• Journal of the KSME
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• v.43 no.11
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• pp.53-55
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• 2003

이 글에서는 저자가 소속된 회사의 경험을 바탕으로 생산 정보화와 관련된 몇 가지 중요한 개념을 다시 정의해 보고 개선 방향을 제시하고자 한다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.02a
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• pp.154-156
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• 2002

• Proceedings of the Korean Nuclear Society Conference
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• 2002.05a
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• pp.209.2-209
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• 2002

• Journal of Korea Water Resources Association
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• v.41 no.5
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• pp.491-501
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• 2008

In order to describe runoff characteristics of urban drainage area, outflow from subbasins divided by considering topography and flow path, is analyzed through stormwater system. In doing so, concentration time and time-area curve change significantly according to basin shape, and runoff characteristics are changed greatly by these attributes. Therefore, in this development study of FFC2Q model by MLTM, we aim to improve the accuracy in analyzing runoff by adding a module that considers basin shape, giving it an advantage over popular urban hydrology models, such as SWMM and ILLUDAS, that can not account for geometric shape of a basin due to their assumptions of unit subbasin as having a simple rectangular form. For subbasin shapes, symmetry types (rectangular, ellipse, lozenge), divergent types (triangle, trapezoid), and convergent types (inverted triangle, inverted trapezoid) have been analyzed in application of time-area curve for surface runoff analysis. As a result, we found that runoff characteristic can be quite different depending on basin shape. For example, when Gunja basin was represented by lozenge shape, the best results for peak flow discharge and overall shape of runoff hydrograph were achieved in comparison to observed data. Additionally, in case of considering subbasin shape, the number of division of drainage basin did not affect peak flow magnitude and gave stable results close to observed data. However, in case of representing the shape of subbasins by traditional rectangular approximation, the division number had sensitive effects on the analysis results.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.4
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• pp.475-484
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• 2000

In this paper, new additional nonconforming modes for the improvement of bending behavior in the distorted 8 node hexahedral element and their effective modification method are studied. The rotational degrees of freedom are introduced by using a functional in which the rotations are independent variables. In an element formulation, the same interpolations are used in displacement and rotation fields, but nonconforming modes we applied only in displacement fields. To verify the developed element various numerical tests are carried out and test results show good behavior.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.888-890
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• 2015

많은 개발자가 참여하는 대형 소프트웨어 시스템 개발의 효율성 증대를 위해서는 컴포넌트 간 인터페이스의 효과적인 관리가 필수적이다. MDMS는 컴포넌트간의 인터페이스 정의 및 변경 이력 관리, 인터페이스 기술서 자동 생성, 소스 코드 자동 생성 등의 기능을 제공하는 도구이다. 한화탈레스는 1998년 MDMS를 처음 개발하여 적용한 이후 다양한 국방 소프트웨어 시스템 개발에 적용하여 소프트웨어 개발 생산성 향상에 효과를 보았다. 하지만, MDMS를 다양한 프로젝트에 적용하는 과정에서 최초 개발시 고려하지 못했던 여러 문제점 및 한계를 발견하였다. 이러한 문제점 및 한계는 다양한 프로젝트의 특성 지원 미흡, 형상관리 및 유지보수 문제, 프로젝트 간 메시지 재사용 미지원, 취약한 보안 등 이다. 본 논문에서는 이를 해결하기 위하여 네가지 개선방안을 제시한다. 첫 번째, 다양한 프로젝트에 적용이 가능한 유연한 SW 구조로 개선해야 한다. 두 번째, 통일되고 일관된 형상관리와 함께 전담 개발 및 유지보수 조직이 필요하다. 세 번째, 프로젝트간 메시지의 재사용 지원을 위한 방안으로 프로젝트 별 MDMS 운용이 아닌 통합된 MDMS의 운용이 필요하며, 그를 통하여 다른 프로젝트의 인터페이스 정의를 상호 참조할 수 있는 구조를 적용해야 한다. 마지막으로, 외부 협력업체와의 협업을 위한 보안 대책을 수립하고, 관련 보안 기능을 지원하여 사외의 협력업체의 개발자가 직접 MDMS에 접속하여 개발할 수 있도록 개선해야 한다.

• Journal of Korean Society of Steel Construction
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• v.16 no.1 s.68
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• pp.123-134
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• 2004

In this research, a multilevel decomposition technique to enhance the efficiency of the configuration optimization of truss structures was proposed. On the first level, the nonlinear programming problem was formulated considering cross-sectional areas as design variables, weight, or volume as objective function and behavior under multiloading condition as design constraint. Said nonlinear programming problem was transformed into a sequential linear programming problem. which was effective in calculation through the approximation of member forces using behavior space approach. Such approach has proven to be efficient in sensitivity analysis and different form existing shape optimization studies. The modified method of feasible direction (MMFD) was used for the optimization process. On the second level, by treating only shape design variables, the optimum problem was transformed into and unconstrained optimal design problem. A unidirectional search technique was used. As numerical examples, some truss structures were applied to illustrate the applicability. and validity of the formulated algorithm.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.2
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• pp.106-112
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• 2005

Modern versions of supersonic jet fighter aircraft have several different weapon loading configuration to support air-to-air combat and air-to-ground delivery of weapon modes. These various aircraft loading conditions could result in asymmetric configurations to the aircraft once delivered. These asymmetric configurations could result in decreased handling qualities for the pilot maneuvering, stability, control issues and aerodynamic performance of the aircraft. In order to eliminate or decrease these adverse impacts on the pilot's ability, development of T-50 flight control law attempts to control the aircraft in both longitudinal and lateral-directional axes. Especially, the design of the lateral-directional roll axis control laws, utilizing a simple roll rate feedback structure and gains such as F-16, is developed for the T-50 aircraft to meet the aircraft's design requirements. Consequently, it is found that the improved control law decreases the roll-off phenomenon in lateral axes during pitch maneuver.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3066-3073
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• 2009

Joint paths of master and branch pipes are induced mathematically for many kinds of joint patterns between both pipes in 3-axis pipe profile-cutting machines. By compensating them with a kerf width, the real cutting paths are determined, and their CL-data are generated, and the tool paths generated by CL-data are verified by a ghost function. A bevelling of welds is implemented through tilting a cutting torch in the $\beta$-axis direction for 8 sections in the chuck rotation of $\alpha$-axis. A PLC controls simultaneously position and velocity in a real time for $\alpha$, X, $\beta$-axis by loading CL-data generated. We developed the PLC-controlled 3-axis pipe profile-cutting system which can cut a master or branch pipe along the cutting path and simultaneously do a bevelling process.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.1170-1175
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• 2014

The purpose of this study is to improve the interoperability of IFC for the basic data such as the size of member section, length, thickness, reference location, and eccentricity of the structural members. For this, the method to represent the basic data of structural member is proposed. In the proposed method, the most important criteria is the way that engineers recognize and treat the basic data of structural members. Then, in this study, an IFC file is generated based on the proposed method for a simple RC building composed of members and it is examined that the correct basic data can be derived from the IFC file in the way that engineers do in practice. From the results of the examination, the proposed method is expected to improve the interoperability of IFC for the basic data.