• Journal of Communications and Networks
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• 제9권3호
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• pp.319-329
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• 2007

This paper presents a price-based quality-of-service (QoS) control framework for two-class network services, in which circuit-switched and packet-switched services are defined as "premium service class" and "best-effort service class," respectively. Given the service model, a customer may decide to use the other class as a perfect or an imperfect substitute when he or she perceives the higher utility of the class. Given the framework, fixed-point problems are solved numerically to investigate how static pricing can be used to control the demand and the QoS of each class. The rationale behind this is as follows: For a network service provider to determine the optimal prices that maximize its total revenue, the interactions between the QoS-dependent demand and the demand-dependent QoS should be thoroughly analyzed. To test the robustness of the proposed model, simulations were performed with gradually increasing customer demands or network workloads. The simulation results show that even with substantial demands or workloads, self-adjustment mechanism of the model works and it is feasible to obtain fixed points in equilibrium. This paper also presents a numerical example of guaranteeing the QoS statistically in the short term-that is, through the implementation of pricing strategies.

• 품질경영학회지
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• 제28권3호
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• pp.145-154
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• 2000

Effective management of knowledge is essential to keep up with demands of this challenging information age. The first step for this kind of management would be to define indicators to evaluate the quality of knowledge. In this paper, we use five latent variables (intrinsic quality, representational quality, ease of use of quality, maintainable quality, usage of quality) as basis for a preliminary path analysis for knowledge management. Preliminary study results showed that high intrinsic quality does not necessarily guarantee high frequency of use. A modified questionnaire is made and is used for SERVQUAL. The result of SERVQUAL shows that customers are not relatively happy about both intrinsic quality and its ease of use. Additional path analyses are done for both expected and observed quality indicators. The path model based on the expectation indicated that the presentation method of knowledge would induce its easy maintenance while that based on observation did not back up the same phenomenon.

• Nuclear Medicine and Molecular Imaging
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• 제42권2호
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• pp.137-144
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• 2008

Positron emission tomography-computed tomography (PET/CT) provides both functional and anatomical images of high quality non-invasively with better precision in localization than PET alone. Increase in the use of PET/CT, coupled with increasing concerns about the quality of medical services accrued the demands for accurate evaluation of system performance and quality assurance. Thus, well designed programs for performance evaluation and quality assurance are needed. Widely used protocols for performance evaluation of PET are the methods proposed by National Electrical Manufacturers Association (NEMA) in 1994 and 2001. In addition, in order to maintain high quality of PET/CT images, quality assurance programs including periodic (daily, monthly, and yearly). Therefore, in this article, the methods and present state of performance evaluation and quality assurance of PET/CT are reviewed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1483-1485
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• 2005

In recent years, customers and power supplies are interested in power quality. Demands of customers are change from standard quality of distribution power system to various high quality of distribution power system. so, it is necessary to apply power quality compensator. in our project, we develop the UPQC(Unfied Power Quality Compensator of 45kVA which compensates power factor and voltage sag, interruption. it is very frequently occurred power quality problems. As a series and shunt compensator, UPQC consists of two inverters with common dc link capacitor bank. It compensates the current quality in the shunt part and the voltage quality in the series part. In this paper, we present simulation and test result of developed UPQC system. Test for UPQC are performed at voltage sag, flickers and non-linear load conditions. For voltage sag and ficker generation, we use RTDS(Real Time Digital Simulator) and power amplifier system.

• 대한안전경영과학회지
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• 제19권4호
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• pp.221-230
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• 2017

Recently, service quality must reflect several demands of customers who show rapid and various changes so as to be compared with the past. So, objective and rapid methods for them are necessary more. For them, first of all, service company must calculate their standard of service quality accurately by measuring service quality exactly. To measure service quality accurately, this researcher collected and analyzed data by survey for customers who are customers of logistics services, grasped potential satisfaction standard(P) by 5 point Likert scale and one survey for accurate classification of quality attributes through weighted customer satisfaction coefficient changing quality attributes by developing the study on Kano model and Timko's customer satisfaction coefficient, and suggested Potential Customer Satisfaction Improvement index(PCSI) for examining the improvement of customer satisfaction so as to utilize them as an index of differentiated and concrete measurement of service quality.

• 인터넷정보학회논문지
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• 제9권5호
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• pp.109-116
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• 2008

컴퓨터와 인터넷 환경의 급속한 변화는 방대한 데이터와 다양한 품질의 데이터를 생산해내고 있다. 이러한 환경의 변화는 데이터의 품질에 따른 수준 평가를 요구한다. 이는 데이터 품질이 기업과 조직에 미치는 영향이 크기 때문이다. 따라서 본 연구는 데이터 품질 기준에 따른 품질 평가 모델을 수학적 모델로 제시하고, 이를 기반으로 데이터의 품질을 분석하고 데이터의 품질을 유지 보완하기 위한 분석 모형을 제안하고자한다.

• 한국전자거래학회지
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• 제6권3호
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• pp.1-16
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• 2001

In this paper, we introduced a POS(Point of Sale) system for a wallpaper company. We designed the database schema for the POS system, and proposed various application areas of the POS system. Especially, we discussed such application areas as inventory control, marketing, product development, and distribution channel. The quality of product management is enhanced by precise ABC inventory control and safety stock control. Marketing strategies can be more precisely established, and their effects can be measured. The development time can be shortened and new products can be developed based on the real market demands. Distributors can improve their management quality using precise sales data.

• 산업경영시스템학회지
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• 제24권65호
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• pp.1-9
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• 2001

Enterprises confronted the Environment of infinite competition should be prepared to abrupt variations of management environment and have the ability to be changed in short term. It has to be studied, the control method of products that correspond to molt-functionalization and reduced product life which is caused by high-quality and varied customers demands. As a process control method, we must be able not only to control varies characteristic in a control at once but also to detected special values quickly for high-quality. In this paper a control method referred above is presented.

• Structural Engineering and Mechanics
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• 제51권5호
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• pp.823-845
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• 2014

Success in the excavation of foundations is commonly known as being very important in asserting stability. Furthermore, when the subjected formation is rocky and the use of explores is required, the demands of successful blasting are multiplied. The quick and correct estimation of excavation's characteristics may help the design of building structures, increasing their safety. The present paper proposes a new classification system which connects blastability and rock mass quality. This new system primarily concerns poor and friable rock mass, heavily broken with mixture of angular and rounded rock pieces. However, it should concern medium and good quality rock mass. The Blastability Quality System (BQS) can be an easy and widely - used tool as it is a quick calculator for blastability index (BI) and rock mass quality. Taking into account the research calculations and the parameters of BQS, what has been at question in this paper is the effect of BI magnitude on a geological structure.

• 정보관리연구
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• 제33권1호
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• pp.31-47
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• 2002

본 연구의 목적은 과학기술전문정보 이용자들에 대한 전반적인 현황을 파악하고 이용자 중심 서비스에 대한 합리적인 방안을 제시하고자 기존에 구축되어 있는 국내 과학기술전문정보에 대한 이용자 중심의 품질평가와 일반 과학기술정보서비스에 대한 이용자 기대사항 등을 분석하였다. 품질평가 조사는 한국과학기술정보원에서 제공하고 있는 과학기술전문정보 데이터베이스 검색서비스 BIST와 SATURN을 중심으로 수행되었다. 그 결과 검색결과의 정확성, 검색성, 사용자지원성은 BIST가 약간 높았으며 완전성에서는 SATURN이 약간 높은 것으로 나타났으나, 전체적으로 비슷한 양상을 보였다. 최신성 평가에서는 BIST가 신속한 것으로 나타났으며, 검색결과 평균건수는 SATURN이 더 많았다. 이용자 요구사항 분석은 일반 과학기술전문이용자에게 설문조사를 하여 전반적인 국내 과학기술전문정보 이용환경 현황을 조사하였다. 그 결과 이용자들이 가장 선호하는 자료유형은 국외 학술지로 나타났고 최신성, 원문입수방법, 정보서비스 선택기준 등에서는 모든 이용자 유형에서 유사한 결과를 보여주었다. 그러나 외국어 정보검색시 번역 지원도와 필요로 하는 도움말의 유형 선호도에 있어서 이용자 유형별로 차이를 나타냈다. 본 연구는 과학기술전문정보 품질평가와 전반적인 이용환경 조사를 병행하여 특정 서비스 품질평가가 내포하는 구체성과 과학기술이용 커뮤니티의 일반성을 동시에 수용하고자 하였다.