Search results for "System model"
showing 10 items of 87 documents
SEA WATER TEMPERATURE RECORDS GATHERED DURING EXPERIMENTAL BOTTOM TRAWL SURVEYS IN THE STRAIT OF SICILY (MEDITERRANEAN SEA)
2009
Depth and sea water temperature values recorded by a Minilog system during several bottom trawl surveys carried out in the Strait of Sicily (Central Mediterranean Sea) in spring (MEDITS) and late summer (GRUND), were analyzed by using an ad hoc developed software (MiSeAT). Depth and temperature profiles were analyzed for each haul. Three sea water temperature (t°C) values were considered: the upper and lower water layers temperature, and the difference between them. Mean values by depth stratum and the corresponding standard deviations were estimated for the three parameters, then compared between the two seasons. Haul parameters recorded during the more heterogeneous GRUND surveys (due to …
Secure interworking with P2PSIP and IMS
2010
In this paper, we propose a secure system model for interconnection between P2PSIP and IMS domains. The interworking solution is based on P2P-IMS GateWay (PIGW), which acts as a normal peer in P2PSIP network and a 3rd party IMS Application Server (AS) in IMS network. The security is achieved by implementing Chord Secure Proxy (CSP) and enhanced with subjective logic based trust model. We also implement this system model and analyze it in several aspects: number of hops and delay, trust improvement and protection against malicious or compromised intermediate peers. We conclude that the proposed architecture is feasible and improves security. As far as we know our research is the first study …
Midground Object Detection in Real World Video Scenes,
2007
Traditional video scene analysis depends on accurate background modeling to identify salient foreground objects. However, in many important surveillance applications, saliency is defined by the appearance of a new non-ephemeral object that is between the foreground and background. This midground realm is defined by a temporal window following the object's appearance; but it also depends on adaptive background modeling to allow detection with scene variations (e.g., occlusion, small illumination changes). The human visual system is ill-suited for midground detection. For example, when surveying a busy airline terminal, it is difficult (but important) to detect an unattended bag which appears…
Adaptive motion estimation and video vector quantization based on spatiotemporal non-linearities of human perception
1997
The two main tasks of a video coding system are motion estimation and vector quantization of the signal. In this work a new splitting criterion to control the adaptive decomposition for the non-uniform optical flow estimation is exposed. Also, a novel bit allocation procedure is proposed for the quantization of the DCT transform of the video signal. These new approaches are founded on a perception model that reproduce the relative importance given by the human visual system to any location in the spatial frequency, temporal frequency and amplitude domain of the DCT transform. The experiments show that the proposed procedures behave better than their equivalent (fixed-block-size motion estim…
3D objects descriptors methods: Overview and trends
2017
International audience; Object recognition or object's category recognition under varying conditions is one of the most astonishing capabilities of human visual system. The scientists in computer vision have been trying for decades to reproduce this ability by implementing algorithms and providing computers with appropriate tools. Hence, several intelligent systems have been proposed. To act in this field, numerous approaches have been proposed. In this paper we present an overview of the current trend in 3D objects recognition and describe some representative state of the art methods, highlighting their limits and complexity.
Importance of the Window Function Choice for the Predictive Modelling of Memristors
2021
Window functions are widely employed in memristor models to restrict the changes of the internal state variables to specified intervals. Here, we show that the actual choice of window function is of significant importance for the predictive modelling of memristors. Using a recently formulated theory of memristor attractors, we demonstrate that whether stable fixed points exist depends on the type of window function used in the model. Our main findings are formulated in terms of two memristor attractor theorems, which apply to broad classes of memristor models. As an example of our findings, we predict the existence of stable fixed points in Biolek window function memristors and their absenc…
Panel Summary One Model for Vision Systems?
1994
This panel reports some considerations about the definition of vision-models. The panellists are scientists working on vision problems from different perspectives. The concept of model in vision seems to remain still open. In fact, it is dynamic, and context dependent. There exists the need for a better exchange of information, among biologists, engineers, physicists, and psychologists in order to improve our knowledge.
On the classification of visual patterns: systems analysis using detection experiments.
1977
Behavioral experiments are indispensable for the analysis of biological systems for cognition and recognition. When these are carried out as detection experiments three types of description can be used for the problem of visual pattern recognition which allow conclusions to be drawn on the operating function of the system. Provided that the signals to be recognized have additive noise superimposed on them, system description is possible: 1. on the basis on the probabilities of recognition and of mix-up,--2. through the analysis of the transformation of distribution densities of the noise,--3. by means of the measurable distances of the patterns from each other in feature space.-The analysis…
A Viable System View of the Japanese Lean Production System
2011
We highlight the main characteristics of lean production and we analyze them using a viable-systemic perspective. Doing so we consider the lean production with its osmotic interactions with the Japanese business system and we create a framework which highlights the key relations which are essential for the viability of the system.
<title>Computerized device for critical flicker fusion frequency determination</title>
2003
The critical fusion flicker frequency of the human visual system is the threshold sensitivity for a sine wave-modulated patch of monochromatic flickering light measured as a function of its temporal frequency and average luminance level. The critical flicker fusion frequency changes in different ocular and non-ocular conditions, for example: high-myopia, AMR, glaucoma, schizophrenia, after alcohol intake, fatigue. A computerized test for critical flicker fusion frequency determination was developed. Visual stimuli are two monochromatic LED light sources that are connected to a microcircuit driven by a computer program. The control of the device is realized through the parallel port of the P…