• Journal of Chest Surgery
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• 제27권6호
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• pp.502-505
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• 1994

Neurogenic tumors of the mediastinum may have an intraspinal component connected by a narrowed segment of tumor in the intervertebral foramen,hence the descriptive term dumbbell.Recently we had an occasion to remove a dumbbell neurilemmoma in a 62 years old woman using an approach designed to allow wide posterolateral thoracotomy and concomitant laminectomy for a single stage removal of the entire tumor. The mass in the posterior mediastinum was discovered on routine chest roentgenography. CT scan demonstrated a dumbbell shaped soft tissue mass density compressing spinal canal but preserving spinal cord. There were no neurologic signs. A standard posterolateral thoracotomy incision was made to remove tumor mass and then T5 unilateral laminectomy has done by Neurosurgeon. 7 x 7 cm sized extrapleural neurilemmoma was round, cystic, soft mass which covered parietal pleural with invaded regional vertebrae. There was no postoperative neurological complication.

• 한국산학기술학회논문지
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• 제20권4호
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• pp.76-85
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• 2019

Vegetable oil은 자연 유래 물질로 낮은 가격 및 친환경적이라는 장점으로 최근 다양한 연구가 진행되고 있다. 하지만 vegetable oil 내의 이중결합의 낮은 반응성으로 인해 고분자 합성의 기반 물질로 사용하기 위해서는 반응성이 높은 관능기로 치환하여 사용하는 경우가 많다. Tung oil은 ${\alpha}$-eleostearic acid를 주성분으로 하는데, 이 구조는 3개의 이중결합이 공명구조 형태로 되어있기 때문에 다른 vegetable oil과는 달리 높은 반응성을 보인다. 본 연구에서는 이러한 tung oil을 styrene 및 divinylbenzene 등의 monomer와 양이온 중합을 통해 tung oil의 관능기 치환 과정이 없는 열경화성 수지를 합성하였으며, 각 monomer의 조성이 합성된 열경화성 수지에 미치는 영향을 확인하기 위해 열적 기계적 물성을 측정하였다. 그 결과, tung oil-styrene-divinybenzene copolymer는 단일 Tg를 갖는 homogeneous한 열경화성 고분자를 형성하는 것을 확인하였으며, 기계적 물성의 변화를 통해 tung oil 및 styrene은 soft segment로써 합성된 copolymer에 elastic한 성질을 부여하고, divinylbenzene은 hard segment로 작용하여 합성된 copolymer에 brittle한 성질을 부여하는 것을 확인하였다.

• 한국산학기술학회논문지
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• 제19권11호
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• pp.24-30
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• 2018

식물유는 자연 유래 물질로 낮은 가격 및 친환경적이라는 장점으로 최근 다양한 연구가 진행되고 있다. 하지만 식물유 내의 이중결합의 낮은 반응성으로 인해 고분자 합성의 기반 물질로 사용하기 위해서는 반응성이 높은 관능기로 치환하여 사용하는 경우가 많다. Tung oil은 ${\alpha}$-eleostearic acid를 주성분으로 하는데, 이 구조는 3개의 이중결합이 공명구조로 되어있기 때문에 다른 식물유와는 달리 높은 반응성을 보인다. 본 연구에서는 이러한 tung oil을 styrene 및 divinylbenzene 등의 단량체와 양이온 중합을 통해 tung oil의 관능기 치환 과정이 없는 열경화성 수지를 합성하였으며, 각 단량체의 조성이 합성된 열경화성 수지에 미치는 영향을 확인하기 위해 열적 기계적 물성을 측정하였다. 그 결과, tung oil-styrene-divinylbenzene 공중합체는 단일 Tg를 갖는 균일(homogeneous)한 열경화성 고분자를 형성하는 것을 확인하였으며, 기계적 물성의 변화를 통해 tung oil 및 styrene은 soft segment로써 합성된 공중합체에 탄성(elasticity)을 부여하고, divinylbenzene은 hard segment로 작용하여 합성된 공중합체에 취성(brittleness)을 부여하는 것을 확인하였다.

• 한국염색가공학회지
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• 제5권3호
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• pp.188-193
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• 1993

Aqueous polyurethanes(APU) were prepared from polypropylene glycol(PPG), dimethylol propionic acid(DMPA), and isophoron diisocyanate(IPDI) following a prepolymer mixing process. APUs were applied as binder for nonwoven fabrics processing. APU treated nonwoven fabrics generally showed better tear and tensile strength as compared with the untreated ones. In addition, depending on the soft segment length and crosslinking density of the PU, tear strength of APU treated fabrics was favorably compared with solvent type treated one. Similar results were obtained with microfiber nonwoven fabrics, however, the effect was less significant.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1998년도 가을 학술발표회논문집
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• pp.29-32
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• 1998

Segmented block copolyetheresters defined as copolymers having sequences of alternating polyester hard blocks and polyether soft blocks create labile physical cross-links upon crystallization of hard polyester blocks Since the nature of the physical interlocking is a crystallite formed exclusively from the crystallizable hard segment, the basic understanding of interrelationship between crystallization condition and phase morphology is very important for the property control of the segmented block copolyetheresters. (omitted)

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1995년도 춘계학술발표회 프로그램 및 초록
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• pp.15-15
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• 1995

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2001년도 학술발표회 논문집(Proceedings of the Korean Textile Conference)
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• pp.363-366
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• 2001

• 센서학회지
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• 제29권4호
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• pp.237-242
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• 2020

This paper deals with relative position estimation using a Kalman filter (KF) based on inertial sensors that have been widely used in various biomechanics-related outdoor applications. In previous studies, the relative position is determined using relative orientation and predetermined segment-to-joint (S2J) vectors, which are assumed to be constant. However, because body segments are influenced by soft tissue artifacts (STAs), including the deformation and sliding of the skin over the underlying bone structures, they are not constant, resulting in significant errors during relative position estimation. In this study, relative position estimation was performed using a KF, where the S2J vectors were adopted as time-varying states. The joint constraint and the variations of the S2J vectors were used to develop a measurement model of the proposed KF. Accordingly, the covariance matrix corresponding to the variations of the S2J vectors continuously changed within the ranges of the STA-causing flexion angles. The experimental results of the knee flexion tests showed that the proposed KF decreased the estimation errors in the longitudinal and lateral directions by 8.86 and 17.89 mm, respectively, compared with a conventional approach based on the application of constant S2J vectors.

• International Journal of Computer Science & Network Security
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• 제24권2호
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• pp.158-168
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• 2024

There is hardly any person in modern times who has not taken soft drinks instead of drinking water. The rate of people taking soft drinks being surprisingly high, researchers around the world have cautioned from time to time that these drinks lead to weight gain, raise the risk of non-communicable diseases and so on. Therefore, in this work an image-based tool is developed to monitor the nutritional information of soft drinks by using deep convolutional neural network with transfer learning. At first, visual saliency, mean shift segmentation, thresholding and noise reduction technique, collectively known as 'pre-processing' are adopted to extract the location of drinks region. After removing backgrounds and segment out only the desired area from image, we impose Discrete Wavelength Transform (DWT) based resolution enhancement technique is applied to improve the quality of image. After that, transfer learning model is employed for the classification of drinks. Finally, nutrition value of each drink is estimated using Bag-of-Feature (BoF) based classification and Euclidean distance-based ratio calculation technique. To achieve this, a dataset is built with ten most consumed soft drinks in Bangladesh. These images were collected from imageNet dataset as well as internet and proposed method confirms that it has the ability to detect and recognize different types of drinks with an accuracy of 98.51%.

• 멤브레인
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• 제15권1호
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• pp.44-51
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• 2005

유기증기에 대한 PDMS의 단점을 보완하기 위해 4,4'-diphenylmethane diisocyanate (MDI)와 1,4-butanediol(BD)를 이용하여 poly(dimethylsiloxane)를 기초로 한 polyurethane-polysiloxanes (PU/PDMS)를 합성하였다. 그리고 poly(tetrafluoroethylene) (PTFE)를 다공성 지지체로 이용하여 복합막을 제조하여 SEM 분석으로 코팅층의 존재와 두께를 확인하였다. 증기투과실험에서 투과온도와 feed의 농도가 증가할수록 flux는 점차 증가하였고, separation factor는 이와 반대로 점차 감소하는 'trade-off'현상을 보였다. 본 연구에서의 PU/PDMS는 soft segment의 함량보다는 비교적 hard segment의 함량이 높기 때문에 투과온도의 증가에 따른 영향이 크지 않았던 것으로 사료된다. PU/PDMS막은 VOCs와 상대적으로 높은 친화도를 가지고 있기 때문에 PU/PDMS 균질막과 비교하여 복합막의 형태에서도 향상된 flux와 높은 separation factor를 나타내었다.