• 제목/요약/키워드: analytical values

검색결과 1,425건 처리시간 0.022초

Analytical correction of vertical shortening based on measured data in a RC high-rise building

  • Song, Eun-seok;Kim, Jae-yo
    • Advances in concrete construction
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    • 제10권6호
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    • pp.527-536
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    • 2020
  • In this study, a process is proposed to calculate analytical correction values for the vertical shortening of all columns on all floors in a high-rise building that minimizes the error between the structural analysis predictions and values measured during construction. The weight ratio and the most probable value were accordingly considered based on the properties of the shortening value analyzed at several points in each construction stage and the distance between these measured points and unmeasured points at which the shortening was predicted. The effective range and shortening value normalization were considered using the column grouping concept. These tools were applied to calculate the error ratio between the predicted and measured values on a floor where a measured point exists, and then determine the estimated error ratio and estimated error value for the unmeasured point using this error ratio. At points on a floor where no measured point exists, the estimated error ratio and the estimated error value were calculated by applying the most probable value considering the weight ratio for the nearest floor where measured points exist. In this manner, the error values and estimated error values can be determined at all points in a structure. Then, the analytical correction value, defined as this error or estimated error value, was applied by adding it to the predicted value. Finally, the adequacy of the proposed correction method was verified against measurements by applying the analytical corrections to all unmeasured points based on the points where the measurement exists.

A Heat Loss Comparison Between the Two Parabolic Fin Models Using Two Different Numerical Methods

  • Kim, K.T.;Kang, H.S.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제2권2호
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    • pp.97-109
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    • 1998
  • A comparison of the two dimensional heat loss, computed using the analytical method and the finite difference method in two models(i.e. one is a parabolic fin whose parabolic curves meet at the fin center line and the other is a transformed parabolic fin whose tip cuts vertically), is made assuming the analytical method is correct. For these methods, the root temperature and surrounding convection coefficients of these fins are assumed as constants. The results show that the relative errors of the heat loss between the two methods for the parabolic fin whose tip cuts vertically are smaller than those for the one whose tip does not cut. In case of Bi=0.01, the values of the heat loss obtained using a finite difference method are close to those values obtained using the analytical method for both models. The values of the heat loss from both models calculated by using the analytical method are almost the same for given range of non-dimensional fin length in case of Bi = 0.01 and 0.1.

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Hexokinase 방법을 이용한 Heparin 혈장과 NaF 혈장 시료의 혈당 분석치 비교 (Comparison of Li-heparinized Versus Na-fluorinated Plasma for Routine Blood Glucose Determination Using Hexokinase Procedure)

  • 문인경
    • 대한임상검사과학회지
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    • 제39권1호
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    • pp.25-30
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    • 2007
  • In this study, the two sampling methods for blood glucose measurement were evaluated in order to reduce pre-analytical error. For this purpose, glucose levels of Li-heparinized plasma (LHP) and Na-fluorinated plasma (NFP) in blood collected from healthy volunteers were determined by using routine hexokinase procedures. The percentage range of pre-analytical error was quantitated by comparing LHP glucose values with NFP glucose values according to delaying analytical time (0, 60, and 120 min). LHP glucose values were decreased by 6.6% in 60 min., 17.7% in 120 min, whereas NFP glucose values decreased by 1.1% in 60 min, 2.0% in 120 min. Therefore it may be recommended that the NFP sampling method should be used for routine blood glucose determination in diabetes mellitus diagnosis.

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Determination of trace elements in food reference materials by instrumental neutron activation analysis

  • Cho, K.H.;Zeisler, R.;Park, K.W.
    • 분석과학
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    • 제18권6호
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    • pp.520-528
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    • 2005
  • Two biological Certified Reference Materials (CRMs), KRISS 108-04-001 (oyster tissue) and 108-05-001 (water dropwort stem), were prepared by Korea Research Institute of Standards and Science (KRISS)during FY '01. The certified values of these materials had been determined by Isotope Dilution Mass Spectrometry (IDMS) for six elements (Cd, Cr, Cu, Fe, Pb and Zn). Additional analytical works are now progressing to certify the concentrations of a number of the environmental and nutrimental elements in these CRMs. The certified values in a CRM are usually determined by using a single primary method with confirmation by other method(s) or using two independent critically-evaluated methods. Instrumental Neutron Activation Analysis (INAA) plays an important role in the determination of certified values as it can eliminate the possibility of common error sources resulting from sample dissolution. In this study INAA procedure was used in determination of 23 elements in these two biological CRMs to acquire the concentration information and the results were compared with KRISS certified values.

공용중 도로하부의 굴착터널 해석 및 계측 연구 (An Analytical and Experimental Study on the Mechanical Behavior of Excavating Turnels beneath the Roadway)

  • 정광모;방명석
    • 한국안전학회지
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    • 제27권5호
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    • pp.99-104
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    • 2012
  • A turnelling work beneath roadways or railways in use is unsafe and dangerous. A turnelling method should be analytically and experimentally studied to verify stability and safety of excavating works by construction step. The conventionally analytical method was ineffective in computational time and cost, so the new analytical method named homogenuity method, was developed and verified compared with analytical results. That method was applied to parameterly study the effect of distance of steel supports and overburdening height of soil. It showed that the homogenuity method was very practical and effective in step-by-step analysis considering construction sequences. A measuring device was set at the construction field and mechanical behavior was monitored during construction. Measuring values are larger than analytical values because impact of inserting steel pipes, lowering level of underground water and vibration of passing vehicles affected soil density during construction, but those values were within allowable limits.

Parallel tunnel settlement characteristics: a theoretical calculation approach and adaptation analysis

  • Liu, Xinrong;Suliman, Lojain;Zhou, Xiaohan;Abd Elmageed, Ahmed
    • Geomechanics and Engineering
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    • 제28권3호
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    • pp.225-237
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    • 2022
  • Settlement evaluation is important for shallow tunnels in big cities to estimate the settlement that occurs due to the excavation of twin tunnels. The majority of earlier research on analytical solutions, on the other hand, concentrated on calculating the settlement for a single tunnel. This research introduces a procedure to evaluate the settlement induced by the excavation of twin tunnels (two parallel tunnels). In this study, a series of numerical analysis were performed to validate the analytical solution results. Two geological conditions were considered to derive the settlement depending on each case. The analytical and numerical methods were compared, which involved considering many sections and conducting a parametric study; the results have good agreement. Moreover, a comparison of the 3D flat model and 2D (FEM) with the analytical solution shows that in the fill soil, the maximum settlement values were obtained by the analytical solution. In contrast, the values obtained by the analytical solution in the rock is more conservative than those in the fill. Finally, this method was shown to be appropriate for twin tunnels dug side by side by utilizing finite element analysis 3D and 2D (PLAXIS 3D and PLAXIS 2D) to verify the analytical equations. Eventually, it will be possible to use this approach to predict settlement troughs over twin tunnels.

Computer simulation for dynamic wheel loads of heavy vehicles

  • Kawatani, Mitsuo;Kim, Chul-Woo
    • Structural Engineering and Mechanics
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    • 제12권4호
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    • pp.409-428
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    • 2001
  • The characteristics of dynamic wheel loads of heavy vehicles running on bridge and rigid surface are investigated by using three-dimensional analytical model. The simulated dynamic wheel loads of vehicles are compared with the experimental results carried out by Road-Vehicles Research Institute of Netherlands Organization for Applied Scientific Research (TNO) to verify the validity of the analytical model. Also another comparison of the analytical result with the experimental one for Umeda Entrance Bridge of Hanshin Expressway in Osaka, Japan, is presented in this study. The agreement between the analytical and experimental results is satisfactory and encouraging the use of the analytical model in practice. Parametric study shows that the dynamic increment factor (DIF) of the bridge and RMS values of dynamic wheel loads are fluctuated according to vehicle speeds and vehicle types as well as roadway roughness conditions. Moreover, there exist strong dominant frequency resemblance between bounce motion of vehicle and bridge response as well as those relations between RMS values of dynamic wheel loads and dynamic increment factor (DIF) of bridges.

국민건강영양조사 자료를 이용한 지방산 데이터베이스 구축 (Development of a fatty acids database using the Korea National Health and Nutrition Examination Survey data)

  • 윤미옥;김기랑;황지윤;이현숙;손태영;문현경;심재은
    • Journal of Nutrition and Health
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    • 제47권6호
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    • pp.435-442
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    • 2014
  • 본 연구에서는 국가적 수준에서 지방산 섭취량을 추정할 수 있도록 국민건강영양조사에서 사용하는 식품목록에 수록된 5,144개의 식품에 대해 지방산 DB를 구축하고, 그 과정을 단계별로 정리하여 향후 개정에 활용할 수 있도록 하였다. 지방산 DB는 국내 국립기관에서 발행한 식품의 지방산 함량 분석 자료를 기본으로 하여, 국외의 권위 있는 기관에서 발간한 자료와 학술지에 보고된 함량 분석 자료를 수집한 후 자료의 질을 검토하고 대체하거나 계산하는 방법으로 구축되었다. 구축된 DB를 2011년 국민건강영양조사 자료에 적용하여 지방산 섭취량을 추정한 결과, 총 지방산 섭취량은 지방섭취량의 84% 수준으로 학술지에 보고되고 있는 섭취량 추정수준보다는 높은 수준이나 DB 구축과정에서 확인된 문제점들을 보완하여 자료의 질을 향상시키는 것이 필요할 것으로 사료된다. 본 연구는 관련 연구 분야와 국가 영양정책의 중요한 기본 자료를 확보하였다는데 의의가 있다.

An analytical model for shear links in eccentrically braced frames

  • Ashtari, Amir;Erfani, Saeed
    • Steel and Composite Structures
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    • 제22권3호
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    • pp.627-645
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    • 2016
  • When an eccentrically braced frame (EBF) is subjected to severe earthquakes, the links experience inelastic deformations while beams outside of the link, braces and columns are designed to remain elastic. To perform reliable inelastic analyses of EBFs sufficient analytical model which can accurately predict the inelastic performance of the links is needed. It is said in the literature that available analytical models for shear links generally predict very well the maximum shear forces and deformations from experiments on shear links, but may underestimate the intermediary values. In this study it is shown that available analytical models do not predict very well the maximum shear forces and deformations too. In this study an analytical model which can accurately predict both maximum and intermediary values of shear force and deformation is proposed. The model parameters are established based on test results from several experiments on shear links. Comparison of available test results with the hysteresis curves obtained using the proposed analytical model established the accuracy of the model. The proposed model is recommended to be used to perform inelastic analyses of EBFs.

닭사료의 섬유소 정량분석방법 개발에 관한 연구 (A Study on the Development of a Quantitative Analytical Method of Chicken Dietary Fiber)

  • 남기홍;성창환
    • 한국가금학회지
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    • 제21권2호
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    • pp.73-82
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    • 1994
  • A study was conducted to develop a new analytical method to quantitate chicken dietary fiber (CDF). Four types of grain diets and 2 types of forages were used. Three broiler chicks at eight weeks of age were used in the Latin square design to estirnate the in vivo digestibility. Six quantitative analytical methods (Southgate method, total dietary fiber or TDF, acid detergent fiber or ADF, neutral detergent fiber or NDF, crude fiber or CF) including CDF were compared in this study. ADF, NDF and CF contained the lowest amount of the unavailable carbohydrate(UC). The value of TDF was higher than the values of ADF, NDF and CF and lower than CDF and the Southgate method. The value of NDF showed the lower values than the CDF, Southgate fiber and TDF. The recovery rate of the fiber in the feces was high in the TDF, ADF, NDF and CF, while CDF and Southgate fiber showed lower recovery rates. TDF, NDF, ADF, or CF can replace chromium in the digestibility test, while the CDF and Southgate fiber can not replace chrorniurn. The digestibility of TDF, NDF, ADF and CF in the chicken showed negative values or values close to zero depending on the types of feed but the digestibility of CDF and Southgate fiber showed relatively high positive values.

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