• Imaging Science in Dentistry
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• v.46 no.4
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• pp.251-258
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• 2016

Purpose: The aim of this study was to examine the radiographic features associated with impacted premaxillary supernumerary teeth, to determine the relationship between their characteristics and their effects on permanent incisors, and to investigate the types of orthodontic treatment that patients received after the extraction of impacted supernumerary teeth. Materials and Methods: The clinical records and radiographs of 193 patients whose impacted premaxillary supernumerary teeth were removed were retrospectively reviewed, and 241 impacted supernumerary teeth were examined. Cone-beam computed tomographic images and panoramic radiographs were examined to determine the number, location, sagittal position, orientation, and morphology of the supernumerary teeth. Their effects on permanent incisors and the orthodontic treatment received by patients after the extraction of the supernumeraries were also investigated. Results: Supernumerary teeth were most frequently observed in the central incisor region, in the palatal position, in the inverted orientation, and were most commonly conical in shape. The most common complication was median diastema, followed by displacement and delayed eruption of the adjacent incisors. Ten (71.4%) of the 14 odontomas showed delayed eruption of the adjacent incisors. Displacement of the incisors was more frequently observed in association with supernumerary teeth with tuberculate or supplemental shapes. Orthodontic traction was most frequently performed after the removal of odontomas. In 32 cases (13.3%), permanent incisors erupted after the orthodontic creation of sufficient space. Conclusion: Median diastema was most common complication. The delayed eruption of incisors was common in supernumerary teeth with a vertical orientation and an odontoma shape.

• Archives of Plastic Surgery
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• v.45 no.2
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• pp.152-157
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• 2018

Background Intraoperative indocyanine green (ICG) lymphography can effectively detect functioning lymph vessels in edematous limbs. However, it is sometimes difficult to clearly identify their course in later-stage edematous limbs. For this reason, many surgeons rely on experience when they decide where to make the skin incision to locate the lymphatic vessels. The purpose of this study was to elucidate lymphatic vessel flow patterns in healthy upper extremities in a Korean population and to use these findings as a reference for lymphedema treatment. Methods ICG fluorescence lymphography was performed by injecting 1 mL of ICG into the second web space of the hand. After 4 hours, fluorescence images of lymphatic vessels were obtained with a near-infrared camera, and the lymphatic vessels were marked. Three landmarks were designated: the radial styloid process, the mid-portion of the cubital fossa, and the lower border of the deltopectoral groove. A straight line connecting the points was drawn, and the distance between the connected lines and the marked lymphatic vessels was measured at 8 points. Results There were 30 healthy upper extremities (15 right and 15 left). The average course of the main lymph vessels passed $26.0{\pm}11.6mm$ dorsal to the styloid process, $5.7{\pm}40.7mm$ medial to the mid-cubital fossa, and $31.3{\pm}26.1mm$ medial to the three-quarters point of the upper landmark line. Conclusions The main functioning lymphatic vessel follows the course of the cephalic vein at the forearm level, crosses the mid-cubital point, and travels medially toward the mid-axilla.

• Tunnel and Underground Space
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• v.25 no.5
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• pp.435-449
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• 2015

Physical and microstructural properties of Pungchon and Maggol limestone were investigated quantitatively during 50 cycles of artificial freezing and thawing test. There were decrease in dry weight and P,S-wave velocity, and increase in absorption rate in both rock types. Porosity, pore volume, equivalent diameter, throat thickness and pore orientation were analyzed using X-ray computed tomography images. Porosity increased, and initiation and expansion of pores were investigated as weathering progresses. Physical and microstructural variation in Maggol limestone was larger than that of Pungchon limestone because Maggol limestone has more pores and microcracks at initial state. As this study analyzes physical and microstructural properties of rock specimens comprehensively, it can be applied to further rock weathering study and can be used as fundamental data of construction and resource development in cold regions.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.5
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• pp.1011-1019
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• 2015

CAPTCHA(Completely Automated Public Turing test to tell Computers and Humans Apart) is a test used in computing to distinguish whether or not the user is computer or human. Many web sites mostly use the character-based CAPTCHA consisting of digits and characters. Recently, with the development of OCR technology, simple character-based CAPTCHA are broken quite easily. As an alternative, many web sites add noise to make it harder for recognition. In this paper, we analyzed the most recent CAPTCHA, which incorporates the addition of the natural images to obfuscate the characters. We proposed an efficient method using support vector machine to separate the characters from the background image and use convolutional neural network to recognize each characters. As a result, 368 out of 1000 CAPTCHAs were correctly identified, it was demonstrated that the current CAPTCHA is not safe.

• Advances in aircraft and spacecraft science
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• v.3 no.4
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• pp.427-445
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• 2016

Star sensors are the attitude estimation sensors of the satellite orbiting in its path. It gives information to the control station on the earth about where the satellite is heading towards. It captures the images of a predetermined reference star. By comparing this image with that of the one captured from the earth, exact position of the satellite is determined. In the process of imaging, stray lights are eliminated from reaching the optic lens by the mechanical enclosures of the star sensors called Baffles. Research in space domain in the last few years is mainly focused on increased payload capacity and reduction in launch cost. In this paper, a star sensor baffle made of Aluminium is considered for the study. In order to minimize the component weight, material wastage and to improve the structural performance, an alternate material to Aluminium is investigated. Carbon Fiber Reinforced Polymer is found to be a better substitute in this regard. Design optimisation studies are carried out by adopting suitable design modifications like implementing an additional L-shaped flange, Upward flange projections, downward flange projections etc. A better configuration of the baffle, satisfying the design requirements and achieving manufacturing feasibility is attained. Geometrical modeling of the baffle is done by using UNIGRAPHICS-Nx7.5(R). Structural behavior of the baffle is analysed by FE analysis such as normal mode analysis, linear static analysis, and linear buckling analysis using MSC/PATRAN(R), MSC-NASTRAN(R) as the solver to validate the stiffness, strength and stability requirements respectively. Effect of the layup sequence and the fiber orientation angle of the composite layup on the stiffness are also studied.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.6
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• pp.555-562
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• 2019

This paper presents soil deformation measurement in model chamber based on photogrammetry. We created an aluminum framed acrylic model chamber with soil inside and applied photogrammetry to measure soil deformation caused by loading tests. The soil consists of 40% black and 60% regular sand to create image contrast in soil images. In preprocessing, the self camera calibration was carried out for IOPs (Interior Orientation Parameters), followed by the space resection to estimate EOPs (Exterior Orientation Parameters) using control points located along the aluminum frame. Image matching was applied to measure the soil displacement. We tested different matching window sizes and the effect of image smoothing. Experimental results showed that 65x65 pixels of window size produced better soil deformation map and the image smoothing was useful to suppress the matching outliers. In conclusion, photogrammetry was able to efficiently generated soil deformation map.

• Archives of design research
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• v.12 no.3
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• pp.43-52
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• 1999

For Bauhaus, the vaious typography experiments developed around the printing workshops, and it was only in the later Weimar Period that L. Moooly-Nagy, who came to be in charge of the rxinting workshops, approached it from the functional way of thinking and demanded print type reforms Using this as the basis, a new form of typograph called "typophoto" was developed by combining images and characters together using photography techniques and Bauhaus Unification Chaacter producyion. Harbert Bayer, striving at molds based on the ideologies of L. Moody-Nagy, prepared the framework for modern informational advertisements by producing a variety of advertisements based on several law of psychology and physiology. Bayer's successor, Joost Schmidt focused on lettering based on functionalism and typographic training and practice, while pioneering in the new area of display design wiwh efficient usage of space for exhibitions a1d dsplays. Thus, despite being carried doWl by the same leader in the sane era, the series of typographic experiments undertaken by the artists Bauhaus present guidelines to the direction modern visual communication must take through creativity and insight into the upcoming future that is not contained within the boundaries of traditions and customs.and customs.

• Korean Institute of Interior Design Journal
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• v.19 no.2
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• pp.66-72
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• 2010

The purpose of this study is to pronounce design trends in contemporary architecture collaborated with new media art concept. Currently, the prevalence of media presence has evolved perspectives on contemporary aesthetics today. To make clear demonstration on the issue, this study categorized new media art's expressional characteristics applied in the contemporary architectural design in conjunction with analytical researches on typologies and expressional characteristics appear in new media art. More specifically, the study selected architects who adopted new media art's expressional characteristics into their works from the year 2000 and performed analytical case studies with regard to the effect of the new media art into their architectural practices. By following methodologies mentioned above, conclusively the study categorized distinct expressional characteristics appears in contemporary architecture as a result of merging with new media art. The characteristics of the new media art appeared in contemporary architecture are categorized into three groups such as the design controlling external environment, the design utilizing web environment and the design participated by users. These observation could be translated that architects could present interactive design between users and building as a result from architect's capability of designing protocols which generate variable forms, colors and patterns in architecture. In particular, architecture utilizing web environment has characteristic capability of configurating user's program in virtual space. Also it is anticipated to suggest new patterns in generating architectural programs and forms. These patterns would not recognize the city merely as an incident or fragmented image but would configurate forms and images constructed by individual notional character. In conclusion, the architecture itself is expected to perform as media to open up opportunities that enables to contribute in expediting interactions among environment, users, and buildings by deviating from perspectives of representation as an object expressed in modernism architecture or as a classical decoration in post-modernism architecture in the past era.

• Journal of The Korean Astronomical Society
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• v.36 no.1
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• pp.33-41
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• 2003

Recent observations have shown that coronal magnetic fields in the northern (southern) hemisphere tend to have negative (positive) magnetic helicity. There has been controversy as to whether this hemispheric pattern is of surface or sub-surface origin. A number of studies have focused on clarifying the effect of the surface differential rotation on the change of magnetic helicity in the corona. Meanwhile, recent observational studies reported the existence of transient shear flows in active regions that can feed magnetic helicity to the corona at a much higher rate than the differential rotation does. Here we propose that such transient shear flows may be driven by the torque produced by either the axial or radial expansion of the coronal segment of a twisted flux tube that is rooted deeply below the surface. We have derived a simple relation between the coronal expansion parameter and the amount of helicity transferred via shear flows. To demonstrate our proposition, we have inspected Yohkoh soft X-ray images of NOAA 8668 in which strong shear flows were observed. As a result, we found that the expansion of magnetic fields really took place in the corona while transient shear flows were observed in the photosphere, and the amount of magnetic helicity change due to the transient shear flows is quantitatively consistent with the observed expansion of coronal magnetic fields. The transient shear flows hence may be understood as an observable manifestation of the pumping of magnetic helicity out of the interior portions of the field lines driven by the expansion of coronal parts as was originally proposed by Parker (1974).

• Journal of Ocean Engineering and Technology
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• v.20 no.1 s.68
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• pp.37-42
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• 2006

In the ocean engineering field, information about the ocean environment is important for planning, design, and operation, especially the wave information. High precision wave data is also important for considering environmental problems, like efficient operation of ships. For this purpose, many methods were considered in the past. However, an on-board directing wave measurement system has not been incorporated. The use of conventional marine radar Plane Position Indicator (PPI) images allows the estimation of wave information on a real-time basis, using both space and time information, regarding the evolution of ocean surface waves. In order to achieve data acquisition, the Radar Scan Converter (RSC) has been developed. Three-dimensional analysis was performed. The comparison of wave information derived from this system, and that of wave buoy, shows that this wave field detecting system can be a useful tool.