• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.135-145
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• 2012

This study is a research development case study on the free-standing Network based camera video recording DVR. The DVR devices till now have recorded data by converting and compressing analogue video to digital, but in the future, digital videos will be recorded directly through the network camera. Also, digital compressing methods are progressing from MPEG-4, MJPEG, to H.264 method, with products considering high definition compression efficiency, minimized data size, network compatibility, and fast pending time. According to this, in 2012, it is predicted that network camera and video devices throughout the world will outrun the current analogue devices. With this transition of technological environment and fast product pending speed, a new, quality focused design is required for product development including technical realization, reliability, high-definition, compression technology, will be essential. Manufacturers are researching a new direction for the product appearance. This study considers the actual end-users as the design target and through consumer survey on preferences, design needs and required elements necessary in the design development process are extracted. Furthermore, usability and preferred images were explored through literature study and market research. Through this research process, appropriate forms for the network based DVR were analyzed, and applied into the design development process. This product will take into consideration its competitiveness and the significance of USP(Unique Selling Proposition) which is the design supremacy and professional technical skills.

• Journal of the Korea Society of Computer and Information
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• v.19 no.1
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• pp.77-84
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• 2014

In this paper, we propose the hierarchical network synchronization scheme that is backward compatible for the existing commercial system, efficient for total system performance, and whose hardware modification is minimized. This system performance is, the relationship among bandwidth efficiency, complexity and MODEM performance, and superiority of network system applicability. The proposed structure can remedy the high hardware complexity and the lower accuracy of network sychronization that the existing satellite communication terminal system in the star network based on TDM/MF-TDMA of DVB-S2/RCS standards has. Besides, It has high efficiency in view of cost and system performance if the system designed for satellite broadcast requires system upgrade. In the body section, its hardware complexity and system performance of the proposed algorithm is analysed theoretically and treated with the related parameters(symbol rate, spreading factor, etc.) and the BER performance of control channel through the computer simulation for its verification that it can be applied for communications system.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.7
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• pp.61-70
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• 2017

In this paper, an Ethernet equalizer that compensates for automotive temperature variations within a broad range is presented. Communications in automotive systems have become increasingly important because of the many electronics in vehicles. Ethernet protocols are a good candidate for automotive communications. However, they should satisfy the AEC-Q100 requirements that stipulate an operational temperature range from -40 to $150^{\circ}C$. This paper proposes an Ethernet equalizer that can recover data up until 100 m length of CAT-5 cable adaptively within a temperature range of -40 to $150^{\circ}C$. To support the wide temperature range, a feedback system is used. The proposed equalizer has a bandwidth of 31.25 MHz with a fully-differential structure and is implemented in a Hynix $0.13{\mu}m$ BCDMOS technology.

• The KIPS Transactions:PartD
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• v.9D no.1
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• pp.43-56
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• 2002

Most of works have been performed on representation of spatiotemporal objects from various points of view. Most of them represent spatiotemporal objects using approaches from GIS, temporal databases, object-oriented databases or data type. Spatiotemporal objects can be classified as objects whose position and shape changes discretely over time, objects whose position changes continuously and objects whose shape changes continuously as well as position. Previous works on spatiotemporal model have focused on only one of them. In this paper, we propose a spatiotemporal model that can represent three types of objects in Euclidean plan. For this purpose, we represent both discrete and continuous moving objects by defining temporal model extended from valid time and by defining relationship between two consecutive versions of objects. The proposed spatiotemporal object model is based on open GIS specification so that it has compatibility with existing spatial data model.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.1
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• pp.87-98
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• 2008

Electronic Navigational Charts (ENCs) are digital charts encoded in S-57 format, which contain navigational informations such as coastlines, depth areas, and nautical marks. Although they have been successfully used for the safe navigation of ships, they have limited usages and applications because of their specialized data format and access systems. To cope with such drawbacks, S-57 ENCs need to be transformed into more generalized format such as Geography Markup Language (GML). The transformed GML ENCs can be kept in a database for efficiency, and can be accessed through Internet for usability. This paper proposes a new method for transforming and managing ENCs with XML database. S-57 ENCs are lust transformed into GML format, and then stored in a XML database. On the database, users can query for their needs. To validate the feasibility of the proposed method, we developed a protype system, and then conducted several test runs. The system can provide users with easy access to the marine information contained in ENCs. It also provides compatibility and efficiency by virtue of GML and XML database, respectively.

• Spatial Information Research
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• v.23 no.6
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• pp.43-55
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• 2015

Currently, each organization has developed its gridded data in the form of respective grid system for its own purpose. Interoperability among the organization had been limited and resulted in inconvenient data access and application across domains. In this study, we investigated potential standards for National grid system and their strength and weakness. We also reviewed existing gridding schemes and had a survey of demand about grid system to those who have used or would plan to use gridded data in academic and business sectors. As the result of survey of demand, we suggested national grid system for national grid data integration management system which has the mutual compatibility and also proposed sharing scheme of the grid type for users who need to grid data.

• Smart Media Journal
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• v.12 no.4
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• pp.27-40
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• 2023

Many researchers have investigated ways to enhance recommender systems by integrating heterogeneous data to address the data sparsity problem. However, only a few studies have successfully integrated heterogeneous data using knowledge graph. Additionally, most of the knowledge graphs built in these studies only incorporate explicit relationships between entities and lack additional information. Therefore, we propose a method for expanding knowledge graphs by using deep learning to model latent relationships between heterogeneous data from multiple knowledge bases. Our extended knowledge graph enhances the quality of entity features and ultimately increases the accuracy of predicted user preferences. Experiments using real music data demonstrate that the expanded knowledge graph leads to an increase in recommendation accuracy when compared to the original knowledge graph.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.12
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• pp.149-158
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• 2005

This paper proposes a congestion avoidance algorithm which provides stable throughput and transmission rate regardless of buffer size by limiting the TCP congestion window in fixed bandwidth networks. Additive Increase, Multiplicative Decrease (AIMD) is the most commonly used congestion control algorithm. But, the AIMD-based TCP congestion control method causes unnecessary packet losses and retransmissions from the congestion window increment for available bandwidth verification when used in fixed bandwidth networks. In addition, the saw tooth variation of TCP throughput is inappropriate to be adopted for the applications that require low bandwidth variation. We present an algorithm in which congestion window can be limited under appropriate circumstances to avoid congestion losses while still addressing fairness issues. The maximum congestion window is determined from delay information to avoid queueing at the bottleneck node, hence stabilizes the throughput and the transmission rate of the connection without buffer and window control process. Simulations have performed to verify compatibility, steady state throughput, steady state packet loss count, and the variance of congestion window. The proposed algorithm can be easily adopted to the sender and is easy to deploy avoiding changes in network routers and user programs. The proposed algorithm can be applied to enhance the performance of the high-speed access network which is one of the fixed bandwidth networks.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.8
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• pp.287-296
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• 2018

In the recent commercial DBMS market, as the users' burden and complaint which are related to high price licensing policy and late technical support service are increasingly rising, the concern for use of open source DBMS which has no problem with compatibility or stability is escalating. Due to the fact, the cases saving the cost are growing by converting Oracle Corporation's applications, which has about 60% share in the DBMS market, to an open source DBMS. However, in converting non-interchange sentences to an ANSI standard-based open source DBMS because of the use of PL/SQL in Oracle Corporation provides, a lot of manual work accompanies, so there is a lot of loss of time and money. Therefore, a tool that automatically converts PL/SQL to standard SQL is required. The proposed automation tool for the conversion of applications converts PL/SQL to Java Stored Procedure, an open source DBMS-based ANSI standard programming language. Through carrying out a test on the automation tool, it is proved that the tool will contribute to shortening time and saving cost by verifying the identity of input-output data and its reliability after correcting errors in converting to Java Stored Procedure.

• 한국공간정보시스템학회:학술대회논문집
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• 2002.03a
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• pp.83-88
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• 2002

최근 들어 무선인터넷 및 모바일 컴퓨팅 기술의 급속한 발전과 함께 향후 그 수요가 증대될 것으로 예상되는 분야가 위치기반 서비스(LBS: Location Based Service) 기술이다. 위치기반 서비스는 이동 통신을 통하여 사람 및 사물의 위치를 파악하고 이를 활용한 부가 응용 서비스로 국가 정보기술 인프라의 주요 영역을 점유하고 있는 GIS의 차세대 핵심 기술로 발전이 예상되는 분야이다[3][4]. 현재 3GPP나 3GPP2, OGC, LIF와 같은 여러 표준화 기구 및 산업체에서 위치기반 서비스와 이를 위한 시스템에 대한 연구가 진행중이며 위치기반 서비스를 위한 데이터 모델 표준화 연구는 거의 이루어지지 않고 있는 상황이다. 위치기반 서비스를 위한 데이터 표준화 모델은 이미 구축된 공간 데이터베이스의 재사용과 위치기반 서비스들간의 상호 운용성을 지원할 수 있어야 한다. 본 연구에서는 위치기반 서비스들 간의 상호 호환 및 통합을 가능하게 하고, 기존 공간데이터베이스와 연계하여 이 데이터를 위치기반 서비스에 활용하기 위한 공간 데이터 표준화 모델을 제안하고자 한다. 이를 위해 위치기반 서비스 표준화 사례를 조사하고, 위치기반 서비스를 위한 공간 데이터 모델을 제시하였다. 본 연구에서는 OpenLS의 위치기반 서비스를 기본서비스로 하고, OpenGIS의 공간 데이터 모델을 기반으로 네 가지 기본 위치 데이터 타입과 모델의 요구 사항을 포함하는 공간 데이터 표준모델을 개발하였다. 위치기반 공간 데이터 표준 모델은 위치기반 서비스와 데이터들과의 연계를 쉽게 하고, 위치기반 서비스들 간의 상호 운용성을 높이며, 기존 사용자 시스템의 수정 없이 인터페이스만을 추가함으로써 표준을 수용할 수 있다.\pm}153.2,\;116.1{\pm}94,\;29.4{\pm}30.3,\;45.1{\pm}44$로 Mel 10군과 Mel 30군이 유의적인 감소를 보였으나(p<0.05) 이들 두 군 간의 차이는 나타나지 않았다. 이상의 결과로, 랫트에서 복강수술 후 melatonin 10mg/kg투여가 복강 내 유착 방지에 효과적이라고 생각된다.-1}{\cdot}yr^{-1}$로서 두 생태계에 축적되었다.여한 3,5,7군에서 PUFA 함량이 증가한 반면, SFA 함량은 감소하여 P/S 비율, n-3P/n-6P 비율은 증가하는 경향이었으며 이는 간장의 인지질, 콜레스테롤 에스테르, 총 지질의 지방산조성에서도 같은 경향을 볼 수 있었다.X>$(C_{18:2})$와 n-3계 linolenic acid$(C_{18:3})$가 대부분을 차지하였다. 야생 돌복숭아 과육 중의 지방산 조성은 포화지방산이 16.74%, 단불포화지방산 17.51% 및 다불포화지방산이 65.73%의 함유 비율을 보였는데, 이 중 다불포화지방산인 n-6계 linoleic acid$(C_{18:2})$와 n-3계 linolenic acid$(C_{18:3})$가 지질 구성 총 지방산의 대부분을 차지하는 함유 비율을 나타내었다.했다. 하강하는 약 4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월