• 제목/요약/키워드: Second derivative

검색결과 347건 처리시간 0.023초

Buckling analysis of partially embedded pile in elastic soil using differential transform method

  • Catal, Seval;Catal, Hikmet Huseyin
    • Structural Engineering and Mechanics
    • /
    • 제24권2호
    • /
    • pp.247-268
    • /
    • 2006
  • The parts of pile, above the soil and embedded in the soil are called the first region and second region, respectively. The forth order differential equations of both region for critical buckling load of partially embedded pile with shear deformation are obtained using the small-displacement theory and Winkler hypothesis. It is assumed that the behavior of material of the pile is linear-elastic and that axial force along the pile length and modulus of subgrade reaction for the second region to be constant. Shear effect is included in the differential equations by considering shear deformation in the second derivative of the elastic curve function. Critical buckling loads of the pile are calculated for by differential transform method (DTM) and analytical method, results are given in tables and variation of critical buckling loads corresponding to relative stiffness of the pile are presented in graphs.

근적외선 분광분석법을 이용한 음주측정기술 개발에 관한 연구 (Fundamental Investigation of Non-invasive Determination of Alcohol in Blood by Near Infrared Spectrophotometry)

  • 장수현;조창희;우영아;김효진;김영만;이강붕;김영운;박성우
    • 분석과학
    • /
    • 제12권5호
    • /
    • pp.375-381
    • /
    • 1999
  • 본 연구는 기존에 사용되고 있는 음주측정기의 부정확성과 비위생적인 면을 개선하기 위한 비침습적인 알코올 측정기를 개발하기 위해 근적외선분광분석법을 적용하였다. 먼저 근적외선분광분석법으로 혈중 알코올을 측정하기 위한 전 단계로 순수한 알코올을 0.01~0.1%의 농도로 함유한 검체를 측정하였다. MLR(multiple linear regression)방법을 통한 통계적 처리에서 1360, 2256, 2012, 그리고 1358 nm의 네 파장을 선택했을 때 SEC(standard error of calibration)은 0.0039, multiple R은 0.99를 나타냈다. 혈중 알코올 시료 측정시 MLR을 적용했을 때 2266과 2326 nm 파장을 선택했을 경우 가장 유의성 있는 결과를 나타냈다. 또 다른 통계적 방법인 PLSR(partial least squares regression)의 경우 이차 미분 스펙트럼의 1100~1340, 1500~1796, 그리고 2064~2300 nm의 범위에서 4개의 factor를 사용했을 때 0.030의 SEP값을 나타냈다. 이로서 근적외선분광분석법을 이용하여 혈액 중의 알코올을 신속하게 분석할 수 있는 가능성을 제시하였다.

  • PDF

중풍 예방 검진에서 중풍 표준화 변증과 가속도맥파의 상관성 연구 (Clinical Study on Relationship between Pattern Identifications for Stroke and the Second Derivative of Photoplethysmogram Waveform from Stroke Preventive Examination)

  • 정소연;허희수;정해룡;김경민;김영균
    • 동의생리병리학회지
    • /
    • 제29권3호
    • /
    • pp.230-239
    • /
    • 2015
  • This study was performed to find a relationship between each pattern identification and vascular status using the second derivative of photoplethysmogram waveform(SDPTG) indices. We analyzed 200 subjects who participated in stroke preventive examination. We classified the subjects into four groups of pattern identifications; Fire-Heat pattern(火熱證; FH), Yin Deficiency pattern(陰虛證; YD), Qi Deficiency pattern(氣虛證; QD) and Dampness-Phlegm pattern(濕痰證; DP) that based on Korean Standard Pattern Identifications for Stroke-Ⅲ. We studied a relationship between each pattern identification and the SDPTG. The total number of the subject group was 200, whereas the groups were divided into four groups; Fire-Heat pattern group(n=49), Yin Deficiency pattern(n=57), Qi Deficiency pattern(n=45), and Dampness-Phlegm pattern(n=49). b/a ratio was related with age and systolic blood pressure, c/a ratio was associated with age, systolic blood pressure, fasting blood sugar and Total cholesterol, d/a ratio was affected with age, diastolic blood pressure, and hypertension, e/a ratio was related with age and sex and SDPTG AI was associated with age. c/a ratio and d/a ratio were significantly higher in the Fire-Heat group than in the Qi Deficiency group. SDPTG AI was significantly higher in the Qi Deficiency group than in the Fire-Heat group. The Qi Deficiency group was significantly older than the Fire-Heat group and the number of hypertension patients was significantly more in the Fire-Heat group than in the Qi Deficiency group. Through this study, we found out some significant relationships between each pattern identification group and the SDPTG indices.

THE INCOMPLETE GENERALIZED τ-HYPERGEOMETRIC AND SECOND τ-APPELL FUNCTIONS

  • Parmar, Rakesh Kumar;Saxena, Ram Kishore
    • 대한수학회지
    • /
    • 제53권2호
    • /
    • pp.363-379
    • /
    • 2016
  • Motivated mainly by certain interesting recent extensions of the generalized hypergeometric function [Integral Transforms Spec. Funct. 23 (2012), 659-683] and the second Appell function [Appl. Math. Comput. 219 (2013), 8332-8337] by means of the incomplete Pochhammer symbols $({\lambda};{\kappa})_{\nu}$ and $[{\lambda};{\kappa}]_{\nu}$, we introduce here the family of the incomplete generalized ${\tau}$-hypergeometric functions $2{\gamma}_1^{\tau}(z)$ and $2{\Gamma}_1^{\tau}(z)$. The main object of this paper is to study these extensions and investigate their several properties including, for example, their integral representations, derivative formulas, Euler-Beta transform and associated with certain fractional calculus operators. Further, we introduce and investigate the family of incomplete second ${\tau}$-Appell hypergeometric functions ${\Gamma}_2^{{\tau}_1,{\tau}_2}$ and ${\gamma}_2^{{\tau}_1,{\tau}_2}$ of two variables. Relevant connections of certain special cases of the main results presented here with some known identities are also pointed out.

유한요소 구조 인자의 2차 민감도에 의한 동적 구조 최적화 (Structural Dynamics Optimization by Second Order Sensitivity with respect to Finite Element Parameter)

  • 김용연
    • 한국공작기계학회논문집
    • /
    • 제15권3호
    • /
    • pp.8-16
    • /
    • 2006
  • This paper discusses design sensitivity analysis and its application to a structural dynamics modification. Eigenvalue derivatives are determined with respect to the element parameters, which include intrinsic property parameters such as Young's modulus, density of the material, diameter of a beam element, thickness of a plate element, and shape parameters. Derivatives of stiffness and mass matrices are directly calculated by derivatives of element matrices. The first and the second order derivatives of the eigenvalues are then mathematically derived from a dynamic equation of motion of FEM model. The calculation of the second order eigenvalue derivative requires the sensitivity of its corresponding eigenvector, which are developed by Nelson's direct approach. The modified eigenvalue of the structure is then evaluated by the Taylor series expansion with the first and the second derivatives of eigenvalue. Numerical examples for simple beam and plate are presented. First, eigenvalues of the structural system are numerically calculated. Second, the sensitivities of eigenvalues are then evaluated with respect to the element intrinsic parameters. The most effective parameter is determined by comparing sensitivities. Finally, we predict the modified eigenvalue by Taylor series expansion with the derivatives of eigenvalue for single parameter or multi parameters. The examples illustrate the effectiveness of the eigenvalue sensitivity analysis for the optimization of the structures.

Practical Second-Order Correlation Power Analysis on the Message Blinding Method and Its Novel Countermeasure for RSA

  • Kim, Hee-Seok;Kim, Tae-Hyun;Yoon, Joong-Chul;Hong, Seok-Hie
    • ETRI Journal
    • /
    • 제32권1호
    • /
    • pp.102-111
    • /
    • 2010
  • Recently power attacks on RSA cryptosystems have been widely investigated, and various countermeasures have been proposed. One of the most efficient and secure countermeasures is the message blinding method, which includes the RSA derivative of the binary-with-random-initial-point algorithm on elliptical curve cryptosystems. It is known to be secure against first-order differential power analysis (DPA); however, it is susceptible to second-order DPA. Although second-order DPA gives some solutions for defeating message blinding methods, this kind of attack still has the practical difficulty of how to find the points of interest, that is, the exact moments when intermediate values are being manipulated. In this paper, we propose a practical second-order correlation power analysis (SOCPA). Our attack can easily find points of interest in a power trace and find the private key with a small number of power traces. We also propose an efficient countermeasure which is secure against the proposed SOCPA as well as existing power attacks.

Reconfiguring Second-order Dynamic Systems via P-D Feedback Eigenstructure Assignment: A Parametric Method

  • Wang Guo-Sheng;Liang Bing;Duan Guang-Ren
    • International Journal of Control, Automation, and Systems
    • /
    • 제3권1호
    • /
    • pp.109-116
    • /
    • 2005
  • The design of reconfiguring a class of second-order dynamic systems via proportional plus derivative (P-D) feedback is considered. The aim is to resynthesize a P-D feedback controller such that the eigenvalues of the reconfigured closed-loop system can completely recover those of the original close-loop system, and make the corresponding eigenvectors of the former as close to those of the latter as possible. Based on a parametric result of P-D feedback eigenstructure assignment in second-order dynamic systems, parametric expressions for all the P-D feedback gains and all the closed-loop eigenvector matrices are established and a parametric algorithm for this reconfiguration design is proposed. The parametric algorithm offers all the degrees of design freedom, which can be further utilized to satisfy some additional performances in control system designs. This algorithm involves manipulations only on the original second-order system matrices, thus it is simple and convenient to use. An illustrative example and the simulation results show the simplicity and effect of the proposed parametric method.

Vector Map Simplification Using Poyline Curvature

  • Pham, Ngoc-Giao;Lee, Suk-Hwan;Kwon, Ki-Ryong
    • Journal of Multimedia Information System
    • /
    • 제4권4호
    • /
    • pp.249-254
    • /
    • 2017
  • Digital vector maps must be compressed effectively for transmission or storage in Web GIS (geographic information system) and mobile GIS applications. This paper presents a polyline compression method that consists of polyline feature-based hybrid simplification and second derivative-based data compression. Experimental results verify that our method has higher simplification and compression efficiency than conventional methods and produces good quality compressed maps.

A METHOD FOR ADJUSTING ADAPTIVELY THE WEIGHT OF FEATURE IN MULTI-DIMENSIONAL FEATURE VECTOR MATCHING

  • Ye, Chul-Soo
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
    • /
    • pp.772-775
    • /
    • 2006
  • Muilti-dimensional feature vector matching algorithm uses multiple features such as intensity, gradient, variance, first or second derivative of a pixel to find correspondence pixels in stereo images. In this paper, we proposed a new method for adjusting automatically the weight of feature in multi-dimensional feature vector matching considering sharpeness of a pixel in feature vector distance curve. The sharpeness consists of minimum and maximum vector distances of a small window mask. In the experiment we used IKONOS satellite stereo imagery and obtained accurate matching results comparable to the manual weight-adjusting method.

  • PDF

Designs for Estimating the Derivatives on Response Surfaces

  • Park, Sung H.
    • Journal of the Korean Statistical Society
    • /
    • 제8권1호
    • /
    • pp.37-64
    • /
    • 1979
  • Criteria and designs are developed for estimating derivatives of P-variable second order polynomial response surfaces. The basic criterion used is mean square error of the estimated derivative, averaged over all directions and then averaged over a region of interest. A new design concept called slope-rotatability is introduced. A simplex optimization program is used to find minimum mena square error designs for the two variable case for $6 \leq N \leq 12$.

  • PDF