• 한국재료학회지
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• 제12권12호
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• pp.955-961
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• 2002

2.7vol%TiNi/6061 Al composites with TiNi shape memory alloy as reinforcement were fabricated by vacuum hot press. It was investigated by OM, SEM, EPMA and XRD analysis for the behavior of diffusion layer formation on various heat treatment condition. Thickness of diffusion layer was increased proportionally according to heat treatment time. The layer was formed by the mutual diffusion of TiNi and Al. The diffusion rate from TiNi fiber to Al matrix was faster than that of reverse diffusion path. The more diffused layer was formed in Al matrix. The diffusion at interface layer was consisted of $A1_3$Ti, $Al_3$Ni analyzed by EPMA, XRD results.

• 한국기계가공학회지
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• 제21권2호
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• pp.130-136
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• 2022

Reducing production costs through net-shaped cold forging is an important aspect in the automobile industry. In this study, we intend to produce a net-shaped electronic parking brake (EPB) serration gear for automobiles, using multi-stage cold forging. These serrations are then assembled to the reduction gear of an EPB actuator. The forging process of the serrations and the cold forging design were verified through finite element analysis (FEA) in order to evaluate metal flow. The forging machine was selected by checking the load using FEA. Based on the FEA results, molds were designed, and parts were made using multi-stage cold forging to produce a net-shaped serration gear.

• Educational Technology International
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• 제6권1호
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• pp.103-119
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• 2005

This study investigated to designand implement web-based collaborative learning system Co-Net and map out students' learning procedure using the system, based upon Student Team Achievement Division (STAD Slavin, 1990, 1996). There are technical process and instructional considerations to be made during the design process. The former are those that concern equipment requirements and specifications and include Ease of Use, Speed of Access, and Flexibility. On the other hand, instructional considerationsare concerned with the delivery and access of instructional materials and their outcomes on learners. They are cooperative interactions within groups and group heterogeneity, learner control, group incentives, individual accountability, equal opportunity for earning high scores and contributing to group effort, task specialization, and competition among groups. A web site for a virtual learning environment designed and built by the authors and known as Co-Net is then explained along with the whole process learners inside the environment. The main page of Co-Net consists of 15 menus to implement cooperative learning process. The cooperative learning activities using 15 menus are composed of six phases (1) preparation of the new knowledge (2) presentation of the new knowledge (3) knowledge assimilation and application (4) team and individual evaluation (5) team and individual recognition Throughout the five phases, the appropriate use of cooperative learning techniques has been shown to have both academic and social benefits to learners.

• 한국정밀공학회지
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• 제17권4호
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• pp.7-21
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• 2000

This paper describes an overview of the thixoforming and thixomolding processes. Semi-solid metalworking (SSM), which is called the thixoforming process of aluminium materials, incorporates the elements of both casting and for the manufacture of near net shape parts. The SSM has some advantages such as net shape or near net shape manufacturing, the ability to form thin walls, excellent surface finish, tight tolerance, and excellent dimensional precision. The thixomolding process of Mg alloy (AZ9l) is a combination of two technologies both conventional die casting and plastic injection molding. The feed material used is a machined chip with a geometry of approximately 1 mm square and a length of 2~3 mm. The semi-solid forming (SSF) of high quality aluminium and magnesium parts will be established in the automotive and electronic industry, in the future. The hybrid method of casting/forging has been caused attention. This process uses a preformed material made by casting instead of the wrought material and finishes it by a single forging process. This process is expected to lower costs without sacrificing the mechanical and finishes it by a single forging process. The process is expected to lower costs without sacrificing the mechanical properties. The authors, intending that the casting/forging process contributes to a reduction in production cost of aluminum automotive parts in Korea, describes the feature of the casting/forging process, aluminum alloys suitable for the cast preform, microstructure and mechanical properties of the cast preform, application examples of cast/forging, and further study.

• 한국약용작물학회지
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• 제19권3호
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• pp.198-204
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• 2011

This study was performed to enhance antifungal activity of anthracnose in chili pepper by nanopaticles of thiamine di-lauryl sulfate (TDS) through high pressure homogenization process. Yield of TDS was 79.14% by reaction of thiamine hydrochloride and sodium lauryl sulfate. TDS nanopaticle solution was manufactured through high pressure homogenization process. The turbidity of nanoparticles solution was increased with increasing the concentration of TDS, and nanoparticles solution of 100 ppm was showed the highest turbidity with absorbance of 3.212. The size of nanoparticles solution was measured as average 258.6 nm by DLS. Nanoparticles solution of 100 ppm showed growth inhibition activity with higher than about 80% compared to the control group against Colletotrichum gloeosporioides. Finally, nanoparticles solution was increased effectively the penetration of the TDS nanopaticles on attached cell membrane of hyphae and started to destruct the cells under microscope observation. Consequently, we suggested that the TDS nanoparticle solution by high pressure homogenization process might be suitable biochemical pesticides for improving the antifungal activities against anthracnose in pepper.

• 한국경영과학회지
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• 제6권2호
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• pp.51-55
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• 1981

In both continuous-review and periodic-review non-stationary inventory systems, the non-stationary Poisson demand process and the associated inventory position processes were proved being mutually independent of each other, which lead to the probability distribution of the corresponding net inventory position process in the form of a finite product sum of those two process distributions. It is also discussed how these results can correspond to analytical stochastic inventory cost function formulations in terms of the probability distributions of the processes.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.619-622
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• 1996

This paper presents the formal integration of process planning and shop floor control with Petri net formalism. Formal integration means that both planning and control problems can be modeled, interfaced, and transformed with the Petri net formalism. This integrated framework provides a systematic approach for rapidly developing a formal shop floor controller from process planning with respect to shop floor configuration.

• 벤처창업연구
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• 제16권2호
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• pp.95-108
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• 2021

기술혁신 활동은 기업이 기술경쟁력을 확보하고 지속적으로 성장하기 위해 매우 중요한 활동이다. 우리나라는 기업의 혁신활동을 촉진하기 위하여 국가차원에서 인증제도를 운영하며, 중소기업의 글로벌 기술경쟁력 제고를 위해 노력하고 있다. 이 가운데 기술혁신과 관련된 대표적인 제도가 신기술(NET) 인증이다. 신기술 인증제도는 엄격한 3단계 심사과정을 거쳐 인증하고 있으며, 기업의 신기술 상용화, 기술거래 및 초기시장 진출 촉진 등을 목적으로 운영되고 있다. 신기술 인증을 획득했다는 것은 해당 기업이 일정 수준 이상의 기술경쟁력을 확보하고 있다는 것을 의미한다. 이에 본 연구에서는 신기술 인증제도를 중심으로 기업의 어떠한 기술혁신활동이 R&D프로젝트 성공과 경영성과 제고에 영향을 미치는 지에 대한 실증분석을 수행하고자 하였다. 이를 검증하기 위해 주요변수로 기술전략, 기술기획, 체계화된 R&D프로세스, 내부협력, 외부협력 활동을 설정하였다. 실증분석 결과, 본 연구에서 설정한 변수 모두 개별적으로 R&D프로젝트 성공과 경영성과 제고에 기여함을 확인하였다. 다만, 모든 변수를 고려한 종합적인 차원에서 살펴보면, R&D프로젝트 성공을 위해서는 체계화된 R&D프로세스 관리와 외부기관과의 협력 활동이, 경영성과 제고를 위해서는 연구개발 초기 단계인 기술전략 수립과 기술기획 활동이 통계적으로 유의미한 영향을 미치는 것으로 분석되었다. 본 연구는 기업부설연구소를 설립·운영하고 있으며, 활발히 연구개발(R&D) 활동을 수행하고 있는 혁신지향적인 중소기업을 대상으로 하였으며, 분석방법으로는 다중회귀분석을 활용하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1376-1379
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• 2004

This study is designed integration and control system of GaAs bonding system consisted of multi-processing using DeviceNet and GEM-Protocol. Developing bonding system is composed of resin coating, pre-baking pre-aligner, bonding, material handler(flip robot), and wafer cassette, etc. This system has process-fluent of each a process and share information using GEM-protocol. This study devised virtual bonding simulator to control and to monitor bonding system efficiently. Also we can verify optimizing of system previously through a virtual bonding simulator.

• 산업공학
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• 제17권2호
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• pp.180-189
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• 2004

In this paper, we propose a reference model for logistics processes to improve the effect of RosettaNet standards application to domestic industry. First of all, implementation cases applied to logistics processes in the world are investigated. Second, logistics processes of domestic manufacturers are analyzed for the application of RosettaNet standards, and the processes are compared with PIP. Finally, a new logistics processes model and corresponding PIP documents which reflect domestic situations are proposed.