After publication of this article (Nishitani et al. 2019), it was brought to our attention that the figure 5 is incorrect, where the positions of DCE and SPS were misplaced. The correct figure 5 is as below, the original publication has been corrected.

Sensorless and torque control of Switched Reluctance Motors (SRMs) is a well-researched field. Many techniques rely on the measurement of phase inductance and or flux-linkage which can be significantly affected by the mutual phase inductance. By measuring the mutual inductance over an electrical cycle or at particular locations, the accuracy of the sensorless and torque control techniques can be improved. This paper presents two novel techniques which profile the mutual inductance without an off-line calibration technique. Methods are discussed to increase the accuracy of the calculated phase inductance and flux-linkage integral using the mutual inductance information. The techniques are developed for three-phase SRMs. Test results of both techniques are investigated using a 1 kW three-phase SRM.

This paper describes and evaluates a novel 3D inspection system to detect anomalies in sewer pipes using stereo vision coupled with novel image processing algorithms. Currently, most commercial pipe inspection systems are designed with one or more Closed-circuit Television (CCTV) cameras. These systems are slow, costly and have limited accuracy (caused by human and environmental factors). More sophisticated systems (Laser-based, Infrared Thermography, Ultrasonic-based and Ground Penetrating Radar) suffer from: low resolution, high noise, high operational costs and an inability to detect water infiltration. The main objective of this research is to apply stereo vision and robust image processing to generate 3D images of anomalies in sewer pipes in order to achieve high efficiency and accuracy for pipe inspection. The results show that various types of defects are successfully detectable. In addition, the correspondence time can be reduced by up to 45% and the accuracy of disparity maps is maintained compared to traditional local correspondence algorithms. Each component of the proposed system was tested individually with real and simulated data sets.

An efficient and reliable key-establishment method is the most important building block of any secure cryptographic channels.Public-key cryptography was a revolution in cyber security key administration and enabled peers to dynamically create keys for each cryptographic session.The Diffie-Hellman (DH) algorithm is the first published public-key cryptosystem.DH and its variants are extensively investigated, standardized, and widely used in network security protocols.However, DH is vulnerable to some concerning mathematical, implementation-related and network-specific attacks.Defending against these attacks is important in secure implementation of DH in network protocols.This paper categorizes various attacks on DH scheme with focuses on attacks related to the DH integration in network protocols (referred as network-specific attacks).Furthermore, we comparatively review the approaches taken by commercial protocols to tackle network attacks and analyze the strength of these solutions.

This paper describes and evaluates a novel algorithm for adaptive local stereo vision, named Successive Disparity Difference Feedback (SDDF). Traditionally, local stereo vision algorithms compute matching cost based on intensity values within a fixed-size window for left and right images. Fixed-size window algorithms encounter problems related to correspondence accuracy over featureless regions. The SDDF algorithm overcomes these problems by adaptively adjusting the window size based on feedback from the disparity map. The SDDF algorithm is shown to significantly enhance correspondence matching in featureless regions, having only a marginal increase in computational complexity. The proposed algorithm was validated on standard stereo data sets, showing significantly improvement to the accuracy of disparity maps compared to traditional local algorithms.

This paper describes and evaluates a novel computer vision algorithm for automatic thin crack detection in pipelines using dou-edge evaluation (DEE). Inspection for pipes is crucial and it is performed periodically to ensure that the structured integrity of the pipe systems is maintained. Thin cracks and fractures are among the defects which can cause critical damage to pipe systems. Numerous techniques have been used to detect cracks in pipes including machine vision, mostly based on edge-detection algorithms (i.e. Sobel, Laplace). However, these algorithms encounter difficulties in extracting cracks from complicated and noisy environments (i.e. sewer pipes). The DEE algorithm overcomes this problem by evaluating the size and shape of each object in the inspection environment. The results show that thin cracks were automatically extracted by the proposed algorithm.

The approach of instantiating authenticated group key exchange (GAKE) protocol from the multikey encapsulation mechanism (mKEM) has an important advantage of achieving classical requirement of GAKE security in one communication round. In spite of the limitations of this approach, for example, lack of forward secrecy, it is very useful in group environments when maximum communication efficiency is desirable. To enrich this mKEM-based GAKE construction, we suggest an efficient solution to convert this static GAKE framework into a partially dynamic scheme. Furthermore, to address the associated lack of forward-secrecy, we propose two variants of this generic construction which can also provide a means of forward secrecy at the cost of extra communication round. In addition, concerning associated implementation cost of deploying this generic GAKE construction in elliptic curve cryptosystem, we compare the possible instantiations of this model from existing mKEM algorithms in terms of the number of elliptic curve scalar multiplications.

Conventional near field inductive wireless power transfer theory shows that systems suffer from splitting frequency behaviors when strong coupling condition exists between the transmitter and the receiver. However, this characteristic has not been explored for communication. Our analysis demonstrates that the splitting behaviour of frequency creates multiple frequencies that support inductive communication in MIMO configuration. As a result, we implement a binary chirp modulation on an FPGA and validate two channel communication using splitting. This paper introduces the use of chirp signals to spread data and excite inductive MIMO systems. The simulation and experiment show that the splitting frequency depends on a quality factor and the flux coupling condition between the data source and receiver. In other words, the degree of mutual coupling defines the splitting mode. This paper proves that multi-channel communication using splitting can be used for data transmission. The results show that data rates of 50 Mbps or 69 Kbps can be achieved for each channel between the transmitters and receivers when the transmitter and receiver operate at the original resonant frequency of 13.56 MHz or 28 KHz, respectively and the distance between them varies from about 1 cm to 10 cm.

This paper describes and evaluates a new sensing methodology for anomaly inspection in sewer pipes using a machine vision approach. Currently, most commercial pipe inspection systems include a mobile remote platform and one or more Closed Circuit Television (CCTV) cameras. These inspection systems are slow, costly and have limited accuracy (caused by humans or environmental reasons). More sophisticated approaches (Laser-based, Infra-red Thermography, Ultrasonic-based and Ground Penetrating Radar) suffer from, lack of resolution and an inability to detect water inflow. The main objective of this research is to apply stereo vision technique to generate 3D images of anomalies in sewer pipes in order to achieve high efficiency and accuracy for pipe inspection. The results showed that various types of defects were successfully reconstructed for later advanced processing.

This paper proposes and evaluates a novel algorithm for local correspondence matching in stereo vision, named Constrained Sliding Window (CSW). Conventional local algorithms compute the disparity map based on intensity values of pixels within a window for left and right images. Local algorithms are considered to be faster than global methods and capable of implementing applications which require prompt responses. Nevertheless, local algorithms exhibit the critical disadvantage of having a fixed search space, resulting in repetitive scanning. The main objective of this paper is to dynamically constrain the search space to reduce unnecessary scanning and hence reduce the processing time. The proposed CSW algorithm was proven to significantly reduce processing time by up to 45% compared to unconstrained algorithms. The proposed algorithm was evaluated experimentally using Tsukuba image pair and stereo data set from the Middlebury database and was compared against traditional algorithms.

This paper proposes a technique to detect the rotor position in a Switched Reluctance Motor(SRM) which only requires knowledge of the phase resistance and the number of stator and rotor poles. Accuracy can be further improved if prior knowledge of the mutual phase inductance is known. The technique operates by sensing the minimum inductance location which allows positional information to be obtained. This is performed using a controlled low level sense current during the un-energised period. A Digital Phase Locked Loop is described to derive rotational positions between minimum inductance locations. Factors affecting the detection of the minimum inductance position are described and proposals to mitigate errors are discussed. The technique is implemented using a Field Programmable Gate Array(FPGA) with results showing good performance over a range of speeds and motor operating conditions.

In radar applications, the target velocity is commonly determined using the Doppler effect. By comparing the transmit-receive differential frequency, the Doppler frequency shift can be measured, and as a result, the target velocity can be determined. The Tasman International Geospace Environment Radars (TIGER) form part of an international network of similar HF radars called Super Dual Auroral Radar Network (SuperDARN) which explores the impact of solar disturbances on the Earth's upper atmosphere. These radars utilise an Auto Correlation Function (ACF) to measure the changing phase of the ACF between lag times to determine the Doppler frequency and the target velocity. Measured velocity results can show large, and sometimes unrealistic errors. As part of the development of the third TIGER radar at Buckland Park, Adelaide, South Australia, a Spectrum Difference Function (SDF) technique for measuring velocity has been proposed as a means for cross-checking results. The SDF technique uses the Fast Fourier Transform (FFT) to calculate the transmit and receive signal magnitude spectrums which are then compared to find the Doppler frequency. In this paper the developed technique is compared to existing interpolation techniques using SuperDARN radar parameters. Simulation results show that the accuracy and computational complexity of the SDF technique are comparable to those of other techniques using FFT.

We present a technique for the automatic detection of Pc5 (150 s to 600 s period) ultralow frequency (ULF) pulsations in ground and ionospheric backscatter from the Super Dual Auroral Radar Network (SuperDARN). This new technique enables rapid identification and visualization of ULF oscillations over the very wide geographical coverage of SuperDARN. The technique detects ULF oscillations using the Lomb-Scargle periodogram method, which provides a natural test for periodic behavior against the null hypothesis of a pure noise distribution. This does not require any interpolation across data gaps and is thus appropriate for SuperDARN data. We demonstrate the application of the technique to SuperDARN data for March 2014 and find that Pc5 pulsations are frequently observed by multiple radars simultaneously. A preliminary investigation using data from all Northern Hemisphere SuperDARN radars indicates that Pc5 pulsation activity occurs most often on the nightside of the magnetosphere, with a mean frequency of about 2 mHz.

This paper proposes that a Field Programmable Gate Array (FPGA) based Switched Reluctance Motor (SRM) controller has greater flexibility and potential performance benefits than a typical Digital Signal Processor (DSP) or Microprocessor based system. The benefits stem from the architecture of an FPGA which allows designers to make a completely customisable controller. The architecture also allows enhanced sampling of the phase current and voltages which allows for higher quality data capture which can improve drive performance. A basic overview of the operation of an FPGA is given to provide context of the system architecture. Comparisons between an FPGA and a DSP based system are made within the context of an SRM controller, which further highlight the potential benefits. Lastly a basic concept design of an FPGA SRM based controller is shown and its enhanced phase current capture design methodology explained.

The Tasman International Geospace Environment Radars (TIGER) form part of an international network of similar HF radars called Super Dual Auroral Radar Network (SuperDARN) which explore the impact of solar disturbances on Earth. These radars utilise an Auto Correlation Function (ACF) to measure the changing phase of the ACF between lag times to determine the Doppler frequency and the target velocity.With the development of TIGER-3, an all digital radar platform, a novel method of determining target velocities has been proposed. In the proposed methoThe Tasman International Geospace Environment Radars (TIGER) form part of an international network of similar HF radars called Super Dual Auroral Radar Network (SuperDARN) which explore the impact of solar disturbances on Earth. These radars utilise an Auto Correlation Function (ACF) to measure the changing phase of the ACF between lag times to determine the Doppler frequency and the target velocity.With the development of TIGER-3, an all digital radar platform, a novel method of determining target velocities has been proposed. In the proposed method, a comparison of the transmit and receive signal magnitude spectrums is performed to determine the Spectrum Difference Function (SDF). The gradient of SDF in the vicinity of the carrier frequency is calculated, from this value the Doppler Frequency Shift fd can be deduced. The result is then multiplied by a precalculated Scale Factor which is necessary to compensate for the systematic error due to the method. This paper will address all the factors which have influence on the value of Scale Factor, therefore minimize the error associated with the process of calculating Scale Factor.d, a comparison of the transmit and receive signal magnitude spectrums is performed to determine the Spectrum Difference Function (SDF). The gradient of SDF in the vicinity of the carrier frequency is calculated, from this value the Doppler Frequency Shift fd can be deduced. The result is then multiplied by a precalculated Scale Factor which is necessary to compensate for the systematic error due to the method. This paper will address all the factors which have influence on the value of Scale Factor, therefore minimize the error associated with the process of calculating Scale Factor.

The Tasman International Geospace Environment Radars (TIGER) form part of an international network of similar HF radars called Super Dual Auroral Radar Network (SuperDARN) which explore the impact of solar disturbances on Earth by monitoring the location and velocity of plasma of plasma irregularities and related phenomena occurring in the ionosphere. These radars utilise an Auto Correlation Function (ACF) to measure the changing phase of the ACF between lag times to determine the Doppler frequency and thus the target velocity. With the development of TIGER-3, an all digital radar platform, a novel method of determining target velocities has been proposed. In the proposed method, a comparison of the transmit and receive signal magnitude spectrums is performed to determine the Spectrum Difference Function (SDF). It has been shown that the gradient of SDF in the vicinity of the carrier frequency is proportional to the target Doppler shift. In this paper we consider the constraints of hardware processing on the implementation of the technique and suggest an alternate architecture for the TIGER-3 radar that will allow a dramatic reduction in computational complexity to allow the real-time determination of velocity in conjunction with the normal operation of the receivers. The proposed technique moves the processing from the RF frequency band to a low frequency IF band to reduce the computational length of the Fast Fourier transform (FFT) without compromising the validity of the technique.

In radar applications, target velocity is commonly determined using the Doppler effect. By comparing the transmit-receive differential frequency the Doppler frequency shift can be measured and as a result the target velocity can be determined. The Tasman International Geospace Environment Radars (TIGER) form part of an international network of similar HF radars called Super Dual Auroral Radar Network (SuperDARN) which explore the impact of solar disturbances on Earth by monitoring the location of aurora and related phenomena occurring in the ionosphere. These radars utilise an Auto Correlation Function (ACF) to measure the changing phase of the ACF between lag times to determine the Doppler frequency and the target velocity. This paper presents a novel method to measure Doppler shifts with high resolution and accuracy in radar applications. In the proposed method, a comparison of the transmit and receive signal spectrums is performed to determine the Spectrum Difference Function (SDF). It is shown that the gradient of SDF in the vicinity of the carrier frequency is proportional to the target Doppler shift. Therefore, by examining the SDF, the target velocity can be detected with a high level of accuracy.

This paper presents a novel antenna impedance matching system used in the latest Australian SuperDARN class HF radar, at Buckland Park, South Australia. Earlier radar designs used an off-the-shelf log-periodic wideband antenna that is significantly easier to match over the SuperDARN frequency band, but expensive to buy and mount, and had limited capability for azimuthal beamforming. The newer TTFD antenna, used in many recent SuperDARN radars, offers improvement in these areas, but is in essence a narrow band antenna. It is capable of wideband operation at the cost of being difficult to match, frequency dependant, high-impedance and complex load. Previous TTFD matching transformers utilising toroids have been measured and evaluated for their suitability for the Buckland Park radar. A new system based on an LC matching network circuit has been devised to replace them. The design approach and results of the new matching circuit are detailed.

This paper describes a novel, binary search pose estimation (BSPE) technique for poses constrained to 3 degrees of freedom (DOF). The technique requires three fiduciary marker points and operates by minimising the angular DOF through a binary search driven algorithm. The technique is less computationally intensive than the standard closed form solutions and quickly converges to a solution which can be verified if additional fiduciary points are available. Evaluation for the technique is presented through a comparison to pose from orthography and scaling with iterations (POSIT) using synthetic data and a real-world application, where the technique is used for pose estimation of a mobile robot with respect to a motor vehicle for inspection purposes.

Traditional radio communication has gained significantly from using multiple input and multiple output (MIMO) architecture in the system. Many wireless applications, such as wireless LAN and cellular network, have adopted this technology to improve their system performance. However, the effect of MIMO systems has not been investigated in the case of inductive near field short range communications. The purpose of this paper is to explore a new method for increasing the magnetic communication range using MIMO. Three system models includingMISO, SIMO and MIMO are proposed to characterize the number of transmitters and receivers to the link. These models have helped to extend not only the range but also the communication channel in NFMIC.