Optimal piecewise constant solutions of the linear regulator problem

Optimal piecewise constant solutions of linear regulator proble

REDD+ on the rocks? Conflict over forest and politics of justice in Vietnam

In Vietnam, villagers involved in a REDD+ (reduced emissions from deforestation and forest degradation) pilot protect areas with rocks which have barely a tree on them. The apparent paradox indicates how actual practices differ from general ideas about REDD+ due to ongoing conflict over forest, and how contestations over the meaning of justice are a core element in negotiations over REDD+. We explore these politics of justice by examining how the actors involved in the REDD+ pilot negotiate the particular subjects, dimensions, and authority of justice considered relevant, and show how politics of justice are implicit to practical decisions in project implementation. Contestations over the meaning of justice are an important element in the practices and processes constituting REDD+ at global, national and local levels, challenging uniform definitions of forest justice and how forests ought to be managed

Cluster virial expansion for the equation of state of partially ionized hydrogen plasma

We study the contribution of electron-atom interaction to the equation of state for partially ionized hydrogen plasma using the cluster-virial expansion. For the first time, we use the Beth-Uhlenbeck approach to calculate the second virial coefficient for the electron-atom (bound cluster) pair from the corresponding scattering phase-shifts and binding energies. Experimental scattering cross-sections as well as phase-shifts calculated on the basis of different pseudopotential models are used as an input for the Beth-Uhlenbeck formula. By including Pauli blocking and screening in the phase-shift calculation, we generalize the cluster-virial expansion in order to cover also near solid density plasmas. We present results for the electron-atom contribution to the virial expansion and the corresponding equation of state, i.e. pressure, composition, and chemical potential as a function of density and temperature. These results are compared with semi-empirical approaches to the thermodynamics of partially ionized plasmas. Avoiding any ill-founded input quantities, the Beth-Uhlenbeck second virial coefficient for the electron-atom interaction represents a benchmark for other, semi-empirical approaches.Comment: 16 pages, 10 figures, and 5 tables, resubmitted to PR

VINYL: The VIrtual Neutron and x-raY Laboratory and its applications

Experiments conducted in large scientific research infrastructures, such as synchrotrons, free electron lasers and neutron sources become increasingly complex. Such experiments, often investigating complex physical systems, are usually performed under strict time limitations and may depend critically on experimental parameters. To prepare and analyze these complex experiments, a virtual laboratory which provides start-to-end simulation tools can help experimenters predict experimental results under real or close to real instrument conditions. As a part of the PaNOSC (Photon and Neutron Open Science Cloud) project, the VIrtual Neutron and x-raY Laboratory (VINYL) is designed to be a cloud service framework to implement start-to-end simulations for those scientific facilities. In this paper, we present an introduction of the virtual laboratory framework and discuss its applications to the design and optimization of experiment setups as well as the estimation of experimental artifacts in an X-ray experiment

Associations of walkability, regional and transit accessibility around home and workplace with active and sedentary travel

Few studies have simultaneously examined whether the neighborhood built environment near work is independently associated with active versus sedentary travel. We investigate the associations of objectively assessed built environment and regional/transit accessibility around home and work locations with active (walking, biking) and sedentary (auto-use) transportation while controlling for attitudinal predispositions, perceptions, and demographic factors. Baseline data from 2012 to 2013 on a sample of 648 participants in the Rails & Health study based in Portland, Oregon were analyzed. Data about active and sedentary travel outcomes, attitudes, perceptions, and demographics were derived from a survey. Road network buffers (with a 1 km range) around each of the home and work locations were used to create detailed measures of walkability, natural environment, regional and transit accessibility. Log-linear and log-linear Tobit regression models tested associations of home and worksite neighborhood features with weekly amount of walking, biking, and auto use. Significant differences in walkability, regional accessibility, and natural environment between home and workplaces were observed. Independent of walkability around home, a one-unit increase in walkability index around work was correlated with a 2.8% [90% CI: 0.5% - 4.9%] and 2.7% [90% CI: 0.5% - 4.8%] higher weekly duration of biking and walking, respectively. Greater walkability around workplace was associated with lower time spent in automobiles. Greater regional and transit accessibility around work was correlated with higher walking/biking and lower automobile travel. The study highlights the important role of more walkable, connected, denser, and diverse workplace environments in enhancing public health

Violation of Boltzmann Equipartition Theorem in Angular Phonon Phase Space Slows down Nanoscale Heat Transfer in Ultrathin Heterofilms

Heat transfer through heterointerfaces is intrinsically hampered by a thermal boundary resistance originating from the discontinuity of the elastic properties. Here, we show that with shrinking dimensions the heat flow from an ultrathin epitaxial film through atomically flat interfaces into a single crystalline substrate is significantly reduced due to violation of Boltzmann equipartition theorem in the angular phonon phase space. For films thinner than the phonons mean free path, we find phonons trapped in the film by total internal reflection, thus suppressing heat transfer. Repopulation of those phonon states, which can escape the film through the interface by transmission and refraction, becomes the bottleneck for cooling. The resulting nonequipartition in the angular phonon phase space slows down the cooling by more than a factor of 2 compared to films governed by phonons diffuse scattering. These allow tailoring of the thermal interface conductance via manipulation of the interface

Expected resolution limits of x-ray free-electron laser single-particle imaging for realistic source and detector properties

The unprecedented intensity of x-ray free-electron laser sources has enabled single-particle x-ray diffraction imaging (SPI) of various biological specimens in both two-dimensional projection and three dimensions (3D). The potential of studying protein dynamics in their native conditions, without crystallization or chemical staining, has encouraged researchers to aim for increasingly higher resolutions with this technique. The currently achievable resolution of SPI is limited to the sub-10 nanometer range, mainly due to background effects, such as instrumental noise and parasitic scattering from the carrier gas used for sample delivery. Recent theoretical studies have quantified the effects of x-ray pulse parameters, as well as the required number of diffraction patterns to achieve a certain resolution, in a 3D reconstruction, although the effects of detector noise and the random particle orientation in each diffraction snapshot were not taken into account. In this work, we show these shortcomings and address limitations on achievable image resolution imposed by the adaptive gain integrating pixel detector noise

Indoor air quality in a restaurant kitchen using margarine for deep-frying

Indoor air quality has a great impact on human health. Cooking, in particular frying, is one of the most important sources of indoor air pollution. Indoor air CO, CO2, particulate matter (PM), and volatile organic compound (VOC) concentrations, including aldehydes, were measured in the kitchen of a small establishment where a special deep-frying margarine was used. The objective was to assess occupational exposure concentrations for cooks of such restaurants. While individual VOC and PM2.5 concentrations were measured before, during, and after frying events using active sampling, TVOC, PM10, CO, CO2, temperature, and relative humidity were continuously monitored through the whole period. VOC and aldehyde concentrations did not increase to considerable levels with deep-frying compared to the background and public indoor environment levels, whereas PM10 increased significantly (1.85 to 6.6 folds). The average PM2.5 concentration of the whole period ranged between 76 and 249 μg/m3. Hence, considerable PM exposures could occur during deep-frying with the special margarine, which might be sufficiently high to cause health effects on cooks considering their chronic occupational exposures.Dokuz Eylul University (BAP-2011.KB.SAG.017

An advanced Bayesian model for the visual tracking of multiple interacting objects

Visual tracking of multiple objects is a key component of many visual-based systems. While there are reliable algorithms for tracking a single object in constrained scenarios, the object tracking is still a challenge in uncontrolled situations involving multiple interacting objects that have a complex dynamics. In this article, a novel Bayesian model for tracking multiple interacting objects in unrestricted situations is proposed. This is accomplished by means of an advanced object dynamic model that predicts possible interactive behaviors, which in turn depend on the inference of potential events of object occlusion. The proposed tracking model can also handle false and missing detections that are typical from visual object detectors operating in uncontrolled scenarios. On the other hand, a Rao-Blackwellization technique has been used to improve the accuracy of the estimated object trajectories, which is a fundamental aspect in the tracking of multiple objects due to its high dimensionality. Excellent results have been obtained using a publicly available database, proving the efficiency of the proposed approach