• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.1
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• pp.258-272
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• 2022

The technology implementation method was diversified into an 'autonomous cooperative driving' method to overcome the limitations of a stand-alone autonomous vehicle with vehicle sensor-based autonomous driving. The autonomous cooperative driving method involves exchanging information between roadside infrastructure and autonomous vehicles. In this process, the concept of dynamic information (LDM), a target of cooperation, was established. But, evaluation methods and standards for dynamic information have not been established. Therefore, this study, a dynamic information evaluation method based on information on pedestrians within the moving objects. In addition, autonomous cooperative driving was demonstrated, and dynamic information was also verified through the evaluation method. The significance of this study is that it established the dynamic information evaluation methodology for autonomous cooperative driving for the first time. Based on this, this study is expected to contribute to the application of safe autonomous cooperative driving technology to the field.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10c
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• pp.304-306
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• 2000

내장형 디바이스를 인터넷과 연결하고자 하는 요구가 늘어나고 있다. 이러한 정보기기들을 동적으로 상호 작용하게 하는 기술로서 지니(Jini)가 최근 주목을 받고 있다. 그러나 내장형 디바이스에서 지니 서비스를 제공하기 위해 요구되는 높은 하드웨어 사양이 문제점으로 지적되고 있다. 본 논문에서는 이러한 non-Java 디바이스를 지니 네트워크에 접속하여 지니 서비스를 제공할 수 있도록 서로게이트 시스템(Surrogate System)과 non-Java 디바이스간의 프로토콜을 설계하였다.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.753-757
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• 2008

In this paper, we propose a new scheduling strategy for dynamic programming in Grid environment. The key idea of this scheme is to reduce the execution time of a job by dividing the dynamic table based on the locality of table and allocating jobs to nodes which minimize network latency. This scheme obtains optimal concurrency by constructing the dynamic table using a distributed top down method. Through simulation, we show that the proposed Grid strategy improves the performance of Grid environment compared to previous branch-bound strategies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.5
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• pp.1101-1105
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• 2013

Due to underutilization of spectrum under the current static spectrum management policy, various kinds of dynamic spectrum access strategies have appeared. Myopic policy is a simple policy with reduced complexity that maximizes the immediate throughput. In this paper, the distribution of its medium access delay is evaluated under saturation traffic conditions. Using the distribution of the medium access delay, we also evaluate its system delay under non-saturated traffic conditions.

• Journal of KIISE:Information Networking
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• v.31 no.1
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• pp.112-122
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• 2004

In this paper, we propose a mobility estimation model based on inner regions in a cell and a dynamic resource reservation scheme which can control dynamically classes of mobile hosts on the mobile network. The mobility estimation model is modeled based on the reducible Markov chain. And the mobility estimation model provides a new hand off probability and a new remaining time for the dynamic resource reservation scheme. The remaining time is n estimated time that mobile hosts can stay in a cell. The dynamic resource reservation scheme can reserve dynamically a requested resource according to the classes of mobile hosts. This scheme can efficiently improve the connection blocking probability and connection dropping probability.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.11
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• pp.2547-2552
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• 2013

To achieve better performance in dynamic spectrum access networks, each secondary user tracks channels and chooses a good channel to transmit its packet. When all secondary users adopt the same dynamic spectrum access policy, they have similar channel information, which leads secondary users to choose the same channel and more collisions among them. To relieve this problem, we propose an access policy using belief vector tracking method for other competing secondary users. Simulation results are provided to show that the proposed policy yields better performance than the existing policies which do not take into account what other secondary users are doing.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1266-1272
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• 2004

Location-Based Services(LBS) give rise to location-dependent queries of which results depend on the positions of moving objects. Because positions of moving objects change continuously, indexes of moving object must perform update operations frequently for keeping the changed position information. Existing spatial index (Grid File, R-Tree, KDB-tree etc.) proposed as index structure to search static data effectively. There are not suitable for index technique of moving object database that position data is changed continuously. In this paper, I propose a dynamic hashing index that insertion/delete costs are low. The dynamic hashing structure is that apply dynamic hashing techniques to combine a hash and a tree to a spatial index. The results of my extensive experiments show the dynamic hashing index outperforms the $R^$ $R^*$-tree and the fixed grid.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.3
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• pp.523-531
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• 2007

In this paper, we are going to develop a newly designed indexing scheme which is compatible to manage the moving objects and propose a cost model of the scheme. We propose a dynamic hashing index that insertion/delete costs are low. The dynamic hashing structure is that apply dynamic hashing techniques to combine a hash and a tree to a spatial index. We analyzed the dynamic index structure and the cost model by the frequent position update of moving objects and verified through a performance assessment experiment. The results of our extensive experiments show that the newly proposed indexing schemes(Dynamic Hashing Index) are much more efficient than the traditional the fixed grid and R-tree.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.4
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• pp.47-52
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• 2007

In this paper, we proposed a constrution that creates Dynamic Pipe Hash Function with a pipe hash function. To increase security lever, dynamic hash function take and additional compression function. Proposed hash function based on the piped hash function. Our proposed Dynamic Pipe Hash Function is as secure against multicollision attack as an ideal hash function. And it have advantage for a number of reasons because of variable digest size. For example, in digital signature protocol, If a user requires increased security by selecting a large key size, useing a dynamic hash function in a protocol make implementation much easier when it is mandated that the size of the digest by increased.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.775-777
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• 2001

지니 기술은 자바 프로그래밍 모델을 기초로 한 클라이언트가 동적으로 서비스를 찾아서 프래그 앤 플레이를 가능하게 해주는 기술이다. 홈네트워킹 환경에 이러한 기술을 적용하였을 때, 허가되지 않은 사용자들이 접근할 수 있어 네트워크 보안에 관한 문제가 발생한다. 또한 룩업서비스에 서비스를 등록한 정보 가전 시스템의 관리를 필요로 한다. 그래서 본 논문은 지니 룩업서비스에 사용자가 접근할 때 인증의 과정을 거치도록 하였고, 정보 가전 시스템의 관리를 위한 기능을 추가하였다.