• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1992년도 춘계학술대회 논문집 92
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• pp.59-70
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• 1992

Appropriate yield criteria are necessary to perform computer simulation for densification processes of powder compacts and sintered metals. Various yield functions have been reviewed and a new form for yield criterion has been advanced. The yield criterion satisfies experimental results from combined tension and torsion tests of sintered porous iron specimens.

• 청정기술
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• 제2권2호
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• pp.44-50
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• 1996

"Pollution prevention" is an important and appropriate part of efforts to minimize the environmental impacts of industrial processes, but it is only a part. Even more important is to assess the environmental characteristics of processes across all stages of their lives. This paper presents a formalism for evaluating the environmental implications of processes at each life stage(a procedure termed "life-cycle assessment").

• Korean Journal of Mathematics
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• 제27권3호
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• pp.819-830
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• 2019

This paper is mainly concerned with the existence and uniqueness of fixed points of $f:X^k{\rightarrow}X$, $k{\in}{\mathbb{N}}$, where X is a quasi-partial metric space and mapping f satisfies appropriate conditions. Results are also supported with relevant examples.

• 한국도로학회논문집
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• 제17권2호
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• pp.71-78
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• 2015

PURPOSES: This study set out to investigate the current state of microsurfacing in Texas and compared the results with the current state of the practice nationwide. METHODS: For this study, case studies were extracted from the existing literature and compared with the data obtained both from site visits by the research team and data obtained from a survey by Texas Department of Transportation (TxDOT) personnel. The successes and failures of microsurfacing are detailed and explanations of different issues are outlined. Forensic studies from Texas are included in the descriptions of those microsurfacings that failed when configured as part of the cape seals. RESULTS : Microsurfacing has been shown to be an effective pavement preservation technique when applied to an appropriate road, at an appropriate timing, and as a remedy for certain issues. The failures experienced in Texas can mostly be attributed to cape seals and an inability to recognize structurally faulty pavement. CONCLUSIONS : When applied to an appropriate road, at an appropriate timing, and as a remedy for certain issues, microsurfacing has been shown to perform well in numerous case studies. The majority of microsurfacing failures are the result of poor project selection, usually involving the treatment being applied to structurally unsound pavement.

• 수산경영론집
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• 제46권3호
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• pp.103-118
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• 2015

The purpose of this paper is to discuss possibilities of applying growth curve models, such as Logistic, Log-Logistic, Log-Normal, Gompertz and Weibull, to three specific technology areas of Fishery Science and Technology in the process of measuring their technology level between Korea and countries with the state-of-the art level. Technology areas of hazard control of organism, environment restoration, and fish cluster detect were selected for this study. Expert panel survey was conducted to construct relevant panel data for years of 2013, 2016, and a future time of approaching the theoretical maximum technology level. The size of data was 70, 70 and 40 respectively. First finding is that estimation of shape and location parameters of each model was statistically significant, and lack-of-fit test using estimated parameters was statistically rejected for each model, meaning all models were good enough to apply for measuring technology levels. Second, three models other than Pearl and Gompertz seemed very appropriate to apply despite the fact that previous case studies have used only Gompertz and Pearl. This study suggests that Weibull model would be a very valid candidate for the purpose. Third, fish cluster detect technology level is relatively higher for both Korea and a country with the state-of-the-art among three areas as of 2013. However, all three areas seem to be approaching their limits(highest technology level point) until 2020 for countries with the state-of-the-art. This implies that Korea might have to speed up her research activities in order to catch up them prior to 2020. Final suggestion is that future study may better apply various and more appropriate models respectively considering each technology characteristics and other factors.

• International Journal of Railway
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• 제5권3호
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• pp.114-116
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• 2012

The technology of high-temperature superconductive (HTSC) maglev trains has become mature and ready for a commercial use ten years after its first prototype was made by Jiasu Wang and Suyu Wang. However, an appropriate roadmap in applying it to the market is crucial for its success because superconductivity mystery remains veiled and public safety concern may prevent it from being used.

• 기술혁신연구
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• 제13권2호
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• pp.1-22
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• 2005

This paper adopts an embeddedness perspective and discusses rationales for government intervention in relation to economic development. Looking at East Asian experiences with industrial and technology policy the paper examines the general requirements, specific areas of focus and appropriate techniques for industrial and technology policy. Eight generic policy requirements are identified, viz. government capacity; monitoring and adjustment; policy sequencing; incremental upgrading; progressive market reliance; performance-orientation; selectivity; and flexibility.

• 적정기술학회지
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• 제6권1호
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• pp.56-64
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• 2020

최근 세계 주요 제조업체들은 스마트팩토리를 통한 글로벌 경쟁력 확보에 노력을 집중하고 있으나, 개발도상국들은 재정적, 기술적 여건으로 인하여 스마트팩토리를 도입하는데 많은 어려움이 있다. 본 연구는 개발도상국에 적용 가능한 ICT 기반의 전력 모니터링 시스템 개발에 대한 선행 연구로서, 개발도상국 중 하나인 인도네시아의 의류 생산 공장 근로자들이 인식하는 스마트팩토리에 대하여 설문을 통해 조사하고 분석하였다. 현지인 관리자와 근로자 126명을 대상으로 전력 모니터링 시스템 설치 전과 설치 후에 각각 설문을 실시하고, 통계기법을 이용하여 상관관계를 분석하였다. 분석 결과, 인도네시아와 같은 개발도상국 공장 근무자들도 스마트팩토리 기술 도입의 필요성에 대하여 긍정적으로 인식하고 있으며, 이러한 기술적 도입이 직무만족도와 공장 환경의 개선에 영향을 미칠 것이라고 응답하였다. 또한, 전력 모니터링 시스템 설치 후에 실시한 설문조사 결과는 설치 전과 비교하여 직무만족도 점수가 5.5% 상승하였으며, 전력 모니터링 시스템의 필요성에 대한 인식과 시스템의 적용이 공장 환경에 미치는 긍정적 영향에 대한 점수가 각각 13%, 5.9% 상승하였다. 부가하여, 근로자들 보다는 관리자들이, 남성 보다는 여성들이 스마트팩토리 기술의 도입에 우호적인 인식을 보이는 것으로 확인하였다. 본 연구 결과는 개발도상국에 적용 가능한 적정 스마트팩토리 기술 개발의 방향과 함께, 개발도상국에서 현지 공장을 운영하는 제조업체들이 스마트팩토리를 도입하는데 있어 중요한 참고사항이 될 것으로 판단된다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.294-297
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• 2007

Due to their low densities and high specific strength and stiffness, magnesium alloy sheets are very attractive lightweight materials for automotive and electrical products. However, the magnesium alloy sheets are usually formed at elevated temperature because of their poor formability at room temperature. To use of the magnesium alloy sheets for an industrial, their mechanical properties at elevated temperature and appropriate forming process conditions have to be developed. In this study, non-isothermal simulations of a square cup drawing from magnesium alloy sheets have been conducted to evaluate a proper forming process conditions such as the tool temperature, the tool shoulder radius, friction between the blank and the tools. According to this study, appropriate forming process conditions of square cup drawing at elevated temperature from magnesium alloy sheets are suggested.

• 한국컴퓨터정보학회논문지
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• 제21권5호
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• pp.91-98
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• 2016

We propose a method to train a model that can predict the probability of a crime being committed. CCTV data by matching criminal events are required to train the crime prediction model. However, collecting CCTV data appropriate for training is difficult. Thus, we collected actual criminal records and converted them to an appropriate format using variables by considering a crime prediction environment and the availability of real-time data collection from CCTV. In addition, we identified new specific crime types according to the characteristics of criminal events and trained and tested the prediction model by applying neural network partial least squares for each crime type. Results show a level of predictive accuracy sufficiently significant to demonstrate the applicability of CCTV to real-time crime prediction.