• Korea-Australia Rheology Journal
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• 제21권1호
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• pp.39-46
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• 2009

Atherosclerosis is a disease that narrows, thickens, hardens, and restructures a blood vessel due to substantial plaque deposit. The geometric models of the considered stenotic blood flow are three different types of constriction of cross-sectional area of blood vessel; 25%, 50%, and 75% of constriction. The computational model with the fluid-structure interaction is introduced to investigate the wall shear stresses, blood flow field and recirculation zone in the stenotic vessels. The velocity profile in a compliant stenotic artery with various constrictions is subjected to prescribed physiologic waveform. The computational simulations were performed, in which the physiological flow through a compliant axisymmetric stenotic blood vessel was solved using commercial software ADINA 8.4 developed by finite element method. We demonstrated comparisons of the wall shear stress with or without the fluid-structure interaction and their velocity profiles under the physiological flow condition in the compliant stenotic artery. The present results enhance our understanding of the hemodynamic characteristics in a compliant stenotic artery.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권3호
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• pp.1076-1094
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• 2022

Technology for emotion recognition is an essential part of human personality analysis. To define human personality characteristics, the existing method used the survey method. However, there are many cases where communication cannot make without considering emotions. Hence, emotional recognition technology is an essential element for communication but has also been adopted in many other fields. A person's emotions are revealed in various ways, typically including facial, speech, and biometric responses. Therefore, various methods can recognize emotions, e.g., images, voice signals, and physiological signals. Physiological signals are measured with biological sensors and analyzed to identify emotions. This study employed two sensor types. First, the existing method, the binary arousal-valence method, was subdivided into four levels to classify emotions in more detail. Then, based on the current techniques classified as High/Low, the model was further subdivided into multi-levels. Finally, signal characteristics were extracted using a 1-D Convolution Neural Network (CNN) and classified sixteen feelings. Although CNN was used to learn images in 2D, sensor data in 1D was used as the input in this paper. Finally, the proposed emotional recognition system was evaluated by measuring actual sensors.

• Archives of Pharmacal Research
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• 제13권3호
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• pp.227-232
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• 1990

A Physiologically based pharmacokinetic model was used to describe the distribition and elimination of cefriazone in the rat. To validate the practical application of the model, the effect of cffeine on the model was also examined. The model consisted of eleven compartments representing the major sites for ceftriaxone distribution including carcass which served as a residual compartment. Elimination was represented by renal and hepatic (metabolic biliary )excretion with GI secretion and re-absorption. The drug concentrations in most of the tissues were simulated using flow limited equations while brain levels were simulated using membrane limited passive diffusion distribution. The experimental data were obtained by averaging the concentration of drug in the plasma and tissues of five rats after i. v. injection of cefriazone 100 mg/kg without and with caffeine 20 mg/kg. The data for the amount of ceftriazone excreted in urine and gut contents were used to apportion total body clearance. HPLC with UV detection was used for the assay with 0.1-0.2 $\mu$g/ml sensitivity. The great majority of drug concentrations with and without caffeine show reasonably good agreements to the simulation results within 20%. The effect of caffeine on renal and hepatic clearances was apparent with 18.8% and 18.6% increase in the model values, respectively.

• 대한인간공학회지
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• 제24권1호
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• pp.9-17
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• 2005

81.1% of traffic accidents is attributed to the drivers. In this regard, D/E model is a practical and effective method in terms of the cost and time in evaluating the road hazardousness. To examine the validity of the threshold values by the levels of demand We selected 10 subjects and collected their physiological signals while they were driving on Honam Highway (Jeonju ${\leftrighttarro}$ Hoideog section). Based on the collected data, the hazardous road condition was evaluated using the new threshold values of the effort level determined by cluster analysis. In applying the D/E model, a decision method based on the demand level was suggested, using a traffic accident prediction model. Additionally, the limit value of the effort level was determined using the drivers' physiological signal data collected at the highway. A comparison analysis of the two D/E models revealed no significant difference: The existing method and the clustering method determined 9 and 7 hazardous road zones, respectively, while actual traffic accidents were reported in 6 and 4 zones, respectively among the predicted road hazardous zones. However, the latter method suggested a more scientific and rational basis in determining the limit value of the Effort level. In conclusion, although D/E model has a great merit as a pioneering method to reflect human factors in evaluating the road hazardousness, it is believed that this method could be improved by a more dynamic method that considers the traffic conditions and the individual physiological signal of the drivers simultaneously in determining a better limit.

• Journal of Ecology and Environment
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• 제40권3호
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• pp.136-143
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• 2016

Background: Mussels are stubborn organisms attached to solid substrata by means of byssus threads. The abundance of marine mussel Mytilus edulis in marine facilities like power stations was reason to select among fouling animals. Methods: Mortality patterns as well as physiological behavior (oxygen consumption, foot activity, and byssus thread production) of two different size groups (14- and 25-mm shell length) of M. edulis were studied at different hydrogen peroxide concentrations ($1-4mg\;l^{-1}$). Results: Studied mussels showed progressive reduction in physiological activities as the hydrogen peroxide concentration increased. Mussel mortality was tested in 30 days exposure, and 14 mm mussels reached the highest percentage of 90% while 25 mm mussels reached 81%. Produced data was echoed by Chick-Watson model extracted equation. Conclusions: This study points that, while it could affect the mussel mortality moderately in its low concentrations, hydrogen peroxide has a strong influence on mussels' physiological activities related to colonization. Therefore, hydrogen peroxide can be an alternative for preventing mussel colonization on facilities of marine environment.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 추계학술대회
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• pp.57-60
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• 1995

The objective of this investigation is to understand the role of hemodynamics in the formation and development of atherosclerosis lesions in the human left coronary artery This study also aims to compare the blood flow characteristics of steady and physiological flows. Three dimensional, steady and physiological flows of blood in the left coronary artery are simulated using the Finite Volume Method. Apparent viscosity of blood is represented as a function of shear rate by the Carreau model. Distributions of velocity, pressure and shear stress in tile left coronary artery bifurcation are presented to compare tile steady and physiological flow characteristics.

• Journal of Advanced Marine Engineering and Technology
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• 제31권5호
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• pp.622-629
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• 2007

Some worker is occupationally exposed to cold and freezing environment. The cold stimuli in the working environment impose physiological and psychological loads on workers to decrease the task performance. The purpose of this study is to investigate the cold stimuli of cold and freezing stores widely used in Busan can make an effect on human's physiological responses and task performance, experimentally and analytically. In the experiment, 5 workers are selected as subjects, and then their skin temperatures of hand and ear, heart rates, blood pressure, and ring test performances in cold($3^{\circ}C$) and freezing($-22^{\circ}C$) stores were measured for 21 minutes and analyzed by using statistical method. It is observed that a physiological variation and the task performance are significantly influenced by an exposure time as well as a strength of cold stimuli. Also, it is suggested the exposure limiting times for the useful manual work and the performance predict model of the ring tasks. The result of this study will be useful for a fundamental data of which design the standard task time of manual tasks and solve the job placement problem of worker selection and placement in cold environment.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.985-987
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• 2010

본 논문에서는 개인별 평균차를 이용한 최대 엔트로피 기반 감성 인식 모델을 제안한다. 정확하게 사용자의 감성을 인식할 수 있도록, 제안하는 모델은 단순하게 주어진 입력 감성 신호 정보만 분석하여 사용하지 않고, 입력 정보를 각 감성 상태의 평균값과 비교한 결과를 활용한다. 그리고, 자료 부족 문제를 완화하기 위해서, 제안하는 모델은 평균차를 +(양수)와 -(음수)로 단순하게 표현하고, 감성 반응 전체 시간 대신 초단위로 분할하여 감성신호의 평균을 계산한다. 또한, 전문적인 지식이 없이도 구축이 용이하도록, 제안하는 모델은 간단한 평균차 계산 기법과 잘 알려진 기계학습기법의 하나인 최대 엔트로피 모델을 이용한다.

• 제어로봇시스템학회논문지
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• 제19권6호
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• pp.513-519
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• 2013

The current vision-based approaches for emotion recognition, such as facial expression analysis, have many technical limitations in real circumstances, and are not suitable for applications that use them solely in practical environments. In this paper, we propose an approach for emotion recognition by combining extrinsic representations and intrinsic activities among the natural responses of humans which are given specific imuli for inducing emotional states. The intrinsic activities can be used to compensate the uncertainty of extrinsic representations of emotional states. This combination is done by using PRMs (Probabilistic Relational Models) which are extent version of bayesian networks and are learned by greedy-search algorithms and expectation-maximization algorithms. Previous research of facial expression-related extrinsic emotion features and physiological signal-based intrinsic emotion features are combined into the attributes of the PRMs in the emotion recognition domain. The maximum likelihood estimation with the given dependency structure and estimated parameter set is used to classify the label of the target emotional states.

• 한국콘텐츠학회논문지
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• 제10권8호
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• pp.168-176
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• 2010

영상을 주의 깊게 시청하는 관객은 보이는 영상의 성격에 따라 여러 심적 변화를 경험한다. 기쁨, 슬픔, 놀람 등 관객이 느낄 수 있는 다양한 감정 상태는 심리학에서 많이 활용되는 제임스 러셀(James Russell)이 정의한 감정 원형모형을 통해 정리된다. 관객이 느낄 수 있는 감정들 중에서도 특히 지그문트 프로이트(Sigmund Freud)가 언급한 언캐니(uncanny)는 기존의 명료한 정서적 개념들의 틈새에 존재하는 첨예한 중간자로 대변된다. 언캐니 현상은 비윤리적으로 인식되는 영상을 시청하는 관객이 보편적으로 느끼는 불쾌한 부분이 쾌로 수용되는 상태, 즉 사회적 금기에 대해 긍정적인 상태이기 때문에 이는 사회윤리적인 해석과 더불어 명확한 수리적 분석이 후행될 때 비로소 첨예한 심리상태로서 분석 가치를 지닌다. 따라서 본 논문에서는 감정 원형모형과 언캐니 상태를 분석하고, 관객의 언캐니 상태에 관한 가설을 설립하여 ECG(Electronic Cardiogram)와 GSR(Galvanic Skin Response) 신호 측청과 같은 생체신호 실험을 수치화한 결과를 러셀의 감정 원형모형을 기반으로 분포, 거리, 시간 등을 분석하는 방향으로 진행된다.