• Title/Summary/Keyword: Radiation technique

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Numerical Calculation of the Deflected Path of Electrons through Water under External Magnetic Fields

  • Jeong, Dong-Hyeok;Kim, Jhin-Kee;Shin, Kyo-Chul;Kim, Ki-Hwan;Kim, Jeung-Kee;Oh, Young-Kee;Ji, Young-Hoo;Lee, Jeong-Ok;Kim, Seung-Kyu
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2003.09a
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    • pp.71-71
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    • 2003
  • The study on magnetic field combined radiation therapy, as a new technique to modify the dose distributions using external magnetic field, has been investigated. The goal of the study is to develop the techniques for dose localization, as a particle beam, from the strong magnetic fields. In this study, in order to study the principle of dose deposition in external fields, as a basic approach, we have calculated approximately the paths of traveling electrons in water under external magnetic fields with numerical methods. The calculations are performed for a primary particle by cumulating the steps which are defined as small path lengths which energy loss can be ignored. In this calculation, the energy loss and direction change for a step was calculated by using total stopping power and Lorentz force equation respectively. We have examined the deflected paths of the electron through water as a function of external magnetic field and incident electron s energy. Since we did not take account of the multiple scattering effects for electrons through water, there are errors in this calculation. However, from the results we can explain the principle of dose variation and dose focusing for electron beams under strong magnetic fields in water.

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Genome Wide Expression Analysis of the Restored Changes by Carthami Flos Extract Treatment on Rat Brain Injury (흰쥐의 손상된 뇌조직에서의 유전자 발현 변화에 대한 홍화(紅花) 추출물 투여의 작용)

  • Kim, Bu-Yeo;Limb, Se-Hyun;Lee, Guem-San;Kim, Hyung-Woo;Lim, Chi-Yeon;Cho, Su-In
    • The Journal of Internal Korean Medicine
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    • v.31 no.4
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    • pp.706-713
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    • 2010
  • Objectives : The source is from the flower of Carthamus tinctorius L., family Compositae. It is used in clinical medicine to promote blood circulation, remove blood stasis, promote menstruation and alleviate pain. In the present study, we investigated the genome wide analysis of Carthami Flos on the intra-cranial hemorrhage(ICH) model. Methods : ICH in rat was induced by injection of collagenase type IV and Carthami Flos extract(CFe) was administered orally. The molecular profile of cerebral hemorrhage in rat brain tissue was measured using microarray technique to identify up- or down- regulated genes in brain tissue. Results : Expression profile showed that diverse genes were up- or down-regulated by ICH induction. Administration of CFe restored the expression level of some of altered genes by ICH to normal expressional level. Interestingly, these recovered genes by CFe were involved in the same biological pathways which were significantly activated or suppressed by ICH. Conclusion : The above results might explain the therapeutic mechanism of CFe on ICH. Further, by analyzing interaction network, core genes was identified which could be key molecular targets of CFe against ICH.

Track Distiribution of Recoil Protons in PN-3 Dosimeters Etched in NaOH Solution (NaOH 용액에 의해 부식된 PN-3 선량측정계에서의 되튕긴 양성자의 궤적 분포)

  • Yoo, Done-Sik;Sim, Kwang-Souk
    • Progress in Medical Physics
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    • v.2 no.2
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    • pp.129-139
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    • 1991
  • The method of etching tracks in PN-3 dosimeter has been applied to tracks of recoil protons from a neutron source. Both the etch and the detection response of PN-3 has been studied as a function of etched-track diameters against various parameters. We could obtain very useful informations about charge, energy, and mass of particles and the relationship between the track etching rate and the track forming procedure in order to analyze the particle recorded in the solid state track detector. The best etching condition could be found by means of changing the etching circumstances for various energies and particles in order to detect the charged particle accurately. It could be influenced widely that the polymer plastic detector could develep the detecting technique for the low energy level neutron and could be used as a neutron dosimeter in the radiation field such as the nuclear power station, the medical institute and the nondtructive testing institute.

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Estimation Method of Evapotranspiration through Vegetation Monitoring over Wide Area (식생해석을 통한 광역증발산량 추정 방법의 개발)

  • 신사철
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.14 no.1
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    • pp.81-88
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    • 1996
  • Remote sensing technique is a probable means to estimate distribution of actual evapotranspiration over wide area in connection with regional characteristics of vegetation and landuse. Factors controlling evapotranspiration from ground are air temperature, humidity, wind, radiation, soil moisture and so on. Not only the vegetation influences directly the evapotranspiration, but also these factors strongly influnce the vegetation at the area. Therefore we can expect high correlation between the evapotranspiration and the vegetation. To grasp the state of vegetation at any point, NDVI calculated from NOAA/AVHRR data is utilized. It can be considered that evapotranspiration at a forest region is linearly proportional to the NDVI. Here, a model which adopts a direct method to estimate actual evapotranspiration is developed by using the relationship between NDVI and evapotranspiration. This method makes possible to estimate evapotranspiration of Korean Peninsula including North Korea where enough meteorological and hydrological data are unavailable.

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A Study on the Telemetering Results of KSR-III Flight Test (KSR-3 비행시험 원격측정시스템 운용 결과)

  • Lee, Sang-Rae;Lee, Soo-Jin;Kim, Sung-Wan;Lee, Jae-Deuk
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.6
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    • pp.96-101
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    • 2003
  • Korea Sounding Rocket(KSR)-III onboard telemetry system has acquired various data from subsystems and sensors in the rocket, and radiated PCM/FM data using two S-band antennas during the flight. Simultaneously, it is necessary that the ground receiving systems track the rocket, and receive and decode telemetry data. Also post processed telemetry data are needed to be broadcasted on ethernet network in real time. Range safety display system displays flight trajectory using telemetry data in mission control center, and so flight manager makes a decision for flight termination from the trajectory This paper describes operating technique about telemetry reception, the development for the realtime data processing system, and the results for telemetering reception on fight test. We telemetered, processed, and broadcasted numerous telemetry data during the flight test successfully.

Family History Attributes and Risk Factors for Breast Cancer in Turkey

  • Gokdemir-Yazar, Ozden;Yaprak, Seval;Colak, Muhteber;Yildirim, Ediz;Guldal, Dilek
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.6
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    • pp.2841-2846
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    • 2014
  • Background: When dealing with breast cancer, early detection is closely associated with determining and closely monitoring high risk groups. The aim of this study was to determine the preventable risk factors that are specific for our country, and to understand which risk factors were most predominant. Materials and Methods: The study was planned as a case-control design. Women diagnosed with breast cancer who visited the Surgery, Obstetrics and Gynaecology, and Radiation Oncology outpatient clinics of the Izmir Dokuz Eylul University (DEU) School of Medicine were accepted as the case group. Then a control group matched for age was established among females who visited the outpatient clinics on the same days. A questionnaire prepared by the researchers was implemented using a face-to-face interview technique. The Mann-Whitney U test was used in the comparisons of the group averages, and the Pearson chi-square test in the comparisons between groups. In order to determine the dominant risk factors, binary logistical regression test was implemented. Results: A total of 138 patients, 69 cases and 69 controls, were included in the study. A significant difference can be detected between the groups in terms of BMI, smoking, breast cancer prevalence among first degree family members, presence of breast cancer among distant family members, existence of other types of cancers among family members and the age of onset of menopause (p<0.05). Logistical regression analysis revealed that the presence of breast cancer among first degree relatives increased the risk of developing breast cancer 5.7 times. Conclusions: Although some results of this study are compatible with findings in the literature, some are not. In order to determine unique risk factors, there is a clear need for large-scale studies.

Ultrasound Guided Shoulder Joint Injection through Rotator Cuff Interval (초음파를 활용한 회전근개 간격으로 접근한 견관절 주사법)

  • Lim, Jong Bum;Kim, Young Ki;Kim, Sung Woo;Sung, Kyu Wan;Jung, Il;Lee, Chung
    • The Korean Journal of Pain
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    • v.21 no.1
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    • pp.57-61
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    • 2008
  • Background: Shoulder joint injection is currently performed under fluoroscopic or computed tomography scan guidance. We performed this study to determine if an ultrasound guided shoulder joint injection through rotator cuff interval would have clinical usefulness. Methods: A total of 17 volunteers [12 women, 5 men; mean age 28 yr (23-32 yr)] received shoulder joint injection under multilinear ultrasound (5-10 MHz). Volunteers were positioned supinely on a table with their arm in a neutral position. The anterior shoulder region of the patient was sterilized using povidone iodine. A 24 gauge needle was introduced and directly visualized in real time as it passed obliquely from the skin surface to the inferior space of the biceps tendon. If there was little or no resistance to the injection, a contrast media (omnipaque) was injected and checked fluoroscopically. Results: Ultrasound guided shoulder joint injection through rotator cuff interval was successful in all cases. The average time taken for the procedure was $27.5{\pm}16.5sec$. The vertical distance from skin to the inferior space of the biceps tendon was $1.6{\pm}0.4cm$ and the distance of needle from the skin to the inferior space of biceps tendon was $2.8{\pm}0.6cm$. The procedure was well tolerated by all volunteers. Conclusions: Ultrasound guided shoulder joint injection through rotator cuff interval is an effective, rapid, and easy-to-perform injection technique. Ultrasound guided injection enables exact needle placement and avoids the use of both ionizing radiation and iodinated contrast material.

Specification of Chemical Properties of Feed Coal and Bottom Ash Collected at a Coal-fired Power Plant

  • Ma, Chang-Jin;Kim, Jong-Ho;Kim, Ki-Hyun;Tohno, Susumu;Kasahara, Mikio
    • Asian Journal of Atmospheric Environment
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    • v.4 no.2
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    • pp.80-88
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    • 2010
  • In order to offer a better understanding of air pollution of China as well as East Asia we attempted to characterize the chemical properties of the raw coal materials mined in China and their combusted bottom ashes generated from coal fired power plant. To this end, we measured the chemical characteristics of individual bottom ashes and feed coal fragments collected at a coal fired power generator which was operated with the raw coal dug at a coal mine in China. The chemical properties of these two sample types were determined by a synchrotron radiation X-ray fluorescence (SR-XRF) microprobe method. Through an application of such technique, it was possible to draw the 2D elemental maps in and/or on raw coal fragments and fired bottom ashes. The pulverized fine pieces of feed coal mainly consisted of mineral components such as Fe, Ca, Ti, Ca, and Si, while Fe was detected as overwhelming majority. The elemental mass of combusted bottom ash shows strong enrichment of many elements that exist naturally in coal. There were significant variations in chemical properties of ash-to-ash and fragment-to-fragment. Although we were not able to clearly distinguish As and Pb peaks because of the folding in their X-ray energies, these two elements can be used as tracers of coal fire origin.

Performance Evaluation of Beamforming Scheme in Millimeter Wave Wireless Communication System (밀리미터파 무선통신 시스템에서의 빔포밍 기법 성능 평가)

  • Nguyen, Thanh Ngoc;Jeon, Taehyun
    • Journal of Satellite, Information and Communications
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    • v.11 no.3
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    • pp.133-137
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    • 2016
  • Millimeter wave wireless communication systems, especially those targeting indoor high rate data transfer, have a strong requirement for high quality wireless link. Unfortunately, in this frequency band, the electromagnetic wave has to sustain the high propagation loss caused by the smaller wavelengths. In this scenario, beamforming technique, which enhances the link quality by focusing the radiation power on a direction, becomes one of the most important techniques in millimeter wave band wireless communication. In recent year, there been conducted many research on beamforming to improve the performance of wireless system. In this paper, we evaluate the performance of a simplified codebook-based beamforming scheme which is based on multiple-procedure and three-state beam selection. The simplified scheme significantly reduces beamforming setup time, comparing to the exhaustive searching, two-level searching adopted in IEEE 802.15.3c standard, and also conventional multi-level scheme.

A Novel Simple Method to Abstract the Entire Parameters of the Solar Cell

  • Park, Minwon;Yu, In-Keun
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.4B no.2
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    • pp.86-91
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    • 2004
  • PV power generation, which directly converts solar radiation into electricity, contains numerous significant advantages. It is inexhaustible and pollution-free, silent, contains no rotating parts, and has size-independent electricity conversion efficiency. The positive environmental effect of photovoltaics is that it replaces the more polluting methods of electricity generation or that it provides electricity where none was available before. This paper highlights a novel simple method to abstract the entire parameters of the solar cell. In development, design and operation of PV power generation systems, a technique for constructing V-I curves under different levels of solar irradiance and cell temperature conditions using basic characteristic values of the PV module is required. Everyone who has performed manual acquisition and analysis of solar cell I versus V data would agree that the job is tedious and time-consuming. A better alternative is to use an automated curve tracer to print out the I versus V curves and compute the four major parameters; $V_{oc}$, $I_{sc}$, FF, and . Generally, the V-I curve tracer indicates only the commonly used solar cell parameters. However, with the conventional V-I curve tracer it is almost impossible to abstract the more detailed parameters of the solar cell; A, $R_{s}$ and $R_{sh}$ , which satisfies the user, who aims at the analysis of the development of the PV power generation system, that being advanced simulation. In this paper, the proposed method provides us with satisfactory results to enable us to abstract the detailed parameters of the solar cell; A, $R_s$ and $R_{sh}$.>.