SCALABLE AND EFFICIENT REAL-TIME CLOCK MAINTENANCE IN A DISTRIBUTED NETWORK

Techniques are described herein for maintaining real-time software clocks in a distributed network. Generally, the techniques may approximate a synchronized timestamp for a delay request sent by a slave node based on a timestamp of a sync request received at the slave node. Then, a time stamping unit associated with the slave node may update the correction factor of the timestamp to adjust the synchronized timestamp appropriately. Notably, this avoids the need to read timestamps from first in, first out buffers of time stamping units and/or from field programmable gate arrays (FGPAs) and, thus, may significantly improve the scale of 1588 sessions while preserving slave node resources

Remote power delivery for hybrid integrated Bio-implantable Electrical Stimulation System

Bio-implantable devices such as heart pacers, gastric pacers and drug-delivery systems require power for carrying out their intended functions. These devices are usually powered through a battery implanted with the system or are wired to an external power source. In this work, a remote power delivery system (RPDS) is considered as a means to charge rechargeable batteries that power a Bio-implanted Electrical Stimulation System (BESS). A loosely coupled inductive power transmitter and receiver system has been designed to recharge batteries for a bio-implanted gastric pacer. The transmitter coil is periodically worn around the waist. The receiver coil, rechargeable batteries, battery-charging chip and the chip containing electrical stimulation circuitry form a bio-implanted hybrid integrated microsystem. The link efficiency between a transmitter coil and the implanted receiver coil when the diameters are markedly different is analyzed. A design methodology for RPDS is proposed based on the load and voltage required at the load. An analytical model is developed with the help of simple Matlab coding. A full wave rectifier with a voltage doubler circuit is used for the conversion of ac voltage to the required dc voltage. This dc voltage supplies power to a battery charging chip which is used to safely and appropriately charge a rechargeable Li-ion battery. For an input supply voltage of 17.67 V rms, operating frequency of 20 kHz and radial coplanar displacement between the coil axes of 7.5 inches, the maximum dc voltage and power obtained across a 65Ω load resistor are 9.65 V and 1.33 W respectively. For a radial coplanar displacement between the coil axes of 6 inches, a 3.7 V nominal, 150 mAh polymer lithium ion battery has been successfully charged in 1 hour and 40 minutes from an initial voltage of 3.39 V to 4.12 V with an input voltage of 19.81 V rms at 20 kHz. An attempt has been made to model coil parasitics at high frequency. Variations in the load power as a function of frequency and radial coplanar displacement of the axes are examined. Design strategies to optimize power delivery with given geometric constraints are considered

Cooperative relaying in cellular networks for improving receiver diversity and cell radius

Title from PDF of title page, viewed on June 28, 2013Thesis advisor: Cory BeardVitaIncludes bibliographic references (pages 54-56)Thesis (M.S.)--School of Computing and Engineering. University of Missouri--Kansas City, 2013Wireless network sharing has been the principal idea in the recent developments of wireless communication systems not only for improvement in capacity, data rates and coverage area but when considering an emergency service model, establishing reliable communication is the foremost requirement. With the inception of cooperative relaying technology, a novel wireless relaying method of sharing the terminal node capabilities to forward the signal created a new paradigm to greatly improve the quality of the services and soon became the significant research area in 3G/4G cellular networks. The cooperative terminals (relays) exploit a larger form of space diversity to relay signals to destinations when placed in between source and destination to combat the effects of fading induced by multipath signal propagation. However, the position of the relay in between the source and destination plays a significant role in affecting the overall network performance. Our attempt in this thesis is to show how a cooperative relay can be used to provide improved coverage at the cell edge with certain reliability and also extend the cell radius by effectively positioning the relay. First, we investigate the famous 3-node relay assisted cellular system model and study the receiver diversity combining results by changing the relay positions with a relay forwarding the signal using the amplitude and forward protocol (AAF). The figure of merit of the considered 3-node system model is expressed in terms of Bit error rate (BER) and signal to noise ratio (SNR). The BER vs. SNR plots are computed for various linear receiver diversity combining techniques and are used to evaluate performance of the system. These results are also compared to the conventional cellular network performance with a single point-to-point link between source and destination. Second, we provide the problem formulation of the diversity results observed and solve to find the effective relay position with respect to the source and also compute the effective cell radius of the 3-node system model. To compute effective relay position, we use the Bernardin's coverage area probability relation with cell radius at the cell edge of the source where the relay is assumed to be placed with its probability of successfully forwarding the signal conditionally depending on its cell edge probability. We have obtained results of the two above problem formulations using MATLAB simulations. We have emulated the cooperative relaying technique in a cellular system to achieve 2nd order diversity when compared to the conventional cellular system. The BER vs. SNR plots for each of the combining techniques show the significant difference in the diversity results when the channel quality estimations are used compared to the other methods which don't. Signal to noise ratio combining (SNRC) and Estimated SNRC (ESNRC) perform 4≅5dB better than the other combining methods provided their SNR estimation is accurate. The highest diversity order (2nd) is achieved when the relay is placed close to the source and drops as the relay is moved towards the destination. Cell range extension results show that moving the relay to its optimal position between source and destination in a cell provides capabilities to extend the cell range to nearly 1.5 times the cell radius of the source and still performs within the acceptable coverage area probabilities.Introduction -- Literature survey -- Legacy cellular system model and problem description -- Relay system model for improved signal quality -- Relay system model for coverage extension -- Conclusion and future wor

A Complete Coverage Algorithm for 3D Structural Inspection using an Autonomous Unmanned Aerial Vehicle

This thesis presents a novel algorithm for complete coverage of three-dimensional structures to address the problem of autonomous structural inspection using an Unmanned Aerial Vehicle (UAV). The proposed approach uses a technique of cellular decomposition based on Morse decomposition to decompose the 3D target structure into 2D coverable faces that are subsequently connected using a graph-based representation. We then use graph traversal techniques such as the Traveling Salesman Problem (TSP) to generate a flight coverage path through the decomposed faces for a UAV to completely cover the target structure, while reducing the coverage time and distance. To test the validity of our proposed approach, we have performed a series of experiments using a simulated AscTec Firefly UAV in different environments with 3D structures of different sizes and geometries, within the Robot Operating System (ROS) Gazebo simulator. Our results show that our approach guarantees complete coverage of the target structure. Comparison of our coverage strategy with other strategies shows that our proposed TSP-based coverage strategy performs up to 50% better in reducing the flight path with an average of 30% fewer turns and 12% less coverage duration than a largest-area-first approach

Control Oriented Modeling of an Automotive Drivetrain for Anti-Jerk Control

Drivability is an important metric during the development of an automobile. Calibration engineers spend a significant amount of time trying to improve the drivability of vehicles for various driving conditions. With an increase in the available computational power in an automobile, novel model-based methods are being implemented for further improving the drivability, while reducing calibration time and effort. Phenomenon known as clunk and shuffle, which are caused due to backlash and compliance in the driveline, are a major cause of issues related to drivability and noise, vibration and harshness (NVH) during tip-in and tip-out scenarios. This thesis focuses on developing a high-fidelity, control-oriented vehicle driveline model, which can be used for developing systems, to improve the drivability of a vehicle, during tip-in and tip-out events. A first principle physics-based model is developed, which includes the engine as a torque generator, backlash elements as discontinuities, and driveshafts as compliant elements. Experimental validation results showed that the accuracy of the developed model, in representing shuffle oscillation frequency, during the tip-in scenarios, with locked torque converter clutch, is approximately 99 %. A parametric analysis is performed to characterize the behavior of the model during different input conditions, and to study the effect of backlash size, and driveshaft compliance on the response of the driveline. Based on the observations from the parametric analysis, the high-fidelity model is later condensed into a reduced-order model, and comparative analysis is carried out between two reduced-order model (ROM) designs. The comparative results between the full-order model and ROM show that the ROM with separate tire parameters is better in predicting the frequency and amplitude of shuffle oscillations during tip-in events

Analysis, Design and Rehabilitation of Structural Members with Timber and FRP

Bridges have been an integral feature of the mountainous West Virginia landscape, carrying roads railways, and pedestrian traffic over creeks and rivers from early 1860. The state of West Virginia has always been a home for well reputed timber bridges in the last two centuries including several pedestrian bridges. This research focuses on designing a covered pedestrian bridge by using a combination of traditional and advanced materials such as timber, steel, and FRP for a length of 104.0\u27 over three spans. Following the design process, structurally feasible and an economical choice of deck and stringer sections will be selected. This research also evaluates the effectiveness of using carbon fiber and glass fiber reinforced polymers to reinforce the timber beams/stringers and piles used for bridge structural elements. Specimens representing an FRP bridge deck (48.0 x10.25 x3.5 ) and glued timber stringers (4 x10 x12\u27 and 4 x12 x16\u27) are tested under four-point bending. For timber elements, feasibility of using circular timber pile sections strengthened with FRP wraps are also investigated. Experimental results of decks, stringers, and pile elements are compared with theoretical and FE values and a good correlation is observed

Clinical implications of novel polymer and lipid based drug delivery systems

The use of lipids in drug delivery is not a new trend, some of the lipid dosage forms have been in use for a long time such as suppositories, creams, and emulsions. However, there has been much advancement in the designs of lipid carriers over the past decade. In the same way from the past two decades, new approaches in biodegradable and bio-reducible polymers have paved a way for many recent drug delivery systems. Applications of these novel drug delivery formulations have been promising clinically. However, each system has its pros and cons in various factors depending upon their use and intended route of administration. This review focuses on upbringing the challenges in the use of novel lipid and polymer drug delivery systems in clinical settings and few insights on how to overcome them

COMPARISON OF STRENGTH, DUCTILITY AND STIFFNESS FOR RADIUS CUT AND STRAIGHT CUT OF REDUCED BEAM SECTION

In 1994 there was an earthquake occurred in Northridge, California which caused damage in structures built with Steel Moment Frames (SMF) due to the brittle fractures in the beam and column connections. It has led to the major modifications and improvements in the connection detailing prior to the earthquake occurred in the Northbridge. These changes came up with better materials for welding and introduced the use of cover plate and Reduced Beam Section (RBS). RBS connections are the most widely used connection today and it allows the SMF systems to yield extensively and deform plastically by avoiding brittle fracturing at connections. The most important factors that affect the response along with the design of Steel Moment Frames (SMF) and Reduced Beam Section (RBS) connections are connection strength, stiffness, connection type, use of deep columns and phenomena associated with its instability, the strength of ductility of the column panel zone-beam instability

Tools and Techniques for testing of Flight Critical Software

Flight control system software is a critical component of the digital flight control computer of light combat aircraft. The problems associated with the testing of flight critical software and the test tools, and techniques used to achieve maintainability, and structural and functional coverage of test cases are presented. Also, the experience gained throughout the cycle of testing-design and implementation, reviews and revisions, test execution and software error detection and modificaton of test cases based on requirements and design changes, and regression testing are enumerated. It presents an object-oriented approach towards testing to make it less tedious, more creative, reviewable and easily miantainable

Investigation of Phishing Attacks and Means to Utilize Anti Phishing Techniques

Advancement of technology have both positive and negative impacts. Some of the negative impacts are cyber crimes. Cyber crimes have become more dangerous. Phishing is one of the cyber crime which results in exploitation of data. There are many phishing attacks which are identified every day. There are different techniques in phishing attacks. We have to reduce those attacks by employing suitable anti-phishing techniques. Some of the anti-phishing techniques and algorithms are discussed in this paper. History of phishing and the lifecycle are also discussed in this paper. People should be aware of all such phishing and the anti-phishing techniques. They have to be careful while checking their mails and should not click on any links or downloadable malware files