Carbon nanotubes (CNTs) are advanced materials that have numerous novel and useful properties. Controlling the synthesis and properties of CNTs is the major challenge toward their future applications. This thesis addresses this challenge with several contributions. This thesis begins with the brief introduction of CNTs, including the history of their discovery, their geometric structure, unique properties and potential applications. Then focus is laid on the subsequent three sections: characterization, synthesis, and manipulation of CNTs. Chapter 2 describes three characterization tools: AFM, SEM and Raman, which are commonly used to analyze CNTs and other nanomaterials. They offer both qualitative and quantitative information on many physical properties including size, morphology, surface texture and roughness. Also, they can be used to determine the structure of CNTS. Chapter 3 addresses the synthesis of CNTS, because synthesis is an important and indispensible process to study CNTs experimentally. Specifically, two controllable synthesis techniques are realized, which are capable to produce iron catalyst nanoparticles for single-walled carbon nanotube (SWNT) growth. Iron nanoparicles of different sizes obtained from both wet chemistry and electrodeposition can be used for diameter-controlled synthesis of SWNTs. Following synthesis, two manipulation methods of CNTs are discussed in Chapter 4. Firstly, effort of electrical breakdown of CNTs is introduced. Both SWNTs and MWNTs (Multi-walled carbon nanotubes) are cut using this method. Moreover, SWNT kink is shown using AFM tip manipulation. These two manipulation methods provide us a possibility to fabricate large cavity from a MWNT for our purposes. In the end of this thesis, conclusions on my master work in research field of CNTs are drawn and future research directions are proposed.

Carbon nanotubes (CNTs) are advanced materials that have numerous novel and useful properties. Controlling the synthesis and properties of CNTs is the major challenge toward their future applications. This thesis addresses this challenge with several contributions. This thesis begins with the brief introduction of CNTs, including the history of their discovery, their geometric structure, unique properties and potential applications. Then focus is laid on the subsequent three sections: characterization, synthesis, and manipulation of CNTs. Chapter 2 describes three characterization tools: AFM, SEM and Raman, which are commonly used to analyze CNTs and other nanomaterials. They offer both qualitative and quantitative information on many physical properties including size, morphology, surface texture and roughness. Also, they can be used to determine the structure of CNTS. Chapter 3 addresses the synthesis of CNTS, because synthesis is an important and indispensible process to study CNTs experimentally. Specifically, two controllable synthesis techniques are realized, which are capable to produce iron catalyst nanoparticles for single-walled carbon nanotube (SWNT) growth. Iron nanoparicles of different sizes obtained from both wet chemistry and electrodeposition can be used for diameter-controlled synthesis of SWNTs. Following synthesis, two manipulation methods of CNTs are discussed in Chapter 4. Firstly, effort of electrical breakdown of CNTs is introduced. Both SWNTs and MWNTs (Multi-walled carbon nanotubes) are cut using this method. Moreover, SWNT kink is shown using AFM tip manipulation. These two manipulation methods provide us a possibility to fabricate large cavity from a MWNT for our purposes. In the end of this thesis, conclusions on my master work in research field of CNTs are drawn and future research directions are proposed.

This thesis examines three computational problems in sports. The first problem addressed is determining the minimum number of points needed to guarantee qualification for the playoffs and the minimum number of points needed to have a possibility of qualification for the playoffs of the National Hockey League (NHL). The problem is solved using a phased approach that incrementally adds more complicated tie-breaking constraints if a solution is not found. Each of the phases is solved using a combination of network flows, enumeration and constraint programming. The experimental results show that the solver efficiently solves instances at any point of the season. The second problem addressed is determining the complexity, either worst-case theoretical or practical, of manipulation strategies in sports tournaments. The two most common types of competitions, cups and round robins, are considered and it is shown that there exists a number of polynomial time algorithms for finding manipulation strategies in basic cups and round robins as well as variants. A different type of manipulation, seeding manipulation, is examined from a practical perspective. While the theoretical worst-case complexity remains open, this work shows that, at least on random instances, seeding manipulation even with additional restrictions remains practically manipulable. The third problem addressed is determining whether manipulation strategies can be detected if they were executed in a real tournament. For cups and round robins, algorithms are presented which identify whether a coalition is manipulating the tournament with high accuracy. For seeding manipulation, it is determined that even with many different restrictions it is difficult to determine if manipulation has occurred.

Taking advantage of proxy variable of stock price manipulation like ownership concentration and earning management to examine the price difference between two market. In addition to liquidity or demand elasticity,etc, using manipulate variable of premium market(A-shares compared to H-share,TDR compared to HK-share) to investigate if manipulation can explain stock price difference. Empricial results show that premium not only concern to market system, but also connect to manipulation factors.The degree of premium will decrease as time progressd.

none

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 95-99). Available also in a digital version from Dissertation Abstracts.

This project investigates laser cutting in relation to textile manipulation and creating three-dimensional form. More precisely, this collection of nine outfits becomes an exploration about expressions of laser cut lines and their interrelation to the body through folding and draping the textile material. The laser cut bridge line used, will be the guiding part for a garments construction and through this different shapes are tested. This way of working with the material, its character and added manipulation will propose a new understanding of and an alternative for constructing a garment. This investigation is also a proposal for a new mind-set when it comes to using laser cutting in fashion design. Laser cutting has mainly been regarded as a technique for decoration, yet the machine could have a much greater role in the design process. Textile manipulation in this work is seen not only as a surface decoration but as a method of creating a 3D form from a 2D material which in this case is a method of design for shaping a garment. Through this, the work will hopefully challenge the industry in terms of working with laser cutting, garment construction and also textile manipulation.

Humans utilize the inherent biomechanical compliance present in their fingers for increased stability and dexterity during manipulation tasks. While series elastic actuation has been explored, little research has been performed on the role of joint compliance arranged in parallel with the actuators. The goal of this thesis is to demonstrate, through simulation studies and experimental analyses, the advantages gained by employing human-like passive compliance in finger joints when grasping. We first model two planar systems: a single 2-DOF (degree of freedom) finger and a pair of 2-DOF fingers grasping an object. In each case, combinations of passive joint compliance and active stiffness control are implemented, and the impulse disturbance responses are compared. The control is carried out at a limited sampling frequency, and an energy analysis is performed to investigate stability. Our approach reveals that limited controller frequency leads to increased actuator energy input and hence a less stable system, and human-like passive parallel compliance can improve stability and robustness during grasping tasks. Then, an experimental setup is designed consisting of dual 2-DOF tendon-driven fingers. An impedance control law for two-fingered object manipulation is developed, using a novel friction compensation technique for improved actuator force control. This is used to experimentally quantify the advantages of parallel compliance during dexterous manipulation tasks, demonstrating smoother trajectory tracking and improved stability and robustness to impacts. / text

<p>Pattern formation is a mysterious phenomenon occurring at all scales in nature. The beauty of the resulting structures and myriad of resulting properties occurring in naturally forming patterns have attracted great interest from scientists and engineers. One of the most convenient experimental models for studying pattern formation are colloidal particle suspensions, which can be used both to explore condensed matter phenomena and as a powerful fabrication technique for forming advanced materials. In my thesis, I have focused on the study of colloidal patterns, which can be conveniently tracked in an optical microscope yet can also be thermally equilibrated on experimentally relevant time scales, allowing for ground states and transitions between them to be studied with optical tracking algorithms. </p><p>In particular, I have focused on systems that spontaneously organize due to particle-surface and particle-particle interactions, paying close attention to systems that can be dynamically adjusted with an externally applied magnetic or acoustic field. In the early stages of my doctoral studies, I developed a magnetic field manipulation technique to quantify the adhesion force between particles and surfaces. This manipulation technique is based on the magnetic dipolar interactions between colloidal particles and their "image dipoles" that appear within planar substrate. Since the particles interact with their own images, this system enables massively parallel surface force measurements (>100 measurements) in a single experiment, and allows statistical properties of particle-surface adhesion energies to be extracted as a function of loading rate. With this approach, I was able to probe sub-picoNewton surface interactions between colloidal particles and several substrates at the lowest force loading rates ever achieved. </p><p>In the later stages of my doctoral studies, I focused on studying patterns formed from particle-particle interaction, which serve as an experimental model of phase transitions in condensed matter systems that can be tracked with single particle resolution. Compared with other research on colloidal crystal formation, my research has focused on multi-component colloidal systems of magnetic and non-magnetic colloids immersed in a ferrofluid. Initially, I studied the types of patterns that form as a function of the concentrations of the different particles and ferrofluid, and I discovered a wide variety of chains, rings and crystals forming in bi-component and tri-component systems. Based on these results, I narrowed my focus to one specific crystal structure (checkerboard lattice) as a model of phase transformations in alloy. Liquid/solid phase transitions were studied by slowly adjusting the magnetic field strength, which serves to control particle-particle interactions in a manner similar to controlling the physical temperature of the fluid. These studies were used to determine the optimal conditions for forming large single crystal structures, and paved the way for my later work on solid/solid phase transitions when the angle of the external field was shifted away from the normal direction. The magnetostriction coefficient of these crystals was measured in low tilt angle of the applied field. At high tilt angles, I observed a variety of martensitic transformations, which followed different pathways depending on the crystal direction relative to the in-plane field. </p><p>In the last part of my doctoral studies, I investigated colloidal patterns formed in a superimposed acoustic and magnetic field. In this approach, the magnetic field mimics "temperature", while the acoustic field mimics "pressure". The ability to simultaneously tune both temperature and pressure allows for more efficient exploration of phase space. With this technique I demonstrated a large class of particle structures ranging from discrete molecule-like clusters to well ordered crystal phases. Additionally, I demonstrated a crosslinking strategy based on photoacids, which stabilized the structures after the external field was removed. This approach has potential applications in the fabrication of advanced materials. </p><p> My thesis is arranged as follows. In Chapter 1, I present a brief background of general pattern formation and why I chose to investigate patterns formed in colloidal systems. I also provide a brief review of field-assisted manipulation techniques in order to motivate why I selected magnetic and acoustic field to study colloidal patterns. In chapter 2, I present the theoretical background of magnetic manipulation, which is the main technique used in my research. In this chapter, I will introduce the basic knowledge on magnetic materials and theories behind magnetic manipulation. The underlining thermodynamic mechanisms and theoretical/computational approaches in colloidal pattern formation are also briefly reviewed. In Chapter 3, I focus on using these concepts to study adhesion forces between particle and surfaces. In Chapter 4, I focus on exploring the ground states of colloidal patterns formed from the anti-ferromagnetic interactions of mixtures of particles, as a function of the particle volume fractions. In Chapter 5, I discuss my research on phase transformations of the well-ordered checkerboard phase formed from the equimolar mixture of magnetic and non-magnetic beads in ferrofluid, and I focus mainly on phase transformations in a slowly varying magnetic field. In Chapter 6, I discuss my work on the superimposed magnetic and acoustic field to study patterns formed from monocomponent colloidal suspensions under vertical confinement. Finally, I conclude my thesis in Chapter 7 and discuss future directions and open questions that can be explored in magnetic field directed self-organization in colloidal systems.</p> / Dissertation

Robots can move, see, and navigate in the real world outside carefully structured factories, but they cannot yet grasp and manipulate objects without human intervention. Two key barriers are the complexity of current approaches, which require complicated hardware or precise perception to function effectively, and the challenge of understanding system performance in a tractable manner given the wide range of factors that impact successful grasping. This thesis presents sensors and simple control algorithms that relax the requirements on robot hardware, and a framework to understand the capabilities and limitations of grasping systems. / Engineering and Applied Sciences