• 산업공학
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• 제17권4호
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• pp.482-489
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• 2004

As the functional characteristics of passenger cars have reached to a satisfactory level, customers place more concerns with the aesthetic aspects of interior designs. The present study developed satisfaction models of passenger car interior materials for six parts including crash pad, steering wheel, transmission gearshift knob, audio panel, metal grain, and wooden grain. Eight to fifteen material design variables such as color, embossing, and smoothness were defined for the six interior parts based on literature survey, customer reviews, and expert opinions. A satisfaction survey was conducted for 30 vehicles with 30 participants ($mean{\pm}SD$ of age = $28.7{\pm}6.6$) by using a modified magnitude estimation scale. Based on the survey results, the material design variables were screened from statistical, technical, and practical aspects. With the screened variables, satisfaction models were developed by using the quantification I method for the six interior parts, indicating the importance of material design variables and preferred material properties.

• 대한기계학회논문집A
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• 제20권2호
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• pp.575-584
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• 1996

The objective of this paper is to develop an expert system for nuclear piping integrity. This paper describes the selection methodology of integrity evalution method and the inference of material properties. To select the integrity evaluation method, the weight factor for respective material properties was obtained by the sensitivity analysis of the effect of material properties on integrity evaluation method. Subsequently the possession ratio for respective integrity evaluation method was computed, and the most appropriate integrity evaluation method for given input information is selected. In the material properties inference, stress-strain curves and J-R curves were predicted from tensile properties such as yield strength and tensile strength.

• 한국CDE학회논문집
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• 제11권3호
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• pp.223-233
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• 2006

Layered manufacturing(LM) is emerging as a new technology that enables the fabrication of three dimensional heterogeneous objects such as Multi-materials and Functionally Gradient Materials (FGMs). Among various types of heterogeneous objects, more attention has recently paid on the fabrication of FGMs because of their potentials in engineering applications. The necessary steps for LM fabrication of FGMs include representation and process planning of material information inside an FGM. This paper introduces a new process planning algorithm that takes into account the processing of material information. The detailed tasks are discretization (i.e., decomposition-based approximation of volume fraction), orientation (build direction selection), and adaptive slicing of heterogeneous objects. In particular, this paper focuses on the discretization process that converts all of the material information inside an FGM into material features like geometric features. It is thus possible to choose an optimal build direction among various pre-selected ones by approximately estimating build time. This is because total build time depends on the complexity of features. This discretization process also allows adaptive slicing of heterogeneous objects to minimize surface finish and material composition error. In addition, tool path planning can be simplified into fill pattern generation. Specific examples are shown to illustrate the overall procedure.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 춘계 학술논문 발표대회
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• pp.1-5
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• 2008

The purpose of this study is to ensure an amicable material quality control in the construction site through investigating a process which can impact the construction material quality. For it, a worker interview and questionnaire survey was conducted through a direct field visit. The visited construction sites are composed of 79% construction site and 21% engineering site. As the respondents of questionnaire survey, the quality control workers were 72% of total respondents. Next, the construction worker, handymen, field representatives and others formed 7%. The interview with the quality control staff was conducted with the items including the construction site quality control guide, incoming inspection and material management. Through this survey, the problems of quality control by progress phase were derived. It could be known that the management and measures by each phase were urgently required. It also was indicated that a selection of low-priced material caused by low price bidding could badly impact the construction and safety. Also, in relation to the opinions such as the insufficient quality control and heavy work-load, the improvements are required. For the effective quality control in the construction site, the material quality control procedures suitable for the phase of construction progress must be presented in the present quality control. Also, the standards for it need to be established.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.553-557
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• 2007

건설산업에서 자재와 관련된 비용은 프로젝트 특성에 따라 다르지만 일반적으로 원가구성비 측면에서 40% 이상을 차지한다. 최근 대형화, 전문화, 복잡화 되어가는 건축 공사에서 자재의 반입, 이동 및 적재공간의 협소로 인해 자재관리가 매우 복잡하다. 하지만 대두분의 경우 자재관리는 현장 관리자의 경험에 의존해 관리되고 있으며 건설관리분야중 자재관리의 중요성에 대한 인식도 낮은 실정이다. 이에 대한 건설 산업에서 자재관리에 대한 연구도 활발히 진행되고 있다. 본 연구에서는 자재의 속성에 따른 ETO, ATO, MTO, MTS의 네가지 분류 방법과 자재 조달 특성 및 자재 고유특성을 통하여 현장 자재의 효율적인 공급관리를 위한 자재의 속성별 관리요소를 파악한다. 이를 이용하여 자재 속성별 자재관리 지표를 선정한다.

• 한국실내디자인학회논문집
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• 제21권3호
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• pp.22-30
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• 2012

Nowadays the issue of environmental pollution and ecological destruction is not a simple issue but an important issue to be continuously considered. It is deemed that a study for recycled new materials is immediately required and this study is to analyze features and processing methods of new materials which can be used to interior space. We found the recycled new materials used for space through researching various web sits. And then we analyzed what the base materials are and classified that base materials are whether natural or artificial of the recycled materials. We classified processing methods of the recycled new materials after researching general processing methods. The result of this study would be an important material to the research and development of new finishing materials with consideration of environment and to the research for a guideline of applicable new materials. The results of this study are as follows : First, we could classify widely 2 categories into natural material and artificial material and then 10 subcategories into metal, glass, wood, rubber, stone, plastic, leather or fabric, ceramic, concrete and so on, and analyzed that which material is mostly used and whether it is single material or multiple material. In order to analyze the feature of processing method. Second, we could classify into 4 categories such as junction, surface process, molding, and insert, and found out which processing method is applied based on objects of research. Third, as an analysis result of the recycled new material feature, in order to develop various new materials, it is required to study on combination and application of 2 materials or more rather than single material. Four, as a analysis result of the processing method feature, I would like to suggest that development and application of various processing methods are required. Especially, it is necessary to grope for a way to develop new functional materials for interior space through a systemic research and analysis of processing method of other fields. Furthermore, a way to reuse recycled new materials should be considered in a stage of selection and application of processing method.

• 마이크로전자및패키징학회지
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• 제22권4호
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• pp.1-5
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• 2015

In high temperature aircraft electronics, aluminium based brazing filler is the prime choice today. Aluminium and its alloys have compatible properties like weight minimization, thermal conductivity, heat dissipation, high temperature precipitation hardening etc. suitable for the aerospace industry. However, the selection of brazing filler for high temperature electronics requires high temperature joint strength properties which is crucial for the aerospace. Thus the selection of proper brazing alloy material, the composition and brazing method play an important role in deciding the final reliability of aircraft electronic components. The composition of these aluminium alloys dependent on the addition of the various elements in the aluminium matrix. The complex shapes of aluminium structures like enclosures, heat dissipaters, chassis for electronic circuitry, in avionics are designed from numerous individual components and joined thereafter. In various aircraft applications, the poor strength caused by the casting and shrinkage defects is undesirable. In this report the effect of various additional elements on Al based alloys and brazing fillers have been discussed.

• 한국생산제조학회지
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• 제19권1호
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• pp.94-100
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• 2010

Nowadays, several nontraditional machining(NTM) processes are widely used to machine a complex and accurate shape part of hard materials, such as titanium, ceramics, high strength temperature resistant and refractory materials which are difficult to machine and having high strength, hardness, toughness. Machining of these complex shapes in such materials by traditional machining processes are very difficult. The NTM processes is important in the areas of micro- and nano scale machining, where high accuracy and superior surface characteristics are required, which can only be achieved using these NTM processes. So, for effective selection of different NTM processes, careful decision making for a given NTM application is often necessary. An appropriate NTM process for a given material and shape condition is very difficult for the novice engineers. In this paper, an expert system based on an analytic network process(ANP) is suggested for a best selection of NTM process in a NTM application considering an prior interdependency effect among various factors.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.8-13
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• 2001

In the turning process, the feed is usually selected by a machining operator considering workpiece, cutting tool and depth of cut. Even if this selection can avoid power saturation or tool breakage, it is usually conservative compared to the capacity of the machine tools and can reduce the productivity significantly. This paper proposes a selection method of the feed and the reference cutting force based on MRR(material removal rate), maximum spindle power and specific energy. In order to estimate and control cutting force accurately in transient and steady state, this study utilizes a synthesized cutting force estimation method and a Fuzzy controller. The experimental results present that these systems can be useful for the FMS(flexible manufacturing system) and unmanned automation system.

• 한국멀티미디어학회논문지
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• 제19권6호
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• pp.1065-1073
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• 2016

In this paper, we examined informatics textbooks for middle school students in accordance with 2009 revised curriculum through conducting both content analysis and surveys. The content analysis was analyzed the composition and contents of textbooks. Survey questionnaires were based on the authorization criteria and selection standards of informatics textbooks. The content analysis demonstrated that there were discrepancies among textbooks in areas such as the total number of pages, related material, the number of core concepts introduced in each chapter, and the application of software. The survey results showed that two sections - 'Expression and Modification' and 'Text' exhibited the most positive results, and the 'Creativity' section the least. Using the findings above, we present alternative ways to improve qualities of these textbooks.