확장된 SSD에 기인한 Electron beam의 Output 및 특성 변화에 관한 연구

이정우,김정만,Lee, Jeong-U,Kim, Jeong-Man 대한방사선치료학회 1996 大韓放射線治療技術學會誌 Vol.8 No.1

We are often faced with the clinical situations that is inevitably extended SSD for electron beam therapy due to anatomical restriction or applicator structure. But there are some difficulties in accurately predicting output and properties. In electron beam treatment , unlike photon beam the decrease in output for extended SSD does not follow inverse-square law accurately because of a loss of side scatter equilibrium, which is particularly significant for small cone size and low energies. The purpose of our study is to analyze the output in changing with the energy, cone size, air gap beyond the standard SSD and to compare inverse-square law factor derived from calculated effective SSD, mominal SSD with measured output factor. In addition, we have analyzed the change of PDD for several cones with different SSDs which range from 100cm to 120cm with 5cm step and with different energies(6MeV, 9MeV, 12MeV, 16MeV, 20MeV). In accordance with our study, an extended SSD produces a significant change in beam output, negligible change in depth dose which range from 100cm to 120cm SSDs. In order to deliver the more accurate dose to the neoplastic tissue, first of all we recommend inverse-square law using the table of effective SSDs with cone sizes and energies respectively or simply to create a table of extended SSD air gap correction factor. The second we need to have an insight into some change of dose distribution including PPD, penumbra caused by extended SSD for electron beam therapy.

3차원 하천/하구/해양 수리모델의 비교분석

이정우,이준,Lee, Jeong-U,Lee, Jun 한국수자원학회 2013 물과 미래(한국수자원학회지) Vol.46 No.11

$\textrm{SiO}_2$-$\textrm{B}_2\textrm{O}_3$-CaO-$\textrm{P}_2\textrm{O}_5$계에서 조성이 Aerosol Flame Deposition법에 의해 제조된 유리박막의 열처리 온도와 굴절률에 미치는 영향

이정우,정형곤,정석종,이형종,문종하,Lee, Jeong-U,Jeong, Hyeong-Gon,Jeong, Seok-Jong,Lee, Hyeong-Jong,Mun, Jong-Ha 한국재료학회 1999 한국재료학회지 Vol.9 No.5

The effects of the composition on the consolidation temperature and refractive index of the glass thin film fabricated by aerosol flame deposition method in SiO$_2$-B$_2$O$_3$-CaO-P$_2$O\ulcorner system were investigated. When the amount of CaO was constant in SiO$_2$-B$_2$O$_3$-CaO system the consolidation temperature of glass thin film decreased with increasing the amount of B$_2$O$_3$. Also, when the amount of SiO$_2$ and B$_2$O$_3$ was constant the consolidation temperature of glass thin film increased with increasing the amount of CaO. P$_2$O\ulcorner was added to 72.5SiO$_2$-25B$_2$O$_3$-2.5CaO in order to decrease its consolidation temperature. As the amount of P$_2$O\ulcorner increased its consolidation temperature decreased and the refractive index linearly increased from 1.4649 to 1.4684. When the amount of CaO and P$_2$O\ulcorner was constant in SiO$_2$-B$_2$O$_3$-CaO-P$_2$O\ulcorner system the consolidation temperature of glass thin film decreased with increasing the ratio of SiO$_2$/B$_2$O$_3$.

공학교육 인증을 위한 메카트로닉스 전공 교육과정의 개발

이정우,정연두,심병민,채경덕,한세범,황영택,Lee Jeong-Woo,Jeong Yeon-Doo,Sim Byoung-Min,Chae Kyung-Duck,Han Seh-Beom,Hwang Yeong-Taik 한국공학교육학회 2005 공학교육연구 Vol.8 No.2

이 논문은 한국공학교육인증원의 공학교육인증 요구조건을 만족시키기 위한 삼척대학교 메카트로닉스 공학전공 교육과정의 연구에 관하여 기술하였다. 국내대학과 외국대학의 메카트로닉스 공학전공의 교육과정을 수집하고 분석하였다. 이 분석결과를 이용하고, 기계공학, 전기공학, 제어공학 그리고 컴퓨터공학의 유기적인 결합을 고려한 교육과정을 제시하였다. 더불어 삼척대학교의 지정학적인 조건과 한국공학교육인증원의 인증요구조건을 반영하였다. 그 결과 학생들에게 분석적인 능력과 실무적인 자질을 개발할 수 있도록 하는 다학제간 교육과정을 개발하였다. This paper describes the development of curriculum for the division of Mechatronics in Samcheok University to meet the requirement of Accreditation Board for Engineering Education of Korea(ABEEK). The curriculum of the department of mechatronics in South Korea and overseas university is analysed and then the curriculum is developed considering the synergistic combination of mechanical engineering, electronic engineering, control engineering and computer engineering. And then the geopolitical condition of university is reflected in the curriculum. ABEEK requirements for major of engineering are also reflected. As a result, interdisciplinary curriculum that provides analytic capability and pragmatic qualification to students is developed.

정상 여성에게서 앞 정강근의 수축훈련방법에 따른 뇌파의 변화

이정우,김문정,윤세원,Lee, Jeong-Woo,Kim, Moon-Jeong,Yoon, Se-Won 대한물리치료학회 2012 대한물리치료학회지 Vol.24 No.2

Purpose: This study aims to examine the power changes in eletrocenphalogram (EEG) detected from the tibialis anterior muscle, during repetitive contraction exercise in normal female adults. Methods: The subjects of this study were 24 normal adult females, with no musculoskeletal or nervous system disorders. The 24 female subjects were divided into two groups: 12 subjects comprised a voluntary stimulation training group, and the other 12 subjects comprised an electrical stimulation training group. A total of thirty contractions were made repetitively by each woman, with maximal voluntary contraction exercise for six seconds, and a resting time of three seconds. During the experiment, their EEG was measured at eight positions. The eight positions were Fpz, Fz, Cz, CPz, C3, C4, P3, and P4, in accordance with the international 10~20 system. Results: The relative alpha power and beta power showed no statistically significant differences between the two groups. But the relative gamma power of the CPz, C3, C4, P3, and P4 areas showed statistically significant differences between the two groups (p<0.05). The relative theta power of the C4 area showed statistically significant differences between the two groups (p<0.05). Conclusion: Our findings show that tibialis anterior muscle contraction by electrical stimulation and by voluntary repeated contraction differentially affected brain activation. In particular, the CPz, C3, C4, P3 positions of relative gamma power showed brain activation in voluntary contraction. The C4 position of relative theta power showed different brain activation between the two groups.

집중호우로 인한 한강변 간선도로 침수 피해

이정우,이정은,이동섭,Lee, Jeong-U,Lee, Jeong-Eun,Lee, Dong-Seop 한국수자원학회 2011 물과 미래(한국수자원학회지) Vol.44 No.10

고무댐에 적용하기 위한 유리섬유보강 복합재료 클랩핑 플레이트의 내구 특성

이정우,박찬기,김종옥,이승기,김필식,Lee, Jeong-Woo,Park, Chan-Gi,Kim, Jong-Ok,Lee, Seung-Kee,Kim, Pil-Sik 한국농공학회 2011 한국농공학회논문집 Vol.53 No.5

Steel clapping plate is used to connecting rubber body in rubber dam. However, once the steel clapping plate corrodes, it may cause faults, such as the same problems experienced by typical reinforcing steel. This study evaluated the applicability of glass fiber reinforced polymer composite(GFRP) clapping plate as a substitute for steel clapping plate. Absorption and load test were conducted to evaluate the decrease in durability of GFRP clapping plate exposed to deterioration environments. In the durability test results, the absorption rate of GFRP clapping plate was appeared as 0.6~1.0% in 50 day of immersion time. Also, the fracture load decreased with accelerated degradation environment exposure. Moreover, the absorption rate in GFRP clapping plate increased as degradation progressed, reducing the fracture load.

논문편 : 신세대 기혼남녀의 라이프스타일 , 가정경영의식 및 행동

이정우,김명자,계선자,박미석,지금수,김경숙,이정숙,박미금 ( Jeong Woo Lee,Myung Cha Kim,Sun Ja Kye,Mee Sok Park,Keum Soo Chi,Kyung Sook Kim,Jung Sook Lee,Mi Kum Park ) 대한가정학회 1997 Human Ecology Research(HER) Vol.35 No.1

신경근전기자극에 의한 척수운동신경원의 흥분성 변화

이정우,김태열,이인학,이준희,Lee, Jeong-Woo,Kim, Tae-Youl,Lee, In-Hak,Lee, Joon-Hee 대한임상전기생리학회 2003 대한임상전기생리학회지 Vol.1 No.1

The purpose of this study was to determine the effect of neuromuscular electrical stimulation(NMES) on the alteration of spinal motor neuron excitability. In this article, I would like to experiment on a standard capacity of clinical electrophysiology, a difference in applying methods and a clinical efficiency of NMES by Nerve conduction velocity. We used normal eight subjects without neuromuscular disease and all subjects participated 3 session, which at least 1 week between session. Participants classified according to each group in Antagonist, Agonist, Antagonist-Agonist by the NMES. The test was measured continuously pre test, post-test, post 20 minute test by EMG including H reflex, F wave, motor nerve conduction velocity(MNCV). The following results were obtained; 1. H-reflex latencies and H/M intervals were significantly increased in agonist and antagonist-agonist group(p<.01). 2. H-reflex amplitudes and H/M ratios were significantly decreased in agonist and antagonist-agonist group(p<.01). In agonist group, H-reflex amplitudes and H/M ratios were more significantly decreased than antagonist group. 3. F-wave latencies were significantly increased in agonist and antagonist-agonist group(p<.01). F/M intervals were significantly increased in antagonist-agonist group(p<.01). F wave conduction velocities were significantly increased in agonist and antagonist-agonist group(p<.01) but F/M ratios were not significant. 4. MNCV were significantly decreased in agonist(p<.01). These results lead us to the conclusion that agonist and Antagonist-agonist was significantly decreased excitability of spinal motor neuron. Conversely, Antagonist does not decreased. Therefore, A further direction of this study will be to provide more evidence that NMES have an effect on excitability of spinal motor neurons in UMN syndrome.

세기변조방사선치료 선량분포 확인을 위한 2차원적 이온전리함 배열의 특성분석

이정우,홍세미,김연래,최경식,정진범,이두현,서태석,Lee, Jeong-Woo,Hong, Se-Mie,Kim, Yon-Lae,Choi, Kyoung-Sik,Jung, Jin-Beom,Lee, Doo-Hyun,Suh, Tae-Suk 한국의학물리학회 2006 의학물리 Vol.17 No.3

본 연구의 목적은 2차원적 이온전리함 배열의 특성을 분석하고 세기변조방사선치료 선량분포 확인의 유용성을 평가하기 위함이다. 본 실험에 사용된 2차원적 이온전리함 배열(MatriXX, Scanditronix-Wellhofer, IBA, Germany)은 $24{\times}24cm^2$ 범위에 1,024개의 평판형 전리함(용적: $0.08cm^3$, 직경: 4.5 mm, 높이: 5 mm, 배열간격: 7.62 mm)이 일정한 간격으로 배열되어있다. MatriXX의 특성분석을 위해 선량 직선성, 선량률 의존도, 출력 계수, 단기 선릉재현성을 분석하였으며, 선량분포 확인의 신뢰도를 평가하기 위해 Varian사의 동적쐐기와 세기변조 방사선치료의 선량분포를 분석하였다. 선량 직선성의 범위는 $1{\sim}800$cGy이었으며, 1% 미만의 오차율을 보였다. 선량률 의존성(범위 $100{\sim}600MU/min$)은 300 Mu/min을 기준으로 했을 때 모든 선량률 범위에서 0.4% 미만의 선량변화를 보였다. 또한, 물팬톰에서 0.1 cc 지두형 전리함으로 측정한 출력계수와 폴리스틸렌 팬톰에서 MatriXX로 측정한 출력계수를 비교하였다. 이 실험의 결과, $3{\times}3{\sim}24{\times}24cm^2$ 범위에서 0.5% 미만의 일치를 나타내었다. 단기 출력재현성 확인을 위하여 15분 간격으로 6회 측정한 결과, 0.5% 내의 차이를 보였다. 동적쐐기와 세기변조 방사선 조사면의 일치성 실험에서도 치료계획장치의 계산값과 필름측정값이 비교적 잘 일치함을 알 수 있었다. 본 연구를 통해 MatriXX의 물리적인 특성을 분석하였으며 세기변조방사선치료의 품질관리를 위한 유용성을 확인하였다. A commercial ion chamber matrix was examined the characteristics and its performance for radiotherapy qualify assurance. The device was the I'mRT 2D-MatriXX (Scanditronix-Wellhofer, Schwarzenbruck, Germany). The 2D-MatriXX device consists of a 1020 vented ion chamber array, arranged in $24{\times}24cm^2$ matrix. Each ion chamber has a volume of $0.08cm^3$, spacing of 0.762 cm and minimum sampling time of 20 ms. For the investigation of the characteristics, dose linearity, output factor, short-term reproducibility and dose rate dependency were tested. In the testing of dose linearity. It has shown a good signal linearity within 1% in the range of $1{\sim}800$cGy. Dose rate dependency was found to be lower than 0.4% (Range: 100-600 Mu/min) relative to a dose rate of 300 Mu/min as a reference. Output factors matched very well within 0.5% compared with commissioned beam data using a ionization chamber (CC01, Scanditronix-Wellhofer, Schwarzenbruck, Germany) in the range of field sizes $3{\times}3{\sim}24{\times}24cm^2$. Short-term reproducibility (6 times with a interval of 15 minute) was also shown a good agreement within 0.5%, when the temperature and the pressure were corrected by each time of measurement. in addition, we compared enhanced dynamic wedge (EDW, Varian, Palo Alto, USA) profiles from calculated values in the radiation planning system with those from measurements of the MatriXX. Furthermore, anon-uniform IMRT dose fluence was tested. All the comparison studies have shown good agreements. In this study, the MatriXX was evaluated as a reliable dosimeter, and it could be used as a simplistic and convenient tool for radiotherapy qualify assurance.