• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.821-832
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• 2011

Recently, the noise of vehicle is the one of the key factors for customers to purchase a vehicle and the most important part which is related to the noise is the exhaust system. Thus, car makers have their own ways to assess this exhaust noise not only to decrease the level of noise but to enhance the feeling of it. Typically, to do these things in the early stage of development, the tuning code of the exhaust system has to be made by CAE tool, which is very reliable but expensive, and the prototype parts of this code would be made for the validation test. Then this process can be iterated to meet the target of the performance. In this study, a new algorithm which adapts the '3 dimensional convective sound wave theory 'and 'Doppler effect' has been developed. With this new algorithm, a brand new system for the calculation of tail pipe noise has been developed and validated by acoustic wind tunnel test. As a result of this study, various comparisons and have been carried out, for example, the comparison with other CAE tool has been performed for the validity and the improvement of the new calculation code could be achieved.

• International Journal of Naval Architecture and Ocean Engineering
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• v.3 no.1
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• pp.27-36
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• 2011

In the proposed paper numerical calculations are carried out using two versions of a three-dimensional, timedomain panel method developed by the group of Prof. P. Sclavounos at MIT, i.e. the linear code SWAN2, enabling optionally the use of the instantaneous non-linear Froude-Krylov and hydrostatic forces and the fully non-linear SWAN4. The analytical results are compared with experimental results for three hull forms with increasing geometrical complexity, the Series 60, a reefer vessel with stern bulb and a modern fast ROPAX hull form with hollow bottom in the stern region. The details of the geometrical modeling of the hull forms are discussed. In addition, since SWAN4 does not support transom sterns, only the two versions of SWAN2 were evaluated over experimental results for the parent hull form of the NTUA double-chine, wide-transom, high-speed monohull series. The effect of speed on the numerical predictions was investigated. It is concluded that both versions of SWAN2 the linear and the one with the non-linear Froude-Krylov and hydrostatic forces provide a more robust tool for prediction of the dynamic response of the vessels than the non-linear SWAN4 code. In general, their results are close to what was expected on the basis of experience. Furthermore, the use of the option of non-linear Froude-Krylov and hydrostatic forces is beneficial for the accuracy of the predictions. The content of the paper is based on the Diploma thesis of the second author, supervised by the first one and further refined by the third one.

• Journal of Communications and Networks
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• v.5 no.2
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• pp.135-140
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• 2003

In this paper, we investigate the error performance of a serially concatenated system using a nonrecursive convolutional code as the outer code and a recursive QPSK space-time trellis code as the inner code on quasi-static and rapid Rayleigh fading channels. At the receiver, we consider iterative decoding based on the maximum a posteriori (MAP) algorithm. The performance is evaluated by means of computer simulations and it is shown that better error performance can be obtained by using low complexity outer and/or inner codes and the Euclidean distance criterion based recursive space-time inner codes. We also obtain new systems with large number of trasmit and/or receive antennas providing good error performance.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.995-998
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• 1995

As the modern industrial processes become more complex, it is getting more difficult to model and control the processes. Naturally, an advanced type of DCS(Distributed Control System) with higher level functions is being sought Advanced DCS is a DCS with advanced functions such as fault diagnosis, GPC(Generalized Predictive Control), NN(Neural Network), and Fuzzy Control. In this thesis, we have studied a fuzzy control algorithm for realizing an advanced DCS. Its algorithm is implemented in a form of function code which is a process control language, being used by the industrial engineers. To verify the realized function code of the fuzzy control, the function code is applied to a continuous casting process of the Pohang Iron & Steel Works in Kwangyang. The rules of the fuzzy control were collected via interviews of the field operators and their operation documents. Finally, usability of the function code of the fuzzy control is shown via simulation for the continuous casting process model.

• Journal of the Korea Society of Computer and Information
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• v.21 no.12
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• pp.219-226
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• 2016

In this paper, we propose an efficient repository model for online software education. The software education of app development consists of 7 stages: coding & debugging, submit, collaboration, review, validate, deployment, certification. Proposed repository model supports all 7 stages efficiently. In the coding & debugging stage, the students repeat coding and debugging of source. In the submit stage, the output of previous process such as source codes, project, and videos, are uploaded to repository server. In the collaboration stage, other students or experts can optimize or upgrade version of source code, project, and videos stored in the repository. In the review stage, mentors can review and send feedbacks to students. In the validate stage, the specialists validate the source code, project, and the videos. In the deployment stage, the verified source code, project, and videos are deployed. In the certification stage, the source code, project, and the videos are evaluated to issue the certificate.

• Structural Engineering and Mechanics
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• v.27 no.1
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• pp.63-75
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• 2007

The code provisions on lap splices are critically assessed in the light of 203 beams without transverse reinforcement and 278 beams with transverse reinforcement. For comparison, the provisions given in the ACI 318, Eurocode 2, and TS 500 Codes are considered. The ACI Committee 408 recommended provision and a new proposal are also taken into account throughout the assessment. The comparison with real beam tests where the splice region was subjected to constant moment indicates that current provisions in the Codes do not agree acceptably with test results. The steel stress prediction graphs calculated by means of the Code provisions show high scatter and remain unsafe especially for test data without transverse reinforcement. Both the recent recommended provision by ACI Committee 408 and a new design expression proposed by the author have much less scatter with fewer unsafe predictions. The simplified design provision proposed by ACI Committee 408 does not yield similar results to that of the advanced design provision proposed by the same committee and therefore it could conveniently be replaced with the simpler equation proposed by the author.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.01a
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• pp.81-84
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• 2018

최근에 WMI를 악용한 악성코드 공격이 증가하고 있다. WMI는 악성 프로그램을 설치하지 않아도 레지스트리, 파일시스템 등 중요한 정보에 접근할 수 있다. 또한, 윈도우 운영체제에 내장된 프로그램이기 때문에 백신에서 탐지하기 어렵다. 본 논문에서는 WMI를 이용한 악성코드 탐지를 위하여 제안하는 방법은 API를 후킹하여 메모리에서 실행될 DLL을 보고 악성코드를 탐지하는 방법을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.733-735
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• 2021

유전 프로그래밍 기법을 이용하여 완성된 프로그램 코드를 생성하는 연구는 최근까지 실용적으로 사용할 만한 결과를 만들지 못하고 있다. 우리는 완성된 프로그램 코드를 만들지 않고, 특정 기능을 갖는 함수 코드를 자동 생성하는 연구에 중점을 두었다. 실제 구현을 위한 시스템을 설계하고 타당성을 검토 하였다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1633-1634
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• 2015

WTO/TBT 협정에 따라 2006년부터 IEC 전선의 전면적인 사용과 전기설비기술기준의 판단기준에 IEC 60364 저압전기설비분야의 도입으로 국내현장에서 국제표준을 적용할 수 있게 되었다. 그러나 국제표준(IEC)은 내용이 포괄적이며, 원론적인 부분을 다루고 있어 실제 현장 적용에 많은 어려움이 있다. 이에 따라 대한전기협회에서는 국제표준(IEC)을 기초로 하여 국제수준과 대등한 "한국전기규정 KEC"를 제정중이며, 본 연구는 KS C IEC 60364-5-52 기초로 작성한 KEC 제2편 저압전기설비분야 제43장 배선설비의 제정현황을 소개하는 것이다.

• Journal of Radiation Industry
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• v.8 no.3
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• pp.155-159
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• 2014

RI-Biomics is a new concept that combines radioisotopes (RI) and Biomics. For efficient collection of information, establishment of database for technical information system and its application to the system, there is an increasing need for constructing the standard classification system of technical information by its systematical classification. In this paper, we have summarized the development process of the standard classification system of technical information in the field of RI-Biomics and its application to the system. Constructing the draft version for the standard classification system of technical information was based on that standard classification one in national science and technology in Korea. The final classification system was then derived through the reconstruction and the feedback process based on the consultation from the 7 experts. These results were applied to the database of technical information system after transforming as standard code. Thus, the standard classification system were composed of 5 large classifications and 20 small classifications, and those classification are expected to establish the foundation of information system by achieving the circular structure of collection-analysis-application of information.