General Dynamics

About: General Dynamics is a company organization based out in Fairfax, Virginia, United States. It is known for research contribution in the topics: Signal & Propellant. The organization has 5722 authors who have published 5819 publications receiving 85768 citations. The organization is also known as: GD & General Dynamics Corporation.

Bell housing sealing assembly for mounted connector

Abstract: A sealing assembly for protecting the exposed components of a mounted electrical connector from the environment provides a seal between a connector backshell and a mounting plate to which the connector is mounted. The bell housing sealing assembly generally comprises a tubular member having a bottom end and a top end, the member being of sufficient inside diameter and length for surrounding an electrical connector having a backshell between the connector backshell and a mounting plate to which the connector is mounted; a top seal for sealing between the top end of the tubular member and the backshell of the surrounded connector; and a bottom seal for sealing between the bottom end of the tubular member and the mounting plate. The sealing assembly is threadably attached to either the connector backshell or, preferably, to the receptacle mounting nut. A second embodiment employs a force fit double lip seal as a top seal.

Association of Participation in the Oncology Care Model With Medicare Payments, Utilization, Care Delivery, and Quality Outcomes.

Abstract: Importance In 2016, the US Centers for Medicare & Medicaid Services initiated the Oncology Care Model (OCM), an alternative payment model designed to improve the value of care delivered to Medicare beneficiaries with cancer. Objective To assess the association of the OCM with changes in Medicare spending, utilization, quality, and patient experience during the OCM's first 3 years. Design, setting, and participants Exploratory difference-in-differences study comparing care during 6-month chemotherapy episodes in OCM participating practices and propensity-matched comparison practices initiated before (January 2014 through June 2015) and after (July 2016 through December 2018) the start of the OCM. Participants included Medicare fee-for-service beneficiaries with cancer treated at these practices through June 2019. Exposures OCM participation. Main outcomes and measures Total episode payments (Medicare spending for Parts A, B, and D, not including monthly payments for enhanced oncology services); utilization and payments for hospitalizations, emergency department (ED) visits, office visits, chemotherapy, supportive care, and imaging; quality (chemotherapy-associated hospitalizations and ED visits, timely chemotherapy, end-of-life care, and survival); and patient experiences. Results Among Medicare fee-for-service beneficiaries with cancer undergoing chemotherapy, 483 319 beneficiaries (mean age, 73.0 [SD, 8.7] years; 60.1% women; 987 332 episodes) were treated at 201 OCM participating practices, and 557 354 beneficiaries (mean age, 72.9 [SD, 9.0] years; 57.4% women; 1 122 597 episodes) were treated at 534 comparison practices. From the baseline period, total episode payments increased from $28 681 for OCM episodes and $28 421 for comparison episodes to $33 211 for OCM episodes and $33 249 for comparison episodes during the intervention period (difference in differences, -$297; 90% CI, -$504 to -$91), less than the mean $704 Monthly Enhanced Oncology Services payments. Relative decreases in total episode payments were primarily for Part B nonchemotherapy drug payments (difference in differences, -$145; 90% CI, -$218 to -$72), especially supportive care drugs (difference in differences, -$150; 90% CI, -$216 to -$84). The OCM was associated with statistically significant relative reductions in total episode payments among higher-risk episodes (difference in differences, -$503; 90% CI, -$802 to -$204) and statistically significant relative increases in total episode payments among lower-risk episodes (difference in differences, $151; 90% CI, $39-$264). The OCM was not significantly associated with differences in hospitalizations, ED visits, or survival. Of 22 measures of utilization, 10 measures of quality, and 7 measures of care experiences, only 5 were significantly different. Conclusions and relevance In this exploratory analysis, the OCM was significantly associated with modest payment reductions during 6-month episodes for Medicare beneficiaries receiving chemotherapy for cancer in the first 3 years of the OCM that did not offset the monthly payments for enhanced oncology services. There were no statistically significant differences for most utilization, quality, and patient experience outcomes.

Dosimetry considerations for electrical stun devices.

Abstract: Electrical dosimetry issues are discussed in relation to electrical stun devices (ESDs). A measure of effectiveness is based on a 'threshold factor,' FT, calculated with a myelinated nerve model that simulates stimulation of a reference-case neuron (20 µm diameter, 1 cm distant). Several ESDs were measured in the laboratory using resistive loads of 100–1000 Ω; some included air gaps bridged via an electric arc. Conducted current waveform parameters and the associated threshold factors depend on the resistance of the load. Thresholds were also determined for ideal monophasic and biphasic square-wave stimuli, and compared with measured ESD waveforms. Although FT is proposed as a metric of strength, an approximate surrogate is the charge within the largest phase of the current versus time waveform. The approximation is reasonably accurate for monophasic waveforms with phase durations below about 100 µs, and for charge-balanced biphasic square-wave stimuli with phase durations between about 40 and 100 µs.

An Equivalent Model for UAV Automated Aerial Refueling Research

Abstract: I. Abstract UTURE combat UAVs will need in-flight refueling to realize their full potential. Refueling brings the benefits of increased range, extended time on station, and rapid deployment. In addition, it allows UAVs to strike from long distances without the need for forward staging bases. However, a significant challenge exists in the precise navigation and control needed to allow UAV receivers to perform refueling in a manner similar to manned aircraft. Boeing and Northrop Grumman are under contract to the Air Force Research Laboratory to develop and flight demonstrate an automatic aerial refueling system for combat unmanned air vehicles. To protect proprietary data associated with their respective competing designs, an equivalent model as shown in Figure 1 was needed. This model would be representative in performance and maneuvering characteristics of a tailless UAV. It was developed from a specification created by a panel of experts at the AFRL with inputs from both contractors. F