• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.4
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• pp.389-397
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• 1998

A loop duct system is often found in a VAV-HVAC(variable air volume heating, ventilating and air conditioning) design. It is known that the simple T-method is not be applicable to the loop duct system and cannot be used to calculate the flow rate and the pressure drop at each duct section of the loop duct system. In this paper, the extended T-method has been developed and it is found to be applicable to the loop duct system to which the simple T-method cannot be applied. The validity of the extended T-method has been verified by using to solve for a simple, ideal loop duct system for which there exists analytical solution. In addition, the extended T-method is employed to compute the loop duct system of a real building with an area of 380$m^2$. The results show that the computed flow rate at the exit differs from the designed flow rate by a range of -13.6~43.5 %. Consequently, three design factors must be adjusted in order that the flow rate may be balanced. These include the duct sizes, in terms of their lengths and diameters, the sub-duct locations and the positioning of damper which is found upstream of the exit duct.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.947-950
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• 2004

프로덕트 라인은 다양하고 빠르게 변화하는 시장의 요구사항과 특정 도메인 영역에 속하는 애플리케이션 간의 재사용 가능한 아키텍처 및 컴포넌트의 구성으로부터 연관된 시스템 구축 시 생산성과 품질의 향상을 제공함으로써 현재 많은 관심의 초점이 되고 있다. 컴포넌트의 가변성은 컴포넌트를 사용자의 요구사항에 알맞게 기능을 특화할 수 있다. 또한 프로덕트 라인에서 컴포넌트 내부에 공통으로 사용할 워크플로를 가지고 있어 컴포넌트 사용자는 순차 다이어그램 등을 통해 메시지 흐름을 직접 구현할 필요가 없고, 재사용 가능한 아키텍처는 많은 변화 계획들과 메카니즘을 포함하고 있다. 하지만, 아키텍처를 설계하기 위한 아키텍처에서의 변화성 관리와 컴포넌트의 변화성에 대한 명확한 방법이 미흡하다. 따라서 본 논문에서는 재사용 가능한 아키텍처를 설계하기 위해 변화성의 명확한 표현과 컴포넌트의 변화성을 설계하기 위해 다중 뷰의 모델링을 통하여 프로덕트 라인의 다양한 측면을 제시하고, 사례연구로 성적관리 컴포넌트 모델링에 적용해 보고자 한다.

• The KIPS Transactions:PartD
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• v.14D no.7
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• pp.773-782
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• 2007

Software produce line engineering is a method that prepares for future reuse and supports seamless reuse in the application development process. Analyzing the commonality and variability between products in a product line is one of the essential concerns that must be considered when building a product line. In this paper, we suggest to combine a product line engineering approach with RFID applications technology. More concretely, common activities are identified among the RFID-enable applications and the variability in the common activities is analyzed in detail. Then, we suggest reusable product line architecture as a product line asset. In addition, as a tool for supporting this research, a framework which provides both reusable product line architecture for REID applications and the components that implement concrete realization of the architecture is developed. Sharing a common architecture and reusing assets to deploy recurrent services may be considered an advantage in terms of economic significance and overall quality.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.3
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• pp.127-132
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• 2005

In order to investigate transient behavior, of the CRW(Canard Rotor Wing) type UAV(Uninhabited Aerial Vehicle) propulsion system during flight mode transition considering flow control valve operation, the propulsion system was modelled using SIMULINK commercial program. The valve system is to control the gas flow of the rotary duct system and the main duct system, and the analysis was performed with an assumption that the total gas mass flow of the main engine is the same as summation of the rotary duct flow and the main duct flow, and with consideration of valve loss, flow rate and effective area in valve angle variation. The performance analysis was carried out during flight mode transitions from the rotary flight mode to the fixed wing flight mode and vice versa mode at altitude of 1km, flight Mach number 0.1 and maximum engine rpm.

• Journal of Service Research and Studies
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• v.13 no.1
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• pp.159-175
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• 2023

Mass production has long been the most important production paradigm in establishing a company's strategy as a method of producing various products. However, mass production cannot now be the most important paradigm as companies' competitive environment and consumer needs diversify. In particular, consumers' needs are becoming more diverse and rapidly changing, making it difficult for companies to respond to consumers' needs. Mass customization is the most notable paradigm reflecting this trend, and mass customization aims to produce a variety of products tailored to the needs of customers at a low cost. In this study, the theory and concept of a product architecture system were used to specify a method of realizing mass-customized services, and a case study was conducted focusing on the internal furniture model of a camping car. In particular, unlike previously when companies developed product platforms and modules focusing on productivity, a method of developing and configuring product platforms and modules was suggested by reflecting consumer requirements first, and its effectiveness was considered. As a result of the study, it was confirmed that it was effective in replacement, recyclability, line-up, and chargeability by designing through internal factors of the product architecture system and verifying the effectiveness of the results with external factors. It is expected that further empirical research will be led through a design process using a product architecture system in the future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.6
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• pp.751-758
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• 2015

Noise prediction for HVAC(Heating, Ventilating and Air Conditioning) systems are normally performed by empirical method suggested by NEBB(National Environmental Balancing Bureau, 1994). However, the method is not suitable for large ducts in ships. In this paper, computational analysis methods are used to develop a noise prediction method for the large ducts in ships. To develop regression formula of attenuation of sound pressure level in large ducts, Boundary Element Method(BEM) is used. BEM and Computational Fluid Dynamics(CFD) are applied to the analysis of flow-induced noise in ducts with stiffeners inside. Loud noise above 100 dB can be generated in some cases. Breakout noises of large ducts are also analyzed by using BEM and Finite Element Method(FEM). The acoustic pressure level shows about 10-15dB difference between inside and outside of the duct. Utilizing the results of this study, it is expected that shipyard planners can predict noise of the HVAC system for ships.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.488-492
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• 1997

원자력 발전소의 공조 시스템에 설치되는 덕트형 소음기를 설계.제작하여 감음성능 시험, 내진해석, 내진시험, 난연시험 및 기밀시험 등을 수행하여 각각의 요구조건에 적합한 소음기를 설계.제작한 결과 원자력 발전소에 기 설치된 소음기와 동등한 성능을 갖는 것으로 나타났다. 소음기를 설계, 제작, 시험하는 과정에서의 노-하우를 바탕으로 어떠한 요구조건에도 만족하는 제품을 국내에서 설계.생산할 수 있는 기술 확보에 있다.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.4
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• pp.87-93
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• 2016

In a Direct Connect(DC) mode altitude engine test, a labyrinth seal is set up between an air intake duct and an engine. The labyrinth seal plays a key role in mechanically isolating them, which contributes to the accurate measurement of thrust and the other component forces. However, when high vertical temperature gradient is generated in the supplied air in the duct, the isolation breaks down. In this paper, a labyrinth seal control device is designed and installed in an effort to eliminate the issue. Test result shows the device successfully gets rid of the contact problem even when high vertical temperature gradient is produced.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.433-435
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• 2004

소프트웨어 프로덕트 라인은 핵심 소프트웨어 자산의 개발을 위한 도메인 공학과 실제 소프트웨어 부품을 조립하여 구체적인 소프트웨어 시스템을 개발하는 응용 공학을 포함한다. 소프트웨어 프로덕트 라인 구축 시 가장 중요한 점은 특정 도메인에 존재하는 가변성(variability)을 지원할 수 있어야 한다는 것으로, 재사용자의 목적에 따라 효율적으로 소프트웨어를 맞춤 생산할 수 있는 컴포넌트 재구성성(reconfigurability)이 핵심 요소라 할 수 있다. 본 논문에서는 재사용자가 선택한 특성 구성을 바탕으로 계층 구조 조립 자동화를 통해 컴포넌트 코드를 자동 생성하는 도구를 구현하였다. 이를 위하여, 컴포넌트 패밀리의 특성 모델에서 표현되는 차이점에 따라 계층 구조의 각 컴포넌트들이 조립되도록 XSLT 스크립트를 사용하였다. 특성 모델과 XML/XSLT 기술을 이용하여 컴포넌트 코드 생성 시에 재구성성을 지원하고 재사용자의 요구에 맞는 컴포넌트 소스 코드를 자동 생성함으로써 소프트웨어 프로덕트 라인 개발 생산성을 향상시킨다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.12a
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• pp.37-40
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• 2001

본 논문에서는 전문가 시스템에서 지식에 대한 규칙을 감소시키기 위해 러프 집합을 이용한 지식 감축 방법을 제안한다. 또한, 속성 항을 클래스로 분류하여 각 클래스와 이웃하는 클래스의 항들을 비교하여 리덕트와 코어를 구하여 최소화하였다. 이러한 방법은 방대한 양의 규칙을 최소화함으로써 의사결정 시간을 단축시킬 수 있다.