3,711 research outputs found
Application of the self-organising map to trajectory classification
This paper presents an approach to the problem of automatically classifying events detected by video surveillance systems; specifically, of detecting unusual or suspicious movements. Approaches to this problem typically involve building complex 3D-models in real-world coordinates
to provide trajectory information for the classifier. In this paper we show that analysis of trajectories may be carried out in a model-free fashion, using self-organising
feature map neural networks to learn the characteristics of normal trajectories, and to detect novel ones. Trajectories are represented using positional and first and second order motion information, with moving-average smoothing. This allows novelty detection to be applied on a point-by-point basis in real time, and permits both instantaneous motion and whole trajectory motion to be subjected to novelty detection
Deregulation and efficiency: the case of private Korean banks
This paper examines the productive efficiency of a sample of private Korean banks over the 1985 to 1995 time period. The goal of the analysis is to identify the key determinants of Korean bank efficiency (inefficiency) following the program of deregulation initiated by the government in the early 1980s and augmented in the early 1990s. Using the stochastic frontier cost function approach, efficiency scores were determined for each bank in the sample. A second stage efficiency regression was then estimated to identify the key determinants of operating efficiency. In general, the results show that banks with higher rates of asset growth, fewer employees per million won of assets, larger amounts of core deposits, and lower expense ratios were more efficient. In addition, banks which branched nationwide were found to be more efficient. The financial deregulation of 1991 was found to have had little or no significant effect on the level of sample bank efficiency.Banks and banking - Korea ; Korea
Novelty detection in video surveillance using hierarchical neural networks
Abstract. A hierarchical self-organising neural network is described for the detection of unusual pedestrian behaviour in video-based surveillance systems. The system is trained on a normal data set, with no prior information about the
scene under surveillance, thereby requiring minimal user input. Nodes use a trace activation rule and feedforward connections, modified so that higher layer nodes are sensitive to trajectory segments traced across the previous layer. Top layer nodes have binary lateral connections and corresponding “novelty accumulator” nodes. Lateral connections are set between co-occurring nodes, generating a signal to prevent accumulation of the novelty measure along normal sequences. In abnormal sequences the novelty accumulator nodes are allowed to increase their activity, generating an alarm state
Proteomics of Carbon Fixation Energy Sources in Halothiobacillus neapolitanus
Through the use of proteomics, it was uncovered that the autotrophic, aerobic purple sulfur bacterium Halothiobacillus neapolitanus displays changes in cellular levels of portions of its carbon dioxide uptake and fixation mechanisms upon switch from bicarbonate to CO2(g) as carbon source. This includes an increase in level of a heterodimeric bicarbonate transporter along with a potential switch between form I and form II of RubisCO. Additional changes are seen in several sulfur oxidation pathways, which may indicate a link between sulfur oxidation pathways as an energy source and carbon uptake/fixation mechanisms
Autonomous real-time surveillance system with distributed IP cameras
An autonomous Internet Protocol (IP) camera based object tracking and behaviour identification system, capable of running in real-time on an embedded system with limited memory and processing power is presented in this paper. The main contribution of this work is the integration of processor intensive image processing algorithms on an embedded platform capable of running at real-time for monitoring the behaviour of pedestrians. The Algorithm Based Object Recognition and Tracking (ABORAT) system architecture presented here was developed on an Intel PXA270-based development board clocked at 520 MHz. The platform was connected to a commercial stationary IP-based camera in a remote monitoring station for intelligent image
processing. The system is capable of detecting moving objects and their shadows in a complex environment with varying lighting intensity and moving foliage. Objects
moving close to each other are also detected to extract their trajectories which are then fed into an unsupervised neural network for autonomous classification. The novel intelligent video system presented is also capable of performing simple analytic functions such as tracking and generating alerts when objects enter/leave regions or cross tripwires superimposed on live video by the operator
The Dual Origin Of The Nitrogen Deficiency In Comets: Selective Volatile Trapping In The Nebula And Postaccretion Radiogenic Heating
We propose a scenario that explains the apparent nitrogen deficiency in comets in away that is consistent with the fact that the surfaces of Pluto and Triton are dominated by nitrogen-rich ice. We use a statistical thermodynamic model to investigate the composition of the successive multiple guest clathrates that may have formed during the cooling of the primordial nebula from the most abundant volatiles present in the gas phase. These clathrates agglomerated with the other ices (pure condensates or stoichiometric hydrates) and formed the building blocks of comets. We report that molecular nitrogen is a poor clathrate former, when we consider a plausible gas-phase composition of the primordial nebula. This implies that its trapping into cometesimals requires a low disk temperature (similar to 20 K) in order to allow the formation of its pure condensate. We find that it is possible to explain the lack of molecular nitrogen in comets as a consequence of their postformation internal heating engendered by the decay of short-lived radiogenic nuclides. This scenario is found to be consistent with the presence of nitrogen-rich ice covers on Pluto and Triton. Our model predicts that comets should present xenon-to-water and krypton-to-water ratios close to solar xenon-to-oxygen and krypton-to-oxygen ratios, respectively. In contrast, the argon-to-water ratio is predicted to be depleted by a factor of similar to 300 in comets compared to solar argon-to-oxygen, as a consequence of poor trapping efficiency and radiogenic heating.CNESJPLAstronom
A synchronous multimedia annotation system for secure collaboratories
In this paper, we describe the Vannotea system - an application designed to enable collaborating groups to discuss and annotate collections of high quality images, video, audio or 3D objects. The system has been designed specifically to capture and share scholarly discourse and annotations about multimedia research data by teams of trusted colleagues within a research or academic environment. As such, it provides: authenticated access to a web browser search interface for discovering and retrieving media objects; a media replay window that can incorporate a variety of embedded plug-ins to render different scientific media formats; an annotation authoring, editing, searching and browsing tool; and session logging and replay capabilities. Annotations are personal remarks, interpretations, questions or references that can be attached to whole files, segments or regions. Vannotea enables annotations to be attached either synchronously (using jabber message passing and audio/video conferencing) or asynchronously and stand-alone. The annotations are stored on an Annotea server, extended for multimedia content. Their access, retrieval and re-use is controlled via Shibboleth identity management and XACML access policies
The Dust Attenuation Curve versus Stellar Mass for Emission Line Galaxies at z ~ 2
We derive the mean wavelength dependence of stellar attenuation in a sample
of 239 high redshift (1.90 < z < 2.35) galaxies selected via Hubble Space
Telescope (HST) WFC3 IR grism observations of their rest-frame optical emission
lines. Our analysis indicates that the average reddening law follows a form
similar to that derived by Calzetti et al. for local starburst galaxies.
However, over the mass range 7.2 < log M/Msolar < 10.2, the slope of the
attenuation law in the UV is shallower than that seen locally, and the UV slope
steepens as the mass increases. These trends are in qualitative agreement with
Kriek & Conroy, who found that the wavelength dependence of attenuation varies
with galaxy spectral type. However, we find no evidence of an extinction "bump"
at 2175 A in any of the three stellar mass bins, or in the sample as a whole.
We quantify the relation between the attenuation curve and stellar mass and
discuss its implications.Comment: Accepted for publication in Ap
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