Advances in signal processing allow us to model the audio signal in terms of mathematical representation. Compressed audio signal are also important for low-bit-rate media in order to minimize transmission cost. Appli...
详细信息
Advances in signal processing allow us to model the audio signal in terms of mathematical representation. Compressed audio signal are also important for low-bit-rate media in order to minimize transmission cost. Applications such as movies on compact disc, audio conferencing, and digital television also require a good model for the audio compression. We present a model for compressed audio signal. By varying different modelling parameters, we obtain the simulation result of the proposed model of the audio coder. Simulation results found that it has a good compression Ssignal-to-noise ratio compared with NICAM, CD, and OCF coders.
The Convex SPP-1000 is the first commercial implementation of a new generation of scalable shared memory parallel computers with full cache coherence. It employs a hierarchical structure of processing communication an...
详细信息
The Convex SPP-1000 is the first commercial implementation of a new generation of scalable shared memory parallel computers with full cache coherence. It employs a hierarchical structure of processing communication and memory name-space management resources to provide a scalableNUMA environment. Ensembles of 8 HP PA-RISC7100 microprocessorsemploy an internal cross-bar switch and directory based cache coherence scheme to provide a tightly coupled *** to 16 processing ensembles are interconnected by a 4 ring network incorporating a full hardware implementation of the SCI protocol for a full system configuration of 128 processors. This paper presents the findings of a set of empirical studies using both synthetic test codes and full applications for the Earth and space sciences to characterize the performance properties of this new architecture. It is shown that overhead and latencies of global primitive mechanisms, while low in absolute time, are significantly more costly than similar functions local to an individual processor ensemble.
A novel execution model for rule application in active databases is developed and applied to the problem of updating derived data in the context of semantic, object-based database models. The execution model is based ...
详细信息
A novel execution model for rule application in active databases is developed and applied to the problem of updating derived data in the context of semantic, object-based database models. The execution model is based on the use of "limited ambiguity rules" (LARs), which permit disjunction in rule actions. The execution model essentially performs a breadth-first exploration of alternative extensions of a user-proposed update, and returns all "completions" of that update, where a "completion" is defined to be an extension of a user-proposed update that satisfies a family of natural conditions (e.g., that no constraints are violated). Given a semantic, object-based database model schema, integrity constraints as well as specifications of derived classes and attributes are compiled into a family of LARs. A formal proof of the correctness of the system is described.< >
To enhance reusability in the field of simulation, model bases must be equipped with powerful tools for retrieval, modification and aggregation of simulation models. In this paper, the role of database management syst...
详细信息
ISBN:
(纸本)078031381X
To enhance reusability in the field of simulation, model bases must be equipped with powerful tools for retrieval, modification and aggregation of simulation models. In this paper, the role of database management systems supporting a modeling environment is discussed and reuse oriented query interfaces are presented. Specifically, we advocate a graph browser operating on a semantic network of reusable components.
To enhance reusability in the field of simulation, model bases must be equipped with powerful tools for retrieval, modification and aggregation of simulation models. In this paper, the role of database management syst...
详细信息
To enhance reusability in the field of simulation, model bases must be equipped with powerful tools for retrieval, modification and aggregation of simulation models. In this paper, the role of database management systems supporting a modeling environment is discussed and reuse oriented query interfaces are presented. Specifically, we advocate a graph browser operating on a semantic network of reusable components.
The design of a prototype knowledge-based system for crystal structure determination is described. This system provides a framework which integrates the direct methods probabilistic strategies for solving crystal stru...
详细信息
The design of a prototype knowledge-based system for crystal structure determination is described. This system provides a framework which integrates the direct methods probabilistic strategies for solving crystal structures and databases of over 90000 fully determined crystal structures. At the core of the system is the concept of imagery, that is, the ability to construct and reason about images in creative and unique ways. The process of determining the structure of a crystal is likened to an iterative scene analysis, which draws from the long-term memory of structural motifs and the application of chemical and crystallographic rules. Taken individually, such analyses result in the recognition and comprehension of a specific chemical scene. Put together they provide insight into the three-dimensional grammar of chemistry and the rules of molecular recognition.< >
The case is made in this paper for encouraging the scientist to become familiar with architectural features of the. supercomputer in use. This is essential for a proper choice of an efficient computational procedure f...
详细信息
The case is made in this paper for encouraging the scientist to become familiar with architectural features of the. supercomputer in use. This is essential for a proper choice of an efficient computational procedure for a given problem, as demonstrated by matching two vectorized algorithms to the CDC CYBER 205 and its special features. The two problems reported here are the Monte Carlo method for lattice gauge theory calculations and the multigrid method for partial differential equation solvers, combined with the description of the relevant aspects of the CDC CYBER 205 architecture.
暂无评论