• Nuclear Engineering and Technology
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• 제54권2호
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• pp.764-769
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• 2022

The United Arab Emirates is currently building and operating four units of the APR-1400 developed by a South Korean vendor, Korea Electric Power Corporation (KEPCO). This paper attempts to perform APR-1400 reactor core analysis by using the well-known two-step method. The two-step method was applied to the APR-1400 first cycle using the open-source nodal diffusion code, KOMODO. In this study, the group constants were generated using CASMO-4 fuel transport lattice code. The simulation was performed in Hot Zero Power (HZP) at steady-state and transient conditions. Some typical parameters necessary for the Nuclear Design Report (NDR) were evaluated in this paper, such as effective neutron multiplication factor, control rod worth, and critical boron concentration for steady-state analysis. Other parameters such as reactivity insertion, power, and fuel temperature changes during the Reactivity Insertion Accident (RIA) simulation were evaluated as well. The results from KOMODO were verified using PARCS and SIMULATE-3 nodal core simulators. It was found that KOMODO gives an excellent agreement.

• 정보보호학회논문지
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• 제29권5호
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• pp.985-996
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• 2019

본 논문에서는 미국에서 암호모듈검증을 획득한 대표적인 소프트웨어 형태의 암호모듈인 FIPS-OpenSSL의 소스 코드를 분석하여 암호모듈 검증 및 시험기준에서 요구하는 보안요구사항이 소프트웨어적으로 어떻게 구현되어있는지 분석한다. 특히, 암호모듈이 반드시 탑재하고 있어야 하는 자가시험기능 (동작 전 자가시험, 조건부 자가시험) 관점으로 소스코드를 분석한다. 비록 미국 암호모듈 검증제도에서는 FIPS 140-2를 검증기준으로 삼고 있지만, FIPS 140-2는 국내 암호모듈 검증제도에서 암호모듈 검증 및 시험기준으로 삼고 있는 암호모듈 국제표준인 ISO/IEC 19790과 24759의 근간이 되었기 때문에 많은 유사함이 존재한다. 본 논문의 분석을 통하여 향후 암호모듈 개발업체에서 자가시험기능을 정확하고 안전하게 구현할 수 있을 것으로 기대한다.

• Journal of Multimedia Information System
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• 제4권4호
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• pp.255-262
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• 2017

In recent software development, repetitive code fragments (i.e., clones) are common due to the copy-and-paste programming practice, the framework-based development, or the reuse of same design patterns. Such similar code fragments are likely to introduce more bugs but are easily disregarded by a code reviewer or a programmer. In this paper, we present a code review tool to help code reviewers identify important code changes written by other programmers and recommend which changes need to be reviewed first. Specifically, to identify important code changes, our approach detects code clones across revisions and investigates them. Then, to help a code reviewer, our approach ranks the identified changes in accordance with several software quality metrics and statistics on those clones and changes. Furthermore, our approach allows the code reviewer to express their preferences during code review time. As a result, the code reviewer who has little knowledge of a code base can reduce his or her effort by reviewing the most significant changes that require an instant attention. To evaluate our approach, we integrated our approach with a modern IDE (e.g., Eclipse) as a plugin and then analyzed two third-party open source projects. The experimental results indicate that our approach can improve code reviewer's productivity.

• 대한조선학회논문집
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• 제49권2호
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• pp.151-157
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• 2012

The present study explored the possibilities of the applications of open source libraries to shipbuilding and marine engineering industries. A computational fluid dynamics (CFD) code, termed SNUFOAM, was developed and tested for turbulent flow around a ship, free surface flow around a hull, cavitating flow, and vortex shedding dynamics around a cylinder. The results using the developed CFD codes were compared against existing experimental data and solution of commercial CFD codes. SNUFOAM showed the nearly same results as commercial CFD codes and proved to be an alternative to commercial CFD codes for shipbuilding and marine engineering industries.

• International Journal of Naval Architecture and Ocean Engineering
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• 제8권1호
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• pp.22-37
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• 2016

This article investigates numerical modeling of surface piercing propeller (SPP) in unsteady open water condition using boundary element method. The home code based on BEM has been developed for the prediction of propeller performance, unsteady ventilation pattern and cross flow effect on partially submerged propellers. To achieve accurate results and correct behavior extraction of the ventilation zone, finely mesh has generated around the propeller and especially in the situation intersection of propeller with the free surface. Hydrodynamic coefficients and ventilation pattern on key blade of SPP are calculated in the different advance coefficients. The values obtained from this numerical simulation are plotted and the results are compared with experiments data and ventilation observations. The predicted ventilated open water performances of the SPP as well as ventilation pattern are in good agreement with experimental data. Finally, the results of the BEM code/experiment comparisons are discussed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.372.2-372
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• 2002

This paper presents an efficient modeling method fur open cracked beam structures. An equivalent bending spring model is introduced to represent the structural weakening effect in the presence of open cracks. The proposed method adopts the exact dynamic element method (EDEM) to avoid the difficulty and numerical errors in association with re-meshing the structure. The proposed method is rigorously compared with a commercial finite element code. (omitted)

• 기술혁신학회지
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• 제5권2호
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• pp.212-227
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• 2002

This study reviews the institutional frameworks of Open Source software and develops the stylized facts of Open Source software innovation. Open Source software have to solve two difficult problems for encouraging innovation. First, the source code of Open Source software program should be open and freely distributed and it is very difficult for developers to appropriate the results of their investments. Second, as Open Source software development process is characterized by the participation of communities of developers, it is not easy to coordinate and manipulate the development process. These difficulties of developing Open Source Software have been solved by the particular incentive schemes and coordinating mechanisms. This study reviews the study on the motivation of Open Source software development and the mechanisms which coordinate innovation process of Open Source software with peer review and meritocracy, and how these characteristics promote innovation in Open Source software communities.

• 한국정밀공학회지
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• 제20권10호
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• pp.169-176
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• 2003

Genetic algorithm (GA), which has a powerful searching ability and is comparatively easy to use and also to apply, is in the spotlight in the field of the optimization for mechanical systems these days. However, it also contains some problems of slow convergence and low efficiency caused by a huge amount of repetitive computation. To improve the processing efficiency of repetitive computation, some papers have proposed paralleled GA these days. There are some cases that mention the use of gray code or suggest using gray code partially in GA to raise its slow convergence. Gray code is an encoding of numbers so that adjacent numbers have a single digit differing by 1. A binary gray code with n digits corresponds to a hamiltonian path on an n-dimensional hypercube (including direction reversals). The term gray code is open used to refer to a reflected code, or more specifically still, the binary reflected gray code. However, according to proposed reports, gray code GA has lower convergence about 10-20% comparing with binary code GA without presenting any results. This study proposes new Full gray code GA (FGGA) applying a gray code throughout all basic operation fields of GA, which has a good data processing ability to improve the slow convergence of binary code GA.

• 한국전산유체공학회지
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• 제20권2호
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• pp.23-36
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• 2015

The $2^{nd}$ generation ice accretion analysis program has been developed and validated for various icing conditions. The essential feature of the $2^{nd}$ generation code lies in its capability of handling general 3-D geometry and improved accuracy. The entire velocity fields are obtained based on Navier-Stokes equations in order to take the massively separated flow field into account. Unlike $1^{st}$ generation code, the droplet trajectories are calculated using Eulerian approach, which is adopted to yield appropriate collection efficiency even in the shadow region. For improved thermodynamic analysis on the surfaces, water film model and modified Messinger model are newly included in the present analysis. The ice shape for a given time step is obtained by considering the exact amount of ice accreted on the surface. Each module of the icing analysis code has been seamlessly integrated on the OpenFOAM platform. The developed code was validated against available experimental data for 2D airfoils and 3D DLR-F4. Due to the lack of experimental data, the computed results of DLR-F4 were compared with those obtained from FENSAP-ICE, which is state-of-the-art 3D icing analysis code. It was clearly shown that the present code produces comparable results to those of FENSAP-ICE, in terms of prediction accuracy and the capability of handling general 3-D geometries.

• 한국주거학회논문집
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• 제6권2호
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• pp.213-223
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• 1995

The purpose of this study is to investigate the housing behavior through the code's housing history. The data were collected by open descriptive answering of 28 students in Y.University. The major findings are as follows: The characteristics of code's housing history were changed by stages of family life. The greastes changes are in the stage of elementary school(3rd stage). Before the 3rd stage, living in out of town, detached house, rental house is to superior than town(Dae Gu). Apt.. own house. And housing adaptation is to superior than housing adjustment. After 3rd stage go by contraies.