297 research outputs found
Dynamic Programming Solution for a Class of Pursuit Evasion Problems: The Herding Problem
A herding dog and sheep problem is studied where the agent “dog” is considered the control action for moving the agent “sheep” to a fixed location using the dynamics of their interaction. The problem is solved for the deterministic case using dynamic programming. Proofs are provided for the correctness of the algorithms. The algorithm is analyzed for its complexity. A software package developed for experimentation is described
Study of a zirconium getter for purification of xenon gas
Oxygen, nitrogen and methane purification efficiencies for a common zirconium
getter are measured in 1050 Torr of xenon gas. Starting with impurity
concentrations near 10^{-6} g/g, the outlet impurity level is found to be less
than 120*10^{-12} g/g for O2 and less than 950*10^{-12} g/g for N2. For methane
we find residual contamination of the purified gas at concentrations varying
over three orders of magnitude, depending on the purifier temperature and the
gas flow rate. A slight reduction in the purifier's methane efficiency is
observed after 13 mg of this impurity has been absorbed, which we attribute to
partial exhaustion of the purifier's capacity for this species. We also find
that the purifier's ability to absorb N2 and methane can be extinguished long
before any decrease in O2 performance is observed, and slower flow rates should
be employed for xenon purification due to the cooling effect that the heavy gas
has on the getter.Comment: 14 pages, 5 figure
Image Processing Based Control for Scaled Automated Vehicles
This paper presents a way to design a lateral controller for an automated vehicle using information gained through image processing with the control objective being to stay on a desired path. Two possible ways to obtain the information necessary for lateral control by image processing are presented, one based on pixel intensity summation and the other on vanishing point calculations. The paper also describes two algorithms for the actual lateral control, one based on classical control theory and the other on modern H∞ control. The resulting control algorithms were implemented on a scaled autonomous vehicle system
Renal cell carcinoma drug and cell therapy: today and tomorrow
The paper also looks at clinically applicable targeted immune drugs and the principle of their effect on tumorous cells. Besides, modern clinical studies of cell drugs have been considere
Cell wall components in torrefied softwood and hardwood samples
© 2015 Elsevier B.V. Torrefaction - the process of soft pyrolysis (200-300. °S(cyrillic)) in inert atmosphere - is considered to promote the usage of lignocellulosic biomass in various technologies. The initial raw material is not uniform in composition and we compared the effect of torrefaction on the samples of hardwood (birch) and softwood (pine). The major differences between the torrefied samples were observed between 225 and 250. °S(cyrillic) and were largely connected with different behavior of hemicelluloses. Monosaccharide analysis revealed the decrease in detectable xylose from 26% to 1% (250. °S(cyrillic)) of the raw sample in birch, and from 11% to 1%-in pine. Mannans were more resistant to degradation. Comparison of data from HPAEC, thermal analysis and IR-spectroscopy revealed that hemicelluloses are modified during torrefaction at 225-250. °S(cyrillic), rather than fully degraded and removed from the sample. This may lead to considerable modification of wood properties, more pronounced in hardwoods. The relative content of aromatic structures went up during torrefaction, part of the effect was due to condensation of modified carbohydrate units. Index of cellulose crystallinity increased in torrefied samples. The content of cellulose in birch samples remained the same as in raw sample up to 250. °S(cyrillic), while in pine it dramatically decreased after the torrefaction at 250. °S(cyrillic). Torrefaction at 300. °S(cyrillic) made the samples of hardwood and softwood very much alike. The perspectives of usage of hardwoods and softwoods torrefied at different temperatures are discussed
Pyrolysis of Fresh and Deposited Sewage Sludge and Investigation of the Products
© 2017 Springer Science+Business Media B.V. The article presents results of studies of pyrolysis of fresh and deposited sewage sludge (DSS) in two regimes of heat input: conductive heating at a rate of 40 °C/s and convective heating at a rate of 10 °C/min. It was determined that the fresh sewage sludge (FSS) had the higher yield of organic liquid and gas, and the lower char yield. The higher heating rate led to a decrease in the char yield and an increase in the liquid yield. The investigation of liquid products showed that those of the FSS had greater proportions of alcohols, organic acids, and nitrogen-containing compounds, including heterocyclics. The liquid products of the DSS had the greater content of carbohydrates, esters, and unidentified compounds, which were probably condensed compounds
The role of hematological parameters as predictors of mortality in elderly patients in the hospital period
The development of algorithms for predicting adverse outcomes, including death in elderly and senile patients, is an urgent issue. Potential predictors include hematologic parameters. A clinical blood test is one of the most affordable diagnostic methods in practical medicine, reflecting systemic pathological processes in the human body based on a quantitative assessment of the cellular composition and blood morphology. The aim of this study was to evaluate hematological parameters as predictors of in-hospital mortality in patients of the elderly and senile age with acute coronary syndrome.Material and methods. The study included 277 patients with acute coronary syndrome. The study of hematological parameters was carried out on a CELL-DYN Sapphire hematology analyzer (Abbott Laboratories, USA). The values of neutrophil-lymphocytes ratio and platelet-lymphocytes ratio were also evaluated as predictors of in-hospital mortality.Results. High content of leukocytes (above 10.45 x 109/l) during hospitalization in patients with ACS aged 60-74 years are associated with a higher risk of death at the hospital stage. Among patients with ACS aged 75-89 years, the risk of death is associated with the following changes in peripheral blood upon admission: a decrease in the absolute number of eosinophils below 0.086 x 109/l, an increase in the absolute number of basophils above 0.079 x 109/l and a decrease in platelet-lymphocytes ratio below 31.06
Low Energy Electron and Nuclear Recoil Thresholds in the DRIFT-II Negative Ion TPC for Dark Matter Searches
Understanding the ability to measure and discriminate particle events at the
lowest possible energy is an essential requirement in developing new
experiments to search for weakly interacting massive particle (WIMP) dark
matter. In this paper we detail an assessment of the potential sensitivity
below 10 keV in the 1 m^3 DRIFT-II directionally sensitive, low pressure,
negative ion time projection chamber (NITPC), based on event-by-event track
reconstruction and calorimetry in the multiwire proportional chamber (MWPC)
readout. By application of a digital smoothing polynomial it is shown that the
detector is sensitive to sulfur and carbon recoils down to 2.9 and 1.9 keV
respectively, and 1.2 keV for electron induced events. The energy sensitivity
is demonstrated through the 5.9 keV gamma spectrum of 55Fe, where the energy
resolution is sufficient to identify the escape peak. The effect a lower energy
sensitivity on the WIMP exclusion limit is demonstrated. In addition to recoil
direction reconstruction for WIMP searches this sensitivity suggests new
prospects for applications also in KK axion searches
Melting Point and Lattice Parameter Shifts in Supported Metal Nanoclusters
The dependencies of the melting point and the lattice parameter of supported
metal nanoclusters as functions of clusters height are theoretically
investigated in the framework of the uniform approach. The vacancy mechanism
describing the melting point and the lattice parameter shifts in nanoclusters
with decrease of their size is proposed. It is shown that under the high vacuum
conditions (p<10^-7 torr) the essential role in clusters melting point and
lattice parameter shifts is played by the van der Waals forces of
cluster-substrate interation. The proposed model satisfactorily accounts for
the experimental data.Comment: 6 pages, 3 figures, 1 tabl
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