Department Publications

Personal and medium scale farming has been showing a downward trend throughout the past few decades. Individuals are demotivated to engage in farming activities, due to lack of time, and the higher efficiency in large-scale farming. However, there is a significant health concern arising from the consumption of these products, as they are grown using artificial fertilizers and contain residues of insecticides and pesticides. Automation can motivate personal and medium scale farming, through cutting down the time requirements for farming and by increasing the farming efficiency. Our solution - Scalable Autonomous Agronomical Smartbot (SAASbot) aims at automating farming activities (planting seeds, watering, fertilizing, weed removal) while providing a scalable robotic platform for personal to medium scale farming. In this paper, design and implementation of the SASSBot and testing and validation of the system …

Fitness related wearables have become ubiquitous in the recent past. Nevertheless, short battery life of these devices is still a pressing issue. Limited battery capacity in small form factor and power hungry continuous monitoring of accelerometer have been significant concerns in this regard. To address these issues we propose a novel low-power step counting solution based on an Electromagnetic energy harvesting mechanism. Extremely simple nature of the step counter removes the requirement of any step detection algorithm, thereby reducing the power consumption, while the energy harvester generates a portion of energy requirement prolonging the battery life.

It is a vital requirement to have passive noise control enclosure in order to depress air borne noise of reciprocating engine type power generators. The design of these enclosures needs to be optimized in terms of the sound pressure level and the designing cost. We have used the existing acoustic equations to obtain the optimization based on the objective functions derived for the sound pressure level and enclosure design cost. Metaheuristic optimization algorithms such as genetic algorithms and particle swarm algorithm are capable of solving these optimization problems which have constraints for different parameters. The results obtained for a real world design problem confirms that particle swarm optimization provides better results than genetic algorithm in terms of optimality of the solutions and also the computational efficiency. Furthermore, it was observed that there is a significant linear relationship (R …

Voice Controlled Robot (VCR) is a mobile robot whose motions can be controlled by the user by giving specific voice commands. The speech recognition software running on a PC is capable of identifying the 5 voice commands ‘Run’,‘Stop’,‘Left’,’Right’and ‘Back’issued by a particular user. After processing the speech, the necessary motion instructions are given to the mobile platform via a RF link. Following is the system overview. The speech recognition software is speaker dependant. The special feature of the application is the ability of the software to train itself for the above voice commands for a particular user. The graphical user interface running along with the software provides a very convenient method for the users to train. It also provides many other facilities in operating the robot.

Dielectric heaters are mainly used in industry for various applications. Due to generation of near field energy from stray electromagnetic fields, these machines were selected for analysis as a source for RF energy harvesting. In this research, the energy harvester was designed using a ferrite core loop antenna, rectifying and smoothing circuit and an ultra-low power management system in order to provide energy to a temperature and humidity sensor node. This application was tested within the footwear manufacturing industry due to availability of dielectric heaters (RF Welding Machine) and temperature and humidity are continuously measured during the production process.

Consumers and companies alike require to make countless informed decisions in the context of commercial activities. Going beyond the trivial purchase of a substandard good or service, the informed decision is a choice made after a comprehensive evaluation of the reasonably predicted possible outcomes of each potential option. A typical example would be a consumer without expert knowledge in energy, investing in a solar power system. Under such circumstances the consumer has to be aware if there will be a benefit compared to the no action alternative which requires both information provided by the manufacturer and possible reliance on expert opinion. Venture capitalists and hedging fund managers face similar circumstances where they need to invest based upon informed decisions of the subject as well as the risks. This paper investigates the available legal remedies in both local and foreign jurisdictions for consumers and companies when deprived of an informed decision due to restriction of information, deception or perfidy. Based on this, a judicial test is formulated to allow a generalized protection of the informed decision in business transactions.

We present a simulation study of a cooperate car following application implemented by the Wireless Access for Vehicular Environ-ments (WAVE) protocol stack, which uses the MAC and Physical lay-ers defined by the IEEE 802.11 p protocol. This is a simple Intelligent

Multiple antenna techniques that allow energy beamforming have been looked upon as a possible candidate for increasing the transfer efficiency between the energy transmitter (ET) and the energy receiver in wireless power transfer. This paper introduces a novel scheme that facilitates energy beamforming by utilizing received signal strength indicator (RSSI) values to estimate the channel. First, in the training stage, the ET will transmit using each beamforming vector in a codebook, which is predefined using a Cramer-Rao lower bound analysis. RSSI value corresponding to each beamforming vector is fed back to the ET, and these values are used to estimate the channel through a maximum likelihood analysis. The results that are obtained are remarkably simple, requires minimal processing, and can be easily implemented. The paper also validates the analytical results numerically, as well as experimentally, and …

Activity recognition in videos in a deep-learning setting-or otherwise-uses both static and pre-computed motion components. The method of combining the two components, while keeping the burden on the deep network less, still remains uninvestigated. Moreover, it is not clear what the level of contribution of individual components is, and how to control the contribution. In this paper, we use a combination of convolutional-neural-network-generated static features and motion features in the form of motion tubes. We propose three schemas for combining static and motion components: based on a variance ratio, principal components, and Cholesky decomposition. The Cholesky-decomposition-based method allows the control of contributions. The ratio given by variance analysis of static and motion features matches well with the experimental optimal ratio used in the Cholesky decomposition-based method. The …

A 5-D depth–velocity filter is proposed for enhancing moving objects in noisy light field videos (LFVs) (also known as plenoptic videos). The proposed filter consists of an ultra-low complexity 5-D IIR depth filter and a 5-D FIR velocity filter. The 5-D IIR depth filter is employed to denoise a noisy LFV. The denoised LFV is then utilized to estimate the 3-D apparent velocity of the moving object of interest. The 5-D FIR velocity filter is designed based on the estimated 3-D apparent velocity and is used to enhance the moving object of interest while attenuating other interfering moving objects. Experimental results confirm the effectiveness of the proposed 5-D depth–velocity filter compared to previously reported 5-D depth–velocity filters.

A low-complexity 2-D FIR trapezoidal filter is proposed for enhancing broadband plane waves. Motivated by the design technique of 1-D interpolated FIR filters, the proposed filter is realized by cascading a low-complexity spatiallyupsampled 2-D FIR filter having a trapezoidal passband and a low-complexity 2-D FIR masking filter having a parallelogram passband. Experimental results confirm that the proposed filter provides 74% reduction of the computational-complexity compared to conventional 2-D FIR fan and conventional 2-D FIR trapezoidal filters without deteriorating the performance in enhancing 2-D broadband plane waves distorted by strong interference and noise signals.

This paper introduces a novel traffic reduction method for Networked Control Systems (NCS) called Deadband Error Modulation (DEM). The deadband modifies the periodic dynamics of Delta Modulation (DM) based techniques such as our previously proposed Event Triggered Adaptive Differential Modulation (ETADM). Like ETADM it can be used for encoding individual scalar elements of a vector (i.e., the state vector or control input). It is also robust to bounded packet drops.

Screen content coding (SCC) extension to High Efficiency Video Coding (HEVC) offers substantial compression efficiency over the existing HEVC standard for computer generated content. However, this gain in compression efficiency is achieved at the expense of further computational complexity with several resource hungry coding tools. Hence, extension of SCC to HEVC hardware encoders can be challenging. This paper presents resource efficient hardware designs for two key SCC tools, Intra Block Copy and Palette Coding. Moreover, a new hash search approach is proposed for Intra Block Copy, while a hardware friendly palette indices coding scheme is suggested for Palette Coding. These designs are targeted to achieve the throughput necessary for an 1080p 30 frames/s encoder, and incurs coding loss of 11.4% and 5.1% respectively in all intra configurations. The designs are synthesized for a Virtex-7 …

Most of the intrusion detection and prevention systems (NIDS/NIPS) are utilizing signature based matching which makes use of a stored rule base for distinguishing malicious network traffic. Dynamic rule-base updates has become a requirement due to the increasingly large number of new attack types identified every day, while the downtime associated with rule base updates has become a major drawback in hardware based Network Intrusion Prevention Systems. In addition, the NIPS are facing the challenge of expanding their throughput to cope with the ever growing high bandwidth requirement. This paper presents a novel scalable architecture for a NIPS with stateful packet inspection. The implementation is capable of processing Snort signatures and also analyzing packet streams to detect attacks with TCP segment manipulation. The system ensures run-time rule reconfigurability, which eliminates the risk of …

A high-gain non-isolated DC-DC converter is proposed with a inversely coupled inductor and a voltage lift cell. Energy stored in the leakage inductance of the coupled inductor is recycled through a voltage lift cell to obtain high voltage conversion ratio. The operation of the proposed converter is explained using its equivalent circuits which are used to derive static gain expression. The operation of the proposed converter is analyzed with non-ideal components to predict their influence on voltage conversion ratio and the efficiency. The operation of the proposed converter is validated using software simulation under ideal and non-ideal conditions.

An ultra-low complexity three-dimensional (3-D) linear-phase infinite-extent impulse response (IIR) velocity filter is proposed for attenuating moving artifacts in videos while enhancing objects moving on smooth approximately-linear trajectories. The proposed 3-D linear-phase IIR velocity filter consists of an ultra-low complexity 3-D wide-angle linear-phase IIR cone filter bank between two two-dimensional (2-D) spatial variable-shift filters. The ultra-low complexity 3-D wide-angle linear-phase IIR cone filter bank consists of a one-dimensional (1-D) temporal modified discrete Fourier transform filter bank and 2-D spatial allpass, IIR highpass and allstop filters. A typical 3-D linear-phase IIR velocity filter of order , applied to enhance a heavily corrupted test video signal, requires only 26 real multiplications and 60 real additions to process a sample and provides a scene-complexity-independent signal-to …

Many real world stochastic processes are non-stationary, which means that the probability distribution that generates data samples is time-varying. In the context of machine learning, this phenomenon is known as concept drift. It is important that machine learning models are able to adapt to concept drift in order to prevent degradation in accuracy. In this paper, we present two algorithms for drift detection and adaptation. Drift is measured by continuously tracking a difference metric between probability distributions estimated from two sample windows preceding a time point. High values for the difference metric indicates that concept drift has occurred, and the model must be adapted. Adaptation is done by training a new model for the drifted process, and adding it to an ensemble of models. Previously trained models are retained, and their weights in the ensemble are adjusted to reflect similarity with the current …

Purpose Automatic Optical Inspection (AOI) systems, used in electronics industry have been primarily developed to inspect soldering defects of Surface Mount Devices (SMD) on a Printed Circuit Board (PCB). However, no commercially available AOI system exists that can be integrated to a desktop soldering robotic system, which is capable of identifying soldering defects of Through Hole Technology (THT) solder joints along with the soldering process. In our research, we have implemented an AOI platform that is capable of performing automatic quality assurance of THT solder joints in a much efficient way. In this paper, we have presented a novel approach to identify soldering defects of THT solder joints, based on the location of THT component lead top. This paper presents the methodologies that can be used to precisely identify and localize THT component lead inside a solder joint. Design/methodology/approach We have discussed the importance of lead top localization and presented a detailed description on the methodologies that can be used to precisely segment and localize THT lead top inside the solder joint. Findings It could be observed that the precise localization of THT lead top makes the soldering quality assurance process more accurate. A combination of template matching algorithms and colour model transformation provide the most accurate outcome in localizing the component lead top inside solder joint, according to the analysis carried out in this paper. Research limitations/implications When the component lead top is fully covered by the soldering, the implemented methodologies will not be able to identify the actual …

A novel multidimensional spatio-temporal signal processing algorithm is proposed for depth-velocity filtering in 5-D light field videos along with a tutorial review of light field video spectra and the general architecture of associated 5-D depth-velocity filters. A 5-D FIR filter having a hyperfan-shaped passband which can selectively enhance the spectra of moving objects in light field videos based on their depth and motion trajectory is employed. A 5-D hyperfan-shaped passband is highly desired to achieve enhanced spatio-temporal selectivity over a wide range of lower frequencies. Experimental results are provided by using a light field videos captured using a Lytro light-field camera and mean structural similarity index is used to verify the effectiveness of the proposed 5-D FIR hyperfan depth-velocity filter.

A throughput analysis is conducted for a large scale peer-to-peer wireless network whose devices are capable of operating in both full- and half-duplex modes, using the tools of stochastic geometry. Each device selects its operating duplex mode based on the distance to its partner node. In both duplex modes, the energy consumption and the hardware configurations of the nodes are made equivalent for fair comparisons between full-duplex and half-duplex operations. Using the results of the analysis, an approach is proposed to determine a distance threshold value for duplex mode selection, and the proposed distance threshold can be computed offline. It is found that the throughput performance of the hybrid full-/half-duplex network generated with the proposed distance threshold based duplex mode selection technique outperforms both the pure half-duplex and pure full-duplex network settings for most …

Software industry has shown an exponential growth during the last decade with regards to technology development. The prime aim of the software industry is to deliver high quality software to the end user satisfying the clients as per the agreed norms of the business. Hence, software testing has become an important phase in the software life cycle, ensuring the ultimate product quality. The purpose of this study is to examine whether there is a relationship between testing constraints and test types executed in software companies. The research expects to provide recommendations to use test types effectively. A conceptual model was developed and three hypotheses were derived based on the extensive literature review carried out. According to the results it can be claimed that there is a negative strong relationship between testing constraints and the level of test type execution. Also there is a positive strong …

We present a simulation study of a cooperate car following application implemented by the Wireless Access for Vehicular Environments (WAVE) protocol stack, which uses the MAC and Physical layers defined by the IEEE 802.11p protocol. This is a simple Intelligent Transportation Systems (ITS) application which forms the foundation for autonomous driving. As with many safety-critical ITS applications, cooperate car following uses beaconing as the primary means of communication. The beacon frequency and the transmit power of the mobile nodes are considered as the key communication parameters, while the vehicle density is considered as the key traffic parameter. The two main factors affecting the performance, the end-to-end delay and the packet loss, are studied for different scenarios defined by the above parameters. Results indicate how the application performance may be improved by adapting the …

We consider a single-input-single-output (SISO) system with quadrature phase shift keying (QPSK) modulation and derive an easy-to-evaluate expression for the symbol error probability (SEP) when a general n-bit phase quantization is used at the receiver. We further evaluate the expressions asymptotically to characterize the diversity order and the quantization penalty at high signal-to-noise ratios (SNRs). We observe that the system with n-bit phase quantization achieves full diversity order of one when n > 2. Numerical examples are used to verify the analysis.

Accurate attitude estimation in high dynamic motion scenarios like unmanned aerial vehicle navigation or human motion and magnetically disturbed indoor environments requires compensation of accelerometer disturbances as well as magnetometer disturbances. This paper proposes a novel algorithm for accelerometer disturbance rejection by adaptive estimation of accelerometer measurement covariance matrix online. Magnetic disturbances are generally lasting long compared to accelerometer disturbances which are generally short term in indoor navigation environments. Novel two step Kalman filter update method is proposed to separate attitude correction from heading correction. The magnetometer is used only for heading update such that the attitude estimation is not affected by errors in magnetometer measurement. Performances of the proposed algorithms are shown by using real world sensor data.