• Proceedings of the KSR Conference
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• 2001.10a
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• pp.287-292
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• 2001

Static behaviors of railway plate girder bridges designed by the L-22, a standard load type of the railway specification in Korea, are evaluated by widely eight load cases. The load cases are three real loads, which contain three locomotive types of Saemaul PMC, diesel, and Korea Train Express(KTX), and three design loads, L-22, L-18, and HL-25 loads, in railway specification. Plate girders for analysis have the length of spans of six types：6m, 9m, 12m, 22m, 24m, and 30m. For analysis SAP2000n ,a commercial FEM tool, is used. Dominant axial load types are taken from these results that are maximum deflections, reaction forces, and absolute maximum bending moment in girders.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.461-462
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• 2018

본 논문에서는 JavaCC를 사용하여 보안약점을 찾아내는 도구를 구현한다. 이 도구는 구문 정보와 흐름 정보를 이용하여 프로그램 소스 코드에서 보안약점을 찾아 진단한다. 이를 통해 컴파일러 단계별 얻을 수 있는 정보와 관련 보안약점을 연계함으로써 보안약점에 대한 진단 방법과 분석 정보의 연계를 기대할 수 있다.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.4
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• pp.127-137
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• 2009

This paper is proposed that in-output Digital module is acquired a vibration signal of a rotating machinery by Data Acquisition System. The module is designed to get ride of nose through low pass filter on the vibration signal from sensors and set the gain value for being able to sampling AC to DC, and also the sampled data by sampler and the conversed data by DIP/FPGA is supplied to the analyzer for analysis at a software tool. The DIP(Digital Signal Processor) of the Digital input/output Board makes Average voltage, Peak to Peak voltage, RMS(Root Mean Square) and Gap voltage, also FFT(Fast Fourier Transform) for rotating vibration diagnosis.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.99-102
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• 2014

리플렉션은 자바 언어의 기능 중 하나로, 자바 프로그램을 실행해서 해당 프로그램을 조사하거나 내부의 동작 구조를 조작할 수 있다. 리플렉션을 사용하게 되면 자바 소스의 난독화 뿐만 아니라 정적 분석 도구의 API 호출 탐지를 방해하게 되어 분석 결과의 정확도를 떨어뜨리게 된다. 만약 이 특성을 악용해 악성 앱 제작자가 특정 API 메소드 호출을 은닉하는 목적으로 사용한다면 정적 분석에 의존하는 기존 분석 도구들이 API 메소드 호출을 탐지하기 어렵기 때문에 큰 위협이 될 수 있다. 본 연구에서는 안드로이드 환경에서 표본 어플리케이션에 직접 설계한 도구를 이용하여 API 메소드에 리플렉션을 적용하고, 원본 소스와 리플렉션 후 디컴파일된 소스를 비교하여 API 메소드 호출이 리플렉션을 통해서 은닉 가능함을 보여준다.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.6
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• pp.133-140
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• 2001

This paper suggests another system for a cutting force measuring tool in a milling process. Generally, tool dynamometer is taken into account for the most appropriate cutting force measuring tool in the analysis of cutting mechanism. However, high price and limited space make it difficult to be in-situ system for controllable milling process. Although an alternative method using AC current of servo-motor has been suggested, it is unsuitable for cutting force control because of small upper frequency limit and noise. The cutting force measuring system is composed of two load cells placed between the moving table bracket and the nut flange part of ballscrew. It has many advantages such as low cost and wide range measurement than tool dynamometer because of the built-in moving table and the low cost load cell. The static and dynamic model of the measuring system using imbeded load cell is introduced. Various Experiments are carried out to validate both models. By comparing the cutting forces from a series of end milling experiments on the tool dynamometer and the system developed in this paper, the accuracy of the cutting force measuring system is verified. Upper frequency limit is measured by the experiment of dynamic characteristics.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.10a
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• pp.204-209
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• 1998

The acceleration of the performance of machine tools influences the development of the semi-conductor and optical technology as the development of NC and measurement technology. We can mention that a traction role of the acceleration for the development like that depends on the development of the measurement technics Stylus instrument method, STM, SEM, Laser interferometer method which are used for measuring the quasi-static error of machine tools. Because the measurement has been done to unload condition without considering of mechanical stiffness in the case of machining center as we measure the quasi-static error of machine tools on general studies, people who works on the spot has many problems on the data value. Therefor we will help working more accurately on the spot by measuring, analyzing, displaying the deflection of the table and support shaft when we load on the table and the support shaft of machining center using laser interferometer. Also we try to settle new conception of the measurement method and more accurate grasp of the deflection tendency by verifing the tendency of the error measured through the comparison of the simulated error using ANSYS, a common finite element analysis program, which is able to measure heat deformation, material deformation, and error resulted form this study.

• Journal of the Korea Society of Computer and Information
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• v.22 no.3
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• pp.17-25
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• 2017

In this paper, we compared four analyzers Clang, CppCheck, Compass, and a commercial one from a domestic startup using the NIST's Juliet test suit and STONESOUP that is introduced recently. Tools showed detection efficacy in the order of Clang, CppCheck, the domestic one, and Compass under Juliet tests; and Clang, the domestic one, Compass, and CppCheck under STONESOUP tests. We expect it would be desirable to utilize symbolic execution for vulnerability analysis in the future. On the other hand, the results of tool evaluation also testifies that Juliet and STONESOUP as a benchmark for static analysis tools can reveal differences among tools. Finally, each analyzer has different CWEs that it can detect all given test programs. This result can be used for selection of proper tools with respect to specific CWEs.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.6
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• pp.17-23
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• 2006

Rubber materials have the nonlinear, large deformation and viscoelastic behavior. W.D. Kim et al. studied these characteristics through the static, fatigue, dynamic, aging and viscoelastic test. This paper discussed that the properties of engine mounting rubber, such as static stiffness, fatigue life and damping factor, are predicted based on CAE by using material properties acquired by the report of Kim et al. In result, the static stiffness of engine mounting rubber is predicted approximately in comparison with test value. Also, it was confirmed that the relationship of fatigue life and Green-Lagrange strain in specimen was the valid tool to predict the fatigue life of engine mounting rubber. From the results of transient viscoelastic analysis the damping factor changed rapidly at the range less than 8hz.

• Geomechanics and Engineering
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• v.9 no.1
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• pp.1-14
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• 2015

Piezovibrocones have been developed to evaluate the liquefaction potential of onshore soils, but have not yet been utilized to evaluate the in-situ liquefaction behavior of offshore marine and volcanoclastic sediments. Two static and vibratory CPTu (Cone Penetration Tests) were performed at Tauranga Harbor, New Zealand. The lithology is known from nearby drillholes and the influence of vibration on different types of marine soils is evaluated using the reduction ratio (RR) calculated from static and vibratory CPTu. A sediment layer with high potential for liquefaction and one with a slight reaction to cyclic loading are identified. In addition to the reduction ratio, the liquefaction potential of sediment is analyzed using classic correlations for static CPTu data, but no liquefaction potential was determined. This points to an underestimation of liquefaction potential with the classic static CPTu correlations in marine soil. Results show that piezovibrocone tests are a sensitive tool for liquefaction analysis in offshore marine and volcanoclastic soil.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.151-157
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• 1996

Postural tremor of the upper arm in a static posture was measured to provide guidelines of hand tool weight. Three types of camera recording postures were selected. Postural tremor was measured on five levels of tool weights; no weight, 400g, 800, 1200g, and 1600g. For each conditions, upper arm postural tremor was measured together with EMG of biceps, deltoid, and pectoralis major, and Borg's CR-20 scale ratings of perceived exertion. Results of the experiment are as follows; Frequency analysis of tremor revealed that increased amplitude of frequency band of 2-4Hz and 10-14Hz was observed. Postural tremor of the upper arm maintained the initial level until fatigue developed. After the development of fatigue, the rate of the change of postural tremor was significantly increased. Different tool weights and hand postures showed different rate of tremor increase. And time to fatigue and the corresponding endurance time was positively correlated with Borg's RPF scores.