• ETRI Journal
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• 제38권3호
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• pp.444-454
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• 2016

Voice service is very demanding in cognitive radio networks (CRNs). The available spectrum in a CRN for CR users varies owing to the presence of licensed users. On the other hand, voice packets are delay sensitive and can tolerate a limited amount of delay. This makes the support of voice traffic in a CRN a complicated task that can be achieved by devising necessary considerations regarding the various network functionalities. In this paper, the support of secondary voice users in a CRN is investigated. First, a novel packet scheduling scheme that can provide the required quality of service (QoS) to voice users is proposed. The proposed scheme utilizes the maximum packet transmission rate for secondary voice users by assigning each secondary user the channel with the best level of quality. Furthermore, an analytical framework developed for a performance analysis of the system, is described in which the effect of erroneous spectrum sensing on the performance of secondary voice users is also taken into account. The QoS parameters of secondary voice users, which were obtained analytically, are also detailed. The analytical results were verified through the simulation, and will provide helpful insight in supporting voice services in a CRN.

• 한국정보시스템학회지:정보시스템연구
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• 제19권3호
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• pp.237-261
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• 2010

IT service is increasing becoming a critical resource firms have to utilize effectively and efficiently. As the importance of IT service increases, the knowledge sharing between IT service people and users becomes more and more important. In this study, the IT service quality is posited as a critical independent construct that influences knowledge sharing attitude of users which in turn change the knowledge sharing intention. Service satisfaction is placed as a mediator between the quality and attitude to compare direct and indirect effect in the model. Results show that (1) IT service quality influences the knowledge sharing attitude of users directly, and indirectly through service satisfaction, (2) at the same time, however, the direct path from quality to attitude is found to be stronger than the indirect path through satisfaction, and (3) interestingly, satisfaction seems to have no direct effect on intention, but only through the attitude change as can be inferred from the theory of reasoned action. Outcome of this study implies the importance of IT service quality in improving the knowledge sharing activities between users and developers, and interestingly the aim of quality would not be targeted on satisfaction but on attitudinal changes.

• International Journal of Advanced Culture Technology
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• 제7권1호
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• pp.1-7
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• 2019

The purpose of this study is to investigate and analyze the service satisfaction of users using community service, and to suggest directions for continuous growth and high service of social service providers in the future. This study was conducted on G metropolitan cities. T-test and one-way ANOVA were conducted for the comparison of 476 users of social service users by gender, income level, and age. In addition, multiple regression analysis was conducted to identify factors affecting user satisfaction. The statistical package analyzed was SPSS 21.0. As a result of the study, the application process, the satisfaction of the service period, and the satisfaction of the service provider were statistically significant at the income level. In addition, in the age group satisfaction, the application procedure, the satisfaction of the service period, the satisfaction of the service frequency, and the satisfaction of the workforce were statistically significant.

• 서비스연구
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• 제8권4호
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• pp.53-75
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• 2018

공유 자전거（bicycle-sharing）는 제품 서비스 시스템을 공유 경제（sharing economy）에 접목시킨 새로운 협력소비경제의 개념이다. 공유 자전거의 차별적 특징은 자전거 이용자가 자전거를 소유하고 있지 않더라도 자신이 원하는 시간에 원하는 지역에서 자전거를 타고 이동할 수 있다는 점이다. 중국의 경우, 공유 자건거가 제공하는 이러한 편익으로 인해 공유 자전거 이용자는 급격히 증가하고 있는 반면, 공유 자전거의 서비스 체험 품질과 사용자 만족도는 지속적으로 하락하고 있는 상황이다. 본 연구는 중국 내의 유저들이 공유 자전거 서비스 체험을 통해 지각하는 서비스의 품질을 실증분석을 통해 파악하고, 서비스가 제공되는 과정에서 발생할 수 잠재적인 문제점을 도출한 다음, 서비스 품질 제고와 사용 만족도를 높일 수 있는 가장 효과적인 방안을 설계하여 제안하고자 하였다. 실증연구는 서비스 디자인 관점에서 중국 내의 공유 자전거 서비스 경험자들을 대상으로 더블 다이아몬드 모델（Double diamond model)에 기반을 두고 진행되었다. 연구결과, 공유 자전거의 승차 단계에 대한 유저 교류, 흥미 및 통제권에 대한 수요를 만족시킬 수 있는 새로운 컨셉을 고안하였다. 이 콘셉트에서 제공하는 새로운 서비스 체험 방식은 인간 친화적인 것이 특징이며, 무엇보다도, 공유 자전거 이용자(또는 고객)의 잠재된 니즈를 충족시킬 수 있는 가능성을 보여주었다는 점에서 중요한 의미를 부여할 수 있다.

• 한국정보시스템학회지:정보시스템연구
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• 제32권1호
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• pp.1-21
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• 2023

Purpose The purpose of this study is to investigate the intention of early application users in consideration of the characteristics of digital finance-based MyData service users. It is expected that user characteristics will affect the intention to use MyData service, which has not yet been advanced, and accordingly, it will examine how the characteristics of the initial users of MyData service and the intention to use it are connected. Design/methodology/approach The model used in this study is a value-based adoption model (VAM), and a lot of research has been conducted on information technology and online user acceptance and continuous use intention of online users. VAM has been proven useful through empirical analysis in many studies. The value-based acceptance model is a method of analyzing the intention to use Benefits and Sacrifices as the main elements of perceived value. It can be said to be a model that can analyze the benefits of use and the sacrifices to be made. Findings According to the analysis results of this study, it was found that usefulness, enjoyment, and reliability, which are the benefits of MyData service apps, had a positive effect on perceived value, which is partially consistent with existing research results. However, it was found that complexity, which is the sacrifice of MyData service apps, negatively affects perceived value and security has no negative impact. The results of security are considered to be complementary to financial institutions because MyData service deals with financial data based on personal information, and the research hypothesis is rejected because users' demands are relatively low. Therefore, MyData service apps should do more to increase benefits (usefulness, enjoyment, and reliability) than to reduce sacrifice (complexity) to users.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제6권2호
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• pp.110-115
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• 2006

In pure P2P environment, it is possible to provide service by using a little real-time information without using accumulated information. But in case of using only a little information that was locally collected, quality of recommendation service can be fallen-off. Therefore, it is necessary to study a method to improve qualify of recommendation service by using users' context information. But because a great volume of users' context information can be recognized in a moment, there can be a scalability problem and there are limitations in supporting differentiated services according to fields and items. In this paper, we solved the scalability problem by clustering context information per each service field and classifying it per each user, using SOM. In addition, we could recommend proper services for users by quantifying the context information of the users belonging to the similar classification to the service requester among classified data and then using collaborative filtering.

• 한국컴퓨터정보학회논문지
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• 제20권7호
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• pp.77-84
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• 2015

The study is to investigate which features are perceived by Social Network Service(SNS) users as the most required one to further boost the usage of service, and to examine the perception of these features of SNS sites varies according to their demographic and service usage characteristics. The study also is to suggest a few of research propositions on the relationships between required features of SNS sites and characteristics of SNS users, based on statistical analyses. To accomplish these research purposes, the study defined characteristics of SNS users including demographic(gender, age) and service usage one(start time of service usage, service usage place), and required features of SNS sites(system, service, information, emotion) based on the literature review of SNS. The results show, based on the statistical analyses using survey questionnaire on Korean and Chinese SNS users, that there are differences in perception of required features of SNS sites among the respondents grouped by age, start time of service usage, service usage place. Finally, the study proposed three research propositions, based on the analysis result, that could be used in SNS related researches in the future.

• ETRI Journal
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• 제34권3호
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• pp.341-351
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• 2012

We deal with a resource allocation problem for multimedia service discrimination in wireless networks. We assume that a service provider allocates network resources to users who can choose and access one of the discriminated services. To express the rational service selection of users, the utility function of users is devised to reflect both service quality and cost. Regarding the utility function of a service provider, total profit and efficiency of resource usage have been considered. The proposed service discrimination framework is composed of two game models. An outer model is a repeated Stackelberg game between a service provider and a user group, while an inner model is a service selection game among users, which is solved by adopting the Kalai-Smorodinsky bargaining solution. Through simulation experiments, we compare the proposed framework with existing resource allocation methods according to user cost sensitivity. The proposed framework performed better than existing frameworks in terms of total profit and fairness.

• Journal of Communications and Networks
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• 제11권2호
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• pp.175-186
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• 2009

A new medium access control (MAC) scheme embedding physical channels into multiband carrier sense multiple access/collision avoidance (CSMA/CA) networks is proposed to provide strict quality of service (QoS) guarantee to high priority users. In the proposed scheme, two priority classes of users, primary and secondary users, are supported. For primary users physical channels are provided to ensure strict QoS, whereas secondary users are provided with best-effort service using CSMA/CA modified for multiband operation. The performance of the proposed MAC scheme is investigated using a new multiband CSMA/CA Markov chain model capturing the primary user activity and the operation of secondary users in multiple bands. The throughput of secondary users is obtained as a function of the primary user activity and other CSMA/CA parameters. It is shown that the new MAC scheme yields larger throughput than the conventional single-band CSMA/CA when both schemes use the same bandwidth.

• 한국도서관정보학회지
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• 제24권
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• pp.81-106
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• 1996

Without an accurate understanding of information needs of library users, an efficient services can't be implement. And we can expect that there is a difference between query statement and actual information needs of users. It also will occur difference in the process of librarian's interpretation of query statement because of an inaccurate presentation and their different working experiences. It means that there is a communication problems between users and librarians. The purpose of this study is to provide the techniques of face to face communication between users and librarians as a method of efficient library service activities. And focused on the importance of non-language communication. The effectiveness of this study are as follows: 1. With the understanding of information flow, librarians can expand the extent of library services. 2. Knowing that how to communicate with users at the a n.0, ppropriate degree, librarians can improve the communication techniques. 3. Expanding the satisfaction of information services and heitening the reliability of users. 4. From the analysis of user information needs, librarians can convert present system to the proper service-oriented system. 5. Knowing the importance of non-language communication, librarians can improve the service environment.