In this paper, we show that for elections in distributed systems the conversion from non-binary choices to binary choices does not always provide optimal results when the preferences of nodes are not identical. With t...
详细信息
作者：
FRANK, EHGRODZINSKY, AJContinuum Electromechanics Group
Laboratory for Electromagnetic and Electronic Systems Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA U.S.A.
Articular cartilage contains a high fixed charge density under physiological conditons associated primarily with the ionized proteoglycan molecules of the extracellular matrix. Oscillatory compression of cartilage usi...
详细信息
Articular cartilage contains a high fixed charge density under physiological conditons associated primarily with the ionized proteoglycan molecules of the extracellular matrix. Oscillatory compression of cartilage using physiological loads produces electrical potentials that have been shown previously to be the result of an electrokinetic (streaming) transduction mechanism. We have now observed two additional electromechanical phenomena not previously seen in cartilage or other soft tissues: ''streaming current'' and ''current-generated stress''. Sinusoidal mechanical compression induced a sinusoidal streaming current density through cartilage disks when the Ag/AgCl electrodes that were used to compress the cartilage were shorted together externally. Conversely, a sinusoidal current density applied to the tissue generated a sinusoidal mechanical stress within the tissue. Both these phenomena were found to be consistent with the same electrokinetic transduction mechanism responsible for the streaming potential. Changes in the measured streaming potential response that resulted from modification of both ionic strength and pH have provided additional insights into the molecular origins of these transduction processes. Finally, we have now observed streaming potentials in living cartilage maintained in organ culture, as well as in previously frozen tissue.
Both sessions on Tuesday morning (March 22, 1983) were devoted Io the discussion of Distributed Debugging. Three papers were presented durhlg the first part;then there was a lively panel discussion on Multiprocess and...
详细信息
Network operators connect their backbone networks together at peering points. It is well known that the peering points are the most congested parts of the backbone network. Network operators have little incentive to p...
详细信息
This paper presents the building blocks and design procedure necessary for creating a component-invariant second-order Switched Current (SI) Sigma-Delta Modulator (Σ M). A novel SI second-order integrator block is pa...
详细信息
Recently, security in embedded system arises attentions because of modern electronic devices need cau- tiously either exchange or communicate with the sensitive data. Although security is classical research topic in...
详细信息
Recently, security in embedded system arises attentions because of modern electronic devices need cau- tiously either exchange or communicate with the sensitive data. Although security is classical research topic in world- wide communication, the researchers still face the problems of how to deal with these resource constraint devices and en- hance the features of assurance and certification. Therefore, some computations of cryptographic algorithms are built on hardware platforms, such as field program gate arrays （FPGAs）. The commonly used cryptographic algorithms for digital signature algorithm （DSA） are rivest-shamir-adleman （RSA） and elliptic curve cryptosystems （ECC） which based on the presumed difficulty of factoring large integers and the algebraic structure of elliptic curves over finite fields. Usu- ally, RSA is computed over GF（p）, and ECC is computed over GF（p） or GF（2P）. Moreover, embedded applications need advance encryption standard （AES） algorithms to pro- cess encryption and decryption procedures. In order to reuse the hardware resources and meet the trade-off between area and performance, we proposed a new triple functional arith- metic unit for computing high radix RSA and ECC operations over GF（p） and GF（2P）, which also can be extended to support AES operations. A new high radix signed digital （SD） adder has been proposed to eliminate the carry propagations over GF（p）. The proposed unified design took up 28.7% less hardware resources than implementing RSA, ECC, and AES individually, and the experimental results show that our proposed architecture can achieve 141.8 MHz using approxi- mately 5.5k CLBs on Virtex-5 FPGA.
This paper presents the design of a switched-current (SI) Double-Integrator Sigma-Delta Modulator (DISDM) for A/D conversion that is intended for voice-band (4kHz) telecommunication applications. With the creation of ...
详细信息
We propose a method for the time scaling of digitally sampled audio signals using a three part signal model consisting of sines+transients+noise. The three part model provides an accurate and flexible parametric repre...
详细信息
The dynamic linear state feedback control problem is addressed for a class of nonlinear systems subject to ***,using the dynamic change of coordinates,the problem of global state feedback stabilization is solved for a...
详细信息
The dynamic linear state feedback control problem is addressed for a class of nonlinear systems subject to ***,using the dynamic change of coordinates,the problem of global state feedback stabilization is solved for a class of time-delay systems under a type of nonhomogeneous growth *** the aid of an appropriate Lyapunov-Krasovskii functional and the adaptive strategy used in coordinates,the closed-loop system can be globally asymptotically stabilized by the dynamic linear state feedback *** growth condition in perturbations are more general than that in the existing *** correctness of the theoretical results are illustrated with an academic simulation example.
Extensive efforts have been made in designing large multiple-input multiple-output(MIMO)arrays. Nevertheless, improvements in conventional antenna characteristics cannot ensure significant MIMO performance improvement...
详细信息
Extensive efforts have been made in designing large multiple-input multiple-output(MIMO)arrays. Nevertheless, improvements in conventional antenna characteristics cannot ensure significant MIMO performance improvement in realistic multipath environments. Array decorrelation techniques have been proposed, achieving correlation reductions by either tilting the antenna beams or shifting the phase centers away from each other. Hence, these methods are mainly limited to MIMO terminals with small arrays. To avoid such problems, this work proposes a decorrelation optimization technique based on phase correcting surface(PCS)that can be applied to large MIMO arrays, enhancing their MIMO performances in a realistic(non-isotropic)multipath environment. First, by using a near-field channel model and an optimization algorithm, a near-field phase distribution improving the MIMO capacity is obtained. Then the PCS(consisting of square elements)is used to cover the array's aperture, achieving the desired near-field phase *** examples demonstrate the effectiveness of this PCS-based near-field optimization technique. One is a1 × 4 dual-polarized patch array(working at 2.4 GHz)covered by a 2 × 4 PCS with 0.6λ center-to-center distance. The other is a 2 × 8 dual-polarized dipole array, for which a 4 × 8 PCS with 0.4λ center-to-center distance is designed. Their MIMO capacities can be effectively enhanced by 8% and 10% in single-cell and multi-cell scenarios, respectively. The PCS has insignificant effects on mutual coupling, matching, and the average radiation efficiency of the patch array, and increases the antenna gain by about 2.5 dB while keeping broadside radiations to ensure good cellular coverage, which benefits the MIMO performance of the *** proposed technique offers a new perspective for improving large MIMO arrays in realistic multipath in a statistical sense.
暂无评论