• Journal of KIISE:Computer Systems and Theory
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• v.29 no.8
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• pp.463-471
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• 2002

In order to implement virtual endoscopy, high-speed rendering algorithm that generates accurate perspective projection images and efficient collision detection method are essential. In this paper we propose an efficient virtual endoscopy system based on volume rendering technique. It is possible to skip over empty (transparent) space using the distance value produced in preprocessing time, and it does not deteriorate image quality since it is an extension of ray-casting. It also accelerates rendering speed with minimal loss of image quality by adjusting sampling interval along a ray according to direction of the ray. Using the distance information, we can simplify the collision detection of volumetric objects.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.601-605
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• 2009

Due to the fact that fish-eye lens can provide super wide angles with the minimum number of cameras, field-of-view over 180 degrees, many vehicles are attempting to mount the camera system. Camera calibration should be preceded, and geometrical correction on the radial distortion is needed to provide the images for the driver's assistance. However, vehicle fish-eye cameras have diagonal output images rather than circular images and have asymmetric distortion beyond the horizontal angle. In this paper, we introduce a camera model and metric calibration method for vehicle cameras which uses feature points of the image. And undistort the input image through a perspective projection, where straight lines should appear straight. The method fitted vehicle fish-eye lens with different field of views.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.11
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• pp.1080-1087
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• 2009

This paper presents an algorithm to acquire 3D geometric information using a virtual plane method. The method to measure 3D information on the plane is easy, because it's not concerning value on the z-axis. A plane can be made by arbitrary three points in the 3D space, so the algorithm is able to make a number of virtual planes from feature points on the target object. In this case, these geometric relations between the origin of each virtual plane and the origin of the target object coordinates should be expressed as known homogeneous matrices. To include this idea, the algorithm could induce simple matrix formula which is only concerning unknown geometric relation between the origin of target object and the origin of camera coordinates. Therefore, it's more fast and simple than other methods. For achieving the proposed method, a regular pin-hole camera model and a perspective projection matrix which is defined by a geometric relation between each coordinate system is used. In the final part of this paper, we demonstrate the techniques for a variety of applications, including measurements in industrial parts and known patches images.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.4
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• pp.512-519
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• 2012

This paper proposes a 3-D pose (positions and orientations) estimation system based on the recognition of circular ring patterns. To deal with monocular vision-based pose estimation problem, we specially design a circular ring pattern that has a simplicity merit in view of object recognition. A pose estimation procedure is described in detail, which utilizes the geometric transformation of a circular ring pattern in 2-D perspective projection space. The proposed method is evaluated through the analysis of accuracy and precision with respect to 3-D pose estimation of a quadrotor-type vehicle in 3-D space.

• Journal of Navigation and Port Research
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• v.34 no.9
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• pp.719-726
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• 2010

As the competition among the container terminals in Korea has become increasingly fierce, every terminal is striving to increase its investments constantly and lower its operational costs in order to maintain the competitive edge and provide satisfactory services to terminal users. The unreasoning behavior, however, has induced that substantial waste and inefficiency exists in container terminal production. Therefore, it is of great importance for the terminal to know whether it has fully used its existing infrastructures and that output has been maximized given the input. From this perspective, data envelopment analysis (DEA) provides a more appropriate benchmark. This study applies three models of DEA to acquire a variety of analytical results about the operational efficiency to the Korean container terminals. According to efficiency value analysis, this study first finds the reason of inefficiency. It is followed by identification of the potential areas of improvement for inefficient terminals by applying slack variable method and giving the projection results. Finally, return to scale approach is used to assess whether each terminal is in a state of increasing, decreasing, or constant return to scale. The results of this study can provide terminal managers with insight into resource allocation and optimization of the operating performance.

• Journal of Sensor Science and Technology
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• v.14 no.4
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• pp.278-285
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• 2005

This paper describes techniques of camera calibration and artificial landmarks detection for the automatic charging of a mobile robot, equipped with a fish-eye camera in the direction of its operation for movement or surveillance purposes. For its identification from the surrounding environments, three landmarks employed with infrared LEDs, were installed at the charging station. When the robot reaches a certain point, a signal is sent to the LEDs for activation, which allows the robot to easily detect the landmarks using its vision camera. To eliminate the effects of the outside light interference during the process, a difference image was generated by comparing the two images taken when the LEDs are on and off respectively. A fish-eye lens was used for the vision camera of the robot but the wide-angle lens resulted in a significant image distortion. The radial lens distortion was corrected after linear perspective projection transformation based on the pin-hole model. In the experiment, the designed system showed sensing accuracy of ${\pm}10$ mm in position and ${\pm}1^{\circ}$ in orientation at the distance of 550 mm.

• Journal of Information Technology Services
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• v.16 no.4
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• pp.1-13
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• 2017

This study examines how specific technology from Information and Communications Technology (ICT)-which plays a critical role in increasing productivity by promoting a spread of technology across the society though the use of big data, mobile or wearable devices-impacts of the productivity of society and productivity of added values, respectively. The impact of technology was studied from the perspective of efficiency levels of input. In order to provide an analysis, we have categorized ICT into 16 specific technologies and have set the number of companies and number of employees each as an input factor while setting the respective output and the output of added values as an output factor. Afterwards, we have applied data envelopment analysis (DEA) which is a form of nonparametric frontier analysis and measured the productivity and efficiency of added values for each technology. According to the analysis results, there were 2 technologies by the CRS standards, and 3 technologies by the VRS standards that showed relative efficiency levels. We have also presented some efficiency improvement strategies for specific technologies that revealed relative inefficiency and offered a reference set and projection point. In addition, we provide an analysis on scale efficiencies (SE), diminishing returns to scale (DRS), and increasing returns to scale (IRS) of each ICT.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.147-153
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• 1998

This paper provides a method for video augmentation using image interpolation. In computer graphics or augmented reality, 3D information of a model object is necessary to generate 2D views of the model, which are then inserted into or overlayed on environmental views or real video frames. However, we do not require any three dimensional model but images of the model object at some locations to render views according to the motion of video camera which is calculated by an SFM algorithm using point matches under weak-perspective (scaled-orthographic) projection model. Thus, a linear view interpolation algorithm is applied rather than a 3D ray-tracing method to get a view of the model at different viewpoints from model views. In order to get novel views in a way that agrees with the camera motion the camera coordinate system is embedded into model coordinate system at initialization time on the basis of 3D information recovered from video images and model views, respectively. During the sequence, motion parameters from video frames are used to compute interpolation parameters, and rendered model views are overlayed on corresponding video frames. Experimental results for real video frames and model views are given. Finally, discussion on the limitations of the method and subjects for future research are provided.

• KSBB Journal
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• v.32 no.1
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• pp.29-34
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• 2017

The completion of the Human Genome Project that identified all 3 billion base pairs in the human genome can be seen as a step towards understanding the relay of information and intention within an organism, or in other words, the language of life. The faculty of human language, key to differentiating humans from other animate species, works for conveying information to others by mapping meaning to sound based on syntactic structures. This resemblance between life and language has not gone unnoticed; the literature on RNA transcription and translation research regularly uses linguistic metaphors and the biolinguistic perspective of language has also been studied. By examining the biological characteristics of language and the linguistic characteristics of life, this study aims to identify key mechanisms shared between the two systems in order to promote a stronger connection between them. It furthers this goal by pointing out two general messages to which these mechanisms aim, productivity and accuracy, and discovers what lesson these messages give to a human society geared for sustainability.

• Korea journal of population studies
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• v.29 no.1
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• pp.209-239
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• 2006

본 연구는 총부양비를 최소화하는 적정인구성장률을 인구학적 부양비와 경제적 부양비로 나누어 계산하구 그것이 무엇을 의미하가를 연구하는 것이 목적이다. 이 연구를 위하여 연구모형을 제시하고, 합계출산율과 적정인구성장률의 관계를 명시하며, 그것이 궁극적으로 적정인구 규모에 어떤 의미를 갖는가를 탐색한다. 인구학적 부양비를 최소화하는 인구성장률은 $-0.03%{\sim}0.15%$의 범위에 있으며, 그것은 합계 출산율로는 $2.1{\sim}2.2$명에 해당한다. 경제적 부양비를 최소화하는 인구성장률은 유년층과 노년층의 상대적 개인 소비비중에 따라 인구성장률과 그것이 함의하는 합계출산율은 달라진다. 예컨대, $u_1:u_3=2:1$일 때 적정인구성장률은 $-1.17{\sim}-0.93%$, 그것이 함의하는 합계출산율은 $1.5{\sim}1.6$명이다. 한편 유년층 대비 노년층의 상대적 소비비중이 증가하는 경우에는 적정인구성장율이 높아져야 한다. 예컨대 $u_1:u_2=1:1.2$일 때 적정인구성장률은 $0.42{\sim}0.45%$이고, 그것이 함의하는 합계출산율은 $2.3{\sim}2.4$명이다. 본 연구에서 적정인구추계를 위한 기초 여론조사에 따라 진행된 상대적 소비비중을 계산한 결과에 따르면, 유년층과 노년층의 상대적 개인 소비비중은 $u_1:u_2=1.25:1$이며, 이에 따른 현재의 상황에서 한국의 적정출산율은 $1.9{\sim}2.0$명 수준으로, 이에 해당하는 적정인구성장률은 대략 약간의 네거티브 성장을 하는 경우라고 할 수 있을 것이다.