• 제목/요약/키워드: Widening process.

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Study on Design Education Plan Using Microcontroller Board Prototyping Tool

  • Nam, Wonsuk
    • International Journal of Contents
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    • 제14권3호
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    • pp.61-68
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    • 2018
  • Unlike in the past, where the expression of the form was given a priority, with the widening of the scopes of the designs, the proportion of design education institution curricula targeting user experience and the application of technology is continually and gradually increasing. Open source microcontroller boards such as Arduino have initiated attracting attention as a countermeasure against these changes. These prototyping tools have many advantages for the diversification of expression and design verification in the design field and therefore have a high likelihood of being introduced into many design education institutes; however, the tools act as high entry barriers for design students who lack engineering knowledge. Although various educational content and tools have been developed to address the issue of barrier, existing solutions remain insufficient as alternatives for the purpose of activation. In this study, we investigated the present state of related education content and conducted a pilot workshop using a prototype microcontroller board with simplified coding. We intend to use the results of this investigation to develop study material for design education. We started by conducting a survey regarding the pre-university education situation. It was observed that engineering education opportunities are insufficient and the problem of mutual application between educations due to course-based education was not realized. We also analyzed the characteristics of simplified training tools using the microcontroller to establish a direction for educational design and conducted a pilot workshop using the microcontroller toolkit with a simplified coding process based on this content. Students who lack a basic knowledge of engineering technology received instruction, and after completing minimum preliminary training, they proceeded to practical exercises that involved utilizing the toolkit. Through this process, we identified the need for a simple-type microcontroller board with low-complexity for use in educating students majoring in design. We also identified some obstacles that serve as barriers to entry of utilizing microcontroller board. Based on these results, we propose several functional requirements and teaching guidelines for prototyping toolkits for design education.

Fabrication of Photo Sensitive Graphene Transistor Using Quantum Dot Coated Nano-Porous Graphene

  • 장야무진;이재현;최순형;임세윤;이종운;배윤경;황종승;황성우;황동목
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.658-658
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    • 2013
  • Graphene is an attractive material for various device applications due to great electrical properties and chemical properties. However, lack of band gap is significant hurdle of graphene for future electrical device applications. In the past few years, several methods have been attempted to open and tune a band gap of graphene. For example, researchers try to fabricate graphene nanoribbon (GNR) using various templates or unzip the carbon nanotubes itself. However, these methods generate small driving currents or transconductances because of the large amount of scattering source at edge of GNRs. At 2009, Bai et al. introduced graphene nanomesh (GNM) structures which can open the band gap of large area graphene at room temperature with high current. However, this method is complex and only small area is possible. For practical applications, it needs more simple and large scale process. Herein, we introduce a photosensitive graphene device fabrication using CdSe QD coated nano-porous graphene (NPG). In our experiment, NPG was fabricated by thin film anodic aluminum oxide (AAO) film as an etching mask. First of all, we transfer the AAO on the graphene. And then, we etch the graphene using O2 reactive ion etching (RIE). Finally, we fabricate graphene device thorough photolithography process. We can control the length of NPG neckwidth from AAO pore widening time and RIE etching time. And we can increase size of NPG as large as 2 $cm^2$. Thin CdSe QD layer was deposited by spin coatingprocess. We carried out NPG structure by using field emission scanning electron microscopy (FE-SEM). And device measurements were done by Keithley 4200 SCS with 532 nm laser beam (5 mW) irradiation.

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폐고속국도의 생태복원 방안 -영동선 192.4K(인천) 지점을 중심으로- (A Study on the Method of Ecological Restoration at the Abandoned Expressways - Focusing on the 192.4k(Incheon) Young-Dong Expressway -)

  • 조동길;최재용;전용철
    • 한국환경복원기술학회지
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    • 제13권5호
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    • pp.38-50
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    • 2010
  • Expressways are often upgraded by widening the lanes and/or by reshaping the roads to be more linear for faster travel time. However, during the process of improving the route of the expressways, the areas where the old expressways used to be are often unused and abandoned. When these neglected sites are left alone, they often become dump sites causing pollution and impacting the surrounding environment. Therefore, it is important to restore the abandoned expressway sites to its full natural beauty. In this study, the abandoned expressway at the Soksa interchange in Pyungchang county, located in Kangwon province was studied for establishing the model of ecological restoration project. Considering the characteristics of the site, the target flora species was chosen to be Quercus species and the target fauna species as amphibians. After the target species were carefully chosen, each species' habitat requirements were studied in order to figure out the appropriate methods toward habitat restoration specifically for these species. In addition, to determine the most efficient method toward restoration of abandoned expressways, the study utilized the planting hole techniques, the crack techniques, and the colonization techniques. In terms of the spatial organization, public education program is incorporated at the main entrance area and the programs for experimenting, and developing vegetation and habitat restoration techniques are placed in the vicinity. In the master plan-to provide natural ecosystem at the site-ASCON (asphalt concrete) was removed first, then plans for restoration including species' habitat restoration were established. Furthermore, the project included plans for improving water quality polluted through non-point source considering the surrounding nearby road and farm lands. Finally, the study established a planning process that will experimentally apply to the abandoned expressway restoration method. In the future, there will be a continuous monitoring of the methods applied to verify if the restoration methods are effective. Also, new restoration techniques should be available according to a variety of abandoned expressways' characteristics.

에탄올 훈증처리한 3D 프린팅 PVB 출력물의 기계적 특성 (Mechanical Properties of PVB 3D Printed Output Fumigated with Ethanol)

  • 강은영;임지호;최승곤;문종욱;이유경;이선곤;정대용
    • 한국재료학회지
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    • 제30권7호
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    • pp.369-375
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    • 2020
  • FDM 3D printing structures have rough surfaces and require post-treatment to improve the properties. Fumigation is a representative technique for removing surface unevenness. Surface treatment by fumigation proceeds by dissolving the surface of the protruding structure using a vaporized solvent. In this study, 3D printed PVB outputs are surface-treated with ethyl-alcohol fumigation. As the fumigation time increases, the surface flattens as ethanol dissolves the mountains on the surface of PVB and the surface valleys are filled with dissolved PVB. Through the fumigation process, the mechanical strength tends to decrease, and deformation rate increases. Ethanol vapor permeates into PVB, widening the distance between chains and resulting in weak bonding strength between chains. In order to confirm the effect of fumigation only, an annealing process is performed at 80 ℃ for 1, 5, 10, 30, and 50 minutes and the results of the fumigation are compared.

Computational Analysis of the Effects of Spray Parameters and Piston Shape on Syngas-Diesel Dual-Fuel Engine Combustion Process

  • Ali, Abubaker Ahmed M.M.;Kabbir, Ali;Kim, Changup;Lee, Yonggyu;Oh, Seungmook;Kim, Ki-seong
    • 한국분무공학회지
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    • 제23권4호
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    • pp.192-204
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    • 2018
  • In this study, a 3D CFD analysis method for the combustion process was established for a low calorific value syngas-diesel dual-fuel engine operating under very lean fuel-air mixture condition. Also, the accuracy of computational analysis was evaluated by comparing the experimental results with the computed ones. To simulate the combustion for the dual-fuel engine, a new dual-fuel chemical kinetics set was used that was constituted by merging two verified chemical kinetic sets: n-heptane (173 species) for diesel and Gri-mech 3.0 (53 species) for syngas. For dual-fuel mode operations, the early stage of combustion was dominated by the fuel burning inside or near the spray plume. After which, the flame propagated into the syngas in the piston bowl and then proceeded toward the syngas in the squish zone. With the baseline injection system and piston shape, a significant amount of unburned syngas was discharged. To solve this problem, effects of the injection parameters and piston shape on combustion characteristics were analyzed by calculation. The change in injection variables toward increasing the spray plume volume or the penetration length were effective to cause fast burning in the vicinity of TDC by widening the spatial distribution of diesel acting as a seed of auto-ignition. As a result, the unburned syngas fraction was reduced. Changing the piston shape with the shallow depth of the piston bowl and 20% squish area ratio had a significant effect on the combustion pattern and lessened the unburned syngas fraction by half.

Faulkner's Narrative Strategies and the Nature of History in Absalom, Absalom!

  • Rhee, Beau La
    • 영어영문학
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    • 제56권6호
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    • pp.1091-1103
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    • 2010
  • Absalom, Absalom! is not only about family history but also about the nature of reconstructing history. Faulkner shows us what will happen if we give too much credit to the person having the authority; he first makes us listen to Rosa, so we just listen without doubt until we arrive at the question of the objectivity of her narration, when we get to know Sutpen's design. Meanings of "facts" change depending on who perceives the facts. The incremental repetition of the narrative in the novel resembles the process of our thinking mind and the process of history being constructed. Time is a significant element in determining the meaning of an event, not only because the event cannot be understood without its social, cultural context of the contemporary, but also because only the later events make it possible for the perceiver to categorize it in its proper place in history. Furthermore, through his narrative strategy, Faulkner suggests that imagination play a large part in recreating history. He blurs the distinction between facts and imagination, making us regard Shreve's and Quentin's conjectures as facts in several ways. The conversation between father and son, and the two brothers, which is an imagination constructed through the clues Mr Compson has offered, becomes a fact willingly accepted by the readers as well as Shreve and Quentin. The people in the past, present, and future may be very much unlikely to agree on the same event, because the gap in temporality will keep widening our perceptions. Faulkner demonstrates the nature of history in such a way that we can compare our understanding of the Sutpens' history in the earlier and later part of the novel through repetitions.

경량 모르터용 건식공정 바텀애시의 입형 개선 효과와 최적 입도 (Shape Improvement and Optimum Gradation of Dry Processed Bottom Ash for Lightweight Mortar)

  • 최홍범;김진만;선정수;한동엽
    • 한국건설순환자원학회논문집
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    • 제3권1호
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    • pp.7-14
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    • 2015
  • 본 연구의 목적은 건식공정을 통해 생산된 바텀애시를 이용하여 친환경적이고 저렴한 경량콘크리트의 잔골재로 활용하는 것이다. 기존의 습식공정과 비교하여 건식공정은 물에 닿지 않고, 염분이 없으며, 다소 느린 공정으로 완전연소를 통해 미연소탄소성분이 거의 없다. 이러한 건식공정 바텀애시를 경량 모르터용 잔골재로서 타당성을 평가하기 위해 골재의 입형 개선 효과와 최적 입도분포의 두가지 단계로 나누어 실험을 실시하였다. 첫 번째 실험에서 추가적인 마쇄과정을 통해 얻어진 양호한 입형의 바텀애시는 유동성과 강도 측면에서 양호한 결과를 나타내었으며 다소간의 단위용적질량 증가를 보였다. 두 번째 실험에서 다양한 입도를 구성하여 실험을 실시하였고, 그 결과 표준입도에 맞추어진 입도에서 굳지 않은 상태 및 경화상태에서 양호한 성능을 나타내었다. 본 연구의 결과를 통해 차후 건식 공정을 통한 바텀애시의 활용방법이 확대되고, 바텀애시를 경량 잔골재로 활용함으로서 부가가치 상승에 기여할 것으로 예상된다.

Comparison of Normalization Methods for Defining Copy Number Variation Using Whole-genome SNP Genotyping Data

  • Kim, Ji-Hong;Yim, Seon-Hee;Jeong, Yong-Bok;Jung, Seong-Hyun;Xu, Hai-Dong;Shin, Seung-Hun;Chung, Yeun-Jun
    • Genomics & Informatics
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    • 제6권4호
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    • pp.231-234
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    • 2008
  • Precise and reliable identification of CNV is still important to fully understand the effect of CNV on genetic diversity and background of complex diseases. SNP marker has been used frequently to detect CNVs, but the analysis of SNP chip data for identifying CNV has not been well established. We compared various normalization methods for CNV analysis and suggest optimal normalization procedure for reliable CNV call. Four normal Koreans and NA10851 HapMap male samples were genotyped using Affymetrix Genome-Wide Human SNP array 5.0. We evaluated the effect of median and quantile normalization to find the optimal normalization for CNV detection based on SNP array data. We also explored the effect of Robust Multichip Average (RMA) background correction for each normalization process. In total, the following 4 combinations of normalization were tried: 1) Median normalization without RMA background correction, 2) Quantile normalization without RMA background correction, 3) Median normalization with RMA background correction, and 4) Quantile normalization with RMA background correction. CNV was called using SW-ARRAY algorithm. We applied 4 different combinations of normalization and compared the effect using intensity ratio profile, box plot, and MA plot. When we applied median and quantile normalizations without RMA background correction, both methods showed similar normalization effect and the final CNV calls were also similar in terms of number and size. In both median and quantile normalizations, RMA backgroundcorrection resulted in widening the range of intensity ratio distribution, which may suggest that RMA background correction may help to detect more CNVs compared to no correction.

전해액 첨가제를 이용한 고전계 양극산화의 자기정렬에 관한 연구 (Extending the Self-ordering Regime of High-field Anodization by Using an Electrolyte Additive)

  • 김민우;박성수;심성주;강태호;신용봉;하윤철
    • 전기화학회지
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    • 제14권4호
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    • pp.219-224
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    • 2011
  • 옥살산 수용액에서의 전기화학적 양극산화에 의한 자기정렬된 알루미나 나노템플레이트의 제조에 있어서 전해액 첨가제를 이용하여 기존 양극산화 법으로는 보고된 바 없는 160~200 V 범위의 자기 정렬 구간을 관찰하였다. 고전계 양극산화와 펄스분리법 및 화학적 기공확장을 거쳐 생성된 자기 정렬구조를 FE-SEM 으로 관찰한 결과 이 전압구간에서의 기공간격과 전압과의 관계는 2.2 nm/V 으로 기존 고전계 양극산화의 결과와 유사하게 나타남을 알 수 있었다. 또한 양극산화막의 성장속도는 약 60 ${\mu}m$/hr로 유사한 기공구조를 얻을 수 있는 인산 수용액에서의 연질 양극산화에 비해 약 30배로 높은 것을 알 수 있었다. 이러한 고찰을 통하여 기공간격 300 nm 이상의 나노템플레이트를 고속으로 제조할 수 있는 조건을 확립하였다.

강원지역 e-비즈니스 현황과 발전과제 (A Field Study on the Present Situation, Tasks and Policies of E-business in Kangwon Province)

  • 민남식
    • 산학경영연구
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    • 제17권
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    • pp.185-214
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    • 2004
  • 본 논문은 강원도지역의 e-비즈니스 수준을 업종별, 매출액별, 종업원 인원별로 전국과 비교하여 평가하였고, 전국 조사의 연구 프레임웍에 따라서 e-비즈니스의 현황과 문제점을 e-비즈니스 환경, 인프라, 프로세스, 수행인력, 효과로 나누어서 분석하였다. 이를 바탕으로 강원도 지역의 열악한 기업의 수준을 재확인할 수 있었으며, 강원도 지역의 e-비즈니스를 활성화하기 위해서는 정부, 강원도, 대기업과 중소기업의 각 추진 주체들의 역할 분담과 협력이 중요하다. 강원도와 각 시군의 지자체는 지역기업의 구심점으로서의 역할을 담당하여, 중앙정부의 지원정책을 내실있게 시행하여야 하며, 각 지자체의 특성을 고려하여 특색있는 e-비즈니스의 환경 조성을 위해 정책지원과 산학협력을 유도하여야 한다. 보다 구체적으로는 강원도 지역기업의 e-비즈니스 추진 인프라를 확충하고 전자상거래 교육 및 홍보활동을 강화하여야 하며, 현재 지역별로 운영되고 있는 전자상거래 지원센터에 대한 지원과 활용도를 높여야 할 것이다. 또한 강원도의 열악한 입지 구조상 소규모의 소호창업 활동이 적극적으로 지원하는 것이 바람직하다. 그리고 지역기업의 자체 기술력 향상을 위해 강원도의 전자상거래 관련 기술에 대한 정책적 비중이 제고되어야 할 것이다.

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