• Title/Summary/Keyword: structural evaluation

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The Evaluation of flexure performance of SCP modules for LNG outer tank (LNG 외조탱크 적용을 위한 SCP 모듈의 휨성능 평가)

  • Park, Jung-Jun;Park, Gi-Joon;Kim, Sung-Wook;Kim, Eon;Shin, Dongkyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.1
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    • pp.447-455
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    • 2019
  • When constructing LNG storage structures using the cast-in-place method in extreme areas, the construction cost and time may be increased due to the poor working environments and conditions. Therefore, demand for modular energy storage tanks is increasing. In this study, we propose using an SCP module as an alternative for lighter-weight LNG storage tanks. The purpose of this study is to evaluate the feasibility of LNG storage outer tanks by performing bending tests on the thickness of composite steel plate concrete under field conditions. The loads on specimens with thicknesses of 100 mm and 200 mm were linearly increased to the design final loads of 413 kN and 822 kN, respectively. The slope was rapidly changed, and fracture occurred. The two test conditions showed linear behavior until the steel plate yielded, and after an extreme load behavior, sudden yielding of the steel plate yield occurred in the SCP bending test according to the INCA guidelines. The results satisfied the design flexural load and showed the possibility of using the specimens in a modular LNG outer tank. However, it is necessary to evaluate the structural performance of the SCP by performing compression and shear tests in future research.

Characteristics of Right Hemispheric Damaged Patients in Korean Focused Prosodic Sentences (한국어 초점 발화 시 우반구 손상인의 초점 운율 특성)

  • Lee, Myung Soon;Park, Hyun
    • Therapeutic Science for Rehabilitation
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    • v.8 no.3
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    • pp.69-81
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    • 2019
  • Objective: The purpose of this study was to examine the characteristics of prosody of ambiguous sentences in patients with right hemisphere damage(RHD). Methods: Sentences with each word prosodically focused were used to investigate. Several acoustic parameters such as intensity, F0, and duration were measured to identify characteristics of prosody in patients with lesions in the right hemisphere and normal controls. All speech samples were recorded using the Praat 4.3.14 software. Data were analyzed with the independent sample t-test using SPSS 18.0. Results: The results of this study are as follows: First, intensity of the first syllable of the focus word was different between the two groups in several sentences. Second, F0 was different between the two groups in all sentences. Third, duration was different between the groups in several sentences. Accordingly, prosody were varied and values of acoustic parameters differed due to the focus of utterance. The group with right hemisphere damage showed restricted prosody. Conclusions: Intensity, duration, and F0 are all used as elements of prosody in emphasizing structural and pragmatic meaning, but according to the focus, strength and duration were related to F0. In contrast, F0 has a significant linguistic difference, but there was a significant difference between the RHD and normal people, so F0 can be a discriminatory factor of rhyme evaluation of the right hemisphere damaged and it is necessary to accumulate more strong evidence through future research.

Seismic Performance Evaluation of the Li-Polymer Battery Rack System for Nuclear Power Plant (원자력발전소용 리튬폴리머 배터리 랙 시스템의 내진성능평가)

  • Kim, Si-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.5
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    • pp.13-19
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    • 2019
  • After the Fukushima nuclear accident, a new power supply using a lithium polymer battery has been proposed the first time in the world as the safety of the emergency battery facility has been required. It is required to have the safety of the rack system in which the battery device is installed in order to apply the proposed technology to the field. Therefore, the purpose of this study is to evaluate the seismic performance of string and rack frame for lithium-polymer battery devices developed for the first time in the world to satisfy 72 hours capacity. (1) The natural frequency of the unit rack system was 9 Hz, and the natural frequency before and after the earthquake load did not change. This means that the connection between members is secured against the design earthquake load. (2) he vibration reduction effect by string design was about 20%. (3) As a result of the seismic performance test under OBE and SSE conditions, the rack frame system was confirmed to be safe. Therefore, the proposed rack system can be applied to the nuclear power plant because the rack system has been verified structural safety to the required seismic forces.

Proper Monitoring Methods for Safety Management of Tailings Dam (광물찌꺼기적치장의 안전관리를 위한 적정 모니터링 방안 연구)

  • Jung, Myung Chae;Kim, Jeong Wook;Hwang, In-ho;Yang, In Jae;Park, Jay Hyun;Park, Ju Hyun;Kim, Tae Youp
    • Journal of the Korean Society of Mineral and Energy Resources Engineers
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    • v.55 no.6
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    • pp.576-587
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    • 2018
  • This study has focused on analysis factors affecting safety monitoring system at tailings sites, and the evaluation equipment to monitor the factors. Twenty sites at eighteen mines with unsafe conditions were selected to examine the equipment. There were three main factors influenced safety in the sites including surface erosion, piping, and slope instability. In detail, the surface erosion was divided into three sub-factors (planting, soil-topping layer, and tailings), piping into three sub-factors (liner, rain protection facility and leachate), and slop instability was also divided into three sub-factors (slop, concrete wall, and reinforcing wall). As results of in-field measurement, a CCTV was the most effective facility, and electrical resistivity survey, acoustic sensing, thermal liner sensor, structure inclinometer, rainfall meter, and flowmeter were also highly effective. According to applications of the facilities in the unstable tailings, structural defects were mainly found in the piping, which was the most important monitoring factor for safety management of tailings sites.

A Study on Dam Exterior Inspection and Cost Standards using Drones (드론을 활용한 댐 외관조사 및 대가기준에 대한 연구)

  • Kim, Tae-Hoon;Lee, Jai-Ho;Kim, Do-Seon;Lee, Suk-Bae
    • Journal of the Society of Disaster Information
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    • v.17 no.3
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    • pp.608-616
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    • 2021
  • Purpose: Safety inspections by existing personnel have been limited in evaluation and data securing due to concerns about the safety of technicians or difficulty in accessing them, and are becoming a bigger problem as the number of maintenance targets increases due to the aging of facilities. As drone technology develops, it is possible to ensure the safety of personnel, secure visual data, and diagnose quickly, and use it is increasing as safety inspection of facilities by drones was introduced recently. In order to further enhance utilization, it is considered necessary to base a consideration standard for facility appearance investigation by drones, and in this paper, research was conducted on dams. Method: To calculate the quality, existing domestic safety inspection and drone-related consideration standards were investigated, and procedures related to safety inspection using drones were compared and analyzed to review work procedures and construction types. In addition, empirical data were collected through drone photography and elevation image production for the actual dam. Result: Work types for safety inspection of facilities using drones were derived, and empirical survey results were collected for two dams according to work types. The existing guidelines were applied for the adjustment ratios for each structural type and standard of the facility, and if a meteorological reference point survey was necessary, the unmanned aerial vehicle survey of the construction work standard was applied. Conclusion: The finer the GSD in appearance investigation using drones, the greater the number of photographs taken, and the concept of adjustment cost was applied as a correction to calculate the consideration standard. In addition, it was found that the problem of maximum GSD indicating limitations should be considered in order to maintain the safe distance.

Assessment of Mild Cognitive Impairment in Elderly Subjects Using a Fully Automated Brain Segmentation Software

  • Kwon, Chiheon;Kang, Koung Mi;Byun, Min Soo;Yi, Dahyun;Song, Huijin;Lee, Ji Ye;Hwang, Inpyeong;Yoo, Roh-Eul;Yun, Tae Jin;Choi, Seung Hong;Kim, Ji-hoon;Sohn, Chul-Ho;Lee, Dong Young
    • Investigative Magnetic Resonance Imaging
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    • v.25 no.3
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    • pp.164-171
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    • 2021
  • Purpose: Mild cognitive impairment (MCI) is a prodromal stage of Alzheimer's disease (AD). Brain atrophy in this disease spectrum begins in the medial temporal lobe structure, which can be recognized by magnetic resonance imaging. To overcome the unsatisfactory inter-observer reliability of visual evaluation, quantitative brain volumetry has been developed and widely investigated for the diagnosis of MCI and AD. The aim of this study was to assess the prediction accuracy of quantitative brain volumetry using a fully automated segmentation software package, NeuroQuant®, for the diagnosis of MCI. Materials and Methods: A total of 418 subjects from the Korean Brain Aging Study for Early Diagnosis and Prediction of Alzheimer's Disease cohort were included in our study. Each participant was allocated to either a cognitively normal old group (n = 285) or an MCI group (n = 133). Brain volumetric data were obtained from T1-weighted images using the NeuroQuant software package. Logistic regression and receiver operating characteristic (ROC) curve analyses were performed to investigate relevant brain regions and their prediction accuracies. Results: Multivariate logistic regression analysis revealed that normative percentiles of the hippocampus (P < 0.001), amygdala (P = 0.003), frontal lobe (P = 0.049), medial parietal lobe (P = 0.023), and third ventricle (P = 0.012) were independent predictive factors for MCI. In ROC analysis, normative percentiles of the hippocampus and amygdala showed fair accuracies in the diagnosis of MCI (area under the curve: 0.739 and 0.727, respectively). Conclusion: Normative percentiles of the hippocampus and amygdala provided by the fully automated segmentation software could be used for screening MCI with a reasonable post-processing time. This information might help us interpret structural MRI in patients with cognitive impairment.

An Analysis of Dwelling Environment of Public Retirement(Silver) Housing Based on Post Occupancy Evaluation (거주 후 평가(P.O.E)에 의한 공공실버주택의 거주환경 분석)

  • Bak, Da-Hye;Kim, Young-Hwa;Lee, Sang-Hong
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.12
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    • pp.65-76
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    • 2018
  • Due to the rapid demographic and structural changes, Korea has faced a variety of social issues and quickly entered the aged society since the 2000s. In order deal with this reality, diverse types of welfare policies are emerging in the society as a whole. The government began to supply domestic public silver housing in 2016 to provide against the quickly growing aged society and now, the government is planning to supply approximately 50,000 housing by 2022 for quantitative growth of aged society, by selecting 1st and 2nd designated areas for the project additionally. This public retirement(silver) housing combines 'space' with 'service'. The lower floors are a public silver welfare Facilities and the upper floors are a housing spaces. This type of housing is to deal with requirements of rental housing residents by combining physical space with supporting service. Based on barrier-free design, the complex and unit house have safety handles and alarm bells in the bathroom, undulating washstands, bathroom sliding doors, corridor safety handles, and emergency safety exit lamps in each housing unit so the aged and the disabled can use easily and conveniently. Also, hand rails are installed and stepped pulleys are removed to promote convenience. Currently, the government is planning to increase the supply, focusing on low-income groups, such as beneficiaries of national basic livelihood and the working poor. Recognizing that the public retirement(silver) housing project is at its early stage, this study examined satisfaction, based on evaluations of real residents. This study aimed to obtain more empirical research data and apply them to public retirement(silver) house space analysis. For analysis, this study targeted Wirye public retirement(silver) housing and Magnolia public retirement(silver) housing that are in operation, and literature review, previous research review, and field survey were conducted to examine the present state. Using the questionnaires consisting of four large classification items; Block Layout, Housing Unit, Welfare Facilities, and Barrier-free Design, and sub-details, a survey was conducted to analyze residents' satisfaction. In conclusion, it is anticipated that this study would serve as basic research data about public retirement(silver) housing to increase continuously in future by analyzing public retirement(silver) housing spaces, on the basis of the analyzed data.

Evaluation of the Standard Support Pattern in Large Section Tunnel by Numerical Analysis and Field Measurement (수치해석 및 현장계측에 의한 대단면 터널 표준지보패턴의 적정성 검증)

  • Byun, Yoseph;Chung, Sungrae;Song, Simyung;Chun, Byungsik;Park, Duhee
    • Journal of the Korean GEO-environmental Society
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    • v.12 no.7
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    • pp.5-12
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    • 2011
  • When choosing the support pattern of tunnel, the characteristics of rock are identified from the result of the surface geologic survey, boring, and geophysical prospecting and laboratory test. And a rock mass rating is classified and excavation method and standard support pattern are designed considering rock classification, domestic and international construction practices, numerical analysis. According to the revised design standard for tunnel, it was recommended to classify the rock mass rating for the design of tunnel into a rating based on RMR. If necessary, it proposed a flexible standard allowed applying more atomized the rock mass rating and Q-System. Also, the resonable verification of the support pattern must be accompanied because the factors affecting the structure and behavior of ground during the construction of tunnel are the main factors of uncertainty factors such as the nature of ground, ground water and the characteristics of structural materials. These days, such verification method is getting more specialized and diversified. In this study, the empirical method, numerical analysis and comparative analysis of in situ measurements were used to prove the reasonableness in the support pattern by RMR and Q-value on the Imha Dam emergency spillway.

Relationship among the Expertise of University Liberal Arts Class Instructor, the Exercise Flow and Persistent Participation Intention Perceived by Non-Sports Major University Students (비체육 전공 대학생이 인지한 대학교 교양 수업 지도자의 전문성과 운동몰입 및 참여지속의도간의 관계)

  • Lee, Young Jun
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.3
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    • pp.735-749
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    • 2021
  • There is true that the evaluation of non-face-to-face swimming classes currently offered by universities due to the COVID-19 outbreak is generally negative. For this reason, the quality of non-face-to-face swimming classes at universities is bound to depend on the expertise of the instructor. However, whether or not of students who lack of practices of swimming could experience exercise flow and could continuously last the swimming exercise after semester or even graduation is difficult to confirm. This is considered to be a significant threat in the future not only for swimming, but also for all liberal arts and lifestyle sports. This study aimed at 281 non-athletic college students with experience of taking both swimming classes, and the need for a study on the structural relationship between exercise flow and participation intention by university swimming class leaders' expertise in non-sports majoring college students. And the results were empirically analyzed. The research results derived in this process are summarized as follows. First, the effect of swimming class leader's expertise (personality, lecture skills, student management, practical skills, basic knowledge) perceived by non-athletic college students on exercise flow (cognitive flow, behavior flow) affects cognitive flow. As a factor influencing, it was found that lecture skills had a statistically positive (+) effect, and as factors influencing behavioral commitment, the positive (+) effect was statistically significant in personality, lecture skills, student management, and basic knowledge. Second, as for the effect of exercise commitment (cognitive commitment, behavior commitment) perceived by non-athletic college students on continuous participation intention, the behavioral commitment factor was found to have a statistically positive (+) effect.

Analysis of Model of Intentions of University Students to Watch Mega Sports Events with People with Disabilities Based on the Theory of Planned Behavior (계획행동이론을 적용한 장애인 메가 스포츠 이벤트에 대한 대학생의 관람 의도 모형 분석)

  • Kim, Kyungjin;Kim, Jaehwa
    • Journal of the Korea Convergence Society
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    • v.13 no.4
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    • pp.433-439
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    • 2022
  • The purpose of the study was to determine the suitability of the research model on the intentions of university students to watch mega sports events for people with disabilities to which the theory of planned behavior was applied, and to examine the influence relationship between variables. Based on the items of sub-variables derived from the previous research, the questionnaire was optimally constructed through expert meetings, validity, and reliability verification. For data analysis, Cronbach's 𝛼 and exploratory factor analysis were performed using SPSS 21.0, and structural equation model analysis (SEM) and confirmatory factor analysis (CFA) were performed using AMOS 18.0. The results were as follows; first, as a result of verification of the research model of intentions of university students to watch mega sports events with people with disabilities to which the theory of planned behavior was applied, the evaluation indices of CFI, NFI, and IFI met the acceptance criteria, indicating that this research model was well suited. Second, as a result of examining the influence relationship of the research model on the intentions of university students to watch mega sports event for people with disabilities, it was found that the behavioral beliefs and normative beliefs of university students had a significantly positive (+) influence to intentions. However, it was found that there was a significantly negative (-) influence on the control beliefs to intentions.