• 한국정보과학회논문지:정보통신
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• 제32권3호
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• pp.404-414
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• 2005

3 세대 이상의 차세대 패킷 기반 이동 통신 시스템은 패킷 네트워크의 특성 때문에 사용자가 받는 서비스의 질이 셀(Cell)의 트랙픽 부하량에 의해 직접적인 영향을 받는 구조로 되어 있다. 또 이동통신 시스템에서 트래픽 집중화 현상은 시스템 자원을 충분히 활용하지 못하면서 호(Call) 탈락률을 높여 전체 시스템 성능이 떨어지는 핫셀(Hot cell) 문제를 야기한다. 그러므로 패킷 네트워크를 기반으로 하는 이동 통신 시스템에서 자원을 효율적으로 사용하기 위해 트래픽을 분산시키는 것은 매우 중요하다. 따라서 본 논문에서는 패킷 기반의 이동 통신 시스템에서 핸드오프 시 주변 셀의 부하 정보를 고려해 몰려있는 트래픽을 주위로 분산시키는 적응적 핸드오프 알고리즘을 제안한다. 또, 패킷 네트워크에서 트래픽 부하를 측정하는 방법으로 MAC 상태도에서 트래픽 전송 및 트래픽 대기 상태에 있는 사용자의 수를 이용하는 기법도 제안한다. 그리고 모의 실험 결과를 통하여 제안하는 핸드오프 기법이 트래픽을 분산시켜 시스템 전체 측면에서의 자원을 효율성을 높이고, 사용자의 서비스 질을 보장함을 보인다.

• 가족자원경영과 정책
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• 제19권2호
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• pp.1-26
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• 2015

The purpose of this study was to analyze the quality of life (QoL) of elderly women and the effect of social support on their QoL. The data were used 'urvey on the Elderly in 2011', which was held from 'Ministry of Health & Welfare' and 'Korea Institute for Health and Social Affairs'. Among the total 15,146 respondents, 3,880 of elderly women whose age was over 65, and who did not live together with their married children were included in the analysis. Multiple regression analysis and path analysis were used to analyze the research model. The findings were as follows. First, from the fact that the elderly women showed the highest mean in 'contact frequency with friends' among social support, it seemed that the elderly women contacted their friends more than their children in their old age. Among the support types from their children, elderly women received emotional support, physical support, instrumental support in order and irregular cash as a way of economic support. Second, from the regression results, the most critical factor that affected the QoL of elderly women was 'subjective physical condition level' and 'subjective standard of living' comes next. Third, the most important factor was 'subjective standard of living' from path analysis results, and 'subjective physical condition level' and 'total amount of annual income' in order. Also, social supports such as 'phone call contact frequency with children', 'emotional support from children', phone call contact frequency with relatives', 'phone call contact frequency with friends' positively affected the QoL of elderly women. Therefore, raising social supports from children, relatives, and friends positively contributes to improve the QoL of elderly women directly and indirectly. The results show that social supporters, which is a part of the structural aspects of social support, and types of social support, which lies in functional aspects, directly affect QoL of the elderly women and turn out to be factors that improve the QoL as mediating variables. It is concluded that the social supports can be the most important resources that make up declining personal and social resources in old age and maintain the QoL of elderly women.

• 기술혁신학회지
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• 제9권4호
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• pp.627-653
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• 2006

국내 이동통신 서비스 제공업체는 하나의 셀룰러 사업자, 두개의 PCS 사업자가 있다. 국내 이동통신 시장의 특징으로서 셀룰러 사업자가 가입자 기준 시장 점유율 50% 이상을 장기간 점유하고 있다. 또한, 2004년 셀룰러 사업자의 당기 순이익 기준 시장 점유율은 80%를 상회하고 있다. 따라서 이러한 시장 구조의 원인을 규명하는 것은 의미 있는 연구라 하겠다. 셀룰러 사업자가 할당받은 주파수 대역의 특징으로 망 구축에 투자하는 비용측면에서 우위에 있음을 상기해 보았을 때, 우리는 할당받은 주파수 대역과 기업 성과에 어떠한 관계가 있음을 유추해 볼 수 있다. 이를 증명하기 위해 우리는 소비자의 관점에서 고객 만족도가 고객 재 가입의향에 긍정적 영향을 끼쳐 소비자의 재가입 행동이 결정되는 연구 모형을 무선인터넷 만족도, 가격 만족도, 부가 서비스 만족도, 통화 품질 만족도, 경쟁사의 이미지를 반영하여 구성하였다. 이 연구모형에 통제변수로서 이동통신사별 할당 주파수 사용 대역이 상이함에 대한 인지를 통제변수로 사용하여 이의 영향을 함께 판별해 보았다. 본 연구의 목적은 1) 이동통신 소비자 재가입 행동을 결정짓는 요인들간 관계를 분석하고, 2) 할당된 주파수 대역이 소비자 재가입 행동에 미치는 영향을 규명하며, 3) 연구 모형을 구조방정식을 사용하여 검정하는 것이다. 구조방정식은 변인들간의 상호 관계를 밝혀내는데 유용한 방법이라고 할 수 있으므로 본 연구에 적용되었다. 연구의 함의와 한계에 대해서는 본론에서 언급하고자 한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1078-1083
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• 2004

We proposed a method to compensate incomplete observations and made a study of environmental problem, water quality of Tama-River in Tokyo.The method is based on interpolations of the multi-layer neural networks. We call the approach as CQSAR method .which can compensate the defect data.The water quality data include defects which will give wrong effect to other normal data. The CQSAR method suppresses the wrong effect .Thus, we believe that the proposed CQSAR method has practical usability for environment examinations.

• 품질경영학회지
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• 제22권2호
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• pp.79-88
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• 1994

Delay has influenced customer satisfaction while using a telephone. It has been ranked second after transmission impairments in annoyance to customers. Therefore, it is important to analyze its behavior not only to increase the quality of service for the customers, but to provide its information to network planners and administrators and to designers of equipment and systems. In this paper, we consider a log-normal model as a candidate for describing the statistical behavior of the post dialling delay, i.e., the time to connect a call to the telephone network after dialling. Based on the real data, the log-normalness of the post dialling delays are convinced for the long distance calls, but not supported for the local calls. Uses of graphical plotting paper and statistical test of fit art discussed.

• 정보관리연구
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• 제40권4호
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• pp.151-171
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• 2009

This study is to investigate dissatisfaction behavior of customers who purchase products on the Internet shopping mall and to find customers' dissatisfaction behavior types for effectively responding to that. Managing dissatisfaction behaviors are related to the customer satisfaction. To conduct this study, Call Center data was collected and analysed by qualitative method. The results showed that dissatisfaction of product quality and disappointment have different effects on post--purchase behaviors. Customers who feel more dissatisfaction with product quality showed the aggressive response such as exchange, refund, while customers who feel disappointment are likely to switch the shopping mall or to cancel the order. These results of customers' dissatisfaction behaviors indicate that company has to manage both product quality and the customer's experience dimension.

• 디지털융복합연구
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• 제9권1호
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• pp.115-124
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• 2011

The property of the mobile phone is taking important role to choose it. In the present situation, exploring, comparing and analyzing the important properties of regular mobile phone(feature phone) and smart phone are very meaningful study. Therefore, the survey was carried out to get the properties of feature phone and smart phone and analyze the difference of those phones. And proposed the important variables for customer satisfaction which must be given priority. The result showed that 'design' and 'Quality' are important to both mobile phone user groups. The problems with mobile phones currently in use were 'poor performance' to feature phone users and 'expensive charge' and 'poor A/S' to smart phone users. Two groups also showed significant difference with the customer satisfactions, and smart phone user group showed higher satisfaction. For smart phone user group, four factors are induced from the properties but 'Hardware Quality' (representing 'call Quality', 'A/S', 'Convenience to use', 'Battery life') and 'Design & Function'(representing 'Internet', 'Convergence Functions', 'Design, 'Color') have significant and positive effects on Customer Satisfaction.

• Journal of the Korean Data and Information Science Society
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• 제17권4호
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• pp.1077-1083
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• 2006

Association rule mining searches for interesting relationships among items in a given database. Association rules are frequently used by retail stores to assist in marketing, advertising, floor placement, and inventory control. There are three primary quality measures for association rule, support and confidence and lift. In this paper we present association rule mining based antecedent variables. We call these rules to antecedent association rules. An antecedent variable is a variable that occurs before the independent variable and the dependent variable.

• Journal of applied mathematics & informatics
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• 제33권1_2호
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• pp.211-217
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• 2015

A dynamic spectrum access scheme with channel partitioning for secondary handover calls in cognitive radio networks is proposed to reduce forced termination probability due to spectrum handover failure. A continuous-time Markov chain method for evaluating its performance such as blocking probability, forced termination probability, and throughput is presented. Numerical and simulation results are provided to demonstrate the effectiveness of the proposed scheme with channel partitioning.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.94-97
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• 1999

In this paper, a new real-time neural network connection admission controller is proposed. The proposed controller measures traffic flows, cell loss rate and cell delay periodically each classes. The Neural network learns the relation between those measured information and service quality by real-time. Also the proposed controller uses the DWRR multiplexer with buffer dedicated to every traffic source in order to measure the delay that cells experience in buffer. Experimental result shows that the proposed method can control effectively heterogeneous traffic sources with diverse QoS requirement.