• Journal of the Korean Society for Precision Engineering
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• v.13 no.9
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• pp.104-113
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• 1996

In robot system, the robot manipulation needs the information of task and objects to be handled in possessing a variaty of positions and orientations. In the current industrial robot system, determining position and orientation of objects under industrial environments is one of major problems. In order to pick up an object, the roblt needs the information about the position and orientation of object, and between objects and gripper. When sensing is accomplished by pinhole model camera, the mathematical relationship between object points and their images is expressed in terms of perspective, i.e., central projection. In this paper, a new approach to determine the information of the supporting points related to position and orientation of the object using the robot vision system is developed and testified in experimental setup. The result will be useful for the industrial, agricultural, and autonomous robot.

• Smart Media Journal
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• v.8 no.1
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• pp.43-50
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• 2019

As numerous devices are connected through a wireless network, there exist many studies conducted to efficiently connect the devices. While earlier studies often use clustering for efficient device management, there is a load-intensive cluster node which may lead the entire network to be unstable. In order to solve this problem, we propose a scheduling model for centralized unequal chain clustering for efficient management of sensor nodes. For the cluster configuration, this study is based on the cluster head range and the distance to the base station(BS). The main vector projection technique is used to construct clustering with concentricity where the positions of the base stations are not the same. We utilize a multiple radio access interface, multiple-input multiple-output (MIMO), for data transmission. Experiments show that cluster head energy consumption is reduced and network lifetime is improved.

• Journal of the Korea Computer Graphics Society
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• v.26 no.3
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• pp.133-142
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• 2020

In this research, we describe the method of implementing a 360-degree panorama using one projector, in terms of hardware and in the production of projected pre-distortion images. We propose a method of installing a projector and a reflector on the central ceiling of the space to minimize the shadows generated based on the position of the spectators. We used a virtual camera and virtual space where the projector and hemisphere positions were set to the same as in the exhibition space in Unity. After the image projected on the screen was mapped on the wall of the virtual space, the pre-distortion image was created by the method of capturing from the virtual camera using the ray tracing technique. When the produced pre-distortion image is hemispherical reflected and projected by the projector installed at the same position as the virtual camera, the image is reflected and projected 360 degrees on the panoramic screen.

• Korean Journal of Optics and Photonics
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• v.6 no.3
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• pp.188-200
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• 1995

A design of unit magnification 2-mirror system with high resolution is presented. It is for soft X-ray(wavelength of 13 nm) projection imaging and suitable for preparation of high density semiconductor chip. In general, a holosymmetric system with unit magnification has the advantage that both coma and distortion are completely eliminated. In our holosymmetric 2-mirror system, spherical aberration is addtionally removed by using two identical paraboloidal mirror surfaces and field curvature aberration is also corrected by balancing Petzval sum and astigmatism which depends on the distance between two mirrors, so that the system is a aplanatic flat-field paraboloidal 2-mirror holosymmetric system. This 2-mirror system is small in size, and has a simple configuration with rotational symmetry about optical axis, and has also small central obscuration. Residual finite aberrations, spot diagrams, and diffraction-based MTF's are analyzed for the check of performances as soft X-ray lithography projection system. As a result, the image sizes for the resolutions of$0.25\mum$and $0.18\mum$are 4.0 mm, 2.5 mm respectively, and depths of focus for those are $2.5\mum$, $2.4\mum$respectively. This system should be useful in the fabrication of 256 Mega DRAM or 1 Giga DRAM. DRAM.

• 한국벤처창업학회:학술대회논문집
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• 2019.04a
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• pp.79-85
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• 2019

대학의 지역 공헌활동에 대한 역할 증대, 학령인구의 지속적 감소와 이에 따른 재정문제에 대비한 대학의 수익원 창출 노력 등, 대학을 중심으로 재정, 지역연계 역할, 정부 및 연구기관과의 활동 등 대학과 지역의 상호발전을 위한 현실적 과제가 증가됨에 따라 대학 스스로 내부자원을 활용한 발전계획을 기획하고 시행할 필요가 있다. 뿐만 아니라 중앙 또는 지방정부의 대학재정 지원 시, 이러한 활동의 표준을 정해보고 활동에 대한 측정 등을 할 수 있는 지표 설정이 필요하다. 기존 대학의 지역연계 활동과 성과지표 선정 등에 대한 다양한 보고서와 논문 등을 선행연구로 하고 대학 중심의 창업지원과제 등을 중심으로 대학을 중심으로 한 다양한 창업혁신활동 주체를 도출, 이들과의 협력관계에 대한 내용을 선별하고 이를 투입, 활동, 실적, 성과 등으로 구분하여 보았다. 활동 및 주체의 타당성 확보를 위해 학계, 창투사, 연구기관의 창업관련 다양한 전문가를 대상으로 측정변수에 대한 타당성 측정 및 AHP 분석을 통한 변수의 적합도를 분석하여 창업활동 주체 및 평가지표 등을 도출 하였다. 본 논문을 통하여 대학은 지역의 기업, 정부/공공기관, 연구기관, 투자기관 등과 협업 연계할 수 있는 주체간의 연관가능 활동과 해당 기관의 자원을 연계하여 지역발전에 기여할 수 있는 모델 및 이를 측정할 수 있는 지표 및 주요 내용을 도출 할 수 있었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.672-678
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• 2017

In this paper, we studied a design method for a broadband quasi-Yagi antenna (QYA) for terrestrial digital television (DTV) reception. The proposed antenna is composed of a dipole driver, a rectangular patch type director close to the dipole, and a ground reflector printed on an FR4 substrate. A balun between a microstrip line and a coplanar strip (CPS) line is a rectangular patch inserted along the center of the CPS. The end of the balun is connected to the CPS line through a shorting pin. An antenna, as an design example for the proposed antenna, is designed for the operation in the frequency band of 470-806 MHz for terrestrial DTV, and the characteristics of the designed antenna are examined. The antenna has a good performance such as a frequency band of 430-842 MHz for a voltage standing wave ratio < 2, a gain > 3.7 dBi, and a front-to-back ratio > 7.4 dB.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.4
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• pp.11-21
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• 2000

This paper proposes a new algorithm for a mobile robot that detects and tracks a moving target, keeping it in the view range of the robot. The sensor system consists of a camera and a line light source. The camera system is placed so that the line light projected into the ground from the light source forms its image along the horizontal center line of the CCD array of the camera. The deformation of the line image from the horizontal center line contains the information on existence of a moving object, its velocity, and position. Since the proposed algorithm reduces the region of the image to be searched, it reduces the computational complexity significantly comparing to the conventional image processing algorithms. The performance of the proposed algorithm has been tested by implementing on a mobile robot.

• Journal of the Daesoon Academy of Sciences
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• v.40
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• pp.303-336
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• 2022

'Otherness' is a major philosophical concept in modern Western thought. It has been a force through which the concept of a subject's rights emerged. This paper focuses on Emmanuel Levinas' discussion of 'otherness.' Levinas emphasizes our ethical responsibility for others, which is meaningful in that it can be applied as a paradigm of communication for use in modern society. In the context of modern times and multicultural societies, it is important to recognize the diversity of others and to promote coexistence. Coexistence at this time should be 'unifying' rather than subject-centered. This paper attempts to understand this narrative. An epic is a cognitive process that constitutes the fundamental desires and experiences of humans. Humans try to project and understand themselves through narratives. The possibility of coexistence with others can be examined by analyzing otherness as found within those narratives. Therefore, this paper suggests the possibility and direction of coexistence by analyzing the storytelling that establishes relationships by shaping characters in Guillermo del Toro's film, Shape of Water.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.4
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• pp.301-309
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• 2015

Purpose: When the edentulous area is restored by implant prostheses, the opposing hypofunctioned teeth will receive physiologic mechanical stimuli. This study evaluated the bone changes around the maxillary teeth opposing an implant restoration installed in the mandibular posterior area. Materials and Methods: Radiographs of the opposing teeth were taken at prostheses delivery (baseline), 3 and 6 months later. A customized film holding device was fabricated to standardize the projection geometry for the serial radiographs of the opposing teeth. The gray values of the region of interest of each digital image were compared according to time. Repeated measured analysis of variance was performed at the 95% significance level. Results: The gray values of the alveolar bone around the antagonist teeth of implants increased with time. The changes in gray values of the middle area were greater than those of the crestal area. However, the gray values of the mesial and distal areas were not different. The changes in gray values were different according to the unloaded time. Conclusion: A change in bone tissue will occur if a proper physiologic load is again applied to the bone tissues around a hypofunctioned tooth.

• Korean Journal of Applied Biomechanics
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• v.18 no.3
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• pp.61-69
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• 2008

The purpose of this study is to examine the success or failure on the balance beam in element group requirements posture which is bending salto side-ward tucked through kinetic analysis. The national team players were participated. The goal was to present training methods to coaches and athletes so as to provide scientifically useful information. The results from this study were summarized as below. When the performance was successful, the features of the body's center of gravity during the side somersault motion showed to spread from the center of the balance beam and the center of the gravity moved to the direction of the body's rotation. In the spring sections - event2 and 3, when the performance was successful, up/down fluctuation became more wider and increased air time. It supported the result that the projecting variable was higher than in failure trial. In addition, the right side hip joint angles and speed, and angular velocity as jumping up for a leap were larger than in failure trial. Those variables showed the optimal conditions for a leap. By increasing the speed of the upper limb from the shoulder and the speed of the shoulder joint angular velocity, the momentum was increased. Especially the right side shoulder joint angular velocity increased dramatically because the right leg was held. As to the side somersault motion, the angular momentum of successful trial with respect to x-axis was bigger than failed trial. It indicated that the increasing angular momentum with respect to x-axis was an important factor in flying motion. Besides, as to side somersault, the appropriate proportion of angular momentum with respect to y-axis and z-axis was a key to successful trails.