Multiple arc FSRT와 Conformal FSRT의 DVH 비교

김기환,김준상,장지영,김재성,김성호,송창준,박민규,존문준,Kim Ki-Hwan,Kim Jun-Sang,Jang JiYoung,Kim Jae-Sung,Kim Seong-Ho,Song Chang-Joon,Park Min-Kyu,Cho Moon-June 대한방사선종양학회 1999 대한방사선종양학회지 Vol.17 No.3

Purpose : In FSRT (Fractionated stereotactic radiotherapy) planning, we studied the usefulness between multiple arc FSRT and conformal FSRT by comparing tumor shape and DVH (dose volume histogram). Materials and Methods In Chungnam Univ. hospital, we had treated the sixteen patients with FSRT from Aug. 1997 to Dec. 1998. In choosing multiple arc FSRT or conformal FSRT, we had considered If (irregular factor) after calculating tumor volume and surface area. We had considered multiple arc FSRT if tumor shape was similar to sphere or the value of If was less than 1.25, conformal FSRT if tumor shape was very irregular or If was more than 1.3. For evaluation of treatment planning, we had considered the appropriate DVH for tumor volume and for critical organs. Results : The errors between reference point and the coordinates point on AP, Lat radiography were less than 1 mm before treatment. We had planned $3\~$5 arcs for multiple arc FSRT, $5\~6$ports for conformal FSRT. The mean dose distribution of tumor volume of cumulative DVH between multiple arc FSRT and conformal FSRT was 90.6, 85%, respectively. The dose of critical organs irradiated was less than $5\%$ maximum dose of cumulative DVH. Conclusion : We had obtained the similar value between multiple arc FSRT and conformal FSRT, so that we had appropriate treatment planning of FSRT for multiple arc FSRT and conformal FSRT according to tumor shape and size.

Monte Carlo Calculation on the Dose Modulation Using Dynamic Magnetic Fields for 10 MV X-rays

김기환,오영기,신교철,김진기,정동혁,김정기,조문준,김선영,Kim, Ki Hwan,Oh, Young Kee,Shin, Kyo Chul,Kim, Jhin Kee,Jeong, Dong Hyeok,Kim, Jeung Kee,Cho, Moon June,Kim, Sun Young Korean Society of Medical Physics 2007 의학물리 Vol.18 No.4

Monte Carlo calculations were performed to demonstrate the dose modulation with dynamic magnetic fields in phantom. The goal of this study is to obtain the uniform dose distributions at a depth region as a target on the central axis of photon beam under moving transverse magnetic field. We have calculated the depth dose curves for two cases of moving magnetic field along a depth line, constant speed and optimal speed. We introduced step-by-step shift and time factor of the position of the electromagnet as an approximations of continuous moving. The optimal time factors as a function of magnetic field position were calculated by least square methods using depth dose data for static magnetic field. We have verified that the flat depth dose is produced by varying the speed of magnetic field as a function of position as a results of Monte Carlo calculations. For 3 T magnetic field, the dose enhancement was 10.1% in comparison to without magnetic field at the center of the target.

최적 TBM 장비 발주를 위한 선정 기준 및 체크리스트 사례 검토

김기환,김혁,김성철,강시온,Kim, Ki-Hwan,Kim, Hyouk,Kim, Seong-Cheol,Kang, Si-On 한국터널지하공간학회 2021 한국터널지하공간학회논문집 Vol.23 No.6

When ordering a slurry shield TBM to be used for power cable tunneling, the client organizes an evaluation committee composed of experts, suggest the criteria and evaluation method for technical specifications for supplier selection, and based on the manufacturer's technical proposal were attempted to evaluate and select. It is expected to be referred to as a guideline for future projects to using Shield TBM as one of the methods of verifying performance and quality in advance and securing economic feasibility in the shield TBM tunneling in the recent increasing trend.

소아청소년 코로나바이러스감염증-19 대응지침

김기환,조은영,김동현,김한울,박지영,은병욱,조대선,최수한,최재홍,한미선,최은화,김종현,대한소아감염학회,Kim, Ki Hwan,Cho, Eun Young,Kim, Dong Hyun,Kim, Han Wool,Park, Ji Young,Eun, Byung-Wook,Jo, Dae Sun,Choi, Soo-Han,Choi, Jae Hong,Han, Mi Seon,C 대한소아감염학회 2020 Pediatric Infection and Vaccine Vol.27 No.1

The Korean Society of Pediatric Infectious Diseases and the Korea Centers for Disease Control and Prevention issued the guidelines about coronavirus disease 2019 (COVID-19) for children and adolescents. Case definitions and management of COVID-19 in neonates, infants, children and adolescents are presented in this guideline. In addition, guidelines for caregiver management are also provided. In this review, we introduce the contents of the current guidelines for COVID-19 in children and adolescents in Korea.

시뮬레이션 기반 육군전술지휘정보체계에 대한 웜 피해평가

김기환,김완주,이수진,Kim, Gi-Hwan,Kim, Wan-Joo,Lee, Soo-Jin 한국국방경영분석학회 2007 한국국방경영분석학회지 Vol.33 No.2

The army developed the ATCIS(Army Tactical Command Information System) for the battlefield information system with share the command control information through the realtime. The using the public key and the encryption equipment in the ATCIS is enough to the confidentiality, integrity. but, it is vulnerable about the availability with the zero day attack. In this paper, we implement the worm propagation simulation on the ATCIS infrastructure through the modelling on the ATCIS operation environment. We propose the countermeasures based on the results from the simulation.

시뮬레이션 기반 육군전술지휘정보체계 웜 피해평가에 관한 연구

김기환,김완주,이수진,Kim, Ki-Hwan,Kim, Wan-Ju,Lee, Soo-Jin 한국군사과학기술학회 2008 한국군사과학기술학회지 Vol.11 No.1

The army developed the ATCIS(Army Tactical Command Information System) for the battlefield information system with share the command control information through the realtime. The using the public key and the encryption equipment in the ATCIS is enough to the confidentiality, integrity. But, it is vulnerable about the availability with the zero day attack. In this paper, we implement the worm propagation simulation on the ATCIS infrastructure through the modelling on the ATCIS operation environment. We propose the countermeasures based on the results from the simulation.

자격증을 땁시다-식품위생학

김기환,Kim, Gi-Hwan 대한제과협회 2000 베이커리 Vol.11 No.-

자격증을 땁시다-재료과학1

김기환,Kim, Gi-Hwan 대한제과협회 2000 베이커리 Vol.12 No.-

비가역성 실혈성 쇽에서 본 가토심근, 혈장의 전해질 및 혈당량 변화

김기환,남기용,Kim, Ki-Whan,Nam, Kee-Yong 대한생리학회 1968 대한생리학회지 Vol.2 No.1

Twenty white rabbits anesthetized with nembutal (30 mg/kg) were employed in this experiment. Five of them served as controls; the remaining rabbits as experimental group were subjected to irreversible hemorrhagic shock. Shock was induced by bleeding the animals until mean blood pressure decreased to a level of 50-40 mmHg. This level of pressure was maintained for 3-4 hours, after which the drawn blood was reinfused. The reinfusion of blood caused the elevation of arterial pressure almost the control level for some minutes, after which a gradual and progressive decline of blood pressure became evident. This decline was thought to be the result from irreversible hemorrhagic shock. When mean blood pressure declined to less than 50 mmHg, chest was opened and samples of arterial blood and left ventricular muscle were taken. Left ventricular muscle and blood plasma were analyzed for potassium, sodium, chloride and water content. Blood glucose concentration was determined by Somogyi-Nelson's method. Extracellular and intracellular myocardial water and electrolyte content were calculated on the basis that electrolytes are distributed between plasma water and interstitial water according to Gibbs-Donnan equilibrium. In this calculation extracellular water was substituted for Na space. The findings obtained were as follows: 1. The concentration of blood glucose was 87mg% in the controls and it rose to 222 mg% in shock (P<0.01). 2. Plasma potassium elevated significantly from 3.3 mEq/l in controls to 8.0 mEq/l in shock (P<0.01), while small decreases in sodium (151-146 mEq/l) and chloride (102-96 mEq/l) were observed (P<0.3, P<0.1), 3. The changes of blood water content (83.1-84.3%) and cardiac water content (77.5-78.3 gm/100gm WT) were observed. 4. In control animals myocardial potassium levels which averaged 30.2 mEq/100 gmDT rose significantly to 40.3 mEq/100 gmDT in shock (P<0.01), while moderate decreases in sodium(16.3-14.3 mEq/100 gmDT) were observed in shock. 5. The calculated transmembrane resting potential of left ventricular muscle of control animals averaged 95 mV, while rabbits in shock averaged 77 mV. (P <0.01). The findings of this experiment do not correspond with the conclusions that myocardial depression seems to be the cause of irreversible hemorrhagic shock, because the excitability of heart muscle is elevated. From the point of view that the lowered transmembrane resting potential, the cause of death in terminal stage of irreversible hemorrhagic shock may be ventricular fibrillation. It can't be said, however, that the lowered transmembrane resting potential is responsible for the transition from reversible to irreversible hemorrhagic shock. The marked increase in blood glucose suggested that glycogenolysis in the liver is favorably active in shock.

반건강과 그 대책-만성피로 그것도 병인가

김기환,Kim, Gi-Hwan 한국건강관리협회 1975 건강소식 Vol.3 No.3