832 research outputs found

    Publication Output of Journal ‘Clinical Cancer Research’ (2005-2018): A Bibliometric Analysis

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    The paper analysis, authorship productivity and collaborative research of research articles available on Clinical Cancer Research for a period of fourteen years from 2005 to 2018. The data were downloaded from the Clarivate Analytics - web of science database. The data included fourteen thousand one hundred fifty six (14156) research articles and sixty eight thousand one hundred seventy (68170) authors. This paper analysis the co-authorship network using CiteSpace Java application with the aim of the understanding of research collaboration in this journal. This paper test the appropriateness of relative growth rate and doubling time

    Improved sparse approximation over quasi-incoherent dictionaries

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    This paper discusses a new greedy algorithm for solving the sparse approximation problem over quasi-incoherent dictionaries. These dictionaries consist of waveforms that are uncorrelated "on average," and they provide a natural generalization of incoherent dictionaries. The algorithm provides strong guarantees on the quality of the approximations it produces, unlike most other methods for sparse approximation. Moreover, very efficient implementations are possible via approximate nearest-neighbor data structure

    High Sulfur Lignite Fired Large CFB Boilers-Design and Operating Experience

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    One of the measures of the prosperity of a nation is per capita consumption of electricity. In developing countries like India the gap between supply and demand is strongly increasing. The demand for all forms of energy is expected to increase substantially in the foreseeable future and is forecasted to double by 2020. Although coal would continue to be a major energy source in India due to its availability, lignite is fast emerging as an alternate source of fuel for electricity generation. In India the total lignite potential is 4177 million tonnes. The varieties found in India (Gujarat & Rajasthan region) have moderate to high sulphur (1 to 15 %wt dry ash free) content. It has become economically necessary to use this lignite for power generation in view of spurt in energy demand while caring for the environment (by controlling the SO2 emission). CFB boilers with their in-furnace SO2 capturing capability perfectly suit these demands and are very attractive while their utilization in comparison with pulverized fuel boilers would require very expensive add-on flue gas conditioning systems. The CFB boiler technology designed by BHEL (see Notation list for acronyms) has been successfully demonstrated for utilities at the 2x125 MWe power project at Surat. Based on the excellent performance of the units at SLPP, BHEL has bagged order for 2x125 MWe CFB power plant for RVUNL at Giral, Rajasthan and 1x75 MWe CFB power plant for GEB, at Kutch, Gujarat. The plant at Giral is now operating after overcoming unique challenges for firing \u3e15%daf sulphur lignite (one of highest sulphur-content fuel used in CFB utility-scale units). This paper provides an overview of the CFB process, its advantages, the development of CFB technology, and the experience gained from these units in particular attention to lignite fired units of 125 MWe capacities. The teething problems experienced during initial operation and their resolution form part of this paper. With the experience gained at Giral, firing high-sulphur lignite, BHEL is uniquely placed among CFB boiler manufacturers to meet market requirement of using such demanding fuels for power generation. The successful operation of the boiler after surmounting the issues is bound to stimulate utility users to adopt CFB technology for their proposed projects for such challenging fuels also. Many other large capacity BHEL CFB boilers (firing range of fuel: from Indonesian coal, lignite with high/medium sulphur to petroleum coke) are under various stages of commissioning and will be in operation in another few months

    One Table to Count Them All: Parallel Frequency Estimation on Single-Board Computers

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    Sketches are probabilistic data structures that can provide approximate results within mathematically proven error bounds while using orders of magnitude less memory than traditional approaches. They are tailored for streaming data analysis on architectures even with limited memory such as single-board computers that are widely exploited for IoT and edge computing. Since these devices offer multiple cores, with efficient parallel sketching schemes, they are able to manage high volumes of data streams. However, since their caches are relatively small, a careful parallelization is required. In this work, we focus on the frequency estimation problem and evaluate the performance of a high-end server, a 4-core Raspberry Pi and an 8-core Odroid. As a sketch, we employed the widely used Count-Min Sketch. To hash the stream in parallel and in a cache-friendly way, we applied a novel tabulation approach and rearranged the auxiliary tables into a single one. To parallelize the process with performance, we modified the workflow and applied a form of buffering between hash computations and sketch updates. Today, many single-board computers have heterogeneous processors in which slow and fast cores are equipped together. To utilize all these cores to their full potential, we proposed a dynamic load-balancing mechanism which significantly increased the performance of frequency estimation.Comment: 12 pages, 4 figures, 3 algorithms, 1 table, submitted to EuroPar'1

    Systematic mapping review on student’s performance analysis using big data predictive model

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    This paper classify the various existing predicting models that are used for monitoring andimproving students’ performance at schools and higher learning institutions. It analyses all theareas within the educational data mining methodology. Two databases were chosen for thisstudy and a systematic mapping study was performed. Due to the very infant stage of thisresearch area, only 114 articles published from 2012 till 2016 were identified. Within this, atotal of 59 articles were reviewed and classified. There is an increased interest and research inthe area of educational data mining, particularly in improving students’ performance withvarious predictive and prescriptive models. Most of the models are devised for pedagogicalimprovements ultimately. It is a huge scarcity in producing portable predictive models that fitsinto any educational environment. There is more research needed in the educational big data.Keywords: predictive analysis; student’s performance; big data; big data analytics; datamining; systematic mapping study

    Stochastic Budget Optimization in Internet Advertising

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    Internet advertising is a sophisticated game in which the many advertisers "play" to optimize their return on investment. There are many "targets" for the advertisements, and each "target" has a collection of games with a potentially different set of players involved. In this paper, we study the problem of how advertisers allocate their budget across these "targets". In particular, we focus on formulating their best response strategy as an optimization problem. Advertisers have a set of keywords ("targets") and some stochastic information about the future, namely a probability distribution over scenarios of cost vs click combinations. This summarizes the potential states of the world assuming that the strategies of other players are fixed. Then, the best response can be abstracted as stochastic budget optimization problems to figure out how to spread a given budget across these keywords to maximize the expected number of clicks. We present the first known non-trivial poly-logarithmic approximation for these problems as well as the first known hardness results of getting better than logarithmic approximation ratios in the various parameters involved. We also identify several special cases of these problems of practical interest, such as with fixed number of scenarios or with polynomial-sized parameters related to cost, which are solvable either in polynomial time or with improved approximation ratios. Stochastic budget optimization with scenarios has sophisticated technical structure. Our approximation and hardness results come from relating these problems to a special type of (0/1, bipartite) quadratic programs inherent in them. Our research answers some open problems raised by the authors in (Stochastic Models for Budget Optimization in Search-Based Advertising, Algorithmica, 58 (4), 1022-1044, 2010).Comment: FINAL versio

    Spatially embedded random networks

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    Many real-world networks analyzed in modern network theory have a natural spatial element; e.g., the Internet, social networks, neural networks, etc. Yet, aside from a comparatively small number of somewhat specialized and domain-specific studies, the spatial element is mostly ignored and, in particular, its relation to network structure disregarded. In this paper we introduce a model framework to analyze the mediation of network structure by spatial embedding; specifically, we model connectivity as dependent on the distance between network nodes. Our spatially embedded random networks construction is not primarily intended as an accurate model of any specific class of real-world networks, but rather to gain intuition for the effects of spatial embedding on network structure; nevertheless we are able to demonstrate, in a quite general setting, some constraints of spatial embedding on connectivity such as the effects of spatial symmetry, conditions for scale free degree distributions and the existence of small-world spatial networks. We also derive some standard structural statistics for spatially embedded networks and illustrate the application of our model framework with concrete examples

    Multipoint boundary value problem for a coupled system of psi-Hilfer nonlinear implicit fractional differential equation

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    This study examines the existence and uniqueness of the solution to the coupled system of the ψ-Hilfer nonlinear implicit fractional multipoint boundary value problem. The uniqueness is shown by the Banach contraction principle, and the existence is shown by Krasnosel’skii’s fixed point theorem in a special working space. An example is presented to verify our results. The existence and uniqueness of the solution are analysed graphically

    Managing Risk of Bidding in Display Advertising

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    In this paper, we deal with the uncertainty of bidding for display advertising. Similar to the financial market trading, real-time bidding (RTB) based display advertising employs an auction mechanism to automate the impression level media buying; and running a campaign is no different than an investment of acquiring new customers in return for obtaining additional converted sales. Thus, how to optimally bid on an ad impression to drive the profit and return-on-investment becomes essential. However, the large randomness of the user behaviors and the cost uncertainty caused by the auction competition may result in a significant risk from the campaign performance estimation. In this paper, we explicitly model the uncertainty of user click-through rate estimation and auction competition to capture the risk. We borrow an idea from finance and derive the value at risk for each ad display opportunity. Our formulation results in two risk-aware bidding strategies that penalize risky ad impressions and focus more on the ones with higher expected return and lower risk. The empirical study on real-world data demonstrates the effectiveness of our proposed risk-aware bidding strategies: yielding profit gains of 15.4% in offline experiments and up to 17.5% in an online A/B test on a commercial RTB platform over the widely applied bidding strategies

    Learning Best Response Strategies for Agents in Ad Exchanges

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    Ad exchanges are widely used in platforms for online display advertising. Autonomous agents operating in these exchanges must learn policies for interacting profitably with a diverse, continually changing, but unknown market. We consider this problem from the perspective of a publisher, strategically interacting with an advertiser through a posted price mechanism. The learning problem for this agent is made difficult by the fact that information is censored, i.e., the publisher knows if an impression is sold but no other quantitative information. We address this problem using the Harsanyi-Bellman Ad Hoc Coordination (HBA) algorithm, which conceptualises this interaction in terms of a Stochastic Bayesian Game and arrives at optimal actions by best responding with respect to probabilistic beliefs maintained over a candidate set of opponent behaviour profiles. We adapt and apply HBA to the censored information setting of ad exchanges. Also, addressing the case of stochastic opponents, we devise a strategy based on a Kaplan-Meier estimator for opponent modelling. We evaluate the proposed method using simulations wherein we show that HBA-KM achieves substantially better competitive ratio and lower variance of return than baselines, including a Q-learning agent and a UCB-based online learning agent, and comparable to the offline optimal algorithm
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