Transparent thin film transistors fabricated at room temperature by radio frequency magnetron sputtering using indium oxide material system were proposed. The electrodes of the transparent thin film transistors were obtained by depositing indium oxide with 10% tim doping. Resistivity as low as 4¡Ñ10-4£[-cm at room temperature was achieved. The channel layers of the transparent thin film transistors were fabricated using pure indium oxide target in an Argon and oxygen environment. Resistivity larger than 10-5£[-cm was obtained with 60% oxygen partial pressure. Silicon nitride prepared by room temperature radio frequency sputtering were used for the gate dielectric layer with low leakage current. Environmental-safe lift-off processes were used to fabricated the electrodes, the isolation layer, and the channel layer. The transistor characteristics were obtained by standard I-V measurement. The on-off ratio of the 30£gm ¡Ñ 150£gm transparent thin film transistor is 100.

Aluminum nitride (AlN) thin films were deposited on SiO2/Si substrates using the reactive RF magnetron sputtering in this thesis. By means of the analysis of XRD, SEM, TEM and AFM, the optimal deposition conditions of highly C-axis oriented AlN films were obtained with RF power of 190W, sputtering pressure of 3mTorr, nitrogen concentration (N2/N2+Ar) of 30%, and substrate temperature of 400¢J. The characteristics of films annealed at temperature range from 600¢J to 1150¢J with N2 flow for 2 hours has been studied. Experimental results reveal that the films retain the high quality up to 800¢J. But when the temperature above 1000¢J, AlN films will be oxided to AlO:N. In addition, the interdigital transducers (IDTs) were fabricated on the films annealed at 800¢J for 2 hours to study the characteristics of SAW devices. The results show that the central frequency, insertion loss and phase velocity of SAW were 182.25 MHz, -12.95 dB and 5824 m/sec, respectively. At the same time, we try to match the impedence of devices and improve the frequency response by using a simulation program. After the impedence was matched, the insertion are not strongly improved but the frequency response and closed-in sidelobe rejection exhibit better. The effects of temperature on the SAW devices show that the central frequency almost does not shift when the temperature increases. But the insertion loss slightly increases with the temperature increased, the variation is about -0.02 dB/¢J.

The maximum weight-independent set problem (MWISP) is one of the most well-known and well-studied NP-hard problems in the field of combinatorial optimization. In the first part of the dissertation, I explore efficient branch-and-price (B&P) approaches to solve MWISP exactly. B&P is a useful integer-programming tool for solving NP-hard optimization problems. Specifically, I look at vertex- and edge-disjoint decompositions of the underlying graph. MWISP’s on the resulting subgraphs are less challenging, on average, to solve. I use the B&P framework to solve MWISP on the original graph G using these specially constructed subproblems to generate columns. I demonstrate that vertex-disjoint partitioning scheme gives an effective approach for relatively sparse graphs. I also show that the edge-disjoint approach is less effective than the vertex-disjoint scheme because the associated DWD reformulation of the latter entails a slow rate of convergence. In the second part of the dissertation, I address convergence properties associated with Dantzig-Wolfe Decomposition (DWD). I discuss prevalent methods for improving the rate of convergence of DWD. I also implement specific methods in application to the edge-disjoint B&P scheme and show that these methods improve the rate of convergence. In the third part of the dissertation, I focus on identifying new cut-generation methods within the B&P framework. Such methods have not been explored in the literature. I present two new methodologies for generating generic cutting planes within the B&P framework. These techniques are not limited to MWISP and can be used in general applications of B&P. The first methodology generates cuts by identifying faces (facets) of subproblem polytopes and lifting associated inequalities; the second methodology computes Lift-and-Project (L&P) cuts within B&P. I successfully demonstrate the feasibility of both approaches and present preliminary computational tests of each.

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Includes supplementary material. / CAPSTONE PROJECT REPORT / System Engineering and Analysis Cohort 18A and Temasek Defense Systems Institute / Approved for public release, distribution unlimited / The aging Whidbey Island and Harpers Ferry class ships, LSD-41 and 49 respectively, comprise just over one third of the amphibious navy. However, a solution to the capability gap created by the loss of these ships is needed to maintain the effectiveness of the amphibious fleet across a broad spectrum of mission areas. This research effort considers future ship designs and fleet architectures to meet the capability gaps left by the decommissioning of the LSD-41 and 49 class ships. With respect to lift capacity, performance capability, cost and a risk assessment, the analysis showed the LPD-17 or a LSD(X) approximately 30% larger than the existing classes to be acceptable replacement classes. This analysis also supports further research to determine the most robust fleet architecture apart from the current eleven LHA or LHD, eleven LPD and eleven LSD paradigm.

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Šiame darbe modeliuojamas žirklinis keltuvas skirtas kroviniams ir žmonėms kelti, nagrinėjama konstrukcija, detalių stipruminiai skaičiavimai atlikti panaudojant medžiagų atsparumo formules, bei programinę įranga skirtą inžineriniams skaičiavimams bei projektavimui(solidWorks). Žirklinio keltuvo techninės charakteristikos: maksimali keliamoji galia mmax¬= 600kg, kėlimo aukštis Hmax¬=4m 1.Patikima ir paprasta konstrukcija, Maži gamybos kaštai,pigi eksploatacija, patogus naudojimas. Darbo uždaviniai: 1.Sumodeliuoti žirklinį keltuvą kuris atitiktu jam keliamus reikalavimus. 2. Pritaikyti sraigto-veržlės pavarą keltuvui. 3. Atlikti detalių analizę su COSMOS Express programa. Darbe modeliavimui ir detalių tyrimui panaudotas automatizuoto projektavimo paketas SolidWorks. Automatizuotu projektavimo paketų panaudojimas, žymiai sumažina gaminių projektavimo laiką, patikimai ir greitai atliekama detalių ar mazgų analizė, sumažėja projektavimo kaštai. Keltuvo žirklių analizei panaudota programa COSMOS Express atlieka skaičiavimus baigtinių elementų metodu, skaičiavimai yra gan greiti ir patikimi. Darbe sumodeliuotas keltuvas atitinka reikalingas technines charakteristikas, nesudėtinga konstrukcija, lengvai eksploatuojamas, patogiai transportuojamas. / Lift tables are used to raise and position work pieces for ergonomic access. They are typically used for material positioning, load positioning, or lifting. Lift tables are work platforms used to raise and lower material and work pieces for loading and work positioning. They are widely used in construction, automotive and garage service, electrical and power service, telecommunications, manufacturing, inventory management, wire and cable industries, painting and other applications where access to above ground locations is crucial. Important specifications when considering lift tables are lift capacity, vertical lift travel, platform width and platform length. The lift capacity is the maximum force or load supported by the lift. Vertical lift travel describes the difference between fully lowered and fully raised lift positions. The platform width is the narrow dimension of the lift platform. Platform length is the long dimension of the lift platform.

The most important issue at a container terminal is to minimize the ship’s turnaround time which is determined by the productivities of quay cranes (QCs). The tandem lift quay cranes have 33% higher productivities than single lift QCs. However, the tandem lift operations bring new challenges to the vehicle dispatching at terminals and this has become a big issue in the application of tandem lift QCs. The vehicle dispatching at terminals is to enhance the QCs’ productivities by coordinating the QCs’ operation schedules and the vehicles’ delivery schedules. The static version of the problem can be formulated as an MILP model and it is a combinational optimization problem. When the type of QC is tandem lift, the problem becomes more complicated because it requires two vehicles side by side under the QC. Thus, the alignments of vehicles have to be considered by coordinating the delivery schedules between vehicles. On the other hand, because the containers are operated alone by the yard cranes, the vehicles could not be grouped and dispatched in pairs all the time. This dissertation investigates the static and dynamic version of the problem and proposes heuristic methods to solve them. For the static version, Local Sequence Cut (LSC) Algorithm is proposed to tighten the search space by eliminating those feasible but undesirable delivery sequences. The time windows within which the containers should be delivered are estimated through solving sub-problems iteratively. Numerical experiments show the capability of the LSC algorithm to find competitive solutions in substantially reduced CPU time. To deal with the dynamic and stochastic working environment at the terminal, the dissertation proposes an on-line dispatching rule to make real-time dispatching decisions without any information of future events. Compared with the longest idle vehicle rule, the proposed priority rule shortens the makespan by 18% and increases the QCs’ average productivities by 15%. The sensitivity analysis stated that the superiority of the priority rule is more evident when the availability of vehicles is not sufficient compared with the frequency of releasing transportation requests.

The objectives of the present body of work were 1) to evaluate the Personal Lift-Assist Device (PLAD) in terms of its effect on lifting technique, interjoint coordination, and whether sex modulates these effects and 2) to explore the use of principal component analysis (PCA) as a method to investigate lifting waveforms. Thirty participants (15M, 15F) completed a freestyle, symmetrical lifting protocol during which three-dimensional kinematics of the ankle, knee, hip, and lumbar and thoracic spine were collected using a two-camera Optotrak 3020 system. There were four testing conditions: a) with and b) without wearing the PLAD; and c) 0% load and d) 10% of maximum back strength load. All data were evaluated using PCA. In the first analysis, the relationship between the PLAD and lifting technique under a loaded condition was explored. Results showed that 8 PCs were significantly different between the PLAD/No PLAD conditions yet there were no significant effects of sex on any of the PCs. It was concluded that wearing the PLAD encourages a lifting technique that is reflective of a squat lift, independent of sex. In the second analysis, the PLAD’s effect on interjoint coordination patterns under both loaded and unloaded conditions was examined using the relative phase angle (RPA). It was found that there were no significant differences between device, sex, or load conditions on any of the PCs retained in the model. A novel approach to enhance interpretability of PCs was developed during this study. Finally, when the PLAD was not worn, male and female differences were further investigated under loaded and unloaded conditions. It was determined that when the load is individualized to personal strength characteristics, sex differences in lifting technique are negligible. This is a contradictory finding from previous research. Overall, the major contributions of this research are: support for the use of the PLAD in industry; the recommendation that load be selected based on individual strength characteristics for lifting research experimental design; the use of PCA as a method to effectively evaluate lifting waveforms; and the development of a novel approach to aid in the interpretation of principal components. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2010-08-18 09:35:19.142

A full-scale ASTM E 1321 Lateral ignition and Flame Transport (LIFT) apparatus was constructed and compared with a Reduced scale Ignition and Flame spread Test apparatus (RIFT) adaptation of the cone calorimeter in the vertical position. The objective was to find a low cost and simple alternative to the LIFT apparatus for measuring opposed flow flame spread. Ignition tests were conducted using the LIFT, RIFT and ISO 5657 ignitability apparatus and flame spread experiments were conducted in the LIFT and RIFT. Nine different types of timber based products were tested for ignition and flame spread, and Quintiere's flame spread model was applied to the results to obtain material properties, such as thermal inertia, flame spread parameter and the minimum heat flux required for flame spread. These materials included plywood, medium density fibreboard (MDF), hardboard, particle board flooring, Melamine (Melteca) covered MDF, New Zealand Rimu, and Beech and New Zealand grown Macrocarpa and Radiata (Monterey) Pine. Further limited tests were conducted on Melteca covered particle board, and a second brand of particle board. The materials in the RIFT were tried with and without preheating to equilibrium. In addition, a view factor for the RIFT was developed, based on earlier work for the cone calorimeter element. The view factor equation was experimentally tested against measured values, and the calculated value was consistently lower than the experimental values, with similar flux profile. The standard procedure is for the material to be preheated before ignition, so that the surface is at equilibrium. The spread of the flame front past points on the sample surface after ignition is recorded, and from the flame front velocity and the model by Quintiere, material specific properties can be derived. The lack of preheating was found to affect the final results, by reducing the flame spread velocity and increasing the scatter in the experimental results. The RIFT gives comparable results to the same materials tested in the LIFT and to the published literature. The results the flame spread parameter and the minimum flux for flame spread are usually higher for the RIFT against the same material in the LIFT. There proved to be an effective limit on suitable materials able to be successfully tested in the RIFT to those that have a minimum flux for flame spread of less than 7kW/m2, with this limitation is dictated by the flux profile along the sample, and the lower resolution dictated by the smaller size. It is approximately equivalent to a minimum ignition flux of 18kW/m2.