• 대한의용생체공학회:의공학회지
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• 제14권2호
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• pp.125-136
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• 1993

The study of Cochlear biomechanics is to clearly define three biomechanical principles of the Cochlea : Activity, Nonlinearity and Feedback. In this article, the Cochlea is linearly and actively modelled in one dimensional time domain. The sharp tunning of the Basilar Membrane displacement is shown when the amplifying activity of hair cells is added to the model. The amplified energy of the travelling displacement wave is emitted throughout the Cochlear fluid, so that the model becomes unstable. A new technique is introduced to reduce strong echos fro the Helicotrema. It makes the model less unstable. Both pure and click tones are used as input stimuli onto the ear durm. When the model is normal, the click response of the model shows that the backward emission of the amplified fluid pressure has mainly the echos from the Helicotrema. However, when the linear and active model is assumed to be abnormal, that is, some of hair cells are damaged not to produce the active process, the effect of the hair cell damage is resulted in the Oto-acoustic emission. The frequency response of the abnormally emitted sound pressure shows that the Oto-acoustic emission has the information about the characteristic frequency of the damaged hair cell. The main aim of this paper is to demonstrate the active biomechanics of the Chchlea in the time domain.

• Journal of Biosystems Engineering
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• 제22권3호
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• pp.333-342
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• 1997

The objective of this research was to develop model equations for measuring rice milling ratio by using visible / HIR spectroscopy. Twelve kinds of brown rice(n = 149) were milled to obtain various milling ratio ranged from 86% to 94%. Visible/NIR spectra were collected with a spectrophotometer with sample transport module. The reflectance and transmission spectra were measured in the range of 400~2, 500nm and 600~1, 400nm, respectively, with 2 nm intervals. Multiple linear regression(MLR), Partial least square (PLS), and Artificial neural network(ANN) were used to develop models. Model developed with reflectance spectra showed better prediction results then those with transmission spectra. The MLR model with six-wavelength obtained from first derivative spectra gave to the best results for measuring the rice milling ratio(SEP = 0.535, , $r^2$ = 0.980). The PLS model(SEP = 0.604, $r^2$= 0.976) and ANN model(SEP = 0.566, $r^2$= 0.978) also can be used to determine the rice milling ratio effectively.

• 한국의류학회지
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• 제30권4호
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• pp.542-553
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• 2006

The purpose of this study were to analyse of craniofacial shape by 3D and to develope of head models for Korean adults with gender and age groups. The 3D measurement technique adapted in this study was a novel approach compared that the same technique has been commonly used in measuring human bodies. The data and the model of head analysis can be used as a basic reference in developing various head related items such as hat, helmet, gas mask, ear phone, and etc. In this study, heads of 836 Korean adults were measured in 3D, analyzed by statistical methods, and modelized in 3D by gender and age groups. From the basic statistical data analysis, vertex-tragion and the length between the pupils were the longest in their twenties for both men and women, and grew shorter in elderly groups. In all categories, a significant difference appeared between men and women in their 20's, but the differences were less noticeable in elderly groups. Compared to the one size standard head model of the Korea Occupational Safety and Health Agency, the above three-dimensional standard head model would provide a more through fit because gender and age groups were sub-divided and analyzed in 3D.

• 대한두개안면성형외과학회지
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• 제15권2호
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• pp.89-93
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• 2014

Background: To refine facial transplantation techniques and achieve sound results, it is essential to develop a suitable animal model. Rat is a small animal and has many advantages over other animals that have been used as transplantation models. The purpose of this study was to describe a rat hemifacial transplantation model and to verify its convenience and reproducibility. Methods: Animals used in this study were Lewis rats (recipients) and Lewis-Brown Norway rats (donors). Nine transplantations were performed, requiring 18 animals. The hemifacial flap that included the ipsilateral ear was harvested based on the unilateral common carotid artery and external jugular vein and was transferred as a single unit. Cyclosporine A therapy was initiated 24 hours after transplantation and lasted for 2 weeks. Signs of rejection responses were evaluated daily. Results: The mean transplantation time was 1 hour 20 minutes. The anatomy of common carotid artery and external jugular vein was consistent, and the vessel size was appropriate for anastomosis. Six of nine allografts remained good viable without vascular problems at the conclusion of study (postoperative 2 weeks). Conclusion: The rat hemifacial transplantation model is suitable as a standard transplantation training model.

• 한국통신학회논문지
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• 제18권7호
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• pp.913-921
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• 1993

질감매핑은 대부분의 모델기반 부호화 시스템에서 영상합성 방식으로 사용 되어진다. 이 영상합성 방법은 정면 얼굴영상의 질감정보로만 영상을 합성한다. 따라서, 모델이 회전 되었을 때, 질감매핑은 명암측면에서 어색한 영상을 합성할 수 있다. 본 논문에서는 명암효과를 고려한 새로운 질감매핑이 연구되었다. 또한 회전에 대비하여 귀의 철선프레임과 머리카락의 변화를 부가하였다. 제안된 방식을 이용하여 실험한 결과, 자연스러운 영상합성이 가능하였다.

• 한국멀티미디어학회논문지
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• 제8권11호
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• pp.1432-1438
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• 2005

심리음향모델을 기반으로 주파수영역에서 잡음을 형상화하여 오디오 신호에 부가하였을 때 부가된 잡음이 지각되지 않는 방법을 제안하였다. 신호의 마스킹 문턱값으로부터 지각되지 않는 잡음의 준위를 구하는 것은 심리음향모델에서 확산함수와 관련된 디컨버루션을 수반하는데 난제(ill-conditioned Problem)로 알려져 있다. 본 논문에서는 최적화 기법을 적용하여 잡음의 여기준위를 신호의 마스킹 준위에 일치시킴으로써 신호에 부가된 잡음이 청각적으로 지각되지 않는 한도 내에서 최대한의 잡음준위가 되도록 형상화하는 방법을 제시하고 실험적으로 그 타당성을 증명하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.617-621
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• 2003

Existing loudness models are specified only to diotic sounds in spite of the fact that normal human beings hear dichotic sounds. Approximately, the arithmetic mean of loudness values of both ear signals has been suggested for the resultant perceived loudness. In this study, the dependence of overall loudness perception on the interaural level differences was investigated by the subjective tests. It was found that the larger the interaural level difference, the louder the perception than the mean of calculated loudness values at both ears and the lower the critical band rate or the reference level, the louder the perception than the mean value. A modified loudness model was proposed to he applicable to dichotic sounds by using the equivalent diotic levels.

• Archives of Pharmacal Research
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• 제29권8호
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• pp.685-690
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• 2006

The effect of a main constituent ginsenoside Rg5 isolated from red ginseng and its metabolite ginsenoside Rh3 in a chronic dermatitis model was investigated. Ginsenosides Rg5 and Rh3 suppressed swelling of oxazolone-induced mouse ear contact dermatitis. These ginsenosides also reduced mRNA expressions of cyclooxygenase-2, interleukin $(IL)-1{\beta}$, tumor necrosis factor $(TNF)-{\alpha}$ and interferon $(IFN)-{\gamma}$. The inhibition of ginsenoside Rh3 was more potent than that of ginsenoside Rg5. These findings suggest that ginsenoside Rh3 metabolized from ginsenoside Rg5 may improve chronic dermatitis or psoriasis by the regulation of $IL-1{\beta}$ and $TNF-{\alpha}$ produced by macrophage cells and of $IFN-{\gamma}$ produced by Th cells.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.301-306
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• 2002

This paper presents the use of the neural network technology to establish a mathematical model for predicting bead geometry (top-bead width, top-bead height, back-bead width and back-bead height) for multi-pass welding, and understand relationships between process parameters and bead geometry for robotic GMA welding process. Using a series of robotic arc welding, additional multi-pass butt welds were carried out in order to verify the performance of the developed neural network model. The results show that not only the proposed model can predict the bead geometry with reasonable accuracy and guarantee the uniform weld quality, but also the neural network model could be better than the linear and curvilin ear equations developed from Lee [8].

• 한국통신학회논문지
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• 제39C권11호
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• pp.1209-1215
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• 2014

기하학적 균일 회절 이론(UTD)은 특정 주파수에서 장애물에 의해 전파가 불연속적인 특성을 가질 때, 전자기학적으로 접근하여 회절 계수와 반사 계수 등을 계산하여 전파를 분석하는 기법이다. 본 논문에서는 실내 무선 채널 환경에서 사용자가 단말기 주변에 있을 때, 사용자에 의한 쉐도잉(Shadowing) 효과를 기하학적 UTD을 통하여 분석하였다. 사용자가 통화를 하고 있는 상황(Head Model)과 가슴 앞쪽에 단말기를 위치하여 사용하는 상황(Chest Model)으로 나누고, 각각에 대하여 복사 모델(Radiation Model)과 산란 모델(Scattering Model)에 적용하여 비교 및 분석하였다.