Miracle-dz/UniFAR-FTUs huggingface dataset:
An approach to remove the clutter and detect the target for ultra-wideband through-wall imaging

Through-wall imaging (TWI) is important from the point of view of rescue operations and surveillance. Several researchers have been working in this field but have still not obtained any concrete results. TWI using narrow band radar faces the problem of low resolution whereas ultra-wideband (UWB) radar provides better resolution, classification and low loss for the imaging signals. TWI faces many challenges in collecting the scattered electromagnetic fields from objects located behind the wall and also in processing the data in order to detect, locate and image the object. One of the important factors for achieving a high-quality image is to use clutter reduction techniques so that clutter as well as false target detection can be minimized. Therefore, in this paper, an attempt has been made to develop a clutter reduction technique for TWI in the UWB range for target detection. For this purpose, an experiment has been carried out with a TWI system in the UWB range for determination of the target position and size along with the development of the signal processing technique to minimize the clutter. A singular value decomposition (SVD) algorithm has been applied for clutter reduction. Encouraging results have been obtained from a metallic target behind a plywood wall of thickness 12 mm and a brick wall of thickness 110 mm. Application of the SVD approach provides a powerful technique for minimizing clutter and false detection for the TWI system in the UWB range. The position of the target behind the wall is predicted quite accurately by taking into account the propagation speed of waves through-walls. The approximate size of the target is also predicted successfully.
MOTIVATION OF ENGLISH LANGUAGE TEACHER-RESEARCHER: A PSYCHOLOGICAL ANALYSIS BASED ON THE INTERCONNECTION BETWEEN POSSIBLE SELVES AND CONTEXT SYSTEMS

Research motivation is an essential element of teacher psychology. This paper attempts to disclose the variation in the possible self of English language teacher-researcher during the research process, and the evolution of his/her research motivation over one semester. For this purpose, a case study of teacher psychology was carried out with the author as a typical English language teacher-researcher. Three types of data were collected through a semester, namely, reflection journal, stimulated recall of student interview and stimulated recall of colleague discussion. Through person-in-context relational approach, the research data were subjected to thematic analysis. The results show that the teacher- researcher’s research motivation declined rapidly at the first month, and fluctuated in the next two months; through the semester, the teacher-researcher struggled to maintain reasonable views on time limitation, correct cognition on teaching, research and learning to teach, as well as effective interaction with students and colleges; the research motivation is enhanced by the dissonance between actual researcher self and ought-to researcher self, and the balance between actual teacher self and actual researcher self. The research results help language teacher-researchers to maintain psychological well-being.
Energy Harvesting Techniques for Autonomous WSNs/RFID with a Focus on RF Energy Harvesting

Supply circuits that harvest energy from surrounding ambient or dedicated sources have drawn much interest recently for providing a possibility of energy-autonomy to the wireless sensing devices. The objective of this thesis is to optimize the power transfer efficiency of the RF/microwave energy transducers in WSN/RFID applications. For this purpose, analysis on the power utilization of the wireless devices at different working states has been done, which implies a space of improving the power transfer efficiency by employing a novel design concept in the RF/microwave energy transducers. In order to observe a deep insight of the charge-pump based energy transducer, an analytical derivation has been implemented based on a compact I/V model for MOSFET working in strong inversion and subthreshold regions. The derivation provides a mathematical direction for the impact of the power consumption of the wireless device on the input impedance of the charge-pump rectifier, which acts as a core element in the energy transducer. With expressing the input impedance of the rectifier into a shunt connection of a resistor and a capacitor, as the load current consumption reduces the shunt resistance increases dramatically while the shunt capacitance holds a relatively constant value. This work proposes a methodology of employing an adaptively adjusted matching network between the rectifier and the antenna in order to optimize the power transfer efficiency according to the instant power consumption of the wireless devices on different working states. For read-only wireless devices with no embedded batteries, like RFID transponders, a tiny storage capacitor of pico-farad which can be charged-up to a certain voltage in microseconds is usually employed as a DC supplier. During the communication between reader and transponder, the reader radiates RF power continuously to supply the transponder. Extra power supply is required to adjust the matching network electrically for optimal power transfer, which raises a new challenge to the batteryless devices. A solution is proposed in this work that an auxiliary rectifier with a smaller constant load current consumption is employed to supply the feedback control circuitries. Besides, the abovementioned methodology is also applied in charging-up procedure of a wireless device which employs a supercapacitor as its charge storage. The charging-up procedure is extended to hours due to the huge volume of the capacitive storage, and the charging speed becomes a critical issue. During the charging-up, the output voltage of the recti- fier increases exponentially, while the charging current reduces exponentially. The input impedance derived for steady-state is not precisely applicable yet theoretically directive in this situation. A novel application of adaptively tunable matching network in transient process is implemented to accelerate the charging process of the wireless devices.
Investigating coupling inductors in the interleaving QSW VRM

The multi-channel interleaving quasi-square-wave (QSW) buck converter has been proved to be suitable for the voltage regulator module (VRM) with low voltage, high current and fast transient response. Integrated magnetic is used to reduce the size of the converter and improve efficiency. However, the structure of the integrated magnetic requires precise adjustment. In this paper, analysis shows that a properly designed integrated magnetic can improve the steady-state and dynamic performance without requiring precise adjustment.
MODELLING OF TOOL LIFE, TORQUE AND THRUST FORCE IN DRILLING: A NEURO-FUZZY APPROACH

This paper presents the application of neuro-fuzzy approach for modelling tool life, torque and thrust force in drilling operation for set of given process parameters, namely cutting speed, feed rate and drill diameter. The proposed approach uses a hybrid-learning algorithm i.e., combination of the back-propagation gradient descent method and least squares method, to identify premise and consequent parameters of the first-order Sugeno-fuzzy inference system. The least square method is used to optimize the consequent parameters with the premise parameters fixed. Once the optimal consequent parameters are found, the back-propagation algorithm gradient descent method is used to adjust optimally the premise parameters corresponding to the fuzzy set in the input domain. The predicted tool life, torque and thrust force values obtained from neuro-fuzzy system were compared with the experimental data. This comparison indicates that the proposed approach can produce optimal knowledge base of fuzzy system for predicting tool life, torque and thrust force in drilling operation. (Received in August 2009, accepted in November 2009. This paper was with the author 1 month for 1 revision.)
An experimental system for vibration sources identification with independent component analysis

Independent Component Analysis (ICA) can recover the original sources in multichannel observations when the original sources and the mixing process are not known. An experiment system with three known sources as an analog of the real world to research the validity and feasibility of ICA in gearbox fault diagnosis was set up. A normal gearbox and an abnormal gearbox were the object, a small motor was used to simulate the effect of the environment, and single tooth failure and the misalignment fault were considered as the inner known sources. Eight selective places where accelerometers glued on presented the full information of gearbox. The experiment results show that when the signal frequency is less than 100hz, it is appropriate to consider the mixing model of vibration sources as instantaneous model. The separation results by mean of FastICA algorithm which obtained from instantaneous model can successfully separate the vibration of disturbing motor, the pulse of single tooth failure and the frequency of misalignment fault from the observation on gearbox with light load. The experiment results suggest that the setup of the experimental system provides us an efficient experimental environment for algorithm research of validity and its feasibility testing and verifying.
Thermal/Mechanical System Level Test Results of the GIFTS 2-Stage Pulse Tube Cryocooler

The Space Dynamics Laboratory (SDL), in partnership with NASA Langley Research Center, is building the Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) instrument. The GIFTS focal plane assemblies (FPAs) must operate below 60 K to work properly. The aft optics and interferometer of the instrument must operate below 150 K. These two temperature zones will be cooled by a 2-stage pulse tube cryocooler built by Lockheed Martin. This cryocooler was designed to cool 1.5 watts at 55 K and 8.0 watts at 140 K with a 300 K reject temperature. System power consumed was to be less than 160 watts. SDL recently completed system level testing of the 2-stage cryocooler integrated into the GIFTS system. The thermal performance of the cryocooler as well as mechanical vibration characteristics observed during these tests will be presented. Preliminary analysis of the thermal data shows that cooling performance was achieved on both stages of the cryocooler with adequate thermal margin. Mechanical vibrations from the cryocooler were also found to be sufficiently low in that the perturbations did not prevent the instrument from meeting the NESR (Noise Equivalent Spectral Radiance) requirements. This paper discusses the effects of the cryocooler vibration on the performance of the GIFTS interferometer, which is highly susceptible to even the smallest vibration inputs. This paper also discusses the thermal performance data obtained dur-
Self-Tuning RBFNs Mobile Robot Systems through Bacterial Foraging Particle Swarm Optimization Learning Algorithm

A radial basis function neural networks (RBFNs) mobile robot control system is automatically developed with the image processing and learned by the bacterial foraging particle swarm optimization (BFPSO) algorithm in this paper. The image-based architecture of robot model is self-generated to travel the routing path in the dynamical and complicated environments. The visible omni-directional image sensors capture the surrounding environment to represent the behavior model of the mobile robot system. Three parameterize RBFNs model with the centers and spreads of each radial basis function, and the connection weights to solve the mobile robot path traveling and routing problems. Several free parameters of radial basis functions can be automatically tuned by the direct of the specified fitness function. In additional, the proper number of radial basis functions of the constructed RBFNs can be chosen by the defined fitness function which takes this factor into account. The desired multiple objectives of the RBFNs control system are proposed to simultaneously approach the shorter path and avoid the unexpected obstacles. Evaluations of PSO and BFPSO show that the developed RBFNs robot systems skip the obstacles and efficiently achieve the desired targets as soon as possible.
Investigation on the ignition of a MEMS solid propellant microthruster before propellant combustion

A MEMS-based solid propellant microthruster with thin film Au/Ti igniter has been fabricated for micropropulsion applications in microspacecraft. Since the propellant ignition process is crucial to the development of solid propellant microthrusters, finite-element based electro-thermal modeling is performed to predict and optimize the transient propellant ignition process. The model is implemented to determine the evolution of the propellant temperature with time, space and voltage and the ignition power, ignition delay and ignition energy. The difference in property between thin film Au/Ti and bulk Au/Ti and heat transfer in the micro-scale thruster are highlighted. A custom-built interface circuitry is employed to measure the igniter temperature experimentally. The electro-thermal model can be employed to find the optimum ignition subsystem for the solid propellant microthruster.
Pulse width modulation technique parameter selection with harmonic injection and frequency- modulated triangular carrier

This study presents a very important feature of the technique of pulse width modulation (PWM) with injection of harmonic and triangular frequency carrier modulated in frequency. This technique is used to improve the quality of the output voltage signal of the power inverters controlled PWM. The purpose of this study is to show a new feature of controllability by the selection of different parameters. This allows multiple responses, from the point of view of the spectrum and the properties of the signal quality, with the same number of pulses per second, allowing the controllability of the modulated output signal. With this ability to control, it is possible to choose, for example, the total harmonic distortion of the signal output from the inverter, or the value of the fundamental term of voltage. It is also possible to select the low order harmonic, of interest for the selective reduction of harmonics. To show this feature, some examples have been developed with different number of pulses per period and with their corresponding parameter selection.
The impact of energy awareness on energy efficiency

The increasing levels of global warming, depleting sources of fossil fuels and increasing energy costs are all having a large detrimental effect on today's society. Many efforts are being made to try and increase energy efficiency all over the world. One of the major problems is unnecessary and excessive energy utilisation. This problem has been identified by Loughborough University and they are making efforts to try and reduce energy wastage. One of their strategies, used up until recently, involved increasing energy awareness within students in halls of residence by means of a reward system called the Residential Halls Energy Efficiency League (Imago Services, Loughborough Students Union, Estates Services 2006). This scheme managed to reduce energy consumption by up to 10%, saving an estimated £9000 in only 52 days. Can those results be improved by targeting students more specifically? How much energy can be saved by increasing energy awareness?
Satellites for power system applications

With the launch of GPS satellites over the past 20 years, extremely accurate timing signals are now available all round the world and for a variety of purposes. By installing low-cost receivers in power system substations, synchronised pulsing is available for applications such as time tagging of data collected by any power system monitor. This article describes how the system works.
Spatially continuous analysis of in-shoe plantar pressure data

Boyer, K.A. and Andriacchi, T.P., 2009. Changes in running kinematics and kinetics in response to a rockered shoe intervention. Clin Biomech, 24 (10), 872–876. DeVita, P. and Bates, B.T. , 1988. Intraday reliability of ground reaction force data. Hum Mov Sci, 7 (1), 73–85. Diss, C.E. , 2001. The reliability of kinetic and kinematic variables used to analyse normal running gait. Gait Posture, 14 (2), 98–103. Heidenfelder, J., Sterzing, T. , and Milani, T.L. , 2010. Systematically modified crash-pad reduces impact shock in running shoes. Footwear Sci, 2 (2), 85–91. Lenhoff, M.W. , et al., 1999. Bootstrap prediction and confidence bands: a superior statistical method for analysis of gait data. Gait Posture, 9 (1), 10–17.
29 GHz modelocked miniature Nd:YVO/sub 4/ laser

A miniature Nd:vanadate (Nd:YVO/sub 4/) laser is presented which was passively modelocked at the very high repetition rate of 29 GHz using a semiconductor saturable absorber mirror (SESAM). An 81 mW average output power was achieved, which corresponds to 2.8 pJ pulse energy, and a pulse duration of 6.8 ps.
Modeling In-patients with Chronic Non-Communicable Diseases Using Parametric Shared Frailty Models

Background Non-communicable diseases, known as chronic diseases, are not contagious in their nature. They progress slowly in affecting the health of a person. They are the leading causes of death in all continents except Africa, but current projections indicated that by 2025 the largest increases in the non-communicable diseases deaths will occur in Africa. In Ethiopian about 34% of patients suffered from chronic non communicable diseases and there is a gap of estimating the time-to-death of these patients to manage the diseases progression in earlier. Thus, this study was aimed in estimating the survival outcome (death times) of the retrospective follow-up studies of registered inpatients for three years in three hospitals of Oromiya National Regional State, Ethiopia. Methods To describe the prediction and diseases progression of non-communicable diseases, different types of parametric frailty models were compared. Hospitals of the patients were considered as the unobserved variable in the models. The Exponential, Weibull and log-logistic as baseline hazard functions and the gamma and inverse Gaussian for the frailty distributions were checked for their performance using both AIC criteria and Likelihood ratio test. Results On average death times of chronic diseases was 12 days with the maximum of 40 days. Of 646 chronic non-communicable hospitalized patients about 41.5% were died. The log-logistic model with inverse Gaussian frailty has the minimum AIC and LRT value among the models compared. The hospital of the patient has a significant effect in modeling time-to-death of chronic diseases datasets. Conclusion The log-logistic with inverse Gaussian frailty model fitted better than other distributions for the chronic diseases data sets. Therefore, considering the hospital as random effects has a significant impact on time-to-death for NCDs patients and therefore, it is recommendable to include frailty to act as covariates for capturing any dependency under clustered time-to-event methods.
Development of circuit model for arcing on solar panels

The increased requirements of payload capacity of the satellites have resulted in much higher power requirements of the satellites. In order to minimize the energy loss during power transmission due to cable loss, use of high voltage solar panels becomes necessary. When a satellite encounters space plasma it floats negatively with respect to the surrounding space plasma environment. At high voltage, charging and discharging on solar panels causes the power system breakdown. Once a solar panel surface is charged and potential difference between surface insulator and conductor exceeds certain value, electrostatic discharge (ESD) may occur. This ESD may trigger a secondary arc that can destroy the solar panel circuit. ESD is also called as primary or minor arc and secondary is called major arc. The energy of minor arc is supplied by the charge stored in the coverglass of solar array and is a pulse of typically several 100 ns to several 100 μs duration. The damage caused by minor arc is less compared to major arcs, but it is observed that the minor arc is cause of major arc. Therefore it is important to develop an understanding of minor arc and mitigation techniques. In this paper we present a linear circuit analysis for minor arcs on solar panels. To study arcing event, a ground experimental facility to simulate space plasma environment has been developed at Facilitation Centre for Industrial Plasma Technologies (Institute for Plasma Research) in collaboration with Indian Space Research Organization's ISRO Satellite Technology Centre (ISAC). A linear circuit model has been developed to explain the experimental results by representing the coverglass, solar cell interconnect and wiring by an LCR circuit and the primary arc by an equivalent LR circuit. The aim of the circuit analysis is to predict the arc current which flows through the arc plasma. It is established from the model that the current depends on various parameters like potential difference between insulator and conductor, arc resistance, stored charge in the solar cell coverglass and the external capacitor that simulates wire harness. A close correlation between the experiments and circuit model results has been observed.
Kontur-, Rauheits- und Kraftmesstechnik mit Silizium-Cantileversonden (Shape, Roughness and Force Metrology using Silicon Cantilever Sensors)

Es werden piezoresistive Cantileversonden beschrieben, die für die Kontur- und Rauheitsbestimmung an mikroskopischen Bauteilen mit hohem Aspektverhältnis konzipiert sind. Sie sind weiterhin als transferierbare Krafteinstellnormale im Bereich von Nano- bis Millinewton einsetzbar. Als ein Beispiel für dimensionelle Messungen werden Rillen- und Rauheitsnormale sowie Eindrücke von Prüfkörpern zur Härtebestimmung charakterisiert. Der Einsatz von transferierbaren Krafteinstellnormalen zur Weitergabe geringer Kräfte wird vorgestellt. Messergebnisse an handelsüblichen Tastschnittgeräten sowie die Messung von Mikronewton-Kräften an lebenden einzelnen Herzmuskelzellen werden gezeigt. Piezoresistive cantilever probes were designed for shape and roughness measurements with high-aspect-ratio micro components and as transferable force standards in the nano-to-milli Newton range. As an example for dimensional metrology calibrated groove and roughness artefacts as well as indentation grooves for hardness measurement are characterized. The use of cantilever transfer standards for the calibration of low forces is presented at commercial stylus instruments as well as micro tools for the measurement of forces at isolated living cardiomyocytes.
Reluctance motors with bulk HTS material

In recent years we have successfully designed, built and tested several reluctance motors with YBCO bulk material incorporated into the rotor, working at 77 K. Our last motor type SRE150 was tested up to 200 kW. The aim of our investigations is the construction of motors with extremely high power density and dynamics. In comparison to conventional motor types the advantage of HTS reluctance motors with respect to size and dynamics could be demonstrated. Some fields of possible future applications will be described. These motors show a significant improvement in performance using high quality HTS bulk elements in the rotor. Until now the motor parameters have been limited by the current density which could be obtained in the bulk material at 77 K and by the geometric dimensions of the segments available. Therefore we expect further improvements in the case of these materials. Since the total motor including stator and rotor is working at low temperature we have to optimize the windings and the magnetic circuit to these operation conditions. A new design of a 200 kW motor in order to achieve increased power density and the theoretical results of our calculations will be shown.