• Title/Summary/Keyword: Component development

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Comparison of aerodynamic loading of a high-rise building subjected to boundary layer and tornadic winds

  • Ashrafi, Arash;Chowdhury, Jubayer;Hangan, Horia
    • Wind and Structures
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    • v.34 no.5
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    • pp.395-405
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    • 2022
  • Tornado-induced damages to high-rise buildings and low-rise buildings are quite different in nature. Tornado losses to high-rise buildings are generally associated with building envelope failures while tornado-induced damages to low-rise buildings are usually associated with structural or large component failures such as complete collapses, or roofs being torn off. While studies of tornado-induced structural damages tend to focus mainly on low-rise residential buildings, transmission towers, or nuclear power plants, the current rapid expansion of city centers and development of large-scale building complexes increases the risk of tornadoes impacting tall buildings. It is, therefore, important to determine how tornado-induced load affects tall buildings compared with those based on synoptic boundary layer winds. The present study applies an experimentally simulated tornado wind field to the Commonwealth Advisory Aeronautical Research Council (CAARC) building and estimates and compares its pressure coefficient effects against the Atmospheric Boundary Layer (ABL) flow field. Simulations are performed at the Wind Engineering, Energy and Environment (WindEEE) Dome which is capable of generating both ABL and tornadic winds. A model of the CAARC building at a scale of 1:200 for both ABL and tornado flows was built and equipped with pressure taps. Mean and peak surface pressures for TLV flow are reported and compared with the ABL induced wind for different time-averaging. By following a compatible definition of the pressure coefficients for TLV and ABL fields, the resulting TLV pressure field presents a similar trend to the ABL case. Also, the results show that, for the high-rise building model, the mean and 3-sec peak pressures are larger for the ABL case compared to the TLV case. These results provide a way forward for the code implementation of tornado-induced pressures on high-rise buildings.

A Study of Virtual IoT System using Edge Computing (엣지 컴퓨팅 기반 가상 IoT 시스템 연구)

  • Kim, Min-A;Seok, Seung-Joon
    • KNOM Review
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    • v.23 no.1
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    • pp.51-62
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    • 2020
  • Open IoT platform that shares communication infrastructure and provides cloud resources can flexibly reduce development period and cost of smart service. In this paper, as an open IoT platform, we propose a virtual IoT system based on edge computing that implements a virtual IoT device for a physical IoT device and allows service developers to interact with the virtual device. A management server in the edge cloud, near the IoT physical device, manages the creation, movement, and removal of virtual IoT devices corresponding to the physical IoT devices. This paper define the operations of the management server, the physical IoT device, and the virtual IoT device, which are major components of the virtual IoT system, and design the communication protocol required to perform the operations. Finally, through simulations, this paper evaluate the performance of the edge computing based virtual IoT system by confirming that each component performs the defined states and operations as designed.

A Study on Conferring Orientation to Myoblast for Realizing Tissue of Cultured Meat (배양육 조직구현을 위한 배향성 부여에 관한 연구)

  • Seok, Yong-Joo;Zo, Sun-Mi;Choi, Soon-Mo;Han, Sung Soo
    • Textile Coloration and Finishing
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    • v.34 no.4
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    • pp.284-301
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    • 2022
  • The limitations of food production caused by global warming, consumption of soil fertility, and land shortage have demanded the development of alternative foods. Their market has been increasing, and in particular, there is an urgent need for an alternative meat. Among them, the non-slaughtered cell-cultured meat that can be manufactured in the laboratory, that is, cultured meat, is in the spotlight, which can solve the problem of meat consumption while including the advantages of meat. It is classified into minced cultured meat and structured one with a structure similar to that of real meat. The latter is currently facing limitations related scaffolds, cells, and the multiplicative problems, and many attempts are being made to solve them. The complex problem is related to secure texture and taste as well as structural similarity to actual meat. To solve the problems, it is necessary to lay emphasis on cells, there are fat cells and vascular cells, and the most fundamental cells, muscle cells. These are the main cells that control the texture and nutrients of meat, and unlike other cells, they grow in the form of fibers. A myofibril (also known as a muscle fibril) is a basic rod-like organelle of a muscle cell, which is a quantitatively major component of meat, and one of the tissues that maintain the appearance of the body and bones. In this review article, we focused on the growth of muscle cells into long, tubular cells known as muscle fibers using the fabricated fibrous scaffold, and reviewed not only research results for muscle tissue engineering but also various results in the related fields for the last five years.

A Scoping Review of Health-Related Intervention Studies Using Intervention Mapping in South Korea (중재 매핑을 활용한 국내 건강관련 중재연구의 주제범위 고찰)

  • Park, Jiyoung;Cho, Jeonghyun;Im, Mihae;Hwang, Gahui
    • Journal of Korean Public Health Nursing
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    • v.35 no.3
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    • pp.448-468
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    • 2021
  • Objectives: This study aimed to understand the trends and issues of health-related intervention research using Intervention Mapping over the last ten years in South Korea. Intervention Mapping is a representative planning protocol to develop theory-and-evidence-based health promotion programs. Methods: The scoping review method was undertaken, and a total of 20 studies were analyzed using Intervention Mapping six steps. Results: The Korean health-related intervention studies using Intervention Mapping showed low methodological quality. In step 1, only 7 out of 20 studies organized a planning group consisting of various stakeholders. In step 2, about half of the studies did not present a matrix, which is the core essential component of Intervention Mapping. In step 5, only 1 out of 20 studies presented program adopters and maintainers. In step 6, most studies described effect evaluation relatively, but only one study mentioned process evaluation. Conclusions: In order to develop sustainable and cost-effective programs, systematic planning using Intervention Mapping is required from the research planning stage. In addition, a concrete and realistic plan needs to be established for the development of programs and adoption, dissemination and maintenance of programs.

Transmission Efficiency of Dual-clutch Transmission in Agricultural Tractors (농업용 트랙터 듀얼 클러치 변속기의 동력전달 효율 분석에 관한 연구)

  • Moon, Seok Pyo;Moon, Sang Gon;Kim, Jae Seung;Sohn, Jong Hyeon;Kim, Yong Joo;Kim, Su Chul
    • Journal of Drive and Control
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    • v.19 no.1
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    • pp.43-50
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    • 2022
  • The aim of this study was to conduct basic research on the development of a dual-clutch transmission(DCT) and automatic transmission for agricultural tractors. The DCT layout and the DCT simulation model were developed using commercial software. Power transmission efficiency of the DCT and component power loss were analyzed to verify the developed simulation model. Power loss analysis of the components was conducted according to previous studies and ISO(International Organization for Standardization) standards. The power transmission efficiency of the DCT simulation model was 68.4-91.5% according to the gear range. The power loss in the gear, bearing, and clutch DCT system components was 0.75-1.49 kW, 0.77-2.99 kW, and 5.24-10.52 kW, respectively. The developed simulation model not include the rear axle, differential gear, final reduction gear. Therefore actual power transmission efficiency of DCT will be decreased. In a future study, an actual DCT can be developed through the simulation model in this study, and optimization design of DCT can be possible by comparing simulation results and actual vehicle test.

Evaluation of Durum Wheat Genotypes for Resistance against Root Rot Disease Caused by Moroccan Fusarium culmorum Isolates

  • Bouarda, Jamila;Bassi, Filippo M.;Wallwork, Hugh;Benchacho, Mohammed;Labhilili, Mustapha;Maafa, Ilyass;El Aissami, Aicha;Bentata, Fatiha
    • The Plant Pathology Journal
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    • v.38 no.1
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    • pp.1-11
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    • 2022
  • Fusarium culmorum is one of the most important causal agents of root rot of wheat. In this study, 10 F. culmorum isolates were collected from farms located in five agro-ecological regions of Morocco. These were used to challenge 20 durum wheat genotypes via artificial inoculation of plant roots under controlled conditions. The isolate virulence was determined by three traits (roots browning index, stem browning index, and severity of root rot). An alpha-lattice design with three replicates was used, and the resulting ANOVA revealed a significant (P < 0.01) effect of isolate (I), genotype (G), and G × I interaction. A total of four response types were observed (R, MR, MS, and S) revealing that different genes in both the pathogen and the host were activated in 53% of interactions. Most genotypes were susceptible to eight or more isolates, while the Moroccan cultivar Marouan was reported resistant to three isolates and moderately resistant to three others. Similarly, the Australian breeding line SSD1479-117 was reported resistant to two isolates and moderately resistant to four others. The ICARDA elites Icaverve, Berghisyr, Berghisyr2, Amina, and Icaverve2 were identified as moderately resistant. Principal component analysis based on the genotypes responses defined two major clusters and two sub-clusters for the 10 F. culmorum isolates. Isolate Fc9 collected in Khemis Zemamra was the most virulent while isolate Fc3 collected in Haj-Kaddour was the least virulent. This work provides initial results for the discovery of differential reactions between the durum lines and isolates and the identification of novel sources of resistance.

Development of Pore-Filled Anion-Exchange Membranes for High Performance Reverse Electrodialysis (고성능 역전기투석을 위한 세공충진 음이온교환막의 개발)

  • Kim, Do-Hyeong;Song, Hyeon-Bee;Yoon, Kyungseok;Kang, Moon-Sung
    • Membrane Journal
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    • v.32 no.5
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    • pp.336-347
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    • 2022
  • Reverse electrodialysis (RED) is one of the promising eco-friendly renewable energy technologies which can generate electricity from the concentration difference between seawater and freshwater by using ion-exchange membranes as a diaphragm. The ion-exchange membrane is a key component that determines the performance of RED, and must satisfy requirements such as low electrical resistance, high permselectivity, excellent durability, and low manufacturing cost. In this study, pore-filled anion-exchange membranes were fabricated using porous polymer substrates having various thicknesses and porosity, and the effects of ion-exchange polymer composition and membrane thickness on the power generation performance of RED were investigated. When the electrical resistance of the ion-exchange membrane is sufficiently low, it can be confirmed that the RED power generation performance is mainly influenced by the apparent permselectivity of the membrane. In addition, it was confirmed that the apparent permselectivity of the membranes can be improved through IEC, crosslinking degree, membrane thickness, surface modification, etc., and the optimum condition must be found in consideration of the trade-off relationship with electrical resistance.

Research on Innovation Technologies for Zero Carbon: Carbon Dioxide Reduction in Construction and Concrete Industries (탄소 제로화를 위한 혁신 기술 연구: 건설 및 콘크리트 산업에서의 이산화탄소 저감 방안 동향)

  • Kim, Joo-Hyun;Park, Jung-Jun;Kim, Jong-Kyu
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.4_2
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    • pp.549-563
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    • 2022
  • Continuous global warming is causing ecosystem destruction and direct damage to human life. The main cause of global warming is greenhouse gases, which account for more than 90 % of carbon dioxide. The leaders of each country signed the Paris Agreement at the United Nations Convention on Climate Change (UNFCCC) to reduce greenhouse gas emissions. Currently, the total amount of CO2 emitted from South Korea is 664.7 million tons as of 2018, ranking eighth in the world. 37 % of South Korea's total CO2 emissions come from the construction & building field, especially the cement production, which is a construction material. Carbon reduction technologies can be largely divided into four types: carbon reduction (CC), carbon reduction and storage technology (CCS), carbon reduction and utilization technology (CCU), and carbon reduction, storage and utilization technology (CCUS). Overseas, CCUS technology is mainly applied to reduce and store CO2 emitted from construction and construction field. A technology for permanently storing CO2 through mineralization by capturing CO2 and utilizing CO2 into a cement production process was developed, and this technology is applied to the entire cement industry. However, the development of CCUS technology applicable to the cement industry is still insignificant in South Korea. In this study, carbon dioxide reduction technology and methods for reducing carbon dioxide emitted during the cement manufacturing process, which is the main component of concrete mainly used in civil engineering construction, were investigated. Overseas, it has reached the commercialization stage beyond the demonstration stage as a way to reduce carbon dioxide by vomiting carbonation reactions. Accordingly, if carbon dioxide reduction plan technology generated during cement manufacturing is developed based on domestic technology differentiated from foreign technology, it is expected to contribute one more step to the carbon neutrality policy.

Development and Validation of a Machine Learning-based Differential Diagnosis Model for Patients with Mild Cognitive Impairment using Resting-State Quantitative EEG (안정 상태에서의 정량 뇌파를 이용한 기계학습 기반의 경도인지장애 환자의 감별 진단 모델 개발 및 검증)

  • Moon, Kiwook;Lim, Seungeui;Kim, Jinuk;Ha, Sang-Won;Lee, Kiwon
    • Journal of Biomedical Engineering Research
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    • v.43 no.4
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    • pp.185-192
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    • 2022
  • Early detection of mild cognitive impairment can help prevent the progression of dementia. The purpose of this study was to design and validate a machine learning model that automatically differential diagnosed patients with mild cognitive impairment and identified cognitive decline characteristics compared to a control group with normal cognition using resting-state quantitative electroencephalogram (qEEG) with eyes closed. In the first step, a rectified signal was obtained through a preprocessing process that receives a quantitative EEG signal as an input and removes noise through a filter and independent component analysis (ICA). Frequency analysis and non-linear features were extracted from the rectified signal, and the 3067 extracted features were used as input of a linear support vector machine (SVM), a representative algorithm among machine learning algorithms, and classified into mild cognitive impairment patients and normal cognitive adults. As a result of classification analysis of 58 normal cognitive group and 80 patients in mild cognitive impairment, the accuracy of SVM was 86.2%. In patients with mild cognitive impairment, alpha band power was decreased in the frontal lobe, and high beta band power was increased in the frontal lobe compared to the normal cognitive group. Also, the gamma band power of the occipital-parietal lobe was decreased in mild cognitive impairment. These results represented that quantitative EEG can be used as a meaningful biomarker to discriminate cognitive decline.

An Artificial Intelligent based Learning Model for BIM Elements Usage (건축 부재 사용량 예측을 위한 인공지능 학습 모델)

  • Beom-Su Kim;Jong-Hyeok Park;Soo-Hee Han;Kyung-Jun Kim
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.1
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    • pp.107-114
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    • 2023
  • This study described a method of designing and implementing an artificial intelligence-based learning model for predicting the usage of building members. Artificial intelligence (AI) is widely used in various fields thanks to the development of technology, but in the field of building information management (BIM), the case of utilizing AI technology is very low due to the specificity of the data in the field and the difficulty of collecting big data. Therefore, AI problems for BIM were discovered, and a new preprocessing technique was devised to solve the specificity of data in the field. An artificial intelligence model was implemented based on the designed preprocessing technique, and it was confirmed that the accuracy of predicting the construction component usage of the implemented artificial intelligence model is at a level that can be used in the actual industry.