulations. Using comparable financial information and information related to energy use, an DEA (Data Envelopment Analysis) model has been used to identify energy efficiency with DMU (Decision Making Unit)s which are companies subjected to reduce greenhouse gas emission in 2009. Through this research, different from existing researches, environmental variables which can influence on energy efficiency are identified. The results show as follows. First, most of companies follow IRS, which means scale of economy exists among units so that they have more opportunity to increase efficiency by increasing scale of inputs. Second, this research identified that depending on the difference of environmental characters such as the emission structure and the size of companies, energy efficiency of the companies turns out differently.

• The Journal of Asian Finance, Economics and Business
• /
• 제8권1호
• /
• pp.751-758
• /
• 2021

This research is conducted to measure the efficiency level of Islamic banking in Indonesia and also to analyze the factors that can affect its efficiency level. This research used a purposive sampling technique to determine the sample size that will be used, with criteria that the bank has been operating since 2010 and consistently published its financial reports during the research period from 2011 until 2019; therefore, the total sample obtained was 11 samples. Analysis for efficiency level is done by using linear programming Stochastic Frontier Analysis (SFA), with test tool in the form of Frontier 4.1 and Eviews9 to find out what factors that affect efficiency. Efficiency test is done by involving input and output, while influence test used bank-specific variables comprising bank size, bank financial ratio, and macro-economy variable. Research result shows that there are only two banks that are almost close to being fully efficient firms, but the result still does not indicate that Islamic bank works efficiently. Results of the influence test show that factors affecting Islamic banking efficiency in Indonesia are bank size, Capital Adequacy Ratio (CAR), Non-Performing Finance (NPF), and Financing to Deposit Ratio (FDR), while other factors are not influential over the study period.

• 한국작물학회지
• /
• 제49권2호
• /
• pp.89-93
• /
• 2004

This experiment was conducted to investigate the variation of nitrogen use efficiency, nitrogen uptake efficiency, physiological utilization efficiency and their relationships with growth characteristics in the 28 Korean rice cultivars. Nitrogen use efficiency of 28 rice cultivars was 47.74, nitrogen uptake efficiency was 0.71, and physiological utilization efficiency was 68.76 in average. Nitrogen use efficiency of rice cultivars had low variation ranged from 44.09 to 51.91, but nitrogen uptake efficiency were relatively high variation from 0.51 to 0.90, and physiological utilization efficiency was from 51.71 to 94.26. The high efficient group in nitrogen uptake efficiency whose value was calculated above 0.80 included Daeanbyeo, Seojinbyeo, Ansungbyeo, Dongjinbyeo, and Hwaanbyeo, while the low efficient group with below 0.60 was Kwanganbyeo, Sampyeongbyeo, Soorabyeo, and Hwasungbyeo. Hwasungbyeo, Sampyeongbyeo, Soorabyeo for physiological utilization efficiency were more efficient cultivars, while Daeanbyeo, Seojinbyeo, Ansungbyeo were less efficient cultivars. Nitrogen uptake efficiency had positive correlation coefficients between dry matter weight of plant ($0.842^{**}$), leaf area index ($0.761^{**}$), and leaf nitrogen content ($0.599^{**}$), respectively. Therefore, the dry matter weight of rice plant and leaf area index was important characters to evaluate nitrogen uptake efficiency in rice cultivars. Also, more efficient cultivar in nitrogen uptake had higher chlorophyll meter value, which was appeared dark green color.

• The Journal of Asian Finance, Economics and Business
• /
• 제8권1호
• /
• pp.741-750
• /
• 2021

The research aims to analyze the level of efficiency by grouping banks during the period 2017 - 2018 into category 1 and category 2 banks and then dividing them as Regional Development Banks (BPD) and Non-BPD Conventional Commercial Banks (BUK) within each category. The research objects are banks within the categories BPD and BUK comprised 18 BPDs and 35 BUKs. The research methodology uses 3 stages, first, using Data Envelopment Analysis (DEA) we measure the level of bank efficiency; second, using the Tobit regression model we evaluate the effect of financial performance on DEA efficiency, and third, using the Mann-Whitney test we determine whether there is a difference in the efficiency of category 1 and 2 banks. The results showed that there was a decrease in the efficiency of category 1 and 2 banks but on average, the efficiency of category 1 banks is higher than category 2 banks. The estimation results of the Tobit regression model show that only the ROA variable affects the efficiency level of category 1 banks, while category 2 banks are influenced by NPL and ROA variables. In the Mann-Whitney test, it was proven that there were differences in efficiency between BUK and BPD in category 1 and 2 banks.

• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회 1996년도 추계학술대회발표논문집; 고려대학교, 서울; 26 Oct. 1996
• /
• pp.235-238
• /
• 1996

In recently, the influence of client-server systems on organizations and how to estimates the efficiency or productivity of organizations and departments has come to be more concerned by many researchers. Especially, information systems(IS) of the financial institutions are greatly used than any other industries. Therefore, the efficiency of IS departments in financial institutions is relatively important. The overall objectives of this research are to estimate the effects of client-server systems and to evaluate whether the client-serve systems really improve the efficiency of information system. The research method used in this research is DEA(Data Envelopment Analysis) estimation method which based on linear programming is used for the efficiency of managerial organizations and other nonprofit organizations. The results of this research showed that the efficiency of IS department was promoted after implementation of client-server systems.