• Title/Summary/Keyword: stress category

Search Result 173, Processing Time 0.023 seconds

Sensitivity Analysis of the 217PlusTM Component Models for Reliability Prediction of Electronic Systems (전자 시스템 신뢰도 예측을 위한 217PlusTM 부품모형의 민감도 분석)

  • Jeon, Tae-Bo
    • Journal of Korean Society for Quality Management
    • /
    • v.39 no.4
    • /
    • pp.507-515
    • /
    • 2011
  • MIL-HDBK-217 has played a pivotal role in reliability prediction of electronic equipments for more than 30 years. Recently, RIAC developed a new methodology $217Plus^{TM}$which officially replaces MIL-HDBK-217. Sensitivity analysis of the 217Plus component models to various parameters has been performed and meaningful observations have been drawn in this study. We first briefly reviewed the $217Plus^{TM}$ methodolog and compared it with the conventional model, MIL-HDBK-217. We then performed sensitivity analysis $217Plus^{TM}$ component models to various parameters. Based on the six parameters and an orthogonal array selected, we have performed indepth analyses concerning parameter effects on the model. Our result indicates that, among various parameters, operating temperature and temperature rise during operation have the most significant impacts on the life of a component, and thus a design robust to high temperature is the most importantly required. Next, year of manufacture, duty cycle, and voltage stress are weaker but may be significant when they are in heavy load conditions. Although our study is restricted to a specific type of diodes, the results are still valid to other cases. The results in this study not only figure out the behavior of the predicted failure rate as a function of parameters but provide meaningful guidelines for practical applications.

An Experimental Study on the Fatigue Behavior of Steel-Concrete Composite Bridge Deck (강-콘크리트 합성 교량 바닥판의 피로거동에 대한 실험적 연구)

  • 심정욱;김상효;정연주;박휘립
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2003.05a
    • /
    • pp.499-504
    • /
    • 2003
  • Future bridge decks must have high load-resistance capacity as well as fatigue strength to withstand the increase in traffic loading and the increase in span length between girders due to the decrease in the number of main girders. Steel-concrete composite bridge decks may be proper deck types to satisfy such requirements. To promote the application of composite bridge decks, a rational process to predict and evaluate the fatigue behavior of steel concrete composite bridge deck is required. Various types of steel-concrete composite bridge decks have been developed in many countries. In this study, combining advantages of the existing composite deck types, a new type of composite bridge deck is proposed. An experimental study is performed to examine the fatigue behavior of the proposed composite bridge deck. This composite bridge deck consists of corrugated steel sheet, welded T-beams, stud-type shear connectors and reinforced concrete filler. The fatigue tests are conducted under four-point bending test with three different stress ranges in constant amplitude. The fatigue category of the fillet welding between corrugated steel sheet and the T-beam is evaluated based on the S-N data obtained from the experiment.

  • PDF

Appearance Management Experiences of Breast Cancer Patients -A Grounded Theory Approach- (유방암 환자의 외모 관리 경험에 대한 근거이론적 접근)

  • Kim, Sunwoo;Son, Hyungjin
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.41 no.3
    • /
    • pp.556-574
    • /
    • 2017
  • This study explored the appearance management experiences of breast cancer patients undergoing mastectomy. For data collection, one-on-one interviews were held with 18 Korean females diagnosed with breast cancer from the first stage to the third stage from 2008 to 2015. The data was analyzed through a three-step analysis of grounded theory. QSR NVivo 11.0 for Mac was applied in order to avoid biased results according to the subjective viewpoint of researchers. From open coding results, six paradigms and 15 categories were drawn. The results of axial coding showed that the psychological changes category was the central phenomenon. Additionally, three categories (skin changes, scalp/hair changes, and general reactions) were found to be causal conditions, and five paradigms (clothing behavior, skin care behavior, makeup behavior, scalp/hair-care behavior, and shopping behavior) were found to be action/interaction strategies. Last, selective coding integrated fragmented qualitative data through open coding and axial coding in order to derive explanatory narratives. A comprehensive examination of the appearance management behaviors of breast cancer patients suffering from extreme stress due to physical/psychological changes enables this study to provide a foundation for related studies to be activated in the clothing and textiles discipline.

Influences of job performance of dental hygienists on emotional labor evaluation (치과위생사의 직무수행능력이 정서적 노동평가에 미치는 영향)

  • Lee, Jong-Ryol;Bae, Soo-Myoung;Kim, Hye-Jin
    • Journal of Korean society of Dental Hygiene
    • /
    • v.16 no.6
    • /
    • pp.835-847
    • /
    • 2016
  • Objectives: The purpose of the study was to investigate the influences of job performance of dental hygienists on emotional labor evaluation. Methods: A self-administered questionnaire was completed by 203 dental hygienists working at dental hospitals and clinics in Gyeongnam and Busan from May 2014 and March 2015. The study instruments comprised general characteristics of the subjects (9 items), job performance competency (44 items), and emotional labor evaluation (29 items) by Likert 5 point scale. Data were analyzed by SPSS 21.0 program and AMOS 18.0 program. Results: Those who had turnover intention showed higher scores in the dental treatment cooperation category and overall job performance than those who had not. Higher job performance was shown in those who had more work experience and higher salary. The scores of emotional labor evaluation were higher in the group of higher salary and team and department leaders. The job performance had a significant impact of the emotional labor evaluation. Conclusions: The job performance of dental hygienists had a significant influence on the emotional labor evaluation. Psychologic stress by work caused the dental hygienists to have depression and lower quality of life.

Loads Analysis of Smart UAV Using ARGON (ARGON을 이용한 스마트 무인기 비행하중해석)

  • Shin, Jeong-Woo;Kim, Sung-Chan;Hwang, In-Hee
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.33 no.7
    • /
    • pp.76-84
    • /
    • 2005
  • For flight loads analysis of Smart UAV, applicable regulations and loads conditions should be prepared in advance, and modeling for aerodynamics, weight, and structure should be performed. Panel method is usually adopted for aircraft loads analysis to obtain aerodynamic loads. In this study, ARGON which is a multidisciplinary fixed wing aircraft design software co-developed by KARI and TsAGI was used for loads analysis. ARGON can be utilized for flutter and stress analysis as well as for flight and ground loads analysis. In this paper, flight loads analysis of Smart UAV which is a FAR 23 category airplane was performed with ARGON and the results were presented.

The Coping Experience of Family Caregivers for the Industrial Disaster Victim (산재 환자를 간병하는 가족원의 대처경험)

  • Kim, Chun Mi;Oh, Jin Joo;Choi, Jeong Myung
    • Korean Journal of Occupational Health Nursing
    • /
    • v.16 no.2
    • /
    • pp.119-129
    • /
    • 2007
  • Purpose: The purposes of this study were to understand the coping experience that family caregivers undergo during the process of care, to grasp coping behaviors used to solve problems and, finally, to develop a substantive theory by analyzing the coping process. Method: The methodology of collecting and analyzing data used in this study followed the ground theory. Data were collected through in-depth interviews with open-ended and descriptive questions about the subjects' coping experiences. The survey was conducted between May 2006 and August. The subjects of this study were 10 women. Result: The result of the study is as follows. Core category of This Study was "Self-Sacrifice". And The coping process of family caregivers while taking care of the industrial disaster victim was found to have five stages: shocked stage; undertaking stage of new role; skilled stage; exhausted stage; and desiderating stage. Seven coping behaviors were found to reduce the stress of role and anguish resulting from care. Conclusion: The result of this study is helpful for developing effective industrial nursing strategies suitable for each coping stage. It is necessary to practice nursing mediation and to analyze the change about nursing effect and family caregivers' adaptation.

  • PDF

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

  • 박남서;이성민
    • The Journal of Engineering Geology
    • /
    • v.1 no.1
    • /
    • pp.38-53
    • /
    • 1991
  • 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.

  • PDF

Experience of Alopecia in Adults: A Grounded Theory Approach (성인의 탈모경험: 근거 이론적 접근)

  • Lee, Su Jung;Kim, Ae-Kyung
    • Journal of Korean Academy of Fundamentals of Nursing
    • /
    • v.25 no.3
    • /
    • pp.185-196
    • /
    • 2018
  • Purpose: The purpose of this study was to investigate the alopecia experience in adults and to explain the process of their experiences. Methods: Using a grounded theory methodology, 18 interviews were performed with fourteen men and four women, 34~57 years of age, suffering from alopecia. Data were analyzed using the constant comparative analysis method. Results: The core category emerged as "inescapable fetters". adults with alopecia engaged in three stages: embarrassment, seeking solution, and acceptance phase. Causal conditions were a vicious cycle of stress, biological factors and poor life style. Contextual conditions were recognition of irreversibleness, negative social awareness, and marriage. The central phenomenon of the adaptation process among the adults with alopecia was withdrawn life due to negative body image. Action/Interaction strategies included rely on medical treatment, efforts to take good care of hair, research for information treatment, efforts to cover up hair loss, and mind control. Intervening conditions were time cost, economic cost, support of surrounding people. Consequences was burden of unfinished lifetime homework. Conclusion: When caring for these adults, it is important to identify needs, allow patients to express what they want at that moment and support them in maintaining a daily life.

A Qualitative Study on the Posttraumatic Growth Experience of Firefighters after Colleague's Suicide (소방공무원의 동료자살 이후 외상 후 성장 경험에 관한 질적연구)

  • Kwak, Min-Yeong
    • Journal of Digital Convergence
    • /
    • v.17 no.2
    • /
    • pp.303-312
    • /
    • 2019
  • The purpose of this study was to describe the semantic system and process of posttraumatic growth experience of firefighters after colleague's suicide. Grounded theory methodology based on symbolic interactionism was utilized. The subjects of this study were 7 firefighters who experienced the colleague's suicide. Data were collected by using in-depth interviews from October 1 to November 30, 2015. The results showed that "Gradually becoming more resilient" was analyzed to be the core category of firefighters' posttraumatic growth. We derived four categories and nine subcategories. Based on the results, it is necessary to develop a convergence intervention program to promote posttraumatic growth of firefighters exposed to various traumatic events.