Miracle-dz/UniFAR-FTUs huggingface dataset:
Modelling, analyses and design of switching converters

The principal objective of this work on modeling and analysis of switching dc-to-dc converters and regulators is to obtain a linear model (either through state-space or linear circuit description), subject to appropriate restrictions, for the inherently nonlinear power state in which the dc conversion is accomplished. A general unified approach to modeling and analysis of switching dc-to-dc converters is developed which is directly applicable to any dc-to-dc operating in either of two conduction modes (continuous or discontinuous inductor current), and which results in a final dynamic linear model either in terms of state-space equations or in terms of their corresponding linear circuit models. In particular, in Part I this analysis technique, called state-space averaging, is applied to the continuous conduction mode of converter operation, while in Part II appropriate extension of the method to the discontinuous conduction mode is made. In each case, the culmination of modeling and analysis is achieved in the development of canonical circuit models which represent any such converter regardless of its detailed configuration. The insights that emerge from the general state-space modeling approach (Parts I and II) lead in Parts III and IV to the design of new converter topologies through the study of generic properties of the cascade connection of basic buck and boost converters. This study paves the way in Part IV to the discovery of a new switching converter based upon capacitive rather than the usual inductive energy transfer. The new converter is shown to have substantial advantages over the conventional converters in its class in efficiency, performance, and also in size and weight. Bothe the state-space averaged models and their corresponding circuit realizations provide the circuit designer with a powerful tool for analysis of existing converters as well as for synthesis of new converter topologies.
Multi-Objective Genetic Algorithm for Hover Stabilization of an Insect-Like Flapping Wing

This paper describes latest results obtained on modeling, simulation and controller design of an insect-like Flapping Wing Micro Air Vehicle (FWMAV). Because of the highly nonlinear and time varying nature of insect flight and the inability to find an equilibrium point, linearization of the model without compromising the accuracy is not possible. Therefore, to address the problem of designing a controller capable of stabilizing and controlling the FWMAV around a hovering point, a metaheuristic optimization approach is proposed, based on the time averaging theorem. The results show that a controller, designed using the proposed method, is capable of stabilizing the FWMAV effectively around its hovering point.
Modelling and control of coiling entry temperature using interval type-2 fuzzy logic systems

Abstract The set-up of the cooling water applied to the strip as it traverses the runout table in order to achieve the coiler entry temperature was made by an intelligent model implemented using interval type-2 fuzzy logic systems. The model uses as inputs the targets for coiling entry temperature, strip thickness, finish mill exit temperature and finishing mill exit speed. The experiments of this application were carried out for three different types of coil in a real hot strip mill. The results proved the feasibility of the system developed for coiler entry temperature prediction. Comparison with the online type-1 fuzzy logic based model shows that the proposed interval type-2 fuzzy logic system improves performance in coiler entry temperature prediction under the tested condition.
Reconfigurable fault-tolerant controller synthesis for a steer-by-wire vehicle using independently driven wheels

In this paper, a synthesis method for a reconfigurable fault-tolerant control system for use in a steer-by-wire vehicle is proposed. The vehicle considered in this paper is also assumed to have independently driven wheels. The control objective in this work is to enable the vehicle yaw rate to track the reference signal even when the steering actuator breaks down. Since the vehicle yaw rate can be controlled with either the front wheel turn angle or the yaw moment generated by the independently driven wheels, this system has actuator redundancy. We attempt to design a control system that manages this actuator redundancy so that the performance degradation due to the actuator failure is minimised. We utilise a control allocator based on on-line optimisation for managing the actuator redundancy. The fault-tolerant control system with a control allocator has several excellent properties. For example, the method can handle various failure situations. Also, since the control allocation problem is reduced to a convex quadratic programming problem, the on-line computational effort is relatively little. However, so far, it has been unclear whether the stability of the control system with the control allocator is guaranteed when the actuator failure occurs. Therefore, we propose a design method of a fault-tolerant controller based on on-line optimisation that guarantees the stability of the overall system. The effectiveness of the method is established through numerical examples.
Training emergency managers for earthquake response: challenges and opportunities

Purpose – This paper aims to highlight the crucial role of decision makers and emergency managers in reducing the unpleasant consequences of disasters.Design/methodology/approach – An attempt has been made to clarify the measures for planning and implementation of training issues in earthquake emergency response for the emergency managers as an essential part at various managerial levels.Findings – The paper reveals that, although the high‐level managers such as ministers are authoritative bodies for managing the routine problems of the country, in situations such as a “major emergency”, specific knowledge and experience of emergency issues are required for the emergency management to be successful. It also explores the ways and opportunities for achieving successful training programmes for the emergency managers.Research limitations/implications – The existing challenges, including the lack of adequate background knowledge and experience in emergency management, insufficient time to train, the inadequacy.
Design of Galvanic Cell Battery for Underwater Applications using Seawater as Electrolyte

Seawater battery is one of the green electricity sources to fulfill energy need for electrical equipment, especially in the coastal area and fishing activity . A survey was conducted among fishermen in which it was found that small scale fishermen uses lead acid battery and fuel cell in order to charge the mobile phone and glow the fishing lights. But major drawback of lead acid battery and fuel cell is that the maintenance cost is higher which is difficult for them to afford. Seawater is one most available sources all over the world and it is of no cost, hence a seawater battery is designed.Thispaper aims to study galvanic cells using sea water as electrolyte for energy harvesting. The electrochemical performances of Galvanic cells were carried out by measuring electric potentials by understanding the nature of conductivity of electrodes. The effect of sea water pH on electric potential was analyzed using sea water from different parts of Bay of Bengal with varying depths. Various combinations of electrodes like Graphite, Zinc, Copper, Aluminium, Brass and Iron were tested. A maximum yield of 1.1 V was obtained using the combination of Graphite–Iron as Cathode–Anode for a single cell. Further, we developed a working prototype for 16 cell. It generates a voltage of 12 V and 20 mA. Since the output current obtained was not as desired so we added a current amplification circuit and obtained a maximum current of 300mA from 20mA
Research on Security Requirement and Improvement Recommendation of Smart Mobile Terminal

The rapid development of wireless technology has been a qualitative leap in the mobile network performance, allowing mobile network terminals to enjoy a variety of service types. But as the important personal information storage carrier to users, the own security of the smart mobile terminal is related to the safety of the entire mobile Internet. This paper introduces the security situation of the smart mobile terminals, analyzes the potential security threats and the security needs, and at last gives improvement recommendations of the smart mobile terminals protection.
Conceptual Design and Kinematic Analysis of a Compliant Parallel Mechanism for Micro/Nano Scale Manipulation

There is a great need in various fields to be able to produce motion on a micro/nano scale with three translational degrees of freedom (DOF). Such fields include optical alignment, cell injection operation, precision manufacturing and micro electro mechanical systems. This research is concerned with the design and analysis of a compliant parallel micromanipulator (CPM) for micro/nano scale manipulation. Several kinematic structures including a novel three-cylindrical-prismatic-revolute CPM is proposed. Based on the established pseudo-rigid-body model of the CPM, the kinematic models are derived. The CPM is featured by pizeo-driven and flexure hinges, thus it has advantages such as sub nanometer resolution, large force generation, sub-millisecond response, and extremely low steady state power consumption.Copyright © 2009 by ASME
An Improved Global Maximum Power Point Tracking Scheme under Partial Shading Conditions

A photovoltaic array exhibits several local and single global maximum power points under partial shading conditions. To track the global maximum power point precisely, a novel global maximum power point tracking scheme is proposed in this paper. In the proposed scheme, robustness of the tracking performance has been improved by enhancing searching profile. In addition, the paper addresses the tracking failure condition, and provides the experimental verification with several simulation and experimental results.
Jitter and phase noise of ADPLL due to PSN with deterministic frequency

In this article, jitter and phase noise of all-digital phase-locked loop due to power supply noise (PSN) with deterministic frequency are analysed. It leads to the conclusion that jitter and phase noise heavily depend on the noise frequency. Compared with jitter, phase noise is much less affected by the deterministic PSN. Our method is utilised to study a CMOS ADPLL designed and simulated in SMIC 0.13 µm standard CMOS process. A comparison between the results obtained by our method and those obtained by simulation and measurement proves the accuracy of the predicted model. When the digital controlled oscillator was corrupted by PSN with 100 mVpk-pk, the measured jitters were 33.9 ps at the rate of fG = 192 MHz and 148.5 ps at the rate of fG = 40 MHz. However, the measured phase noise was exactly the same except for two impulses appearing at 192 and 40 MHz, respectively.
The Influence on Sensitivity of Hardware Trojans Detection by Test Vector

Hardware Trojans have emerged as a new threat to the security of chip and the reliability of computing systems. As such, methods of determining whether a “security chip” contains hardware Trojans are a research concern. This study proposes power relative variation (PRV) parameters to analysis the relation between test vectors and detection sensitivity. Following a brief introduction into Trojans and detection methods, we present the S-box circuit noise model in AES core and simulate the power tracks of various sizes of hardware Trojans using HSPICE. We also apply different sets of test vectors in 40 nm processing. Experimental results show that the power of the entire circuit is reduced by 41% and the PRV value increased 12.71% and 3.34% at most corresponding to combinational and sequential Trojan circuits. The valid test vectors can enhance the activity of hardware Trojans. They can also limit the noise from process, supply voltage, and temperature and extrude the features from the Trojan circuit to increase PRV value. As a result, a sample amount can be compressed at a reduced cost given a similar detection effect. Hence, the investigation into the influence of test vectors on the detection methods of hardware Trojans based on side-channel analysis is extremely important.
Compliance based MIP model and heuristic for support layout optimization

Machining-fixture supports are used to increase workpiece rigidity. A critical problem of machining fixture design is where to place a fixed number of supports in order to minimize the affect of workpiece deformation on machined feature geometric error during machining. In a previous effort, a linear Mixed Integer Programming (MIP) model was developed to solve this problem. This model is based upon a statically reduced FEA model of the workpiece, and is capable of solving the more general problem of locator button-support layout. A major disadvantage of this model is that its size is sensitive to the square of the number of machining response points considered. Since the difficulty of solving an MIP model increases with model size, this presents a severe limitation to the use of the MIP model in applications in which a large number of machining response points must be considered. This paper illustrates a technique that can be used to make the MIP model size strictly proportional to the number of machining.
Ultrawideband SAR signature investigations based on electromagnetic models and measurements

The performance of an electric field integral equation (EFIE) model is discussed in the context of target detection and classification. This EFIE model, which is a modified version of the Finite Element Radiation model developed at MIT Lincoln Laboratory, was used to simulate VHF SAR signatures of ground targets. These SAR signatures were studied and compared with signatures generated from data colelcted by the CARABAS sensor during a 1993 Foliage Penetration Radar experiment. It was found that the EFIE model can provide adequate RCS values and distributions for gound target detection studies. It was also found that the simulated images have reasonable spatial appearance and may be useful for ground target classification studies.
The Growth of Firms: A Survey of Theories and Empirical Evidence

Research into firm growth has been accumulating at a terrific pace, and Alex Coad's survey of this multifaceted field provides a detailed, comprehensive overview of the latest developments. Much progress has been made in empirical research into firm growth in recent decades due to factors such as the availability of detailed longitudinal datasets, more powerful computers and new econometric techniques. This book provides an up-to-date catalog of empirical work, as well as a coherent theoretical structure within which these new results can be interpreted and understood. It brings together a large body of recent research on firm growth from a multidisciplinary perspective, providing an up-to-date synthesis of stylized facts and empirical regularities. Numerous empirical findings and theories of firm growth are also surveyed and compared in order to evaluate their validity. Drawing on a vast and diverse body of research, this book will prove invaluable to students, academics, policy makers and practitioners with a need to keep abreast of studies in industrial organization, firm growth and management.
DOMINATION AND DEPENDENCE IN MASS COMMUNICATIONS: IMPLICATIONS FOR THE USE OF BROADCASTING IN DEVELOPING COUNTRIES

Introduction 'Cultural patterns once established are endlessly persistent. The opportunity to freshly mould a new nation's outlook arid behaviour is historically unique and merits most careful deliberation. Yet in modern mass communications hard and inflexible laws economic and technological operate. If these are not taken into account in the beginning and at least partially overcome, courses of development automatically unfold that soon become unquestioned "natural patterns". ' (Schiller, 1969).
Tunable band-pass filter with wide stopband and high selectivity using centre-loaded coupled structure

A tunable band-pass filter using a coupled structure that is centrally tapped with a resonator is proposed for wideband applications. The utilised resonator includes parallel-coupled lines loaded with a short-ended varactor. The resonator enables the independent tunability of two transmission zeroes (TZs), which define the passband of the filter. Moreover, the structure creates multiple TZs in upper stopband which enable realising a wide spurious-free stopband. A thorough theoretical analysis is used to verify the performance and calculate the initial design parameters. To validate the proposed design procedure, a prototype is designed, fabricated and tested. The simulated and measured results agree with the derived theory, and indicate a tuning range for the 3 dB bandwidth from 47.8 to 105.7% with, 1.4 dB of insertion loss and more than 12 dB of return loss. It also has more than 18 dB of attenuation across a stopband extending to around four times the centre frequency.
Advanced Control for a Fire-Tube Shell Boiler System

The design of a fire-tube shell boiler consists of a bundle of tubes contained inside a shell. The heat transfer process from the combustion gas to the boiling water via the tube surface is extremely complicated as it involves combustion, convection, conduction, and boiling process. Severe boiling and evaporating processes take place outside the fire-tube shell boiler where the steam is generated. However, many processes such as the regeneration of absorbent for CO2 removal needs optimum steam consumption, which reflects its high costs for operation. Therefore, good control performance of steam pressure becomes important. This study is aimed at developing a control scheme to minimize the effect of over-firing on the fire-tube shell boiler which impacts on excessive fuel consumption. The Neural Network Predictive Controller (NNPC) is used in this work, using the optimization and neural toolboxes which are written in the MATLAB code and were compared with the PID controller for set-point tracking and disturbance rejection ability. The comparison reveals that NNPC gives an excellent alternative to PID controller due to the non-linearity of the fire-tube shell boiler system. Since NNPC can reduce the fuel consumption by minimizing actuator moves, the control of boiler and burners in this plant in Brunei is recommended to be upgraded to replace the existing PID controller.
Reflection Property of the Two-Dimensional High Impedance Surface

One of the properties of high impedance surface is that the phase of the reflection wave by the surface is zero.A high impedance surface was used as antenna reflecting surface. A dipole antenna was designed as radiation source. Simulation demonstrated that when the patches number of surface changed the radiation pattern changed and the gain varied also. The distance between antenna and the reflection face varied the radiation pattern also changed. Controlling the number of cells or distance between antennas from reflection plane the gain of antenna can be improved.
Attitude Maneuver Control of Flexible Spacecraft with Finite-Time Convergence

The attitude maneuver control of flexible spacecraft with finite-time convergence is investigated in this paper. Two terminal sliding mode controllers are proposed to achieve the finite-time control, which guarantee the convergence of attitude maneuver errors in finite time. The singularity problem associated with the terminal sliding mode control is solved by employing a new sliding variable. Numerical simulations are finally provided to illustrate the performance of the proposed controllers.
Wing Design by Numerical Optimization

A study was conducted to assess the feasibility of performing computerized wing design by numerical optimization. The design program combined a full-potential, inviscid aerodynamic code with a conjugate gradient optimization algorithm. Three design problems were selected to demonstrate the design technique. The first involved modifying the upper surface of the inboard 50% of a swept wing to reduce the shock drag subject to a constraint on wing volume. The second involved modifying the entire upper surface of the same swept wing (except the tip section) to increase the lift-drag ratio, subject to constraints on wing volume and lift coefficient. The final problem involved modifying the inboard 50% of a low-speed wing to achieve good stall progression. Results from the three cases indicate that the technique is sufficiently accurate to permit substantial improvement in the design objectives.
Elevated Plasma Factor VIII in Non-Pyogenic Cerebral Venous Thrombosis after Head Trauma without Skull Fracture

Cerebral Venous Thrombosis (CVT) is a relatively uncommon but important cause of stroke that tends to affect young adults, especially women. Head trauma with or without skull fracture was reported to be triggering factors for CVT, but the underlying pathophysiology was not well elucidated. Endothelial injury and coexistent hypercoagulability were supposed to contribute to CVT after head trauma without skull fracture. We report a 49-year-old female patient who presented with headache with vomiting after head trauma and was initially diagnosed as post-traumatic Intracerebral Hemorrhage (ICH), but subsequently, progressed to CVT that resulted in cerebral venous infarction with hemorrhagic transformation. Magnetic Resonance brain Venography (MRV) confirmed CVT in superior sagittal sinus as well as right transverse and sigmoid sinuses. She was treated with endovascular mechanical thrombectomy followed by anticoagulation. The coagulopathy panel was checked both in hospital and in outpatient clinic for evaluating the etiology underlying post-traumatic nonpyogenic CVT. Persistently elevated level of plasma Factor VIII was identified. We should consider that patients with recent head trauma history without skull fracture and coexistent hypercoagulability could develop CVT resulting in cerebral venous infarction with hemorrhagic transformation even when the patient showed no definite focal neurologic deficit or the patient’s initial CT scan revealed no intracranial hemorrhage.