A Study of Actor and Action Semantic Retention in Video Supervoxel Segmentation

Existing methods in the semantic computer vision community seem unable to deal with the explosion and richness of modern, open-source and social video content. Although sophisticated methods such as object detection or bag-of-words models have been well studied, they typically operate on low level features and ultimately suffer from either scalability issues or a lack of semantic meaning. On the other hand, video supervoxel segmentation has recently been established and applied to large scale data processing, which potentially serves as an intermediate representation to high level video semantic extraction. The supervoxels are rich decompositions of the video content: they capture object shape and motion well. However, it is not yet known if the supervoxel segmentation retains the semantics of the underlying video content. In this paper, we conduct a systematic study of how well the actor and action semantics are retained in video supervoxel segmentation. Our study has human observers watching supervoxel segmentation videos and trying to discriminate both actor (human or animal) and action (one of eight everyday actions). We gather and analyze a large set of 640 human perceptions over 96 videos in 3 different supervoxel scales. Furthermore, we conduct machine recognition experiments on a feature defined on supervoxel segmentation, called supervoxel shape context, which is inspired by the higher order processes in human perception. Our ultimate findings suggest that a significant amount of semantics have been well retained in the video supervoxel segmentation and can be used for further video analysis.Comment: This article is in review at the International Journal of Semantic Computin

“No Shut-off” Policies and Natural Gas Consumption

Many U.S. states have regulations that prevent natural gas utility companies from turning off service to non-paying consumers. The goal of these policies, termed “no shut-off” (NSO) regulations, is to provide a guaranteed minimum level of residential comfort by reducing the marginal cost of consumption to zero for a period of time. This paper employs a difference-in-difference approach applied to residential U.S. Energy Information Administration data to evaluate whether NSO policies generate higher levels of gas usage. Our preferred specifications suggest that activation of a NSO policy increases natural gas consumption by between 4.7–4.8%, resulting in a total increase of between 66 and 67 billion cubic feet of natural gas consumed per winter season in covered states, at a value of as much as $950–970 million annually

Flow, sediment transport, and bed topography in straight and curved gravel-bed channels

2016 Fall.Includes bibliographical references.In recent years, many river restoration projects have aimed to restore natural channel stability and dynamism by re-establishing channel meanders lost to historical channelization. An understanding of meandering channel behavior is crucial to successful restoration of these rivers. Meandering and straight channels differ greatly in terms of sediment transport, velocity, and flow patterns under equilibrium conditions. The primary objective of this study was to investigate the mechanisms responsible for sorting patterns in mixed-grain straight and curved channels using flume experiments. After an absence of sorting was observed in the flume experiments, the study objective was modified to: 1) investigate the formation, behavior, and dynamics of free and forced bars within a straight channel with and without an upstream barrier and 2) explore the mechanism that accommodates for spatial boundary shear stress variations in curved gravel bed channels. The flume experiments involved detailed measurements of bed topography, velocity, and sediment transport in both a curved channel and straight channel with and without an upstream obstruction. It was expected that the gravel bed meandering river would compensate for spatial variability in boundary shear stress through surface grain size adjustment (sorting), as opposed to sediment transport convergence. Instead, the data reveal sediment transport divergence as the primary mechanism for balancing shear stress variability. The lack of sorting may likely be attributed to low excess shear stress and steady, rather than unsteady flow conditions. Regarding free and forced bar behavior, no stability was achieved in the straight channel without an obstruction. This can be attributed to a range of factors related to upstream boundary conditions, shear stress, and lack of forcing topography. It is suggested that future studies utilize both higher excess shear stress and unsteady flow conditions in investigating shear stress variability in curved gravel-bed channels

Dense Sample Deep Learning

Deep Learning (DL) , a variant of the neural network algorithms originally proposed in the 1980s, has made surprising progress in Artificial Intelligence (AI), ranging from language translation, protein folding, autonomous cars, and more recently human-like language models (CHATbots), all that seemed intractable until very recently. Despite the growing use of Deep Learning (DL) networks, little is actually understood about the learning mechanisms and representations that makes these networks effective across such a diverse range of applications. Part of the answer must be the huge scale of the architecture and of course the large scale of the data, since not much has changed since 1987. But the nature of deep learned representations remain largely unknown. Unfortunately training sets with millions or billions of tokens have unknown combinatorics and Networks with millions or billions of hidden units cannot easily be visualized and their mechanisms cannot be easily revealed. In this paper, we explore these questions with a large (1.24M weights; VGG) DL in a novel high density sample task (5 unique tokens with at minimum 500 exemplars per token) which allows us to more carefully follow the emergence of category structure and feature construction. We use various visualization methods for following the emergence of the classification and the development of the coupling of feature detectors and structures that provide a type of graphical bootstrapping, From these results we harvest some basic observations of the learning dynamics of DL and propose a new theory of complex feature construction based on our results

Buying Unicorns: The Impact of Consumer-to-Consumer Branded Buy/Sell/Trade Communities on Traditional Retail Buying Behavior

Branded buy/sell/trade (BBST) is a consumer-to-consumer (C2C) selling phenomenon that is both massive in scale and meaningful in its impact on consumer behavior and the traditional retailing landscape. Consumers buy, sell, and trade one focal brand’s products in these social media-hosted, consumer-initiated communities. This article introduces the phenomenon, differentiates it from other forms of C2C exchange, and explores relationships between members and the brand. Although brands may view these activities as a potential threat to retail sales, the effects are more complex and paradoxical. The authors present data collected from Facebook, in-depth interviews, and a survey. Findings suggest that buyer-sellers experience greater member closeness and spend more in traditional retail settings on the brand’s products than strictly buyers, indicating that transactional engagement has positive member and brand outcomes. This research contributes to our understanding of C2C exchange and BBST engagement’s effects on consumers and brands

The ACTwatch project: methods to describe anti-malarial markets in seven countries.

BACKGROUND: Policy makers, governments and donors are faced with an information gap when considering ways to improve access to artemisinin-based combination therapy (ACT) and malaria diagnostics including rapid diagnostic tests (RDTs). To help address some of these gaps, a five-year multi-country research project called ACTwatch was launched. The project is designed to provide a comprehensive picture of the anti-malarial market to inform national and international anti-malarial drug policy decision-making. METHODS: The project is being conducted in seven malaria-endemic countries: Benin, Cambodia, the Democratic Republic of Congo, Madagascar, Nigeria, Uganda and Zambia from 2008 to 2012.ACTwatch measures which anti-malarials are available, where they are available and at what price and who they are used by. These indicators are measured over time and across countries through three study components: outlet surveys, supply chain studies and household surveys. Nationally representative outlet surveys examine the market share of different anti-malarials passing through public facilities and private retail outlets. Supply chain research provides a picture of the supply chain serving drug outlets, and measures mark-ups at each supply chain level. On the demand side, nationally representative household surveys capture treatment seeking patterns and use of anti-malarial drugs, as well as respondent knowledge of anti-malarials. DISCUSSION: The research project provides findings on both the demand and supply side determinants of anti-malarial access. There are four key features of ACTwatch. First is the overlap of the three study components where nationally representative data are collected over similar periods, using a common sampling approach. A second feature is the number and diversity of countries that are studied which allows for cross-country comparisons. Another distinguishing feature is its ability to measure trends over time. Finally, the project aims to disseminate findings widely for decision-making. CONCLUSIONS: ACTwatch is a unique multi-country research project that threads together anti-malarial supply and consumer behaviour to provide an evidence base to policy makers that can help determine where interventions may positively impact access to and use of quality-assured ACT and RDTs. Because of its ability to detect change over time, it is well suited to monitor the effects of policy or intervention developments in a country

Comparative analysis of two methods for measuring sales volumes during malaria medicine outlet surveys.

BACKGROUND: There is increased interest in using commercial providers for improving access to quality malaria treatment. Understanding their current role is an essential first step, notably in terms of the volume of diagnostics and anti-malarials they sell. Sales volume data can be used to measure the importance of different provider and product types, frequency of parasitological diagnosis and impact of interventions. Several methods for measuring sales volumes are available, yet all have methodological challenges and evidence is lacking on the comparability of different methods. METHODS: Using sales volume data on anti-malarials and rapid diagnostic tests (RDTs) for malaria collected through provider recall (RC) and retail audits (RA), this study measures the degree of agreement between the two methods at wholesale and retail commercial providers in Cambodia following the Bland-Altman approach. Relative strengths and weaknesses of the methods were also investigated through qualitative research with fieldworkers. RESULTS: A total of 67 wholesalers and 107 retailers were sampled. Wholesale sales volumes were estimated through both methods for 62 anti-malarials and 23 RDTs and retail volumes for 113 anti-malarials and 33 RDTs. At wholesale outlets, RA estimates for anti-malarial sales were on average higher than RC estimates (mean difference of four adult equivalent treatment doses (95% CI 0.6-7.2)), equivalent to 30% of mean sales volumes. For RDTs at wholesalers, the between-method mean difference was not statistically significant (one test, 95% CI -6.0-4.0). At retail outlets, between-method differences for both anti-malarials and RDTs increased with larger volumes being measured, so mean differences were not a meaningful measure of agreement between the methods. Qualitative research revealed that in Cambodia where sales volumes are small, RC had key advantages: providers were perceived to remember more easily their sales volumes and find RC less invasive; fieldworkers found it more convenient; and it was cheaper to implement than RA. DISCUSSION/CONCLUSIONS: Both RA and RC had implementation challenges and were prone to data collection errors. Choice of empirical methods is likely to have important implications for data quality depending on the study context

Secondbrand Exchange: When Traditional Retail Brands Resell Used Products

This paper explores the novel context of secondbrand exchange, wherein traditional “firsthand” retail brands directly engaging in the reselling of their own previously used items. This research is the first to investigate how and why traditional brands engage in secondhand activities and to consider the influence of this strategy on consumer judgements about new products, used products, and the brand. The authors outline four consumer motives (frugality, sustainability, fashionability, and durability) for purchasing used items that are mapped onto strategic positioning for secondbrands. A framework of item transformation is introduced from refresh to renew to remake. Next, using brand extension, the authors suggest that consumers consider fit and direction of alignment when forming evaluations of secondbrands. Contagion theory informs how secondbrands may avoid negative stigma related to prior ownership and use and capitalize on positive associations. Research propositions are presented for future research to better understand this novel strategy

Clinical and histological implications of genotyping in Crohn's disease

Crohn’s disease is a common inflammatory bowel disease affecting approximately 1 in 1000 of the population in the UK. Surgery for Crohn’s disease is common with the majority of patients requiring surgery at some point in the course of the disease. Both genetic and environmental factors influence Crohn’s disease. Smoking significantly influences the disease course in Crohn’s disease with more frequent relapses and increased need for surgery. Recent research had concentrated on the genes predisposing to the development of Crohn’s disease. In 2001 the CARD15 (NOD2) gene was identified and since then ~30 genes have been found to be associated with Crohn’s disease. This thesis aimed to investigate the influence of CARD15 (NOD2) on the time to second operation in terminal ileal Crohn’s disease. Crohn’s disease affects all parts of the gastrointestinal tract but particularly the terminal ileum. A particular cell type, the Paneth cell, has been implicated in the pathogenesis of Crohn’s disease. Paneth cells are located at the base of Crypts of Liberkühn throughout the small intestine but are found in greatest numbers in the terminal ileum. Paneth cells contain and secrete antimicrobial peptides in response to bacterial products. They have been found to express CARD15 (NOD2). The expression of antimicrobial peptides and the CARD15 (NOD2) genotype were investigated using the technique of in situ hibridization. There are well characterized histological features of Crohn’s disease. The are no known histological features of Crohn’s disease associated with the CARD15 (NOD2) genotype. These features were investigated. Osteoporosis is an important complication of Crohn’s disease and it’s treatment. Predictors of those at risk for the development of Crohn’s disease would be clinically useful in targeting therapy. Genetic influences on bone mineral density and Crohn’s disease were investigated. Recent publications have furthered our knowledge of the genetic factors influencing the development of Crohn’s disease. The Newcastle cohort of patients contributed to this knowledge. The aim of this study was to investigate survival to second operation in terminal ileal Crohn’s disease. The effect of environmental factors including smoking and exposure to thiopurines was investigated. In particular the effect of CARD15(NOD2) genotype and carriage of the 5q31 haplotype was studied.EThOS - Electronic Theses Online ServiceMargaret Simm LegacyNational Association for Colitis and Crohn's DiseaseGBUnited Kingdo