• 제목/요약/키워드: Physical model test

검색결과 928건 처리시간 0.023초

수리모형실험과 FLOW-3D를 이용한 배수갑문 통수능력 검토 (Estimation of Gate Discharge Capacity by Physical Model Test and FLOW-3D)

  • 박병준;이상화
    • 한국해안·해양공학회논문집
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    • 제20권2호
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    • pp.168-175
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    • 2008
  • 군장 국가산업단지(장항지구) 조성공사 후 단지를 가로지르는 솔리천 하구에 새로 건설될 배수갑문 설계안에 대해 축척모형을 제작하고 현장과 동일한 수리조건을 적용한 수리모형실험을 수행하여 통수능력을 검토함과 동시에 결과의 신뢰도 확보를 위해 상용 3차원 전산유체역학 코드인 FLOW-3D를 이용하여 수치모의를 실시하였다. 수리모형실험과 수치모의에서는 얻어진 통수능은 유사한 결과를 보여주었다.

Polynomial model controlling the physical properties of a gypsum-sand mixture (GSM)

  • Seunghwan Seo;Moonkyung Chung
    • Geomechanics and Engineering
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    • 제35권4호
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    • pp.425-436
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    • 2023
  • An effective tool for researching actual problems in geotechnical and mining engineering is to conduct physical modeling tests using similar materials. A reliable geometric scaled model test requires selecting similar materials and conducting tests to determine physical properties such as the mixing ratio of the mixed materials. In this paper, a method is proposed to determine similar materials that can reproduce target properties using a polynomial model based on experimental results on modeling materials using a gypsum-sand mixture (GSM) to simulate rocks. To that end, a database is prepared using the unconfined compressive strength, elastic modulus, and density of 459 GSM samples as output parameters and the weight ratio of the mixing materials as input parameters. Further, a model that can predict the physical properties of the GSM using this database and a polynomial approach is proposed. The performance of the developed method is evaluated by comparing the predicted and observed values; the results demonstrate that the proposed polynomial model can predict the physical properties of the GSM with high accuracy. Sensitivity analysis results indicated that the gypsum-water ratio significantly affects the prediction of the physical properties of the GSM. The proposed polynomial model is used as a powerful tool to simplify the process of determining similar materials for rocks and conduct highly reliable experiments in a physical modeling test.

Spud-can penetration depending on soil properties: Comparison between numerical simulation and physical model test

  • Han, Dong-Seop;Kim, Moo-Hyun
    • Ocean Systems Engineering
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    • 제7권2호
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    • pp.107-120
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    • 2017
  • Spud-can is used for fixing jack-up rig on seabed. It needs to be inserted up to the required depth during the installation process to secure enough soil reaction and prevent overturning accidents. On the other hand, it should be extracted from seabed soils as fast as possible during the extraction process to minimize the corresponding operational cost. To achieve such goals, spud-can may be equipped with water-jetting system including monitoring and control. To develop such a smart spud-can, a reliable numerical simulation tool is essential and it has also to be validated against physical model tests. In this regard, authors developed a numerical simulation tool by using a commercial program ANSYS with extended Drucker-Prager (EDP) formula. Authors also conducted small-scale (1/100) physical model tests for verification and calibration purpose. By using the numerical model, a systematic parametric study is conducted both for sand and K(kaolin)-clay with varying important soil parameters and the best estimated soil properties of the physical test are deduced. Then, by using the selected soil properties, the numerical and experimental results for a sand/K-clay multi-layer case are cross-checked to show reasonably good agreement. The validated numerical model will be useful in the next-stage study which includes controllable water-jetting.

Physical model test of Jintan underground gas storage cavern group

  • Chen, Yulong;Wei, Jiong
    • Geomechanics and Engineering
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    • 제30권1호
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    • pp.45-49
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    • 2022
  • In the present study, a physical model was built for the Jintan underground gas storage cavern group according to the similarity theory. In this regard, four ellipsoid caverns were built with scaled in-situ stresses and internal pressure. Then the stability of underground caverns was analyzed. The obtained results demonstrate that loss of internal pressure adversely affects the safety of caverns and attention should be paid during the operation of gas storage.

계측기(計測器)를 이용한 O-Ring Test법(法)의 검증(檢證)에 관(關)한 연구(硏究) (The Study of Verification Bi-Digital O-Ring Test by gauges)

  • 김정렬;김달래
    • 대한한의학회지
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    • 제16권2호
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    • pp.225-247
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    • 1995
  • Using Bi-Digital O-Ring Test which was developed by Ohmura Toshiaki, constiution classification by the vegetables' was Measured by various muscle power measurement meters and the results are as follow: 1. Pinch Gauge (Model:pc5030HPG, Japan) is the gauge to measure finger power between the thumb and the second finger, Grip Strength Dynamometer (Model: T.K.K. 5101, Japan) is to measure the hand power (hand dynamometer), Back Strength Dynamometer (Model: T.K.K. 5102, Japan) is to measure back muscle strength, Vertical jump Meter (Model: T.K.K. 5106, Japan) is to measure the height of jump. The above gauges were and its result found that the radish, potato, carrot and cucumber can influence to muscle strength was not true. 2. When the physical constitution is distinguished by the O-Ring Test method, Taeyangin's rate appeared as average 21% although it was insisted that there will be only 0.03-0.1%. This means that the physical constitution but it appears accidently according to the examinee's emotion about the material such as vegetable etc. as favor or unfavor. 3. It was found that the result of O-Ring Test is the same at any time and at any place was not true. there is no reemergence character. 4. The import of O-Ring Test mehtod to the physical discrimination disregarded that the mental factor influences absolutely to the physical heath in the ideological physi cal constitution medical science. 5. 'O-Ring Test method is a objective judgement method.' is wrong judgement. As you see on the above result, Bi-Digital O-Ring Test set the changeable voluntary muscle as the standard of the judgument, that was first mistake logically, second in spite of leass influence of mental influence by the examiner and examinee than the vegetable discrimination influence, the test disregarded the influence. Third, only grasp of some material on hand can influence to the voluntary muscle was a wrong theory disregarding the physiology. Finally the misunderstaning his subjective view as an objective view in spite of examiner and examinee's strong influence. Therefore such kind of physical descrimination method must be sublated.

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Numerical analysis and fluid-solid coupling model test of filling-type fracture water inrush and mud gush

  • Li, Li-Ping;Chen, Di-Yang;Li, Shu-Cai;Shi, Shao-Shuai;Zhang, Ming-Guang;Liu, Hong-Liang
    • Geomechanics and Engineering
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    • 제13권6호
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    • pp.1011-1025
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    • 2017
  • The geological conditions surrounding the Jijiapo Tunnel of the Three Gorges Fanba Highway project in Hubei Province are very complex. In this paper, a 3-D physical model was carried out to study the evolution process of filling-type fracture water inrush and mud gush based on the conditions of the section located between 16.040 km and 16.042 km of the Jijiapo Tunnel. The 3-D physical model was conducted to clarify the effect of the self-weight of the groundwater level and tunnel excavation during water inrush and mud gush. The results of the displacement, stress and seepage pressure of fracture and surrounding rock in the physical model were analyzed. In the physical model the results of the model test show that the rock displacement suddenly jumped after sustainable growth, rock stress and rock seepage suddenly decreased after continuous growth before water inrushing. Once water inrush occured, internal displacement of filler increased successively from bottom up, stress and seepage pressure of filler droped successively from bottom up, which presented as water inrush and mud gush of filling-type fracture was a evolving process from bottom up. The numerical study was compared with the model test to demonstrate the effectiveness and accuracy of the results of the model test.

ICF 모델 기반 신경계 환자 물리치료 평가 도구 사용 조사 (Evaluation Tools for Patients with Neurologic Disorders Based on the ICF Model: A Survey of Korean Physical Therapists)

  • 이지아;우영근;원종임;김수진
    • PNF and Movement
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    • 제20권3호
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    • pp.359-370
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    • 2022
  • Purpose: Physical therapists are required to properly choose the most appropriate treatment for each patient within the framework of the International Classification of Functioning, Disability, and Health (ICF model). The aims of this study were to determine whether neurological physical therapists in clinical settings in South Korea know about the ICF model and to investigate the current trends of outcome measures (OMs) used by them. Methods: Two hundred and one physical therapists who worked with patients with neurological disorders participated in this study. The survey was conducted via e-mail and asked about commonly used OMs and the considerations for selecting OMs. Results: All physical therapists involved in this study responded completely, and 45.8% of participants learned about the ICF model, while 37.3% understood the detailed information related to the ICF model. The rest of the participants did not know or just heard about the ICF model. The most frequently used tools at the body function/structure level were the Range of Motion (98%), Manual Muscle Test (97%), Berg Balance Scale (83.1%), and Modified Ashworth Scale (70.6%) when allowing repetition. At the activity level, the 10-meter walk test (71.1%), 6-minute walk test (54.2%), and Functional Ambulatory Category (43.3%) were used, while the Activity-Specific Balance Confidence Scale (23.9%) was used at the participation level. There was a positive relationship between the number of tools used and years of work, as well as the level of understanding of the ICF model. Conclusion: The results of this study suggest that it is necessary to learn the ICF model in a clinical setting. In addition, the medical system needs to be modified to encourage physical therapists in South Korea to use proper OMs within the ICF model.

한국 물리치료사 국가 면허시험 합격 여부의 예측요인 탐색 (Exploring the Predictive Factors of Passing the Korean Physical Therapist Licensing Examination)

  • 김소현;조성현
    • 대한통합의학회지
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    • 제10권3호
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    • pp.107-117
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    • 2022
  • Purpose : The purpose of this study was to establish a model of the predictive factors for success or failure of examinees undertaking the Korean physical therapist licensing examination (KPTLE). Additionally, we assessed the pass/fail cut-off point. Methods : We analyzed the results of 10,881 examinees who undertook the KPTLE, using data provided by the Korea Health Personnel Licensing Examination Institute. The target variable was the test result (pass or fail), and the input variables were: sex, age, test subject, and total score. Frequency analysis, chi-square test, descriptive statistics, independent t-test, correlation analysis, binary logistic regression, and receiver operating characteristic (ROC) curve analyses were performed on the data. Results : Sex and age were not significant predictors of attaining a pass (p>.05). The test subjects with the highest probability of passing were, in order, medical regulation (MR) (Odds ratio (OR)=2.91, p<.001), foundations of physical therapy (FPT) (OR=2.86, p<.001), diagnosis and evaluation for physical therapy (DEPT) (OR=2.74, p<.001), physical therapy intervention (PTI) (OR=2.66, p<.001), and practical examination (PE) (OR=1.24, p<.001). The cut-off points for each subject were: FPT, 32.50; DEPT, 29.50; PTI, 44.50; MR, 14.50; and PE, 50.50. The total score (TS) was 164.50. The sensitivity, specificity, and the classification accuracy of the prediction model was 99 %, 98 %, and 99 %, respectively, indicating high accuracy. Area under the curve (AUC) values for each subject were: FPT, .958; DEPT, .968; PTI, .984; MR, .885; PE, .962; and TS, .998, indicating a high degree of fit. Conclusion : In our study, the predictive factors for passing KPTLE were identified, and the optimal cut-off point was calculated for each subject. Logistic regression was adequate to explain the predictive model. These results will provide universities and examinees with useful information for predicting their success or failure in the KPTLE.

작업시간과 육체적인 작업부하를 고려한 혼합모델 조립공정의 라인밸런싱 (Line Balancing for the Mixed Model Assembly Line Considering Processing Time and Physical Workloads)

  • 문성민;권금섭;최경현
    • 산업공학
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    • 제17권3호
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    • pp.282-293
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    • 2004
  • Line Balancing is the problem to assign tasks to stations while satisfying some managerial viewpoints. Most researches about the Mixed-Model Line Balancing problems are focused on the minimizing the total processing time or the number of workstations. Independently, some research reports consider the balance issues of the physical workloads on the assembly line. In this paper, we are presenting a new mathematical model to accomplish the line balance considering both the processing time and the workloads at the same time. To this, end, we propose an zero-one integer program problem, and we use the Chebyshev Goal Programming approach as the solution method. Some computational test runs are performed to compare the pay-offs between the processing time and the workloads. And, the test results show us that the reliable balanced work schedules can be obtained through the proposed model.

모형시험과 수치해석을 이용한 조적식 석축옹벽의 거동 특성 (Behavior of Dry-stone Segmental Retaining Wall Using Physical Modeling and Numerical Simulation)

  • 김성수;목영진;정영훈
    • 한국지반공학회논문집
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    • 제27권9호
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    • pp.25-36
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    • 2011
  • 조적식 석축옹벽의 거동 특성을 규명하기 위하여 실내 모형시험과 수치해석을 수행하였다. 실내 모형시험에서 옹벽 블록과 뒤채움재의 변위를 측정하기 위해 PIV 기법의 디지털 이미지 해석을 실시하였다. 유한요소 수치해석을 위해 상용프로그램인 ABAQUS를 사용하였다. 모형시험에서 관찰된 뒤채움재의 변위 발생 과정은 파괴면의 형성이 점진적임을 보여준다. 수치해석 결과에서 석축옹벽의 시공 과정에서 발생하는 전체적인 수평 토압 분포는 기존의 Rankine 이론과 큰 차이가 없지만, 뒤채움재의 내부 마찰각과 석축을 구성하는 석재 간의 마찰각이 작으면 토압의 분포가 불규칙해짐을 확인하였다.