The distribution of station locations in a CSMA network can have significant effect on network throughput. In this paper, we develop an analytic model for unslotted, non-persistent CSMA bus network where the stations are uniformly distributed along the bus. We derive a closod form expression for throughput approximation, and discuss the fairness of CSMA protocol using the bus topology. Analytic and simulation results are presented and compared.

This paper proposes a Tree-structured Database Machine (TDM), which is designed for supporting large relational database systems. The TDM aims at totally improving three level performance bottlenecks in relational database systems, i.e. data transfer bottleneck, data processing bottleneck, and multiquery optimization bottleneck. For reducing these bottlenecks, the TDM provides the approaches of data partition and data distribution upon data storages for concurrent data accesses, the tree-structured multipro…

C-POREL is a distributed relational data base management system, with full distribution transparency. A relation can be horizontally fragmented into several subrelations allocated to different sites. When two or more fragmented relations appear in a join query, many-to- many semijoins between correspondent relations are usually needed in order to fully reduce relations involved. Distribution dependent attributes of a relational schema are defined in this paper. An optimization approach of distributed join w...

In addition to Chinese character I/O, one of the most important issues for Chinese information processing is automatic extraction of words from textual data. Having discussed the characteristics of Chinese words and sentences, we proved in this paper that this problem cannot be thoroughly resolved. Then, various algorithms for extraction of words from Chinese sentences are reviewed. Finally, a new algorithm is put forward, based on which a highly automatic Chinese information processing system has been deve…

A real-time synchronization algorithm for interprncessor communication is presented, which is based on the techniques of Reference 2, except that buffered communication is used. The upper and lower bounds of the mean response time of this algorithm is derived.

This paper proposes a systolic finite multiplier, which appears to function reasonably. And it shows that systolic architecture is a useful design tool for compute- bound applications.

This paper presents an online diagnosable fault-tolerant system: N-unit t-fault tolerablesystem. The number of units N in the system can be either odd or even. The relationshipbetween N and t (the number of faulty units which can be tolerated) is presented. The approachof an optimum N- unit t-fault tolerable system is also given. As an example, a 4-unit 2-faulttolerable system is discussed. The reliability and mean time to failure of 4-unit 2-fault tolerablesystem are shown to be higher than 5MR (5-modular redundancy) and TMR (Triple ModulerRedundancy) system reliabilities. The amount of hardware components in a 4-unit t-faulttolerable system is simpler than 5MR. The complexity of switching circuit for N-unit t-faulttolerable system increases only linearly with respect of the number of modules. Our scheme isalso simpler than the hybrid redundancy system. Some theorems for the online diagnosis of N-unit t-fault systems are given and proved.