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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

Harmonic and interharmonic current distortion in variable frequency synchronous motor drives

Delaney, Eamon John January 1993 (has links)
No description available.
2

Implementation av Microsoft Exchange ActiveSync mot en molntjänst

Thomke, Sven January 2013 (has links)
This report describes a bachelor thesis work performed at the cloud storage company CloudMe in Linköping, Sweden. The storage service provided by CloudMe allows users to access their files seamlessly from multiple units at the same time. In the cloud there is storage provided for contacts, calendar and e-mail, which is data nowadays normally used by smart phones.Exchange ActiveSync is a protocol developed by Microsoft which, among much more, provides functionality to synchronize the previously described data. This protocol is supported by the smart phone developers and the ability to synchronize over the exchange protocol is implemented in products by default. Due to this fact it would be preferable to implement support for synchronization from CloudMe to phones over this protocol. Therefore a decision was made to create a proxy server which handles communication with clients (smart phones) over Exchange ActiveSync and talks with CloudMes SOAP-based open API to extract the needed data. With the help of this server a user would be able to synchronize the described data between different phones and tablets, independently of label and model and would never have to worry about loss of data.The purpose of this bachelor thesis work was therefore to design and implement such a proxy server, so that clients would be able to connect, through the standard support for exchange in smart phones,and synchronize data between phones and the cloud. The report describes the methods used when designing the project and also the problems that occurred during the process.
3

THE SEARCHING METHOD OF QUASI-OPTIMUM GROUP SYNC CODES ON THE SUBSET OF PN SEQUENCES

Jie, Cao, Qiu-cheng, Xie 11 1900 (has links)
International Telemetering Conference Proceedings / October 29-November 02, 1990 / Riviera Hotel and Convention Center, Las Vegas, Nevada / As the code length is increasing, the search of optimum group sync codes will be more and more difficult, even impossible. This paper gives the searching method of quasi-optimum group sync codes on the small subset of PN sequences -- CVT-TAIL SEARCHING METHOD and PREFIX-SUFFIX SEARCHING METHOD. We have searched out quasi-optimum group sync codes for their lengths N=32-63 by this method and compared them with corresponding optimum group sync codes for their lengths N=32-54. They are very approximative. The total searching time is only several seconds. This method may solves the problems among error sync probability, code length and searching time. So, it is a good and practicable searching method for long code.
4

NTSC Video Sync Separator and A Gm-C Anti-Aliasing Filter Design with Digitally Tunable Bandwidth for DVB-T Receivers

Hung, Chien-Chih 24 June 2005 (has links)
The first topic of this thesis is a novel NTSC video sync separator (NSS) with a high-PSR (power supply rejection) bias generation circuitry (BGC) comprising a temperature compensation circuitry. The proposed BGC is composed of step-down regulators and a bandgap-based bias with cascode current control. The clamping voltages required for sync separation from an NTSC signal are generated. The second topic is a temperature-compensated 6th order transconductance-C (Gm-C) anti-aliasing filter (AAF) with digitally tunable bandwidth which can be applied in the analog front-end circuit of DVB-T receivers. The proposed AAF is controlled by digital signals to provide three different baseband bandwidth (6, 7, 8 MHz) selection. A regulator with a bandgap circuitry supplies a stable voltage to suppress the variations of power and temperature. Moreover, a temperature -compensated circuitry is used to neutralize bandwidth drifting caused by the temperature variation. The bandwidth accuracy of the proposed design verified by HSPICE post-layout simulations is better than 3.28% at every PVT (process, supply voltage, temperature) corner. It is adequate for the DVB-T receivers¡¦ baseband processing.
5

Protocol Analysis for Networked Acquirement System

Lu, Chun, Song, Jian 10 1900 (has links)
ITC/USA 2014 Conference Proceedings / The Fiftieth Annual International Telemetering Conference and Technical Exhibition / October 20-23, 2014 / Town and Country Resort & Convention Center, San Diego, CA / This paper analyzed protocols may be used in each layer in networked telemetry systems, and also presents some deeper researches of the advantages of using synchronous time-division for the physical layer of a networked telemetry system.
6

Seshat : A sync system for Audiobooks and eBooks

Dervisevic, Adnan, Oskarsson, Tobias January 2014 (has links)
In this degree project we present a way to construct a synchronization system that is able to create a timings file, which is the file the system uses to know how to sync the eBook and audiobook, using speech recognition and estimation algorithms. This file is then used by the system to let the user select a sentence and have the audiobook start reading from that sentence, or vice versa. This system can create these files with a mean offset from a manu-ally timed file which is within our expectations for the system. We use estimation algorithms to fill in the blanks where the speech recognition falls short. Speech recognition accuracy is typically between 40-60%, sometimes dipping lower, so there are blanks to fill in. Using basic algebraic principles of calculating velocity we can ex-trapolate the speed of a reader, using the duration of the audiobook as the time and the amount of characters written as the distance. For increased accuracy we derive this value on a per-chapter basis. Using this method we are able to create accurate files, which the user can use to freely sync any location in the book. Our system is designed to work for any book in the world that does not have an audiobook which cuts off between sentences in the audio files. We manually create timings files for four different books with widely varying publishing dates, author styles, reader style and gender to create as wide and representative a testing pool as possible for the project
7

Empirical Approch For Rate Selection In MIMO OFDM

Hebbar, Anil Madhava 11 January 2005 (has links)
Orthogonal Frequency Division Multiplexing (OFDM) is fast gaining ground as a preferred modulation technique for short range wireless data application such as 802.11a/g, 802.15.3a and 802.16. Recently, use of multiple transmit and receive antenna for improving spectral efficiency in a wireless system has received much interest. IEEE 802.11 has set up the Work Group 802.11n to develop a standard for enhanced rate 802.11 based on OFDM using Multi Input/Multiple Output (MIMO) techniques. The most dominant proposal is the use of singular value decomposition based MIMO methods to achieve the high data rate. The selection of modulation and coding rates plays a significant role in the overall throughput of the system, more so in cases where the traffic between the transmitter and the receiver consists of short bursts and the user location is not fixed. The performance of a given modulation and coding technique depends on the channel condition. Closed form or bounding solutions exists for various modulation and coding techniques. But these techniques are not suitable for real time application where the channel is dynamic. The approach taken in this thesis is to decouple frequency selective MIMO OFDM channel into orthogonal spatial and frequency domains channels using Fast Fourier Transforms and Singular Value Decomposition. The channels can be viewed as parallel flat fading channels for which the expected BER rate can be computed. A SNR-BER table is used to efficiently compute the performance efficiently. An effective SNR is computed using the table and compared with rate threshold to select a suitable rate. Improvements of 15 dB and above are shown the link budget while using a four transmit four receive MIMO system. Proposed 802.11n TGn Sync physical layer standard is used to evaluate the performance. The performance in case of one of the systems being a legacy 802.11a/g nodes is also looked into. Gains up to 7 dB are shown in the link budget. / Master of Science
8

Deepfake detection by humans : Face swap versus lip sync / Människors förmåga att upptäcka deepfakes : Face swap mot lipsync

Sundström, Isak January 2023 (has links)
The term “deepfakes” refers to media content that has been manipulated using deep learning. This thesis project seeks to answer the question of how well humans are able to detect deepfakes. In particular, the project compares people’s ability to detect deepfakes between two different deepfake categories; face swap and lip sync. In order to achieve this, a perceptual user test was performed, in which 30 participants were given a number of lip sync, face swap and unaltered videos and were asked to classify which of them were unaltered and which of them were manipulated using deepfake technology. These results serve to fill in the gap in knowledge regarding perceptual user tests on deepfakes, for which only a small amount of research has been made. The results also serve to shed light on which types of deepfakes pose the biggest threat regarding the problem of malicious impersonation. The main conclusion from this study was that lip sync is likely harder for humans to detect than face swap. The percentage of correct classifications of lip sync videos was 52.7%, and the percentage of correct classifications of face swap videos was 91.3%. / Deepfakes är videor som har blivit manipulerade med hjälp av deep learning. Detta examensarbete utforskar huvudsakligen två olika kategorier av deepfakes, dessa två är: face swap och lip sync. Syftet med projektet är att svara på frågan: Hur bra är människor på att se om en video innehåller deepfakes eller inte? Dessutom ställs frågan: Vilken typ av deepfake mellan face swap och lip sync är svårare för människor att märka av? För att svara på dessa frågor genomfördes en användarsudie där 30 deltagare fick titta på ett antal lip sync, face swap och icke-manipulerade videor, och fick sedan försöka avgöra vilka av dom som var manipulerade och vilka som inte var manipulerade. Resultaten från den här studien hjälper till att fylla kunskapsklyftan som finns angående människors förmåga att upptäcka deepfakes, där bara en väldigt begränsad mängd studier finns. Resulaten kan också användas för att peka ut på vilka typer av deepfakes som utgör större hot angående lurendrejeri. Slutsatsen från studien var att lip sync är troligtvis svårare för människor att märka av än face swap, eller åtminstone för datasetet FakeAVCeleb. Andelen korrekta gissningar för lip sync videorna i studien var 52.7%, medan andelen korrekta gissningar för face swap var 91.3%.
9

Precious Bits: Frame Synchronization in Jet Propulsion Laboratory's Advanced Multi-Mission Operations System (AMMOS)

Wilson, Elizabeth (Betsy) 10 1900 (has links)
International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Jet Propulsion Laboratory’s (JPL) Advanced Multi-Mission Operations System (AMMOS) system processes data received from deep-space spacecraft, where error rates are high, bit rates are low, and every bit is precious. Frame synchronization and data extraction as performed by AMMOS enhance data acquisition and reliability for maximum data return and validity. Unique aspects of data phase determination, sync acquisition and sync loss and other bit-level topics are covered.
10

Low-Variation 1 MHz Clock Generator,High Sensitivity Linear Voltage-to-Frequency Converter,and High-PSR Bias Circuit for NTSC SYNC Separation

Lee, Tzung-Je 13 July 2004 (has links)
This thesis includes three topics. The first topic is a low-variation 1 MHz clock generator. The second one is a high sensitivity linear voltage-to-frequency converter. The last one is a high-PSR bias circuit for NTSC SYNC separation. All of the circuits can be applied to related consumer electronic products. The low-variation 1 MHz clock generator includes a bias circuit which automatically compensates the drifting caused by temperature variations. Furthermore, the circuit contains neither BJTs nor diodes to reduce the area cost. The frequency variation is measured to be less than 2.55\% in the range of 0¢J~90¢J. The high sensitivity linear voltage-to-frequency converter is mainly constructed by a window comparator[11]. We analyze and improve the performance of accuracy to achieve both high accuracy and high sensitivity. The accuracy error is less than 1% and sensitivity is 84 KHz/V in the voltage range of 0.1V~0.8V. The high-PSR bias circuit for NTSC SYNC Separation is implemented by a bandgap reference which is controlled by a feedback loop to reduce the interference of the environment. The measurement variation of the bandgap reference is less than 1\% when the variation of power supply is 10\%. The sensitivity of the bandgap reference to temperature is measured to be 0.0006V/¢J.

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