• 대한방사선치료학회지
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• 제24권1호
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• pp.1-10
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• 2012

목 적: 동적다엽콜리메이터를 이용한 세기변조방사선 치료 시 선량률 임의 변경 되었을 경우 선량 분포 차와 변화를 평가하고자 한다. 대상 및 방법: 소조사야와 대조사야의 두 가지 세기변조방사선치료계획을 임상적 치료계획시스템(Eclipse, Varian, Palo Alto, CA)을 이용하여 계획하였다. 각각의 치료계획은 선량률 100, 400, 600 MU/min으로 변화시켜 조사야별 세 종류로 치료계획을 하였다. 측정기 2D-Array (2D-Array Seven729, PTW-Freiburg)는 측정 깊이 0.5 cm를 고려하여 위로 Solid water phantom ($30{\times}30{\times}4.5cm$)와 아래로 후방산란을 고려한 Solid water phantom 5 cm 사이에 위치 시켰다. MLC-120엽을 갖춘 에너지 6 MV 선형가속기(Clinac 21EX, Varian, Palo Alto, CA)를 사용하여 실험하였다. 첫 번째로 선량률 100, 400, 600 MU/min의 치료 계획한 것을 같은 선량률로 측정 하여 각각의 기준값을 얻었다. 1) 선량률 100 MU/min일 때 임의로 200, 300, 400, 500, 600 MU/min로 변화하고, 2) 400 MU/min일 때 100, 200, 300, 500, 600 MU/min으로 변화시켰으며, 3) 600 MU/min일 때 100, 200, 300, 400, 500 MU/min를 측정하였다. 끝으로 분석 프로그램(Verisoft 3.1, PTW-Freiburg)을 이용하여 기준 값과 선량률 변화 시의 선량차와 분포를 평가 하였다. 결 과: 치료 계획한 선량률 100 MU/min, 400 MU/min, 600 MU/min을 치료 계획한 대로 측정한 기준 값은 미세한 선량차를 보였고 선량분포도 일치하였다. 이를 기준 값으로 하여 소조사야에 대해 측정한 결과 100 MU/min에서는 200, 300, 400, 500, 600MU/min으로 변경하며 측정 시 -0.8, -1.1, -1.3, -1.5, -1.6%로 선량차가 있었으며, 400 MU/min (소조사야)에서 100, 200, 300, 500, 600 MU/min일 때 +0.9, +0.3, +0.1, -0.2, -0.2%의 선량변화가 있었고, 선량률 600 MU/min (소조사야)에서는 100, 200, 300, 400, 500 MU/min으로 변경 시 +1.4, +0.8, +0.5, +0.3, +0.2%로 나타났다. 다른 한편, 대조사야에서 100 MU/min(대조사야)는 -1.3, -1.6, -1.8, -2.0, -2.4%로 조금 더 큰 감소를 보였고, 400 MU/min (대조사야)는 +2.0, +1.8, +0.5, -1.2, -1.6%의 선량변화가 있었다. 600 MU/min (대조사야)에서는 +1.5, +1.9, +1.7, +1.9, +1.2%였다. 선량률 변화에 따른 선량 차는 -2.4~+2.0%로 측정되었다. 결 론: 120-MLC를 갖춘 선형가속기를 사용하여 측정한 세기변조방사선 치료 시 선량률 변화에 따른 선량분포는 거의 변화가 없었으며 선량 차는 ${\pm}3%$ 미만이었다.

• 한국의학물리학회지:의학물리
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• 제29권2호
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• pp.66-72
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• 2018

The proper position of a multi-leaf collimator (MLC) is essential for the quality of intensity-modulated radiation therapy (IMRT) and volumetric modulated arc radiotherapy (VMAT) dose delivery. Task Group (TG) 142 provides a quality assurance (QA) procedure for MLC position. Our study investigated the QA validation of the mechanical leaf gap measurement and the maintenance procedure. Two $VitalBeam^{TM}$ systems were evaluated to validate the acceptance of an MLC position. The dosimetric leaf gaps (DLGs) were measured for 6 MV, 6 MVFFF, 10 MV, and 15 MV photon beams. A solid water phantom was irradiated using $10{\times}10cm^2$ field size at source-to-surface distance (SSD) of 90 cm and depth of 10 cm. The portal dose image prediction (PDIP) calculation was implemented on a treatment planning system (TPS) called $Eclipse^{TM}$. A total of 20 VMAT plans were used to confirm the accuracy of dose distribution measured by an electronic portal imaging device (EPID) and those predicted by VMAT plans. The measured leaf gaps were 0.30 mm and 0.35 mm for VitalBeam 1 and 2, respectively. The DLG values decreased by an average of 6.9% and 5.9% after mechanical MLC adjustment. Although the passing rates increased slightly, by 1.5% (relative) and 1.2% (absolute) in arc 1, the average passing rates were still within the good dose delivery level (>95%). Our study shows the existence of a mechanical leaf gap error caused by a degenerated MLC motor. This can be recovered by reinitialization of MLC position on the machine control panel. Consequently, the QA procedure should be performed regularly to protect the MLC system.

• 한국물환경학회지
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• 제20권6호
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• pp.589-596
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• 2004

In this study, the reduction rates of nutrients were suggested to prevent eutrophication on the Hwaong reservoir in the year of 2008 and 2012. With EPA's WASP6 model, future water quality were simulated. In 2008, T-N would be 1.36mg/L and T-P 0.100mg/L on average. ; In 2012, T-N 2.66mg/L and T-P 0.128mg/L. With all the water quality management plans that the government authorities are carrying out, these results indicate that the reservoir would be reach the eutrophic or hypertrophic state according to the Vollenweider's trophic states. Therefore, the Hwaong reservoir requires additional plans for nutrients management. Here, the target water quality to prevent eutrophication of the reservoir sets into mesotrophic state ; T-N 0.475mg/L and T-P 0.02mg/L.(median of Vollenweider index for mesotropphic state) The reduction rates of nutrients on Namyang and Eoeun streams were estimated with uniform treatment method to meet the goal. The results showed that nutrients from two streams should be reduced up to 78% in 2008, and 84% in 2012. Since the ratio of T-N/T-P would be higher than 16 at target years, T-N was not considered as the limiting factor and was not reduced.

• Imaging Science in Dentistry
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• 제40권3호
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• pp.143-147
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• 2010

Purpose : This study was to investigate whether cervical vertebrae can be utilized in evaluating the growth of the maxilla. Materials and Methods : Fifty one male patients took lateral cephalometric radiographs once in every two years from the age of 8 till 14. Measured parameters were the concavity depth at the lower border of the third and fourth cervical vertebrae, and three analytical maxillary dimensions. Results : The analysis of the maxillary measurements and the concavity depth at the lower border of the cervical vertebrae in the lateral cephalometric radiographs showed that the measured parameters gradually increased as the patients aged. Moreover, while the parameters of the patients in age 8 and 10 did not show any correlation, those of the patients in age 12 and 14 definitely showed the correlations. Conclusions : Although certain correlations were seen in particular parameters, further researches and studies with various parameters and shorter age intervals are needed. The result of this study will help clinicians in making plans and evaluating the proposed treatment plans.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제29권3호
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• pp.17-28
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• 2023

Purpose: This study aims to provide basic data for the future construction plans of the Infectious Disease Hospitals by analyzing the area composition and required room ratios in the wards and ICU of currently under-construction infectious disease hospitals. Methods: 3 Methods have been used in this paper. 1) This study conducted a literature review on major considerations and related guidelines for hospitals specializing in infectious diseases using existing data. 2) Based on the objects and activities of the hospital space, zones and areas were set for each department according to infection control. 3) Based on the established zones and areas, basic plan drawings of three hospitals specializing in infectious diseases currently under construction were collected and architectural drawing analysis was performed. Results: 1) Infectious Diseases Hospital must have a spatial organization that can accommodate patient isolation, infection control, efficiency of medical service, and changes. 2) Zones for infection control are divided into negative pressure and non-negative pressure zones based on airborne precaution isolation. It is divided into clean and contaminated zone according to class of cleanliness by Aseptic technique. Areas are classified by objects (patients, healthcare workers, supplies) and activities (access, medical treatment, support), and a system for organizing space is established based on this. 3) By analyzing the area composition of each departmental area, each required room, and each required space in the wards and intensive care units, it provides basic data for the spatial organization for architectural planning of the infectious disease hospital. Implication: It can be used as basic data when planning related facilities by analyzing the characteristics of the space plan of the required room according to the relationship between activities, movement lines, and operation plans based on user behavior.

• International Journal of Computer Science & Network Security
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• 제22권1호
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• pp.241-247
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• 2022

This study examines teachers' implementation of strategies to modify the aggressive behavior of students with intellectual disabilities in Saudi Arabia, to determine the obstacles to their real-world execution. In addition, it presents potential approaches to overcome the obstacles to implementing strategies with this group of students. The research employed a qualitative design using semi-structured interviews as a data collection tool and applied a thematic analysis. The study population comprised 35 teachers of students with intellectual disabilities and the study sample numbered six teachers. The interviews were conducted via different methods: three by phone, two face-to face, and one using the Zoom platform. The results revealed inadequate understanding among teachers of intellectual disability and behaviour modification strategies, and this affected their capacity to develop plans that were compatible with the needs of students with intellectual disability. The findings also identified multiple obstacles that impede teachers' implementation of strategies to modify aggressive behaviour among students with intellectual disabilities; the most important being the lack of input from a psychological specialist when developing programs to modify aggressive behaviour. In general, it is apparent that programs for modifying aggressive behaviour are neither structured nor complementary, due to the scarcity of administrators with sufficient knowledge and familiarity with the characteristics and personalities of students with intellectual disabilities. This study presents several recommendations, the most important of which is that teachers of students with intellectual disability should develop themselves through training courses to enable them to deal with these students and create treatment plans that include strategies and clear steps to modify the aggressive behaviour of students with intellectual disabilities. To support teachers, it is also necessary to remove the obstacles facing education centres by providing financial support to create an environment in which they can access the required devices and equipment in their classes.

• 한국방사선학회논문지
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• 제9권7호
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• pp.449-457
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• 2015

전립선암의 방사선치료에서 토모테라피와 용적변조회전치료(volumetric modulated arc therapy, VMAT)의 치료계획에 따른 유용성 평가를 위해 흡수선량, 선량체적곡선(dose volume histogram, DVH), 치료효율성, MapCHECK2를 이용한 선량 검증 정확도 결과를 각각 비교 분석하였다. 대상으로는 2014년 7월부터 12월까지 H 대학병원 방사선종양학과에서 토모테라피 치료를 받은 전립선암 환자 중 12명을 무작위로 선택하였다. 흡수선량과 DVH를 분석한 결과 종양조직과 방광에서 두 방사선 치료계획이 근소한 차이를 나타냈지만 처방선량의 오차범위인 -5%에서+3%안에 포함됐고 정상조직 부작용 확률 권고치인 견딤선량 범위를 넘지 않았다. 치료시간은 2.5배 짧고 MU(monitor unit)도 10.3배 작아 VMAT가 치료효율성이 높았다. 선량정확도는 모두 95% 이상의 통과기준에 포함 되었으며 VMAT가 2.3% 더 높게 나타났다. 토모테라피와 VMAT 모두 종양조직에 적합한 선량이 흡수되었으며 정상조직의 견딤선량 범위를 넘지 않아 선량분포특성에서 큰 차이는 없었다. 하지만 치료시간이 짧고, total MU가 낮아 치료효율성이 좋고 선량 검증의 정확도 또한 우수한 VMAT를 선택하는 것이 치료에 더 유용할 것으로 사료된다.

• 한국물환경학회지
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• 제27권2호
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• pp.200-209
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• 2011

The purpose of the study is to optimally manage sewage treatment plant with analysis of phosphorus contribution and improvement of water quality contributing rate in the effect of inflowing point of effluent and Pal-Dang lake after reducing T-P discharge from large scale public sewage treatment plant at upstream of Pal-Dang lake. Also, this study, for enforcement of T-P in effluent, plans optimal management of effluent T-P through examining propriety of environmental, technological, and economical aspect such as water quality standard of domestic and foreign T-P and related policy. In regarding optimal management of T-P discharged from public sewage treatment plant located in upstream of Pal-Dang lake, the study drew following conclusions. With the optimal management of public sewage treatment plant, it showed that a pollution level became higher in the order of Sumgang E in South-Han river, C in Dalcheon, B1 B2, A in North-Han river, and J in Kyungancheon, and it is required reduction of T-P first. The highest value in analysis of benefit-costs from sewage treatment plant in the selected research area was Kyungan B, and the others are with the order of Jojong A, Bokha A, Kyungan A, and Yanghwa A. With result of this study, all 14 areas are required more enforced phosphorus treatment. The study resulted that the most top priority areas were Hangang F, Sumgang B, and Gyungan A, top priority areas were Bokha A, Dalcheon B, and Cheongmi A, priority areas were Hangang E, Heukcheon A, Gyungan B, and Jojong A, and potential areas were Sumgang A, Yanghwa A, Dalcheon A, and Hangang D. It seems to be appropriate to apply 0.2 mg/L of T-P treatment for water supply source reservation, 0.5 mg/L for the other areas by locally, and 0.2~0.5 mg/L for biological nitrogen phosphorus treatment method and 0.5~1 mg/L for Conventional Activated Sludge by technologically. Also, it may be appropriate to apply 0.2 mg/L for the most top priority area(I), 0.3 mg/L for the top priority area(II), 0.4 mg/L for priority area(III), and 0.5 mg/L for potential area(IV) by the separation of priority area.

• 한국전자거래학회지
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• 제7권3호
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• pp.1-19
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• 2002

This research investigates several essential topics of m-business by conducting a questionnaire to the professional experts. The topics include the market structure and business, the demand for available m-business service and its development, the market size and market growth factors, the service fee, the core technologies and technology development prediction. This paper contributes to the development of m-business in that it provides criteria and policies for more active and efficient treatment of m-business market under IMT2000 environment and also offers guides and plans of m-business activation for both government and enterprise.

• 한국축산시설환경학회지
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• 제4권1호
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• pp.63-71
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• 1998

The dramatic increase in both swine and cattle production in Korea has presented problems related to protection of water resources. Animal wastes are a potentially valuable source of plant nutrients. Modern liquid waste management plans for a livestock housing need to focus on the slurry aeration and composting control methods and cost effective equipments. Recent developments in the animal manure liquid composting make it possible to improve the manure more easier to handle, reduce the odorous, labors and bedding materials, kill the weed seeds etc. However, there are some disadvantages, the aerator consumes much electrical power and initial cost is high. To solve these problems, this study is intended to develop a key points such as slurry aeration and dilution, liquid waste composting equipments.