Human operator modeling, joystick input notch filtering, and safety constraint enforcement for powered wheelchair operation under Parkinson’s tremor

This study considers use of a notch filter and enforcement of performance safety limits to mitigate the effects of Parkinson tremors on a battery powered wheelchair directed by a joystick. The wheelchair has regenerative braking to extend range of operation between charges. Regenerative braking transforms the wheelchair model into an autonomously switched hybrid system. The wheelchair is represented as a joystick controlled wheeled mobile robot having two modes of operation per drive wheel, propelling and regenerative braking. In this study, a Parkinson’s patient is directed to follow a path that includes moving from a stopped position to a trajectory along a wall that includes a 90˚ corner. A cognitive model of a human operator is incorporated for simulation of an operator with Parkinson’s tremor. The human operator model output provides the joystick with noisy velocity, orientation, and position commands. The article delineates a notch filter to remove the main Parkinson’s tremor from the joystick input followed by the application of velocity and acceleration performance safety limits. Results show significant feasible advantages for safe wheelchair operation by Parkinson’s patients with tremor

Guarantee schemes : an alternative to the supervised credit program

Paper presented during the ACPC-PIDS-OSU sponsored Seminarworkbhop on "Financial Intermediation in the Rural Sector: Research Rebultb and Policy Ibbueb" held on 26-27 September 1988 at the Cuaderno Hall, Central Bank of the Philippines. This ib part of a larger Study on comparative bank analysis jointly conducted by the Agricultural Credit Policy Council (ACPC), Philippine Institute for Development Studied (PIDS) and Ohio State University (OSU). The project wab coordinated by Dr. Mario B. Lamberte (PIDS) and Dr. V. Bruce J. Tolentino (ACPC)

Fault Detection in Surface PMSM with Applications to Heavy Hybrid Vehicles

This report explores detecting inter-turn short circuit (ITSC) faults in surface permanent magnet synchronous machines (SPMSM). ITSC faults are caused by electrical insulation failures in the stator windings and can lead to shorts to ground and even fires. This report proposes methods for detecting these faults using a moving horizon observer (MHO) to reduce the chance of electrical shocks and fires. Specifically, this report constructs a MHO for ITSC fault detection in SPMSM. ITSC fault tolerant control is investigated for a 2004 Toyota Prius hybrid vehicle having a traction SPMSM. Once the supervisory-level powertrain power flow control becomes aware of the presence of a fault and its degree from the MHO, the control (i) reduces the maximum possible vehicle speed to ensure SPMSM thermal constraints are not violated and (ii) switches to a traction motor input-output power efficiency appropriate for the degree of fault. These steps are taken during a fault rather than shutting down the traction motor to provide a “limp home” capability. The traction motor cannot simply be turned off because its rotation is not independent of drive wheel rotation. The control is demonstrated by simulating the Prius over a 40 s drive velocity profile with faults levels of 0.5%, 1%, 2%, and 5% detected at the midpoint of the profile. For comparison, the Prius is also simulated without a traction motor fault. Results show that the control reduced vehicle velocity upon detection of a fault to appropriate safe values. Further, the challenges of ITSC fault tolerant control for heavy hybrid vehicles are examined. This work is partially supported by the Department of Energy, Award No. DE-EE0005568. The authors would like to acknowledge the support of Greg Shaver and the Hoosier Heavy Hybrid Center of Excellence. S. Johnson, R. DeCarlo, and S. Pekarek are with the Department of Electrical and Computer Engineering at Purdue University, 610 Purdue Mall, West Lafayette, IN 47907 (email: [email protected], [email protected], [email protected]). R. Meyer is with the Department of Mechanical and Aerospace Engineering at Western Michigan University, 1903 West Michigan Avenue, Kalamazoo, MI 49008 (email: [email protected])

Timed Insemination vs. Modified Estrus Detection in Beef Heifers

Th e objective of this study was to compare a modified estrus detection and fixed time AI vs. no estrus detection and fixed time AI on subsequent pregnancy rates. Yearling heifers were estrus synchronized and AI at 72 ± 2 h after prostaglandin injection. In one group estrus was not detected and all heifers received gonadotropin releasing hormone at the fixed- time AI; in the other group estrus was detected at 58 ± 2 and 70 ± 2 h after prostaglandin and inseminated in the following order at 72 ± 2 h: heifers in estrus at 58 h, heifers in estrus at 70 h, and heifers not appearing in estrus at either observation. Similar AI conception and final pregnancy rates were achieved without the added labor of estrus detection

Environmental Evaluation Report onn Various Completed Channel Improvement Projects in Eastern Arkansas

The objective of this report is to evaluate the beneficial and adverse effects that certain channel improvement projects have had on the natural or man-made environments of selected areas in eastern Arkansas. This evaluation will be used as a baseline for determining the immediate and long-term effects that a project may have on the existing environment of the Village Creek Basin

Compact Resolved Ejecta in the Nearest Tidal Disruption Event

Tidal disruption events (TDEs) occur when a star or sub-stellar object passes close enough to a galaxy's supermassive black hole to be disrupted by tidal forces. NGC 4845 (d=17 Mpc) was host to a TDE, IGR J12580+0134, detected in November 2010. Its proximity offers us a unique close-up of the TDE and its aftermath. We discuss new Very Long Baseline Array (VLBA) and Karl G. Jansky Very Large Array (JVLA) observations, which show that the radio flux from the active nucleus created by the TDE has decayed in a manner consistent with predictions from a jet-circumnuclear medium interaction model. This model explains the source's broadband spectral evolution, which shows a spectral peak that has moved from the submm (at the end of 2010) to GHz radio frequencies (in 2011-2013) to <1 GHz in 2015. The milliarcsecond-scale core is circularly polarized at 1.5 GHz but not at 5 GHz, consistent with the model. The VLBA images show a complex structure at 1.5 GHz that includes an east west extension ~40 milliarcsec (3 pc) long as well as a resolved component 52 milliarcsec (4.1 pc) northwest of the flat-spectrum core, which is all that can be seen at 5 GHz. If ejected in 2010, the NW component must have had v=0.96 c over five years. However, this is unlikely, as our model suggests strong deceleration to speeds < 0.5c within months and a much smaller, sub-parsec size. In this interpretation, the northwest component could have either a non-nuclear origin or be from an earlier event.Comment: 12 pages, 8 figures, ApJ, in press; v2 includes error corrections and slight additions to the analysi

Unusual photoemission resonances of oxygen-dopant induced states in Bi2_{2}Sr2_2CaCu2_2O8+x_{8+x}

We have performed an angular-resolved photoemission study of underdoped, optimally doped and overdoped Bi$_{2}$Sr$_2$CaCu$_2$O$_{8+x}$ samples using a wide photon energy range (15 - 100 eV). We report a small and broad non-dispersive A$_{1g}$ peak in the energy distribution curves whose intensity scales with doping. We attribute it to a local impurity state similar to the one observed recently by scanning tunneling spectroscopy and identified as the oxygen dopants. Detailed analysis of the resonance profile and comparison with the single-layered Bi$_{2}$Sr$_2$CuO$_{6+x}$ suggest a mixing of this local state with Cu via the apical oxygens.Comment: 4 pages, 4 figure

Stability and Evolution of Supernova Fallback Disks

We show that thin accretion disks made of Carbon or Oxygen are subject to the same thermal ionization instability as Hydrogen and Helium disks. We argue that the instability applies to disks of any metal content. The relevance of the instability to supernova fallback disks probably means that their power-law evolution breaks down when they first become neutral. We construct simple analytical models for the viscous evolution of fallback disks to show that it is possible for these disks to become neutral when they are still young (ages of a few 10^3 to 10^4 years), compact in size (a few 10^9 cm to 10^11 cm) and generally accreting at sub-Eddington rates (Mdot ~ a few 10^14 - 10^18 g/s). Based on recent results on the nature of viscosity in the disks of close binaries, we argue that this time may also correspond to the end of the disk activity period. Indeed, in the absence of a significant source of viscosity in the neutral phase, the entire disk will likely turn to dust and become passive. We discuss various applications of the evolutionary model, including anomalous X-ray pulsars and young radio pulsars. Our analysis indicates that metal-rich fallback disks around newly-born neutron stars and black holes become neutral generally inside the tidal truncation radius (Roche limit) for planets, at \~10^11 cm. Consequently, the efficiency of the planetary formation process in this context will mostly depend on the ability of the resulting disk of rocks to spread via collisions beyond the Roche limit. It appears easier for the merger product of a doubly degenerate binary, whether it is a massive white dwarf or a neutron star, to harbor planets because it can spread beyond the Roche limit before becoming neutral.[Abridged]Comment: 34 pages, 2 figures, accepted for publication in Ap

Guarantee Schemes: An alternative to the Supervised Credit Program

Do guarantee programs lead to additionality in agricultural lending? Do guarantee programs contribute to small loans? Do guarantee programs encourage banks to use their own funds? Do guarantee programs reduce the cost of lending to banks and how cost effective are the guarantee programs? These are the issues that this paper addresses as it examines the effectiveness of the credit guarantee programs in increasing the amount of credit that goes to agriculture and indigenous industries.financial sector, financial reform, credit program, credit market, financial services