• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권3호
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• pp.1065-1085
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• 2020

With rapid growth of content demands, device-to-device (D2D) content sharing is exploited to effectively improve the service quality of users. Considering the limited storage space and various content demands of users, caching schemes are significant. However, most of them ignore the influence of the asynchronous content reuse and the selfishness of users. In this work, the user preferences are defined by exploiting the user-oriented content popularity and the current caching situation, and further, we propose the social-aware rate, which comprehensively reflects the achievable contents download rate affected by the social ties, the caching indicators, and the user preferences. Guided by this, we model the collaborative caching problem by making a trade-off between the redundancy of caching contents and the cache hit ratio, with the goal of maximizing the sum of social-aware rate over the constraint of limited storage space. Due to its intractability, it is computationally reduced to the maximization of a monotone submodular function, subject to a matroid constraint. Subsequently, two social-aware collaborative caching algorithms are designed by leveraging the standard and continuous greedy algorithms respectively, which are proved to achieve different approximation ratios in unequal polynomial-time. We present the simulation results to illustrate the performance of our schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권5호
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• pp.1146-1165
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• 2013

Collaborative awareness between persons with various smart multimedia devices is a new trend in the Internet of Things (IoT). Because of the mobility, randomness, and complexity of persons, it is difficult to achieve complete data awareness and data transmission in IoT. Therefore, research must be conducted on mobile-aware service models. In this work, we first discuss and quantify the social relationships of mobile nodes from multiple perspectives based on a summary of social characteristics. We then define various decision factors (DFs). Next, we construct a directed and weighted community by analyzing the activity patterns of mobile nodes. Finally, a mobile-aware service routing algorithm (MSRA) is proposed to determine appropriate service nodes through a trusted chain and optimal path tree. The simulation results indicate that the model has superior dynamic adaptability and service discovery efficiency compared to the existing models. The mobile-aware service model could be used to improve date acquisition techniques and the quality of mobile-aware service in the IoT.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권1호
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• pp.152-171
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• 2019

In opportunistic networks, nodes may appear some selfishness while transmitting the message, however, most of the existing research works consider the individual selfishness or social selfishness respectively, and these two types of selfishness may coexist in opportunistic networks. In this paper, we propose an Incentive Aware Routing based on Game Theory for selfish OPPNETs, named IAR-GT, which uses Rubinstein-Stahl bargaining game model to incentivize selfish nodes cooperation in data forwarding. IAR-GT scheme not only considers the resources of nodes, but also uses a new method to calculate the social ties between them. Trace-driven simulations show that our incentive aware routing scheme achieves better performances than comparing schemes under two types of selfishness coexistence environments.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권8호
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• pp.3568-3584
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• 2016

In mobile opportunistic networks (MONs), human-carried mobile devices such as PDAs and smartphones, with the capability of short range wireless communications, could form various intermittent contacts due to the mobility of humans, and then could use the contact opportunity to communicate with each other. The dynamic changes of the network topology are closely related to the human mobility patterns. In this paper, we propose a social motivation-aware mobility model for MONs, which explains the basic laws of human mobility from the psychological point of view. We analyze and model social motivations of human mobility mainly in terms of expectancy value theory and affiliation motivation. Furthermore, we introduce a new concept of geographic functional cells, which not only incorporates the influence of geographical constraints on human mobility but also simplifies the complicated configuration of simulation areas. Lastly, we validate our model by simulating three real scenarios and comparing it with reality traces and other synthetic traces. The simulation results show that our model has a better match in the performance evaluation when applying social-based forwarding protocols like BUBBULE.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(A)
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• pp.116-119
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• 2011

Mobile devices are increasingly used, and changed persons' social habits of creating new relationship. While existed systems can not satisfied the principles of user-centered, convenient and ensure privacy. This paper describes an intelligent name-card exchange technique in context-aware smart phone, which has no verbose user operation, ability of intelligent match based on context-aware information, and privacy protection.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2013년도 춘계 종합학술대회 논문집
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• pp.51-52
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• 2013

Recent advances in WSN and the wide use of social sensing technologies have been changing our daily lives. In the process of creating intertwining connections and interconnections greatly influencing on the way we communicate with other people, WSN and social communication media have a number of important capabilities that support their utilization in distress broadcast during emergency situations. This paper proposes a system model that makes better utilization of WSN and social sensing capabilities in sending out distress messages to the intended recipients more efficiently and effectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권10호
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• pp.2732-2749
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• 2023

Device-to-Device (D2D) communication has received increasing attention and been studied extensively thanks to its advantages in improving spectral efficiency and energy efficiency of cellular networks. This paper proposes a novel relay selection algorithm for multi-hop full-duplex D2D communications underlaying cellular networks. By selecting the relay of each hop in a reverse manner, the proposed algorithm reduces the heavy signaling overhead that traditional relay selection algorithms introduce. In addition, the social domain information of mobile terminals is taken into consideration and its influence on the performance of D2D communications studied, which is found significant enough not to be overlooked. Moreover, simulations show that the proposed algorithm, in absence of social relationship information, improves data throughput by around 70% and 7% and energy efficiency by 64% and 6%, compared with two benchmark algorithms, when D2D distance is 260 meters. In a more practical implementation considering social relationship information, although the proposed algorithm naturally achieves less throughput, it substantially increases the energy efficiency than the benchmarks.

• 한국가구학회지
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• 제26권4호
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• pp.334-345
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• 2015

The social design, which appeared at the end of the 19th century, is getting attention along with problems in modern society. The purpose of this paper is to analyze several cases of social furniture designs, and to present its necessity and future direction. It classifies the cases of furniture, lighting and design project regarding social design into three types. First is furniture design for social minority. Second is sustainable design, and third is social design that delivers social message. The expected effects of social design are cost-efficiency, sociality, and environment-friendliness. Also, social design requires certain direction which is first; the designer should recognize the minorities in the world. Second, the designer is obliged to accomplish social mission, and last, he or she should be aware that the design creates added values.

• 한국콘텐츠학회논문지
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• 제17권5호
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• pp.602-612
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• 2017

본 연구는 사회적기업이 추구하는 사회적 가치와 경제적 가치에 대한 근로자들의 인식을 확인하여 사회적기업 종사자 교육을 위한 함의를 제공하기 위해서 수행되었다. 주요 연구결과는 다음과 같다. 첫째, 사회적기업 근로자들의 절반 이상이 경제적 가치와 사회적 가치를 모두 동일하게 중요하다고 인식하고 있었다. 또한, 기업의 사회적 가치의 실현의 책임에 대해서는 종사자 보다는 경영자 책임을 다소 높게 보고 있었으며, 사회적기업 외부에 대한 사회적 가치를 기업 내부와 구성원을 위한 가치 보다 우선적으로 추구해야 한다고 인식하였다. 그러나 사회적기업의 사회적 가치 실현을 위한 목표설정 노력은 부족하였다. 둘째, 사회적기업 근로자들은 대체로 경제적 가치에 대하여 높은 인식을 가지고 있었고, 경제적 가치의 실현을 위해서는 종사자 보다 경영자의 책임과 노력이 더 중요하다고 인식하고 있었다. 셋째, 근로자의 연령이 높을수록 경제적 가치 보다 사회적 가치의 중요성을 높게 평가하고 경영자 책임을 강조하였다. 아울러 근로자의 근무경력이 적을수록 사회적 가치를 중요하게 여기고 경영자의 책임을 중요시하고 있었다. 영리기업 근로자들이 상대적으로 경제적 가치의 중요성을 높게 인식하는 반면에 비영리기업 근로자들은 사회적 가치의 중요성을 높게 인식하고 있었다. 향후 사회적기업의 사회적 가치와 경제적 가치를 근로자들이 균형있게 인식할 수 있는 교육지원 프로그램이 필요할 것이다. 또한 사회적기업의 가치측정을 위한 표준화된 척도를 개발하고 지속적으로 모니터링하기 위한 노력이 요구된다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.573-576
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• 2014

본 논문에서는 상황인식 기법을 이용한 관광 소셜 네트워크 서비스(Social Network Service: SNS)를 제공한다. 이를 위해서 사용자에게 제공되는 서비스는 자연스럽고 의인화된 처리가 필요하다. 즉, 사용자에게 제공하고자 하는 서비스 객체는 사용자의 행위를 저장 분석하고 이를 처리하는 기능을 제공해야 한다. 본 논문에서는 사용자들에게 개인화된 서비스를 상황인식에 따라 제공할 수 있도록 분석 처리하기 위한 알고리즘을 제공한다. 제공되는 서비스는 소셜 네트워크 서비스를 제공하는 알고리즘으로 '친구 추천 알고리즘'을 통해 사용자간의 관계 맺기를 보조하고, '관광지 추천 알고리즘'을 통해 사용자로 하여금 유의미한 관광지를 추천하는 방법을 연구하였다. 특히 가이드의 이용에서 서버는 사용자의 현재 위치와 여러 사용자들의 과거 방문 기록을 상황인식 기반으로 분석하여 최적의 여행 경로를 제공하는 서비스로 '관광지 여행 경로 추천 알고리즘'을 사용하였다. 이러한 관광 소셜 네트워크 기술은 사용자에게 보다 편의성과 친밀성 있는 서비스를 제공한다. 제안된 상황인식 기반의 관광 소셜 네트워크 서비스 응용기술로 제공되는 관광가이드 시스템은 보다 다양한 응용서비스로 적용될 수 있을 것으로 기대된다.