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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Aplicações das técnicas de multiplexação por divisão no tempo à concentração remota de dados / Aplications of time division multiplex techniques to remote data concentration

Piqueira, José Roberto Castilho 30 November 1982 (has links)
Apresentamos e analisamos as técnicas de multiplexação TDM convencional e estatística, para concentração remota de dados. Como exemplo estudamos o problema da Rede Transdata, em função da taxa de utilização dos terminais (p) e do fator de compressão dos códigos (d). As principais conclusões são: - A técnica TDM convencional proporciona uma economia da ordem de 50% em canais de voz, sem introduzir atrasos. - A técnica TDM estatística proporciona uma economia da ordem de 70% em canais de voz, introduzindo cerca de 80 ms de atraso, por terminal. Em vista do exposto, os fabricantes, os usuários e as concessionárias de telecomunicações devem procurar realizar um trabalho integrado, no sentido de viabilizar a utilização de tais técnicas. / The conventional and statistical TDM techniques are presented and analysed for remote data concentration. The Transdata network problem was analysed according to terminal utilization factors (p) and code compression factors (d). As main conclusions, we have: - TDM conventional multiplexers can give a 50% voice channel economy without delay. - TDM statistical multiplexers can give a 70% voice channel economy with 80 ms delay per terminal. Due to these factors, the producer, user and telecommunications operating company should try to implement an integrated programme in order to make possible the utilization of such techniques.
2

Aplicações das técnicas de multiplexação por divisão no tempo à concentração remota de dados / Aplications of time division multiplex techniques to remote data concentration

José Roberto Castilho Piqueira 30 November 1982 (has links)
Apresentamos e analisamos as técnicas de multiplexação TDM convencional e estatística, para concentração remota de dados. Como exemplo estudamos o problema da Rede Transdata, em função da taxa de utilização dos terminais (p) e do fator de compressão dos códigos (d). As principais conclusões são: - A técnica TDM convencional proporciona uma economia da ordem de 50% em canais de voz, sem introduzir atrasos. - A técnica TDM estatística proporciona uma economia da ordem de 70% em canais de voz, introduzindo cerca de 80 ms de atraso, por terminal. Em vista do exposto, os fabricantes, os usuários e as concessionárias de telecomunicações devem procurar realizar um trabalho integrado, no sentido de viabilizar a utilização de tais técnicas. / The conventional and statistical TDM techniques are presented and analysed for remote data concentration. The Transdata network problem was analysed according to terminal utilization factors (p) and code compression factors (d). As main conclusions, we have: - TDM conventional multiplexers can give a 50% voice channel economy without delay. - TDM statistical multiplexers can give a 70% voice channel economy with 80 ms delay per terminal. Due to these factors, the producer, user and telecommunications operating company should try to implement an integrated programme in order to make possible the utilization of such techniques.
3

THE DEVELOPMENT OF TELEMETRY SYSTEM IN CHINA

Chengliang, Li, Qishan, Zhang 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Telemetry as a research interest began to appear in the early days of this century. Since then it has gained great progress with its application fields growing all the time. This paper reviews briefly the history of telemetry introduces its state-of-the-art technology. The research activities and technological levels in this field inside China are included.
4

Možnosti implementace signalizačního systému číslo 7 v PBX Asterisk / Signalling system No. 7 implementations for Asterisk

Janíček, Martin January 2009 (has links)
Semestral project describes signaling system number 7, it's settings options and options of signaling over IP networks, especially two transport protocols SCTP and BICC for signaling SS7 over IP. Analyses kinds of implemetations of this signaling system to the Asterisk PBX with TDM E1 card support. Further part of this work is dedicated to the open source implementations libss7 of Digium and chan_ss7 which is currently developed by Dicea. Describes in detail their installation to the open source PBX Asterisk including testing of both and comparing these two open source solutions. Last part is focused on realization of gateway which converts communication from TDM network to IP network. For this part, three computers are used. First as SS7 signalling end softswitch, second as SIP signalling end softswitch and last as gateway between them. This gate works as interface between SS7 signalling and SIP signalling. Testing call was realized successfully for both directions.
5

AFFORDABLE GROUND STATION EQUIPMENT FOR COMMERCIAL AND SCIENTIFIC REMOTE SENSING APPLICATIONS

Chesney, James R., Bakos, Roger 11 1900 (has links)
International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / The remote sensing industry is experiencing an unprecedented rush of activity to deploy commercial and scientific satellites. NASA and its international partners are leading the scientific charge with The Earth Observation System (EOS) and the International Space Station Alpha (ISSA). Additionally, there are at least ten countries promoting scientific/commercial remote sensing satellite programs. Within the United States, commercial initiatives are being under taken by a number of companies including Computer Technology Associates, Inc., EarthWatch, Inc., Space Imaging, Inc., Orbital Imaging Corporation and TRW, Inc. This activity is due to factors including: technological advances which have lead to significant reductions in the costs to build and deploy satellites; an awareness of the importance of understanding human impact on the ecosystem; and a desire to collect and sell data some believe will be worth $1.5 billion (USD) per year within five years. The success and usefulness of these initiatives, both scientific and commercial, depends largely on the ease and cost of providing remotely sensed data to value added resellers and end-users. A number of these spacecraft will provide an interface directly to users. To provide these data to the largest possible user base, ground station equipment must be affordable and the data must be distributed in a timely manner (meaning seconds or minutes, not days) over commercial network and communications equipment. TSI TelSys, Inc. is developing ground station equipment that will perform both traditional telemetry processing and the bridging and routing functions required to seamlessly interface commercial local- and wide-area networks and satellite communication networks. These products are based on Very Large Scale Integration (VLSI) components and pipelined, multi-processing architectures. This paper describes TelSys’ product family and its envisioned use within a ground station.
6

A Framework for Quantifying Suburban Parking Maxima

LaPointe, James January 2009 (has links)
The provision and pricing of parking are recognized as important tools for achieving transportation demand management (TDM) objectives. Much of the existing literature on the topic concentrates on downtown cores and calls for the application of maximum parking allowances to limit supplies. This thesis presents an analysis of existing suburban parking supplies in order to quantify parking maxima. The total number of spaces provided, footprint required to accommodate the spaces and the employment to which parking is providing are quantified. The totals are separated by different land use categories and quantities of employment are normalized to account for high trip-generating jobs such as retail. Parking supplies are examined as a function of traditional land use market theory and across primary land use categories. The results indicate that employment is a fairly weak indicator of parking supply, while weighted employment that considers the effects of retail is a much stronger indicator. On average, very high and very low land use densities have the lowest parking requirements per employee (0.39 spaces per employee) while moderate land use densities have the least diversity of land use, yet the highest supply of employee parking (4.01 spaces per employee). The methodology applied may be used to produce quantitative maxima to be incorporated into local parking bylaws that are recognized as potentially strong TDM tools. Further research that compares the observed parking supply patterns across a series of mid-sized cities is recommended to make stronger conclusions regarding the range of maximum values.
7

A Framework for Quantifying Suburban Parking Maxima

LaPointe, James January 2009 (has links)
The provision and pricing of parking are recognized as important tools for achieving transportation demand management (TDM) objectives. Much of the existing literature on the topic concentrates on downtown cores and calls for the application of maximum parking allowances to limit supplies. This thesis presents an analysis of existing suburban parking supplies in order to quantify parking maxima. The total number of spaces provided, footprint required to accommodate the spaces and the employment to which parking is providing are quantified. The totals are separated by different land use categories and quantities of employment are normalized to account for high trip-generating jobs such as retail. Parking supplies are examined as a function of traditional land use market theory and across primary land use categories. The results indicate that employment is a fairly weak indicator of parking supply, while weighted employment that considers the effects of retail is a much stronger indicator. On average, very high and very low land use densities have the lowest parking requirements per employee (0.39 spaces per employee) while moderate land use densities have the least diversity of land use, yet the highest supply of employee parking (4.01 spaces per employee). The methodology applied may be used to produce quantitative maxima to be incorporated into local parking bylaws that are recognized as potentially strong TDM tools. Further research that compares the observed parking supply patterns across a series of mid-sized cities is recommended to make stronger conclusions regarding the range of maximum values.
8

The study of time- division multiplexed fiber-optic current sensing systems

Huang, Ji-Yao 09 July 2003 (has links)
In this essay, we developed an environmental immunity of multiplexed In-line sagnac interferometric fiber-optic current sensing system. The multiplexedwas used the time-division technique, were proposed to meet this research objective. The theoretical inference and experimental results were presented. The experimental results the system have sensitivity 56£gV/A¡Eturns, and the signal to noise ratio is 70dB. Besides, the multiplexed sensed two current in the same time, those two responses are still linearity. The uniform of these multiplex sensed are less than 2%. The system is hysteresis-free operator, no saturation limit. These features are suit for fiber-optic current sensor in measuring large range variable current. The current waveform can be read directly. In this research, the result let the fiber-optic current sensor approach to application on industrial power delivery line and monitor more current by this system.
9

Investigation of commuting mode choice with respect to TDM policies

Zaman, Hamid Unknown Date
No description available.
10

Investigation of commuting mode choice with respect to TDM policies

Zaman, Hamid 06 1900 (has links)
Travel Demand Management (TDM) is now considered one of the most important aspects of transportation planning and operation. The prime objective of TDM is to develop a sustainable transportation system utilizing the existing infrastructure. It is now a well known fact that excessive use of single occupancy vehicle causes numerous problems like traffic congestion, environmental pollution etc. Thus, from TDM perspective, it is of great importance to analyze travel behaviour in order to influence people to reduce car use and choose more sustainable modes such as carpool, public transit, park & ride, walk, bike etc. This study attempts an in-depth analysis of commuting mode choice behaviour using workplace commuter survey data from the City of Edmonton. Unlike traditional mode choice models, this study uses both instrumental and latent variables to better understand the choice process and analyzes their sensitivities with respect to TDM policies. / Transportation Engineering

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