• Journal of the Ergonomics Society of Korea
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• v.30 no.1
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• pp.195-202
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• 2011

Objective: The aim of this study is to investigate and review the previous researches about objective measuring fatigue caused by visual stimuli. Also, we analyze possibility of alternative visual fatigue measurement methods using facial expression recognition and gesture recognition. Background: In most previous researches, visual fatigue is commonly measured by survey or interview based subjective method. However, the subjective evaluation methods can be affected by individual feeling's variation or other kinds of stimuli. To solve these problems, signal and image processing based visual fatigue measurement methods have been widely researched. Method: To analyze the signal and image processing based methods, we categorized previous works into three groups such as bio-signal, brainwave, and eye image based methods. Also, the possibility of adopting facial expression or gesture recognition to measure visual fatigue is analyzed. Results: Bio-signal and brainwave based methods have problems because they can be degraded by not only visual stimuli but also the other kinds of external stimuli caused by other sense organs. In eye image based methods, using only single feature such as blink frequency or pupil size also has problem because the single feature can be easily degraded by other kinds of emotions. Conclusion: Multi-modal measurement method is required by fusing several features which are extracted from the bio-signal and image. Also, alternative method using facial expression or gesture recognition can be considered. Application: The objective visual fatigue measurement method can be applied into the fields of quantitative and comparative measurement of visual fatigue of next generation display devices in terms of human factor.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.333-336
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• 2007

본 논문에서는 감정인식 분야에서 가장 많이 사용되어지는 음성신호와 얼굴영상을 가지고 4개의(기쁨, 슬픔, 화남, 놀람) 감정으로 인식하고 각각 얻어진 감정인식 결과를 Multi modal 기법을 이용해서 이들의 감정을 융합한다. 이를 위해 얼굴영상을 이용한 감정인식에서는 주성분 분석(Principal Component Analysis)법을 이용해 특징벡터를 추출하고, 음성신호는 언어적 특성을 배재한 acoustic feature를 사용하였으며 이와 같이 추출된 특징들을 각각 신경망에 적용시켜 감정별로 패턴을 분류하였고, 인식된 결과는 감정표현 시스템에 작용하여 감정을 표현하였다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1819_1820
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• 2009

본 논문에서는 로봇의 감정과 의사표현을 위해서 3D모델 기반의 시뮬레이션이 가능한 에디팅 툴킷을 이용하였고, 사람과 로봇의 감정 상호 작용과 로봇이 제공하는 서비스의 구현을 위해서 다양한 멀티모달 표현을 생성하였다. 로봇은 얼굴표정, 그리고 목과 팔의 움직임으로 멀티모달 표현을 하였으며, 멀티모달 감정/의사 표현을 구성하는 각 모달리티별 표현들은 에디팅 툴킷을 통하여 동기화되었다. 이렇게 생성된 로봇의 멀티모달 감정/의사 표현은 DB형태로 저장되고, 이를 재조합하고 수정하여 새로운 표현을 생성할 수 있도록 하였다.

• Journal of KSNVE
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• v.4 no.2
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• pp.137-146
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• 1994

An analytical method for linear free vibration of fully liquid-filled circular cylindrical shell with various boundary conditions is developed by the Fourier series expansion based on the Stokes' transformation. A set of modal displacement functions and their derivatives of a circular cylindrical shell is substituted into the Sanders' shell equations in order to explicitily represent the Fourier coefficients as functions of the end point displacements, forces, and moments. For the vibration relevant to the liquid motion, the velocity potential of liquid is assumed as a sum of linear combination of suitable harmonic functions in the axial directions. The unknown parameter of the velocity potential is selected to satisfy the boundary condition along the wetted shell surface. An explicit expression of the natural frequency equation can be obtained for any kind of classical boundary conditions. The natural frequencies of the liquid-filled cylindrical shells with the clamped-free, the clamped-clamped, and the simply supported-simply supported boundary conditions examined in the previous works, are obtained by the analytical method. The results are compared with the previous works, and excellent agreement is found for the natural frequencies of the shells.

• Structural Engineering and Mechanics
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• v.39 no.2
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• pp.223-239
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• 2011

This paper presents a methodology to detect and locate damages and faults in orthotropic plate structures. A specific damage index based on dynamic mode shapes of the damaged and undamaged structures has been introduced. The governing differential equation on transverse deformation, the transverse shear force equations and the invariant expression for the sum of transverse loading of an orthotropic plate are employed to obtain the aforementioned damage indices. The validity of the proposed methodology for isotropic and orthotropic damage states is demonstrated using a numerical example. It is shown that the algorithm is able to detect damages for both isotropic and orthotropic damage states acceptably.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.1002-1003
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• 2019

Face recognition is an extensively researched area of computer vision. Visible, infrared, thermal, and 3D modalities have been used against various challenges of face recognition such as illumination, pose, expression, partial information, and disguise. In this paper we present a multi-modal approach to face recognition using convolutional neural networks. We use visible and thermal face images as two separate inputs to a multi-input deep learning network for face recognition. The experiments are performed on IRIS visible and thermal face database and high face verification rates are achieved.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.273-280
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• 1999

The base shear and the veritcal distribution of shears along the height of a building are two fundamental measures that define the design seismic load. But the method specified in Korean building code does not give an appropriate distribution for buildings of tall or longer period because it roughly account for the contributions of the higher modes. several methods to give a better distribution of seismic forces have been proposed. But they have not been introduced into the seismic codes yet probably because they cannot solve all the above-mentioned problems. This paper deals with the distribution of lateral seismic forces along the height of a building to account for the contribution of the higher modes. After reviewing some existing distributions in seismic codes and literatures moment-resisting frames with various stories were studied by modal analysis for a wide range of fundamental period and the stiffness ratio of the buiding. As a result of the analysis a new expression for the distribution of seismic forces is proposed and compared with those of some codes and dynamic analysis.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.6
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• pp.11-18
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• 2018

Isogeometric concept is introduced to find out the optimum layout of plane structure under free vibration. Eigenvalue problem is formulated and numerically solved in order to obtain natural frequencies and mode shapes of plane structures. For the exact geometric expression of the structure, the Non-Uniform Rational B-spline Surface (NURBS) basis functions is employed and it is also used to define the material density functions. A node-wise design variables is adopted to deal with the updating of material density in topology optimization (TO). The definition of modal strain energy is employed to achieve the maximization of fundamental frequency through its minimization. The verification of the proposed TO technique is performed by a series of benchmark test for plane structures.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.1
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• pp.20-26
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• 2008

As they have more and more intelligence robots or computers these days, so the interaction between intelligence robot(computer) - human is getting more and more important also the emotion recognition and expression are indispensable for interaction between intelligence robot(computer) - human. In this paper, firstly we extract emotional features at speech signal and facial image. Secondly we apply both BL(Bayesian Learning) and PCA(Principal Component Analysis), lastly we classify five emotions patterns(normal, happy, anger, surprise and sad) also, we experiment with decision fusion and feature fusion to enhance emotion recognition rate. The decision fusion method experiment on emotion recognition that result values of each recognition system apply Fuzzy membership function and the feature fusion method selects superior features through SFS(Sequential Forward Selection) method and superior features are applied to Neural Networks based on MLP(Multi Layer Perceptron) for classifying five emotions patterns. and recognized result apply to 2D facial shape for express emotion.

• Journal of Internet Computing and Services
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• v.23 no.2
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• pp.71-77
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• 2022

In this paper, a database is collected for extending the speech synthesis model to a model that synthesizes speech according to emotions and generating facial expressions. The database is divided into male and female data, and consists of emotional speech and facial expressions. Two professional actors of different genders speak sentences in Korean. Sentences are divided into four emotions: happiness, sadness, anger, and neutrality. Each actor plays about 3300 sentences per emotion. A total of 26468 sentences collected by filming this are not overlap and contain expression similar to the corresponding emotion. Since building a high-quality database is important for the performance of future research, the database is assessed on emotional category, intensity, and genuineness. In order to find out the accuracy according to the modality of data, the database is divided into audio-video data, audio data, and video data.