Finite Impulse Response (FIR) filters can be designed to be linear phase, causal, and they are guaranteed to be stable. These advantages result in their wide adoption in audio processing, communications, image processing, and pattern recognition, among other applications. Some common design methods of FIR filters include windowing, multiband with transition bands, constrained least squares, frequency-sampling, arbitrary response, and raised cosine. Yet, despite the ubiquity of FIR filters, no open-source implementation of the frequency-sampling method of FIR design in the popular C# language is available.This paper presents open-source FIR filter design code that implements the frequency-sampling method in C#, and verifies its operation. This well-known filter design method takes a set of frequencies and the desired filter’s amplitude at each, and then interpolates these points to create the same number of frequency/amplitude pairs as the desired FIR filter order, using equally-spaced frequencies spanning ω=0 to π rad/s. The inverse Discrete Fourier Transform is applied to this data to create a time-domain response, and then this is windowed to create the impulse response of the system that implements the desired filter. Performance testing compared paired filters in MATLAB and C# that were each designed to mimic several audiograms. Each audiogram specified desired attenuations from -80 dB to 6 dB at eight logarithmically spaced frequencies from 250 Hz to 8 kHz, and these were realized with the design of a 1000 tap FIR filter.In all cases, the C#-computed filter’s frequency domain performance matched the one designed by MATLAB essentially perfectly, to within two orders of magnitude of the precision of the double data type, suggesting that the open-source FIR filter design method we describe is successful.

This chapter aim to investigate the pedagogic effect of demonstration construction quality. The hypothesis that the construction finish of a classroom demonstration affects its pedagogic value will be assessed by constructing two different demonstrations: a remote controlled vehicle and a laser-based audio communication device. This study looks at two types of construction: "raw" and "polished." Raw demonstrations use prototype-quality construction techniques that include exposed solderless breadboards, whereas polished demos use production-quality construction techniques aimed to replicate conventional consumer electronics. The impact of the demonstrations on student interest was measured by creating paired pairs of demos of raw and polished quality. These were utilized in lectures to 119 students, and post-lecture surveys were conducted to gauge student interest and comprehension. Implementing only a single demonstration in both raw and polished forms, preliminary findings reveal that students in both technical and nontechnical majors score higher in objective assessment and report more interest in the topic when employing raw construction techniques (two-tailed p=0.051 and 0.01 respectively). The findings indicate that demonstrations are more valuable in their raw form.

Recent concern for local drug delivery and withdrawal of the first Food and Drug Administration-approved bioresorbable scaffold emphasizes the need to optimize the relationships between stent design and drug release with imposed arterial injury and observed pharmacodynamics. In this study, we examine the hypothesis that vascular injury is predictable from stent design and that the expanding force of stent deployment results in increased circumferential stress in the arterial tissue, which may explain acute injury poststent deployment. Using both numerical simulations and ex vivo experiments on three different stent designs (slotted tube, corrugated ring, and delta wing), arterial injury due to device deployment was examined. Furthermore, using numerical simulations, the consequence of changing stent strut radial thickness on arterial wall shear stress and arterial circumferential stress distributions was examined. Regions with predicted arterial circumferential stress exceeding a threshold of 49.5 kPa compared favorably with observed ex vivo endothelial denudation for the three considered stent designs. In addition, increasing strut thickness was predicted to result in more areas of denudation and larger areas exposed to low wall shear stress. We conclude that the acute arterial injury, observed immediately following stent expansion, is caused by high circumferential hoop stresses in the interstrut region, and denuded area profiles are dependent on unit cell geometric features. Such findings when coupled with where drugs move might explain the drug-device interactions.

Computer simulations are commonly employed to teach intuitive causal engineering relationships, yet there is little research regarding what aspects make such simulations maximally pedagogically effective. This paper investigates how the discrete vs. continuous nature of user input, such as moving a dial vs. typing a parameter, affects actual learning as well as the user-perceived learning. The N = 91 cohort size was not sufficient to establish statistical differences at the \(\alpha\) = 0.05 level, but at \(\alpha\) = 0.1 it was observed that simulations using continuous input caused students to learn more effectively, and that students who used continuous input methods believed, following their use, that continuous input learning methods were more effective than discrete input learning methods. Surprisingly, an inverse correlation was found between objectively-measured student understanding and subjectively-rated student belief of their own subject mastery. In other words, students who used continuous input simulations believed they were better teaching tools in general, even though they believed their specific learning was inadequate.

The team of nine students from the Virginia Military Institute (VMI) collectively held their breath during the countdown. The result of their yearlong project-an 11-fttall, 60-lb rocket-stood on the launchpad, holding an autonomous soi l-col lect ing robot they had designed. There was little doubt the engines would ignite, developing 450 lbf of thrust within 200 ms; their worry was whether the robot would eject at apogee and survive the resulting 1,000-ft fall.

NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract Main Menu Session 2793 Robotics in Introduction to Electrical and Computer Engineering at the Virginia Military Institute David L. Livingston, James C. Squire Virginia Military Institute Abstract Increasingly universities are adopting a robotics-centric approach to teach their freshmen Introduction to Electrical Engineering: 23% of this year’s top-rated engineering schools with an introductory course incorporate a significant amount of robotics into their curricula. Besides teaching concepts from analog, digital, control, and programming courses, students find robots inherently appealing – an important attribute in this national climate of decreasing engineering enrollment. Published data indicate universities tend to either have students build prepackaged robot kits, which stress programming skills, or less commonly have students design their own from discrete components, which stresses interdisciplinary (e.g. mechanical) design and team collaboration. In this paper we describe an intermediate approach we have taken at the Virginia Military Institute. Our students begin with a pre-built mobile base, and then using discrete parts they breadboard a controller, the sensor arrays, and control electronics. In this manner we concentrate on core electrical engineering topics: basic analog and digital circuitry, computer architecture, and machine-level programming, while providing some controlled opportunities for students to make design choices and experiment with the open-architecture system. I. Introduction There is a clear national trend towards the adoption of robotics as an aid to teaching undergraduate electrical engineering courses in general, and introductory courses in particular. In 1990, less than 1% of the ASEE conference abstracts dealt with robotics in undergraduate education; this rose to 10% in 2000 and 12% in 2001. Today, 23% of the top-rated electrical engineering schools 1 with introductory courses either are entirely robotics-centric or else use them in a major block of instruction, versus 0% in 1990. This emphasis on using robotics as a learning tool for introductory courses extends to other disciplines as well, such as in aerospace engineering 2, mechanical engineering 3, computer engineering 4, and even in pre-engineering high school courses 5. There are several reasons for the increasing popularity of robotics in introductory courses. Undeniably freshmen find them fascinating; questionnaires distributed following our introductory course are laced with comments such as “loved building the modules [that ultimately produced] a robot,” “this is why I became an EE major,” and the more succinct “cool robot.” Students also “Proceedings of the 2002 American Society for Engin eering Education Annual Conference & Exposition Copyright © 2002, American Society for Engineering Education” Main Menu

Computer demonstrations and simulations are well-researched tools for teaching; resources such as The Guide to Simulation Games for Education and Training have existed for half a century (Zuckerman, 1970) and numerous studies have investigated the value of interactive simulations in the engineering and mathematical academic setting. The ubiquity of mobile computing devices, the rise of Massive Open Online Courses (MOOC), and changes as textbook publishers embrace electronic media have further spurred the use of simulations as an important method to provide an intuitive, self-guided understanding of quantitative cause-and-effect relationships. Such simulations may use discrete methods to interact with them, such as setting simulation parameters, pressing a calculate button, and observing the results, or they may employ a continuous method of interaction, such as dragging a slider and observing in real-time how the results are affected. Although demonstrations using continuous input methods are considerably more difficult to program, no studies have attempted to quantify the pedagogical benefits, if any, of adopting one manner of user interaction over the other. This Work-In-Progress (WIP) paper describes a set of experiments to test the hypothesis that interactive software demonstrations using continuous input methods are more pedagogically efficient than those using discrete input methods. We propose to test this hypothesis by creating two different interactive computer demonstrations. The demonstration chosen develops student intuition connecting a phasor representation and its time-domain sinusoidal waveform. Both demonstration programs have identical output areas displaying the sinusoid, and identically appearing input areas showing the phasor. The discrete version requires the user to input the magnitude and angle of the phasor and press a calculate button; the continuous version uses a similar input screen but allows the user to drag a point to establish the phasor magnitude and angle. A ten-minute self-guided student tutorial identical for the two software versions will explain the mathematics linking phasors with their time-domain sinusoid in a manner that requires the student to use the software demonstration. It will then ask a series of questions to determine objective subject understanding as well as to assess the student’s subjective self-perception of subject mastery and enjoyment of the experience. The answer key will be coded to determine which software version the student used. The WIP paper will present preliminary results of our investigation based upon data to be collected in the fall 2019 semester. Differences in the level of mastery attained by students between the two test programs will be documented to help refine our proposed methods for future data collection.

Tick-borne diseases are becoming increasingly common in the United States, including Lyme, Rocky Mountain spotted fever, ehrlichiosis, and babesiosis. Their increase in infection rates closely tracks a rise in the geographic area of infected ticks, prompting interest in new methods of tick population control. The most common existing method involves spraying the environment with permethrin, which, although highly effective, also poisons fish, fowl, bees, and other wildlife. This paper describes a novel robotic method designed to reduce tick populations without the associated environmental toxicity of chemical spraying. It employs a robot that follows a wire emitting a magnetic signal beacon around the perimeter of a property while dispensing a chemoattractant. The magnetic signal is generated by a small battery-run constant-current frequency generator. The robot's steering is controlled by proportional-integral controllers that compare the magnetic signal detected by left and right side resonant inductors mounted on the robot, and its forward speed is controlled by a second proportional integral controller calibrated to move the robot at the speed of a slow walk. A chemoattractant, such as CO2, is released by the robot, which, with the vibration associated with the robot's movement, establishes the biomimicry necessary to cause the tick to latch onto the robot's fabric-covered drag mat and wings. The fabric is infused with permethrin, killing the ticks in seconds while leaving virtually no trace of the chemical in the environment. An early prototype of the robot showed it acutely reduced tick populations by 88% ± 10% after 5 passes, but 48 hours after treatment the population returned to approximately pre-treatment levels. This was hypothesized to occur because only a percentage of ticks emerge from stasis on any given day to feed, but the early prototype robot proved unreliable and difficult to use for repeated-day operation needed to test this theory. The robot described in this paper incorporates a number of changes to allow multi-day testing including improved steering algorithms, water-resistant electronics, a manual mode to allow the user to remotely pilot the vehicle back on track should it lose tracking in a tight turn, and multiple indicators to assist debugging in the field. This will enable time-longitudinal studies of the robot's effects on tick population reduction planned by researchers in the summer of 2020 and may ultimately lead to a new method for tick population control.

Classroom demonstrations have been shown to enhance student learning retention by providing greater intellectual stimulation when compared to lecture-only presentations. [Bradford 2000, Klosky 2002, Morgan 2007] Yet, comparatively little research has been conducted to determine the presentation type and style that is most effective in pedagogical demonstrations. This investigation builds upon previous work which counterintuitively found that crudely-built demonstrations devices tend to confer greater learning retention than similar professionally built devices. [Squire 2009] Specifically, we sought to determine how preference for crudely vs. professionally-built demonstrations changed with academic maturity. The current study employed a larger population of students pursuing an undergraduate degree in Science, Technology, Engineering and Math (STEM) in a two by two grid of experimental groups. The rows refer to whether the students were in their freshman or sophomore years, and the columns refer to whether the students were taught using the crudely-built or professionally-built demonstrations. The results of the investigation revealed that both year groups experienced greater learning retention when the low-cost, homemade demonstrator was employed when compared to the professionally manufactured demonstrator. The results also show no significant difference in learning retention between year groups.

Major challenges inhibit modern analysis of debt litigation in eighteenth-century Virginia. Entries about individual suits are scattered throughout manuscript county order books, and their interpretation requires an understanding of arcane English common law. Most suits settled out of court before trial. Historians disagree whether these were genuine contests between plaintiffs and defendants. From a game-theory perspective, pretrial settlements demonstrate sophisticated economic processes. To analyze those processes, individual case records for five counties have been assembled for the period January 1746 through May 1755, producing a study group of 2,142 suits on a writ of debt. The writ of debt dealt primarily with written, signed, and witnessed promises to pay a particular amount. When litigated, suits unfolded as what in game theory is called a sequential game, each party responding in turn to the other side's move. Litigants' maneuvering expressed their expectations for the legal system. Both parties' strategic considerations can be discovered by working backward from the conclusions of suits to the creation of contested debts. The data reveal a high volume of effective and uncontroversial debt enforcement by Virginia courts, a reality that continually bolstered popular perceptions that elite-dominated county courts were both fair and just.

Despite the ubiquity of microcontrollers, widespread use of soft-core microprocessors is much less common. Most undergraduate curricula have a digital course involving fieldprogrammable gate array (FPGA) programming, in languages such as VHDL or Verilog, and separately have a microcontroller course that uses the C language. But few synthesize these two topics to involve programming an FPGA to simulate a microcontroller.

For a generation, legal historians investigating colonial Virginia have emphasized the dramaturgy of court day. According to the dramaturgical school of interpretation, administrative and judicial activities of county court officials amounted to theatrical performances that simultaneously enforced economic order and stabilized traditional social relationships. Such interpretations assume a large audience routinely attended county courts to observe legal dramas. Often, however, only a small number of persons can be documented as present during court day. The independence theorem from probability theory suggests that the number of documentable attendees is a useful and easily calculated estimate for actual total crowd size. If so, some Virginia court sessions were attended by hundreds of people, while others drew only a few participants. A variety of factors apparently inhibited court attendance in older Virginia counties. By contrast, in newer frontier counties, mid-eighteenth-century revisions of court calendars produced heavy attendance at court day. Regardless of the number of people in attendance, any Virginia county court could still effectively enforce credit contracts.

As enrollment in online courses increases faster than the overall enrollments in higher education, the differences in learning styles and academic disciplines need to be identified. Further, the focus on the demand for students pursuing degrees in the sciences, technology, engineering and mathematics (STEM) has gained prominence in the past decade. An experiment was conducted to study the interaction of objective learning and subjective learning, objective learning and enjoyment, and subjective learning and enjoyment on the longitudinal effects of network latency on students who were classified as STEM majors or non-STEM majors (humanities and social sciences). The findings indicate that students from different majors responded differently by the time students have progressed to their senior year in reference to their learning styles and sensitivity to network delays than it was when they were freshmen. The study suggests that the accumulation of experience and choice of major are important factors in mitigating the effects of network delay on learning.

Despite developments in safety methods and equipment, mining is still a dangerous industry, and coal mining is a good example of this. When there is an accident, rescuers need to know where trapped personnel are, how many there are, and other information such as air quality. To achieve this requires, as a minimum, effective communications from underground to surface. Unfortunately, these are the very circumstances in which communications between underground and surface can easily be disrupted.

ABSTRACT This essay investigates economic connections between Virginia frontier settlements and Pennsylvania during the period 1746–55. We explore how frontier debtors in remote Augusta County, Virginia, acquired Pennsylvania monetary obligations, what happened when debts involving Pennsylvania money were litigated in Augusta County, and what exchange rate was used in judgments for debts denominated in Pennsylvania money. We find that fluctuations in Augusta County exchange rates correlated to the overall regional market for monetary exchanges involving pounds sterling and Pennsylvania or Virginia money. A statistical tool called the two-tailed student t-test indicates the correlation was not the result of random chance. We therefore conclude that ordinary settlers in the Virginia backcountry were thoroughly acquainted with Pennsylvania market conditions at an earlier period than previously has been recognized.

Over 800 ft underground, surrounded by rough-hewn walls under such tremendous pressure that leaning on them could cause them to violently explode, tests are run on a device that might someday be integral to rescuing miners trapped by cave-ins. The device, under development by a group of Virginia Military Institute (VMI) cadets and professors, relies on seismic waves to transmit distress signals using the earth itself as a conduit. Essentially a modified speaker mounted on a spiderlike frame, the VMIne is affixed to the roof of a mine tunnel and can produce vibrations that travel through the intervening rock, which can be acquired by receivers many hundreds of feet above (Fig. 1).

Tick bites are a calculated risk of enjoying outdoor activities; yet in certain geographic regions, deer ticks are more likely than not infected with Lyme disease even to the extent that some medical journals recommend physicians automatically begin antibiotic treatment following bites in high-risk areas regardless of a patient's symptoms. There exists no Lyme vaccine approved for use in humans, a...