• 제목/요약/키워드: Whole field

검색결과 1,830건 처리시간 0.031초

전뇌조사시(全腦照射時) 뇌(腦)에 있어서의 선량분포(線量分布) (Dose Distribution in the Brain in Radiotherapy of Whole Brain)

  • 강위생;하성환;박찬일
    • Radiation Oncology Journal
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    • 제1권1호
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    • pp.37-40
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    • 1983
  • Whole brain irradiation is one mode in the treatment of brain cancer and brain metastasis, but it might cause brain injury such as brain necrosis. It has been studied whether the dose distribution could be a cause of brain injury. The dose distribution in whole brain irradiated by Co-60 beam has been measured by means of calibrated TLD chips inserted in the brain of Humanoid phantom. The following results were obtained. 1. Dose distribution on each transverse section of the brain was uniform. 2. On the midsagital plane of the brain, the dose was highest in upper portion and lowest in lower portion, varying 8 from 104% to 90%. 3. When the radiation field includes free space of 2cm or more width out of the head, the dose distribution in the whole brain is almost independent of the field width. 4. It is important to determine adequate shielding area and to set shielding block exactly in repetition of treatment.

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모드해석과 관측기를 이용한 1차원 온도분포의 실시간 예측 (Real Time Estimation in 1-Dimensional Temperature Distribution Using Modal Analysis and Observer)

  • 안중용;박영민;정성종
    • 대한기계학회논문집B
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    • 제25권2호
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    • pp.195-201
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    • 2001
  • An inverse heat conduction problem(IHCP) arises when unknown heat fluxes and whole temperature field are to be found with temperature measurements of a few points. In this paper, observers are proposed as solution algorithm for the IHCP. A 1-dimensional heat transfer problem is modeled with modal analysis and state space equations. Position of the heat source is estimated through test heat inputs and the autocorrelation among a few of temperature data. The modified Bass-Gura method is used to design a state observer to estimate the intensity of heat source and the whole temperature field of a 1-dimensional body. To verify the reliability of this estimator, analytic solutions obtained from the proposed method are compared.

수확시기가 사료용 벼의 초장, 건물수량 및 사료성분에 미치는 영향 (Plant Height, Dry Matter Yield and Forge Quality at Different Maturity of Whole Crop Rice)

  • 성경일;홍석만;김병완
    • 한국초지조사료학회지
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    • 제24권1호
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    • pp.53-60
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    • 2004
  • Recently, there has been a growing tendency to use whole crop rice for feeds as there is an increased rice supply and a decrease in the demand for rice in Korea. Little information, however, is available about the management and utilization of whole crop rice for feeds. This study was conducted to decide the optimum harvest date through examining the plant height, dry matter(DM) yield and feed composition of whole crop rice harvested at different maturity. Field study was established early in May until October 7th on a rice field at Yupori, Sinbuk-yeup, Chunchon, Kangwon-Do. "Ilpum" mutant rice was sown at 52 kg/ha, and N, P and K were applied at 209, 113 and 81 kg/ha, respectively. The rice was harvested at six different mature stages for analysis; booting stage; 17 Aug., milk-ripe stage; 27 Aug., dough stage; 7 Sep., yellow ripe stage; 17 Sep., dead ripe stage; 27 Sep. and full ripe stage; 7 Oct. Plant height was 77 cm in booting stage (P<0.05) which was lower when compared to the other stages among which the heights did not differ with average range of 93∼97 cm. The highest dry matter yield was observed in yellow ripe stage (22.8 T/ha), which was followed by dead ripe stage (19.3 T/ha), full ripe stage (19.3 T/ha), and dough stage (15.1 T/ha). Crude protein (CP) and Neutral detergent fiber (NDF) concentrations consistently decreased with maturity. The highest concentrations of CP and NDF were obtained in booting stage with 9 and 73.6%, respectively (P<0.05), and lowest in full ripe stage with 5.8 and 64.6%, respectively (P<0.05). The concentration of total digestible nutrient (TDN) was highest in booting stage (59.7%); however no significant difference was found among other stages. The concentrations of Ca and P were not different among mature stages. According to these results, the yellow ripe period is appropriate to harvest the whole crop rice for forage considering dry matter yields, feed compositions and TDN concentrations.

CuCl2 노출에 의해 유도되는 제브라피시의 행동과 내분비계의 변화 (Exposure to Copper (II) Chloride Induces Behavioral and Endocrine Changes in Zebrafish)

  • Sung, Jiwon;Lee, Jeongwon;Lee, Seungheon
    • 생명과학회지
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    • 제30권4호
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    • pp.321-330
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    • 2020
  • 본 연구의 목표는 CuCl2가 지브라피시에 미치는 영향을 조사하는 것이다. CuCl2에 대한 지브라피시의 반수치사농도를 조사하기 위하여 각기 다른 시간에 따른 농도를 설정하여 노출시켰다. 본 연구에서는 스트레스 반응의 증가를 보기 위하여 whole-body cortisol level 측정과 행동약리학적 변화를 측정하기 위해서 open field test와 novel tank test를 실시하였다. Whole-body cortisol의 sample을 수집하거나 행동실험을 실시하기 전에 CuCl2 또는 vehicle을 1시간 동안 처리하였다. CuCl2의 반수치사농도는 24시간, 48시간, 96시간에서 각각 30.3, 25.3, 14.8 ㎍/l으로 측정되었다. CuCl2에 노출된 지브라피시의 novel tank test의 결과는 총 이동거리, 움직이는 시간 그리고 속도는 유의성이 있게 감소한 반면, turn angle은 최고농도에서 유의성이 있게 증가하였다(p<0.05). 다른 행동실험인 open field test의 결과에서도 총 이동거리, 움직이는 시간 속도가 CuCl2의 노출에 의해서 감소하였으며, turn angle과 meandering이 유의하게 증가하였다(p<0.05). CuCl2에 노출된 지브라피시의 whole-body cortisol은 1.5 or 15 ㎍/l의 농도에서는 유의하게 증가하였으나, 150 ㎍/l의 농도에서는 유의성 있는 변화를 발견하지 못하였다(p<0.05). 본 연구의 결과는 CuCl2의 노출이 지브라피시에서 치사율 증가, 행동 및 내분비의 변화 등을 포함하는 독성 반응을 야기하는 것을 나타낸다.

자동 선구조 추출 알고리즘을 이용한 경북 의성지역의 선구조 분석 (Lineament analysis in the euiseong area using automatic lineament extraction algorithm)

  • 김상완
    • 자원환경지질
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    • 제32권1호
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    • pp.19-31
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    • 1999
  • In this study, we have estimated lineaments in the Euiseong area, Kyungbuk Province, from Landsat TM by applying the algorithm developed by Kim and Won et al. which can effectively reduce the look direction bias associated with the Sun's azimuth angle. Fratures over the study area were also mapped in the field at 57 selected sites to compare them with the results from the satellite image. The trends of lineaments estimated from the Landsat TM images are characterized as $N50^{\circ}$~70W, NS~$N10^{\circ}$W, and $N10^{\circ}$~$60^{\circ}$E trends. The spatial distribution of lineaments is also studied using a circular grid, and the results show that the area can be divided into two domains : domain A in which NS~$N20^{\circ}$E direction is dominant, and domain B in which west-north-west direction is prominent. The trends of lineaments can also be classified into seven groups. Among them, only C, D and G trends are found to be dominant based upon Donnelly's nearest neighbor analysis and correlations of lineament desities. In the color composite image produced by overlaying the lineament density map of these C-, D-, and G-trends, G-trend is shown to be developed in the whole study area while the eastern part of the area is dominated by D-trend. C-trend develops extensively over the whole are except the southeastern part. The orientation of fractures measured at 35 points in the field shows major trends of NS~$N30^{\circ}$E, $N50^{\circ}$~$80^{\circ}$W, and N80$^{\circ}$E~EW, which agree relatively well with the lineaments estimated form the satellite image. The rose diagram analysis fo field data shows that WNW-ESE trending discontinuities are developed in the whole area while discontinuities of NS~$N20^{\circ}$E are develped only in the estern part, which also coincide with the result from the satellite image. The combined results of lineaments from the satellite image and fracture orientation of field data at 22 points including 18 minor faults in Sindong Group imply that the WNW-ESE trend is so prominent that Gumchun and Gaum faults are possibly extended up to the lower Sindong Group in the study area.

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Non-coplanar whole brain radiotherapy is an effective modality for parotid sparing

  • Park, Jaehyeon;Park, Jae Won;Yea, Ji Woon
    • Journal of Yeungnam Medical Science
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    • 제36권1호
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    • pp.36-42
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    • 2019
  • Background: The purpose of this study was to evaluate the efficacy and feasibility of non- coplanar whole brain radiotherapy (NC-WBRT) for parotid sparing. Methods: Fifteen cases, previously treated with WBRT were selected. NC-WBRT plans were generated. The beam arrangement for the non-coplanar plans consisted of superior anterior, right, and left beams. After generation of the non-coplanar plans a field-in-field technique was applied to the bilateral parallel opposed beams in order to reduce maximum dose and increase dose homogeneity. The NC-WBRT plans were subsequently compared with the previously generated bilateral WBRT (B-WBRT) plans. A field-in-field technique was also used with the B-WBRT plans according to our departmental protocol. As per our institutional practice a total dose of 30 Gy in 10 fractions of WBRT was administered 5 days a week. Results: The mean dose to the parotid gland for the two different plans were 16.2 Gy with B-WBRT and 13.7 Gy with NC-WBRT (p<0.05). In the NC-WBRT plan, the V5Gy, V10Gy, V15Gy, V20Gy, and V25Gy of the parotid were significantly lower (p<0.05) than those of the B-WBRT plan. The $D_{max}$ of the lens was also lower by 10% with NC-WBRT. Conclusion: The use of NC-WBRT plans could be a simple and effective method to reduce irradiated volumes and improve the dose-volume parameters of the parotid gland.

Ballooning Instability Induced by Coronal Flux Rope Merging

  • Choe, G.S.;Jun, Hong-Dal;Kim, Sun-Jung;Ahn, Ji-Eun
    • 천문학회보
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    • 제35권2호
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    • pp.48.1-48.1
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    • 2010
  • A numerical simulation study of the solar coronal plasma reveals that a ballooning instability can develop in the course of flux rope merging. When magnetic field lines from different flux ropes reconnect, a new field line connecting farther footpoints is generated. Since the field line length abruptly increases, the field line expands outward. If the plasma beta is low, this expansion takes place more or less evenly over the whole field line. If, on the other hand, the plasma beta is high enough somewhere in this field line, the outward expansion is not even, but is localized as in a bulging balloon. This ballooning section of the magnetic field penetrates out of the overlying field, and eventually the originally underlying field and the overlying field come to interchange their apex positions. This process may explain how a field structure that has stably been confined by an overlying field can occasionally show a localized eruptive behavior.

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Development of Ballooning Instabilities in the Solar Atmosphere

  • Jun, Hong-Dal;Choe, G.S.;Kim, Sun-Jung
    • 천문학회보
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    • 제36권2호
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    • pp.84.2-84.2
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    • 2011
  • A numerical simulation study of the solar coronal plasma reveals that a ballooning instability can develop in the course of flux rope merging. When magnetic field lines from different flux ropes reconnect, a new field line connecting farther footpoints is generated. Since the field line length abruptly increases, the field line expands outward. If the plasma beta is low, this expansion takes place more or less evenly over the whole field line. If, on the other hand, the plasma beta is high enough somewhere in this field line, the outward expansion is not even, but is localized as in a bulging balloon. This ballooning section of the magnetic field penetrates out of the overlying field, and eventually the originally underlying field and the overlying field come to interchange their apex positions. This process may explain how a field structure that has stably been confined by an overlying field can occasionally show a localized eruptive behavior.

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전신 정위 방사선 치료시의 적정 조사면 크기 (Optimum Field Size for the Whole Body Stereotactic Radiosurgery)

  • 이병용;민철기;정원규;최은경
    • 한국의학물리학회지:의학물리
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    • 제13권1호
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    • pp.15-20
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    • 2002
  • 전신 정위 방사선 시술 시 적정 치료 조사면에 대한 연구를 실시하였다. 치료표적 직경이 1cm에서 7cm까지 1cm 간격인 경우에 다양한 크기의 치료 조사면 크기에서 만들어낸 선량 분포를 분석하였다. 치료조사면은 표적 크기에서 -1cm~2cm를 각각 더한 크기로 하였다. 치료 계획의 성적은 TCI(Target Conformity Index)로 표현하였다. 모든 표적 크기에서 -0.5cm~0.5cm를 더한 치료 조사면에서 가장 높은 TCI를 보였다. 6cm 이상의 표적 크기에서는 -0.5cm 또는 0cm를 더한 조사면에서 우수한 성적을 보였으며, 표적 크기 2cm 이하에서는 0cm 또는 0.5cm를 더한 조사면이 좋은 결과를 보였다. 표적 크기와 관계없이 동중심점 선량의 80%~90%에 처방하는 것이 가장 효율적으로 나타났다.

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Consideration of fractionation or field size prior to radiation therapy in patients with breast cancer and psoriasis: a case report

  • Jin Yi Hyun;So Hyun Park;Dae-Hyun Kim;Jinhyun Choi
    • Journal of Medicine and Life Science
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    • 제20권2호
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    • pp.89-93
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    • 2023
  • We present three cases of patients with breast cancer and psoriasis who received radiotherapy following breast-conserving surgery. One patient developed an extensive flare-up of psoriasis during chemotherapy. After discontinuing chemotherapy, she received conventional radiotherapy to the ipsilateral whole breast, axillary, and supraclavicular lymph nodes with 50.4 Gy in 28 fractions and boosted with 10 Gy in five fractions to the tumor bed. Two patients received hypofractionated whole-breast radiotherapy at a total dose of 40.05-42.4 Gy in 15-16 fractions. In all three cases, there was no flare-up of psoriatic events at least 6 months after the completion of radiotherapy. We hypothesized that there is a close relationship between psoriatic events and the extent of trauma rather than the daily dose of the fraction. Therefore, we confirmed that the effect of radiotherapy on psoriatic events is minimal if the radiation field size does not exceed that of the whole breast.