• Title/Summary/Keyword: stress category

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Study on Convergence Technique through Structural Analysis due to The Configuration of Door Hinge (경첩의 형상에 따른 구조 해석을 통한 융합 기술 연구)

  • Lee, Jung-Ho;Cho, Jae-Ung
    • Journal of the Korea Convergence Society
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    • v.6 no.3
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    • pp.59-64
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    • 2015
  • A hinge is the most important part constituting door. Nowadays, the hinge is subdivided all the more under the category of the function, shape and material and is enlarged at the usage. Therefore, it is necessary to improve the manufacturing technique and more specialized design must be developed. As the structural analysis is carried on the hinge model mounted at door in this study, the deformation, stress distribution and fatigue life are analyzed when the door is applied with uniform force. The durabilities of hinge models due to each shape are anticipated through this study. It is thought to be contributed at developing and designing more improved hinge model with durability. And it is possible to be grafted onto the convergence technique at design and show the esthetic sense.

Effect of the factor developing the Heat of Hydration on Durability Design in the Subway Concrete Structure (수화열 발생인자가 지하철 콘크리트 구조물의 내구설계에 미치는 영향)

  • Lim Young-Su;Kim Eun Kyum;Sung Ki Han
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1131-1137
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    • 2004
  • With the recent continuous expansion of subways, newly created subways tend to have lower locations and wider sections. Furthermore. since box structures and evacuating tunnels are classified into a category of mass-concrete. the thermal-stress, emitted from the inside. causes cracks to structures from the inception of constructing. In this paper, thermal-stress analysis and durability evaluation of box structure were carried out to investigate relationship between durability and parameter causing the heat of hydration. Through the examination, this paper tries to find out satisfactory solutions to regulated thermal crack and ensure the required duration period. The results of this paper showed that to control thermal crack and guarantee the required duration period it was more effective to use low-heat-portland cement and moderateheat-portland cement. As cement volume due to reduction of water-cement ratio increased, the possibility of thermal cracks occurrence increased but results of durability evaluation was different depending on evaluation method. The results showed that the appropriate water-cement ratio to control the heat of hydration and satisfy the required durability was $45\∼55\%$. And it was showed that during placement of concrete blocks ambient temperature affect the heat of hydration. thermal crack and long-term durability largely and when concrete was placed at low temperature to control thermal crack. it need to try to guarantee the required duration period. Henceforth, by studying not only internal and external conditions, such as the relative humidity and the unit weight. but also methods, to evaluate durability, in accordance with domestic situations, more reasonable design of durability should be achieved.

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Fatigue Strength of In-plane Welded Attachments (면내 거셋 용접연결부의 피로강도)

  • Bae, Doobyong
    • Journal of Korean Society of Steel Construction
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    • v.15 no.6 s.67
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    • pp.629-637
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    • 2003
  • This s paper presented the results of the three phases of fatigue tests to determine the fatigue strength of in-plane welded gusset joints, which are the most common details inevitably existing in the region of high stress range. A total of 57 fatigue specimens with varying thickness and strengths were made and tensile fatigue tests performed. One full-scale beam fatigue test was also performed. The validity of the fatigue strength of those details in the specification was confirmed, with the effects of thickness of flanges and welded attachments, length of attachments, and strength of applied steel examined. The characteristics of crack initiation and propagation were also observed. The test result was evaluated by comparing it with other test data and fatigue criteria of other countries. To determine the degree of stress concentration in the weld toe depending on geometric configuration such as attachment length and transition radius, analyses were performed. Compared to the present specification, analytical results indicate the need to revise and subdivide the detail categories.

Unidirectional cyclic shearing of sands: Evaluation of three different constitutive models

  • Oscar H. Moreno-Torres;Cristhian Mendoza-Bolanos;Andres Salas-Montoya
    • Geomechanics and Engineering
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    • v.35 no.4
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    • pp.449-464
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    • 2023
  • Advanced nonlinear effective stress constitutive models are started to be frequently used in one-dimensional (1D) and two-dimensional (2D) site response analysis for assessment of porewater generation and liquefaction potential in soft soil deposits. The emphasis of this research is on the assessment of the implementation of this category of models at the element stage. Initially, the performance of a coupled porewater pressure (PWP) and constitutive models were evaluated employing a catalogue of 40 unidirectional cyclic simple shear tests with a variety of relative densities between 35% and 80% and effective vertical stresses between 40 and 80 kPa. The authors evaluated three coupled constitutive models (PDMY02, PM4SAND and PDMY03) using cyclic direct simple shear tests and for decide input parameters used in the model, procedures are recommended. The ability of the coupled model to capture dilation as strength is valuable because the studied models reasonably capture the cyclic performance noted in the experiments and should be utilized to conduct effective stress-based 1D and 2D site response analysis. Sandy soils may become softer and liquefy during earthquakes as a result of pore-water pressure (PWP) development, which may have an impact on seismic design and site response. The tested constitutive models are mathematically coupled with a cyclic strain-based PWP generation model and can capture small-strain stiffness and large-strain shear strength. Results show that there are minor discrepancies between measured and computed excess PWP ratios, indicating that the tested constitutive models provide reasonable estimations of PWP increase during cyclic shear (ru) and the banana shape is reproduced in a proper way indicating that dilation and shear- strain behavior is well captured by the models.

Percentile Approach of Drought Severity Classification in Evaporative Stress Index for South Korea (Evaporative Stress Index (ESI)의 국내 가뭄 심도 분류 기준 제시)

  • Lee, Hee-Jin;Nam, Won-Ho;Yoon, Dong-Hyun;Hong, Eun-Mi;Kim, Taegon;Park, Jong-Hwan;Kim, Dae-Eui
    • Journal of The Korean Society of Agricultural Engineers
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    • v.62 no.2
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    • pp.63-73
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    • 2020
  • Drought is considered as a devastating hazard that causes serious agricultural, ecological and socio-economic impacts worldwide. Fundamentally, the drought can be defined as temporarily different levels of inadequate precipitation, soil moisture, and water supply relative to the long-term average conditions. From no unified definition of droughts, droughts have been divided into different severity level, i.e., moderate drought, severe drought, extreme drought and exceptional drought. The drought severity classification defined the ranges for each indicator for each dryness level. Because the ranges of the various indicators often don't coincide, the final drought category tends to be based on what the majority of the indicators show and on local observations. Evaporative Stress Index (ESI), a satellite-based drought index using the ratio of potential and actual evaporation, is being used as a index of the droughts occurring rapidly in a short period of time from studies showing a more sensitive and fast response to drought compared to Standardized Precipitation Index (SPI), and Palmer Drought Severity Index (PDSI). However, ESI is difficult to provide an objective drought assessment because it does not have clear drought severity classification criteria. In this study, U.S. Drought Monitor (USDM), the standard for drought determination used in the United States, was applied to ESI, and the Percentile method was used to classify drought categories by severity. Regarding the actual 2017 drought event in South Korea, we compare the spatial distribution of drought area and understand the USDM-based ESI by comparing the results of Standardized Groundwater level Index (SGI) and drought impact information. These results demonstrated that the USDM-based ESI could be an effective tool to provide objective drought conditions to inform management decisions for drought policy.

Impact of Job Stress, Organizational Culture and Professional Identity on Job Satisfaction of Post-anesthesia Care Unit Nurses (회복마취간호사의 직무만족도 영향 요인)

  • Yoo, Je Bog;Won, Jongsoon
    • Journal of the Korean Data Analysis Society
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    • v.20 no.6
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    • pp.3211-3225
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    • 2018
  • The purpose of this study was to identify the factors affecting job satisfaction of PACU (post-anesthesia care unit) nurses in the context of job stress, organizational culture and professional identity. A total of 149 nurses participated in the cross-sectional, descriptive study suing a structured questionnaire. Job stress in pay and treatment category, innovation-oriented culture, relation-oriented culture, and professional identity were positively correlated with job satisfaction (r=.373, p<.001; r=.507, p<.001; r=.559, p<.001; r=.544, p<.001). The factors related to job satisfaction were professional identity (${\beta}=.391$, p<.001), relation oriented culture (${\beta}=.302$, p<.001), innovation oriented culture (${\beta}=.209$, p=.004), which accounted for 48.7% of the variance in job satisfaction. Professional identity was the most significant predictor of job satisfaction. Thus, in order to enhance the job satisfaction of nurses in the PACU, it is necessary to develop an education program that can improve professional identity and apply strategies for fostering relation and innovation oriented organization culture.

An Ethnographic Study on a Welfare Facility for Single Father Families: Focusing on the Experiences of Single Fathers (부자가족복지시설에 대한 문화기술지 연구: 부자가족아버지의 경험을 중심으로)

  • Kim, Gihwa;Yang, Sungeun
    • Journal of Families and Better Life
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    • v.33 no.6
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    • pp.15-33
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    • 2015
  • The present study conducted ethnography of a welfare facility for single-father families. The participants were 13 single-fathers living in a welfare facility. To explore life within the welfare facility, the qualitative research method of ethnography was used with Spradley's developmental research sequence (DRS). The major results of this study were as follows. The first theme was 'finding a way to overcome the crisis: the facility is a lifeline.' For fathers, choosing to enter a facility meant enduring a social stigma, but the decision was made with the hope of achieving successful parenting and economic independence amidst pressing difficulties. The category of living in the facility was represented by the theme 'build the family: preparing for independence through living in a welfare facility.' The fathers achieved psychological recovery through the decrease in parenting stress, improvements in their economic situation brought by living in a facility, and used this time as the foundation to gain independence and build a stable life. The event of departure from the facility was seen as 'incomplete preparation for departure' by the single fathers. The fathers with infants or younger children admitted to being anxious about leaving the facility, which involved the burden of raising the children on their own. There are practical and policy-related implications based on the results of this study.

Effects of Job-related Characteristics on Alcohol Consumption among Female Workers in Korea (직업관련 특성이 여성의 음주소비에 미친 영향)

  • 김명순;김광기
    • Korean Journal of Health Education and Promotion
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    • v.21 no.1
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    • pp.1-23
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    • 2004
  • The purpose of this study is to examine the effects of job-related characteristics on alcohol consumption among female workers. The Data was collected from a sample of 1,000 female workers by a stratified proportional quota sampling method derived from those who were working in Seoul. Drinking behavior pattern includes total amount of pure alcohol consumed during the last month (AC) measured by graduated quantity-frequency. Job-related characteristics (JRC) were measured by job-related stress, work characteristics, and organizational structure including length of working hours, number of times dining out together with workers per year, number of staff to supervise, employment status, occupational category, and proportion of female workers to male counterpart. Confounding variables include sociodemogrphic and socio-cultural attitudes toward alcohol expectancy, subjective norm of drinking, and gender-role attitude. Hierarchical multiple regression models show that the variability of AC was accounted for by some JRC including number of times dining together and employment status, with confounding variables held constant. However, the relationship between AC and JRC varied across occupational categories. Some implications were discussed in terms of health policy for female workers and further study for female drinking behavior.

Analysis of Ground Behavior applied to the Design of Underground Opening Structures (지하공동구조물의 설계시 적용되는 지반거동해석)

  • 박남서;이성민
    • Explosives and Blasting
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    • v.15 no.1
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    • pp.44-60
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    • 1997
  • The design of underground cavern is basically governed by the mechanical properties of ground mass distributed around excavation. It is seldom possible to consider all the factors of ground mass properties in the evaluation of ground mass behavior as well as to classify those factors to a simple category. Until computer sciences have developed to calculate complex and laborious mechanical simulation of underground openings, ground behavior was quantitatively and qualitatively evaluated using empirical classification system. In this paper, analysis methods of ground behavior for underground cavern using the prediction of loosening zone, empirical method derived from rock mass classification and element stress analysis are described with chronological sequence.

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Development of Empowerment Program for the Diabetes Patients and the Experiences of Diabetes Patient's Empowerment Process - A Grounded Theory Methodology Approach (당뇨병 환자를 위한 엠파워먼트 프로그램 개발 및 당뇨병 환자의 엠파워먼트 과정 경험 -근거이론 방법론 적용-)

  • Choi, Eun-Ok
    • Research in Community and Public Health Nursing
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    • v.12 no.2
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    • pp.317-328
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    • 2001
  • The purposes of this study were to develop the empowerment education program, to describe the experiences of diabetes patient's empowerment process and to develop a theoretical model of the diabetes patient's empowerment process. Method 1. : The development of the empowerment program for the diabetes patients: The strategies of the empowerment education program were enhancement of problem - solving, decision making, self-efficacy, self-control. participation and mutual support. Method 2. : According to the grounded theory methodology of Strauss and Corbin, the qualitative data was collected with in depth interviews and participants observations until its saturation when the 25 consented subjects were participating and interacting with the other subjects in the empowerment education program. Results: With the analysis of the data, 29 categories were generated. The core category generated, which was a central phenomenon of the empowerment process, was named powerlessness. The intervening conditions facilitating or impeding the empowerment process were discovered as supportive systems through the participation of group meeting, problem solving dialogue, and the knowledge deficit of self-care. The action/interaction strategies were developed as the paricipating, dialoguing, questioning, supporting system, self-controlling, self efficacy, enhancing self-esteem. stress relaxing and instillation of hope.

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