• 제목/요약/키워드: Characteristic radiation

Search Result 615, Processing Time 0.024 seconds

Design and Performance Evaluation of IR-UWB Tapered Slot Antenna for Optimum Impulse Radio Radiation (임펄스 신호 방사를 위한 IR-UWB용 테이퍼 슬롯 안테나 설계 및 성능평가)

  • Kim, Jong-Min;Koh, Young-Mok;Ra, Keuk-Whan
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.11 no.5
    • /
    • pp.103-115
    • /
    • 2012
  • In this paper, design and performance evaluation of Tapered Slot Antenna for IR-UWB which propagates impulse radio is performed. TSA which has directional characteristic in UWB band should have low radiation loss and minimized impulse radiation distortion. In order to achieve these objectives, the paper designed wide band Impedance transformer and microstrip-slotline transit region structured TSA feeder line. By using the fabricated TSA, the radiation pattern was measured in the radio anechoic chamber. Pulse fidelity and distortion equation was induced to evaluate time domain characteristics according to the impulse radiation. Pulse fidelity of Impulse radiation show favorable results more than 93% within ${\pm}30^{\circ}$ beam width.

Estimation of Future Trend for Solar Radiation Data Management (일사량 데이터 관리를 위한 미래 변화 추이 예측)

  • Oh, In-Bae;Lee, Bong-Keun;Ahn, Yoon-Ae
    • The Journal of the Korea Contents Association
    • /
    • v.7 no.12
    • /
    • pp.218-230
    • /
    • 2007
  • Measured values of solar radiation data have a characteristic that they change almost by the minute, so original data can be massive. Therefore, we need to construct a database which stores and manages history data of solar radiation data systematically. A study of an estimation method of the future change trend is also required. In this paper, we present a data structure in order to store history data of solar radiation data and propose an estimation method for the change trend of solar radiation that applies to a time-series decomposition method. Also, we present the results of experiments based on measured data from 20 domestic cities in Korea.

Performance evaluation of an adjustable gantry PET (AGPET) for small animal PET imaging

  • Song, Hankyeol;Kang, In Soo;Kim, Kyu Bom;Park, Chanwoo;Baek, Min Kyu;Lee, Seongyeon;Chung, Yong Hyun
    • Nuclear Engineering and Technology
    • /
    • v.53 no.8
    • /
    • pp.2646-2651
    • /
    • 2021
  • A rectangular-shaped PET system with an adjustable gantry (AGPET) has been developed for imaging small animals. The AGPET system employs a new depth of interaction (DOI) method using a depth dependent reflector patterns and a new digital time pickoff method based on the pulse reconstruction method. To evaluate the performance of the AGPET, timing resolution, intrinsic spatial resolution and point source images were acquired. The timing resolution and intrinsic spatial resolution were measured using two detector modules and Na-22 gamma source. The PET images were acquired in two field of view (FOV) sizes, 30 mm and 90 mm, to demonstrate the characteristic of the AGPET. As a result of in the experiment results, the timing resolution was 0.9 ns using the pulse reconstruction method based on the bi-exponential model. The intrinsic spatial resolution was an average of 1.7 mm and the spatial resolution of PET images after DOI correction was 2.08 mm and 2.25 mm at the centers of 30 mm and 90 mm FOV, respectively. The results show that the proposed AGPET system provided higher sensitivity and resolution for small animal imaging.

Radiation Exposure Analysis of Female Nuclear Medicine Radiation Workers (여성 핵의학 방사선종사자의 피폭요인 분석)

  • Lee, Juyoung;Park, Hoon-Hee
    • Journal of radiological science and technology
    • /
    • v.39 no.2
    • /
    • pp.209-225
    • /
    • 2016
  • In this study, radiation workers who work in nuclear medicine department were analyzed to find the cause of differences of radiation exposure from General Characteristic, Knowledge, Recognition and Conduct, especially females working on nuclear medicine radiation, in order to pave the way for positive defense against radiation exposure. The subjects were 106 radiation workers who were divided into two groups of sixty-four males and forty-two females answered questions about their General Characteristic, Knowledge, Recognition, Conduct, and radiation exposure dose which was measured by TLD (Thermo Luminescence Dosimeter). The results of the analysis revealed that as the higher score of knowledge and conduct was shown, the radiation exposure decreased in female groups, and as the higher score of conduct was shown, the radiation exposure decreased in male groups. In the correlation analysis of female groups, the non-experienced in pregnancy showed decreasing amount of radiation exposure as the score of knowledge and conduct was higher and the experienced in pregnancy showed decreasing amount of radiation exposure as the score of recognition and conduct was higher. In the regression analysis on related factors of radiation exposure dose of nuclear medicine radiation workers, the gender caused the meaningful result and the amount of radiation exposure of female groups compared to male groups. In the regression analysis on related factors of radiation exposure dose of female groups, the factor of conduct showed a meaningful result and the amount of radiation exposure of the experienced in pregnancy was lower compared to the non-experienced. The conclusion of this study revealed that radiation exposure of female groups was lower than that of male groups. Therefore, male groups need to more actively defend themselves against radiation exposure. Among the female groups, the experienced in pregnancy who have an active defense tendency showed a lower radiation exposure. Thus, those who have never been pregnant need to have a more active defensive conduct for the future possibility of pregnancy.

Experimental Evaluation of Far Infrared Characteristic for Bio Liquid Ceramics used in Bulding finishing Materials (액상세라믹의 원적외선 특성의 실험적평가)

  • 지철근;최태섭;장성일
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.16 no.6
    • /
    • pp.7-12
    • /
    • 2002
  • This paper presents the Experimental Evaluation for the physical, chemical property and Far Infrared Characteristic, the effects to the living body of liquid ceramics which was made by the a Bio ceramic(co).

Evaluation of Scatter Radiation in Digital Radiological Condition by using Photostimulated Luminescence (BaFBr:$Eu^{2+}$) (휘진성 형광체 (BaFBr:$Eu^{2+}$)를 이용한 영상의학분야에서 산란선 특성에 관한 평가)

  • Min, Jung-Whan;Han, Seong-Gyu;Kim, Jung-Min;Lee, Joo-Ah;Kim, Ki-Won;Jeong, Hoi-Woun
    • Journal of radiological science and technology
    • /
    • v.37 no.2
    • /
    • pp.85-91
    • /
    • 2014
  • The purpose of this study is evaluated scatter radiation in digital radiological condition by using photo-stimulated luminescence (BaFBr:$Eu^{2+}$). Experiment condition changed kVp (from 50 kVp to 120 kVp), filed size (from $4{\times}4cm^2$ to $26{\times}26cm^2$) and phantom thickness (from 1 cm to 15 cm). This method was analysed ImageJ and characteristic curve of CR. This results was scatter radiation to primary radiation ratio increased from 50 kVp to 70 kVp, and it was fixed at over 80 kVp. The scatter radiation to primary radiation ratio are increased according to increasing the ratio of field size. Scatter radiation is also increased by increasing the phantom thickness.

Inductively Coupled Plasma discharge characteristic of Ne, Ar, Kr mixed gas (유도결합형 플라즈마에서의 Ne, Ar, Kr 혼합가스 방전특성)

  • Her, In-Sung;Choi, Yong-Sung;Lee, Chong-Chan;Park, Dae-Hee
    • Proceedings of the KIEE Conference
    • /
    • 2004.11a
    • /
    • pp.306-309
    • /
    • 2004
  • Recently, the environmental problem has received considerable attention. so, many lamps have been developing for environmental requirement and energy efficiency. also, at glow discharge lamp researchers try to reduce energy spending that is power saving lamp. this kind requirement agree with strong points of electrodeless fluorescent lamp has received to now lighting sauce. At low pressure as mTorr I.C.P make high density plasma easily, is good to maintain discharge, has high ionization and does not have failing lighting and losing ability of electron radiation by oxidation and volatilization of electrodes, because this tape does not have electrodes. This point of I.C.P can use at electrodeless fluorescent lamp in this study ICP display elements and Ar, Ne, Kr are researched for optical characteristic. each gas is looked into optical characteristic, also mixed gases is experiment for optical characteristic.

  • PDF

Radiological Accident and Acute Radiation Syndrome (방사선 사고와 급성 방사선 증후군)

  • Roh, Hyung-Keun
    • Journal of The Korean Society of Clinical Toxicology
    • /
    • v.9 no.2
    • /
    • pp.39-48
    • /
    • 2011
  • In mass casualty situation due to radiological accidents, it is important to start aggressive management with rapid triage decisions. External contamination needs immediate decontamination and internal contamination should be treated with special expertise and equipment to prevent the rapid uptake of radionuclides by target organs. Acute radiation syndrome shows a sequence of events that varies with the severity of the exposure. More severe exposures generally lead to more rapid onset of symptoms and severe clinical findings. After the massive exposure, various systems of the body reflect their severe damages that can lead to death within hours or up to several months. The disease progression has classically been divided into four stages: prodromal, latent, manifest illness, and recovery or death. Three characteristic clusters of symptoms including the hematopoietic syndrome, the gastrointestinal syndrome and the cerebrovascular syndrome are all associated with the acute radiation syndrome. The standard medical management of the patients with a potentially survivable radiation exposure includes good medical, surgical and supportive measures. Specific treatment with cytokines and bone marrow transplantation should be considered. The management of internal contamination is much the same as the treatment of poisoning. The standard decontamination should be applied to reduce uptake, and the chelating agents can be administered to enhance the clearance of radioisotopes. Radioactive iodine ($^{131}I$) as one of the nuclear fission products can increase the incidence of thyroid cancer in children. Potential benefit of potassium iodide prophylaxis is greater especially in neonates, infants and small children.

  • PDF

Establishment of Short-Term Teratogenicity Study for Detecting Developmental Toxicity Induced by Gamma Radiation (방사선의 발생독성 검색을 위한 단기 최기형성 시험법의 확립)

  • 김종춘;김성호;신동호;신진영;김세라;이해준;박승춘;조성기;이윤실
    • Toxicological Research
    • /
    • v.20 no.2
    • /
    • pp.117-122
    • /
    • 2004
  • The present study was carried out to establish a short-term teratogenicity study for detecting developmental toxic potential induced by gamma radiation in ICR mice. Pregnant mice were exposed at dose levels of 0, 0.5, 1, 2, or 4 Gy on gestational day 8.5. All dams were subjected to caesarean section on gestational day 10.5 and their embryos were examined for growth, differentiation, and morphological abnormalities. An increase in the number of resorption was found at 4 Gy in a dose-dependent manner. Dose-dependent decreases in the developmental score of yolk sac circulation and olfactory system at above 1 Gy, in the number of somite pairs and developmental score of allantois, optic system, and maxillary process at above 2 Gy, and in the all growth and developmental parameters examined at 4 Gy were found. Various types of morphological abnormalities were seen at dose levels of 0.5 Gy or greater. Characteristic malformations induced by gamma radiation were abnormal axial rotation, hematoma, craniofacial hypoplasia, open neuropore, shortened prosencephalon, kinked somites, irregular somites, swelling, hydropericardium, absent branchial bar, and absent limb bud. Morphological alterations such as hematoma, craniofacial hypoplasia, open neuropore, and kinked somites were noted even in the lowest dose (0.5 Gy). These results indicated that the short-term teratogenicity study established in this study can be a useful tool for not only detecting the developmental toxic potential induced by gamma radiation, but also screening radio-protective agents in ICR mice.

Study on Rocket-Borne Antenna (비행체 탑재 안테나에 관한 연구)

  • 이호선;우종명
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.11 no.4
    • /
    • pp.627-633
    • /
    • 2000
  • In this paper, new printed-type inverted F antenna is designed and fabricated to gain the ideal radiation pattern of a rocket-borne antenna which is expected to show the omni-directional pattern characteristic in rear direction. The radiation pattern of this antenna is measured in condition that the antenna is mounted on the side of the fin which is located on the tail of a rocket or a missile. Measurement result shows that the improved symmetrical radiation pattern is obtained with respect to the radiation pattern of the existing inverted F antenna. Besides parasite element which can be operated as reflector is attached in front of the antenna with the distance between the antenna and the parasite element $\lambda$/8. The result shows that the ratio of the front to the rear radiation level is improved by 8 dB.

  • PDF