• Journal of Communications and Networks
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• 제15권3호
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• pp.283-291
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• 2013

In this paper, we propose new multiuser detectors (MUDs) based on compressed sensing approaches for the large-scale multiple antenna systems equipped with dozens of low-power antennas. We consider the scenarios where the number of receiver antennas is smaller than the total number of users, but the number of active users is relatively small. This prior information motivates sparsity-embracing MUDs such as sparsity-embracing linear/nonlinear MUDs where the detection of active users and their symbol detection are employed. In addition, sparsity-embracing MUDs with maximum a posteriori probability criterion (MAP-MUDs) are presented. They jointly detect active users and their symbols by exploiting the probability of user activity, and it can be solved efficiently by introducing convex relaxing senses. Furthermore, it is shown that sparsity-embracing MUDs exploiting common users' activity across multiple symbols, i.e., frame-by-frame, can be considered to improve performance. Also, in multiple multiple-input and multiple-output networks with aggressive frequency reuse, we propose the interference cancellation strategy for the proposed sparsity-embracing MUDs. That first cancels out the interference induced by adjacent networks and then recovers the desired users' information by exploiting the low user activity. In simulation studies for binary phase shift keying modulation, numerical evidences establish the effectiveness of our proposed MUDs exploiting low user activity, as compared with the conventional MUD.

• 한국정보시스템학회지:정보시스템연구
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• 제29권1호
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• pp.267-287
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• 2020

Purpose Online platform companies can increase the spread of content by communicating with users who have diverse preferences through social networks. Previous studies show the mixed effect on the network overlap, and there was a limited examinations for the underlying mechanism. This study expects high academic and practical implications that can be provided by studying on the user's viewership network. The purpose of this research is to examine the effects of network overlap on the users' viewership for creators of user-generated content in YouTube. We explain the direct and in-direct effects through the content sharing and the valence of user ratings. Design/methodology/approach The data contains 45 channels and 4,085 video clips from YouTube. We control the effect of the categories, channel characteristics, and vide clip characteristics on the viewership. PROCESS macro were used to analyze the direct and in-direct effects of network overlap. Findings The analysis results showed that the network overlap directly affect on the users' viewership. The variable decreases the moderators (i.e., content sharing and the valence of user ratings). This result implies that the users can not satisfy their need for uniqueness which is achieved by content sharing and rating in the overlapped network.

• 한국문헌정보학회지
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• 제49권2호
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• pp.75-109
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• 2015

본 연구에서는 정책정보 이용자의 수요 및 요구조사와 맞춤형서비스 사례분석을 기반으로 이용자맞춤형정책정보서비스 모형을 개발하고자 하였다. 이를 위해 이용자맞춤형서비스 관련 문헌분석, 사례조사, 그리고 정책정보 수요자들을 대상으로 한 설문조사를 수행하였다. 이를 기반으로 본 연구에서는 이용자맞춤형정책정보서비스가 제공해야 할 세부적인 서비스를 정보검색 및 자료제공서비스, 참고정보서비스, 정책정보 네트워크 서비스, 도서관 마케팅서비스, 개인화서비스 등으로 제안하였다.

• Journal of Communications and Networks
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• 제10권4호
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• pp.430-436
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• 2008

Recent studies have convinced that network coding can improve the performance of live media streaming in terms of startup delay, resilience to peer dynamics, as well as reduced bandwidth cost on dedicated streaming servers. However, there still exist some strategy drawbacks and neglected problems which need to be further researched. In addition to the commonly used evaluation parameters of the network and user experiences mentioned above, we focus on additional key factors, playback lag and switch lag, which have not been fully explored in previous work. In this paper, we present SonicStream, a novel and fully implemented live peer to peer (P2P) media streaming system with consideration of rich user experiences, including startup delay, playback continuity, playback lag, switch lag, etc. In pursuit of a further enhanced user experience, we revise traditional peer selection/data scheduling methods. Through a series of experimental evaluations and a cautious comparison with the latest similar work $R^2$, the superior performance of SonicStream has been preliminarily verified.

• 정보관리연구
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• 제42권1호
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• pp.157-171
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• 2011

본 연구의 목적은 컨벤션 활동에 따른 모바일 지원서비스 영역과 세부 지원서비스를 개발하고 사용자 선호도를 분석하는 것이다. 질적인 연구방법을 사용하여 모바일 지원서비스 영역과 세부 지원서비스를 추출하였으며 전문가 서베이 방법을 통해 사용자 선호도를 분석하였다. 연구결과 20개의 지원서비스 영역과 43개의 세부지원서비스 항목들이 추출되었으며 컨벤션 참가자들을 위한 서비스 항목의 설계를 위한 사용자 선호도가 분석되었다.

• Computers and Concrete
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• 제16권2호
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• pp.287-309
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• 2015

FormWorks-Plus is a generalized public domain user-friendly preprocessor developed to facilitate the process of creating finite element models for structural analysis programs. The lack of a graphical user interface in most academic analysis programs forces users to input the structural model information into the standard text files, which is a time-consuming and error-prone process. FormWorks-Plus enables engineers to conveniently set up the finite element model in a graphical environment, eliminating the problems associated with conventional input text files and improving the user's perception of the application. In this paper, a brief overview of the FormWorks-Plus structure is presented, followed by a detailed explanation of the main features of the program. In addition, demonstration is made of the application of FormWorks-Plus in combination with VecTor programs, advanced nonlinear analysis tools for reinforced concrete structures. Finally, aspects relating to the modelling and analysis of three case studies are discussed: a reinforced concrete beam-column joint, a steel-concrete composite shear wall, and a SFRC shear panel. The unique mixed-type frame-membrane modelling procedure implemented in FormWorks-Plus can address the limitations associated with most frame type analyses.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.792-793
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• 2016

최근 의료시스템과 정보통신기술을 융합하여 언제 어디서나 제약을 받지 않고 사용자의 생체정보를 측정하는 웨어러블에 대한 연구가 진행되고 있다. 그러나 기존의 웨어러블 기기는 측정된 생체정보를 모니터링 할뿐 사용자가 위급한상황이 발생할 경우에 대한 대처는 미흡한 실정이다. 본 논문에서는 이러한 문제점을 해결하기 위해 생체정보를 측정하는 센서들과 알고리즘을 활용하여 사용자의 상태를 식별하는 시스템을 제안한다. 이를 통해 사용자가 낙상이나 넘어짐 같은 위험상황이 발생할 경우 지정된 보호자에게 긴급 알림 메시지를 전송하여 위험상황을 신속하게 대처할 수 있을 것으로 사료된다.

• International Journal of Computer Science & Network Security
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• 제21권6호
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• pp.222-230
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• 2021

Mobile wallets have been in continuous demand and developed over the past few years, especially during the COVID-19 pandemic. Several studies have examined user intentions and perspectives. This study develops a conceptual model combining behavioral factors with the technology acceptance model (TAM). The goal is to identify key factors that influence user's intention to adopt mobile payments. This study uses the TAM and the unified theory of acceptance and use of technology (UTAUT) models with additional factors. The additional factors are security, trust, facilitating conditions, and lifestyle compatibility. The study analyzes the results of a survey of 394 Saudi citizens conducted via an online survey. The results indicate that user attitudes and intentions are positively influenced by all of the factors. Perceived usefulness, perceived ease of use, lifestyle compatibility, and facilitating conditions are direct predictors of user behavior in accepting mobile wallet payments. This study provides an empirical contribution to the literature on mobile payment acceptance on the effect of perceived usefulness and lifestyle compatibility. The results demonstrate that about 26% of the respondents started using mobile wallet services because of the COVID-19 pandemic.

• 문화기술의 융합
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• 제7권1호
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• pp.454-460
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• 2021

본 연구의 목적은 포털 뉴스 콘텐츠의 이용정도가 이용자들의 의견·정보 교환이나 사회적 신뢰수준과 어떤 연관성을 가지고 있는지에 대해 실증적으로 분석하는데 있다. 이를 위해 인구 사회학적 대표성을 갖춘 1,100명의 표본을 대상으로 온라인 서베이 조사를 실시했다. 포털 뉴스 이용 정도는 PNRBS(Portal News Readership Behavior Score)라 불리는 복합지수를 구성해 측정했고, 의견·정보교환 정도나 사회적 신뢰수준은 관련 연구들에서 사용된 지표들 중에서 일부를 취합해 구성한 지수로 측정했다. 연구 결과 포털뉴스이용과 사회적 신뢰는 선형적 상관성이 아닌 V자형 관계를 보이고 있었다. 구체적으로 포털 뉴스를 전혀 이용하지 않는 집단의 사회적 신뢰 수준이 가장 높았고 경이용(Light user) 집단의 신뢰 수준이 가장 낮았다. 중이용 집단의 신뢰 수준은 비용자들보다는 낮았지만 경이용자들 보다는 높았다.

• 감성과학
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• 제24권4호
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• pp.79-90
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• 2021

Consumers have an increasingly active role in the marketing cycle, using social media channels to create, distribute, and consume digital content. In this context, this paper investigates the impact of user- and marketer-generated content on consumer purchase intentions and the approach to designing an effective social media marketing platform. Referencing a literature review of social media marketing and consumer purchase intentions, a case study of the social media-marketing platform, 0.8L, was undertaken using both qualitative and quantitative results through content analysis and a participatory survey. First, about 450 consumer reviews for ten sunscreen products posted on the 0.8L platform were compared with products' marketer-generated content. Next, 55 subjects participated in a survey regarding purchase intentions toward moisturizing creams on the 0.8L platform. The results indicated that user-generated content (i.e., texts and photos) provided more personal experiences of the product usage process, whereas marketers focused on distinctive product photos and features. Moreover, customer reviews (particularly high volume and narrative format) had more impact on purchase decisions than marketer information in the online cosmetics market. Real users' honest reviews (both positive and negative) were found to aid companies' prompt and straightforward assessment of newly released products. In addition to the importance of customer-driven marketing practices, distinctive user experience design features of a competitive social media-marketing platform are identified to facilitate the creation and sharing of sincere customer reviews that resonate with potential buyers.