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The Global ETD Search service is a free service for researchers
to find electronic theses and dissertations. This service is
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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.
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Design and Fabrication of Free-Space Transmitter and ReceiverYang, Heng-Yi 02 July 2000 (has links)
There are several advantages for optical communication in free space such as simplification,convenience, high bit rate,and sasy design,Free-space optical communication is an alternative for short distance communication. In this work, we desighn and fabricate the optical transmitter and receiver for delivery of audio signal in free-space communication. In circuit design section, audio signals proceed to analog to digital conversion (A/D)and then encode the data. The procedures of encoding block include parallel-series conversion, data cell process adding starter and stop bit, thereby modulate the laser by PCM format in free space. Data cell at receiver terminal will be decoded exactly and synchronized with transmitter terminal for data transmission. After digital to analog conversion, parallel-series data will decode to audio signals. We have accomplished the circuit design of optical transmitter and receiver for transmission of audio signals. Transmission bit rate, optical output power, and transmission distance at transmitter terminal are 200kbit/s,15mW,and >50m, respectively.
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Dálkové ovládání televizního přijímače / TV Remote ControllerBordács, Balázs January 2010 (has links)
This master’s thesis deals with parameters of the TV Remote Controller. Aim of this work is studying standards of remote controling of TV receiver by the way of infra-red light. For succesful solving of this project is important to learn about the theory of IrDA. In the second part ot this thesis is designed measurement unit for measuring the parameters of the remote control. The measurement unit includes an integrated IR receiver and photodiode for receive IR signals from remote control. The description of measurement unit blocks and principles of measuring parameters are also placed there. The final part is devoted to processing the measurement results of measuring levels and time waveforms of signal in the receiver module, directional characteristics of remote control and receiver. For measuremented unit is created laboratory task including the role specification and protocol.
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Evaluation of Wireless Techniques for Short-Range Communication / Utvärdering av trådlösa tekniker för kommunikation över korta avståndSöderkvist, Jonas January 2003 (has links)
<p>On radar level gauges currently shipped by Saab Rosemount, some adjustments of the unit's parameters has to be performed in the field. Presently, this is a cumbersome procedure; the operator has to be very close to the gauge and he either has to carry with him a bulky configuration unit or use a basic control unit on the gauge. A wireless solution, where a portable device and a receiver replace the control unit, would both allow the operator to work from a distance and eliminate the need for the bulky device. </p><p>The most conspicuous restraint for such a solution is a very low allowed power dissipation. The reason for this is that some gauges do not have a separate power supply, but are fed directly off the communication bus. A viable solution should also be commercially available and robust enough to operate in an industrial environment. </p><p>To meet these requirements both a theoretical and a practical assessment was conducted, where the two techniques for wireless communication, IrDA, and Bluetooth, was given special consideration. As for the portable device, the market for hand-held computers was investigated and ultimately a PDA from Palm was selected for this project. Together with this PDA, a prototype for each of the two wireless techniques was tested to ascertain their performance with respect to power dissipation, communication range, and communication robustness. </p><p>This investigation revealed that Bluetooth could be used over a much greater distance than IrDA and it did also provide a more robust solution overall. IrDA is nonetheless also a competent technique, and has its primary advantage in terms of much lower power dissipation compared to Bluetooth.</p>
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Evaluation of Wireless Techniques for Short-Range Communication / Utvärdering av trådlösa tekniker för kommunikation över korta avståndSöderkvist, Jonas January 2003 (has links)
On radar level gauges currently shipped by Saab Rosemount, some adjustments of the unit's parameters has to be performed in the field. Presently, this is a cumbersome procedure; the operator has to be very close to the gauge and he either has to carry with him a bulky configuration unit or use a basic control unit on the gauge. A wireless solution, where a portable device and a receiver replace the control unit, would both allow the operator to work from a distance and eliminate the need for the bulky device. The most conspicuous restraint for such a solution is a very low allowed power dissipation. The reason for this is that some gauges do not have a separate power supply, but are fed directly off the communication bus. A viable solution should also be commercially available and robust enough to operate in an industrial environment. To meet these requirements both a theoretical and a practical assessment was conducted, where the two techniques for wireless communication, IrDA, and Bluetooth, was given special consideration. As for the portable device, the market for hand-held computers was investigated and ultimately a PDA from Palm was selected for this project. Together with this PDA, a prototype for each of the two wireless techniques was tested to ascertain their performance with respect to power dissipation, communication range, and communication robustness. This investigation revealed that Bluetooth could be used over a much greater distance than IrDA and it did also provide a more robust solution overall. IrDA is nonetheless also a competent technique, and has its primary advantage in terms of much lower power dissipation compared to Bluetooth.
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IS pro evidenci telefonních hovorů / IS for Phone Calls AccountingŠitka, Petr January 2009 (has links)
This contribution refers to development of information system working with mobile communication devices. The information system is mainly for collecting and analyzing data made through the mobile devices. In the contribution there are described possibilities of connection between PC and mobile device, also there are described the most common information system for mobile devices, and tools for application development. Design and implementation of information system is based on this study.
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Čtyřnohý kráčejicí robot / Four legged walking robotFischer, Jan January 2008 (has links)
The object of this thesis is an analysis of the possibilities of a wireless communication and a sensor‘s equipment for a four legged walking robot. The thesis is divided into three parts. In the first part there is a particular sale’s exploration in the section of the wireless communication modules. It refers to the differences among technologies in the methods of signal transmission, the technical parameters but also in the communication protocols. The next part of this thesis is focused on sensor’s equipment with the accent on the possibility of use for a four legged walking robot. It contains a short listing of sensors, which are available in the Czech Republic with division based on the type of sensing magnitude. These two parts make a base for the last part where I have chosen suitable communication modules along with sensors and realization wireless data transfer including control and visualization. The result of this thesis is the complete communication block from the user to the robot.
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Návrh a realizace navigačního systému pro autonomní mobilní robot. / The navigation system design for autonomous mobile robot.Růžička, Michal January 2012 (has links)
This thesis deals with design of navigation system for autonomous mobile robots, which is based on the infrared light. The system is based on measuring the relavive angles using landmarks in the enviroment that make the robot can orient and recognize its absolute position in an environment in which it operates.
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Zabezpečovací systém pro rodinný dům / Security system for family houseSohr, Martin January 2011 (has links)
This thesis deals with complete theoretical design of security system for a family house, from the selection of technologies, security principles and selection of elements, theoretical suggestions of their placement to practical realization. I this thesis, securing of entry points, such as doors and windows, is done by magnetic contact sensors. Windows are secured also against breaking of glass. Inner space is secured using motion sensors. Further, the function principle of optical latches as secondary securing element of inner space is explained. The designed security system implements a central control unit, which is able to provide status information on all security elements to the host system. IQRF wireless communication operationg in licence-free is used for communication among elements of the security system. GSM SIM9000 module is used for communication with the security system.
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PDA software pro robotický fotbal / PDA software for robot soccerUhlíř, Luděk January 2008 (has links)
Robotic soccer is a game like a real soccer but here the game is played by robots. The rules are the same, only there are few exceptions (foul, penalty kick, stalemate situation). Game is running without the human intervention. Just a human referee is supervising the game. Two teams are attending the game. Each of them has a control computer. The control computer is the brain of the game. It has a camera, it is making decisions for the next step of robots and sending them configuration data. The thesis deals with testing of communication interface and designs the new communication protocol for the next generation of the robots. The testing is provided by pocket pc Palm TX. It will send data over the Bluetooth interface to the control pc and will configure particular constants, like constants of PID regulator and an address of a robot. This will be provided by the IrDA interface.
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Mobiliųjų paslaugų portalų technologijų tyrimas / Research of mobile portals technologiesNajulis, Mindaugas 03 June 2005 (has links)
Information technologies and mobile telecommunications rapidly enter our personal and social life. Mobile phone is no longer luxury – it has become a necessity. Growing volumes of the mobile services has caused a need to expand the mobile service employment opportunities in the Internet portals. Today’s portals, created using the means, offered by software manufacturers, employ exclusively the mobile Internet service, thanks to which the users can see and manage the necessary information and process of the portal at any time and from anywhere. The problem is related with the fact that mobile Internet services are still expensive in Lithuania. Therefore one should look for cheaper ways to reach and manage portal information. In order to solve this problem one can consider the SMS and MMS message sending, suggested by mobile technologies.
Basic aim of the work is to create an entertainment portal, rendering the user both various Internet entertainments (e.g. Internet acquaintances, games), and mobile entertainment (e.g. sending messages, logos, melodies, animations and games for mobile phone) as well as a wide range of mobile services to be used to obtain and to manage the portal information.
In the work I describe: portal evolution, classification and creation measures („BroadVision Portal“, „IBM WebSphere Portal for Multiplatforms v5.x“, „Sun One Portal Server v6.0“, „Red Hat Enterprise Portal Server“, „Microsoft SharePoint® Portal Server 2003“, „ORACLE 9ias Portal“, „PHP:... [to full text]
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