• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.2
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• pp.163-169
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• 2015

In many nuclear power plant sites in Korea, high density storage racks were installed in the spent fuel pool to expand the spent fuel storage capacity. Nevertheless, the capability of the Hanbit nuclear site will be saturated by 2024. Also, 10 NPPs will reach their design life expiration date by 2029. In the case of the US, SFPI (Spent Fuel Pool Island) operated temporarily as a spent fuel storage option before spent nuclear fuels were transported to an interim storage facility or a final disposal facility. As a spent fuel storage option after shutdown during decommissioning, the SFPI concept can be expected to have the following effects: reduced occupational exposure, lower cost of operation, strengthened safety, and so on. This paper presents a case study associated with the regulations, operating experiences, and systems of SFPI in the US. In conclusion, the following steps are recommended for applying SFPI during decommissioning in Korea: confirmation of design change scope of SFPI and expected final cost, the submission of a decommissioning plan which is reflected in SFPI improvement plans, safety assessment using PSR, application of an operating license change for design change, regulatory body review and approval, design change, inspection by the regulatory body, education and commissioning for SFPI, SFPI operation and periodic inspection, and dismantling of SFPI.

• Journal of Korea Multimedia Society
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• v.14 no.1
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• pp.94-102
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• 2011

To alleviate the size and bandwidth requirement in JPEG2000 system, a new Embedded Compression(EC) algorithm with minor image quality drop is proposed. For both random accessibility and low latency, very simple and efficient hadamard transform based compression algorithm is devised. We reduced LL intermediate memory and code-block memory to about half size and achieved significant memory bandwidth reductions(about 52~73%) through proposed multi-mode algorithms, without requiring any modification in JPEG2000 standard algorithm.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.69-72
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• 2011

플래시 메모리 기반의 저장 시스템은 빠른 접근 속도, 작고 가벼운 특성, 저전력 소모 등의 이유로 하드 디스크를 대체하는 저장 매체로 주목 받고 있다. 플래시 메모리는 하드 디스크와 다르게 읽기 쓰기 소거 연산이 필요하며 수혈 단위와 수혈 시간 이 비대칭적이다. 또한 제자리 갱신이 불가능하기 때문에 가장 느린 소거 동작을 선행하여 갱신 연산을 수행한다. 기존 호스트 시스템은 읽기 쓰기 연산 만을 수행하기 때문에 플래시 메모리를 바로 사용하기 위해서는 별도의 소프트웨어 중간 계층인 플래시 전환 계층이 필요하다. 그러나 디스크 기반의 B-트리를 플래시 전환 계층 위에서 인덱스로 사용하면 B-트리 특성상 제자리 갱신이 빈번하게 발생하기 때문에 성능 저하가 발생한다. 따라서 플래시 메모리 특성을 고려한 새로운 인덱스 구조가 필요하게 되었다. 플래시 메모리 전용의 인덱스 ${\mu}$-트리와 LSB-트리가 제안 되었지만, ${\mu}$-트리는 페이지 관리의 비효율성, LSB-트리는 임시 노드 관리 추가 비용의 문제점을 가지고 있다. 본 논문에서 ${\mu}$-트리와 LSB 트리의 문제점을 해결하기 위하여 지연 갱신을 이용한 B-트리를 제안한다. 제안하는 인덱스는 변경이 일어나는 노드를 메모리에 적재시켜 데이터 삽입 시 노드 갱신을 지연시키고 노드 분할 없이 데이터의 순차 삽입을 처리하여 검색 및 쓰기 성능을 향상시킨다. 본 논문에서는 관련 연구인 ${\mu}$-트리와 LSB-트리를 수식을 통하여 제안하는 인덱스 구조의 우수성을 보인다.

• Journal of the Korean Society for Library and Information Science
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• v.51 no.2
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• pp.73-93
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• 2017

The National Library of Korea installs and operates various signs for the purpose of efficient use of visitor and information transmission. In this study, the present status of the existing signatures of the National Library of Korea was surveyed and the satisfaction survey was conducted for the patron and staff. Based on this, we suggested the improvement of visual continuity (connectivity), changing the installation location, reduction of excess sign, limitations of temporary attachment signatures, and easy to understand contents as user's guide to efficient library use and improvement of National Central Library sign system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.6
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• pp.157-161
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• 2006

GSM(Global System for Mobile communications) that is the most popular standard for mobile phones, has more than 70% users in the world and the number of users increase continuously. However GSM system has the problem that cannot normally authenticate a user by the exposure of IMSI that is able to uniquely authenticate MS? during the user authentication procedure. In this paper? we provide security enhancement and user privacy by adopting a temporary id and an encryption scheme. Moreover we provide fast user authentication via architecture modification of the conventional GSM user authentication protocol.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.2
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• pp.132-139
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• 2016

The progressive attrition of teeth is a normal process by aging. However, excessive tooth wear with decreased vertical dimension of occlusion and collapse of occlusal plane may cause pathologic pulpal condition, occlusal disharmony, functional disorders and esthetic problems. The change of vertical dimension is required in case that there is no sufficient clearance for restoration or in case that the occlusal relationship is modified. For gaining the vertical dimension, a careful diagnosis is essential prior to starting the restoration treatment. After evaluating adaptation of neuromuscular system of patient during provisional phase, the final restorations can be fabricated. In this case, a 78 year old male with severely worn down dentition was treated. To improve the esthetic appearance and to achieve the ideal occlusal relationship, the full mouth rehabilitation with minimal increase of vertical dimension is planned and diagnostic wax-up was performed at the increased vertical dimension. After evaluation of provisional restorations for 12 weeks, final restorations were fabricated and routine clinical assessments were made. After 1 year, the restorations with newly established occlusal scheme are well maintained without significant complications and esthetically and functionally satisfactory results were obtained.

• Journal of Legislation Research
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• no.53
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• pp.269-310
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• 2017

This article aims at the study on Improvement of legal System which is related to automated vehicles in the era of the 4th industrial revolution. Legal aspects of driving automation have two view points. One is to permit a automated vehicle, the other is to regulate the behavior of driver on the road. Signifying elements of the 4th industrial revolution are IoT, AI, big data, cloud computing etc. Automated vehicles are the imbodiment of those new ICT technologies. The vehicle management act(VMA) rules about vehicle registration and approval of vehicle types. VMA defines a automated vehicle as a vehicle which can be self driven without handling of driver or passenger. Vehicle makers can take temporary driving permission for testing and research the driving automation. Current definition of automated vehicle of VMA is not enough for including all levels of SAE driving automation. In the VMA must be made also a new vehicle safty standard for automated vehicle. In the national assembly is curruntly pending three draft bills about legislation of artificial intelligence. Driving automation and AI technologies must be parallel developed. It is highly expected that more proceeding research of driving automation can be realized as soon as possible.

• Journal of Internet Computing and Services
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• v.23 no.3
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• pp.21-33
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• 2022

This paper is to suggest the secure secret sharing system in order to outstandingly reduce the damage caused by the leakage of the corporate secret. This research system is suggested as efficient P2P distributed system kept from the centrally controlled server scheme. Even the bitcoin circulation system is also based on P2P distribution scheme recenly. This research has designed the secure circulation of the secret shares produced by Threshold Shamir Secret Sharing scheme instead of the shares specified in the torrent file using the simple, highly scalable and fast transferring torrent P2P distribution structure and its protocol. In addition, this research has studied to apply both Shamir Threshold Secret Sharing scheme and the securely strong multiple user authentication based on Collaborative Threshold Autentication scheme. The secure transmission of secret data is protected as using the efficient symmetric encryption with the session secret key which is safely exchanged by the public key encryption. Also it is safer against the leakage because the secret key is effectively alive only for short lifetime like a session. Especially the characteristics of this proposed system is effectively to apply the threshold secret sharing scheme into efficient torrent P2P distributed system without modifying its architecture of the torrent system. In addition, this system guaranttes the confidentiality in distributing the secret file using the efficient symmetric encryption scheme, which the session key is securely exchanged using the public key encryption scheme. In this system, the devices to be taken out can be dynamically registered as an user. This scalability allows to apply the confidentiality and the authentication even to dynamically registerred users.

• Journal of the Korea Convergence Society
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• v.8 no.11
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• pp.21-27
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• 2017

Internet of Things(IoT), which is developing for the hyper connection society, is based on OSHW (Open Source Hardware) such as Arduino and various small products are emerging. Because of the limitation of low performance and low memory, the IoT is causing serious information security problem that it is difficult to apply strong security technology. In this paper, we analyze the vulnerability that can occur as a result of compiling and loading the application program of Arduino on the host computer. And we propose a new attack method that allows an attacker to arbitrarily change the value input from the sensor of the arduino board. Such as a proposed attack method may cause the arduino board to misinterpret environmental information and render it inoperable. By understanding these attack techniques, it is possible to consider how to build a secure development environment and cope with these attacks.

• Journal of Navigation and Port Research
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• v.39 no.1
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• pp.61-67
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• 2015

Inland transport becomes more and more important in connecting ports with inland. Therefore, studying on cargo flow from ports to regions has been active in progress by many researchers. However current statistical data of freight flow from origin locations to destination locations does not reflect the exact characteristics of freight flow. Also, they also do not reflect the characteristics of multimodal transport system in which cargos go through intermediate locations such as logistics center or inland container depot. In growing up the emergent need of rebuilding statistical data for freight flow from origin locations to destination locations, this paper will propose a freight flow model with logistics center and it will be verified by genetic algorithm through the simulation scenarios.