• Journal of Advanced Marine Engineering and Technology
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• v.35 no.6
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• pp.809-813
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• 2011

Turbulent flows are numerically simulated in the three dimensional inlet duct for heat recovery steam generator. The present study is aimed to analyze the effect of a variation in turbulent flow pattern by the change of roof angle in the transition duct. The finite volume based Navier-Stokes equations with unstructured grids are solved to make clear the flow dynamic phenomena. Reviews are made on with the data of path lines, velocity vectors, dynamic pressure, residuals for numerical convergence and so on. The k-epsilon, k-omega, Reynolds stress and RNG k-epsilon are used for generation of turbulence. Two types of roof angle are applied with and without the swirl in the duct. Turbulent flow patterns could be investigated for the optimum duct design based on the computational results.

• The KIPS Transactions:PartD
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• v.15D no.3
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• pp.361-374
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• 2008

In the latest intelligent computing environments, the self-adaptive software, as new software paradigm, which modifies its own behavior in response to changes in its operating environment is needed. To develop the self-adaptive software, it is necessary to analyze and design the context of software as well as the structure and the behavior of software. We need more efforts for self-adaptive software development than for traditional software development because we need more activities and technologies like context modeling and adaptation to develop the self-adaptive software. In this paper, we present the product line architecture for self-adaptive software and templates of artifacts to improve the efficiency of development through a reuse methodology. The artifacts of the architecture support the systematic reuse activities of core assets by expressing the commonality and variability of product line.

• The KIPS Transactions:PartD
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• v.13D no.4 s.107
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• pp.593-602
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• 2006

Software development methodology has been developed for satisfying goals of improvement in productivity and reduction in time-to-market through the reuse of software assets. The current methods that implement software product-line, one of software development methodologies, interfere massively with the core assets, which require high cost in assembly level reducing the effectiveness. In this paper, we introduce Aspect-Oriented Programming (AOP) as a method for improving assembly process in software product-line. The method that assembles core assets and variabilities is described by grammar elements such as Join point, pointcut and advice without code-change. We analyze requirements of a mini-system as an example adapting AOP and design using UML. Our study implements the variabilities, which are from design stage, using an Aspect-Oriented Programming Language, AspectJ and prove usability and practicality by implementing the proposed idea using an Aspect-Oriented Programming Language, AspectJ.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.99-106
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• 2002

Researches on integration of design and construction information from earlier era focused on the conceptual data models. Development and prevalent use of commercial database management system led many researchers to design database schemas for enlightening of relationship between non-graphic data items. Although these researches became the foundation fur the proceeding researches. they did not utilize the graphic data providable from CAD system which is already widely used. 4D CAD concept suggests a way of integrating graphic data with schedule data. Although this integration provided a new possibility for integration, there exists a limitation in data dependency on a specific application. This research suggests a new approach on integration for design and construction information, 'Product Model Centered Integration Methodology'. This methodology achieves integration by preliminary research on existing methodology using 4D CAD concept. and by development and application of new integration methodology, 'Product Model Centered Integration Methodology'. 'Design Component' can be converted into digital format by object based CAD system. 'Unified Object-based Graphic Modeling' shows how to model graphic product model using CAD system. Possibility of reusing design information in latter stage depends on the ways of creating CAD model, so modeling guidelines and specifications are suggested. Then prototype system for integration management, and exchange are presented, using 'Product Frameworker', and 'Product Database' which also supports multiple-viewpoints. 'Product Data Model' is designed, and main data workflows are represented using 'Activity Diagram', one of UML diagrams. These can be used for writing programming codes and developing prototype in order to automatically create activity items in actual schedule management system. Through validation processes, 'Product Model Centered Integration Methodology' is suggested as the new approach for integration of design and construction information.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.672-680
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• 2018

The opening angle of the duct cap assembly during the operation of a refrigerator ice dispenser was evaluated by transient structural analysis, and an improved design to maximize the opening angle was obtained. The opening angle of the existing design was found to be 78% of the upper limit. Several design modifications were proposed and analyzed to examine the effects of the design factors on the opening angle. As a result of the design modifications, the opening angle was improved by changing the lever material to a material with a high elastic modulus, moving the position of the support to the motor side, or increasing the lever shaft diameter. Considering the manufacturing cost of the new design, the design modification changing only the lever material was found to be the best because it does not require a change in the structure of the ice dispenser case. In conclusion, the opening angle can be improved by up to 95% of the upper limit value if the lever material is changed to an aluminum alloy. The methods and results presented in this study were found to be of great help in designing the duct cap assembly structure to facilitate the discharge of ice.

• Bulletin of the Society of Naval Architects of Korea
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• v.32 no.1
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• pp.21-27
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• 1995

초고속선에 관련된 점성유동은 저한성능 향상과 운항자세 제어를 위해 사용되는 다양한 선체부 가물의 저항 예측과 초고속선에 많이 사용되는 물분사 추진장치 입구 형상의 설계 그리고 임펠 러에 이르는 덕트 유동의 예측을 중심으로 관심을 받아왔다. 본 소고에서는 통상적인 선박의 경우와는 구별되는 초고속선 고유의 점성유동 특성에 관하여 간략히 논의하기로 하고 내용을 크게 선체-부가물 점성유동과 물분사 추진장치에 관련되어 있는 덕트유동으로 나누어 기술하 였다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.28 no.2
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• pp.94-107
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• 1999

• Journal of Aerospace System Engineering
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• v.11 no.6
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• pp.84-91
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• 2017

The dynamic characteristics of a ducted fan in hovering condition were investigated. The section properties of the fan blade were calculated, and a simulation model was developed according to the rotor system components. Dynamic analyses were conducted relative to the rotational speed and the collective pitch. The proposed ducted fan system showed less aero-elastic instability within the designated operating ranges. To verify the analytical approach, a rotating test stand of the ducted fan was set up. A functional test of the assembly was carried out to determine the kinematics and interference between components. The non-rotating and rotating normal frequencies were measured by excitation of the collective pitch using hydraulic actuators. The results indicated a correlation between the test equipment and the simulation model.

• Aerospace Engineering and Technology
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• v.13 no.2
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• pp.1-6
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• 2014

Power system of the tilt-duct VTOL aerial robot has been developed. This paper focuses on the power train with small liquid-type engine for the R/C boat and presents the test results with design procedures. The hardware aspects of the power system include details about the hardware configurations for the interfaces with the vehicle. The ground test and tether test for measuring the thrust performance of vehicle and evaluating the endurance of power train carried out.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.331-333
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• 2005

소프트웨어 프로덕트 라인 공학은 공통성과 가변성 식별을 통해 소프트웨어 재사용을 극대화 시키는 접근방법으로 이를 지원하는 도구에 대한 연구가 다수 진행되고 있다. 하지만 기존의 도구는 특성 다이어그램만을 지원하고 있고, 특성구성 정보를 이용한 프로덕트의 조립을 수행하지 못하고 있다. 따라서 본 연구에서는 소프트웨어 개발자에게 공통적 언어인 UML을 이용하여 특성모델을 표현하고 특성구성에 따라 조립을 수행하는 특성모델링 지원도구를 제안한다. 이러한 UML 기반의 특성모델링 지원도구를 통하여 보다 쉽게 특성모델링과 프로덕트 조립을 수행할 수 있다.