• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.327-330
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• 2011

CFD simulation is widely used in various industries, universities and research centers. In Korea most of the researchers use foreign commercial S/W packages especially in industries. But commercial CFD packages have some problems as limit to source code and very high license foe. So from several years ago open source CFD code has been widely spread as an alternative. But in Korea there are a few users of open source code. Insufficiency of performance validation as for accuracy, robustness, convenience and parallel speed-up is important obstacles of open source code. So we tested some validation cases as to incompressible external aerodynamics and internal flaws and now are doing compressible flaws. As the first stage of compressible flow validation, we simulated Korea next generation high speed train(HEMU). It's running condition is 400km/hr and maximum Mach number reaches up to 0.4. With the high speed train we tested accuracy, robustness and parallel performance of open source CFD code OpenFOAM Because there isn't experimental data we compared results with widely used commercial code. When use $1^{st}$ order upwind scheme aerodynamic forces are very similar to commercial code. But using $2^{nd}$ order upwind scheme there was some discrepancy. The reason of the difference is not clear yet. Mesh manipulation, domain decomposition, post-processing and robustness are satisfactory. Paralle lperformance is similar to commercial code.

• 인터넷정보학회논문지
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• 제7권5호
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• pp.95-108
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• 2006

국가 경쟁력 제고를 위해서도 디지털콘텐츠에서 확대하여 소프트웨어 소스 코드에 대한 지적재산권 제도와 기술의 정비는 매우 중요한 의미를 지닌다. 이러한 지적재산권 중에서 특히 소프트웨어 보호에 대한 인지는 매우 낮은 편이다. 소프트웨어 소스코드의 소유권 분쟁이 발생 시 소유권을 증명하기 위해서는 원본의 소프트웨어 소스코드를 판별해야만 하는 문제점을 갖고 있다. 또한 소프트웨어가 복제되어도 복잡성과 독해 능력 부족으로 정확한 판정을 내리기가 쉽지 않다. 본 논문에서는 이러한 소프트웨어 복제에 대한 판별을 하나의 개별 코드 단위로 시행하지 않고, 전체 소스가 가지는 구조적 일치성을 기반으로 복제를 판별할 수 있는 XMI 타입의 디지털 라이센스 프로토타입을 개발하였다. 소프트웨어는 구조적으로 Context Free Grammar 기반이며, 그러므로 BNF표기 형태로 표현할 수 있고, 이는 다시 계층 구조로 표현할 수 있기 때문에 가능한 것이다. 그러므로 소프트웨어 소스코드의 구조적 일치성을 비교하기 위한 계층구조를 갖는 소스코드의 아키텍처를 표현할 수 있다.

• ETRI Journal
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• 제30권3호
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• pp.394-402
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• 2008

Domain analysis is the process of analyzing related software systems in a domain to find their common and variable parts. In the case of device drivers, they are highly suitable for domain analysis because device drivers of the same domain are implemented similarly for each device and each system that they support. Considering this characteristic, this paper introduces a new approach to the domain analysis of device drivers. Our method uses a code clone detection technique to extract similarity among device drivers of the same domain. To examine the applicability of our method, we investigated whole device drivers of a Linux source. Results showed that many reusable similar codes can be discerned by the code clone detection method. We also investigated if our method is applicable to other kernel sources. However, the results show that the code clone detection method is not useful for the domain analysis of all kernel sources. That is, the applicability of the code clone detection method to domain analysis is a peculiar feature of device drivers.

• Nuclear Engineering and Technology
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• 제52권9호
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• pp.1990-1997
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• 2020

To support the safe operation of the Miniature Neutron Source Reactor (MNSR), a thermo-hydraulic transient model using the RELAP5/Mod3.2 code was simulated. The model was verified by comparing the results with the measured and the previously calculated data. The comparisons consisted of comparing the MNSR parameters under normal constant power operation and reactivity insertion transients. Reactivity Insertion Accident (RIA) for three different initial reactivity values of 3.6, 6.0, and 6.53 mk have been simulated. The calculated peaks of the reactor power, fuel, clad and coolant temperatures in hot channel were calculated in this model. The reactor power peaks were: 103 kW at 240 s, 174 kW at 160 s and 195 kW at 140 s, respectively. The fuel temperature reached its maximum value of 116 ℃ at 240 s, 124 ℃ at 160 s and 126 ℃ at 140 s respectively. These calculation results ensured the high inherently safety features of the MNSR under all phases of the RIAs.

• 한국생산제조학회지
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• 제9권6호
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• pp.9-18
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• 2000

This study includes noise automatic inspection system for washing machine auto-transmission one of modern home necessary. We effort to find and certificate sound noise source by sound power and sound intensity, and apply to frequency analysis in vibration related sound noise. still more we have been studying to data acquisition and programming for MS VisualBasic version 5.0. System component is below. 1) Pentium PC or data acquisition. 2) DSO for noise acquisition. 3)S/W for comparison and decision. 4) I/F Board for data communication. Wave form data through the DSO are converting to ASCII code data. The ASCII code through binary converting S/W. Finally we will making noise monitoring system and automatic inspection system.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2015년도 제52차 하계학술대회논문집 23권2호
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• pp.75-76
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• 2015

본 논문에서는 S/W 개발 보안 지침을 알려준다. S/W 개발 보안에서 S/W의 보안 취약점 유형에 대하여 설명한다. S/W 보안 취약점 유형인 입력 데이터 검증 및 표현, API 악용, 보안 특성, 시간 및 상태, 에러처리 코드품질, 그리고 캡슐화에 대하여 설명하도록 한다. 즉, 본 논문에서는 보안 취약점에 대한 소스코드 레벨에서의 대응조치에 대한 가이드를 제시하고자 한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 춘계학술대회 논문집
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• pp.341-346
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• 2001

This paper presents a concept design of detail design software for high speed catenary system. In this software, M.D.(mounting diagram) can be peformed and parts D/B can be also managed. french one, used in Kyung-bu high-speed line, is not good at user's interface, and the source code is not opened. So, it is impossible to use it in the different environment and catenary system. Through this program, automation of detail design and user's convenience can be derived.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1998년도 추계 학술대회논문집
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• pp.167-174
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• 1998

The numerical methodology for simulating water entry behaviors of the high-speed bodies has been developed. Since the present method assumed the impact occurs within a very short time interval, the viscous effects do not have enough time to play a significant role in the impact forces, that is, the flow around a water-entry object was assumed as an incompressible potential flow and is solved by the source panel method. The elements fully submerged into the water are routinely teated, but the elements intersected by the effective planar free surface are redefined and reorganized to be amenable to the source panel method. To validate the present code, it has been applied to the ogive model and compared with experimental data. Good agreement has been obtained. The water entry behavior of the bouncing phenomena from the free surface has been also simulated using the impact forces and two degree of freedom dynamic equation. Physically, acceptable results have been obtained.

• Journal of Welding and Joining
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• 제18권3호
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• pp.76-82
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• 2000

In this study, three-dimensional heat flow in laser beam welding for deep penetration was analyzed by using F.E.M common code, and then the results were compared with the experimental data. The models for analysis are full penetration welds and are made at three different laser powers (6, 9.9, 4.5 kW) with two different welding speeds (5.8mm/s, 5mm/s). The characteristics of thermal absorption by the workpiece during deep penetration laser welding can be represented by a combination of line heat source through the workpiece and distributed heat source at the top surface due to the plasma plume above the top surface. This gives an insight into the way in which the beam interacts with the material being welded. The analyses performed with the combined heat source models show comparatively good agreement between the experimental and calculated melt temperature isotherm, i.e, the fusion zone boundary. The results are used to explain the "nail head" appearance of fusion zone, which is quite common in laser beam welds.eam welds.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 추계 학술대회논문집
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• pp.131-135
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• 2006

The aerodynamic characteristics of a T-50 aircraft configuration are investigated by a subsonic panel method. Panel methods are best applicable to the lifting surfaces such as wings and airfoils. Source and doublets are used in the present code as a basic singularities of the panel technique. The panel method is first assessed by applying it to several benchmark problems for which other solutions and experimental data are available, such as a swept wing and wing body configuration. The prediction results are compared with experimental data and show good agreement in all cases considered. Finally, the method is applied to a T-50 aircraft configuration and excellent agreement with flight test data in lift coefficients is found.