• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4780-4785
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• 2012

As many mobile devices such as smart phones and tablets are widely spread, optimized mobile video encoder used during video recording application is needed. In this paper, we implemented H.264/AVC base profile video encoder on a mobile device and empirically optimized control parameters of the encoder. As the experiment, we more than 100 test cases were designed with varying Lagrangian optimization, Hadamard Transform, search range, I-frame period, and reference frames. During the experiment, we measured picture quality, bit-rate, encoding time, motion estimation time, and power consumption. From the result, we can determine optimal values for the H.264 control parameters.

• Journal of KIISE:Software and Applications
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• v.30 no.9
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• pp.843-849
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• 2003

Web usage mining is the technique of data mining that analyzes web users' usage patterns by large web log. To use the web usage mining technique, we have to classify correctly users and users session in preprocessing, but can't classify them completely by only log files with standard web log format. To classify users and user session there are many problems like local cache, firewall, ISP, user privacy, cookey etc., but there isn't any definite method to solve the problems now. Especially local cache problem is the most difficult problem to classify user session which is used as input in web mining systems. In this paper we propose a heuristic method which solves local cache problem by using only click stream data of server side like referrer log, agent log and access log, classifies user sessions and completes session.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.11a
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• pp.63-66
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• 2009

기존의 H.264/AVC 비디오 표준은 고화질 비디오 부호화를 지원하지만 고해상도에 특화된 요소 기술이 도입되지 않아 만족할만한 성능을 보이지 못한다. 현존하는 동영상 압축 표준 중 가장 뛰어난 H.264/AVC 표준의 인트라 $16{\times}16$ 예측은 매크로블록에 인접한 최대 33개의 주변 화소를 이용하여 매크로블록에 속한 256개의 화소 값을 예측한다. 특히, 전체 예측 모드 중 수직과 수평 예측 모드에서는 16개의 수직 또는 수평 위치에 위치한 주변 화소로 전체 매크로블록 내의 화소 값을 예측하므로 매크로 블록의 끝으로 갈수록 예측의 정확도가 떨어져 부호화 비트가 증가한다. 고화질 영상에서는 인트라 $16{\times}16$ 모드로 부호화되는 블록이 많으므로 수행되므로 인트라 $16{\times}16$ 예측의 정확도를 높일 수 있는 기술이 필요하다. 본 논문에서는 기존의 H.264/AVC의 예측 방법보다 예측 정확도가 높은 새로운 라인 기반 $16{\times}16$ 인트라 예측 방법을 제안한다. 일반적으로 편평한 특성을 보이는 인트라 $16{\times}16$ 블록이라도 좀 더 가까운 화소를 참조 화소로 사용하면 예측의 정확도를 높여 부호화 비트를 줄일 수 있다. 이를 이용하여 제안하는 알고리즘에서는 인트라 $16{\times}16$ 블록에서 16개 화소 한 줄을 단위로 예측 및 부호화를 수행한다. 1080p HD급 테스트 영상을 이용하여 실험한 결과, 기존의 H.264/AVC FRExt High 프로파일에 비해 평균 약 6.92%의 부호화 비트를 감소시킬 수 있음을 보였다.

• Journal of Broadcast Engineering
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• v.6 no.1
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• pp.82-97
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• 2001

In this paper, we describe a software implementation of a digital TV stream analyzer that can be used for analyzing and verifying digital TV bitstreams on personal computes. It accepts as input MPEG-2 transport streams (TS's) already stored on hard disks and doesn't require any special hardware. After classifying TS packets into program specific information(PSI) TS section auido, video, program clock reference (PCR) private data and null packets, it displays their contents through a graphic user interface along with the syntax elements of the TS header. Also it displays the decoded I frame nearest in time axis the TS packet currently shown This feature helps pin pointing the specific location of problematic parts in bitstreams. The bitsteam analyzer provides the compliance test of MPEG-2 Systems standard and the data injection functionality with which one can easily insert additional data to existing MPEG-2 bitstreams. Using the resulting system one can produce at low test streams for interactive broadcasting and data broadcasting for laboratory use.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.3
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• pp.227-240
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• 2003

When we develop and use the java-based distributed object system, the system developer must deploy distributed object, which is implemented to predefined interface, to network and the system user acquires reference about distributed object and changes reference to interface type. Sharing of interface is essential for these works In this paper, we propose the IRSJ(interface repository service based on jim) to improve efficiency of interface sharing at the JINI system development. the IRSJ is consisted of the java classes for JINI system and interface sharing service. If development teams perform collaborative work in short distance, the IRSJ can search interface file without information of lookup server or interface writer If development teams perform collaborative work in long distance, the IRJS can search interface with only an address of server that executes lookup service. Although the interface object not requires additional search, the interface object that failed search interface can download interface and use interface using remote event model. When the message service fails in interface search, the message service sends interface request message to a development team member who use the IRSJ automatically, so that interface sharing may be possible in short time.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.115-116
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• 2017

In this paper, we propose a standardization strategy for next generation electronic navigational chart which can be classified as S-100 Universal Hydrographic Data Model, to accept various requirements arising from various marine information and services as well as support e-navigation service strategies. IMO uses the next generation electronic chart standard, S-100 as Common Maritime Data Structure. It means that a common data model is needed as a key element for realization of e-Navigation and also points out that a new ICT convergence paradigm is needed not only for marine safety but also for maritime information and services. this paper considers he model-based data representation and reference model in order to understand the content and use of the S-100 standard and also considers the interconnectivity and role of the ISO/TC211 standards, which are being used as base standards for profiling to develop S-100 standard. Finally, we look at what standardization items are required for standardization of next generation electronic navigational chart supporting multi-purpose and how they are used mutually.

• Journal of Cadastre & Land InformatiX
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• v.48 no.1
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• pp.55-70
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• 2018

The field of cadastre and land administration is susceptible to changes in technological development and requires a robust system to respond. In Mongolia, there is a need for a future-oriented and robust cadastral system to cope with these changes. Therefore, this study chose the Land Administration Domain Model (LADM) which is created by the International Organization for Standardization(ISO), and analyzed for its application to the cadastral system of Mongolia. For the application of LADM for Mongolia, we analyzed four packages and each class of LADM based on characteristics of Mongolia's cadastral system and cases of countries applying LADM. As a result of this analysis, we have completed LADM national profiling in Mongolia and proposed the possibility of applying LADM. In the future, based on this research, application of LADM will play an important role in Mongolian cadastral system where the current data model standardization is not established and is useful as a reference model.

• Journal of the Korea Convergence Society
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• v.8 no.10
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• pp.61-66
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• 2017

Recently, IoT technology is rapidly developing with the keyword "Anytime, Anywhere, Convenient". In addition, security problems in IoT systems are exploding and the damage is increasing as well. In this paper, we propose a method to develop IoT system safely by using internationally recognized CC evaluation in ICT by identifying the standardization and security technology development status defining IoT system security requirements. For this purpose, IoT system and service security aspects are analyzed. Based on this, it is possible to design the security functional requirements and to demonstrate the rationale of the security objective through the correspondence relation, and it is possible to design the protection profile for the IoT system. This is a sufficient basis for the development methodology to be presented in this paper because it is used as a means of referring to the set of security requirements of administrators, developers, and users.

• The Journal of Korean Association of Computer Education
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• v.7 no.3
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• pp.45-56
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• 2004

Java provides support for Web, concurrent programming, safety, portability, and GUI, so there is a steady increase in the number of Java users. Java is based on the object-oriented concepts such as classes, instances, encapsulation, inheritance, and polymorphism. However the JVM(Java Virtual Machine) hides most of the phenomena related to the concepts. This is why most of Java users have much difficulty in learning and using Java. As a solution to the problem, I have developed a tool Alpha that visualizes the phenomena occurred in the JVM from the standpoint of the concepts and will describe the design and features of the tool in this paper. For practicality and extendability Alpha has an MVC(Model-View-Controller) architecture and visualizes the phenomena such as object instantiations, method invocations, field accesses, cross-references among objects, and execution flows of threads in the various ways according to the levels and purposes of the users.

• Journal of the Korean Society for Library and Information Science
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• v.35 no.4
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• pp.25-50
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• 2001

The purpose of this study Is to investigate the possibility and the limit of the application of the registration data to the description of records and archives by analyzing of the elements in the registration of records prescribed in the Record and Archives Management Act of Korea. Registration data provides the descriptive information of records at item or file levels. And also the registration data makes an important role of providing the primary descriptive information for progressively describing the series and group level of archives by archivist, which eventually conform the principle of the multi-level description. Therefore the registration of records is one of the management process of records which makes records to be a manageable objects. In addition to that the registration of records is the first level in building the multi-level description of records and archives.