• Title/Summary/Keyword: System-level design

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Prediction of radioactivity releases for a Long-Term Station Blackout event in the VVER-1200 nuclear reactor of Bangladesh

  • Shafiqul Islam Faisal ;Md Shafiqul Islam;Md Abdul Malek Soner
    • Nuclear Engineering and Technology
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    • v.55 no.2
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    • pp.696-706
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    • 2023
  • Consequences of an anticipated Beyond Design Basis Accident (BDBA) Long-Term Station Blackout (LTSBO) event with complete loss of grid power in the VVER-1200 reactor of Rooppur Nuclear Power Plant (NPP) of Unit-1 are assessed using the RASCAL 4.3 code. This study estimated the released radionuclides, received public radiological dose, and ground surface concentration considering 3 accident scenarios of International Nuclear and Radiological Event Scale (INES) level 7 and two meteorological conditions. Atmospheric transport, dispersion, and deposition processes of released radionuclides are simulated using a straight-line trajectory Gaussian plume model for short distances and a Gaussian puff model for long distances. Total Effective Dose Equivalent (TEDE) to the public within 40 km and radionuclides contribution for three-dose pathways of inhalation, cloudshine, and groundshine owing to airborne releases are evaluated considering with and without passive safety Emergency Core Cooling System (ECCS) in dry (winter) and wet (monsoon) seasons. Source term and their release rates are varied with the functional duration of passive safety ECCS. In three accident scenarios, the TEDE of 10 mSv and above are confined to 8 km and 2 km for the wet and dry seasons, respectively in the downwind direction. The groundshine dose is the most dominating in the wet season while the inhalation dose is in the dry season. Total received doses and surface concentration in the wet season near the plant are higher than those in the dry season due to the deposition effect of rain on the radioactive substances.

Study on the Development of K-City Roadmap through the Standard Analysis of the Test-Bed for Automated Vehicles in China (중국 자율주행차 테스트베드 관련 표준 분석을 통한 K-City 고도화 방안 수립에 관한 연구)

  • Lee, Sanghyun;Ko, Hangeom;Lee, Hyunewoo;Cho, Seongwoo;Yun, Ilsoo
    • Journal of Auto-vehicle Safety Association
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    • v.14 no.1
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    • pp.6-13
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    • 2022
  • The Ministry of Land, Infrastructure and Transport (MoLIT) and the Korean Automobile Testing and Research Institute (KATRI) are supporting the development of Lv.3 automated vehicle (hereinafter, AV) technology by constructing an automated driving pilot city (as known as K-City) equipped with total 5 evaluation environments (urban, motorway, suburban, community road, and autonomous parking facility) which is a test bed exclusively for AV (2017~2018). An upgrade project is in a progress to materialize harsh environments such as bad weather (rain, fog, etc.) and reproduction of communication jamming (GPS blocking, etc.) with the purpose of supporting the development of Lv.4 connected & automated vehicle (hereinafter, CAV) technology (2019~2022). We intend to proactively establish a national level standard for CAV test-bed and test road requirements, test method, etc. for establishment of a road map for the construction of the test bed which is being promoted step by step and analyze and, when required, benchmark the case of China that has announced and is utilizing it. Through this, we plan to define standardized requirements (evaluation facility, evaluation system, etc.) on the test bed for the development of Lv.4/4+ CAV technology and utilize the same for the design and construction of a test bed, establishment of a road map for the construction of a real car-based test environment related to the support for autonomous driving service substantiation, etc. through provision of an evaluation environment utilizing K-City, and the establishment of a K-City upgrade strategies, etc.

Channel Modeling and RF Performance Verification in mmWave Bands Based on NS-3 (NS-3 기반의 mmWave 대역 채널 모델링 및 RF 성능 검증)

  • Seung-Min Lee;Jun-Seok Seo;Hong-Je Jang;Myung-Ryul Choi
    • Journal of IKEEE
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    • v.27 no.4
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    • pp.650-656
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    • 2023
  • This paper implements a channel model for mmWave bands using an NS-3-based 5G system-level simulator and analyzes the reliability and validity of the implemented model through RF performance verification. The channel model for RF performance verification in the mmWave bands consider parameters such as characteristics defined in 3GPP TR 38.901, beam-forming, antenna configuration, scenarios, among others. Furthermore, the simulation results verify compliance within the ranges permitted by the 3GPP standards and verify reliability in indoor environmental scenarios by exploiting the Radio Environment Map (REM). Therefore, the channel model implemented in this study is applicable to the actual design and establishment of 5G networks, presenting a method to evaluate and validate RF performance by adjusting various parameters.

Analysis of Characteristics and Determinants of Household Loans in Korea: Focusing on COVID-19 (국내 가계대출의 특징과 결정요인 분석: COVID-19를 중심으로)

  • Jin-Hee Jang;Jae-Bum Hong;Seung-Doo Choi
    • Asia-Pacific Journal of Business
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    • v.14 no.2
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    • pp.51-61
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    • 2023
  • Purpose - Since COVID-19, the government's expansion of liquidity to stimulate the economy has resulted in an increase in private debt and an increase in asset prices of such as real estate and stocks. The recent sharp rise of the US Federal fund rate and tapering by the Fed have led to a fast rise in domestic interest rates, putting a heavy burden on the Korean economy, where the level of household debt is very high. Excessive household debt might have negative effects on the economy, such as shrinking consumption, economic recession, and deepening economic inequality. Therefore, now more than ever, it is necessary to identify the causes of the increase in household debt. Design/methodology/approach - Main methodology is regression analysis. Dependent variable is household loans from depository institutions. Independent variables are consumer price index, unemployment rate, household loan interest rate, housing sales price index, and composite stock price index. The sample periods are from 2017 to May 2022, comprising 72 months of data. The comparative analysis period before and after COVID-19 is from January 2017 to December 2019 for the pre-COVID-19 period, and from Jan 2020 to December 2022 for the post-COVID-19 period. Findings - Looking at the results of the regression analysis for the entire period, it was found that increases in the consumer price index, unemployment rate, and household loan interest rates decrease household loans, while increases in the housing sales price index increase household loans. Research implications or Originality - Household loans of depository institutions are mainly made up of high-credit and high-income borrowers with good repayment ability, so the risk of the financial system is low. As household loans are closely linked to the real estate market, the risk of household loan defaults may increase if real estate prices fall sharply.

Analysis and Utilization Plan of International Archivists' Competency Frameworks (해외 기록전문직 역량 체계 분석 및 활용 방안)

  • Bobae Jun;Moon-won Seol
    • Journal of Korean Society of Archives and Records Management
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    • v.24 no.1
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    • pp.137-161
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    • 2024
  • Professional competencies serve to demonstrate and develop expertise. As such, the study summarized theories on the concept of competency and competency model development and utilization, proposing ways to utilize the competency system to strengthen domestic archivists' expertise through a case study of international archivist competency systems. Five competency frameworks for archivists developed by international archivist associations were analyzed. Results showed that the archival profession's competency frameworks were primarily utilized in two ways. First, they are used to verify professional definitions, which are used as verification standards for registering certified professionals at the archivist association level. Second, they are used to enhance expertise in conjunction with individual professional self-assessment and continuing professional development program design. These two applications can operate in a complementary relationship to utilize the competency framework in demonstrating and strengthening competencies.

Design of a Mapping Framework on Image Correction and Point Cloud Data for Spatial Reconstruction of Digital Twin with an Autonomous Surface Vehicle (무인수상선의 디지털 트윈 공간 재구성을 위한 이미지 보정 및 점군데이터 간의 매핑 프레임워크 설계)

  • Suhyeon Heo;Minju Kang;Jinwoo Choi;Jeonghong Park
    • Journal of the Society of Naval Architects of Korea
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    • v.61 no.3
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    • pp.143-151
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    • 2024
  • In this study, we present a mapping framework for 3D spatial reconstruction of digital twin model using navigation and perception sensors mounted on an Autonomous Surface Vehicle (ASV). For improving the level of realism of digital twin models, 3D spatial information should be reconstructed as a digitalized spatial model and integrated with the components and system models of the ASV. In particular, for the 3D spatial reconstruction, color and 3D point cloud data which acquired from a camera and a LiDAR sensors corresponding to the navigation information at the specific time are required to map without minimizing the noise. To ensure clear and accurate reconstruction of the acquired data in the proposed mapping framework, a image preprocessing was designed to enhance the brightness of low-light images, and a preprocessing for 3D point cloud data was included to filter out unnecessary data. Subsequently, a point matching process between consecutive 3D point cloud data was conducted using the Generalized Iterative Closest Point (G-ICP) approach, and the color information was mapped with the matched 3D point cloud data. The feasibility of the proposed mapping framework was validated through a field data set acquired from field experiments in a inland water environment, and its results were described.

Evaluation of Neutron Flux Accounting for Shadowing Effect Among the Dry Storage Casks (경수로 사용후핵연료 건식저장용기 간 중성자 표면선속 간섭률 평가)

  • Min Woo Kwak;Shin Dong Lee;Kwang Pyo Kim
    • Journal of Radiation Industry
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    • v.18 no.2
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    • pp.133-140
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    • 2024
  • The Korean 2nd basic plan for management of high-level radioactive waste presented a plan to manage spent nuclear fuel through dry storage facilities in NPP on-site. For the construction and operation of the facility, it is necessary to develop the monitoring system of the integrity of spent nuclear fuel before operation. NUREG-1536 recommends that the theoretical cask array, typically in the 2×10 array, should account for shadowing effect among the dry storage casks. The objective of this study was to evaluate neutron flux accounting for shadowing effect among dry storage casks. The neutron release rate was evaluated using ORIGEN based on the design basis fuel condition. And the simulation of dry storage casks and evaluation of the shadowing effect were performed using MCNP. Shadowing effect of other dry storage casks was the highest at the center of the dry storage facility of the 2×10 array compared with the outside of the cask. The shadowing effect of neutron flux on the surface among the metal casks was approximately 18% at point 1, 23% at point 2, and 43% at point 3. For the concrete casks, the shadowing effect of neutron flux on the surface was approximately 46% at point 1, 51% at point 2, and 52% at point 3. This means that correction is necessary to monitor the integrity of spent nuclear fuel in each dry storage cask through evaluation of shadowing effect. The results of this study will be used for comparative analysis of neutron measurement data from spent nuclear fuels in dry storage cask. Additionally, the neutron flux evaluation procedure used in this study could be used as the basic data of safety assessment of dry storage cask and development of safety guide.

Changes in the Korea's port industry due to global supply chain reorganization (글로벌 공급망 재편에 따른 한국 항만업의 경기 변화)

  • Sung-Eun Kim;Soo-Bin Jeong;Jeong-In Chang
    • Asia-Pacific Journal of Business
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    • v.15 no.2
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    • pp.257-270
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    • 2024
  • Purpose - The purpose of this study is to analyze the changes in the business environment, business conditions, and detailed indicators related to management of Korea's port industry companies as global supply chains have been reorganized since the shock of COVID-19 in 2020 and uncertainties in the global economy have expanded. Design/methodology/approach - This study use the business survey index of the port industry to analyze. It is a weighted BSI with the weight of workers applied. Findings - Since 2020 the BSI in the port industry including business conditions, sales unit price, profitability, and financial conditions fluctuated, but it has been generally above normal level(100). During the analysis period, the BSI for export sales was found to be better than that of domestic sales. Employment BSI was generally stable, and in the case of facility BSI, the port industry was shown to be very active in facility investment. Research implications or Originality - First, it is necessary to make manpower training systems to cultivate experts in the port industry to cope with uncertainties caused by the rapidly changing global economy and the global supply chain environment. Second, it is necessary to support for investment in technology and facilities for automation and smartization. Finally, it is necessary to establish a continuous monitoring system for the business conditions.

Analysis of Location Patterns, Concentration, and Accessibility of Medical Facilities with GIS: Focusing on Clinics in Seoul (GIS를 이용한 의료기관의 입지 패턴, 집중도, 접근성에 관한 분석 - 서울특별시 의원급 의료기관을 중심으로 -)

  • Sung Ho Cho;Chang Gyu Choi
    • Korea Journal of Hospital Management
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    • v.29 no.3
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    • pp.54-69
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    • 2024
  • Purposes: This study aims to analyze the location patterns, concentration, and accessibility of clinics in Seoul with the grids of a geographic information system(GIS) and provide useful indicators for research on hospital and clinic management and policies based on the results. The study especially sets out to identify areas falling behind in the service of the essential medical care departments based on an analysis with 250m×250m grids and contribute to efficient medical business management and public healthcare policies based on the results. Methodology: The study analyzed clinics in Seoul in terms of concentration, distribution and clustering patterns, accessibility, and hot spots by dividing the entire city into 500m×500m cells and generating grids. The accessibility analysis for the essential medical care departments was especially in detail based on grids in a 250m×250m cell size. Findings: The Herfindahl results show that plastic surgery and rehabilitation medicine recorded the highest concentration level. General medicine and dermatology recorded the highest Moran's I value, and internal medicine was the highest in hot spots. Obstetrics and gynecology capable of child delivery showed considerably lower accessibility in the grids corresponding to Gangseo-gu, Yangcheon-gu, and Gwanak-gu. Surgery had low accessibility in the grids corresponding to the northern parts of Gangseo-gu for the total population. Practical Implication: Unlike previous studies whose analyses covered wide areas, the present study examined minute spatial patterns, concentration, and accessibility based on an analysis with 500m×500m or 250m×250m grids. Based on its findings, the study expects a more minute analysis for future research on medical business management and policies.

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Development of Certification Mark of Food Quality for Children's Favorite Foods Safety Management (어린이 기호식품 품질인증을 위한 인증마크 개발 연구)

  • Cho, Sun-Duk;Lee, Sung-Jin;Yun, Jee-Hye;Kim, Seo-Young;Lee, Eun-Ju;Park, Hye-Kyung;Kim, Myung-Chul;Chung, Kee-Hey;Kim, Gun-Hee
    • Journal of Food Hygiene and Safety
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    • v.23 no.1
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    • pp.31-39
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    • 2008
  • This study was performed to develop children's food quality certification system as part of the children's favorite foods safety management projects. As a component of the research, we developed a quality certification logo to build up brand image which is familiar with children, as well as to offer the right standard and opportunity for food selection. The age level contains elementary graders from 8 to 13. The logo concept was focused on 'Safety', 'Certification, Guidance' and 'Health' in accordance with the vision of the Korea Food and Drug Administration (KFDA), "Safe food, good nutrition and healthy children". The logo name was proposed as "Best Food for Children", "Safety Food for Children" and "Children Good Food", which was decided by public subscription in the KFDA. The 36 tentative plans for a seal were proposed depending on names. We conducted a survey for the 12 logo samples, designed by the name of "Children Good Food", to use as the basic material for the development of logo to convey the meaning of children's food quality certification system effectively. This survey was conducted among 321 elementary graders and 331 parents of elementary graders. We selected the most favorite design through the survey and applied it for products practicality. It is expected that a steady policy may be possible to implement by applying the basis of the children's food project.