• 제목/요약/키워드: rating life

검색결과 542건 처리시간 0.024초

작동하중과 회전속도를 고려한 자동차용 휠 베어링의 수명평가 (Bearing Life Evaluation of Automotive Wheel Bearing Considering Operation Loading and Rotation Speed)

  • 이승표
    • 대한기계학회논문집A
    • /
    • 제40권6호
    • /
    • pp.595-602
    • /
    • 2016
  • 자동차용 휠 베어링은 회전운동을 전달하고 차량의 무게를 지지해주는 중요한 부품이다. 최근 $CO_2$ 배출가스 저감과 연비 규제에 따라서 자동차 경량화 및 소형화 요구는 점점 증가하고 있고, 이에 부응하여 베어링의 수명 평가기술은 더욱 그 필요성이 증가하고 있다. 휠 베어링의 내구수명은 고려해야 할 인자들이 매우 다양하며 이들이 서로 복잡하게 연관되어 있으므로 수명을 예측하는 것이 쉽지 않다. 본 논문에서는 자동차용 휠 베어링의 수명에 영향을 끼치는 많은 인자들 중에서 작동하중과 회전속도를 변화시키면서 수명을 시험하였고, 이를 ISO 국제표준에서 제안하는 이론수명인 기본정격수명과 보정정격수명 결과와 비교하였다. 이들 수명을 비교한 결과, 기본정격수명과 보정정격수명 모두 시험수명과 차이가 존재하며, 기본정격수명 보다 보정정격수명이 시험수명을 상대적으로 잘 예측함을 알 수 있었다.

치매노인 가족의 치매특별등급서비스 이용 경험 (Experience of a Special Rating Dementia Service for Family Caregivers of Elderly People with Dementia)

  • 조희경;장수정
    • 지역사회간호학회지
    • /
    • 제29권2호
    • /
    • pp.231-243
    • /
    • 2018
  • Purpose: This study tries to explore experiences with a special rating dementia service among family caregivers of elderly people with dementia. Methods: The participants were 11 family caregivers of elderly people with dementia and had used a day-care service from the special rating dementia service for more than 3 months. Data were collected through individual in-depth interviews and analyzed using content analysis. Results: Three categories emerged: "reminiscence of an entangled life", "feeling relieved from a stifled life", and "hope for a better life through help and support" with 8 sub-categories and 23 codes. By using the special rating dementia service, the participants experienced relief from the burden of caring for their elderly family member with dementia and restored their social relations or family relationships. They experienced a positive transition in which their caring for elderly family members with dementia was integrated into their daily lives, and they expressed their desires for better policies. Conclusion: These findings imply the importance and necessity of the special rating dementia service. Practical and systematic family support programs are necessary and proactive publicity activities by the government and public agencies are suggested to ensure that family caregivers can easily use the special rating dementia system.

베어링강의 개발동향 (The Current Status of the Development of Bearing Steels)

  • 유선준
    • 소성∙가공
    • /
    • 제12권2호
    • /
    • pp.88-93
    • /
    • 2003
  • Several alloy bearing steels have been starting to replace for conventional high carbon and high chromium bearing steel since 1980. In this paper the global bearing developing trends were summarized in several important aspects- developments in alloy bearing steels for improved service life, development of inclusion rating method in bearing steel and developments in bearing service life testing.

안면홍조 증상으로 치료 중인 갱년기 여성에서 안면홍조 점수와 Kupperman's Index, MENQOL, MRS과의 상관성 연구 (A Study on Relations between Hot flush and the Kupperman's Index, MENQOL, MRS during Treatment for Hot Flush in Menopausal Women)

  • 윤문희;유성진;김형준
    • 대한한방부인과학회지
    • /
    • 제24권1호
    • /
    • pp.87-98
    • /
    • 2011
  • Objectives: To evaluate the clinical use of Kupperman's Index, Menopausespecific quality of life questionnaire(MENQOL), Menopause Rating Scale(MRS) by comparison with the Subjective measures of hot flush. Methods: The participants were 107 women (45-60 yr) who were not currently on hormone therapy, and had reached hot flash scores of 10 or higher. The evaluating indexes of this trial are hot flush score, hot flush VAS, Hot flush consistence time, sweating VAS, Kupperman`s Index, Menopause-specific quality of life questionnaire (MENQOL), Menopause Rating Scale(MRS). Results: 1. The hot flush score, hot flush VAS, sweating VAS were significantly correlated with each other, but the Hot flush consistence time with no special relationship was found on Subjective measures of hot flush 2. The Kupperman's Index, Menopause-specific quality of life questionnaire (MENQOL) and Menopause Rating Scale(MRS) were significantly correlated with each other. 3. There was significant correlation between Subjective measures of hot flush and Menopause-specific quality of life questionnaire(MENQOL), Thus Menopausespecific quality of life questionnaire(MENQOL) is considered the most suitable on hot flush related research. Conclusions: There was significant correlation between Subjective measures of hot flush and Menopausal scale, thus the use of various indicators are needed for the assessment of climacteric symptoms.

경량 베어링 수명 특성에 관한 연구 (A Study on the Life Characteristics of Lightweight Bearings)

  • 이충성;박종원;임신열;강보식
    • 한국산업융합학회 논문집
    • /
    • 제24권6_2호
    • /
    • pp.819-825
    • /
    • 2021
  • In the industry, the use of lightweight bearings is increasing to minimize motor power loss, and in particular, the application of next-generation systems such as robots and drones is increasing. Bearing manufacturers are producing lightweight bearings by changing the bearing material, but related researches is insufficient. In this paper, life test and structural analysis were performed for lightweight bearings, and shape parameters and scale parameters were derived based on the life test results. It was confirmed that the shape parameter was 2.52 and the scale parameter was 164 hours. As a result of calculating the dynamic load rating based on the B10 life, it was confirmed that the dynamic load rating of the lightweight bearing was 7% compared to the formula suggested by ISO 281. The reason is that the material of the retainer, which is a major failure part, is a polyamide 66 series that reacts sensitively to heat, so It is judged to show a lot of difference from the ISO 281 calculation formula.

공동주택 수리용이성 주택 성능등급 인정 실태연구(II) - 공용공간을 중심으로 - (A Study on the Assessment and Performance Indicator criteria for Repair Convenience of Apartment Building (II) - Public sector -)

  • 임석호;지장훈;김수암
    • 한국주거학회논문집
    • /
    • 제20권6호
    • /
    • pp.57-65
    • /
    • 2009
  • In Korea, Housing Performance Rating Indication System was first adopted in 2006. Main purpose of the System is on developing criteria which can systematically measure the level of housing performance. Among the five categories of Housing Performance Rating Indication System, Repair Convenience is closely related to Remodeling which has been widely recognized as an alternative to the building reconstruction. Especially, as the actual housing supply level in Korea is reaching almost 100%, it is crucial to expand Long-life Housing through the effective maintenance and management. In addition, consumers should have an access to the performance ratings of apartment buildings on which they can rely on in choosing their own housings. And for construction companies, a performance code enacted by government will provide them with a standard that they can utilize in determining performance level of buildings that they build. This study examines data which has been obtained from the recent application of Housing Performance Rating Indication System and Repair Convenience category is main concern. Findings from the study will provide vital information in improving current Housing Performance Rating Indication System.

공동주택 수리용이성 주택 성능등급 인정 실태연구(I) - 전용공간을 중심으로 - (A Study on the Assessment and Performance Indicator Criteria for Repair Convenience of Apartment Building (I) - Private sector -)

  • 임석호;지장훈;김수암
    • 한국주거학회논문집
    • /
    • 제20권6호
    • /
    • pp.47-56
    • /
    • 2009
  • Housing Performance Rating Indication System was started in 2006. The aim of Housing Performance Rating Indication is to provide the guideline of housing performance. Repair Convenience is similar to Remodeling. Remodeling has been paid more attention as an alternative for reconstruction. Especially, now the actual house supply is facing almost 100%, it is time to keep and maintenance management of apartment buildings, and ultimately it will expand the Long life housing. Especially consumers has to have a right to select apartment buildings by comparing performance of house. For construction companies, they need a performance code that standardized by government, so they can provide a Certain performing house. This study examines data which has been obtained from the recent application of Housing Performance Rating Indication System and Repair Convenience category is main concern. Findings from the study will provide vital information in improving current Housing Performance Rating Indication System.

각 어긋남을 고려한 각접촉 볼베어링의 피로수명 해석 (Fatigue Life Analysis for Angular Contact Ball Bearing with Angular Misalignment)

  • 배규현;통반칸;홍성욱
    • 한국정밀공학회지
    • /
    • 제33권1호
    • /
    • pp.53-61
    • /
    • 2016
  • Angular misalignment has a significant effect on the characteristics of angular contact ball bearings (ACBBs). This paper presents an analysis of fatigue life for ACBBs subjected to angular misalignment. A simulation model is developed with de Mul's bearing model and the ISO basic reference rating life model. Simulation is performed to calculate the life of the ACBBs subjected to angular misalignment. The numerical results show that angular misalignment influences the load distribution significantly, thus reducing the bearing rating life. The fatigue life of ACBBs is decreased by angular misalignment regardless of axial preload, external radial load and rotational speed. The results show that angular misalignment should be maintained at less than 1mrad for ACBBs.

항우울제와 우울증 환자의 삶의 질 - 삼환계 항우울제와 Sertraline을 중심으로 - (Antidepressant and the Quality of Life of Depressive Patient)

  • 함병주;이민수
    • 생물정신의학
    • /
    • 제4권1호
    • /
    • pp.116-120
    • /
    • 1997
  • This study investigated the antidepressant efficacy and it's impact on the quality of life of depressed patients. We performed Hamilton Depression Rating Scale(HDRS), and Montgomery-Asberg Depression Rating Scale(MADRS), and Health-related Quality of Life Questionnaire(HQLQ) to both tricyclic antidepressant(TCA) and sertraline groups. There were 16 subjects in this study. The tricyclic group had 9 subjects and the sertraline group had 7. The TCA and sertraline produced a similar degree of response. Both groups experienced a reduction of 70% or more in mean HDRS and MADRS total score after 6wks. In HQLQ, the TCAs group also showed improved bed disability days, alertness behavior, and social interaction, the sertraline group showed improved health perception, alertness behavior, home management, and social interaction. We suggested that the improvement of "Quality of life" were not in proportion to the clinical symptom's improvement. Therefore, clinicians should consider the benefit of antidepressant treatment in terms of quality of life.

  • PDF

유지관리보수가 된 교량의 내하력평가 및 잔존수명 예측 (Rating and Lifetime Prediction of a Bridge with Maintenance)

  • Seung-Ie Yang;Han-Jung Kim
    • 한국안전학회지
    • /
    • 제18권1호
    • /
    • pp.108-115
    • /
    • 2003
  • 교량은 강도설계법이나 허용응력 설계 법에 의해, 두 가지 단계에서 평가된다. 낮은 단계를 Inventory 높은 단계를 Operating이라 부른다. 교량을 효과적으로 유지관리 보수하기 위하여, 교량의 실제하중수용 능력을 평가하고 시스템 신뢰성으로부터 교량의 잔여 수명을 예측하는 것은 매우 시급하다. 생애함수가 시간 의존적 파괴확률을 예측하기 위하여 소개되고 설명된다. 이 논문에서 연구되는 교량은30년 전 농촌지역에 시공되었다. 이 교량에 대하여 하중시험과 보강이 이루어졌다. 시간 의존적 파괴확률이 보수보강 된 경우와 그렇지 않은 경우 대하여 예측되었다. 또 다른 연구로서 새로운 보수보강이 제시되고 이 보수보강에 대하여 내하력이 평가되었고 시간 의존적 파괴확률이 예측되었다. 유지관리 가격과 확장된 교량의 생애를 기본으로, 최적의 보수보강 기법이 제시되었다.