• Title/Summary/Keyword: hazard rate order

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The Treatment of Uterine Cervical Cancer Using High Dose Rate Co-60 Sources (고선량율(高線量率) 강내조사법(腔內照射法)을 이용(利用)한 자궁경암(子宮頸癌) 방사선(放射線) 치료(治療))

  • Kim, G.E.;Suh, C.O.;Lee, D.H.;Park, C.Y.
    • Radiation Oncology Journal
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    • v.1 no.1
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    • pp.95-102
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    • 1983
  • The radical treatment of uterine cervical cancer by interacavitary radium or cesium, in combination with teletherapy are well known. Although the result of such treatment should not give rise to complacency, problem of radiation exposure to medical staff had not been resolved. Fortunately, many attempts have been made to reduce this hazard, most of which take the form of afterloading applicators with a suitably shielded radioisotope. In order to avoid hazardous radiation exposure to staffs concerned with brachytherapy, RALS using high intensity source of Co-60, have been employed at Yonsei Cancer Center since May, 1979. It allows rectal and bladder doses to be kept low, while maintaining a satifactory usual dose distribution of the other type of applicators, and the short treatment time allow four or five patients to be treated per hour. It also removes much patient's discomfort and the difficulties of nursing these patients. Since the first introduction in Korea, over seven hundred cases with various stage of uterine cervical cancer have been treated on a radical basis at this center last 4 years. These authors have strongly attracted attention to the results in terms of local control rate, survival s and morbidity compared with those of conventional low dose rate radiotherapy. Retrospective interim analysis of data was preliminarily accomplished through the labored follow-up study of 340 cases treated during initial 2 years and the radiobiologic standpoint of high dose rate intracavitary irradiation will be discussed.

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Benzene Contents and Reliability of Material Safety Data Sheets for Paint Thinners sold in Busan, Ulsan, and Gyeongnam (부·울·경에서 판매되는 도료 희석제의 구성성분 함량과 물질안전보건자료의 신뢰성에 관한 연구)

  • Sungjun, Woo;Kwonchul, Ha
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.32 no.4
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    • pp.340-349
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    • 2022
  • Objectives: The importance of MSDS is emphasized for communicating hazardous information due to the increase in the types and usage of chemical substances. The purpose of this study is to assess the reliability of MSDS by collecting and examining paint thinners commercially available in South Korea. Methods: Twenty-five paint thinners were purchased at paint stores and the provision of MSDS was checked. Quantitative and qualitative analysis was performed on the chemical constituents of the thinners using GC-MSD and GC-FID. Reliability was evaluated by the MSDS collection rate for the paint thinners and calculating the rate of matching between laboratory analysis results and the contents and composition of chemical constituents given in the MSDS. Results: Unlike a study conducted in 2006, MSDS were provided for all 25 thinners. As a result of qualitative analysis using GC-MSD, 104 chemical substances were detected. The substances with the highest detection rate were identified in the order of toluene, butyl acetate, acetone, xylene, and ethyl benzene. A component matching rate of 41% was found by comparing the differences between the number of substances detected in laboratory testing and the number of substances listed in the MSDS. Benzene, a carcinogen not listed in the MSDS, was detected in two thinners produced by a small company. The detected benzene contents were 0.039 and 0.040%. When benzene is used, it should be strictly handled according to the Industrial Safety and Health Act. However, since it is not listed on the MSDS, it is judged that benzene was not being managed as a carcinogen in the workplaces where it is used. Conclusions: Since the reliability of MSDS, which play an important role in hazard communication, was evaluated to be low, it is necessary to systematically and continuously secure this reliability. In particular, carcinogens should be managed more strictly.

Evaluation on De-Icing Salts Laden Environment of Road in Seoul (제설제에 노출된 서울시내 도로 시설물의 열화 환경 분석)

  • Yoon, In-Seok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.1
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    • pp.1-9
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    • 2022
  • De -icing salts have been used commonly in areas where snow or ice is a seasonal safety hazard for roadway, however, the salts is one of main causes on serious deterioration of road infrastructures in crowded urban city like Seoul. In order to establish maintenance strategy of road infrastructures under de-icing salts laden environment, it is necessary to examine environmental characteristics and its response to the existing facilities. The purpose of this study is to evaluate the deterioration environment of road infrastructures. Additional purpose is to develop a design model and details for durability design of infrastructures under de-icing salts laden environment, considering mainly a build-up rate of surface chlorides. Concentration of external chloride solution and surface chloride content were calculated at the level of average de-icing salts for 5 years, ratio of auxiliary road of 17.5 to 30%, and effective exposure area to snow 50 to 80%. The chloride build-up rate was 0.073 ~ 0.077% / year and the maximum surface chloride content was calculated to be 2.2 ~ 2.31% by concrete wt. This study is expected to be used for establishing integrated strategy of road infrastructures, such as predicting chloride profiles or degree of chemical corrosion to exposure concrete.

Derivation of Flood Hazard Curves for SOC Facilities under Local Intensive Precipitation (LIP(극한강우) 조건하에서 중요 SOC 시설물에 대한 재해도 곡선 작성)

  • Kim, Beom Jin;Han, Kun Yeun*
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.1
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    • pp.183-194
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    • 2019
  • In recent years, the risk of external flooding of major national facilities has increased significantly since 2000 due to the increase in local heavy rainfall events. For important domestic national facilities, it is necessary to analyze the risk of external flooding as flooding in major sites due to heavy rain can cause functional paralysis in major facilities and ultimately lead to massive trouble events. In order to manage the safety of main facilities and its related facilities at a high level, it is necessary to analyze the degree of disaster such as flood depth, flood flow rate, flood time and flood intensity when extreme floods (LIP) are introduced. In addition, the degree of vulnerability of these related facilities should be assessed and risk assessments should be reassessed through linkage analysis that combines the degree of disaster and vulnerability. By calculating a new flood hazard curve for the flood depth and flood intensity in major national facilities under the heavy rainfall conditions through this study, it is expected to be a basis for the waterproof design of important SOC facilities, flood prevention function design, advancement of flood prevention measures and procedures and evaluation of flood mitigation functions.

An Effective Procedure for Development of Industrial Safety Signs Corresponding to International Criteria (국제기준에 부합하는 효과적인 안전표지의 개발절차)

  • Lim, Hyeon-Kyo;Park, Young-Won;Lee, Joon-Won;Jung, Kwang-Tae
    • Journal of the Korean Society of Safety
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    • v.22 no.4
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    • pp.96-101
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    • 2007
  • Usually pictograms embedded in safety signs are such final means to transmit hazard information that the importance of them cannot be emphasized too much. Nevertheless, in Korea, few people are interested in safety signs and their functions so that evaluation of safety signs are seldom committed nor safety signs draw workers' attention to fulfill their functions. Therefore this research aimed to standardize the procedure for developing safety signs in order not only to give practical help to industrial workers but to match them international standards, and to develop a few examples through the suggested standard procedure. As results, a procedure for developing industrial safety signs was developed by combining both ANSI Z535.3 and ISO 9186 with a special emphasis on action inducibility as the former emphasized as well as comprehensibility as the latter suggested. According to test results with undergraduate students as well as industrial workers on a few signs developed through the suggested procedure, action inducibility was higher whereas confusion rate was lower than expected on one hand, and it could be concluded that the procedure would supply results that can be satisfied on the other hand.

A Study on the Intensive Safety Management Items of Small-Sized Construction Sites (소규모 건축공사 중점안전관리항목에 관한 연구)

  • Go, Seong-Seok;Song, Do-Heom;Jang, Yun-Ra
    • Journal of the Korean Society of Safety
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    • v.28 no.5
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    • pp.27-34
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    • 2013
  • Almost accidents in construction sites are occurred by unsafe work conditions and failure making safe environment. As recent construction projects become more complex, various and diversified, So the potential of construction-related accidents is increased as well. Comparing the frequency of construction-related accidents in large-sized construction sites, small-sized construction sites are more vulnerable because of lack of workforce and less effective technology system. Furthermore, the absence of safety committee, poor financial condition leads to lack of safety education, installation of safety facilities, and provision of individual protective equipment, which indicates difficulties handling even basic safety management. Therefore, in order to lower the hazard rate at small-Sized construction sites, it is necessary to proceed with more structural and thorough actions for preventing accidents. In other words, it is necessary to analyze the causes of the accidents at small-sized construction sites, set criteria for safety management, and suggest safety management items according to work classification by evaluating the relative importance of the items.

GAMMA-SPECTROMETRY IN ENVIRONMENTAL MONITORING OF NUCLEAR POWER

  • Cechak, Tomas;Gerndt, Josef;Kluson, Jaroslav;Musilek, Ladislav;Thinova, Lenka
    • Journal of Radiation Protection and Research
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    • v.26 no.3
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    • pp.203-206
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    • 2001
  • The mathematical processing (unfolding) of pulse height spectra from a scintillation detector helps to calculate the photon fluence rate energy distribution in a measured photon field. The data processing is based on the knowledge of detection system response function and directional dependence respectively. The experimental results of the photon fields measurements in the vicinity of the spent fuel temporary storage and inside the storage hall are presented. The containers Castor 440 are used for temporary storing of the burnt up fuel assemblies in the Czech nuclear power plant Dukovany. A set of periodical measurements was performed in order to get basic information on the time dependence of the photon fields spatial distributions and spectral characteristics in the temporary storage hall and its vicinity. The photon fields were measured by the scintillation system. The obtained photon fields spatial distributions and spectral characteristics present the information on the radiation hazard in the storage.

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Allocation of Safety Integrity Level for Railway Platform Screen Door System based on Consequence Severity and Risk Graph (결과 심각도 및 리스크 그래프에 기반한 철도 승강장 도어시스템의 안전 무결성 수준 할당)

  • Song, Ki Tae;Lee, Sung Ill
    • Journal of the Korean Society of Safety
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    • v.30 no.6
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    • pp.164-173
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    • 2015
  • There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. However, application standard differs from every industry in domestic or international for application on mythology for allocation and demonstration of SIL. Application or assessment is not easy since absence on clear criteria or common definition. This research studied not only fundamental concept of SIL required to guarantee safety in accordance with international standards for safety related equipment and system, but different types of methodologies for SIL allocation. Specifically, SIL allocation for Platform Screen Door system of railway is studied applying methodology of severity of accidents and risk graph among different methodologies for SIL allocation.

A Branch Predictor with New Recovery Mechanism in ILP Processors for Agriculture Information Technology (농업정보기술을 위한 ILP 프로세서에서 새로운 복구 메커니즘 적용 분기예측기)

  • Ko, Kwang Hyun;Cho, Young Il
    • Agribusiness and Information Management
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    • v.1 no.2
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    • pp.43-60
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    • 2009
  • To improve the performance of wide-issue superscalar processors, it is essential to increase the width of instruction fetch and the issue rate. Removal of control hazard has been put forward as a significant new source of instruction-level parallelism for superscalar processors and the conditional branch prediction is an important technique for improving processor performance. Branch mispredictions, however, waste a large number of cycles, inhibit out-of-order execution, and waste electric power on mis-speculated instructions. Hence, the branch predictor with higher accuracy is necessary for good processor performance. In global-history-based predictors like gshare and GAg, many mispredictions come from commit update of the branch history. Some works on this subject have discussed the need for speculative update of the history and recovery mechanisms for branch mispredictions. In this paper, we present a new mechanism for recovering the branch history after a misprediction. The proposed mechanism adds an age_counter to the original predictor and doubles the size of the branch history register. The age_counter counts the number of outstanding branches and uses it to recover the branch history register. Simulation results on the SimpleScalar 3.0/PISA tool set and the SPECINT95 benchmarks show that gshare and GAg with the proposed recovery mechanism improved the average prediction accuracy by 2.14% and 9.21%, respectively and the average IPC by 8.75% and 18.08%, respectively over the original predictor.

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Estimation of seismicity parameters of the seismic zones of the Korean Peninsula using incomplete and complete data files (불완전한 자료 및 완전한 자료 목록을 이용한 한반도 지진구들의 지진활동 매개변수 평가)

  • 이기화
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1998.04a
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    • pp.23-30
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    • 1998
  • An estimation of seismic risk parameters by seismic zones of the Korea Peninsula in order to calculate the seismic hazard values using these was erformed. Seven seismic source zones were selected in consideration of seismicity and geology of Korean Peninsula. The seismicity parameters that should be estimated are maximum intensity, activity rate and b value in the Gutenberg - Richter relation. For computation of these parameters, least square method or maximum likelihood method is applied to the earthquake data in two ways; the one for the data without maximum intensity and the other with maximum intensity. Earthquake data since Choseon Dynasty is regarded as complete and estimation of parameters was made for these data using above two ways. And recently, a new method is published that estimate the seismicity parameters using mixed data containing large historical events and recent complete observations. Therefore, this method is applied to the whole earthquake data of the Korean Peninsula. It turns out that the b value computed considering maximum intensity is slightly lower than that computed considering without maximum intensity, and it becomes still lower when the incomplete data prior to Choseon Dynasty is used. In the case of the activity rates, the values obtained without maximum intensity and that with maximum intensity are similar, though they are lower when the incomplete data is used. The values of maximum intensities are usually lower when considering incomplete data. In the seismic source zone including the Yangsan Fault zone, however, the values are higher when considering the incomplete data.

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