4,974 research outputs found
A Search for Higgs Boson in
A search for the Higgs boson decaying to has been performed on
fb of pp collision data at TeV collected with the
Compact Muon Solenoid (CMS) detector in 2011. No significant excess above
Standard Model background expectation is observed, and upper limits on Higgs
boson cross section production are derived, excluding the presence of a Higgs
boson with mass in the range of GeV at 95% confidence
level.Comment: DPF 2011 Conference Proceeding
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A Literature Review of Implementing Response to Intervention for English Language Learners
Response to intervention (RTI) has actively been used for identifying reading difficulties and providing supplemental instructions for students with disabilities. Recent developments of RTI show that the method expands its applicability to other areas and populations. In particular, it is difficult to distinguish learning disability (LD) from English as a second language acquisition. RTI could successfully be implemented for English language learners (ELLs). A systematic literature review has been conducted to delineate various components, strategies, and implications of RTI for ELL students. Twenty six articles that meet the criteria are analyzed for themes and important findings. The result of the literature review along with the implications of the identified studies is reported. It is identified that direct instruction used in tier 2 is an effective technique when infusing linguistic and cultural aspects of ELL with diverse needs
Implementing implicit OpenMP data sharing on GPUs
OpenMP is a shared memory programming model which supports the offloading of
target regions to accelerators such as NVIDIA GPUs. The implementation in
Clang/LLVM aims to deliver a generic GPU compilation toolchain that supports
both the native CUDA C/C++ and the OpenMP device offloading models. There are
situations where the semantics of OpenMP and those of CUDA diverge. One such
example is the policy for implicitly handling local variables. In CUDA, local
variables are implicitly mapped to thread local memory and thus become private
to a CUDA thread. In OpenMP, due to semantics that allow the nesting of regions
executed by different numbers of threads, variables need to be implicitly
\emph{shared} among the threads of a contention group. In this paper we
introduce a re-design of the OpenMP device data sharing infrastructure that is
responsible for the implicit sharing of local variables in the Clang/LLVM
toolchain. We introduce a new data sharing infrastructure that lowers
implicitly shared variables to the shared memory of the GPU. We measure the
amount of shared memory used by our scheme in cases that involve scalar
variables and statically allocated arrays. The evaluation is carried out by
offloading to K40 and P100 NVIDIA GPUs. For scalar variables the pressure on
shared memory is relatively low, under 26\% of shared memory utilization for
the K40, and does not negatively impact occupancy. The limiting occupancy
factor in that case is register pressure. The data sharing scheme offers the
users a simple memory model for controlling the implicit allocation of device
shared memory
Combustion of the butanol isomers: reaction pathways at elevated pressures from low-to-high temperatures
NASA Marshall Space Flight Center Tri-gas Thruster Performance Characterization
Historically, spacecraft reaction control systems have primarily utilized cold gas thrusters because of their inherent simplicity and reliability. However, cold gas thrusters typically have a low specific impulse. It has been determined that a higher specific impulse can be achieved by passing a monopropellant fluid mixture through a catalyst bed prior to expulsion through the thruster nozzle. This research analyzes the potential efficiency improvements from using tri-gas, a mixture of hydrogen, oxygen, and an inert gas, which in this case is helium. Passing tri-gas through a catalyst causes the hydrogen and oxygen to react and form water vapor, ultimately heating the exiting fluid and generating a higher specific impulse. The goal of this project was to optimize the thruster performance by characterizing the effects of varying several system components including catalyst types, catalyst lengths, and initial catalyst temperatures
Simplified three-dimensional tissue clearing and incorporation of colorimetric phenotyping.
Tissue clearing methods promise to provide exquisite three-dimensional imaging information; however, there is a need for simplified methods for lower resource settings and for non-fluorescence based phenotyping to enable light microscopic imaging modalities. Here we describe the simplified CLARITY method (SCM) for tissue clearing that preserves epitopes of interest. We imaged the resulting tissues using light sheet microscopy to generate rapid 3D reconstructions of entire tissues and organs. In addition, to enable clearing and 3D tissue imaging with light microscopy methods, we developed a colorimetric, non-fluorescent method for specifically labeling cleared tissues based on horseradish peroxidase conversion of diaminobenzidine to a colored insoluble product. The methods we describe here are portable and can be accomplished at low cost, and can allow light microscopic imaging of cleared tissues, thus enabling tissue clearing and imaging in a wide variety of settings
Towards the First Practical Applications of Quantum Computers
Noisy intermediate-scale quantum (NISQ) computers are coming online. The lack of error-correction in these devices prevents them from realizing the full potential of fault-tolerant quantum computation, a technology that is known to have significant practical applications, but which is years, if not decades, away. A major open question is whether NISQ devices will have practical applications.
In this thesis, we explore and implement proposals for using NISQ devices to achieve practical applications. In particular, we develop and execute variational quantum algorithms for solving problems in combinatorial optimization and quantum chemistry. We also execute a prototype of a protocol for generating certified random numbers. We perform our experiments on a superconducting qubit processor developed at Google. While we do not perform any quantum computations that are beyond the capabilities of classical computers, we address many implementation challenges that must be overcome to succeed in such an endeavor, including optimization, efficient compilation, and error mitigation. In addressing these challenges, we push the limits of what can currently be done with NISQ technology, going beyond previous quantum computing demonstrations in terms of the scale of our experiments and the types of problems we tackle. While our experiments demonstrate progress in the utilization of quantum computers, the limits that we reached underscore the fundamental challenges in scaling up towards the classically intractable regime. Nevertheless, our results are a promising indication that NISQ devices may indeed deliver practical applications.PHDComputer Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/163016/1/kevjsung_1.pd
Cross-National Differences in Victimization : Disentangling the Impact of Composition and Context
Varying rates of criminal victimization across countries are assumed to be the outcome of countrylevel structural constraints that determine the supply ofmotivated o¡enders, as well as the differential composition within countries of suitable targets and capable guardianship. However, previous empirical tests of these ‘compositional’ and ‘contextual’ explanations of cross-national di¡erences
have been performed upon macro-level crime data due to the unavailability of comparable individual-level data across countries. This limitation has had two important consequences for cross-national crime research. First, micro-/meso-level mechanisms underlying cross-national differences cannot be truly inferred from macro-level data. Secondly, the e¡ects of contextual measures (e.g. income inequality) on crime are uncontrolled for compositional heterogeneity. In this
paper, these limitations are overcome by analysing individual-level victimization data across 18 countries from the International CrimeVictims Survey. Results from multi-level analyses on theft and violent victimization indicate that the national level of income inequality is positively related to risk, independent of compositional (i.e. micro- and meso-level) di¡erences. Furthermore, crossnational variation in victimization rates is not only shaped by di¡erences in national context, but
also by varying composition. More speci¢cally, countries had higher crime rates the more they consisted of urban residents and regions with lowaverage social cohesion.
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