• 한국주조공학회지
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• 제37권1호
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• pp.1-13
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• 2017

The purpose of this study is to increase the part recovery rate (to more than 70%) during the casting of a ductile cast iron turbo charger housing using a heater around the riser. Before creating a casting mold, various runner and riser systems were designed and analyzed with a casting simulation analysis tool. The design variables were the heater temperature, top insulation, riser location, riser diameter and the riser shape. During the feeding from the riser to the part, the reverse model was better than the forward model. When heating the riser (above $600^{\circ}C$), solidification of the riser was delayed and the feeding effect was suitable compared to that without heating. At a higher heating temperature, less solidification shrinkage and porosity were noted inside the part. On the basis of a casting simulation, eight molds were fabricated and casting experiments were conducted. According to the experimental conditions, external and internal defects were analyzed and mechanical properties were tested. The ultimate tensile strength and elongation outcome were correspondingly more than 540MPa and 5% after a heat treatment. In addition, a maximum part recovery rate of 86% was achieved in this study.

• 대한수의학회지
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• 제43권1호
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• pp.129-137
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• 2003

Porcine reproductive and respiratory syndrome (PRRS) is characterized by reproductive failures in sows and respiratory problems in piglets. The nucleocapsid(N) protein, encoded by the open reading frame 7 (ORF7) gene, is known to be the most abundant and antigenic protein in PRRS virus. Therefore, it was suggested that the N protein could be a suitable candidate for the detection of PRRS virus-specific antibodies and diagnosis of PRRS. In the present study, the ORF7 gene encoding the N protein was cloned and expressed as a fusion protein with the glutathione S-transferase (GST) in Escherichia coli. The resulting GST-N recombinant protein was used as an antigen for an indirect sandwich enzyme-linked immunosorbent assay (i-ELISA). Expressed GST-N recombinant protein was migrated at 41 kDa and reacted with ORF7-specific monoclonal antibody by Western blotting. In order to increase the specificity of the ELISA for the detection of PRRS virus-specific antibodes, an i-ELISA was developed using an anti-GST antibody as a capture antibody. The sensitivity and specificity of developed i-ELISA were 92% and 96%, respectively. Based on these results, it was suggested that the i-ELISA is a simple and rapid test for screening a large number of swine sera for the anti-PRRS virus antibodies.

• 정보교육학회논문지
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• 제21권5호
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• pp.497-507
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• 2017

그동안의 소프트웨어교육과 타 교과의 연계 융합에 대한 연구는 주로 수학과 과학교과에 편중되어왔다. 이는 학생의 교과에 대한 다양한 선호와 학습 성격 유형 등을 만족시키지 못하여 학습 격차를 유발할 수 있다. 뿐만 아니라, 컴퓨팅 사고를 적용할 수 있는 다양한 융 복합적 문제의 해결과정을 다루어야 함을 감안할 때 바람직하지 않다. 그리하여 기존의 수학과학적 접근에서 벗어난 언어적인 접근인 영어교과와의 연계를 통해 학생들의 다양한 성향과 선호를 포용하고, 영어교과와 소프트웨어교육의 새로운 언어를 배우는 과정과 방법상의 유사점을 접목시켜 교육 효과의 향상을 도모하고자 하였다. 이를 위하여 초등 영어교과와 소프트웨어교육의 교수학습모델 분석을 토대로 연계에 적합하도록 기존의 영어교과와 소프트웨어 교수학습모델을 변형하여 수업모형을 개발하였다. 이후 초등학교 영어교과내용 중 소프트웨어교육에 적용 가능한 학습 요소를 추출하여 개발된 수업모형에 적용한 프로그램을 설계하여 실제적인 학습 활용 방안을 모색하였다.

• 디지털융복합연구
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• 제15권6호
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• pp.155-164
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• 2017

본 연구는 페이스북과 인스타그램의 형태적 차이에 따른 이용동기 및 사용행태의 공통점과 차이점을 분석하는데 그 목적이 있다. 직관적 이미지, 제한된 네트워크 등 3세대 SNS의 형태적 차별화는 SNS 연구에 있어 개별 서비스 이용자를 동질적 집단이 아닌 차별적 집단으로 인식해야 할 필요성을 제기한다. 따라서, 본 연구는 SNS 주이용 집단인 대학생 255명을 대상으로, 페이스북과 인스타그램에 대한 이용동기 및 이용동기에 따른 사용행태의 차이를 요인분석과 회귀분석을 통해 분석하였다. 연구결과, SNS 이용동기로 총 7개 요인이 도출되었으며, 페이스북과 인스타그램의 이용동기 및 이용 동기에 따른 사용행태(피드백 측면, 만족도 측면)의 차이가 밝혀졌다. 본 연구를 통해 향후 SNS의 형태적 진화에 따른 이용자의 태도변화를 예측하는데 기여함과 동시에, 형태적 속성을 기반으로 한 GUI 설계, 기업홍보 마케팅 등 관련 융복합연구로의 확대 적용을 기대한다.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2303-2309
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• 2007

Expressed protein ligation (EPL) technique, joining recombinantly expressed proteins to polypeptides, has been widely adopted for addressing various biological questions and for drug discovery. However, joining two recombinant proteins together is sometimes difficult when proteins are expressed insoluble and unrefoldable, because ligation-active proteins via intein-fusion are obtainable when they are folded correctly. We overcame this limitation coexpressing target protein with additional methionine aminopeptidase (MAP) which enhances removal of the initiation methionine of recombinantly expressed protein. Our approach demonstrated that two domains of 46 kDa 5-Enolpyruvylshikimate-3-phosphate (EPSP) synthase, a target of herbicide glyphosate, were successfully joined by native chemical ligation, although its C-terminal domain was expressed as an inclusion body. The intein-fused N-terminal fragment of EPSP synthase (EPSPSN, residues 1-237) was expressed and the ligation-active thioester tagged N-terminal fragment (EPSPSN-thioester) was purified using a chitin affinity chromatography and mercapto-ethanesulphonate (MESNA) as intein thiolysis reagent. Its Cterminal fragment (EPSPSC, residues Met237-238CYS-427), expressed as an inclusion body, was prepared from an additional MAP-expressing strain. Protein ligation was initiated by mixing ~1 mM of EPSPSN-thioester with ~2 mM of EPSPSCCYS (residues 238CYS-427). Also we found that addition of 2% thiophenol increased the ligation efficiency via thiol exchange. The ligation efficiency was ~85%. The ligated full-length EPSP synthase was dissolved in 6 M GdHCl and refolded. Circular dichroism (CD) and enzyme activity assay of the purified protein showed that the ligated enzyme has distinct secondary structure and ~115% specific activity compared to those of wild-type EPSP synthase. This work demonstrates rare example of EPL between two recombinantly expressed proteins and also provides hands-on protein engineering protocol for large proteins.

• Journal of Radiation Protection and Research
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• 제44권4호
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• pp.149-155
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• 2019

Background: Magnetic resonance (MR) image guided radiation therapy system, enables real time MR guided radiotherapy (RT) without additional radiation exposure to patients during treatment. However, MR image lacks electron density information required for dose calculation. Image fusion algorithm with deformable registration between MR and computed tomography (CT) was developed to solve this issue. However, delivered dose may be different due to volumetric changes during image registration process. In this respect, synthetic CT generated from the MR image would provide more accurate information required for the real time RT. Materials and Methods: We analyzed 1,209 MR images from 16 patients who underwent MR guided RT. Structures were divided into five tissue types, air, lung, fat, soft tissue and bone, according to the Hounsfield unit of deformed CT. Using the deep learning model (U-NET model), synthetic CT images were generated from the MR images acquired during RT. This synthetic CT images were compared to deformed CT generated using the deformable registration. Pixel-to-pixel match was conducted to compare the synthetic and deformed CT images. Results and Discussion: In two test image sets, average pixel match rate per section was more than 70% (67.9 to 80.3% and 60.1 to 79%; synthetic CT pixel/deformed planning CT pixel) and the average pixel match rate in the entire patient image set was 69.8%. Conclusion: The synthetic CT generated from the MR images were comparable to deformed CT, suggesting possible use for real time RT. Deep learning model may further improve match rate of synthetic CT with larger MR imaging data.

• 한국인터넷방송통신학회논문지
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• 제17권4호
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• pp.107-114
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• 2017

일반적으로 신뢰성 분석결과는 모든 의사결정자에게 중요하다. 특히 제한된 무기체계로 최대효과를 만들어야 하는 군 지휘관의 경우에는 시뮬레이션 결과에 의해 방책을 결정해야 하기 때문에 더욱 중요하게 된다. 따라서 군사분야 연구에서 시뮬레이션 결과의 신뢰성 향상문제는 중요한 이슈가 되고 있다. 본 논문에서는 무기효과분석 결과의 신뢰성 향상을 위한 새로운 시뮬레이션 프레임웍을 제안하였다. 이를 위해 다중에이션트 시뮬레이션 기법을 적용하였고 이 결과를 기존의 절차에 의한 결과와 비교하였다. 결과비교를 위하여 지휘영역 확장을 위한 통신중계기 설치를 사례로 제시하였다. 본 사례분석을 통해 본 논문에서 제안된 다중에이전트 프레임웍을 적용했을 경우에 시뮬레이션 결과의 신뢰성이 향상되는 것을 보여주었다.

• 한국통신학회논문지
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• 제39B권12호
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• pp.842-855
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• 2014

스마트폰 시장이 성숙기에 들어서면서 새로운 성장동력으로 웨어러블 컴퓨터가 주목받고 있다. 웨어러블 컴퓨팅 시스템은 무선 네트워크 기술, 임베디드 기술, 센서 기술, 신소재 기술 등 다양한 기술의 복합적인 융합체이다. 이러한 특징들은 기존의 소프트웨어가 가지고 있는 품질특성 이외에 활용성, 이동성 등의 특성을 내포하고 있기 때문에 국제표준인 ISO/IEC 9126의 표준만으로 정확한 품질 평가를 하기에는 어려움이 따른다. 본 논문에서는 이러한 필요성에 따라 기존의 ISO/IEC 9126과 웨어러블 컴퓨팅의 특징에 의해 도출된 품질특성을 추가해 웨어러블 컴퓨터 품질평가모델을 제안하였다. 웨어러블 컴퓨터 품질평가모델의 개발을 위해 웨어러블 컴퓨터의 기능적 요구사항과 품질특성을 도출하여 메트릭과 품질 기준을 제안하였다. 본 연구에서는 시나리오에 제안된 모델을 적용하고 S사, L사, G사의 웨어러블 기기의 품질을 비교하여 품질평가모델의 실용성을 확인하였다. 본 연구에서 제안한 평가모델은 웨어러블 컴퓨터의 품질평가를 위한 가이드라인으로 활용할 수 있을 것으로 기대된다.

• 전자공학회논문지
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• 제53권12호
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• pp.57-63
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• 2016

본 논문은 $0.18{\mu}m$ 실리콘 CMOS 기술을 이용한 IEEE802.15.4g SUN 체계의 센서노드 무선통신부에 적용할 수 있는 RF 주파수 합성기의 구현에 대하여 기술하였다. 제안한 주파수 합성기는 고속 저잡음 특성을 얻기 위하여 VCO, 프리스케일러, 1/N 분주기, ${\Delta}-{\Sigma}$ 모듈레이터 그리고 PLL 공통 회로 등의 설계 최적화가 이루어졌으며, 특히 VCO는 NP 코어 구조와 13단 캡 뱅크를 각각 적용하여 고속, 저잡음 및 광대역 튜닝 범위를 확보하였다. 제안된 주파수 합성기를 칩으로 제작하여 측정한 결과 출력 주파수 범위는 1483MHz~2017MHz, 위상잡음은 100KHz 오프셋에서는 -98.63dBc/Hz, 1MHz 오프셋에서는 -122.05dBc/Hz로 양호한 특성을 얻을 수 있었다.

• 복식
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• 제53권5호
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• pp.65-77
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• 2003

Due to the rapid changes occurring in many aspects of contemporary society, the need for a means to actively combat widespread feelings of emptiness and alienation among the public, while satisfying its visual pleasure, is increasing. Thus the need for humorous elements which bring freedom to the human psyche is urgently requested. Of course, the field of fashion cannot be left out in this trend, and humor image design is a good example of this. Humor image in fashion endeavors to release the tension accumulated in the modern world, while trying to find a way to recover the original pureness of mankind. Another aspect currently important is computers. The creation of images in modern visual art relies a lot upon computers. Traditional visual processes such as painting, photography and video are now merged within digital technology. and are now quite symbiotic to each other. With the development of computers came computer art. which uses all applicable functions of a computer to create art. Any artistic action which uses a computer in any stage of its creation can be called computer art. The common factor in humor and computer art in modern fashion can be classified as follows : repetition, deformation and distortion. exaggeration and abridgement. juxtaposition. and Tromp l'oeil. This study has placed its objective on the fusion of humor image fashion and computer art, by manufacturing a work with humor and computers, two important aspects of modern culture. Expanding the field of fashion design while promoting creativity In fashion by finding a verging point between art and science is also necessary. I have designed and made five costumes using the above cited techniques in computer humor images, on a theoretical basis.