• Journal of KIISE:Software and Applications
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• v.36 no.8
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• pp.653-663
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• 2009

In this paper, we propose a blind spots elimination system using three cameras. A wide-angle camera is attached on trunk for eliminating blind spots of a rear-view mirror and two cameras are attached on each side-view mirror for eliminating blind spots of vehicle's sides. In order to eliminate blind spots efficiently, we suggest a method to build a panoramic mosaic view with two side images and one wide-angle rear image. First, we obtain an undistorted image from a wide-angle camera of rear-view and calculate the focus-of-contraction (FOC) in undistorted images of rear-view while the car is moving straight forward. Second, we compute a homography among side-view images and an undistorted image of rear-view in flat road scenes. Next, we perform an image registration process after road and background region segmentation. Finally, we generate various views such as a cylinder panorama view, a top view and an information panoramic mosaic view.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04b
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• pp.42-44
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• 2002

The experimental model of the 8-view stereoscopic display system using the photopolymer-based VHOE is proposed. At first, the VHOE is implemented by angle-multiplexed recording of 8-view's diffraction gratings using the optimized exposure-time scheduling scheme in the photopolymer (HRF-150-100) and then. the VHOE-based 8-view stereoscopic display system is implemented by sequentially synchronizing the incident angles of the reference beam of the VHOE with the 8-view stereo images on the LCD pannel. Accordingly, from some experimental results using 8-view images generated by the toed-in stereo camera system, it is found that 8-view stereo images can be diffracted to eight different directions time-sequentially and there is some disparity between the stereo images.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.62-65
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• 2000

In this paper we propose skewed angle detection methods for images that contain text that is not aligned horizontally. In most images text areas are aligned along the horizontal axis, however there are many occasions when the text may be at a skewed angle (denoted by 0 < ${\theta}\;{\leq}\;{\pi}$). In the work described, we adapt the Hough transform, Shadow and Threshold Projection methods to detect the skewed angle of text in an input image using the orthogonal angle view property. The results of this method are a primary text skewed angle, which allows us to rotate the original input image into an image with horizontally aligned text. This utilizes document image processing prior to the recognition stage.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.6 no.1
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• pp.53-61
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• 2011

Objective: The purpose of this study is to evaluate the disc block subluxation for lumbar scoliosis and herniation of nucleus pulpous (HNP). Methods: We used AP & Lateral view X-ray for patients. And we measured of disc wedge angle, vertebral body rotation to evaluate the typical and atypical disc block subluxation. Results: On the analysis of the lateral view X-ray, 4th lumbar intervertebral disc angle (I.V.D angle) showed $4^{\circ}$, $5^{\circ}$, $3^{\circ}$, $0^{\circ}$ in the cases. On the 4th lumbar analysis of the AP view X-ray, lumbar scoliosis showed right disc wedge angle was $11^{\circ}$ (case 1), $17^{\circ}$ (case 2) and left vertebral body rotation was 13mm, 6mm. Lumbar HNP showed left disc wedge angle was $5^{\circ}$ (case 3), $4^{\circ}$ (case 4) and left vertebral body rotation was 2mm, 4mm. Conclusions: Disc block subluxation has been in lumbar scoliosis, but not been in lumbar HNP.

• Journal of Korean Foot and Ankle Society
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• v.15 no.3
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• pp.159-164
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• 2011

Purpose: This study was performed to analyze the results of radiologic parameters between weight bearing affected single ankle anteroposterior (AP) view and both ankle AP view in ankle osteoarthritis (OA). Materials and Methods: Between January 2009 and August 2010, 41 patients (50 ankles) who visited our institution to treat ankle OA were reviewed retrospectively. In radiographic assessment, weight bearing affected single ankle AP view and both ankle AP view were checked, and measured tibial anterior surface angle (TAS), tibial medial malleolar angle (TMM), talar tilting angle (TT), maximum and minimun joint space width (JSW) of ankle, width between articular surface of medial malleolar and medial articular surface of talus as radiologic parameters. Results: On weight bearing both ankle AP view, TAS was $85.4{\pm}4.1^{\circ}$, TMM was $33.1{\pm}9^{\circ}$, TT was $5.4{\pm}6.1^{\circ}$, maximum JSW was $3.2{\pm}2.7$ mm, minimum JSW was $1.1{\pm}1.3$ mm, width between articular surface of medial malleolar and medial articular surface of talus was $1.8{\pm}1.8$ mm and on weight bearing affected ankle AP view, TAS was $85.3{\pm}3.9^{\circ}$, TMM was $34.3{\pm}10.9^{\circ}$, TT was $5.4{\pm}6.5^{\circ}$, maximum JSW was $3.2{\pm}2.7$ mm, minimum JSW was $1.1{\pm}1.3$ mm, width between articular surface of medial malleolar and medial articular surface of talus was $1.6{\pm}1.7$ mm. Conclusion: There is no statistical significance in radiologic parameters between weight-bearing affected single ankle AP view and both ankle AP view in ankle OA.

• Journal of the Korean Orthopaedic Association
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• v.54 no.1
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• pp.59-66
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• 2019

Purpose: Several radiologic reference lines have been used to evaluate individuals with a clubfoot but there is no consensus as to which is most reliable. The aim of this study was to identify which radiologic parameters have relevance to the predictability of additional surgery after Ponseti casting on clubfoot and the effect of clubfoot treatments that contain Ponseti casting and additional surgery. Materials and Methods: A total of 102 clubfeet (65 patients, 37 bilateral) were reviewed from 2005 to 2013. The patients were divided into two groups (Group A, those for whom the result of the Ponseti method was successful and did not require additional surgery; and Group B, those for whom the result of the Ponseti method was unsuccessful and required additional surgery), and the following parameters were measured on the plain radiographs: i) talo-calcaneal angle on the anteroposterior and lateral view, ii) talo-1st metatarsal angle on the anteroposterior view, and iii) Tibio-calcaneal angle on the lateral view with the ankle full-dorsiflexion state. Each radiograph was reviewed on two separate occasions by one orthopedic doctor to characterize the intra-observer reliability, and the averages were analyzed. Next, 20 cases were chosen using a random number table, and two orthopedic doctors measured the angle separately to characterize the interobserver reliability. Results: Groups A and B included 73 clubfeet (71.6%) and 29 clubfeet (28.4%), respectively. The initial talo-calcaneal angle and tibiocalcaneal angle in the lateral view were significantly different among the groups. In addition, inter- and intra-observer biases were not detected. The talo-1st metatarsal angle on the anteroposterior view and tibio-calcaneal angle on the lateral view were significantly different after treatment in both groups. Conclusion: Congenital clubfeet treated with the Ponseti method showed successful results in more than 70% of patients. The initial talocalcaneal angle and tibio-calcaneal angle on the lateral view were the radiologic parameters that could predict the need for additional surgical treatments. The talo-1st metatarsal angle on the anteroposterior view and tibio-calcaneal angle on the lateral view could effectively evaluate the changes in clubfoot after treatment.

• Korean Journal of Optics and Photonics
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• v.23 no.5
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• pp.179-188
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• 2012

Lenses with an ultra wide angle of view are usually called fisheye lenses since a fish can see an ultra wide panoramic view under water. As the angle of view for these kinds of lenses reaches a wide angle, the illumination on an image sensor is reduced by a rapid drop. In this paper, we discuss the causes and the ways to correct for a rapid drop. First, it is treated for the sign convention of directional cosine vectors and normal vectors on the curved surface by means of analytic geometry. And, from the fundamental discussion for these vectors, the rapid illumination drop is numerically analyzed for various kinds of causes by utilizing geometrical optics and radiometry as well as Fresnel equations derived from electromagnetic boundary conditions. As a result, we are able to get the full understanding for the rapid illumination drop and to propose ways to correct effects due to an wide angle of view.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.949-952
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• 2017

Spray characteristics of the impinging injectors in subsonic crossflows were experimentally studied and compared with the plain-orifice injectors. By changing the impingement angle (60, 90, 120) which is the same orifice length to diameter ratio (L/d = 5), spray characteristics were investigated. In the view of the top view from the impinging injectors, as the impingement angle increases, the liquid column breakup length in the y-direction was decreased. On the other hand, when the impinging injector is viewed from the side view, the breakup length in the x direction is smaller than the previous plain-orifice injectors, which mean that the atomizing performance of the impingement-type injector is better than that of the single-hole orifice.

• Journal of Korean Foot and Ankle Society
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• v.17 no.3
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• pp.189-195
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• 2013

Purpose: We investigated a statistical difference of tibial-articular surface (TAS) angles between radiographs of standing ankle anteroposterior (AP) and whole lower extremity view, and evaluated whether the tibial axis obtained from the standing ankle AP view reflects the original mechanical axis of lower extremity. Materials and Methods: Both the standing ankle AP and whole lower extremity view were taken from 60 legs of 30 healthy volunteers without a history of ankle surgery or deformity of lower limb. To determine the tibial axis, Takakura's and Hintermann's method were employed in the standing ankle AP view. To compare these results with the original TAS angle, ANOVA and multiple comparison test were used. Results: The mean TAS angle was 88.3 degrees(from hip joint to ankle), 89.5 degrees (from knee joint to ankle), 88.5 degrees (Takakura's method), and 90.2 degrees(Hintermann's method). Although there was a statistical significance (p=0.000) between these results, Takakura's method had no significant difference, compared to the results of whole extremity view by the multiple comparison test. Conclusion: The tibial axis obtained by Takakura's method reflects the original mechanical axis of lower extremity. When a surgical procedure is planned, however, it is necessary to consider that the ankle radiographs do not provide any information on the proximal deformity without the whole lower extremity view.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.719-728
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• 2017

This paper proposes a synthesis of new guidance law to generate an evasive maneuver against enemy's missile interception while considering its impact angle, acceleration, and field-of-view constraints. The first component of the synthesis is a new function of repulsive Artificial Potential Field to generate the evasive maneuver as a real-time dynamic obstacle avoidance. The terminal impact angle and terminal acceleration constraints compliance are based on Time-to-Go Polynomial Guidance as the second component. The last component is the Logarithmic Barrier Function to satisfy the field-of-view limitation constraint by compensating the excessive total acceleration command. These three components are synthesized into a new guidance law, which involves three design parameter gains. Parameter study and numerical simulations are delivered to demonstrate the performance of the proposed repulsive function and guidance law. Finally, the guidance law simulations effectively achieve the zero terminal miss distance, while satisfying an evasive maneuver against intercept missile, considering impact angle, acceleration, and field-of-view limitation constraints simultaneously.