• Journal of the Society of Naval Architects of Korea
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• v.48 no.5
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• pp.414-420
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• 2011

Decades of studies of geophysical flow have unveiled that the flow downstream of obstacles in stratified flow consists of attached wake and strong gravity waves, or separated, fluctuating wake and persistent late wakes. Among unique and interesting characteristics of the stratified flow past obstacles is the generation of coherent vortex in the late wake far downstream of the object. Unlike in homogeneous fluid, the flow field downstream self-develops coherent vortex even after diminishing of the near wake, no matter how small the stratification is. This paper present a computational approach to simulate the generation of the coherent vortex structure in the late wake of a moving sphere submerged in weakly stratified fluid. The results are in consistent with several experimental observations and the vortex stretching mechanism is employed to explain the process of coherence.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.443-446
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• 2002

Wake downstream of an object in the stratified flow has been of long-standing interest in fluid dynamics because of its similarity to geophysical flow over topographical terrains and more recently, concerns about the wake left behind a body moving through the ocean thermocline. Decades of studies of geophysical flow have unveiled that the flow downstream of obstacles in stratified flow consists of attached wake and strong internal waves, or separated, fluctuating wake and persistent late wakes, all of which depend on the flow conditions. Among unique and interesting characteristics of the stratified flow past obstacles is the generation of coherent vortex structure in the late wake far downstream of the object. Without the density stratification, the flow field downstream becomes undisturbed after relatively fast diminishing of the near wake. However, no matter how small the stratification is, the flow field downstream self-develops coherent vortex structures even after diminishing of the near wake. This paper present a computational approach to simulate the generation mechanism of the coherent vortex and analysis of the vortical structure.

• Korean Journal of Computational Design and Engineering
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• v.11 no.6
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• pp.455-463
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• 2006

Hidden line removal(HLR) algorithms can be devised either in the image space or in the object space. This paper describes a hidden line removal algorithm in the object space specifically for the CAD viewer data. The approach is based on the Appel's 'Quantitative Invisibility' algorithm and fundamental concept of 'back face culling'. Input data considered in this algorithm can be distinguished from those considered for HLR algorithm in general. The original QI algorithm can be applied for the polyhedron models. During preprocessing step of our proposed algorithm, the self intersecting surfaces in the view direction are divided along the silhouette curves so that the QI algorithm can be applied. By this way the algorithm can be used for any triangulated freeform surfaces. A major advantage of this algorithm is the applicability to general CAD models and surface-based visualization data.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2002.11a
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• pp.179-182
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• 2002

Today, augmentation of industrial wastes with industrial development demands diminution and recycling technical development for industrial wastes reduction. A statistical research of industry and constructional wastes as a request of the times can achieve the conservation of resource and the protection of environment. The ultimate object of the study is not only diminution and recycling of industrial wastes but also the degree of self-sufficiency in resource and the attainment of comfortable life environment, which can the accomplish the resource circulation system and make progress into the environmentally advanced country. The object of this investigation is industrial classification, a waste discharge quantity, a waste sort, waste disposal of industrial wastes in Yeung-nam area. The investigation of special quality in industrial wastes can be used to establish a wastes management policy and a disposition method .

• Journal of information and communication convergence engineering
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• v.17 no.4
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• pp.274-278
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• 2019

It is important that students are provided opportunities to practice their skills in acquiring radiographic images. However, these opportunities are currently limited because of the risk of radiation exposure. To overcome this limitation, a new augmented reality-based radiography simulator was developed that enables students to practice radiographic techniques as part of self-directed learning without time and space constraints. Subsequently, cross-sectional images of a manikin phantom head obtained via computed tomography were reconstructed into a three-dimensional object. An image marker that could be recognized by a mobile device and could allow users to practice dental radiography techniques was devised. The three-dimensional object was augmented to the mobile device; consequently, among 106 stored dental radiographs on the device, a radiograph corresponding to specific imaging conditions was opened when users performed radiographic procedures. This technology could improve dental students' understanding of dental anatomy and contribute to improving their competency in acquiring dental radiographs.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1237-1239
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• 1996

3-D object recognition and restoration independent of the translation and rotation using an ultrasonic sensor array, neural networks and invariant moment are presented. Using invariant moment vectors on the acquired $16{\times}8$ pixel data, 3-D objects can be classified by SOFM(Self Organizing Feature Map) neural networks. Invariant moment vectors kept constant independent of the translation and rotation. The experiment result shows the suggested method can be applied to the environment recognition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.321-324
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• 1997

In this study, Efficiency estimation of ultrasonic sensor fabricated with porous piezoelectric resonator by experiment of 3-D underwater object recognition are presented. The sensor was satisfied with requirement of ultrasonic sensor. The recognition rates for the fixed objects and the translation-rotation objects are 95.3 and 92.7[%], respectively using porous piezoelectric ultrasonic sensor and SOFM neural network. According to the experimental results, It is believed that the self-made ultrasonic sensor can be applied as underwater ultrasonic sensor.

• Journal of Korea Multimedia Society
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• v.12 no.12
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• pp.1728-1735
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• 2009

Human action tracking plays an important place in human-computer-interaction, human action tracking is a challenging task because of the exponentially increased computational complexity in terms of the degrees of freedom of the object and the severe image ambiguities incurred by frequent self-occlusions. In this paper, we will propose a novel method to track human action, in our technique, a dynamic background estimation algorithm will be applied firstly. Based on the estimated background, we then extract the human object from the video sequence, and the skeletonization method and Hough transform method will be used to detect the main structure of human body and each part rotation angle. The calculated rotation angles will be used to control a crane in the port, thus we can just control the container crane by using signalman body. And the experimental results can show that our proposed method can get a preferable result than the conventional methods such as: MIT, JPF or MFMC.

• Research in Community and Public Health Nursing
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• v.10 no.1
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• pp.140-153
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• 1999

This study is designed to furnish basic data for development of health -care program to promote health of the middle-aged adult by making the middle-aged adult an object who have radically increasing death rate because of chronic degenerative diaease, finding out the executive degree of health -promoting behaviors, and verifying the relation between self-efficacy/perceived health status and health -promoting behaviors. The results are as follows. 1) The hypothesis that 'the higher the self-efficacy, the better the health -promoting behaviors' was supported on a meaningful level(r=.30l, p=.000) 2) The hypothesis that 'The health-promoting behaviors will have differences according to the perceived health status' was supported on a meaningful level in the sections of the control of stress(p=.000), the self-achievement (p=.000), the exercise(p=.002), the control of interpersonal relation(p=.014) and the eating habit(p=.061) and was rejected in the sections of drinking' smoking(p=.787), heath-responsibility (p=.061). The fact that executive degree of health -promoting life-style have correlation with self-efficacy was found out and we need to develop health-education program to promote self-efficacy.

• Therapeutic Science for Rehabilitation
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• v.3 no.2
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• pp.59-69
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• 2014

Objective : This study was done to see that upper limb reaching task have an effect on stroke patient's upper limb function and self-efficacy. Methods : The object of the study was done to see for diagnosed with stroke man on the thirty-ninth of this month. upper limb reaching task was done to see three times a for 6 week and by a per for thirty minutes. To find changing upper limb function and self-efficacy before-after upper limb reaching task, they were measured using Box & block test and self-efficacy scale. Results : Box & block test and self- efficacy scale were increased mark of revaluation, evaluation result than one of early evaluation result. Conclusion : Through this study, upper limb reaching task applied to stroke patient was found that it improved stroke patient's upper limb function and self-efficacy.