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We present an adaptive compression and resampling technique using wavelet packet shrinkage. The motivating application is surface digitization for computer-aided manufacturing. The objective is to improve estimation accuracy using...
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We present an adaptive compression and resampling technique using wavelet packet shrinkage. The motivating application is surface digitization for computer-aided manufacturing. The objective is to improve estimation accuracy using a sparse and irregular, but more accurate, resampling of the data. We provide modified thresholds for wavepacket shrinkage, heuristics for choosing the resampling grid, and a mean estimator using measured data. Computed results illustrate application of the proposed technique.
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A study was conducted to examine the accuracy of the keyboard requirements of MIL-STD-1472D and to assess the consequences of operating an aircraft keyboard which was reduced in size to values below the requirements of the militar...
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A study was conducted to examine the accuracy of the keyboard requirements of MIL-STD-1472D and to assess the consequences of operating an aircraft keyboard which was reduced in size to values below the requirements of the military standard. Four keyboard configurations were examined: key size and separation within MIL-STD-1427D requirements: key size and separation within the requirements, with key barriers; key separation below the requirements; and key separation below the requirements, with key barriers. The barrier design was proposed as a technique for reducing the probability of inadvertent key activation, especially for the smaller keyboard configuration. The experiment was conducted in two phases. Phase 1 consisted of keyboard training, and examined data entry (keying speed and accuracy) in a ground environment. Phase 2 examined both the extent of keyboard entry degradation during a simulated flying task, and the consequences of increasing flying task workload on keying performance. High levels of accuracy (<96%) were attained for all keyboards. Under the simulated flying task, increased error rates were obtained with the close-separation keyboards. Under the simulated flying task, error rates were slightly higher than under the training condition when the barrier was used. Barriers increase entry time without reducing errors.
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A smart power device can be defined as an intelligent power circuit used for interfacing a microcomputer/controller and an actuator such as an electromagnetic valve or an electric motor. With DC ratings up to 50 V, the first produ...
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A smart power device can be defined as an intelligent power circuit used for interfacing a microcomputer/controller and an actuator such as an electromagnetic valve or an electric motor. With DC ratings up to 50 V, the first products of this category are designed for automotive and industrial electronics. There are various alternative approaches to the isolation problem, and strenuous efforts are being made by developers to determine the optimum isolation scheme for smart power devices intended for key applications. Smart power devices generally consist of an IC section and one or more power switches, for which VDMOS transistors may advantageously be chosen. The operating voltage is significantly higher than that of logic ICs, especially in the case of the widely used VLSI circuits.
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After establishing more than 27 vermiculture waste treatment plants in diverse industries to convert wastes into value added biofertilizers and earthworm biomass into protein feed over the last 12 years; now the Biotechnology Reso...
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After establishing more than 27 vermiculture waste treatment plants in diverse industries to convert wastes into value added biofertilizers and earthworm biomass into protein feed over the last 12 years; now the Biotechnology Resource Centre [BRC] has taken considerable interest in some vital biomedical aspects of vermiculture. Our experiments clearly suggested significant antipyretic activity from the powdered extract of the Red American Earthworm species viz. Lumbricus rubellus when tested in the Swiss Albino Mouse in which fever had been induced by injection of Escherichia collpyrogen. In addition, we have also extracted a strong fibrinolytic enzyme from another earthworm species, viz. Pheretima asiatica. It was further revealed that oral administration of 600 mg powdered extract in old volunteers significantly increased fibrinolytic activity of the plasma euglobulin fraction. Thus, we at BRC believe that an increased scientific interest in biomedical aspects of vermiculture over the next few years is inevitable,.
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This paper presents two new theories for the fault diagnosis of the linear analog networks of unknown impedance matrices but of known terminal (port) voltages. The concept of the companion network is proposed to fault diagnose the...
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This paper presents two new theories for the fault diagnosis of the linear analog networks of unknown impedance matrices but of known terminal (port) voltages. The concept of the companion network is proposed to fault diagnose the network under test. The impedance matrices of the nominal network and its companion network constitute two overdetermined systems of equations with the two corresponding network port voltage vectors. The idea is based on the block dependency between the nominal impedance matrix of the network under test and the impedance matrix of its companion network after excluding the circuit element or subnetwork under test. If the companion impedance matrix is consistent with the measured port voltage vector, then, the nominal impedance matrix corresponding to the circuit element or subnetwork under test must also be consistent with the same measured port voltage vector which means that this circuit element is faulty or is one of the entities of the ambiguity fault set. By this way all circuit elements can be tested using the companion network only.
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Multiplexers are used in communications networks to increase link efficiency. A multiplexer receives traffic from many sources on access lines and sends it to its destination on a trunk line. This technique results in a great savi...
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Multiplexers are used in communications networks to increase link efficiency. A multiplexer receives traffic from many sources on access lines and sends it to its destination on a trunk line. This technique results in a great savings when the traffic of the sources is bursty. A problem arises, however, if the access lines are imperfect, in the sense that they may introduce errors in the traffic they carry. A normal multiplexer unknowingly transmits the erroneous traffic to the destination. The destination, with the help of an error-detection routine, detects the errors and discards that traffic, but of course after it has wasted much needed bandwidth on the trunk. This paper proposes an enhanced multiplexer, which is just a normal multiplexer with an error-detection routine similar to that of the destination. The function of this routine is to discard the erroneous traffic right at the multiplexer, thus saving the bandwidth of the trunk for only the error-free traffic. A discrete queueing theoretic model is developed in this paper for the enhanced multiplexer. By analyzing the model, using the generating function approach, it is shown that the enhanced multiplexer is superior in performance to its normal counterpart. For conciseness, it is assumed that the multiplexer is hooked to an asynchronous transfer mode (ATM) network. However the model presented can be easily modified to suit other network standards.
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Utah State University is building a nanosatellite that will cooperate with satellites built by the University of Washington and Virginia Tech to perform important ionospheric investigations, as well as test various aspects of form...
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Utah State University is building a nanosatellite that will cooperate with satellites built by the University of Washington and Virginia Tech to perform important ionospheric investigations, as well as test various aspects of formation flying around the earth. These satellites must be able to communicate with each other as well as communicate with the ground stations. This paper describes the nanosatellite program at Utah State University (USUsat). In addition, the communication link budget and antenna designs for this satellite are described in detail. The ground station will have an array of helical antennas, while the antennas on the satellites will be circularly polarized microstrip patches.
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Because of the current and future importance of the Atomic Force Microscope (AFM) in education and research, our team has been working on transferring this technology to the college classroom. In this paper we present the initial ...
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Because of the current and future importance of the Atomic Force Microscope (AFM) in education and research, our team has been working on transferring this technology to the college classroom. In this paper we present the initial findings of a case study in which two years of cutting-edge AFM research was transferred to the college classroom in the form of a one-semester course. The course was developed before the research was completed and published in final form. While, the course centered on the re-creation and explanation of the most recent advances in building high-throughput AFMs, it also implemented and assessed the use of two online AFMs. Student response to the initial course offering, its content, and the tools used, was very positive. The students rated the course above the department average on 14 of the 15 survey metrics and claimed that the teaching method would help them remember more than other classes (average 8 on a ten-point scale. N=24). As a result of the course, several students have shown interest in pursuing work and research in this field. These results indicate that the course has successfully broadened the horizons of undergraduate and graduate students at the University of Nevada Reno, which had no microtechnology or AFM course offering prior to this work. It has also demonstrated the potential of using the AFM as the center focus of a MEMS/Nano-technology course. Finally, this case study may serve as a model for future technology transfer to the classroom by Ph.D. candidates who have not fully completed their technical research.
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Project Aria began in 1998 as a space projects course in the School of Engineering & Applied Science at Washington University, St. Louis. The first mission, Aria-1, was a passive GAS canister payload launched with STS-101 in September 2000; it contained 45 science experiments submitted by local K-12 schools. The success of Aria-1 has led to additional missions under Project Aria, inc...
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Project Aria began in 1998 as a space projects course in the School of Engineering & Applied Science at Washington University, St. Louis. The first mission, Aria-1, was a passive GAS canister payload launched with STS-101 in September 2000; it contained 45 science experiments submitted by local K-12 schools. The success of Aria-1 has led to additional missions under Project Aria, including follow-on Shuttle flights, a student CubeSat project, a Mars rover prototype, research in spacecraft operations, and a high-altitude balloon prototype of a Venus probe. Project Aria is following the lead of other university space systems programs by incrementally developing student expertise and program capabilities. However, programs such as Aria must also meet the challenge of effectively educating students while producing meaningful research results. In addition, Project Aria was chartered to provide educational initiatives for the St. Louis public, and therefore these broader educational needs must also be addressed. The conflict among these three objectives forms a case study for this paper. This paper briefly describes the history of Project Aria and discusses the missions currently in development. Particular attention is paid to the manner in which Aria missions are managed, and also to successes and failures in balancing the needs of research, education, and public outreach. Lessons learned from Aria missions can be applied to other universities seeking to develop project-based programs.
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NASA and the computer science research community are poised to enter a critical era. An era in which - it seems - each needs the other. Market forces, driven by the immediate economic viability of computer science research results...
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NASA and the computer science research community are poised to enter a critical era. An era in which - it seems - each needs the other. Market forces, driven by the immediate economic viability of computer science research results, place computer science in a relatively novel position. These forces impact how research is done, and could, in the worst case, drive the field away from significant innovation - opting instead for incremental advances that result in greater stability in the market place. NASA, however, requires significant advances in computer science research in order to accomplish the exploration and science agenda it has set out for itself. NASA may indeed be poised to advance computer science research in this century, much the way it advanced aero-based research in the last.
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