Time filter

Source Type

Cleveland, OH, United States

Machining time reduction is a critical issue when machining a sculptured surface on multi-axis NC machines. In order to reduce the machining cost the machining time must be the shortest possible. Definitely, this is the case where the sentence "Time is money!" works. Generally speaking, the optimization of surface generation on multi-axis NC machine results in time savings. It is the right point to recall the wise words (John Shebbeare 1709-1788) "gaining time is gaining everything!" An analytical approach that makes it possible the development of the most efficient methods of sculptured surfaces machining on multi-axis NC machine is briefly outlined in this paper. The approach is based on wide application of the powerful methods those developed in Differential Geometry of surfaces, as well as in Kinematics of multi-parametric motion of a rigid body in E3 space. Due to that the approach is commonly referred to as the DG/K-based approach of surface generation. The author began working on the development of the approach in late 1970th-early 1980th. © 2012 Springer Basel AG. Source

Lee K.,EATON Inc | Blasko V.,UTRC - United Technologies Research Center | Jahns T.M.,University of Wisconsin - Madison | Lipo T.A.,University of Wisconsin - Madison
IEEE Transactions on Power Delivery

Active rectifiers using pulsewidth-modulation voltage-source converters are popular choices for adjustable-speed drives to provide high input power quality. However, input current harmonics are often generated as a result of input voltage source disturbances. Since the frequencies of the fifth-, seventh-, and higher-order harmonics can easily exceed the current controller bandwidth in high-power applications, the elimination of these harmonic disturbances imposes difficult control challenges. Cost-effective observer-based harmonic estimation and mitigation methods are introduced in this paper that compensate delay effects caused by the digital signal processing. These delays can significantly limit the current controller bandwidth if not compensated. Analytical, simulation, and experimental results are developed to illustrate the effectiveness of the new harmonic estimation and control techniques. © 2010 IEEE. Source

Greenfield S.,EATON Inc
10th International Conference on Condition Monitoring and Machinery Failure Prevention Technologies 2013, CM 2013 and MFPT 2013

Over a period over 12 million flight hours in airline service, the electronic oil debris monitoring system of the GE90 engine has demonstrated its operational and cost effectiveness. Lessons have been learned from two in-flight shutdowns that progressed beyond the timely alerts generated by the hardware. These have led to software and maintenance-procedure changes which most GE90 operators have now implemented. As a result, the GE90 debris monitoring system has become a mature, proven system. The sophisticated condition monitoring and communications systems of the Boeing 777 aircraft and the GE90 engine can now take full advantage of its capabilities. The unprecedented reliability and reduced maintenance burden have guaranteed Eaton QDM systems placement on all subsequent gas turbines from GE90 through to the new Rolls Royce XWB engine for the Airbus A350 XWB to take her first flight next year. Source

Eaton J.W.,EATON Inc
Journal of Process Control

GNU Octave 1 has been available for nearly two decades. During that time the scope of the project has grown from a simple interface to numerical tools intended for classroom use to a capable system with hundreds of thousands of users worldwide. This paper provides an overview of the Octave project, summarizes some recently completed additions, and describes in detail the ways in which Octave may be used to perform reproducible research. © 2012 Elsevier Ltd. Source

Stern A.,A+ Network | Mitsakakis N.,University of Toronto | Paulden M.,University of Alberta | Alibhai S.,EATON Inc | And 5 more authors.
BMC Health Services Research

Background: The study was conducted to determine the clinical and cost effectiveness of enhanced multi-disciplinary teams (EMDTs) vs. 'usual care' for the treatment of pressure ulcers in long term care (LTC) facilities in Ontario, Canada. Methods. We conducted a multi-method study: a pragmatic cluster randomized stepped-wedge trial, ethnographic observation and in-depth interviews, and an economic evaluation. Long term care facilities (clusters) were randomly allocated to start dates of the intervention. An advance practice nurse (APN) with expertise in skin and wound care visited intervention facilities to educate staff on pressure ulcer prevention and treatment, supported by an off-site hospital based expert multi-disciplinary wound care team via email, telephone, or video link as needed. The primary outcome was rate of reduction in pressure ulcer surface area (cm2/day) measured on before and after standard photographs by an assessor blinded to facility allocation. Secondary outcomes were time to healing, probability of healing, pressure ulcer incidence, pressure ulcer prevalence, wound pain, hospitalization, emergency department visits, utility, and cost. Results: 12 of 15 eligible LTC facilities were randomly selected to participate and randomized to start date of the intervention following the stepped wedge design. 137 residents with a total of 259 pressure ulcers (stage 2 or greater) were recruited over the 17 month study period. No statistically significant differences were found between control and intervention periods on any of the primary or secondary outcomes. The economic evaluation demonstrated a mean reduction in direct care costs of $650 per resident compared to 'usual care'. The qualitative study suggested that onsite support by APN wound specialists was welcomed, and is responsible for reduced costs through discontinuation of expensive non evidence based treatments. Insufficient allocation of nursing home staff time to wound care may explain the lack of impact on healing. Conclusion: Enhanced multi-disciplinary wound care teams were cost effective, with most benefit through cost reduction initiated by APNs, but did not improve the treatment of pressure ulcers in nursing homes. Policy makers should consider the potential yield of strengthening evidence based primary care within LTC facilities, through outreach by APNs. Trial registration. ClinicalTrials.gov identifier NCT01232764. © 2014 Stern et al.; licensee BioMed Central Ltd. Source

Discover hidden collaborations