• 한국의상디자인학회지
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• 제23권4호
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• pp.105-116
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• 2021

Pillows are tools that humans have used for a long time to sleep or lie down and rest. It is bedding, and the oldest literature dealing with it is Volume 29 of 'GoryeoDogyeong', which describes embroidered pillows. The oldest relic is the queen's pillow (National Treasure No. 164) excavated from the tomb of King Muryeong, and is in the Gongju National Museum. This study attempts to investigate and reproduce the materials used in traditional pillows Yukgol pillows and pine nut pillows designs are based on literature and artifacts from the Joseon period to modern times. Regarding the research method, after reviewing literature and the relics of traditional pillows, the process of reproducing the traditional Yukgol pillow and the pine nut pillow production method were explained step by step. This study found the plain attitudes in the lives of people who used materials that could be easily gained from their daily lives in rural communities oriented to rice farming never recklessly threw out any piece of cloth or cotton and use it for pillow stuffing or pillow ends. Also, the sophisticated sense of aesthetics that you can see from the pine nut pillows, whose ends were made of remnants from making clothing are exquisitely similar to what was shown in patchwork previously. The biggest meaning of restoring traditional pillows was looking into traditional culture, particularly the ordinary people's living culture. It was very difficult because the researcher had to find materials that were difficult to obtain in this age, the making process was complex, and it took much time; however, it is significant in that the restoration of traditional pillows allows for the succession of tradition.

• 한국산업융합학회 논문집
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• 제25권6_2호
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• pp.1103-1110
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• 2022

The old machine tools that have been used for a long time cause both increase in defective rate and decrease in productivity compared to new machines due to wear and failure of their components. In order to improve productivity and quality of machined components through remanufacturing, it is necessary to analyze the wear and failure of major components of old machine tools. In this study, the process for reverse engineering is designed for the remanufacture of planner millers, which belong to a very large machine tool. Also, the suitability of the designed process is verified through the analysis of the selected remanufactured components. In the first step of the process, some major components of the aging planner miller are scanned using a 3D laser scanner. In the next step, reverse engineering is performed using the data obtained through 3D scanning. Finally, wear and failure analysis is performed by comparing the reverse engineering data with the scan data. As a result, this reverse design and wear analysis can complement the insufficient design database and reduce costs in the maintenance of remanufactured products.

• ETRI Journal
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• 제45권1호
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• pp.171-179
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• 2023

We have developed an InAlAs/InGaAs metamorphic high electron mobility transistor device fabrication process where the gate length can be tuned within the range of 0.13㎛-0.16㎛ to suit the intended application. The core processes are a two-step electron-beam lithography process using a three-layer resist and gate recess etching process using citric acid. An electron-beam lithography process was developed to fabricate a T-shaped gate electrode with a fine gate foot and a relatively large gate head. This was realized through the use of three-layered resist and two-step electron beam exposure and development. Citric acid-based gate recess etching is a wet etching, so it is very important to secure etching uniformity and process reproducibility. The device layout was designed by considering the electrochemical reaction involved in recess etching, and a reproducible gate recess etching process was developed by finding optimized etching conditions. Using the developed gate electrode process technology, we were able to successfully manufacture various monolithic microwave integrated circuits, including low noise amplifiers that can be used in the 28 GHz to 94 GHz frequency range.

• 문화기술의 융합
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• 제9권6호
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• pp.935-940
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• 2023

인공지능과 빅데이터 분석을 위해 웹 스크래핑으로 수집된 대부분의 텍스트 데이터들은 일반적으로 대용량이고 비정형이기 때문에 빅데이터 분석을 위해서는 정제과정이 요구된다. 그 과정은 휴리스틱 전처리 정제단계와 후처리 머시인 정제단계를 통해서 분석이 가능한 정형 데이터가 된다. 따라서 본 연구에서는 후처리 머시인 정제과정에서 한국어 딕셔너리와 불용어 딕셔너리를 이용하여 워드크라우드 분석을 위한 빈도분석을 위해 어휘들을 추출하게 되는데 이 과정에서 제거되지 않은 불용어를 효율적으로 제거하기 위한 "사용자 정의 불용어 시소러스" 적용에 대한 방법론을 제안하고 R의 워드클라우드 기법으로 기존의 "불용어 딕셔너리" 방법의 문제점을 보완하기 위해 제안된 "사용자 정의 불용어 시소러스" 기법을 이용한 사례분석을 통해서 제안된 정제방법의 장단점을 비교 검증하여 제시하고 제안된 방법론의 실무적용에 대한 효용성을 제안한다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권3호
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• pp.319-325
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• 2017

Through silicon via (TSV) technology is extensively used in 3D IC integrations. The special structure of the TSV is realized by CMP (Chemically Mechanical Polishing) process with a high Cu removal rate and, low dishing, yielding fine topography without defects. In this study, we investigated the electrochemical behavior of copper slurries with various inhibitors in the Cu CMP process for advanced TSV applications. One of the slurries was carried out for the most promising process with a high removal rate (${\sim}18000{\AA}/Min$ @ 3 psi) and low dishing (${\sim}800{\AA}$), providing good microstructure. The effects of pH value and $H_2O_2$ concentration on the slurry corrosion potential and Cu static etching rate (SER) were also examined. The slurry formula with a pH of 6 and 2% $H_2O_2$, hadthe lowest SER (${\sim}75{\AA}/Min$) and was the best for TSV CMP. A novel Cu TSV CMP process was developed with two CMPs and an additional annealing step after some of the bulk Cu had been removed, effectively improving the condition of the TSV Cu surface and preventing the formation of crack defects by variations in wafer stress during TSV process integration.

• Composites Research
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• 제24권4호
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• pp.17-22
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• 2011

본 연구에서는, 복합재 샌드위치를 수중운동체용 구조물에 적용하기 위한 기초연구로서, 샌드위치 복합재 원통의 제작, 좌굴 해석 및 시험 방법, 중량저감 효과를 분석하였다. 우선 변재에 주름이 생기지 않도록 하는 2단계 샌드위치 제작 방법을 소개하고, 이를 사용하여 원통을 제작하여 수압시험을 수행하였다. 동시에 MSC Nastran의 셀요소와 고체요소를 사용한 유한 요소해석을 수행하여 시험결과와 비교하였다. 시험과 해석의 결과 비교로부터 선형 유한요소해석으로도 샌드위치 원통의 좌굴압력을 3% 내외의 오차로 정확히 예측할 수 있음을 확인하였다. 또한 필라멘트 와인딩 원통에 대한 인자연구를 통해 샌드위치를 사용할 경우 동일한 지지압력에서 필라멘트 와인딩 원통보다 최소 30% 이상 무게가 줄어드는 것을 확인하였다.

• 한국생산제조학회지
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• 제22권3호
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• pp.429-436
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• 2013

In this study, we researched a pendant-type aspherical optical system, which could be applied to street lighting and security lighting in Europe. The goal of this research was eco-friendly artificial lighting that could be used for the one-to-one replacement of ordinary lighting. LED lighting was miniaturized by using one COB LED Module and one aspherical optical system, which could control the luminosity of the LED. Through the aspherical optical system, the light distribution angle could be controlled in a range of $140^{\circ}$ for the X-axis and $40^{\circ}$ for the Y-axis. This means that this optical system is appropriate for catenary-type lighting, which is widely used in Europe on both narrow and broad roads. The performance was determined using a lighting simulation program. This lighting system simulation showed that road rates M4 and M5 could be satisfied, with the condition of a 13-m height and 50-m distance (U0 and TI). The simulation program estimated that light pollution, which disturbs sleep, could beeliminated in the European streetlight case. Determining methods for the light distribution control, performance, and optimal lighting setup conditions is very important to prevent light pollution. Moreover, the initial step of developing the lighting system design and post management will require an effort with much analysis.

• 한국산학기술학회논문지
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• 제20권11호
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• pp.217-223
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• 2019

복합 형상 부품 제작 및 제작 공정의 일체화 장점으로 3D 프린팅 기술의 적용 분야가 확대되고 있으며, 지속적인 연구 개발에 의해 다양한 기술방안들이 등장하고 있다. 대표적인 기술로는 파우더 형태의 소재 위에 레이저를 조사함으로써 원하는 영역을 소결 및 적층 제작하는 방식의 SLS 기술이 있으며, 고성능의 엔지니어링 플라스틱을 활용하여 실제 사용할 수 있는 부품을 제작하는 사례가 늘어나고 있다. 본 연구에서는 활용도가 높은 고분자 소재인 폴리아미드 12 소재 및 글라스 비드가 보강된 폴리아미드 12 소재를 대상으로 인장시편을 제작하여 시편 제작 방향 및 인장 시험 온도에 따른 특성 결과를 비교 분석하였다. 시편 제작방향은 작업 평면 기준으로 0°, 45°, 90° 로 구분하였으며, 인장시험온도는 -25℃, 25℃, 60℃로 조건을 구분하였다. 시험 결과로부터 제작 방향이 90°에 가까울수록 두 소재 모두 탄성률의 미세한 감소를 보였으며, 인장강도는 PA12보다 글라스 비드 보강 PA12가 제작방향에 대한 의존성을 명확하게 보였다. 또한 시험 온도 증가에 따라 탄성률 및 인장강도의 저하를 확인할 수 있었다.

• 대한조선학회논문집
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• 제41권6호
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• pp.126-133
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• 2004

As the automation of ship production system proliferates, it is unavoidable to move the real machinery, facility, application software, and virtual environment from the heterogeneous data environment to the integrated one. However, it is a prevailing situation that each component operates under the different environment, due to the inability of interchanging the data in a structured manner between the components. The issue is obstacles to improvement of the application system. To facilitate seamless exchange of data among the manufacturing systems, STEP, PDML, and XML has been tried by other studies. This study has investigated how XML data can be applied to exchange the data among the ship production system components. XML data is applied to the forming shop in shipyard to overcome the present difficulties on sharing and exchanging of the information. An example of forming information is represented by XML to demonstrate the feasibility of the proposed approach. In addition, an application of XML information applicable to virtual factory and electronic work order sheet is included.

• 보존과학연구
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• 통권21호
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• pp.177-206
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• 2000

In the study of iron artifacts, microstructure investigation is an indispensable step to find out the manufacturing method and skill. The iron weapons that we have excavated and investigated at the ruins of Gohyun Castle site, Hadong-gun, Kyungnam Province are traced to the era of Choson Dynasty. By sampling specimens of some artifacts, we have made microstructure investigation and component analysis of them. For microstructure investigation we used metallographic microscopes, and for component analysis we used the methods of C/S analysis and Inductively coupled plasma emission spectrometry (ICP) analysis which is designed to verify components and contenets of a very small amount elememt. Microstructure of the artifacts is mainly divided into three parts. Inner part is Widmanstatten, a typical overheated structure, upon which we can see another part with fine grains and with extremely small quantities of carbon. And on the surface, there is a carbonized part. When the shape is formed through forging process at a high temperature the carbon content of the surface is getting down and the grains come to be finer. Next, carbonizing process is to be done for hardening the surface, which is followed by cooling process. Cooling rates seem to be different from artifacts to artifacts. All artifacts have clearly distinguishable grain boundaries in their unique structure. Since this kind of structure is rarely found, it seems to offer a clue to find out the manufacturing method. The outcome of component analysis is almost the same with that of microstructure investigation. As is demonstrated by C/S analysis, carbon content is 0.39-1.24% and sulfur is contained 0.0005-0.010%.