On Loss Probabilities for Delayed - Access Circuit - Switched Multiplexers

Multiplexing schemes for packetized circuit-switched sources are characterized by an avoidable accessing delay. In the present work it is shown that, contrary to conventional immediate-access multiplexing schemes, one can introduce two different definitions of loss probability in the delayed-access case. Explicit analytical expressions are given for each definition, and a numerical example is presented which highlights the difference between them

Structural Design Of Arch Profile And Depth — A Computer-Aided Study

This paper presents a comparative study of some of the best known and widely used arch profiles, in an endeavour to investigating their structural performance and to determining optimum arch form and depth. Arch profiles herein studied comprise three categories, namely: 1) Profiles each with one center on axis of symmetry, 2) Profiles with two centres symmetrically disposed on arch base, 3) Profiles with three centres, two of which are located at the extrados points of base while the third common center is positioned on the axis of symmetry. For all these profiles, both bending moment and normal force distributions are obtained using the stiffness matrix method, the arch being subdivided into twenty elements. Computations were run on computer. This study shows that while the lancet and segmental arch types rank best among the investigated arch profiles, the horseshoe profile proved to possess the least favourable form in as -far as developing stresses are concerned

Three Dimensional Analysis Of Skeletal Structures Considering Cracking

A three dimensional computer model has been developed to analyze space structures containing cracked members. A new stiffness matrix for cracked space members has been obtained. This model takes into consideration crack surface mixed mode displacements due to the presence of axial and shearing forces and bending and torsional moments. Based on the present analysis, the redistribution of internal forces and moments and deformations in structural members can be obtained taking into consideration the effect of crack size and location and geometry of the structure. Examples of place frame, plane grid and space frame have been analyzed using a computer program developed based on the present model. This analysis can be employed to identify overstressed regions in plane or space structures due to members cracking

Software For On-Line Monitoring Of E10-B Telephone Exchange

The proposed software aims at enhancing the monitoring of the E10-B telephone exchange. It combines functions normally performed by two dedicated hardware devices and facilitates access to detailed maintenance information contained in manuals. The equipment required to run the software is a standard IBM-compatible XT (or higher) computer. Field trials of the software demonstrate its successful operation. In addition, a demo version has been compiled to illustrate the program features on any standard IBM compatible PC

Design Of An E-Mail System For Personal Computers

The design of an Electronic-Mail system that can operate in a personal computer (PC) environment is presented. The underlying philosophy is based on a centralized mailbox approach, wherein a dedicated SERVER stores the mail submitted by an originating USER, and then delivers it to the recipient USER upon request. The software components for each of the USER and the SERVER are described in some detail, and the communication protocol governing the interaction between them is also presented