Denoising Criterion for Variational Auto-Encoding Framework

Denoising autoencoders (DAE) are trained to reconstruct their clean inputs with noise injected at the input level, while variational autoencoders (VAE) are trained with noise injected in their stochastic hidden layer, with a regularizer that encourages this noise injection. In this paper, we show that injecting noise both in input and in the stochastic hidden layer can be advantageous and we propose a modified variational lower bound as an improved objective function in this setup. When input is corrupted, then the standard VAE lower bound involves marginalizing the encoder conditional distribution over the input noise, which makes the training criterion intractable. Instead, we propose a modified training criterion which corresponds to a tractable bound when input is corrupted. Experimentally, we find that the proposed denoising variational autoencoder (DVAE) yields better average log-likelihood than the VAE and the importance weighted autoencoder on the MNIST and Frey Face datasets.Comment: ICLR conference submissio

Droplet-Microfluidic Device for the Characterization of Perfluorinated Emulsions

Microfluidics is being used throughout academia and industry today to perform large numbers of experiments with extremely small volumes of fluids. By doing this, those that study microfluidics hope to raise through-put, lower cost and limit the environmental impact of scientific research.2 Complementing the increased use of microfluidics, the use of perfluorinated emulsions in the field of droplet-based microfluidics is also experiencing large growth.3 However, many of the products available today are either proprietary and/or poorly understood. While some chemical structures are known, some of the most scientifically intriguing perfluorinated oils and surfactants do not have their chemical structures or characteristics available to the public research community. During the course of our senior design project, we isolated one particular perfluorinated oil and surfactant mixture and performed a number of tests on the stability of the emulsions over a variety of different biologically relevant variables. To achieve this, we were required to design multiple iterations of droplet-microfluidic chips to create the simplest emulsions for study. The resulting designs gave us an excellent platform to study not only our emulsion system, but many future emulsions systems in a novel manner. We proved its efficacy by using the system to show great variance in the stability and surface energy of different pH droplets in QX100 perfluorinated oil with surfactant as well as a characterizable change in stability when changing the concentration of phosphate and media constituents in the droplets. Finally, we further analyzed the emulsion with the help of Dr. Gerald Fuller’s coalescence lab in Stanford University’s chemical engineering department and observed changes in the viscoelastic nature of aqueous-perfluorinated oil interfaces over a variety of biologically relevant conditions. Though much was accomplished, there is still a need to further characterize both more aqueous conditions and more perfluorinated systems to truly shed light on the field. Additionally, more detailed viscoelastic analysis needs to be performed on these new conditions and oil-surfactant mixtures as well as a thorough pendant-drop style surface tension experiment on all experiments performed

A Methodology for Three-Dimensional Quantification of Anterior Tooth Width

The use of cone-beam computed tomography (CBCT) technology has been shown to be more accurate in measuring individual incisor tooth widths than the use of wax exemplars. There were fewer differences by investigators using CBCT than others using an F-test in a mixed model of the measurement differences of investigators, wax type, and which tooth was measured. In addition, the frequency of outliers was less in the CBCT method (a total of 5) as compared to the two-dimensional measurements in ether Aluwax (a total of 8) or Coprwax (a total of 12). Both results indicate that CBCT measurements accounted more precisely for tooth width and level of eruption

Learning a Manifold-Constrained Map between Image Sets: Applications to Matching and Pose Estimation

This paper proposes a method for matching two sets of images given a small number of training examples by exploiting the underlying structure of the image manifolds. A nonlinear map from one manifold to another is constructed by combining linear maps locally defined on the tangent spaces of the manifolds. This construction imposes strong constraints on the choice of the maps, and makes possible good generalization of correspondences between all of the image sets. This map is flexible enough to approximate an arbitrary diffeomorphism between manifolds and can serve many purposes for applications. The underlying algorithm is a non-iterative efficient procedure whose complexity mainly depends on the number of matched training examples and the dimensionality of the manifold, and not on the number of samples nor on the dimensionality of the images. Several experiments were performed to demonstrate the potential of our method in image analysis and pose estimation. The first example demonstrates how images from a rotating camera can be mapped to the underlying pose manifold. Second, computer generated images from articulating toy figures are matched using the underlying 4 dimensional manifold to generate image-driven animations. Finally, two sets of actual lip images during speech are matched by their appearance manifold. In all these cases, our algorithm is able to obtain reasonable matches between thousands of large-dimensional images, with a minimum of computation

Term question in Korea 1882-1911, and its Chinese roots: a study in continuity and divergence

This thesis aims to study Western missionaries’ theological debate over the choice of the name of God, known as the Term Question, in the Korean Bible, a controversy which implied a certain theological position in terms of the degree of continuity or discontinuity between existing Korean theistic belief and faith in the God of Bible. This thesis seeks three goals. First, it attempts to analyse the Chinese roots of the Term Question in Korea. In China, the Term Question first arose among Roman Catholic missions from 1637 to 1742 between an indigenous Confucian term, Shangti 上帝 (Sovereign on High), favoured by the Jesuits, notably Matteo Ricci, and a neologism, T’ienzhu 天主 (the Lord of Heaven), used by the Dominicans and the Franciscans. A second phase of the Chinese Term Question involved nineteenth-century Protestant missions, and confronted missions with a choice between Shangti, most notably advocated by James Legge of the London Missionary Society, and Shen 神 (a generic term for god), supported by a majority of American missionaries. These three Chinese theistic terms were imported into the Korea mission field. John Ross of the United Presbyterian Church in Manchuria, in his first Korean New Testament (1877-1887), translated the name of God as Hananim, the Supreme Lord of Korean indigenous religion, on the basis of the Shangti edition of the Delegates’ Version. The first Korean Roman Catholics and later the Anglican missions in Korea adopted Ch’onzhu (Chinese T’ienzhu), following Catholic practice in China. A Korean diplomat in Japan, Su-Jung Lee, adopted Shin (Chinese Shen) from the Shen edition of the Chinese Bible, in his Korean Bible translations (1883-1885). The need to choose between the these three Korean theistic terms, derived theologically from the three corresponding Chinese theistic terms, consequently triggered the Term Question in Korea from 1882 to 1911. Second, the thesis argues that there was a significant theological continuity between the Chinese and Korean Term Questions. The Term Question in both China and Korea proceeded on a similar pattern; it was a terminological controversy between an indigenous theistic term (Shangti and Hananim) on the one hand and a neologism (T’ienzhu and Korean Ch’onzhu) or a generic term (Shen and Korean Shin) on the other hand. Central to both Term Questions was the theological issue of whether a primitive monotheism, congruent with Christian belief, had existed among the Chinese and Koreans. It will suggest that whilst those who adhered to a degeneration theory of the history of religions used either Shangti or Hananim as the name of the God of the Bible, those who rejected the existence of primitive monotheism preferred to use the neologism or the generic term. Third, this thesis suggests that there was, nevertheless, a significant divergence between the Term Question in China and that in Korea. Whereas the Term Question in China became polarised for over three centuries between two equal and opposite parties – between the Jesuits (Shangti) and the Dominicans-Franciscans (T’ienzhu), and later between the Shangti party and the Shen party in Protestant missions, that in iv Korea was a short-term argument for three decades between a vast majority (of the Hananim party) and a small minority (the opponents of Hananim). It is argued that the disproportion in Korea in favour of Hananim was due to the much closer analogy between Hananim and the Christian trinity, as seen in the Dan-Gun myth, than was the case with Shangti in Chinese religion. For this reason, the thesis concludes by suggesting that the adoption of the indigenous monotheistic term, Hananim, in a Christian form contributed to the higher rate of growth of the Korean church compared to that of the church in China

Mapping the Reading Improvement Sector in New York City The Role of External Support Providers in Improving K-3 Reading Outcomes

This report shares the results of a project designed to help build the collective capacity and increase the impact of the external support providers working to improve K-3 reading outcomes in New York City public elementary schools. In the first phase of the project, we identified all the programs in what we call the K-3 reading improvement sector in NYC 2014-15. In the second phase, we examined the extent to which a sample of these programs have the goals, resources, and personnel to improve reading outcomes system-wide. In the third phase, we mapped the relationships among a sample of programs in the sector in 2016-17, the sources they rely on to support their work, and the NYC schools with whom they partner. Making these relationships visible shows the extent to which students from different backgrounds and schools can get access to information, resources, and expertise, and the extent to which programs are in a position to increase their collective impact through coordination and collaboration. Among the findings: Over 100 programs are working in the K-3 Reading Improvement Sector in NYC The sample programs in the sector focus on a wide range of reading-related goals, but a limited number of programs have demonstrated effectiveness Twenty-six sample programs are connected to 161 different schools comprising 16% of all elementary schools in NYC (including 28% of the elementary schools in the Bronx and 26% of the elementary schools in Manhattan); and the programs are partnering with schools with relatively high levels of need in terms of both performance and poverty Just over half of the sample programs describe themselves as collaborating or partnering with at least one other sample program, but almost half were not in regular contact with any other sample program Sample programs received support from 57 different funders and 75 different sources for literacy expertise with little overlap These results suggest that sector programs have the goals, services, and personnel that could help improve K-3 reading outcomes in New York City; they have the connections to share resources and expertise with a large percentage of elementary schools; and several clusters of connected programs could serve as a powerful force for increased focus and collaboration in reading improvement across the city. However, the collective impact of the sector suffers from the evidence that goals vary considerably. Student and teacher programs differ in terms of their goals and personnel, and only a few programs have had formal outside evaluations completed. In addition, many of the sample programs in the sector are working in isolation from other sample programs and are informed by a wide range of sources of funding and expertise that are themselves likely to be only loosely connected. Although the clusters of collaborating and frequently connected programs could serve as a basis for expansion within the sector, the unconnected programs and the disparate sources of funding and expertise suggest that explicit strategies will need to be developed to support greater coherence in the sector and to increase the effectiveness of the sector overall

Business cycle and herding behavior in stock returns: theory and evidence

This study explains the role of economic uncertainty as a bridge between business cycles and investors’ herding behavior. Starting with a conventional stochastic differential equation representing the evolution of stock returns, we provide a simple theoretical model and empirically demonstrate it. Specifically, the growth rate of gross domestic product and the power law exponent are used as proxies for business cycles and herding behavior, respectively. We find stronger herding behavior during recessions than during booms. We attribute this to economic uncertainty, which leads to strong behavioral bias in the stock market. These findings are consistent with the predictions of the quantum model.</p