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City University of New York (CUNY)

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2014

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Articles 1 - 30 of 61

Full-Text Articles in Physical Sciences and Mathematics

Nuclear Structure Aspects Of Neutrinoless Double Beta Decay, B. Alex Brown, Mihai Horoi, Roman A. Sen′Kov Dec 2014

Nuclear Structure Aspects Of Neutrinoless Double Beta Decay, B. Alex Brown, Mihai Horoi, Roman A. Sen′Kov

Publications and Research

We decompose the neutrinoless double-beta decay matrix elements into sums of products over the intermediate nucleus with two less nucleons. We find that the sum is dominated by the J^pi=0^+ ground state of this intermediate nucleus for both the light and heavy neutrino decay processes. This provides a new theoretical tool for comparing and improving nuclear structure models. It also provides the connection to two-nucleon transfer experiments.

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Dynamics Of Propagation Of Premature Impulses In Structurally Remodeled Infarcted Myocardium: A Computational Analysis, Candido Cabo Dec 2014

Dynamics Of Propagation Of Premature Impulses In Structurally Remodeled Infarcted Myocardium: A Computational Analysis, Candido Cabo

Publications and Research

Initiation of cardiac arrhythmias typically follows one or more premature impulses either occurring spontaneously or applied externally. In this study, we characterize the dynamics of propagation of single (S2) and double premature impulses (S3), and the mechanisms of block of premature impulses at structural heterogeneities caused by remodeling of gap junctional conductance (Gj) in infarcted myocardium. Using a sub-cellular computer model of infarcted tissue, we found that |INa,max|, prematurity (coupling interval with the previous impulse), and conduction velocity (CV) of premature impulses change dynamically as they propagate away from the site of initiation. There are fundamental differences between the dynamics …

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C-Metrics In Gauged Stu Supergravity And Beyond, H. Lu, Justin F. Vázquez-Poritz Dec 2014

C-Metrics In Gauged Stu Supergravity And Beyond, H. Lu, Justin F. Vázquez-Poritz

Publications and Research

We construct charged generalizations of the dilaton C-metric in various fourdimensional theories, including STU gauged supergravity as well as a one-parameter family of Einstein-Maxwell-dilaton theories whose scalar potential can be expressed in terms of a superpotential. In addition, we present time-dependent generalizations of the dilaton C-metric and dilaton Ernst solutions, for which the time evolution is driven by the dilaton. These C-metric solutions provide holographic descriptions of a strongly-coupled three-dimensional field theory on the background of a black hole, a gravitational soliton, and a black hole undergoing time evolution.

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A Partner-Matching Framework For Social Activity Communities, Chunyu Ai, Wei Zhong, Mingyuan Yan, Feng Gu Dec 2014

A Partner-Matching Framework For Social Activity Communities, Chunyu Ai, Wei Zhong, Mingyuan Yan, Feng Gu

Publications and Research

A lot of daily activities require more than one person to participate and collaborate with each other; however, for many people, it is not easy to find good partners to engage in activities with one another. With the rapid growth of social network applications, more and more people get used to creating connections with people on the social network. Therefore, designing social network framework for partner-matching is significant in helping people to easily find good partners. In this paper, we proposed a framework which can match partners for an active community. In order to improve the matching performance, all users …

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Performance Analysis Of A Hybrid Raman Optical Parametric Amplifier In The O- And E-Bands For Cwdm Pons, Sasanthi Peiris, Nicolas Madamopoulos, Neophytos A. Antoniades, Dwight Richards, Roger Dorsinville Dec 2014

Performance Analysis Of A Hybrid Raman Optical Parametric Amplifier In The O- And E-Bands For Cwdm Pons, Sasanthi Peiris, Nicolas Madamopoulos, Neophytos A. Antoniades, Dwight Richards, Roger Dorsinville

Publications and Research

We describe a hybrid Raman-optical parametric amplifier (HROPA) operating at the O- and E-bands and designed for coarse wavelength division multiplexed (CWDM) passive optical networks (PONs). We present the mathematical model and simulation results for the optimization of this HROPA design. Our analysis shows that separating the two amplification processes allows for optimization of each one separately, e.g., proper selection of pump optical powers and wavelengths to achieve maximum gain bandwidth and low gain ripple. Furthermore, we show that the proper design of optical filters incorporated in the HROPA architecture can suppress idlers generated during the OPA process, as well …

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Nnlo Hard Functions In Massless Qcd, Alessandro Broggio, Andrea Ferroglia, Ben D. Pecjak, Zhibai Zhang Dec 2014

Nnlo Hard Functions In Massless Qcd, Alessandro Broggio, Andrea Ferroglia, Ben D. Pecjak, Zhibai Zhang

Publications and Research

We derive the hard functions for all 2 → 2 processes in massless QCD up to next-to-next-to-leading order (NNLO) in the strong coupling constant. By employing the known one- and two-loop helicity amplitudes for these processes, we obtain analytic expressions for the ultraviolet and infrared finite, minimally subtracted hard functions, which are matrices in color space. These hard functions will be useful in carrying out higher-order resummations in processes such as dijet and highly energetic top-quark pair production by means of soft-collinear effective theory methods.

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Postmodern Fuzzy System Theory: A Deconstruction Approach Based On Kabbalah, Gabriel Burstein, Constantin Virgil Negoita, Menachem Kranz Nov 2014

Postmodern Fuzzy System Theory: A Deconstruction Approach Based On Kabbalah, Gabriel Burstein, Constantin Virgil Negoita, Menachem Kranz

Publications and Research

Modern general system theory proposed a holistic integrative approach based on input-state-output dynamics as opposed to the traditional reductionist detail based approach. Information complexity and uncertainty required a fuzzy system theory, based on fuzzy sets and fuzzy logic. While successful in dealing with analysis, synthesis and control of technical engineering systems, general system theory and fuzzy system theory could not fully deal with humanistic and human-like intelligent systems which combine technical engineering components with human or human-like components characterized by their cognitive, emotional/motivational and behavioral/action levels of operation. Such humanistic systems are essential in artificial intelligence, cognitive and behavioral science …

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Reduction Of The Long-Term Inaccuracy From The Avhrr–Based Ndvi Data, Md Zahidur Rahman, Leonid Roytman, M. Nazrul Islam Nov 2014

Reduction Of The Long-Term Inaccuracy From The Avhrr–Based Ndvi Data, Md Zahidur Rahman, Leonid Roytman, M. Nazrul Islam

Publications and Research

This paper investigated the normalized difference vegetation index (NDVI) stability in the NOAA/NESDIS Global Vegetation Index (GVI) data during 1982-2003, which was collected from five NOAA series satellites. An empirical distribution function (EDF) was developed to eliminate the long-term inaccuracy of the NDVI data derived from the AVHRR sensor on NOAA polar orbiting satellite. The instability of data results from orbit degradation as well as from the circuit drifts over the life of a satellite. Degradation of NDVI over time and shifts of NDVI between the satellites were estimated using the China data set, because it includes a wide variety …

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Remote Sensing And Ground-Based Weather Forcing Data Analysis For Streamflow Simulation, José Alberto Infante Corona, Tarendra Lakhankar, Soni M. Pradhanang, Reza Khanbilvardi Oct 2014

Remote Sensing And Ground-Based Weather Forcing Data Analysis For Streamflow Simulation, José Alberto Infante Corona, Tarendra Lakhankar, Soni M. Pradhanang, Reza Khanbilvardi

Publications and Research

Hydrological simulation, based on weather inputs and the physical characterization of the watershed, is a suitable approach to predict the corresponding streamflow. This work, carried out on four different watersheds, analyzed the impacts of using three different meteorological data inputs in the same model to compare the model’s accuracy when simulated and observed streamflow are compared. Meteorological data from the Daily Global Historical Climatology Network (GHCN-D), National Land Data Assimilation Systems (NLDAS) and the National Operation Hydrological Remote Sensing Center’s Interactive Snow Information (NOHRSC-ISI) were used as an input into the Soil and Water Assessment Tool (SWAT) hydrological model and …

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Near Horizon Geometry Of Strings Ending On Intersecting D8/D4-Branes, J. Estes, D. Krym, B. Van Pol Oct 2014

Near Horizon Geometry Of Strings Ending On Intersecting D8/D4-Branes, J. Estes, D. Krym, B. Van Pol

Publications and Research

We consider solutions of massive IIA supergravity corresponding to the half- BPS intersection of D8/D4-branes with fundamental strings. The 1 + 1-dimensional intersection preserves the symmetry D(2, 1; ; 1) × SO(4). We give a reduction and partial integration of the BPS equations for this symmetry group. We then specialize to the cases of enhanced supersymmetry corresponding to = −1/2,−2 or = 1. In the first case, we show that the only solution with enhanced symmetry is given by the AdS6 geometry describing the near horizon geometry of D8/D4-branes in the presence of an O8-plane. In the second case, we …

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Sedimentology Of The Upper Scotland Formation (Eocene), Barbados, Krishna Mahabir, Nazrul I. Khandaker, Jay P. Persaud, Stanley Schleifer Oct 2014

Sedimentology Of The Upper Scotland Formation (Eocene), Barbados, Krishna Mahabir, Nazrul I. Khandaker, Jay P. Persaud, Stanley Schleifer

Publications and Research

Representative samples collected from the Lower Scotland Formation (Eocene) outcropping in northeastern Barbados were investigated in conjunction with overall facies distribution and stratigraphic and sedimentological characteristics to interpret depositional environment and provenance of the fine-grained clastics. The Lower Scotland Formation is, for the most part, a fine-grained clastic-dominated sequence with occasional thin intercalations of gypsum, ironstone, and kaolinite. Distinctive deep-water-facies have been well-documented in dark gray shale units containing load cast, flutes, grooves and prods. In addition, turbiditic brown sandstone with a sharp erosive base and pelagic caps also characterize the base of the formation. Notable marine fauna observed include …

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End Of The Cosmic Neutrino Energy Spectrum, Luis A. Anchordoqui, V. Barger, H. Goldberg, J.G. Learned, D. Marfatia, S. Pakvasa, T. C. Paul, T. J. Weiler Oct 2014

End Of The Cosmic Neutrino Energy Spectrum, Luis A. Anchordoqui, V. Barger, H. Goldberg, J.G. Learned, D. Marfatia, S. Pakvasa, T. C. Paul, T. J. Weiler

Publications and Research

There may be a high-energy cutoff of neutrino events in IceCube data. In particular, IceCube does not observe either continuum events above 2PeV, or the Standard Model Glashow-resonance events expected at 6.3PeV. There are also no higher energy neutrino signatures in the ANITA and Auger experiments. This absence of high-energy neutrino events motivates a fundamental restriction on neutrino energies above a few PeV. We postulate a simple scenario to terminate the neutrino spectrum that is Lorentz-invariance violating, but with a limiting neutrino velocity that is always smaller than the speed of light. If the limiting velocity of the neutrino applies …

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Semi-Fredholm Solvability In The Framework Of Singular Solutions For The (3+1)-D Protter-Morawetz Problem, Nedyu Popivanov, Todor Popov, Allen Tesdall Oct 2014

Semi-Fredholm Solvability In The Framework Of Singular Solutions For The (3+1)-D Protter-Morawetz Problem, Nedyu Popivanov, Todor Popov, Allen Tesdall

Publications and Research

For the four-dimensional nonhomogeneous wave equation boundary value problems that are multidimensional analogues of Darboux problems in the plane are studied. It is known that for smooth right-hand side functions the unique generalized solution may have a strong power-type singularity at only one point. This singularity is isolated at the vertex �� of the boundary light characteristic cone and does not propagate along the bicharacteristics.The present paper describes asymptotic expansions of the generalized solutions in negative powers of the distance to ��. Some necessary and sufficient conditions for existence of bounded solutions are proven and additionally a priori estimates for …

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Effects Of Extreme Climate Events On Tea (Camellia Sinensis) Functional Quality Validate Indigenous Farmer Knowledge And Sensory Preferences In Tropical China, Selena Ahmed, John Richard Stepp, Colin M. Orians, Timothy S. Griffin, Corene Matyas, Albert Robbat, Sean Cash, Dayuan Xue, Chunlin Long, Uchenna Unachukwu, Sarabeth Buckley, Edward J. Kennelly Oct 2014

Effects Of Extreme Climate Events On Tea (Camellia Sinensis) Functional Quality Validate Indigenous Farmer Knowledge And Sensory Preferences In Tropical China, Selena Ahmed, John Richard Stepp, Colin M. Orians, Timothy S. Griffin, Corene Matyas, Albert Robbat, Sean Cash, Dayuan Xue, Chunlin Long, Uchenna Unachukwu, Sarabeth Buckley, Edward J. Kennelly

Publications and Research

Climate change is impacting agro-ecosystems, crops, and farmer livelihoods in communities worldwide. While it is well understood that more frequent and intense climate events in many areas are resulting in a decline in crop yields, the impact on crop quality is less acknowledged, yet it is critical for food systems that benefit both farmers and consumers through high-quality products. This study examines tea (Camellia sinensis; Theaceae), the world’s most widely consumed beverage after water, as a study system to measure effects of seasonal precipitation variability on crop functional quality and associated farmer knowledge, preferences, and livelihoods. Sampling was conducted in …

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Financial Literacy: An Essential Component Of Mathematics Literacy And Numeracy, Marla A. Sole Oct 2014

Financial Literacy: An Essential Component Of Mathematics Literacy And Numeracy, Marla A. Sole

Publications and Research

With rising personal and public debt, public and private employers increasingly shifting financial responsibility to individuals, and an increase in both the number of financial investment options and predatory lending practices, today’s students need to be financially literate. This paper defines financial literacy and justifies its place in the mathematics curriculum. After describing the gaps in young people’s understanding of financial literacy, which is more pronounced among women and minorities, this paper provides examples of financial literacy exercises. College students’ solutions demonstrated that the level of financial literacy is low. The majority of students were unfamiliar with financial principles and …

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Carbon Losses From Pyrolysed And Original Wood In A Forest Soil Under Natural And Increased N Deposition, B. Maestrini, S. Abiven, N. Singh, J. Bird, M. W. I. Schmidt Sep 2014

Carbon Losses From Pyrolysed And Original Wood In A Forest Soil Under Natural And Increased N Deposition, B. Maestrini, S. Abiven, N. Singh, J. Bird, M. W. I. Schmidt

Publications and Research

Pyrogenic organic matter (PyOM) plays an important role as a stable carbon (C) sink in the soils of terrestrial ecosystems. However, uncertainties remain about in situ turnover rates of fire-derived PyOM in soil, the main processes leading to PyOM-C and nitrogen (N) losses from the soil, and the role of N availability on PyOM cycling in soils. We measured PyOM and native soil organic carbon losses from the soil as carbon dioxide and dissolved organic carbon (DOC) using additions of highly 13C-labelled PyOM (2.03 atom %) and its precursor pinewood during 1 year in a temperate forest soil. The field …

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Finite N And The Failure Of Bulk Locality: Black Holes In Ads/Cft, Daniel N. Kabat, Gilad Lifschytz Sep 2014

Finite N And The Failure Of Bulk Locality: Black Holes In Ads/Cft, Daniel N. Kabat, Gilad Lifschytz

Publications and Research

We consider bulk quantum fields in AdS/CFT in the background of an eter- nal black hole. We show that for black holes with finite entropy, correlation functions of semiclassical bulk operators close to the horizon deviate from their semiclassical value and are ill-defined inside the horizon. This is due to the large-time behavior of correlators in a unitary CFT, and means the region near and inside the horizon receives corrections. We give a prescription for modifying the definition of a bulk field in a black hole background, such that one can still define operators that mimic the inside of the …

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Generalized Least-Squares Regressions Iv: Theory And Classification Using Generalized Means, Nataniel Greene Sep 2014

Generalized Least-Squares Regressions Iv: Theory And Classification Using Generalized Means, Nataniel Greene

Publications and Research

The theory of generalized least-squares is reformulated here using the notion of generalized means. The generalized least-squares problem seeks a line which minimizes the average generalized mean of the square deviations in x and y. The notion of a generalized mean is equivalent to the generating function concept of the previous papers but allows for a more robust understanding and has an already existing literature. Generalized means are applied to the task of constructing more examples, simplifying the theory, and further classifying generalized least-squares regressions.

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Peak Electric Load Relief In Northern Manhattan: An Exploratory Data Analysis, Hildegaard D. Link, José Pillich, Yehuda L. Klein Aug 2014

Peak Electric Load Relief In Northern Manhattan: An Exploratory Data Analysis, Hildegaard D. Link, José Pillich, Yehuda L. Klein

Publications and Research

The aphorism “Think globally, act locally,” attributed to René Dubos, reflects the vision that the solution to global environmental problems must begin with efforts within our communities. PlaNYC 2030, the New York City sustainability plan, is the starting point for this study. Results include (a) a case study based on the City College of New York (CCNY) energy audit, in which we model the impacts of green roofs on campus energy demand and (b) a case study of energy use at the neighborhood scale. We find that reducing the urban heat island effect can reduce building cooling requirements, peak electricity …

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Facile Synthesis Of 1-Alkoxy-1h-Benzo- And 7-Azabenzotriazoles From Peptide Coupling Agents, Mechanistic Studies, And Synthetic Applications, Mahesh K. Lakshman, Manish K. Singh, Mukesh Kumar, Raghu Ram Chamala, Vijayender R. Yedulla, Domenick Wagner, Evan Leung, Lijia Yang, Asha Matin, Sadia Ahmad Aug 2014

Facile Synthesis Of 1-Alkoxy-1h-Benzo- And 7-Azabenzotriazoles From Peptide Coupling Agents, Mechanistic Studies, And Synthetic Applications, Mahesh K. Lakshman, Manish K. Singh, Mukesh Kumar, Raghu Ram Chamala, Vijayender R. Yedulla, Domenick Wagner, Evan Leung, Lijia Yang, Asha Matin, Sadia Ahmad

Publications and Research

(1H-Benzo[d][1,2,3]triazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP), 1H-benzo[d][1,2,3]triazol-1-yl 4-methylbenzenesulfonate (Bt-OTs), and 3H-[1,2,3]triazolo[4,5-b]pyridine-3-yl 4-methylbenzenesulfonate (At-OTs) are classically utilized in peptide synthesis for amide-bond formation. However, a previously undescribed reaction of these compounds with alcohols in the presence of a base, leads to 1-alkoxy-1H-benzo- (Bt-OR) and 7-azabenzotriazoles (At-OR). Although BOP undergoes reactions with alcohols to furnish 1-alkoxy-1H-benzotriazoles, Bt-OTs proved to be superior. Both, primary and secondary alcohols undergo reaction under generally mild reaction conditions. Correspondingly, 1-alkoxy-1H-7-azabenzotriazoles were synthesized from At-OTs. Mechanistically, there are three pathways by which these peptide-coupling agents can react with alcohols. From 31P{1H}, [18O]-labeling, and other chemical experiments, phosphonium and tosylate derivatives of …

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Gosam-2.0: A Tool For Automated One-Loop Calculations Within Thestandard Model And Beyond, Gavin Cullen, Hans Van Deurzen, Nicolas Greiner, Gudrun Heinrich, Gionata Luisoni, Pierpaolo Mastrolia, Edoardo Mirabella, Giovanni Ossola, Tiziano Peraro, Johannes Schlenk, Johann Felix Von Soden-Fraunhofen, Francesco Tramontano Aug 2014

Gosam-2.0: A Tool For Automated One-Loop Calculations Within Thestandard Model And Beyond, Gavin Cullen, Hans Van Deurzen, Nicolas Greiner, Gudrun Heinrich, Gionata Luisoni, Pierpaolo Mastrolia, Edoardo Mirabella, Giovanni Ossola, Tiziano Peraro, Johannes Schlenk, Johann Felix Von Soden-Fraunhofen, Francesco Tramontano

Publications and Research

We present the version 2.0 of the program pack-ageGoSamfor the automated calculation of one-loop ampli-tudes.GoSamis devised to compute one-loop QCD and/orelectroweak corrections to multi-particle processes withinand beyond the Standard Model. The new code containsimprovements in the generation and in the reduction of theamplitudes, performs better in computing time and numer-ical accuracy, and has an extended range of applicability.The extended version of the “Binoth-Les-Houches-Accord”interface to Monte Carlo programs is also implemented. Wegive a detailed description of installation and usage of thecode, and illustrate the new features in dedicated examples.

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Wigner High-Electron-Correlation Regime Of Nonuniform Density Systems: A Quantal-Density-Functional-Theory Study, Douglas Achan, Lou Massa, Viraht Sahni Aug 2014

Wigner High-Electron-Correlation Regime Of Nonuniform Density Systems: A Quantal-Density-Functional-Theory Study, Douglas Achan, Lou Massa, Viraht Sahni

Publications and Research

The Wigner regime of a system of electrons in an external field is characterized by a low electron density and a high electron-interaction energy relative to the kinetic energy. The low-correlation regime is in turn described by a high electron density and an electron-interaction energy smaller than the kinetic energy. The Wigner regime of a nonuniform-electron-density system is investigated via quantal density functional theory (QDFT). Within QDFT, the contributions of electron correlations due to the Pauli exclusion principle, Coulomb repulsion, and correlation-kinetic effects are separately delineated and explicitly defined. The nonuniform-electron-density system studied is that of the Hooke's atom in …

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Decolorization Of Hair Dye By Lignocellulosic Waste Materials From Contaminated Waters, Habib Zahir, Michelle Naidoo, Rada-Mayya Kostadinova, Karla A. Ortiz, Rosario Sun-Kuo, Abel E. Navarro Jul 2014

Decolorization Of Hair Dye By Lignocellulosic Waste Materials From Contaminated Waters, Habib Zahir, Michelle Naidoo, Rada-Mayya Kostadinova, Karla A. Ortiz, Rosario Sun-Kuo, Abel E. Navarro

Publications and Research

Basic yellow 57 (BY57) was chosen as a model hair dye due to its prevalence in cosmetics wastewaters. This study proposes the use of lignocellulosic materials like spent tea leaves of peppermint (PM), chai tea (CT), and chamomile (CM) as raw adsorbents for the removal of BY57 from contaminated solutions. Batch adsorption experiments were carried out at room temperature to achieve the maximum adsorption capacity. Results indicate that the highest removal is achieved at pH 6–8, with a minimum adsorbent mass of 75 mg and in the absence of salinity, crowding agents and heavy metals. Adsorption equilibria were modeled according …

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On The Effects Of Competition Between Agent-Based Double Auction Markets, Kai Cai, Jinzhong Niu, Simon Parsons Jul 2014

On The Effects Of Competition Between Agent-Based Double Auction Markets, Kai Cai, Jinzhong Niu, Simon Parsons

Publications and Research

Real market institutions, stock and commodity exchanges for example, do not occur in isolation. The same stocks and commodities may be listed on multiple exchanges, and traders who want to deal in those goods have a choice of markets in which to trade. While there has been extensive research into agent-based trading in individual markets, there is little work on this kind of multiple market scenario. Our work seeks to address this imbalance, examining how standard economic measures, like allocative efficiency, are affected by the presence of multiple markets for the same good. We find that while dividing traders between …

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Looking For Cosmic Neutrino Background, Chiaki Yanagisawa Jun 2014

Looking For Cosmic Neutrino Background, Chiaki Yanagisawa

Publications and Research

Since the discovery of neutrino oscillation in atmospheric neutrinos by the Super-Kamiokande experiment in 1998, study of neutrinos has been one of exciting fields in high-energy physics. All the mixing angles were measured. Quests for (1) measurements of the remaining parameters, the lightest neutrino mass, the CP violating phase(s), and the sign of mass splitting between the mass eigenstates m3 and m1, and (2) better measurements to determine whether the mixing angle θ23 is less than π/4, are in progress in a well-controlled manner. Determining the nature of neutrinos, whether they are Dirac or Majorana particles …

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Data-Based Perfect-Deficit Approach To Understanding Climate Extremes And Forest Carbon Assimilation Capacity, Suhua Wei, Chuixiang Yi, George Hendrey, Timothy Eaton, Gerald Rustic, Shaoqiang Wang, Heping Liu, Nir Y. Krakauer, Weiguo Wang, Ankur R. Desai, Leonardo Montagnani, Kyaw Tha Paw U, Matthias Falk, Andrew Black, Christian Bernhofer, Thomas Grünwald, Tuomas Laurila, Alessandro Cescatti, Eddy Moors, Rosvel Bracho, Riccardo Valentini Jun 2014

Data-Based Perfect-Deficit Approach To Understanding Climate Extremes And Forest Carbon Assimilation Capacity, Suhua Wei, Chuixiang Yi, George Hendrey, Timothy Eaton, Gerald Rustic, Shaoqiang Wang, Heping Liu, Nir Y. Krakauer, Weiguo Wang, Ankur R. Desai, Leonardo Montagnani, Kyaw Tha Paw U, Matthias Falk, Andrew Black, Christian Bernhofer, Thomas Grünwald, Tuomas Laurila, Alessandro Cescatti, Eddy Moors, Rosvel Bracho, Riccardo Valentini

Publications and Research

Several lines of evidence suggest that the warming climate plays a vital role in driving certain types of extreme weather. The impact of warming and of extreme weather on forest carbon assimilation capacity is poorly known. Filling this knowledge gap is critical towards understanding the amount of carbon that forests can hold. Here, we used a perfect-deficit approach to identify forest canopy photosynthetic capacity (CPC) deficits and analyze how they correlate to climate extremes, based on observational data measured by the eddy covariance method at 27 forest sites over 146 site-years. We found that droughts severely affect the carbon assimilation …

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China’S Water Sustainability In The 21st Century: A Climate-Informed Water Risk Assessment Covering Multi-Sector Water Demands, X. Chen, Naresh Devineni, L. Upmanu, Z. Hao, L. Dong, Q. Ju, J. Wang, S. Wang May 2014

China’S Water Sustainability In The 21st Century: A Climate-Informed Water Risk Assessment Covering Multi-Sector Water Demands, X. Chen, Naresh Devineni, L. Upmanu, Z. Hao, L. Dong, Q. Ju, J. Wang, S. Wang

Publications and Research

China is facing a water resources crisis with growing concerns as to the reliable supply of water for agricultural, industrial and domestic needs. High inter-annual rainfall variability and increasing consumptive use across the country exacerbates the situation further and is a constraint on future development. For water sustainability, it is necessary to examine the differences in water demand and supply and their spatio-temporal distribution in order to quantify the dimensions of the water risk. Here, a detailed quantitative assessment of water risk as measured by the spatial distribution of cumulated deficits for China is presented. Considering daily precipitation and temperature …

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Intelligent Sampling For Big Data Using Bootstrap Sampling And Chebyshev Inequality, Ashwin Satyanarayana May 2014

Intelligent Sampling For Big Data Using Bootstrap Sampling And Chebyshev Inequality, Ashwin Satyanarayana

Publications and Research

The amount of data being generated and stored is growing exponentially, owed in part to the continuing advances in computer technology. These data present tremendous opportunities in data mining, a burgeoning field in computer science that focuses on the development of methods that can extract knowledge from data. In many real world problems, these data mining algorithms have access to massive amounts of data. Mining all the available data is prohibitive due to computational (time and memory) constraints. Much of the current research is concerned with scaling up data mining algorithms (i.e. improving on existing data mining algorithms for larger …

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Multi-Leg One-Loop Massive Amplitudes From Integrand Reduction Via Laurent Expansion, Hans Van Deurzen, Gionata Luisoni, Pierpaolo Mastrolia, Edoardo Mirabella, Giovanni Ossola, Tiziano Peraro Mar 2014

Multi-Leg One-Loop Massive Amplitudes From Integrand Reduction Via Laurent Expansion, Hans Van Deurzen, Gionata Luisoni, Pierpaolo Mastrolia, Edoardo Mirabella, Giovanni Ossola, Tiziano Peraro

Publications and Research

We present the application of a novel reduction technique for one-loop scattering amplitudes based on the combination of the integrand reduction and Laurent expansion. We describe the general features of its implementation in the computer code Ninja, and its interface to GoSam. We apply the new reduction to a series of selected processes involving massive particles, from six to eight legs.

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Uranium And Radon In Private Bedrock Well Water In Maine: Geospatial Analysis At Two Scales, Qiang Yang, Paul Smitherman, C. T. Hess, Charles W. Culbertson, Robert G. Marvinney, Andrew E. Smith, Yan Zheng Mar 2014

Uranium And Radon In Private Bedrock Well Water In Maine: Geospatial Analysis At Two Scales, Qiang Yang, Paul Smitherman, C. T. Hess, Charles W. Culbertson, Robert G. Marvinney, Andrew E. Smith, Yan Zheng

Publications and Research

In greater Augusta of central Maine, 53 out of 1093 (4.8%) private bedrock well water samples from 1534 km2 contained [U] >30 μg/L, the U.S. Environmental Protection Agency’s (EPA) Maximum Contaminant Level (MCL) for drinking water; and 226 out of 786 (29%) samples from 1135 km2 showed [Rn] >4,000 pCi/L (148 Bq/L), the U.S. EPA’s Alternative MCL. Groundwater pH, calcite dissolution and redox condition are factors controlling the distribution of groundwater U but not Rn due to their divergent chemical and hydrological properties. Groundwater U is associated with incompatible elements (S, As, Mo, F, and Cs) in water samples within …

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