in this paper, the effects of reflected waves of the facets on the internal optical intensity of semiconductor dfb lasers are investigated. the uniformity of optical intensity along the cavity length is evaluated with flatness parameter. the dependence of this parameter on coupling coefficient, reflectivity and grating phase at the facets is also studied. this investigation shows that in some s...

With the aim of automatically extracting fine change information from ground objects, detection (CD) for very high resolution (VHR) remote sensing images is extremely essential in various applications. However, increase spatial resolution, more complicated interactive relationships evident diversity spectra, and severe speckle noise make accurately identifying relevant changes challenging. To a...

Existing formulations for optical flow estimation and image segmentation have used Bayesian Networks and Markov Random Field (MRF) priors to impose smoothness of segmentation. These approaches typically focus on estimation in a single time slice based on two consecutive images. We develop a motion segmentation framework for a continuous stream of images using inference in a corresponding Dynami...

the informal settlements are those parts of city which have been formed without plan or minimum facilities and services. therefore, they are considered as priorities in management cities for services and improving quality of life. in this regard, it is important to get solutions to make positive changes with the lowest cost and direct intervention. therefore, this study aims to explore the link...

Research on the interpretation of image flow (or optical flow) until now has mainly focused on instantaneous flow fields. This limits the scope of the problems that one can address and the accuracy of the results. Here we extend a previous formulation of the problem to incorporate temporal variation of image flow. We illustrate our approach by solving specific cases which are of practical signi...

In this paper, we describe a simple strategy for mitigating variability in temporal data series by shifting focus onto long-term, frequency domain features that are less susceptible to variability. We apply this method to the human action recognition task and demonstrate how working in the frequency domain can yield good recognition features for commonly used optical flow and articulated pose f...

Research on the interpretation of image flow (or optical flow) until now has mainly focused on instantaneous flow fields. This limits the scope of the problems that one can address and the accuracy of the results. Here we extend a previous formulation of the problem to incorporate temporal variation of image flow. We illustrate our approach by solving specific cases which are of practical signi...

Optical flow refers to the visual motion observed between two consecutive images. Since the degree of freedom is typically much larger than the constraints imposed by the image observations, the straightforward formulation of optical flow inference is an ill-posed problem. By setting some type of additional “regularity” constraints, classical approaches formulate a well-posed optical flow infer...

Knowledge discovery in databases (KDD) is an important task in spatial databases since both, the number and the size of such databases are rapidly growing. This paper introduces a set of basic operations which should be supported by a spatial database system (SDBS) to express algorithms for KDD in SDBS. For this purpose, we introduce the concepts of neighborhood graphs and paths and a small set...