• Title/Summary/Keyword: 분산 네트워크

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Encryption Scheme for MPEG-4 Media Transmission Exploiting Frame Dropping (대역폭 감소를 적용한 MPEG-4 미디어 전송시의 암호화 기법 연구)

  • Shin, Dong-Kyoo;Shin, Dong-Il;Park, Se-Young
    • The KIPS Transactions:PartB
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    • v.15B no.6
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    • pp.575-584
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    • 2008
  • According to the network condition, the communication network overload could be occurred when media transmitting. Many researches are being carried out to lessen the network overload, such as the filtering, load distributing, frame dropping and many other methods. Among these methods, one of effective method is frame dropping that reduces specified video frames for bandwidth diminution. B frames are dropped and then I, P frames are dropped according to dependency among the frames in frame dropping. This paper proposes a scheme for protecting copyrights by encryption, when we apply frame dropping to reduce bandwidth of media following MPEG-4 file format. We designed two kinds of frame dropping: first one stores and then sends the dropped files and the other drops frames in real-time when transmitting. We designed three kinds of encryption methods in which DES algorithm is used to encrypt MPEG-4 data: macro block encryption in I-VOP, macro block and motion vector encryption in P-VOP, and macro block and motion vector encryption in I, P-VOP. Based on these three methods, we implemented a digital right management solution for MPEG-4 data streaming. We compared the results of dropping, encryption, decryption and quality of video sequences to select an optimal method, and there is no noticeable difference between the video sequences recovered after frame dropping and the ones recovered without frame dropping. The best performance in encryption and decryption of frames was obtained when we apply the macro block and motion vector encryption in I, P-VOP.

The Design and Implementation of Access Control framework for Collaborative System (협력시스템에서의 접근제어 프레임워크 설계 및 구현)

  • 정연일;이승룡
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.10C
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    • pp.1015-1026
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    • 2002
  • As per increasing research interest in the field of collaborative computing in recent year, the importance of security issues on that area is also incrementally growing. Generally, the persistency of collaborative system is facilitated with conventional authentication and cryptography schemes. It is however, hard to meet the access control requirements of distributed collaborative computing environments by means of merely apply the existing access control mechanisms. The distributed collaborative system must consider the network openness, and various type of subjects and objects while, the existing access control schemes consider only some of the access control elements such as identity, rule, and role. However, this may cause the state of security level alteration phenomenon. In order to handle proper access control in collaborative system, various types of access control elements such as identity, role, group, degree of security, degree of integrity, and permission should be taken into account. Futhermore, if we simply define all the necessary access control elements to implement access control algorithm, then collaborative system consequently should consider too many available objects which in consequence, may lead drastic degradation of system performance. In order to improve the state problems, we propose a novel access control framework that is suitable for the distributed collaborative computing environments. The proposed scheme defines several different types of object elements for the accessed objects and subjects, and use them to implement access control which allows us to guarantee more solid access control. Futhermore, the objects are distinguished by three categories based on the characteristics of the object elements, and the proposed algorithm is implemented by the classified objects which lead to improve the systems' performance. Also, the proposed method can support scalability compared to the conventional one. Our simulation study shows that the performance results are almost similar to the two cases; one for the collaborative system has the proposed access control scheme, and the other for it has not.

Design of Intrusion Detection System to be Suitable at the Information System Organized by Homogeneous Hosts (동질형 호스트들로 구성된 정보시스템에 적합한 침입탐지시스템의 설계)

  • 이종성;조성언;조경룡
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.1
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    • pp.267-282
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    • 2000
  • With the development of computer&network technology and the growth of its dependance, computer failures not only lose human and material resources but also make organization's competition weak as a side-effect of information society. Therefore, people consider computer security as important factor. Intrusion Detection Systems (IDS) detect intrusions and take an appropriate action against them in order to protect a computer from system failure due to illegal intrusion. A variety of methods and models for IDS have been developed until now, but the existing methods or models aren't enough to detect intrusions because of the complexity of computer network the vulnerability of the object system, insufficient understanding for information security and the appearance of new illegal intrusion method. We propose a new IDS model to be suitable at the information system organized by homogeneous hosts and design for the IDS model and implement the prototype of it for feasibility study. The IDS model consist of many distributed unit sensor IDSs at homogeneous hosts and if any of distributed unit sensor IDSs detect anomaly system call among system call sequences generated by a process, the anomaly system call can be dynamically shared with other unit sensor IDSs. This makes the IDS model can effectively detect new intruders about whole information system.

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The Spatial Characteristics on the Mobile Industry's Value Chain in Daegu-Gyeongbuk Region (대구.경북지역 모바일산업의 가치사슬 구조와 공간적 특성)

  • Jeon, Ji Hye;Lee, Chul Woo
    • Journal of the Korean association of regional geographers
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    • v.19 no.1
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    • pp.45-59
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    • 2013
  • This paper was to examine the spatial characteristics on the mobile industry's value chain based on the structure of value chain, the process of development, and the industrial linkages of mobile industry in Daegu-Gyeongbuk region. The mobile industry's value chain in Daegu-Gyeongbuk region consists of the infrastructure, mobile device, platform & embedded SW, and mobile contents sector. Among these sectors, the leading value chain sector in mobile governance is the mobile device sectors, especially the finished products sector. These sectors have developed by policies as well as networks with large enterprises such as Samsung and LG, and it forms a hub-and-spoke cluster. The infrastructure and mobile device sector are located in Gumi, Gyeongbuk, the embedded SW and mobile contents sectors are located in Daegu, which means decentralized agglomeration. The sectors of infrastructure and mobile device form the strong forward-backward linkages with firms in Daegu-Gyeongbuk region. For the embedded SW sector, the forward-backward linkages are active with firms located in Seoul metropolitan area. For mobile contents sector, the backward linkages are formed with firms in Daegu and the forward linkages are formed with firms in Seoul metropolitan area.

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연구개발의 세계화와 외국인 연구 인력의 활용 전략

  • 임덕순
    • Proceedings of the Korea Technology Innovation Society Conference
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    • 1999.11c
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    • pp.521-543
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    • 1999
  • 최근 과학기술 혁신 활동의 세계화 현상과 함께 한국의 연구개발 활동도 점차 세계화되고 있다. 그러나 한국의 연구개발 활동의 세계화 현상 및 바람직한 방향에 관한 연구는 별로 없다. 세계화에 따라 국내 연구개발 자원의 유출현상도 발생하지만, 해외 연구개발 자원을 활용할 수 있는 기회도 증가한다. 본 논문에서는 연구개발 활동의 세계화에 관한 흐름 및 개념을 제시하고, 국내 외국인 연구 인력의 활용 현황 및 활용성과 영향 요인을 조사하여 외국인 연구인력 활용 방안을 탐색하였다. 외국과의 연구자 교류는 1996년 현재 유입이 약 4,300명, 유출이 약 16,000명으로 유출이 크지만, 많은 규모는 아니다. 국내 활용 외국인 연구자의 경우 1998년에는 주춤하였지만 꾸준한 증가 추세에 있다. 외국인은 비선진국, 특히 러시아 및 중국의 연구자들을 많이 활용되고 있다. 활용 분야는, 기초, 응용, 개발 연구별로 고루 분포되어 있으며, 상대적으로 정보 전자통신, 에너지 및 자원 분야에서 활용을 많이 하고 있었다. 외국인 연구자들이 참가한 프로젝트는 한국에서 기술도입기나 기술성장기에 해당하는 프로젝트들이 거의 대부분이었다. 월평균 급여는 1,500,000원부터 2,300,000원 정도의 범위에 속했다. 활용 기간을 보면 50%이상이 1년 미만이었으며 2년 이상은 약 10%정도 수준으로 단기간 활용을 위주로 하고 있는 편이다. 외국인 연구자 활용의 이유로써는 외국인 연구자가 가지고 있는 과학기술 지식을 흡수하거나 공동으로 신기술 지식을 개발하려는 목적 등이 지원제도 이용 차원이나, 해외 연구 네트워크 구축, 단순한 연구인력 충원 차원 등의 목적보다 많은 것으로 나타났다. 이는 기초과학 수준이 높은 북방권 국가들의 과학자들이 주로 활용되고 있다는 점에서도 잘 알 수 있으며 우리의 과학기술 약점을 보완하는 원천으로써 외국인 연구 인력이 대안이 되고 있음을 시사한다. 본 연구에서는 한국 연구 조직에서 일하는 외국인 연구자들의 동기 및 성과에 영향을 미치는 많은 요인들을 확인할 수 있었다. 상관관계, 분산분석, 회귀분석 등을 통해 활용 성과에 미치는 영향 요인들을 도출하였다. 설문 분석을 통하여 동기 및 성과 사이에는 강한 상관관계가 존재하는 것을 확인할 수 있었으며 이는 전통적인 동기 이론들과 부합한다. 대부분의 변수가 동기 및 성과에 동시에 영향을 미치는 것으로 조사되었으며 그중에서도 조직 협력 문화, 외국인 연구자의 의사소통 및 협력성, 외국인 연구자의 연구 능력 관련 변수들 및 연구 프로젝트의 기술수명주기, 외국인 연구자의 기존 기술지식의 흡수 등이 가장 중요한 변수로 나타났다. 이는 우리가 주로 중국 및 러시아 과학자들을 활용하여 상업화하는 외국인 연구인력 활용 패턴과도 일치하는 결과이다. 즉 우호적인 조직문화를 가지고 있는 연구 조직에서, 이미 과학기술 지식을 많이 가지고 있고 연구 능력도 높은 외국인 과학기술자를, 한국에서 기술이 태동 또는 성장하고 있는 연구 분야에서 활용하는 것이 가장 성과가 좋다는 사실을 확인시켜 주고 있다. 국내에서 최초로 수행된 본 연구는 외국인 연구 인력의 활용 성과가 매우 높으며, 우리의 과학기술혁신시스템을 보완하는 유효한 수단으로써 외국인 연구 인력이 중요한 대안이 될 수 있음을 발견하였다. 외국인 연구 인력을 잘 활용하기 위하여 문제점 및 개선방안을 활용 환경, 연구 인력이 중요한 대안이 될 수 있음을 발견하였다. 외국인 연구 인력을 잘 활용하기 위하여 문제점 및 개선 방안을 활용 환경, 연구 인력관리. 인력 교류사업, 외국인 과학자 지원 창구 등으로 나누어서 정리하였다. 연구시설, 주거시설 등의 하드웨어적 환경에 대한 개선도 중요하지만 연구 인력의 관리 능력 제고, 인력 교류 사업의 개선, 정보 제공 등 소프트웨어적인 활용 능력을 제고하는데 정책적인 관심을 기울이는 것이 중요하다고 판단된다.

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A Process to Design and Implement Service-based Android Applications (서비스 기반 안드로이드 어플리케이션의 설계 및 구현 프로세스)

  • Lee, Ho-Joong;La, Hyun-Jung;Keum, Chang-Sup;Kim, Soo-Dong
    • The KIPS Transactions:PartD
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    • v.18D no.4
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    • pp.245-260
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    • 2011
  • Mobile Devices, which are developed with the fast growing of the Internet, have flexible internet accessibility and can access the network anywere so that they can execute software applications. However, it is very challenging to deploy highly complex applications on mobile devices since they have limited resources. To overcome the limitation, researches on applying a concept of services to mobile applications have been proposed. Android is one of the popular mobile platforms and is designed to effectively execute mobile applications on the mobile devices having limited resources. Since service-based Android applications, which adopt a concept of services and Android platform, invoke remote services and are built with Android-specific components, they are much different from traditional software applications. Consequently, it is not straightforward to apply object-oriented (OO) analysis and design methods to developing service-based Android applications, although they have been frequently applied to developing traditional applications. In this paper, we present a process to develop service-based Android mobile applications, which extends a traditional OO development process. First, we raise design issues to be considered in developing service-based Android applications. Then, to solve the issues, we present detailed guidelines for essential phases of OO-based development process that are customized to service-based Android applications. Finally, to show applicability of the process, we perform a case study. The proposed design process is effectively utilized as a set of guidelines to develop service-based Android applications more systematically and effectively.

Implementation and Validation of EtherCAT Support in Integrated Development Environment for Synchronized Motion Control Application (동기 모션 제어 응용을 위한 통합개발환경의 EtherCAT 지원 기능 구현 및 검증)

  • Lee, Jongbo;Kim, Chaerin;Kim, Ikhwan;Kim, Youngdong;Kim, Taehyoun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.2
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    • pp.211-218
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    • 2014
  • Recently, software-based programmable logic controller (PLC) systems, which are implemented in standard PLC languages on general hardware, are gaining popularity because they overcome the limitations of classical hardware PLC systems. Another noticeable trend is that the use of integrated development environment (IDE) is becoming important. IDEs can help developers to easily manage the growing complexity of modern control systems. Furthermore, industrial Ethernet, e.g. EtherCAT, is becoming widely accepted as a replacement for conventional fieldbuses in the distributed control domain because it offers favorable features such as short transmission delay, high bandwidth, and low cost. In this paper, we implemented the extension of open source IDE, called Beremiz, for developing EtherCAT-based real-time, synchronized motion control applications. We validated the EtherCAT system management features and the real-time responsiveness of the control function by using commercial EtherCAT drives and evaluation boards.

The Representative Technology Field Analysis of Domestic Defense Companies in Communication-electronics based on Patent Information Data (특허 자료 정보 기반 국내 통신전자 방산업체 대표 기술 분야 분석)

  • Kim, Jang-Eun;Cho, Yu-Seup
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.4
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    • pp.446-458
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    • 2017
  • In order to make a decision about the acquisition of command control communication weapon systems considering the client's technology level requirements, the improvement of the domestic technology level and security of core technology, the person in charge can perform technology evaluation/analysis based on command control communication weapon system patent data. As a method of collecting such patent data, we can collect the patent data of government-designated (Defense Acquisition Program Act Article 35) companies (11 Major defense companies/9 General defense companies) through the Korea Intellectual Property Rights Information System (KIPRIS) of the Korean Intellectual Property Office (KIPO) In this way, we collected 1,526 patents and 134 International Patent Classification (IPC) types through the KIPRIS of the KIPO. Based on these data, we performed three types of analysis, General information analysis, Principal Components Analysis (PCA) and Network analysis, and extracted 27, 19 and 13 IPC types from them, respectively. Based on the above three analysis results, we confirmed 8 IPC types (F41A, F41G, G06F, G01S, H04B, H04L, H04M and H04W) as the key technologies and representative technology fields of domestic communication-electronics defense companies.

Agile Framework for SOA-based Application Development (SOA 기반 애플리케이션 개발을 위한 Agile 프레임워크)

  • Shin, Seung-Woo;Kim, Haeng-Kon
    • The KIPS Transactions:PartD
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    • v.16D no.1
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    • pp.55-64
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    • 2009
  • Various business model and computing environments are currently merged into web services and many web related application products are also develop. Most of IT enterprises in Korea use the Service-oriented architecture (SOA) whenever they develop the web applications. SOA is an approach to loosely coupled, protocol independent, standards-based distributed computing where software resources available on the network are considered as Services. SOA is believed to become the future enterprise technology solution that promises the agility and flexibility the business users have been looking for by leveraging the integration process through composition of the services spanning multiple enterprises. But, There are no specific development methodology to apply into SOA standard model until now. The developer uses the currently existing methodology to develop the application with SOA. The users have some limitations to use it. In this paper, we suggest a Frameworks for applying agile methodology into SOA to address the productivity and quality of small web related project. We design and implement a frameworks architecture for applying the agile method into SOA and describe the process model to implement it. We finally evaluate the frameworks with productivity, flexibility and maintainability.

Semantic Topic Selection Method of Document for Classification (문서분류를 위한 의미적 주제선정방법)

  • Ko, kwang-Sup;Kim, Pan-Koo;Lee, Chang-Hoon;Hwang, Myung-Gwon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.1
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    • pp.163-172
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    • 2007
  • The web as global network includes text document, video, sound, etc and connects each distributed information using link Through development of web, it accumulates abundant information and the main is text based documents. Most of user use the web to retrieve information what they want. So, numerous researches have progressed to retrieve the text documents using the many methods, such as probability, statistics, vector similarity, Bayesian, and so on. These researches however, could not consider both the subject and the semantics of documents. As a result user have to find by their hand again. Especially, it is more hard to find the korean document because the researches of korean document classification is insufficient. So, to overcome the previous problems, we propose the korean document classification method for semantic retrieval. This method firstly, extracts TF value and RV value of concepts that is included in document, and maps into U-WIN that is korean vocabulary dictionary to select the topic of document. This method is possible to classify the document semantically and showed the efficiency through experiment.