A Convex Model for Edge-Histogram Specification with Applications to Edge-preserving Smoothing

The goal of edge-histogram specification is to find an image whose edge image has a histogram that matches a given edge-histogram as much as possible. Mignotte has proposed a non-convex model for the problem [M. Mignotte. An energy-based model for the image edge-histogram specification problem. IEEE Transactions on Image Processing, 21(1):379--386, 2012]. In his work, edge magnitudes of an input image are first modified by histogram specification to match the given edge-histogram. Then, a non-convex model is minimized to find an output image whose edge-histogram matches the modified edge-histogram. The non-convexity of the model hinders the computations and the inclusion of useful constraints such as the dynamic range constraint. In this paper, instead of considering edge magnitudes, we directly consider the image gradients and propose a convex model based on them. Furthermore, we include additional constraints in our model based on different applications. The convexity of our model allows us to compute the output image efficiently using either Alternating Direction Method of Multipliers or Fast Iterative Shrinkage-Thresholding Algorithm. We consider several applications in edge-preserving smoothing including image abstraction, edge extraction, details exaggeration, and documents scan-through removal. Numerical results are given to illustrate that our method successfully produces decent results efficiently

Spectroscopic characterization of the oxo-transfer reaction from a bis(µ-oxo)dicopper(III) complex to triphenylphosphine

The oxygen-atom transfer reaction from the bis(µ-oxo)dicopper(III) complex [CuIII2(µ-O)2(L)2]2+1, where L =N,N,N,N -tetraethylethylenediamine, to PPh3 has been studied by UV-vis, EPR, 1H NMR and Cu K-edge X-ray absorption spectroscopy in parallel at low temperatures (193 K) and above. Under aerobic conditions (excess dioxygen), 1 reacted with PPh3, giving OPPh3 and a diamagnetic species that has been assigned to an oxo-bridged dicopper(II) complex on the basis of EPR and Cu K-edge X-ray absorption spectroscopic data. Isotope-labeling experiments (18O2) established that the oxygen atom incorporated into the triphenylphosphine oxide came from both complex 1 and exogenous dioxygen. Detailed kinetic studies revealed that the process is a third-order reaction; the rate law is first order in both complex 1 and triphenylphosphine, as well as in dioxygen. At temperatures above 233 K, reaction of 1 with PPh3 was accompanied by ligand degradation, leading to oxidative N-dealkylation of one of the ethyl groups. By contrast, when the reaction was performed in the absence of excess dioxygen, negligible substrate (PPh3) oxidation was observed. Instead, highly symmetrical copper complexes with a characteristic isotropic EPR signal at g= 2.11 were formed. These results are discussed in terms of parallel reaction channels that are activated under various conditions of temperature and dioxygen

Serum S-100B as a Potential Biomarker for Meningitis in Febrile Infants: An Interim Analysis

The purpose of this study is to identify the utility of serum S-100B levels as a marker for meningitis in febrile infants younger than 3 months of age. All infants younger than 3 months of age who presented to the Pediatric Emergency Department (PED) of Yale-New Haven Children\u27s Hospital and required both a lumbar puncture and venipuncture due to either a confirmed rectal temperature ≥38.0°C or an overall presentation that concerned the responsible physician for possible meningitis and required a lumbar puncture as part of their PED evaluation, were prospectively enrolled. A total of 111 patients participated after a 1.5-year recruitment period or about 40% of the 260 subjects calculated a priori to be required over 3 years in order to achieve 80% power. After informed written consent, approximately 1 mL of blood was obtained for the analysis of the serum level of S-100B, in addition to the volume normally drawn for standard laboratory analysis. Patients with confirmed meningitis as defined by a positive viral or bacterial culture, a positive polymerase chain reaction (PCR) for enterovirus or herpes simplex virus, and/or cerebrospinal fluid (CSF) pleocytosis, were compared with those subjects without meningitis. S-100B levels for 101 subjects were available for interim analysis, of which 27 (26.7%)met the criteria for meningitis and 74 (73.3%) did not. The median S-100B level in infants with meningitis was 247.0 ng/L (95% CI: 103.5, 804), as compared to 199.1 ng/L (142.5, 384.0) in those without meningitis (p\u3e0.05). Receiver operating characteristic analysis revealed an area under the curve of 0.4917 (0.3940, 0.5863). Ad hoc power calculations demonstrated a 57% probability of detecting a difference of 390 ng/L between the two groups when using this sample size. At this time, this interim analysis of this ongoing study suggests that a larger sample size will still be required to determine if serum S-100B is a useful marker for meningitis in febrile young infants. Because CSF fluid analysis and the associated risks of lumbar puncture remain the only means by which to identify infants with meningitis, the search for a simple serum test for to determine the likelihood of meningitis will continue to be worthwhile

Information erasure without an energy cost

Landauer argued that the process of erasing the information stored in a memory device incurs an energy cost in the form of a minimum amount of mechanical work. We find, however, that this energy cost can be reduced to zero by paying a cost in angular momentum or any other conserved quantity. Erasing the memory of Maxwell's demon in this way implies that work can be extracted from a single thermal reservoir at a cost of angular momentum and an increase in total entropy. The implications of this for the second law of thermodynamics are assessed.Comment: 8 pages with 1 figure. Final published versio

Online Predictive Optimization Framework for Stochastic Demand-Responsive Transit Services

This study develops an online predictive optimization framework for dynamically operating a transit service in an area of crowd movements. The proposed framework integrates demand prediction and supply optimization to periodically redesign the service routes based on recently observed demand. To predict demand for the service, we use Quantile Regression to estimate the marginal distribution of movement counts between each pair of serviced locations. The framework then combines these marginals into a joint demand distribution by constructing a Gaussian copula, which captures the structure of correlation between the marginals. For supply optimization, we devise a linear programming model, which simultaneously determines the route structure and the service frequency according to the predicted demand. Importantly, our framework both preserves the uncertainty structure of future demand and leverages this for robust route optimization, while keeping both components decoupled. We evaluate our framework using a real-world case study of autonomous mobility in a university campus in Denmark. The results show that our framework often obtains the ground truth optimal solution, and can outperform conventional methods for route optimization, which do not leverage full predictive distributions.Comment: 34 pages, 12 figures, 5 table

Learning Tasks for Multitask Learning: Heterogenous Patient Populations in the ICU

Machine learning approaches have been effective in predicting adverse outcomes in different clinical settings. These models are often developed and evaluated on datasets with heterogeneous patient populations. However, good predictive performance on the aggregate population does not imply good performance for specific groups. In this work, we present a two-step framework to 1) learn relevant patient subgroups, and 2) predict an outcome for separate patient populations in a multi-task framework, where each population is a separate task. We demonstrate how to discover relevant groups in an unsupervised way with a sequence-to-sequence autoencoder. We show that using these groups in a multi-task framework leads to better predictive performance of in-hospital mortality both across groups and overall. We also highlight the need for more granular evaluation of performance when dealing with heterogeneous populations.Comment: KDD 201

Crescimento econômico e geração de emprego : o caso da Libéria

Orientador: Carlos Salas PaezDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de EconomiaResumo: Libéria, como muitas economias em desenvolvimento têm se esforçado para incentivar o investimento em uma tentativa de facilitar o crescimento econômico e a criação de emprego. Este tem sido reforçada pelos esforços do governo para atrair investidores através de políticas favoráveis ao investimento. O desempenho recente da economia da Libéria tem sido um pouco prejudicada pela taxa de aumento da informalidade e do subemprego. Políticas voltadas estritamente para alcançar a estabilidade macroeconômica e ao crescimento do emprego acelerado sem consideração aos problemas da qualidade do emprego criado. Esta situação é, provavelmente, um reflexo do fato de que o ímpeto de crescimento na Libéria é alcançado inadequadas ou não está direcionado para as atividades de trabalho intensivo. Setores com alta taxa de absorção de trabalho: como a manufatura, turismo, agricultura e exportações de mercadorias não têm atraído o investimento necessário para aumentar o crescimento e desempenho do emprego. A economia da Libéria, portanto, requer uma revisão profunda das atuais políticas nacionais de desenvolvimento para gerar crescimento que iria melhorar as condições de vida da população. Promover a criação de emprego e renda para a realização de suas metas de redução da pobreza, é uma tarefa inadiável. Para que o crescimento do emprego possa ser realizado, este texto propõe várias iniciativas destinadas a reforçar o empregoAbstract: Liberia like many developing economies have endeavored to encourage investment in a bid to facilitate economic growth and job creation. This has been enhanced by the government's efforts to attract investors through many favorable investment policies. The fairly decent growth performance of the Liberian economy has been somewhat dented by the increasing rate of informality and underemployment. Policies narrowly focused on achieving macroeconomic stability and accelerated growth without adequate employment consideration and facilitation. This situation is probably a reflection of the fact that the growth impetus achieved in Liberia is either inadequate or does not come from investment directed into the labour intensive activities. Sectors with high labour absorption rate such as manufacturing, tourism, merchandize agriculture and exports have not attracted the necessary investment to enhance growth and employment performance. The Liberian economy therefore requires a thorough review of the current national development policies to generate growth that would promote job creation and improve incomes for the realization of its poverty reduction goals. For employment-friendly growth to be realized, this paper attempts to propose various initiatives aimed at enhancing employmentMestradoEconomia Social e do TrabalhoMestre em Desenvolvimento Econômic