• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1752-1755
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• 2002

The world wide web (WWW) already accounts f3r more Internee network traffic than any other application, including il and simple file transfer. It is also a collaborative technology in a weak sense of the word - it allows people to share information. Synchronous collaboration is where an interactive activity is simultaneous and in teal-time. Computer based real time collaborative systems like shared whiteboards. collaborative editor etc. are only beginning to emerge recently. These applications invoking more than two users exchanging information, require Multicast communication. Multicast communication is a transmission mode that is now supported by a variety of local and wide area networks. Multicasting enables multiparty communication across a wide area to sparsely distributed groups by minimizing the network load. Multicasting itself is one of the key technologies in the nut generation of the Internet This paper describes the technical issues from the aspect of multicast communication and its reliability in synchronous collaborative application.

• Journal of Information Processing Systems
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• 제7권1호
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• pp.137-150
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• 2011

Mobile ad hoc networks are expected to be widely used in the near future. However, they are susceptible to various security threats because of their inherent characteristics. Malicious flooding attacks are one of the fatal attacks on mobile ad hoc networks. These attacks can severely clog an entire network, as a result of clogging the victim node. If collaborative multiple attacks are conducted, it becomes more difficult to prevent. To defend against these attacks, we propose a novel defense mechanism in mobile ad hoc networks. The proposed scheme enhances the amount of legitimate packet processing at each node. The simulation results show that the proposed scheme also improves the end-to-end packet delivery ratio.

• 한국멀티미디어학회논문지
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• 제11권9호
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• pp.1213-1226
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• 2008

추천시스템은 사용자가 제공한 선호, 관심, 구매경험과 같은 정보를 근거로 하여 다른 사용자에게 가장 알맞은 정보를 제공하는 일련의 가치교환 과정인 개인화를 가능하게 하는 시스템으로 고객의 선호도를 정확히 분석하고, 정제하여 정확한 예측력으로 고객이 원하는 가장 적절한 상품을 추천 해줄 수 있어야 한다. 대부분의 추천시스템들이 협동적 필터링 기법을 적용하고 있어 본 논문에서는 협동적 필터링 기법의 연산수행 량을 개선한 새로운 결합 모델인 SOM(Self-Organizing Map) 신경망 회로와 결합한 추천시스템을 제안하였다. 먼저, 사용자 그룹을 인구통계학적인 특징으로 세그먼트하고 SOM 신경망회로를 이용하여 item 특징에 대한 선호도를 입력 값으로 학습하여 클러스터를 생성하였다. 임의의 사용자에 대한 추천은 선호도가 유사한 클러스터를 결정하여 협동적 필터링 기법을 적용하였으며, 기존의 협동적 필터링 기법의 연산 수행량과 비교 분석하였다. 또한 영화를 대상으로 한 실험을 통하여 추천효율이 향상되었음을 나타내었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권5호
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• pp.1516-1539
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• 2022

This article shows a set of physical information fusion IoT systems that we designed for smart buildings. Its essence is a computer system that combines physical quantities in buildings with quantitative analysis and control. In the part of the Internet of Things, its mechanism is controlled by a monitoring system based on sensor networks and computer-based algorithms. Based on the design idea of the agent, we have realized human-machine interaction (HMI) and machine-machine interaction (MMI). Among them, HMI is realized through human-machine interaction, while MMI is realized through embedded computing, sensors, controllers, and execution. Device and wireless communication network. This article mainly focuses on the function of wireless sensor networks and MMI in environmental monitoring. This function plays a fundamental role in building security, environmental control, HVAC, and other smart building control systems. The article not only discusses various network applications and their implementation based on agent design but also demonstrates our collaborative information fusion strategy. This strategy can provide a stable incentive method for the system through collaborative information fusion when the sensor system is unstable in the physical measurements, thereby preventing system jitter and unstable response caused by uncertain disturbances and environmental factors. This article also gives the results of the system test. The results show that through the CPS interaction of HMI and MMI, the intelligent building IoT system can achieve comprehensive monitoring, thereby providing support and expansion for advanced automation management.

• 한국IT서비스학회지
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• 제13권4호
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• pp.93-107
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• 2014

Interests on collaborative research and academic relationship among researchers have been increased. Collaborative researchers can maximize productivity, time and cost savings, and reduce the risk of research. An empirical study on the research productivity of co-authors' network and review efficiency of the reviewer network was conducted based on co-author networks and reviewer networks in Korea Society of IT Service. This study aims to find the characteristics of the co-author and reviewer networks, and to analyze research productivity and review efficiency in order to draw some implications. The meaning of interactions among professional groups was analyzed. Research productivity index was calculated using 728 authors' papers submitted to the society. In order to verify the effects of indicators of social network analysis on research productivity and review efficiency, correlation and regression analyses were used. As a result, the indicators of network centrality did not affect the review efficiency, but affect the research productivity.

• Journal of Information Processing Systems
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• 제11권1호
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• pp.1-21
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• 2015

This paper aims to assess the feasibility of a new and less-focused type of online sociability (the watching network) as a useful information source for personalized recommendations. In this paper, we recommend scientific articles of interests by using the shared interests between target users and their watching connections. Our recommendations are based on one typical social bookmarking system, CiteULike. The watching network-based recommendations, which use a much smaller size of user data, produces suggestions that are as good as the conventional Collaborative Filtering technique. The results demonstrate that the watching network is a useful information source and a feasible foundation for information personalization. Furthermore, the watching network is substitutable for anonymous peers of the Collaborative Filtering recommendations. This study shows the expandability of social network-based recommendations to the new type of online social networks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권7호
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• pp.1749-1773
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• 2024

Recent advances in deep neural networks (DNNs) have greatly improved the accuracy and universality of various intelligent applications, at the expense of increasing model size and computational demand. Since the resources of end devices are often too limited to deploy a complete DNN model, offloading DNN inference tasks to cloud servers is a common approach to meet this gap. However, due to the limited bandwidth of WAN and the long distance between end devices and cloud servers, this approach may lead to significant data transmission latency. Therefore, device-edge collaborative inference has emerged as a promising paradigm to accelerate the execution of DNN inference tasks where DNN models are partitioned to be sequentially executed in both end devices and edge servers. Nevertheless, collaborative inference in heterogeneous edge environments with multiple edge servers, end devices and DNN tasks has been overlooked in previous research. To fill this gap, we investigate the optimization problem of collaborative inference in a heterogeneous system and propose a scheme CIS, i.e., collaborative inference scheme, which jointly combines DNN partition, task offloading and scheduling to reduce the average weighted inference latency. CIS decomposes the problem into three parts to achieve the optimal average weighted inference latency. In addition, we build a prototype that implements CIS and conducts extensive experiments to demonstrate the scheme's effectiveness and efficiency. Experiments show that CIS reduces 29% to 71% on the average weighted inference latency compared to the other four existing schemes.

• 한국IT서비스학회지
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• 제13권2호
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• pp.173-184
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• 2014

As social network services has become one of the most successful web-based business, recommendation in social network sites that assist people to choose various products and services is also widely adopted. Collaborative Filtering is one of the most widely adopted recommendation approaches, but recommendation technique that use explicit or implicit social network information from social networks has become proposed in recent research works. In this paper, we reviewed and compared research works about recommendation using social network analysis and collaborative filtering in social network sites. As the results of the analysis, we suggested the trends and implications for future research of recommendation in SNSs. It is expected that graph-based analysis on the semantic social network and systematic comparative analysis on the performances of social filtering and collaborative filtering are required.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권1호
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• pp.229-240
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• 2012

Advances in MEMS and CMOS technologies have motivated the development of low cost/power sensors and wireless multimedia sensor networks (WMSN). The WMSNs were created to ubiquitously harvest multimedia content. Such networks have allowed researchers and engineers to glimpse at new Machine-to-Machine (M2M) Systems, such as remote monitoring of biosignals for telemedicine networks. These systems require the acquisition of a large number of data streams that are simultaneously generated by multiple distributed devices. This paradigm of data generation and transmission is known as event-streaming. In order to be useful to the application, the collected data requires a preprocessing called data fusion, which entails the temporal alignment task of multimedia data. A practical way to perform this task is in a centralized manner, assuming that the network nodes only function as collector entities. However, by following this scheme, a considerable amount of redundant information is transmitted to the central entity. To decrease such redundancy, data fusion must be performed in a collaborative way. In this paper, we propose a collaborative data alignment approach for event-streaming. Our approach identifies temporal relationships by translating temporal dependencies based on a timeline to causal dependencies of the media involved.

• 한국컴퓨터정보학회논문지
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• 제16권11호
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• pp.17-24
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• 2011

협업적 여과 시스템은 사용자에 대한 클러스터링을 구축한 후, 구축된 클러스터를 기반으로 사용자에게 아이템을 추천한다. 그러나 사용자 클러스터링 구축에 많은 시간이 소요되고, 사용자가 평가한 아이템이 피드백 되었을 경우 재구축이 쉽지 않다. 본 논문에서는 영화 추천 시스템에서의 사용자 클러스터링의 재구축 시간을 단축시키기 위해서 빈발 패턴 네트워크를 이용하여 사용자가 선호하는 장르 패턴을 추출하고, 추출된 패턴을 통해 사용자 클러스터링을 구축한다. 구축된 사용자 클러스터링을 협업적 여과에 적용하여 사용자에게 영화를 추천한다. 사용자 정보가 피드백 될 때, 전통적 협업적 여과는 사용자 클러스터링을 재구축하기 위해 모든 이웃 사용자를 재탐색하여 클러스터링 한다. 하지만 빈발 패턴 네트워크를 이용하여 장르 패턴 기반의 사용자 클러스터링을 적용한 협업적 여과는 사용자 클러스터링을 재구축시 사용자 탐색 공간을 국한시킴으로써 탐색 시간을 줄일 수 있다. 제안하는 장르 패턴기반의 사용자 클러스터링을 통해 사용자 정보가 피드백 된 후 사용자 클러스터를 재구축시 소요되는 시간을 줄일 수 있고, 전통적인 협업적 여과 시스템과 유사한 성능의 추천이 가능하게 되었다.