Alphanumeric character generator for oscilloscope

Compact portable alphanumeric display device can be used with any general-purpose externally-triggered oscilloscope without need for Z-axis modulation. Factors limiting size of display are: output line capacitance, read-only memory speed, and persistence of cathode-ray-tube

X-Y alphanumeric character generator for oscilloscopes

A method and apparatus is disclosed by which any general purpose external trigger laboratory oscilloscope can be utilized to display alphanumeric characters. Each character to be displayed is composed of a plurality of segments appearing at various segment positions in various segment rows to define a conventional matrix. In between character segments to be displayed, or when no display is desired, the trace is effectively blanked by a vertical clamping voltage so as to position the oscilloscope trace in an off-screen position. The clamping technique of the invention, i.e., biasing the oscilloscope trace to an off-screen position when no character segment is to be displayed; it eliminates the necessity of providing Z-axis modulation to effect blanking

A Characterization of Deterministic Sampling Patterns for Low-Rank Matrix Completion

Low-rank matrix completion (LRMC) problems arise in a wide variety of applications. Previous theory mainly provides conditions for completion under missing-at-random samplings. This paper studies deterministic conditions for completion. An incomplete $d \times N$ matrix is finitely rank-$r$ completable if there are at most finitely many rank-$r$ matrices that agree with all its observed entries. Finite completability is the tipping point in LRMC, as a few additional samples of a finitely completable matrix guarantee its unique completability. The main contribution of this paper is a deterministic sampling condition for finite completability. We use this to also derive deterministic sampling conditions for unique completability that can be efficiently verified. We also show that under uniform random sampling schemes, these conditions are satisfied with high probability if $O(\max\{r,\log d\})$ entries per column are observed. These findings have several implications on LRMC regarding lower bounds, sample and computational complexity, the role of coherence, adaptive settings and the validation of any completion algorithm. We complement our theoretical results with experiments that support our findings and motivate future analysis of uncharted sampling regimes.Comment: This update corrects an error in version 2 of this paper, where we erroneously assumed that columns with more than r+1 observed entries would yield multiple independent constraint

Experiments with Geometric Non-Linear Coupling for Analytical Validation

This study was focused on obtaining accurate experimental data for the validation of the geometrically exact beam theory from a series of experiments in which high quality surface shape and deflection data was collected. Many previous experiments have experienced issues with data collection or test articles which the researchers were unable to overcome. The test program was performed in two stages: qualification and joined-wing. The qualification stage validated the experimental procedures on simple 72 in long aluminum beams with 8 in x 0.5 in cross-sections. The joined-wing stage was the primary experiment focused on obtaining quality data for use in validation and each joined-wing had an overall length of 57 in. The fore wing was designed with a chord of 8 in and a thickness of 0.5 in; the aft wing was designed with a chord of 6 in and a thickness of 0.5 in. These dimensions were chosen so the joined-wing produced a non-linear bend-twist couple before permanent deformation. The bend-twist couple in a solid cross-section aluminum joined-wing was successfully captured with surface shape, deflection points, and strain data

Developing Secondary Mathematics Teachers' Knowledge of and Capacity to Implement Instructional Tasks with High-Level Cognitive Demands

DEVELOPING SECONDARY MATHEMATICS TEACHERS'KNOWLEDGE OF AND CAPACITY TO IMPLEMENT INSTRUCTIONAL TASKS WITH HIGH LEVEL COGNITIVE DEMANDSMelissa D. Boston, EdD University of Pittsburgh, 2006This study analyzed mathematics teachers' selection and implementation of instructional tasks in their own classrooms before, during, and after their participation in a professional development workshop focused on the cognitive demands of mathematical tasks. Eighteen secondary mathematics teachers participated in a six-session professional development workshop under the auspices of the Enhancing Secondary Mathematics Teacher Preparation (ESP) Project throughout the 2004-2005 school year. Data collected from the ESP workshop included written artifacts created during the professional development sessions and videotapes of each session. Data collected from teachers included a pre/post measure of teachers' knowledge of the cognitive demands of mathematical tasks, collections of tasks and student work from teachers' classrooms, lesson observations, and interviews. Ten secondary mathematics teachers who did not participate in the ESP workshop served as the contrast group, completed the pre/post measure, and participated in one lesson observation.Analysis of the data indicated that the ESP workshop provided learning experiences for teachers that transformed their previous knowledge and instructional practices. ESP teachers enhanced their knowledge of the cognitive demands of mathematical tasks; specifically, they improved their ability to identify and describe the characteristics of tasks that influence students' opportunities for learning. Following their participation in ESP, teachers were more frequently selecting high-level tasks as the main instructional tasks in their own classrooms. ESP teachers also improved their ability to maintain high-level cognitive demands during implementation. Student work implementation significantly improved from Fall to Spring, and comparisons of the implementation of high-level student work tasks indicated that high-level demands were less likely to decline in Spring than in Fall. Lesson observations did not yield statistically significant results from Fall to Spring; however, significant differences existed between ESP teachers and the contrast group in task selection and implementation during lesson observations. ESP teachers also outperformed the contrast group on the post-measure of the knowledge of cognitive demands of mathematical tasks. None of the significant differences were influenced by the use of a reform vs. traditional curricula in teachers' classrooms. Teachers who exhibited greater improvements more frequent contributions and more comments on issues of implementation than teachers who exhibited less improvement

Low‐temperature crystallization of La0.15Sr0.775TiO3 using ionic liquids

The n‐type thermoelectric oxide La0.15Sr0.775TiO3 (LST) has been synthesized at 600°C using an ionic liquid method. The method uses the ionic liquid 1‐ethyl 3‐methylimidazolium acetate as the sole complexing agent: the lack of a second, carbon‐rich template decreases the quantity of reduced intermediate phases which form during heating. By suppressing these phases, greatly reduced temperatures can be used to crystallize the perovskite LST phase, on the nanoscale. These nanoparticles have the potential to be used to increase the figure of merit in n‐type thermoelectric oxide devices

An Analysis of the Telecommunication Performance of a Data Relay Satellite System

The Data-Relay Satellite System (DRSS) has been proposed as a means of providing a communication capability between a number of earth-orbiting space vehicles and the Mission Control Center- Houston (MCC-H) using earth-orbiting synchronous satellites as relay devices. The purpose of this paper is to report the investigation of the performance characteristics of the relay system and to determine the expected communications capabilities of the DRSS operating with Apollo spacecraft systems and with an advanced spacecraft-systems concept. When the DRSS is used with the spacecraft high-gain antenna (Apollo or modified spacecraft), positive circuit margins can be expected for all up-link and down-link, pulse modulated (PM) modes, which include pseudorandom noise (PRN) ranging, telemetry, and voice. Wideband frequency modulated (FM) modes (television or 1-Mbps data dump) have positive circuit margins for the modified spacecraft system configuration; however, only marginal performance can be expected with the Apollo system

Deterministic Conditions for Subspace Identifiability from Incomplete Sampling

Consider a generic $r$-dimensional subspace of $\mathbb{R}^d$, $r<d$, and suppose that we are only given projections of this subspace onto small subsets of the canonical coordinates. The paper establishes necessary and sufficient deterministic conditions on the subsets for subspace identifiability.Comment: To appear in Proc. of IEEE ISIT, 201

A new technique for elucidating β\beta-decay schemes which involve daughter nuclei with very low energy excited states

A new technique of elucidating $\beta$-decay schemes of isotopes with large density of states at low excitation energies has been developed, in which a Broad Energy Germanium (BEGe) detector is used in conjunction with coaxial hyper-pure germanium detectors. The power of this technique has been demonstrated on the example of 183Hg decay. Mass-separated samples of 183Hg were produced by a deposition of the low-energy radioactive-ion beam delivered by the ISOLDE facility at CERN. The excellent energy resolution of the BEGe detector allowed $\gamma$ rays energies to be determined with a precision of a few tens of electronvolts, which was sufficient for the analysis of the Rydberg-Ritz combinations in the level scheme. The timestamped structure of the data was used for unambiguous separation of $\gamma$ rays arising from the decay of 183Hg from those due to the daughter decays

Equine cheek tooth extraction: Comparison of outcomes for five extraction methods

BACKGROUND: Post-operative complications are reported for all methods of equine cheek tooth extraction but not all methods carry the same risks. An outcome comparison for commonly used methods is needed so that clinicians can make informed treatment decisions. OBJECTIVES: We conducted a side-by-side comparison of five cheek tooth extraction methods, comparing types and incidence of complications among oral extraction, tooth repulsion (three surgical approaches) and lateral buccotomy techniques. STUDY DESIGN: Retrospective clinical study using hospital medical records. METHODS: Medical records of all horses undergoing cheek tooth extraction between 1997 and 2013 were reviewed. Logistic regression was used to determine the likelihood of various post-operative complications, comparing oral extraction, tooth repulsion by maxillary and mandibular trephination or maxillary sinus bone flap, and lateral buccotomy. RESULTS: The study included 137 horses and 162 cheek teeth extractions. Oral extraction was successful in 71% of patients in which it was attempted. Oral extraction (n = 55) had the lowest incidence of complications (20%) and repulsion by sinus bone flap (n = 20) the highest (80%). Complication rates for repulsion by maxillary (n = 19) and mandibular trephination (n = 28), and extraction by lateral buccotomy (n = 15) were 42, 54 and 53%, respectively. Cheek tooth repulsion by sinus bone flap significantly increased the odds of damage to adjacent teeth, post-operative sinusitis, damage to alveolar bone, delayed alveolar granulation and orosinus fistulation. Repulsion by maxillary trephination significantly increased the odds of superficial incisional surgical site infection; and extraction by lateral buccotomy significantly increased the odds of facial nerve neuropraxia. Post-operative pyrexia was more common in all repulsion methods. MAIN LIMITATIONS: Some clinically relevant differences may have been missed due to small group numbers in several categories. CONCLUSIONS: Oral extraction was associated with fewer post-operative complications than any other methods. Standing oral extraction remains the preferred choice, and recent surgical advances promise to further improve its success rate