• International Journal of Vascular Biomedical Engineering
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• 제3권1호
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• pp.23-29
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• 2005

We developed a three dimensional cardiac tissue model based on human cardiac cell and mono-domain approximation for action potential propagation. The human myocyte model proposed by ten Tusscher et al. (TNNP model) (2004) for cell electrophysiology and a mono-domain method for electric wave propagation are used to simulate the cardiac tissue propagation mechanism using a finite element method. To delineate non-homogeneity across cardiac tissue layer, we used three types of cardiac cell models. Ansiotropic effect of action potential propagation is also considered in this study. In this 3D anisotropic cardiac tissue with three cell layers, we generated a reentrant wave using S1-S2 protocol. Computational results showed that the reentrant wave was affected by the anisotropic properties of the cells. To test the reentrant wave under pathological state, we simulated a hypertopic model with non-excitable fibroblasts in stochastic manner. Compared with normal tissue, the hypertropic tissue result showed another center of reentrant wave, indicating that the wave pattern can be more easily changed from regular with a concentric focus to irregular multi-focused reentrant waves in case of patients with hypertrophy.

• Asian-Australasian Journal of Animal Sciences
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• 제8권6호
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• pp.533-555
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• 1995

Direct-fed microbials (DFM) have been used to enhance milk production in lactating cattle and to increase feed efficiency and body weight gain in growing ruminants. Primary microorganisms that have been used as DFM for ruminants are fungal cultures including Aspergillus oryzae and Saccharomyces cerevisiae and lactic acid bacteria such as Lactobacillus or Streptococcus. Attempts have been made to determine the basic mechanisms describing beneficial effects of DFM supplements. Various modes of action for DFM have been suggested including : stimulation of ruminal microbial growth, stabilization of ruminal pH, changes in ruminal microbial fermentation pattern, increases in digestibility of nutrients ingested, greater nutrient flow to the small intestine, greater nutrient retention and alleviation of stress, however, these responses have not been observed consistently. Variations in microbial supplements, dosage level, production level and age of the animal, diet and environmental condition or various combinations of the above may partially explain the inconsistencies in response. This review summarizes production responses that have been observed under various conditions with supplemental DFM and also corresponding modification of ruminal fermentation and other changes in the gastrointestinal tract of ruminant animals.

• 제어로봇시스템학회논문지
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• 제16권10호
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• pp.957-962
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• 2010

If we want to recognize the human's emotion via the facial image, first of all, we need to extract the emotional features from the facial image by using a feature extraction algorithm. And we need to classify the emotional status by using pattern classification method. The AAM (Active Appearance Model) is a well-known method that can represent a non-rigid object, such as face, facial expression. The Bayesian Network is a probability based classifier that can represent the probabilistic relationships between a set of facial features. In this paper, our approach to facial feature extraction lies in the proposed feature extraction method based on combining AAM with FACS (Facial Action Coding System) for automatically modeling and extracting the facial emotional features. To recognize the facial emotion, we use the DBNs (Dynamic Bayesian Networks) for modeling and understanding the temporal phases of facial expressions in image sequences. The result of emotion recognition can be used to rehabilitate based on biofeedback for emotional disabled.

• The Journal of Korean Physical Therapy
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• 제22권6호
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• pp.43-51
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• 2010

Purpose: This study examined the influence of visuomotor congruency on learning a relative phase relationship between a single joint movement and an external signal. Methods: Participants (N=5) were required to rhythmically coordinate elbow flexion-extension movements with a continuous sinusoidal wave (0.375 Hz) at a $90^{\circ}$ relative phase relationship. The congruent group was provided online feedback in which the elbow angle decreased (corresponding to elbow flexion) as the angle trajectory was movingup, and vice versa. The incongruent group was provided online feedback in which the elbow angle decreased as the angle trajectory was moving down, and vice versa. There were two practice sessions (day 1 and 2) and each session consisted of 6 trials per block (5 blocks per session). Retention tests were performed 24 hours after session 2, and only the external sinusoidal wave was provided. Repeated ANOVAs were used for statistical analysis. Results: During practice, the congruent group was significantly less variable than the incongruent group. Phase variability in the incongruent group did not significantly change across blocks, while variability decreased significantly in the congruent group. In retention, the congruent group produced the required $90^{\circ}$ relative phase pattern with significantly less phase variability than the incongruent group. Conclusions: Congruent visual feedback facilitates learning. Moreover, the deprivation of online feedback does not affect the congruent group but does affect the incongruent group in retention.

• The Korean Journal of Physiology and Pharmacology
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• 제5권6호
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• pp.457-466
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• 2001

Glutamate is the most common excitatory amino acid in the brain. Responsiveness of dendrites to the glutamate greatly varies depending on the application sites. Especially, a point of the maximal response to the glutamate of the dendrite is called as 'hot spot'. In our experiment, the responsiveness of the hot spot to the glutamate was investigated in the CA1 pyramidal neuron of the rat hippocampal slice. CNQX, the antagonist of AMPA receptor, blocked 95% of membrane current to the glutamate focal application $(I_{gl}).$ Train ejection of glutamate on one point of the dendrite increased or decreased the amplitude of $I_{gl}$ with the pattern of train, and the changes were maintained at least for 30 min. In some cases, glutamate train ejection also induced calcium dependent action potentials. To evoke long-term change of synaptic plasticity, we adopted ${\theta}-burst$ in the glutamate train ejection. The ${\theta}-burst$ decreased the amplitude of glutamate response by 60%. However, after ${\theta}-burst$ glutamate train ejection, the calcium dependent action potential appeared. These results indicated that the focal application of glutamate on the neuronal dendrite induced response similar to the synaptic transmission and the trains of glutamate ejection modulated the change of AMPA receptor.

• 약학회지
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• 제49권6호
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• pp.484-489
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• 2005

Streptococcus pmeumoniae is the leading cause of pneumonia and bacterial meningitis. The current polysaccharide vaccine has been reported ineffective in elderly adults and children less than 2 years of age. Thus, in recent many researchers have been focused on a different approach, DNA vaccine. In our laboratory we developed a Streptococcus pneumoniae DNA (SPDNA) vaccine. This SPDNA vaccine was formulated by inserting the region encoding part of the capsule in the S. pneumoniae into the LAMP-1. In present work, with use of the SPDNA vaccine we attempted to establish a certain methodology useful for evaluation of effectiveness and immunoresponse of a DNA vaccine. Results showed that the subcutaneous route was the most effective for production of antisera specific for S. pneumoniae in mice. By isotyping analyses, IgM, IgGl, IgG2a, and IgG2b were determined. In addition, INF-$\gamma$ and IL-4 were predominantly detected. Combination of those data resulted in a pattern of IgGl < IgG2a=IgG2b and INF$\gamma\>$ >IL-4, which indicates the inmmunity towards the Thl response predominantly; furthermore, the SPDNA vaccination induced resistance of the CD4+T lymphocyte-depleted mice against disseminated pneumococcal infection. These data appear to be possibly due to activation of CDS8+T cell-activation. Taken together, this methodology can be applied for evaluating efficacy and mode of action of a DNA vaccine as minimum critera.

• 말소리와 음성과학
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• 제6권2호
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• pp.123-131
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• 2014

The purpose of this study is to investigate the comprehension and production of various tense markings in Korean-speaking children with and without language delay. Thirty children with language delay(LD) and 30 typically developing(TD) children participated in the study. In each group, half were at the age of 4-years and the other half at 7-years. In both the comprehension and production task, 28 verbs containing four types of tense markings were used: past tense '-et ta', two present progressives '-ko itta', '-enta', and future tense '-elyeko hanta'. In the comprehension task, the children were presented with three printed still-scenes of video recording of a verb action, each representing future, present progressive, and past tense of the verb, respectively. Then they listened to the action verb with one of the 4 tense markings and had to pick the scene that matched the verb tense. In the production task, the children were given one of the three scenes and asked to produce the verb with appropriate tense marking. In both tasks, the LD children performed significantly worse than the TD children, and the older children performed significantly better than the younger children. Interestingly, the pattern of performances across different types of tense markings at the two language-age levels were closely similar in LD children and TD children. This similarity of groups seemed stronger in the comprehension task than the production task.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3092-3094
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• 1999

This paper deals with the gait generation of Biped Walking Robot (IWR-III) to have a continuous walking pattern like human. For this, trajectory planning with the consideration of kick action is done in each walking step, and the coordinate transformation is done for simplifying the kinematics. The trunk moves continuously for all walking time and moves toward Z-axis. Balancing motion is acquired by FDM(Finite Difference Method) during the walking. By combining 4-types of pre-defined steps, multi-step walking is done. Using numerical simulator, dynamic analysis and system stability is confirmed. Walking motion is visualized by 3D-Graphic simulator. As a result, the motion of balancing joints can be reduced by the trunk ahead effect during kick action, and impactless smooth walking is implemented by the experiment.

• 한국생활과학회지
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• 제18권1호
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• pp.157-166
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• 2009

This study was conducted to evaluate the differences in external appearances and functional qualities between the slacks which were patterned on existing designs and on a new design in order to improve on their level of comfort of ready-made clothes for abdominally fat women. Five abdominally fat women in their 60's were chosen as experimental participants. Twenty-four external evaluation items, and seven different actions involving six moving parts of the body were investigated with a 5-level scale in the repeated wearing test. The results were analyzed by statistical methods. The newly designed pattern in this study was definitely superior to the other two patterns(L-type and K-type) on the external appearance evaluation. The newly pattern removed a waist belt and a dart from the front part of the garment and gave surplus space around the waist. It prevented superfluous wrinkles at the abdominal region and thighs. The superfluous wrinkles at the side regions also disappeared due to the length (inseam) reduction from waist to crotch. The newly pattern made the center-line of the back side slightly sloped to the main pattern in order to remove the drooped line. The newly pattern showed the highest score in the functional test of several actions. It was due to the reduction of the length from waist to crotch as well as the belt width. It made waist-line movement better, and made it easier and more comfortable to sit down. The newly pattern also showed the highest score in the functional test classified by specific movements of parts of the body for the same purpose. The slacks which were made of elastic materials showed better results than the non-elastic ones on external appearances and functional test items. It showed that the elastic materials played a better role in the increase of functional action of abdominally fat, aged women. This study suggests that the newly designed slacks pattern could give abdominally fat, aged women better external features and a more comfortable fitting sensation. As well, the results were significant as basic data to produce ready-made and/or tailer-made garments.

• 한국건설관리학회논문집
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• 제14권4호
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• pp.55-64
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• 2013

온실가스 에너지 목표관리제가 시행됨에 따라, 해당 사업장은 2020년까지 온실가스 배출 전망치 대비 30% 이상을 의무적으로 감축해야 한다. 에너지소비의 큰 비중을 차지하는 대학교 부문 역시 온실가스 감축이 요구됨에도 불구하고, 교육기관의 특성 상 에너지 절감에 투자할 수 있는 예산은 한정적이므로 고가의 대응책 적용에는 한계가 따른다. 따라서 본 연구는 서울대학교 관악캠퍼스를 대상으로 실 레벨에서 쉽게 적용 가능한 저가의 에너지감축 방안을 도출하고, 이를 통한 최대감축잠재량을 산정하는 사례연구를 목적으로 한다. 먼저, 관악캠퍼스 내 표본이 될 11개 용도의 실을 뽑아 1월 1일부터 7월 31일까지 에너지소비량을 매일 실측하였고, 실별 전력기기 계수 조사를 통해 실용도별 표준모형을 구축하였으며, 사용자 인터뷰와 설문 및 행정조사를 통해 전력소비패턴을 분석함으로써 실용도 표준모형 기반의 기기별 소비전력량을 산출하였다. 이를 기반으로, 32개의 감축기술 및 실천프로그램을 도출하여 실용도 표준모형에 적용하고 각 프로그램별 최대감축비율을 기기별 소비전력량에 곱해 기기별 최대감축량을 유도함으로써, 실별 월별 최대감축량과 관악캠퍼스 최대감축잠재량을 산정하였다. 그 결과, 본 연구가 제안한 감축기술 및 실천프로그램의 적용 시 1월부터 7월까지 약 $5,311tCO_2$-eq 즉 동일기간 관악캠퍼스 전체 에너지 사용량의 12.66%에 해당되는 양을 감축할 수 있으며, 2016년까지 서울대학교 필요감축량의 24.48%를 감축할 수 있는 것으로 조사되었다.