• The Korean Journal of Applied Statistics
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• v.37 no.2
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• pp.139-155
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• 2024

This study performed a multi-classification task to classify mesial temporal lobe epilepsy with left hippocampal sclerosis patients (left mTLE), mesial temporal lobe epilepsy with right hippocampal sclerosis (right mTLE), and healthy controls (HC) using magnetoencephalography (MEG) data. We applied various artificial neural networks and compared the results. As a result of modeling with convolutional neural networks (CNN), recurrent neural networks (RNN), and graph neural networks (GNN), the average k-fold accuracy was excellent in the order of CNN-based model, GNN-based model, and RNN-based model. The wall time was excellent in the order of RNN-based model, GNN-based model, and CNN-based model. The graph neural network, which shows good figures in accuracy, performance, and time, and has excellent scalability of network data, is the most suitable model for brain research in the future.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.25-28
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• 2021

블록체인은 탈집중화, 위변조 방지, 추적 가능, 노드 간 공동 유지 및 보수가 가능한 데이터베이스로서 서로 신뢰하지 않은 노드 간 통신 신뢰 문제를 해결할 수 있는 점 대 점 통신 네트워크를 실현할 수 있다. 최근 몇 년 동안, 블록체인 기술은 지속적으로 발전하여 데이터 보안 문제를 해결하기 위한 중요한 기술로 주목받고 있다. 블록체인의 응용은 최초의 디지털 화폐 영역에서 금융·정무·공업 제조 영역으로 확대되고 있다. 블록체인의 특성에 따라 블록체인의 성능은 분산형 데이터 통신에 비해 크게 떨어지고 처리량이 제한되는 문제점이 존재한다. 본 논문에서는 최근 연구되고 있는 블록체인의 보안 구조 및 성능 분석에 대해 조사하고, 기존에 연구되었던 기술과 비교하여 블록체인의 안전성을 유지하며 성능을 향상시키는 방법에 대해 고찰한다. 이후 유향 비순환 그래프 (DAG: Directed Acyclic Graph) 및 샤딩 (Sharding)을 이용하여 안전성과 성능을 강화시키는 방법에 대해 제안한다. 제안하는 시스템은 DAG를 사용하여 위변조 방지 및 처리 속도 향상의 이점을 가지고 있으며, 샤딩을 사용함으로써 데이터 처리량을 향상시킨다. 마지막으로 제안하는 시스템은 기존 블록체인과 비교하여 안정성과 데이터 처리량 측면에서 비교 분석을 진행한다.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06c
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• pp.58-60
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• 2006

근래에 XML 문서가 인터넷에서 정보 교환의 방법으로 표준화됨에 따라, 많은 양의 데이터가 XML 문서 포맷으로 저장되고 있다. XML 문서의 유사성 연구는 크게 edit-distance를 이용하는 방법, 문서의 그래프 모델을 이용하는 방법, 문서의 매트릭스 모델을 이용하는 방법 등이 있다. 최근에는 문서를 encoding 하고 푸리에 변환을 이용하는 방법이 보고되었다. 본 논문에서는 XML 문서를 함수로 변환하여 모델링하여 문서의 구조적 유사성을 비교하는 방법을 제안한다. 제안된 방법을 사용하여 XML 문서를 함수로 모델링하였으며 XML 문서 간의 유사성을 비교해 보았다.

• Journal of the Korea Society of Computer and Information
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• v.18 no.7
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• pp.111-123
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• 2013

To verify software vulnerability, the method of conjecturing software structure and then testing the software based on the conjectured structure has been highlighted. To utilize the method, an efficient way to conjecture software structure is required. The popular graph and tree methods such as DFG(Data Flow Graph), CFG(Control Flow Graph) and CFA(Control Flow Automata) have a serious drawback. That is, they cannot express software in a hierarchical fashion. In this paper, we propose a method to overcome the drawback. The proposed method applies various input data to a binary code, generate CFG's based on the code output and construct a HCFG (Hierarchical Control Flow Graph) to express the generated CFG's in a hierarchical structure. The components required for HCFG and progressive algorithm to construct HCFG are also proposed. The proposed method is verified through constructing the software architecture of an open SMTP(Simple Mail Transfer Protocol) server program. The structure generated by the proposed method and the real program structure are compared and analyzed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.12
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• pp.874-880
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• 2019

This paper introduces a method which can be effectively used for the path planning of UAV in a realistic map which has mountainous terrains, air defense networks and radars based on the Visibility Graph. Existing studies of Visibility Graph have been studied mainly for simple shape obstacles in 2-dimensional environment such as self-driving cars which avoid buildings. However, for UAV, Visibility Graph must be used in 3-dimensional environment for the variance of altitude. This occurs significant elapsed time increase because of the increase of the amount of the visibility of node sets. To solve this problem, this paper decrease the number of nodes which consists the complex terrain environments using convex hull based on Layered Visibility Graph. With convex hull method, this paper confirmed that the elapsed time is decreased about 99.5% compared to the case which has no decrease of the number of nodes.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.8
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• pp.445-455
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• 2002

In this paper, we present a new task scheduling scheme ior the efficient execution of the tasks of compound nodes of hierarchical task graph(HTG) on shared memory system. The proposed scheme for exploitation functional parallelism is autoscheduling that performs the role of scheduling by processor itself without any dedicated global scheduler. To adapt the proposed scheduling scheme for various platforms, Including a uni-processor systems, Java threads were used for implementation, and the performance is analyzed in comparison with a conventional bit vector method. The experimental results showed that the proposed method was found to be more efficient in its execution time and exhibited good load-balancing when using the experimental parameter values. Furthermore, the memory size could be reduced when using the proposed algorithm compared with a conventional scheme.

• The Transactions of the Korea Information Processing Society
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• v.5 no.9
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• pp.2323-2333
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• 1998

Software engineers generally analyze the program behavior under the test case that revealed the error, not under any teneric est case. In this paper we discuss the dynamic slice consisting of all statements that actually affect the value of a variable occurrence for a given program input. We propose an efficient algorithm to make dynamic program slices. The eficiency of this algorithm is evaluated on some developed program. results are shown by a marking table of execution history. Dynamic Dependence Graph, and Reduced Dynamic Dependence Graph, Consequently, the efficiency of the proosed algorithm is also presented by the compariso with algorithm that was announced previously.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.2
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• pp.216-226
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• 2000

This paper presents a new method to synthesize timed asynchronous circuits directly from the specification without generating a state graph. The synthesis procedure begins with a deterministic signal transition graph specification with timing constraints. First, a timing analysis extracts the timed concurrency and timed causality relations between any two signal transitions. Then, a hazard-free implementation under the timing constraints is synthesized by constructing a precedence graph and finding paths in the graph. The major result of this work is that the method does not suffer from the state explosion problem, achieves significant reductions in synthesis time, and generates circuits that have nearly the same area as compared to previous methods.

• Journal of KIISE:Information Networking
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• v.27 no.1
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• pp.12-21
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• 2000

Arrangement graph has desirable properties for design requirements of a multihop lightwave network, such as node and edge symmetry, low diameter, simple routing, etc. In this paper, arrangement lightwave network based on arrangement graph model is proposed as new logical topology of multihop lightwave network. In the proposed scheme, multistar and grouping of network are used for improving reusability of wavelength and scalability. Also, this paper shows that the proposed scheme is an alternative logical topology for application requiring more nodes with limited wavelengths by evaluating performance with related works.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.6
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• pp.677-682
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• 2015

The mnemonic-system in numbers is helped you to remember numbers. In this mnemonic-system, a graph or image is a rather neat mnemonic. In graph-based systems, there are many ways such as dot, line, bar, and etc to represent a mnemonic system. Mnemonics aim to translate information into a form that the brain can retain better than its original form. This is the same in the mnemonic-system in numbers. Alternative methods in mnemonic-system for numbers are a image. In this paper, we suggest a simple graph algorithm and arranged image algorithm for the mnemonic-system in numbers, and show comparative results based on the retention of the mnemonic system about two methods.