Microfluidic assessment of swimming media for motility-based sperm selection     

Lise Eamer  Reza Nosrati  Marion Vollmer  Armand Zini  David Sinton 《Biomicrofluidics》2015,9(4)

Selection medium is important in sperm isolation for assisted reproductive technologies. Contrary to the naturally occurring human cervical mucus which has a high viscosity, most current practices for motility based sperm selection use a low viscosity medium. In this study, we used a microfluidic device to assess the effects of high viscosity media made with hyaluronic acid (HA) and methyl cellulose (MC) on bovine and human sperm motility and viability (sperm transferred directly from cryoprotectant). The microfluidic penetration test, viability, and motility were compared for sperm swimming in both HA and MC media with about 20cp viscosity (measured at 20 °C). Our resulted indicate that MC medium resulted in a significantly higher number of viable bovine sperm penetrating the medium as compared to HA. Furthermore, MC resulted in the selection of a sperm subpopulation with a 274% increase in sperm viability in comparison to the raw semen, while HA increased viability by only 133%. In addition to viability, bovine sperm motility parameters were significantly higher in the MC medium as compared with HA. Experiments with human sperm swimming in MC indicate that sperm swim slower and straighter at higher viscosities. In conclusion, the results indicate that in a micro-confined environment representative of the in vivo environment, MC is a preferred high viscosity medium to ensure the highest concentration of motile and viable sperm.  相似文献   

Fuzzy sliding mode control design for a class of disturbed systems     

Bo Wang  Peng Shi  Hamid Reza Karimi 《Journal of The Franklin Institute》2014

This paper discusses the problem of the fuzzy sliding mode control for a class of disturbed systems. First, a fuzzy auxiliary controller is constructed based on a feedback signal not only to estimate the unknown control term, but also participates in the sliding mode control due to the fuzzy rule employed. Then, we extend our theory into the cases, where some kind of system information can not be obtained, for better use of our theoretical results in real engineering. Finally, some typical numerical examples are included to demonstrate the effectiveness and advantage of the designed sliding mode controller.  相似文献   

Expert group formation using facility location analysis     

Mahmood Neshati  Hamid Beigy  Djoerd Hiemstra 《Information processing & management》2014

In this paper, we propose an optimization framework to retrieve an optimal group of experts to perform a multi-aspect task. While a diverse set of skills are needed to perform a multi-aspect task, the group of assigned experts should be able to collectively cover all these required skills. We consider three types of multi-aspect expert group formation problems and propose a unified framework to solve these problems accurately and efficiently. The first problem is concerned with finding the top k experts for a given task, while the required skills of the task are implicitly described. In the second problem, the required skills of the tasks are explicitly described using some keywords but each expert has a limited capacity to perform these tasks and therefore should be assigned to a limited number of them. Finally, the third problem is the combination of the first and the second problems. Our proposed optimization framework is based on the Facility Location Analysis which is a well known branch of the Operation Research. In our experiments, we compare the accuracy and efficiency of the proposed framework with the state-of-the-art approaches for the group formation problems. The experiment results show the effectiveness of our proposed methods in comparison with state-of-the-art approaches.  相似文献   

Adaptive output feedback neural network control of uncertain non-affine systems with unknown control direction     

Mohammad M. Arefi  Jafar Zarei  Hamid R. Karimi 《Journal of The Franklin Institute》2014

This paper deals with the problem of adaptive output feedback neural network controller design for a SISO non-affine nonlinear system. Since in practice all system states are not available in output measurement, an observer is designed to estimate these states. In comparison with the existing approaches, the current method does not require any information about the sign of control gain. In order to handle the unknown sign of the control direction, the Nussbaum-type function is utilized. In order to approximate the unknown nonlinear function, neural network is firstly exploited, and then to compensate the approximation error and external disturbance a robustifying term is employed. The proposed controller is designed based on strict-positive-real (SPR) Lyapunov stability theory to ensure the asymptotic stability of the closed-loop system. Finally, two simulation studies are presented to demonstrate the effectiveness of the developed scheme.  相似文献   

A new continuous action-set learning automaton for function optimization     

Hamid Beigy  M.R. Meybodi 《Journal of The Franklin Institute》2006,343(1):27-47

In this paper, we study an adaptive random search method based on continuous action-set learning automaton for solving stochastic optimization problems in which only the noise-corrupted value of function at any chosen point in the parameter space is available. We first introduce a new continuous action-set learning automaton (CALA) and study its convergence properties. Then we give an algorithm for optimizing an unknown function.  相似文献   

An investigation of the Gregorian chronology of early Islamic history : A Pilot Study     

Shaykh Muhammad al‐casnazāni al‐Husseini  Jamāl N. Hussein  Shetha al‐Dargazelli  Hamid M. An‐Ni'aymi  Louay J. Fatoohi 《Al-Masaq: Islam & the Medieval Mediterranean》1994,7(1):227-266

This pilot study presents a lunar and Gregorian chronology of the Sira, that is the biography of the prophet Muhammad. The paper discusses the problems surrounding the chronology of very early Islamic history, namely, the pre‐Hijra era. This history is not covered by the Hijra calendar, and therefore, historians dated its events using other primitive dating systems, resulting in considerable difficulties and inaccuracies when comparing Gregorian dates of this early Islamic history. In order to overcome this problem and establish an accurate chronology of the early Islamic history, the introduction of a new lunar calendar (the Muhammadi calendar) which starts with the birth month and year of the prophet Muhammad, and covers all Islamic history including the pre‐Hijra era, is suggested. The Muhammadi calendar was used to study the earliest three versions of the Sira. All dated events of the Sira were compiled from these sources and presented, for the first time, according to their historical order. The Muhammadi dates of these events were then calculated. For the first time, a computer program was designed to convert the Muliammadi dates to their Christian equivalent. The program was then used to compute the Gregorian dates of the events of the Sira.  相似文献   

Linear-constant log-map,a fast accurate algorithm for map decoding     

Hamid Samadian  Amir Mousavie Nia 《Journal of The Franklin Institute》2012,349(5):1721-1733

This paper proposes a new approximation to be used for the correction function in the turbo decoding algorithm, called Linear-Constant-log Map. Max-log Map, Linear-log Map and Constant-log Map are the well known simplified versions of Jacobi-log Map (Maximum a Posteriori) algorithm already in use but they cannot meet a proper performance in term of output BER and clock consumption of the CPU decoding encoded bits. The proposed algorithm first breaks the correction function domain of the Jacobi logarithm to three subsections by determining the border points between these sections and then uses a linear function and two constant values as an approximation of this function. Using an AWGN channel model, simulation results show that the new algorithm is almost more than six times faster than Jacobi-log Map algorithm with a Bit Error Rate (BER) very close to it.  相似文献   

Evaluation of the remaining lateral torsional buckling capacity in corroded steel members     

Yasser Sharifi  Reza Rahgozar 《浙江大学学报(A卷英文版)》2010,11(11):887-897

Corrosion is one of the main causes of deterioration in steel structures. Loss of thickness in flanges and web of corroded steel beams leads to reduction in section properties which can reduce the lateral torsional buckling capacity of the member. In this paper, thickness loss data were compiled from four samples of corrosion damaged I-beams removed from a petro-chemical plant. Visual examination of the four corroded beams showed that they were corroded uniformly. To improve the accuracy of the results, a large number of measurements for surface roughness were taken for each beam, totally 770 values to obtain the average thickness of flanges and web of each beam. The data was used to develop a corrosion decay model in order to calculate the percentage remaining lateral torsional buckling capacity of long and short span beams which are laterally unrestrained. To estimate the percentage of remaining lateral torsional buckling capacity in the corroded damaged I-beams, the readily available minimum curves for different types of universal beams in conj unction with information on the thickness loss were used. The results can be used by practicing engineers for better estimation on the service life of deteriorated steel structures.  相似文献   

The Normal Family of Linear Systems     

F. M. Reza 《Journal of The Franklin Institute》1985,320(6)

The normal family of linear (time-variant) n-ports is introduced as the most natural extension of ordinary scalar driving-point immittance behaviour. The normality induces a certain symmetry and simplicity which merits due emphasis in future n-port research investigations. As an application of the concept of normality the overdamped-underdamped criterion is extended to n-ports. Also, an interesting problem of maximal power transfer is solved and the absolute energy invariant index calculated. This paper invites attention to the development of circuit synthesis procedures based on the algebraic structure of the normal family.  相似文献   

Restrictions of the derivatives of positive real functions     

F.M. Reza 《Journal of The Franklin Institute》1981,312(5):335-343

Dissipative operators appear in abundance in the study of dynamical systems. In the classical circuit theory they are presented as Positive Real Functions. The coefficients of the Taylor expansion of PRF (driving-point impedance or admittance) must satisfy certain derived inequalities. A method is suggested for obtaining restrictions of the derivative of Positive Real Functions (Dissipative Operators).  相似文献