Automated Debugging Methodology for FPGA-based Systems

Electronic devices make up a vital part of our lives. These are seen from mobiles, laptops, computers, home automation, etc. to name a few. The modern designs constitute billions of transistors. However, with this evolution, ensuring that the devices fulfill the designer’s expectation under variable conditions has also become a great challenge. This requires a lot of design time and effort. Whenever an error is encountered, the process is re-started. Hence, it is desired to minimize the number of spins required to achieve an error-free product, as each spin results in loss of time and effort. Software-based simulation systems present the main technique to ensure the verification of the design before fabrication. However, few design errors (bugs) are likely to escape the simulation process. Such bugs subsequently appear during the post-silicon phase. Finding such bugs is time-consuming due to inherent invisibility of the hardware. Instead of software simulation of the design in the pre-silicon phase, post-silicon techniques permit the designers to verify the functionality through the physical implementations of the design. The main benefit of the methodology is that the implemented design in the post-silicon phase runs many order-of-magnitude faster than its counterpart in pre-silicon. This allows the designers to validate their design more exhaustively. This thesis presents five main contributions to enable a fast and automated debugging solution for reconfigurable hardware. During the research work, we used an obstacle avoidance system for robotic vehicles as a use case to illustrate how to apply the proposed debugging solution in practical environments. The first contribution presents a debugging system capable of providing a lossless trace of debugging data which permits a cycle-accurate replay. This methodology ensures capturing permanent as well as intermittent errors in the implemented design. The contribution also describes a solution to enhance hardware observability. It is proposed to utilize processor-configurable concentration networks, employ debug data compression to transmit the data more efficiently, and partially reconfiguring the debugging system at run-time to save the time required for design re-compilation as well as preserve the timing closure. The second contribution presents a solution for communication-centric designs. Furthermore, solutions for designs with multi-clock domains are also discussed. The third contribution presents a priority-based signal selection methodology to identify the signals which can be more helpful during the debugging process. A connectivity generation tool is also presented which can map the identified signals to the debugging system. The fourth contribution presents an automated error detection solution which can help in capturing the permanent as well as intermittent errors without continuous monitoring of debugging data. The proposed solution works for designs even in the absence of golden reference. The fifth contribution proposes to use artificial intelligence for post-silicon debugging. We presented a novel idea of using a recurrent neural network for debugging when a golden reference is present for training the network. Furthermore, the idea was also extended to designs where golden reference is not present

Compositional analysis of dark colored particulates homogeneously emitted with combustion gases (dark plumes) from brick making kilns situated in the area of Khyber Pakhtunkhwa, Pakistan

In Pakistan raw coal and a little quantity of waste plastics are burnt to sustain high temperature inside brick making kilns. The gaseous emissions of the kilns contain a considerable amount of darkish colored particulates. It is currently believed that the plastic burning produces these particulates. Advanced characterization instruments, such as a scanning electron microscope, energy dispersive spectroscopy, X-ray fluorescence, X-ray diffractometer, surface area analyzer using nitrogen gas adsorption isotherms, and thermogravimetric analyzer, were used to find out the chemistry and physics of the particulates. At a magnification of 30,000x, the SEM picture shows masses that are roughly roundish in shape and their size is in between 0.1 to 0.5 microns. The elements detected in these particles are carbon, oxygen, and sulfur (EDS analysis), or in other words, these elements are a typical composition of raw coal. This elemental analysis suggest that fine coal particles come out with usual combustion gases and these emitted particulates are not plastic combustion product. To strengthen this finding, the sample when calcined discarded a significant amount of sulphur oxides species, as determined in the XRF study by noticing a considerable decrease of sulphur content in the calcined particles, suggesting that the particles are actually a coal. The N2 isotherm graph reveals that the light weight flying coal particles has a very low surface area. Additionally, the XRD and TGA studies supports the conclusion that these dark colored particulate emissions are primarily fine coal particles (cenosphere)

Covid-19 vaccines status, acceptance and hesitancy among maintenance hemodialysis patients : a cross-sectional study and the implications for Pakistan and beyond

COVID-19 vaccine hesitancy continues to be a widespread problem in Pakistan due to various conspiracy beliefs, myths and misconceptions. Since the hemodialysis population is at higher risk of contracting infections, we sought to investigate the current COVID-19 immunization status and reasons for any vaccine hesitancy among these patients in Pakistan. This cross-sectional study was conducted among maintenance hemodialysis patients at six hospitals of Punjab Province of Pakistan. Data were collected anonymously using a questionnaire. 399 hemodialysis patients took part in the survey, the majority of them were male (56%) and aged 45 – 64 years. 62.4% of the patients reported receiving at least one dose of COVID-19 vaccine. Of those vaccinated (249), 73.5% had received two dose and 16.9% had received a booster dose. The most common reasons for vaccination were “being aware they were at high risk” (89.6%), “fear of getting infected” (89.2%) and “willingness to fight against COVID-19 pandemic” (83.9%). Of the 150 patients who had not yet been vaccinated, only 10 showed willingness to take the COVID-19 vaccine. The major reasons for refusal included “COVID-19 is not a real problem” (75%), “corona vaccine is a con-spiracy (72.1%)” and “I don’t need the vaccine” (60.7%). Our study revealed that only 62% pa-tients receiving hemodialysis were partially or completely vaccinated against COVID-19. Con-sequently, there is a need to initiate aggressive approaches to educate this high-risk population in order to address their vaccine safety and efficacy concerns and correct current myths and mis-conceptions to improve the COVID-19 immunization status in this population

Automated Debugging Methodology for FPGA-based Systems

Electronic devices make up a vital part of our lives. These are seen from mobiles, laptops, computers, home automation, etc. to name a few. The modern designs constitute billions of transistors. However, with this evolution, ensuring that the devices fulfill the designer’s expectation under variable conditions has also become a great challenge. This requires a lot of design time and effort. Whenever an error is encountered, the process is re-started. Hence, it is desired to minimize the number of spins required to achieve an error-free product, as each spin results in loss of time and effort. Software-based simulation systems present the main technique to ensure the verification of the design before fabrication. However, few design errors (bugs) are likely to escape the simulation process. Such bugs subsequently appear during the post-silicon phase. Finding such bugs is time-consuming due to inherent invisibility of the hardware. Instead of software simulation of the design in the pre-silicon phase, post-silicon techniques permit the designers to verify the functionality through the physical implementations of the design. The main benefit of the methodology is that the implemented design in the post-silicon phase runs many order-of-magnitude faster than its counterpart in pre-silicon. This allows the designers to validate their design more exhaustively. This thesis presents five main contributions to enable a fast and automated debugging solution for reconfigurable hardware. During the research work, we used an obstacle avoidance system for robotic vehicles as a use case to illustrate how to apply the proposed debugging solution in practical environments. The first contribution presents a debugging system capable of providing a lossless trace of debugging data which permits a cycle-accurate replay. This methodology ensures capturing permanent as well as intermittent errors in the implemented design. The contribution also describes a solution to enhance hardware observability. It is proposed to utilize processor-configurable concentration networks, employ debug data compression to transmit the data more efficiently, and partially reconfiguring the debugging system at run-time to save the time required for design re-compilation as well as preserve the timing closure. The second contribution presents a solution for communication-centric designs. Furthermore, solutions for designs with multi-clock domains are also discussed. The third contribution presents a priority-based signal selection methodology to identify the signals which can be more helpful during the debugging process. A connectivity generation tool is also presented which can map the identified signals to the debugging system. The fourth contribution presents an automated error detection solution which can help in capturing the permanent as well as intermittent errors without continuous monitoring of debugging data. The proposed solution works for designs even in the absence of golden reference. The fifth contribution proposes to use artificial intelligence for post-silicon debugging. We presented a novel idea of using a recurrent neural network for debugging when a golden reference is present for training the network. Furthermore, the idea was also extended to designs where golden reference is not present

Ni-Doped In₂O₃ Nanoparticles and Their Composite with rGO for Efficient Degradation of Organic Pollutants in Wastewater under Visible Light Irradiation

The efficient degradation of organic effluent is always desirable when using advanced photocatalysts with enhanced activity under visible light. Nickel-doped indium oxide (Ni-In2O3) is synthesized via a hydrothermal route as well as its composites with reduced graphene oxide (rGO). Facile synthesis and composite formation methods lead to a well-defined morphology of fabricated nanocomposite at low temperatures. The bandgap energy of indium oxide lies in the range of 3.00–4.30 eV. Its high light absorption capacity, high stability, and non-toxicity make it a choice as a photocatalyst that is active under visible light. The transition metal Ni-doping changes the indium oxide’s chemical, optical, and physicochemical properties. The Ni-In2O3 and rGO composites improved the charge transport and reduced the charge recombination. The phase analysis of the developed photocatalysts was performed using X-ray diffraction (XRD), and the morphological and structural properties were observed using advanced microscopic techniques (SEM and TEM), while UV-vis and FTIR spectroscopic techniques were used to confirm the structure and optical and chemical properties. The electrochemical properties of the photocatalysts were investigated using cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS), and the charge-transfer properties of the obtained photocatalysts and the mechanism of the photocatalytic degradation mechanism of methylene blue, a common dye used in the dyeing industry, were determined

A systematic study of influence of process variables on the overall heat transfer coefficient in a shell and tube heat exchanger

A systematic experimental study was carried out on a shell and tube heat exchanger (STHx) to examine the influence of process variables such as hot and cold water flow rate, and the hot water inlet temperature on the overall heat transfer coefficient (U). The results show that the U increased with increasing the hot water and cold water flow rates. Similarly, the increase in hot water inlet temperature, improved heat transfer rate. It was observed that the increase in the U by increasing the cold water flow rate was significantly higher than with increasing the hot water flow rate. Under similar process conditions, at 36 oC hot water inlet temperature, the U increased from 709.96 to 1045.50 W/(m2.oC) with the increasing cold water flow rate from 0.75 to 2.5 L/min. While for the hot water case, the U increased from 709.96 to 940.43 W/(m2.oC) for the corresponding hot water flow rate. An empirical model correlating the outlet temperature of the STHx fluids with the inlet conditions has also been proposed. The proposed model was used to calculate the outlet temperatures of the hot and cold water and the heat flux. The model predictions were compared with the experimental results and a good agreement was foun

A Common Ground-type Single-Phase Dual Mode Five-Level Switched-Capacitor Transformerless Inverter

© 2020 IEEE. This paper presents a novel dual mode five-level common ground type (5L-DM-CGT) transformerless inverter topology with a wide input range (200 V - 400 V). It consists of eight switches, one diode, two capacitors, and an LC filter at the output. The topology eliminates common mode (CM) leakage current by connecting the negative terminal of the photovoltaic (PV) directly to the neutral point of the grid, which bypasses the PV array's stray capacitance. Depending on the magnitude of the input voltage, the converter can operate in buck or boost mode to produce the same AC voltage output. The analysis shows the advantages of dual mode inverter for various industrial applications. MATLAB Simulink simulations and experimental results verify the concept of the proposed topology and control method