Buckling Strength of Cold-Formed Circular Steel Column Subjected to Axial Load

In this study, the global buckling behavior of a cold-formed circular steel column was discussed with a focus on the effects of its mechanical properties and initial imperfections on the behavior. As the first step, the stress–strain curves of the column under tensile and compressive loads as well as its residual stresses were investigated. Subsequently, a finite element analysis was conducted to clarify if the analysis properly simulated the stub column behavior. The analysis results obtained using measured compressive stress–strain curves and residual stresses agreed well with experimental results. Finally, another finite element analysis was performed on the long column buckling to examine the effects of its mechanical properties and initial imperfections. It was shown that the global buckling strength was affected not only by imperfections such as residual stress and out-of-straightness but also by the anisotropic mechanical properties of the material

Change in pharmacokinetics of mycophenolic acid as a function of age in rats and effect of coadministered amoxicillin/clavulanate

Changes of mycophenolic acid (MPA) pharmacokinetics with aging were investigated in rats. We also compared the effect of concomitant amoxicillin/clavulanate combination (CVA/AMPC) on the pharmacokinetics of MPA in 4-week-old and 12-week-old rats (the package insert of CVA/AMPC warns of possible interaction with MPA). Four-week-old rats showed a 1.4-fold higher total body clearance of MPA and a lower volume of distribution of MPA (65%), compared to the values in 12-week-old rats. However, the difference in MPA pharmacokinetics disappeared when enterohepatic circulation was eliminated by bile duct cannulation (BDC). Concomitant CVA/AMPC significantly reduced plasma MPA concentration in intact rats of both age groups, and the age-dependent difference of MPA pharmacokinetics was no longer apparent. The effect of CVA/AMPC was not seen in rats that had undergone BDC, suggesting that the drug-drug interaction can be attributed to inhibition of enterohepatic circulation by CVA/AMPC. These results indicate that the aging-related alteration of MPA pharmacokinetics is a consequence of immature enterohepatic circulation in 4-week-old rats. Higher doses of MPA may be necessary in juveniles. © 2012 The Pharmaceutical Society of Japan

FRオペレータによるサンプル値系の周波数領域における研究

京都大学0048新制・論文博士博士(工学)乙第12547号論工博第4054号新制||工||1519(附属図書館)28845京都大学大学院工学研究科電気工学第二専攻(主査)教授 萩原 朋道, 教授 土居 伸二, 教授 山本 裕学位規則第4条第2項該当Doctor of Philosophy (Engineering)Kyoto UniversityDFA

Security Analysis of Anonymous Communication System 3-Mode Net Against Collaborating Nodes

This paper analyzes the security of an anonymous communication system 3-Mode Net (3MN) against collaborating relay nodes. We evaluate the anonymity of a message sender under the situation that some relay nodes collaborate each other to find out the message sender. As in the case of Crowds, we define the measure of the anonymity of the message sender as the probability that the first immediate predecessor among the immediate predecessors of all collaborating relay nodes is in fact the message sender. This paper gives an explicit formula for this probability. Some numerical examples are also presented.APSIPA ASC 2009: Asia-Pacific Signal and Information Processing Association, 2009 Annual Summit and Conference. 4-7 October 2009. Sapporo, Japan. Oral session: Signal Processing and Security in Communications (5 October 2009)

Bisection Algorithm for Computing the Frequency Response Gain of Sampled-Data Systems - Infinite-Dimensional Congruent Transformation Approach

This paper derives a bisection algorithm for computing the frequency response gain of sampled-data systems with their intersample behavior taken into account. The properties of the infinite-dimensional congruent transformation (i.e., the Schur complement arguments and the Sylvester law of inertia) play a key role in the derivation. Specifically, it is highlighted that counting up the numbers of the negative eigenvalues of self-adjoint operators is quite important for the computation of the frequency response gain. This contrasts with the well-known arguments on the related issue of the sampled-data problem, where the key role is played by the positivity of operators and the loop-shifting technique. The effectiveness of the derived algorithm is demonstrated through a numerical example. Index Terms---Bisection algorithm, frequency response gain, numerical computation, sampled-data systems, Schur complement arguments. I