• Title/Summary/Keyword: 개인선량

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Efficacy of a Protective Grass Shield in Reduction of Radiation Exposure Dose During Interventional Radiology (방사선학적 중재적 시술시 납유리의 방사선 방어효과에 관한 연구)

  • Jang, Young-Ill;Song, Jong-Nam;Kim, Young-Jae
    • Journal of the Korean Society of Radiology
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    • v.5 no.5
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    • pp.303-308
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    • 2011
  • Background/Aims : The increasing use of diagnostic and therapeutic interventional radiology calls for greater consideration of radiation exposure risk to radiologist and radiological technician, and emphasizes the proper system of radiation protection. This study was designed to assess the effect of a protective grass shield. Methods : A protective grass was following data depth, 0.8 cm; width, 100 cm; length, 100 cm, lead equivalent, 1.6 mmPb. The protective shield was located between the patient and the radiologist. Thirty patients (13 male and 17 female) undergoing interventional radiology between September 2010 and December 2010 were selected for this study. The dose of radiation exposure was recorded with or without the protective grass shield at the level of the head, chest, and pelvis. The measurement was made at 50 cm and 150 cm from the radiation source. Results : The mean patient age was 69 years. The mean patient height and weight was $159.7{\pm}6.7$ cm and $60.3{\pm}5.9$ kg, respectively. The mean body mass index (BMI) was $20.5{\pm}3.0$ kg/m2. radiologists received $1530.2{\pm}550.0$ mR/hr without the protective lead shield. At the same distance, radiation exposure was significantly reduced to $50.3{\pm}85.2$ mR/hr with the protective lead shield (p-value<0.0001). The radiation exposure to radiologist and radiological technician was significantly reduced by the use of a protective lead shield (p value <0.0001). The amount of radiation exposure during interventional radiology was related to the patient' BMI (r=0.749, p=0.001). Conclusions : This protective shield grass is effective in protecting radiologist and radiological technician from radiation exposure.

Active Inferential Processing During Comprehension in Poor Readers (미숙 독자들에 있어 이해 도중의 능동적 추리의 처리)

  • Zoh Myeong-Han;Ahn Jeung-Chan
    • Korean Journal of Cognitive Science
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    • v.17 no.2
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    • pp.75-102
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    • 2006
  • Three experiments were conducted using a verification task to examine good and poor readers' generation of causal inferences(with because sentences) and contrastive inferences(with although sentences). The unfamiliar, critical verification statement was either explicitly mentioned or was implied. In Experiment 1, both good and poor readers responded accurately to the critical statement, suggesting that both groups had the linguistic knowledge necessary to the required inferences. Differences were found, however, in the groups' verification latencies. Poor, but not good, readers responded faster to explicit than to implicit verification statements for both because and although sentences. In Experiment 2, poor readers were induced to generate causal inferences for the because experimental sentences by including fillers that were apparently counterfactual unless a causal inference was made. In Experiment 3, poor readers were induced to generate contrastive inferences for the although sentences by including fillers that could only be resolved by making a contrastive inference. Verification latencies for the critical statements showed that poor readers made causal inferences in Experiment 2 and contrastive inferences in Experiment 3 doting comprehension. These results were discussed in terms of context effect: Specific encoding operations performed on anomaly backgrounded in another passage would form part of the context that guides the ongoing activity in processing potentially relevant subsequent text.

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Establishment of Release Limits for Airborne Effluent into the Environment Based on ALARA Concept (ALARA 개념(槪念)에 의한 기체상방사성물질(氣體狀放射性物質)의 환경방출한도(環境放出限度) 설정(設定))

  • Lee, Byung-Ki;Cha, Moon-Hoe;Nam, Soon-Kwon;Chang, Si-Young;Ha, Chung-Woo
    • Journal of Radiation Protection and Research
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    • v.10 no.1
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    • pp.50-63
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    • 1985
  • A derivation of new release limit, named Derived Release Limit(DRL), into the atomsphere from a reference nuclear power plant has been performed on the basis of the new system of dose limitation recommended by the ICRP, instead of the (MPC)a limit which has been currently used until now as a general standard for radioactive effluents in Korea. In DRL Calculation, a Concentration Factor Method was applied, in which the concentrations of long-term routinely released radionuclides were in equilibrium with dose in environment under the steady state condition. The analytical model used in the exposure pathway analysis was the one which has been suggested by the USNRC and the exposure limits applied in this analysis were those recommended by the USEPA lately. In the exposure pathway analysis, all of the pathways are not considered and some may be excluded either because they are not applicable or their contribution to the exposure is insignificant compared with other pathways. In case, the environmental model developed in this study was applied to the Kori nuclear power plant as the reference power plant, the highest DRL value was calculated to be as $9.10{\times}10^6Ci/yr$ for Kr-85 in external whole body exposure from the semi-infinite radioactive cloud, while the lowest DRL value was observed 3.64Ci/yr for Co-60 in external whole body exposure from the contaminated ground, by the radioactive particulates. The most critical exposure pathway to an individual in the unrestricted area of interest (Kilchun-Ri, 1.3 km to the north of the release point) seems to be the exposure pathway from the contaminated ground and the most critical radionuclide in all pathways appears to be Co-60 in the same pathway. When comparing the actual release rate from KNU-l in 1982 with the DRL's obtained here the release of radionuclides from KNU-1 were much lower than the DRL's and it could be conclued that the exposure to an individual had been kept below the exposure limits recommended by the USEPA.

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Level of Understanding and Requirement of Education of Patients on Radiotherapy (방사선 치료 관련 정보에 대안 환자의 이해정도 및 교육요구도)

  • Kang, Soo-Man;Lee, Choul-Soo
    • The Journal of Korean Society for Radiation Therapy
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    • v.18 no.2
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    • pp.97-103
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    • 2006
  • The purpose of this study is to understand preliminary education. level of understanding and the degrees of educational requirement for cancer patients on radiotherapy and to present the preliminary data to development of effective and practical patients treatment programs. Based on the abovementioned results of this study. Relationship betweendegrees of knowledge and demand for educational requirement for patients who are undertaking radiotherapy could be varied with different factors such as educational background, ages, regions of treatment, experience of symptoms. In general, patients do not have enough information, on the other hand, have very high demand for educational requirement. Customized education patients by patients would not be possible in reality. However, if we could provide standard for patients and establish systematic sessions during treatment based on this study, more and better patients satisfaction and results of treatments could be achieved.

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Effects of Entrepreneurship Motivation on Entrepreneurial Opportunity Competence in Preliminary Young Entrepreneurs: Focusing on Mediating Effects Of Entrepreneurial Efficacy and Entrepreneurial Orientation (예비청년창업가의 창업동기가 창업기회역량에 미치는 영향: 창업효능감과 기업가지향성의 매개변수의 효과 중심으로)

  • Shan, Liang;Heo, Chul Moo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.14 no.1
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    • pp.117-137
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    • 2019
  • In young entrepreneurs, the individual situation of opportunity discovery is very important. It is very important that the opportunities that are created for a particular individual entrepreneur are also recognized and assessed through the process. The need for the development of entrepreneurial opportunity competencies, which have a low proportion of opportunistic entrepreneurship, is low in the entrepreneurship education. In particular, young entrepreneurs are in desperate need of opportunistic entrepreneurship. The purpose of this study is to examine the effect of entrepreneurship motivation on entrepreneurial opportunity competence, using entrepreneurial orientation and entrepreneurship orientation as mediation variables for preliminary young entrepreneurs (19-39 old). In the case of young entrepreneurs, there is a tendency to study entrepreneurship policies and education through the system of youth entrepreneurship schools, mainly on college students and youths, and on the effects of institutional support on entrepreneurship. There is little research on the effect of a entrepreneurial motivation on the entrepreneurial opportunity competence needed to promote an entrepreneurial venture in a model with multiple mediators. The purpose of this study is to investigate the effect of start - up motivation on the entrepreneurial opportunity competence. To do this we analyzed 374 questionnaires collected from preliminary young entrepreneurs in Seoul and Gyeonggi provinces. The results of the analysis using SPSS v22.0 and Process macro v3.0 showed that the motivation of start - up had a significant effect on both opportunity recognition and opportunity evaluation of entrepreneurial opportunity competence. Second, motivation of entrepreneurs has a significant effect on entrepreneurial efficacy. Third, entrepreneurial efficacy has a significant effect on entrepreneurial orientation. Fourth, entrepreneurial orientation has a significant effect on entrepreneurial opportunity competence. Fifth, there is a significant indirect effect between entrepreneurial motivation and entrepreneurial opportunity recognition when passing through entrepreneurial orientation, entrepreneurial efficacy and entrepreneurial orientation at the same time, But indirect effects was insignificant when only entrepreneurship efficacy is passed. There is a significant indirect effect on all mediators between entrepreneurial motivation and entrepreneurial opportunity valuation. It is suggested that strengthening education on entrepreneurship is necessary to cultivate awareness of entrepreneurship opportunities and strengthening education on both entrepreneurial efficacy and entrepreneurship is necessary to cultivate evaluation of entrepreneurship opportunities by type of entrepreneurial motivation.