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Thermal hydraulic analysis of core flow bypass in a typical research reactor

  • Ibrahim, Said M.A.;El-Morshedy, Salah El-Din;Abdelmaksoud, Abdelfatah
    • Nuclear Engineering and Technology
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    • v.51 no.1
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    • pp.54-59
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    • 2019
  • The main objective of nuclear reactor safety is to maintain the nuclear fuel in a thermally safe condition with enough safety margins during normal operation and anticipated operational occurrences. In this research, core flow bypass is studied under the conditions of the unavailability of safety systems. As core bypass occurs, the core flow rate is assumed to decrease exponentially with a time constant of 25 s to new steady state values of 20, 40, 60, and 80% of the nominal core flow rate. The thermal hydraulic code PARET is used through these calculations. Reactor thermal hydraulic stability is reported for all cases of core flow bypass.

Analysis on the Trade-off between an Hydro-power Project and Other Alternatives in Myanmar

  • Aye, Nyein Nyein;Fujiwara, Takao
    • Asian Journal of Innovation and Policy
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    • v.8 no.1
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    • pp.31-57
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    • 2019
  • Myanmar's current power situation remains severely constrained despite being richly endowed in primary energy sources. With low levels of electrification, the demand for power is not adequately met. Cooperation in energy has been a major focus of future initiative for all developed and developing nations. If we want to solve climate change, and change our energy infrastructure, we need to be innovative and entrepreneurial in energy generation. This paper will help us in examining Bayesian MCMC Analysis for the parameters estimation among the arrival rates of disaster occurrences, firm's expected income-based electricity tariffs, and estimated R&D investment expenses in new energy industry. Focusing on Japan's electric power business, we would like to search the potential for innovative initiatives in new technological energy industry for the regional development and ecological sustainability in Myanmar.

An efficient reliability estimation method for CNTFET-based logic circuits

  • Jahanirad, Hadi;Hosseini, Mostafa
    • ETRI Journal
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    • v.43 no.4
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    • pp.728-745
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    • 2021
  • Carbon nanotube field-effect transistors (CNTFETs) have been widely studied as a promising technology to be included in post-complementary metal-oxide-semiconductor integrated circuits. Despite significant advantages in terms of delay and power dissipation, the fabrication process for CNTFETs is plagued by fault occurrences. Therefore, developing a fast and accurate method for estimating the reliability of CNTFET-based digital circuits was the main goal of this study. In the proposed method, effects related to faults that occur in a gate's transistors are first represented as a probability transfer matrix. Next, the target circuit's graph is traversed in topological order and the reliabilities of the circuit's gates are computed. The accuracy of this method (less than 3% reliability estimation error) was verified through various simulations on the ISCAS 85 benchmark circuits. The proposed method outperforms previous methods in terms of both accuracy and computational complexity.

A Study on the Optimal Allocation of Maintenance Personnel in the Military Emergency Maintenance System Considering the Property of Impatience (Impatience 특성을 고려한 군 긴급정비시스템 정비인력 최적할당 연구)

  • Kim, Sungwoo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.4
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    • pp.449-456
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    • 2021
  • Impatience characteristics are an important factor to be considered in the defense field, which is sensitive to time, but there are not many cases applied. In addition, due to the difficulty of analysis that must consider various probabilistic factors (breakdown/maintenance distribution, impatience characteristics, etc.), military decision makers consider only simple data (number of occurrences per year, maintenance time, etc.) Therefore, in this study, a model capable of analyzing the performance of the emergency maintenance system for determining the appropriate size and organization of military and civilian maintenance personnel was presented in consideration of impatience characteristics and probabilistic factors. And through numerical analysis, the appropriate size of the military and civilian emergency maintenance teams was analyzed. This study is significant in that it can improve readiness of operational power and prevent waste of defense budget through efficient operation of the military's emergency maintenance system.

Analysis of Vulnerable Parts based on Non-destructive Testing Data of Tower Crane Welding Parts (타워크레인의 용접부 비파괴검사 데이터 기반 취약부위 분석)

  • Jeong, SeongMo;Lim, Jae-Yong
    • Journal of Auto-vehicle Safety Association
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    • v.13 no.2
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    • pp.50-56
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    • 2021
  • The purpose of this study is to investigate vulnerable parts of tower crane structures by analyzing extensive non-destructive test data. Approximately ten percent of domestically registered tower cranes were inspected by using magnetic particle inspection. The testing was carried out as advised in KS B 0213. The non-destructive results was analyzed with respect to jib types, age and crane size. As a result, the number of crack occurrences were the largest in mast parts, followed by main jib part. Moreover, it was found that turntables were important parts deserved to be noticed at the perspective of safe maintenance.

Constructing Japanese MeSH term dictionaries related to the COVID-19 literature

  • Yamaguchi, Atsuko;Takatsuki, Terue;Tateisi, Yuka;Soares, Felipe
    • Genomics & Informatics
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    • v.19 no.3
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    • pp.25.1-25.5
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    • 2021
  • The coronavirus disease 2019 (COVID-19) pandemic has led to a flood of research papers and the information has been updated with considerable frequency. For society to derive benefits from this research, it is necessary to promote sharing up-to-date knowledge from these papers. However, because most research papers are written in English, it is difficult for people who are not familiar with English medical terms to obtain knowledge from them. To facilitate sharing knowledge from COVID-19 papers written in English for Japanese speakers, we tried to construct a dictionary with an open license by assigning Japanese terms to MeSH unique identifiers (UIDs) annotated to words in the texts of COVID-19 papers. Using this dictionary, 98.99% of all occurrences of MeSH terms in COVID-19 papers were covered. We also created a curated version of the dictionary and uploaded it to Pub-Dictionary for wider use in the PubAnnotation system.

Revisiting Rhytisma lonicericola: Morphological Characterization and Molecular Phylogenetic Analysis

  • Jung, Bok-Nam;Park, Ji-Hyun;Shin, Hyeon-Dong
    • Mycobiology
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    • v.50 no.2
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    • pp.150-154
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    • 2022
  • Rhytisma lonicericola was identified as a tar spot fungus on Lonicera sp. in 1902, and has since been recorded on several species of Lonicera in China, Japan, and Korea. Most of the previous records of R. lonicericola have been based on a list of disease occurrences in the absence of any formal morphological identification or molecular analyses. Using six newly obtained specimens collected in the past 2 years, we confirmed the tar spot fungus found on L. japonica in Korea as R. lonicericola based on morphological examinations and molecular phylogenetic analyses. This fungus was distinguished from R. xylostei, another tar spot fungus on Lonicera, by ascospore size and geographical distributions. We present detailed mycological information and, for the first time, DNA sequence data useful for the identification of R. lonicericola.

The risk assessment, outbreak and control of BSE in Japan (일본에서 소해면상뇌증(BSE)의 현재 상황)

  • Yokoyama, T.
    • 한국환경농학회:학술대회논문집
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    • 2009.07a
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    • pp.283-297
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    • 2009
  • Bovine spongiform encephalopathy (BSE) has become an important concern in food safety. Until now, 36 cases of BSE have been detected in Japan. Control programs have led to a decrease in the annual numbers, and Japan has now been categorized as a "controlled risk" country by the World Animal Health Organization (OIE). In spite of a worldwide decrease in the number of BSE cases, sporadic occurrences of atypical BSE cases have been reported. In Japan, 2 atypical BSE cases were confirmed. A Japanese L-type-BSE (BSE/JP24) has exhibited transmissibility to bovinized transgenic mice (TgBoPrP) it has a shorter incubation period than that of classical BSE. Although the origin of atypical BSE is obscure, risk analysis of newly emerged BSE prions of cattle and humans is required.

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CRITICAL FACTORS AFFECTING SAFETY IN THE SINGAPORE CONSTRUCTION INDUSTRY

  • Sze Ming Woo;Charles Y.J. Cheah;Wai Fan Wong
    • International conference on construction engineering and project management
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    • 2007.03a
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    • pp.759-768
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    • 2007
  • Construction is one of the most hazardous industries due to its unique nature. Recent occurrences of highly publicised and criticized construction site accidents have highlighted the immediate need for the construction industry to address safety hazards. Safety used to be addressed as an isolated issue in the past, but the problem of safety is an emergent property of a system. In general, it seems that both industrial practitioners and government officials have tended to address safety by focusing on technical aspects and looking for immediate causes of accidents after they have taken place. The objective of this paper is to examine issues and critical factors that affect the safety standards from a holistic point of view. The job of making worksites safe should not just fall squarely on the contractors but should be shared by all parties in the value chain of construction activities.

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New record of a blood-feeding terrestrial leech, Haemadipsa rjukjuana Oka, 1910 (Haemadipsidae, Arhynchobdellida) on Heuksando Island and possible habitat estimation in the current and future Korean Peninsula using a Maxent model

  • Tae-Yeong Eom;Hyeon-Soo Kim;Yeong-Seok Jo
    • Journal of Species Research
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    • v.12 no.1
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    • pp.109-113
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    • 2023
  • To build a distribution model for Haemadipsa rjukjuana, we collected current occurrences of the species on Heuksando with adjacent islands. Based on current locations and 19 climate variables with DEM (digital elevation model), we built the MaxEnt (maximum entropy) species distribution model for H. rjukjuana in the islands. Then, we applied the MaxEnt model to the mainland of Korea with the current climate condition and topology. In addition to the current distribution scenario, we predicted the future distribution scenarios in Korea by Coupled Model Intercomparison Project Phase 6 (CMIP6) global climate models. Shared Socioeconomic Pathway (SSP) 585 of two CMIP6 models(GISS-E2-1 and INM-CM4-8) from 2040 to 2100 were used for the future projection.