• Title/Summary/Keyword: SSI effects

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GFRP retrofitting effect on the dynamic characteristics of model steel structure

  • Tuhta, Sertac
    • Steel and Composite Structures
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    • v.28 no.2
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    • pp.223-231
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    • 2018
  • Nowadays, there are a great number of various structures that have been retrofitted by using different FRP Composites. Due to this, more researches need to be conducted to know more the characteristics of these structures, not only that but also a comparison among them before and after the retrofitting is needed. In this research, a model steel structure is tested using a bench-scale earthquake simulator on the shake table, using recorded micro tremor data, in order to get the dynamic behaviors. Columns of the model steel structure are then retrofitted by using GFRP composite, and then tested on the Quanser shake table by using the recorded micro tremor data. At this stage, it is needed to evaluate the dynamic behaviors of the retrofitted model steel structure. Various types of methods of OMA, such as EFDD, SSI, etc. are used to take action in the ambient responses. Having a purpose to learn more about the effects of GFRP composite, experimental model analysis of both types (retrofitted and no-retrofitted models) is conducted to evaluate their dynamic behaviors. There is a provision of ambient excitation to the shake table by using recorded micro tremor ambient vibration data on ground level. Furthermore, the Enhanced Frequency Domain Decomposition is used through output-only modal identification. At the end of this study, moderate correlation is obtained between mode shapes, periods and damping ratios. The aim of this research is to show and determine the effects of GFRP Composite implementation on structural responses of the model steel structure, in terms of changing its dynamical behaviors. The frequencies for model steel structure and the retrofitted model steel structure are shown to be 33.916% in average difference. Finally, it is shown that, in order to evaluate the period and rigidity of retrofitted structures, OMA might be used.

The Effects of Alcohol Use, Depression, and Self-esteem on Suicidal Ideation of the Aged (노인의 알코올 사용, 우울 및 자존감이 자살생각에 미치는 영향)

  • Kwak, Yun-Bock;Ko, Sung-Hee;Kim, Hyun-Kyung
    • Journal of Digital Convergence
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    • v.11 no.9
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    • pp.221-228
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    • 2013
  • The purpose of this study was to examine the effects of alcohol use, depression, and self-esteem on suicidal ideation of older adults. Community-dwelling older adults aged 65 years and older were recruited from three welfare centers. A total of 245 older adults was assessed with the Alcohol Use Disorder Identification Test-Korean (AUDIT-K), Geriatric Depression Scale Short Form-Korea Version (GDSSF-K), Self-Esteem Scale (SES), and Scale for Suicidal Ideation (SSI). Descriptive statistics, Pearson's correlation, independent t-test, one-way ANOVA, and multiple regression analysis were performed using the SPSS WIN 19.0 program. Higher depression, lower self-esteem, no religion, and poorly perceived health were statistically significant determinants of higher level of suicidal ideation in older adults. To prevent or reduce suicidal ideation of older adults, health care providers should consider the determinants identified in this study.

Control strategy for the substructuring testing systems to simulate soil-structure interaction

  • Guo, Jun;Tang, Zhenyun;Chen, Shicai;Li, Zhenbao
    • Smart Structures and Systems
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    • v.18 no.6
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    • pp.1169-1188
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    • 2016
  • Real-time substructuring techniques are currently an advanced experimental method for testing large size specimens in the laboratory. In dynamic substructuring, the whole tested system is split into two linked parts, the part of particular interest or nonlinearity, which is tested physically, and the remanding part which is tested numerically. To achieve near-perfect synchronization of the interface response between the physical specimen and the numerical model, a good controller is needed to compensate for transfer system dynamics, nonlinearities, uncertainties and time-varying parameters within the physical substructures. This paper presents the substructuring approach and control performance of the linear and the adaptive controllers for testing the dynamic characteristics of soil-structure-interaction system (SSI). This is difficult to emulate as an entire system in the laboratory because of the size and power supply limitations of the experimental facilities. A modified linear substructuring controller (MLSC) is proposed to replace the linear substructuring controller (LSC).The MLSC doesn't require the accurate mathematical model of the physical structure that is required by the LSC. The effects of parameter identification errors of physical structure and the shaking table on the control performance of the MLSC are analysed. An adaptive controller was designed to compensate for the errors from the simplification of the physical model in the MLSC, and from parameter identification errors. Comparative simulation and experimental tests were then performed to evaluate the performance of the MLSC and the adaptive controller.

Research and Development of Urban Health Infrastructure for Home Health Care for the Elderly (도시의 노인보건방문서비스를 위한 자원 및 모델 개발에 관한 연구)

  • Kang, Pock-Soo;Hwang, In-Soo;Kim, Chang-Yoon;Kim, Seok-Beom;Lee, Kyeong-Soo
    • Journal of agricultural medicine and community health
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    • v.21 no.1
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    • pp.47-60
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    • 1996
  • Home health care is one of the important components of health care services. Today, the need and demand for the home health care is increasing. To assess the effects of home visit health services by public health nurses in health center on the stat of health, use of medical services and quality of life by elderly people living at home, a randomized controlled trial was implemented for 65 years or more old people randomly allocated to intervention(93) and control(118) group. Intervention group received 2 visits a month over 6 months. Control group received no home visits. The data was collected in a one-year follow-up survey conducted at Kyongju before and after the intervention which composed of health risk assessment, risk factor education and health related behavior counseling. The prevalence rate of chronic illness was more decreased in intervention group than control group after intervention. The intervention group visited medical facilities less frequently than control group. And the home visit health services encouraged the elderly to practice regular exercise. After the intervention, the score of ADL(activities of daily living), LSI(life satisfaction index) and SSI(social support index) in intervention group were more increased than control group. And the increase of scores was more prominent in 70 years or more old people, female, non-smoker and non-chronic illed elderly rather than others. In conclusion, the regular home visit health services provided by public health nurses were beneficial for the elderly in terms of health promotion and quality of life.

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Case Study of Dynamic Amplification Characteristics of the Seismic Stations Using Observed Seismic Waves (관측지진파를 이용한 지반증폭특성 사례분석)

  • Lee, Jundae;Kim, Junkyoung
    • Journal of the Korean GEO-environmental Society
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    • v.10 no.1
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    • pp.35-41
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    • 2009
  • It is necessary to consider the site amplification for estimating SSI (soil structure interaction) and seismic source with more confidence. The horizontal to vertical (H/V) ratio technique in spectral domain is one of several techniques to estimate empirical site transfer function. The technique, originally proposed by Nakamura (1989), is applied to analyze the surface waves in the microtremor records. However, the application of this technique has been widened to the shear wave energy of strong motions for estimating site amplification. The purpose of this paper is to estimate spectral ratio using observed data at the seismic stations distributed within Southern Korean Peninsula from the Fukuoka earthquake including 11 aftershocks. The results show that each station has the its own characteristics of the specific resonance, high-band, and low-band frequency. The characteristics of the resonance frequency is more important because the quality of the seismic records are dependent on the resonance frequency. The result can be used for the study of site classification and removal of the site amplification effects from observed records can give us more reliable seismic source parameters.

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A Case Study of an ENACT Model-based Engineering Design Online Course for Fostering Social Responsibility of Engineers (사회적 책임의식 함양을 위한 ENACT 모형 기반 기초설계 교과목의 비대면 수업 운영 사례)

  • Kim, Gahyoung;Ok, Seung-Yong;Lee, Hyunju;Ko, Yeonjoo;Hwang, Yohan
    • Journal of Engineering Education Research
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    • v.24 no.6
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    • pp.3-19
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    • 2021
  • This study aimed to introduce a case study of a basic engineering design course using the ENACT model for fostering social responsibility of engineers, and to investigate the educational effects of the course. Since the ENACT model was designed to encourage STEM college students to pursue responsible problem solving based on their understanding of socioscientific issues, we assumed that it would be beneficial for engineering students to foster their social responsibility as well as their understanding of science/engineering-related issues. A total of 49 engineering students who enrolled in the course participated in the study. Data included students' course artifacts, reflection papers, and responses to survey questionnaires. Results indicated that the students became more aware of nature of science and technology after the program, and began to solve the problems while considering the views of multiple stakeholders. They highly valued the experience of communicating with others as engaging in the civic activities. They also expressed high satisfaction and feeling of achievement on the course learning. We expect the ENACT model to be an effective teaching guideline that fosters the social responsibility of engineering students and furthermore, engineering ethics.

Development of the ENACT Model for Cultivating Social Responsibility of College Students in STEM Fields (이공계 대학생의 사회적 책임감 함양을 위한 ENACT 모형의 개발과 교육적 함의)

  • Lee, Hyunju;Choi, Yuhyun;Nam, Chang-Hoon;Ok, Seung-Yong;Shim, Sungok Serena;Hwang, Yohan;Kim, Gahyoung
    • Journal of Engineering Education Research
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    • v.23 no.6
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    • pp.3-16
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    • 2020
  • This study aims to introduce the ENACT model, which is a systematic teaching-learning model for cultivating social responsibility of science and engineering college students, and to discuss its educational implications. For the development of the ENACT model, we conducted extensive literature reviews on RRI, STEM education, and science and technology studies (STS). In addition, we examined exemplary overseas education programs emphasizing social responsibility of scientists/engineers and citizens. The ENACT model consists of five steps; 1) Engage in SSIs, 2) Navigate SSIs, 3) Anticipate consequences, 4) Conduct scientific and engineering practice, and 5) Take action. This model links Socioscientific Issues (SSI) education with engineering education, dividing the major elements of social responsibility education for scientists and engineers into the dimensions of epistemology and praxis, and reflected them in the model. This effort enables science and engineering college students to pursue more responsible and sustainable development by carrying out the responsible problem-solving process based on an understanding of the nature of science and technology. We plan to implement ENACT model based programs for science and engineering college students and to examine the effects.

EFFECTS OF GROUP THERAPY ON SPEECH FLUENCY IN ELEMENTARY SCHOOL STUTTERING CHILDREN (학령기 말더듬 아동 치료에 있어 그룹지도의 효과)

  • Shin, Moon-Ja
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.2 no.1
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    • pp.102-115
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    • 1991
  • This study reviewed the stuttering literature and reported the clinical experiment in stuttering intervention. There is still no single answer as to the cause of stuttering or to the most effective therapy for stutterers despite the vast amount of research. One certain thing is that we have come closer to a better understanding of the stuttering and to more effective therapy. There have been three main statements about the origins of stuttering ; biologic origins ; psychodynamic origins ; environmental-learning origins. There also have been various methods of the treatment of stuttering. Broadly, two major treatment approaches are attentive ; stuttering modification therapy and fluency shaping therapy. In this experiment, the researcher attempted to investigate complex elements that each child might have and to use an integrative approach rather than to keep the specific one. Individual subjects were evaluated by a multidisciplinary team. Initially, the subjects received individual therapy. They then were placed in group therapy. The purpose of the group therapy was to raise their fluencies to the higher communicative situation and to maintain improved fluency over time. All three subjects improved their fluencies in reading and in conversation and showed the better(SSI)scores in total stuttering behaviors. It was also discussed that it is necessary to have sensitive assessment tools to investigate each element of stuttering ; and to develop a therapy program reflecting current advanced stuttering theories.

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Study on the Multilevel Effects of Integrated Crisis Intervention Model for the Prevention of Elderly Suicide: Focusing on Suicidal Ideation and Depression (노인자살예방을 위한 통합적 위기개입모델 다층효과 연구: 자살생각·우울을 중심으로)

  • Kim, Eun Joo;Yook, Sung Pil
    • 한국노년학
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    • v.37 no.1
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    • pp.173-200
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    • 2017
  • This study is designed to verify the actual effect on the prevention of the elderly suicide of the integrated crisis intervention service which has been widely provided across all local communities in Gyeonggi-province focusing on the integrated crisis intervention model developed for the prevention of elderly suicide. The integrated crisis intervention model for the local communities and its manual were developed for the prevention of elderly suicide by integrating the crisis intervention theory which contains local community's integrated system approach and the stress vulnerability theory. For the analysis of the effect, the geriatric depression and suicidal ideation scale was adopted and the data was collected as follows; The data was collected from 258 people in the first preliminary test. Then, it was collected from the secondary test of 184 people after the integrated crisis intervention service was performed for 6 months. The third collection of data was made from 124 people after 2 or 3 years later using the backward tracing method. As for the analysis, the researcher used the R Statistics computing to conduct the test equating, and the vertical scaling between measuring points. Then, the researcher conducted descriptive statistics analysis and univariate analysis of variance, and performed multi-level modeling analysis using Bayesian estimation. As a result of the study, it was found out that the integrated crisis intervention model which has been developed for the elderly suicide prevention has a statistically significant effect on the reduction of elderly suicide in terms of elderly depression and suicide ideation in the follow-up measurement after the implementation of crisis intervention rather than in the first preliminary scores. The integrated crisis intervention model for the prevention of elderly suicide was found to be effective to the extent of 0.56 for the reduction of depression and 0.39 for the reduction of suicidal ideation. However, it was found out in the backward tracing test conducted 2-3 years after the first crisis intervention that the improved values returned to its original state, thus showing that the effect of the intervention is not maintained for long. Multilevel analysis was conducted to find out the factors such as the service type(professional counseling, medication, peer counseling), characteristics of the client (sex, age), the characteristics of the counselor(age, career, major) and the interaction between the characteristics of the counselor and intervention which affect depression and suicidal ideation. It was found that only medication can significantly reduce suicidal ideation and that if the counselor's major is counseling, it significantly further reduces suicidal ideation by interacting with professional counseling. Furthermore, as the characteristics of the suicide prevention experts are found to regulate the intervention effect on elderly suicide prevention in applying integrated crisis intervention model, the primary consideration should be given to the counseling ability of these experts.