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        검색결과 313

        121.
        2015.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Porous metals are called as a new material of 21th century because they show not only extremely low density, but also novel physical, thermal, mechanical, electrical, and acoustic properties. Since the late in the 1990‘s, considerable progress has been made in the production technologies of many kinds of porous metals such as aluminum, titanium, nickel, copper, stainless steel, etc. The commercial applications of porous metals have been increased in the field of light weight structures, sound absorption, mechanical damping, bio-materials, thermal management for heat exchanger and heat sink. Especially, the porous metals are promising in automotive applications for light-weighting body sheets and various structural components due to the good relation between weight and stiffness. This paper reviews the recent progress of production techniques using molten metal bubbling, metal foaming, gas expansion, hollow sphere structure, unidirectional solidification, etc, which have been commercialized or under developing, and finally introduces several case studies on the potential applications of porous metals in the area of heat sink, automotive pannel, cathod for Ni-MH battery, golf putter and medical implant.
        4,000원
        122.
        2015.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper has been carried out the forming analysis, die stress analysis, and relevant tests for the straightness improvement of hollow shafts with blocktooth. Hollow forward extrusion is a process that a material in a die is pressed with a punch and the material is formed into the same direction through the gap of a mandrel and a bottom die. For an asymmetric shaped product, due to the difference of reduction ratios of the cross sections in its extruding, a phenomenon that the product bends from the difference of the flow speed comes to occur. As applying the key to the mandrel has a uniform flow speed, bending problem was solved. These were processed using Deform-3D as a finite-element analysis program. Analysis was compared with the experiment. Keyway height of the mandrel has been confirmed that the straightness best when it comes 0.1mm. These study are expected to be available as fundamental data in die design necessary for the manufacture of asymmetric goods in the future.
        4,000원
        123.
        2014.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To elucidate the effects of a pretreatment process on the uniformity of Ag electroless plating on Cu flakes, pretreatment time was mainly considered with a mixed solution of 0.15 M ammonium hydroxide and 0.0375 M ammonium sulphate. Optical inspection of Ag-coated Cu flakes determined that the optimal pretreatment time is 120 s. Repetition of the sequence in which Ag plating was done immediately after the pretreatment of 120 s clearly enhanced the plating uniformity. Scanning electron microscopy revealed that holes were formed irregularly on some Cu flakes during the period from the asdropping of an Ag precursor solution to 5 min. The hole formation was judged to be due to continuous removal of Cu on the local surfaces by the repetitive formation and elimination of Cu2O or Cu(OH)2 layers. However, the increase of the amount of Ag coating suppressed the hole creation and increasingly enhanced the antioxidant property.
        4,000원
        124.
        2014.07 구독 인증기관·개인회원 무료
        Research on new product development has emphasized the importance of integrating customers, employees, and suppliers in an organization’s innovation processes. While several studies evaluate respective participatory processes, there is, surprisingly, no consensus on which dimension participation quality consists of, and how to measure them consistently. The present study contributes to the literature by identifying the dimensions of participation quality and by constructing a participation quality scale that includes six dimensions, namely (1) project-related resources, (2) early involvement, (3) degree of influence, (4) transparency of processes, (5) incentive mechanisms, and (6) voluntariness of participation. Furthermore, a 24-item measure of participation quality is developed using a mixed-method design. Results of our study show that the developed measure impacts important innovation-related outcomes such as innovation performance, acceptance of the innovation, and intention to participate in future innovation projects. Given that the six identified dimensions of participation quality differentially affect these outcomes, the scale provides the opportunity to better design participatory innovation projects, and thus helps managers to integrate stakeholders more successfully in these projects.
        125.
        2014.07 구독 인증기관·개인회원 무료
        This research examines the influence of network position, identity construction and role playing within business to business (B2B) interactions processes. The framework used as the basis for considering interaction processes developed from the AAR model (Håkansson & Snehota, 1995) and includes: accessing resources; developing actor bonds and conducting activities. There has been little research conducted into network position (Abrahamsen et al., 2012; Schepis et al., 2014); identity construction (Huemer, 2013; Schepis et al., 2014) and role playing (Abrahamsen et al., 2012; Lowe et al., 2012). This research develops a framework for incorporating all three concepts into the interaction process, rather than investigating them individually or paired, commonly undertaken in previous research. The research is conducted within an interpretive paradigm with 20 interviews conducted within the junior mining industry in Western Australia. Interviews were analysed using Leximancer™ and a comparison of the perceptions from companies playing different roles within the network examined. Results highlight that network position is influenced through accessing resources and developing actor bonds; identity construction occurs through developing actor bonds and conducting activities and role playing occurs when conducting activities and accessing resources. A theoretical framework highlights each of the above concepts within the framework of interaction processes. The value of this paper is that the each of these concepts is influenced through different aspects of the interaction process. Thus, highlighting which aspects of the interactions processes managers can adapt to improve their network position, identity construction and role perceptions.
        126.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A pilot plant (Q=5 m3/d) study was implemented for small and medium sized personal wastewater treatment plant effluent to evaluate MBR and A/O processes utilizing self-sufficient energy composed of wind and solar energy. The removal efficiencies of BOD, SS, turbidity and color were sufficient for legal water quality standards for gray water. However, those of nitrogen and phosphorus could not meet legal regulations which suggested that further removal of those contaminants were needed for reuse of the treated water.Self-sufficient energy rate was 100 % for the pilot plant due to excessive design capacity. In this research, wind and solar energy system was applied considering geological characteristics, which significantly improved energy self-sufficiency. Substantial improvement on energy self-sufficiency can be obtained by optimized investment and operation at a full scale wastewater treatment plant.
        4,000원
        127.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper suggests a specific model that could efficiently improve the interaction and the interface between WMS(Warehouse Management System) terminal and PDA terminal through real time processing in manufacturing shop. The proposed model shows that the new method can more efficiently perform to reduce processing time for shipping and receiving, compared with the current approach. As a result of the certain test among the main server, WMS system, and PDA terminal, it is noted in case of the new proposed system that the effects of proposed model are as follows: (a) While the receiving lead time for carrying by the current method was 2 hours, the receiving lead time by the new method was 20 minutes. (b) While the shipping lead time for carrying by the current method was 1 hours, the shipping lead time by the new method was 15 minutes. (c) While the inventory rate of accuracy by the current method was 85%, the inventory rate of accuracy by the new method was 98%.
        4,000원
        128.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As weapon systems become complex in terms of the scale and functionality, the required time to complete the test and evaluation (T&E) process is inevitably getting longer. However, nowadays the reduction of T&E period becomes one of the core targets in the weapon systems acquisition programs. This is because the reduced time for T&E process can yield the reduction of defense budget and also faster deployment of the weapon systems, thereby having a competitive edge over rival countries. On the other hand, in weapon systems development the management of reliability, availability, maintainability and safety (RAMS), and risk is considered important to keep competitiveness and thus has been carried out separately. Thus, the objective of this paper is to study on improving the T&E process by integrating the RAMS and risk management process in it. To do so, the related processes are analyzed and modeled first. Then an integrated process model is developed. The resulting model is equipped with the traceability among the data and interfaces that are generated from the T&E and RAMS/risk processes. As a case study, the model developed is applied in tanks development. The effective use of the traceability is expected to reduce the time and cost required to complete T&E process.
        4,300원
        129.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to develop tea by using the leaves of stevia, which is a herbal plant, and to solve the disadvantages of stevia dried leaf tea, we have manufactured the steamed tea, stir-fried tea and fermented tea by changing the manufacturing processes. As a result of the sensory tests, the steamed tea, stir-fried tea and fermented tea received higher evaluations than the dried leaf tea. In terms of efficiency, it is desired that the total number of steaming and stir-frying is only once, but the fermentation is found to be the most desirable for 2 days. There are no trends for changes in the general ingredients, mineral and free amino acid contents of stevia leaf teas by different manufacturing processes. As a result for the measurement of antioxidant activities, the steamed tea and dried leaf tea did not show significant differences, but the stir-fried tea and the fermented tea show significantly low antioxidant activities as compared to the steamed tea. The contents of stevioside in both the stir-fried tea and the fermented tea were less than that in the dried leaf tea, but in the steamed tea, there was no significant difference in the content of stevioside. Base on the present observations, this study supports high potentials of steaming process in order to produce new stevia leaf tea.
        4,000원
        130.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 축산분뇨 처리장(바이오가스 플랜트) 액비의 고도처리에 적합한 공정을 도출하기 위한 기초 연구이다. 액비를 고도처리하기 위하여 나노여과 및 역삼투(reverse osmosis) 공정을 각각 사용하였고, 전처리공정으로서 담체를 첨가하지 않은 MBR과 담체를 첨가한 MBR을 각각 적용하여 비교하였다. 액비의 질소는 주로 암모니아성 질소의 형태로 존재하였다. MBR의 운전에서 담체(biomedia) 유무에 따른 COD, T-N 및 T-P의 제거효율에서 큰 차이는 없었으나, 담체를 첨가한MBR의 TMP는 담체를 첨가하지 않은 MBR에 비해 매우 서서히 증가하였다. 전처리 공정으로 담체를 첨가한 MBR 공정을사용한 경우, NF에 의한 COD, T-N 및 T-P의 제거효율은 각각 99.8, 86.5% 및 99.8%이었으며, RO에 의한 제거효율은 각각99.9, 86.8% 및 99.9%이었다. MBR과 NF/RO 공정을 이용하여 처리한 액비의 최종 수질은 분뇨처리장 방류수 수질기준과비교하였을 때, COD와 T-P는 방류수 수질기준을 만족하였으나, T-N은 수질기준에 부적합하였다. 따라서 T-N에 대한 방류수 기준을 만족시키기 위해서는 MBR 조업 cycle의 조정 또는 나노여과/역삼투에 의한 2차 재처리 등의 개선이 필요한 것으로 판단된다.
        4,000원
        131.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Medical technologies are gaining in importance because of scientific and technical progress in medicine andthe increasing average lifetime of people. This has opened up a huge market for medical devices, where complex-shapedmetallic parts made from biocompatible materials are in great demand. Today many of these components are alreadybeing manufactured by powder metallurgy technologies. This includes mass production of standard products and alsocustomized components. In this paper some aspects related to metal injection molding of Ti and its alloys as well asmodifications of microstructure and surface finish were discussed. The process chain of additive manufacturing (AM)was described and the current state of the art of AM processes like Selective Laser Melting and electron beam meltingfor medical applications was presented.
        4,000원
        132.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        주류를 제외한 과일 및 탄산음료 등을 제조하는 비알코올성 음료품 제조시설에서 발생되는 폐수는 높은 농도의유기물과 낮은 농도의 질소, 인 등을 함유한다. 이러한 폐수의 처리 시설은 주로 호기성 공정과 약품응집 공정으로 구성하고 후단에 사여과지 또는 활성탄 공정을 추가하기도 한다. 하지만 이러한 방식은 긴 체류시간과 침전지 설치로 인해 많은 부지를 필요로 하는 문제가 있다. 본 연구에서는 부지소요 문제와 슬러지 유출로 인한 수질저하 문제를 해결하고자 W식품공장 폐수처리장 인근에 MBR pilot plant를 설치하고 장기간 운영을 통해 데이터를 확보하고 처리 효율을 평가하였다. 약 3개월간음료수 제조공정 폐수를 평막을 적용한 MBR pilot plant로 운전조건을 변화하며 처리한 결과, 처리유량 20 m3/day, HRT 29hr, 4Q 반송조건까지는 유기물 제거율 97% 이상으로 안정적인 처리가 가능했다. 하지만 그 이상의 운전조건에서는 생물반응조의 오염물질 제거율이 감소하였고 TMP가 급격히 증가하는 모습을 보였다.
        4,000원
        133.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 독특한 식감과 풍미로 인하여 가공성이 낮은 C. lanceolata의 응용성을 높이기 위해 발효차를 제조하고, 열처 리가 미치는 영향에 대하여 이화학 특성 및 항산화력 분석을 통하여 확인하였다. 열처리 온도 및 시간이 증가함에 따라 pH는 감소하는 경향을 보였으나, 갈색도, 탁도, 환원당, 총 폴 리페놀 및 총 플라보노이드 함량은 유의한 수준으로 증가하 는 경향을 보였다. 특히 200℃ 15분 열처리한 시료의 총 폴리페놀 함량은 713.71 ㎎/100 ㎖로 대조구에 비해 약 4.5배 증가 하였다. 항산화력 측정 결과, DPPH radical 소거능, FRAP 및 환원력에서 열처리 온도 및 시간이 증가함에 따라 항산화력 이 뚜렷하게 증가되는 경향을 나타냈다. DPPH radical 소거 능에서 200℃ 15분 열처리한 시료의 경우, 85.40%로 대조구 45.17%에 비해 약 2배 이상 증가되었으며, FRAP 및 환원력 또한 200℃ 15분 열처리한 경우, 대조구에 비해 약 2~3배 이 상 증가하였다. 열처리에 따른 관능검사 결과, 열처리 온도 및 시간이 증가함에 따라 선호도 역시 높게 나타났다.
        4,000원
        134.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 전선공장 에나멜와이어 코팅과정에서 발생하는 악취의 저감방안을 마련하고, 악취를 저감한 사례를 소개하는 목적으로 수행하였다. 조사방법은 악취 발생원과 오염물 질의 이동경로를 확인하고, 복합악취와 지정악취물질을 측정하였다. 또한, 악취저감시설 인 촉매산화장치의 효율에 관한 실험을 실시하고, 전선공장의 악취 문제점을 제시하였다. 조사 결과, 공정상에서 관리 부주의로 인하여 악취를 저감 시켜주는 촉매산화장치의 촉 매가 높은 온도에서 제 역할을 수행하지 못했고, 발생된 오염물질이 옥상의 Push-Pull 덕 트 및 다양한 이동경로를 통하여 외부로 악취가 확산되는 것으로 나타났다. 이와 같이 측정된 자료를 토대로 사업장 실정에 알맞은 개선안을 마련하였고, 실제로 사업장 관리 를 개선한 결과 악취가 50 % 정도 저감된 것을 확인 할 수 있었다.
        4,200원
        135.
        2013.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 건조 공정을 통하여 인삼의 생리 활성을 유지하기 위해 수행되었다. 인삼의 생리활성을 유지하면서 인삼을 건조하기 위해서 낮은 온도와 압력에서의 균형 잡힌 감압 건조 공정을 적용하였다. 감압 건조 공정은 일반적인 열풍 건조보다 긴 공정 시간이 걸리지만 훨씬 낮은 온도에서 건조를 진행할 수 있기 때문에 열에 불안정한 인삼의 다당류의 파괴를 막을 수 있으며, 동결건조 공정보다 낮은 에너지로도 비슷한 생리 활성을 유지할 수 있어 경제적으로도 이점이 있다. 이러한 결과는 열풍건조 공정의 단점인 높은 온도로 인한 페놀성 화합물과 같은 휘발성 생리 활성 성분들의 파괴를 줄여 높은 항산화 활성을 유지하였다. 더 나아가, 감압건조 공정을 통한 건조인삼의 열수 추출물은 열풍건조와 동결건조 공정을 통한 건조인삼 보다 면역 B세포와 T 세포의 생육도가 증진되었으며, IL-6와 TNF-α와 같은 cytokine의 분비량도 증가하였다. 이러한 결과는 낮은 온도와 압력의 감압 건조 공정을 인삼에 함유된 진세노사이드 외의 열에 약한 성분들의 파괴를 막아 생리활성의 저하를 줄일 수 있을 것으로 사료된다.
        4,000원
        137.
        2013.04 구독 인증기관 무료, 개인회원 유료
        제조공정에서 사용되어 지는 SPC(Statistical Process Control)관리 기법은 가피원인을 탐지하여 변동을 감소시키는 통계적 공정관리 시스템이다. SPC의 대표적인 관리 기법으로는 Shewhart관리도, Cusum관리도, EWMA관리도가 있으며 이러한 관리 기법들은 공정을 보다 안정적으로 관리 할 수 있도록 유지 및 예측하는데 사용 되어 진다. 하지만 제조 공정의 유형에 따라 샘플링 방법, 관리한계선 등을 다양하게 설정하여 보다 효율적인 관리를 모색하고 있다. 공정 형태에 따라 다양한 관리 방법과 분석 결과가 나타난다. 일반적으로 Xbar-R 관리도와 같은 Shewhart 관리도를 사용하지만 Batch 단위의 공정, 연속 공정의 라인에서 사용되기에는 부분적인 한계를 보이고 있다. 본 논문에서는 일반적인 관리도와 공정 변화에 민감하게 반응 할 수 있는 누적합 관리도와 지수가중치이동평균 관리도를 비교해 보고 작은 변동에 대한 탐지 능력이 우수한 지수가중치이동평균 관리도에 대한 연구동향과 사례를 분석하여 제조 공정에 적합한 관리 방법을 모색하고자 한다.
        4,200원
        138.
        2013.04 구독 인증기관·개인회원 무료
        The paper is devoted to the field work carried out by outstanding psychologist Alexander R. Luria and his team in isolated villages in Uzbekistan and mountain Kyrgyzstan (1931- 1932) and its place in cross-cultural studies. Many people of these places never went out of own villages. That time, in the Western social science racist theories that interpreted the differences in ways of thought in terms of biology were popular. These theories were based on application of "standard intellectual tests" to illiterate peoples in Asia, Africa and Latin America. A. Luria has criticized these "standard intellectual tests", and results of his survey gave strong proof of ties between level of social conditions and peculiarities of mental processes but not between race and mind. Long before the famous Western works on comparative psychology and cultural anthropology (J. S. Bruner, M. Cole, P.M. Greenfield, J. Gay, C. Levi-Strauss, etc.) published in 1950-1970-s, the A. Luria' research expedition has anticipated the main directions and results of future crosscultural studies.
        139.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to identify control points through microbiological hazard analysis in the manufacturing processes of starch noodles. Samples were collected from the ingredients, manufacturing processes, equipment and environment. Microbiological hazard assessments were performed using aerobic plate counts (APC), Enterobacteriaceae (EB), E. coli and five pathogens including B. cereus, E. coli O157:H7, L. monocytogenes, Salmonella spp., and S. aureus. The APC levels in raw materials were from 2.12 to 3.83 log CFU/g. The contamination levels after kneading were 4.31 log CFU/g for APCs and 2.88 log CFU/g for EB counts. APCs decreased to 1.63 log CFU/g and EB were not detected after gelatinization, but their levels slightly increased upon cooling, cutting, ripening, freezing, thawing, and separating. The reuse of cooling and coating water would be a critical source of microbial increase after cooling. After drying, APCs and EB counts decreased to 5.05 log CFU/g and 2.74 log CFU/ g, respectively, and the levels were maintained to final products. These results suggest that the cooling process is a critical control point for microbiological safety, and the cooling water should be treated and controlled to prevent cross contamination by pre-requisite program.
        4,000원
        140.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The issues raised so far in the development of safety-critical systems have centered on how effectively the safety requirements are met in systems design. The systems are becoming more complex due to the increasing demand on the functionality and performance. As such, the integration of both the systems design and systems safety processes becomes more important and at the same time quite difficult to carry out. In this paper, an approach to solving the problem is presented, which is based on an integrated data model. To do so, the data generated from the inputs and outputs of the systems design and systems safety processes are analyzed first. The results of analysis are used to extract common attributes among the data, thereby making it possible to define classes. The classes then become the cores of the interface data model through which the interaction between the two processes under study can be modeled and interpreted. The approach taken has also been applied in a design case to demonstrate its value. It is expected that the results of the study could play a role of the stepping stone in extending to the architecture development of the integrated process.
        4,000원