• Journal of information and communication convergence engineering
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• 제7권2호
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• pp.92-97
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• 2009

Lately, influence of information rises and interest about satisfaction estimation of information providing service is risin. According to rapid change in information environment, information-providing service is being changed in various form, in which center development is made in relation to the effort for customer satisfaction intended to enhance user's satisfaction level through providing more convenient and higher service centered on information service user rather than information service provider. Organizations providing information service is also changing their service from traditional one centered on service provider to that for user's satisfaction and service quality, and evaluation of information service quality and measurement of user's satisfaction as the result of using information service are regarded important. In this respect, it is needed to measure user's satisfaction level for environmental factors of information service and analyze what kind of influence they have to enhance user's satisfaction level of information service. Also function and efficiency of information offer service are important. Therefore, interest for satisfaction survey to heighten contents satisfaction of information-providing service, service satisfaction, satisfaction of user of system satisfaction is increased. In this paper, we propose a model of the user satisfaction index for information-providing services and present the user satisfaction index is measured to the model. Also we this study suggest qualitative improvements of information-providing service required for change to user-centric information-providing service through measuring user satisfaction index of ITFIND system and schemes to improve information quality

• 한국전자파학회논문지
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• 제19권2호
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• pp.161-167
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• 2008

본 논문은 IMT 이동통신 서비스에 있어서 ITU-R의 권고안 ITU-R M.1390, ITU-R (IMT.METH)에 권고한 주파수 소요량 산출의 개요와 그 차이점을 기술하고, ITU-R (IMT.METH) 방법론을 최근의 IMT 서비스에 대한 주파수 소요량을 산출하는데 적용하였다. 발생 호량(offered traffic)과 시스템 용량, 서비스 품질(quality of service) 기준에 의하여 결정되는 운반 호량(carried traffic)에 대한 모델과 알고리즘을 기술하고 산출예로서 최근에 서비스가 개시되고 있는 IMT의 배치에 따른 2010년부터 2015년까지 국내에서 운용되고 있는 IMT 서비스에 대하여 여러 가지 시장 자료와 ITU의 예측 자료를 통하여 얻은 후 주파수 소요량을 산출하였다.

• 한국정보과학회논문지:정보통신
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• 제37권6호
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• pp.494-498
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• 2010

시스템의 성능 요구 사항은 일반적으로 해당 시스템이 제공하는 서비스의 품질과 높은 연관성을 가진다. 예를 들어 이동통신 시스템에서 통화 성공률은 서비스 품질과 직결되는 사항으로 매우 높은 중요도를 가지며 체계적인 성능 시험 방법이 요구되고 있다. 본 논문에서는 구간 추정 기법을 이용하여 이동통신 시스템의 통화 성공률을 시험하는 방안을 제안한다. 또한 제안된 시험 방안을 기반으로 방송통신위원회에서 최근 시행한 3G 이동전화 서비스 품질 평가에서 사용된 판정 기준에 대해 고찰해 보고 문제점에 대해 살펴본다.

• International Journal of Quality Innovation
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• 제9권2호
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• pp.1-9
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• 2008

This paper proposes a scheme to estimate the technical efficiency at child care centers for the less-than-three-year-old infants by Data Envelopment Analysis (DEA) and to manage the quality of care service through implementing flexible and efficient government subsidy system. The result of technical efficiency estimation shows that there exists the heterogeneity in technical efficiency a substantial opportunity for improvement in technical efficiency across child care centers. This result implies that government may bring up the competition by giving subsidy differentially based on efficiency and use the money which has been used inefficiently other purposes. Both can improve the quality of child care service.

• Journal of Communications and Networks
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• 제7권3호
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• pp.235-242
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• 2005

Multimedia applications and especially encoded video services, are expected to playa major role in the 3rd generation (3G) and beyond mobile communication systems. Given that future service providers are expected to provide video applications at various price and quality levels, quick and economically affordable methods for preparing/encoding the offering media at various qualities are necessary to be developed. This paper presents a method for objective evaluation of the perceived quality of MPEG­4 video content, based on a quantification of subjective assessments. Showing that subjectively derived perceived quality of service (PQoS) vs. bit rate curves can be successfully approximated by a group of exponential functions, the proposed method exploits a simple objective metric, which is obtained from the mean frame rate vs. bit rate curves of an encoded clip. The validity of this metric is assessed by comparing subjectively derived PQoS results to the corresponding ones, which come from the proposed objective method, showing that the proposed technique provides satisfactory PQoS estimation.

• 한국산학기술학회논문지
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• 제8권3호
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• pp.639-645
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• 2007

본 연구에서는 우리나라의 인터넷전화 통화수요함수를 2001년 6월부터 2004년 12월까지의 월별 데이터를 이용하여 추정하고 있다. 추정식에서 인터넷 통화수요는 통화요금, 타서비스의 요금, 소득, 품질 등의 함수로 가정하였으며, 통화량의 부분적응모형을 이용하여 시차변수도 설명변수에 포함시켰다. 추정결과 인터넷전화는 해당 요금에 대해 탄력적인 것으로 파악되었고 소득에 대하여는 비탄력적으로 나타났다. 품질은 인터넷전화수요에 큰 영향을 미치는 것으로 파악되었으며 인터넷전화 통화수요가 설명변수의 변화에 대하여 반응하는데 있어 시차가 존재함을 보이고 있다.

• 대한산업공학회지
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• 제29권4호
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• pp.312-320
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• 2003

Recently there is a growing interest in mobile cellular network providing multimedia service. However, the link bandwidth of mobile cellular network is not sufficient enough to provide satisfactory services to users. To overcome this problem, an adaptive framework has been proposed. In this study, we propose a new method of estimating DPR(Degradation Period Ratio) in an adaptive multimedia network where the bandwidth of ongoing call can be dynamically adjusted during its lifetime. DPR is a QoS(Quality of Service) parameter which represents the ratio of allocated bandwidth below a pre-defined target to the whole service time of a call. We improve estimation method of DPR using DTMC(Discrete Time Markov Chain) model by calculate mean degradation period, degradation probability more precisely than in existing studies. Under Threshold CAC(Call Admission Control) algorithm, we present analytically how to guarantee QoS to users and illustrate the method by numerical examples. The proposed method is expected to be used as one of CAC schemes in guaranteeing predefined QoS level of DPR.

• 조명전기설비학회논문지
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• 제21권4호
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• pp.104-114
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• 2007

In this paper, an Ad-hoc Routing Protocol that works in wireless Ad-hoc communication networks with multiple radios and multiple channels and that controls call admission based on bandwidth measurement is proposed. Unlike the conventional Ad-hoc node with a single radio using a single channel, an Ad-hoc node of the protocol proposed, the MCQosR(Multiple Channel Quality of Service Routing), has multiple radios and uses multiple channels, which allows full duplex transmission between wireless Ad-hoc nodes, and reduces intra interference on the route. Also, a fixed channel only for reception at each node enables the estimation of the available bandwidth, which is used to control the call admission for QoS provision. The performance of the MCQosR was verified by simulation.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제23권5호
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• pp.310-315
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• 2017

Software-Defined Network의 등장은 하드웨어적인 네트워크 기능들을 소프트웨어적인 형태의 모듈로 Controller에 보다 유연하게 적용시키도록 함으로써 전통적인 네트워크의 구조를 변화시키고 있다. 이러한 환경 속에서 최근 네트워크 트래픽에 대한 Quality of Service 및 자원관리와 같은 다양한 관점에서의 네트워크 관리정책에 대한 연구개발이 진행되고 있고, 이러한 관리정책을 뒷받침 할 수 있는 네트워크 모니터링에 대한 기법들 또한 제시되어 왔다. 이에 본 논문에서는 기계 학습 기법인 Naive Bayesian Classification을 통하여 Flow를 분류한 후, 전송 지연 측정 모듈을 통하여 효율적인 전송경로를 선정하는 기법을 제안한다. 이는 다양한 대역폭을 갖는 여러 경로들로 이루어진 네트워크상에서 효율적인 경로 분배 역할을 할 수 있고, 부하를 분산시킴으로써 보다 원활한 네트워크 환경 및 서비스 품질을 제공할 수 있다.

• 산업공학
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• 제14권2호
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• pp.182-189
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• 2001

Recently the number of wireless internet service user is increasing rapidly but there are some areas in which service level has not reached the expected level yet. In this paper, we apply ACSI model to measure the current level of customer satisfaction. As a result of ML estimation, we observe that satisfaction increases as the level of perceived quality increases. However, this model does not provide flexibility of adjusting data characteristics that wireless internet service has, and it is not easy to find direct controllable feedback for better service. We propose a structural equation model that can overcome these problems and obtain that information transmission quality and proper fare policy can significantly improve the satisfaction level of wireless Internet users.