The GENREL teletype package

A collection is presented of programs designed specifically for use on a teletype (or similar conversational time-sharing terminal). The criteria for designing these programs are given, and a description of each program is included

A Study of Educational Simulations Part I - Engagement and Learning

Interactive computer simulations with complex representations and sophisticated graphics are a relatively new addition to the classroom, and research in this area is limited. We have conducted over 200 individual student interviews during which the students described what they were thinking as they interacted with simulations. These interviews were conducted as part of the research and design of simulations for the Physics Education Technology (PhET) project. PhET is an ongoing project that has developed over 60 simulations for use in teaching physics, chemistry, and physical science. These interviews are a rich source of information about how students interact with computer simulations and what makes an educationally effective simulation. We have observed that simulations can be highly engaging and educationally effective, but only if the student's interaction with the simulation is directed by the student's own questioning. Here we describe our design process, what features are effective for engaging students in educationally productive interactions and the underlying principles which support our empirically developed guidelines. In a companion paper we describe in detail the design features used to create an intuitive simulation for students to use

Developing and Researching PhET simulations for Teaching Quantum Mechanics

Quantum mechanics is difficult to learn because it is counterintuitive, hard to visualize, mathematically challenging, and abstract. The Physics Education Technology (PhET) Project, known for its interactive computer simulations for teaching and learning physics, now includes 18 simulations on quantum mechanics designed to improve learning of this difficult subject. Our simulations include several key features to help students build mental models and intuitions about quantum mechanics: visual representations of abstract concepts and microscopic processes that cannot be directly observed, interactive environments that directly couple students' actions to animations, connections to everyday life, and efficient calculations so students can focus on the concepts rather than the math. Like all PhET simulations, these are developed using the results of education research and feedback from educators, and are tested in student interviews and classroom studies. This article provides an overview of the PhET quantum simulations and their development. We also describe research demonstrating their effectiveness and share some insights about student thinking that we have gained from our research on quantum simulations.Comment: accepted by American Journal of Physics; v2 includes an additional study, more explanation of research behind claims, clearer wording, and more reference

Trigonometric Parallaxes of Massive Star Forming Regions: VIII. G12.89+0.49, G15.03-0.68 (M17) and G27.36-0.16

We report trigonometric parallaxes for three massive star forming regions, corresponding to distances of $2.34^{+0.13}_{-0.11}$ kpc for G12.89+0.49 (also known as IRAS 18089-1732),$1.98^{+0.14}_{-0.12}$ kpc for G15.03-0.68 (in the M17 region), and $8.0^{+4.0}_{-2.0}$ kpc for G27.36-0.16. Both G12.89+0.49 and G15.03-0.68 are located in the Carina-Sagittarius spiral arm

Wireless integrated circuit for 100-channel neural stimulation

Journal ArticleWe present the design of an integrated circuit for wireless neural stimulation, along with bench-top and in-vivo experimental results. The chip has the ability to drive 100 individual stimulation electrodes with constant-current pulses of varying amplitude, duration, interphasic delay, and repetition rate. The stimulation is done using a biphasic (cathodic and anodic) current source, injecting and retracting charge from the nervous system. Wireless communication and power are achieved over a 2.765-MHz inductive link. Only two off-chip components are needed to operate the stimulator: a 10-nF capacitor to aid in power supply regulation and a coil for power and command reception. The chip was fabricated in a commercially available 0.6-μm 2P3M BiCMOS process. The chip was able to activate motor fibers to produce muscle twitches via a Utah Slanted Electrode Array implanted in cat sciatic nerve, and to activate sensory fibers to recruit evoked potentials in somatosensory cortex

MIP/MTMR14 and muscle aging

No abstract

Parallaxes for W49N and G048.60+0.02: Distant Star Forming Regions in the Perseus Spiral Arm

We report trigonometric parallax measurements of 22 GHz H$_2$O masers in two massive star-forming regions from VLBA observations as part of the BeSSeL Survey. The distances of $11.11^{+0.79}_{-0.69}$ kpc to W49N (G043.16+0.01) and $10.75^{+0.61}_{-0.55}$ kpc to G048.60+0.02 locate them in a distant section of the Perseus arm near the solar circle in the first Galactic quadrant. This allows us to locate accurately the inner portion of the Perseus arm for the first time. Combining the present results with sources measured in the outer portion of the arm in the second and third quadrants yields a global pitch angle of 9.5 deg +/- 1.3 deg for the Perseus arm. We have found almost no H$_2$O maser sources in the Perseus arm for 50 deg $< \ell <$ 80 deg, suggesting that this $\approx 6$ kpc section of the arm has little massive star formation activity.Comment: 22 pages, 14 figures, published in Ap