Search results for " estimation"
showing 10 items of 562 documents
Any AND-OR Formula of Size N Can Be Evaluated in Time $N^{1/2+o(1)}$ on a Quantum Computer
2007
Consider the problem of evaluating an AND-OR formula on an $N$-bit black-box input. We present a bounded-error quantum algorithm that solves this problem in time $N^{1/2+o(1)}$. In particular, approximately balanced formulas can be evaluated in $O(\sqrt{N})$ queries, which is optimal. The idea of the algorithm is to apply phase estimation to a discrete-time quantum walk on a weighted tree whose spectrum encodes the value of the formula.
Quantum Random Walks – New Method for Designing Quantum Algorithms
2008
Quantum walks are quantum counterparts of random walks. In the last 5 years, they have become one of main methods of designing quantum algorithms. Quantum walk based algorithms include element distinctness, spatial search, quantum speedup of Markov chains, evaluation of Boolean formulas and search on "glued trees" graph. In this talk, I will describe the quantum walk method for designing search algorithms and show several of its applications.
The Quest for available bandwidth measurement techniques for large-scale distributed systems
2009
In recent years the research community has developed many techniques to estimate the end-to-end available bandwidth of an Internet path. This important metric can be potentially exploited to optimize the performance of several distributed systems and, even, to improve the effectiveness of the congestion control mechanism of TCP. Thus, it has been suggested that some existing estimation techniques could be used for this purpose. However, existing tools were not designed for large-scale deployments and were mostly validated in controlled settings, considering only one measurement running at a time. In this paper, we argue that current tools, while offering good estimates when used alone, migh…
Results of a literature review on methods for estimating buildings energy demand at district level
2019
Abstract In the framework of distributed energy planning, evaluating reliable energy profiles of different sectors has a prominent role. At the same time, it is a quite challenging task, since the availability of actual energy profiles of buildings at the district level is not widespread. A survey of over 70 studies in scientific literature has been accomplished and a set of criteria has been defined for classifying the selected contributions based on the energy demand data features, source and/or estimation methods, highlighting the ones adopting hourly energy profiles. As final results, tables summarizing the main methods characteristics and a selection of studies providing directly useab…
Non-Contact Measurement of River Surface Velocity and Discharge Estimation with a Low-Cost Doppler Radar Sensor
2020
River discharge is an important variable to measure in order to predict droughts and flood occurrences. Once the cross-sectional geometry of the river is known, discharge can be inferred from water level and surface flow velocity measurements. Since river discharges are of particular interest during extreme weather events, when river sites cannot be safely accessed, noncontact sensing technologies are particularly appealing. To this purpose, this work proposes a prototype of a low-cost continuous wave (CW) Doppler radar sensor, which is able to monitor the surface flow velocity of rivers. The prototype is tested at two gauged sites in central Italy, along the Tiber River. The surface flow v…
One diode circuital model of light soaking phenomena in Dye-Sensitized Solar Cells
2018
Abstract In this work, we report on the modelling of light soaking effect on Ruthenium-based Dye Sensitized Solar cells (DSSCs). Such a phenomenon can be detected when exposing the cells at increasing hours of illumination and produces a reversible performance increase. Starting from the results obtained through the electro-optical characterization of the cells, we applied a one-diode circuital-model. Our results show a good agreement between the experimental and the simulated data, with a mean square error in the order of 10−12 and a maximum error in current lower than 0.6%. Finally such results allowed us to infer some precise trends followed by the cells main electrical parameters and of…
Feasibility of Linear Parametric Estimation of Dynamic Information Measures to assess Physiological Stress from Short-Term Cardiovascular Variability
2021
Extensive efforts have been recently devoted to implement fast and reliable algorithms capable of assessing the physiological response of the organism to physiological stress. In this study, we propose the comparison between model-free and linear parametric methods as regards their ability to detect alterations in the dynamics and in the complexity of cardiovascular and respiratory variability evoked by postural and mental stress. Dynamic entropy (DE) and information storage (IS) measures were calculated on three physiological time-series, i.e. heart period, respiratory volume and systolic arterial pressure, on 61 healthy subjects monitored in resting conditions as well as during head-up ti…
Problemas en la estimación y en el contraste de los rendimientos anormales a largo plazo: Estado de la cuestión
2002
-Jose.E.Farinos@uv.es -Ana.M.Ibanez@uv.es El paradigma de la eficiencia ha sido puesto en entredicho en las últimas décadas como consecuencia de la obtención de rendimientos anormales, estadística y económicamente significativos, durante amplios periodos de tiempo tras algunas importantes decisiones empresariales. No obstante, los problemas conceptuales y estadísticos que presenta la medición y contrastación de los rendimientos anormales a largo plazo ha supuesto que la evidencia obtenida pase a calificarse como anomalía. Dada la escasa proliferación de este tipo de estudios en nuestro mercado y el desafortunado desarrollo de algunos de los existentes, en este trabajo presentamos estos prob…
Climatic Characterization and Phenology of Local Peach Genotypes in the Udzungwa Uplands of Tanzania
2014
The phenology of two local peach genotypes was studied to verify whether peaches can be produced in the Tanzanian uplands. Observations were conducted on trees of one early- and one late-ripening peach genotype in 2010 and 2011. Temperature trends were reconstructed and three chilling estimation models were tested. The two peach genotypes differed for timing of flower and leaf bud-break. Common symptoms of insufficient chilling (presence of numerous stages at a specific date and about 20% of undeveloped flower buds) were observed in the late genotype. Both Utah and Dynamic models indicated low chilling accumulation, lower than the Mean Temperature model in most cases. This is inconsistent w…
Image is everything! Professional football players’ visibility and wages: evidence from the Italian Serie A
2021
Sport is one of the most popular forms of entertainment and its worldwide spread has turned athletes into icons who have economic impact and international visibility as global brands. In our paper we would like to show how marketing strategies in the sports industry, amplified by social networks, have put the athlete at the centre of media attention In the world of football, football players have come to play a key role, since their image is the face of their clubs, and this can affect the number of digital fans, that is, fans who are not bound to a club by constant passion but who can change team depending on the athletes that have been lined up. This could explain why the teams playing in…