• Journal of the Korean Society for Precision Engineering
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• v.26 no.6
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• pp.68-73
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• 2009

One of the traditional optical methods to monitor a tool is a CCD sensor-based vision system which captures an aspect of the tool in real time. In the case using the CCD sensor, specific lens-modules are necessary to monitor the tool with higher resolution than its pixel size, and a microprocessor is required to attain desired data from captured images. Thus theses additional devices make the entire measurement system complex. Another method is to use a pair of an optical source and a detector per measuring axis. Since the method is based on the intensity modulation, the structure of the measurement system is simper than the CCD sensor-based vision system. However, in the case measuring the three dimensional position of the tool, it is difficult to apply to micro machine-tools because there may not be space to integrate three pairs of an optical source and a detector. In this paper, in order to develop a tool-origin measurement system which is employed in micro machine-tools, the improved method to measure a tool origin in x, y and z axes is introduced. The method is based on the intensity modulation and employs one pair of an optical source radiating divergent beams and a quadrant photodiode to detect a three dimensional position of the tool. This paper presents the measurement models of the proposed tool-origin sensor. The models were verified experimentally The verification results show that the proposed method is possible and the induced models are available for design.

• Tunnel and Underground Space
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• v.27 no.5
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• pp.333-342
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• 2017

In this study, the heterogeneity of internal structure of various igneous rocks acquired in Korea was quantified and correlated with the seismic velocity and the point load strength. Three-dimensional X-ray Computed Tomography (CT) was used to obtain information on the internal structure of the rock specimen, and the representative unit length (LR) was calculated by applying a statistical technique to the CT images. We also proposed an estimation equation to predict the mechanical properties of rocks from the relationship between LR, acoustic velocity and point load strength. In the proposed method, it is shown that the characterization of internal structure of rocks could be utilized as an indirect index to account for the mechanical behavior of rocks by substituting physical laboratory testing for non-destructive test.

• Journal of Veterinary Clinics
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• v.30 no.5
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• pp.366-370
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• 2013

A 7-month-old Pomeranian presented with non-weight bearing lameness on the right pelvic limb. Physical examination revealed pain on extension of the right hip joint, and serum chemistry results showed an increased concentration of creatine kinase. Radiographic findings at admission included a weak radiolucent line on the right femoral head and widening of the right hip joint space, and mild displacement of the right capital femoral epiphysis was additionally identified on day 14. Computed tomography (CT) showed a decreased Hounsfield Unit measurement and a fracture line on the right femoral head. Early stage Legg-Calve-Perthes disease (LCPD) was diagnosed and femoral head and neck ostectomy was performed on the right femur. A fracture fissure and osteophytes at the epiphyseal plate of the femoral head were identified surgically. Necrosis in the femoral metaphysis and epiphysis was observed histologically. This case report describes the radiography, CT images, and surgical and histological findings in a dog with early stage LCPD.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.32.1-32.1
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• 2018

Searching for low surface brightness (LSB) dwarf galaxies in low density environments (isolated and group) can help us resolve the discrepancy between observation and theory known as the 'missing satellite' problem. They are also important to study the evolution of low mass galaxies in these environments. Although the number of dwarfs in such environments is rapidly increasing in many recent studies, it is still not easy to characterize their general properties. Motivated by this, we present preliminary results of our search for LSB dwarf galaxies around 60 nearby galaxies (D<50Mpc) using deep optical images. Imaging data from Maidanak Astronomical Observatory (MAO) in Uzbekistan as a part of Intensive Monitoring Survey of Nearby Galaxies (IMSNG; Im in prep.) and other archival data are used to find previously unknown LSB dwarf galaxies. Extended LSB sources (central surface brightness ${\mu}_0$ > $23mag/arcsec^2$) are first selected in the ${\mu}_0$ - magnitude plane (Rines & Geller 2008). The dwarf galaxy candidates are chosen by visual inspection. We discuss whether these candidates are actual satellite galaxies, by measuring the projected number densities in group environments and in the field. Also, their structural and photometric properties are compared with those of previously discovered dwarf galaxies in the literature.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.11
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• pp.1029-1035
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• 2013

This paper proposes a real time lane detection algorithm using LRF (Laser Range Finder) for autonomous navigation of a mobile robot. There are many technologies for safety of the vehicles such as airbags, ABS, EPS etc. The real time lane detection is a fundamental requirement for an automobile system that utilizes outside information of automobiles. Representative methods of lane recognition are vision-based and LRF-based systems. By the vision-based system, recognition of environment for three dimensional space becomes excellent only in good conditions for capturing images. However there are so many unexpected barriers such as bad illumination, occlusions, and vibrations that the vision cannot be used for satisfying the fundamental requirement. In this paper, we introduce a three dimensional lane detection algorithm using LRF, which is very robust against the illumination. For the three dimensional lane detections, the laser reflection difference between the asphalt and lane according to the color and distance has been utilized with the extraction of feature points. Also a stable tracking algorithm is introduced empirically in this research. The performance of the proposed algorithm of lane detection and tracking has been verified through the real experiments.

• Aerospace Engineering and Technology
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• v.12 no.2
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• pp.30-39
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• 2013

In this study, calibration processes and methods of evaluating the radiometric quality of satellite images from the meteorological payload on the GEO-KOMPSAT-2A were described. MTF(Modulation Transfer Function), SNR(Signal-To-Noise Ratio), NEdT(Noise Equivalent Delta Temperature), and Dynamic Range, which are the major parameters for assessment of data radiometric quality of space-borne visible and infrared sensors, are focused. Key process of the quality check of the satellite data is the comparing the image radiometric performance parameters during the In-Oribit Test with those acquired from the ground tests. Validation plan of the image quality of the GEO-KOMPSAT-2A Meteorological Imager is addressed based on the analyses results of COMS MI data during the COMS In-Orbit Test period

• The Journal of the Korea Contents Association
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• v.6 no.2
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• pp.44-50
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• 2006

This study has proposed a method of content-based image retrieval using object region in order to overcome disadvantages of existing color histogram methods. The existing color histogram methods have a weak point of reducing accuracy, because these have both a quantization error and an absence of spatial information. In order to overcome this problem, we convert a color information to a HSV space, quantize hue factor being pure color information, and calculate histogram. And then we use hue for retrieval feature that is robust in brightness, movement, and rotation. To solve the problem of the absence of spatial information, we select object region in terms of color feature and region correlation. And we use both the edge and the DC in the selected region for retrieving. As a result of experiment with 1,000 natural color images, the proposed method shows better precision and recall than the existing methods.

• Korea Multimedia Society
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• v.14 no.4
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• pp.88-98
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• 2010

It is now the era of ubiquitous which is highly integrated on the convergence technologies with not only ICT bul also BT, CT, NT and ST. Through this convergence technology, the understanding on visualization of 3D virtual reality which make more human's 5 feelings activate beyond the wall of time and space is recently very important. We search the visualization technology of 3D virtual reality and estimate the future development, and give the perspectives. Since the visualization technology of virtual reality is strongly depended on 3D computer graphics representations, 3D image visualization technology being able to get immersion has been possible. The new paradym on computer interactions is implemented by making images augment on the base of the PC and display equipments. The studies is established on the direction of more intensity on humanity. And also, these technologies will be able to achieve actively the implementations for ubiquitous society dueing to get the high-technology on the superhighway networks.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.2
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• pp.337-345
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• 1994

Arthrography of the temporomandibular joint is a useful method of demonstrating the soft tissue abnormalities related to disc dysfunction. In this study, 19 asymptomatic joints, 31 joints with anterior disc displacement with reduction, 31 joints with anterior disc displacement without reduction which were classified by arthrotomography under fluoroscopy were evaluated to determine the linear measurement of anterior recess of inferior joint space and the relationship between the condylar anterior translation and the severity of the internal derangements. Their fluoroscopic images were also evaluated to describe the characteristics of condylar paths in internal derangements of the temporomandibular joints. The results were as follows; 1. The mean lengths of the anterior recess in asymptomaic group. reduction group. and non-reduction group were 8.7±1.6㎜. 11.2±1.7㎜, 12.8±1.7㎜ respectively. The length of the anterior recess was increased according to the severity of the internal derangements(P<0.05). 2. Linear measurements of anterior movement of condyle on maximum mouth opening were 13.1 ±4.2㎜, 15.9±4.1㎜, 5.0±3.7㎜ in asymptomatic group. reduction group, and non-reduction group respectively. Compared with asymptomatic group, reduction group showed hypermobolity of the condyle and non-reduction group showed hypomobility. 3. Condyles moved beyond the crest of articular eminence in 80% of reduction group and did not reach it in 70% of non-reduction group. 4. The condyle moved mainly superiorly in reduction group(66%) and horizontally in asymptomatic group(47%). There were no cases to move superiorly in non-reduction group.

• Journal of the Korean Society of Costume
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• v.57 no.4 s.113
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• pp.70-80
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• 2007

Clothes and human body are inseparably related. Aesthetic consciousness of the body determines the form of clothing, reflecting the time and culture as well as the individual and society. Clothes can even reorganize the meaning of the body, while transcending their instrumental functions of protecting, expanding and deforming the body. Using 'body' to analyze the clothing form, my study develops a framework by which to classify transfiguration in fashion design. In order to inquire tile formative style and aesthetic values expressed in transfiguration in fashion, my study examines subjects from the discourse on the body to the fashion collections of the late 20th and 21st century. The results of the study are as follows. Transfiguration signifies absence of body which questions the three dimensional construction of the body in more conventional clothing system. Transfiguration is expressed in non-figural forms which implies metaphorical plasticity and abstract extensity. Transfiguration in fashion stresses a will-to-form rather than mere bodily proportion and structure, which explores trans-extensity that goes beyond the boundary of the body. Ultimately, this phase also betrays the correspondence between signifiant and $signifi\acute{e}$ in sartorial convention. Aesthetic ideal of the body is visualized in the form of a dress. Some clothes prioritize the body, particularly the feminine bodily curves, while others focus on the clothing itself as abstract and sculptural forms. Fashion continues to explore forms and images that transcend the traditional representations of the clothed body. As a type of intimate architecture, fashion always mediates the dialogue between clothes and body, or fashion and figure. My study suggests a framework to analyze bodily representation in transfiguration in fashion, focusing on the relationship between the clothes and body.