• Membrane and Water Treatment
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• 제6권5호
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• pp.411-422
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• 2015

Membrane modification by different concentrations of acrylic acid has been described. Grafting of acrylic acid to the surface of a polypropylene membrane was obtained by a Fenton-type reaction. Membrane permeability seemed to have been dependent on the value of pH in the solution. To explain tendency, a simple theoretical model was developed. The model incorporates explicitly statistical conformations of a polyacid chain grafted onto the pore surface. The charged capillary model with a varying diameter for porous membranes was then used to evaluate the permeability of the membrane. It has been shown both theoretically and experimentally that the permeability of a grafted membrane depends on the pH of the solution.

• 산업경영시스템학회지
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• 제29권1호
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• pp.94-100
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• 2006

The risk management is an organized method for identifying and measuring risk and for selecting, developing, and implementing options for the handling of risk. The risk management covers all programatic and technical factors which affect the system development performance, cost, and schedule. While technical issues are primary concern for systems engineering, the three elements(performance, cost, and schedule) must be balanced for a successful risk management process. This paper proposes the risk management process for the KSLV-I(Korea Space Launch Vehicle-I) program using computer-aided systems engineering tool, Cradle. The risk management process of KSLV-I program is similar to the general risk management process, but it has its own specific features to manage large-scale complex characteristics of KSLV-I program.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.306-309
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• 2000

In this work, we investigated A1 cluster deposition on Al (100) surface using molecular dynamics simulation. A result of simulations showed that large cluster with low energy was proper for good surfaced-films without craters at the low temperatures. We investigated the maximum substrate temperature and the time taken for substrate temperature to reach its maximum as a function of cluster size in the case of the same total energy and in the case of the same energy Per atom. The correlated collisions play an important role in interaction between energetic cluster and surface, and as cluster size and cluster energy increases, the correlated collisions effect affects interaction between energetic cluster and surface.

• 한국정보통신학회논문지
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• 제17권10호
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• pp.2473-2478
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• 2013

최근 개발되는 무기 체계는 품질 확보를 위해 시스템 공학을 적용하여 개발하고 있다. 무기 체계 개발의 프로세스는 기본적으로 미국에서 개발된 표준서(MIL-STD-499)와 시스템공학(ISO/IEC 15288)를 적용하여 개발되고 있다. 최근에는 카네기 멜론대학의 개발 성숙도를 평가하는 CMM(Capability Maturity Model) 및 CMMI(Capability Maturity Model Integration)의 기준을 회사의 개발 성숙도로 측정하고 평가를 하여 성숙도 레벨을 부여하고 있다. 이글은 CMMI 프로세스를 추가 적용하여 개발한 무기 체계에 대해 프로세스의 적용 범위를 소개한다. 다양한 프로세스를 적용하여 개발한 장비의 산출물을 통해 프로세스 적용의 장점을 제안한다.

• Journal of Welding and Joining
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• 제24권5호
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• pp.37-42
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• 2006

The robotic arc welding is widely employed in the fabrication industry fer increasing productivity and enhancing product quality by its high processing speed, accuracy and repeatability. Basically, the bead geometry plays an important role in determining the mechanical properties of the weld. So that it is very important to select the process variables for obtaining optimal bead geometry. In this paper, the possibilities of the Infrared camera in sensing and control of the bead geometry in the automated welding process are presented. Both bead width and thermal images from infrared thermography are effected by process parameters. Bead width and isotherm radii can be expressed in terms of process parameters(welding current and welding speed) using mathematical equations obtained by empirical analysis using infrared camera. A linear relationship exists between the isothermal radii producted during the welding process and bead width.

• 청정기술
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• 제9권1호
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• pp.1-8
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• 2003

청정기술을 석유화학분야에 적용하기 위해서는 주어진 공정에 대한 모사기가 요구된다. 본 연구에서는 주어진 공정에 대한 모사기화 과정에서 반응부분과 재순환 부분에 대한 모사기화 과정을 각각 EA(Ethanol) 공정과 MEK(Methyl Ethyl Ketene) 공정을 예로 들어 설명하였다. 완성된 모사기를 기반으로 여러 가지 개선안을 도출하고 그 개선안들에 대한 타당성 검증을 수행함으로써 청정 기술을 현장에 보급하고 이러한 과정을 지속적으로 유지할 수 있는 환경을 제공하였다.

• International Journal of Precision Engineering and Manufacturing
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• 제5권1호
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• pp.36-41
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• 2004

The blanking of thin sheet metal using progressive dies is an important process on production of precision electronic machine parts such as IC leadframe. This paper summarizes the results of simulating the progressive blanking process by means of LS/DYNA. In order to verify the influence of blanking order on the final lead profile and deformed configuration, simulation technique has been proposed and analyzed using a commercial FEM code, LS/DYNA. The results of FE-simulations are in good agreement with the experimental result. After then, to construct rule base in progressive blanking process, FE-simulation has been performed using a simple model. Based on this result rule base is set up and then the blanking order of inner lead is rearranged. Consequently, from the results of FE-simulation using suggested method in this paper, it is possible to predict the shift of lead to manufacture high precision lead frame in progressive blanking process. The proposed method can give more systematic and economically feasible means for designing progressive blanking process.

• 한국금형공학회:학술대회논문집
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• 한국금형공학회 2008년도 하계 학술대회
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• pp.203-208
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• 2008

Recently, the modern society in development and industrial growth is investing a lot of time and much effort to improvement and environment of life quality. Thus, the casting tape which uses environmentally friendly and human body friendly water hardening process Polymer is rapidly substituted for the gypsum cast product which has been plentifully used in medical treatment. Until currently, prior researches have a tendency to focusing the analysis about chemical creation expense and reaction quality rather than the issue about optimization of the process for this polymerization. In the polymerization process which has been accomplished with actual same chemical creation expense, there has been a problem which is the possibility of getting a different result. This is because the optimization of respectively control factors is not accomplished which affect at polymerization process. Therefore, this research sees the chemical qualities of casting tape Polymer, consequently selects the polymerization process which is suitable. And, by using a experimental design, this research will evaluate the affects which the respective factors have on remaining NCO and viscosity. futhermore, this research will carry out the process optimization which can get the above results.

• International Journal of Precision Engineering and Manufacturing
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• 제7권2호
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• pp.8-11
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• 2006

Gas-assisted injection molding (GAIM) process reduces the required injection pressure during mold filling stage as well as the shrinkage and warpage of the part and cycle time. Despite of these advantages, this process needs new parameters and makes the application more difficult because gas and melt interact during the injection molding process. Important GAIM factors involved in this process are gas penetration design, locations of gas injection points, shot size, delay time to inject gas as well as common injection molding parameters. In this study, the experiments are conducted to investigate effects of GAIM process variables on the gas penetration for PP (Polypropylene) and ABS (Acrylonitrile Butadiene Styrene) moldings by changing the gas injection point. Taguchi method is used for the design of the experiments. When the gas is injected at a cavity's center, the most effective factor is the shot size. When the gas is injected at a cavity's end, the most effective factor is the melt temperature. The injection speed is also an effective factor in GAIM process.

• International Journal of Computer Science & Network Security
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• 제23권8호
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• pp.199-203
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• 2023

Influential trend that widely reflected the software engineering industry is service oriented architecture. Vendors are migrating towards cloud environment to benefit their organization. Companies usually offer products and services with a goal to solve problems at customer end. Because customers are more interested in solution of their problem rather than focusing on products or services. In software industry the approach in which customers' problems are solved by providing services is known as software as a service. However, software development life cycle encounters enormous changes when migrating software from product model to service model. Enough research has been done on the overall development process but a limited work has been done on the factors that influence requirements elicitation process. This paper focuses on those changes that influence requirement elicitation process and proposes a systematic methodology for transformation of software from product to service model in a successful manner. The paper then elaborates the benefits that inherently come along with elicitation process in cloud environment. The paper also describes the problems during transformation. The paper concludes that requirement engineering process turn out to be more profitable after transformation of traditional software from product to service model.