• 재무관리연구
• /
• 제20권2호
• /
• pp.263-291
• /
• 2003

이 연구는 Generalized Malmquist 지수를 이용하여 1997년 외환위기 때부터 2001년까지 국내 생명보험산업의 생산성변화를 기술효율성, 규모효율성 및 기술진보의 변화로 구분하여 측정하였다. 생명보험 산업의 생산성은 외환위기에도 불구하고 매년 증가하였음을 확인하였으며, 기술진보와 규모효율성의 변화는 순수기술효율성의 하락을 상쇄하고 생산성향상에 기여하였으며, 특히 기술변화가 더 크게 생산성향상에 공헌하였음을 확인하였다. 이러한 생산성의 증가는 구조조정으로 기인한 것으로 보인다. 외환위기 이후에 효율성은 계속하여 하락하였으며, 이것은 선도 생명보험회사의 효율적 프론티어가 일반 생명보험화사의 생산성보다 더 크게 증가하였기 때문에 발생한 것으로 확인되었다. 낮은 효율성은 생산성의 증가에도 불구하고 경영개선에 의하여 생산성을 크게 증가시킬 수 있다는 것을 말해주고 있다.

• 수산경영론집
• /
• 제41권3호
• /
• pp.21-44
• /
• 2010

The paper estimates changes in total factor productivity and technical efficiency change index and technical change index using Malmquist productivity index(MPI) in fisheries wholesale products over the time period of 2006 through 2008. The model considers a number of employees and operating costs as input factors, and sales and EBIT(earnings before tax and interest) as output factors. The results indicate that, between 2006 and 2007, there is in general technical progress in which TCI(Technical Change Index) indicates 2.7994 in the sale scale of 50 million won through 100 million won, while there are no efficiency in TECI(Technical Efficiency Change Index), PECI(Pure Efficiency Change Index) and SECI(Scale Efficiency Change Index) which are estimated to be around 1. Between 2007 and 2008 technical efficiency and technical progress are generally declined, compared to those of 2006 and 2007. Wilcoxon's rank-sum test shows that there are statistically significant difference of TCI and MPI between two periods at the level of 5%, while there are statistically significant difference of TECI, PECI and SECI between two periods at the level of 5%.

• 한국항만경제학회지
• /
• 제24권4호
• /
• pp.47-70
• /
• 2008

본 연구의 목적은 확률적 생산변경함수를 이용하여 총요소생산성 성장을 도출하고 그 내부요소를 기술효율성 변화, 기술진보, 규모효율변화, 배분적 효율변화로 구분하여 생산성 성장의 요인을 파악해 보고자 함이다. 1990-2003년간 항만물류산업의 총요소생산성 증가율은 연간 0.019 (1.9%)로서 전산업의 증가율 0.010보다 높다. 그 내부의 주된 기여요인은 기술진보이고 기술효율성변화는 감소하였다. 총요소생산성의 주된 기여요인으로는 항만산업은 배분효율성, 해운산업은 기술진보, 수송장비산업은 규모효율변화를 들 수 있다. 총요소생산성 변화는 1990년대 후반이후에 감소하는 추이를 보였다. 항만물류산업은 전산업에 비하여 매우 낮은 수준의 기술효율성수준을 보여주고 있고 산출탄력성 관점에서는 1990-2003년간 자본의 탄력성(0.391)이 노동의 탄력성(0.227)보다 높지만 규모에 대한 보수는 0.618로서 최적규모에 상당히 벗어나 있다.

• 한국항만경제학회지
• /
• 제34권1호
• /
• pp.51-64
• /
• 2018

본 고는 Malmquist 생산성 지수를 이용하여 글로벌 금융위기 이전인 2001-2008년, 그 이후인 2008-2015년 두 기간 동안 조선 산업의 생산성변화를 기술효율성변화, 순효율성변화, 규모효율성변화, 기술변화로 구분하여 측정함과 동시에 두 기간 동안 생산성 변화를 비교하였다. 전반기(2001-2008년)에는 2.8%의 생산성 향상되었으며, 이는 기술효율성 보다는 기술진보에 기인된 것으로 나타났다. 후반기(2008-2015)에는 -3.4%의 생산성 하락으로 나타났다. 이는 글로벌 금융위기이후 세계경제의 침체로 인한 선박수주 물량의 감소, 중국 조선 산업의 부상 등으로 인해 기술효율성 저하, 기술퇴보 등에 기인된 것으로 나타났다. 두 기간 중 전반기 가 후반기보다 생산성이 높게 나타났다. 특히 두 기간 간에 이러한 차이는 기술변화에 의해 기인된 것으로, 즉, 기술 퇴보는 생산성 감소로 나타났으며, 통계적 검증을 통해서도 이를 입증할 수 있었다. 본 연구 결과에 의한 정책적 시사점으로는 정부 그리고 각 DMU들은 향후 생산성 증대를 위해, 글로벌 조선 산업의 환경변화에 대응하는 신기술개발 그리고 비효율적 요인을 제거하는 전략이 필요하다는 점을 제시하고 있다.

• KIEAE Journal
• /
• 제12권6호
• /
• pp.29-38
• /
• 2012

The current building energy efficiency rating certification regulation on apartment houses evaluates only the saving rate of energy consumed during operation, i.e. use, of a building, but doesn't consider the energy consumptions and environmental load($CO_2$) emissions occurring during the whole lifetime of a building. So this study calculated the energy consumptions and environmental load emissions occurring during the whole lifetime of a building, selected reference schemes and alternative items by design variables to present a design draft considering energy efficiency and environmental performance, and evaluated the total cost by combining and calculating its direct cost(material and heating cost) and indirect cost(environmental cost), for an existing apartment house as an evaluation object. As a result of analysis, the change of heating cost by alternative items of design variables showed a 4~8% change rate compared to the reference scheme, and the material cost of design variable 7 showed a maximum 4.4 times change rate in the alternative plan 6 compared to the reference scheme. The environmental cost showed a similar change rate to the material cost change rate in general, but showed a similar environmental cost change rate to the heating cost change rate in case of design variables 4-1, 4-2, 7.

• 전기학회논문지
• /
• 제62권9호
• /
• pp.1223-1227
• /
• 2013

If the factory test efficiency and field operation efficiency of water turbine are different from each other, issues for efficiency warranty can be raised. So, This paper shows the result for comparative analysis of field operating efficiency vs plant testing efficiency of the water turbine generator installed in agricultural reservoir. The efficiency of the induction generator is analyzed by the change of rotational speed with the parameter obtained by test, the efficiency of water turbine is calculated by the change of head with the design flow. Efficiency deviation of induction generator is lower but the variation of developed power is pretty high near the rated speed and the efficiency variation of water turbine is high by the fluctuation of head for constant flow. It was found that factory test efficiency and total efficiency of water turbine generator calculated according to the rotational speed are very close.

• 한국입자에어로졸학회지
• /
• 제15권1호
• /
• pp.15-25
• /
• 2019

The influences of corona charging parameters on collection efficiency and surface potential of air filters were investigated. A polypropylene filter medium was electrically charged using a corona charger, and the resulting surface potential and filtration efficiency against neutralized KCl particles were measured. The filter media was charged under different conditions of applied voltage, voltage polarity, charging time, and distance between electrodes. In addition, we considered charging both sides of the filter as well as charging one side of the filter. As a result, electrical force obtained by charged fiber affected filtration efficiency when the apply voltage strength was higher than 7 kV. Negatively charged filter had higher filtration efficiency than positively charged filter while the surface potential of the negatively charged filter was slightly lower than those of positively charged filter. Moreover, the filtration efficiency increased as the charging time of filter fiber increased and the distance between electrodes decreased. The filtration efficiency was more sensitive to changes of charging time than to those of electrode distance, and the efficiency of both sides charged filter was higher than that of single side charged filter.

• 한국대기환경학회지
• /
• 제32권4호
• /
• pp.384-393
• /
• 2016

In this study, two kinds of industrial filter bags were tested for their filtration performance to apply the existing bag filter systems. Experimental variables were examined for pressure drop, cleaning interval, residual pressure drop, cleaning efficiency, fractional grade efficiency, total collection efficiency according to the filter bag structure. According to these results, the filter bags tested in this study demonstrated good performance in dust collection. This was also true for the double surface filter bag. The lifetime was longer than the round type filter bag because the filtration area was more than 1.6 times wider and the filter quality factor was much higher. Therefore, double surface filter bags are suggested to be used in order to increase filtration performance of the bag filter systems.

• 설비공학논문집
• /
• 제12권2호
• /
• pp.189-199
• /
• 2000

This paper investigates the thermodynamic performance of latent heat thermal energy storage system using two phase change materials(2-PCM system). The thermodynamic merit of using 2-PCM is clear in terms of exergetic efficiency, which is substantially higher than that of 1-PCM system. Optimum phase change temperature to maximize the exergetic efficiency exists for each case. The heat transfer area ratio of high temperature storage unit, X, becomes another important parameter for 2-PCM system if the phase change temperatures of given materials are different from those of optimum conditions. It is a good approximation for X$_{opt}$ to be 0.5 when optimum phase change temperatures are used. Otherwise X$_{opt}$ is determined differently as a function of given phase change temperatures.res.

• 한국광학회:학술대회논문집
• /
• 한국광학회 2004년도 하계학술발표회
• /
• pp.172-173
• /
• 2004

Recently there has been many understood the basis device physics OLEDs and their basic operating principle. We demonstrate that there have many relation in order to improve luminescence efficiency both emitting light material physics characteristics and luminary. Efficient Electro Luminescence from organic materials was first reported in 1987 at Kodak. OLEDs emitting light material use tris-(8-hydroxyquinoline)(Alq3). Sudied maximum luminescence efficiency about structure of optimized emitting light layer of OLED which do observing change of luminescence efficiency by structure change of organic material in this paper.