• Journal of the HCI Society of Korea
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• v.1 no.1
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• pp.37-44
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• 2006

Specular reflections provide the visual feedback that describes the material type of an object, its local shape, and lighting environment. In photorealistic rendering, there have been a number of research available to render specular reflections effectively based on a local reflection model. In traditional cel animations and cartoons, specular reflections plays important role in representing artistic intentions for an object and its related environment reflections, so the shapes of highlights are quite stylistic. In this paper, we present a method to render and control stylized specular reflections using projective textures based on principal curvature analysis. Specifying a texture as a pattern of a highlight and projecting the texture on the specular region of a given 3D model, we can obtain a stylized representation of specular reflections. For a given polygonal model, a view point, and a light source, we first find the maximum specular intensity point, and then locate the texture projector along the line parallel to the normal vector and passing through the point. The orientation of the projector is determined by the principal directions at the point. Finally, the size of the projection frustum is determined by the principal curvatures corresponding to the principal directions. The proposed method can control the position, orientation, and size of the specular reflection efficiently by translating the projector along the principal directions, rotating the projector about the normal vector, and scaling the principal curvatures, respectively. The method is be applicable to real-time applications such as cartoon style 3D games. We implement the method by Microsoft DirectX 9.0c SDK and programmable vertex/pixel shaders on Nvidia GeForce FX 7800 graphics subsystems. According to our experimental results, we can render and control the stylized specular reflections for a 3D model of several ten thousands of triangles in real-time.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.4
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• pp.244-252
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• 2019

Proper positioning of maxillary incisors is key to success of surgery combined treatment. Establishing surgery plan would be a difficult job if maxillary incisors are lost. Patient who lost all of her maxillary incisors due to accident came for orthodontic treatment. Through careful modification of maxillary archform, pre-surgical orthodontic treatment was conducted with four prosthetic space consolidation. Position of incisors was decided by help of 3D prosthetic set-up, and 1-jaw surgery was planned. After relative short treatment period of 28 months, final prosthesis was done. When alveolar bone loss happens, harmonious prosthesis of upper incisors is difficult. Utilizing mandibular set-back surgery and incisor positioning using 3D set-up could make a better environment for treatment outcome. Strategic pre-surgical orthodontic treatment can allow shorter time and less number of prosthetics.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.44-50
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• 2001

Objectives : The objective of this study was to investigate the role of postoperative three dimensional short-range magnetic resonance angiography(3D-TOF MRA) in predicting the clinical outcomes following microvascular decompression(MVD) for the treatment of a hemifacial spasm(HFS). Material and Method : Postoperative magnetic resonance(MR) imaging was performed on 123 patients with a HFS between March 1999 and May 2000. All patients who had postoperative MR imaging were undertaken preoperative MR imaging. Of the 123 patients, 122 patients were included in this retrospective study. The degree of the detachment of vascular contact, and change of the position of offender were determined by pre- and postoperative 3D-TOF MRA. These findings were compared with the surgical findings and clinical outcomes. Results : Of 122 patients who had successful MVD, clear decompression of offenders of the root entry zone(REZ) of facial nerve was found in 106 patients(86.9%), partial decompression in 10 patients(8.2%) and contact of offenders to the REZ of facial nerve in 6 patients(4.9%) by the postoperative 3D-TOF MRA. Our patients demonstrated that the types of offender did not influence with the degree of decompression of REZ of facial nerve and with surgical outcomes(p>0.05). Also, there was no significant relationship between the degree of decompression of the REZ of facial nerve from offenders and an improvement of symptoms(p>0.05). Futhermore, there was no significant relationship between the degree of decompression of the REZ of facial nerve from offenders and an improvement time (p>0.05). Conclusion : Our data suggests that MVD of facial nerve alone may not be sufficient to resolve the symptoms in all patients with hemifacial spasm. Therefore, another unknown factors besides vascular compression may be involved to cause symptoms in certain patients and it may be necessary to remove these factors with MVD simultaneously to obtain the resolution of symptom.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.2
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• pp.218-222
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• 2014

In this paper, we introduce an autonomous calibration method for a 2D laser displacement sensor (e.g. laser vision sensor and laser range finder) by matching a single point on a flat structure. Many arc welding robots install a 2D laser displacement sensor to expand their application by recognizing their environment (e.g. base metal and seam). In such systems, sensing data should be transformed to the robot's coordinates, and the geometric relation (i.e. rotation and translation) between the robot's coordinates and sensor coordinates should be known for the transformation. Calibration means the inference process of geometric relation between the sensor and robot. Generally, the matching of more than 3 points is required to infer the geometric relation. However, we introduce a novel method to calibrate using only 1 point matching and use a specific flat structure (i.e. circular hole) which enables us to find the geometric relation with a single point matching. We make the rotation component of the calibration results as a constant to use only a single point by moving a robot to a specific pose. The flat structure can be installed easily in a manufacturing site, because the structure does not have a volume (i.e. almost 2D structure). The calibration process is fully autonomous and does not need any manual operation. A robot which installed the sensor moves to the specific pose by sensing features of the circular hole such as length of chord and center position of the chord. We show the precision of the proposed method by performing repetitive experiments in various situations. Furthermore, we applied the result of the proposed method to sensor based seam tracking with a robot, and report the difference of the robot's TCP (Tool Center Point) trajectory. This experiment shows that the proposed method ensures precision.

• Progress in Medical Physics
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• v.14 no.2
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• pp.90-98
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• 2003

Purpose : A new virtual simulation technique for craniospinal irradiation (CSI) that uses a CT-simulator was developed to improve the accuracy of field and shielding placement as well as patient positioning. Materials and Methods : A CT simulator (CT-SIM) and a 3-D conformal radiation treatment planning system (3D-CRT) were used to develop CSI. The head and neck were immobilized with a thermoplastic mask while the rest of the body was immobilized with a Vac-Loc. A volumetric image was then obtained with the CT simulator. In order to improve the reproducibility of the setup, datum lines and points were marked on the head and body. Virtual fluoroscopy was performed with the removal of visual obstacles, such as the treatment table or immobilization devices. After virtual simulation, the treatment isocenters of each field were marked on the body and on the immobilization devices at the conventional simulation room. Each treatment fields was confirmed by comparing the fluoroscopy images with the digitally reconstructed radiography (DRR) and digitally composited radiography (DCR) images from virtual simulation. Port verification films from the first treatment were also compared with the DRR/DCR images for geometric verification. Results : We successfully performed virtual simulations on 11 CSI patients by CT-SIM. It took less than 20 minutes to affix the immobilization devices and to obtain the volumetric images of the entire body. In the absence of the patient, virtual simulation of all fields took 20 min. The DRRs were in agreement with simulation films to within 5 mm. This not only reducee inconveniences to the patients, but also eliminated position-shift variables attendant during the long conventional simulation process. In addition, by obtaining CT volumetric image, critical organs, such as the eyes and the spinal cord, were better defined, and the accuracy of the port designs and shielding was improved. Differences between the DRRs and the portal films were less than 3 m in the vertebral contour. Conclusion : Our analysis showed that CT simulation of craniospinal fields was accurate. In addition, CT simulation reduced the duration of the patient's immobility. During the planning process. This technique can improve accuracy in field placement and shielding by using three-dimensional CT-aided localization of critical and target structures. Overall, it has improved staff efficiency and resource utilization by standard protocol for craniospinal irradiation.

• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.149-163
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• 2004

This study analyzed kinematic variables about the cross step, the delivery and the release for women's javelin athletics recorded over 50m in the 2004 Busan International Athletics Competition. It was used the Kwon3D Motion Analysis Package Ver. 3.1 Program(Kwon, 2000) for analysing the kinematic variables about the distance, the velocity, and the angle, then we had the results as follows; 1 In the Cross step phase, the COG velocity was low because their step length was short. To keep the CM velocity from the approach to the last cross over step contact, the athletes have to keep the longer step length within about 130% of the athletics' height. 2. In the Delivery phase, the athletics' COG height was gradually lower, and the deceleration of the COG was going up. As the same in the cross step, Therefore the athletes have to increase the step length within about 100% of their height, in order to increasing the COG velocity. And it was shown they have to make small angle of the elbow as possible from the right foot contact to the left foot contact in order to being the big acceleration of the upperarm at the release phase. 3. In the release phase, it was shown to being low position of the release point as the COG was low and then the release velocity of the upperarm was low. Specially when the shoulder lean lateral angle is big at the release phase, it was shown they have a excessive release angle. And, when it was shown the high rotation angle of the shoulder, the shoulder was opened forward bigger than the trunk was opened forward. So the transmission of velocity from the proximal segments was a fast change.

• Animal Systematics, Evolution and Diversity
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• v.27 no.3
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• pp.228-238
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• 2011

Two urostyloid ciliates, collected from brackish water in Korea, were identified as Diaxonella pseudorubra pseudorubra (Kaltenbach, 1960) Berger, 2006 and Pseudokeronopsis flava (Cohn, 1866) Wirnsberger, Larsen and Uhlig, 1987. The description was based on living, protargol impregnated specimens. These species are described as follows: Diaxonella pseudorubra pseudorubra: body size in vivo $145-230{\times}40-60\;{\mu}m$, elongated ellipsoidal in shape. Cytoplasm reddish and flexible. Adoral zone of membranelles occupied 30-40% of the body; composed of 33-44 membranelles; 1-3 frontoterminal cirri, 1-4 frontal row cirri, 4-6 buccal cirri, 6-10 transverse cirri. Midventral rows composed of 14-24 cirri, four left marginal rows, one right marginal row. Two kinds of cortical granules; the larger one is yellowish and the smaller one is reddish. Pseudokeronopsis flava: body size in vivo $150-210{\times}30-45\;{\mu}m$, elongated ellipsoidal shape. Cytoplasm yellowish and flexible. Adoral zone of membranelles occupied 25-30% of body; composed of 44-58 membranelles in number. Frontal cirri forming bicorona composed of 5-7 cirral pairs, 2-3 frontoterminal cirri, one buccal cirrus, and 2-3 transverse cirri. Midventral rows composed of 18-33 cirri, 34-53 left marginal cirri, and 40-58 right marginal cirri. Two kinds of cortical granules; the larger one is colorless and "blood-cell-shaped," and the smaller one is yellowish. Diaxonella pseudorubra pseudorubra is different from the most similar subspecies, D. pseudorubra pulchra, in cytoplasmic color and number of midventral cirri. Pseudokeronopsis flava is different from its most similar congeners in pigment granular color, number of bicorona, number of midventral cirri, and position of the contractile vacuole.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.1
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• pp.25-31
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• 1999

A real-time holography system using LCD with CCD camera is proposed. In this system, the rainbow hologram is used since it can be reconstructed by white light source. And to record on CCD camera, a kind of in-line holography method is used to widen the width of the fringe pattern. The interference fringe pattern by proposed system is detected with CCD camera and transferred to the LCD. A 3-dimensional image is reconstructed when the white light source illuminates the LCD. If the position of the input image is changed, that of the reconstructed image is also changed. So it can represent 3-dimensional moving images at real-time. In this paper, to confirm the usefulness of the proposed method, the reconstructed image by holographic film is compared to the same reconstructed image by LCD. In the recording process, the optimal ratio of the reference and object beam intensity is also investigated.

• Journal of Ginseng Research
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• v.36 no.4
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• pp.418-424
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• 2012

This study focused on the enzymatic biotransformation of the major ginsenoside Rb1 into Rd for the mass production of minor ginsenosides using a novel recombinant ${\beta}$-glucosidase from Flavobacterium johnsoniae. The gene (bglF3) consisting of 2,235 bp (744 amino acid residues) was cloned and the recombinant enzyme overexpressed in Escherichia coli BL21(DE3) was characterized. This enzyme could transform ginsenoside Rb1 and gypenoside XVII to the ginsenosides Rd and F2, respectively. The glutathione S-transferase (GST) fused BglF3 was purified with GST-bind agarose resin and characterized. The kinetic parameters for ${\beta}$-glucosidase had apparent $K_m$ values of $0.91{\pm}0.02$ and $2.84{\pm}0.05$ mM and $V_{max}$ values of $5.75{\pm}0.12$ and $0.71{\pm}0.01{\mu}mol{\cdot}min^{-1}{\cdot}mg$ of $protein^{-1}$ against p-nitrophenyl-${\beta}$-D-glucopyranoside and Rb1, respectively. At optimal conditions of pH 6.0 and $37^{\circ}C$, BglF3 could only hydrolyze the outer glucose moiety of ginsenoside Rb1 and gypenoside XVII at the C-20 position of aglycon into ginsenosides Rd and F2, respectively. These results indicate that the recombinant BglF3 could be useful for the mass production of ginsenosides Rd and F2 in the pharmaceutical or cosmetic industry.

• Journal of the Korean GEO-environmental Society
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• v.23 no.12
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• pp.25-31
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• 2022

Unlike structures installed on land, the structures installed on the offshore ground must consider long-term cyclic loads such as wave loads, wind loads and tidal loads at sea. Therefore, it is important to analyze the behavior of the ground subjected to long-term cyclic loads in order to design a structure installed on the ocean ground. In this paper, cyclic simple shear tests were performed to analyze the ground behavior for long-term cyclic loads according to the confining pressure, and a three-dimensional design failure curve was prepared that can easily check the failure characteristics according to the confining pressure. As a result of the analysis, it was confirmed that the position of the design failure curve is different depending on the confining pressure even under the same conditions of the cyclic shear stress ratio and the average shear stress ratio, and the number of cyclic loads reaching failure is affected by the confining pressure. From the created 3-D design failure curve under different confining pressure, the tendency and approximate value of the design failure curve according to the confining pressure can be estimated.