• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.473-475
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• 1998

본 논문에서는 색상 변화 분석을 통하여 차량의 속도와 수량을 측정하는 방법을 제안한다. 동영상에서 색상 변화를 분석하기 위하여 시간 흐름에 따른 화소의 색상 변화를 그래프로 표현한다. 차량 진행 방향에 있는 두 개의 화소에 대하여 이 그래프를 구하여 두 그래프가 가지는 시간차이를 계산하여 이동하는 차량의 속도를 구한다. 차량의 진행 방향을 추정한다. 차량의 수량은 도로 색에 경계 값을 설정하여 구하고, 이를 속도로 보완한다. 제안한 시스템은 날씨와 밝기에 영향을 적게 받으며 수행시간이 적게 드는 장점을 가진다.

• Journal of KIISE
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• v.42 no.1
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• pp.44-53
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• 2015

Control flow information is useful in the analysis and comparison of programs. Virtualization-obfuscation hides control structures of the original program by transforming machine instructions into bytecode. Direct examination of the resulting binary reveals only the structure of the interpreter. Recovery of the original instructions requires knowledge of the virtual machine architecture, which is randomly generated and hidden. In this paper, we propose a method to reconstruct original control flow using only traces generated from the obfuscated binary. We consider traces as strings and find an automaton that represents the strings. State transitions in the automaton correspond to the control transfers in the original program. We have shown the effectiveness of our method with commercial obfuscators.

• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.70-79
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• 2010

We perform static program analysis for the binary code. The reason you want to analyze at the level of binary code, installed on your local computer, run the executable file without source code. And the reason we want to perform static analysis, static program analysis is to understand what actions to perform on your local computer. In this paper, execution flow graph representing information such as the execution order among functions and the flow of control is generated. Using graph, User can find execution flow of binary file and calls of insecure functions at the same time, and the graph should facilitate the analysis of binary files. In addition, program to be run is ensured the safety by providing an automated way to search the flow of execution, and program to be downloaded and installed from outside is determined whether safe before running.

• Journal of the Korea Society of Computer and Information
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• v.1 no.1
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• pp.147-158
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• 1996

This paper proposed a concurrency control structure based on specialized data flow graphs that was analysed a run-time concurrency control activity to be integrated with the task scheduler Data were viewed as flowing on the arcs from one node to another in a stream of discrete to tokens. The network that Is based upon the Entity-Relationship model, can be viewed a fixed problems used query tokens as a data flow graph. The performance was measured used in the various expriments compared the overall performance of the different concurrency control methods, DBFG (DataBase Flow graphs) scheduling had the knowledge to obtain better performance than 2PL in a distributed environment.

• The KIPS Transactions:PartD
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• v.15D no.2
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• pp.197-206
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• 2008

The CTOC framework was implemented to efficiently perform analysis and optimization of the Java bytecode that is often being used lately. In order to analyze and optimize the bytecode from the CTOC, the eCFG was first generated. Due to the bytecode characteristics of difficult analysis, the existing bytecode was expanded to be suitable for control flow analysis, and the control flow graph was drawn. We called eCFG(extended Control Flow Graph). Furthermore, the eCFG was converted into the SSA Form for a static analysis. Many loops were found in the conversion program. The previous CTOC performed conversion directly into the SSA Form without processing the loops. However, processing the loops prior to the SSA Form conversion allows more efficient generation of the SSA Form. This paper examines the process of finding the loops prior to converting the eCFG into the SSA Form in order to efficiently process the loops, and exhibits the procedures for generating the loop tree.

• The Journal of the Korea Contents Association
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• v.6 no.1
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• pp.160-169
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• 2006

This paper describes the data structure for program analysis and optimization of bytecode level. First we create an extended CFG(Control Flow Graph). Because of the special properties of bytecode, we must adaptively extend the existing control flow analysis techniques. We build basic blocks to create the CFG and create various data that can be used for optimization. The created CFG can be tested for comprehension and maintenance of Java bytecode, and can also be used for other analyses such as data flow analysis. This paper implements CTOC's CTOC-BR(CTOC-Bytecode tRanslator) for control flow analysis of bytecode level. CTOC(Classes To Optimized Classes) is a Java bytecode framework for optimization and analysis. This paper covers the first part of the CTOC framework. CTOC-BR is a tool that converts the bytecode into tree form for easy optimization and analysis of bytecode in CTOC.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.354-356
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• 2022

소셜 네트워크 및 웹 데이터와 같은 대규모 그래프 데이터를 처리하기 위해 병렬 처리 기반의 기법들이 많이 사용되어 왔다. 본 연구에서는 그래프 형식의 대규모 교통 데이터를 하둡 맵리듀스를 이용하여 처리하는 효과적인 기법을 제안한다. 제안하는 방식에서는 도시의 유동 인구 흐름을 가중치로 고려할 수 있도록 Weighted PageRank 알고리즘을 기반으로 하는 병렬 그래프 알고리즘을 사용하며, 해당 알고리즘을 하둡 맵리듀스에 적용하여 주거 및 근무지 등의 지역을 분류하도록 결과를 분석하였다. 제안 기법을 통한 분석 결과를 기반으로 지역 간 유동 인구 그래프 데이터에서 각 도시의 영향력을 측정하는 페이지랭크, 하둡 맵리듀스 기반의 기법을 제시한다.

• Journal of Internet Computing and Services
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• v.17 no.4
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• pp.51-60
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• 2016

Embedded software has requirements such as real-time and environment independency. The real-time requirement is affected from worst-case execution time of loaded tasks. Therefore, to guarantee real-time requirement, we need to determine a program's worst-case execution time using static analysis approach. However, the existing methods for worst-case execution time analysis do not consider the environment independency. Thus, in this paper, in order to provide environment independency, we propose a method for measuring task's execution time from the source codes. The proposed method measures the execution time through the control flow graph created from the source codes instead of the executable codes. However, the control flow graph created from the source code does not have information about execution time. Therefore, in order to provide this information, the proposed method identifies the relationships between statements in the source code and instructions in the executable code. By parameterizing those parts that are dependent on processors based on the relationships, it is possible to enhance the flexibility of the tool that measures the worst-case execution time.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11a
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• pp.313-316
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• 2003

객체지향 프로그래밍 방식으로 인해 프로그램의 재사용성이 증대되었다. 객체들을 재사용함으로서 프로그램을 수정 갱신하는 일이 더욱 많아져 점진적 데이터 흐름 분석 기법은 코드 최적화의 성능을 향상하는 중요한 방안이 되었다. 이에 본 논문에서는 데이터 흐름 분석을 위한 지배자연결그래프를 점진적으로 구성하는 알고리즘을 제안하고 이의 타당성과 성능을 실험을 통하여 제시하였다.

• Journal of Digital Contents Society
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• v.19 no.2
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• pp.363-370
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• 2018

Ransomware detection has become a hot topic in computer security for protecting digital contents. Unfortunately, current signature-based and static detection models are often easily evadable by compress, and encryption. For overcoming the lack of these detection approach, we have proposed the dynamic ransomware detection system using data mining techniques such as RF, SVM, SL and NB algorithms. We monitor the actual behaviors of software to generate API calls flow graphs. Thereafter, data normalization and feature selection were applied to select informative features. We improved this analysis process. Finally, the data mining algorithms were used for building the detection model for judging whether the software is benign software or ransomware. We conduct our experiment using more suitable real ransomware samples. and it's results show that our proposed system can be more effective to improve the performance for ransomware detection.