Data-Efficient Minimax Quickest Change Detection with Composite Post-Change Distribution

The problem of quickest change detection is studied, where there is an additional constraint on the cost of observations used before the change point and where the post-change distribution is composite. Minimax formulations are proposed for this problem. It is assumed that the post-change family of distributions has a member which is least favorable in some sense. An algorithm is proposed in which on-off observation control is employed using the least favorable distribution, and a generalized likelihood ratio based approach is used for change detection. Under the additional condition that either the post-change family of distributions is finite, or both the pre- and post-change distributions belong to a one parameter exponential family, it is shown that the proposed algorithm is asymptotically optimal, uniformly for all possible post-change distributions.Comment: Submitted to IEEE Transactions on Info. Theory, Oct 2014. Preliminary version presented at ISIT 2014 at Honolulu, Hawai

Degrees of Freedom of Interference Channels with CoMP Transmission and Reception

We study the Degrees of Freedom (DoF) of the K-user interference channel with coordinated multi-point (CoMP) transmission and reception. Each message is jointly transmitted by M_t successive transmitters, and is jointly received by M_r successive receivers. We refer to this channel as the CoMP channel with a transmit cooperation order of M_t and receive cooperation order of M_r. Since the channel has a total of K transmit antennas and K receive antennas, the maximum possible DoF is equal to K. We show that the CoMP channel has K DoF if and only if M_t + M_r is greater than or equal to K+1. For the general case, we derive an outer bound that states that the DoF is bounded above by the ceiling of (K+M_t+M_r-2)/2. For the special case with only CoMP transmission, i.e, M_r = 1, we propose a scheme that can achieve (K+M_t-1)/2 DoF for all K < 10, and conjecture that the result holds true for all K . The achievability proofs are based on the notion of algebraic independence from algebraic geometry.Comment: Submitted to IEEE Transactions on Information Theor

Optimal Timer Based Selection Schemes

Timer-based mechanisms are often used to help a given (sink) node select the best helper node among many available nodes. Specifically, a node transmits a packet when its timer expires, and the timer value is a monotone non-increasing function of its local suitability metric. The best node is selected successfully if no other node's timer expires within a 'vulnerability' window after its timer expiry, and so long as the sink can hear the available nodes. In this paper, we show that the optimal metric-to-timer mapping that (i) maximizes the probability of success or (ii) minimizes the average selection time subject to a minimum constraint on the probability of success, maps the metric into a set of discrete timer values. We specify, in closed-form, the optimal scheme as a function of the maximum selection duration, the vulnerability window, and the number of nodes. An asymptotic characterization of the optimal scheme turns out to be elegant and insightful. For any probability distribution function of the metric, the optimal scheme is scalable, distributed, and performs much better than the popular inverse metric timer mapping. It even compares favorably with splitting-based selection, when the latter's feedback overhead is accounted for.Comment: 21 pages, 6 figures, 1 table, submitted to IEEE Transactions on Communications, uses stackrel.st

Unmanned Aerial Vehicles an Overview and Applications

A drone that is not manned Automated vehicles are rational admirers of the latest planes, and they\u27re always looking for ways to improve. Wartime and re-exploration capabilities are the primary emphases of the current generation of UAVs, leaving the existing market impacted by UAV technology unaffected. UAV technology has a wide range of current uses, ranging from emergency response to media to agriculture to communications experts. However, the adaptable unmanned aerial vehicle is not yet available to the general public. As a result, a UAV that can carry a wide range of flexible tools should be light and lightweight. In commercial applications, UAV technological ideas and adaptable components may be a strong instrument, and they can help define the future of aviation. It is possible to categorize drones depending on their applications, such as photography, aerial mapping, surveillance, and so on. However, the easiest way to classify \u27Drones\u27 is to use aerial platforms. Drones may be classified into four broad categories based on the sort of airborne platform they employ

Specific features of deformation of the nitinol alloy after electrolytic hydrogenation

Specific features of the effect of hydrogenation on the susceptibility of a Ni–Ti alloy with shape memory to deformation are determined with the use of metallographic, electrochemical, and mechanical studies. Three sections are detected in the tensile curves of the specimens of nickel–titanium alloy in the initial state. The first section is linear due to the elastic deformation of the alloy with initial austenitic struc-ture. The second section is nonlinear and associated with pseudoelastic structural transformations of the original austenitic structure into a martensitic structure. The third section is also linear and caused by the elastic deformation of martensite formed in the course of deformation of austenite. After hydro-genation of the Ni–Ti alloy, the pseudoelastic structural transformation starts at a somewhat lower level of stresses than without hydrogenation. In this case, the specimens are destroyed after the termination of this transformation for a much lower level of plasticity than in the nonhydrogenated alloy. It is assumed that the electrolytic hydrogenation of the alloy promotes the formation of a very brittle hydride phase on the surface of Ti-type inclusions revealed in the structure of alloy in the initial state. Its thickness is determined by the duration of the process of hydrogenation rather than by the current used for hydro-genation

Analysis of the frequency of maxillary sinus pathology among male and female adults

The maxillary sinuses diseases are an actual clinical problem today. The aim of our study was to determine the frequency of pathology of the maxillary sinuses of different origin and its age dynamics in adults. 500 series of anonymized tomograms of adults were analyzed: 22-35 years (1st group) and 36-60 years (2nd group in men) and 36-55 years (2nd group in women). Cone-beam computed tomography (CT) of the nose, paranasal sinuses, and upper jaw was performed on a Point 3D Combi 500 cone-beam tomograph. RealScan software was used to analyze the test results. The results of the study showed that among the adults who applied for examination of the maxillary sinus, only 20% had no pathology. Patients of the first age group are most often diagnosed with pathological changes of the maxillary sinus, which have a rhinogenic origin. In persons of the second age group, regardless of gender, the pathology of the maxillary sinus of odontogenic origin is most often diagnosed. With age, the number of pathologies of odontogenic origin increase both in men and in women, and the number of pathologies of other origin, including rhinogenic - decreases

Clinicopathological study of viral skin lesions

Abstract Introduction: Many viral infections have prominent skin manifestations. simplex, molluscum contagiosum and human papilloma virus which causes verruca vulgaris, condyloma acuminatum, deep palmoplantar wart and verucca plana. They are of increased significance in immunocompromised patients. the viral lesions are diagnosed clinically and serologically, some require biopsy confirmation. identify the specific histological changes in individual viral lesions. To differentiate the lesions that can clinically mimi as bullous lesion or soft tissue mass. SMVMCH for a period of 3 years from 2011 to 2013 were taken for this study. studied, 31 patients were diagnosed to have skin manifestations of various viral infections. The most commonly encountered entity was Verruca molluscum contagiosum (4), herpes (2) and verucca plana the diagnosis were, intranuclear inclusions in herpes; cytoplasmic viral inclusion bodies in MC, deep palmoplantar wart; koilocytes in Verruca and condyloma .These were also associated with o produce warty, bullous and mass like lesions which can mimic non infectious conditions. Histopathological evaluation serves as a valuable tool for identification of virus induced skin changes and aids in approp lesions. In our study most common infection was HPV