Variation of Bragg Curve Characteristic Induced by Changing the Position of Inhomogeneous Material: Geant4 Simulation Study

정원균,박소현,서태석,장홍석,최병옥,나정은,박성용,이세병 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.2

When proton beam passes through the human body, the stopping power and the depth-dose distribution of the proton are influenced by the relative location among adjacent materials or the difference in material conditions. Our study demonstrates the effect of inhomogeneous materials placed in the Plateau and Bragg peak regions of the Bragg curve in water. We evaluated the Bragg peak position, range, penumbra and integrated doses by using the Geant4 simulation toolkit. The positions of inhomogeneities were selected as the proximal 36% and 50% points of the maximum dose, which indicates the location at entrance regions of the Plateau and the Bragg peak, respectively. Bone (density ρ = 1.85 g/cm^3) and adipose tissue (density ρ = 0.92 g/cm^3) were selected as inhomogeneous materials. The thickness of each material was varied by 0.1 cm between 0.1 cm and 1.0 cm. In addition, the initial energy of the proton beam was changed in 30 MeV steps between 108 MeV and 220 MeV. The effects of inhomogeneous conditions were performed for various parameters: Bragg peak position, range, penumbra width, full width at half maximum and dose of Bragg curve. A dose perturbation was observed in the region of the Bragg peak and inhomogeneous material, especially, When the bone equivalent material was inserted within the Bragg curve. However, there were no significant variations in the other parameters, except for the dose perturbation depending on the inserted location of each material. This study shows the characteristic changes in the Bragg curve due to inhomogeneous materials.

두개인두종과 동반한 다발성 특발성 치근 외흡수

정원균,윤정훈 대한치과보존학회 2001 Restorative Dentistry & Endodontics Vol.26 No.2

Idiopathic external root resorption is an apparently infrequently occurrence involving single or multiple teeth. Presented is an unusual case of multiple external root resorption associated with craniopharyngioma. Although the cause of this resorption was not determined, several possibilities are discussed. The literature to a systemic etiology for external root resorption is briefly reviewed.

SOME IDENTITIES FOR DEGENERATE COSINE(SINE)-EULER POLYNOMIALS

정원균 장전수학회 2020 Advanced Studies in Contemporary Mathematics Vol.30 No.1

The aim of this paper is to introduce the degenerate cosine{Euler and degenerate sine-Euler polymonials which are related to the cosine-Euler and sine-Euler polynomials, respectively. We investigate some identities and properties for the polynomials. We also give the relation between the degenerate cosine(resp. sine)-Euler polynomials and the cosine(resp. sine)-Euler polynomials

SOME RESULTS ON FUZZY IDEAL EXTENSIONS OF BCK-ALGEBRAS

정원균 영남수학회 2010 East Asian mathematical journal Vol.26 No.3

In this paper, we prove that the extension ideal of a fuzzy characteristic ideal of a positive implicative BCK-algebra is a fuzzy characteristic ideal. We introduce the notion of the extension of intuitionistic fuzzy ideal of BCK-algebras and some properties of fuzzy intuitionistic ideal extensions of BCK-algebra are investigated.

독소루비신과 알로퓨리놀이 화학적 근절제에 미치는 영향

정원균,고한웅,강동희,구상환,박승하 大韓成形外科學會 2004 Archives of Plastic Surgery Vol.31 No.3

3차원 전신 정위 방사선 치료 장치의 개발

정원균,이병용,최은경,김종훈,안승도,이석,민철기,박참복,장혜숙,Jung, Won-Kyun,Lee, Byung-Yong,Choi, Eun-Kyung,Kim, Jong-Hoon,An, Seung-Do,Lee, Seok,Min, Chul-Ki,Park, Cham-Bok,Jang, Hye-Sook 한국의학물리학회 1999 의학물리 Vol.10 No.2

입체조형 치료와 전신 방사선 수술에의 이용을 목적으로 3차원 전신 정위 방사선 치료 장치를 개발하였다. Couch 위에 놓을 수 있는 전신 정위 치료판을 제작하여 방사선 비투과성 카테타 선을 이용하여 치료판 위에 좌표계를 설치하고, MeV-Green(전성 물산, 한국)으로 고정틀을 만들어 환자 자세를 고정시키고, 플라스틱 봉과 봉 지지판을 이용하여 고정틀을 고정하였다. 이러한 설계, 제작으로 입체 조형 치료 등에서 갠트리 회전에 의한 기하학적 제약을 최소화하고 방사선 조사 투과율 이 특정한 방향에서 영향을 받는 문제점을 해소하였다. CT 영상을 통해 치료 표적의 위치를 파악하고 치료판 기준점에 대하여 좌표화하여 모의 치료시와 방사선 치료시의 환자 자세 변화 오차를 줄였다. 3대의 CCTV 카메라를 사용하여 환자 자세 변화를 감지, 수정함으로써 체표변의 외곽선으로 부터 setup 오차를 최소화 할 수 있었다. 치료 효용성을 높이기 위해 이러한 과정을 모니터를 보면서 실시간으로 처리 할 수 있도록 하였고, IDL(Interactive Data Language, RSI, U.S.A.)을 사용하여 image subtraction 방식으로 환자 자세 변화를 가시화하여 오차를 줄이도록 하였다. 내부 장기 움직임에 따른 표적의 움직임을 추적할 목적으로 rotating X-ray 장치를 제작하였다. Landmark 나사를 표적주위 뼈나 표적중심에 삽입하여 이 rotating X-ray 장치를 이용해서 anterior, lateral 두 방향에서 얻은 영상 정보로부터 marker 에 대한 표적의 위치 변화를 가시화 하여 내부 표적의 움직임에 따른 setup 오차를 줄였다. CT 모의치료를 할 수 있도록 IDL 을 이용하여 PC용 모의치료 프로그램을 GUI 환경에서 구현하였고 이 프로그램을 통해서 치료 계획을 위해 CT 에서 수집된 영상정 보를 이용하여 표적을 포함한 장기들의 그래픽 처리, 편집, 전송 등의 작업을 수행하도록 하였다. For the purpose of utilization in 3-D conformal radiotherapy and whole body radiosurgery, the Whole Body 3-Dimensional Topographic Radiation Therapy System has been developed. Whole body frame was constructed in order to be installed on the couch. Radiopaque catheters were engraved on it for the dedicated coordinate system and a MeV-Green immobilizer was used for the patient setup by the help of side panels and plastic rods. By designing and constructing the whole body frame in this way, geometrical limitation to the gantry rotation in 3-D conformal radiotherapy could be minimized and problem which radiation transmission may be altered in particular incident angles was solved. By analyzing CT images containing information of patient setup with respect to the whole body frame, localization and coordination of the target is performed so that patient setup error may be eliminated between simulation and treatment. For the verification of setup, the change of patient positioning is detected and adjusted in order to minimize the setup error by means of comparison of the body outlines using 3 CCTV cameras. To enhance efficiency of treatment procedure, this work can be done in real time by watching the change of patient setup through the monitor. The method of image subtraction in IDL (Interactive Data Language) was used to visualize the change of patient setup. Rotating X-ray system was constructed for detecting target movement due to internal organ motion. Landmark screws were implanted either on the bones around target or inside target, and variation of target location with respect to markers may be visualized in order to minimize internal setup error through the anterior and the lateral image information taken from rotating X-ray system. For CT simulation, simulation software was developed using IDL on GUI(Graphic User Interface) basis for PC and includes functions of graphic handling, editing and data acquisition of images of internal organs as well as target for the preparation of treatment planning.

21세기치과병원 사례발표

정원균 대한치과의사협회 1999 대한치과의사협회지 Vol.37 No.11

BIPOLAR-VALUED FUZZY IDEAL EXTENSIONS OF BCK-ALGEBRAS

정원균 충청수학회 2013 충청수학회지 Vol.26 No.1

The notions of the extensions of bipolar fuzzy ideals,bipolar fuzzy prime ideals and bipolar fuzzy commutative ideals in BCK-algebras are introduced, and several properties are investi-gated.

[심포지엄 지상강좌 ③ ] 21세기치과병원 공동개원 사례발표 강연내용

정원균 대한치과의사협회 2000 대한치과의사협회지 Vol.38 No.8

Mayer-Rokitansky-Kuster-Hauser 증후군 환자에서 전층 피부 이식술을 이용한 질성형술 치험례

한재식,이종문,정원균 大韓成形外科學會 1998 Archives of Plastic Surgery Vol.25 No.5

Mayer-Rokitansky-Kuster-Hauser Syndrom is characterized by the absence of the vagina and the uterus, the presence of apparently normal tubes and ovaries, feminine appearance, normal female secondary sexual characteristics, a normal 46, XX karyotypes, and a feminine psychosexual orientation. Absence of the vagina results from an embryological arrest in the development of the lower portion of the Mullerian system. Various methods of surgical treatment for the vaginal absence in this syndrom have been introduced but the ideal method to restore the original dimension and function of the normal vagina was not found. The two cases reviewed in this paper were all treated with modified McIndoe operation using full thickness skin grafts. Postoperatively both women were satisfied without complications, i,e. lack of skin graft, bleeding, urethrovaginal fistula, perforation of the rectum, rectovaginal fistula and significant vaginal stricture. This paper reveals the satisfactory results that were uniformly good.