No / A low-profile (λ/43) miniaturized multi-element antenna is presented, which displays vertical polarization with an omni-directional radiation pattern. The antenna uses a logarithmic spiral shape as the main radiating element such that the impedance bandwidth of the antenna is much improved in comparison with both a strip-line square spiral design and a strip-line circular spiral design. The antenna demonstrates stable gain and useful efficiency over the operating frequency band. Significantly, the antenna provides a low profile, omnidirectional pattern in the azimuth plane, polarizes normal to the ground-plane with a 1.2% bandwidth and 0.5 dBi gain.

The water crisis has been an increasing challenge in some places in the world. One proposed solution that has drawn lots of attention is fog harvesting. A commonly used fog collector is a vertical mesh, usually made of poly materials. Small water droplets can easily get pinned and quick evaporation is the major common challenge for vertical meshes. Coating the fog mesh with superhydrophobic chemicals is one of the solutions. However, superhydrophobicity is not durable and it may contaminate the collected water. In addition, it requires a high professional maintenance and laboratory operation standard. As a result, it is impractical to set such fog collectors in regions and countries with water crisis. Low cost, harmless, easily fabricated, higher coalesce rate and low maintenance are the five pillars for this research. This thesis topic is inspired by spider silk's ability to direct water droplets to certain locations to further enhance water collecting rate. This directional droplet movement is caused by spindle-knot and joint structure on the biomimetic silk. The spindle-knot is randomly porous, and the joint is stretched porous. In addition, the spindle-knot has a tilted angle β above the joint region. Due to these unique structures, there are three droplet movement controlling forces – surface tension force, hysteresis force, and Laplace pressure force. This thesis presents detailed equation derivations for each driving force in the introduction section. Spindle-knot is the pivot point to direct water, forming the spindle-knot structure is another focus of this thesis. Fluid coating and dip-coating with dimethylformamide (DMF), a solvent with a low evaporation rate, is the highly used methods to form the spindle-knot structures due to its simple setup and low cost. However, DMF is an extremely hazardous organic compound, and it requires high laboratory operation standards. In the second section of this thesis, DMF has been replaced with water/ethanol and photocurable materials to construct the spindle-knots. Furthermore, Additive manufacturing (3D printing method) was adopted to synthesize bionic spider web with spindle-knot structures. / Master of Science / Water shortage is one of the highest concerns all around the world and collecting fog water has drawn lots of attention recently. The focus of this thesis is to increase the fog collection rate by using less hazardous, low maintenance and low-cost methods. Commonly used fog collector is a large vertical plastic mesh. However, those large meshes suffer from water pinning and easily evaporation issues. Water repellent chemicals have been studied and used to dissolve those issues, however, the chemical coating will not last long and it will contaminate the collected water easily. Moreover, coating the water repellent chemicals requires professional operation and maintenance. To solve this issue without using chemical coating, we have learned unique water collection and directional behavior from spider silk. In a humid day, you will easily find the spider web with fully covered water droplets in an organized order. If we zoom in on single spider silk, the spider silk is composed of many puff and joint regions. Those puff regions have higher water collection ability than the joint regions, and this puff region shrinks down to form the spindle-knot shape with angle β above the joint region. This unique spindle-knot structure induces the water directional movement, and three forces- surface tension force, pinning force, and Laplace pressure force – are controlling the moving direction. Chapter 1 shows equation derivations with surface material effects, surface roughness effects and water droplet landing location effects. To form such special spindle-knot structure, commonly used formation methods are fluid coating and dip coating by using an organic polymer solvent. However, commonly used organic polymer-solvent suffer from a high level of hazardous, resulting in high laboratory requirement and operation cost. In Chapter 2 of this thesis, that commonly used organic polymer-solvent will be replaced by water/ethanol mixture and light-sensitive materials to form the spindle-knots. Furthermore, the 3D printing method is adopted to build a spider web with spindle-knot structures.

Yes / This communication complements the DEA model proposed by Lovell and Pastor (1999), by incorporating both positive and negative criteria in the model. As such, we propose a DEA model, known as pure DEA, using a directional distance function approach.

<p>Ericsson develops a new stripline directional coupler. Its design is described in appendix B and differs from the directional couplers Ericsson uses in current products. The new directional coupler will be used for transmission power measurement in future UMTS 3G base stations.</p><p>The most important parts of directional coupler theory are presented. It is necessary to study this theory to understand how the coupler works and how it should be designed to get good performance.</p><p>Optimal directional coupler termination component values to get high directivity and broad directivity bandwidth have been investigated.</p><p>The trim screws trim ranges have been studied.</p><p>A simple analysis of serial production performance when termination component tolerances are taken into consideration has been done.</p><p>The resistance components reactive (inductive/capacitive) characteristics at 2.14 GHz have been analyzed.</p><p>The directivity performance limitations of the directional coupler, when Ericsson’s band pass filter is connected, are investigated.</p><p>Design changes leading to better performance are proposed. Some important relations between design choices and performance are explained.</p> / <p>Ericsson utvecklar en ny typ av striplineriktkopplare. Dess utformning beskrivs i appendix B och skiljer sig från de riktkopplare Ericsson använder i nuvarande produkter. Den nya riktkopplaren ska användas för uteffektmätning i framtida UMTS 3G basstationer.</p><p>De viktigaste delarna av riktkopplarteori gås igenom. Det är nödvändigt att studera teorin för att förstå riktkopplarens funktion och för att förstå hur den ska designas för att få bra prestanda.</p><p>Optimala värden på riktkopplartermineringskomponenter har laborerats fram för att få så hög direktivitet och stor direktivitets-bandbredd som möjligt.</p><p>Trimskruvarnas trimområde har kartlagts.</p><p>En enkel analys av serieproduktionsprestanda har gjorts med hänsyn till termineringskomponenternas toleranser.</p><p>Resistanskomponenternas reaktiva (induktiva/kapacitiva) karakteristik vid 2.14 GHz har undersökts.</p><p>Riktkopplarens direktivitetsprestandabegränsningar när Ericssons bandpassfilter är inkopplat utreds.</p><p>Förslag till möjliga förbättringar ges. Vissa viktiga samband mellan designval och prestanda klarläggs.</p>

This thesis presents the design and development of a unique omni-directional platform known as the Omnibot which was built in the Mechatronic and Robotic Systems Laboratory at UOIT. The Omnibot's layout is novel because its drive axes do not intersect with the geometric center of the body, which is typical for omni-directional platforms using segmented omni-directional wheels. This design enables the center of mass to be lower in the design and increases the stability. A suspension system was designed for each of the four wheels to limit vibrations and to ensure contact between the wheels and operating surface. The Omnibot was built to modularly support many systems, including a robot arm, without altering the mechanical design of the frame. Two control modes were developed: local and global. Commands to drive the Omnibot can be received from either a joystick that can be directly interfaced with the controller or with commands that are sent from other systems that are either on or o of the Omnibot. Both control modes require encoder feedback to ensure commanded velocities are being executed as specified. Global control requires feedback from an indoor localization system to determine the Omnibot's pose. Early implementation of the localization system is discussed. An open source robotics software, known as Robot Operating System (ROS) was selected for implementation of the Omnibot systems. ROS serves as a middleware which allows components, such as the localization system and remote desktop, to communicate with each other through a decoupled messaging system. ROS is modular and exible, allowing for easy adaptation of future components. Test results of the Omnibot in operation are presented.

Ericsson develops a new stripline directional coupler. Its design is described in appendix B and differs from the directional couplers Ericsson uses in current products. The new directional coupler will be used for transmission power measurement in future UMTS 3G base stations. The most important parts of directional coupler theory are presented. It is necessary to study this theory to understand how the coupler works and how it should be designed to get good performance. Optimal directional coupler termination component values to get high directivity and broad directivity bandwidth have been investigated. The trim screws trim ranges have been studied. A simple analysis of serial production performance when termination component tolerances are taken into consideration has been done. The resistance components reactive (inductive/capacitive) characteristics at 2.14 GHz have been analyzed. The directivity performance limitations of the directional coupler, when Ericsson’s band pass filter is connected, are investigated. Design changes leading to better performance are proposed. Some important relations between design choices and performance are explained. / Ericsson utvecklar en ny typ av striplineriktkopplare. Dess utformning beskrivs i appendix B och skiljer sig från de riktkopplare Ericsson använder i nuvarande produkter. Den nya riktkopplaren ska användas för uteffektmätning i framtida UMTS 3G basstationer. De viktigaste delarna av riktkopplarteori gås igenom. Det är nödvändigt att studera teorin för att förstå riktkopplarens funktion och för att förstå hur den ska designas för att få bra prestanda. Optimala värden på riktkopplartermineringskomponenter har laborerats fram för att få så hög direktivitet och stor direktivitets-bandbredd som möjligt. Trimskruvarnas trimområde har kartlagts. En enkel analys av serieproduktionsprestanda har gjorts med hänsyn till termineringskomponenternas toleranser. Resistanskomponenternas reaktiva (induktiva/kapacitiva) karakteristik vid 2.14 GHz har undersökts. Riktkopplarens direktivitetsprestandabegränsningar när Ericssons bandpassfilter är inkopplat utreds. Förslag till möjliga förbättringar ges. Vissa viktiga samband mellan designval och prestanda klarläggs.

Indiana University-Purdue University Indianapolis (IUPUI) / This study presents a novel converter configuration that is related to the area DC-DC power converters. To begin with, a brief introduction is given by stating the importance of power electronics. Different types of converters, their operating principles and several new topologies that are being proposed over the years, to suit a particular application with specific advantages are listed in detail. In addition, pro- cedure for performing small signal analysis, which is one among the several averaging techniques is summarized in the first chapter. In the second chapter, small signal modeling is carried out on the single input dual output DC-DC buck converter. This analysis is performed to get a clear un- derstanding on the dynamics of this novel configuration. Routh stability criterion is also applied on this converter topology to determine the limiting conditions for operating the converter in its stability. Third chapter proposes the single input multiple output DC-DC synchronous buck converter. It’s operation, implementation and design are studied in detail. In further, small signal analysis is performed on this topology to determine the transfer function. In the following chapter, results obtained on comparison of a losses between the conventional and traditional topologies are presented in detail. In addition, results achieved during the analysis performed in the previous chapter are displayed. In the end, advantages and its highlights of this novel configuration proposed in this study is summarized. Future course of actions to be done, in bringing this configuration in to practice are discussed as well.

Published Article / Automatic guided vehicles are being used increasingly in a manufacturing environment. Developing a platform that could be easily reconfigured is perhaps a desirable option for a user with low capacity outputs. The research described in this article concentrates on such a vehicle and the development of the actuators and sensors for navigation and proper functionality.

ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / The US Army Research Laboratory has been involved in the design and implementation of electromagnetic gun technology for the past several years. One of the primary factors of this research is an accurate assessment of in-bore structural loads on the launch projectiles. This assessment is essential for the design of mass-efficient launch packages for electromagnetic guns. If not properly accounted for, projectile failure can result. In order to better understand the magnitude of the in-bore loads, a data-recorder was integrated with an armature and on-board payload that included tri-directional accelerometers and magnetic field sensors. Several packages were launched from an electromagnetic railgun located at Aberdeen Proving Ground, MD. Substantial effort was placed on soft-catching the rounds in order to facilitate data recovery. Analysis of the recovered data provided acceleration and magnetic field data acquired during the launch event.

Mobility is something able-bodied people take for granted. Approximately 132,500 people in the United Kingdom have disabilities which permanently confine them to a wheelchair; 40,000 of these require a powered wheelchair. The opportunity to lead a normal life and be accepted as an equal by the able-bodied population is limited by their reduced mobility. As much freedom of movement as possible is therefore crucial for these people. Powered wheelchair users' mobility depends upon the manoeuvrability of the chair. For optimum manoeuvrability a chair must be capable of moving in any direction. Currently no omni-directional powered wheelchairs are commercially available. This thesis describes the design and deVelopment of a powered base unit for a wheelchair, controlled to instantaneously move in any direction. The novelty is principally represented by the innovative design and configuration of four omni-directional roller wheels* (LUMAN wheels) which, when individually controlled, produce the omni-directional movement of the base unit. Further novelty within the design is a set of bi-directional angled roller couplings that simultaneously disengage the wheels from the motors, via a cable linkage mechanism, and simple control system. Mathematical data models illustrate the theoretical performance of the wheel configuration, and a prototype base unit is tested to prove these hypotheses.