• 한국정보처리학회논문지
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• 제6권10호
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• pp.2752-2763
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• 1999

On account of the text based mail system has it's limit to support multimedia applications, GUI based mail system platform was developed to control document flow and automatize information process. The existing mail systems's to transmit data must need additional functions to automate document flow control. The platform of document flow control is deeply related to EDMAS(Electronic document Management System), workflow, Electronic Banking, DMS(Document Management System) automation, so it needs an ability to control proper data and document correctly. To resolve this problems, we are need of browser and engine to design work flow and to control documents flow. In this paper, we develope a mail browser to design document flow by follow user's requirements. This system can generate executive script code for document flow, and we add the function of workflow and process management to automatize the document flow in this system, and then we implement this Data flow engine.

• 한국전자거래학회지
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• 제15권1호
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• pp.1-16
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• 2010

Confidentiality is one of the most important requirements of information protection systems. The access control technique has been used to provide confidentiality, but it has fundamental problems in that it cannot prevent violations of confidentiality committed by authorized users. Information flow control is a technique introduced to resolve such problems, and many approaches based on programming languages have been proposed. However, it is not easy for a programmer to implement the technique at the source code level. Furthermore, the practicality of information flow control is difficult to demonstrate because it does not provide control over programs that have already been developed. This paper proposes a method that enables a practical information flow control through using a protected area, a separate part of computer system storage. Case studies are given to show its usefulness.

• 정보보호학회논문지
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• 제22권5호
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• pp.1159-1168
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• 2012

기존의 Control Flow Integrity(CFI)와 Control Flow Locking(CFL) 기법은 프로그램이 개발자의 의도대로만 실행되도록 강제하여 실행 흐름의 무결성을 제공하고 안전한 프로그램 실행을 보장한다. 하지만, 함수 호출 문맥을 인지하는 보호 기법을 제공하지 않아 정밀도가 떨어지고 이를 악용한 공격을 허용하는 취약점을 가지고 있다. 본 논문에서는 이러한 문제점들을 해결하는 Source-code CFI(SCFI) 시스템을 제안한다. 제안한 시스템에서는 정밀도 높은 CFI 기능을 제공하여 프로그램의 안전성을 높인다.

• 한국정보처리학회논문지
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• 제6권3호
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• pp.750-757
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• 1999

The protocol conformance testing is to check whether an implementation of a protocol conforms to its specification. And it is important to improve the interoperability of protocol and the efficiency of cost. In general, protocol is composed of the control flow representing observable behaviors and the data flow representing internally used variables. Until now, research for generation of test suite has been realized only consideration the control flow of protocol or separation control flow from data flow. Case of considering control flow, contents of test was simple and definite. Length of test was short. But it was of little application, and it didn't manage each kind errors in data flow. Therefore, we must generate test case that can manage control and data flow. So, anomaly of variable must be removed for efficient conformance testing. Therefore in this dissertation, we proposed algorithm which can remove anomaly of variable for efficient conformance testing. And it showed that anomaly of variable was got rid of applying this algorithm to real protocol.

• 한국정보통신학회논문지
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• 제4권3호
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• pp.681-687
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• 2000

최적화란 비효율적인 코드를 구분해 내서 실행 속도 및 기억 공간의 효율성을 높여 주는 방법으로 컴파일러의 각 단계에서 수행된다. Augustus K. Uh떼 의해 제안된 Ideograph는 입력 프로그램에 대한 제어 의존성과 자료 의존성에 관한 정보를 동시에 표현할 수 있어 코드 최적화 단계에서 효과적으로 이용될 수 있으며 프로그램에 존재하는 병렬성을 표현하는데 효과적이다. 구문 트리는 원시 프로그램 정보를 효율적으로 표현할 수 있는 중간 표현으로서 컴파일러 구천에 널리 사용되고 있다. 본 논문에서는 원시 프로그램의 중간 표현인 구문 트리를 입력으로 받아 최적화 정보를 추출한 후 제어 흐름 및 자료 흐름 분석 정보를 추출하여 제어 의존성과 자료 의존성을 Ideouaph에 동시에 표현한다.

• 전자공학회논문지
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• 제50권1호
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• pp.246-253
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• 2013

본 논문에서는 유동의 안정된 흐름 제어를 위한 유동제어에 대해 다룬다. 전산유체역학 해석을 통해 제공된 대용량의 유동 데이터를 POD 방법을 통하여 축약하고, 제어측면에서 시간 및 주파수 영역에서의 분석에 근거하여 적절한 수준의 저차 모델링한다. 한편, 유동장 표면에 부착된 압력센서로부터 공간상의 유동상태 추정을 위해 신경망 구조를 갖는 유동추정기를 구성하고, 되먹임 유동제어기를 설계함으로써 유동제어루프를 구성한다.

• 한국전산유체공학회지
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• 제10권1호
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• pp.80-86
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• 2005

In order to control the transonic flow field with a shock wave, a condensing flow was produced by an expansion of moist air on a circular bump model and shock waves were occurred in the supersonic parts of the fields. Furthermore, the additional passive technique of shock-boundary layer interaction using the porous wall with a cavity underneath was adopted in this flow field. The effects of these methods on the shock wave characteristics were investigated numerically. The result showed that the flow fields might be effectively controlled by the suitable combination between non-equilibrium condensation and the position of porous wall.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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• pp.187-188
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• 2003

In order to control the transonic flow field with shock wave, a condensing flow was produced by an expansion of moist air on a circular bump model and shock waves were occurred in the supersonic parts of the fields. Furthermore, the additional passive technique of shock - boundary layer interaction using the porous wall with a cavity underneath was adopted in this flow field. The effects of these methods on the shock wave characteristics were investigated numerically. The result showed that the flow fields might be effectively controlled by the suitable combination between non-equilibrium condensation and the position of porous wall.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.396-413
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• 2017

Dynamically checking the integrity of software at run-time is always a hot and difficult spot for trusted computing. Control-flow integrity is a basic and important safety property of software integrity. Many classic and emerging security attacks who introduce illegal control-flow to applications can cause unpredictable behaviors of computer-based systems. In this paper, we present a software-based approach to checking violation of control flow integrity at run-time. This paper proposes a high-performance and low-overhead software control flow checking solution, control flow checking at virtual edges (CFCVE). CFCVE assigns a unique signature to each basic block and then inserts a virtual vertex into each edge at compile time. This together with insertion of signature updating instructions and checking instructions into corresponding vertexes and virtual vertexes. Control flow faults can be detected by comparing the run-time signature with the saved one at compile time. Our experimental results show that CFCVE incurs only 10.61% performance overhead on average for several C benchmark programs and the average undetected error rate is only 9.29%. Compared with previous techniques, CFCVE has the characteristics of both high fault coverage and low memory and performance overhead.

• 한국컴퓨터정보학회논문지
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• 제16권6호
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• pp.41-50
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• 2011

악의적인 소프트웨어 역공학으로부터 프로그램이 가지는 코드를 보호하기 위해서 코드 난독화가 제안되었다. 이것은 기존에 존재하는 프로그램 코드를 어렵게 변환시키는 것으로 프로그램 코드에 대한 악의적인 정적 분석을 어렵게 만든다. 코드 난독화는 난독화 목적에 따라 레이아웃, 데이터, 제어 난독화로 분류되어진다. 이 중 제어 난독화는 프로그램이 가지는 제어 흐름에 대한 추상적인 정보를 보호하는 것으로 다양한 종류의 개별 제어 흐름 난독화 변환이 제안되었지만, 이를 효과적으로 적용할 수 있는 방법은 제안되지 않았다. 본 논문에서는 제어 흐름 난독화 변환을 프로그램에 효과적으로 적용할 수 있는 난독화 전략을 제안하고, 실험을 통해서 제안한 난독화 전략의 효용을 보였다.