• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.851-856
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• 2007

수화는 청각장애인이 주로 사용하는 시각적인 언어이다. OpenGL 기반의 가상현실 공간을 배경으로 하여 청각장애인들이 쉽게 이해할 수 있는 수화 아바타의 움직임을 구현하기 위해, 본 논문에서는 수화 동작 데이터베이스를 구축하는 그래픽 사용자 인터페이스를 개발한다. 개발한 시스템에서는 아바타의 사실적인 표현과 친근감을 강조하기 위해 3D MAX 기반의 인체 아바타 모델의 픽셀 값을 ASE를 사용하여 C언어 코드로 변환함으로써 인간과 거의 비슷한 모델을 생성하였다. 손 모양 편집프로그램은 슬라이드 바를 사용하여 21개의 손 관절 각도를 조정할 수 있으며, 손 모양 코드번호와 손 모양 이름을 지정하여 수화단어 편집프로그램에서 사용하는 손 모양 데이터 형식으로 저장할 수 있다. 수화단어 편집프로그램은 수화단어 데이터 형식의 값을 설정하는 기능과 함께 손 모양 대칭복사, 검색, 추가, 수정, 삭제 기능을 제공함으로써 사용자가 손 모양을 쉽게 편집할 수 있도록 하였다. 손 모양 편집프로그램과 수화단어 편집프로그램을 사용하여 구성한 데이터베이스를 기반으로 수화 아바타가 가상현실 공간에서 인간과 유사한 움직임을 표현할 수 있도록 하였다.

• International Journal of Fluid Machinery and Systems
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• v.2 no.3
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• pp.197-205
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• 2009

Since large-scale commercial wind turbine generator systems such as MW-class wind turbines are becoming widely operated, the vibration and distortion of the blade are becoming larger and larger. Therefore the soft structure design instead of the solid-design is one of the important concepts to reduce the structural load and the cost of the wind turbine rotors. The objectives of the study are development of the fluid-structure coupled analysis code and evaluation of soft rotor-blade design to reduce the unsteady structural blade load. In this paper, fluid-structure coupled analysis for the HAWT rotor blade is performed by free wake panel method coupled with hinge-spring blade model for the flapwise blade motion. In the model, the continuous deflection of the rotor blade is represented by flapping angle of the hinge with one degree of freedom. The calculation results are evaluated by comparison with the database of the NREL unsteady aerodynamic experiment. In the analysis the unsteady flapwise moments in yawed inflow conditions are compared for the blades with different flapwise eigen frequencies.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.7
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• pp.1038-1046
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• 2004

In order to acquire high-speed and high-precision performances in servomechanisms, an integrated design method have been proposed. Based on strict mathematical modeling and analysis of system performance according to design and operating parameters, a nonlinear constrained optimization problem including the relevant subsystem parameters of the servomechanism is formulated. Optimum design results of mechanical and electrical parameters are obtained according to the design parameters specified by designers through the integrated design processes. Motors are optimally selected from the servo motor database. Both the geometric errors referring to Abbe offset and the contour errors are minimized while required constraints such as stability conditions and saturated conditions are satisfied. This design methodology both offers the improved possibility to evaluate and optimize the dynamic motion performance of the servomechanism and improves the quality of the design process to achieve the required performance for high-speed/precision servomechanisms.

• Nuclear Engineering and Technology
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• v.41 no.1
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• pp.11-20
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• 2009

Radiation effects on materials are inherently multiscale phenomena in view of the fact that various processes spanning a broad range of time and length scales are involved. A multiscale modeling approach to embrittlement of pressure vessel steels is presented here. The approach includes an investigation of the mechanisms of defect accumulation, microstructure evolution and the corresponding effects on mechanical properties. An understanding of these phenomena is required to predict the behavior of structural materials under irradiation. We used molecular dynamics (MD) simulations at an atomic scale to study the evolution of high-energy displacement cascade reactions. The MD simulations yield quantitative information on primary damage. Using a database of displacement cascades generated by the MD simulations, we can estimate the accumulation of defects over diffusional length and time scales by applying kinetic Monte Carlo simulations. The evolution of the local microstructure under irradiation is responsible for changes in the physical and mechanical properties of materials. Mechanical property changes in irradiated materials are modeled by dislocation dynamics simulations, which simulate a collective motion of dislocations that interact with the defects. In this paper, we present a multi scale modeling methodology that describes reactor pressure vessel embrittlement in a light water reactor environment.

• Advances in concrete construction
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• v.9 no.4
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• pp.337-343
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• 2020

In the present study, by employing fragility analysis, the seismic vulnerability of a concrete girder bridge, one of the most common existing structural bridge systems, has been performed. To this end, drift demand model as a fundamental ingredient of any probabilistic decision-making analyses is initially developed in terms of the two most common intensity measures, i.e., PGA and Sa (T₁). Developing a probabilistic demand model requires a reliable database that is established in this paper by performing incremental dynamic analysis (IDA) under a set of 20 ground motion records. Next, by employing Bayesian statistical inference drift demand models are developed based on pre-collapse data obtained from IDA. Then, the accuracy and reasonability of the developed models are investigated by plotting diagnosis graphs. This graphical analysis demonstrates probabilistic demand model developed in terms of PGA is more reliable. Afterward, fragility curves according to PGA based-demand model are developed.

• Journal of Korea Multimedia Society
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• v.6 no.5
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• pp.797-804
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• 2003

Scene change detection algorithm, which is very important preprocessing technique for video indexing and retrieval and determines the performance of video database system, is being studied widely. In this paper, we propose a more effective abrupt scene change detection, which is robust to large motion, sudden change of light and successive abrupt shot transitions rapidly. And we also propose a new gradual scene change detection algorithm, which can detect dissolve, and fade in/out precisely. Furthermore, we also propose a representative frame extraction algorithm which performs content-based video summary by novel DCT DC image buffering technique and accumulative histogram intersection measure (AHIM).

• Journal of Korea Multimedia Society
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• v.20 no.7
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• pp.986-993
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• 2017

Object Tracking is a technique for tracking moving objects over time in a video image. Using object tracking technique, many research are conducted such a detecting dangerous situation and recognizing the movement of nearby objects in a smart car. However, it still remains a challenging task such as occlusion, deformation, background clutter, illumination variation, etc. In this paper, we propose a novel deep visual object tracking method that can be operated in robust to many challenging task. For the robust visual object tracking, we proposed a Convolutional Neural Network(CNN) which shares weight of the convolutional layers. Input of the CNN is a three; first frame object image, object image in a previous frame, and current search frame containing the object movement. Also we propose a method to consider the motion of the object when determining the current search area to search for the location of the object. Extensive experimental results on a authorized resource database showed that the proposed method outperformed than the conventional methods.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.384-386
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• 1998

The use of hand gesture provides an attractive alternative to cumbersome interface devices for human-computer interaction(HCI). Many methods hand gesture recognition using visual analysis have been proposed such as syntactical analysis, neural network(NN), Hidden Markov Model(HMM) and so on. In our research, a HMMs is proposed for alphabetical hand gesture recognition. In the preprocessing stage, the proposed approach consists of three different procedures for hand localization, hand tracking and gesture spotting. The hand location procedure detects the candidated regions on the basis of skin-color and motion in an image by using a color histogram matching and time-varying edge difference techniques. The hand tracking algorithm finds the centroid of a moving hand region, connect those centroids, and thus, produces a trajectory. The spotting a feature database, the proposed approach use the mesh feature code for codebook of HMM. In our experiments, 1300 alphabetical and 1300 untrained gestures are used for training and testing, respectively. Those experimental results demonstrate that the proposed approach yields a higher and satisfying recognition rate for the images with different sizes, shapes and skew angles.

• Journal of the Korean Society of Marine Environment & Safety
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• v.7 no.3
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• pp.1-16
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• 2001

In view of the fact that marine casualties have more often occurred recently, there is a need for ship-handling simulator as a useful tool for maritime training, safety assessment and so on. Moreover various kinds of hull forms have appeared for the purpose of improving ship manoeuvrality. Therefore ship-handling simulator is in need of a database for various ships, and it can make diverse maneuvering simulations possible to apply respective mathematical model to ship-handling simulator. In this paper, we adopted twin-screw and twin-rudder ship and discussed mathematical model of maneuvering motions for her. It was discussed from the viewpoint of hull damping forces at low advance speed and interaction between hull, propeller and rudder. Using this model, maneuvering motion of twin-screw and twin-propeller ship was simulated numerically and her principal manoeuvrability was examined.

• Journal of Internet Computing and Services
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• v.7 no.2
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• pp.1-8
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• 2006

Study of effective synthesis has been amplified in working-level image process corresponding to one of postproduction synthesis ares. However, it is very role to recognize the overall procedure of image composition and unprepared state on a research on variety and complexity for the specific composition method, it is necessary to materialize the overall pattern that can understand stream of image and standardization. In order to embody, it may be desirable that improve working efficiency of database by form called resources. In this paper, by providing the several values such as matte, key, motion, scale, position, or opacity characteristics, we directed th solving problems through the detailed examples while the user has the difficulty on image synthesis.