• Title/Summary/Keyword: manufacturing theory

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Life Prediction of Composite Pressure Vessels Using Multi-Scale Approach (멀티 스케일 접근법을 이용한 복합재 압력용기의 수명 예측)

  • Jin, Kyo-Kook;Ha, Sung-Kyu;Kim, Jae-Hyuk;Han, Hoon-Hee;Kim, Seong-Jong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.9
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    • pp.3176-3183
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    • 2010
  • A multi-scale fatigue life prediction methodology of composite pressure vessels subjected to multi-axial loading has been proposed in this paper. The multi-scale approach starts from the constituents, fiber, matrix and interface, leading to predict behavior of ply, laminates and eventually the composite structures. The multi-scale fatigue life prediction methodology is composed of two steps: macro stress analysis and micro mechanics of failure based on fatigue analysis. In the macro stress analysis, multi-axial fatigue loading acting at laminate is determined from finite element analysis of composite pressure vessel, and ply stresses are computed using a classical laminate theory. The micro stresses are calculated in each constituent from ply stresses using a micromechanical model. Three methods are employed in predicting fatigue life of each constituent, i.e. a maximum stress method for fiber, an equivalent stress method for multi-axially loaded matrix, and a critical plane method for the interface. A modified Goodman diagram is used to take into account the generic mean stresses. Damages from each loading cycle are accumulated using Miner's rule. Monte Carlo simulation has been performed to predict the overall fatigue life of a composite pressure vessel considering statistical distribution of material properties of each constituent, fiber volume fraction and manufacturing winding angle.

A Study on the Location Factors of Foreign Direct Investment Firms in Korea (국내 외국인직접투자기업의 입지결정요인에 관한 연구)

  • Lee, Ho-Yeong;Park, Won-Seok
    • Journal of the Korean association of regional geographers
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    • v.17 no.1
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    • pp.58-74
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    • 2011
  • This study analyzed and compared the importance and priority of location decision factors in Foreign Direct Investment Firms managing the manufacturing business in the nation's southeastern economic zone, and in expert group by using AHP analytical technique based on examining the location theory and the prior research of real estate for industry. Also, it analyzed difference in importance and priority for location factors by corporate scale, by business category, and by location type targeting only foreign direct investment firms, and offered references necessary for location decision-making. In addition, to elicit useful information for policy related to location decision factors for foreign direct investment firms, the implications were elicited by analyzing the results recognized between foreign direct investment firms and expert group on information elements regarding investment satisfaction, business bottlenecks, and location decision process. The considerable gap was indicated in importance and priority of location decision factors considered between the nation's foreign direct investment firms and real-estate expert group for industry. As a result of analyzing by reflecting the corporate characteristic variable in location assessment model unlike before, the importance of the competitive advantage factor and the business strategic factor was indicated to be very high.

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Color Image Segmentation and Textile Texture Mapping of 2D Virtual Wearing System (2D 가상 착의 시스템의 컬러 영상 분할 및 직물 텍스쳐 매핑)

  • Lee, Eun-Hwan;Kwak, No-Yoon
    • Journal of KIISE:Computer Systems and Theory
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    • v.35 no.5
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    • pp.213-222
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    • 2008
  • This paper is related to color image segmentation and textile texture mapping for the 2D virtual wearing system. The proposed system is characterized as virtually wearing a new textile pattern selected by user to the clothing shape section, based on its intensity difference map, segmented from a 2D clothes model image using color image segmentation technique. Regardless of color or intensity of model clothes, the proposed system is possible to virtually change the textile pattern or color with holding the illumination and shading properties of the selected clothing shape section, and also to quickly and easily simulate, compare, and select multiple textile pattern combinations for individual styles or entire outfits. The proposed system can provide higher practicality and easy-to-use interface, as it makes real-time processing possible in various digital environment, and creates comparatively natural and realistic virtual wearing styles, and also makes semi-automatic processing possible to reduce the manual works to a minimum. According to the proposed system, it can motivate the creative activity of the designers with simulation results on the effect of textile pattern design on the appearance of clothes without manufacturing physical clothes and, as it can help the purchasers for decision-making with them, promote B2B or B2C e-commerce.

The Concept of Reproduction and the Criteria of an Exhibition in Contemporary Arts (현대미술에 있어서 '복제'의 개념과 전시규범의 문제 -${\gg}$살바도르 달리 탄생 100주년 특별전${\gg}$의 전시물 <성경> 연작을 중심으로)

  • Chang, Dong-Kwang
    • The Journal of Art Theory & Practice
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    • no.2
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    • pp.169-190
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    • 2004
  • The purpose of this article is to delve into the problems of originality of the artwork by examining issues of reproduction within the contemporary art market. In contemporary arts, especially in terms of art production and consumption, we can't overlook society and its economic structure and its connection with of capitalism. As the purity of art creation has turned into an exchange value, art, especially an object as artwork, has fallen into the status of production in an economic marketing system. Walter Benjamin mainly referred to that point in his thesis Das Kunstwerk im Zeitalter seiner technischen Reproduzierbarkeit, which originated the sociology of plastic arts. This thesis, published in 1936, traced how the artistic functions of photograph and movie had been changed through the social development. His main concerns were movie and photograph but what I am concentrating from his point of view, is that even in the field of plastic arts, the manufacture of reproduction has been practiced as a primary method within the social and political contexts and development. Though I am referring to this in the main body of this article, reproduction in contemporary art strongly needs a new definition since it has been spread all over like a newest virus, not only by collector's personal taste or hut also by commercial circulations of these reproductions to the public. This relates to Benjamin's argument about the value of an exhibition at a museum(Ausstellungswert). Since the function of an artwork has been one of cultural industry, the manufacturing of reproduction raises unexpected problems, such as, the originality of the artwork, the value of an exhibition at a museum, its achievement as documentary and as a territory of art criticism. In this point of view, I want to inquire into the value and criteria of an exhibition in contemporary art through the review of the definitions and the intrinsic attributes of reproduction. Somehow in a broad sense, the reproduction is a product coming out of representation or copy (replica) of an original art work or an model. Therefore, the problems it presents differ from the Simulacre, which is an image without an original one. In terms of the Meanings of reproduction, we can distinguish it as reproductions, copies, and productions. These types of reproductions are not the original artworks reflected by the creative intention of the artists. For example, a publishing company reproduced some of lithographs of Salvador Dali in the 1960s. They are commercial copies in the form of representation or reproduction with no artistic and creative intention of the artist. However, In despite of this theoretical basis, reproductions of the famous artists are still displayed without any verification for of the public's quest for the artworks. Moreover, many commercial companies that are planning to exhibit art works of the world-famous artists only for their profits keep trying to speak ill of and judging by the law the honest art critics' articles which discuss the true values of exhibition. If freedom of expression is one of the ideals of democracy, even the judgment of the originality of the artworks should be freely expressed.

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The Effect of the Supervisor's Transformational Leadership on Employees' Work Engagement : Focusing on the Mediating Effects of Psychological Contract Breach and Organizational Anomie (변혁적 리더십이 직무열의에 미치는 영향: 심리적 계약 위반과 조직아노미의 매개효과를 중심으로)

  • Bae, Chae-Yoon;Shin, Je-Goo
    • The Journal of the Korea Contents Association
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    • v.16 no.11
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    • pp.281-307
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    • 2016
  • The goal of this study was to verify that effectiveness of transformational leadership in impacting work engagement with the psychological contract breach among members of the organization and organizational anomie as mediating factors. The mediating effect of psychological contract breach and organizational anomie on the relationship between transformational leadership and work engagement was explored using a theoretical approach based on Social Exchange Theory, Social Information Processing Model and Job Demands- Resources Model. To avoid common method bias, the dependent variable was surveyed using employee peer review. 277 surveys were collected from 18 companies in diverse industries including manufacturing, distribution, and finance. The results of the analysis showed that transformational leadership has a significant positive effect on employees' work engagement, while having a significant negative effect on psychological contract breach and organizational anomie. In addition, psychological contract breach and organizational anomie were found to act as partial mediators in the relationship between transformational leadership and employees' work engagement. Overall, this study showed that if leaders at organizations can assist employees to overcome negative factors such as psychological contract breach and organizational anomie through transformational leadership, it is possible to improve employees' work engagement.

A Study on the Trade Insurance System through Risk Management of Trade Payment of Korea's Export and Import Manufacturing Companies (한국수출기업의 무역대금결제의 위험관리에 따른 무역보험제도에 관한 실증적 연구)

  • Kim, Chang Bong;Park, Se Hwan;Kwon, Seung Ha
    • International Commerce and Information Review
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    • v.19 no.2
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    • pp.213-236
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    • 2017
  • World trade has entered a stagnant state, protection trade measures are spread due to delayed economic recovery in developed countries, sluggish investment in emerging economies such as China, economic recession in resource exporting countries, and geopolitical and political uncertainties along with the election period in the US and other major industrialized countries. Thus, in the economic structure of our country with a focus on export, for small and medium enterprises to grow, efforts for having various markets are necessary. The importance of the trade insurance system, which can support the risk management of enterprises, is emphasized by the fact that the majority of SME exporters have a risk management level and a lack of corporate capacity to enter the global market. This study was surveyed with 87 small and medium export companies in South Korea. The purpose of this study is to verify the effect relationship how service quality of trade insurance and utilization of trade insurance impact on the risk management of trade payment and export performance. The research hypothesis and model was derived from the basis of existing theory and empirical research, and obtained the following results. Firstly, Service Quality of Trade Insurance showed positive (+) effect on Export Performance. Secondly, Utilization of Trade Insurance showed positive (+) effect on Risk Management of Trade Payment. Thirdly, Risk Management of Trade Payment showed positive (+) effect on Export Performance. This study is differentiated from previous research information by empirically evaluating the relationship between the risk management of trade payment and export performance through utilization of trade insurance. This study contributed to academic by examining the research on the risk management of trade insurance and also practically suggested the direction how small and medium export company is to take the advantage of the trade insurance.

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The examination of application possibility and development of new welding joint shape for aluminum alloy (Al어선 선체용접부의 신형상 개발 및 적용 가능성 검토)

  • Jong-Myung Kim;Chong-In Oh;Han-Sur Bang
    • Journal of the Society of Naval Architects of Korea
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    • v.38 no.1
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    • pp.99-107
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    • 2001
  • Manufacture of fishing vessel is needed the effective material for light, strength, fire and corrosion of water in order to improve durability by high-speed and fishing. These fishing vessel can be divided into FRP and AI alloys fishing vessel. FRP fishing vessel is light and effective for strength but highly ignited and susceptible to heat during the manufacturing ship by-produce noxious component for human. In the case of a scrapped ship, it cause environmental pollution. On the other hand, aluminum is a material in return for FRP and has merit of high-strength and lightness. It's more heat proof and durable than FRP and superior to prevent from corrosion. Al alloys fishing vessel development is rising as an urgent matter. But, al alloy has some defect of bad weldability, welding transformation, cracks and overcost of construction. Therefore this study is to develop the new welding joint shape solving aluminum defects and mechanical behavior. First of all, strength was compared and reviewed by analysis of plate, stiffen plate, new model simplified by using plate theory. On the base of this result, plate and new model of temperature distribution, weld residual stress and strength of tensile, compressive force were compared and reviewed by finite element computer program has been developed to deal with heat conduction and thermal elasto plastic problem. Also, new model is proved application possibility and excellent mechanic by strength comparison is established to tensile testing result.

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Emerging New Industrial Cluster along the Cheonggyechon-ro and Its Social Capital (청계천로변 전문상가의 신산업집적체형성과 사회적 자본의 특성)

  • 남기범
    • Journal of the Economic Geographical Society of Korea
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    • v.4 no.2
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    • pp.79-96
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    • 2001
  • This paper introduces a new type of industrial cluster developed at the CBD of Seoul. Conventionally, clusters are said to be consisted of hi-tech, often If activities, manufacturing industries or artisan craft industries with increasing vertical integration and performance usually supported by venture capitals and favorable business infrastructure, not to mention governments', be it central or local, incentive plans. The study area, Cheonggyechon region has long been a traditional CBD frame of Seoul, Korea, being troubled by deterioration, traffic jams, and environmental degradation as most inner cities experience. Recently. this region has transformed to the most dynamic and productive area not by IT industries but by apparel and fashion activities. The study of the developmental trajectory and key characteristics for this kind of industrial cluster can give us insight both for the transition of inner city and for the cluster theory. This Paper firstly briefly Profiles the growth of the Cheonggyechon region over the past decade. It then shows the current spatial and business structure of the new industrial cluster, focusing on the fact that transactions costs are reduced, the creation and flow of information improves. and the local institutions are prone to be most responsive to the new cluster's specialized needs. The third section presents the key components of the customized production-distribution-shopping cluster development process, emphasizing the localized networking. social capital, spontaneous institutionalization of associational economic climate, and cultural economy based on place-specific inertia. The paper concludes with some comments about the prospects and perils of the new industrial cluster of Seoul.

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Endpoint Detection in Semiconductor Etch Process Using OPM Sensor

  • Arshad, Zeeshan;Choi, Somang;Jang, Boen;Hong, Sang Jeen
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.237.1-237.1
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    • 2014
  • Etching is one of the most important steps in semiconductor manufacturing. In etch process control a critical task is to stop the etch process when the layer to be etched has been removed. If the etch process is allowed to continue beyond this time, the material gets over-etched and the lower layer is partially removed. On the other hand if the etch process is stopped too early, part of the layer to be etched still remains, called under-etched. Endpoint detection (EPD) is used to detect the most accurate time to stop the etch process in order to avoid over or under etch. The goal of this research is to develop a hardware and software system for EPD. The hardware consists of an Optical Plasma Monitor (OPM) sensor which is used to continuously monitor the plasma optical emission intensity during the etch process. The OPM software was developed to acquire and analyze the data to perform EPD. Our EPD algorithm is based on the following theory. As the etch process starts the plasma generated in the vacuum is added with the by-products from the etch reactions on the layer being etched. As the endpoint reaches and the layer gets completely removed the plasma constituents change gradually changing the optical intensity of the plasma. Although the change in optical intensity is not apparent, the difference in the plasma constituents when the endpoint has reached leaves a unique signature in the data gathered. Though not detectable in time domain, this signature could be obscured in the frequency spectrum of the data. By filtering and analysis of the changes in the frequency spectrum before and after the endpoint we could extract this signature. In order to do that, first, the EPD algorithm converts the time series signal into frequency domain. Next the noise in the frequency spectrum is removed to look for the useful frequency constituents of the data. Once these useful frequencies have been selected, they are monitored continuously in time and using a sub-algorithm the endpoint is detected when significant changes are observed in those signals. The experiment consisted of three kinds of etch processes; ashing, SiO2 on Si etch and metal on Si etch to develop and evaluate the EPD system.

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Performance of Serial Communication Protocols through Conducting Threads (전도성사를 매체로 한 직렬 통신 프로토콜 성능)

  • Kim, Na-Young;Kim, Hwan;Kim, Juk-Young;Kwon, Young-Mi
    • Journal of Internet Computing and Services
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    • v.12 no.5
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    • pp.21-28
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    • 2011
  • Recently medical and entertainment applications using conducting textile are suggested, but the data of conducting threads are not characterized, classified and verified. Only the data sheet published by manufacturing companies is available. Thus we need to verify the performances of the threading threads in communication. And we need a guideline if the existing communication protocols can be used for the conducting threads communication or the new specific communication protocols have to be developed for the communication. This paper classifies the characteristics of conducting threads made by domestic and overseas companies. Based on the criteria we classified conducting threads into three classes: class A, class B and class C. Further we carried out experiments to verify the adaptability of existing simple serial communication protocols such as RS232. Six different conducting threads are used in experiments and the length of each thread was 0.5m, 1m, 2m and 3m. The data transmission rate and error rate are collected and analyzed. RS485 is very prone to error due to static electricity from human and environment. So it may not be appropriate as long-distance communication protocol up to 12km which is possible in theory. RS232 shows stable and error-less data transmission ability even though every conducting thread didn’t show transmission capability over RS232. USB protocol shows high data rate transmission but the distance cannot be exceeded over 2m. Additionally, USB requires stable power supply. But if the power is supplied through conducting thread, its function is not.