• 제목/요약/키워드: Impact Response Behaviors

검색결과 73건 처리시간 0.032초

다양한 차량주행에 의한 박스형 장대교량의 동적 응답에 관한 실험적 연구 (Experimental Study on the Dynamic Response of Box Girder Long-Span Bridges under Various Travelling Vehicles)

  • 이래철;이상열;임성순
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제8권1호
    • /
    • pp.129-138
    • /
    • 2004
  • 본 연구는 현장 계측 실험에 의하여 주행 차량하중을 받는 2경간 P.S.C. 박스형 교량의 동적 해석을 수행하였다. 본 연구에서 적용한 이동하중은 차량 속도의 증가에 대해 주행하중, 급제동하중, 연행하중, 역주행하중, 역 주행 충격하중 등으로 분류하여 실험을 행하였다. 각 주행 하중에 대해 박스 거더 단면에서의 계측위치를 달리하여 동적 거동의 변화 및 특성을 살펴보았으며, 절점당 6개의 자유도를 갖는 4절점 쉘요소를 이용한 유한요소 해석 프로그램을 개발하고 수치해석을 하여 실험결과와 비교 분석하였다. 박스 거더의 동적 거동은 주행하중에 의한 응답보다 급제동이나 역주행 충격하중에 의한 응답이 더 크게 나왔으며 수치해석 결과는 기존의 1차원 보요소를 사용하여 해석한 결과보다 실험값에 근접함을 보였다.

Complementary health education and clinical guidance for treating women experiencing infertility along with unexplained resistant hyperprolactinemia

  • Atef M.M. Darwish;Dina A.M. Darwish
    • Journal of Medicine and Life Science
    • /
    • 제20권4호
    • /
    • pp.158-165
    • /
    • 2023
  • This study prospective randomized controlled trial aims to test the impact of adding health education, awareness of some contributing factors and clinical guidance to therapeutic cabergoline given to infertile women with unexplained resistant hyperprolactinemia. It comprised 120 infertile women with unexplained persistent hyperprolactinemia not responding to therapeutic doses of cabergoline 1.5-2 mg/week who were subjected to proper history taking to exclude concomitant drug intake or possible brain problems in all cases. They were classified into group A (60 cases) who received health education and clinical guidance to search for possible contributing factors and were instructed to avoid them in addition to proper therapeutic doses of cabergoline, while group B (60 cases) received proper therapeutic doses of cabergoline only without clinical guidance. After 1 month, serum prolactin (PRL) was measured for all cases. All cases had high PRL level at the start of the study (79.9±28.4 [39-195] and 78.2±19.9 [42-189] in group A and B, respectively) without any significant difference. Pretreatment counselling revealed that lifestyle factors, sexual behaviors or feeding habits may contribute to resistant hyperprolactinemia in all cases without a significant difference between both groups. Serum PRL dropped significantly more in group A (20.14±10.31 [11-45] vs. 49.32±37.03 [12-100]) after combined health education, clinical guidance of the couple and proper treatment. It is concluded that lifestyle factors, sexual behaviors, and feeding habits would affect the response of hyperprolactinemia to treatment. Health education and clinical guidance with some advice to avoid them, would concomitantly improve the response of resistant hyperprolactinemia to therapeutic doses of dopamine agonists.

이차원(二次元) 파전파(波傳波) 이론(理論)에 의한 충돌현상(衝突現狀) 해석(解析) (Two-Dimensional Wave Propagation Analysis of Impact Phenomena)

  • 이상호;안병기
    • 대한토목학회논문집
    • /
    • 제14권2호
    • /
    • pp.245-255
    • /
    • 1994
  • 충돌현상을 재현할 수 있는 이차원 파전파 컴퓨터 프로그램을 개발하였다. 불연속인 충격전면에 연속성을 부여하기 위한 기법으로 Von Neumann과 Ritchmyer가 제안한 인공점성을 수치해석시 도입하였다. 본 연구에서는 충돌물체의 재료모델로서 Von-Mises 항복함수를 이용한 탄소성 모델을 사용하였다. 개발된 컴퓨터 프로그램을 검증하기 위하여 충격을 가하는 물체와 받는 물체로 구성된 충돌현상을 재현하였다. 본 연구에서 개발된 컴퓨터 프로그램은 이차원 평면요소를 사용하였기 때문에 재현된 충돌해석 결과를 3차원에서 발생하는 실제값과 정량적으로 비교할 수는 없었으나 충돌실험시 실제로 발생하는 파괴현상을 정성적으로 분석할 수 있었다.

  • PDF

우리나라 병원의 경영전략 실태 (Management Strategy of Hospitals in Korea)

  • 문옥륜;이기효
    • 한국병원경영학회지
    • /
    • 제1권1호
    • /
    • pp.108-135
    • /
    • 1996
  • This paper investigates the current feature of management strategy of hospitals in Korea, and examines the relationships between adoption of a particular strategic orientation and the hospitals environmental and organizational characteristics, strategic behaviors and management improvement activities, and financial performance. Data were collected from CEOs of 88 hospitals among 650 hospitals for a 13.5% response rate using the self-administered questionnaire by mail survey. The major findings that obtained are as follows: 1. Only 37.2% of response hospitals carried out strategic planning, Most of these hospitals established the first strategic planning in 1991(81.3%) and renovated strategic planning by 4 or 5 years(56.3%), and modified strategic planning with flexibility(59.4%). Most strategic plans were documented, but informalized(68.8%). And only 29.0% of these hospitals had independent planning division. 2. Hospital services that CEOs assessed rank ordered for their impact on profitability are as follows: i)diagnostic ultrasound facility, computerized tomography scanner, obstetric inpatient unit, therapeutic X-ray, and physical therapy at present. ii)diagnostic ultrasound facility, physical therapy, computerized tomography scanner, emergency department, and health screening at future. And the services rank ordered that CEOs hoped to introduce are as follows: emergency department, physical therapy, health screening, volunteer services, and computerized tomography scanner. 3. Using a typology developed by Miles and Snow(l978), the strategic orientation of response hospitals are shifting significantly from defenders in the past to analyzers in the present, and to prospectors in the future(p<.01). 4. With regard to hospital environmental and organizational characteristics such as ownership, physician training, location, bed size, and hospital management training career and specialty of CEOs, the four strategic orientation archetypes varied not significantly. But, hospitals with a analyser orientation in the present and a reactor orientation in the future perceived competition significantly higher than the other three archetypes(p<.05). 5. The four archetypes rank ordered in terms of appling strategic behaviors and management improvement activities are as follows: prospector, analyzer, reactor, and defender. 6. The four archetypes differed significantly in terms of their financial performance using revenue per bed(p<.05). Reactors and prospectors in terms of total revenue per bed, prospectors in terms of outpatient revenue per bed, and reactors and prospectors in terms of inpatient revenue per bed had the best performance.

  • PDF

승용차 충돌시 승객해석을 위한 모델링의 예 (A modeling example of occupant analysis for crashworthiness in a passenger car)

  • 신문균;박경진;김형중;정근섭
    • 오토저널
    • /
    • 제14권2호
    • /
    • pp.88-98
    • /
    • 1992
  • Real automobiles have been utilized to study the occupant behaviors and the response of the structures in the crash environment. Since various parameters are involved in the automobile crashworthiness, a number of experiments must be conducted. The experiments have been contributed to increasing the cost due to the fact that the test is quite expensive. Therefore, computer simulation is adopted to reduce the number of experiments. A few computer programs have been developed specifically to solve the occupant responses in the crash environment. In this research, a software is used to study the occupant dynamic analysis. A modeling of occupant analysis is established for a passenger car and the results are verified through comparisons with real experiments. In the modeling, data are tuned very carefully so that simulated results such as HIC(Head Injury Criterion) and acceleration of each body may approximate to the experimental results. The compared experiment is a barrier test which is carried out by frontal impact. A feedback to the design process is suggested from the result of this research.

  • PDF

고변형률 속도 압축 하중 하에서의 고무와 황동의 동적 거동 특성 (Dynamic deformation behavior of rubber and brass under high strain rate compressive loading)

  • 이억섭;김경준;이종원
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2003년도 춘계학술대회 논문집
    • /
    • pp.1491-1494
    • /
    • 2003
  • A specific experimental method, the Split Hopkinson Pressure Bar (SHPB) technique has been widely used to determine the dynamic material properties under the impact compressive loading conditions with strain-rate of the order of 103/s∼104/s. This type of test procedure has been used to examine the dynamic response of materials in various modes of testing. In this paper, dynamic deformation behaviors of rubber materials widely used for the isolation of vibration from varying structures under dynamic loading are determined using a Split Hopkinson Pressure Bar technique.

  • PDF

P-$\Delta$ 효과를 고려한 철골 구조물의 비선형 동적거동 평가 (Evaluation of Nonlinear Dynamic Behavior for Steel Moment Frame Structures Considering P-$\Delta$ Effects)

  • 최원호;이주완;이동근
    • 한국지진공학회:학술대회논문집
    • /
    • 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
    • /
    • pp.235-242
    • /
    • 2001
  • Inelastic seismic response of steel moment frame structures, which are usually quite gravity load and subject to large displacement under severe earthquake, may be severly influenced by the structure P-Δ effects. The P-Δ effect may have an important impact on the dynamic behavior of the structure in the nonlinear seismic analysis. In multi degree of freedom systems P-Δ effects may significantly affect only a subset of stories or a single story alone. Therefore, a story drift amplification of structure is happened by P-Δeffects and such nonlinear dynamic behaviors are very difficult to evaluate in the structures. In this study, two systems having different design methods of steel moment frame structures are investigated to evaluate the P-Δ effects due to gravity load. The plastic hinge formations, maximum rotational ductility demands, and energy distribution will be compared and evaluated following whether the P-Δ effects are considered or not. And design methods are proposed for the prevention of the instability of structures which due to the P-Δ effects.

  • PDF

의복 착용 동기에 따른 의복 효용 감소에 대한 방응 (Response to Clothing Utility-Reduction according to Clothing-Wearing Motives)

  • 정인희;박상진;권영일
    • 한국의류학회지
    • /
    • 제25권7호
    • /
    • pp.1332-1340
    • /
    • 2001
  • This study was designed (1) to examine the results of previous qualitative research on clothing-wearing motives by quantitative approach, (2) to explore the concept of clothing utility, utility-reduction and discard, and (3) to investigate the impact of clothing-wearing motives on consumer attitudes and consuming-behaviors. Date were collected by questionnaire from 443 collegiate students between August and September of 2000, and 396 questionnaires were analyzed. 3 groups were identified on the basis of clothing-wearing motives and named by extroversion group, introversion group, and least clothing-congnizing group respectively. This supported the qualitative results in part, especially in the direction of motives. Clothing utility-reduction factors were identified as appearance demage, social-psychological damage, and abandonment-causing damage. The 3 groups were responded on utility-reduction differently, thus clothing-wearing motive variable was determined as useful in fashion marketing.

  • PDF

SHPB 기법을 사용한 고변형률 속도 하중하에서의 합성수지의 동적 변형 거동 (Dynamic deformation behavior of Ethylene Copolymer under high strain rate compressive loading)

  • 이종원;이억섭;황시원;김성현
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2004년도 춘계학술대회
    • /
    • pp.371-376
    • /
    • 2004
  • It is well known that a specific experimental method such as the Split Hopkinson Pressure Bar (SHPB) technique is the simplest experimental technique to determine the dynamic material properties under the impact compressive loading conditions with strain-rate of the order of $10^3/s{\sim}10^4/s$. This type of experimental procedure has been widely used with proper modification on the test setups to determine the varying dynamic response of materials for the dynamic boundary conditions such as tensile and fracture as well. In this paper, dynamic compressive deformation behaviors of an Ethylene Copolymer materials widely used for the isolation of vibration from varying structures under dynamic loading are estimated using the SHPB technique.

  • PDF

SHPB기법을 사용한 고무와 합성수지의 고변형률 속도 하중 하에서의 동적 변형 거동 (Dynamic Deformation Behavior of Rubber and Ethylene Copolymer Under High Strain Rate Compressive Loading)

  • 이억섭;이종원;김경준
    • 한국정밀공학회지
    • /
    • 제21권6호
    • /
    • pp.122-130
    • /
    • 2004
  • It is well known that a specific experimental method, the Split Hopkinson Pressure Bar (SHPB) technique is a best experimental technique to determine the dynamic material properties under the impact compressive loading conditions with strain-rate of the order of 10$^3$/s∼10$^4$/s. This type of experimental procedure has been widely used with proper modification on the test setups to determine the varying dynamic response of materials for the dynamic boundary conditions such as tensile and fracture as well. In this paper, dynamic compressive deformation behaviors of a rubber and an Ethylene Copolymer materials widely used for the isolation of vibration from varying structures under dynamic loading are estimated using a Split Hopkinson Pressure Bar technique.