• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.1
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• pp.82-91
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• 2009

Routing (or path selection) is one of the key issues of multi-hop relay networks such as the IEEE 802.16j. Moreover, the allocation of appropriate resource such as bandwidth should not only be made in accordance with the paths selected, but the utilization of radio resource of an entire cell should also be maximized. Due to this interdependency between the problems of resource allocation and routing, it is desired these two problems are addressed simultaneously. In this paper, we propose a joint resource allocation and routing scheme for an OFDMA-based multi-hop cellular system. This scheme uses a polynomial time heuristic algorithm called Multi-Dimensional Multi-choice Knapsack Problem (MMKP) in order to find an approximate solution maximizing the total downlink throughput. In the simulation results, we show that the proposed scheme finds a sub-optimal solution which is superior to a link quality-based routing scheme, but slightly worse than the optimal solution.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.1
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• pp.73-81
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• 2021

When downloading files using an app or web-based application on the user's mobile phone, the path is set to be saved in the pre-defined default directory. Many applications requiring access to storage, including file managers, require a write or read permission of storage to provide numerous functions and services. This means that the application will have direct access to the download folder where the numerous files downloaded. In this paper, to prove our feasibility of attack using the security vulnerabilities mentioned above, we developed a file hacking function disguised as an encryption function in the file management application. The file that encrypted will be sent to hackers via E-mail simultaneously on the background. The developed application was evaluated from VirusTotal, a malicious analysis engine, was not detected as a malicious application in all 74 engines. Finally, in this paper, we propose a defense technique and an algorithm based on the Trusted Execution Environment (TEE) to supplement these storage vulnerabilities.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4A
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• pp.496-501
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• 2000

In this thesis, we propose more confidence required backup-VP allocation. First, we assigned backup VP considering Reserved resource on realtime QoS with each QoS parameter priority and then allocated backup VP of non-realtime QoS. The proposed algorithm provides more confidential backup VP by priority method for relative high cost realtime QoS error.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.412-414
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• 2006

그리드 네트워크에서 MPI를 사용하여 지리적으로 산재된 컴퓨팅 자원을 활용하고 복잡한 문제를 해결하기 위한 MPICH-G2는 사설 IP 클러스터를 지원하지 못한다는 단점을 가지고 있다. MPICH-G2가 가지는 이러한 문제점을 해결하는 방법으로서 사설 IP 클러스터를 지원하는 MPICH-GP를 NAT와 프락시를 병용하여 설계하고 구현하였다. 사설 IP 클러스터의 프론트 노드에 프락시를 두고, 이를 통해 내부 계산 노드로의 통신 링크를 중계한다. 따라서 사설 IP 클러스터와 공인 IP 클러스터가 혼재된 네트워크에서도 적정한 경로를 설정하고 성공적으로 MPI 작업을 수행할 수 있다. 본 논문에서는 MPICH-GP의 성능을 기존의 MPICH-G2와 비교하였다. 그리드 환경에서 MPICH-GP는 MPICH-G2의 80% 이상의 성능을 보이며 rank 관리기법을 적용한 경우는 95% 이상의 성능을 나타낸다.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.338-343
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• 2006

모바일 Ad-hoc 네트워크는 기간망을 활용할 수 없는 특수한 지역이나 응용에 활용되는 네트워크를 의미한다. 이 네트워크 내에서는 노드의 이동성이 높고 노드 자체의 에너지 제약 등으로 인해 빈번한 네트워크 단절등이 발생하게 된다. 노드의 이동성에 따른 토플로지 변경에 유연하게 반응하면서 패킷의 전달성을 향상시키는 기법이 모바일 Ad-hoc 네트워크 분야에 반드시 요구되며 본 논문에서는 이를 위해 혼합형 프로토콜인 PAOMDV(Possibility based AOMDV)와 OLSR-ME(OLSR with Modify Energy Efficiency)를 제안한다. 이 프로토콜을 기존의 프로토콜인 AODV, AOMDV, ZRP와 비교 실험을 수행하고 그 성능을 검증하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.274-276
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• 2005

본 논문에서는 단백질 상호작용 네트워크의 복잡성을 제어하고 생물학자가 자신이 설정한 조건을 만족시키는 환경에서 추가적인 다양한 제약 조건을 가하면서 원하는 상호작용 네트워크를 구성하고 조작할 수 있도록 지원하는 Constraints Based Dynamic Protein Interaction Network 이라는 새로운 개념의 단백질 상호작용 네트워크를 소개한다. 본 기법에서는 기존의 단백질 상호작용 네트워크에서 주로 사용하는 단백질 상호작용 정보뿐 아니라 단백질 상호작용에 영향을 미칠 수 있는 개개 단백질의 물리 화학적 특성 및 위치 정보와 상호작용의 환경 정보도 단백질 상호작용 네트워크 구성에 활용한다. 제안된 네트워크상에서 생물학자는 단백질 상호작용 네트워크 구성 조건을 변경하거나 얻어진 네트워크에 변경을 가하면서 점차 자신이 원하는 의미 일은 대사경로 모델을 찾거나, 제약조건의 다양한 조작을 통하여 생물학적 실험을 통하여 얻어진 대사모델의 유효성을 검증하는 것도 가능하다.

• Journal of Information Technology Applications and Management
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• v.14 no.2
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• pp.1-10
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• 2007

The ubiquitous computing system is expected to be widely utilized in digital home, logistics control, environment/disaster management, medical/health-care services and other applications. The ubiquitous sensor network (USN) is a key infra-structure of this system. Nodes in the USN are exposed to adverse environments and required to perform their missions with very limited power supply only. Also the sensor network is composed of much more nodes. In case some node consumes up its power capacity under a certain required level, the network topology should change and re-routing/ re-transmission of data is necessitated. Resultantly communication protocols studied for conventional wireless networks or ad-hoc networks are not suitable for the sensor network. Schemes should be devised to control the efficient usage of node power in the sensor network. This paper proposes a routing algorithm to enhance the efficiency of power consumption for USN node and analyzes its performance by simulation.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.410-417
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• 2002

We consider the constraint based explicit routing problem in MPLS based IP Network. In this problem, we are given a set of traffic demands and a network with different link capacities. The problem is to assign the demand commodities to the paths in the network while minimizing the maximum link load ratio. We formulate this problem as an integer programming problem and propose an efficient column generation technique. To strengthen the formulation, we consider some valid inequalities. We also incorporate the column generation technique with variable fixing scheme Computational results show that the algorithm gives high quality solutions in a short execution time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.5
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• pp.857-859
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• 2015

In this letter, we consider a directional routing protocol that reduces the duplicated packets for AODV-based flooding in the course of establishing the end-to-end route in the multi-hop maritime ad-hoc networks. We propose an adaptive means of reducing the routing overhead subject to the node density and the target probability of successful routing that is analyzed by the stochastic geometry.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.3-4
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• 2007

Wireless Sensor Network is a form of network which consumes relatively less data trasmisson rate and energy. In this type of network, minimizing the consumption of energy so that it maximizes life time is very important. To be able to improve the energy comsumption, we propose the mechnism to trasmit broadcasted packet according to level value with priority assiagned to each relay node.