ISSN:0253-3839    

DOI:10.1080/02533839.1995.9677725

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Optically interconnecteddistributed shared memory(OIDSM) systems offer significant performance advantages due to the fast interconnection network. The photonic network of the proposed approach is based on a wavelength‐division multiplexed (WDMA) passive star‐coupled configuration.Optical self‐routingwhich partitions the traffic and relaxes the design constraints on the receiver subsystem is achievable since a node now only receives and processes a fraction of the network traffic. A major concern with the multi‐access approach is that a media access control and a cache coherence protocol are required to provide access to a distributed arbitration of the WDMA photonic network. In particular, one class of media access protocol (TDMA‐C) requires a control channel to broadcast reservation requests. The broadcast capability is also able to support coherence level control signals such as invalidations which enable a snooping based coherence protocol. The object of this paper is to evaluate how OIDSM can ease the traffic in large‐scale snooping‐based shared memory multiprocessors. A semi‐Markov model‐is developed to study the performance of OIDSM. The analytical model has been validated by extensive simulation and evaluates the performance by varying the system's parameters.

ISSN:0253-3839    

DOI:10.1080/02533839.1995.9677726

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

On the basis of the experimental results, the behavior of the alkylation of 2,4,6‐tribromophenol in an alkaline solution of KOH/ organic solvent by phase transfer catalysis is described by a simplified kinetic model. This is due to a measured constant concentration of tetrabutylammonium 2,4,6‐tribromophenoxide (activecatalyst, ArOQ) during the reaction leads to the use of a pseudo‐steady‐state hypothesis in conjunction with the system parameters to build up the simplified kinetic model. The results of the model's prediction are very consistent with the experimental data which are obtained from the two‐phase phase transfer catalytic reaction. The mass transfer resistance of tetrabutylammonium 2,4,6‐tribromophenoxide from the aqueous phase to the organic phase, as well as the mass transfer resistance of tetrabutylammonium bromide from the organic phase to the aqueous phase is negligible. The step of the reaction in the organic phase will also be the rate‐determining step for the whole reaction system. The intrinsic reaction rate constant in the organic phase which is obtained from the organic phase reaction is almost equal to the value obtained in the two‐phase reaction.

ISSN:0253-3839    

DOI:10.1080/02533839.1995.9677727

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Two optic fiber sensing systems for temperature and voltage have been developed which utilize the mode‐mode interference of the two orthogonally polarized modes, HExIIand HEyII, in two commencal polarization‐maintaining fibers (bow‐tie and elliptical core fibers). A package of controlled programs in a Macintosh computer, which can record and process all related data automatically, is established for temperature sensing. The signal drifting problem in voltage sensings has been investigated, and the elimination of signal drifting is obtained by the phase tracking with direct current technology The agreement between the sensing results for temperature and dynamic voltage and those predicted by experimental principles is satisfactory, which confirms the validity of the developed sensing systems.

ISSN:0253-3839    

DOI:10.1080/02533839.1995.9677728

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

This study examines the effect of polyester multifilament oil, mill absolute humidity, and the effect of spreading voltage on multifilament spread width on properties of composite yarn. The results show the yarn spinnability and properties can be improved by the correct selection of oil type with oil contents at 0.7%, by controling absolute humidity and by adjusting spreading voltage to stabilize spread width at about 8∼10 mm. In addition, it can be increased about 30% in production with low twist and still retain excellent yarn properties; especially on a high tenacity, low imperfection index and only about 10% hairiness when compared with cotton‐rich spun yarn.

ISSN:0253-3839    

DOI:10.1080/02533839.1995.9677729

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Based on the concept of rhermoelasticity in a single‐phase elastic solid, we have investigated thermal stresses in a two‐phase composite media. A two‐phase composite slab and a concentric solid sphere were considered. The temperature distribution has been obtained by means of the Laplace transform. General formulas of thermal stresses in two‐phase composite are derived, and numerical examples are provided. For a constant average temperature and a constant surface temperature, the maximum transverse (or tangential) stress is located at the surface for both slab and sphere.

ISSN:0253-3839    

DOI:10.1080/02533839.1995.9677730

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

This paper first presents hierarchical scheduling and control architecture for a flexible manufacturing cell (FMC) that is currently set up at the Mechanical Industrial Research Laboratories of the Industrial Technology Research Institute at Hsinchu, Taiwan. With this architecture, we focus on the scheduling problem of the FMC and present a scheduling mechanism based on a colored timed Petri net (CTPN) model. The CTPN model has three functions in the proposed mechanism: the first one is to formally describe pallet flows and resource constraints in the FMC by the event‐condition relation; the second one is to analyze conflict points among the pallet flows; the third one is to evaluate the used dispatching rules concerned with the selection of machine routings, the selection of work‐in‐process pallets in inter‐medium buffers and the assignment of the commonly used material‐handling device. Using the CTPN‐based scheduler, anappropriatecombination of dispatching rules for each given batch can be selected to fit given criteria, e.g. minimum batch completion time, maximum resource utilization or minimum tardiness, etc. Moreover, real‐time status of the FMC can be represented in the mechanism for obtaining the on‐line scheduling effect.

ISSN:0253-3839    

DOI:10.1080/02533839.1995.9677731

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In this paper we apply the balancing reduction method to derive reduced‐order models for linear systems having multiple delays. The time‐domain balanced realization is achieved through computing the controllability and observability gramians in the frequency domain. With the variable transformations=itan(θ/2), the gramians of linear multi‐delay systems can be accurately evaluated by solving first‐order differential equations over a finite domain. The proposed approach is computationally superior to that of using the two‐dimensional realization of delay differential systems.

ISSN:0253-3839    

DOI:10.1080/02533839.1995.9677732

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In this study, we consider a Mixed Chinese Postman Problem in the form of an Integer Program and investigate its properties with both algebraic solutions and geometric configurations. The insights this study provides into their relationship have paved a way toward designing more efficient structural algorithm for finding an exact solution. Theoretical proofs are provided with numerical illustrations.

ISSN:0253-3839    

DOI:10.1080/02533839.1995.9677733

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A multi‐phase, multi‐component model which describes contaminant transport in the unsaturated zone is developed in this work. The model incorporates the heterogeneity of pore fluid distribution and inducing gas‐phase advective transport. The numerical approximation scheme consists of finite difference method and the method of characteristics. For solving the system of equations, the method of over‐relaxation is employed. This model has been verified by a one‐dimensional analytical solution. The application of the model to the soil vapor extraction (SVE) system further demonstrates the suitability of the model. From analyzing the results from the application, we found that gas‐phase transport of volatile contaminants nearly above the water table is relatively ineffective (due to low volumetric content of pore air and correspondingly low gas‐phase permeability). In addition to the assessment of the effectiveness of SVE systems, aqueous‐gas interphase mass transfer is observed dominating the contaminant transport during the process of sensitivity analysis. Therefore, Henry's law constant is strongly suggested to be included in the definition of mobility of volatile organic contaminants in the unsaturated zone.

ISSN:0253-3839    

DOI:10.1080/02533839.1995.9677734

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor