摘要:

AbstractThis paper considers the simulation method for the performance evaluation based on the formally described protocol specifications. Here, the simulation using the FSM model is outlined first, and a model called unitary token model, which is derived by simplifying the FSM model, is proposed. The configuration of an experimental system is presented which reads in such a model and executes the simulation. Then the data transfer by four layers, i.e., the transport and the lower layers in OSI model, is considered and an example is shown where the simulation actually is executed for evaluation.From the viewpoint of the method of analysis, the model for the individual process in this paper is the general FSM model, but the waiting due to the sharing of the CPU and the channel among processes is considered as a part of the computation in the simulation. By this elaboration, the performance can be evaluated based on the independent descriptions, even in a situation where several kinds of communications exist as in the case of the two‐way communication and the multiplex system. In the simplified model, the result of evaluation can be obtained in a simple way by reducing the task in the execution, by pre‐examining the communication protocol that is executed iteratively by the proc

ISSN:0882-1666    

DOI:10.1002/scj.4690231301

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractIn the deductive database, a large number of query processing techniques has been proposed for the efficient processing of a large amount of data. Several deductive databases actually were proposed based on those techniques. There are only few cases among those, however, where such a system is applied to the practical problem. Consequently, it is not clear to what type of actual problems the deductive database can be applied.In the CAD system, the “indirect” and “conditional” connection relations among components must be specified to utilize the design diagram more efficiently. It is proposed that the techniques of the deductive database can effectively be applied to such a problem to determine efficiently the connection relations. A prototype system was constructed to demonstrate the idea. The prototype is applied to a practical problem and the performance is evaluated. It is shown that the deductive database can effectively be applied to the forementioned problem.In the course of this experiment, several observations are made concerning the realization of the query processing method in the deductive database. This paper outlines the constructed prototype system and discusses the result of evaluation. The range of application for the deductive database as well as the practical usefulness are di

ISSN:0882-1666    

DOI:10.1002/scj.4690231302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThis paper considers a relational database processing system and proposes a new high‐performance secondary memory system and a functional disk system aiming at the high‐speed processing. The traditional commercial relational DBMS employs the simple nest‐loop and sort‐merge as processing methods for relational algebra operations. However, the proposed functional disk system employs the dynamic clustering algorithm so that the processing load is reduced drastically. Such processes as the hash operation, the cluster management mechanism, the record extraction from the physical block and on‐the‐fly operation, which takes time by the software, are implemented by hardware. The clustering following the data transfer from the disk is then realized.The performance is improved further by using several processors so that the generated clusters are processed in parallel. Usually, the performance is deteriorated greatly due to the mismatch between OS and DBMS constructed on OS. To solve this problem, the dedicated input/output driver and the buffer management routine were developed in the functional disk system by optimizing the dynamic clustering technique.The functional disk system aims at the drastic performance improvement by introducing the database processing mechanism into the secondary memory system. To verify the effectiveness of this idea, an experimental system was constructed. In spite of the simple structure composed of a disk and 4 MC68020, the experimental system achieved a much higher performance than the existing commercial relational database system in the performance evaluation using the Wisconsin benchmark. Thus, the effectiveness of the functional disk system

ISSN:0882-1666    

DOI:10.1002/scj.4690231303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractA system is proposed for high‐speed switching from the on‐line unit to the back‐up unit in hot‐standby systems for high reliability. In a hot‐standby system it is necessary to transfer periodically the memory contents of the on‐line unit as checkpoint data to the memory of the back‐up unit so that the back‐up unit can take over in case of a system fault. The proposed method guarantees that there is no file update between consecutive checkpoints by transferring checkpoint data whenever a file is updated. Because of that, the journal for file recovery is not necessary, thus making the downtime short. The downtime and overhead of this method are compared quantitatively with those of the conventional method. The results show that in this proposed method the overhead is within the allowable range, the downtime is about 2 s, and the system downtime cannot be reco

ISSN:0882-1666    

DOI:10.1002/scj.4690231304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThis paper proposes a parallel optimization algorithm PDF/IHS for the minimum execution‐time multiprocessor scheduling problem which is a strong NP‐hard optimization problem. PDF/IHS is a parallelization and efficient implementation of the only practical optimization algorithm DF/IHS among those which have been proposed for this scheduling problem. In PDF/IHS, processors perform depth‐first search in parallel on a heuristically generated search tree in such a way that it is searched hierarchically from the left‐ and right‐hand sides.The effectiveness of PDF/IHS has been verified by simulation and practical parallel processing on Alliant FX4. As a result, it has been recognized that most of the problems which required a long time by DF/IHS can be solved approximately in time 1/mby PDF/IHS usingmprocessors. Moreover, even for a problem which required a very long time or could not be solved in a practical time by DF/IHS, it has been verified that PDF/IHS can give solutions in time less

ISSN:0882-1666    

DOI:10.1002/scj.4690231305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractIn the real world, there are many propositions which cannot be determined to be true or false. In order to treat such propositions, multivalued logic systems which are permitted to take more than true (1) or false (0) values have been developed. In this paper, we will describe fundamental properties of multivalued Kleenean functions, which are effective for treating ambiguity. First, we will introduce a partial order relation into the set of truth values {0, 1/(m‐ 1), …, (m‐ 2)/(m‐ 1), 1}. It will be shown that any multivalued Kleenean function is monotone for this partial order relation. Next, it will be shown that any multivalued Kleenean function can be determined uniquely for inputs {0, 1/2, 1} only. Finally, we will describe P‐type logic functions for multivalued Kleenean functions which are capable of correcting input

ISSN:0882-1666    

DOI:10.1002/scj.4690231306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThis paper discusses the system “IDATEN,” which can process color dynamic images at the video rate. The pipeline architecture, which has previously been presented, has a high potential for high‐speed image processing. However, a problem in this architecture is the lack of flexibility since processors are connected in cascade.To cope with this problem, the authors have devised a “reconfigurable pipeline,” where high‐speed processors can be connected by a network in a flexible way. This flexible architecture utilizes a control mechanism to synchronize the image processing to the start of the frame, a color dynamic image processor, and hardware which sends control instructions simultaneously to the RGB processors.A basic software system also is developed which provides convenient control of IDATEN while maintaining the hardware functions. The software allows the user to specify the connections among the processors, set the parameters of the processors, and read or update the image memory and the result of operation of the feature variables at a high speed. The high speed and flexibility of IDATEN is verified by

ISSN:0882-1666    

DOI:10.1002/scj.4690231307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractIn recent years there has been a renewal of interest in recurrent neural networks (RNN) because learning algorithms for RNN have been derived by several independent groups. The network can express spatiotemporal patterns as the states of the neurons change with time. Since the network has connections with feedback loops between each neuron, it includes the majority of conventional neural network models.The characteristics of three supervised learning algorithms are discussed from the viewpoint of: (1) formulations of gradient of the total squared error function; and (2) the number of calculations and amount of storage space, respectively. Through computer simulations the differences of convergence for each learning algorithm are investigated. For the backpropagation through time algorithm it is shown that the learning surface of RNN has two specific shapes, i.e., hills and valleys, and the learning descends gently on the steepest gradient forward along the bottom of a curved valley. These characteristics are basically consistent with those of the multilayer neural networks (MNN) analyzed by Gouhara and others.

ISSN:0882-1666    

DOI:10.1002/scj.4690231308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY