Investigation of Motor Current Signature Analysis in Detecting Unbalanced Motor Windings of an Induction Motor with Sensorless Vector Control Drive

Maintaining the efficiency of AC motors in site equipment is important, given the increasing cost of energy. Reduction of motor efficiency from baseline manufacturer data can go undetected until total failure of the equipment is experienced. This paper introduces motor current signature analysis methods used to detect the early onset of motor efficiency reduction in AC motors controlled by modern Sensorless-Vector Variable Speed Control inverters. A step increase in the resistance of one stator winding is simulated in stages. Off-line processing of motor current data signals using data analysis methods developed for the MATLAB platform is used to identify imbalances caused by subtle stator resistance increases. Initial results indicate that small increases in stator resistances can be observed in the motor current signals received after data processing techniques have been used on the measured signals. The test results are presented herein along with details on the research work to be continued

Fault Detection of Gearbox from Inverter Signals Using Advanced Signal Processing Techniques

The gear faults are time-localized transient events so time-frequency analysis techniques (such as the Short-Time Fourier Transform, Wavelet Transform, motor current signature analysis) are widely used to deal with non-stationary and nonlinear signals. Newly developed signal processing techniques (such as empirical mode decomposition and Teager Kaiser Energy Operator) enabled the recognition of the vibration modes that coexist in the system, and to have a better understanding of the nature of the fault information contained in the vibration signal. However these methods require a lot of computational power so this paper presents a novel approach of gearbox fault detection using the inverter signals to monitor the load, rather than the motor current. The proposed technique could be used for continuous monitoring as well as on-line damage detection systems for gearbox maintenance

Licensure Portability: Assuring Access to Quality Care in Physical Therapy

The concurrent circumstances of an increasingly mobile workforce, disparities in access to healthcare, and the ability to deliver care through technology (e.g., telehealth) present the need and the opportunity to practice across state borders. Over the past four years, the Federation of State Boards of Physical Therapy (FSBPT) has explored professional licensure models that will allow cross border practice. This paper reviews FSBPT's exploratory process and describes some of the advantages of an interstate compact. It concludes that if agreement among state licensing boards can be achieved, a compact could serve as a viable means to increase patient access to quality physical therapy care.

Planning for Digital Preservation

Session presented at 2019 Towson Conference for Academic Libraries, Towson, MD. What does it take to plan for successful digital preservation of organizational assets? Who should be involved? How do you manage stakeholder expectations and keep your project on track? Learn how librarians preserved an at-risk collection of performance recordings and explore digital preservation project planning from a variety of perspectives in a scenario-based activity

Digital Preservation in Practice: Implementing Solutions at JMU

Poster presented at JMU Libraries Showcase

Digital Image Curation Tools

Workshop presented to JMU faculty and staff

Top Secret or Real Genius? Developing a Meaningful Internship for LIS Grad Students at Your Out-of-the-Way Library

Session presented at The Collective Conference, Knoxville, TN

Tributes to Professor Cyril A. Fox, Jr.

Cy Fox often forgets that he was supposed to be “only” an academic. For three decades, as he helped thousands of law students through the intricacies of the Rule in Shelley’s Case, or watched them calculate a “life in being plus twenty one years” for the Rule Against Perpetuities, he failed to appreciate that law school was supposed to be an amalgam of theory and confusion, not the place for his teaching law students about helping real people solve real life problems