• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2811-2816
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• 2007

We conducted a numerical study of AC-electroosmotic (alternating current) effect on the fluid flow and mixing in a 3-D microchannel. The microchannel used as an efficient micro-mixer is composed of a channel and a series of pairs of electrodes attached in zigzag pattern on the bottom wall. The AC electric field is applied to the electrodes so that a steady flow current takes place around the electrodes. This current is flowing across the channel and thus contributing to the mixing of the fluid within the channel. We performed numerical simulations by using a commercial code to obtain a steady flow field. This steady flow is then used in evaluation of the mixing performance via the concept of mixing index. It was found that good combination of two kinds of electrode, which gave us a good mixing, is not simple harmonic. And when the length ratio of these two kinds of electrode is 2:1, we can get the best mixing effect.

• Journal of Power Electronics
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• 제18권3호
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• pp.817-825
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• 2018

In this paper, a current hysteresis control with good decoupling properties for doubly-fed brushless induction machines (BDFIMs) has been proposed based on a generalized vector model. The independent control of the reactive power and speed for BDFIMs has been achieved by controlling the d-axis and the q-axis current of the control windings (CW). The proposed vector control method has been developed for the power winding (PW) flux frame. Experimental verification of a type Y180M-4 BDFIM prototype with 1/4 pole-pairs has been presented. Evidence of its good performance has been shown through experimental results.

• Bulletin of the Korean Chemical Society
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• 제29권5호
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• pp.963-968
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• 2008

For the [$Cr_2(H_2tmp)_2Cl_4$] compound, simplified models with two bridging methoxo ligands have been studied. The influence of the bridging Cr-O-Cr bond angles on the exchange coupling between metal atoms in the model compound has been analyzed by means of density functional calculations with the broken-symmetry approach. Coupling constant calculated for the full structure is in good agreement with the experimentally reported value, confirming the validity of the computational strategy used in this work to predict the exchange coupling in a family of related dinuclear Cr(III) compounds. The calculations indicate a good correlation between the calculated coupling constant and the sum of the squared energy gap of three pairs of metal $t_{2g}$ OMSOs with a limited variation of the Cr-O-Cr angle. The spin density distribution and the mechanism of magnetic coupling interactions are discussed.

• 디지털산업정보학회논문지
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• 제8권2호
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• pp.95-104
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• 2012

In this paper, an estimation of person height and 3D location of a moving person by using the pan/tilt-embedded stereo tracking system is suggested and implemented. In the proposed system, face coordinates of a target person is detected from the sequential input stereo image pairs by using the YCbCr color model and phase-type correlation methods and then, using this data as well as the geometric information of the stereo tracking system, distance to the target from the stereo camera and 3-dimensional location information of a target person are extracted. Basing on these extracted data the pan/tilt system embedded in the stereo camera is controlled to adaptively track a moving person and as a result, moving trajectory of a target person can be obtained. From some experiments using 780 frames of the sequential stereo image pairs, it is analyzed that standard deviation of the position displacement of the target in the horizontal and vertical directions after tracking is kept to be very low value of 1.5, 0.42 for 780 frames on average, and error ratio between the measured and computed 3D coordinate values of the target is also kept to be very low value of 0.5% on average. These good experimental results suggest a possibility of implementation of a new stereo target tracking system having a high degree of accuracy and a very fast response time with this proposed algorithm.

• 환경영향평가
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• 제8권1호
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• pp.61-70
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• 1999

The purpose of this study is to understand an appreciation and a perceptive structure of "keijeok" image by Semantic Differential Technique and Factor Analysis. The data used in this study was obtained by the questionnaire survey carried out in Pusan metropolitan city. 15 adjective pairs in the survey were evaluated by the Semantic Differential scales graded 7 ranges from 1(very good) to 7(very bad). A total of 452 samples were collected by the survey and analyzed for this study. The results are as follows; First, 15 variables comprehended to "keijeok" image were estimated as a positive conception(LT 4.0). What's more, residents may perceive "keijeok" image as intangible and aesthetic aspect such as "fresh", "pleasant", "clean". Second, the result of factor analysis shows that factor I which express the major conceptual meaning of "keijeok" image tends to have intangible or aesthetic adjective pairs rather than concrete, whereas factor II which has the weaker meaning compared with factor I may represent a functional aspect of "keijeok" image. It can explain that the perceptive structure of "keijeok" image may be largely influenced by subjective sense, then added or concreted with objective conception or environmental situation. The results can be considered as an important matter which should be reflected at the stage of environmental planning for people's amiable and desirable place.

• 한국의류산업학회지
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• 제10권1호
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• pp.11-21
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• 2008

The purpose of this study was to provide the guidance in more objective and proper clothing design and a strategy of fashion marketing from consumer sensibilities about adult women's town wear in un-limited circumstance. The specific objectives were 1) to investigate relationship between fashion sensibility and consumer sensibility of Good and Bad women's town wear, 2) to compare fashion sensibility with consumer sensibility of Good and Bad women's town wear, and 3) to investigate a dimension of Good and Bad women's town wear in fashion sensibility. Because they can affect estimators, the collected photos at shopping mall, department stores, and churches (S/S, F/W: April 28, 2004~May 1, 2005) were prepared removing face and background and attached on gray board. To investigate consumer sensibilities, the stimulus were 80 photos (40 for 'good', 40 for 'Bad'). The questionnaire consisted of bi-polar 25 pairs adjective scale of consumer sensibility was distributed 600 female (20's~40's) living in Busan (June 28, 2005~July 11, 2005). The data were analyzed by ANOVA, Regression analysis, and MDS. The results of practical study are summarized as follows. Fashion sensibility on the preference in Good and Bad women's town wear is closely related in 'want to buy-do not want to buy' and buying need is 'like-dislike'. For the fashion sensibility dimension at Good women's town wear, X axis showed from Young to Adult and Y axis showed from Hard to Comfortable following positioned design characters. For the fashion sensibilities dimension at Bad women's town wear, X axis showed from Young to Adult, Y axis showed from Normal to Unique, and Z axis showed from Heavy to Light following positioned design characters.

• 한국의류산업학회지
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• 제9권4호
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• pp.380-390
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• 2007

The purpose of this study(Part I) was to provide the guidance in more objective and proper clothing design and wearing rule to make good image making by analysis of fashion sensibilities about adult women's town wear in unlimited circumstance. The specific objectives were; 1)to investigate about fashion sensibility of women's town wear at season 2)to investigate about fashion sensibilities of women's town wear of properties which are age, marriage or not, job, average income per month, and schooling. 3)to compare fashion sensibility between Good and Bad women's town wear. The collected photos at shopping mall, department stores, and churches(S/S, F/W:2004.4.28~2005.5.1) were prepared removing face and background that can affect in estimator and attached on gray board. To investigate fashion sensibilities, the stimulus were 80 photos('good':40, 'Bad':40). The questionnaire consisted of bi-polar 25 pairs adjective scale of fashion sensibilities was distributed 60 female(20's~40's) living in Busan. The data were analyzed by t-test, ANOVA, and Scheffe. The results of this study are summarized as follows; For fashion sensibilities at 'Good' and 'Bad' wear, the variances(season, age, marriage or not, job, average income per month, and schooling) are important. Especially, the fashion sensibility at 30's women are very unique and importance age zone to catch both young women's fashion sensibility and old women's fashion sensibility, Through that age zone, we could read women's various fashion sensibility and prospect complicate consumers' fashion mind. This study result will be utilized in the clothing design for target age zone of women's town wear, database of wearing rule and good image making, and planning fashion marketing strategies.

• Korean Journal of Radiology
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• 제22권2호
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• pp.281-290
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• 2021

Objective: To assess the performance of content-based image retrieval (CBIR) of chest CT for diffuse interstitial lung disease (DILD). Materials and Methods: The database was comprised by 246 pairs of chest CTs (initial and follow-up CTs within two years) from 246 patients with usual interstitial pneumonia (UIP, n = 100), nonspecific interstitial pneumonia (NSIP, n = 101), and cryptogenic organic pneumonia (COP, n = 45). Sixty cases (30-UIP, 20-NSIP, and 10-COP) were selected as the queries. The CBIR retrieved five similar CTs as a query from the database by comparing six image patterns (honeycombing, reticular opacity, emphysema, ground-glass opacity, consolidation and normal lung) of DILD, which were automatically quantified and classified by a convolutional neural network. We assessed the rates of retrieving the same pairs of query CTs, and the number of CTs with the same disease class as query CTs in top 1-5 retrievals. Chest radiologists evaluated the similarity between retrieved CTs and queries using a 5-scale grading system (5-almost identical; 4-same disease; 3-likelihood of same disease is half; 2-likely different; and 1-different disease). Results: The rate of retrieving the same pairs of query CTs in top 1 retrieval was 61.7% (37/60) and in top 1-5 retrievals was 81.7% (49/60). The CBIR retrieved the same pairs of query CTs more in UIP compared to NSIP and COP (p = 0.008 and 0.002). On average, it retrieved 4.17 of five similar CTs from the same disease class. Radiologists rated 71.3% to 73.0% of the retrieved CTs with a similarity score of 4 or 5. Conclusion: The proposed CBIR system showed good performance for retrieving chest CTs showing similar patterns for DILD.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1997년도 한국감성과학회 연차학술대회논문집
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• pp.220-223
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• 1997

The International Affective Picture System (IAPS) developed by Lang and colleagues[1] is widely used in studies relating a variety of physiological indices to subjective emotions. In this study we investigated whether the IAPS can be used for Koreans without significant cultural biases in their subjective emotional reactions. Thirty IAPS picture slides were presented to a group of 52 college students and different 30 slides with similar 3 dimensional emotion ratings to another group of 42 students. Fof each slieds with exposal time of 8sec, subjects were asked to rate on the Semantic Differential Scale (SDS) and Self-Assessment Manikin (SAM) in the 3 dimensions of pleasure valence, arousal, and domensions of pleasure valence, arousal, and dominance. Fnctor analysis was done for SDS ratings, and correlations of SDS and SAM were calculated. Eighteen bipolar adjective were grouped into 3 dimensions of pleasure, arousal, dominance showing good agreement with previous study. SAM were calculated. Eighteen bipolar adjectives were grouped into 3 dimensions of pleasure, arousal, dominance showing good agreement with the previous study. SAM ratings were highly corrlated with two of the 6 SDS adjective pairs associated with the pleasure and dominance dimensions, but not with those associated with arousal dimension suggerting some cultural differences.

• 한국통신학회논문지
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• 제28권11C호
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• pp.1169-1176
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• 2003

본 논문에서는 인간의 심리 시각적 특성을 고려한 HVS(Human Visual System) 모델과 웨이블릿 중간주파수 대역의 계수쌍을 이용한 블라인드 워터마킹 기법을 제안한다. 중간주파수 대역의 계수쌍은 각종 영상처리를 이용한 공격과 압축 공격 등에 대해서 비슷한 왜곡 현상을 보인다. 따라서 웨이블릿 계수를 일정한 크기로 양자화 하는 기존 방법들보다 중간주파수대역의 계수쌍 사이의 관계를 이용한 양자화 방법이 보다 안정적인 성능을 나타낸다. 또한 Noise Visibility Function(NVF)을 이용한 HVS 모델을 적용함으로써 워터마크 삽입 후의 비가시성을 확보하였다. 실험을 통하여 이진 워터마크를 삽입한 영상이 평균 44㏈ 이상의 우수한 화질을 유지하면서도 각종 영상처리 공격 및 JPEG 압축 공격에 대해서 견고성이 우수함을 확인하였다.