42567371
Token Systems that Self-Stabilize
Presents a novel class of mutual exclusion systems, in which processes circulate one token, and each process enters its critical section when it receives the token. Each system in the class is self-stabilizing; i.e. it it starts at any state, possibly one where many tokens exist in the system, it is guaranteed to converge to a good state where exactly one token exists in the system. The systems are better than previous systems in that their state transitions are noninterfering; i.e., if any state transition is enabled at any instant, then it will continue to be enabled until it is executed. This makes the systems easier to implement as delay-insensitive circuits. >
19852972
Distributed Instruction Set Computer Architecture
The Distributed Instruction Set Computer Architecture (DISC) is proposed as a fine-grained multiprocessing computer architecture. DISC uses a parallel instruction set and a distributed control mechanism to explore fine-grained, parallel processing in a multiple-functional-unit system. Multiple instructions are executed in parallel and/or out of order at the highest speed of n instructions/cycle, where n is the number of functional units. Based on this architecture, a hardware system is developed. Extensive studies were conducted on a behavioral DISC system model to investigate the performance level, the effect of program sizes, and the hardware utilization. Simulation showed that a DISC system incorporating 16 functional units can run 7.7 times faster than a single-functional-unit DISC system. >
27793990
Fail Safe Distributed Fault Diagnosis of Multiprocessor Systems
15881866
Performance analysis of circuit switching, baseline interconnection networks
Performance evaluation, using both analytical and simulation models, of circuit switching baseline networks is presented. Two configurations of the baseline networks, single and dual, are evaluated. In each configuration, two different conflict resolution strategies, drop and hold, are tried to see the performance difference. Our analytical models are based on a more realistic assumption. New analyses are given and are verified by simulation results. In single network configuration, it is shown that the drop strategy is better than the hold strategy in the case that the data transfer time is longer than 10 cycles under a high request rate. In the dual network configuration, five different communication strategies are investigated and the optimum performance level is shown to be dependent on the length of the data transfer time.
19123449
Operating System Kernel for a Reconfigurable Multiprocessor System
16106791
A microprocessor-controlled asynchronous circuit switching network
This paper describes an asynchronous circuit switching network for multiple-processor systems. Several circuit switching networks for various applications have been proposed and constructed. However, there are problems associated with these networks. The asynchronous circuit switching network possesses several features that can solve these problems. A three-stage fully connected topology is utilized to construct the network. Each switching element is functionally and physically identical and this facilitates a cost-effective LSI implementation and software development. The control structure of the switching element and the routing algorithm are re-organized to fit the asynchronous operation. The network takes advantage of low-cost microcomputers to do the distributed routing control and to implement the communication protocols. The graceful degradation characteristic in the network is provided by independent multiple paths existing between any pair of the source and the destination. A network monitor is incorporated to facilitate an adaptive routing strategy and to have the fault diagnostic capability. Three alternatives for the switching element implementation are described to demonstrate the hardware and software tradeoffs.
26993316
Construction of Cryptographically Important Boolean Permutations
Abstract.In this paper a new general methodology is developed to construct Boolean permutations such that any non-trivial linear combination of their components has the largest algebraic degree.
40955091
Hash channels
It is believed that in authentication protocols where no random numbers are involved, it is hard to introduce subliminal channels. In this paper we show that subliminal channels exist in digital signature schemes where no random numbers are used. The source where the subliminal channels exist is widely acceptable hash functions with their outputs being of some randomness. Because the subliminal channels are established by using hash functions, the subliminal channels are called hash channels in this paper. This indicates that there exist subliminal channels in any authentication protocols that use hash functions.
6331913
Speech content integrity verification integrated with ITU G.723.1 speech coding
A speech content integrity verification scheme integrated with ITU G.723.1 speech coding to minimize the total computational cost is proposed in this research. Speech features relevant to the semantic meaning are extracted, encrypted and attached as the header information. This scheme is not only much faster than cryptographic bitstream integrity algorithms, but also more compatible with a variable of applications. The speech signal could go through recompression, amplification, transcoding, re-sampling, D/A and A/D conversion and minor white noise pollution without triggering the verification alarm.
15660415
On-the-fly sharing for streamed aggregation
Data streaming systems are becoming essential for monitoring applications such as financial analysis and network intrusion detection. These systems often have to process many similar but different queries over common data. Since executing each query separately can lead to significant scalability and performance problems, it is vital to share resources by exploiting similarities in the queries. In this paper we present ways to efficiently share streaming aggregate queries with differing periodic windows and arbitrary selection predicates. A major contribution is our sharing technique that does not require any up-front multiple query optimization. This is a significant departure from existing techniques that rely on complex static analyses of fixed query workloads. Our approach is particularly vital in streaming systems where queries can join and leave the system at any point. We present a detailed performance study that evaluates our strategies with an implementation and real data. In these experiments, our approach gives us as much as an order of magnitude performance improvement over the state of the art.
11513370
A Quantitative Evaluation of Cache Types for High-Performance Computer Systems
Parallel accesses to the table lookaside buffer (TLB) and cache array are crucial for high-performance computer systems, and the choice of cache types is one of the most important factors affecting cache performance. The authors classify caches according to both index and tag. Since both index and tag could be either virtual (V) or real (R), their classification results in four combinations or cache types. The real address caches with virtual tags for high-performance computer systems in this study are prediction-based, since index bins are generated from a small array and predictions could be false. As a result, they also discuss and evaluate real address MRU caches with real tags, and propose virtually indexed MRU caches with real tags. Each of the four cache types and MRU caches are discussed and evaluated using trace-driven simulation. The results show that a virtually indexed MRU cache with real tags is a good choice for high-performance computer systems. >