• Journal of Korea Multimedia Society
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• v.5 no.5
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• pp.488-493
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• 2002

MPEG-4 movies are composed of several media objects, organized in a hierarchical fashion. Those media objects are served to the clients as elementary streams. To play the movie, client players compose the elementary streams according to the meta- information called the scene graph. The meta-information streams are delivered as BIFS and OD elementary stream. Using dynamically generated BIFS and OD streams, we can provide a service something differs from traditional file services. For example, we can insert weather or stock information into the bottom of the screen while an existing movie was played in the screen. In this paper, we propose a dynamic service framework and dynamic server. Dynamic service framework is an object-oriented framework dynamically generating BIFS and OD streams based on the external DB information. Dynamic server provides a GUI for the server management and interface for registering dynamic services. In this framework, the dynamic service has the same interface as a file service. So, a dynamic service is considered as a file service by clients and other services.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2670-2677
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• 2014

The technique of virtual machine construction using hypervisor such as Xen and KVM is mainly used for implementation of cloud computing infrastructure. This technique is efficient in allocating and managing resources compared to the existing operation methods. However it requires high resource usage when constructing virtual machines and results in wasting of resources when not using the allocated resources. Docker is a technique based on the container method to resolve such a problem. This paper shows the container method such as Docker is efficient as a web construction technique by comparing virtual machine method to container method. It is shown to be especially useful when storing data into DB or storage devices in such environments of web server or program development. In the upcoming cloud computing environment the container method such as Docker is expected to improve the resource efficiency and the convenience of management.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.6
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• pp.1317-1330
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• 2017

To collect server information and construct network map enable us to prevent security breach, prepare for national cyber warfare and make effective policies. In this paper, we analyze well-known network scanners, Nmap and ZMap, and construct network map using banner grabbing. We use multiple threads in order to increase scanning speed and arrange IP lists by specific order to reduce the load on information gathering targets. Also, we applied performance tests to compare the real-time banner grabbing tool with the existing network scanners. As a result, we gathered server information from domestic and overseas servers and derived a risk index based on the collected database. Although there are slight differences among countries, we can identify the risky situation that many users in every country are exposed to several security breaches.

• Journal of the Korea Institute of Building Construction
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• v.13 no.6
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• pp.619-626
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• 2013

Many pictures are taken at a construction site, but the information of the pictures is not managed in an efficient and systematic manner. For this reason, when a construction worker has scant field experience or knowledge, it is hard to communicate with others efficiently. Therefore, the information of the pictures taken is not fully utilized in any deliberation or conflict among interested parties, facilities maintenance, and construction of another structure, although they were taken for those purposes. This study discusses the need for combining vector-photos with image and 5W and 1H information, and develops a prototype module for creating vector-photos and saving them in a server. The vector-photos taken can be saved to a server in real time, and efficiently managed by a DB system. If a system to link the vector-photos with a BIM model is developed in the future, it is expected that the vector information in the picture can be connected with the property information of an object. As a result, the vector-photos can be utilized in more diverse ways.

• Journal of the Korea Computer Industry Society
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• v.9 no.3
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• pp.121-128
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• 2008

This paper suggested a location-based traffic information service system using TPEG and GIS. Measurement technique, location server, applied service technique, and linkage technique with database were used to provide the location-based traffic information service. In particular, TPEG-RTM includes location information and load traffic message. The location information to be included in each message displayed a specific point, section or region limit of the load. Actually, because it was impossible to receive data using TPEG receiver, a proposed program included in this paper was used to produce an arbitrary database and read it, Also, TPEG event happened time was indicated on the map for matching test of a TPEG message and WGS84 coordinate, and finally it was verified with art example of a vehicle approaching to an event happened place.

• Journal of IKEEE
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• v.19 no.4
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• pp.617-624
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• 2015

In this paper, an adult authentication system based on authentication certificate was designed and implemented using smartphone and near-field communication. It has three advantages. First, it achieves easy, convenient, and fast authentication by using smartphone and near-field communication. Second, it achieves extremely high security and reliability by exploiting authentication certificate. Third, it achieves extremely low risk of personal information leakage by generating and sending only virtual identification code. Finally, it has a proper legal basis by Digital Signature Act. It consists of adult authentication module, near-field communication control module, policy server module, and database server module. A prototype of the proposed system was designed and implemented, and it was verified to have correct operation.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.10
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• pp.311-322
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• 2014

IoT(Internet of Things) is a concept of connected internet pursuing direct access to devices or sensors in fused environment of personal, industrial and public area. In IoT environment, it is possible to access realtime data, and the data format and topology of devices are diverse. Also, there are bidirectional communications between users and devices to control actuators in IoT. In this point, IoT is different from the conventional internet in which data are produced by human desktops and gathered in server systems by way of one-sided simple internet communications. For the cloud or portal service of IoT, there should be a file management framework supporting systematic naming service and unified data access interface encompassing the variety of IoT things. This paper implements a DB-based virtual file system maintaining attributes of IoT things in a UNIX-styled file system view. Users who logged in the virtual shell are able to explore IoT things by navigating the virtual file system, and able to access IoT things directly via UNIX-styled file I O APIs. The implemented virtual file system is lightweight and flexible because it maintains only directory structure and descriptors for the distributed IoT things. The result of a test for the virtual shell primitives such as mkdir() or chdir() shows the smooth functionality of the virtual file system, Also, the exploring performance of the file system is better than that of Window file system in case of adopting a simple directory cache mechanism.

• Convergence Security Journal
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• v.2 no.2
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• pp.209-216
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• 2002

This treatise deals with designing a database encryption model that interworks with Intranet within a system. Today attempts are being made to substitute legacy client/server computing environment with what interworks with web and database, and thus the question how the security for the database that interworks with Intranet can be secured is emerging as a matter of great importance. This treatise, therefore, offers an encryption model which offers how to create an encryption key using an ID and a password most widely used in Intranet access and by using this key, how to encipher information ill a DB table, providing a maintenance scheme for the Key as well.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.937-940
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• 2005

인터넷 기반 자원 공유 시스템은 네트워크에 연결된 피어의 자원을 이용하여 고성능의 컴퓨팅 구현을 위한 시스템이다. 인터넷 기반 자원 공유 시스템의 가변적인 환경은 피어의 등록 및 삭제가 자유로워 연산 처리에 대한 신뢰성 문제를 발생시킨다. 본 논문에서는 인터넷 기반 자원 공유 시스템의 신뢰성 향상을 위해서 이기종 시스템간의 협업 그룹을 생성하여 관리하는 협업 관리 시스템을 설계한다. 효율적인 협업 관리를 위해 이기종 피어를 관리하는 협업 그룹을 정의하고 계층 구조의 중간DB서버를 제안한다. 그리고 협업 관리 시스템에서 제공되는 협업 그룹 서비스, 디스커버리 서비스, 작업 관리 서비스를 제안한다.

• 한국공간정보시스템학회:학술대회논문집
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• 1999.06a
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• pp.149-156
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• 1999

지형정보시스템(이하 GIS)에 있어서 공간 데이타베이스의 구축은 GIS 전체 구축비용의 많은 부분을 차지하며 막대한 시간과 비용이 소요되는 과정이다. 수치지도를 이용한 공간 데이타베이스 구축은 데이타 수집비용의 절감이라는 측면에서 점차 그 유용성이 증대되고 있지만 경계선 불일치, 객체의 불연속성과 같은 새로운 문제점들이 나타나게 되어 공간 데이터베이스를 생성하기 전에 수치지도에 대한 수정 및 편집작업이 수행되어야 한다. 이 논문에서는 클라이언트-서버 환경에서 여러 클라이언트가 수치지도에 대하여 동시에 수정작업을 하기 위해 영역 잠금(region lock)을 이용한 협동 트랜잭션 모델을 제시한다. 그리고 경계선 작업 시에 클라이언트간의 협동작업을 위한 메시지 전파 프로토콜을 제시한다.