Joint face and head tracking inside multi-camera smart rooms

The paper introduces a novel detection and tracking system that provides both frame-view and world-coordinate human location information, based on video from multiple synchronized and calibrated cameras with overlapping fields of view. The system is developed and evaluated for the specific scenario of a seminar lecturer presenting in front of an audience inside a “smart room”, its aim being to track the lecturer’s head centroid in the three-dimensional (3D) space and also yield two-dimensional (2D) face information in the available camera views. The proposed approach is primarily based on a statistical appearance model of human faces by means of well-known AdaBoost-like face detectors, extended to address the head pose variation observed in the smart room scenario of interest. The appearance module is complemented by two novel components and assisted by a simple tracking drift detection mechanism. The first component of interest is the initialization module, which employs a spatio-temporal dynamic programming approach with appropriate penalty functions to obtain optimal 3D location hypotheses. The second is an adaptive subspace learning based 2D tracking scheme with a novel forgetting mechanism, introduced to reduce tracking drift and increase robustness. System performance is benchmarked on an extensive database of realistic human interaction in the lecture smart room scenario, collected as part of the European integrated project “CHIL”. The system consistently achieves excellent tracking precision, with a 3D mean tracking error of less than 16 cm, and is demonstrated to outperform four alternative tracking schemes. Furthermore, the proposed system performs relatively well in detecting frontal and near-frontal faces in the available frame views. This work was performed while Zhenqiu Zhang was on a summer internship with the Human Language Technology Department at the IBM T.J. Watson Research Center.     

Application of a modified Anaerobic Digestion Model 1 version for fermentative hydrogen production from sweet sorghum extract by Ruminococcus albus

The aim of the present study was to evaluate the effectiveness of a developed, ADM1-based kinetic model for the hydrogen production process in batch and continuous cultures of the bacterium Ruminococcus albus grown on sweet sorghum extract as the sole carbon source. Although sorghum extract is known to contain at least two different sugars, i.e. sucrose and glucose, no biphasic growth was observed in batch cultures as such growth is reported to occur in cultures of R. albus with mixed substrates. Thus, taking into account that the main sugar of sweet sorghum extract is sucrose, batch experiments with different initial concentrations of sucrose were performed in order to estimate the growth kinetics of the bacterium on this substrate. The kinetic parameters used, concerning the endogenous metabolism of the bacterium as well as those concerning the effect of pH and hydrogen partial pressure (P_H2), were the same as those estimated in a previous study with glucose as carbon source. Subsequently, the experimental data of batch and continuous experiments with sweet sorghum extract were simulated based on the already developed, modified ADM1 model accounting for the use of sugar-based substrate. It was shown that the model which was developed on synthetic substrates was successful in adequately describing the behavior of the microorganism on a real substrate such as sweet sorghum extract and predicting the experimental results quite well with a deviation of the model predictions from the experimental results being between 5-18% for the hydrogen yield.     

Information and competitive equilibria in the housing market

This paper derives necessary and sufficient conditions for the existence and occurrence likelihood of competitive equilibria in urban land and housing markets: (i) when there is imperfect information causing costly search trips and (ii) when land and housing are differentiated according to between‐zone and within‐zone heterogeneity. Such competitive equilibria are contingent on the possibility that consumers spill over into the markets of less preferred zones. The main conclusions are that markets tend to be partitioned into homogeneous sub‐groups and when they do not, heterogeneity may hamper the effectiveness of search and hence work against the existence of competitive equilibria.     

Simulated annealing: An application in fine particle magnetism

Using a model of a system of interacting fine ferromagnetic particles, a computer simulation of the dynamical approach to local or global minima of the system is developed for two different schedules of the application of ac and dc magnetic fields. The process of optimization, i.e., the achievement of a global minimum, depends on the rate of reduction of the ac field and on the symmetry of the ac field cycles, The calculations carried out to illustrate these effects include remanence curves and the zero field remanence for both schedules under different conditions. The growth of the magnetization during these processes was studied, and the interaction energy was calculated to best illustrate the optimization.     

Anaerobic digestion of olive mill wastewater in a periodic anaerobic baffled reactor (PABR) followed by further effluent purification via membrane separation technologies

BACKGROUND: The combined treatment of olive mill wastewater (OMWW) by applying the anaerobic digestion process and further treatment in a system consisting of filters and membranes is presented. The anaerobic digestion of the OMWW took place in a high rate system, the periodic anaerobic baffled reactor (PABR). Application of the membrane system aimed at purifying the anaerobic effluent. RESULTS: An increase in the organic loading rate was achieved by increasing the influent chemical oxygen demand (COD) and alternatively by decreasing the hydraulic retention time (HRT). The first option caused process failure, since the volatile fatty acids accumulation resulted in negligible biogas production. In contrast, the second change (decrease in HRT) led to stable operation that permitted the reduction of the HRT to 3.75 d and increase of the organic loading rate to 8.9 g tCOD L^?1 d^?1 with satisfactory total COD removal (72%). Higher total COD removal (up to 80%) was observed at lower organic loading rates (<3.5 g tCOD L^?1 d^?1). Further purification in the membrane units resulted in a final permeate of less than 0.1 g tCOD L^?1. The membrane systems proved to be more efficient on the anaerobic effluent than on the raw OMWW (the final permeate in that case contained 1g tCOD L^?1). CONCLUSIONS: The anaerobic digestion of OMWW in a PABR was stable even at high organic loading rates. Filtering and membrane fractionation of the PABR effluent resulted in a final permeate stream of high quality, suitable for irrigation and/or reuse in the proposed operating scheme for diluting the OMWW prior to anaerobic digestion. Copyright © 2009 Society of Chemical Industry     

Toxic effect of pharmaceuticals on methanogenesis.

Pharmaceuticals present in sewage may inhibit the biological processes in a sewage treatment plant. In this work, the toxic-effect of six pharmaceuticals (carbamazepine, sulfamethoxazole, propranolol hydrochloride, diclofenac sodium, ofloxacin and clofibric acid) on the anaerobic digestion process is assessed. Acetoclastic methanogenes are the most sensitive group of microorganisms participating in the anaerobic digestion process. Appropriate toxicity tests for these microorganisms were then based on assessing the impact of pharmaceuticals on the specific methanogenic activity (SMA) of the anaerobic biomass. The toxicity was expressed by the IC80 and IC50 values, i.e. the concentration at which bioactivity was 80% and 50% of the control, respectively. Results showed that the pharmaceuticals tested caused a mild inhibition to the methanogenes in most cases, related directly to the tendency of the compounds to adsorb on the anaerobic biomass.     

Assessment of the flexural capacity of RC beam/column elements allowing for 3d effects

The paper describes an experimental investigation of the deformational response and the stress conditions developing in the compressive zone of reinforced concrete beam-like structural elements in bending and bending combined with axial force. The results obtained confirm the findings of earlier work and demonstrate that the compressive zone at its ultimate-limit state is characterised by the development of triaxial rather than uniaxial-as widely considered-stress conditions. These findings form the basis for introducing a simple modification in the method currently used for calculating flexural capacity and it is shown that, by complementing the proposed method with an approach that takes into account the effect of yielding of the compression reinforcement on structural behaviour, it is possible to achieve predictions of flexural capacity which are considerably closer to experimentally established values than the values obtained through the use of currently adopted methods.