• Journal of KIISE
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• v.43 no.9
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• pp.963-973
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• 2016

Providing a semantic knowledge system using media ontologies requires not only conventional axiom reasoning but also knowledge extension based on various types of reasoning. In particular, spatio-temporal information can be used in a variety of artificial intelligence applications and the importance of spatio-temporal reasoning and expression is continuously increasing. In this paper, we append the LOD data related to the public address system to large-scale media ontologies in order to utilize spatial inference in reasoning. We propose an RDFS/Spatial inference system by utilizing distributed memory-based framework for reasoning about large-scale ontologies annotated with spatial information. In addition, we describe a distributed spatio-temporal SPARQL parallel query processing method designed for large scale ontology data annotated with spatio-temporal information. In order to evaluate the performance of our system, we conducted experiments using LUBM and BSBM data sets for ontology reasoning and query processing benchmark.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.219-222
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• 2013

Recently, rapid innovation of Smartphone is changing the paradigm of our daily life. With the launch of Apple iPhone, there is an explosion of interest in Smartphone itself as well as Internet-based services using Smartphone are being revitalized. Smartphone users, opinion experts more than 99 percent of the economically active population is using, it has reached the saturation past the early stages of formation. Smartphone is equipped with a general purpose OS possible the implementation of high performance environment similar level as a personal computer. Also, it is a mobile communication terminal scalable which can be removed or installed various applications. New information technology like Smartphone gives us a very important and interesting research issue that is to find and prove the factors influencing the purchase intention. At this point, study identifying on the influence factors to the behavioral intention of Smartphone is very important. This study was targeted a total of 99 research papers that are setting up the related Smartphone in among the research papers published in domestic academic journals since 2008. Empirical research related behavioral intention using was summarized on the papers 76.

• Journal of the Korea Society of Computer and Information
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• v.11 no.2 s.40
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• pp.131-143
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• 2006

The rapid growth of mobile communication technology has provided the expansion of mobile internet services, particularly mobile realtime transaction takes much weight among mobile fields. Current mobile transaction service has serious problems which check its development, such as low bandwidths, hand over, expensive charge system, and low response time. but, There is an increasing demand for various mobile applications to process transactions in a mobile computing fields. In mobile computing environments. A mobile host computing system demands for new concurrency control method to use the bandwidth efficiently, to improve the bottleneck and the response time of transactions. This study suggests about an efficient concurrency control in a mobile computing environment. Concurrency control method in existing method uses two phases locking method. In this method, Many clients can't use the same segment simultaneously, and so useless waiting time increases. The characteristic of this proposed method unlike existing one, Enable the transaction approaching different data in the same segment to minimize the useless waiting time by permitting segments, and therefore improves the coexistence of system. Also, It shows the algorithm of the proposed concurrence control method.

• Journal of the Korea Society of Computer and Information
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• v.15 no.3
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• pp.73-80
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• 2010

The advancement of communication and networking technologies has enabled e-science and commercial application that often require the transport of large volume of data over wide-area network. Schedulable high-bandwidth low-latency connectivity is required to transport the large volume of data. But the public Internet does not provide predictable service performance. Especially, if data providers and users are far away, dedicated bandwidth channels are needed to support remote process efficiently. Currently several network research projects are in progress to develop dedicated connectionsy sA bandwidth scheduler computes an user requested path based on network topology information and link bandwidth allocationsy In this paper, we have proposed an efficient algorithm for finding the earliest time interval when minimum bandwidth and duration are giveny Our algorithm is experimentally compared with the known algorithm.

• The Korean Journal of Applied Statistics
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• v.26 no.6
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• pp.903-913
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• 2013

Social network services generate a considerable amount of social data every day on personal feelings or thoughts. This social data provides changing patterns of information production and consumption but are also a tool that reflects social phenomenon. We analyze negative emotional words from daily blogs to detect the change in blooger sentiment using multivariate control charts. We used the all the blogs produced between 1 January 2008 and 31 December 2009. Hotelling's T-square control chart control chart is commonly used to monitor multivariate quality characteristics; however, it assumes that quality characteristics follow multivariate normal distribution. The performance of a multivariate control chart is affected by this assumption; consequently, we introduce the support vector data description and its extension (K-control chart) suggested by Sun and Tsung (2003) and they are applied to detect the chage in blogger sentiment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.6
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• pp.454-472
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• 2013

The development of wireless network technology and the increasing use of wireless networks to mobile users with a variety of wireless network systems has arisen. Wireless sensor networks, they can be nested together, and the need to switch between the network, depending on your needs. Next Generation Wireless Networks(NGWN) gives the mobile user a wide coverage and optimized service etc. Previous hand off management protocol is not enough to secure support of the NGWN application program. Cross-layer Handoff(CLH) protocol technique has been developed to support between and inside networks of handoff management of NGWN. CLH supports mobility management in a wireless network environment and also utilizes mobility speed and handoff signaling delay information to improve the handoff performance ability. For the analysis of handoff performance ability, we analyzed sensitivity of link layer and network layer, therefore, CLH technique is suggested based on this analysis.

• The Journal of the Korea Contents Association
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• v.8 no.9
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• pp.42-54
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• 2008

In recent years, embedded systems have been expanding their application domains from traditional embedded systems such as military weapons, robots, satellites and digital convergence systems such as celluar phones, PMP(Portable Multimedia Player), PDAs(Personal Digital Assistants) to Next Generation Personal Computers(NGPCs) such as eating PCs, wearable computers. The NGPCs are network-based, human-centric digital information devices diverged from the traditional PCs used mainly for document writing, internet searching and database management. Wearable computers with battery capacity and memory size limitations have to use real-time operating systems with small footprints and low power management techniques to provide user's QoS in spite of hardware constraints. In this paper, we have designed and implemented a low-power RTOS (called eRTOS) for wearable computers. The implemented eRTOS has 18KB footprints and the dynamic power management and the device power management schemes are adapted in it. Experimental results with wearable computer applications show that the low power techniques could save energy up to 47 %.

• The Journal of the Korea Contents Association
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• v.13 no.7
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• pp.1-8
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• 2013

As yet the use of 3D projection mapping facade has been limited to advertising and performance in the outside. And interactive elements are lacking. In this paper, propose a interaction system which control of projection mapping facade for multi-audience participation using smart devices. The system can be interaction for the multi-façade. And single or multiple can participate in the game. A user test based on the result confirmed an effectiveness of the proposed method. This research showed a practical method in which interaction of projection facade system can be used to user devices. The results of this study can be used as a base module for projection facade interaction system. In addition, It can be utilized for converged content development such as performances, games, education and various applications services.

• Journal of KIISE:Software and Applications
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• v.30 no.1_2
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• pp.129-139
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• 2003

The PC cluster architecture is considered as a cost-effective alternative to the existing supercomputers for realizing a high-performance information retrieval (IR) system. To implement an efficient IR system on a PC cluster, it is essential to achieve maximum parallelism by having the data appropriately distributed to the local hard disks of the PCs in such a way that the disk I/O and the subsequent computation are distributed as evenly as possible to all the PCs. If the terms in the inverted index file can be classified to closely related clusters, the parallelism can be maximized by distributing them to the PCs in an interleaved manner. One of the goals of this research is the development of methods for automatically clustering the terms based on the likelihood of the terms' co-occurrence in the same query. Also, in this paper, we propose a method for duplicate distribution of inverted index records among the PCs to achieve fault-tolerance as well as dynamic load balancing. Experiments with a large corpus revealed the efficiency and effectiveness of our method.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.9
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• pp.19-28
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• 2010

The GTS(Guaranteed Time Slot) of the IEEE 802.15.4 standard, which is the contention free access mechanism, is used for low-latency applications or applications requiring specific data bandwidth. But it has some problems such as delay of service due to FIFS(First In First Service) scheduling. In this paper, we proposes a weight based GTS allocation scheme for fair queuing in IEEE 802.15.4 LR-WPAN. The proposed scheme uses a weight that formed by how much more weight we give to the recent history than to the older history for a new GTS allocation. This scheme reduces service delay time and also guarantees transmission simultaneously within a limited time. The results of the performance analysis shows that our approach improves the performance as compared to the native explicit allocation mechanism defined in the IEEE 802.15.4 standard.