• Title/Summary/Keyword: Component development

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Performance-based seismic evaluation and practical retrofit techniques for buildings in China

  • Wang, Hao;Sun, Baitao;Chen, Hongfu
    • Earthquakes and Structures
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    • v.22 no.5
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    • pp.487-502
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    • 2022
  • China is prone to earthquake disasters, and the higher seismic performance is required by many existing civil buildings. And seismic evaluation and retrofit are effective measures to mitigate seismic hazards. With the development of performance-based seismic design and diverse retrofit technology for buildings, advanced evaluation methods and retrofit strategies are in need. In this paper, we introduced the evolution of seismic performance objectives in China combined with performance-based seismic design. Accordingly, multi-phase evaluation methods and comprehensive seismic capacity assessment are introduced. For buildings with seismic deficiency or higher performance requirements, the retrofit technologies are categorized into three types: component strengthening, system optimization, and passive control. Both engineering property and social property for the retrofit methods are discussed. The traditional seismic retrofit methods usually are costly and disturbing, and for example in Beijing, seismic strengthening costs approx. 1000 RMB/m2 (for 160 USD/m2), for hospital building even more expensive as 5000 RMB/m2(for 790 USD/m2). So cost-efficient and little disturbance methods are promising techniques. In the end, some opinions about the retrofit strategy and schemes category are shared and wish to discuss the situation and future of seismic retrofit in China.

Issues of New Technological Trends in Nuclear Power Plant (NPPs) for Standardized Breakdown Structure

  • Gebremichael, Dagem D.;Lee, Yunsub;Jung, Youngsoo
    • International conference on construction engineering and project management
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    • 2020.12a
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    • pp.353-358
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    • 2020
  • Recent efforts to develop a common standard for nuclear power plants (NPPs) with the aim of creating (1) a digital environment for a better understanding of NPPs life-cycle management aspect and (2) engineering data interoperability by using existing standards among different unspecified project participants (e.g., owners/operators, engineers, contractors, equipment suppliers) during plants' life cycle process (EPC, O&M, and decommissioning). In order to meet this goal, there is a need for formulating a standardized high-level physical breakdown structure (PBS) for NPPs project management office (PMO). However, high-level PBS must be comprehensive enough and able to represent the different types of plants and the new trends of technologies in the industry. This has triggered the need for addressing the issues of the recent operational NPPs and future technologies' ramification for evaluating the changes in the NPPs physical components in terms of structure, system, and component (SSC) configuration. In this context, this ongoing study examines the recent conventional NPPs and technological trends in the development of future NPPs facilities. New reactor models regarding the overlap of variant issues of nuclear technology were explored. Finally, issues on PBS for project management are explored by the examination of the configuration of NPPs primary system. The primary systems' configuration of different reactor models is assessed in order to clarify the need for analyzing the new trends in nuclear technology and to formulate a common high-level PBS. Findings and implications are discussed for further studies.

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Big Data Analytics Applied to the Construction Site Accident Factor Analysis

  • KIM, Joon-soo;Lee, Ji-su;KIM, Byung-soo
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.678-679
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    • 2015
  • Recently, safety accidents in construction sites are increasing. Accordingly, in this study, development of 'Big-Data Analysis Modeling' can collect articles from last 10 years which came from the Internet News and draw the cause of accidents that happening per season. In order to apply this study, Web Crawling Modeling that can collect 98% of desired information from the internet by using 'Xml', 'tm', "Rcurl' from the library of R, a statistical analysis program has been developed, and Datamining Model, which can draw useful information by using 'Principal Component Analysis' on the result of Work Frequency of 'Textmining.' Through Web Crawling Modeling, 7,384 out of 7,534 Internet News articles that have been posted from the past 10 years regarding "safety Accidents in construction sites", and recognized the characteristics of safety accidents that happening per season. The result showed that accidents caused by abnormal temperature and localized heavy rain, occurred frequently in spring and winter, and accidents caused by violation of safety regulations and breakdown of structures occurred frequently in spring and fall. Plus, the fact that accidents happening from collision of heavy equipment happens constantly every season was acknowledgeable. The result, which has been obtained from "Big-Data Analysis Modeling" corresponds with prior studies. Thus, the study is reliable and able to be applied to not only construction sites but also in the overall industry.

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Analysis of Dynamic Characteristics of 20 kW Hydrogen Fuel Cell System Based on AMESet (AMESet 기반 20 kW급 수소 연료전지 시스템 동특성 모델 해석)

  • JONGBIN WOO;YOUNGHYEON KIM;SANGSEOK YU
    • Transactions of the Korean hydrogen and new energy society
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    • v.34 no.5
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    • pp.465-477
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    • 2023
  • In proton exchange membrane fuel cell (PEMFC), proper thermal management of the stack and moisture generation by electrochemical reactions significantly affect fuel cell performance. In this study, the PEMFC dynamic characteristic model was developed through Simcenter AMESim, a development program. In addition, the developed model aims to understand the thermal resin balance of the stack and performance characteristics for input loads. The developed model applies the thermal management model of the stack and the moisture content and permeability model to simulate voltage loss and stack thermal behavior precisely. This study extended the C based AMESet (adaptive modeling environment submodeling tool) to simulate electrochemical reactions inside the stack. Fuel cell model of AMESet was liberalized with AMESim and then integrated with the balance of plant (BOP) model and analyzed. And It is intended to be used in component design through BOP analysis. The resistance loss of the stack and thermal behavior characteristics were predicted, and the impact of stack performance and efficiency was evaluated.

Generative Artificial Intelligence for Structural Design of Tall Buildings

  • Wenjie Liao;Xinzheng Lu;Yifan Fei
    • International Journal of High-Rise Buildings
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    • v.12 no.3
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    • pp.203-208
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    • 2023
  • The implementation of artificial intelligence (AI) design for tall building structures is an essential solution for addressing critical challenges in the current structural design industry. Generative AI technology is a crucial technical aid because it can acquire knowledge of design principles from multiple sources, such as architectural and structural design data, empirical knowledge, and mechanical principles. This paper presents a set of AI design techniques for building structures based on two types of generative AI: generative adversarial networks and graph neural networks. Specifically, these techniques effectively master the design of vertical and horizontal component layouts as well as the cross-sectional size of components in reinforced concrete shear walls and frame structures of tall buildings. Consequently, these approaches enable the development of high-quality and high-efficiency AI designs for building structures.

Genetically Encoded Biosensor Engineering for Application in Directed Evolution

  • Yin Mao;Chao Huang;Xuan Zhou;Runhua Han;Yu Deng;Shenghu Zhou
    • Journal of Microbiology and Biotechnology
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    • v.33 no.10
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    • pp.1257-1267
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    • 2023
  • Although rational genetic engineering is nowadays the favored method for microbial strain improvement, building up mutant libraries based on directed evolution for improvement is still in many cases the better option. In this regard, the demand for precise and efficient screening methods for mutants with high performance has stimulated the development of biosensor-based high-throughput screening strategies. Genetically encoded biosensors provide powerful tools to couple the desired phenotype to a detectable signal, such as fluorescence and growth rate. Herein, we review recent advances in engineering several classes of biosensors and their applications in directed evolution. Furthermore, we compare and discuss the screening advantages and limitations of two-component biosensors, transcription-factor-based biosensors, and RNA-based biosensors. Engineering these biosensors has focused mainly on modifying the expression level or structure of the biosensor components to optimize the dynamic range, specificity, and detection range. Finally, the applications of biosensors in the evolution of proteins, metabolic pathways, and genome-scale metabolic networks are described. This review provides potential guidance in the design of biosensors and their applications in improving the bioproduction of microbial cell factories through directed evolution.

Pharmacological Analyses of HIMH0021 Extracted from Acer Tegmentosum and Efficacy Tests of Steatohepatitis and Hepatic Fibrosis in NASH/ASH (산겨릅나무로부터 추출된 HIMH0021의 알콜성·비알콜성 지방간염 질환에서의 약리학적 분석 및 지방간염 및 간섬유화 억제능 평가)

  • Ji Hoon Yu;Yongjun Lee
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2021.04a
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    • pp.5-5
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    • 2021
  • Alcoholic and nonalcoholic steaohepatitis is a leading form of chronic liver disease with few biomakers ad treatment options currently available. a progressive disease of NAFLD may lead to fibrosis, cirrhosis, and hepatocellular carcinoma. Recently, we extracted HIMH0021, which is an active flavonoid component in the Acer tegmentosum extract, has been shown to protect against liver damage caused by hepatic dysfunction. Therefore, in this study, we aimed to investigate whether HIMH0021 could regulate steatohepatitis and liver fibrosis during alcoholic or nonalcoholic metabolic process. HIMH0021, which was isolated from the active methanol extract of A. tegmentosum, inhibited alcohol-induced steatosis and attenuated the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) during hepatocellular alcohol metabolism, both of which promote lipogenesis as well as liver inflammation. Treatment with HIMH0021 conferred protection against lipogenesis and liver injury, inhibited the expression of cytochrome P4502E1, and increased serum adiponectin levels in the mice subjected to chronic-plus-binge feeding. Furthermore, in hepatocytes, HIMH0021 activated fatty acid oxidation by activating pAMPK, which comprises pACC and CPT1a. These findings suggested that HIMH0021 could be used to target a TNFα-related pathway for treating patients with alcoholic hepatitis.

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Galvanic Corrosion Between Component Parts of Aluminum Alloys for Heat Exchanger of Automobile

  • Y. R. Yoo;D. H. Kim;G. B. Kim;S. Y. Won;S. H. Choi;Y. S. Kim
    • Corrosion Science and Technology
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    • v.22 no.5
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    • pp.322-329
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    • 2023
  • There are a variety of heat exchangers used in automobiles, such as shell and tube heat exchangers, double tube heat exchangers, and plate heat exchangers. Most of them are water-cooled to prevent engine overheating. There have been reports of corrosion damage to these heat exchangers due to continuous wetting caused by external temperature differences, road pollutants, and snow removal. In addition, galvanic corrosion, which occurs when two dissimilar materials come into contact, has been identified as a major cause. In this study, corrosion characteristics and galvanic corrosion behavior of Al alloy (AA3003, AA4045 and AA7072) used in automobile heat exchangers were analyzed. Effective clad materials for heat exchanger tubes and fins were also evaluated. It was found that AA7072 should be applied as the cladding material for fin AA3003 and that AA4045 was suitable as a cladding material for tube AA3003 because this clad materials application was the most effective clad design to delay the occurrence of pinhole in the tube. Main factors influencing galvanic corrosion dissolution were found to be galvanic corrosion potential difference and galvanic corrosion current density.

Density Change Adaptive Congestive Scene Recognition Network

  • Jun-Hee Kim;Dae-Seok Lee;Suk-Ho Lee
    • International journal of advanced smart convergence
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    • v.12 no.4
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    • pp.147-153
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    • 2023
  • In recent times, an absence of effective crowd management has led to numerous stampede incidents in crowded places. A crucial component for enhancing on-site crowd management effectiveness is the utilization of crowd counting technology. Current approaches to analyzing congested scenes have evolved beyond simple crowd counting, which outputs the number of people in the targeted image to a density map. This development aligns with the demands of real-life applications, as the same number of people can exhibit vastly different crowd distributions. Therefore, solely counting the number of crowds is no longer sufficient. CSRNet stands out as one representative method within this advanced category of approaches. In this paper, we propose a crowd counting network which is adaptive to the change in the density of people in the scene, addressing the performance degradation issue observed in the existing CSRNet(Congested Scene Recognition Network) when there are changes in density. To overcome the weakness of the CSRNet, we introduce a system that takes input from the image's information and adjusts the output of CSRNet based on the features extracted from the image. This aims to improve the algorithm's adaptability to changes in density, supplementing the shortcomings identified in the original CSRNet.

Development of Digital Fault Detection Systems for Screening Open and Short of Wire Harness (와이어 하네스 단선 단락 선별을 위한 디지털 고장 검출 시스템 개발)

  • A Ran Kim;Jae Wan Park;Ha Seon Kim;Jae Hoon Jeong;Sun Young Kim
    • Journal of Drive and Control
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    • v.20 no.4
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    • pp.140-149
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    • 2023
  • Wire harness is a component for efficient control when electronic parts are required such as construction machinery and electric vehicles. With emerging issues such as autonomous driving and automation in construction, a wire harness composed of multiple cables has become an essential part because more electronic parts are required. However, when a wire harness failure occurs, systems can be stopped, accidents can occur, and economic damage can be significant. Therefore, in this paper, we developed a digital fault screening system that could easily and quickly diagnose faults in the wire harness. The principle of the developed system was to sequentially send pulse signals to the wire harness and use returned signals to perform fault detection. As a result of diagnosing faults using the developed failure detection system, a detection accuracy of 99.9 % was confirmed through the experiments.