Supervisory Control for Behavior Composition

We relate behavior composition, a synthesis task studied in AI, to supervisory control theory from the discrete event systems field. In particular, we show that realizing (i.e., implementing) a target behavior module (e.g., a house surveillance system) by suitably coordinating a collection of available behaviors (e.g., automatic blinds, doors, lights, cameras, etc.) amounts to imposing a supervisor onto a special discrete event system. Such a link allows us to leverage on the solid foundations and extensive work on discrete event systems, including borrowing tools and ideas from that field. As evidence of that we show how simple it is to introduce preferences in the mapped framework

Master of Science in Computing

thesisDetecting community structure in networks has been a widely studied area. While most of the methods produce an exclusive membership of the nodes, the nodes in real-world networks tend to partially belong to more than one community. In this thesis, we study some methods that have been used to quantify the strength of memberships of nodes in di erent communities (or community-a nity, as we call it) and also de ne three of our own methods. Our rst method is based on personalized PageRanks of the nodes, the second is based on the individual contribution of nodes to the modularity of the graph, and the last is based on the common neighborhood between two nodes. We rst discuss di erent notions of community-a nity, each of which is followed by formulations that capture that notion. We then discuss the concept of stability, which uses community-a nity scores of the nodes to compute how "stable" each node is in a given community structure and how we can use this information in estimating the quality of a given community structure. Towards the end, we introduce a community detection algorithm, which "peels" communities one by one from a graph. The results of our experiments show that our algorithm is very accurate even for a large number of nodes in a graph. Our algorithm is fast and it performs very well on real-world graphs compared to the state of the art algorithms

Finite State Testing of Graphical User Interface using Genetic Algorithm

Graphical user interfaces are the key components of any software. Nowadays, the popularity of the software depends upon how easily the user can interact with the system. However, as the system becomes complex, this interaction is also complicated with many states. The testing of graphical user interfaces is an important phase of modern software. The testing of GUI is possible only by interacting with the system, which may be a time-consuming process and is generally automated based on the test suite. The test suite generation proposed in this paper is based on the genetic algorithm in which various test cases are generated heuristically. For performance validation of the proposed approach, the same has been compared with a variant of PSO, and it found that GA is slightly better in comparison to the PSO

Simulations Show that Vortex Flows could Heat the Chromosphere in Solar Plage

The relationship between vortex flows at different spatial scales and their contribution to the energy balance in the chromosphere is not yet fully understood. We perform three-dimensional (3D) radiation-magnetohydrodynamic (MHD) simulations of a unipolar solar plage region at a spatial resolution of 10 km using the MURaM code. We use the swirling-strength criterion that mainly detects the smallest vortices present in the simulation data. We additionally degrade our simulation data to smooth-out the smaller vortices, so that also the vortices at larger spatial scales can be detected. Vortex flows at various spatial scales are found in our simulation data for different effective spatial resolutions. We conclude that the observed large vortices are likely clusters of much smaller ones that are not yet resolved by observations. We show that the vertical Poynting flux decreases rapidly with reduced effective spatial resolutions and is predominantly carried by the horizontal plasma motions rather than vertical flows. Since the small-scale horizontal motions or the smaller vortices carry most of the energy, the energy transported by vortices deduced from low resolution data is grossly underestimated. In full resolution simulation data, the Poynting flux contribution due to vortices is more than adequate to compensate for the radiative losses in plage, indicating their importance for chromospheric heating.Comment: 8 pages, 5 figures, accepted in ApJ

Implementation of Transform Based Techniques in Digital Image Watermarking

Digital image watermarking is used to resolve the problems of data security and copyright protection. In many applications of digital watermarking, watermarked image of good quality are required. But here is a trade-off between number of embedded watermark images and quality of watermarked images. This aspect is quite important in case of multiple digital image watermarking. This project presents a robust digital image watermarking using discrete cosine transform (DCT) method. Compression on a watermarked image can significantly affect the detection of the embedded watermark. The detection of the presence or absence of a watermarked in an image is often affected if the watermarked image has undergone compression. Compression can also be considered as an attack on watermarked images. To show that a particular watermarking scheme is robust against compression, simulation is often relied DOI: 10.17762/ijritcc2321-8169.15084

Wave transformations near a coronal magnetic null-point

We investigate the viability of MHD waves, in particular acoustic p-modes, in causing strong current accumulation at the null points. We begin with a three-dimensional numerical setup incorporating a gravitationally stratifed solar atmosphere and an axially symmetric magnetic feld including a coronal magnetic null point. To excite waves, we employ wave drivers mimicking global p-modes. We found that most of the vertical velocity transmits through the Alfv\'en acoustic equipartition layer maintaining acoustic nature while a small fraction generates fast waves via the mode conversion process. The fast waves undergo almost total refection at the transition region due to sharp gradients in density and Alfv\'en speed. There are only weak signatures of Alfv\'en wave generation near the transition region due to fast-to-Alfv\'en mode conversion. Since the slow waves propagate with the local sound speed, they are not much afected by the density gradients at the transition region and undergo secondary mode conversion and transmission at the Alfv\'en-acoustic equipartition layer surrounding the null point, leading to fast wave focusing at the null point. These fast waves have associated perturbations in current density, showing oscillatory signatures compatible with the second harmonic of the driving frequency which could result in resistive heating and enhanced intensity in the presence of fnite resistivity. We conclude that MHD waves could be a potential source for oscillatory current dissipation around the magnetic null point. We conjecture that besides oscillatory magnetic reconnection, global p-modes could lead to the formation of various quasiperiodic energetic events.Comment: accepted for publication in Astronomy and Astrophysics journa

In Vivo characterization of Epileptic Tissue with Optical Spectroscopy

For children with intractable seizures, surgical removal of epileptic foci, if identifiable and feasible, can be an effective way to reduce or eliminate seizures. The success of this type of surgery strongly hinges upon the ability to identify and demarcate those epileptic foci. The ultimate goal of this research project is to develop an effective technology for detection of unique in vivo pathophysiological characteristics of epileptic cortex and, subsequently, to use this technology to guide epilepsy surgery intraoperatively. In this PhD dissertation the feasibility of using optical spectroscopy to identify unique in vivo pathophysiological characteristics of epileptic cortex was evaluated and proven using the data collected from children undergoing epilepsy surgery. In this first in vivo human study, static diffuse reflectance and fluorescence spectra were measured from the epileptic cortex, defined by intraoperative ECoG, and its surrounding tissue from pediatric patients undergoing epilepsy surgery. When feasible, biopsy samples were taken from the investigated sites for the subsequent histological analysis. Using the histological data as the gold standard, spectral data was analyzed with statistical tools. The results of the analysis show that static diffuse reflectance spectroscopy and its combination with static fluorescence spectroscopy can be used to effectively differentiate between epileptic cortex with histopathological abnormalities and normal cortex in vivo with a high degree of accuracy. To maximize the efficiency of optical spectroscopy in detecting and localizing epileptic cortex intraoperatively, the static system was upgraded to investigate histopathological abnormalities deep within the epileptic cortex, as well as to detect unique temporal pathophysiological characteristics of epileptic cortex. Detection of deep abnormalities within the epileptic cortex prompted a redesign of the fiberoptic probe. A mechanical probe holder was also designed and constructed to maintain the probe contact pressure and contact point during the time dependent measurements. The dynamic diffuse reflectance spectroscopy system was used to characterize in vivo pediatric epileptic cortex. The results of the study show that some unique wavelength dependent temporal characteristics (e.g., multiple horizontal bands in the correlation coefficient map g(λref = 800 nm, λcomp,t)) can be found in the time dependent recordings of diffuse reflectance spectra from epileptic cortex defined by ECoG

Bilobed right lung: a case of absent horizontal fissure

The human lungs are organs of respiration present in the greater part of thoracic cavity on each side of heart in the mediastinum resting on diaphragm. The right lung is classically divided into three lobes namely superior, middle and inferior by the oblique and horizontal fissures. The left lung is divided into superior and inferior lobes by a single deep oblique fissure. The fissures help in expansion of lungs during respiration. During the routine dissection of thoracic region of human cadaver, bilobed right lung with absent horizontal fissure was observed. The right lung was divided into superior and inferior lobe by a single oblique fissure. The left lung had normal anatomy in this case. The variations in the fissures and lobar pattern of lungs are common and are due to altered developmental process during intrauterine life. The anatomical knowledge of these disparities in fissures is important for clinicians prior to performing any pulmonary surgical procedures and to prevent postoperative complications.

Vortex Flow Properties in Simulations of Solar Plage Region: Evidence for their role in chromospheric heating

Vortex-flows exist across a broad range of spatial and temporal scales in the solar atmosphere. Small-scale vortices have been proposed to play an important role in energy transport in the solar atmosphere. However, their physical properties remain poorly understood due to the limited spatial resolution of the observations. We aim to explore and analyze the physical properties of small-scale vortices inside magnetic flux tubes using numerical simulations, and to investigate whether they contribute to heating the chromosphere in a plage region. Using the three-dimensional (3D) radiative magnetohydrodynamic (MHD) simulation code 'MURaM', we perform numerical simulations of a unipolar solar plage region. To detect and isolate vortices, we use the Swirling Strength criterion and select the locations where the fluid is rotating with an angular velocity greater than a certain threshold. We concentrate on small-scale as they are the strongest and carry most of the energy. We explore the spatial profiles of physical quantities viz. density, horizontal velocity, etc. inside these vortices. Moreover, to apprehend their general characteristics, a statistical investigation is performed. Magnetic flux tubes have a complex filamentary substructure harbouring an abundance of small-scale vortices. At the interfaces between vortices strong current sheets are formed that may dissipate and heat the solar chromosphere. Statistically, vortices have higher densities and higher temperatures than the average values at the same geometrical height in the chromosphere. We conclude that small-scale vortices are ubiquitous in solar plage regions, and they are denser and hotter structures that contribute to chromospheric heating, possibly by dissipation of the current sheets formed at their interfaces.Comment: accepted for publication in A&