Michigan Technological University

About: Michigan Technological University is a education organization based out in Houghton, Michigan, United States. It is known for research contribution in the topics: Population & Volcano. The organization has 8023 authors who have published 17422 publications receiving 481780 citations. The organization is also known as: MTU & Michigan Tech.

Heartbeat-Driven Medium-Access Control for Body Sensor Networks

Abstract: In this paper, a novel time division multiple access based MAC protocol designed for body sensor networks (BSNs) is presented. H-medium-access control (MAC) aims to improve BSNs energy efficiency by exploiting heartbeat rhythm information, instead of using periodic synchronization beacons, to perform time synchronization. Heartbeat rhythm is inherent in every human body and observable in various biosignals. Biosensors in a BSN can extract the heartbeat rhythm from their own sensory data by detecting waveform peaks. All rhythms represented by peak sequences are naturally synchronized since they are driven by the same source, i.e., the heartbeat. Following the rhythm, biosensors can achieve time synchronization without having to turn on their radio to receive periodic timing information from a central controller, so that energy cost for time synchronization can be completely eliminated and the lifetime of the network can be prolonged. An active synchronization recovery scheme is also developed, including two resynchronization approaches. The algorithms are simulated using the discrete event simulator OMNet ++ with real-world data from the Massachusetts Institute of Technology-Boston's Beth Israel Hospital multiparameter database Multiparameter Intelligent Monitoring for Intensive Care. The results show that H-MAC can prolong the network life dramatically.

Electrical Engineering: Principles and Applications

Abstract: (NOTE: Each chapter concludes with Summary and Problems.) I. CIRCUITS. 1. Introduction. Overview of Electrical Engineering. Circuits, Currents, and Voltages. Power and Energy. Kirchhoff's Current Law. Kirchhoff's Voltage Law. Introduction to Circuit Elements. Introduction to Circuits. 2. Resistive Circuits. Resistances in Series and Parallel. Network Analysis by Using Series and Parallel Equivalents. Voltage-Divider and Current-Divider Circuits. Node-Voltage Analysis. Mesh-Current Analysis. Thevenin and Norton Equivalent Circuits. Superposition Principle. Wheatstone Bridge. 3. Inductance and Capacitance. Capacitance. Capacitances in Series and Parallel. Physical Characteristics of Capacitors. Inductance. Inductances in Series and Parallel. Practical Inductors. Mutual Inductance. 4. Transients. First-Order RC Circuits. DC Steady State. RL Circuits. RC and RL Circuits with General Sources. Second-Order Circuits. 5. Steady-State Sinusoidal Analysis. Sinusoidal Currents and Voltages. Phasors. Complex Impedances. Circuit Analysis with Phasors and Complex Impedances. Power in AC Circuits. Thevenin and Norton Equivalent Circuits. Balanced Three-Phase Circuits. 6. Frequency Response, Bode Plots, and Resonance. Fourier Analysis, Filters, and Transfer Functions. First-Order Lowpass Filters. Decibels, the Cascade Connection, and Logarithmic Frequency Scales. Bode Plots. First-Order Highpass Filters. Series Resonance. Parallel Resonance. Ideal and Second-Order Filters. Digital Signal Processing. II. DIGITAL SYSTEMS. 7. Logic Circuits. Basic Logic Circuit Concepts. Representation of Numerical Data in Binary Form. Combinatorial Logic Circuits. Synthesis of Logic Circuits. Minimization of Logic Circuits. Sequential Logic Circuits. 8. Microcomputers. Computer Organization. Memory Types. Digital Process Control. The Motorola 68HC11/12. The Instruction Set and Addressing Modes for the 68HC11. Assembly-Language Programming. 9. Computer-Based Instrumentation Systems. Measurement Concepts and Sensors. Signal Conditioning. Analog-to-Digital Conversion. LabVIEWaA A . III. ELECTRONICS. 10. Diodes. Basic Diode Concepts. Load-Line Analysis of Diode Circuits. Zener-Diode Voltage-Regulator Circuits. Ideal-Diode Model. Piecewise-Linear Diode Models. Rectifier Circuits. Wave-Shaping Circuits. Linear Small-Signal Equivalent Circuits. 11. Amplifiers: Specifications and External Characteristics. Basic Amplifier Concepts. Cascaded Amplifiers. Power Supplies and Efficiency. Additional Amplifier Models. Importance of Amplifier Impedances in Various Applications. Ideal Amplifiers. Frequency Response. Linear Waveform Distortion. Pulse Response. Transfer Characteristic and Nonlinear Distortion. Differential Amplifiers. Offset Voltage, Bias Current, and Offset Current. 12. Field-Effect Transistors. NMOS and PMOS Transistors. Load-Line Analysis of a Simple NMOS Amplifier. Bias Circuits. Small-Signal Equivalent Circuits. Common-Source Amplifiers. Source Followers. CMOS Logic Gates. 13. Bipolar Junction Transistors. Current and Voltage Relationships. Common-Emitter Characteristics. Load-Line Analysis of a Common-Emitter Amplifier. pnp Bipolar Junction Transistor. Large-Signal DC Circuit Models. Large-Signal DC Analysis of BJT Circuits. Small-Signal Equivalent Circuits. Common-Emitter Amplifiers. Emitter-Followers. 14. Operational Amplifiers. Ideal Operational Amplifiers. Summing-Point Constraint. Inverting Amplifiers. Noninverting Amplifiers. Design of Simple Amplifiers. Op-Amp Imperfections in the Linear Range of Operation. Nonlinear Limitations. DC Imperfections. Differential and Instrumentation Amplifiers. Integrators and Differentiators. Active Filters. IV. ELECTROMECHANICS. 15. Magnetic Circuits and Transformers. Magnetic Fields. Magnetic Circuits. Inductance and Mutual Inductance. Magnetic Materials. Ideal Transformers. Real Transformers. 16. DC Machines. Overview of Motors. Principles of DC Machines. Rotating DC Machines. Shunt-Connected and Separately Excited DC Motors. Series-Connected DC Motors. Speed Control of DC Motors. 17. AC Machines. Three-Phase Induction Motors. Equivalent Circuit and Performance Calculations for Induction Motors. Synchronous Machines. Single-Phase Motors. Stepper Motors. Appendix A: Complex Numbers. Appendix B: Nominal Values and the Color Code for Resistors. Appendix C: Preparing for the Fundamentals of Engineering Exam. Appendix D: Computer-Aided Circuit Analysis. Index.

3D Underwater Sensor Network Localization

Abstract: We transform the 3D underwater sensor network (USN) localization problem into its 2D counterpart by employing sensor depth information and a simple projection technique. We first prove that a nondegenerative projection preserves network localizability. We then prove that given a network and a constant k, all of the geometric k-lateration localization methods are equivalent. Based on these results, we design a purely distributed bilateration localization scheme for 3D USNs termed as underwater sensor positioning (USP). Through extensive simulations, we show that USP has the following nice features: (1) improved localization capabilities over existing 3D methods, (2) low storage and computation requirements, (3) predictable and balanced communication overhead, and (4) robustness to errors from the underwater environment.

Atmospheric co2 and the composition and function of soil microbial communities

Abstract: Elevated atmospheric CO2 has the potential to increase the production and alter the chemistry of organic substrates entering soil from plant production, the magnitude of which is constrained by soil-N availability. Because microbial growth in soil is limited by substrate inputs from plant production, we reasoned that changes in the amount and chemistry of these organic substrates could affect the composition of soil microbial com- munities and the cycling of N in soil. We studied microbial community composition and soil-N transformations beneath Populus tremuloides Michx. growing under experimental atmospheric CO2 (35.7 and 70.7 Pa) and soil-N-availability (low N 5 61 ng N·g 21 ·d 21 and high N 5 319 ng N·g 21 ·d 21 ) treatments. Atmospheric CO2 concentration was modified in large, open-top chambers, and we altered soil-N availability in open-bottom root boxes by mixing different proportions of A and C horizon material. We used phospholipid fatty-acid analysis to gain insight into microbial community composition and coupled this analysis to measurements of soil-N transformations using 15 N-pool dilution techniques. The infor- mation presented here is part of an integrated experiment designed to elucidate the phys- iological mechanisms controlling the flow of C and N in the plant-soil system. Our ob- jectives were (1) to determine whether changes in plant growth and tissue chemistry alter microbial community composition and soil-N cycling in response to increasing atmospheric CO2 and soil-N availability and (2) to integrate the results of our experiment into a synthesis of elevated atmospheric CO2 and the cycling of C and N in terrestrial ecosystems. After 2.5 growing seasons, microbial biomass, gross N mineralization, microbial im- mobilization, and nitrification (gross and net) were equivalent at ambient and elevated CO2, suggesting that increases in fine-root production and declines in fine-root N concentration were insufficient to alter the influence of native soil organic matter on microbial physiology; this was the case in both low- and high-N soil. Similarly, elevated CO2 did not alter the proportion of bacterial, actinomycetal, or fungal phospholipid fatty acids in low-N or high-N soil, indicating that changes in substrate input from greater plant growth under elevated CO2 did not alter microbial community composition. Our results differ from a substantial number of studies reporting increases and decreases in soil-N cycling under elevated CO 2. From our analysis, it appears that soil-N cycling responds to elevated atmospheric CO 2 in experimental situations where plant roots have fully colonized the soil and root-associated C inputs are sufficient to modify the influence of native soil organic matter on microbial physiology. In young developing ecosystems where plant roots have not fully exploited the soil, microbial metabolism appears to be regulated by relatively large pools of soil organic matter, rather than by the additional input of organic substrates under elevated CO 2.