This paper presents an adaptive QoS management scheme to accommodate dynamic variations in network resources, due to the mobility of the users and location-dependent errors. The scheme ensures that satisfactory levels...
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This paper presents an adaptive QoS management scheme to accommodate dynamic variations in network resources, due to the mobility of the users and location-dependent errors. The scheme ensures that satisfactory levels of QoS guarantees are met regardless of the user mobility. QoS adaptation is achieved based on the use of application specific quality satisfaction curves, while enforcing a fair allocation of bandwidth among the competing flows. The performance of the proposed scheme is evaluated and results indicate that the scheme yields fair adaptation under heavy loads.
This paper proposes an interactive architecture compiler for SC multirate circuits that allows the automated design from frequency specifications to building block implementation, here applied to the design and synthe...
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This paper proposes an interactive architecture compiler for SC multirate circuits that allows the automated design from frequency specifications to building block implementation, here applied to the design and synthesis of multistage SC decimators. The compiler provides a library of different topologies that comprises a few independent multi-decimation building blocks. New building blocks defined by the users are also available for design of a specific stage. A design example of a 7th order SC decimator illustrates the efficient synthesis of the corresponding resulting circuits that achieve the required anti-aliasing amplitude responses with respect to the speed requirements of the operational amplifiers and also the minimum capacitance spread and total capacitor area.
This paper presents an approach for grasping virtual objects in virtual environments with a data glove. Our focus lies on developing new methods that allow sensible realistic grasping gestures which correspond to huma...
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This paper presents an approach for grasping virtual objects in virtual environments with a data glove. Our focus lies on developing new methods that allow sensible realistic grasping gestures which correspond to human grasping behavior. To meet the demands of industrial applications, users must be able to grasp an object in an intuitive way with one or two hands and, beyond that, manipulate grasped objects between their fingers. To avoid the use of expensive force or touch feedback hardware, but also to ensure a safe grip on virtual objects, several forms of visual feedback are provided. First, we describe the basic algorithm for grasping with one or two hands and finally, we present a method to precisely manipulate the grasped objects between the virtual fingers.
A system of linear constraints is represented as a set of half-planes S = {(a j X + b j Y + c j ≤ 0) j = 1...N}. Therefore, in the context of linear constraints two terms “set” and &#...
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(纸本)354066856X
A system of linear constraints is represented as a set of half-planes S = {(a j X + b j Y + c j ≤ 0) j = 1...N}. Therefore, in the context of linear constraints two terms “set” and “system” can be used interchangeably whenever one of two is suitable. A set of linear constraints represents a convex polygon that is the intersection of all half-planes in the set. The convex polygon represented by S is called the feasible polygon of S. Such sets of linear constraints can be used as a new way of represent spatial data. These sets need to be manipulated efficiently and stored using minimal storage. It is natural to store only sets of linear constraints which are feasible and in irredundant format. Therefore, it is very important to find out if a given system is feasible and/or bounded and to find the minimal (irredundant) set of linear constraint which have the same feasible area with the given one. LASSEZ and MAHER (1988) have investigated algorithms to check if a system of linear constraints over multidimensional R d is feasible. LASSEZ et al (1989) have investigated algorithms to eliminate redundant constraints from a system of linear constraints over R d . Their algorithms are based on the Fourier variable elimination (similar with Gaussian elimination in solving the linear system of equations) and therefore have the running time O(N 2) where N is the number of constraints, and as such it is not efficient. DYER (1984) and MEGIDDO (1983) have independent proposed linear time algorithms to solve the linear programming problem in 2- and 3-dimension cases.
A modeling approach is introduced in this paper to capture the real characteristics of the WWW traffic, using a combination of Box-Jenkins models with seasonality removal. Fourier analysis and standardization are used...
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Hierarchical WWW cache formation which provides both higher hit rates and saves overall bandwidth consumption through fetching WWW objects and periodically redistributing them among member caches is proposed as an app...
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Software systems composed of highly reliable components may experience few, if any, failures while undergoing heavy testing or field usage. L.M. Kaufman et al. (1997, 1998) applied "statistics of the extremes&quo...
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Software systems composed of highly reliable components may experience few, if any, failures while undergoing heavy testing or field usage. L.M. Kaufman et al. (1997, 1998) applied "statistics of the extremes" to software reliability analysis for failure as an infrequent, unlikely occurrence /sub -/ /sub a/ so-called rare event. This paper combines (i) software failure as a rare event with (ii) a finite-state, discrete-parameter recurrent Markov chain that models both the failures (as transitions to a rare fail state) and the software usage probabilities (as transitions among usage states not involving the fail state). When conditions for rare events are met, reliability analysis in greater detail, with fewer assumptions, may be possible, and there may be additional justification for using the popular Poisson and exponential distributions for certain random variables. We describe how the Markov chain and the "Poisson law of small numbers", which has a central role in the study of rare events and extreme values, yield (a) an explicit error bound on a Poisson approximation for counts of failures as rare events in long realizations of the chain, and (b) an approximate exponential distribution for the interoccurrence time of failures as rare events. We compute both the Poisson error bound and /spl chi//sup 2/ goodness-of-fit tests for samples and the approximate distributions for a small Markov chain. A typical application of these results would be in the analysis of software reliability for systems of high-quality COTS components.
This paper proposes an interactive architecture compiler for SC multirate circuits, here applied to the design of multistage IIR SC decimators with large decimating factors M. This methodology is implemented based on ...
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This paper proposes a computer-automated synthesis of SC decimators with a high decimating factor based on the statistical approach of the program (ISCMRATE). This methodology is implemented based on multi-decimation ...
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This paper proposes a computer-automated synthesis of SC decimators with a high decimating factor based on the statistical approach of the program (ISCMRATE). This methodology is implemented based on multi-decimation building blocks, such as externally cascaded, internally cascaded or ladder structures and polyphase input networks. The design criteria are given to obtain and evaluate the performance of the corresponding resulting circuits. A design example of a 7/sup th/ order SC lowpass elliptic decimator with M=10 is given to illustrate the above proposed methodology.
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