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Research on rapid source term estimation in nuclear accident emergency decision for pressurized water reactor based on Bayesian network

  • Wu, Guohua;Tong, Jiejuan;Zhang, Liguo;Yuan, Diping;Xiao, Yiqing
    • Nuclear Engineering and Technology
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    • v.53 no.8
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    • pp.2534-2546
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    • 2021
  • Nuclear emergency preparedness and response is an essential part to ensure the safety of nuclear power plant (NPP). Key support technologies of nuclear emergency decision-making usually consist of accident diagnosis, source term estimation, accident consequence assessment, and protective action recommendation. Source term estimation is almost the most difficult part among them. For example, bad communication, incomplete information, as well as complicated accident scenario make it hard to determine the reactor status and estimate the source term timely in the Fukushima accident. Subsequently, it leads to the hard decision on how to take appropriate emergency response actions. Hence, this paper aims to develop a method for rapid source term estimation to support nuclear emergency decision making in pressurized water reactor NPP. The method aims to make our knowledge on NPP provide better support nuclear emergency. Firstly, this paper studies how to build a Bayesian network model for the NPP based on professional knowledge and engineering knowledge. This paper presents a method transforming the PRA model (event trees and fault trees) into a corresponding Bayesian network model. To solve the problem that some physical phenomena which are modeled as pivotal events in level 2 PRA, cannot find sensors associated directly with their occurrence, a weighted assignment approach based on expert assessment is proposed in this paper. Secondly, the monitoring data of NPP are provided to the Bayesian network model, the real-time status of pivotal events and initiating events can be determined based on the junction tree algorithm. Thirdly, since PRA knowledge can link the accident sequences to the possible release categories, the proposed method is capable to find the most likely release category for the candidate accidents scenarios, namely the source term. The probabilities of possible accident sequences and the source term are calculated. Finally, the prototype software is checked against several sets of accident scenario data which are generated by the simulator of AP1000-NPP, including large loss of coolant accident, loss of main feedwater, main steam line break, and steam generator tube rupture. The results show that the proposed method for rapid source term estimation under nuclear emergency decision making is promising.

An On-line Survey on the Perception and Usage of Korean Medicine Doctors about Pattern Identification of Eight Principles (국내 한의사의 팔강변증에 관한 인식 및 활용현황 조사)

  • Bae, Jung Hyeon;Park, Shin Hyung;Lee, In Seon;Kim, Jong Won;Jeon, Soo Hyung;Kang, Chang Wan;Chi, Gyoo Yong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.35 no.6
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    • pp.211-218
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    • 2021
  • In order to increase the clinical value of an identification of patterns according to the eight principles (IPEP) in Korean medicine practice, The research on the Clinical Practice Guideline (CPG) of IPEP should comprehend the situation of clinical usage of IPEP practiced by Korean medicine doctors at first. Google survey form were emailed to Korean Medicine doctors registered in the Association of Korean Medicine on 04/15/2021 and the survey was closed at 04/22/2021. Data of 505 answered cases were analyzed by Frequency analysis, Chi-Square analysis, correlation analysis for understanding differences by groups. Out of 505 respondents, 57.6% have answered that they are using IPEP. It means that 42.4% of KM doctors don't use in the medical practice reversely in spite of fundamental diagnostic theory. The 64.7% respondents of no using IPEP presented their opinion about the theoretical problem that it is difficult to use because the concept of IPEP is ambiguous. And next, the 52.1% of the respondents expressed that there is no objective tools to measure and record the IPEP evidences in actual implementation. And 49.6% of the respondents also suggested that it is hard to trust and use IPEP similar to the previous comment. Even about 50% of the respondents are carrying out diagnosis and treatment using IPEP, it showed that there were several unsolved problems such as lack of understanding and practical tools or objective indicators for diagnosis of IPEP. Through the above results, the concept, usage, measurement requirements with indices and discriminant logic of IPEP were manifested as the main hopes of attending members of Korean medicine in the survey, so the IPEP CPG should make clear about these difficult but necessary assignment in the near future.

A Study on College Students' Experiences for UCC Assignment in a Character Education Class (교양 인성 수업에서 대학생들의 인성을 주제로 한 UCC 과제 경험에 관한 현상학적 연구)

  • Kim, Byung-Sun;Son, Eun-Kyoung;Lee, Jun-Gil
    • Journal of the Korea Convergence Society
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    • v.13 no.3
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    • pp.239-253
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    • 2022
  • The purpose of this study is to have college students who took 'University Character Education Using YouTube Videos', which was opened as a liberal arts course in college, directly produce UCC assignments with the theme of personality. Despite the recent paradigm shift in learner-centered education, teacher-centered education still hinders learners' motivation to participate in classes. To solve this problem, a learner-led UCC production process is necessary for the practice of effective learner-centered education. For this purpose, a phenomenological research method was applied. The research participants were 10 students, in-depth interview was used for data collection, and Colaizzi's research method was selected for data analysis. As a result of the analysis, 9 themes, 4 theme clusters, and 2 categories were derived. The results are as follows. First, they recognized that the UCC assignments were a field of maturity, such as practicing the right thoughts and actions, and re-establishing the concept of character. Second, they said that the UCC production process was an opportunity to increase their self-esteem. Third, they showed a more mature personality by recognizing that the UCC assignments became a chance to pay attention to others beyond themselves. Fourth, they had the greatest difficulty in selecting a topic while carrying out the UCC project, and they were experiencing the limitations of high-quality projects due to the technical immaturity of UCC production. Finally, this study was concluded by discussing the educational implications based on the results. These results provide a suggestion that more effective character education can be expected when tasks led by learners will be developed and an interactive arena where students can be shared are provided.

Trip Assignment for Transport Card Based Seoul Metropolitan Subway Using Monte Carlo Method (Monte Carlo 기법을 이용한 교통카드기반 수도권 지하철 통행배정)

  • Meeyoung Lee;Doohee Nam
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.22 no.2
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    • pp.64-79
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    • 2023
  • This study reviewed the process of applying the Monte Carlo simulation technique to the traffic allocation problem of metropolitan subways. The analysis applied the assumption of a normal distribution in which the travel time information of the inter-station sample is the basis of the probit model. From this, the average and standard deviation are calculated by separating the traffic between stations. A plan was proposed to apply the simulation with the weights of the in-vehicle time of individual links and the walking and dispatch interval of transfer. Long-distance traffic with a low number of samples of 50 or fewer was evaluated as a way to analyze the characteristics of similar traffic. The research results were reviewed in two directions by applying them to the Seoul Metropolitan Subway Network. The travel time between single stations on the Seolleung-Seongsu route was verified by applying random sampling to the in-vehicle time and transfer time. The assumption of a normal distribution was accepted for sample sizes of more than 50 stations according to the inter-station traffic sample of the entire Seoul Metropolitan Subway. For long-distance traffic with samples numbering less than 50, the minimum distance between stations was 122Km. Therefore, it was judged that the sample deviation equality was achieved and the inter-station mean and standard deviation of the transport card data for stations at this distance could be applied.

A Methodology of Multimodal Public Transportation Network Building and Path Searching Using Transportation Card Data (교통카드 기반자료를 활용한 복합대중교통망 구축 및 경로탐색 방안 연구)

  • Cheon, Seung-Hoon;Shin, Seong-Il;Lee, Young-Ihn;Lee, Chang-Ju
    • Journal of Korean Society of Transportation
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    • v.26 no.3
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    • pp.233-243
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    • 2008
  • Recognition for the importance and roles of public transportation is increasing because of traffic problems in many cities. In spite of this paradigm change, previous researches related with public transportation trip assignment have limits in some aspects. Especially, in case of multimodal public transportation networks, many characters should be considered such as transfers. operational time schedules, waiting time and travel cost. After metropolitan integrated transfer discount system was carried out, transfer trips are increasing among traffic modes and this takes the variation of users' route choices. Moreover, the advent of high-technology public transportation card called smart card, public transportation users' travel information can be recorded automatically and this gives many researchers new analytical methodology for multimodal public transportation networks. In this paper, it is suggested that the methodology for establishment of brand new multimodal public transportation networks based on computer programming methods using transportation card data. First, we propose the building method of integrated transportation networks based on bus and urban railroad stations in order to make full use of travel information from transportation card data. Second, it is offered how to connect the broken transfer links by computer-based programming techniques. This is very helpful to solve the transfer problems that existing transportation networks have. Lastly, we give the methodology for users' paths finding and network establishment among multi-modes in multimodal public transportation networks. By using proposed methodology in this research, it becomes easy to build multimodal public transportation networks with existing bus and urban railroad station coordinates. Also, without extra works including transfer links connection, it is possible to make large-scaled multimodal public transportation networks. In the end, this study can contribute to solve users' paths finding problem among multi-modes which is regarded as an unsolved issue in existing transportation networks.

A Study of Radiation Exposure in Proton Therapy Facility (양성자치료기 가속기 시설에서의 작업종사자의 방사선 피폭 연구)

  • Lee, Sang-Hoon;Shin, Dong-Ho;Yoon, Myong-Geun;Shin, Jung-Wook;Rah, Jeong-Eun;Kwak, Jung-Won;Park, Sung-Yong;Shin, Kyung-Hwan;Lee, Doo-Hyun;Ahn, Sung-Hwan;Kim, Dae-Yong;Cho, Kwan-Ho;Lee, Se-Byeong
    • Progress in Medical Physics
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    • v.20 no.1
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    • pp.37-42
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    • 2009
  • Proton therapy facility, which is recently installed at National Cancer Center in Korea, generally produces a large amount of radiation near cyclotron due to the secondary particles and radioisotopes caused by collision between proton and nearby materials during the acceleration. Although the level of radiation by radioisotope decreases in length of time, radiation exposure problem still exists since workers are easily exposed by a low level of radiation for a long time due to their job assignment for maintenance or repair of the proton facility. In this paper, the working environment near cyclotron, where the highest radiation exposure is expected, was studied by measuring the degree of radiation and its duration for an appropriate level of protective action guide. To do this, we measured the radiation change in the graphite based energy degrader, the efficiency of transmitted beam and relative activation degree of the transmission beam line. The results showed that while the level of radiation exposure around cyclotron and beam line during the operation is much higher than the other radiation therapy facilities, the radiation exposure rate per year is under the limit recommended by the law showing 1~3 mSv/year.

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A STUDY ON THE PARENTAL MARITAL RELATIONSHIP OF CHILD PSYCHIATRIC PATIENTS (소아정신과 환아 부모의 부부관계에 대한 연구)

  • Lim, Ke-Won;Hong, Kang-E;Rhee, Kun-Hoo
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.2 no.1
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    • pp.160-175
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    • 1991
  • The purpose of this study is to investigate the parental marital relationships and the parent-child relationships of child psychiatric parents and its control group. This study was carried out two questionnaire instruments ; The marital satisfaction inventory(MSI) and the dyadic adjustment scale(DAS). The subjects are parents of the child psychiatric patients. A matched control group and parents of child psychiatric parents in Seoul area which were collected from July 1987 to September 1987, and classified into five subgroups : 1 Psychiatric disorder 2) Neurotic disorder 3) Tic disorder 4) Autistic disorder 5) Mental retardation. The results are as following ; 1) M.S.I scale scores of parents of patients group are lower than that of control group. 2) D.A.S scale score of parents of patients group is significantly lower than that of the control group(P<0.01). 3) The global distress scale(GDS) of the M.S.I. was most positively correlated with affective communication(AFC) and problem-sloving communication(PSC). 4) Female shoed more modern concept of role identification than male but tend to have heavier role assignment especially in child rearing practices which could be characterized by maternal domination. 5) Affective communication and sexual relationship between married couple and child rearing practices are influenced by their own family history of distress. 6) The marital global distress scale(GDS) score was highest in the parents of psychosis, the next in the parents of neurosis, autism, mental retardation, and tic disorder in descending order of severity. 7) The dyadic maladjustment score was highest in the parents of psychosis, the next in the parents of neurosis, tic, autism and mental retardation in descending order of severity. 8) Conflict in child rearing and parenting problems were particularly prominent in parents of the tic patients, and their marital relationship was not significantly disturbed. The above finding suggested that couple adjustment and marital dissatisfaction were closely related with child rearing problems and the children's disorder. So marital dissatisfaction and marital maladjustment seem to play a significant role in the genesis of psychosis and neurosis not much in autism and mental retardation.

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Legal status of Priave Transaction Regarding the Geostationary Satellite Orbit (지구정지궤도의 사적 거래의 국제법상 지위에 관한 연구)

  • Shin, Hong Kyun
    • The Korean Journal of Air & Space Law and Policy
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    • v.29 no.2
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    • pp.239-272
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    • 2014
  • The rights and obligations of the Member States of ITU in the domain of international frequency management of the spectrum/orbit resource are incorporated in the Constitution and Convention of the ITU and in the Radio Regulations that complement them. These instruments contain the main principles and lay down the specific regulations governing the major elements such as rights and obligations of member administrations in obtaining access to the spectrum/orbit resource, as well as international recognition of these rights by recording frequency assignments and, as appropriate, any associated orbits, including the geostationary-satellite orbits used or intended to be used in the Master International Frequency Register (MIFR) Coordination is a further step in the process leading up to notification of the frequency assignments for recording in the MIFR. This procedure is a formal regulatory obligation both for an administration seeking to assign a frequency in its network and for an administration whose existing or planned services may be affected by that assignment. Regulatory problem lies in allowing administrations to fulfill their "bringing into use" duty for preserving his filing simply putting any satellites, whatever nationlity or technical specification may be, into filed orbit. This sort of regulatory lack may result in the emergence of the secondary market for satellite orbit. Within satellite orbit secondary market, the object of transaction may be the satellite itself, or the regulatory rights in rem, or the orbit registered in the MIFR. Recent case of selling the Koreasat belongs to the typical example of orbit transaction between private companies, the legality of which remains doubtedly controversial from the perspective of international space law as well as international transaction law. It must be noted, however, that the fact is the Koreasat 3 and its filed orbit is for sale.

Improvement of State Ownership of Excavated Cultural Heritage System and Establishment of Policy Direction (발굴매장문화재 국가귀속제도의 정책 개선방안 연구)

  • Kim, Jong soo
    • Korean Journal of Heritage: History & Science
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    • v.49 no.1
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    • pp.22-43
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    • 2016
  • State Ownership of Excavated Cultural Heritage System was originated from the legislations concerning cultural objects during the Japanese colonial period (1910~1945) and was succeeded by the present Buried Cultural Properties Act enacted in 2011. Despite the importance of the system that completes the outcomes of excavations and determines the state-owned cultural properties, the foundation of national heritage, it has been limitedly regarded as administrative area and neglected by the academic scholars or policy researchers. Recently the traditional culture has drawn increasing domestic interest and awareness that the cultural heritage contributes to building cultural identity and vitalizing tourism has led to increasing the demand of a local government's role in management of the state-designated cultural heritage and even fighting for hegemony in securing the cultural objects between the central and local governments. Despite the continuing efforts for improving the selection process of cultural heritage and its management institution, establishment of an advanced objective system has been requested. This paper is intended to suggest the policy direction through demonstrating the problem and assignment caused in the process of implementing the Buried Cultural Properties Act and reviews the State Ownership of Excavated Cultural Heritage System from the legal point of view accordingly. First, I suggest improving the selection process of the state-owned cultural properties. Even though current law states that Administrator of Cultural Heritage Administration reviews the research reports and selects the possible candidates for the state-owned cultural properties almost all the cultural objects listed on the reports are practically selected. In this regard, two possible resolutions can be made; newly establishing a separate process for selecting the state-owned cultural properties after publishing the report or adding the selection process of the state-owned cultural properties during the heritage selection meeting. Either way should contribute to strengthening the impartiality and objectivity of the policy. My second suggestion is improving the operating system of the heritage selection meeting in which the cultural properties to be listed on the reports are determined. Given the present extensive assessment criteria, there is much room for certain experts' subjective opinions. Therefore, in order to enhance the fairness and credibility of the heritage selection meeting, specifying the assessment criteria and advance review of the expert list are necessary. Third, this paper suggests increasing the local government's role in management of the state-owned cultural heritage and diversifying the heritage management institution. Development of a local self-governing system has led to the increased demand for delegating the authority of the state-owned heritage management to the local governments. Along with this, the gradual improvements of public museum management raises the need for expanding the cultural benefits through increasing the local government's role in management of the state-owned heritage. Considering the fact that overall majority of the art collections housed at national or public museums is owned by the central government, developing a variety of heritage contents and vitalizing the heritage tourism are crucial. The true meaning and value of the state-owned cultural heritage hidden at the storage of a museum can be found when they are shared together with the public.

Function and Use Evaluation of 'Classification & Disposal Schedule Management' in the Standard Records Management System (표준 기록관리시스템의 '기준관리' 기능 및 이용 평가)

  • Chung, Sang-hee
    • The Korean Journal of Archival Studies
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    • no.37
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    • pp.189-237
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    • 2013
  • Since central governments began to establish and use the Standard Records Management System(RMS) in 2007, more and more local governments and other public organizations have constructed RMS. RMS is the essential tool for records management in electronic environments, but it is not known how well the functions of RMS reflect standards and practice related records management or how many records managers use RMS in performing their works. This paper deals with analyzing the evaluation of 'classification & disposal schedule management' function in RMS. 'Classification & disposal schedule management' function has 4 subfunctions of review of classification & preservation period, management of the schedule items, assignment of classification scheme and reclassification. Classification and disposal schedule is at the heart of intellectual control of records and core area of records management. So it is important to analyze whether this function plays well a role in RMS or not. This research carried out evaluation of function and use about classification & disposal schedule management in RMS. Functional evaluation is to compare and analyze how well RMS meets the functional requirements which home and foreign standards give. Use evaluation is to investigate how records managers use RMS in accomplishing their task of managing classification & disposal schedule and to look into what is the problem with the use. This paper could get the implications through the survey of records managers who are working at central governments, regional local governments and basic local governments. And these implications are considered in institutional, functional, use and administrative aspect. It is important to communicate with stakeholders so that 'classification & disposal schedule management' function, further, all functions of the RMS in practice of records management could be used smoothly. Users of RMS have to raise demands or call for technical solutions of the problems which come up in use, while RMS developers and administrators must make more of an effort to satisfy their demands, reflect them on the RMS and enhance the system.