• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.274-276
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• 2002

Ad Hoc망은 전형적인 무선 네트워킹과는 다른 새로운 무선 네트워킹 파라다임으로써 기존 유선 망의 하부 구조에 의존하지 않고 이동 호스트들로만 구성된 네트워크이다. Ad Hoc망에서 통신을 하기 위해서는 출발지 노드에서 목적지 노드까지 데이터 전송을 위한 라우팅에 관한 문제이다. Ad Hoc망에서는 모든 단말기의 위치변화가 가능하기 때문에 경로설정에 어려움이 따른다. 노드간에 정보를 보내고자 할 때 노드가 인접한 상태가 아니면 정보를 직접 보낼 수 없고 여러 중간 노드들을 거쳐서 정보를 보내는 다중-홉 라우팅 방식을 사용해야 한다. 따라서 중간 노드들은 패킷 라우터의 역할을 해야하는데 무선 통신자체가 좁은 대역폭과 한정된 채널을 가지고 전송 범위가 제한되는 문제가 있다. 또한 노드자체의 이동성과 전력 소모 등으로 인한 이탈은 망 위상을 수시로 변화시키므로 노드간에 정보를 전송하는데 가장 좋은 경로는 수시로 변경될 수 있으므로 많은 어려움이 따르게 된다. 본 논문에서는 이러한 문제의 해결방안으로 경로유지 과정에서 Ad Hoc망 내의 노드들은 이동성의 특성으로 인해 현재 사용되는 경로 보다 더 짧고 효율적인 경로가 발생하고 중간 노드가 이동 될 때 새로운 경로로 갱신하여 솔기없는 최적의 경로를 유지할 수 있는 방법을 제안한다. 제안 방법은 ZRP의 IERP에서 감청모드를 통하여 사용중인 경로보다 최적의 경로를 감지하여 새로운 경로로 갱신하는 방법과 중간 노드가 이동하여 경로가 깨진 경우 부분적으로 경로를 복구하는 방법을 제시하여 항상 최적화된 경로를 유지함으로써 Ad Hoc망의 위상변화에 대한 적응성을 높일 수 있도록 한다.기반으로 하는 교육용 애플리케이션 개발의 용이성의 증대를 기대할 수 있으며, 모델의 재사용성을 보장할 수 있다. 제안한다.수행하였다. 분석에서는 제품의 효율성뿐만 아니라 보안성을 중요하게 생각하였으며, 앞으로 보안 관련 소프트웨어 개발에 사용될 수 있는 도구들이 가이드 라인에 대한 정보를 제공한다.용할 수 있는지 세부 설계를 제시한다.다.으로서 hemicellulose구조가 polyuronic acid의 형태인 것으로 사료된다. 추출획분의 구성단당은 여러 곡물연구의 보고와 유사하게 glucose, arabinose, xylose 함량이 대체로 높게 나타났다. 점미가 수가용성분에서 goucose대비 용출함량이 고르게 나타나는 경향을 보였고 흑미는 알칼리가용분에서 glucose가 상당량(0.68%) 포함되고 있음을 보여주었고 arabinose(0.68%), xylose(0.05%)도 다른 종류에 비해서 다량 함유한 것으로 나타났다. 흑미는 총식이섬유 함량이 높고 pectic substances, hemicellulose, uronic acid 함량이 높아서 콜레스테롤 저하 등의 효과가 기대되며 고섬유식품으로서 조리 특성 연구가 필요한 것으로 사료된다.리하였다. 얻어진 소견(所見)은 다음과 같았다. 1. 모년령(母年齡), 임신회수(姙娠回數), 임신기간(姙娠其間), 출산시체중등(出産時體重等)의 제요인(諸要因)은 주산기사망(周産基死亡)에 대(對)하여 통계적(統計的)으로 유의(有意)한 영향을 미치고 있어 $25{\sim}29$세(歲)의 연령군에서, 2번째 임신과 2번째의 출산에서 그리고 만삭의 임신 기간에, 출산시체중(出産時體重

• Asia pacific journal of information systems
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• v.17 no.2
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• pp.83-95
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• 2007

We are motivated by how offline and online firms compete. The Internet made many conventional offline firms build a dynamic online business as another sales channel using their advantages such as brand equity, an existing customer base with comprehensive purchasing data, integrated marketing, economies of scale, and longtime experience with the logistics of order fulfillment and customer service. Even though the hybrid selling using both offline and online channel seems to have advantages over a pure online retailer, all the conventional offline firms are not seen to create an online business. Many conventional offline firms began to launch online business since the Internet era, however, just being online business is not likely to guarantee success. According to Bizate.com's report whether the hybrid channel strategy is successful is still under investigation. For example, consider the classic case of Barnes and Noble versus Amazon.com, Barnes and Noble was already the largest chain of bookstores in the U,S., when Amazon.com was established in 1995, BarnesandNoble.com followed suit in 1997, After suffering losses in its initial years, Amazon finally turned profitable in 2003. In 2004, Amazon's net income was $588 million on revenues of $6.92 billion, while Barnes and Noble earned $143 million on revenues of $4.87 billion, which included BarnesandNoble.com's loss of $21 million on revenues of $420 million. While these examples serve to motivate our thinking, it does not explain when offline firms should venture online. It also does not provide an analytical framework that can generalized to other competitive online-offline situations. We attempt to do this in this paper and analyze a hybrid channel model where a conventional offline firm competes against online firms using its own direct online channels. We are particularly interested in an optimal channel strategy when a conventional offline firm sells its products through its own direct online channel to compete with other rival online firms. We consider two situations where its direct online channel and other online firms are symmetric and asymmetric in the brand effect. The analysis of this paper presents several findings. In the symmetric model where a hybrid firm's online channel is not differentiated from a pure online firm, (i) a conventional offline firm will not launch its online business. In the asymmetric model where a hybrid firm's online channel is differentiated from a pure online firm, (ii) a conventional offline firm can launch its online business if its brand effect is greater than a certain threshold. (iii) there is a positive relationship between its brand effect and online customer costs showing that a conventional offline firm needs more brand effect in order to launch online business as online customer costs decrease. (iv) there is a negative relationship between its brand effect and the number of customers with access to the Internet showing that a conventional offline firm tends to launch its online business when customers with access to the Internet increases.

• Journal of Korea Port Economic Association
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• v.29 no.3
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• pp.73-94
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• 2013

The necessity of shipping market information services has been on the rise which emphasizes the relevance of transaction information and market information to parties both in and outside the shipping industry. However, previous related researches have been restricted to explorations limited by the offerings of existing shipping market information providers. Users today require effective information, an efficient contents management system, interfacing to help the information provider, graphing and spread sheets to facilitate and present the analyzed information through diverse formats, and reliable web and mobile services to provide information effectively with limited human resources. As a first step, service information has to be defined, so that it takes into account user utility, information retrieval and data development. Second, benchmark information and services must be provided from leading shipbrokers and research institutes. Third, a review of the latest technical trends is required to identify the most suitable technologies for servicing shipping market information. Finally, analysis is required on the implementation of a system with selected technologies, as well as the development of channels to post information which have been analyzed by users. Such a process would enable the continual redefinition of the shipping market information users actively need. The application of an X-Internet based WCMS, with a single-window dashboard providing user-customized information, and used to obtain and manage processes, add spread sheets to sustain calculations using the latest information, graph results, and to input additional information following predefined rules. Access to data and use of the system would require agreement that the system will incorporate user data and user-analyzed information into the market report, web portal, and hybrid app to provide current shipping market information appropriately and accurately to service users.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.33 no.3
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• pp.239-265
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• 2022

The purpose of this study is to examine the status of RDA adoption in Korea and the perception of university librarians on RDA adoption. For this purpose, the adoption status of two libraries that adopted RDA among domestic libraries was analyzed. In addition, interviews were conducted with eight university librarians, and narrative responses related to the adoption of RDA were collected and analyzed. As a result of the interview survey, the research participants recognized that the concept of RDA is very difficult and abstract, there are few implementation cases where RDA is applied, and that it would be very difficult to adopt RDA due to the personnel and budget conditions of the local library. The RDA adoption method recognized by the research participants is to improve RDA awareness, conduct RDA education, prepare guidelines for constructing hybrid bibliographic records when RDA is adopted, operate an RDA pilot institution, and establish a performance model. In addition, research participants need coordination with companies for implementation, prefer to change a specific point in time rather than batch retroactive conversion, discover success stories, establish RDA-related online channels, build and utilize national authority DB, and use the national budget and system support. In this study, based on the research results, a plan to adopt RDA for university libraries in Korea was presented.

• Journal of Broadcast Engineering
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• v.16 no.1
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• pp.23-32
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• 2011

Design and Implementation of Clipcast Service via Terrestrial DMB This paper outlines the system design and the implementation process of clipcast service that can send clips of video, mp3, text, images, etc. to terrestrial DMB terminals. To provide clipcast service in terrestrial DMB, a separate data channel needs to be allocated and this requires changes in the existing bandwidth allocation. Clipcast contents can be sent after midnight at around 3 to 4 AM, when terrestrial DMB viewship is low. If the video service bit rate is lowered to 352 Kbps and the TPEG service band is fully used, then 320 Kbps bit rate can be allocated to clipcast. To enable clipcast service, the terminals' DMB program must be executed, and this can be done through SMS and EPG. Clipcast service applies MOT protocol to transmit multimedia objects, and transmits twice in carousel format for stable transmission of files. Therefore, 72Mbyte data can be transmitted in one hour, which corresponds to about 20 minutes of full motion video service at 500Kbps data rate. When running the clip transmitted through terrestrial DMB data channel, information regarding the length of each clip is received through communication with the CMS(Content Management Server), then error-free files are displayed. The clips can be provided to the users as preview contents of the complete VOD contents. In order to use the complete content, the user needs to access the URL allocated for that specific content and download the content by completing a billing process. This paper suggests the design and implementation of terrestrial DMB system to provide clipcast service, which enables file download services as provided in MediaFLO, DVB-H, and the other mobile broadcasting systems. Unlike the other mobile broadcasting systems, the proposed system applies more reliable SMS method to activate the DMB terminals for highly stable clipcast service. This allows hybrid, i.e, both SMS and EPG activations of terminals for clipcast services.

• Journal of Broadcast Engineering
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• v.22 no.6
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• pp.829-849
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• 2017

Due to the large-scale TV display, the convergence of broadcasting and broadband, and the advancement of signal compression and transmission technology, terrestrial digital broadcasting has evolved into UHD broadcasting capable of providing simultaneous broadcasting of fixed UHD and mobile HD. The Korean standard for terrestrial UHDTV broadcasting is based on ATSC 3.0, the broadcasting standard of North America. The terrestrial UHDTV broadcasting standard chose that as a new AV codec standard, HEVC video codec which can compress with higher efficiency compared to AVC, and MPEG-H 3D audio codec for realistic audio. Also, DASH and MMT are adopted as transmission format instead of MPEG-2 TS to support broadband as well as broadcasting network, and in order to provide 4K UHD/mobile HD service simultaneously ROUTE multiplexing technology is applied. In this paper, we propose an audio/video encoder, which is required to provide HDR/WCG supported high quality video service, 10.2 channel/4 object supporting stereo sound service, fixed UHD and mobile HD simultaneous broadcasting service based on ATSC3.0, also we implemented the ATSC 3.0 LDM system for ROUTE/DASH packager, multiplexing system and physical layer transmission/reception, and verified the service ability by applying it to real time broadcast environment.