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Articles 1 - 30 of 72326

Full-Text Articles in Physical Sciences and Mathematics

An Optimal Threshold Strategy In The Two-Envelope Problem With Partial Information, Martin Egozcue, Luis Fuentes García Oct 2015

An Optimal Threshold Strategy In The Two-Envelope Problem With Partial Information, Martin Egozcue, Luis Fuentes García

Martin Egozcue

No abstract provided.


A Right To Cyber Counter Strikes - The Risks Of Legalizing Hack Back, Jan Kallberg Apr 2015

A Right To Cyber Counter Strikes - The Risks Of Legalizing Hack Back, Jan Kallberg

Jan Kallberg

The idea to legalize hacking back has gained traction the last years and received several influential corporate and political proponents in the United States and Europe. The growing frustration with repeated cyberattacks and lack of credible law enforcement pushes for alternative ways to prevent future cyberattacks. As of today, counter cyberattacks are illegal in a majority of the nations because it constitutes another cybercrime independent from the initial attack. If cyber counter attacks were legalized it raises a set of questions. The first line of questions are linked to the underlying assumptions that the proposal to legalize counter cyberattacks are ...


A Comparative Study Of The Oxidation Characteristics Of Two Gasoline Fuels And An N-Heptane/Iso-Octane Surrogate Mixture, Tamour Javed, Ehson F. Nasir, Et-Touhami Es-Sebbar, Aamir Farooq Jan 2015

A Comparative Study Of The Oxidation Characteristics Of Two Gasoline Fuels And An N-Heptane/Iso-Octane Surrogate Mixture, Tamour Javed, Ehson F. Nasir, Et-Touhami Es-Sebbar, Aamir Farooq

Dr. Et-touhami Es-sebbar

Ignition delay times and CO, H2O, OH and CO2 time-histories were measured behind reflected shock waves for two FACE (Fuels for Advanced Combustion Engines) gasolines and one PRF (Primary Reference Fuel) blend. The FACE gasolines chosen for this work are primarily paraffinic and have the same octane rating (∼RON = 84) as the PRF blend, but contain varying amounts of iso- and n-paraffins. Species time-histories and ignition delay times were measured using laser absorption methods over a temperature range of 1350–1550 K and pressures near 2 atm. Measured species time-histories and ignition delay times of the PRF blend and the ...


Alignment Of The Western And Eastern Passage Tombs At Knowth Tomb 1, Frank Prendergast, Tom Ray Jan 2015

Alignment Of The Western And Eastern Passage Tombs At Knowth Tomb 1, Frank Prendergast, Tom Ray

Book/Book Chapter

This report presents a summary account of two surveys undertaken by the authors to determine and interpret the alignments of the western and eastern passage tombs at Knowth, Co. Meath. The findings indicate that contrary to earlier suggestions, the eastern passage and the western passage (inner and outer) are not aligned towards sunrise and sunset respectively at the period of the vernal and autumnal equinoxes.


Functional Regression, Jeffrey S. Morris Jan 2015

Functional Regression, Jeffrey S. Morris

Jeffrey S. Morris

Functional data analysis (FDA) involves the analysis of data whose ideal units of observation are functions defined on some continuous domain, and the observed data consist of a sample of functions taken from some population, sampled on a discrete grid. Ramsay and Silverman's 1997 textbook sparked the development of this field, which has accelerated in the past 10 years to become one of the fastest growing areas of statistics, fueled by the growing number of applications yielding this type of data. One unique characteristic of FDA is the need to combine information both across and within functions, which Ramsay ...


Matlab Programs, David D. Nolte Jan 2015

Matlab Programs, David D. Nolte

David D Nolte

No abstract provided.


Appendix, David D. Nolte Jan 2015

Appendix, David D. Nolte

David D Nolte

No abstract provided.


Joint Search By Social And Spatial Proximity, Kyriakos Mouratidis, Jing Li, Yu Tang, Nikos Mamoulis Jan 2015

Joint Search By Social And Spatial Proximity, Kyriakos Mouratidis, Jing Li, Yu Tang, Nikos Mamoulis

Research Collection School Of Information Systems

The diffusion of social networks introduces new challenges and opportunities for advanced services, especially so with their ongoing addition of location-based features. We show how applications like company and friend recommendation could significantly benefit from incorporating social and spatial proximity, and study a query type that captures these two-fold semantics. We develop highly scalable algorithms for its processing, and enhance them with elaborate optimizations. Finally, we use real social network data to empirically verify the efficiency and efficacy of our solutions.


Notes And Errata, David D. Nolte Jan 2015

Notes And Errata, David D. Nolte

David D Nolte

No abstract provided.


Automated Detection Of Puffing And Smoking With Wrist Accelerometers, Qu Tang Jan 2015

Automated Detection Of Puffing And Smoking With Wrist Accelerometers, Qu Tang

Electrical and Computer Engineering Master's Theses

Real-time, automatic detection of smoking behavior could lead to novel measurement tools for smoking research and "just-in-time" interventions that may help people quit, reducing preventable deaths. This paper discusses the use of machine learning with wrist accelerometer data for automatic puffing and smoking detection. A two-layer smoking detection model is proposed that incorporates both low-level time domain features and high-level smoking topography such as inter-puff intervals and puff frequency to detect puffing then smoking. On a pilot dataset of 6 individuals observed for 11.8 total hours in real-life settings performing complex tasks while smoking, the model obtains a cross ...


Resource Management In Enterprise Cluster And Storage Systems, Jianzhe Tai Jan 2015

Resource Management In Enterprise Cluster And Storage Systems, Jianzhe Tai

Computer Engineering Dissertations

In this thesis, we present our works on resource management in large scale systems, especially for enterprise cluster and storage systems. Large-scale cluster systems become quite popular among a community of users by offering a variety of resources. Such systems require complex resource management schemes for multi-objective optimizations and should be specific to different system requirements. In addition, burstiness has often been found in enterprise workloads, being a key factor in performance degradation. Therefore, it is an extremely challenging problem of managing heterogeneous resources (e.g., computing, networking and storage) for such a large scale system under bursty conditions while ...


Application Of Colloidal Gas Aphron Suspensions Produced From Sapindus Mukorossi For Arsenic Removal From Contaminated Soil, Soumyadeep Mukhopadhyay Dr Jan 2015

Application Of Colloidal Gas Aphron Suspensions Produced From Sapindus Mukorossi For Arsenic Removal From Contaminated Soil, Soumyadeep Mukhopadhyay Dr

Soumyadeep Mukhopadhyay Dr

Colloidal gas aphron dispersions (CGAs) can be described as a system of microbubbles suspended homogenously in a liquid matrix. This work examines the performance of CGAs in comparison to surfactant solutions for washing low levels of arsenic from an iron rich soil. Sodium Dodecyl Sulfate (SDS) and saponin, a biodegradable surfactant, obtained from Sapindus mukorossi or soapnut fruit were used for generating CGAs and solutions for soil washing. Column washing experiments were performed in down-flow and up flow modes at a soil pH of 5 and 6 using varying concentration of SDS and soapnut solutions as well as CGAs. Soapnut ...


An Algebra Unit On Quadratics For Teachers With Students With Ebd, Christopher Williams Dec 2014

An Algebra Unit On Quadratics For Teachers With Students With Ebd, Christopher Williams

Education and Human Development Master's Theses

The number of students identified as having an emotional and behavioral disorder (EBD) are increasing rapidly and still underreported. These students often have significant behavioral, social and academic deficits that pose challenges within and outside the school setting and are among some of the most difficult students to teach with the bleakest post-school success or employment rates. Research reveals several effective procedures for conducting interventions to increase performance, participation and engagement and in lowering the number of inappropriate behavior occurrences within the classroom. Based on these findings, an algebra unit plan on quadratics has been developed to assist and direct ...


Trophic Status Of Conesus Lake 2014: Long-Term Trends In Lake Chemistry And The Plankton Community, Joseph C. Makarewicz, Theodore W. Lewis Dec 2014

Trophic Status Of Conesus Lake 2014: Long-Term Trends In Lake Chemistry And The Plankton Community, Joseph C. Makarewicz, Theodore W. Lewis

Technical Reports

Conesus Lake, considered a eutrophic lake in the late 1960s (Mills, 1975) and one of the smaller of the Finger Lakes of western New York, is used for recreation and fishing and is a source of municipal water for several local communities. The shoreline area is densely populated with residences, primarily year-round homes. The upstream area is a mixture of agricultural land and mixed deciduous hardwood forests encompassing an area of 16,714 ha. In 1999 about half of the entire land use within the Conesus Lake watershed was and continues to be in agriculture. Much of the agriculture (~70 ...


Turbidity-Based Sediment Monitoring In Northern Thailand: Hysteresis, Variability, And Uncertainty, Shawn G. Benner, Spencer H. Wood Nov 2014

Turbidity-Based Sediment Monitoring In Northern Thailand: Hysteresis, Variability, And Uncertainty, Shawn G. Benner, Spencer H. Wood

Geosciences Faculty Publications and Presentations

Annual total suspended solid (TSS) loads in the Mae Sa River in northern Thailand, determined with an automated, turbidity-based monitoring approach, were approximately 62,000, 33,000, and 14,000 Mg during the three years of observation. These loads were equivalent to basin yields of 839 (603-1170), 445 (217-462), and 192 (108-222) Mg km-2 for the 74.16-km2 catchment during 2006, 2007, and 2008, respectively. The yearly uncertainty ranges indicate our loads may be underestimated by 38-43% or overestimated by 28-33%. In determining the annual loads, discharge (Q) and turbidity (T) values were compared against 333 hand-sampled total ...


Modeling Count Data; Errata And Comments, Joseph M. Hilbe Nov 2014

Modeling Count Data; Errata And Comments, Joseph M. Hilbe

Joseph M Hilbe

Modeling Count Data: Errata and Comments PDF. Will be updated on a continuing basis.


Mdc-R-Code, Joseph M. Hilbe Nov 2014

Mdc-R-Code, Joseph M. Hilbe

Joseph M Hilbe

Modeling Count Data: R code for download and use.


Mdc-R-Code, Joseph M. Hilbe Nov 2014

Mdc-R-Code, Joseph M. Hilbe

Joseph M Hilbe

Modeling Count Data: R code in book provided for use


Range Of Horizontal Transport And Residence Time Of Nitrate In A Mature Karst Vadose Zone, Jiri Kamas, Jiri Bruthans, Helena Vysoka, Miroslav Kovařík Nov 2014

Range Of Horizontal Transport And Residence Time Of Nitrate In A Mature Karst Vadose Zone, Jiri Kamas, Jiri Bruthans, Helena Vysoka, Miroslav Kovařík

International Journal of Speleology

Nitrate concentrations in drips in Amaterska, Spolecnak, and Holstejnska caves situated below a 25 to 120 m thick vadose zone in the Moravian Karst, Central Europe were studied during several periods from 1992. Each cave runs below a land-use boundary between fertilized lands and forest, which enabled study of the range of horizontal components of nitrate transport in the vadose zone. Parts of the fertilized land were turned into grassland in 1998 and 2003, and the cave drips were sampled both prior and after the changes in land use. The mean residence time of nitrate is - 30 m thick vadose ...


Hairy Stalagmites, A New Biogenic Root Speleothem From Botswana, Gerhard C. Du Preez, Paolo Forti, Gerhard Jacobs, Anine Jordaan, Louwrens Tiedt Nov 2014

Hairy Stalagmites, A New Biogenic Root Speleothem From Botswana, Gerhard C. Du Preez, Paolo Forti, Gerhard Jacobs, Anine Jordaan, Louwrens Tiedt

International Journal of Speleology

Ngamiland in northwestern Botswana hosts the Gcwihaba Caves which present unique subterranean environments and host speleothems never before recorded. Cave atmospheric conditions can be extreme with temperatures as high as 28°C and relative humidity nearing 99.9%. Within Dimapo and Diviner’s Caves peculiar root speleothems that we named ‘Hairy Stalagmites’ were found. These stalagmites are closely associated with the roots of Namaqua fig (Ficus cordata) trees that enter the cave environment in search of water. Pieces of broken stalagmites were sampled from Dimapo Cave for further investigations. Stereo and electron microscopy revealed that the Hairy Stalagmites consist of ...


High-Resolution Digital 3d Models Of Algar Do Penico Chamber: Limitations, Challenges, And Potential, Ivo Silvestre M.Sc., José I. Rodrigues Phd, Mauro Figueiredo Phd, Cristina Veiga-Pires Phd Nov 2014

High-Resolution Digital 3d Models Of Algar Do Penico Chamber: Limitations, Challenges, And Potential, Ivo Silvestre M.Sc., José I. Rodrigues Phd, Mauro Figueiredo Phd, Cristina Veiga-Pires Phd

International Journal of Speleology

The study of karst and its geomorphological structures is important for understanding the relationships between hydrology and climate over geological time. In that context, we conducted a terrestrial laser-scan survey to map geomorphological structures in the karst cave of Algar do Penico in southern Portugal. The point cloud data set obtained was used to generate 3D meshes with different levels of detail, allowing the limitations of mapping capabilities to be explored.

In addition to cave mapping, the study focuses on 3D-mesh analysis, including the development of two algorithms for determination of stalactite extremities and contour lines, and on the interactive ...


Making Water Resource Decisions More "Informationally" Efficient: Development Of A Geospatial Water Rights Decision Support System For Kittitas County, Washington, Michael Pease, Jeremy Murray Nov 2014

Making Water Resource Decisions More "Informationally" Efficient: Development Of A Geospatial Water Rights Decision Support System For Kittitas County, Washington, Michael Pease, Jeremy Murray

International Journal of Geospatial and Environmental Research

In semi-arid river basins like the Yakima River Basin in central Washington State, United States of America, water demand can exceed available supply on an annual basis. More informed decisions about water supply and current allocation have the potential to improve water management. This research created a geospatial water rights database for the Yakima River Basin. The creation of a publicly available decision support system mapping water rights can provide water managers another tool to help achieve this goal. This paper describes the creation of the Decision Support System. In addition it looks at the current utility of the system ...


On The Restricted Mean Survival Time Curve Survival Analysis, Lihui Zhao, Brian Claggett, Lu Tian, Hajime Uno, Marc A. Pfeffer, Scott D. Solomon, Lorenzo Trippa, L. J. Wei Nov 2014

On The Restricted Mean Survival Time Curve Survival Analysis, Lihui Zhao, Brian Claggett, Lu Tian, Hajime Uno, Marc A. Pfeffer, Scott D. Solomon, Lorenzo Trippa, L. J. Wei

Harvard University Biostatistics Working Paper Series

No abstract provided.


Quantifying An Adherence Path-Specific Effect Of Antiretroviral Therapy In The Nigeria Pepfar Program, Caleb Miles, Ilya Shpitser, Phyllis Kanki, Seema Meloni, Eric J. Tchetgen Tchetgen Nov 2014

Quantifying An Adherence Path-Specific Effect Of Antiretroviral Therapy In The Nigeria Pepfar Program, Caleb Miles, Ilya Shpitser, Phyllis Kanki, Seema Meloni, Eric J. Tchetgen Tchetgen

Harvard University Biostatistics Working Paper Series

No abstract provided.


Can Xrf Scanning Of Speleothems Be Used As A Non-Destructive Method To Identify Paleoflood Events In Caves?, Martin Finné, Malin Kylander, Meighan Boyd, Hanna S. Sundqvist, Ludvig Löwemark Nov 2014

Can Xrf Scanning Of Speleothems Be Used As A Non-Destructive Method To Identify Paleoflood Events In Caves?, Martin Finné, Malin Kylander, Meighan Boyd, Hanna S. Sundqvist, Ludvig Löwemark

International Journal of Speleology

We have developed a novel, quick and non-destructive method for tracing flood events in caves through the analysis of a stalagmite thick section with an XRF core scanner. The analyzed stalagmite has multiple horizons of fine sediments from past flood events intercalated with areas of cleaner calcite. Flood events detected from the elemental XRF core scanning data show good agreement with the position of flood horizons identified in petrographic thin sections. The geochemical composition of the individual flood layers shows that in certain cases the clay horizons had a distinct geochemical fingerprint suggesting that it may be possible to distinguish ...


Microstratigraphic Logging Of Calcite Fabrics In Speleothems As Tool For Palaeoclimate Studies, Silvia Frisia Nov 2014

Microstratigraphic Logging Of Calcite Fabrics In Speleothems As Tool For Palaeoclimate Studies, Silvia Frisia

International Journal of Speleology

The systematic documentation of calcite fabrics in stalagmites and flowstones provides robustness to palaeoclimate interpretation based on geochemical proxies, but it has been neglected because it is difficult to transform crystal morphologies into numerical values, and construct fabric time series. Here, general criteria that allow for coding fabrics of calcite composing stalagmites and flowstones is provided. Being based on known models of fabric development, the coding ascribes sequential numbers to each fabric, which reflect climate-related parameters, such as changes in drip rate variability, bio-mediation or diagenetic modifications. Acronyms are proposed for Columnar types, Dendritic, Micrite, Microsparite and Mosaic fabrics, whose ...


Top Of The Order: Modeling The Optimal Locations Of Minor League Baseball Teams, W. Coleman Conley Nov 2014

Top Of The Order: Modeling The Optimal Locations Of Minor League Baseball Teams, W. Coleman Conley

Undergraduate Economic Review

Over the last twenty-five years, minor league baseball franchises have defined firm mobility. Revisiting the work of Michael C. Davis (2006), I construct a logistic regression model to predict which cities house minor league baseball teams. Six variables are tested for inclusion in the model, including population, income level, the number of major-league professional sports teams in a city, five-year population change, and distance from the closest professional team. Based on the model's predicted probabilities, cities are ranked in order of highest probability of having a team at each of the different levels from Class A to Class AAA.


The Critical Role Of Cubesat Spacecraft In A Multi-Tier Mission For Mars Exploration, Jeremy Straub Nov 2014

The Critical Role Of Cubesat Spacecraft In A Multi-Tier Mission For Mars Exploration, Jeremy Straub

Jeremy Straub

A multi-tier architecture is under development (with similar craft heterogeneity to Fink's work on ‘tier scalable’ missions) which will facilitate autonomous local control of multiple heterogeneous craft. This mission architecture has been developed with a Mars mission in mind and has included CubeSats in a variety of critical mission roles.

Two concepts will be presented: the addition of CubeSats to a larger-scale multi-tier mission, where the CubeSats serve a supporting role and a mission driven by CubeSat orbital capabilities. In the first, CubeSats are utilized to augment the area of spatial coverage that can be obtained and the temporal ...


Negative Binomial Regerssion, 2nd Ed, 2nd Print, Errata And Comments, Joseph Hilbe Nov 2014

Negative Binomial Regerssion, 2nd Ed, 2nd Print, Errata And Comments, Joseph Hilbe

Joseph M Hilbe

Errata and Comments for 2nd printing of NBR2, 2nd edition. Previous errata from first printing all corrected. Some added and new text as well.


Constrained Bayesian Estimation Of Inverse Probability Weights For Nonmonotone Missing Data, Baoluo Sun, Eric J. Tchetgen Tchetgen Nov 2014

Constrained Bayesian Estimation Of Inverse Probability Weights For Nonmonotone Missing Data, Baoluo Sun, Eric J. Tchetgen Tchetgen

Harvard University Biostatistics Working Paper Series

No abstract provided.