• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.224-225
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• 2019

The purpose of this study was to develop a technology to prevent leakage of construction structures for the Chinese market. The first key development factor is to establish a joint quality standard that corresponds to all performance criteria set out in Chinese Standard JC / T 2428-2017. The second key development factor is to develop a product capable of exhibiting performance in a low temperature environment of $-30^{\circ}C$ and coping with 15mm structure behavior.

• International Journal of Computer Science & Network Security
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• v.22 no.5
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• pp.61-66
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• 2022

The main purpose of the article is to analyze the key aspects of didactic games and exercises in the sensory development of preschoolers. The relevance of the chosen subject determines the fact that there are a number of problems in the specifics of the development of preschoolers and their characteristics, which manifest themselves individually. The importance of using didactic games and exercises in the development of preschoolers has been proved. The methodology includes a number of theoretical and practical methods, which together form the research methodology. Based on the results of the study, key aspects of the importance of the influence of dadactic games and exercises in the sensory development of preschoolers were identified. Further research requires the question of analyzing modern technologies for the formation of modern methods of sensory development for preschoolers.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.1218-1221
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• 2007

센서 네트워크는 유비쿼터스 컴퓨팅 환경을 실현하기 위한 네트워크로 센싱 및 통신 능력으로 인간이 접근하기 어려운 다양한 곳에 설치되어 감시나 탐지 등을 통하여 데이터를 수집한다. 이러한 환경의 구현을 위하여 센서 네트워크에서 센서 노드가 수집한 데이터는 사용자에게 전달될 때 안전한 통신을 보장하기 위해 센서 노드간 키를 설정하는 것은 보안을 위한 기본적인 요구사항이 되고 있다. 따라서 초소형, 빈번한 데이터 이동, 제한적인 계산 능력 및 저장 능력 그리고 베터리 전력 사용이라는 특성을 갖는 센서 노드에 알맞은 암호화를 위한 키 관리 구조가 요구된다. 따라서 본 논문에서는 센서 네트워크에서의 효율적인 키 설정을 위해 클러스터에 기반한 구조와 다항식을 사용한 pair-wise key설정 방법을 제안 하였다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.11
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• pp.67-77
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• 2007

In sensor networks, it is very important to refresh communication keys of sensors in a periodic or on-demand manner. To perform a dynamic key management efficiently, sensor networks usually employ cluster architecture and each CH (Cluster Head) is responsible for key management within its cluster. In cluster-based sensor networks, CHs are likely to be targets of capture attacks, and capture of CHs threatens the survival of network significantly. In this paper, we propose a periodical key refreshment scheme which counteracts against capture of CHs. First, the proposed scheme reduces the threat caused by compromise of CHs by forcing each CH to manage a small number of sensors and changing CH role nodes periodically. Second, the proposed scheme flings attackers into confusion by involving other nodes in a key establishment between BS (Base Station) and a CH. Our numerical analyses showed that the proposed scheme is more secure than other schemes and robust against compromise of CHs.

• Journal of the Korean Society for Marine Environment & Energy
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• v.20 no.2
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• pp.117-125
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• 2017

SNS Big-data Analysis means to find potential value from big data which has produced by the social media. In this paper, SNS Big-data has been analysed to find Korean concerns by using 24 key words from the marine and fisheries sector. Among 24 key words, seafood, shipping and Dokdo Island are the most mentioned ones. Some key words such as ocean policies and marine security that have less concerns have bess mentioned less. Also, key words that are led by government are mostly mentioned by news media, but key words that are led by private sector and have intimate relationship with people's lives are mostly mentioned by Blogs and Twitters. Therefore, reflecting close national concerns by SNS Big-data Analysis and especially resolving negative factors are the most significant part of the policy establishment. Also, differentiated promotion methods need to be prepared because the frequency of key words mentioned from each type of media are different.

• Journal of KIISE:Information Networking
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• v.27 no.2
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• pp.175-186
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• 2000

Over the years, the extensive use of networks and distributed systems has increased the need for authentication and digital signatures. Inperforming authentication on a massive scale, authentication servers that use multiple workstations or PCs are more economical than servers that use one inicomputer or mainframe. However, the establishment of authentication servers with multiple platforms can cause some security problems and increases the cost of key management because all platforms within the server must have the private key of the authentication server. We propose a scheme which can solve these problems. The proposed scheme can establish a strong authentication server with no additional key management and improve the performance of the authentication server up to 13 times.

• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.57-63
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• 2007

Due to the strong influence of nitrogen(N) on plant productivity, a vast amount of N fertilizers is used to maximize crop yield. Over-use of N fertilizers leads to severe pollution of the environment, especially the aquatic ecosystem, as well as reducing farmer's income. Growing of N-efficient cultivars is an important prerequisite for integrated nutrient management strategies in both low- and high-input agriculture. Taking maize as a sample crop, this paper reviews the response of plants to low N stress, the physiological processes which may control N-use efficiency in low-N input conditions, and the genetic and molecular biological aspects of N-use efficiency. Since the harvest index(HI) of modern cultivars is quite high, further improvement of these cultivars to adapt to low N soils should aim to increase their capacity to accumulate N at low N levels. To achieve this goal, establishment and maintenance of a large root system during the growth period may be essential. To reduce the cost of N and carbon for root growth, a strong response of lateral root growth to nitrate-rich patches may be desired. Furthermore, a large proportion of N accumulated in roots at early growth stages should be remobilized for grain growth in the late filling stage to increase N-utilization efficiency. Some QTLs and genes related to maize yield as well as root traits have been identified. However, their significance in improving maize NUE at low N inputs in the field need to be elucidated.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.6
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• pp.1569-1592
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• 2015

The purpose of this study was to examine educational performance of key competencies in the situation by introducing NCS of junior college. And also, this study aimed at investigating the effects of individual characteristics on the relationship between characteristics of key competencies based on NCS and educational transfer. Data was collected from samples of 389 freshman and sophomore students who took the classes about communication skills and problem solving skills of key competencies. All of the students major in secretarial science. Based on the collected data, this study analyzed structural equating model, using AMOS Graphics. The result of analysis showed that there was a significant positive effect of educational training characteristics on educational transfer in some research models planned in this study. The findings in analysis of mediating effect showed that there was a full mediation effect of determinacy of career attitude maturity, and there was a partial mediation effect of readiness of career attitude maturity. Based on the result, this study proposed theoretical and practical ways considering individual characteristics for establishment and development of NCS.

• Journal of Information Technology Services
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• v.5 no.3
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• pp.173-186
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• 2006

The local public organizations, to secure the Confidentiality, Integrity, Authentication and Non-Repudiation of cyber administrative environment is giving it a try to consolidate the official documents among them by standardizing all the documents into XML formats together with the establishment of the GPKI(Government Public Key Infrastructure). The Authentication System based on the PKI(Public Key Infrastructure) used by the GPKI, however, provides only the simple User Authentication and thus it results in the difficulty in managing the position, task, role information of various users required under the applied task environment of public organizations. It also has a limitation of not supporting the detailed access control with respect to the XML-based public documents.In order to solve these issues, this study has analyzed the security problems of Authentication and access control system used by the public organizations and has drawn the means of troubleshoot based on the analysis results through the scenario and most importantly it suggests the access control model applied with PMI and SAML and XACML to solve the located problem.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.1010-1013
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• 2007

와이브로 서비스는 고속 이동 인터넷 환경 속에서 고속으로 무선 인터넷 서비스를 제공하는 기술이다. 기존의 무선인터넷 서비스와 달리 이동성을 제공한다는 점에서 차별화를 제공한다. 이렇게 이동하는 단말에게 양질의 데이터를 안전하게 전송하기 위해서는 보안기술이 중요한 요소로 작용한다. 서비스를 제공하기 전에 단말(Mobile Station)과 RAS(Radio Access Stations)간의 인증을 바탕으로 상호 키(TEK:Traffic Encryption Key)를 분배하고 TEK를 바탕으로 데이터를 암호화해서 전송하게 된다. 기존의 인증 프로토콜에서는 RAS에서 단독으로 키를 생성하는 방식이지만, 본 논문에서는 기존의 프로토콜의 문제점으로 지적된 Replay Attack에 대해 DH(Diffie-Hellman) 키 분배(Key Distribution) 방식을 적용하는 프로토콜을 제안함으로써 취약점에 대비 하였다. 이를 통해 RAS에 집중되는 키 생성에 대한 오버헤드를 단말에 분산 시킬 수 있다. 이로써 제안된 프로토콜을 사용해서 기존의 프로토콜을 사용했을 때보다 보안강도를 높일 수 있다.