This thesis presents a method for fault detection and precedent-free isolation for two types of channel flow systems, which were modeled with the finite element method. Unlike previous fault detection methods, this method requires no a priori knowledge or training pertaining to any particular fault. The basis for anomaly detection was the model of normal behavior obtained using the recently introduced Growing Structure Multiple Model System (GSMMS). Anomalous behavior is then detected as statistically significant departures of the current modeling residuals away from the modeling residuals corresponding to the normal system behavior. Distributed anomaly detection facilitated by multiple anomaly detectors monitoring various parts of the thermal-fluid system enabled localization of anomalous partitions of the system without the need to train classifiers to recognize an underlying fault. / text

Vacuum Arc Remelting (VAR) is a secondary process used for homogenization of high-melting-point and oxygen-sensitive materials such as superalloys and titanium alloys. The VAR process is carried out with the aim of melting a large consumable electrode in such a way that the resulting ingot has improved homogeneity. The Specialty Metals Processing Consortium (SMPC) has spent the past 20 years developing technology to improve control over the final ingot remelting and solidification processes to alleviate conditions that lead to the formation of inclusions and segregation. Channel segregates are concentration defects arising during the solidification of large-diameter solute-rich alloys. As manufacturers for turbine engines and generators call for larger ingots, it becomes more difficult to produce them without these defects. If, however, liquid pool depth can be controlled precisely to stabilize the solidification zone in the ingot, we could, in principle, produce larger ingots that are defect free. A problem arises because measurements obtained from the VAR furnace do not give enough information to accurately estimate the liquid pool shape in dynamic melting situations. Also, the solidification process in VAR is extremely complex due to the multiple physical domains present and a high-fidelity model is required to give an accurate description of the dynamic process. The Basic Axisymmetric Remelting (BAR) code was initially developed by Lee Bertram at Sandia National Laboratories as a high-fidelity multi-energy model to describe ingot casting in this system. In this work we present a new strategy to improve the accuracy of the estimates used in the control system. This strategy consists of implementing BAR as a new set of measurements to be used by the estimator. This new strategy was used in tests jointly sponsored by SMPC and Los Alamos National Laboratory (LANL) in February 2011 using a laboratory-scale furnace and alloy 718 electrodes. / text

Modifications were made to the turbulent channel flow facility to allow for fully developed rough quasi-2D Poiseuille flow with flow injection through one surface and flow suction through the opposing surface. The combination of roughness and flow injection is designed to be analogous to the flow field over a thermal protection system which produces ablative pyrolysis gases during ablation. It was found that the additional momentum through the surface acted to reduce skin friction to a point below smooth-wall behavior. This effect was less significant with increasing Reynolds number. It was also found that the momentum injection modified the wake region of the flow.

This dissertation will present the four manuscripts I published or am ready to publish on the study of the pathophysiology of migraine headache. The first chapter will discuss the background of the current understanding of migraine pathophysiology. Chapter 2 is focused on studying how Transient receptor potential vanilloid 4 (TRPV4) might play a role in migraine headache. Chapter 3 is the study of a novel cell type: dural fibroblasts might also play an active role in migraine headache. Chapter 4 is discussing Norepinephrine's role in headache pathophysiology. Chapter 5 is studying the combined effect of Acid and ATP in the pathophysiology of migraine headache. The dissertation will end in a conclusion in Chapter 6.

Context. Digital counterparts of handwritten signatures are known as Digital Signatures. The Elliptic Curve Digital Signature Algorithm (ECDSA) is an Elliptic Curve Cryptography (ECC) primitive, which is used for generating and verifying digital signatures. The attacks that target an implementation of a cryptosystem are known as side-channel attacks. The Flush+Reload attack is a cache side-channel attack that relies on cache hits/misses to recover secret information from the target program execution. In elliptic curve cryptosystems, side-channel attacks are particularly targeted towards the point multiplication step. The Gallant-Lambert-Vanstone (GLV) method for point multiplication is a special method that speeds up the computation for elliptic curves with certain properties. Objectives. In this study, we investigate the applicability of the Flush+Reload attack on ECDSA signatures that employ the GLV method to protect point multiplication. Methods. We demonstrate the attack through an experiment using the curve secp256k1. We perform a pair of experiments to estimate both the applicability and the detection rate of the attack in capturing side-channel information. Results. Through our attack, we capture side-channel information about the decomposed GLV scalars. Conclusions. Based on an analysis of the results, we conclude that for certain implementation choices, the Flush+Reload attack is applicable on ECDSA signature generation process that employs the GLV method. The practitioner should be aware of the implementation choices which introduce vulnerabilities, and avoid the usage of such ECDSA implementations.

The fluid flow channels of modern heat exchangers are often equipped with different flow disturbance elements which enhance the convective heat transfer coefficient in each channel. These structural or surface roughness elements induce enhanced flow mixing and convective heat transfer at low Reynolds numbers (500 < Re < 2200) by fluid mixing near the channel walls and increasing the surface area. These elements, however, are accompanied by higher pressure drops in comparison to hollow smooth channels (without inserts). The Run-Around Membrane Energy Exchanger (RAMEE) system is an air-to-air energy recovery system comprised of two remote liquid-to-air membrane energy exchangers (LAMEEs) coupled by a pumped liquid desiccant loop. LAMEEs use semi-permeable membranes that are permeable to water vapor, but impermeable to liquid water. The membranes separate the liquid desiccant from the air flow channels, while still allowing both heat and water vapor transfer. The air channels are equipped with turbulence enhancing inserts which serve dual purposes: (a) to support the adjacent flexible membranes, and (b) to enhance the convective heat and mass transfer. This research experimentally investigates the increase in the air pressure drop and average convective heat transfer coefficient after an air-side insert is installed in a Small-scale wind tunnel for exchanger insert testing (WEIT) facility that is designed to simulate the air channels of a LAMEE and to measure all the properties required to determine the flow friction factor and Nusselt number. Experiments are conducted in the test section under steady state conditions at Reynolds numbers between 900 and 2200 for a channel with and without inserts. The 500-mm-long test section has a rectangular cross section (5 mm wide and 152.4 mm high) and is designed to maintain a specified constant heat flux on each side wall. The flow is laminar and hydrodynamically fully developed at the entrance of the test section and, within the test section, thermal development occurs. Nine different insert panels are tested. Each insert is comprised of several plastic rib spacers, each aligned parallel to the stream-wise direction, and several cross-bars aligned normal to the flow direction. The plastic rib spacers are placed either 30 mm, 20 mm or 10 mm apart, and the distance between the cylindrical bars is either 30 mm, 45 mm, 60 mm or 90 mm. The measured convective heat transfer coefficient and the friction factor have uncertainties that are less than ±7% and ±11%, respectively. It is found that the Nusselt number and friction factor are dependent on the insert geometry and the Reynolds number. An empirical correlation is developed for the inserts to predict Nusselt number and friction factor within an air channel of a LAMEE. The correlations are able to determine the Nusselt number and the friction factor within ±9% and ±20% of the experimental data. Results show the flow insert bar spacing is the most important factor in determining the convective heat transfer improvement. As an application of the experimental data in this thesis, the experimental and the numerical results from a LAMEE which has an insert in each airflow channel are presented. The results show that the insert within the air channel of the LAMEE is able to improve the total effectiveness of the LAMEE by 4% to 15% depending on the insert geometry and air flow Reynolds number and operating inlet conditions for the exchanger.

Transmission power control (TPC) has been used in wireless networks to improve channel reuse and/or reduce energy consumption. It has been mainly applied to single-input single-output (SISO) systems. Significant improvement in performancecan be achieved by employing multi-input multi-output (MIMO) techniques. In this dissertation, we propose adaptive medium-access control (MAC) protocols for power-controlled MIMO-capable wireless networks. In these protocols, we adapt the number of transmit/receive antennas, along with the transmission powers/rates, for the purpose of minimizing total energy consumption and/or maximizing network throughput. Our first protocol, called E-BASIC, exploits the diversity gain of MIMO by adapting the transmission mode, transmission power, and modulation order so as to minimize the total energy consumption. We incorporate E-BASIC in the design of an energy-efficient routing (EER) scheme that selects the least-energy end-to-end path. We then propose two MAC protocols that exploit the multiplexing gain of MIMO, and consider their integration into legacy systems. We alsopropose a combined energy/throughput MAC protocol, called CMAC, which dynamically switches between diversity and multiplexing modes so as to maximize a utility function that depends on both energy consumption and throughput. Finally, we consider employing "virtual" MIMO capability into single-antenna wireless sensor networks (WSNs). We propose a distributed MIMO-adaptive energy-efficient clustering/routing protocol, coined CMIMO, which aims at reducing energy consumption in multi-hop WSNs. In CMIMO, each cluster has up to two cluster heads (CHs), which are responsible for routing traffic between clusters. Simulation results indicate that our proposed protocols achieve significant energy/throughput improvement compared with non-adaptive protocols.

Wireless communication is a rapidly growing segment of the communication industry, with the potential to provide low-cost, high-quality, and high-speed information exchange between portable devices. To harvest the available bandwidth efficientlyin a wireless network, they employ multiple orthogonal channels over multiple ra-dios at the nodes. In addition, nodes in these networks employ directional antennasas radios to improve spatial throughput. This dissertation develops algorithms forrouting and broadcasting with channel assignment in such networks. First, we com-pute the minimum cost path between a given source-destination pair with channelassignment on each link in the path such that no two transmissions interfere witheach other. Such a path must satisfy the constraint that no two consecutive links onthe path are assigned the same channel, referred to as "channel discontinuity con-straint." To compute such a path, we develop two graph expansion techniques basedon minimum cost perfect matching and dijkstra's algorithm. Through extensive sim-ulations, we study the effectiveness of the routing algorithms developed based onthe two expansion techniques and the benefits of employing the minimum cost per-fect matching based solution. Secondly, we study the benefits of sharing channelbandwidth across multiple flows. We model the routing and channel assignmentproblem in two different ways to account for the presence and absence of inter-flowbandwidth sharing. Benefits of multiple paths between a source-destination pairmotivates the problem of computing multiple paths between a source-destinationpair with channel assignment such that all the paths can be active simultaneouslyto achieve maximal flow between the pair in the considered network. Since finding even two such paths is NP-hard, we formulate the problem as an integer linearprogram and develop efficient heuristic to find these paths iteratively. Thirdly, wecompute a broadcast tree from a given root with channel assignment such that all the links in the broadcast tree can be active simultaneously without interferingwith each other. Since finding such a tree is an NP-hard problem, we formulatethe problem as an integer linear program (ILP) and develop heuristics to find thebroadcast tree with channel assignment. We evaluate and compare the performanceof the developed heuristics with respect to their success rate, average depth of theobtained tree, and average path length from root to a node in the network. Thisdissertation also analyzes the blocking performance of a channel assignment schemein a multi-channel wireless line network. We assume that the existing calls in thenetwork may be rearranged on different channels to accommodate an incoming call.The analysis is limited to single-hop calls with different transmission ranges.Finally, this dissertation evaluates the performance of disjoint multipath routingapproaches for all-to-all routing in packet-switched networks with respect to packetoverhead, path lengths, and routing table size. We develop a novel approach basedon cycle-embedding to obtain two node-disjoint paths between all source-destinationpairs with reduced number of routing table entries maintained at a node (hence thereduced look up time), small average path lengths, and less packet overhead. Westudy the trade-off between the number of routing table entries maintained at anode and the average length of the two disjoint paths by: (a) formulating the cycle-embedding problem as an integer linear program; and (b) developing a heuristic.We show that the number of routing table entries at a node may be reduced toat most two per destination using cycle-embedding approach, if the length of thedisjoint paths are allowed to exceed the minimum by 25%.

Nicotinic acetylcholine receptors (nAChR) are neurotransmitter-gated ion channels that exist as a family of subtypes defined by unique subunit compositions. nAChR containing α6 subunits (α6*-nAChR) have attracted interest because α6 subunits are thought to be localized in brain regions implicated in reward, mood and drug dependence. To provide new information necessary toward a more complete understanding of roles of α6*-nAChR in neuropsychiatric health and disease, three lines of investigation were pursued. A set of stably transfected, human, immortalized cell lines were generated that heterologously express nAChR α6 subunits in combination with other nAChR subunits found in reward brain regions (nAChR subunit combinations α6β2, α6β4, α6β2β3, α6β4β3, α6β2β3α5, α6β4β3α5, α6α4β2β3 and α6α4β4β3). The α6α4β2β3 combination may have a functional response to epibatidine that differs from that of the α4β2 nAChR. A unique binding site was identified in cells transfected with the α6β4β3α5 nAChR subunit combination. Messenger RNA fluorescence in situ hybridization (mRNA FISH) studies established regional and celluar distribution of nAChR α6 subunit mRNA in the mouse brain. The third line of study extended this work to examine potential co-expression of nAChR α6 subunits and glutamic acid decarboxylase (GAD) or tyrosine hydroxylase (TH) as labels of GABAergic and dopaminergic/catecholaminergic neurons respectively, using tandem mRNA FISH and fluorescence immunohistochemistry. nAChR α6 subunit signal in the substantia nigra (SN) and ventral tegmental area (VTA) was congruent with previous studies. Message was also detected in the amydala, dentate gyrus, striatum, zona incerta, and cingulate, entorhinal, perirhinal, piriform, and prelimbic cortices. nAChR α6 mRNA was coexpressed with GAD in the amygdala, dentate gyrus, striatum, SN, VTA and cingulate, entorhinal, prelimbic and prelimbic cortices. TH was exclusively co-localized with nAChR α6 mRNA in the SN and VTA. Findings suggest extended roles for α6*-nAChR in the brain, particularly in the control of GABAergic neuronal activity and/or GABA release. These studies provide new insights into the composition of α6*-nAChR, the localization and cellular origins of nAChR α6 subunit expression. Data collected suggest roles for α6*-nAChR in many brain regions, including those involved in higher order processes involved in drug dependence and reward, and in modulation of inhibitory neurotransmission.

Telecommunication systems are under constant development. Currently 3GPP is working on an evolution of the 3G-standard, under the name 3G Long Term Evolution (LTE). Some of the goals are higher throughput and higher peak bit rates. A crucial part to achieve the higher performance is channel dependent scheduling (CDS). CDS is to assign users when they have favorable channel conditions. Channel dependent scheduling demands accurate and timely channel quality reports. These channel quality indication (CQI) reports can possibly take up a large part of the allocated uplink. This thesis report focuses on the potential gains from channel dependent scheduling in contrast to the loss in uplink to reporting overhead. System simulations show that the gain from channel dependent scheduling is substantial but highly cell layout dependent. The gain with frequency and time CDS, compered to CDS in time domain only, is also large, around 20\%. With a full uplink it can still be a considerable gain in downlink performance if a large overhead is used for channel quality reports. This gives a loss in uplink performance, and if the uplink gets to limited it will severely affect both uplink and downlink performance negatively. How to schedule and transmit CQI-reports is also under consideration. A suggested technique is to transmit the CQI reports together with uplink data. With a web traffic model simulations show that a high uplink load is required to get the reports often enough. The overhead also gets unnecessary large, if the report-size only depends on the allocated capacity.