2,663 research outputs found

    Attribute-Guided Face Generation Using Conditional CycleGAN

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    We are interested in attribute-guided face generation: given a low-res face input image, an attribute vector that can be extracted from a high-res image (attribute image), our new method generates a high-res face image for the low-res input that satisfies the given attributes. To address this problem, we condition the CycleGAN and propose conditional CycleGAN, which is designed to 1) handle unpaired training data because the training low/high-res and high-res attribute images may not necessarily align with each other, and to 2) allow easy control of the appearance of the generated face via the input attributes. We demonstrate impressive results on the attribute-guided conditional CycleGAN, which can synthesize realistic face images with appearance easily controlled by user-supplied attributes (e.g., gender, makeup, hair color, eyeglasses). Using the attribute image as identity to produce the corresponding conditional vector and by incorporating a face verification network, the attribute-guided network becomes the identity-guided conditional CycleGAN which produces impressive and interesting results on identity transfer. We demonstrate three applications on identity-guided conditional CycleGAN: identity-preserving face superresolution, face swapping, and frontal face generation, which consistently show the advantage of our new method.Comment: ECCV 201

    Definition, Analysis, And An Approach For Discrete-Event Simulation Model Interoperability

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    Even though simulation technology provides great benefits to industry, it is largely underutilized. One of the biggest barriers to utilizing simulation is the lack of interoperability between simulation models. This is especially true when simulation models that need to interact with each other span an enterprise or supply chain. These models are likely to be distributed and developed in disparate simulation application software. In order to analyze the dynamic behavior of the systems they represent, the models must interoperate. However, currently this interoperability is nearly impossible. The interaction of models also refers to the understanding of them among stakeholders in the different stages of models¡Š lifecycles. The lack of interoperability also makes it difficult to share the knowledge within disparate models. This research first investigates this problem by identifying, defining, and analyzing the types of simulation model interactions. It then identifies and defines possible approaches to allow models to interact. Finally, a framework that adopts the strength of Structured Modeling (SM) and the Object-Oriented (OO) concept is proposed for representing discrete event simulation models. The framework captures the most common simulation elements and will serve as an intermediate language between disparate simulation models. Because of the structured nature of the framework, the resulting model representation is concise and easily understandable. Tools are developed to implement the framework. A Common User Interface (CUI) with software specified controllers is developed for using the proposed framework with various commercial simulation software packages. The CUI is also used to edit simulation models in a neutral environment. A graphical modeling tool is also developed to facilitate conceptual modeling. The resulting graphic can be translated into the common model representation automatically. This not only increases the understanding of models for all stakeholders, but also shifts model interactions to the ¡§formulating¡š stage, which can prevent problems later in the model¡Šs lifecycle. Illustration of the proposed framework and the tools will be given, as well as future work needs

    The use of turbulence energy equation in boundary layer study

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    A turbulent boundary layer problem has been studied analytically and compared with an available experiment in the literature. Correlations of the experimental data were made to investigate the validity of the commonly used empirical relations on turbulent shear stresses. It was found that the model which related the local turbulent shear stress linearly with the local turbulent kinetic energy, as used by Bradshow et. al., appeared to be most reasonable. combining this model with the expression of turbulent viscosity given by Boussinesq, it was then possible to introduce the turbulence-energy equation in addition to the governing equations of continuity and momentum. consequently, the turbulent viscosity was able to be considered as one of the dependent variables to be solved for simultaneously with all other related flow parameters. Using the main-flow direction and the stream function as the two independent variables, the governing equations were reduced to two simultaneous parabolic-type partial differential equations through the von Mises transformation. The finite difference technique of Partankar was applied. The numerical solutions were obtained for the average velocity and the turbulent kinetic energy distributions. In comparison with the experimental results of Klebanoff in the fully developed region along a flat plate, very good agreement was reached on average velocity distribution. However, the turbulent kinetic energy distribution was not completely satisfactory, since the energy dissipation term of the turbulence-energy equation was not able to be expressed adequately due to the lack of sufficient experimental information. It is then concluded that the use of the turbulence-energy equation in boundary layer study is possible to eliminate the uncertainty resulting with empirical models of the turbulent viscosity. However, further experimental investigations are needed to improve the understanding of the structure of turbulence --Abstract, page i-ii

    Advanced eddy-current methods for quantitative NDE

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    The objectives of this dissertation were to devise and develop advanced eddy-current methods for quantitative NDE. The techniques used include time-domain methods (pulsed eddy current), frequency-domain methods (swept-frequency eddy current), and the photoinductive imaging method that combines eddy-current and laser-based thermal-wave techniques. We first developed theoretical models to predict the pulsed eddy current signal and showed this technique can be used to characterize metallic coatings on metal substrates. A feature-based rapid inversion method was developed to determine the conductivity and thickness of the coating simultaneously. In the second work, we studied the fundamentals of eddy current interactions with magnetic metals using swept-frequency eddy current method. We have found that the eddy current response of well-annealed, demagnetized commercially-pure nickel is dominated by a thin region at the sample\u27s surface that has a very significantly reduced permeability--i.e., a surface dead-layer. This dead layer may be due to the presence of surface damage. We calculated the impedance of the coil based on the hypothesized single layer structure and found excellent quantitative agreement between the model and experiment. These results may have important consequences for many aspects of the interaction of low frequency electromagnetic fields with magnetically soft metals. In the third work, we developed theoretical calculations and practical measurement methods using both swept-frequency eddy current and pulsed eddy current methods for determining the thickness, conductivity, and permeability of metallic coatings on metal substrates for the case when either coating, metal, or both are ferromagnetic. This work paves the way for development of new, quantitative methods to characterize surface layers on ferrous materials, such as depth of case hardening. In the fourth work, we applied the photoinductive imaging technique to characterize corner cracks on the surface around a bolt hole. The photoinductive signals reflect the geometrical shape of the triangular and rectangular electrical-discharge-machined (EDM) notches as well as real fatigue cracks. The results show promise for using this technique to characterize the shape, depth, and length of corner cracks. The capability of the photoinductive imaging technique is demonstrated in this work

    Design, fabrication and characterization of monolithic embedded parylene microchannels in silicon substrate

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    This paper presents a novel channel fabrication technology of bulk-micromachined monolithic embedded polymer channels in silicon substrate. The fabrication process favorably obviates the need for sacrifical materials in surface-micromachined channels and wafer-bonding in conventional bulk-micromachined channels. Single-layer-deposited parylene C (poly-para-xylylene C) is selected as a structural material in the microfabricated channels/columns to conduct life science research. High pressure capacity can be obtained in these channels by the assistance of silicon substrate support to meet the needs of high-pressure loading conditions in microfluidic applications. The fabrication technology is completely compatible with further lithographic CMOS/MEMS processes, which enables the fabricated embedded structures to be totally integrated with on-chip micro/nano-sensors/actuators/structures for miniaturized lab-on-a-chip systems. An exemplary process was described to show the feasibility of combining bulk micromachining and surface micromachining techniques in process integration. Embedded channels in versatile cross-section profile designs have been fabricated and characterized to demonstrate their capabilities for various applications. A quasi-hemi-circular-shaped embedded parylene channel has been fabricated and verified to withstand inner pressure loadings higher than 1000 psi without failure for micro-high performance liquid chromatography (µHPLC) analysis. Fabrication of a high-aspect-ratio (internal channel height/internal channel width, greater than 20) quasi-rectangular-shaped embedded parylene channel has also been presented and characterized. Its implementation in a single-mask spiral parylene column longer than 1.1 m in a 3.3 mm × 3.3 mm square size on a chip has been demonstrated for prospective micro-gas chromatography (µGC) and high-density, high-efficiency separations. This proposed monolithic embedded channel technology can be extensively implemented to fabricate microchannels/columns in high-pressure microfludics and high-performance/high-throughput chip-based micro total analysis systems (µTAS)

    Application of Remote Sensing for the Prediction, Monitoring, and Assessment of Hazards and Disasters that Impact Transportation

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    Although remote sensing has been used in predicting, monitoring, and assessing hazards and disasters for over 50 years, its use in the transportation domain is still in its infancy. This study was conducted to identify the research needs involving the use of remote sensing for such applications within the transportation domain. The first step taken was to determine the current state of remote sensing applications in the transportation domain associated with the prediction, monitor, and assessment of hazards and disasters. The second step was to identify the impacts that such events may cause and the information needed to prevent or reduce their impacts. With the knowledge of the required information, remote sensing requirements and technology limitations were defined. Then according to the knowledge of the current state of research and the limitations of remote systems, future research needs were identified. Finally, the Analytic Hierarchy Process (AHP) was used to rank these research needs
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