Charles Kim, Ph.D.
Professor
Department of Electrical and Computer Engineering
Howard University
2300 6th St. NW
Washington, DC 20059
Tel: 202-806-4821
E-mail: ckim@howard.edu
Office: L. K. Downing Hall #3014
  •   Web Site: www.mwftr.com


  • Areas of Interest
     
    1. Anticipation and Predictive Detection/Location of Incipient Cable, Line, and Arcing faults
    2. Embedded Systems and their safety and cyber-security:  Workshop Invitation - Exploring Cybersecurity Challenges in Electrified Transportation: A Focused Workshop, Feb 24- 25, 2016, Howard University Interdisciplinary Research Building, 2201 Georgia Ave NW, Washington DC 20059.  Workshop Flyer and Draft Schedule
    3. Modeling and Simulation by Cellular Automata  - Link to CA application page
  • 4. High Power Density Electro-Thermal System Diagnostics [Power Electronics] Link to the Research Description Page
  • 5. Vertically Integrated Projects (VIP) Program -a new approach for STEM education - Link to VIP at Howard University
  • 6. Entropy Minimax and Inductive Reasoning for Probabilistic Decision Making System under Incomplete knowledge and data

  • Publication

    Ph.D. Dissertation: An Intelligent Decision Making System for Detecting High Impedance Faults (Texas A&M University, 1989)

    A. Incipient Fault/Failure Detection and Anticipation

    U. S. Patent 8941387 "Apparatus and Method for Fault Detection and Location Determination" (January 27, 2015) -- Abstract: An electrical waveform is received over an electrical power line. A plurality of nominal electrical parameters are determined for the electrical power network and the plurality of nominal electrical parameters are associated with a state of the electrical power network in the absence of at least one transitory electrical fault in the network.  Subsequently, a plurality of electrical parameters of the electrical waveform are sampled when the at least one transitory electrical fault exists in the network.  A plurality of inductances are determined based at least in part upon a comparison of the nominal electrical parameters and the plurality of sampled electrical parameters.  The plurality of inductances are representative of inductances present in the network when the at least one transitory electrical fault exists in the network.  The plurality of inductances are analyzed to determine a distance and/or direction to the at least one electrical fault.

    Charles Kim, "Lecture Notes on Fault Detection and Location in Distribution Systems, 2010" -- This lecture note is the product of a post-graduate course (3 credit hours) I taught at Aalto University, formerly known as TKK or Helsinki University of Technology, (Department of Electrical Engineering), Espoo, Helsinki, in June 2010.
    Lecture 1 (Introduction), Lecture 2 (Faulted Power System), Lecture 3 (Fault Location Algorithms), Lecture 4 (Fault Indicators), Lecture 5 (Sub-cycle fault location method. Contact me if you need this note or read this transaction paper), Lecture 6 (Fault Location by Smart Meters), and Lecture 7 (Final Exam). Extra Lecture (Line Monitoring for Fault Anticipation and Vegetation Control. Contact me if you need this note.)

    Frank Zoko Ble, Matti Lehtonen, and Charles Kim, Arcing Faults Localization using RF-Signal Angle of Arrival Method, (2014) International Review of Electrical Engineering (IREE), 9(6), pp. 1136-1147. December 2014.

    Frank Zoko Ble, Matti Lehtonen, and Charles Kim, Novel Approach of Arcing Faults Electromagnetic Radiated Energy Source Location Using Antennas in Power Systems, (2014) International Review of Electrical Engineering (IREE), 9(5), pp. 1049-1059. October 2014.

    U.S. Patent 8897635 "System and Method of Detecting and Locating Intermittent and Other Faults" (November 25, 2014) - Abstract: A signal is conducted from a controller module onto a network via a first coupling.  The signal is transmitted across the network and received at one or more receiver modules via one or more second coupling.  At the one or more receiver modules, the received signal is analyzed and based upon the analysis, a determination is made as to whether a fault had occurred in the network and/or where the occurrence occurred.

    Frank Zoko Ble, Matti Lehtonen, Ari Sihvola, and Charles Kim, "Cross Correlation Method for Power Arcing Source Monitoring System," International Review of Electrical Engineering, 9(2), 440-452, April 2014.

    Frank Zoko Ble, Matti Lehtonen, Ari Sihvola, and Charles Kim, "Power Arcing Source Location using First Peak of Arrival RF-Signal," International Review of Electrical Engineering, 9(4), 873-881, August 2014.

    Frank Zoko Ble, Matti Lehtonen, Ari Sihvola, and Charles Kim, "Leading Edge Detection of RF-Signal for Power Arcing Source Location," International Review of Electrical Engineering, 9(5), 1060-1070, October 2014.

    Charles Kim, Tom Bialek, and Jude Awiylika (2013), "An Initial Investigation for Locating Self-Clearing Faults in Distribution Systems,"  IEEE Transactions on Smart Grid, 4(2), pp. 1105-1112, June 2013.  Proof.

    U. S. Patent 8050002 "Housing Arrangement for Fault Determination Apparatus and Method for Installing the Same" (November 1, 2011.) - Abstract:  A fault determination apparatus includes a housing.  The housing includes a circuit board disposed there within.  The housing is shaped and dimensioned for non-intrusive placement within an existing electrical system.  The circuit board is configured to provide one of a transmitter or a receiver within a fault determination system.  A first set of connectors is disposed at a first side of the housing and a second set of connectors disposed at the second end of the housing.  The first set of connectors and the second set of connectors are directly connected through the wires provided inside the apparatus while at least one wire under fault monitoring are tapped to the circuit board and configured so as to be electrically coupled to the existing electrical system.
     
    U. S. Patent 8102779 "System and Method of Detecting and Locating Intermittent Electrical Faults in Electrical Systems." (January 24, 2012) - Abstract:  Signals are transmitted from at least one transmitter that is positioned in an electrical network.  The signals that have been transmitted are received by the at least one single receiver at a single receiver positioned within the electrical network.  At the single receiver, the received signals are analyzed and a determination from the analyzing the received signals is made as to whether a fault has occurred in the electrical network.

    U. S. Patent 8711711 "System and Method of Detecting and Locating Intermittent and Other Faults" (April 29, 2014) - Abstract: Data associated with at least one building condition or status is sensed by one or more sensors.  The data from theses sensors may be sent over a data bus and received by the central computer.  In addition, a modulated signal may be transmitted by one or both of the transmitters across the data bus.  The modulated signal is received at the receiver, which analyzes the received modulated signal, and determines whether an intermittent fault has occurred on the data bus based upon the analyzing.  For example, the receiver may compare the received signal to an expected pattern and when a discrepancy exists, an intermittent fault is determined to exist.  The receiver may also determine the location of the fault based upon the analysis.

     
    Charles Kim, Tom Bialek, Matti Lehtonen, and Mohamed Abdel-Fattah, "Location of Underground Cable Transitory Faults," 2011 International Conference of Power System Transients (IPST), Delft, The Netherlands, June 14-17, 2011.
    Mohamed Abdel-Fattah, Matti Lehtonen, John Millar, and Charles Kim, "The Impact of the Distribution Network Type and Configuration on the Transient Behavior of the Fault and Neutral Points during Earth Faults," 2011 International Conference of Power System Transients (IPST), Delft, The Netherlands, June 14-17, 2011.
    Charles Kim and Tom Bialek, "Sub-Cycle Ground Fault Location - Formulation and Preliminary Results," 2011 IEEE Power Systems Conference & Exposition, March 20-23, 2011. Phoenix AZ.
     

    Charles Kim, "Detection and Location of Intermittent Faults by Monitoring Carrier Signal Channel Behavior of Electrical Interconnection System, Proceedings of 2009 IEEE Electric Ship Technologies Symposium p. 449-455. April 20 - 22, 2009. Baltimore, MD.

    Charles Kim, "Electromagnetic Radiation behavior of Low Voltage Arcing Fault," IEEE Transactions on Power Delivery, Jan 2009.
     
    Charles Kim, "Functionality Test of PLC Data Error Approach for Detecting Intermittent Faults," 11th Joint FAA/DoD/NASA Conference on Aging Aircraft, April 21-24, 2008.
     
    "HU Professor's Invention May Save Lives," The Hilltop, January 23, 2007
     
    Charles Kim and Robert Sowah, "Arcing Fault Detection with Experimental Verification using Antenna for Signal Capture of Radiated Electromagnetic Energy," 10th Aging Aircraft Conference, April 16 - 19, 2007. Palm Springs, CA.
     
    Charles Kim and Nicholas Johnson, "Detection of Intermittent Faults in Aircraft Electrical Wire by Utilizing Power Line Communication," Presented in the 9th joint FAA/DOD/NASA Conference on Aging Aircraft, March 7, 2006. Atlanta, GA.
     
    Charles Kim, S. J. Lee, and S. H, Kang, "Evaluation of Feeder Monitoring Parameters for Incipient Fault Detection Using Laplace Trend Statistic," IEEE Transaction on Industry Applications, vol.6, no. 6, pp. 1718-1724. Nov/Dec 2004
     
    Charles Kim, James A. Momoh and Heung-Jae Lee, "Phase-Time Analysis of the Leakage Impulse Current of Unhealthy Line-Post Pin Insulators," IEEE Transaction on Power Delivery. vol.18, no. 1, pp.323-328, January 2003
     
    Charles Kim and Mohamed F. Chouikha, "An Uncertainty Reasoning Method for Synergistic Diagnosis," International Journal of Computers and Their Applications,Vol.11, No.1, Mach 2004. pp.1-7
     
    Charles Kim, "Home Networking with Power Line Communication and Faulty-Wire Detection" Final Report.
    C. J. Kim, H. J. Lee, J. H. Shin, "Analysis of the Leakage Impulse Current in Faulty Insulators for Detection of Incipient Failures," Journal of Electrical Engineering and Information Science, vol. 49, no.8, August 2000.
     
    C. J. Kim, Peter Bofah, "Evidence Based Power Plant Diagnosis for Reliable Electric Energy Production in Power Utility," 4th International Conference on Power Systems Operation and Planning, July 31 - August 3, 2000, Accra, Ghana, pp.323-326
    Charles J. Kim, "Identification of Symptom Parameters for Failure Anticipation by Timed-Event Trend Analysis," Power Engineering Letter, pp.48-50, September 2000.
    C. J. Kim, J. H. Shin, M. H. Yoo, G. W. Lee, “A Study on the Characterization of the Incipient Failure Behavior of Insulators in Power Distribution Line,” IEEE Transactions on Power Delivery, Vol. 14, No. 2, pp. 519-524, April 1999.
     
    C. J. Kim, "Discrimination of Arcing Faults from Normal Distribution Disturbances by Wave Form Distortion Analysis," Journal of Electrical Engineering and Information Science, 1(2), 52-57, 1996.
    C. J. Kim and B. D. Russell, "Analysis of Distribution Disturbances and Arcing Faults using the Crest Factor", Electric Power Systems Research, volume 35, pp.141-148, 1995.
    C. J. Kim and B. D. Russell, "A Structure of Fuzzy Decision-Making System for Power System Protection," Second IEEE International Conference on Fuzzy Systems, March 28 - April 1993.
    C. J. Kim and B. D. Russell, "Automatic Generation of Membership Function and Fuzzy Rule using Inductive Reasoning," 3rd International Conference on Industrial Fuzzy Control and Intelligent Systems, 1993.

    C. J. Kim and B. D. Russell, "Application of Fuzzy Expert Model for Power Systems Protection," Proc. of 5th International Fuzzy Systems Association World Congress, 1993.

    C. J. Kim and B. D. Russell, "High Impedance Fault Detection using an Adaptive Element Model," IEEE Proceedings - Generation, Transmission and Distribution, Volume 140, Issue 2, pp. 153-159, March 1993.
     
    C. J. Kim and B. D. Russell, "A Learning Method for Use in Intelligent Computer Relays for High Impedance Faults", IEEE Transactions on Power Delivery, Vol. 6, no.1, pp. 109-115, January 1991. IEEE Explore.
     
    C. J. Kim, B. D. Russell, and Karan Watson, "Parameter-Based Process for Selecting High Impedance Fault Detection Techniques Using Decision Making Under Incomplete Knowledge," IEEE Transactions on Power Delivery, vol. 5, no. 3, 1314-1320, July 1990.
     
    C. J. Kim and B. D. Russell, "Classification of Faults and Switching Events by Inductive Reasoning and Expert System Methodology," IEEE Trans. on Power Delivery, vol. 4, no.3, July 1989. p. 1631 . IEEEXplore
     
    B. D. Russell, R. P. Chinchali, and C. J. Kim, "Behavior of Low Frequency Spectra During Arcing Fault and Switching Events," IEEE Trans. on Power Delivery, vol. 3, no. 4. October 1988. p. 1485-

    C. J. Kim and B. D. Russell, "Harmonic Behavior during Arcing Faults on Power Distribution Feeders," Electric Power Systems Research, vol. 14, 1988. p. 219 -

     

    B. Renewable Energy Systems

    Afoma Ihekwaba and Charles Kim, "Analysis of Electric Vehicle Charging Impact to Grid Voltage Regulation," 2017 North American Power Symposium, Sept 17 -19, 2017.  Morgantown, WV

    J. G. Seo, K. H. Kim, S. H. Park, and Charles Kim, "Analysis of Lightning Strike on Offshore Wind Farm", International Conference on Electrical Engineering, University of Hong Kong, Hong Kong, July 5 - 9, 2015.

    S. Y. Lim, J. G. Seo, K. H. Kim, and Charles Kim, "Optimal Network Configuration to Operate Economical Electric Stations," Wind Energy Grid-Adaptive Technologies 2014, 20 - 22 October 2014, Jeju, Korea.

    Charles Kim. "Lecture on Hybrid Renewable Micro-Power System Design using HOMER" at Korea University of Technology and Education,  Some material of the lecture are available here (Jan 2013 Lecture) and here (December 2013 Lecture).

    J. W. Ahn, Y. T. Oh, Charles Kim, and C. W. Park, "Configuration of a Renewable Micro-Power System for a Remote Village in Mongolia," International Smart Grid Conference and Exhibition, July 8 -10, 2013, Jeju-do, Korea.

    C.Air Traffic Flow Assessment and Modeling

    Daniel Akinbodunse, Obinna Obah, and Charles Kim, "Operational Evaluation of Traffic Management Advisor using Statistical Performance Metrics and Simulation Approach," Air Traffic Control Quarterly, Vol 14 (2) 311-327, 2006.
     
    Charles Kim, Daniel Akinbodunse, Khalid Abubaker, and Chimaobi Mbanaso, "Performance Evaluation of TMA in Arrival Traffic at IAH," Proc. of the 50th Annual Meeting of Air Traffic Controllers Association, August 11, 2005. pp.85-92.
     
    Charles Kim, Khalid Abubaker, and Obinna Obah, "Cellular Automata Modeling of En Route and Arrival Self-Spacing for Autonomous Aircraft," Proc. of the 50th Annual Meeting of Air Traffic Controllers Association, August 11, 2005. pp.127-134.
     
    Charles Kim, Daniel Akinbodunse, Chibuike Nwakamma, "Modeling Arrival Traffic using Arena", Proc. of 18th International Conference of Computer Applications in Industry and Engineering, Nov. 9-11, 2005. pp. 9-14. Arena Animation View.

     

    D. Intelligent Systems and Systems Safety & Security

    Charles Kim, "A Cyber Resilient Industrial Control System through Diversified Redundancy and Intrusion Detection," Keynote Speaker Presentation, World Congress on Industrial Control System Security (WCISCSS 2017), December 11 - 14, 2017.  Cambridge, UK.

    Dayne Robinson and Charles Kim, "A Cyber-Defensive Industrial Control System with Redundancy and Intrusion Detection," 2017 North American Power Symposium, Sept 17-19, 2017, Morgantown WV.

    Charles Kim and Dayne Robinson, "Modbus Monitoring for Networked Control Systems of Cyber-Defensive Architecture," 2017 IEEE SysCon, April 24-27, 2017.

    Charles Kim, "Cyber-Defensive Architecture for Networked Industrial Control Systems," International Journal of Engineering and Computer Science, Vol. 2, No. 1, pp. 1 - 9, Jan. 2017.  doi:10.24032/IJEACS/0201/01.https://doi.org/10.24032/ijeacs/0201/01

    Charles Kim, "A Cyber-Resilient Industrial Control System with Diversified Architecture and Control Bus Monitoring," World Congress on Industrial Control System Security (WCISCSS 2016), December 12 - 14, 2016.  London, UK.

    Charles Kim and Ravindranath Jaglal, "A cyber-robust connected-control system: Experimental validation,"  Proc. of the 29th International Conference on Computer Application in Industry and Engineering, pp. 133 - 138, Denver, CO. September 26-28, 2016.

    Charles Kim, Karen Green, and Andre Duarte Palhares, "Cybersecurity testbed experimentation of a resilient control system for power substations," Proc. of the 29th International Conference on Computer Application in Industry and Engineering, pp. 139 - 144, Denver, CO. September 26-28, 2016.

    Charles Kim, "Safety Challenges for Connected Cars", IEEE Transportation Electrification Community Newsletter June 2016.

    Charles Kim, "High-Tech Cars: Safety-Critical Computer Systems," Invited Talk in an IEEE Focused workshop for Exploring Cybersecurity Challenges in Electrified Transportation.  Feb 24 & 25, 2016. Washington DC.

    "Global Decision-Making System and Social Behavior Identification/Prediction," DARPA Next Generation Social Science (NGS2) Scientific Exchange and Profile, March 2016

    Derssie Mebratu and Charles Kim, "Combination of clustering algorithms to maximize the lifespan of distributed wireless sensors," J. Sens. Sens. Syst., 5, 63-72, 2016 (jssss-5-63-2016).  Link to the article in the Journal of Sensors and Sensor Systems.  

    Andres Alarcon-Ramirez, Madeline Martinez-Pabon, Charles Kim, "Design and Prototype of a Wireless Tailgate Detection System Using Sun Spot Platform," International Journal of Embedded Systems and Applications, Vol.1, No.1, September 2011.
     
    Erwin Tom Gilmore, Chukwunweike Ugbome, and Charles Kim, "An IR-based Pedestrian Detection System Implemented with Matlab-equipped Laptop and Low-Cost Microcontroller," International Journal of Computer Science & Information Technology, Vol. 3, No. 5, pp. 79-87. October 2011
    Charles Kim and Peter Bofah, "An Evaluation Framework for Power Electronic Device Models Using Decision Making Under Uncertainties," 51st National Aerospace and Electronics Conference, October 10 - 12, 2000, Dayton, Ohio.
    C. J. Kim, "A Practical Framework for Managing Uncertainties in Power Device Model Evaluation," 9th IEEE workshop on Computers in Power Electronics, July 16 -18, Virginia Tech, 2000.
     
    C. J. Kim, "An Algorithmic Approach for Fuzzy Inference," IEEE Transactions on Fuzzy Systems, Vol.5, no.4, pp.585-598, Nov 1997
     
    Obinna Obah and Charles Kim, "Fast Static Contingency Screening based on Reactive Loss Compensation Index," 2008 IEEE PES General Meeting, 20 - 24 July, 2008. Pittsburgh, PA.
     
    Charles Kim and Obinna Obah, "Vulnerability Assessment of Power Grid Using Graph Topological Indices", International Journal of Emerging Electric Power Systems, vol.8, Issue 6, 2007. article 4. http://www.bepress.com/ijeeps/vol8/iss6/art4
     
    Charles Kim and Jamshid Goshtasbi, "Internet-Based Global Decision Making Architecture", Proceedings of the ICSA 14th International Conference on Computers in Industry and Engineering, November 27-29, 2001, pp. 130-133, Las Vegas, NV
     
    Charles Kim and Mohamed F. Chouikha, "Attenuation Characteristics of High Rate Home-Networking PLC Signals," ; IEEE Transactions on Power Delivery Vol.17, No.4, pp.945-950, October 2002.
    Charles Kim, "Power System Stability in Small World Perspective",  CRIS2006: Third Conference on Critical Infrastructure, Alexandria, VA, September 25-27, 2006.

    Charles Kim, Deborah Jackson, and Peter Keiller (2013) "Development and Team-Teaching of 'Computers and Nuclear Energy' for Non-Nuclear Engineering Students," 2013 Conference on Nuclear Training and Education, Jacksonville, FL.  Feb 3-6, 2013. 

    Charles Kim, Ronderio Hunt, and Peter Keiller (2012) “Analysis of Emergency Diesel Generator Failure Incidents in Nuclear Power Plants” 30th International System Safety Conference. August 2012. Atlanta, GA.

    Madeline Martinez-Pabon and Charles Kim (2012) “Quantification of Complexity and Coupling Indices to Validate Normal Accident Theory in Telecommunication Network Accidents.” 30th International System Safety Conference. August 2012. Atlanta, GA.

    Keiller, Peter A; Kim, Charles J. ; Trimble, John; Mejias, Marlon, "Revisiting the Performance of Mixtures of Software Reliability Growth Models," The 7th International Symposium on   Management, Engineering and Informatics: MEI 2011  in the Context of The 15th Multi-conference on Systemics, Cybernetics and Informatics: WMSCI 2011 July 19th - July 22nd, 2011 – Orlando, Florida, USA

    Charles Kim and Peter Keiller (2011) "A Course Development Project for Hardware Diversity and Software Reliability Education for Digital Instrumentation and Control of Nuclear Power Plant," 2011 Conference on Nuclear Training and Education, Feb 6-9. 2011. Jacksonville, FL. 
     
    Oluwayeminisi Sonoiki and Charles Kim (2011) "Development of a Hardware Diversity Training Kit for Nuclear Industry", ANS 2011 Student Conference, April 14-17, 2011. Atlanta, GA.
    E. Engineering Education and Other Interests

    "Vertically Integrated Projects (VIP) Programs: Multidisciplinary Projects with Homes in Any Discipline," Paper presented at 2017 ASEE Annual Conference & Exposition, Columbus, Ohio. https://peer.asee.org/29103

    Experimental Centric Pedagogy in Circuits and Electronics Courses at 13 Universities, 2016 ASEE Annual Conference & Exposition

    Experimental Centric Pedagogy in First-Year Engineering Courses, 2016 ASEE Annual Conference & Exposition

    Charles Kim, Deborah Jackson, and Peter Keiller, "Interdisciplinary Team-Teaching Experience For A Computer And Nuclear Energy Course For Electrical And Computer Engineering Students," American Journal of Engineering Education, Vol. 7, No .1 June 2016.  Link to the AJEE for the paper and the Vol 7 No 1 Issue (2016).

    Connor, K. A., & Astatke, Y., & Kim, C. J., & Eldek, A. A., & Majlesein, H. R., & Andrei, P., & Attia, J. O., & Gullie, K. A., & Graves, C. A., & Osareh, A. R. (2015, June), Simultaneous Implementation of Experimental Centric Pedagogy in 13 ECE Programs Paper presented at 2015 ASEE Annual Conference and Exposition, Seattle, Washington. 10.18260/p.24712

    The Implementation of Experimental Centric Pedagogy in 13 ECE Programs - The View from Students and Instructors, 2016 ASEE Annual Conference & Exposition

    Peter Keiller, Charles Kim, and Robert Rwebangira, "Interdisciplinary Team Teaching Experience of a Computer and Nuclear Energy Course Designed for Non-Nuclear Engineering Students,"  The 2014 International Conference on Frontiers in Education: Computer Science and Computer Engineering, July 21-24, 2014. Las Vegas, NV, USA.

    Charles Kim. Mohamed Chouikha, and Kojo Linder, "Bridging Lecture and Lab by Mobile Studio - Experience in Electrical Engineering Courses, " 2009 International Conference on Engineering Education (ICEE_iCEER), August 23-28, 2009.  Seoul, Korea.

    Charles Kim, Mohamed Chouikha, and Veronica Thomas, "Mobile Studio Experience of Experiential Learning in Electrical Engineering Class," ASEE 2008 Annual Conference and Exposition, June 22-25, 2008.  Pittsburgh, PA.

    Charles Kim, "Assessment Experience in Learning Outcomes and the Student Criterion", presented in the Best Assessment Processes VIII, February 27-28, 2006, Terre Huate, IN (at Rose-Hulman Institute)
     
    Charles Kim et al, "Mobile Studio Lab Classroom for Minority Students at Howard University," The 2006 HP Technology for Teaching Worldwide Higher Education Conference, Feb 2-3, 2006. Monterey, CA.
    Charles Kim. "Electric Power Engineering Education in Korea: Status Report," IEEE Transactions on Power Systems, Vol. 14, No.4., pp1187-1192, Nov 1999.
     
    U. S. Patent 8067916 "Power Cutting Tool with Synchronized Dust Control Device." (November 29, 2011.) - Abstract: A cutting tool such as a miter saw, arranged to have an arrangement for selectively making and breaking power of a first circuit and an independent second circuit each connected respectively to a first motor operating the cutting tool and to a second motor operating a dust suppressor such as a vacuum device.  The arrangement enables the two circuits to serve the first and second motros in synchrony and to be operated by the switch of the cutting tool.  The arrangement may comprise a relay adapted to energize and de-energize the second circuit.  The second circuit may comprise one or more electrical receptacles enabling the second motor to operate under control of the switch after being plugged in to one of the receptacles.  The cutting tool may comprise a receptacle which is hard wired to the first circuit.  The cutting tool may incorporate a dynamic brake.
             
    U. S. Patent 8525421 "Lighting Apparatus and Method" (September 3, 2013)- Abstract: A lighting element is disposed in an array of lighting elements.  At the lighting element, a lighting status of at least one neighboring lighting element is sensed.  Independent of any other lighting element, a lighting adjustment for the lighting element by applying the sensed lighting status to a predetermined rule is determined.  The lighting apparatus is applied to the lighting elements to adjust an illumination of the lighting element.