1336097
Distributed synchronous control units for dataflow graphs under allocation of telescopic arithmetic units
In order to enjoy the performance improvement effects of variable computation time arithmetic units at a system level, we propose a new synchronous control unit design methodology for dataflow graphs under allocation of a telescopic arithmetic unit, which is one of the well-known synchronous variable computation time arithmetic units. The proposed method generates an independent synchronous controller for each component arithmetic unit, and builds a distributed synchronous control unit through integrating the derived controllers. The distributed structure of the final synchronous control unit maximizes the performance improvement effect of telescopic arithmetic units through a complete preservation of original concurrency among operations.
1639783
High performance asynchronous on-chip bus with multiple issue and out-of-order/in-order completion
In this paper, we propose a high performance asynchronous on-chip bus with multiple issue and in-order/out-of-order completion for a Globally Asynchronous Locally Synchronous (GALS) design. The proposed bus implementation can be characterized with distributed and modularized control units based on a layered architecture to support multiple issue and in-order/out-of-order completion. Simulation results reveal that throughputs of asynchronous on-chip buses with multiple issue and in-order/out-of-order completion increases by 31.3% / 34.3%, while power consumption overhead is only 6.76% / 3.98% respectively, compared to a simple asynchronous on-chip bus with only a single issue feature.
14687978
Procedural Constraints in the Extended RBAC and the Coloured Petri Net Modeling
This paper presents the Coloured Petri Net modeling for security analysis of the Extended Role Based Access Control systems.
7800252
Imprecise data computation for high performance asynchronous processors
Instruction level parallelism(ILP) is strictly limited by various dependencies. In particular , data dependency is the major performance bottleneck of data intensive applications. To accelerate the execution of sequential code serialized due to data dependencies, this paper proposes an imprecise computation as a fast data computing technique for a high-performance asynchronous processor. To show the performance benefits of the suggested computing model, simulation results are presented. The imprecise computation can be used effectively in data intensive processing with a microprocessor, a Digital Signal Processor or a multimedia processor.
47092701
Loop formulas for circumscription
Clark's completion is a simple nonmonotonic formalism and a special case of many nonmonotonic logics. Recently there has been work on extending completion with "loop formulas" so that general cases of nonmonotonic logics such as logic programs (under the answer set semantics) and McCain-Turner causal logic can be characterized by propositional logic in the form of "comple(ion + loop formulas". In this paper, we show that the idea is applicable to McCarthy's circumscription in the propositional case. We also show how to embed propositional circumscription in logic programs and in causal logic, inspired by the uniform characterization of "completion + loop formulas".
3162456
Predicting human interruptibility with sensors
A person seeking another person's attention is normally able to quickly assess how interruptible the other person currently is. Such assessments allow behavior that we consider natural, socially appropriate, or simply polite. This is in sharp contrast to current computer and communication systems, which are largely unaware of the social situations surrounding their usage and the impact that their actions have on these situations. If systems could model human interruptibility, they could use this information to negotiate interruptions at appropriate times, thus improving human computer interaction.This article presents a series of studies that quantitatively demonstrate that simple sensors can support the construction of models that estimate human interruptibility as well as people do. These models can be constructed without using complex sensors, such as vision-based techniques, and therefore their use in everyday office environments is both practical and affordable. Although currently based on a demographically limited sample, our results indicate a substantial opportunity for future research to validate these results over larger groups of office workers. Our results also motivate the development of systems that use these models to negotiate interruptions at socially appropriate times.
1519617
Distributed parallel data storage systems: a scalable approach to high speed image servers
We have designed, built, and analyzed a distributed parallel storage system that will supply image streams fast enough to permit multi-user, “real-time”, video-like applications in a wide-area ATM network-based Internet environment. We have based the implementation on user-level code in order to secure portability; we have characterized the performance bottlenecks arising from operating system and hardware issues, and based on this have optimized our design to make the best use of the available performance. Although at this time we have only operated with a few classes of data, the approach appears to be capable of providing a scalable, high-performance, and economical mechanism to provide a data storage system for several classes of data (including mixed multimedia streams), and for applications (clients) that operate in a high-speed network environment.
1514436
Dynamic monitoring of high-performance distributed applications
Developers and users of high-performance distributed systems often observe performance problems such as unexpectedly low throughput or high latency. Determining the source of the performance problems requires detailed end-to-end instrumentation of all components, including the applications, operating systems, hosts, and networks. However, one must be very careful to design the instrumentation to have extremely low overhead, and not affect the system being monitored. In this paper we present a very light-weight instrumentation system that can be dynamically activated to unobtrusively collect and aggregate detailed end-to-end monitoring information from distributed applications. We also show how emerging "web services" can be used to facilitate remote interaction with this system.
26557344
A Knowledge-Based Approach to Rank Documents for Boolean Queries