• 제목/요약/키워드: direct determination

검색결과 511건 처리시간 0.027초

The influences of equivalent viscous damping ratio determination on direct displacement-based design of un-bonded post-tensioned (UPT) concrete wall systems

  • Anqi, Gu;Shao-Dong, Shen
    • Smart Structures and Systems
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    • 제30권6호
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    • pp.627-637
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    • 2022
  • Recent years, direct displacement-based design (DDBD) procedure is proposed for the design of un-bonded posttensioned (UPT) concrete wall systems. In the DDBD procedure, the determination of the equivalent viscous damping (EVD) ratio is critical since it would influence the strength demand of the UPT wall systems. Nevertheless, the influence of EVD ratio determination of the UPT wall systems were not thoroughly evaluated. This study was aimed to investigate the influence of different EVD ratio determinations on the DDBD procedure of UPT wall systems. Case study structures with four, twelve and twenty storeys have been designed with DDBD procedure considering different EVD ratio determinations. Nonlinear time history analysis was performed to validate the design results of those UPT wall systems. And the simulation results showed that the global responses of the case study structures were influenced by the EVD ratio determination.

Direct position tracking method for non-circular signals with distributed passive arrays via first-order approximation

  • Jinke Cao;Xiaofei Zhang;Honghao Hao
    • ETRI Journal
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    • 제46권3호
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    • pp.421-431
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    • 2024
  • In this study, a direct position tracking method for non-circular (NC) signals using distributed passive arrays is proposed. First, we calculate the initial positions of sources using a direct position determination (DPD) approach; next, we transform the tracking into a compensation problem. The offsets of the adjacent time positions are calculated using a first-order Taylor expansion. The fusion calculation of the noise subspace is performed according to the NC characteristics. Because the proposed method uses the signal information from the previous iteration, it can realize automatic data associations. Compared with traditional DPD and two-step localization methods, our novel process has lower computational complexity and provides higher accuracy. Moreover, its performance is better than that of the traditional tracking methods. Numerous simulation results support the superiority of our proposed method.

Direct and indirect methods for determination of mode I fracture toughness using PFC2D

  • Sarfarazi, Vahab;Haeri, Hadi;Shemirani, Alireza Bagher
    • Computers and Concrete
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    • 제20권1호
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    • pp.39-47
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    • 2017
  • In this paper, mode I fracture toughness of rock was determined by direct and indirect methods using Particle Flow Code simulation. Direct methods are compaction tension (CT) test and hollow centre cracked quadratic sample (HCCQS). Indirect methods are notched Brazilian disk (NBD) specimen, the semi-circular bend (SCB) specimen, hollow centre cracked disc (HCCD), the single edge-notched round bar in bending (SENRBB) specimen and edge notched disk (END). It was determined that which one of indirect fracture toughness values is close to direct one. For this purpose, initially calibration of PFC was undertaken with respect to data obtained from Brazilian laboratory tests to ensure the conformity of the simulated numerical models response. Furthermore, the simulated models in five introduced indirect tests were cross checked with the results from direct tests. By using numerical testing, the failure process was visually observed. Discrete element simulations demonstrated that the macro fractures in models are caused by microscopic tensile breakages on large numbers of bonded discs. Mode I fracture toughness of rock in direct test was less than other tests results. Fracture toughness resulted from semi-circular bend specimen test was close to direct test results. Therefore semi-circular bend specimen can be a proper test for determination of Mode I fracture toughness of rock in absence of direct test.

인체에서 Pick 원리 및 열희석법에 의한 심박출량 측정의 비교 연구 (Comparison of Cardiac Output Determination by Direct Fick and Thermodilution Method in Man)

  • 장병철
    • Journal of Chest Surgery
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    • 제14권3호
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    • pp.228-234
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    • 1981
  • Measurement of cardiac output by thermodilution method is easy to perform and can be repeated at very short intervals and offers a number of theoretical and practical advantages. The purpose of this paper is to reevaluate the accuracy and reproducibility of the thermodilution cardiac output by comparing the results with those obtained by the direct Fick technique. From January through April 1981 [4 months], 26 simultaneous cardiac output measurements were made using thermodilution and direct Fick methods in 12 patients in the intensive care unit of Severance Hospital following open heart surgery. The average age of the patients was $34.8{\pm}12.0$ [SD] years [range; 17-57 years]. For cardiac output determination by thermodilution technique [$CO_TD$], a Swan-Ganz Thermodilution Catheter, Model 93A-131-7F [Edwards Laboratories], a Cardiac Output Computer, Model 9520A, and Strip Chart Recorder, Model 9810 [Edwards Laboratories] were used. For the determination of cardiac output by direct Fick principle [$CO_Fick$], a Van Slyke Manometric Apparatus [Thomas] for the measurements of arteriovenous oxygen content difference and a Collin`s Respirometer with Kymograph for the measurement of oxygen consumption were used. The correlation between the simultaneously measured $CO_TD$ and $CO_Fick$ was found to be $CO_Fick$ = 0.95.$CO_TD$ + 0.1073, [r= 0.9777, P < 0.001 ]. For 26 double or triple determinations of $CO_TD$, the values ranged from 1.77 L/min to 6.66 L/min, with a reproducibility of 2.18%. The maximum difference of $CO_TD$ for $CO_Fick$ was between +11.99% and -12,99% [$Mean{\pm}SD$ = $6.07{\pm}3.97$%]. Measurement of cardiac output by thermodilution method provides a simple, rapid, reproducible and highly accurate method for multiple cardiac output measurements suitable for use at the bedside. Comparison of Cardiac Output Determination by Direct Fick and Thermodilution Method in Man.

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중환자실에서의 환자분류체계 확립을 위한 결정지표 개발에 관한 연구 (The study of critical indicator development for establishing patient classification system in the Intensive Care Unit)

  • 김길엽;장금성
    • 간호행정학회지
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    • 제8권3호
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    • pp.475-488
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    • 2002
  • Purpose : The purpose of this study is to establish a basis of patient classification in the ICU by selecting the determination critical indicator of special nursing activities that show high interrilation with daily total nursing care time. Method : This study is composed of the six steps. The first step is the listing direct nursing activities in the ICU. The last step is the determination indicator of each group were selected on the basis of their relationship to the daily total nursing care time of each patient classification group and each nursing activity. Result : Result shows that: 1. direct nursing activities in the ICU are 149 items of 13 territories. 2. the average time and frequency for each direct nursing activities 3. total direct nursing care time of 42 patients in ICU for 2 days. According to the results of the Cluster analysis, the first group is 10 people, the second group is 13 people, the third group is 16 people, the fourth group is 3 people. 4. Determination critical indicator is the item that is r>0.6(p<0.05) of Pearson Correlation between each patient daily total nursing care time and 149 items of nursing activities. The nursing activities selected were as follows: 2 items in the first group, 17 items in the second group. 16 items in the third group, 8 items in the fourth group. Conclusion : This study can help future studies which measure nursing activities standard time or assigns value to nursing activities time.

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가족탄력성, 자기결정성, 진로결정 몰입의 구조적 관계 분석 (An Analysis of the Structural Relationship Among Family Resilience, Self-Determination and Commitment to Career Choice)

  • 이지혜;이재신;류진숙
    • 한국가정과교육학회지
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    • 제23권4호
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    • pp.19-34
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    • 2011
  • 본 연구의 목적은 대학생의 가족탄력성, 자기결정성, 그리고 진로결정 몰입간의 구조적 관계를 밝히는데 있다. 연구대상은 충북과 경북 소재 4개 대학교에 재학 중인 학생 277명이었으며, 연구결과는 다음과 같다. 첫째, 대학생의 가족탄력성은 자기결정성(자율성, 유능성, 관계성)과 진로결정 몰입에 직접적인 영향을 미치는 것으로 나타났다. 즉 가족탄력성이 높은 환경의 대학생일수록 더 자기결정적이고, 진로결정에 대한 몰입의 정도가 높다고 할 수 있다. 둘째, 대학생의 자기결정성(자율성, 유능성, 관계성)은 진로결정 몰입에 직접적인 영향을 미치는 것으로 나타났다. 즉 더 자기결정적인 대학생일수록 더 높은 수준의 진로결정 몰입을 경험한다고 할 수 있다. 셋째, 대학생의 가족탄력성은 자기결정성(자율성, 유능성, 관계성)을 통하여 진로결정 몰입에 간접적인 영향을 미치는 것으로 나타났다. 즉 대학생의 가족탄력성이 진로결정 몰입에 영향을 미치는 과정에 자기결정성(자율성, 유능성, 관계성)이 매개효과를 가진다고 할 수 있다.

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위성 회전축 및 센서 바이어스 결정을 위한 확장 Shuster 알고리즘에 관한 연구 (Extension of shuster's algorithm for spin-axis attitude and sensor bias determination)

  • 노태수
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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    • pp.238-242
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    • 1994
  • Shuster's algorithm for spin-axis determination is extended to include sensor bias and mounting angle as its solve-for parameters. The relation between direct and derived measurements bias is obtained by linearizing their kinematic equations. A one-step least-square estimation technique referred to as the 'closed form' solution is used, and the solution provides a more refined and decent initial guess for the subsequent filtering process contained within the differential correction module. The modified algorithm is applied for attitude determination of a GEO communication satellite in transfer orbit, and its results are presented.

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First Derivative Spectrophotometric and Gas-Liquid Chromatographic Determination of Caffeine in Foods and Pharmaceuticals III. Simultaneous assay of caffeine and some antihistaminics

  • Abdel-Moety, Ezzat M.;El-Tarras, Mohamed F.;El-Zeany, Badr-Eldin A.;Kelani, Khadiga O.
    • Archives of Pharmacal Research
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    • 제13권3호
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    • pp.215-220
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    • 1990
  • Two different, derivative spectrophotometric and gas-liquid chromatographic, procedures for direct quantitation of caffeine and some commonly dispensed antihistaminics in bulk forms, in their laboratory prepared mmixtures and in dosage formulations, have been investigated. The limit, sensitivity reproducibility and accuracy of each method were studied for each individual drug substance and in some usual pharmaceutical formulations.

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