• Journal of Advanced Marine Engineering and Technology
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• 제32권6호
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• pp.847-853
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• 2008

Although combustion is essential in most energy generation processes, it is one of the major causes of air pollution. Circle fin exhaust pipes were designed to study the effect of cooling the recirculated exhaust gases (EGR) of Diesel engines on the chemical composition of the exhaust gases and the reduction in the percentages of pollutant emissions. The designs adopted in this study were exhaust pipes with solid and hollow fins around them direct surface force measurement in water using a nano size colloidal probe Technique The direct force measurement between colloidal surfaces has been an essential topic in both theories and applications of surface chemistry. As particle size is decreased from micron size down to true Carbon nano Colloid size (<10nm), surface forces are increasingly important. Nanoparticles at close proximity or high solids loading are expected to show a different behavior than what can be estimated from continuum and mean field theories. This paper use Water and CNC fluid at normal cooling system of EGR. Experimental result showed all good agreement at Re=$2.54{\times}10^{4}$.

• 대한기계학회논문집A
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• 제25권4호
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• pp.685-694
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• 2001

In this study, a transfemoral prosthesis system of which both stance phase and swing phase are controllable has been developed for the recovery of the biomechanical function of the amputated leg. It consists of a 5 bar link mechanism, a hydraulic-rubber knee damper for stance phase control and a pneumatic cylinder controlled via a microprocessor for stance phase control. The mechanical characteristics of the knee damper which absorbs the impact energy generated at the heel contact were investigated. The characteristics of the pneumatic cylinder essential for the speed adaptation of the prosthesis during swing phase were also studied for its mechanical characteristics. The prosthesis was subject to the clinical tests, and the gait characteristics obtained were very close to those of normal subjects. The stance and swing controlled prosthesis that were developed in this study showed good stability during the stance phase and showed good controllability during the swing phase.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.504-509
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• 2000

In this study, a transfemoral prosthesis system of which stance phase and swing phase are controlled during walking has been developed for the recovery of the biomechanical function of the amputated leg. It consists of a 5 bar link mechanism, a hydraulic-rubber knee damper for stance phase control and a pneumatic cylinder controlled via a microprocessor for stance phase control. The mechanical characteristics and behaviour of the knee damper which absorbs the impact energy generated at the heel contact was investigated. The characteristics of the pneumatic cylinder essential for the speed adaptation of the prosthesis during swing phase was also studied for its mechanical characteristics. The prosthesis was subject to the clinical test ant the gait characteristics obtained were very close to those of normal. The stance and swing controlled prosthesis that were developed in this study showed good stability during the stance phase and showed good controllability during the swing phase.

• Journal of Chest Surgery
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• 제16권3호
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• pp.362-367
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• 1983

Pulmonary arteriovenous fistula is a congenital malformation resulting from errant capillary development, with incomplete formation or disintegration of the vascular septa that normally divide the primitive connections between the venous and arterial plexuses. It generally occurs as part of the disorder known as hereditary hemorrhagic telangiectasia [Rendu-Osler-Weber disease]. The hereditary lesion is transmitted as a simple non-sex-linked dominant trait. It may be single or multiple, too small to see on plain chest films or large and easily recognized. One third of the lesions are multiple on plain chest film. The pathogenesis of its symptoms is that unoxygenated, desaturated arterial blood enters into the pulmonary venous system, directly. Recently we have experienced a case of the pulmonary arteriovenous fistula in 26 years old male soldier, which was confirmed by pulmonary angiography preoperatively. 2 thumb-tip sized, well circumscribed cystic masses filled with bright red colored blood were seen in subpleural and anterolateral portion of the right upper lobe. Right upper Iobectomy was performed due to close approximation of the fistula with pulmonary vein. Microscopically, it shows angiomatous dilatation of the abnormal vessels embedding in the parenchyma. Postoperative physiologic studies show nearly normal arterial oxygen saturation, hemoglobin and RBC count. There was good, uneventful postoperative course.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2018년도 학술발표회
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• pp.446-446
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• 2018

The urban rivers have unique hydraulic characteristics between natural rivers and artificial canals. These hydraulic characteristics determine the characteristics of urban rivers with small environmental capacity and fragile ecosystems. With the development and utilization of natural resources, the pollutants that have been produced enter the river through different channels, which seriously damages the urban river ecosystem. Therefore, how to restore contaminated water to a normal state and reproduce a natural, self-regulating ecosystem is one of the most concerned issues in recently. Eco-hydraulics is a cross-disciplinary subject of hydraulics biology and ecology. It is closely related to the protection of rivers, wetlands, and ecological self-repair. In this study, The basic principle of eco-hydraulics is concisely described and its approaches to protection and rehabilitation of river are introduced. The conception of establishing gardenesque eco-pond for urban use is suggested. The strategies including changing the hydrodynamic features of rivers, adjusting the breeds and species and constructing the gardenesque eco-pond for improving the exist ing urban rivers are proposed. It provides scientific information and guidance for the restoration of rivers and wetlands by studying the close relationship between river hydraulic characteristics, currents, and rivers and ecosystems.

• International journal of advanced smart convergence
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• 제8권1호
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• pp.141-146
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• 2019

These days, there are many applications using neural networks as parts of their system. On the other hand, adversarial examples have become an important issue concerining the security of neural networks. A classifier in neural networks can be fooled and make it miss-classified by adversarial examples. There are many research to encounter adversarial examples by using denoising methods. Some of them using GAN (Generative Adversarial Network) in order to remove adversarial noise from input images. By producing an image from generator network that is close enough to the original clean image, the adversarial examples effects can be reduced. However, there is a chance when adversarial noise can survive the approximation process because it is not like a normal noise. In this chance, we propose a research that utilizes high-level representation in the classifier by combining GAN network with a trained U-Net network. This approach focuses on minimizing the loss function on high representation terms, in order to minimize the difference between the high representation level of the clean data and the approximated output of the noisy data in the training dataset. Furthermore, the generated output is checked whether it shows minimum error compared to true label or not. U-Net network is trained with true label to make sure the generated output gives minimum error in the end. At last, the remaining adversarial noise that still exist after low-level approximation can be removed with the U-Net, because of the minimization on high representation terms.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2009년도 학술대회
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• pp.1172-1175
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• 2009

본 연구는 청각장애인들의 통신기기에 대한 요구를 발견하고 이를 제품 및 인터페이스 개발에 반영함으로써 청각장애인들의 의사소통에 대한 문제를 해결하고자 한 디자인 연구이다. 청각장애인들과 통역사들에 대한 3회의 FGI를 통하여 청각장애인들의 일상생활에서의 의사소통 방법, 의사소통을 위한 도구의 사용, 그리고 소통에 대한 요구 등을 이해하고, 이들의 효과적인 의사소통을 가능하게 하는 방법 및 체계를 제안하였다. 이를 바탕으로 의사소통 시스템을 제안하고, 원격 통역서비스 및 전화 중개통역 서비스를 포함한 청각장애인과 건청인간의 실시간 의사소통을 효과적으로 지원할 수 있는 의사소통 시스템의 기능적 측면, 수화영상통화와 디지털 필담 및 문자 메시지에서 청각장애인들의 의사소통의 특성을 반영하여 디자인된 인터페이스의 측면, 그리고 수화영상통화 및 청각장애인들의 일상생활에서 발생되는 문제점들을 해소하기 위한 도구의 하드웨어 디자인 측면에서 청각장애인들의 요구사항을 반영하기 위한 디자인 대안의 탐색이 이루어졌다. 제안된 디자인 안은 사용자 평가를 통하여 청각장애인들의 요구에 부합함을 검증하고 개발을 위한 디자인의 구체화 단계에 있다.

• 대한한방내과학회지
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• 제26권3호
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• pp.575-586
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• 2005

FC(free choresterol) plays an important role in normal and pathophysiological cells including that of messenger molecule or dilator of blood vessels in such illnesses as artheriosclerosis, hypertension and myocardial infarction. Smooth muscle and endothelial cell functions in the arteria wall are unified by complex intercellular signalling processes. In arteria comprised of one layer of smooth muscle cells surrounding the endothelium, the close apposition of the two cell types enables a signal derived from one cell to rapidly diffuse to neighboring cells. Experimentation was conducted to investigate the potential contribution of Sohaphyangwon(SHHW) on levels of FC generated by goaded microphages, and mechanisms of protection against ACAT inhibitor. It was found that J774 macrophages, which normally do not express FC were expressed by oxLDL and ACAT inhibitor. SHHW protected cells were found to be resistant to oxLDL and delayed death following the FC. Inhibition of FC formation abolished the protective effect against ACAT inhibitor exposure. Cadiovascular diseases include abnormalities of blood vessels dysfunction of the renin-angiotension system. What relation herbal medicine may have with vessel endothelium necrosis was here studied. In Oriental Medicine, SHHW water extract used for diseases in relation to cardiovascular systems. The resistence to cardiovascular disease of ACAT inhibitor induced J774 macrophage cells were studied through analysis of cell morphological patterns and immunochemistry of SHHW. The results of this study suggest that SHHW has protective effects on the cardiovascular system, and that it is effective in both prevention and treatment of diseases of the cardiovascular system, particularity against necrosis of blood.

• 감성과학
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• 제8권4호
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• pp.385-391
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• 2005

화장품을 바를 때 피부와 손가락 사이에서 일어나는 마찰계수는 화장품의 주관적 평가에 많은 영향을 주는 요소이다. in-vivo상태에서 피부와 접촉자 간의 마찰계수는 접촉자의 모양이나 거칠기의 정도 그리고 누르는 하중에 따라 변할 수 있다. 본 실험에서는 리니어 모터와 다축 로드셀을 이용하여 여러 가지 접촉자를 in-vivo상태에서 직접 피부에 접촉시키고 실시간으로 마찰계수를 측정할 수 있는 장치를 개발하였다. 이 장치를 이용하여 피부와 접촉자 간의 마찰계수를 측정하고 그 데이터를 화장품을 바를 때의 전후와 비교$\cdot$분석하였다. 또한 화장품을 바를 때 주관적인 평가에서 이용되는 형용사를 조사하며 마찰계수와의 그 상관관계를 분석하였다. 그 결과, 피부와 접촉자 간의 마찰계수는 화장품의 종류와 접촉자의 성질에 따라 0.17-1.2사이에서 나타나며, 주관적인 평가 또한 화장품을 바른 후 시간의 경과함에 따라 변하며, 그것은 마찰계수와 관련이 있음을 확인할 수 있었다.

• 천문학회보
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• 제46권2호
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• pp.50.3-51
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• 2021

The progenitor of Type Ia supernovae is largely expected as a close binary system of a carbon/oxygen white dwarf (WD) primary and its secondary non-degenerate (single degenerate; SD) or degenerate companion (double degenerate; DD). Here we present a high-cadence monitoring observation of SN 2021hpr in a spiral galaxy, NGC 3147. SN 2021hpr shows typical characteristics as a normal type Ia supernova from its photometric (Δm₁₅(B)=1.01±0.03, dust free M_B,max=-19.45±0.02) and spectroscopic data. To investigate its progenitor system, we fit the early part of BVRI-band light curve simultaneously with a combined version of ejecta-companion and simple power-law model. As a result, we found a significant feature of an early excess possibly from a 7.63±0.52R_⊙-sized companion at the optimal viewing angle while the fit is not successful at the common viewing angle. No possible red sources brighter than F555W=-7.01 AB mag is detected at the SN location in Hubble Space Telescope (HST) pre-explosion images, excluding massive stars with initial mass of >16M_⊙ as companions. We suggest the progenitor system of SN 2021hpr can be a fairly large companion such as a main sequence, a low mass subgiant, and a helium giant star. In addition, a possibility of the ejecta-Disk Originated Matter (DOM) interaction for the DD scenario considering linearly-rising early flux still remains.