scholarly journals The Effect of Messaging on School Attendance

2021 ◽  
Author(s):  
Aditya Mittal
Keyword(s):  
High Performance ◽  
Academic Motivation ◽  
School Attendance ◽  
Large Fraction ◽  
At Risk Students ◽  
Critical Issue ◽  
Performance Curve ◽  
Attendance Rates ◽  
Communication Models ◽  
K 12

School absenteeism is a critical issue in many K-12 districts. There have been previous studies that have looked at the problem but they have focused on at-risk students in under-achieving districts. This study looked at the same problem at the other end of the spectrum: why do some of the top students in high performance schools miss classes consistently? And can messaging be used to boost attendance rates? Our hypothesis is that a large fraction of the absences at the higher end of the performance curve are strategic absentees: those who cut a class as a need to prepare for another one. This subcategory of chronic absenteeism is the focus of this paper. This subcategory differs in their academic motivation and attendance patterns from those studied earlier. We examined four different communication models: direct and indirect communication using both positive and negative information. The results, though preliminary, were unexpected: (i) none improved attendance, (ii) most seemed to marginally worsen it, contrary to previous results, and (iii) likely due to reactance.

Efficient Instruction and Data Caching for High Performance Embedded Processors

1970 ◽  
pp. 9
Author(s):  
A. Ferrerón Labari ◽  
D. Suárez Gracia ◽  
V. Viñals Yúfera
Keyword(s):  
Embedded Systems ◽  
Power Consumption ◽  
Low Power ◽  
Interconnection Networks ◽  
High Performance ◽  
Critical Issue ◽  
Content Management ◽  
Structure Design ◽  
Portable Devices ◽  
On Chip

In the last years, embedded systems have evolved so that they offer capabilities we could only find before in high performance systems. Portable devices already have multiprocessors on-chip (such as PowerPC 476FP or ARM Cortex A9 MP), usually multi-threaded, and a powerful multi-level cache memory hierarchy on-chip. As most of these systems are battery-powered, the power consumption becomes a critical issue. Achieving high performance and low power consumption is a high complexity challenge where some proposals have been already made. Suarez et al. proposed a new cache hierarchy on-chip, the LP-NUCA (Low Power NUCA), which is able to reduce the access latency taking advantage of NUCA (Non-Uniform Cache Architectures) properties. The key points are decoupling the functionality, and utilizing three specialized networks on-chip. This structure has been proved to be efficient for data hierarchies, achieving a good performance and reducing the energy consumption. On the other hand, instruction caches have different requirements and characteristics than data caches, contradicting the low-power embedded systems requirements, especially in SMT (simultaneous multi-threading) environments. We want to study the benefits of utilizing small tiled caches for the instruction hierarchy, so we propose a new design, ID-LP-NUCAs. Thus, we need to re-evaluate completely our previous design in terms of structure design, interconnection networks (including topologies, flow control and routing), content management (with special interest in hardware/software content allocation policies), and structure sharing. In CMP environments (chip multiprocessors) with parallel workloads, coherence plays an important role, and must be taken into consideration.

scholarly journals Intrinsic Self-Healing Epoxies in Polymer Matrix Composites (PMCs) for Aerospace Applications

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 201
Author(s):  
Stefano Paolillo ◽  
Ranjita K. Bose ◽  
Marianella Hernández Santana ◽  
Antonio M. Grande
Keyword(s):  
High Performance ◽  
Polymer Matrix Composites ◽  
Critical Issue ◽  
General Description ◽  
Self Healing ◽  
Matrix Composites ◽  
Testing Procedures ◽  
Aerospace Applications ◽  
Polymer Properties ◽  
Healing Efficiency

This article reviews some of the intrinsic self-healing epoxy materials that have been investigated throughout the course of the last twenty years. Emphasis is placed on those formulations suitable for the design of high-performance composites to be employed in the aerospace field. A brief introduction is given on the advantages of intrinsic self-healing polymers over extrinsic counterparts and of epoxies over other thermosetting systems. After a general description of the testing procedures adopted for the evaluation of the healing efficiency and the required features for a smooth implementation of such materials in the industry, different self-healing mechanisms, arising from either physical or chemical interactions, are detailed. The presented formulations are critically reviewed, comparing major strengths and weaknesses of their healing mechanisms, underlining the inherent structural polymer properties that may affect the healing phenomena. As many self-healing chemistries already provide the fundamental aspects for recyclability and reprocessability of thermosets, which have been historically thought as a critical issue, perspective trends of a circular economy for self-healing polymers are discussed along with their possible advances and challenges. This may open up the opportunity for a totally reconfigured landscape in composite manufacturing, with the net benefits of overall cost reduction and less waste. Some general drawbacks are also laid out along with some potential countermeasures to overcome or limit their impact. Finally, present and future applications in the aviation and space fields are portrayed.

Continuous Finite-Time Torque Control for Flexible Assistance Exoskeleton with Delay Variation Input

Robotica ◽  
2020 ◽  
pp. 1-26
Author(s):  
Tao Xue ◽  
ZiWei Wang ◽  
Tao Zhang ◽  
Ou Bai ◽  
Meng Zhang ◽  
...  
Keyword(s):  
Finite Time ◽  
Disturbance Rejection ◽  
High Performance ◽  
Control Strategies ◽  
Fractional Power ◽  
Critical Issue ◽  
Human Robot Interaction ◽  
Torque Control ◽  
Finite Time Stability ◽  
Control Scheme

SUMMARY Accurate torque control is a critical issue in the compliant human–robot interaction scenario, which is, however, challenging due to the ever-changing human intentions, input delay, and various disturbances. Even worse, the performances of existing control strategies are limited on account of the compromise between precision and stability. To this end, this paper presents a novel high-performance torque control scheme without compromise. In this scheme, a new nonlinear disturbance observer incorporated with equivalent control concept is proposed, where the faster convergence and stronger anti-noise capability can be obtained simultaneously. Meanwhile, a continuous fractional power control law is designed with an iteration method to address the matched/unmatched disturbance rejection and global finite-time convergence. Moreover, the finite-time stability proof and prescribed control performance are guaranteed using constructed Lyapunov function with adding power integrator technique. Both the simulation and experiments demonstrate enhanced control accuracy, faster convergence rate, perfect disturbance rejection capability, and stronger robustness of the proposed control scheme. Furthermore, the evaluated assistance effects present improved gait patterns and reduced muscle efforts during walking and upstair activity.

PERFORMANCE AT THE EDGE: GALLIUM ARSENIDE AND SILICON ICs FOR OPTICAL ELECTRONICS

1991 ◽  
Vol 02 (03) ◽  
pp. 147-162 ◽  
Author(s):  
ROBERT G. SWARTZ
Keyword(s):  
Gallium Arsenide ◽  
Optical Communication ◽  
Optical Communications ◽  
Integrated Circuit ◽  
High Performance ◽  
Compound Semiconductor ◽  
Performance Curve ◽  
Semiconductor Technology ◽  
Market Trends ◽  
Circuit Technology

Compound semiconductor technology is rapidly entering the mainstream, and is quickly finding its way into consumer applications where high performance is paramount. But silicon integrated circuit technology is evolving up the performance curve, and CMOS in particular is consuming ever more market share. Nowhere is this contest more clearly evident than in optical communications. Here applications demand performance ranging from a few hundreds of megahertz to multi-gigahertz, from circuits containing anywhere from tens to tens of thousands of devices. This paper reviews the high performance electronics found in optical communication applications from a technology standpoint, illustrating merits and market trends for these competing, yet often complementary IC technologies.

scholarly journals The Developmental and Educational Impact of Hearing Impairment in Aboriginal Children Living in Remote Australia – A Data Linkage Study

2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Md Shajedur Rahman Shawon,
Keyword(s):  
Academic Achievement ◽  
Early Childhood ◽  
Hearing Impairment ◽  
Early Childhood Development ◽  
School Attendance ◽  
Childhood Development ◽  
Effect Sizes ◽  
Attendance Rates ◽  
Confounding Variables ◽  
Aboriginal Children

IntroductionHigh prevalence of otitis media (OM) and hearing impairment (HI) in Aboriginal children in Australia’s Northern Territory (NT) is well documented. HI may be associated with poorer outcomes in early childhood development, school attendance and academic achievement. However, these associations have not been investigated in this population. Objectives and ApproachRetrospective cohort studies were conducted to investigate the association between HI and three education-related outcomes in Aboriginal children living in remote NT communities. The explanatory variable for all studies was audiometrically determined hearing levels. The outcome measures were Australian Early Development Census (AEDC) results, representing developmental outcomes at around age 5 years; Year 1 school attendance rates; and, National Assessment Program – Literacy and Numeracy (NAPLAN) results for Year 3 for academic achievement. Relevant confounding variables from available linked datasets were controlled for in the statistical analyses. ResultsCompared with normal hearing children, after adjustment for selected confounding factors, children with HI had higher risk for being developmentally vulnerable in two or more of the five AEDC domains (adjusted odds ratio 1.69); lower AEDC domain score sum (-1.60~-2.40); scoring lower in Numeracy (by 15.2 points), Writing (by 13.4-15.6 points) and Spelling (by 5.0 points) domains of NAPLAN; and having lower attendance rates (attending 4.0-5.6 fewer days in Year 1). Severer HI categories generally yielded greater effect sizes. Notably, across the studies, some confounding variables included in the analysis yielded substantially greater effect sizes. Conclusion / ImplicationsOM-related HI has a negative impact on early childhood development, Year 1 school attendance and academic achievement in Year 3 in Aboriginal children living in remote NT communities. To improve the developmental and educational outcomes it is important to detect HI at an early age and provide effective educational support, in addition to clinical and audiometric management.

Power Estimation and Validation of Embedded Multiplier Based on ANN and Regression Technique

2021 ◽  
Author(s):  
Neerja Singh ◽  
Gaurav Verma ◽  
Vijay Khare
Keyword(s):  
Curve Fitting ◽  
High Performance ◽  
Timing Analysis ◽  
Digital Signal ◽  
Power Estimation ◽  
Critical Issue ◽  
Regression Technique ◽  
Design Stage ◽  
Early Design Stage ◽  
Post Synthesis

Nowadays, high-end Field-Programmable Gate Arrays (FPGAs) are capable of implementing relatively high-performance systems in the field of Digital Signal Processing (DSP). Due to the abundant application of multipliers, their implementation efficiency and performance have become a critical issue in designing the DSP systems. On the other hand, FPGAs consume a large amount of power due to their complex circuitry. So, the power estimation of FPGA implementations at an early design stage has become a critical design metric. Various models are available in the literature based on Look-up Tables (LUTs), but not much literature is available on speed-optimized multiplier design using DSP slices only. In this paper, an embedded multiplier (12.0 IP core) has been analyzed and customized for different Input/Output (I/O) configurations to estimate the power using Vivado Design Suite (2014.4) targeted to the Zynq-family FPGA device (Zynq evolution and development kit). The embedded multiplier IP has been optimized for performance using two different approaches, i.e., Mults (DSP)-based and LUTs-based. Post-synthesis attributes have been used for formulating the power estimation models based on Artificial Neural Network (ANN) and curve fitting and regression technique. The power values estimated from the proposed models have been authenticated with reference to those assessed from the commercial tool. Based on the results obtained, ANN-based model provides average errors of 0.73% and 0.88% for the LUTs and DSP-based designs, respectively. Whereas, the model based on curve fitting and regression technique provides average errors of 3.61% and 1.59% for the LUTs and DSP-based designs, respectively. The timing analysis has been done to get the design performance and time complexity of the proposed models. Area analysis of the design has also been performed in order to report the resource utilization.

CFD Methodology for the Simulation of Mixture Formation of High Performance PFI Engines

2011 ◽  
Author(s):  
Claudio Forte ◽  
Gian Marco Bianchi ◽  
Enrico Corti ◽  
Gaspare Argento ◽  
Stefano Fantoni
Keyword(s):  
High Performance ◽  
Experimental Tests ◽  
Critical Issue ◽  
Spark Ignition Engines ◽  
Mixture Formation ◽  
Injection Process ◽  
Cfd Models ◽  
Cycle Simulation ◽  
Spark Plug ◽  
The Stability

Mixture composition strongly influences the stability of combustion of spark ignition engines. The control of air to fuel ratio at ignition is a critical issue for high performance engines: due to the low stroke-to-bore ratio the maximum power is reached at very high regimes, letting little time to the fuel to evaporate and mix with air. The aim of this work is to present a CFD methodology for the evaluation of mixture formation applied to a Ducati high performance engine. The phenomena involved in the process are highly heterogeneous, and particular care must be taken to the choice of CFD models and their validation. In the present work all the main models involved in the simulations are validated against experimental tests available in the literature, selected based on the similarity of physical conditions with those of the engine configuration under analysis. The multi-cycle simulation methodology here presented reveals to be a useful tool for the evaluation of the mixture quality around the spark plug at ignition, allowing a parametric analysis of the effects of the injection process on engine output.

Multi-Cycle Simulation of the Mixture Formation Process of an High Performance Engine at Part Load Condition

2012 ◽  
Author(s):  
Claudio Forte ◽  
Gian Marco Bianchi ◽  
Enrico Corti ◽  
Stefano Fantoni
Keyword(s):  
High Performance ◽  
Load Condition ◽  
Experimental Tests ◽  
Fuel Mixture ◽  
Critical Issue ◽  
Transient Condition ◽  
Mixture Formation ◽  
Part Load ◽  
Cycle Simulation ◽  
Load Conditions

Transient operation of engines leads to air fuel (A/F) ratio excursions, which can increase engine emissions. These excursions have been attributed to the formation of fuel films in the intake port, which are caused by a portion of the intake fuel impinging and adhering on the relatively cool port surface. These films act as a source or sink which cause the AF variations depending upon the transient condition. Gaining a fundamental understanding of the nature and quantity of such films may assist in future fuel mixture preparation designs that could aid in emission reductions, yet would not require overly expensive nor complicated systems. The control of air to fuel ratio is a critical issue for high performance engines: due to the low stroke-to-bore ratio the maximum power is reached at very high regimes, letting little time to the fuel to evaporate and mix with air. The injector located upstream the throttle causes a lot of fuel to impinge the throttle and intake duct walls, slowing the dynamics of mixture formation in part load conditions. The aim of this work is to present a CFD methodology for the evaluation of mixture formation dynamics applied to a Ducati high performance engine under part load conditions. The phenomena involved in the process are highly heterogeneous, and particular care must be taken to the choice of CFD models and their validation. In the present work all the main models involved in the simulations are validated against experimental tests available in the literature, selected based on the similarity of physical conditions of those of the engine configuration under analysis. The multi-cycle simulation methodology here presented reveals to be a useful tool for the evaluation of the mixture dynamics and for the evaluation of injection wall film compensator models.

scholarly journals Mapping out-of-school adolescents and youths in low- and middle-income countries

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
V. A. Alegana ◽  
C. Pezzulo ◽  
A. J. Tatem ◽  
B. Omar ◽  
A. Christensen
Keyword(s):  
Secondary School ◽  
Secondary Schools ◽  
Survey Data ◽  
School Attendance ◽  
School Age ◽  
Fine Scale ◽  
Attendance Rates ◽  
Middle Income ◽  
Middle Income Countries ◽  
Out Of School

AbstractEducation is a human right and a driver of development, but, is still not accessible for a vast number of adolescents and school-age-youths. Out-of-school adolescents and youth rates (SDG 4.3.1) in lower and middle-income countries have been at a virtual halt for almost a decade. Thus, there is an increasing need to understand geographic variation on accessibility and school attendance to aid in reducing inequalities in education. Here, the aim was to estimate physical accessibility and secondary school non-attendance amongst adolescents and school-age youths in Tanzania, Cambodia, and the Dominican Republic. Community cluster survey data were triangulated with the spatial location of secondary schools, non-proprietary geospatial data and fine-scale population maps to estimate accessibility to all levels of secondary school education and the number of out-of-school. School attendance rates for the three countries were derived from nationally representative household survey data, and a Bayesian model-based geostatistical framework was used to estimate school attendance at high resolution. Results show a sub-national variation in accessibility and secondary school attendance rates for the three countries considered. Attendance was associated with distance to the nearest school (R2 > 70%). These findings suggest increasing the number of secondary schools could reduce the long-distance commuted to school in low-income and middle-income countries. Future work could extend these findings to fine-scale optimisation models for school location, intervention planning, and understanding barriers associated with secondary school non-attendance at the household level.

scholarly journals Hierarchical Ensembles of Intrinsically Disordered Proteins at Atomic Resolution in Molecular Dynamics Simulations

2019 ◽  
Author(s):  
Lisa M. Pietrek ◽  
Lukas S. Stelzl ◽  
Gerhard Hummer
Keyword(s):  
Molecular Dynamics ◽  
Local Structure ◽  
High Performance ◽  
Intrinsically Disordered Proteins ◽  
Large Fraction ◽  
Conformational Dynamics ◽  
Full Length ◽  
Atomic Resolution ◽  
Disordered Proteins ◽  
Intrinsically Disordered

AbstractIntrinsically disordered proteins (IDPs) constitute a large fraction of the human proteome and are critical in the regulation of cellular processes. A detailed understanding of the conformational dynamics of IDPs could help to elucidate their roles in health and disease. However the inherent flexibility of IDPs makes structural studies and their interpretation challenging. Molecular dynamics (MD) simulations could address this challenge in principle, but inaccuracies in the simulation models and the need for long simulations have stymied progress. To overcome these limitations, we adopt an hierarchical approach that builds on the “flexible meccano” model of Bernadó et al. (J. Am. Chem. Soc. 2005, 127, 17968-17969). First, we exhaustively sample small IDP fragments in all-atom simulations to capture local structure. Then, we assemble the fragments into full-length IDPs to explore the stereochemically possible global structures of IDPs. The resulting ensembles of three-dimensional structures of full-length IDPs are highly diverse, much more so than in standard MD simulation. For the paradigmatic IDP α-synuclein, our ensemble captures both local structure, as probed by nuclear magnetic resonance (NMR) spectroscopy, and its overall dimension, as obtained from small-angle X-ray scattering (SAXS) in solution. By generating representative and meaningful starting ensembles, we can begin to exploit the massive parallelism afforded by current and future high-performance computing resources for atomic-resolution characterization of IDPs.

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