• Journal of Broadcast Engineering
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• v.22 no.1
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• pp.1-14
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• 2017

This paper proposes adaptive reference structure decision method to improve the performance of HEVC (High Efficiency Video Coding) encoder. When an event occurs in the input sequence, such as scene change, scene rotation, fade in/out, or light on/off, the proposed algorithm changes the reference structure to improve the inter prediction performance. The proposed algorithm divides GOP (Group Of Pictures) into two sub-groups based on the picture that has such event and decides the reference pictures in the divided sub-groups. Also, this paper proposes fast encoding method which changes the picture type of first encoded picture in the GOP that has such event to CRA (Clean Random Access). With the statistical feature that intra prediction is selected by high probability for the first encoded picture in the GOP carrying such event, the proposed fast encoding method does not operate inter prediction. The experimental result shows that the proposed adaptive reference structure decision method improves the BD-rate 0.3% and reduces encoding time 4.9% on average under the CTC (Common Test Condition) for standardization. In addition, the proposed reference structure decision method with the picture type change reduces the average encoding time 12.2% with 0.11% BD-rate loss.

• Journal of KIISE:Information Networking
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• v.35 no.6
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• pp.538-548
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• 2008

In the Internet Engineering Task Force(IETF), Next Step in Signaling(NSIS) working group, proposed a mechanism to discover the Crossover Node(CRN), when the route is changed by Mobile Node(MN) handover. The CRN is divergence or convergence node on old and new path for reserving resources. Trough the CRN discovery mechanism, it possible to reduce a signaling delay and avoid the redundant reservation on the common path between old and new path. However, the QoS(Quality of Service) can be guaranteed continuously while the MN is performing handover, it is needed to pre-reserve the resource on the new path before completion of the handover. When the nodes on the new path try to make a pre-resource reservation before the handover, it is difficult to pre-reserve the resource with the existing CRN discovery mechanism. Therefore, we proposed a Passive CRN(PCRN) discovery scheme and pre-resource reservation mechanism. The PCRN which means an initial common point between the current reserved and the new paths, where the handover can take place.

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.186-195
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• 2009

This research is intended to provide basal material on institute composition of nursing homes that will be built in the near future. According to the result, five of the passages are central type, one of them is extensive type, and the other is group type. Secondly, in living space bedroom area is widest, and both sizes of bedroom system and floor heating system are the same. Thirdly, the sizes of clinic room and physical therapy room are similarly widest in medical space, and people use physical therapy room most frequently. Fourth, dining room and kitchen area are widest in public space, and it is hard to move to program room. Fifth, office area is widest in superintendent space, and it is located near lobby on the first floor. Sixth, the dimension per individual doesn't reach the standard of bedroom size per individual. Seventh, in each space, the rate of whole dimension of living space is highest.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.12C
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• pp.208-217
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• 2001

In mobile Internet environment, providing multicast requires much more complex mechanism comparing with the unicast Mobile IP routing protocol. This is because multicast datagrams are sent to a group address that do not belong to a specific network. The IETF Mobile IP suggested two approaches for mobile multicasting, namely remote subscription and hi-directional tunneling. In remote subscription, a mobile node may join a group via a local multicast router on the visited subnet. Therefore remote subscription may cause much datagram loss while reconstructing the delivery tee. In bi-directional tunneling, a mobile node may join a group via a hi-directional tunnel to its home agent. Bi-directional tunneling may suffer from inefficient routing. In this paper, we proposed a new mobile multicasting protocol, Mobile If Multicast using Local Broadcast(MIMLB) which can receive multicast datagrams as fast as possible and optimize routing path for multicast delivery. The MIMLB protocol uses hi-directional tunneling to receive multicast datagrams. And the MIMLB protocol can resolve datagram duplicated problem and optimize routing path by using local broadcast. Simulation results show that MIMLB reduces delivery path length and optimizes multicast routing path when a mobile nod? moves into a foreign network.

• The Journal of the Korea Contents Association
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• v.14 no.10
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• pp.20-31
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• 2014

Recently, cache sharing methods have been studied in order to effectively reply to user requests in mobile P2P networks. In this paper, we propose a cache sharing scheme based on a cluster considering the peer connectivity in mobile P2P networks. The proposed scheme shares caches by making a cluster that consists of peers preserving the connectivity among them for a long time. The proposed scheme reduces data duplication to efficiently use the cache space in a cluster. The cache space is divided into two parts with a data cache and a temporary cache for a cache space. It is possible to reduce the delay time when the cluster topology is changed or the cache data is replaced utilizing a temporary cache. The proposed scheme checks the caches of peers in a route to a cluster header and the caches of one-hop peers in order to reduce the communication cost. It is shown through performance evaluation that the proposed scheme outperforms the existing schemes.

• Explosives and Blasting
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• v.24 no.1
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• pp.21-28
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• 2006

Rock mass classification systems such as RMR and Q system have been widely served as a simple empirical approach for the design of various rock mass structures in the stage of site survey as well as under the construction. For the RQD determination, the boring is partially carried out and what is more, the survey boring is not normally carried out under construction. Therefore RQD is frequently determined by empirical method or indirect method. Since it is difficult to determine the discontinuity characteristics such as RQD, spacing, persistence, filling and so on, it is essential to develop suitable and simple systems without drilled core and a cert 없 n number of representative parameters. One of the primary objectives of the classification systems for a practicing engineer has been to make it simple to use as a preliminary design tool for the structures in rock mass. In the present study, the modifications for both the RMR and GSI system are suggested by authors to introduce new classification system as well as to improve the scope of some of the existing classification systems for a practicing engineer.

• The KIPS Transactions:PartD
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• v.12D no.4 s.100
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• pp.507-520
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• 2005

The R-trees are usually used for an index of trajectories in moving-objects databases. However, they need to access a number of nodes to trace same trajectories because of considering only a spatial proximity. Overlaps and dead spaces should be minimized to enhance the performance of range queries in moving-objects indexes. Trajectories of moving-objects should be preserved to enhance the performance of the trajectory queries. In this paper, we propose the TP3DR-tree(Trajectory Preserved 3DR-tree) using clusters of trajectories for range and trajectory queries. The TP3DR-tree uses two split policies: one is a spatial splitting that splits the same trajectory by clustering and the other is a time splitting that increases space utilization. In addition, we use connecting information in non-leaf nodes to enhance the performance of combined-queries. Our experiments show that the new index outperforms the others in processing queries on various datasets.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.387-394
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• 2013

Data mining is the process of discovering hidden, non-trivial patterns in large amounts of data records in order to be used very effectively for analysis and forecasting. Because hundreds of variables give rise to a high level of redundancy and dimensionality with time complexity, they are more likely to have spurious relationships, and even the weakest relationships will be highly significant by any statistical test. Hence cluster analysis is a main task of data mining and is the task of grouping a set of objects in such a way that objects in the same group are more similar to each other than to those in other groups. In this paper system implementation is of great significance, which defines a new definition based on information-theoretic entropy and analyse the analogue behaviors of objects at hand so as to address the measurement of uncertainties in the classification of categorical data. The sources were taken from a survey aimed to identify of job guidance from students in high school pyeongtaek. we show how variable precision information-entropy based rough set can be used to group student in each section. It is proved that the proposed method has the more exact classification than the conventional in attributes more than 10 and that is more effective in job guidance for students.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.3
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• pp.269-275
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• 2004

Geographic data have widely been applied in different areas including landuse, city planning and management, environment, disaster management and even daily use of citizens. Since geographic data have been built individually using different methods, many problems such as data inconsistency, duplicated investment, and confusion in decision making have arisen. Thus, the necessity of national framework database that can be shared by different areas has increased. As a result, eight fields of the framework database were defined by NGIS Law and 19 detailed items were selected. This study used the AHP (Analytical Hierarchy Process) and the decision tree to evaluate the relative importance of the items (eg. roads, railroads, coastline, surveying control points, and etc.) and presented the groups classified according to the priorities of the items. The result of this study is believed to contribute to effective budget planning for building national framework database.

• Information and Communications Magazine
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• v.31 no.5
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• pp.39-45
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• 2014

기업활동에서 IT에 대한 의존도가 증가함에 따라 기업들은 다양한 소프트웨어 및 하드웨어 플랫폼에서 제공되는 서비스들을 운영하고 있다. 서비스들이 보급, 확대되는 과정에서 새로운 보안 취약점들이 나타나고, 이들 취약점을 악용한 기업정보의 유출 및 해킹 등 보안사고의 발생도 비례하여 증가하고 있다[1]. 특히 다양한 유형의 사업을 운영하는 지주회사 또는 대기업 그룹사의 경우, 사업영역별로 운영 중인 IT 인프라의 보안 취약점이 네트워크로 연결된 타 사업용 IT 인프라에 대한 사이버 침해의 통로로 악용될 가능성이 있다. 이 같은 문제의 해결을 위해 기업들은 사업영역 별로 보유한 IT 인프라의 보안 취약점 진단과 대응을 위한 솔루션들을 도입, 운영해 오고 있다. 하지만 기업의 보안 거버넌스 관점에서 보안 취약점 관리도 전사적인 보안 정책과의 연계 강화, 투자 중복의 방지, 효과적인 관리와 통제에 대한 필요성이 대두되기 시작했다. 보안 거버넌스 체계 강화에 대한 기업의 요구변화에 맞춰 보안 취약점의 통합관리를 지원하는 상용 솔루션들이 일부 출시되고 있으나 기업들이 기 운영하고 있는 개별 취약점 진단 솔루션과의 연동, 로그관리 및 기업이 요구하는 특화된 기능 구현 등의 어려움이 도입에 장애가 되고 있다. 따라서, 대기업을 중심으로 개별 보안 취약점 진단 솔루션들을 연동하여 기업보안 거버넌스를 효과적으로 지원할 수 있도록 취약점 관리업무 프로세스의 재설계와 함께 취약점 진단 통합관리 체계를 구축하고 있다[2][3][4]. 본고는 보안 취약점 관리업무의 문제점을 소개하고, 최근 대 기업을 중심으로 활발히 구축이 추진되고 있는 웹 기반의 취약 점 진단 통합관리 체계의 개념, 기능 및 운영 프로세스를 소개한다. 아울러, 기업 IT 인프라에 대한 보안 취약점 진단 데이터를 축적하여 기업 내부의 보안위험 요소를 사전예측하고, 정보보호의 투자 대비 효과(ROSI: Security Return on Investment)를 효과적으로 산정하는 인프라로서 활용 가치를 소개한다.