• 제목/요약/키워드: repeated

검색결과 8,633건 처리시간 0.036초

반복하중 하에서 부착응력-슬립 거동 실험적 연구 (Experimental Study of Bond Stress-Slip Behavior under Repeated Loading)

  • 오병환;김세훈;김지상;신용석
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2003년도 가을 학술발표회 논문집
    • /
    • pp.215-218
    • /
    • 2003
  • To analyze a bond stress-slip behavior between a reinforcing bar and concrete under repeated loading, pull-out fatigue test was performed. Major variables were repeated stress levels and cycle numbers. Test specimen was taken repeated constant amplitude loading before it was fractured by pull-out test. Increments of bond strength and slip according to repeated stress level and cycle numbers were analyzed. On the basis of test results, Local bond stress-slip relationship under repeated loading were formulated

  • PDF

반목하중으로 인한 지반의 변형 예측 (Approximate Prediction of Soil Deformation Caused by Repeated Loading)

  • 도덕현
    • 한국농공학회지
    • /
    • 제30권3호
    • /
    • pp.69-81
    • /
    • 1988
  • The Repeated Load Triaxial and Oedometer Tests to the weathered granite & silty clay soil have been fulfilled to investigate their dynarnic characteristics. The results obtained are summarized as follows ; 1. In the relation between the repeated triaxial compression and the oedometer test, the recoverable strain of weathered granite soil showed a tendency to decrease by the increase of the repeated loads number(N), and that of silty clay showed approximately constant values while the total strain increased continuously. 2. The changes of plastic strain was dependent to the level of deviator stress which is the most important element in the calculation of soil deformation under repeated load condition. And there was a significance of 10% between the level of stress and plastic strain. 3. When the soil was aimost dried or saturated to 100%, the deformation by the repeated loads was small. However the deformation showed peak around the saturation of 50%. 4. When the deformation was predicted by the repeated triaxial load tests of a laboratory, it is desirable to introduce the threshold stress concept in the calculation of deformation of subgrade of the pavement. 5. The improved design equation (Eq. 16) introducing the modulus of conversion(Fo), which is based on the Boussineq' s theory, is considered to be rational in the design of flexible pavement. From the above results, the deformation to the repeated traffic loads could be predicted by the repeated triaxial tests on the pavement materials or undisturbed soil layers, therefore it is think that the durable and econornic pavement could be constructed by reflecting that to the design.

  • PDF

보호관찰 청소년의 사회 심리적 특성 -초범과 재범군의 비교- (Psycho-Social Comparison among First Time Offenders and Repeated Offenders on Probation)

  • 이희정;이성칠
    • 아동학회지
    • /
    • 제26권5호
    • /
    • pp.367-377
    • /
    • 2005
  • Semi-structured in-depth interview method were used to test psycho-social comparison among first time offenders and repeated offenders. Data were analyzed by t-test and chi-square. Differences between first time offenders and repeated offenders were that there were more male offenders than female offenders, and violent and theft offenders were more than sex offenders fraud and traffic offenders; early starters were more repeated offenders than late starters; there were some variables such as runway of home, parents' caring attitude, school drop out and maladjustment affecting in repeated offenses; developmental environment of repeated offenders were more negative than first time offenders. Therefore, intervention and prevention program development of good parenting and schooling and forensic counseling focused on optimal developmental environment is needed.

  • PDF

개방형 반복구조물의 진동국부화 (Vibration Localization of Open Loop Repeated Structures)

  • 하동진;유홍희
    • 한국소음진동공학회논문집
    • /
    • 제13권12호
    • /
    • pp.911-917
    • /
    • 2003
  • Vibration localization characteristics of open loop repeated mistuned structures are investigated. The mistuning often creates significant response discrepancies among subcomponents of the repeated structures. As a result of the discrepancies, critical fatigue problems often occur in repeated structures. Therefore. it is of great importance to predict the vibration response of the mistuned repeated structures accurately in this Paper, a simplified model for an open-loop repeated structure is introduced and dimensionless parameters that influence the localization characteristics are identified. The effects of the parameters on the localization characteristics are investigated through numerical study.

Exploring Impact of Positive/Negative Valence Order on Repeated Exposure to Suspenseful Stories

  • Chang Ui Chun
    • International Journal of Advanced Culture Technology
    • /
    • 제11권3호
    • /
    • pp.182-189
    • /
    • 2023
  • This study investigates the psychological effects of positive/negative valence order in repeated exposure to a suspenseful text. Specifically, the study seeks to understand how the order in which positive and negative elements are presented in a narrative impacts the experience of suspense, arousal, and enjoyment in readers or listeners. Using a suspenseful short story, participants were exposed to narratives with varying valence orders in a repeated-measures design. The study employed self-report questionnaires and psychophysiological measurements to capture participants' psychological responses. The results supported the hypothesis that repeated exposure impacts suspense, with negative valence enhancing suspense and arousal. Moreover, the order of valence influenced participants' psychological responses, indicating that positive valence can mitigate the impact of repeated exposure. However, the influence on enjoyment was not significant. Psychophysiological measures, specifically skin conductance level (SCL), revealed trends of habituation over repeated exposure. The findings underscore the significance of negative valence in heightening suspense and suggest directions for future research in exploring diverse factors that contribute to suspense in both fictional and real-life contexts.

치의학 연구에서 반복 계측한 자료의 일치도 평가방법 (Statistical methods for accessing agreement between repeated measurements in dental research)

  • 김기열
    • 대한치과의사협회지
    • /
    • 제54권11호
    • /
    • pp.880-896
    • /
    • 2016
  • The comparison of the repeated measurements is often needed to see whether they agree sufficiently, when a measurement is repeated under identical conditions by different raters. Such investigations are often analyzed inappropriately, by using correlation coefficient. The purpose of this study is to introduce statistical methods for accessing the agreement of the repeated measurements, which include Bland-Altman plot, intra class correlation, Passing-Bablok regression and Cohen's kappa coefficient, and to show how to execute them using examples.

  • PDF

개방형 반복구조물의 진동국부화 (Vibration Localization of Open Loop Repeated Structures)

  • 하동진;유홍희
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2003년도 춘계학술대회논문집
    • /
    • pp.489-494
    • /
    • 2003
  • Vibration localization characteristics of open loop repeated structures with mistuning are investigated in this paper. Mistuning of a periodic structure often creates significant non-uniformity in vibration responses. As a result of the localization, critical fatigue problems often occur in repeated structures. Therefore, it is of great importance to predict the vibration response of the mistuned repeated structures accurately. In this paper, a simplified model for the open-loop repeated structure is introduced and dimensionless parameters which influence the localization characteristics are identified. The effects of the parameters on the localization characteristics are investigated through numerical study.

  • PDF

반복적인 Valsalva Maneuver가 정상인의 순환에 미치는 영향에 관한 연구 (An Effects of Repeated Valsalva Maneuver on Circulation of Normal Men)

  • 최명애;김종임
    • 대한간호학회지
    • /
    • 제16권1호
    • /
    • pp.49-54
    • /
    • 1986
  • As patients on bed rest perform repeated Valsalva maneuver, it is necessary for them to prevent the-danger inherent in repeated Valsalva maneuver through intelligent rehabilitative nursing care. In this regard, it seems to be important to furnish a scientific rationale underlying rehabilitative nursing care. This study was undertaken to find the effects of repeated Valsalva maneuver upon circulation of nor-mal men. The subjects for this study were twenty normal and healthy college students of age from 19 to 26. For the first time, the ECG of standard 12 leads was recorded and the blood pressure was measured under the resting state. And the subjects performed Valsalva maneuver for 10 seconds, then expired air for 2 seconds. After the subjects carried out in this menner for 1 minute, the ECG and the blood pres-sure were recorded and measured again. The Changes of heartbeats, systolic and diastolic pressures after the practice of repeated Valsalva maneuver were compared with those of the letting state. The results obtained were as follows : 1. The heartbeats after the practice of repeated Valsalva maneuver generally increased but did not show statistical significance. 2. The systolic pressure measured after the practice of repeated Valsalva maneuver was higher than that of the resting state. 3. The diastolic pressure measured after the practice of repeated Valsalva maneuver was higher than that of the resting state.

  • PDF

반복하중을 받는 철근콘크리트 부재의 부착응력-슬립 모델 (Bond Stress-Slip Model of Reinforced Concrete Member under Repeated Loading)

  • 오병환;김세훈;김지상
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
    • /
    • pp.104-107
    • /
    • 2004
  • The crack widths of reinforced concrete flexural members are influenced by repetitive fatigue loadings. The bond stress-slip relation is necessary to estimate these crack widths realistically. The purpose of the present study is, therefore, to propose a realistic model for bond stress-slip relation under repeated loading. To this end, several series of tests were conducted to explore the bond-slip behavior under repeated loadings. Three different bond stress levels with various number of load cycles were considered in the tests. The present tests indicate that the bond strength and the slip at peak bond stress are not influenced much by repeated loading if bond failure does not occur. However, the values of loaded slip and residual slip increase with the increase of load cycles. The bond stress after repeated loading approaches the ultimate bond stress under monotonic loading and the increase of bond stress after repeated loading becomes sharper as the number of repeated loads increases. The bond stress-slip relation after repeated loading was derived as a function of residual slip, bond stress level, and the number of load cycles. The models for slip and residual slip were also derived from the present test data. The number of cycles to bond slip failure was derived on the basis of safe fatigue criterion, i.e. maximum slip criterion at ultimate bond stress.

  • PDF

국내 반복입원의 현황과 환자 특성: 외래진료 민감질환을 중심으로 (Current Status of Repeated Hospitalization in South Korea: Focused on Ambulatory Care Sensitive Conditions)

  • 정혜민;김현주;이진용
    • 한국의료질향상학회지
    • /
    • 제27권2호
    • /
    • pp.45-56
    • /
    • 2021
  • Purpose: Repeated hospitalization could be a proxy of unnecessary or preventive admission in South Korea where barriers to hospitalization are relatively low. This study aimed to estimate the current status of repeated hospitalization due to ambulatory care sensitive conditions (ACSC) in South Korea. Methods: Using the National Health Information Database, repeated hospitalization databases were constructed in units of episodes for patients who had been admitted more than twice between January 2017 and December 2018. The number of hospitalizations, total in-hospital days, and total medical expenditure were calculated and compared by patient characteristics in both of the entire patient group and the ACSC patient group. Results: Of total hospitalization episodes, 26.6% reported repeated admission, and 6.7% of repeated hospitalization was due to ACSC. A total of 183,110 patients with ACSC had been admitted an average of 2.9 times and spent an average of KRW5,630,118. In other words, KRW1,309 billion had been spent for repeated hospitalization due to ACSC. The scale of medical expenditure was relatively large in the highest and lowest socioeconomic status. Conclusion: Repeated hospitalization for ACSC can be considered a simple and intuitive indicator when assessing unnecessary hospitalizations or evaluating healthcare policy.