A recursive cellular representation for configuration space is presented along with an algorithm for searching that space for collision-free paths. The details of the algorithm are presented for polygonal obstacles an...
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A recursive cellular representation for configuration space is presented along with an algorithm for searching that space for collision-free paths. The details of the algorithm are presented for polygonal obstacles and a moving object with two translational and one rotational degrees of freedom.
The diffraction of TE- and TM-polarized plane waves by planar gratings is numerically analyzed using a combined FEM/MoM algorithm based on the generalized network formulation. The interior region, treated using the FE...
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The diffraction of TE- and TM-polarized plane waves by planar gratings is numerically analyzed using a combined FEM/MoM algorithm based on the generalized network formulation. The interior region, treated using the FEM, is truncated to a single unit cell with the introduction of an exact periodic boundary condition, which is enforced as a natural boundary condition. By employing the finite element method to compute the fields within the periodic structure, gratings of arbitrary cross section and material composition can be efficiently modeled.
A new LMS-type adaptive filter with a variable step size is introduced. The step size increases or decreases as the mean-square error increases or decreases, allowing the adaptive filter to track changes in the system...
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A new LMS-type adaptive filter with a variable step size is introduced. The step size increases or decreases as the mean-square error increases or decreases, allowing the adaptive filter to track changes in the system as well as produce a small steady state error. The convergence and steady state behavior of the algorithm are analyzed. These results reduce to well-known ones when specialized to the constant step size case. Simulation results are presented to support the analysis and to compare the performance of the new algorithm with the usual LMS algorithm and another variable step algorithm. They show that the performance of the new algorithm compares favorably with these existing algorithms.
Antenna design involves a set of complex requirements that may conflict. Some of these requirements are frequently expressed in terms of antenna parameters, such as radiation pattern, voltage standing wave ratio (VSWR...
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Antenna design involves a set of complex requirements that may conflict. Some of these requirements are frequently expressed in terms of antenna parameters, such as radiation pattern, voltage standing wave ratio (VSWR) or impedance. In general, antenna requirements are specified for a frequency band or a set of frequencies. In some cases, the designer may create an antenna draft by trial and error until some performance goals are reached. Occasionally, this process may be simple, but in others, the number of variables makes it difficult to easily meet all of the goals. Alternatively, antenna design can be seen as an intricate error surface in an N-dimensional space. In this space, moving the solution over its surface in one direction may be good for some of the goals, but bad for others. Regularly, this error surface is difficult to travel through for most optimization algorithms. In previous works, genetic algorithms (GAs) have been used to assist the designer in this complicated process. This article proposes a hybrid method using artificial intelligence to design and optimize antennas. First, simulated annealing (SA) is used to draft the antenna. Second, the draft is improved until most of the performance goals are achieved.
We present the analytical model and the electrical characterization of a controllable delay component for a micropipeline architecture suitable for being designed with a semicustom design approach. An interesting feat...
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We present the analytical model and the electrical characterization of a controllable delay component for a micropipeline architecture suitable for being designed with a semicustom design approach. An interesting feature of the component is that it is lockable, i.e., it can be controlled in an on/off fashion, permitting synchronous operation for testing purposes by means of an opportune architecture model.
Lower bounds on the number of states are exhibited in a fixed rate finite-state encoder that maps unconstrained n-ary sequences into a given set of constrained sequences, defined by a finite labeled graph G. In partic...
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Lower bounds on the number of states are exhibited in a fixed rate finite-state encoder that maps unconstrained n-ary sequences into a given set of constrained sequences, defined by a finite labeled graph G. In particular, one simple lower bound is given by min(x)max-upsilon-x-upsilon where x = [x-upsilon] ranges over certain (nonnegative integer) approximate eigenvectors of the adjacency matrix for G. In some sense, our bounds are close to what can be realized by the state splitting algorithm, and in some cases, they are shown to be tight. In particular, these bounds are used to show that the smallest (in number of states) known encoders for the (1,7) and (2,7) runlength-limited systems are indeed the smallest possible. For any given constrained set S of sequences, we apply these bounds to study the growth of the number of states in families of encoders whose rates approach the capacity of S.
A description is given of the algorithms designed for use in residential load control systems. The authors present the functions to be fulfilled by such a price-responsive device and describe the end-user devices avai...
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A description is given of the algorithms designed for use in residential load control systems. The authors present the functions to be fulfilled by such a price-responsive device and describe the end-user devices available in residences and the control logics applicable to each. It is concluded that there is a need to understand customer attitudes and acceptance in the design of the response strategies and in the design of the man-machine interface.< >
We investigate 100 Mb/s wireless nondirectional infrared communication in the indoor environment using baseband nonreturn-to-zero (NRZ) on-off keying (OOK) modulation, We show that intersymbol interference induced by ...
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We investigate 100 Mb/s wireless nondirectional infrared communication in the indoor environment using baseband nonreturn-to-zero (NRZ) on-off keying (OOK) modulation, We show that intersymbol interference induced by multipath propagation impairs detection efficiency, Analytical and simulation results on specific channels demonstrate that an adaptive decision-feedback equalizer adapted according to the least-mean-squares algorithm recovers most of the performance degradation, We also evaluate the performance of a timing-recovery phase-locked loop operating independent of the adaptive equalizer;showing that it quickly and accurately determines the sampling phase with negligible performance degradation, We discuss effective methods of mitigating low-frequency noise induced by fluorescent lighting, We present a packet-based communication method and describe its features and performance, Our results support the feasibility of communication at 100 Mb/s over the infrared channel.
This paper analyzes adaptive algorithm 3 (AA3) of adaptive self-organizing concurrent systems (ASOCS) and proves that AA3 correctly fulfills the rules presented. Several different models for ASOCS have been developed....
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This paper analyzes adaptive algorithm 3 (AA3) of adaptive self-organizing concurrent systems (ASOCS) and proves that AA3 correctly fulfills the rules presented. Several different models for ASOCS have been developed. AA3 uses a distributed mechanism for implementing rules so correctness is not obvious. An ASOCS is an adaptive network composed of many simple computing elements operating in parallel. An ASOCS operates in one of two modes: learning and processing. In learning mode, rules are presented to the ASOCS and incorporated in a self-organizing fashion. In processing mode, the ASOCS acts as a parallel hardware circuit that performs the function defined by the learned rules.
The existence of redundant stuck-faults in a logic circuit is potentially detrimental to high-speed operation, especially when there are false paths that are longer than the circuit delay [13], [10]. Keutzer, Malik, a...
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The existence of redundant stuck-faults in a logic circuit is potentially detrimental to high-speed operation, especially when there are false paths that are longer than the circuit delay [13], [10]. Keutzer, Malik, and Saldanha (KMS) [10] have proved that redundancy is not necessary to reduce delay by presenting an algorithm that derives an equivalent irredundant circuit from a given redundant circuit, with no increase in delay. The KMS algorithm consists of an iterative loop of timing analysis, gate duplications, and redundancy removal to successively eliminate long false paths. In this paper we resolve the main bottlenecks of the KMS algorithm by providing an efficient single-pass algorithm to simultaneously remove all long false paths from a given circuit. We achieve this by relating a circuit structure property based on path lengths to the testability (redundancy) and delay. The application of this algorithm to a variety of related logic synthesis problems is described.
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