• 제목/요약/키워드: Efficiency Measurement

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실시간 서지데이터베이스 평가방법에 관한 연구 (A Study on Real-time Quality Evaluation Method of Bibliographic Database)

  • 노경란;권오진;유현종;문영호;홍성화
    • 한국콘텐츠학회논문지
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    • 제2권4호
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    • pp.76-84
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    • 2002
  • The conventional database evaluation method is carried out by the way in which the person in charge of each specialty database(DB manager) composes the evaluation sheets for corretionㆍrevision on the already-constructed database in a manual method and carries out the measurement and re-education of DB workers based upon it. As a result, that way consumes much time on career information and measurement works about DB workers, causing low time and cost efficiency and lack of systematic management of DB workers, resulting in becoming the hindrance factor of databases quality improvement. This research provides on-line, red-time results of measurements about the efficiency of DB production and DB workers by combining the static measurement with dynamic measurement by DB manager, both of which utilize the System. Therefore, the DB manager can contribute to the improvement of DB quality by determining the continuation of DB production by DB workers or carrying out the re-education of DB workers without being affected by time or spacial constraints.

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RF and Microwave Power Standards from 10 MHz to 40 GHz over Decades

  • Kang, Tae-Weon;Kwon, Jae-Yong;Park, Jeong-Il;Kang, No-Weon
    • Journal of electromagnetic engineering and science
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    • 제18권2호
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    • pp.88-93
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    • 2018
  • Radio frequency (RF) and microwave power is one of the key quantities in the framework of electromagnetic measurement standards. Therefore, the stability of the power standard is essential to users' reliable measurements in various areas. Coaxial and waveguide thermistor mounts are used as transfer standards of RF and microwave power. Over decades, the effective efficiencies of thermistor mounts have been measured using coaxial and waveguide microcalorimeters in the frequency range of 10 MHz-40 GHz. The measurement uncertainty of the effective efficiency is evaluated. Results show that the power standards have been well maintained within the measurement uncertainty.

Distribution Channel Performance Measurement: Valid Measures From Customers' Perspective

  • Kim, Sang-Youl
    • 한국항해항만학회지
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    • 제32권2호
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    • pp.141-148
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    • 2008
  • This paper is structured into three main parts and a conclusion. The main section provide definitions of efficiency, effectiveness and performance in terms of the distribution channel, followed by a review of related performance measurement, before discussing difficulties of measurement. According to the theoretical approach, it appears that key theroretical issues are centered around customer service, logistics excellence, time compression, the use of IT, and a move towards integrated logistics. The empirical approach shows that in the past, various financial performance indicators were regarded as relevant management information. However, today, management needs additional performance indicators. Therefore, external assessments of effectiveness must be performed to measure customers' satisfaction with the physical flow of product through the distribution channel network. So, what is needed is to take previous normative and explorative research and progress through a framework by developing valid measures of distribution channel's effectiveness and efficiency, and identifying research methodologies suited to the data collection requirements.

주파수 공유를 고려한 전파자원 이용효율 측정 방안 (Measurement of Spectrum Utilization Efficiency Considering Spectrum Sharing)

  • 김태한;박현민;성기원
    • 한국콘텐츠학회논문지
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    • 제14권9호
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    • pp.589-597
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    • 2014
  • 전파자원을 이용한 다양한 무선 서비스에 대한 급증하는 수요는 더 많은 주파수 자원의 확보를 요구한다. 그러나 주파수 자원의 희소성과 고대역 주파수 발굴의 어려움을 감안하면, 늘어나는 전파자원의 수요를 충족시킬 수 있는 유일한 방법은 기존 전파자원의 이용 효율을 극대화시키는 것이다. 이러한 상황에서, 전파자원에 대한 초과 수요를 해결하기 위한 다양한 주파수 공유 방안이 최근 활발히 논의되고 있다. 이와 더불어, 주파수 공유의 실효성 검증과 무선시스템의 성과 예측을 위해, 주파수 이용효율 측정의 중요성이 높아지고 있다. 본 연구에서는 전파자원 이용효율의 합리적 측정 방법을 제안한다. 국제전기통신연합(ITU) 권고안을 토대로 전파자원 이용효율의 다양한 측정 방법을 고찰하고, 대기행렬모형을 이용한 전파 자원 이용효율 측정의 대안 모델을 제시한다. 이를 통해, 주파수 공유 시 전파자원의 이용효율이 어느 정도 증대되는지를 합리적으로 예측할 수 있다.

Improvement in LED structure for enhanced light-emission

  • Park, Seong-Ju
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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    • pp.21-21
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    • 2003
  • To increase the light-emission efficiency of LED, we increased the internal and external quantum efficiency by suppressing the defect formation in the quantum well and by increasing the light extraction efficiency in LED, respectively. First, the internal quantum efficiency was improved by investigating the effect of a low temperature (LT) grown p-GaN layer on the In$\sub$0.25/GaN/GaN MQW in green LED. The properties of p-GaN was optimized at a low growth temperature of 900oC. A green LED using the optimized LT p-type GaN clearly showed the elimination of blue-shift which is originated by the MQW damage due to the high temperature growth process. This result was attributed to the suppression of indium inter-diffusion in MQW layer as evidenced by XRD and HR-TEM analysis. Secondly, we improved the light-extraction efficiency of LED. In spite of high internal quantum efficiency of GaN-based LED, the external quantum efficiency is still low due to the total internal reflection of the light at the semiconductor-air interface. To improve the probability of escaping the photons outside from the LED structure, we fabricated nano-sized cavities on a p-GaN surface utilizing Pt self-assembled metal clusters as an etch mask. Electroluminescence measurement showed that the relative optical output power was increased up to 80% compared to that of LED without nano-sized cavities. I-V measurement also showed that the electrical performance was improved. The enhanced LED performance was attributed to the enhancement of light escaping probability and the decrease of resistance due to the increase in contact area.

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DEA를 이용한 서비스효율성 측정에 관한 연구 - 국내 5개 시중은행의 서비스품질지수를 중심으로 - (A Study on the Measurement of Service Efficiency using DEA - Focused on the SQI of Five Domestic Banks in Korea -)

  • 김진왕;유한주;송광석
    • 품질경영학회지
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    • 제37권1호
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    • pp.80-90
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    • 2009
  • Nowadays, there are many companies which employ the SQI measurement to assess service quality. The purpose of this study is to measure the service efficiency for Bank Industry. In this paper, we tried to measure the efficiency of service quality and overall customer satisfaction by using Data Envelopment Analysis(DEA). Rather than using the usual method of converting the Service Quality Index(SQI) into mean value, we applied CCR/BCC models in DEA to service quality efficiency. Also, DEA/PS Model is recommended as appropriate model for evaluating service efficiency by complementing the shortfalls of the weighted value of DEA Model. In this study, six dimensions of service quality were considered as input variables and output variables(overall customer satisfaction, reusing intention, and word of mouth). The result of this study statistically verifies that 5 DMUs are relatively efficient, and intensive activities for service efficiency are needed for 20 sample branches. Managerial implications based on the analysis were suggested.

DEA 모형에 의한 서비스 운영의 기술적 효율성 평가: 컨택센터 서비스를 중심으로 (Evaluating the Technical Efficiency of Service Operations Using DEA Models: An Application to Contact Center Services)

  • 조건;이경재;소순후
    • 품질경영학회지
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    • 제37권2호
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    • pp.1-11
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    • 2009
  • Recently, many companies have been very interested in CRM(Customer Relationship Management). Most companies have been also considering the contact center as a key CRM channel, because it is a contact point between customers and companies. It turns out that the contact center handles over 70% of all customer-company interactions and the success or failure of a company can be determined by the customer satisfaction with contact center experiences. Despite of the strategic importance of the contact center, there has been few empirical study on the efficiency of contact center operations in the literature. One of the main purposes of this study is to evaluate the efficiency of contact centers so as to not only identify the current status of contact center operations, but also suggest ways to improve operational efficiency. For this purpose, we apply a non-parametric efficiency measurement method, DEA (Data Envelopment Analysis), to 57 domestic contact centers in order to compare their relative efficiency. It is expected that the measurement methods suggested in this study can be applied to various issues such as service KS certification, outsourcing service management, and the productivity analysis of service personnel.

펌프의 효율측정 장비에 관한 연구 (Study on the Device for Pump Efficiency Measurement)

  • 배철오
    • 선박안전
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    • 통권33호
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    • pp.53-62
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    • 2012
  • 펌프는 산업 및 건설현장에 급수, 냉난방 및 산업공정에서 다양하게 사용되고 있으며, 전체 국가 전력의 약 20%를 소비하고 있다. 하지만 에너지 낭비요소에 대한 관리는 거의 이루어지지 않고 있는 실정이다. 따라서 만일 효율이 저하된 상태로 펌프가 운전된다면 그의 에너지 낭비는 대단히 크게 된다. 펌프의 경우 초기 구입비용에 비해 사용하면서 발생하는 전력비용이 대단히 크기 때문에 이러한 낭비를 줄이기 위해서는 펌프의 효율을 정기적으로 측정하여 펌프의 운전 상태를 진단함으로써 펌프의 최적운전상태 및 교환주기 등을 제시할 수 있을 것이다. 본 연구에서는 펌프의 효율측정을 위해 열역학적 방법과 수력학적 방법(전통적인 방법)의 두 가지 방법으로 측정할 수 있는 장비에 대해서 소개하고 실제 펌프의 효율을 계산하여 그 유효성을 확인하였다.

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감마핵종 In-Situ 측정 연구 동향 분석 및 방사능 측정 효율 민감도 평가 (In-Situ Gamma Spectrometry Research Analysis and Radiation Efficiency Sensitivity Evaluation)

  • 라현준;김혁재;이성연;곽민우;김광표
    • 방사선산업학회지
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    • 제17권1호
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    • pp.1-9
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    • 2023
  • Since a large amount of radioactive waste is expected to be generated due to permanent shutdown of many nuclear power plants, it is necessary to prepare efficient management methods for radioactive waste. Therefore, there is a need for a based study to apply the In-Situ gamma spectrometry, which can simplify the measurement procedure. The purpose of this study is to analyze research cases of In-Situ gamma spectrometry and to analyze the sensitivity of measurement according to influencing factors on In-Situ gamma spectrometry. Research cases of five institutions, including the CERN and the Imperial College Reactor Centre (ICRC), were selected as the institutions to be investigated. Research on the In-Situ gamma spectrometry was conducted on the satisfaction of the acceptance criteria for radioactive waste and the analysis of residual radioactivity in the site. In-Situ Objective Counting System (ISOCS) was used as a major measuring device. Sampling and computer code were used to verify the analysis results. For evaluation of measuring sensitivity according to influencing factors on In-Situ gamma spectrometry, the thickness of the measurement target, the distance between the detector and the target, the angle of the collimator, and the contamination location were performed using ISOCS's Geometry Composer. In every case, based on 122 keV, the efficiency decreased as the energy increased in the high energy region, and the efficiency decreased as the energy decreased in the low energy region. As the target thickness increased, the efficiency decreased, and as the distance between target and detector increased, the efficiency decreased. As the distance between contamination and detector increased, the efficiency decreased, and as the angle of the collimator increased, the measurement efficiency increased. However, when simulating the measurement situation using Geometry Composer, the background is not considered, and the probability of incident in the background increases as the angle increases, so further research needs to be conducted in consideration of these. This study can be utilized when applying the In-Situ gamma spectrometry of radioactive waste clearance in the future.

삼천포 해양소수력 성능평가 (Performance Evaluation of the Samcheonpo Small-Hydro Power Plant)

  • 조홍연;조범준;강금석
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2007년도 춘계학술대회
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    • pp.617-620
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    • 2007
  • The performance evaluation of the Samcheonpo small-hydropower plant constructed on the October 25th,2006, was carried out focused on the turbine and generator efficiency analysis by using the measurement data. The unreasonable and unrealistic efficiency results are occurred in some periods because of the data variability, uncertainty, and measurement errors and mistakes. Whereas, the big mismatch is the tidal elevation predicted in the design processes. The difference between the measured and estimated tidal elevation is obvious during the low water period. It should be considered and checked in depth on the efficiency analysis of the planned and constructing small-hydro power plants in other coastal areas.

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