• Transactions of Materials Processing
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• v.32 no.1
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• pp.5-11
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• 2023

The aim of this study is to manufacture an aluminum pipe yoke of automotive steering system for lightweight. In a multistage cold forging process for aluminum pipe yoke, the surface defects frequently occur due to excessive deformation or friction during extrusion process for forming hollow pipe part. It is import to reduce the friction between the material and the forging die. This study investigated a multistage forging process with sliding die to reduce friction for aluminum pipe yoke. After evaluating by FE analysis, the forging experiment with the sliding die was carried out. As a result, it was possible to manufacture a sound aluminum pipe yoke.

• The Korean Journal of Air & Space Law and Policy
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• v.29 no.2
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• pp.55-86
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• 2014

The U.S. General Aviation Revitalization Act of 1994 (the "GARA") created a statute of repose that bars any claims arising from an aviation product or component more than 18 years after its date of delivery. The statute was enacted to protect general aviation aircraft manufacturers from the excessive product liability costs. The GARA included four exceptions: (a) medical emergency patients, (b) those not on the aircraft, (c) those based on written warranties, and (d) those causally related to a "knowing misrepresentation" made by the manufacturer to the FAA. The GARA also incorporates a provision for revised starting point of reckoning to which any repairs or replacements of an aviation product. This note aimed to discuss General Aviation and GARA in depth including the meaning of statue of repose, its exceptions. The various precedents about GARA were also reviewed in here as well. From the GARA, as a comparative legal issue in aviation product liability, there can be some suggestions for revision of Korean Products Liability Act. First, it seems to be reasonable to regulate the specific statute of repose provisions for various category of products. In GARA, the period of 18 years is reasonable concerning to the average aircraft life. Second, in order to avoid exhausting debate and for the judicial economy, it needs to clarify when the statute begins to run. GARA's 18 year limitation period begins to run on the different date whether it was delivered to its first purchaser or a person engaged in the business of selling the aircraft. Last but not least, proper exceptions should be added into the law for equity matter of the statute of repose does not apply. For example, a manufacturer is not protected by GARA if it knowingly misrepresents certain safety information to the FAA.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.649-656
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• 2011

In this study, we made Sulgidduk with commercialized dried nonglutinous rice flour and different levels of soybean curd. For physical properties of the bean curd-Sulgidduk, its water content was increased significantly with a growing addition of soybean curd. In chromaticity, its L value(brightness) and a value(redness) were decreased significantly with more bean curd while b value(yellowness) went up in Sulgidduk with a large amount of rice flour but went down significantly in the Sulgidduk with a small amount of it. Its hardness of texture was found to be the highest in the Sulgidduk with the most dried nonglutinous rice flour and it tended to be higher with more rice flour and less soybean curd. For cohesiveness, it was recorded to be the highest in the Sulgidduk without soybean curd and showed a tendency of decreasing by adding the bean curd but increased later significantly. In addition, its springiness and brittleness became larger with addition of more dried nonglutinous rice flour. From these results, the best ratio of the bean curd-Sulgidduk to increase nutrition and absorption and to satisfy physical and sensory properties, was 420 g to 500 g of soybean curd to dried nonglutinous rice flour. Moreover, it was considered to decline the calorie of Sulgidduk by adding soybean curd as a material and to contribute to its commercialization by extending storage and preservation time of soybean curd with a short expiration date.

• Journal of the Korean Ceramic Society
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• v.36 no.2
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• pp.203-209
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• 1999

LaAlO3d single phase used as the butter layer on Si wafer for YBa2Cu3O7-$\delta$ superconductor application were prepared by solid state reaction method and by self-sustaining combustion process. The microstructure and crystallity of synthesiszed LaAlO3 powder studied using scanning electron microscope (SEM) and X-ray diffractometer(XRD), specific surface area and sintering characteristics fo powder were investigated by Brunauer-Emmett-Teller (BET) method and dilatometer respectively. In solid state reaction method, it is difficult to obtain LaAlO3 single phase up to 150$0^{\circ}C$ period. However, in self-sustaining combustion process, it is to easy to do it only $650^{\circ}C$. Based on the results of analysis of dilatometer it is easier to obtain high sintering density (98.87%) in self-sustaining combustion process than in the solid state reaction method. This reason is that the average particle size prepared by self-sustaining combustion process is nano crystal size and has high specific surface are value(56.54 $m^2$/g) compared with that by solid state reaction method. Also, LaAlO3 layer on the Si wafer has been achieved by screen printing and sintering method. Even though the sintering temperature is 130$0^{\circ}C$, the phenomena of silicon out diffusion in LaAlO3/Si interphase are not observed.

• Smart Media Journal
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• v.9 no.3
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• pp.31-40
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• 2020

Currently, black-box-based machine learning algorithms are used to analyze big data in manufacturing. This algorithm has the advantage of having high analytical consistency, but has the disadvantage that it is difficult to interpret the analysis results. However, in the manufacturing industry, it is important to verify the basis of the results and the validity of deriving the analysis algorithms through analysis based on the manufacturing process principle. To overcome the limitation of explanatory power as a result of this machine learning algorithm, we propose a manufacturing big data analysis method using genetic programming. This algorithm is one of well-known evolutionary algorithms, which repeats evolutionary operators such as selection, crossover, mutation that mimic biological evolution to find the optimal solution. Then, the solution is expressed as a relationship between variables using mathematical symbols, and the solution with the highest explanatory power is finally selected. Through this, input and output variable relations are derived to formulate the results, so it is possible to interpret the intuitive manufacturing mechanism, and it is also possible to derive manufacturing principles that cannot be interpreted based on the relationship between variables represented by formulas. The proposed technique showed equal or superior performance as a result of comparing and analyzing performance with a typical machine learning algorithm. In the future, the possibility of using various manufacturing fields was verified through the technique.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.508-510
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• 2005

국내의 IT제조업체들은 자사제품 및 생산설비에 들어가는 소프트웨어 품질과 개발업무 능력에 대한 객관적인 검증 및 평가가 필요하다는 판단 하에 CMM및 SPICE의 등급인증 획득에 큰 관심을 기울이고 있으며, 특히 소프트웨어 프로젝트에 대한 정량적 평가방법을 통해 궁극적인 목표인 경영효과 창출로 이끌기 위한 노력을 경주하고 있다. 본 논문은 SPICE를 이미 꾸준히 적용하고 있는 국내 IT제조업체를 조사하여 소프트웨어 품질을 정량적으로 평가하기 위해 반드시 적용되야 하는 필수 메트릭스(Metrics)를 도출하고 이를 프로세스에 적용하는 방안을 제시하였다.

• 한국IT서비스학회:학술대회논문집
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• 2006.11a
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• pp.551-555
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• 2006

Ubiquitous technology(UT)의 발전과 더불어 특성 산업에 가시적인 적용 성과가 나타남으로써, 전통적인 제조업에서도 ubiquitous 환경 구현 및 제조기술(MT: Manufacturing Technology)과의 융합을 통한 제조혁신의 필요성이 대두되고 있다. 따라서, 본 연구에서는 ubiquitous factory 구현을 위한 체계적인 서비스 개발을 위해서, factory에 적용할 수 있는 특정 서비스 platform 개발을 목적으로 한다. 이를 위해, 서비스 개발 platform과 관련된 연구와 ubiquitous 서비스 개발 방법론 등을 분석하여 factory 현장에 바로 적용할 수 있는 platform을 개발하였다. 개발된 platform을 검증하기 위해 사례분석을 통해 연관분석을 실시함으로써 본 연구의 타당성을 검토하였다. 본 연구에서 개발된 platform은 ubiquitous factory를 구현하는데 활용될 예정이며, 향후 적용을 통한 개선사항을 도출하여 제조혁신을 위한 방법론으로 정립할 예정이다.

• Journal of the Korea Society of Computer and Information
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• v.25 no.11
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• pp.115-122
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• 2020

In this paper, we propose an MES system based on real-time process capability management and how to manage the manufacturing process using the system. The current MES system presents a KPI report that makes it easy to recognize the manufacturing site, but has not been able to derive an improvement method to improve the actual manufacturing site KPI. In other words, it is difficult to extract the cause of the increase in defective rate, decrease in yield, and increase in production lead-time, and to draw an improvement plan and apply it to the manufacturing site. The purpose of the MES system based on real-time process capability management proposed in this paper is to establish an manufacturing operation management system that overcomes the limitations of the existing MES by managing the distribution of major factors of the equipment that determines the process capability. In addition, by presenting a speed improvement method for real-time large-capacity data processing, it is intended to be applied so that the system can operate well.

• Journal of Sensor Science and Technology
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• v.10 no.2
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• pp.118-124
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• 2001

When particles are dissolved in solution, they have different zeta-potentials depending on pH. Zeta-potential has an influence on particle separation, which can control particle size. And the size of $WO_3$ particle affects the sensitivity of $WO_3$ sensor for detecting NO gas. Therefore we study influence of pH on NO-sensing $WO_3$ gas sensor fabricated by Sol-Coprecipitation method. As pH increases from 2 to 7, dynamic mobility of $WO_3$ precursor was increased. When pH was 7, it showed the largest distribution separation. It means when pH is 7, we can make $WO_3$ powder which has smaller particle size. And it is confirmed by particle size analysis of $WO_3$ powder, X-ray diffration result of $WO_3$ sensing layer and surface morphology. It also affect NO sensing characteristics of $WO_3$ gas sensor. The sensing film synthesized at pH 7 showed the largest sensitivity.

• Composites Research
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• v.34 no.4
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• pp.199-211
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• 2021

As an additive manufacturing achieves technological advances, it enables to manufacture complex structures with saving a cost and time. Therefore, metamaterials, which has geometric complexity, have gradually gathered attention due to the unprecedented properties: the unprecedented mechanical, thermal, electromagnetic, and optical properties. The metamaterials could exhibit a high potential in engineering applications, and thus it has been steadily investigated to design or/and develop novel metamaterials. Here, mechanical metamaterials, which had been reported, were reviewed to suggest the way to design and fabricate the metamaterials for industrial applications.