134 research outputs found

    Barrel Shifter Physical Unclonable Function Based Encryption

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    Physical Unclonable Functions (PUFs) are circuits designed to extract physical randomness from the underlying circuit. This randomness depends on the manufacturing process. It differs for each device enabling chip-level authentication and key generation applications. We present a protocol utilizing a PUF for secure data transmission. Parties each have a PUF used for encryption and decryption; this is facilitated by constraining the PUF to be commutative. This framework is evaluated with a primitive permutation network - a barrel shifter. Physical randomness is derived from the delay of different shift paths. Barrel shifter (BS) PUF captures the delay of different shift paths. This delay is entangled with message bits before they are sent across an insecure channel. BS-PUF is implemented using transmission gates; their characteristics ensure same-chip reproducibility, a necessary property of PUFs. Post-layout simulations of a common centroid layout 8-level barrel shifter in 0.13 {\mu}m technology assess uniqueness, stability and randomness properties. BS-PUFs pass all selected NIST statistical randomness tests. Stability similar to Ring Oscillator (RO) PUFs under environment variation is shown. Logistic regression of 100,000 plaintext-ciphertext pairs (PCPs) failed to successfully model BS- PUF behavior

    Future agricultural systems competencies of beginning Texas agricultural science teachers as determined by agricultural education professionals and administrators of agricultural education programs: a Delphi study

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    It has always been the initiative of agricultural education to provide our American society with the educational "needs of the day" (Meyer, 1999). As our nation and state enters a new era, it is fitting for an examination of the future needs of agricultural education teachers. In Texas, the State Board of Educator Certification (SBEC) currently has no assessment of the agricultural systems knowledge of agricultural education teaching candidates. This study examines the future agricultural systems competencies of beginning agricultural education teachers. Two groups, agricultural education professionals and administrators of agricultural education programs, were asked "what the future agricultural systems competencies of beginning agricultural science teachers should be." Two independent panels, the first composed of eleven (11) educators and the second composed of twelve (12) school administrators, were identified to serve as experts. A three-round Delphi was used to collect the data. Each round allowed the expert panelists to converge to a consensus of agreement that identified future competencies for beginning agricultural science teachers. Panelists were asked to provide competencies associated with the five powerful and fundamental conceptual areas of biological, physical, social, informational, and other integrative science which underpin agricultural education (Paul, 1995). The study revealed a three-fourths consensus with one-hundred (100) future competencies necessary for beginning Texas agricultural science teachers. Among these competencies twenty-three (23) were associated with the biological sciences, twenty-seven (27) were associated with the physical sciences, twenty-five (25) were associated with the social sciences, twenty (20) were associated with the informational sciences, and five (5) were associated with other integrative sciences. The study found seventeen (17) "highly recommended" topics and six (6) "recommended" topics related to the future agricultural systems competencies identified by the expert panelists. Cooper and Layard (2001) reveal that our future society will be much more technologically and sociologically advanced requiring teacher preparation institutions and state agencies associated with teacher preparation to develop new, innovative programs to better prepare tomorrow's educator. This study recommends that new agricultural systems standards be developed to adequately prepare future beginning agricultural science teachers

    Building Conceptual Understanding through Vocabulary Instruction

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    Instructional design is an integral part of a balanced approach to teaching vocabulary instruction. This article presents several instructional procedures using research-based vocabulary strategies and explains how to design and adapt those strategies in order to reach desired learning outcomes. Emphasis is placed on research-based principles that guide effective vocabulary instruction and on the importance of incorporating vocabulary instruction into all phases of the reading lesson framework--before, during, and after reading (Blair, Rupley, & Nichols 2007; Vacca, Vacca, & Mraz 2011). Vocabulary instruction should encourage students to make associations and accommodations to their experiences and provide them with varied opportunities to practice, apply, and discuss their word knowledge in meaningful contexts (Beck & McKeown, 2002; Rupley & Nichols, 2005). The ultimate goal of teaching vocabulary is for the students to expand, refine, and add to their existing conceptual knowledge and enhance their comprehension and understanding of what they read (Baumann, Font, Edwards, & Boland , 2005; Stahl & Fairbanks, 1986). This article seeks to provide educators with both a theoretical framework and practical classroom instructional suggestions for doing so

    Literacity: A multimedia adult literacy package combining NASA technology, recursive ID theory, and authentic instruction theory

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    An important part of NASA's mission involves the secondary application of its technologies in the public and private sectors. One current application under development is LiteraCity, a simulation-based instructional package for adults who do not have functional reading skills. Using fuzzy logic routines and other technologies developed by NASA's Information Systems Directorate and hypermedia sound, graphics, and animation technologies the project attempts to overcome the limited impact of adult literacy assessment and instruction by involving the adult in an interactive simulation of real-life literacy activities. The project uses a recursive instructional development model and authentic instruction theory. This paper describes one component of a project to design, develop, and produce a series of computer-based, multimedia instructional packages. The packages are being developed for use in adult literacy programs, particularly in correctional education centers. They use the concepts of authentic instruction and authentic assessment to guide development. All the packages to be developed are instructional simulations. The first is a simulation of 'finding a friend a job.

    Landsat Imagery from a CubeSat: Results and Operational Lessons from the R3 Satellite\u27s First 18 Months in Space

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    R3 is a 3-U CubeSat launched on a RocketLab Electron into a 500 km circular orbit at 85Ā° inclination on December 16th, 2018. The spacecraft flies a multispectral sensor that takes data in the six Landsat visible and near infrared bands. The R3 sensor mates a custom refractive telescope with a Materion Precision Optics Landsat filter, and an ON Semiconductor fast-framing high-sensitivity Si CMOS array, to produce 50-km wide, 44-m resolution Landsat-like image strips. Data are taken in push-broom mode and are downlinked via a 100Mbps compact lasercom system. Frames are then co-added on the ground in time-delay-integration (TDI) fashion to increase signal-to-noise ratio and create multi-spectral Earth images from the compact sensor. The system is an engineering concept demonstration of a compact multispectral sensor in CubeSat form. We describe our ConOps, flight operations, sensor focus and alignment, initial imaging check out, and initial comparisons of R3 data to Landsat-8 imagery of the same Earth locations. RGB, color infrared, and normalized differential vegetation index (NDVI) products are compared between CUMULOS and Landsat-8. Results show good multispectral image quality from the CubeSat sensor, and illustrate the ability of R3 to detect vegetation and other features in a manner similar to Landsat, as well as the challenge in perfectly exposing all 6 VIS/NIR Landsat bands using our commercial 10-bit CMOS array. We also highlight the performance of the compact laser communications system which enabled the successful performance of this mission

    A report on the piloting of a novel computer-based medical case simulation for teaching and formative assessment of diagnostic laboratory testing

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    Objectives: Insufficient attention has been given to how information from computer-based clinical case simulations is presented, collected, and scored. Research is needed on how best to design such simulations to acquire valid performance assessment data that can act as useful feedback for educational applications. This report describes a study of a new simulation format with design features aimed at improving both its formative assessment feedback and educational function. Methods: Case simulation software (LabCAPS) was developed to target a highly focused and well-defined measurement goal with a response format that allowed objective scoring. Data from an eight-case computer-based performance assessment administered in a pilot study to 13 second-year medical students was analyzed using classical test theory and generalizability analysis. In addition, a similar analysis was conducted on an administration in a less controlled setting, but to a much large sample (n=143), within a clinical course that utilized two random case subsets from a library of 18 cases. Results: Classical test theory case-level item analysis of the pilot assessment yielded an average case discrimination of 0.37, and all eight cases were positively discriminating (range=0.11–0.56). Classical test theory coefficient alpha and the decision study showed the eight-case performance assessment to have an observed reliability of σ=G=0.70. The decision study further demonstrated that a G=0.80 could be attained with approximately 3 h and 15 min of testing. The less-controlled educational application within a large medical class produced a somewhat lower reliability for eight cases (G=0.53). Students gave high ratings to the logic of the simulation interface, its educational value, and to the fidelity of the tasks. Conclusions: LabCAPS software shows the potential to provide formative assessment of medical students’ skill at diagnostic test ordering and to provide valid feedback to learners. The perceived fidelity of the performance tasks and the statistical reliability findings support the validity of using the automated scores for formative assessment and learning. LabCAPS cases appear well designed for use as a scored assignment, for stimulating discussions in small group educational settings, for self-assessment, and for independent learning. Extension of the more highly controlled pilot assessment study with a larger sample will be needed to confirm its reliability in other assessment applications

    Hospitalizations for Pandemic (H1N1) 2009 among Maori and Pacific Islanders, New Zealand

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    Community transmission of influenza A pandemic (H1N1) 2009 was followed by high rates of hospital admissions in the Wellington region of New Zealand, particularly among Maori and Pacific Islanders. These findings may help health authorities anticipate the effects of pandemic (H1N1) 2009 in other communities

    Moisture transport by Atlantic tropical cyclones onto the North American continent

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    Tropical Cyclones (TCs) are an important source of freshwater for the North American continent. Many studies have tried to estimate this contribution by identifying TC-induced precipitation events, but few have explicitly diagnosed the moisture fluxes across continental boundaries. We design a set of attribution schemes to isolate the column-integrated moisture fluxes that are directly associated with TCs and to quantify the flux onto the North American Continent due to TCs. Averaged over the 2004ā€“2012 hurricane seasons and integrated over the western, southern and eastern coasts of North America, the seven schemes attribute 7 to 18 % (mean 14 %) of total net onshore flux to Atlantic TCs. A reduced contribution of 10 % (range 9 to 11 %) was found for the 1980ā€“2003 period, though only two schemes could be applied to this earlier period. Over the whole 1980ā€“2012 period, a further 8 % (range 6 to 9 % from two schemes) was attributed to East Pacific TCs, resulting in a total TC contribution of 19 % (range 17 to 22 %) to the ocean-to-land moisture transport onto the North American continent between May and November. Analysis of the attribution uncertainties suggests that incorporating details of individual TC size and shape adds limited value to a fixed radius approach and TC positional errors in the ERA-Interim reanalysis do not affect the results significantly, but biases in peak wind speeds and TC sizes may lead to underestimates of moisture transport. The interannual variability does not appear to be strongly related to the El Nino-Southern Oscillation phenomenon

    Effects of fenofibrate on renal function in patients with type 2 diabetes mellitus: the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) Study

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    Abstract Aims/hypothesis Fenofibrate caused an acute, sustained plasma creatinine increase in the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) and Action to Control Cardiovascular Risk in Diabetes (ACCORD) studies. We assessed fenofibrateā€™s renal effects in a FIELD washout sub-study. Methods Type 2 diabetic patients (n=9795) aged 50 to 75 years were randomly assigned to fenofibrate (n=4895) or placebo (n=4900) for 5 years, after 6 weeks fenofibrate run-in. Albuminuria (urinary albumin:creatinine ratio) measured at baseline, year 2 and close-out) and estimated GFR, measured 4 to 6 monthly according to the Modification of Diet in Renal Disease study, were pre-specified endpoints. Plasma creatinine was re-measured 8 weeks after treatment cessation at close-out (washout sub-study, n=661). Analysis was by intention-to-treat. Results During fenofibrate run-in, plasma creatinine increased by 10.0 Āµmol/l (p<0.001), but quickly reversed on placebo assignment. It remained higher on fenofibrate than on placebo, but the chronic rise was slower (1.62 Āµmol/l vs 1.89 Āµmol/l annually, p=0.01), with less estimated GFR loss (1.19 vs 2.03 ml mināˆ’1 1.73 māˆ’2 annually, p<0.001). After washout, estimated GFR had fallen less from baseline on fenofibrate (1.9 ml mināˆ’1 1.73 māˆ’2, p=0.065) than on placebo (6.9 ml mināˆ’1 1.73 māˆ’2, p<0.001), sparing 5.0 ml mināˆ’1 1.73 māˆ’2 (95% CI 2.3-7.7, p<0.001). Greater preservation of estimated GFR with fenofibrate was observed during greater reduction over the active run-in period (pre-randomisation) of triacylglycerol (n=186 vs 170) and baseline hypertriacylglycerolaemia (n=89 vs 80) alone, or combined with low HDL-cholesterol (n=71 vs 60). Fenofibrate reduced urine albumin concentrations and hence albumin:creatinine ratio by 24% vs 12% (p<0.001; mean difference 14% [95% CI 9-18]; p<0.001), with 14% less progression and 18% more albuminuria regression (p<0.001) than in participants on placebo. End-stage renal event frequency was similar (n=21 vs 26, p=0.48). Conclusions/interpretation Fenofibrate reduced albuminuria and slowed estimated GFR loss over 5 years, despite initially and reversibly increasing plasma creatinine. Fenofibrate may delay albuminuria and GFR impairment in type 2 diabetes patients. Confirmatory studies are merited. Trial registration: ISRCTN64783481 Funding: The study was funded by grants from Laboratoires Fournier, Dijon, France (now part of Solvay and Abbott Pharmaceuticals) and the NHMRC of Australia.Laboratoires Fournier, Dijon, France (now part of Solvay and Abbott Pharmaceuticals
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