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Automata and game theoretic models of computationGandhi, Aniruddh January 2012 (has links)
In this thesis we investigate two finite state models of computation: automata and games on graphs. First we investigate the state complexity of finite word and tree automata from two directions. One direction is to study the interplay between non-deterministic automata (NFA) and deterministic automata (DFA) state complexity. In particular, we show that the exponential gap of the state explosion caused by the subset construction and the complementation of NFA may be filled. Another direction is to investigate the DFA state complexity of natural subclasses of regular languages. We focus on finite word and tree languages and provide improved upper bounds on the state complexity of union and intersection of such languages. Secondly we generalize finite automata by introducing automata over arbitrary algebraic structures. For a structure S, we use the term S-automata for the class of automata operating over S. An S-automaton has a fixed number of registers and processes finite sequences of elements from the (possibly infinite) domain of S. At every stage, it may test the input against the values in the registers using the relations of S and then based on the outcome of this test, move to another state after applying some operations from S to the registers. We investigate certain natural problems such as the validation problem and the emptiness problem and show that they may become decidable or undecidable if we change the underlying structure or the structure of the automaton in various natural ways. Lastly we investigate the problem of solving Bu��chi and parity games on trees with back-edges. We present an efficient algorithm that solves a Bu��chi game played on trees with back-edges and then apply our analysis to parity games. We then present experimental evidence which shows that our algorithm for Bu��chi games performs asymptotically better than the classical algorithm in many cases. Also we present a concrete class of Bu��chi games for which the classical algorithm has a quadratic running time and our algorithm has linear running time.
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School social work the emerging models of practice in InidaGandhi, Anjali 03 1900 (has links)
Emerging models of practive in Inida
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Ngugi Wa Thiong’o and Mulk Raj Anand: A comparative studyGandhi, Lingaraja 12 1900 (has links)
A comparative study
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A study of shool climate as a function of personality of school personnel and pupil control ideologyGandhi, K A 02 1900 (has links)
Pupil control ideology
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Academic achievement in relation to achievement motive affiliation motive and power motiveGandhi, Pritty 06 1900 (has links)
Motive affiliation motive and power motive
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Determination of dispersion curves for acoustoelastic lamb wave propagationGandhi, Navneet 30 August 2010 (has links)
The effect of stress on Lamb wave propagation is relevant to both nondestructive evaluation and structural health monitoring because of changes in received signals due to both the associated strain and the acoustoelastic effect. A homogeneous plate that is initially isotropic becomes anisotropic under biaxial stress, and dispersion of propagating waves becomes directionally dependent. The problem is similar to Lamb wave propagation in an anisotropic plate, except the fourth order tensor in the resulting wave equation does not have the same symmetry as that for the unstressed anisotropic plate, and the constitutive equation relating incremental stress to incremental strain is more complicated. Here we review the theory of acoustoelastic and develop theory for acoustoelastic Lamb wave propagation and show how dispersion curves shift anisotropically for an aluminum plate under biaxial tension. We also develop an approximate method using the effective elastic constants (EECs) and show that existing commercial tools to generate dispersion curves can be used under restricted conditions to describe wave propagation in biaxially stressed plates. Predictions of changes in phase velocity as a function of propagation direction using theory and the EEC method are compared to experimental results for a single wave mode.
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Vendor managed inventory a new approach to supply chain management /Gandhi, Ujval. January 1900 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 2004. / Title from electronic submission form. Vita. Abstract. Includes bibliographical references.
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Modeling, design, fabrication and demonstration of 3D IPAC glass power modulesGandhi, Saumya 21 September 2015 (has links)
The advent of smart and wearable systems along with their Internet of Things (IoT) applications are driving unparalleled product miniaturization and multifunctional integration with computing, wireless communications, wireless healthcare, security, banking, entertainment, and navigation and others. This evolution is primarily enabled by the integration of multiple technologies such as RF, analog, digital, MEMS, sensors and optics in the same system. Integration of these heterogeneous technologies creates a new need for multiple power supply rails to provide device-specific voltage and current levels. Hence, multiple power converters, each requiring several passive components, are used to create stable power-supplies. However, state-of-art power supplies employ SMD passives that are relatively large, forcing these modules to be placed on the board far from the active IC. This leads to significantly sub-par frequency performance and poses a challenge for ultra-miniaturized and reliable power supplies. Hence, novel packaging technologies that can improve miniaturization, electrical performance and reliability at a relatively low-cost are required to address these challenges. Georgia Tech-PRC proposes 3D integration of passives and actives (3D IPAC) as doubleside thin components on ultra-thin glass substrates with through-package-vias (TPVs) to meet these requirements. This thesis focuses on a comprehensive methodology to demonstrate a 3D IPAC power module, starting with modeling, design, fabrication and characterization to validate 3D integrated ultra-thin inductors and capacitors in ultra-thin substrates. Another key focus of this thesis is to advance building block technologies such as thinfilm inductors and capacitors to achieve the target properties for 3D IPAC integration.
As a first building block technology, advanced capacitor technologies were explored with high-k thinfilm barium strontium titanate dielectrics and lanthanum nickel oxide electrodes as an alternative to Cu, Ni and Pt electrodes for improved performance and cost. The BST capacitors with LNO electrodes resulted in a capacitance density of 20-30 nF/cm2 with leakage as low as nA/nF up to 3 V. A glass-compatible process was developed with crystallization temperatures less than 650 C. These capacitors with thinfilm electrodes and dielectrics can be integrated into ultra-thin interposers and packages. This can help improve the capacitor performance up to the GHz range.
As a next build block, Si-nanowires were studied as high surface area electrodes for high-density capacitors. Analytical modeling was performed to understand the length of the nanowires based on the catalyst size. This modeling study was then extended to understand the cut-off frequency of the capacitors based on the RC time constant. The wires were fabricated using both chemical vapor deposition (CVD) and wet-etch processes. However, it was noticed that the wet-etch process provided more control on the geometry, density and orientation of the nanowires. Si-oxide was thermally grown on the surface of the wires. A capacitance density of 200 nF/mm2 was achieved. It was noticed that the cut-off frequency of such capacitors was limited to the lower kHz range. However, the operating frequency can be improved by simply using a highly conductive Si-substrate.
The second part of the thesis focuses on inductor and capacitor integration on ultra-thin glass substrates for high-frequency power modules using the 3D IPAC approach. Analytical models were used to calculate the required passive component values based on the target frequency, ripple currents and voltages of the power module. Next, a SPICE model was used to optimize the value of the required passives based on the output parasitics. The L and C structures were then modeled using 2.5D method of moments (MOM) approach. The modeling results showed 7-8 X improvement in Q-factor when the structures were fabricated using the 3D IPAC approach relative to those fabricated on the same side of the substrate. A fabrication process flow was designed based on through-via and doubleside metallization with semi-additive patterning (SAP). The components were fabricated as thinfilms on either sides of the substrate and interconnected with through-vias. The LC network was characterized using a two-port vector network analyzer. The results showed low-pass filter response, which matched the design targets of cut-off frequencies upto 100 MHz. This study, therefore, demonstrates advanced thinfilm component technologies for ultra-high frequency power-supply. It also presents, for the first time, a 3D integrated passives and actives (3D IPAC) approach with integrated L and C for power modules.
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Construction of static and dynamic multi-layer petrophysical models in Camisea gas reservoirs, PeruGandhi, Ankur 03 January 2011 (has links)
Estimation of static and dynamic petrophysical properties of multi-layer hydrocarbon reservoirs is crucial for the assessment of storage and flow capacities, compartmentalization, and for best primary or enhanced recovery practices. Interactive numerical simulation to reproduce field logs and core data is a reliable procedure to estimate static and dynamic petrophysical properties of complex rock formations.
Previously, Voss et al. (2009) introduced the concept of Common Stratigraphic Framework (CSF) to construct and cross-validate multi-layer static/dynamic petrophysical models by invoking the interactive, numerical simulation of well logs both before and after invasion. This thesis documents the successful implementation of the CSF concept to examine and quantify the effects of mud-filtrate invasion on apparent resistivity, nuclear, and magnetic resonance logs acquired in San Martin, Cashiriari and Pagoreni gas fields in Camisea, Peru. Conventional petrophysical interpretation methods yield abnormally high estimates of water saturation in some of the reservoir units that produce gas with null water influx. This anomalous behavior is due to relatively low values of deep apparent electrical resistivity, and has otherwise been attributed to the presence of clay-coating grains and/or electrically conductive grain minerals. On the other hand, electrical resistivity logs exhibit substantial invasion effects as evidenced by the separation of apparent resistivity logs (both LWD and wireline) with multiple radial lengths of investigation. In extreme cases, apparent resistivity logs “stack” because of very deep invasion. We diagnose and quantify invasion effects on resistivity and nuclear logs with interactive numerical modeling before and after invasion. The assimilation of such effects in the interpretation consistently decreases previous estimates of water saturation to those of irreducible water saturation inferred from core data. It is shown that capillary pressure effects are responsible for the difference in separation of resistivity curves in some of the reservoir units.
The final multi-layer CSF is in agreement with gas production measurements and permits reliable flow predictions to assist in reservoir engineering and production studies. / text
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State (under)development, transnational activism, and tribal resistance in India's Narmada valleyGandhi, Ajay. January 2002 (has links)
This thesis examines how the Narmada damming project in India is constituted and contested by the state, affected tribal peoples ( adivasis), and a transnational advocacy network led by the Narmada Bachao Andolan (Save the Narmada Movement). Based on ethnographic fieldwork, and employing critical anthropological perspectives on development and globalization, the power relations underlying dominance and resistance are mapped out. The conflicting discourses, strategies and practices of Narmada proponents and opponents are conceptualized within local, regional, national, and transnational sites and modalities. Further, the negotiation of state dominance and adivasi resistance is analyzed through contradictory practice and shifting political alignments. Lastly, this thesis delineates how the Narmada conflict is permeated by complex symbolic and moral mechanisms activated by both state authorities and activist resistors.
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