• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.1190-1191
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• 2004

New $4^{th}$ generation synchrotron facility, XFEL, is almost similar to previous $3^{rd}$ generation synchrotron facility in the view of radiological aspects and most important positions are a dump and synchrotron radiation beam line. In this paper, tile radiation protection solutions for them and undulator are suggested and discussed.

• Proceedings of the KSMRM Conference
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• 2002.11a
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• pp.117-122
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• 2002

Contrast-enhanced MR angiography has become a widely used method useful for clinical diagnosis. Early studies identified a number of technical issues, and many of these have been addressed with various MRI physics innovations over the last several years. The quality of the results is high enough that CE MRA is replacing conventional x-ray angiography methods at many institutions. Ongoing research is expected to provide further improvements in performance, most notably in additional reductions in examination time, in time-resolved 3D imaging, and in improved imaging of the peripheral vasculature with extended fields of view.

• Journal of electromagnetic engineering and science
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• v.15 no.1
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• pp.1-5
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• 2015

A high-frequency analysis technique, called the hidden rays of diffraction (HRD), is reviewed in this paper. The physical optics and the rigorous diffraction coefficients of a perfectly conducting wedge illuminated by a plane wave are compared. The physical existence of hidden rays on the shadow boundary is explained in view of the geometric theory of diffraction (GTD). In particular, a systematic tracing of hidden rays and its visualization are precisely described by introducing the concept of the supplementary boundary. The physical meaning of the null-field condition in the complementary region is also explained.

• Radiation Oncology Journal
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• v.3 no.1
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• pp.59-64
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• 1985

Computation of three dimensional dose distribution using CT image and RT plan was applied to a case of pituitary adenoma. Algorithm was based on two dimensional Tissue Maximun Ratio model extended to the third dimension. The resulting isodose curve of transeverse, coronal and sagittal section was demonstrated. This RT plan allows computation of dose distribution in any arbitarily defined plane in addition to conventional cross sectional view.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.4 no.1
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• pp.7-14
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• 2011

Purpose: The purpose of this study was to analyze the correlation between the medial joint space on weight bearing simple X-ray and the ultrasonographic articular cartilage thickness. Materials and Methods: The articular cartilage thickness of 91 osteoarthritic knees of 73 patients were measured with weight bearing simple X-ray and ultrasonography between June 2010 and September 2010. Male were 13 and female were 60. Right knees were 35, left knees were 20 and bilateral involvements were 18. Medial joint spaces on X-ray were measured in full extension view and $45^{\circ}$ PA(Rosenberg) view. Femoral cartilage thicknesses at and those at the point between the middle 1/3 and posterior 1/3 area were measured by ultrasonography, that were scanned coronally at $30^{\circ}$ flexion and $130^{\circ}$ flexion respectively. The results were analyzed statistically by Pearson correlation test and Bland-Altman plot test. Results: Medial joint spaces measured in full extension view and femoral articular cartilage thicknesses at the point between the anterior 1/3 and middle 1/3 area measured with sonography were statistically correlated and medial joint spaces measured in $45^{\circ}$ PA view and those at the point between the middle 1/3 and posterior 1/3 area measured with sonography were also correlated (P<0.05, $SD{\pm}2$). Conclusion: The measurement of articular cartilage thicknesses by the ultrasonography was easy even in the patient who are unable to take weight bearing view and was thought to be a useful diagnostic and follow up method to examine the degenerative change in addition to simple radiographic examination in the knee osteoarthritis.

• Journal of Acupuncture Research
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• v.19 no.3
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• pp.230-239
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• 2002

Kyphotic cervical curvature, straghtening is commonly caused by trauma, muscle spasm without trauma and wrong posture, etc. Objective : This study is performed to evaluate the clinical effect of neck pain associated with Kyphotic cervical curvatre on cervical x-ray lateral view. Methods : One of the many causes, We examined the patients with neck pain & upper back pain who visited to Department of Acupuncture & Moxibustion, Gumi Oriental Hospital of Kyung-San University from 16th June 1999 to 22th June 2000. Pre and post treatment, We evaluated the cervical angle, Jochumsen's method, VAS(visual analogue scale) and effective score of treatment. Results & Conclusion : 1. Kyphotic cervical curvature is mainly caused by wrong posture during long term, sudden trauma, etc. therfore, postcervical muscles and tendon are injuryed by strong stress. So, muscle imbalance and pain is occured. 2. On these cases, The improvement index for pre/post treatment showed 28/42, 10/15, 9/30, 28/42 degree in cervical angle. Jochumsen's method showed -1/+2, -9/-3, -5/-2, -1/+2mm. Afer treatment VAS is 2, 1, 1, 1 and effective score of treatment is above good. The results suggest that treatments of Oriental Medicine(Acupuncture & Moxibustion, Chu-Na, Cupping and Physical therapy) are effective methods for neck pain with kyphotic cervical curvature on cervical x-ray lateral view.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.293-300
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• 2011

This study was to find out the effect of cervical and thoracic stretching and strengthening exercise program on forward head posture. 32 adults had forward head posture were selected as the subjects for the study. The training program of the exercise group(n=16) consist of postural education with exercise program, subjects in the control group(n=16) participated in a postural education only. Postural measurements of Craniovertebral Angle(CVA) and Cranial Rotation Angle(CRA) were obtained from the using x-ray and PACS(Picture Archiving and Communications System) ${\pi}view^{TM}$. The results were compared with change of CVA and CRA exercise group were significant(p<.05) compared to the control group. However CRA of contol group was significant(P<.05). Also, there were no significant difference(p>.05) between groups on any pre-test measure. however there were significant difference(p<.05) between groups on CVA and CRA post-test measure. This study showed that cervical and thoracic stretching and strengthening exercise program can improve spinal posture alignment for decreasing forward head posture in subjects. These results can be fundamental data for further development of exercise program in interventions of postural improvement.

• Imaging Science in Dentistry
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• v.44 no.4
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• pp.279-285
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• 2014

Purpose: To assess the influence of anatomic location on the relationship between computed tomography (CT) number and X-ray attenuation in limited and medium field-of-view (FOV) scans. Materials and Methods: Tubes containing solutions with different concentrations of $K_2HPO_4$ were placed in the tooth sockets of a human head phantom. Cone-beam computed tomography (CBCT) scans were acquired, and CT numbers of the $K_2HPO_4$ solutions were measured. The relationship between CT number and $K_2HPO_4$ concentration was examined by linear regression analyses. Then, the variation in CT number according to anatomic location was examined. Results: The relationship between $K_2HPO_4$ concentration and CT number was strongly linear. The slopes of the linear regressions for the limited FOVs were almost 2-fold lower than those for the medium FOVs. The absolute CT number differed between imaging protocols and anatomic locations. Conclusion: There is a strong linear relationship between X-ray attenuation and CT number. The specific imaging protocol and anatomic location of the object strongly influence this relationship.

• Korean Journal of Optics and Photonics
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• v.9 no.2
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• pp.59-62
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• 1998

One dimensional inhomogeneous aperture modulation effects on the MTF of optical system was investigated. The lens undertest was a doublet made in Korea. It was 10 mm effective diameter, 87.8 mm effective focal length. The ray-fans and spot diagrams were caluculated and presented on the picture for on-axis and off-axis (field of view, 1$^{\circ}$ and 2$^{\circ}$). Aperture modulation was carried out by positioning a aperture modulator close contacted with the lens undertest. We bought two modulators from Edmud Company in U.S.A. One was linear type and the other was stepped type. The MTFs were measured on the best of focus for unmodulated apertue where the MTF has the largest value for 60 c/mm and were compared with one another. The MTFs of modulated apertures had a little lower values than the MTF of unmodulated aperture for on-axis but in the case off-axis, the values are highly improved as much as the wider field of view by modulating on the aperture.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.4
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• pp.385-394
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• 1999

제품을 설계하는 디자이너나 엔지니어는 많은 시간과 노력을 들이지 않고서 그들이 설계한 3차원 제품 모델에 대한 사실적인 이미지를 원한다. 디자인 프로세스의 초기인 개념 설계에서부터 설계검증, 그리고 가공 과정에서 사실적인 이미지가 매우 유용하므로, 대부분의 주요 CAD 제작사는 그들의 CAD 소프트웨어에 고급 렌더링 기능을 추가하고 있다. 상용의 CAD/CAM 모델러에서는 NURB 곡면을 기초로 모델링을 수행하므로, NURB 곡면을 렌더링할 수 있는 패키지가 필요하다. VIF(Visual InterFace) 렌더링 라이브러리는 A-buffer 방식과 Ray tracing 방식의 두 가지 고급 렌더링 모드를 제공한다. 다각형은 물론 NURB 곡면을 입력으로 받아 사용자가 설정한 표면의 각종 계수, 원하는 view와 설정된 광원에 따라 이미지를 만들고 다양한 형태로 출력시킬 수 있는 다양한 기능을 제공한다. 본 논문에서는 VIF 렌더링 라이브러리에 대한 구조와 기능별로 분류된 함수에 대하여 설명하며, 실제로 CAD/CAM 시스템과 통합되어 구상설계에서부터 3차원 설계 모델링에 이르기까지의 제조공정에서 설계검증 툴로써 어떻게 활용되고 있는가에 대하여 기술한다.Abstract Engineers and industrial designers want to produce a realistic-looking images of a 3D model without spending a lot of time and money. Photo-realistic images are so useful from the conceptual design, through its verification, to the machining, that most major CAD venders offer built-in as well as add-on photo-realistic rendering capability to their core CAD software. Since 3D model is consists of a set of NURB surfaces in commercial CAD packages, we need a renderer which handles NURB surface as well as other primitives.A new rendering library called VIF (Visual InterFace) provides two photo-realistic rendering modes: A-buffer and Ray tracing. As an input data it takes NURB surfaces as well as polygonal data and produces images in accordance with the surface parameters, view and lights set by user and outputs image with different formats. This paper describes the overall architecture of VIF and its library functions classified by their functionalities, and discusses how VIF is used as a graphical verification tool in manufacturing processes from the conceptual design to 3D modeling.