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Full-Text Articles in Engineering

Anonymous Query Processing In Road Networks, Kyriakos Mouratidis, Man Lung Yiu Dec 2010

Anonymous Query Processing In Road Networks, Kyriakos Mouratidis, Man Lung Yiu

Kyriakos MOURATIDIS

The increasing availability of location-aware mobile devices has given rise to a flurry of location-based services (LBSs). Due to the nature of spatial queries, an LBS needs the user position in order to process her requests. On the other hand, revealing exact user locations to a (potentially untrusted) LBS may pinpoint their identities and breach their privacy. To address this issue, spatial anonymity techniques obfuscate user locations, forwarding to the LBS a sufficiently large region instead. Existing methods explicitly target processing in the euclidean space and do not apply when proximity to the users is defined according to network distance …


Continuous Monitoring Of Spatial Queries In Wireless Broadcast Environments, Kyriakos Mouratidis, Spiridon Bakiras, Dimitris Papadias Dec 2010

Continuous Monitoring Of Spatial Queries In Wireless Broadcast Environments, Kyriakos Mouratidis, Spiridon Bakiras, Dimitris Papadias

Kyriakos MOURATIDIS

Wireless data broadcast is a promising technique for information dissemination that leverages the computational capabilities of the mobile devices in order to enhance the scalability of the system. Under this environment, the data are continuously broadcast by the server, interleaved with some indexing information for query processing. Clients may then tune in the broadcast channel and process their queries locally without contacting the server. Previous work on spatial query processing for wireless broadcast systems has only considered snapshot queries over static data. In this paper, we propose an air indexing framework that 1) outperforms the existing (i.e., snapshot) techniques in …


Ecg Based Personal Identification Using Extended Kalman Filter, Chee-Ming Ting Phd, Sh-Hussain Salleh May 2010

Ecg Based Personal Identification Using Extended Kalman Filter, Chee-Ming Ting Phd, Sh-Hussain Salleh

Chee-Ming Ting

This paper proposes a new approach for electrocardiogram (ECG) based personal identification based on extended Kalman filtering (EKF) framework. The framework uses nonlinear ECG dynamic models formulated to represent noisy ECG signal. The advantage of the models is the ability to capture distinct ECG features used for biometric recognition such as temporal and amplitude distances between PQRST points. Moreover the inherent modeling of additive noise provides robust recognition. Log-likelihood scoring is proposed for classification. The algorithm is evaluated on identification task on 13 subjects of MIT-BIH Arrhythmia Database using single lead data. Identification rate of 87.50% is achieved on 30s …


The Effect Of The Digit Slicing Architecture On The Fft Butterfly, Yazan Samir, Rozita Teymourzadeh Dec 2009

The Effect Of The Digit Slicing Architecture On The Fft Butterfly, Yazan Samir, Rozita Teymourzadeh

Dr. Rozita Teymourzadeh, CEng.

Most communications systems tend to achieve bandwidth, power and cost efficiencies to capable to describe modulation scheme. Hence for signal modulation orthogonal frequency division multiplexing (OFDM) transceiver is introduced to cover communications demand in four generation. However high performance Fast Fourier Transforms (FFT) as a main heart of OFDM acts beyond the view. In order to achieve capable FFT, design and realization of its efficient internal structure is key issues of this research work. In this paper implementation of high performance butterfly for FFT by applying digit slicing technique is presented. The proposed design focused on the trade-off between the …


Vlsi Implementation Of Novel Class Of High Speed Pipelined Digital Signal Processing Filter For Wireless Receivers, Rozita Teymourzadeh, Yazan Samir, Shabuil Islam, Masuri Othman, Mok Vh Dec 2009

Vlsi Implementation Of Novel Class Of High Speed Pipelined Digital Signal Processing Filter For Wireless Receivers, Rozita Teymourzadeh, Yazan Samir, Shabuil Islam, Masuri Othman, Mok Vh

Dr. Rozita Teymourzadeh, CEng.

The need for high performance transceiver with high Signal to Noise Ratio (SNR) has driven the communication system to utilize latest technique identified as over sampling systems. It was the most economical modulator and decimation in communication system. It has been proven to increase the SNR and is used in many high performance systems such as in the Analog to Digital Converter (ADC) for wireless transceiver. This research work presented the design of the novel class of decimation and its VLSI implementation which was the sub-component in the over sampling technique. The design and realization of main unit of decimation …


Design Of Automatic Soil Humidity Control Using Maximum Power Point Tracking Controller, Hoe Ck, Vaithlingam A.C., Rozita Teymourzadeh, Rajkumar R Dec 2009

Design Of Automatic Soil Humidity Control Using Maximum Power Point Tracking Controller, Hoe Ck, Vaithlingam A.C., Rozita Teymourzadeh, Rajkumar R

Dr. Rozita Teymourzadeh, CEng.

The photovoltaic system uses the photovoltaic array as a source of electrical power for the direct conversion of the sun’s radiation to direct current without any environmental hazards. The main purpose of this research is to design of a converter with Maximum Power Point Tracker (MPPT) algorithm for any typical application of soil humidity control. Using this setup the major energy from the solar panel is used for the control of soil humidity. The design of the converter with MPPT together with the soil humidity control logic is presented in this paper. Experimental testing of the design controller is implemented …


On-Chip Implementation Of Pipeline Digit-Slicing Multiplier-Less Butterfly For Fast Fourier Transform Architecture, Yazan Samir, Rozita Teymourzadeh, Masuri Othman, Shabiul Islam, Mok Vh Dec 2009

On-Chip Implementation Of Pipeline Digit-Slicing Multiplier-Less Butterfly For Fast Fourier Transform Architecture, Yazan Samir, Rozita Teymourzadeh, Masuri Othman, Shabiul Islam, Mok Vh

Dr. Rozita Teymourzadeh, CEng.

The need for wireless communication has driven the communication systems to high performance. However, the main bottleneck that affects the communication capability is the Fast Fourier Transform (FFT), which is the core of most modulators. This study presents on-chip implementation of pipeline digit-slicing multiplier-less butterfly for FFT structure. The approach taken; in order to reduce computation complexity in butterfly, digit-slicing multiplier-less single constant technique was utilized in the critical path of Radix-2 Decimation In Time (DIT) FFT structure. The proposed design focused on the trade-off between the speed and active silicon area for the chip implementation. The new architecture was …


On-Chip Implementation Of High Resolution High Speed Floating Point Adder/Subtractor With Reducing Mean Latency For Ofdm, Rozita Teymourzadeh, Yazan Samir, Nooshin Mahdavi, Masuri Othman Dec 2009

On-Chip Implementation Of High Resolution High Speed Floating Point Adder/Subtractor With Reducing Mean Latency For Ofdm, Rozita Teymourzadeh, Yazan Samir, Nooshin Mahdavi, Masuri Othman

Dr. Rozita Teymourzadeh, CEng.

Fast Fourier transform (FFT) is widely applied in OFDM trance-receiver communications system. Hence Efficient FFT algorithm is always considered. This paper proposed FPGA realization of high resolution high speed low latency floating point adder/subtractor for FFT in OFDM trance-receiver. The design was implemented for 32 bit pipelined adder/subtractor which satisfied IEEE-754 Standard for floating-point Arithmetic. The design was focused on the trade-off between the latency and speed improvement as well as resolution and silicon area for the chip implementation. In order to reduce the critical path and decrease the latency, the novel structure was designed and investigated. Consequently, synthesis report …