• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.529-533
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• 1996

Recently, manufacturing industries are doing their best to increase productivity and to reduce production time. One of tile efforts is to develop user-friendly and effective CAM systems. For this purpose, a CAM system for turning was developed. In the developed system. user interacts with tile CAM system using graphical user interface (GUI) and manufacturing support functions to make NC programs effectively. Manufacturing support functions include cycle decoder. interference check be ween tool and workpicce. bar turning without air cut and dynamic/wireframe simulation. In the cycle decoder. basic options are provided to novices for their convenience. and advanced options are provided to help expert to modify the program using their knowledge. Interference check has been nil issue in tile CAM system for tuning. In this paper. when a user selects a tool. interference check between selected tools and workpieces is done automatically. Moreover. remaining shapes are calculated automatically. Then, tile CAM system requests user to input all additional tool and generates NC codes to cut tile remaining shapes. In bar turning of forged raw material, air cut should be prevented for effective machining. For this purpose, a new algorithm for bar turning was developed. Dynamic and wireframe simulation was used to verify the generated NC code.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권2호
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• pp.766-783
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• 2012

Recently, many malicious users have attacked web browsers using JavaScript code that can execute dynamic actions within the browsers. By forcing the browser to execute malicious JavaScript code, the attackers can steal personal information stored in the system, allow malware program downloads in the client's system, and so on. In order to reduce damage, malicious web pages must be located prior to general users accessing the infected pages. In this paper, a novel framework (JsSandbox) that can monitor and analyze the behavior of malicious JavaScript code using internal function hooking (IFH) is proposed. IFH is defined as the hooking of all functions in the modules using the debug information and extracting the parameter values. The use of IFH enables the monitoring of functions that API hooking cannot. JsSandbox was implemented based on a debugger engine, and some features were applied to detect and analyze malicious JavaScript code: detection of obfuscation, deobfuscation of the obfuscated string, detection of URLs related to redirection, and detection of exploit codes. Then, the proposed framework was analyzed for specific features, and the results demonstrate that JsSandbox can be applied to the analysis of the behavior of malicious web pages.

• 한국화재소방학회논문지
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• 제21권2호
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• pp.36-41
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• 2007

본 연구에서는 분기배관의 강도해석을 통해 분기배관이 화재안전기준상에서 사용할 수 있는지를 판단하였다. 그 판단 방법으로 상용유한요소프로그램(ABACUS)를 사용하였고, 강도해석결과를 증명하기 위해 해당 분기배관에 본체강도시험을 실시하였다. 그 결과를 통해 분기배관의 사용가능성을 확인하였다. 또한, 분기배관으로 가장 많이 사용되는 배관인 배관용 탄소강관(KS D 3507)과 같은 용도로 사용할 수 있는 스테인리스배관이 KS D 3576(배관용 스테인리스 강관) 10S임을 확인하여 스테인리스배관이 소화배관에 적용될 수 있도록 하였다.

• 한국지반환경공학회 논문집
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• 제14권7호
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• pp.13-18
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• 2013

As a new foundation treatment technology, long-short pile composite's design theory is still in primary phase, and there are no explicit settlement calculation methods in active codes. So it is necessary to study the working mechanism and the methods of settlement calculation. In this paper, the mechanics of long-short pile composite foundation are fully discussed. Meanwhile, based on the shear deformation method, the Mylonakis & Gazetas models about mutual action between two piles and the one between pile and soil are introduced, Considering the performance of cushion, the flexible factors of mutual actions are provided. Then the settlement calculation of long-short pile composite foundation which can consider the mutual actions between pile, soil and cap is deduced, and the correlated program is also developed. Finally, an engineering example is discussed with the method. A comparison shows that calculated results and measured data from a field test pile are in a good agreement, indicating that the presented approach is feasible and applicable in engineering practice.

• 한국공간구조학회논문집
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• 제1권1호
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• pp.125-134
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• 2001

The objective of this study is the development of size discrete optimum design algorithm which is based on the GAs(genetic algorithms). The algorithm can perform size discrete optimum designs of space trusses. The developed algorithm was implemented in a computer program. For the optimum design, the objective function is the weight of space trusses and the constraints are limite state design codes(1998) and displacements. The basic search method for the optimum design is the GAs. The algorithm is known to be very efficient for the discrete optimization. This study solves the problem by introducing the GAs. The GAs consists of genetic process and evolutionary process. The genetic process selects the next design points based on the survivability of the current design points. The evolutionary process evaluates the survivability of the design points selected from the genetic process. In the genetic process of the simple GAs, there are three basic operators: reproduction, cross-over, and mutation operators. The efficiency and validity of the developed discrete optimum design algorithm was verified by applying GAs to optimum design examples.

• 한국컴퓨터정보학회논문지
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• 제16권6호
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• pp.51-59
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• 2011

국내에는 바이너리 코드에 대한 분석 기술이 많이 부족한 상태이다. 일반적으로 컴퓨터에 설치되는 실행 파일은 소스 코드 없이 단지 바이너리로 된 실행 파일만 주어지는 경우가 대부분이다. 따라서 위험하거나 알 수 없는 동작이 수행되는 경우가 발생할 수 있다. 따라서 이 논문에서는 바이너리 수준에서 정적으로 프로그램 분석을 수행할 수 있는 프레임워크를 설계 및 구현한다. 이 논문에서는 바이너리 실행 파일로부터 실행 순서 및 제어 흐름 등의 정보를 표현할 수 있는 제어 흐름 그래프를 작성하여 실행 흐름과 위험한 함수의 호출 여부를 동시에 파악하고 개발된 프레임워크를 통해 바이너리 파일에 대한 분석을 용이하게 한다.

• 한국컴퓨터정보학회논문지
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• 제11권5호
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• pp.149-156
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• 2006

복잡하고 규모가 큰 소프트웨어 개발 요구가 증가하는 것에 비해 상대적으로 느린 소프트웨어 개발 속도의 대안으로 여러 가지 개발 방법론이 소개되어 왔으며, 이들 대부분의 핵심 개념으로 코드의 재사용성이라는 속성을 포함하고 있다. 이러한 코드의 재사용적인 측면에서 소개되는 소프트웨어 개발 방법론들은 시간이 지남에 따라 재사용 될 코드의 단위가 점점 커져 왔다. 한편, 제조 공정 관련한 설계 자동화 시스템은 단순하게 제도판을 대신하는 기능을 넘어 설계 이후 공정에 활용 될 다양한 데이터 생성까지를 목표로 하고 있어 규모가 크고 복잡해지는 소프트웨어의 한 분야이다. 본 논문에서는 코드의 재사용성을 위한 여러 단위-객체, 컴포넌트, 모듈, 상업용 소프트웨어-기반의 소프트웨어 개발 방법이 실제로 어떻게 반영될 수 있는지를 금속제품을 위한 설계 자동화 시스템 개발 사례로 소개하고자 한다.

• 대한조선학회논문집
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• 제53권3호
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• pp.188-194
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• 2016

Accurate estimation of shear flows in thin-walled beam section is the key issue to evaluate shear stress distribution of ship hull transverse section under the shear forces acting on hull girder. It is regarded that the method using the warping functions obtained by finite element formulation is the state of the art of this field. Recently, however, IACS took effect the new version of CSR in which direct calculation process of shear flow was suggested. In the direct calculation process, shear flow of ship hull section can be obtained by the addition of determinate and indeterminate shear flows calculated respectively. So, in this paper, the shear flow evaluation codes based on the process proposed by IACS CSR and warping function based method were developed respectively. The calculated results of shear flows for the several examples of ship sections were compared with each other and considered in detail.

• 항공우주시스템공학회지
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• 제2권1호
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• pp.7-12
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• 2008

The three-dimensional finite element modeling of a composite rotor blade is very hard and requires much computation effort. The efficient method to model a composite beam is necessary for the dynamic and aeroelastic analyses of rotor blades. In this study, the beam modeling method of a composite rotor blade is studied using VABS. The computer program, VABS (Variational Asymptotic Beam Section Analysis), uses the variational asymptotic method to split a 3-D nonlinear elasticity problem into 2-D cross-sectional analysis and 1-D nonlinear beam problem. The VABS can produce the sectional stiffness coefficients of composite rotor blades with various cross section and initial twist/curvatures, and recover the original 3-D distribution of displacement/strain/stress fields. The results of various cross section beams show that VABS gives us the accurate results comparared to commercial codes and does not need much computation effort. It can be concluded that VABS provides the efficient method to establish the FE model of a composite rotor blade.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.302-309
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• 2004

The transmission capacity of wireless communication systems may become dramatically high by employ multiple transmit and receive antennas with space-time coding techniques appropriate to multiple transmit antennas. For large number of transmit antennas and at high bandwidth efficiencies, the receiver may become too complex whenever correlation across transmit antennas is introduced. Reducing decoding complexity at receiver by combining array processing and space-time codes (STC) helps a communication system using STC to overcome the big obstacle that prevents it from achieving a desired high transmission rate. Multi-carrier CDMA (MC-CDMA) allows providing good performance in a channel with high inter-symbol interference. Antenna array, STC and MC-CDMA system have a similar characteristic that transmit-receive data streams are divided into sub-streams. Thus, there may be a noticeable reduction of receiver complexity when we combine them together. In this paper, the combination of array processing and STC in MC-CDMA system over slow selective-fading channel is investigated and compared with corresponding existing MC-CDMA system using STC. A refinement of this basic structure leads to a system design principle in which we have to make a trade off between transmission rate, decoding complexity, and length of spreading code to reach a given desired design goal.