• Title/Summary/Keyword: reliability and safety

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A Study on the Necessity and Importance of AI Smart Housing Services for the Housing Disadvantaged Persons (주거약자를 위한 AI 스마트하우징 주거서비스의 필요성과 중요도에 관한 연구)

  • Bae, Yoongho;Kim, Sungwan;Ha, Chun
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.29 no.4
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    • pp.45-56
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    • 2023
  • Purpose: Recently, Korea has been promoting smart cities that combine artificial intelligence(AI), big data, ICT, and the Internet of Things(IoT), and these technologies are being applied to housing services and are developing into smart housing services. This study try to analyze what is the most necessary and important the AI smart housing services for the housing disadvantaged persons through a survey of experts and the housing disadvantaged persons. And by collecting these necessary and important services, we aim to present elements and directions for the AI smart housing services policy for the housing disadvantaged persons. Methods: Firstly, we asked 11 experts, Secondly, the desire and necessity for the above smart housing service was identified through an online survey targeting the housing disadvantaged persons. Thirdly, the survey was analyzed and reliability was measured through descriptive statistical analysis using SPSS program. Fourthly, based on the results of descriptive statistics analysis, the necessity and importance of AI smart housing services from the perspective of the housing disadvantaged were derived. Results: The results of this study are that firstly, both experts and the housing disadvantaged persons viewed safety and health-related services as the most important and necessary among AI smart housing services, secondly, there is a difference in perspectives on the services that should be priority between experts and people with disabilities, and lastly there are differences in perspectives and needs for services that should be priority between the disabled and the elderly.

A Study on the Primary Energy Change Amount and Grade Correlation following Factor Changes such as Area, Point of the Compass, Standard Layer, Insulation, Airtight Joint and Others (지역, 방위, 기준층, 단열재, 기밀등 요소변화에 따른 1차에너지 변화량 과 연관성 연구)

  • Kim, Dae-Won;Chung, Kwang-Seop;Kim, Young-Il;Nam, Ariasae;Kim, Sung-Min;Cho, Young-Wook
    • Journal of Energy Engineering
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    • v.24 no.4
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    • pp.183-191
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    • 2015
  • Studies on the environment-friendly and permanent low energy saving measure are and will continue to be an eternal challenge. However, the demand is high for the technologies that can save energy significantly in everyday life that produce tangible benefits for the users by applying saving factors and that anyone can access easily when it comes the related procedure. Government policies related to the improvement of energy effect in the existing building structure are characterized by complex procedure. Moreover, cost required and reliability issue emerge when request is made to an expert. Accordingly, this study seeks to present energy improvement plan that can be utilized simply and conveniently at any place, any time by enabling customized design according to individual taste by enabling energy change amount and grade prediction when the users select only the part that they want to replace by using a simple program.

A Study on the Additional Installation of Coastal Wave Buoys in Smooth Water Areas to Prevent Marine Accidents (해양사고 예방을 위한 평수구역 내 파고부이 추가설치 검토)

  • Min-Kyoon Kang;Dong-Il Seol
    • Journal of Navigation and Port Research
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    • v.47 no.6
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    • pp.350-357
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    • 2023
  • Marine accidents frequently occur due to the unreasonable operation of ships excluded from ship departure control during marine special weather warnings within smooth water areas. Coastal wave buoys installed in smooth water areas are major reference indicators for ship departure control and can be seen as being directly connected to the safety of ships navigating smooth water areas and the coast. In this study, the location appropriateness of currently operating coastal wave buoys and additional installation in the smooth water areas were assessed by analyzing coastal marine accidents over the past 30 years (1991-2020), the main wind direction and wind speed of each major trading port, and the GICOMS ship track data in 2018. The study results showed that an additional coastal wave buoy should be installed at each of the major trading ports(Inchon Port, Pohang Port, Ulsan Port, and Busan Port) and that the location of the coastal wave buoy needs to be moved in the case of Busan Port. Based on various data analysis in this study, the suggestion for an additional installation and movement of the coastal wave buoy presented in this study is expected to contribute to improving the reliability of ship departure control and resolving safety blind spots.

Development of Real Time Monitoring Program Using Geostatistics and GIS (GIS 및 지구통계학을 이용한 실시간 통합계측관리 프로그램 개발)

  • Han, Byung-Won;Park, Jae-Sung;Lee, Dae-Hyung;Lee, Gye-Choon;Kim, Sung-Wook
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1046-1053
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    • 2006
  • In the large scale recent reclaiming works performed within the wide spatial boundary, evaluation of long-term consolidation settlement and residual settlement of the whole construction area is sometimes made with the results of the limited ground investigation and measurement. Then the reliability of evaluation has limitations due to the spatial uncertainty. Additionally, in case of large scale deep excavation works such as urban subway construction, there are a lot of hazardous elements to threaten the safety of underground pipes or adjacent structures. Therefore it is necessary to introduce a damage prediction system of adjacent structures and others. For the more accurate analysis of monitoring information in the wide spatial boundary works and large scale urban deep excavations, it is necessary to perform statistical and spatial analysis considering the geographical spatial effect of ground and monitoring information in stead of using diagrammatization method based on a time-series data expression that is traditionally used. And also it is necessary that enormous ground information and measurement data, digital maps are accumulated in a database, and they are controlled in a integrating system. On the abovementioned point of view, we developed Geomonitor 2.0, an Internet based real time monitoring program with a new concept by adding GIS and geo-statistical analysis method to the existing real time integrated measurement system that is already developed and under useful use. The new program enables the spatial analysis and database of monitoring data and ground information, and helps the construction- related persons make a quick and accurate decision for the economical and safe construction.

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Analysis of the Flow Field of Carrier-Based Aircraft Exhaust Jets Impact on the Flight Deck

  • Yue, Kuizhi;Sun, Yicheng;Liu, Hu;Guo, Weigang
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.1
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    • pp.1-7
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    • 2015
  • In order to provide some references for suitability of carrier-based aircrafts, this paper studies the flow field of exhaust jets and its impact on the flight deck. The geometrical models of aircraft carrier and carrier-based aircrafts are firstly built, on which unstructured tetrahedral meshes are generated for numerical analysis. Then, this paper simulates the flow field of exhaust jets to evaluate its impact on the Jet Blast Deflector (JBD) and the flight deck, when four carrier-based aircrafts are ready to start off in the bow. The standard k-${\varepsilon}$ equations, three-dimension N-S equations and the Computational Fluid Dynamics (CFD) theory are used in the analysis process. To solve the equations, the thermal coupling of the wind and the jet flow are also considered. The velocity and temperature distributions are provided with the simulation of the CFD software, FLUENT. The results indicate that: (1) this analytical method can be used to simulate aerodynamic problems with complex geometrical models, and the results are of high reliability; (2) the safety working area, the installation scheme of the JBD and the arrangement of the take-off position can be optimized through analysis.

Quasi-optical design and analysis of a remote steering launcher for CFETR ECRH system

  • Zhang Chao;Xiaojie Wang;Dajun Wu;Yunying Tang;Hanlin Wang;Dingzhen Li;Fukun Liu;Muquan Wu;Peiguang Yan;Xiang Gao;Jiangang Li
    • Nuclear Engineering and Technology
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    • v.56 no.5
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    • pp.1619-1626
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    • 2024
  • In order to optimize the operational safety and reliability of the upper launcher for the CFETR ECRH system, a design of the launcher for NTM control based on the remote steering concept is currently being carried out for comparison with the front steering equivalent. This paper presents the layout design and analysis of the quasi-optical system in the remote steering launcher. A 3D visual quasi-optical design tool has been developed for the quasi-optical system, which can parameterize modeling, perform general astigmatic beam calculation and show the accurate beam propagation path in the upper port. Three identical sets of quasi-optical modules are arranged in the launcher, and each one consists of two fixed double-curvature focusing mirrors, which focus and reflect the steering beams (- 12°-12°) from two square corrugated waveguides. The beam characteristics at the resonance layer are described, and the average beam radius is < 100 mm. The peak head loads on the surfaces of the two fixed mirrors are 1.63 MW/m2 and 1.52 MW/m2. The position and size of the beam channel in the blanket are obtained, and the opening apertures on the launcher-facing and plasma-facing sides of the blanket module are 0.54 m2 and 0.4 m2, respectively.

Adulterated Food Management Characteristics according to Dietary Lifestyles among Adolescents (청소년의 식생활 라이프스타일 유형에 따른 불량식품관리 특성)

  • Kim, Yunhwa
    • Korean Journal of Community Nutrition
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    • v.21 no.6
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    • pp.509-519
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    • 2016
  • Objectives: Adulterated food education in adolescence period is very important because dietary management related to food safety is not made in a short period. This study aimed to identify dietary lifestyle factors which drive adulterated food management among middle and high school students. Methods: Data was collected from 270 middle and high school students in Daegu using a self-administered questionnaire in March and April of 2015. Data was analyzed using frequency analysis, one-way analysis of variance, ${\chi}^2$-test, factor analysis, reliability analysis, regression analysis, and cluster analysis. Results: The results of factor analysis indicated that adulterated food management awareness was classified into necessity, difficulty, and food purchasing anxiety. The adulterated food management capability was sub-grouped into environmental grasp, food identification, cooking hygiene, and situation management. The adulterated food management efficacy composed of management confidence, action intention, and knowledge. Dietary lifestyle comprised of gustation, family, and health factors after factor analysis, and it consisted of all seeking group, gustation seeking group, family seeking group, health seeking group, and family and health seeking group after cluster analysis. The gustation, family and health factors were significantly affected the factors of awareness, capability and efficacy of adulterated food management (p < 0.05). The frequency of health conditions, helping with meal preparation, and the times of eating out were significantly different according to seeking groups of dietary lifestyle (p < 0.01). The scores of awareness, capability and efficacy of adulterated food management of family and health seeking group were significantly higher than the other seeking groups (p < 0.05). Conclusions: This study suggests that adulterated food management education programs should account for gustation, family and health factors of dietary lifestyle to be effective for adolescents.

Perception Difference between Korean Medicine Doctors, Western Medicine Doctors, and Patients on the Collaborative and Integrated Medicine for the Functional Dyspepsia (기능성 소화불량의 의한 협진과 통합의료에 대한 한의사, 의사, 환자의 인식도 차이)

  • Kim, Keumji;Jeon, Hye-jin;Ko, Seok-jae;Cha, Jae Myung;Park, Jae-Woo
    • The Journal of Internal Korean Medicine
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    • v.42 no.6
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    • pp.1285-1302
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    • 2021
  • Objectives: The aim of this study was to investigate the perception difference between Korean Medicine doctors, Western Medicine doctors, and functional dyspepsia (FD) patients on the 'Collaborative and Integrated Medicine (CIM)' for FD management. Methods: Between February and April 2021, 545 Korean Medicine doctors, 121 Western Medicine doctors, and 186 FD patients were invited to participate in this survey. A questionnaire was developed by both the Korean and Western Medicine doctors and consisted of questions about general perceptions of FD and perceptions of CIM for FD. Results: Responses from 424 Korean Medicine doctors, 113 Western Medicine doctors, and 153 FD patients were analyzed for the CIM of FD. Significant perceptional differences were noted between Korean Medicine doctors, Western Medicine doctors, and FD patients on the CIM for FD, including necessity, effectiveness, safety, cost, and reliability of CIM for the management of FD (p<0.001). The FD patients also more strongly supported the necessity of developing CIM for FD than did the Korean and Western Medicine doctors (p<0.001), and 87.6% of the FD patients strongly agreed or agreed with the use of CIM for FD. Conclusions: A significant perception difference was detected between Korean Medicine doctors, Western Medicine doctors, and FD patients regarding the use of CIM for FD. Patients with FD favored the necessity and were more willing to accept CIM for FD than were the doctors. Therefore, more efforts may be warranted for doctors to promote CIM for FD.

Stochastic fracture behavior analysis of infinite plates with a separate crack and a hole under tensile loading

  • Khubi Lal Khatri;Kanif Markad
    • Computers and Concrete
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    • v.32 no.1
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    • pp.99-117
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    • 2023
  • The crack under the influence of the higher intensities of the stresses grows and the structure gets collapsed with the time when the crack length reaches to critical value. Therefore, the fracture behavior of a structure in terms of stress intensity factors (SIF) becomes important to determine the remaining fracture strength and capacity of material and structure for avoiding catastrophic failure, increasing safety and further improvement in the design. The robustness of the method has been demonstrated by comparing the numerical results with analytical and experimental results of some problems. XFEM is used to model cracks and holes in structures and predict their strength and reliability under service conditions. Further, XFEM is extended with a stochastic method for predicting the sensitivity in terms of output COVs and fracture strength in terms of mean values of stress intensity factors (SIFs) of a structure with discontinuities (cracks and holes) under tensile loading condition with input individual and combined randomness in different system parameters. In stochastic technique, the second order perturbation technique (SOPT) has been used for the predicting the fracture behavior of the structures. The stochastic/perturbation technique is also known as Taylor series expansion method and it provides the reliable results if the input randomness is less than twenty percentage. From the present numerical analysis it is observed that, the crack tip near to the hole is under the influence of the stress concentration and the variational effect of the input random parameters on the crack tip in terms of the SIFs are lesser so the COVs are the less sensitive. The COVs of mixed mode SIFs are the most sensitive for the crack angles (α=45° to 90°) for all the values of c1 and d1. The plate with the shorter distance between hole and crack is the most sensitive with all the crack angles but the crack tip which is much nearer to the hole has the highest sensitivity.

Design of Fault Diagnostic and Fault Tolerant System for Induction Motors with Redundant Controller Area Network

  • Hong, Won-Pyo;Yoon, Chung-Sup;Kim, Dong-Hwa
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.11a
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    • pp.371-374
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    • 2004
  • Induction motors are a critical component of many industrial processes and are frequently integrated in commercially available equipment. Safety, reliability, efficiency, and performance are some of the major concerns of induction motor applications. Preventive maintenance of induction motors has been a topic great interest to industry because of their wide range application of industry. Since the use of mechanical sensors, such as vibration probes, strain gauges, and accelerometers is often impractical, the motor current signature analysis (MACA) techniques have gained murk popularity as diagnostic tool. Fault tolerant control (FTC) strives to make the system stable and retain acceptable performance under the system faults. All present FTC method can be classified into two groups. The first group is based on fault detection and diagnostics (FDD). The second group is independent of FDD and includes methods such as integrity control, reliable stabilization and simultaneous stabilization. This paper presents the fundamental FDD-based FTC methods, which are capable of on-line detection and diagnose of the induction motors. Therefore, our group has developed the embedded distributed fault tolerant and fault diagnosis system for industrial motor. This paper presents its architecture. These mechanisms are based on two 32-bit DSPs and each TMS320F2407 DSP module is checking stator current, voltage, temperatures, vibration and speed of the motor. The DSPs share information from each sensor or DSP through DPRAM with hardware implemented semaphore. And it communicates the motor status through field bus (CAN, RS485). From the designed system, we get primitive sensors data for the case of normal condition and two abnormal conditions of 3 phase induction motor control system is implemented. This paper is the first step to drive multi-motors with serial communication which can satisfy the real time operation using CAN protocol.

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