• 재활복지공학회논문지
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• 제8권4호
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• pp.305-312
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• 2014

본 연구에서는 재활정도를 정량적으로 표현하기 위하여 정상 보행과 모의 비정상 보행 시 보행주기에 따른 근전도 패턴에 고차 곡선 맞춤을 적용하여 분석하였다. 보행 근전도 패턴에 적합한 다항식을 생성하였으며, 그 변수를 군집분석 하여 5개의 그룹으로 분류하였다. 정상패턴을 포함한 그룹을 기준으로 거리가 가까운 그룹을 나열하여 각 변수의 분포를 확인하였다. 진폭감소 패턴, 불규칙 패턴, 역상 패턴 순으로 정상 패턴에 유사하였으며, 분류된 그룹의 분포는 중첩되는 범위가 작아 변수 값을 이용한 그룹 분류가 가능하였다. 분류된 재활정도를 정량적으로 나타내기 위하여 각 계수항의 표준편차를 패턴별로 비교하였고, 정상에 가까울수록 큰 값을 가지는 것을 확인하였다. 역상 패턴의 경우는 편차 값은 크지만 부호가 음의 값을 가지므로 가장 작았다. 본 연구의 결과인 정량적인 재활정도의 표현은 보다 효율적인 재활방법 연구에 기여할 것으로 예상된다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권11호
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• pp.1096-1100
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• 2010

본 논문에서는 MR 영상에서 중간형상정보를 이용한 활성형상모델 기반의 반월상 연골 자동 분할 기법을 제안한다. 첫째, 훈련집합 내의 형상 변형을 반영하기 위해 반월상 연골 통계형상모델을 생성한다. 둘째, 큰 변형을 갖는 반월상 연골의 견고한 분할을 위해 유사도에 따른 가중치 기법을 이용하여 중간형상정보 생성 기법을 제안한다. 마지막으로 활성형상모탤 적합을 통해 반월상 연골 자동 분할을 수행한다. 제안 방법의 평가를 위하여 육안평가와 정확성 평가 그리고 수행시간을 측정하였다. 정확성 평가는 자동 분할과 반자동 분할 결과간의 평균거리차이를 측정하였고 이를 컬러맵으로 표현하였다. 실험 결과 평균거리차이는 내측 반월상 연골은 $0.54{\pm}0.16mm$, 외측 반월상 연골은 $0.73{\pm}0.39mm$으로 측정되었고, 수행시간은 평균 4.87초로 측정되었다.

• 한국의류학회지
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• 제8권1호
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• pp.57-67
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• 1984

The purpose of this study is to develop a devided skist Pattern drafting method for Korean Women between the ages of 18$\~$24 on the basis of their physical characteristics which differs from those of other races in its size and figure. The study procednras are as follows : 1, A new devided skirt pattern drafting method is developed based on the results of draping to find the essential measuring items for devided skirt construction, 27 items of KAIST measurement data analysis to establish representative and independent items and fitting tests. 2. To establish fittness and comfort in the new pattern comparing it with in a conventional one, asensory evaluation is applied. According to the statistical analysis of the results of the sensory evaluation, the findings are as followings ; 1. Composite reliability coefficient is 0.68. 2. Qut of 30 items, 25 items for fittness show significant differences (pp$\leqq$0.05, p$\leqq$0.01, P$\leqq$0.001) between the two, with the new pattern better fitted, presenting a pleasing appearance in hormony with the figure and contributing to the wearer's sense of wellbeing. 3. Hip crotch and hem dimensions for comfort show significant differences (p$\leqq$0.05) between the two, with the new pattern more comfortable, but no significant difference is showed between the two in activity variable. 4. The new pattern drafting method is shown in figuke 4.

• 한국의류학회지
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• 제29권8호
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• pp.1092-1101
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• 2005

The purpose of this study is to analyze the size of ready-made clothing for elderly women and to evaluate their fit according to body type. Subjects were 33 women aged 60 and older, and they were classified by stature and drop index. The size of clothing which manufactured by four apparel brands were measured and compared with body size, and the size designation of four brands was compared. The questionnaire was carried out to subjects, and the size recognition and dissatisfaction with ready-made clothing were analyzed. The fitting test were carried out, and the subjects evaluated the fit of jackets and slacks of four brands. In the result of questionnaire, we found that subjects had little recognition about their clothing size. Subjects responded that they often felt dissatisfaction in their jacket length, sleeve length, shoulder width, bust girth, slacks, and waist girth. We found that each apparel brands had different sizing system and that even if the size designation of label was same, the clothing size was quite different. So the elderly women who didn't have so much knowledge about their own clothing size had a tendency to confuse with choosing proper clothing for themselves. In the wearer's evaluation, the significant difference in the degree of unsatisfaction were certified in several body parts according to wearer's body type. Especially, the degree of unsatisfaction in the case of subjects of having very small stature or very small hip was higher than other body types. From the result, we certified that it was necessary to consider the characteristics of each body type to increase the satisfaction of elderly women with clothing.

• 대한임상검사과학회지
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• 제36권1호
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• pp.43-48
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• 2004

Cerebral vasoreactivity is an index of autoregulation of cerebral perfusion, and can be measured using functional images such as Xe CT, SPECT and PET in reponse to hypercapneic stimulus. In order to measure cerebral $CO_2$ vasoreactivity in routine TCD study conveniently and reliably, we devised a method of rebreathing into closed volume of reservoir bag as a hypercapneic stimulus, and applied it to 44 healthy volunteers. As a hypercapneic stimulus, we applied fitting mask connected with closed reservoir bag for about 90 seconds, and mean blood flow velocity(MBFV) and pulsatility index(PI) were evaluated at proximal middle cerebral arteries(MCA) of 50-55 mm depth, before and after the hypercapneic stimulus. Age affected the MFV and PI value showed significant and the MFV was 56.45(SD=9.75)cm/sec, while PI was 0.406(SD=0.089). As age increases the flow velocity decreased significantly whereas PI value increased(P<0.05). The vasoreactvity significantly decreased with age(P<0.05). The decrease of cerebral blood flow quantity and cerebral blood flow velocity is not only because of increase of diameter of cerebrovascular resulting from aging, but the resistance increase of small blood vessel resulting from the increase of PI & RI value is regarded. We suppose that the rebreathing method is a reliable and convenient technique as a hypercapneic stimulus in determining cerebral $CO_2$ vasoreactivity. The rebreathing method could be non-invasive and useful methods in estimation of the cerebrovascular reactivity and could be applied to the basal and follow-up evaluation of the cerebrovascular reserve of the ischemic stroke patients.

• 한국자동차공학회논문집
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• 제24권2호
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• pp.242-254
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• 2016

This paper is the forth investigation on the evaluation methods of flow characteristics in a steady flow bench. In the previous works, it was concluded that the assumption of the solid rotation might cause serious problems and both of the eccentricity and the velocity profile distort the flow characteristics when using the ISM at 1.75B plane. Also particle image velocimetry (PIV) measurement at this position showed that the real velocity profile was far from the assumption of ISM evaluation. In this paper, the planar velocity profiles were measure from 1.75B to 6.00B position by PIV and the characteristics were examined according to the valve angles and lifts for further investigations about the effect of the position on the velocity profile. The results show that $26^{\circ}$ valve angle is always an unique exceptional case in all aspects. If the valve angle is $21^{\circ}$ and below, the planar velocity profiles according to the lift and the position are similar to each other, however, the tangential velocity curves along with the radial direction have common tendencies up to $16^{\circ}$ angle. Also the well arranged swirl behaviors are generally observed at the position above 3.00B and the velocity contour lines come closer to the concentric circle as the valve lift increases. In addition, the gradient of tangential velocity along with the radial direction from the swirl center becomes stable and constant as the position goes downstream. Concurrently the velocity gradient is larger to the eccentric direction of the center. In the meantime the tangential velocity curves along with the radial direction are irregular and various at 1.75B, however, they become regular and reach higher level as the evaluation position goes downstream. At this time the curves of 4.50B are the best fitted to the ideal one. On the other hand in an exceptional case, $26^{\circ}$, the velocity contours are very complicated over 6mm valve lift regardless the position and the gradient increases to the opposite direction of the eccentric center. Also, 6.00B is a best fitting position in the geometrical cylinder center base. With respect to the swirl center, the distribution range of centers for 1.75B is different to that for the other positions and the eccentricities of this plane are larger regardless the valve angle. After 1.75B, there is no certain tendency in the center position change according to the valve angle and lift. Additionally, the eccentricities are not sufficiently small to neglecting the effect on ISM measurement.

• 분석과학
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• 제24권6호
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• pp.503-509
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• 2011

비표면적은 기능성 나노소재의 특성평가에 있어 매우 중요한 지표가 되고 있다. 하지만 비표면적 측정은 측정방법 및 해석 방법에 따라 결과에 많은 차이가 있어왔다. 국내에 보급된 비표면적 측정장치의 신뢰성 검증을 위하여, 21개 산학연 기관을 대상으로 순회평가(RRT)를 수행하였다. 순회평가 분석 결과 많은 기관에서는 비표면적 측정장비의 흡착량 측정 성능에 문제가 있음을 확인 하였으며, 이는 인증기준물질의 필요성을 확인시켜 주었다. 또한 BET 분석방법이 분석자의 주관에 의해 많이 좌우됨을 확인 하였다. 즉 BET 분석구간의 선택영역에 따라 CRM I의 경우 16% 까지 차이를 줄 수 있음을 확인하였는데, 이는 적정한 BET 구간의 선택을 위한 BET 매개변수 C 값과 fitting 상관계수 R 값에 대한 기준이 필요함을 확인시켜 주었다. 이러한 순회평가의 경험과 검증된 비표면적 인증물질 및 표준 절차서의 보급은 산업계에 신뢰성 있는 비표면적 측정결과를 주게 됨으로서, 일관성 있는 공정운용에 의한 품질관리, 생산성 향상, 안정성 판단 및 신제품 개발 등에 기여할 것이다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제37권4호
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• pp.273-281
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• 2010

본 논문에서는 CT 영상에서 밝기값 분포와 기울기 정보를 고려한 방사선 추적 기반의 좌심실 내외벽 자동 분할 기법을 제안한다. 첫째, 심근 내벽 경계는 임계값 기법과 영역확장법으로 분할하고, 꼭지근을 포함하는 위하여 방사형의 방사선 추적 기법을 이용하여 분할한다. 둘째, 심근 외벽 경계는 적응적 기울기 프로파일 내에 심근의 밝기값과 최대 기울기를 갖는 점을 추출한다. 마지막으로, 타원이나 원의 형태를 유지하기 위하여 내외벽의 잘못된 경계점들을 타원방정식으로 선형 보간하고 B-스플라인을 적용하여 최종 분할된 결과를 추출한다. 제안방법의 평가를 위해 육안평가와 정확성 평가, 수행시간을 측정하였다. 정확성 평가를 위하여 임상의의 수동 분할 결과와 제안 방법 분할 결과 간의 평균거리차이와 중복영역비율을 측정하였다. 실험 결과 평균거리차이는 $0.56{\pm}0.24mm$로 측정되었고, 평균 중복영역비율은 평균 $82{\pm}4.2%$로 측정되었다. 제안 방법을 적용한 수행 시간은 평균 1초로 수행을 완료하였다.

• 한국지반환경공학회 논문집
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• 제10권7호
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• pp.25-32
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• 2009

본 연구는 팽창질석을 사용하여 수용액 상의 구리이온 흡착 제거능을 평가 하고자 하였다. 질석의 화학적 조성분석은 XRF, 구리이온 농도분석은 UV-VIS를 각각 사용하여 이루어졌다. 수용액 상의 구리이온의 제거양상을 살펴보기 위해 batch kinetic test와 batch sorption test가 실시되었고, 그 결과 구리의 제거속도($K_{obs}$, 1/hr)는 초기pH 3일때 0.73, pH 4일때 1.52, pH 5일때 1.71였고 초기농도가 $1mg\;L^{-1}$ 일때 3.19, 5일때 1.90, 10일때 0.73으로 초기구리농도와 반비례하고 초기 pH와는 비례하여 증가하는 양상을 보였다. 하지만 초기용액의 농도차이보다 초기pH의 영향이 지배적일 것이라는 예상하에 동일한 농도에 pH만 달리하여 실험해본 결과 역시 예상대로 pH에 따라 제거속도가 크게 차이남을 알 수 있었다. 최종적으로 batch sorption test를 통해 얻은 결과를 각각 Freundlich와 Langmuir 등온흡착식에 대입한 결과 두 식 모두 양호한 fitting 결과를 얻을 수 있었으나 Freundlich 식의 결정계수가 0.965로 Langmuir 식의 결정계수 0.936보다 좀 더 높게 나타나 좀 더 정확한 fitting 결과를 보여주었다. Langmuir 모델로부터 얻은 최대흡착용량($Q_{max}$), Freundlich 모델의 분배계수, n 값은 각각 $1,250mg\;kg^{-1}$, $635.1L\;kg^{-1}$, 1.69였다. 이러한 결과는 팽창질석이 다양한 형태의 수용액 상에 존재하는 구리이온을 효과적으로 제거할 수 있음을 보여준다.

• 대한의용생체공학회:의공학회지
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• 제32권3호
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• pp.245-250
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• 2011

Parallel imaging technique can provide several advantages for a multitude of MRI applications. Especially, in SENSE technique, sensitivity maps were always required in order to determine the reconstruction matrix, therefore, a number of difference approaches using sensitivity information from coils have been demonstrated to improve of image quality. Moreover, many filtering methods were proposed such as adaptive matched filter and nonlinear diffusion technique to optimize the suppression of background noise and to improve of image quality. In this study, we performed SENSE reconstruction using computer simulations to confirm the most suitable method for the feasibility of filtering effect and according to changing order of polynomial fit that were applied on variation of spatial resolution of sensitivity map. The image was obtained at 0.32T(Magfinder II, Genpia, Korea) MRI system using spin-echo pulse sequence(TR/TE = 500/20 ms, FOV = 300 mm, matrix = $128{\times}128$, thickness = 8 mm). For the simulation, obtained image was multiplied with four linear-array coil sensitivities which were formed of 2D-gaussian distribution and the image was complex white gaussian noise was added. Image processing was separated to apply two methods which were polynomial fitting and filtering according to spatial resolution of sensitivity map and each coil image was subsampled corresponding to reduction factor(r-factor) of 2 and 4. The results were compared to mean value of geomety factor(g-factor) and artifact power(AP) according to r-factor 2 and 4. Our results were represented while changing of spatial resolution of sensitivity map and r-factor, polynomial fit methods were represented the better results compared with general filtering methods. Although our result had limitation of computer simulation study instead of applying to experiment and coil geometric array such as linear, our method may be useful for determination of optimal sensitivity map in a linear coil array.