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Sample records for acoustic design implementation

  1. Acoustic camera design and implementation

    NASA Astrophysics Data System (ADS)

    Brandes, Thomas Scott

    An acoustic camera for 2-dimensional imaging is developed from concept to physically realized system. The mathematics of the system are described for far-field sound sources, both narrow and broadband. Camera performance for a variety of logarithmically spaced arrays is simulated, as well as stochastically determined configurations from a simulated annealing method. Additionally, hardware development for a 32-microphone log-spaced acoustic camera array, 3.5m by 3.5m, that is built and tested is described. The imaging results of a small aircraft flyover at 400 feet above the array are included. The camera provides actual images that are as detailed as expected from simulations for the aircraft at 250 Hz and 500 Hz. Suggestions are provided for design improvements to image birds as well as bats.

  2. International Space Station Crew Quarters Ventilation and Acoustic Design Implementation

    NASA Technical Reports Server (NTRS)

    Broyan, James L., Jr.; Cady, Scott M; Welsh, David A.

    2010-01-01

    The International Space Station (ISS) United States Operational Segment has four permanent rack sized ISS Crew Quarters (CQs) providing a private crew member space. The CQs use Node 2 cabin air for ventilation/thermal cooling, as opposed to conditioned ducted air-from the ISS Common Cabin Air Assembly (CCAA) or the ISS fluid cooling loop. Consequently, CQ can only increase the air flow rate to reduce the temperature delta between the cabin and the CQ interior. However, increasing airflow causes increased acoustic noise so efficient airflow distribution is an important design parameter. The CQ utilized a two fan push-pull configuration to ensure fresh air at the crew member's head position and reduce acoustic exposure. The CQ ventilation ducts are conduits to the louder Node 2 cabin aisle way which required significant acoustic mitigation controls. The CQ interior needs to be below noise criteria curve 40 (NC-40). The design implementation of the CQ ventilation system and acoustic mitigation are very inter-related and require consideration of crew comfort balanced with use of interior habitable volume, accommodation of fan failures, and possible crew uses that impact ventilation and acoustic performance. Each CQ required 13% of its total volume and approximately 6% of its total mass to reduce acoustic noise. This paper illustrates the types of model analysis, assumptions, vehicle interactions, and trade-offs required for CQ ventilation and acoustics. Additionally, on-orbit ventilation system performance and initial crew feedback is presented. This approach is applicable to any private enclosed space that the crew will occupy.

  3. International Space Station USOS Crew Quarters Ventilation and Acoustic Design Implementation

    NASA Technical Reports Server (NTRS)

    Broyan, James Lee, Jr.

    2009-01-01

    The International Space Station (ISS) United States Operational Segment (USOS) has four permanent rack sized ISS Crew Quarters (CQ) providing a private crewmember space. The CQ uses Node 2 cabin air for ventilation/thermal cooling, as opposed to conditioned ducted air from the ISS Temperature Humidity Control System or the ISS fluid cooling loop connections. Consequently, CQ can only increase the air flow rate to reduce the temperature delta between the cabin and the CQ interior. However, increasing airflow causes increased acoustic noise so efficient airflow distribution is an important design parameter. The CQ utilized a two fan push-pull configuration to ensure fresh air at the crewmember s head position and reduce acoustic exposure. The CQ interior needs to be below Noise Curve 40 (NC-40). The CQ ventilation ducts are open to the significantly louder Node 2 cabin aisle way which required significantly acoustic mitigation controls. The design implementation of the CQ ventilation system and acoustic mitigation are very inter-related and require consideration of crew comfort balanced with use of interior habitable volume, accommodation of fan failures, and possible crew uses that impact ventilation and acoustic performance. This paper illustrates the types of model analysis, assumptions, vehicle interactions, and trade-offs required for CQ ventilation and acoustics. Additionally, on-orbit ventilation system performance and initial crew feedback is presented. This approach is applicable to any private enclosed space that the crew will occupy.

  4. International Space Station USOS Crew Quarters Ventilation and Acoustic Design Implementation

    NASA Technical Reports Server (NTRS)

    Broyan, James Lee, Jr.

    2009-01-01

    The International Space Station (ISS) United States Operational Segment (USOS) has four permanent rack sized ISS Crew Quarters (CQ) providing a private crewmember space. The CQ uses Node 2 cabin air for ventilation/thermal cooling, as opposed to conditioned ducted air from the ISS Temperature Humidity Control System or the ISS fluid cooling loop connections. Consequently, CQ can only increase the air flow rate to reduce the temperature delta between the cabin and the CQ interior. However, increasing airflow causes increased acoustic noise so efficient airflow distribution is an important design parameter. The CQ utilized a two fan push-pull configuration to ensure fresh air at the crewmember s head position and reduce acoustic exposure. The CQ interior needs to be below Noise Curve 40 (NC-40). The CQ ventilation ducts are open to the significantly louder Node 2 cabin aisle way which required significantly acoustic mitigation controls. The design implementation of the CQ ventilation system and acoustic mitigation are very inter-related and require consideration of crew comfort balanced with use of interior habitable volume, accommodation of fan failures, and possible crew uses that impact ventilation and acoustic performance. This paper illustrates the types of model analysis, assumptions, vehicle interactions, and trade-offs required for CQ ventilation and acoustics. Additionally, on-orbit ventilation system performance and initial crew feedback is presented. This approach is applicable to any private enclosed space that the crew will occupy.

  5. Design and implementation of low complexity wake-up receiver for underwater acoustic sensor networks

    NASA Astrophysics Data System (ADS)

    Yue, Ming

    This thesis designs a low-complexity dual Pseudorandom Noise (PN) scheme for identity (ID) detection and coarse frame synchronization. The two PN sequences for a node are identical and are separated by a specified length of gap which serves as the ID of different sensor nodes. The dual PN sequences are short in length but are capable of combating severe underwater acoustic (UWA) multipath fading channels that exhibit time varying impulse responses up to 100 taps. The receiver ID detection is implemented on a microcontroller MSP430F5529 by calculating the correlation between the two segments of the PN sequence with the specified separation gap. When the gap length is matched, the correlator outputs a peak which triggers the wake-up enable. The time index of the correlator peak is used as the coarse synchronization of the data frame. The correlator is implemented by an iterative algorithm that uses only one multiplication and two additions for each sample input regardless of the length of the PN sequence, thus achieving low computational complexity. The real-time processing requirement is also met via direct memory access (DMA) and two circular buffers to accelerate data transfer between the peripherals and the memory. The proposed dual PN detection scheme has been successfully tested by simulated fading channels and real-world measured channels. The results show that, in long multipath channels with more than 60 taps, the proposed scheme achieves high detection rate and low false alarm rate using maximal-length sequences as short as 31 bits to 127 bits, therefore it is suitable as a low-power wake-up receiver. The future research will integrate the wake-up receiver with Digital Signal Processors (DSP) for payload detection.

  6. Design and Implementation of an Acoustic X-ray Detector to Measure the LCLS Beam Energy

    SciTech Connect

    Loos, Jennifer L.; /San Jose State U. /SLAC

    2010-08-25

    On April 11, 2009, first light was seen from LCLS. The present apparatus being used to measure the x-ray beam energy is the Total Energy Sensor which uses a suite of thermal sensors. Another device is needed to cross-check the energy measurements. This new diagnostic tool utilizes radiation acoustic phenomena to determine the x-ray beam energy. A target is hit by the x-rays from the beam, and a voltage is generated in two piezoelectric sensors attached to the target in response to the consequent deformation. Once the voltage is known, the power can be obtained. Thermal sensors will also be attached to the target for calibration purposes. Material selection and design were based on: durability, ultra-high vacuum compatibility, safety and thermal properties. The target material was also chosen for its acoustic properties which were determined from tests using a frequency generator and laser. Initial tests suggest the device will function as anticipated.

  7. Indoor acoustic gain design

    NASA Astrophysics Data System (ADS)

    Concha-Abarca, Justo Andres

    2002-11-01

    The design of sound reinforcement systems includes many variables and usually some of these variables are discussed. There are criteria to optimize the performance of the sound reinforcement systems under indoor conditions. The equivalent acoustic distance, the necessary acoustic gain, and the potential acoustic gain are parameters which must be adjusted with respect to the loudspeaker array, electric power and directionality of loudspeakers, the room acoustics conditions, the distance and distribution of the audience, and the type of the original sources. The design and installation of front of the house and monitoring systems have individual criteria. This article is about this criteria and it proposes general considerations for the indoor acoustic gain design.

  8. Reliable data storage system design and implementation for acoustic logging while drilling

    NASA Astrophysics Data System (ADS)

    Hao, Xiaolong; Ju, Xiaodong; Wu, Xiling; Lu, Junqiang; Men, Baiyong; Yao, Yongchao; Liu, Dong

    2016-12-01

    Owing to the limitations of real-time transmission, reliable downhole data storage and fast ground reading have become key technologies in developing tools for acoustic logging while drilling (LWD). In order to improve the reliability of the downhole storage system in conditions of high temperature, intensive shake and periodic power supply, improvements were made in terms of hardware and software. In hardware, we integrated the storage system and data acquisition control module into one circuit board, to reduce the complexity of the storage process, by adopting the controller combination of digital signal processor and field programmable gate array. In software, we developed a systematic management strategy for reliable storage. Multiple-backup independent storage was employed to increase the data redundancy. A traditional error checking and correction (ECC) algorithm was improved and we embedded the calculated ECC code into all management data and waveform data. A real-time storage algorithm for arbitrary length data was designed to actively preserve the storage scene and ensure the independence of the stored data. The recovery procedure of management data was optimized to realize reliable self-recovery. A new bad block management idea of static block replacement and dynamic page mark was proposed to make the period of data acquisition and storage more balanced. In addition, we developed a portable ground data reading module based on a new reliable high speed bus to Ethernet interface to achieve fast reading of the logging data. Experiments have shown that this system can work stably below 155 °C with a periodic power supply. The effective ground data reading rate reaches 1.375 Mbps with 99.7% one-time success rate at room temperature. This work has high practical application significance in improving the reliability and field efficiency of acoustic LWD tools.

  9. Design and implementation of an omni-directional underwater acoustic micro-modem based on a low-power micro-controller unit.

    PubMed

    Won, Tae-Hee; Park, Sung-Joon

    2012-01-01

    For decades, underwater acoustic communication has been restricted to the point-to-point long distance applications such as deep sea probes and offshore oil fields. For this reason, previous acoustic modems were typically characterized by high data rates and long working ranges at the expense of large size and high power consumption. Recently, as the need for underwater wireless sensor networks (UWSNs) has increased, the research and development of compact and low-power consuming communication devices has become the focus. From the consideration that the requisites of acoustic modems for UWSNs are low power consumption, omni-directional beam pattern, low cost and so on, in this paper, we design and implement an omni-directional underwater acoustic micro-modem satisfying these requirements. In order to execute fast digital domain signal processing and support flexible interfaces with other peripherals, an ARM Cortex-M3 is embedded in the micro-modem. Also, for the realization of small and omni-directional properties, a spherical transducer having a resonant frequency of 70 kHz and a diameter of 34 mm is utilized for the implementation. Physical layer frame format and symbol structure for efficient packet-based underwater communication systems are also investigated. The developed acoustic micro-modem is verified analytically and experimentally in indoor and outdoor environments in terms of functionality and performance. Since the modem satisfies the requirements for use in UWSNs, it could be deployed in a wide range of applications requiring underwater acoustic communication.

  10. Design and Implementation of an Omni-Directional Underwater Acoustic Micro-Modem Based on a Low-Power Micro-Controller Unit

    PubMed Central

    Won, Tae-Hee; Park, Sung-Joon

    2012-01-01

    For decades, underwater acoustic communication has been restricted to the point-to-point long distance applications such as deep sea probes and offshore oil fields. For this reason, previous acoustic modems were typically characterized by high data rates and long working ranges at the expense of large size and high power consumption. Recently, as the need for underwater wireless sensor networks (UWSNs) has increased, the research and development of compact and low-power consuming communication devices has become the focus. From the consideration that the requisites of acoustic modems for UWSNs are low power consumption, omni-directional beam pattern, low cost and so on, in this paper, we design and implement an omni-directional underwater acoustic micro-modem satisfying these requirements. In order to execute fast digital domain signal processing and support flexible interfaces with other peripherals, an ARM Cortex-M3 is embedded in the micro-modem. Also, for the realization of small and omni-directional properties, a spherical transducer having a resonant frequency of 70 kHz and a diameter of 34 mm is utilized for the implementation. Physical layer frame format and symbol structure for efficient packet-based underwater communication systems are also investigated. The developed acoustic micro-modem is verified analytically and experimentally in indoor and outdoor environments in terms of functionality and performance. Since the modem satisfies the requirements for use in UWSNs, it could be deployed in a wide range of applications requiring underwater acoustic communication. PMID:22438765

  11. Acoustic tomography. Laboratory technique Implementation.

    NASA Astrophysics Data System (ADS)

    Galvis, Jorge; Carvajal, Jenny

    2010-05-01

    From geomechanical tests carried out on rocks it is possible to determine its physico-mechanical properties, which relate the strain and applied stress; even so, conventional tests do not allow to identify how stress is distributed and how it has affected porous media. Today, techniques like acoustic tomography widely used in medicine, geophysics and others sciences, generates images by sections of the interior of a body. Acoustic tomography allows inferring the stress state within porous media; since wave velocities are closely related to media density, if a stress is applied to a rock, it will generate grains compaction and this will be showed by an increase of wave velocity. Implementation was conducted on rock plugs under diverse stress fields, simultaneously recording P-wave velocities (Compressional) on perpendicular planes to sample vertical axis. Transmission and reception of acoustic waves through porous media were done by piezoelectric crystals (PZT) used as sensors. A transmitting crystal excited by a voltage pulse causes a mechanical vibration, which travels across media; this is known as inverse piezoelectric effect. This vibration is recorded by a receiving crystal in which the direct piezoelectric effect appears; which dictates that if a piezoelectric is disturbed mechanically, an electrical signal between its terminals will appear. This electrical signal is used to obtain the wave velocity. Nevertheless, acoustic tomography corresponds to one of those called inverse Problems that arise when from observed data the model parameters must be obtained; in this way, tomography involves iterative reconstruction techniques (ART or SIRT) which are projections of observed data and its later inversion. Obtained results are cross-sectional images of velocity within the rock. In these images it is possible to identify where stress has a greater concentration observing the color map generated; thus, a greater velocity density area corresponding to a greater

  12. Bifunctional acoustic metamaterial lens designed with coordinate transformation

    NASA Astrophysics Data System (ADS)

    Zhu, Rongrong; Ma, Chu; Zheng, Bin; Musa, Muhyiddeen Yahya; Jing, Liqiao; Yang, Yihao; Wang, Huaping; Dehdashti, Shahram; Fang, Nicholas X.; Chen, Hongsheng

    2017-03-01

    We propose a method to design bifunctional acoustic lens using acoustic metamaterials that possess separate functions at different directions. The proposed bifunctional acoustic lens can be implemented in practice with subwavelength unit cells exhibiting effective anisotropic parameters. With this methodology, we experimentally demonstrate an acoustic Luneburg-fisheye lens at operational frequencies from 6300 Hz to 7300 Hz. Additionally, a bifunctional acoustic square lens is proposed with different focal lengths for multi directions. This method paves the way to manipulating acoustic energy flows with functional lenses.

  13. Design and implementation of improved LsCpLp resonant circuit for power supply for high-power electromagnetic acoustic transducer excitation

    NASA Astrophysics Data System (ADS)

    Zao, Yongming; Ouyang, Qi; Chen, Jiawei; Zhang, Xinglan; Hou, Shuaicheng

    2017-08-01

    This paper investigates the design and implementation of an improved series-parallel inductor-capacitor-inductor (LsCpLp) resonant circuit power supply for excitation of electromagnetic acoustic transducers (EMATs). The main advantage of the proposed resonant circuit is the absence of a high-permeability dynamic transformer. A high-frequency pulsating voltage gain can be achieved through a double resonance phenomenon. Both resonant tailing behavior and higher harmonics are suppressed by the improved resonant circuit, which also contributes to the generation of ultrasonic waves. Additionally, the proposed circuit can realize impedance matching and can also optimize the transduction efficiency. The complete design and implementation procedure for the power supply is described and has been validated by implementation of the proposed power supply to drive a portable EMAT. The circuit simulation results show close agreement with the experimental results and thus confirm the validity of the proposed topology. The proposed circuit is suitable for use as a portable EMAT excitation power supply that is fed by a low-voltage source.

  14. Design and implementation of improved LsCpLp resonant circuit for power supply for high-power electromagnetic acoustic transducer excitation.

    PubMed

    Zao, Yongming; Ouyang, Qi; Chen, Jiawei; Zhang, Xinglan; Hou, Shuaicheng

    2017-08-01

    This paper investigates the design and implementation of an improved series-parallel inductor-capacitor-inductor (LsCpLp) resonant circuit power supply for excitation of electromagnetic acoustic transducers (EMATs). The main advantage of the proposed resonant circuit is the absence of a high-permeability dynamic transformer. A high-frequency pulsating voltage gain can be achieved through a double resonance phenomenon. Both resonant tailing behavior and higher harmonics are suppressed by the improved resonant circuit, which also contributes to the generation of ultrasonic waves. Additionally, the proposed circuit can realize impedance matching and can also optimize the transduction efficiency. The complete design and implementation procedure for the power supply is described and has been validated by implementation of the proposed power supply to drive a portable EMAT. The circuit simulation results show close agreement with the experimental results and thus confirm the validity of the proposed topology. The proposed circuit is suitable for use as a portable EMAT excitation power supply that is fed by a low-voltage source.

  15. Conceptual architectural/acoustical design

    NASA Astrophysics Data System (ADS)

    Marshall, A. Harold

    2004-05-01

    The thinking which characterizes acoustics as a branch of physics and engineering has difficulty with the architectural design process-the process that generates a room concept in the imagination and experience of the architect. The architect has learned to ``sense'' the visual properties of a room as the design develops in the interaction between mind and media. Phrases such as ``wanting to be'' express the architectural intention but too often such intentions are dismissed as arbitrary; acoustics may then be about fixing the design with acoustical add-ons. Occasionally there is a true meeting of minds-a creative and receptive architect and an acoustician able to communicate at the level of the architectural intention. There is evidently an auditory dimension of wanting to be which is one with the visual. This paper explores the idea in several examples and concludes with suggestions for the training of acousticians.

  16. What Perception Implies about Implementation of Interactive Acoustic Environments

    NASA Technical Reports Server (NTRS)

    Wenzel, Elizabeth M.; Null, Cynthia H. (Technical Monitor)

    1996-01-01

    Virtual acoustics, also known as 3-D sound and auralization, is the simulation of the complex acoustic field experienced by a listener within an environment. Going beyond the simple intensity panning of normal stereo techniques, the goal is to process sounds so that they appear to come from particular positions in three-dimensional space. Current techniques use digital signal processing to synthesize the acoustical properties that people use to localize a sound source. This paper briefly reviews these techniques as well as the results of a number of psychoacoustical studies designed to validate the synthesis. In particular, the relationship between the results of recent perceptual studies on the role of head motion to the implementation of interactive spatial audio systems is addressed.

  17. Implementation of acoustic demultiplexing with membrane-type metasurface in low frequency range

    NASA Astrophysics Data System (ADS)

    Chen, Xing; Liu, Peng; Hou, Zewei; Pei, Yongmao

    2017-04-01

    Wavelength division multiplexing technology, adopted to increase the information density, plays a significant role in optical communication. However, in acoustics, a similar function can be hardly implemented due to the weak dispersion in natural acoustic materials. Here, an acoustic demultiplexer, based on the concept of metasurfaces, is proposed for splitting acoustic waves and propagating along different trajectories in a low frequency range. An acoustic metasurface, containing multiple resonant units, is designed with various phase profiles for different frequencies. Originating from the highly dispersive properties, the resonant units are independent and merely work in the vicinity of their resonant frequencies. Therefore, by combing multiple resonant units appropriately, the phenomena of anomalous reflection, acoustic focusing, and acoustic wave bending can occur in different frequencies. The proposed acoustic demultiplexer has advantages on the subwavelength scale and the versatility in wave control, providing a strategy for separating acoustic waves with different Fourier components.

  18. Acoustic metamaterial design and applications

    NASA Astrophysics Data System (ADS)

    Zhang, Shu

    The explosion of interest in metamaterials is due to the dramatically increased manipulation ability over light as well as sound waves. This material research was stimulated by the opportunity to develop an artificial media with negative refractive index and the application in superlens which allows super-resolution imaging. High-resolution acoustic imaging techniques are the essential tools for nondestructive testing and medical screening. However, the spatial resolution of the conventional acoustic imaging methods is restricted by the incident wavelength of ultrasound. This is due to the quickly fading evanescent fields which carry the subwavelength features of objects. By focusing the propagating wave and recovering the evanescent field, a flat lens with negative-index can potentially overcome the diffraction limit. We present the first experimental demonstration of focusing ultrasound waves through a flat acoustic metamaterial lens composed of a planar network of subwavelength Helmholtz resonators. We observed a tight focus of half-wavelength in width at 60.5 KHz by imaging a point source. This result is in excellent agreement with the numerical simulation by transmission line model in which we derived the effective mass density and compressibility. This metamaterial lens also displays variable focal length at different frequencies. Our experiment shows the promise of designing compact and light-weight ultrasound imaging elements. Moreover, the concept of metamaterial extends far beyond negative refraction, rather giving enormous choice of material parameters for different applications. One of the most interesting examples these years is the invisible cloak. Such a device is proposed to render the hidden object undetectable under the flow of light or sound, by guiding and controlling the wave path through an engineered space surrounding the object. However, the cloak designed by transformation optics usually calls for a highly anisotropic metamaterial, which

  19. Design and Performance Analysis of a Digital Acoustic Telemetry System

    DTIC Science & Technology

    1988-05-01

    Charles D. Hollister Dean of Graduate Students DESIGN AND PERFORMANCE ANALYSIS OF A DIGITAL ACOUSTIC TELEMETRY SYSTEM by Josko A. Catipovic B. S...light of available digital hard- ware. This section is not intended as a detailed design guide , but gives a clear indication that the proposed and...ocean acoustic channels and confirm the theoretical predictions for system behavior, a complete simulation of the proposed system was implemented on a

  20. Design and performance of duct acoustic treatment

    NASA Technical Reports Server (NTRS)

    Motsinger, R. E.; Kraft, R. E.

    1991-01-01

    The procedure for designing acoustic treatment panels used to line the walls of aircraft engine ducts and for estimating the resulting suppression of turbofan engine duct noise is discussed. This procedure is intended to be used for estimating noise suppression of existing designs or for designing new acoustic treatment panels and duct configurations to achieve desired suppression levels.

  1. Acoustical Design of Music Education Facilities.

    ERIC Educational Resources Information Center

    McCue, Edward, Ed.; Talaske, Richard H., Ed.

    This publication provides essays on the acoustical design of music education facilities and reproductions of posters describing 50 projects presented at the 117th Meeting of the Acoustical Society of American held in Syracuse, New York in May 1989. Essays are as follows: "Introduction to the Design Process" (Richard Talaske); "The…

  2. New schools design: Acoustics as main target

    NASA Astrophysics Data System (ADS)

    Maffei, Luigi; Lembo, Paola

    2005-04-01

    The effects of poor intelligibility and high background noise levels on the cognitive development of school children and on the dissatisfaction of teachers has been largely investigated. National standards have been implemented and attempts to harmonize these standards in international guidelines are ongoing. All these activities have led to the awareness that design of new schools must be centered on the achievement of a good acoustic environment. At this point a strong research effort to study and implement best solutions must be conducted, in collaboration, by architects, acousticians, pedagogues, psychologists, builders and acoustic materials producers. Recently an international competition for the planning of new primary schools in Rome, Italy has been announced. The aim of the competition is to study new architectural and running features of primary schools to obtain, among other parameters such as lighting, low cost energy solutions and air quality, the control of reverberation time, sound insulation and mechanical equipments noise. In these school buildings, as innovative requirement, children must be also able to elaborate interpretative hypothesis of physical phenomena such as sound emission and perception and be aware of their influence on these phenomena. Different possible solutions are presented.

  3. Design Report for Low Power Acoustic Detector

    DTIC Science & Technology

    2013-08-01

    the hardware design, target detection algorithm design in both MATLAB and VHDL , and typical performance results. 15. SUBJECT TERMS Acoustic low...diagram. .......................................................................................................3 Figure 4. HED VHDL block diagram...6 Figure 5. DCD VHDL block diagram

  4. Design considerations for a PVDF acoustic transducer

    NASA Astrophysics Data System (ADS)

    Wu, Bin; Wang, Qingfeng; Jiao, Jingpin; He, Cunfu

    2006-11-01

    Much work has been published on the design of transducers using piezoelectric polymers, but a great of this work is theoretical modeling and derivations, and the proposed design methods can't be available easily. The purpose of the paper is review and applies several important considerations for the design of polyvinylidene fluoride (PVDF) acoustic emission transducer: transducer construction, active element selection, backing material design, matching layer design, and preamplifier design. Besides reviewing these design considerations, this paper also present that a PVDF acoustic emission transducer has been fabricated. To achieve the transducer's characteristic parameter, the transducer has been calibrated using a precise impedance analyzer; by which the admittance conductance parameters of the acoustic transducer have been obtained. Pencil lead break tests also have been conducted on the transducer, and the test results certified that the transducer can detect acoustic emission events.

  5. Graphical Acoustic Liner Design and Analysis Tool

    NASA Technical Reports Server (NTRS)

    Howerton, Brian M. (Inventor); Jones, Michael G. (Inventor)

    2016-01-01

    An interactive liner design and impedance modeling tool comprises software utilized to design acoustic liners for use in constrained spaces, both regularly and irregularly shaped. A graphical user interface allows the acoustic channel geometry to be drawn in a liner volume while the surface impedance calculations are updated and displayed in real-time. A one-dimensional transmission line model may be used as the basis for the impedance calculations.

  6. Design of a programmable active acoustics metamaterial

    NASA Astrophysics Data System (ADS)

    Smoker, Jason J.

    Metamaterials are artificial materials engineered to provide properties which may not be readily available in nature. The development of such class of materials constitutes a new area of research that has grown significantly over the past decade. Acoustic metamaterials, specifically, are even more novel than their electromagnetic counterparts arising only in the latter half of the decade. Acoustic metamaterials provide a new tool in controlling the propagation of pressure waves. However, physical design and frequency tuning, is still a large obstacle when creating a new acoustic metamaterial. This dissertation describes active and programmable design for acoustic metamaterials which allows the same basic physical design principles to be used for a variety of application. With cloaking technology being of a great interest to the US Navy, the proposed design approach would enable the development of a metamaterial with spatially changing effective parameters while retaining a uniform physical design features. The effective parameters would be controlled by tuning smart actuators embedded inside the metamaterial structure. Since this design is based on dynamic effective parameters that can be electrically controlled, material property ranges of several orders of magnitude could potentially be achieved without changing any physical parameters. With such unique capabilities, physically realizable acoustic cloaks can be achieved and objects treated with these active metamaterials can become acoustically invisible.

  7. Cooperative implementation of a high temperature acoustic sensor

    NASA Technical Reports Server (NTRS)

    Baldini, S. E.; Nowakowski, Edward; Smith, Herbert G.; Friebele, E. J.; Putnam, Martin A.; Rogowski, Robert; Melvin, Leland D.; Claus, Richard O.; Tran, Tuan; Holben, Milford S., Jr.

    1991-01-01

    The current status and results of a cooperative program aimed at the implementation of a high-temperature acoustic/strain sensor onto metallic structures are reported. The sensor systems that are to be implemented under this program will measure thermal expansion, maneuver loads, aircraft buffet, sonic fatigue, and acoustic emissions in environments that approach 1800 F. The discussion covers fiber development, fabrication of an extrinsic Fabry-Perot interferometer acoustic sensor, sensor mounting/integration, and results of an evaluation of the sensor capabilities.

  8. Cooperative implementation of a high temperature acoustic sensor

    NASA Technical Reports Server (NTRS)

    Baldini, S. E.; Nowakowski, Edward; Smith, Herbert G.; Friebele, E. J.; Putnam, Martin A.; Rogowski, Robert; Melvin, Leland D.; Claus, Richard O.; Tran, Tuan; Holben, Milford S., Jr.

    1991-01-01

    The current status and results of a cooperative program aimed at the implementation of a high-temperature acoustic/strain sensor onto metallic structures are reported. The sensor systems that are to be implemented under this program will measure thermal expansion, maneuver loads, aircraft buffet, sonic fatigue, and acoustic emissions in environments that approach 1800 F. The discussion covers fiber development, fabrication of an extrinsic Fabry-Perot interferometer acoustic sensor, sensor mounting/integration, and results of an evaluation of the sensor capabilities.

  9. The acoustic design of outside broadcast vehicles

    NASA Astrophysics Data System (ADS)

    Taylor, E. W.

    1984-05-01

    A review is given of the acoustic design of outside broadcast vehicles in terms of the constraints implicit in the use of road vehicles. A new design of vehicle wall construction is described, the provision of sound absorbing material suitable for use in small enclosures is discussed, and particular factors involved in utilizing large (articulated) vehicles are mentioned. As an illustration, an account is given of the acoustic design of the BBC's Digital Control Vehicle: priority was given, in this vehicle, to the provision of the best possible environment for sound monitoring and control.

  10. Implementing Target Value Design.

    PubMed

    Alves, Thais da C L; Lichtig, Will; Rybkowski, Zofia K

    2017-04-01

    An alternative to the traditional way of designing projects is the process of target value design (TVD), which takes different departure points to start the design process. The TVD process starts with the client defining an allowable cost that needs to be met by the design and construction teams. An expected cost in the TVD process is defined through multiple interactions between multiple stakeholders who define wishes and others who define ways of achieving these wishes. Finally, a target cost is defined based on the expected profit the design and construction teams are expecting to make. TVD follows a series of continuous improvement efforts aimed at reaching the desired goals for the project and its associated target value cost. The process takes advantage of rapid cycles of suggestions, analyses, and implementation that starts with the definition of value for the client. In the traditional design process, the goal is to identify user preferences and find solutions that meet the needs of the client's expressed preferences. In the lean design process, the goal is to educate users about their values and advocate for a better facility over the long run; this way owners can help contractors and designers to identify better solutions. This article aims to inform the healthcare community about tools and techniques commonly used during the TVD process and how they can be used to educate and support project participants in developing better solutions to meet their needs now as well as in the future.

  11. Student design projects in applied acoustics.

    PubMed

    Bös, Joachim; Moritz, Karsten; Skowronek, Adam; Thyes, Christian; Tschesche, Johannes; Hanselka, Holger

    2012-03-01

    This paper describes a series of student projects which are intended to complement theoretical education in acoustics and engineering noise control with practical experience. The projects are also intended to enhance the students' ability to work in a team, to manage a project, and to present their results. The projects are carried out in close cooperation with industrial partners so that the students can get a taste of the professional life of noise control engineers. The organization of such a project, its execution, and some of the results from the most recent student project are presented as a demonstrative example. This latest project involved the creation of noise maps of a production hall, the acoustic analysis of a packaging machine, and the acoustic analysis of a spiral vibratory conveyor. Upon completion of the analysis, students then designed, applied, and verified some simple preliminary noise reduction measures to demonstrate the potential of these techniques.

  12. ACOUSTICS IN ARCHITECTURAL DESIGN, AN ANNOTATED BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS.

    ERIC Educational Resources Information Center

    DOELLE, LESLIE L.

    THE PURPOSE OF THIS ANNOTATED BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS WAS--(1) TO COMPILE A CLASSIFIED BIBLIOGRAPHY, INCLUDING MOST OF THOSE PUBLICATIONS ON ARCHITECTURAL ACOUSTICS, PUBLISHED IN ENGLISH, FRENCH, AND GERMAN WHICH CAN SUPPLY A USEFUL AND UP-TO-DATE SOURCE OF INFORMATION FOR THOSE ENCOUNTERING ANY ARCHITECTURAL-ACOUSTIC DESIGN…

  13. Acoustic design criteria in a general system for structural optimization

    NASA Technical Reports Server (NTRS)

    Brama, Torsten

    1990-01-01

    Passenger comfort is of great importance in most transport vehicles. For instance, in the new generation of regional turboprop aircraft, a low noise level is vital to be competitive on the market. The possibilities to predict noise levels analytically has improved rapidly in recent years. This will make it possible to take acoustic design criteria into account in early project stages. The development of the ASKA FE-system to include also acoustic analysis has been carried out at Saab Aircraft Division and the Aeronautical Research Institute of Sweden in a joint project. New finite elements have been developed to model the free fluid, porous damping materials, and the interaction between the fluid and structural degrees of freedom. The FE approach to the acoustic analysis is best suited for lower frequencies up to a few hundred Hz. For accurate analysis of interior cabin noise, large 3-D FE-models are built, but 2-D models are also considered to be useful for parametric studies and optimization. The interest is here focused on the introduction of an acoustic design criteria in the general structural optimization system OPTSYS available at the Saab Aircraft Division. The first implementation addresses a somewhat limited class of problems. The problems solved are formulated: Minimize the structural weight by modifying the dimensions of the structure while keeping the noise level in the cavity and other structural design criteria within specified limits.

  14. Acoustic Cymbal Transducers - Design, Hydrostatic Pressure Compensation, and Acoustic Performance

    DTIC Science & Technology

    2004-03-01

    applications is the composite metal-ceramic flextensional type transducer . The configuration of such a transducer can be quite diverse and many of these... transducers , so named for their geometric similarity to the percussion instruments, are miniature “class V” flextensional transducers that consist of a...Calibration, Underwater Acoustics, Underwater Sound, Transducer , Flextensional , Acoustic Cymbal, Broadband, USRD, APTF, Piezoelectric, Piezoceramic, Array

  15. Fluids and Combustion Facility Acoustic Emissions Controlled by Aggressive Low-Noise Design Process

    NASA Technical Reports Server (NTRS)

    Cooper, Beth A.; Young, Judith A.

    2004-01-01

    The Fluids and Combustion Facility (FCF) is a dual-rack microgravity research facility that is being developed by Northrop Grumman Information Technology (NGIT) for the International Space Station (ISS) at the NASA Glenn Research Center. As an on-orbit test bed, FCF will host a succession of experiments in fluid and combustion physics. The Fluids Integrated Rack (FIR) and the Combustion Integrated Rack (CIR) must meet ISS acoustic emission requirements (ref. 1), which support speech communication and hearing-loss-prevention goals for ISS crew. To meet these requirements, the NGIT acoustics team implemented an aggressive low-noise design effort that incorporated frequent acoustic emission testing for all internal noise sources, larger-scale systems, and fully integrated racks (ref. 2). Glenn's Acoustical Testing Laboratory (ref. 3) provided acoustical testing services (see the following photograph) as well as specialized acoustical engineering support as part of the low-noise design process (ref. 4).

  16. Turbomachinery design and tonal acoustics computations

    NASA Technical Reports Server (NTRS)

    Rangwalla, Akil A.

    1995-01-01

    The objective of this research was two-fold. The first objective was to complete the three-dimensional unsteady calculations of the flow through a new transonic turbine and study the effects of secondary flows due to the hub and casing, tip clearance vortices, and the inherent three-dimensional mixing of the flow. It should be noted that this turbine was and is still in the design phase and the results of the calculations have formed an integral part of the design process. The second objective of this proposal was to evaluate the capability of rotor-stator interaction codes to calculate tonal acoustics.

  17. Enhanced surface acoustic wave cell sorting by 3D microfluidic-chip design.

    PubMed

    Ung, W L; Mutafopulos, K; Spink, P; Rambach, R W; Franke, T; Weitz, D A

    2017-10-10

    We demonstrate an acoustic wave driven microfluidic cell sorter that combines advantages of multilayer device fabrication with planar surface acoustic wave excitation. We harness the strong vertical component of the refracted acoustic wave to enhance cell actuation by using an asymmetric flow field to increase cell deflection. Precise control of the 3-dimensional flow is realized by topographical structures implemented on the top of the microchannel. We experimentally quantify the effect of the structure dimensions and acoustic parameter. The design attains cell sorting rates and purities approaching those of state of the art fluorescence-activated cell sorters with all the advantages of microfluidic cell sorting.

  18. STEREO Mission Design Implementation

    NASA Technical Reports Server (NTRS)

    Guzman, Jose J.; Dunham, David W.; Sharer, Peter J.; Hunt, Jack W.; Ray, J. Courtney; Shapiro, Hongxing S.; Ossing, Daniel A.; Eichstedt, John E.

    2007-01-01

    STEREO (Solar-TErrestrial RElations Observatory) is the third mission in the Solar Terrestrial Probes program (STP) of the National Aeronautics and Space Administration (NASA) Science Mission Directorate Sun-Earth Connection theme. This paper describes the successful implementation (lunar swingby targeting) of the mission following the first phasing orbit to deployment into the heliocentric mission orbits following the two lunar swingbys. The STEREO Project had to make some interesting trajectory decisions in order to exploit opportunities to image a bright comet and an unusual lunar transit across the Sun.

  19. Affordable Acoustic Disdrometer: Design, Calibration, Tests

    NASA Astrophysics Data System (ADS)

    van de Giesen, N.; Degen, C.; Hut, R.

    2009-12-01

    It would be a hydrological understatement to say that measuring rainfall correctly is important. Recent years have seen important lowering of the costs of raingauges capable of measuring rainfall intensities. Such raingauges are typically tipping bucket raingauges, connected to an event logger. Costs for such a raingauge are about 100. Accuracy is not always very high, especially during high intensity storms. The moving parts make them vulnerable to slight disruptions such as insects. We set out to design a raingauge without moving parts and at a better price/quality ratio than existing raingauges. After testing several potential candidates, we settled on a very simple piezo ceramic element, which measures the impact of single drops. Such an element costs around 1. The impact of each drop causes an acoustic signal that is transformed into a voltage. A typical impact gives an upswing of up to 1 V and the ringing lasts about 50 ms. With a surface area of about 20 cm2, there is almost never overlap between the signals of different drops. The basic assumption is that each drop will have reached terminal velocity and that the total energy of the impact can, thereby, be related to drop size. We calibrated this acoustic disdrometer by letting drops of different size fall on the disdrometer. A very encouraging calibration curve was obtained in this way. Further testing consisted of comparisons during rainstorms between the acoustic disdrometer and standard tipping bucket raingauges. During intensive storms, the acoustic disdrometer gave results that were very close to those of a nearby totaling raingauge. The signal of the tipping bucket raingauges was clearly saturated as these were not capable of keeping up with the rain. During low intensity events, tipping bucket raingauges performed better as drops too small to detect by the acoustic disdrometer became a significant part of the total rainfall. In first instance, a simple MP3 player with recording functionality ($50

  20. Design and optimization of membrane-type acoustic metamaterials

    NASA Astrophysics Data System (ADS)

    Blevins, Matthew Grant

    One of the most common problems in noise control is the attenuation of low frequency noise. Typical solutions require barriers with high density and/or thickness. Membrane-type acoustic metamaterials are a novel type of engineered material capable of high low-frequency transmission loss despite their small thickness and light weight. These materials are ideally suited to applications with strict size and weight limitations such as aircraft, automobiles, and buildings. The transmission loss profile can be manipulated by changing the micro-level substructure, stacking multiple unit cells, or by creating multi-celled arrays. To date, analysis has focused primarily on experimental studies in plane-wave tubes and numerical modeling using finite element methods. These methods are inefficient when used for applications that require iterative changes to the structure of the material. To facilitate design and optimization of membrane-type acoustic metamaterials, computationally efficient dynamic models based on the impedance-mobility approach are proposed. Models of a single unit cell in a waveguide and in a baffle, a double layer of unit cells in a waveguide, and an array of unit cells in a baffle are studied. The accuracy of the models and the validity of assumptions used are verified using a finite element method. The remarkable computational efficiency of the impedance-mobility models compared to finite element methods enables implementation in design tools based on a graphical user interface and in optimization schemes. Genetic algorithms are used to optimize the unit cell design for a variety of noise reduction goals, including maximizing transmission loss for broadband, narrow-band, and tonal noise sources. The tools for design and optimization created in this work will enable rapid implementation of membrane-type acoustic metamaterials to solve real-world noise control problems.

  1. Microsupercomputers: Design and Implementation

    DTIC Science & Technology

    1988-04-01

    cell, referred to as a CMOS Storage Emitter Access ( CSEA ) cell, combines ECL level word-line voltage swings and emitter-follower bit line coupling...with a static CMOS latch. Compared with conven- tional multiport memory designs, the CSEA memory offers ’ Thi« roearch was supported in part by a...initial prototypes. BiCMOS CSEA MEMORY CELL The schematic of the CSEA memory cell and its associ- ated bit line sensing circuit is shown in

  2. Microsupercomputers: Design and Implementation

    DTIC Science & Technology

    1989-10-01

    tools for BiCMOS. In the area of fast sRAM we were very pleased to find out that our new BiCMOS memory cell design, the CSEA cell, was used by a...while maintaining a reasonable power dissipation (1.5W). It uses the CSEA cell, with a bipolar transistor in each memory cell that we reported... Journal of Solid State Circuits. April, 1989. 4. Gasbarro, J. and Horowitz, M., Integrated Pin Electronics for VLSI Functional Testers, IEEE, Custom

  3. Effectiveness-implementation Hybrid Designs

    PubMed Central

    Curran, Geoffrey M.; Bauer, Mark; Mittman, Brian; Pyne, Jeffrey M.; Stetler, Cheryl

    2013-01-01

    Objectives This study proposes methods for blending design components of clinical effectiveness and implementation research. Such blending can provide benefits over pursuing these lines of research independently; for example, more rapid translational gains, more effective implementation strategies, and more useful information for decision makers. This study proposes a “hybrid effectiveness-implementation” typology, describes a rationale for their use, outlines the design decisions that must be faced, and provides several real-world examples. Results An effectiveness-implementation hybrid design is one that takes a dual focus a priori in assessing clinical effectiveness and implementation. We propose 3 hybrid types: (1) testing effects of a clinical intervention on relevant outcomes while observing and gathering information on implementation; (2) dual testing of clinical and implementation interventions/strategies; and (3) testing of an implementation strategy while observing and gathering information on the clinical intervention’s impact on relevant outcomes. Conclusions The hybrid typology proposed herein must be considered a construct still in evolution. Although traditional clinical effectiveness and implementation trials are likely to remain the most common approach to moving a clinical intervention through from efficacy research to public health impact, judicious use of the proposed hybrid designs could speed the translation of research findings into routine practice. PMID:22310560

  4. Wavenumber transform analysis for acoustic black hole design.

    PubMed

    Feurtado, Philip A; Conlon, Stephen C

    2016-07-01

    Acoustic black holes (ABHs) are effective, passive, lightweight vibration absorbers that have been developed and shown to effectively reduce the structural vibration and radiated sound of beam and plate structures. ABHs employ a local thickness change that reduces the speed of bending waves and increases the transverse vibration amplitude. The vibrational energy can then be effectively focused and dissipated by material losses or through conventional viscoelastic damping treatments. In this work, the measured vibratory response of embedded ABH plates was transformed into the wavenumber domain in order to investigate the use of wavenumber analysis for characterizing, designing, and optimizing practical ABH systems. The results showed that wavenumber transform analysis can be used to simultaneously visualize multiple aspects of ABH performance including changes in bending wave speed, transverse vibration amplitude, and energy dissipation. The analysis was also used to investigate the structural acoustic coupling of the ABH system and determine the radiation efficiency of the embedded ABH plates compared to a uniform plate. The results demonstrated that the ABH effect results in acoustic decoupling as well as vibration reduction. The wavenumber transform based methods and results will be useful for implementing ABHs into real world structures.

  5. Piezoelectric transducer design for a miniaturized injectable acoustic transmitter

    NASA Astrophysics Data System (ADS)

    Li, H.; Jung, K. W.; Deng, Z. D.

    2015-11-01

    Implantable acoustic transmitters have been used in the last 20 years to track fish movement for fish survival and migration behavior studies. However, the relatively large weights and sizes of commercial transmitters limit the populations of studied fish. The surgical implantation procedures may also affect fish adversely and incur a significant amount of labor. Therefore, a smaller, lighter, and injectable transmitter was needed, and similar or better acoustic performance and service life over those provided by existing commercial transmitters was desired. To develop such a small transmitter, a number of technical challenges, including design optimization of the piezoelectric transducer, needed to be overcome. Our efforts to optimize the transducer focused on improving the average source level in the 180° range in which the signal was not blocked by the transmitter body. We found that a novel off-center tube transducer improved the average source level by 1.5 dB. An acoustic reflector attached to the back of the transducer also improved the source level by 1.3 dB. We found that too small a gap between the transducer and the component placed behind it resulted in distortion of the beam pattern. Lastly, a tuning inductor in series with the transducer was used to help optimize the source level. The findings and techniques developed in this work contributed to the successful development and implementation of a new injectable transmitter.

  6. Piezoelectric transducer design for a miniaturized injectable acoustic transmitter

    SciTech Connect

    Li, Huidong; Jung, Ki Won; Deng, Zhiqun D.

    2015-10-07

    Acoustic telemetry has been an important tool in the last 20 years for studying fish survival and migration behaviors during and after dam passage. This technology uses implantable acoustic transmitters as tags to three-dimensionally track the movement of fish. However, the relatively large weights and sizes of commercially available transmitters limit the populations of fish that could be studied. The surgical implantation procedures required may also injure fish and also incur a significant amount of labor. Therefore, a smaller, lighter, and injectable tag was needed, and similar or better acoustic performance and service life over that provided by existing commercial tags was desired. To develop such a small transmitter, a number of technical challenges, including design optimization of the piezoelectric transducer, needed to be overcome. The goal of our efforts to optimize the transducer focused on improving the average source level in the 180° range in which the transmitter was facing the receiving hydrophone, so as to increase the transmitter’s detection probability. This paper reports the techniques that were explored and developed to achieve this goal. We found that a novel off-center tube transducer improved the average source level of the front half of the transducer by 1.5 dB. An acoustic reflector attached to the back of the transducer also improved the source level by 3 dB when the transducer was pointed toward the receiving hydrophone, although the source level on the sides of the transducer was reduced. We found that too small a gap between the transducer and the component placed behind it resulted in distortion of the beam pattern. To overcome that issue, we connected a tuning inductor in series with the transducer to help optimize the source level. Furthermore, the findings and techniques developed in this work contributed to the successful development and implementation of a new injectable transmitter.

  7. Piezoelectric transducer design for a miniaturized injectable acoustic transmitter

    DOE PAGES

    Li, Huidong; Jung, Ki Won; Deng, Zhiqun D.

    2015-10-07

    Acoustic telemetry has been an important tool in the last 20 years for studying fish survival and migration behaviors during and after dam passage. This technology uses implantable acoustic transmitters as tags to three-dimensionally track the movement of fish. However, the relatively large weights and sizes of commercially available transmitters limit the populations of fish that could be studied. The surgical implantation procedures required may also injure fish and also incur a significant amount of labor. Therefore, a smaller, lighter, and injectable tag was needed, and similar or better acoustic performance and service life over that provided by existing commercialmore » tags was desired. To develop such a small transmitter, a number of technical challenges, including design optimization of the piezoelectric transducer, needed to be overcome. The goal of our efforts to optimize the transducer focused on improving the average source level in the 180° range in which the transmitter was facing the receiving hydrophone, so as to increase the transmitter’s detection probability. This paper reports the techniques that were explored and developed to achieve this goal. We found that a novel off-center tube transducer improved the average source level of the front half of the transducer by 1.5 dB. An acoustic reflector attached to the back of the transducer also improved the source level by 3 dB when the transducer was pointed toward the receiving hydrophone, although the source level on the sides of the transducer was reduced. We found that too small a gap between the transducer and the component placed behind it resulted in distortion of the beam pattern. To overcome that issue, we connected a tuning inductor in series with the transducer to help optimize the source level. Furthermore, the findings and techniques developed in this work contributed to the successful development and implementation of a new injectable transmitter.« less

  8. Acoustic Treatment Design Scaling Methods. Phase 2

    NASA Technical Reports Server (NTRS)

    Clark, L. (Technical Monitor); Parrott, T. (Technical Monitor); Jones, M. (Technical Monitor); Kraft, R. E.; Yu, J.; Kwan, H. W.; Beer, B.; Seybert, A. F.; Tathavadekar, P.

    2003-01-01

    The ability to design, build and test miniaturized acoustic treatment panels on scale model fan rigs representative of full scale engines provides not only cost-savings, but also an opportunity to optimize the treatment by allowing multiple tests. To use scale model treatment as a design tool, the impedance of the sub-scale liner must be known with confidence. This study was aimed at developing impedance measurement methods for high frequencies. A normal incidence impedance tube method that extends the upper frequency range to 25,000 Hz. without grazing flow effects was evaluated. The free field method was investigated as a potential high frequency technique. The potential of the two-microphone in-situ impedance measurement method was evaluated in the presence of grazing flow. Difficulties in achieving the high frequency goals were encountered in all methods. Results of developing a time-domain finite difference resonator impedance model indicated that a re-interpretation of the empirical fluid mechanical models used in the frequency domain model for nonlinear resistance and mass reactance may be required. A scale model treatment design that could be tested on the Universal Propulsion Simulator vehicle was proposed.

  9. The Development of the Acoustic Design of NASA Glenn Research Center's New Reverberant Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    Hughes, William O.; McNelis, Mark E.; Hozman, Aron D.; McNelis, Anne M.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is leading the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC's Plum Brook Station in Sandusky, Ohio, USA. Benham Companies, LLC is currently constructing modal, base-shake sine and reverberant acoustic test facilities to support the future testing needs of NASA s space exploration program. The large Reverberant Acoustic Test Facility (RATF) will be approximately 101,000 ft3 in volume and capable of achieving an empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world s known active reverberant acoustic test facilities. The key to achieving the expected acoustic test spectra for a range of many NASA space flight environments in the RATF is the knowledge gained from a series of ground acoustic tests. Data was obtained from several NASA-sponsored test programs, including testing performed at the National Research Council of Canada s acoustic test facility in Ottawa, Ontario, Canada, and at the Redstone Technical Test Center acoustic test facility in Huntsville, Alabama, USA. The majority of these tests were performed to characterize the acoustic performance of the modulators (noise generators) and representative horns that would be required to meet the desired spectra, as well as to evaluate possible supplemental gas jet noise sources. The knowledge obtained in each of these test programs enabled the design of the RATF sound generation system to confidently advance to its final acoustic design and subsequent on-going construction.

  10. The Development of the Acoustic Design of NASA Glenn Research Center's New Reverberant Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    Hughes, William O.; McNelis, Mark E.; Hozman, Aron D.; McNelis, Anne M.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is leading the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC s Plum Brook Station in Sandusky, Ohio. Benham Companies, LLC is currently constructing modal, base-shake sine and reverberant acoustic test facilities to support the future testing needs of NASA s space exploration program. The large Reverberant Acoustic Test Facility (RATF) will be approximately 101,000 ft3 in volume and capable of achieving an empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world s known active reverberant acoustic test facilities. The key to achieving the expected acoustic test spectra for a range of many NASA space flight environments in the RATF is the knowledge gained from a series of ground acoustic tests. Data was obtained from several NASA-sponsored test programs, including testing performed at the National Research Council of Canada s acoustic test facility in Ottawa, Ontario, Canada, and at the Redstone Technical Test Center acoustic test facility in Huntsville, Alabama. The majority of these tests were performed to characterize the acoustic performance of the modulators (noise generators) and representative horns that would be required to meet the desired spectra, as well as to evaluate possible supplemental gas jet noise sources. The knowledge obtained in each of these test programs enabled the design of the RATF sound generation system to confidently advance to its final acoustic design and subsequent on-going construction.

  11. Acoustic design of boundary segments in aircraft fuselages using topology optimization and a specialized acoustic pressure function

    NASA Astrophysics Data System (ADS)

    Radestock, Martin; Rose, Michael; Monner, Hans Peter

    2017-04-01

    In most aviation applications, a major cost benefit can be achieved by a reduction of the system weight. Often the acoustic properties of the fuselage structure are not in the focus of the primary design process, too. A final correction of poor acoustic properties is usually done using insulation mats in the chamber between the primary and secondary shell. It is plausible that a more sophisticated material distribution in that area can result in a substantially reduced weight. Topology optimization is a well-known approach to reduce material of compliant structures. In this paper an adaption of this method to acoustic problems is investigated. The gap full of insulation mats is suitably parameterized to achieve different material distributions. To find advantageous configurations, the objective in the underlying topology optimization is chosen to obtain good acoustic pressure patterns in the aircraft cabin. An important task in the optimization is an adequate Finite Element model of the system. This can usually not be obtained from commercially available programs due to the lack of special sensitivity data with respect to the design parameters. Therefore an appropriate implementation of the algorithm has been done, exploiting the vector and matrix capabilities in the MATLABQ environment. Finally some new aspects of the Finite Element implementation will also be presented, since they are interesting on its own and can be generalized to efficiently solve other partial differential equations as well.

  12. Design for an Aspherical Acoustic Fresnel Lens with Phase Continuity

    NASA Astrophysics Data System (ADS)

    Sato, Yuji; Mizutani, Koichi; Wakatsuki, Naoto; Nakamura, Toshiaki

    2008-05-01

    A convex acoustic lens using room temperature vulcanizing (RTV) silicone rubber, whose acoustic impedance is similar to that of water, is a typical acoustic lens. A phase-continuous Fresnel lens was proposed to thin the shape of the lens because a convex acoustic lens has large attenuation due to its thickness. However, a Fresnel lens based on a convex spherical acoustic lens could not concentrate sound pressure completely on the focal point because of a spherical aberration. We designed an aspherical Fresnel lens by ray theory to remove the spherical aberration. A two dimensional finite difference time domain (2-D FDTD) method was used to survey the sound pressure field focused by the acoustic lens under condition in which the angle of incidence and the aperture were varied. Results showed that the aspherical Fresnel lens can concentrate greater sound pressure than the spherical Fresnel lens at normal and small angles of incidence.

  13. Implementation and performance evaluation of acoustic denoising algorithms for UAV

    NASA Astrophysics Data System (ADS)

    Chowdhury, Ahmed Sony Kamal

    Unmanned Aerial Vehicles (UAVs) have become popular alternative for wildlife monitoring and border surveillance applications. Elimination of the UAV's background noise and classifying the target audio signal effectively are still a major challenge. The main goal of this thesis is to remove UAV's background noise by means of acoustic denoising techniques. Existing denoising algorithms, such as Adaptive Least Mean Square (LMS), Wavelet Denoising, Time-Frequency Block Thresholding, and Wiener Filter, were implemented and their performance evaluated. The denoising algorithms were evaluated for average Signal to Noise Ratio (SNR), Segmental SNR (SSNR), Log Likelihood Ratio (LLR), and Log Spectral Distance (LSD) metrics. To evaluate the effectiveness of the denoising algorithms on classification of target audio, we implemented Support Vector Machine (SVM) and Naive Bayes classification algorithms. Simulation results demonstrate that LMS and Discrete Wavelet Transform (DWT) denoising algorithm offered superior performance than other algorithms. Finally, we implemented the LMS and DWT algorithms on a DSP board for hardware evaluation. Experimental results showed that LMS algorithm's performance is robust compared to DWT for various noise types to classify target audio signals.

  14. Acoustic attenuation design requirements established through EPNL parametric trades

    NASA Technical Reports Server (NTRS)

    Veldman, H. F.

    1972-01-01

    An optimization procedure for the provision of an acoustic lining configuration that is balanced with respect to engine performance losses and lining attenuation characteristics was established using a method which determined acoustic attenuation design requirements through parametric trade studies using the subjective noise unit of effective perceived noise level (EPNL).

  15. Design-Based Implementation Research

    ERIC Educational Resources Information Center

    LeMahieu, Paul G.; Nordstrum, Lee E.; Potvin, Ashley Seidel

    2017-01-01

    Purpose: This paper is second of seven in this volume elaborating different approaches to quality improvement in education. It delineates a methodology called design-based implementation research (DBIR). The approach used in this paper is aimed at iteratively improving the quality of classroom teaching and learning practices in defined problem…

  16. Design-Based Implementation Research

    ERIC Educational Resources Information Center

    LeMahieu, Paul G.; Nordstrum, Lee E.; Potvin, Ashley Seidel

    2017-01-01

    Purpose: This paper is second of seven in this volume elaborating different approaches to quality improvement in education. It delineates a methodology called design-based implementation research (DBIR). The approach used in this paper is aimed at iteratively improving the quality of classroom teaching and learning practices in defined problem…

  17. Quiet Structure Design Using Acoustic Black Holes

    NASA Astrophysics Data System (ADS)

    Feurtado, Philip Andrew

    In recent years Acoustic Black Holes (ABHs) have been developed and demonstrated as effective, passive, lightweight vibration absorbers of flexural bending waves in beam and plate like structures. ABHs employ a local power-law thickness profile into a beam or plate, typically resulting in a one dimensional wedge or a two dimensional indentation in the structure. By reducing the thickness of the structure the ABH effect decreases the bending wave speed and increases the transverse vibration amplitude. In the limit where the thickness goes to zero the wave speed goes to zero and the bending waves never reach the thin edge, thus they are 'absorbed'. Real, machined ABHs necessarily have some finite truncation thickness. This results in local strain concentrations that effectively dissipate energy when coupled with a high loss material such as a traditional applied damping layer. While the effectiveness of ABHs has been established and demonstrated, there is still a need to develop new insights that can help designers tailor the performance of ABHs for practical, realizable, noise and vibration control applications. This research aimed to expand the existing understanding of ABHs in ways that will be useful and instructive for designing ABH systems for practical noise and vibration control problems. One of the ultimate goals of this branch of ABH research is to be able to prescribe a specific ABH design to suit a given noise and vibration control problem. The results and methods developed here represent a significant and useful step towards that goal. The first step involved investigating the limitations and implications of analytic ABH theory, the frequency dependent performance of ABH systems, and the structural acoustic coupling of embedded ABH systems with both response to distributed pressure excitations and radiation to the fluid surrounding the structure. Analytic ABH theory provides predictions for the vibration reduction from a one dimensional ABH wedge, but

  18. Design and demonstration of broadband thin planar diffractive acoustic lenses

    SciTech Connect

    Wang, Wenqi; Xie, Yangbo; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A.

    2014-09-08

    We present here two diffractive acoustic lenses with subwavelength thickness, planar profile, and broad operation bandwidth. Tapered labyrinthine unit cells with their inherently broadband effective material properties are exploited in our design. Both the measured and the simulated results are showcased to demonstrate the lensing effect over more than 40% of the central frequency. The focusing of a propagating Gaussian modulated sinusoidal pulse is also demonstrated. This work paves the way for designing diffractive acoustic lenses and more generalized phase engineering diffractive elements with labyrinthine acoustic metamaterials.

  19. Luminaire layout: Design and implementation

    NASA Technical Reports Server (NTRS)

    Both, A. J.

    1994-01-01

    The information contained in this report was presented during the discussion regarding guidelines for PAR uniformity in greenhouses. The data shows a lighting uniformity analysis in a research greenhouse for rose production at the Cornell University campus. The luminaire layout was designed using the computer program Lumen-Micro. After implementation of the design, accurate measurements were taken in the greenhouse and the uniformity analysis for both the design and implementation were compared. A study of several supplemental lighting installations resulted in the following recommendations: include only the actual growing area in the lighting uniformity analysis; for growing areas up to 20 square meters, take four measurements per square meter; for growing areas above 20 square meters, take one measurement per square meter; use one of the uniformity criteria and frequency graphs to compare lighting uniformity amongst designs; and design for uniformity criterion of a least 0.75 and the fraction within +/- 15% of the average PAR value should be close to one.

  20. Design of optimum acoustic treatment for rectangular ducts with flow

    NASA Technical Reports Server (NTRS)

    Motsinger, R. E.; Kraft, R. E.; Zwick, J. W.

    1976-01-01

    A design optimization technique for acoustic treatment in rectangular ducts with uniform mean flow is presented. The technique is based on the acoustic wave solution in terms of series of characteristic duct modes. The analysis allows multiple axial treatment sections along the length of the duct and requires a known modal characterization of the sound source. Conditions of acoustic pressure and acoustic velocity continuity are used to match modal solutions at planes of impedance discontinuity in the duct. Experimental techniques for obtaining this modal characterization are presented. Using duct modes measured at the source plane, the optimization technique is exercised to design an optimized single element liner in a case without mean flow, and optimized single and dual element liners in cases with mean flow. The validity of the program for predicting noise suppression is demonstrated by comparing analytical predictions with measured data for several (non-optimum) cases. Application to treatment design in turbomachinery exhaust ducts is considered.

  1. Acoustical enhancement systems: Design criteria and evaluation of room acoustical parameters based on in situ measurements

    NASA Astrophysics Data System (ADS)

    van Munster, Bjorn; Prinssen, Wim

    2003-10-01

    Acoustic enhancement systems have evolved significantly during the years. Where the early systems only aimed to increase the reverberation time in a hall, nowadays the increase of the reverberation time is only one of the features of such a system. Contrary and additionally to passive acoustics, an acoustic enhancement system enables a designer or acoustical consultant to change the acoustical characteristics of a hall in a more flexible way. Due to the sophisticated convolution processes and layout of such a system besides the reverberation time also, e.g., speech intelligibility and spaciousness can be improved or special effects can be added to shows. In this paper the applications of an enhancement system in general will be outlined in more detail. Furthermore, design criteria will be given which can be formulated for the installation of such a system. These criteria can be used to evaluate proposed designs, but also to estimate the required provisions to be included in the planning of a system installation. Besides, the paper describes the results of in situ measurements of one such system (SIAP) whereby the increase of the reverberation time is evaluated with respect to certain important room acoustical parameters, i.e., reverberant level, lateral efficiency and clarity.

  2. A broadband polygonal cloak for acoustic wave designed with linear coordinate transformation.

    PubMed

    Zhu, Rongrong; Zheng, Bin; Ma, Chu; Xu, Jun; Fang, Nicholas; Chen, Hongsheng

    2016-07-01

    Previous acoustic cloaks designed with transformation acoustics always involve inhomogeneous material. In this paper, a design of acoustic polygonal cloak is proposed using linear polygonal transformation method. The designed acoustic polygonal cloak has homogeneous and anisotropic parameters, which is much easier to realize in practice. Furthermore, a possible acoustic metamaterial structure to realize the cloak is proposed. Simulation results on the real structure show that the metamaterial acoustic cloak is effective to reduce the scattering of the object.

  3. Design of active structural acoustic control systems using eigenassignment approaches

    NASA Astrophysics Data System (ADS)

    Li, Zhonglin

    beam using PZT actuators and shaped PVDF film as error sensor. The filtered-x LMS algorithm was used in the experiment. Excellent global sound attenuation was achieved in the low frequencies. The minimum supersonic wavenumber design stems from the fact that only supersonic wavenumber components of the structural velocity spectra radiate to the far field. A SISO eigenassignment technique is used to modify the eigenproperties of a planar structure so that the eigenfunctions of the controlled system have minimum supersonic wavenumber in the frequency range of study. The sound pressure or sound power radiated by the structure is therefore reduced. The design was demonstrated on a simply supported beam to minimize the supersonic wavenumber components contributed by the odd- order modes only. Significant global sound attenuation was achieved in the frequency range of study. The main advantage of the proposed design methods is that they do not depend on the characteristics of the external disturbance, such as the form, location and frequency contents. Also, the error sensor and control input are optimized simultaneously, resulting in better acoustic control performance. The practical implementations of the proposed designs require accurate system modeling, this is the major limitation of the proposed designs.

  4. Acoustic control in a tractor cabin using two optimally designed Helmholtz resonators

    NASA Astrophysics Data System (ADS)

    Driesch, Patricia L.; Koopmann, Gary H.

    2003-10-01

    A virtual design methodology is developed to minimize the noise in enclosures with optimally designed, passive, 20 acoustic absorbers (Helmholtz resonators). A series expansion of eigenfunctions is used to represent the acoustic=20 absorbers as external volume velocities, eliminating the need for a solution of large matrix eigenvalue problems. A determination of this type (efficient model/reevaluation approach) significantly increases the design possibilities when optimization techniques are implemented. As a full-scale demonstration, the acoustic response from 90-190 Hz of a tractor cabin was investigated. The lowest cabin mode proposes a significant challenge to a noise control engineer since its anti-node is located near the head of the operator and often generates unacceptable sound-pressure levels. Exploiting the low-frequency capability of Helmholtz resonators, lumped parameter models of these resonators were coupled to the enclosure via an experimentally determined acoustic model of the tractor cabin. The virtual design methodology uses gradient optimization techniques as a post-processor for the modeling and analysis of the unmodified acoustic interior to determine optimal resonator characteristics. Using two optimally designed Helmholtz resonators, potential energy was experimentally reduced by 3.4 and 10.3 dB at 117 and 167 Hz, respectively.

  5. Ocean Acoustic Tomography Mooring Design Study.

    DTIC Science & Technology

    1982-04-01

    Figure 5 A- 13 APPENDIX B Power Systems for the Long-Range Acoustic Transmitter STRAWMAN #1 Lithium Primary Battery Lithium Thionyl Chloride ...buoyancy provided by a syntactic foam sphere. - LRT and the top buoyancy at the same depth. - Lithium primary battery placed with LRT. - Tension member...much less pressure). 4. Same as 1. except: - Lithium primary battery placed upon the anchor. - Electromechanical cable (also the tension member

  6. Implementing Safeguards-by-Design

    SciTech Connect

    Trond Bjornard; Robert Bean; Phillip Casey Durst; John Hockert; James Morgan

    2010-02-01

    Executive Summary Excerpt Safeguards-by-Design (SBD) is an approach to the design and construction of nuclear facilities whereby safeguards are designed-in from the very beginning. It is a systematic and structured approach for fully integrating international and national safeguards (MC&A), physical security, and other proliferation barriers into the design and construction process for nuclear facilities. SBD is primarily a project management or project coordination challenge, and this report focuses on that aspect of SBD. The present report continues the work begun in 2008 and focuses specifically on the design process, or project management and coordination - the planning, definition, organization, coordination, scheduling and interaction of activities of the safeguards experts and stakeholders as they participate in the design and construction of a nuclear facility. It delineates the steps in a nuclear facility design and construction project, in order to provide the project context within which the safeguards design activities take place, describes the involvement of safeguards experts in the design process, the nature of their analyses, interactions and decisions, as well as describing the documents created and how they are used. Designing and constructing a nuclear facility is an extremely complex undertaking. The stakeholders in an actual project are many – owner, operator, State regulators, nuclear facility primary contractor, subcontractors (e.g. instrument suppliers), architect engineers, project management team, safeguards, safety and security experts, in addition to the IAEA and its team. The purpose of the present report is to provide a common basis for discussions amongst stakeholders to collaboratively develop a SBD approach that will be both practically useful and mutually beneficial. The principal conclusions from the present study are: • In the short term, the successful implementation of SBD is principally a project management problem.

  7. Acoustical pipe lagging systems design and performance

    SciTech Connect

    Stevens, R.D.; Chapnik, B.V.; Howe, B.

    1998-10-30

    HGC Engineering was retained by the PRC International at the American Gas Association, to undertake a study of acoustical pipe lagging systems. The study included gathering input from PRCI member companies regarding their concerns and their established material specifications for lagging systems; conducting a comprehensive acoustical measurement program; using the measured results in conjunction with computer modeling to identify optimal lagging configurations; and developing material specifications for several standardized lagging systems for use by PRCI member companies. For all the lagging configurations, the measurement and modeling results showed amplification of sound at frequencies less than about 315 Hz. This result is a well known phenomenon, widely discussed the published acoustical literature, which means that pipe lagging is only effective for controlling higher frequencies noise (above about 500 Hz). Fortunately, in many gas piping applications, it is this higher frequency range that is of concern. The measurement and modeling results further showed that the high frequency performance of a lagging system is dependent primarily on having sufficient jacket mass and insulation thickness. The performance can be improved using an intermediate mass loaded barrier layer.

  8. Acoustical design of the new Cathay Pacific first class lounge

    NASA Astrophysics Data System (ADS)

    Hong, Westwood K. W.

    Cathay Pacific Airways' requirement of a first class lounge for attracting the high-yield passenger market to Hong Kong presented a special challenge for the Acoustical consultant. The 500-seating lounge covers more than 2000 square meters and is claimed by Cathay to be the biggest in Asia for its first class passengers. Arup acoustics was required to design a space that provided a quiet and relaxed environment for the Commercial Important Persons after a 16 to 17-hour flight. Arup Acoustics has designed the acoustics of the Lounge in meeting a stringent low noise specification requested by the user. The design work gave a comprehensive service both to support the lead consultant Ova Arup & Partners in controlling the external aircraft noise and internal noise and to assist the architect and interior designer in providing an excellent acoustical atmosphere for the passengers to rest while waiting for an onward connection. This paper will discuss the design of the lightweight roof and special double glazing system, featured by a 20-mm-thick laminated glass for the outer pane and a 600 to 1000-mm air gap to combat aircraft noise at the Hong Kong International Airport.

  9. The design of synthesized structural acoustic sensors for active control of interior noise with experimental validation

    NASA Astrophysics Data System (ADS)

    Li, D. S.; Cheng, L.

    2010-01-01

    In this paper, the feasibility of using synthesized structural acoustic sensors (SSAS) for active noise control inside irregularly shaped enclosures is investigated. A SSAS consists of a cluster of inter-connected discrete PVDF elements, located on the surface of a vibrating structure enclosing a sound field. An optimal design ensures the sensor output to be directly related to the acoustical potential energy inside the enclosure. Hence, synthesized structural acoustic sensors can provide error signals for an active noise control system, and the use of microphones inside the enclosure can be avoided. A cylindrical shell with a floor partition, which can be used to model an aircraft cabin, is used as a test case. PZT actuators are used as control actuators. Both SISO (single input and single output) and MIMO (multi-input and multi-output) control systems are optimally designed using Genetic Algorithms and implemented with a Filtered-X Feedforward LMS (least-mean-square) controller. Their control performances are evaluated with different types of disturbances. To show the effectiveness of the optimal design approach, some non-optimal control systems are also tested and compared with the optimal one. It is shown that with optimally designed SSAS, an active structural acoustic control system can effectively reduce noise inside the enclosures without using any acoustic transducers.

  10. Design of an acoustic metamaterial lens using genetic algorithms.

    PubMed

    Li, Dennis; Zigoneanu, Lucian; Popa, Bogdan-Ioan; Cummer, Steven A

    2012-10-01

    The present work demonstrates a genetic algorithm approach to optimizing the effective material parameters of an acoustic metamaterial. The target device is an acoustic gradient index (GRIN) lens in air, which ideally possesses a maximized index of refraction, minimized frequency dependence of the material properties, and minimized acoustic impedance mismatch. Applying this algorithm results in complex designs with certain common features, and effective material properties that are better than those present in previous designs. After modifying the optimized unit cell designs to make them suitable for fabrication, a two-dimensional lens was built and experimentally tested. Its performance was in good agreement with simulations. Overall, the optimization approach was able to improve the refractive index but at the cost of increased frequency dependence. The optimal solutions found by the algorithm provide a numerical description of how the material parameters compete with one another and thus describes the level of performance achievable in the GRIN lens.

  11. Acoustics

    NASA Technical Reports Server (NTRS)

    Goodman, Jerry R.; Grosveld, Ferdinand

    2007-01-01

    The acoustics environment in space operations is important to maintain at manageable levels so that the crewperson can remain safe, functional, effective, and reasonably comfortable. High acoustic levels can produce temporary or permanent hearing loss, or cause other physiological symptoms such as auditory pain, headaches, discomfort, strain in the vocal cords, or fatigue. Noise is defined as undesirable sound. Excessive noise may result in psychological effects such as irritability, inability to concentrate, decrease in productivity, annoyance, errors in judgment, and distraction. A noisy environment can also result in the inability to sleep, or sleep well. Elevated noise levels can affect the ability to communicate, understand what is being said, hear what is going on in the environment, degrade crew performance and operations, and create habitability concerns. Superfluous noise emissions can also create the inability to hear alarms or other important auditory cues such as an equipment malfunctioning. Recent space flight experience, evaluations of the requirements in crew habitable areas, and lessons learned (Goodman 2003; Allen and Goodman 2003; Pilkinton 2003; Grosveld et al. 2003) show the importance of maintaining an acceptable acoustics environment. This is best accomplished by having a high-quality set of limits/requirements early in the program, the "designing in" of acoustics in the development of hardware and systems, and by monitoring, testing and verifying the levels to ensure that they are acceptable.

  12. Fluid mechanics, acoustics, and design of turbomachinery, part 2

    NASA Technical Reports Server (NTRS)

    Lakshminarayana, B. (Editor); Britsch, W. R. (Editor); Gearhart, W. S. (Editor)

    1974-01-01

    A conference was conducted to investigate various parameters involved in the design of turbomachinery. The acoustic properties of compressor rotors at subsonic speeds are described to show the sources of sound in fluid flows and sound radiation from the rotors. The design criteria for turbomachinery are examined to show impeller design methods, transonic compressor technology, and blade selection for an axial flow compressor. Specific applications of turbomachinery used as pumps for aerospace applications and turbomachinery for marine propulsion are described.

  13. Sustained participatory design and implementation of ITHC.

    PubMed

    Simonsen, Jesper

    2010-01-01

    Participatory design includes engaging in large-scale information-systems development where participatory design approaches have been applied throughout design and organizational implementation. The keynote suggest to extend the iterative prototyping approach by (1) emphasizing participatory design experiments and pilot implementations as transcending traditional prototyping by evaluating fully integrated systems exposed to real work practices; (2) incorporating improvisational change management including anticipated, emergent, and opportunity-based change; and (3) extending initial design and development into a sustained and ongoing implementation that constitutes an overall technology-driven organizational change. This sustained participatory design and implementation approach is exemplified through a large-scale project in the Danish healthcare sector.

  14. The acoustical design of vehicles-a challenge for qualitative evaluation

    NASA Astrophysics Data System (ADS)

    Schulte-Fortkamp, Brigitte; Genuit, Klaus; Fiebig, Andre

    2005-09-01

    Whenever the acoustical design of vehicles is explored, the crucial question about the appropriate method of evaluation arises. Research shows that not only acoustic but also non-acoustic parameters have a major influence on the way sounds are evaluated. Therefore, new methods of evaluation have to be implemented. Methods are needed which give the opportunity to test the quality of the given ambience and to register the effects and evaluations in their functional interdependence as well as the influence of personal and contextual factors. Moreover, new methods have to give insight into processes of evaluation and their contextual parameters. In other words, the task of evaluating acoustical ambiences consists of designating a set of social, psychological, and cultural conditions which are important to determine particular individual and collective behavior, attitudes, and also emotions relative to the given ambience. However, no specific recommendations exist yet which comprise particular descriptions of how to assess those specific sound effects. That is why there is a need to develop alternative methods of evaluation with whose help effects of acoustical ambiences can be better predicted. A method of evaluation will be presented which incorporates a new sensitive approach for the evaluation of vehicle sounds.

  15. Acoustical Considerations in Planning and Design of Library Facilities.

    ERIC Educational Resources Information Center

    Wrightson, Denelle; Wrightson, John M.

    1999-01-01

    Discusses acoustical demands in public libraries to consider during the design and construction process of new or renovated library space. Topics include intrusive noises; overly reverberant spaces; lack of speech privacy; sound transmission class; noise criteria; reverberation time and noise reduction coefficient; space planning; sound systems;…

  16. Design and performance analysis of digital acoustic underwater telemetry system

    NASA Astrophysics Data System (ADS)

    Catipovic, J. A.; Baggeroer, A. B.; Vonderheydt, K.; Koelsch, D. E.

    1985-11-01

    The work discusses the design and performance characteristics of a Digital Acoustic Telemetry System (DATS) which incorporates the current state-of-the-art technology and is capable of reliable data transmission at rates useful to a wide range of ocean exploration and development gear.

  17. Transducer Design Experiments for Ground-Penetrating Acoustic Systems

    DTIC Science & Technology

    2007-11-02

    subsurface imaging experiments have utilized a source (Tx) and receiver (Rx) configuration in which signals produced by a transmitter at the soil surface...development in the field of acoustic subsurface imaging are as follows. First, a transmitter designed to minimize the emission of surface waves, while

  18. Design Criteria for Learning Spaces. Seating - Lighting - Acoustics.

    ERIC Educational Resources Information Center

    Koppes, Wayne F.; And Others

    The results of a project undertaken to assist the Office of Facilities of the State University of New York in the development of design and planning criteria for "learning spaces" with particular emphasis on the considerations for seating, lighting and acoustics. The learning spaces referred to are classified as large group instructional…

  19. Acoustical Considerations in Planning and Design of Library Facilities.

    ERIC Educational Resources Information Center

    Wrightson, Denelle; Wrightson, John M.

    1999-01-01

    Discusses acoustical demands in public libraries to consider during the design and construction process of new or renovated library space. Topics include intrusive noises; overly reverberant spaces; lack of speech privacy; sound transmission class; noise criteria; reverberation time and noise reduction coefficient; space planning; sound systems;…

  20. Optimizing acoustical treatment. [structural design criteria for theater

    NASA Technical Reports Server (NTRS)

    Beuran, N.; Ramboiu, S.; Farcas, I.; Halpert, E.

    1974-01-01

    A mathematical linear programming model is presented for optimizing acoustical treatment and interior decoration of concert and other public halls. This method provides the designer with a range of acoustically correct solutions at increased economical efficiency. The mathematical model uses geometrical data about the room, recommended reverberation time values, the architect's choice of given sound absorbing structures and finishing materials. The model permits inclusion of aesthetical considerations about conditioning, proportioning, or, on the contrary, reciprocal exclusion of any classes of material and/or sound absorbing structure.

  1. Thermo-acoustic fatigue design for hypersonic vehicle skin panels

    NASA Astrophysics Data System (ADS)

    Wentz, Kenneth R.; Blevins, Robert D.; Holehouse, Ian

    1994-09-01

    Thermo-vibro-acoustic analysis and test of skin panels for airbreathing hypersonic vehicles is made for a generic vehicle and trajectory. Aerothermal analysis shows that impingement of the bow shock wave on the vehicle and engine noise produce high fluctuating pressures and local heat fluxes. Maximum temperatures will exceed 2700 F (1480 C) at the top of the ascent trajectory and engine sound levels will exceed 170 dB at takeoff. As a result, loads due to engine acoustics and shock impingement dominate the design of many transatmospheric vehicle skin panels.

  2. Design, characterization and modeling of biobased acoustic foams

    NASA Astrophysics Data System (ADS)

    Ghaffari Mosanenzadeh, Shahrzad

    Polymeric open cell foams are widely used as sound absorbers in sectors such as automobile, aerospace, transportation and building industries, yet there is a need to improve sound absorption of these foams through understanding the relation between cell morphology and acoustic properties of porous material. Due to complicated microscopic structure of open cell foams, investigating the relation between foam morphology and acoustic properties is rather intricate and still an open problem in the field. The focus of this research is to design and develop biobased open cell foams for acoustic applications to replace conventional petrochemical based foams as well as investigating the link between cell morphology and macroscopic properties of open cell porous structures. To achieve these objectives, two industrially produced biomaterials, polylactide (PLA) and polyhydroxyalkanoate (PHA) and their composites were examined and highly porous biobased foams were fabricated by particulate leaching and compression molding. Acoustic absorption capability of these foams was enhanced utilizing the effect of co-continuous blends to form a bimodal porous structure. To tailor mechanical and acoustic properties of biobased foams, blends of PLA and PHA were studied to reach the desired mechanical and viscoelastic properties. To enhance acoustic properties of porous medium for having a broad band absorption effect, cell structure must be appropriately graded. Such porous structures with microstructural gradation are called Functionally Graded Materials (FGM). A novel graded foam structure was designed with superior sound absorption to demonstrate the effect of cell arrangement on performance of acoustic fixtures. Acoustic measurements were performed in a two microphone impedance tube and acoustic theory of Johnson-Champoux-Allard was applied to the fabricated foams to determine micro cellular properties such as tortuosity, viscous and thermal lengths from sound absorption impedance tube

  3. Computer method for design of acoustic liners for turbofan engines

    NASA Technical Reports Server (NTRS)

    Minner, G. L.; Rice, E. J.

    1976-01-01

    A design package is presented for the specification of acoustic liners for turbofans. An estimate of the noise generation was made based on modifications of existing noise correlations, for which the inputs are basic fan aerodynamic design variables. The method does not predict multiple pure tones. A target attenuation spectrum was calculated which was the difference between the estimated generation spectrum and a flat annoyance-weighted goal attenuated spectrum. The target spectrum was combined with a knowledge of acoustic liner performance as a function of the liner design variables to specify the acoustic design. The liner design method at present is limited to annular duct configurations. The detailed structure of the liner was specified by combining the required impedance (which is a result of the previous step) with a mathematical model relating impedance to the detailed structure. The design procedure was developed for a liner constructed of perforated sheet placed over honeycomb backing cavities. A sample calculation was carried through in order to demonstrate the design procedure, and experimental results presented show good agreement with the calculated results of the method.

  4. A Case Study in Acoustical Design.

    ERIC Educational Resources Information Center

    Ledford, Bruce R.; Brown, John A.

    1992-01-01

    Addresses concerns of both facilities planners and instructional designers in planning for the audio component of group presentations. Factors in the architectural design of enclosures for the reproduction of sound are described, including frequency, amplitude, and reverberation; and a case study for creating an acceptable enclosure is presented.…

  5. Distribution theory approach to implementing directional acoustic sensors.

    PubMed

    Schmidlin, Dean J

    2010-01-01

    The objective of directional acoustic sensors is to provide high directivity while occupying a small amount of space. An idealized point sensor achieves this objective from a knowledge of the spatial partial derivatives of acoustic pressure at a point in space. Direct measurement of these derivatives is difficult in practice. Consequently, it is expedient to come up with indirect methods. The use of pressure sensors to construct finite-difference approximations is an example of such a method. This paper utilizes the theory of distributions to derive another indirect method for estimating the various spatial partial derivatives of the pressure. This alternate method is then used to construct a multichannel filter which processes the acoustic pressure by mean of three-dimensional integral transforms throughout a 6epsilon-length cube centered at the origin. The output of the multichannel filter is a spatially and temporally filtered version of the pressure at the origin. The temporal filter is a lowpass Gaussian filter whose bandwidth is inversely proportional to epsilon. Finally, the lattice method for numerical multiple integration is utilized to develop a discrete-spatial version of the multichannel filter.

  6. Implementation of algorithms to discriminate chemical/biological airbursts from high explosive airbursts utilizing acoustic signatures

    NASA Astrophysics Data System (ADS)

    Hohil, Myron E.; Desai, Sachi; Morcos, Amir

    2006-05-01

    The Army is currently developing acoustic sensor systems that will provide extended range surveillance, detection, and identification for force protection and tactical security. A network of such sensors remotely deployed in conjunction with a central processing node (or gateway) will provide early warning and assessment of enemy threats, near real-time situational awareness to commanders, and may reduce potential hazards to the soldier. In contrast, the current detection of chemical/biological (CB) agents expelled into a battlefield environment is limited to the response of chemical sensors that must be located within close proximity to the CB agent. Since chemical sensors detect hazardous agents through contact, the sensor range to an airburst is the key-limiting factor in identifying a potential CB weapon attack. The associated sensor reporting latencies must be minimized to give sufficient preparation time to field commanders, who must assess if an attack is about to occur, has occurred, or if occurred, the type of agent that soldiers might be exposed to. The long-range propagation of acoustic blast waves from heavy artillery blasts, which are typical in a battlefield environment, introduces a feature for using acoustics and other sensor suite technologies for the early detection and identification of CB threats. Employing disparate sensor technologies implies that warning of a potential CB attack can be provided to the solider more rapidly and from a safer distance when compared to current conventional methods. Distinct characteristics arise within the different airburst signatures because High Explosive (HE) warheads emphasize concussive and shrapnel effects, while chemical/biological warheads are designed to disperse their contents over immense areas, therefore utilizing a slower burning, less intensive explosion to mix and distribute their contents. Highly reliable discrimination (100%) has been demonstrated at the Portable Area Warning Surveillance System

  7. Analytic Formulation and Numerical Implementation of an Acoustic Pressure Gradient Prediction

    NASA Technical Reports Server (NTRS)

    Lee, Seongkyu; Brentner, Kenneth S.; Farassat, Fereidoun

    2007-01-01

    The scattering of rotor noise is an area that has received little attention over the years, yet the limited work that has been done has shown that both the directivity and intensity of the acoustic field may be significantly modified by the presence of scattering bodies. One of the inputs needed to compute the scattered acoustic field is the acoustic pressure gradient on a scattering surface. Two new analytical formulations of the acoustic pressure gradient have been developed and implemented in the PSU-WOPWOP rotor noise prediction code. These formulations are presented in this paper. The first formulation is derived by taking the gradient of Farassat's retarded-time Formulation 1A. Although this formulation is relatively simple, it requires numerical time differentiation of the acoustic integrals. In the second formulation, the time differentiation is taken inside the integrals analytically. The acoustic pressure gradient predicted by these new formulations is validated through comparison with the acoustic pressure gradient determined by a purely numerical approach for two model rotors. The agreement between analytic formulations and numerical method is excellent for both stationary and moving observers case.

  8. The Standards Implementation Design (SID) System.

    ERIC Educational Resources Information Center

    Hawaii State Dept. of Education, Honolulu. Div. of Learner, Teacher, and School Support.

    The Standards Implementation Design (SID) system is a comprehensive framework for analyzing school performance, planning for improvement based on the analysis, implementing the improvements, and evaluating results. It is designed to engage school personnel in introspection about student achievement as related to curriculum, the teaching and…

  9. Implementing wavelet inverse-transform processor with surface acoustic wave device.

    PubMed

    Lu, Wenke; Zhu, Changchun; Liu, Qinghong; Zhang, Jingduan

    2013-02-01

    The objective of this research was to investigate the implementation schemes of the wavelet inverse-transform processor using surface acoustic wave (SAW) device, the length function of defining the electrodes, and the possibility of solving the load resistance and the internal resistance for the wavelet inverse-transform processor using SAW device. In this paper, we investigate the implementation schemes of the wavelet inverse-transform processor using SAW device. In the implementation scheme that the input interdigital transducer (IDT) and output IDT stand in a line, because the electrode-overlap envelope of the input IDT is identical with the one of the output IDT (i.e. the two transducers are identical), the product of the input IDT's frequency response and the output IDT's frequency response can be implemented, so that the wavelet inverse-transform processor can be fabricated. X-112(0)Y LiTaO(3) is used as a substrate material to fabricate the wavelet inverse-transform processor. The size of the wavelet inverse-transform processor using this implementation scheme is small, so its cost is low. First, according to the envelope function of the wavelet function, the length function of the electrodes is defined, then, the lengths of the electrodes can be calculated from the length function of the electrodes, finally, the input IDT and output IDT can be designed according to the lengths and widths for the electrodes. In this paper, we also present the load resistance and the internal resistance as the two problems of the wavelet inverse-transform processor using SAW devices. The solutions to these problems are achieved in this study. When the amplifiers are subjected to the input end and output end for the wavelet inverse-transform processor, they can eliminate the influence of the load resistance and the internal resistance on the output voltage of the wavelet inverse-transform processor using SAW device.

  10. Design and acoustic characterization of limited diffraction ultrasonic devices.

    PubMed

    Aulet, A; Núñez, I; Moreno, E; Eiras, J A; Negreira, C A

    2010-05-01

    Limited diffraction ultrasonic transducers are devices that have a large depth of acoustic field without important effects of diffraction, which make them optimal in applications of medical images, among others. This report details how this special type of piezoelectric device was designed by means of a simple technology using three electrodes in the form of concentric rings in both faces of a ferroelectric ceramic disk, which were used to apply a profile of non-homogeneous polarization. Once designed, the radiation fields emitted by these resonators were characterized experimentally by electro-acoustic and acousto-optic techniques and were compared with those emitted by conventional devices. As shown in the experimental characterizations, ultrasonic transducers with optimal properties for use in medical applications such as good collimation of the ultrasound beam, high lateral resolution, as well as little effects of diffraction were obtained.

  11. Design and demonstration of an underwater acoustic carpet cloak.

    PubMed

    Bi, Yafeng; Jia, Han; Lu, Wenjia; Ji, Peifeng; Yang, Jun

    2017-04-06

    The carpet cloak, which is designed to hide the objects placed on a reflecting surface, has become a topic of considerable interest. Inspired by those theoretical works, the experimental realization of acoustic carpet cloak in air host has been reported. However, due to the difficulty in obtaining the unit cell in reality, the underwater carpet cloak still remains in simulation thus far. Here, we design and fabricate a realizable underwater acoustic carpet cloak. By introducing a scaling factor, the structure of the carpet cloak, which is comprised of layered brass plates, is greatly simplified at the cost of some impedance match. The experimental results demonstrate a good performance of the proposed carpet cloak in a wide frequency range. Our work paves the way for future applications in the practical underwater devices.

  12. Design Parameters of a Miniaturized Piezoelectric Underwater Acoustic Transmitter

    PubMed Central

    Li, Huidong; Deng, Zhiqun Daniel; Yuan, Yong; Carlson, Thomas J.

    2012-01-01

    PZT ceramics have been widely used in underwater acoustic transducers. However, literature available discussing the design parameters of a miniaturized PZT-based low-duty-cycle transmitter is very limited. This paper discusses some of the design parameters—the backing material, driving voltage, PZT material type, power consumption and the transducer length of a miniaturized acoustic fish tag using a PZT tube. Four different types of PZT were evaluated with respect to the source level, energy consumption and bandwidth of the transducer. The effect of the tube length on the source level is discussed. The results demonstrate that ultralow-density closed-cell foam is the best backing material for the PZT tube. The Navy Type VI PZTs provide the best source level with relatively low energy consumption and that a low transducer capacitance is preferred for high efficiency. A 35% reduction in the transducer length results in 2 dB decrease in source level. PMID:23012534

  13. On the design of long T-shaped acoustic resonators

    NASA Astrophysics Data System (ADS)

    Li, Deyu; Vipperman, Jeffrey S.

    2004-11-01

    In this work we present a more general mathematical model for the calculation of resonance frequencies for long, T-shaped acoustic resonators. The method is based upon wave propagation and, unlike previous theories, no constraints on the geometry of the resonator are imposed. In addition, a new end-correction model based upon Rayleigh's end corrections is proposed and evaluated. The theory is used to develop a plane-wave multimodal-based design theory, which permits higher-order 1-dimensional modes of the T-shaped acoustic absorber to be used for absorbing high-frequency noise within enclosures. A series of experiments are conducted on round and square cross section resonators to validate the theory, evaluate the end correction models, and demonstrate design examples. .

  14. Acoustic Sensor Network Design for Position Estimation

    DTIC Science & Technology

    2009-05-01

    utility is K(ñ) = ( T∑ t=1 ω̃1,tñt )( T∑ t=1 ω̃2,tñt )ρ . (17) We start by noting that the following is a necessary KKT condition for the op- timal...Analysis]: Optimization —Constrained optimization , convex pro- gramming, integer programming, nonlinear programming; G.3 [Probability and Statistics...subsections describe general multiple-objective optimization , exact integer programming methods to find the “ optimal ” designs, and approximate non

  15. Acoustic design of rotor blades using a genetic algorithm

    NASA Technical Reports Server (NTRS)

    Wells, V. L.; Han, A. Y.; Crossley, W. A.

    1995-01-01

    A genetic algorithm coupled with a simplified acoustic analysis was used to generate low-noise rotor blade designs. The model includes thickness, steady loading and blade-vortex interaction noise estimates. The paper presents solutions for several variations in the fitness function, including thickness noise only, loading noise only, and combinations of the noise types. Preliminary results indicate that the analysis provides reasonable assessments of the noise produced, and that genetic algorithm successfully searches for 'good' designs. The results show that, for a given required thrust coefficient, proper blade design can noticeably reduce the noise produced at some expense to the power requirements.

  16. Acoustic design of rotor blades using a genetic algorithm

    NASA Technical Reports Server (NTRS)

    Wells, V. L.; Han, A. Y.; Crossley, W. A.

    1995-01-01

    A genetic algorithm coupled with a simplified acoustic analysis was used to generate low-noise rotor blade designs. The model includes thickness, steady loading and blade-vortex interaction noise estimates. The paper presents solutions for several variations in the fitness function, including thickness noise only, loading noise only, and combinations of the noise types. Preliminary results indicate that the analysis provides reasonable assessments of the noise produced, and that genetic algorithm successfully searches for 'good' designs. The results show that, for a given required thrust coefficient, proper blade design can noticeably reduce the noise produced at some expense to the power requirements.

  17. Design of a Subsurface Moored Acoustic Array in Deep Water

    DTIC Science & Technology

    2007-01-01

    concepts were a culmination of many years design teams past experience with undersea cable structures. Offshore structural analysis software [2] was...concept as a baseline, the complete STAFAC mooring with umbilicals is shown in Fig 8., both in elevation view and plan view. Umbilical cables are...navigation. The umbilicals are attached near the upper portion of the HGMS arrays to be consistent with the associate Southeast Alaska Acoustic

  18. Utilizing numerical techniques in turbofan inlet acoustic suppressor design

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J.

    1982-01-01

    Numerical theories in conjunction with previously published analytical results are used to augment current analytical theories in the acoustic design of a turbofan inlet nacelle. In particular, a finite element-integral theory is used to study the effect of the inlet lip radius on the far field radiation pattern and to determine the optimum impedance in an actual engine environment. For some single mode JT15D data, the numerical theory and experiment are found to be in a good agreement.

  19. Banning design automation software implementation

    NASA Technical Reports Server (NTRS)

    Kuehlthau, R. L.

    1975-01-01

    The research is reported for developing a system of computer programs to aid engineering in the design, fabrication, and testing of large scale integrated circuits, hybrid circuits, and printed circuit boards. The automatic layout programs, analysis programs, and interface programs are discussed.

  20. Mixed Method Designs in Implementation Research

    PubMed Central

    Aarons, Gregory A.; Horwitz, Sarah; Chamberlain, Patricia; Hurlburt, Michael; Landsverk, John

    2010-01-01

    This paper describes the application of mixed method designs in implementation research in 22 mental health services research studies published in peer-reviewed journals over the last 5 years. Our analyses revealed 7 different structural arrangements of qualitative and quantitative methods, 5 different functions of mixed methods, and 3 different ways of linking quantitative and qualitative data together. Complexity of design was associated with number of aims or objectives, study context, and phase of implementation examined. The findings provide suggestions for the use of mixed method designs in implementation research. PMID:20967495

  1. Mixed method designs in implementation research.

    PubMed

    Palinkas, Lawrence A; Aarons, Gregory A; Horwitz, Sarah; Chamberlain, Patricia; Hurlburt, Michael; Landsverk, John

    2011-01-01

    This paper describes the application of mixed method designs in implementation research in 22 mental health services research studies published in peer-reviewed journals over the last 5 years. Our analyses revealed 7 different structural arrangements of qualitative and quantitative methods, 5 different functions of mixed methods, and 3 different ways of linking quantitative and qualitative data together. Complexity of design was associated with number of aims or objectives, study context, and phase of implementation examined. The findings provide suggestions for the use of mixed method designs in implementation research.

  2. Acoustic Sensor Design for Dark Matter Bubble Chamber Detectors

    PubMed Central

    Felis, Ivan; Martínez-Mora, Juan Antonio; Ardid, Miguel

    2016-01-01

    Dark matter bubble chamber detectors use piezoelectric sensors in order to detect and discriminate the acoustic signals emitted by the bubbles grown within the superheated fluid from a nuclear recoil produced by a particle interaction. These sensors are attached to the outside walls of the vessel containing the fluid. The acoustic discrimination depends strongly on the properties of the sensor attached to the outer wall of the vessel that has to meet the requirements of radiopurity and size. With the aim of optimizing the sensor system, a test bench for the characterization of the sensors has been developed. The sensor response for different piezoelectric materials, geometries, matching layers, and backing layers have been measured and contrasted with FEM simulations and analytical models. The results of these studies lead us to have a design criterion for the construction of specific sensors for the next generation of dark matter bubble chamber detectors (250 L). PMID:27294937

  3. Acoustic Sensor Design for Dark Matter Bubble Chamber Detectors.

    PubMed

    Felis, Ivan; Martínez-Mora, Juan Antonio; Ardid, Miguel

    2016-06-10

    Dark matter bubble chamber detectors use piezoelectric sensors in order to detect and discriminate the acoustic signals emitted by the bubbles grown within the superheated fluid from a nuclear recoil produced by a particle interaction. These sensors are attached to the outside walls of the vessel containing the fluid. The acoustic discrimination depends strongly on the properties of the sensor attached to the outer wall of the vessel that has to meet the requirements of radiopurity and size. With the aim of optimizing the sensor system, a test bench for the characterization of the sensors has been developed. The sensor response for different piezoelectric materials, geometries, matching layers, and backing layers have been measured and contrasted with FEM simulations and analytical models. The results of these studies lead us to have a design criterion for the construction of specific sensors for the next generation of dark matter bubble chamber detectors (250 L).

  4. Design and manufacturing of scanning probe acoustic microscope test phantom

    NASA Astrophysics Data System (ADS)

    Chen, Xiaohui; Fang, Xiaoyue; Song, Jitao; Ding, Mingyue

    2015-03-01

    Acquiring nondestructive internal structures acoustic image as well as the morphology images using scanning probe acoustic microscope (SPAM) is a challenge and no known metrology tools to identify the ultrasonic internal resolution and detectable depth of SPAM in a nondestructive way. Monitoring these defects necessitates the identification of their technical parameters of SPAM. In this paper, the specific materials (test phantoms) were designed and processed so that the ultrasound internal resolution of SPAM in nondestructive imaging of the embedded or buried substructures as well as the morphology images were measured. Experimental results demonstrated the successful identification of embedded or buried defects under the test phantom with the resolution of 50nm for SPAM as well as the detectable depth of more than 100μm.

  5. SPHEREx: Instrument design and implementation

    NASA Astrophysics Data System (ADS)

    Korngut, Phillip

    2016-01-01

    SPHEREx, a mission in NASA's Small Explorer (SMEX) program that was selected for Phase A in July 2015, is an all-sky survey satellite designed to address all three science goals in NASA's astrophysics division: probe the origin and destiny of our Universe; explore whether planets around other stars could harbor life; and explore the origin and evolution of galaxies.SPHEREx has a simple, high heritage design with large optical throughput to maximize spectral mapping speed, ideal for an all-sky spectral survey. The 20 cm telescope is based on a wide-field off-axis three-mirror astigmat. With an instantaneous field of view of 3.5x7.0 degrees imaged by four H2RG focal plane arrays of 6.2 arcsecond pixels, SPHEREx produces spectra without the use of any dispersive elements. Instead, it uses four linear variable filters (LVFs) placed above the detectors to yield R=41.5 and R=150 spectra covering wavelengths 0.75 to 4.8 um. Spectra are constructed by stepping the telescope boresight across the sky, modulating the location of an object within the FOV and varying the observation wavelength in each image. Each pointing provides a long > 96 s integration so that the detectors realize background-limited sensitivity. The telescope is cooled by a series of three deployable thermal shields with V-groove radiators to < 80K, with the two long-wavelength focal planes to < 55K. The design has ample technical margins on detector, optical, thermal, and pointing performance, and carries an additional large margin on point source sensitivity.

  6. Design and Implementation of Online Communities

    DTIC Science & Technology

    2001-09-01

    EBay Commercial Forums, Chat Rooms Comments posted by patrons Buyers, Sellers N/A Community Values Online training courses Recognition of...NAVAL POSTGRADUATE SCHOOL Monterey, California THESIS DESIGN AND IMPLEMENTATION OF ONLINE COMMUNITIES by Michael Del Grosso September...

  7. Characterization and Design of Spiral Frequency Steerable Acoustic Transducers

    NASA Astrophysics Data System (ADS)

    Repale, Rohan

    Structural Health Monitoring (SHM) is an emerging research area devoted to improving the safety and maintainability of civil structures. Guided wave structural testing method is an effective approach used for SHM of plate-like structures using piezoelectric transducers. These transducers are attached to the surface of the structure and are capable of sensing its health by using surface waves. Transducers with beam steering i.e. electronic scanning capabilities can perform surface interrogation with higher precision and ease. A frequency steerable acoustic transducer (FSAT) is capable of beam steering and directional surface wave sensing to detect and localize damage in structures. The objective of this research is to further explore the possibilities of FSAT technology by designing and testing new FSAT designs. The beam steering capability of FSAT can be controlled by manipulating its design parameters. These design parameters therefore play a significant role in FSAT's performance. Studying the design parameters and documenting the performance improvements based on parameter variation is the primary goal of this research. Design and characterization of spiral FSAT was performed and results were simulated. Array FSAT documented results were validated. Modified designs were modeled based on design parameter variations. Characterization of these designs was done and their performance was recorded. Plate simulation results confirm direct relationship between design parameters and beam steering. A set of guidelines for future designs was also proposed. Two designs developed based on the set guidelines were sent to our collaborator Genziko Inc. for fabrication.

  8. Design Parameters of a Miniaturized Piezoelectric Underwater Acoustic Transmitter

    SciTech Connect

    Li, Huidong; Deng, Zhiqun; Yuan, Yong; Carlson, Thomas J.

    2012-07-02

    The Juvenile Salmon Acoustic Telemetry System (JSATS) project supported by the U.S. Army Corps of Engineers, Portland District, has yielded the smallest acoustic fish tag transmitter commercially available to date. In order to study even smaller fish populations and make the transmitter injectable by needles, the JSATS acoustic micro transmitter needs to be further downsized. As part of the transmitter downsizing effort some of the design parameters of the lead zirconate titanate (PZT) ceramic tube transducer in the transmitter were studied, including the type of PZT, the backing material, the necessary drive voltage, the transmitting bandwidth and the length of the transducer. It was found that, to satisfy the 156-dB source level requirement of JSATS, a square wave with a 10-volt amplitude is required to drive 'soft' PZT transducers. PZT-5H demonstrated the best source level performance. For Navy types I and II, 16 volts or 18 volts were needed. Ethylene-propylene-diene monomer (EPDM) closed-cell foam was found to be the backing material providing the highest source level. The effect of tube length on the source level is also demonstrated in this paper, providing quantitative information for downsizing of small piezoelectric transmitters.

  9. Multi-acoustic lens design methodology for a low cost C-scan photoacoustic imaging camera

    NASA Astrophysics Data System (ADS)

    Chinni, Bhargava; Han, Zichao; Brown, Nicholas; Vallejo, Pedro; Jacobs, Tess; Knox, Wayne; Dogra, Vikram; Rao, Navalgund

    2016-03-01

    We have designed and implemented a novel acoustic lens based focusing technology into a prototype photoacoustic imaging camera. All photoacoustically generated waves from laser exposed absorbers within a small volume get focused simultaneously by the lens onto an image plane. We use a multi-element ultrasound transducer array to capture the focused photoacoustic signals. Acoustic lens eliminates the need for expensive data acquisition hardware systems, is faster compared to electronic focusing and enables real-time image reconstruction. Using this photoacoustic imaging camera, we have imaged more than 150 several centimeter size ex-vivo human prostate, kidney and thyroid specimens with a millimeter resolution for cancer detection. In this paper, we share our lens design strategy and how we evaluate the resulting quality metrics (on and off axis point spread function, depth of field and modulation transfer function) through simulation. An advanced toolbox in MATLAB was adapted and used for simulating a two-dimensional gridded model that incorporates realistic photoacoustic signal generation and acoustic wave propagation through the lens with medium properties defined on each grid point. Two dimensional point spread functions have been generated and compared with experiments to demonstrate the utility of our design strategy. Finally we present results from work in progress on the use of two lens system aimed at further improving some of the quality metrics of our system.

  10. Comparison of STRUCTURAL-ACOUSTIC Control Designs on AN Active Composite Panel

    NASA Astrophysics Data System (ADS)

    BINGHAM, B.; ATALLA, M. J.; HAGOOD, N. W.

    2001-07-01

    This work presents a comparison of three technologies for structural-acoustic control that, while prevalent in the literature, had not been compared on a single structure. The comparison is generalizable because the techniques are implemented on a panel structure representative of a more complex structure (e.g., an aircraft fuselage, a submarine vehicle hull, a satellite payload shroud, etc.). The test-bed used for this comparison is a carbon-fiber composite panel manufactured with embedded active fiber composite actuators. Since such integrated structures constitute a continued avenue of research, the manufacturing and performance of this structure is illustrated. The design of the test-bed is guided by an effort to achieve a dynamic response similar to a single panel in a typical aircraft or rotorcraft fuselage.Existing active control architectures for broadband acoustic radiation reduction are compared both analytically and experimentally on a representative structure to quantify the capabilities and limitations of the existing control methodologies. Specifically, three broad categories of control are compared: classical feedback (rate feedback), optimal feedback (linear quadratic Gaussian), and adaptive feedforward control (x -filtered least mean square). The control architectures implemented during this study are all single-input/single-output in order to allow a fair comparison of the issues involved in the design, as well as the use and performance of each approach. Both the vibration and the acoustic performance are recorded for each experiment under equivalent conditions to allow a generalizable comparison. Experimental results lead to conclusions pertaining to the application of active structural-based control to improve the acoustic performance of more complex structures.

  11. Acoustic Characteristics of Various Treatment Panel Designs for HSCT Ejector Liner Acoustic Technology Development Program

    NASA Technical Reports Server (NTRS)

    Salikuddin, M.; Kraft, R. E.; Syed, A. a.; Vu, D. D.; Mungur, P.; Langenbrunner, L. E.; Majjigi, R. K.

    2006-01-01

    The objectives of the initial effort (Phase I) of HSR Liner Technology Program, the selection of promising liner concepts, design and fabrication of these concepts for laboratory tests, testing these liners in the laboratory by using impedance tube and flow ducts, and developing empirical impedance/suppression correlation, are successfully completed. Acoustic and aerodynamic criteria for the liner design are established. Based on these criteria several liners are designed. The liner concepts designed and fabricated include Single-Degree-of-Freedom (SDOF), Two-Degree-of-Freedom (2DOF), and Bulk Absorber. Two types of SDOF treatment are fabricated, one with a perforated type face plate and the other with a wiremesh (woven) type faceplate. In addition, special configurations of these concepts are also included in the design. Several treatment panels are designed for parametric study. In these panels the facesheets of different porosity, hole diameter, and sheet thickness are utilized. Several deep panels (i.e., 1 in. deep) are designed and instrumented to measure DC flow resistance and insitu impedance in the presence of grazing flow. Basic components of these panels (i.e., facesheets, bulk materials, etc.) are also procured and tested. The results include DC flow resistance, normal impedance, and insertion loss.

  12. Principles in Call Software Design and Implementation.

    ERIC Educational Resources Information Center

    Gimeno, Ana

    2002-01-01

    Discusses a number of principles to bear in mind when designing and implementing multimedia language learning materials. A general overview is provided on the template approach to designing and creating a multimedia computer assisted language learning package. Examples are given from experience in multimedia development for language learning…

  13. Designing, Implementing, and Evaluating Secure Web Browsers

    ERIC Educational Resources Information Center

    Grier, Christopher L.

    2009-01-01

    Web browsers are plagued with vulnerabilities, providing hackers with easy access to computer systems using browser-based attacks. Efforts that retrofit existing browsers have had limited success since modern browsers are not designed to withstand attack. To enable more secure web browsing, we design and implement new web browsers from the ground…

  14. Designing, Implementing, and Evaluating Secure Web Browsers

    ERIC Educational Resources Information Center

    Grier, Christopher L.

    2009-01-01

    Web browsers are plagued with vulnerabilities, providing hackers with easy access to computer systems using browser-based attacks. Efforts that retrofit existing browsers have had limited success since modern browsers are not designed to withstand attack. To enable more secure web browsing, we design and implement new web browsers from the ground…

  15. Enhanced sensitive love wave surface acoustic wave sensor designed for immunoassay formats.

    PubMed

    Puiu, Mihaela; Gurban, Ana-Maria; Rotariu, Lucian; Brajnicov, Simona; Viespe, Cristian; Bala, Camelia

    2015-05-05

    We report a Love wave surface acoustic wave (LW-SAW) immunosensor designed for the detection of high molecular weight targets in liquid samples, amenable also for low molecular targets in surface competition assays. We implemented a label-free interaction protocol similar to other surface plasmon resonance bioassays having the advantage of requiring reduced time analysis. The fabricated LW-SAW sensor supports the detection of the target in the nanomolar range, and can be ultimately incorporated in portable devices, suitable for point-of-care testing (POCT) applications.

  16. Design of Fresnel Lens-Type Multi-Trapping Acoustic Tweezers

    PubMed Central

    Tu, You-Lin; Chen, Shih-Jui; Hwang, Yean-Ren

    2016-01-01

    In this paper, acoustic tweezers which use beam forming performed by a Fresnel zone plate are proposed. The performance has been demonstrated by finite element analysis, including the acoustic intensity, acoustic pressure, acoustic potential energy, gradient force, and particle distribution. The acoustic tweezers use an ultrasound beam produced by a lead zirconate titanate (PZT) transducer operating at 2.4 MHz and 100 Vpeak-to-peak in a water medium. The design of the Fresnel lens (zone plate) is based on air reflection, acoustic impedance matching, and the Fresnel half-wave band (FHWB) theory. This acoustic Fresnel lens can produce gradient force and acoustic potential wells that allow the capture and manipulation of single particles or clusters of particles. Simulation results strongly indicate a good trapping ability, for particles under 150 µm in diameter, in the minimum energy location. This can be useful for cell or microorganism manipulation. PMID:27886050

  17. Design of Fresnel Lens-Type Multi-Trapping Acoustic Tweezers.

    PubMed

    Tu, You-Lin; Chen, Shih-Jui; Hwang, Yean-Ren

    2016-11-23

    In this paper, acoustic tweezers which use beam forming performed by a Fresnel zone plate are proposed. The performance has been demonstrated by finite element analysis, including the acoustic intensity, acoustic pressure, acoustic potential energy, gradient force, and particle distribution. The acoustic tweezers use an ultrasound beam produced by a lead zirconate titanate (PZT) transducer operating at 2.4 MHz and 100 Vpeak-to-peak in a water medium. The design of the Fresnel lens (zone plate) is based on air reflection, acoustic impedance matching, and the Fresnel half-wave band (FHWB) theory. This acoustic Fresnel lens can produce gradient force and acoustic potential wells that allow the capture and manipulation of single particles or clusters of particles. Simulation results strongly indicate a good trapping ability, for particles under 150 µm in diameter, in the minimum energy location. This can be useful for cell or microorganism manipulation.

  18. Facilities for music education and their acoustical design.

    PubMed

    Koskinen, Heli; Toppila, Esko; Olkinuora, Pekka

    2010-01-01

    Good rehearsal facilities for musicians are essential. Directive 2003/10/EC necessitates that musicians are protected from noise exposure. A code of conduct gives the guidelines how this should be done. This study examines room acoustics recommendations provided by the Finnish code of conduct, and discusses whether they are adequate. Small teaching facilities were measured after renovation and compared to earlier measurements. Teachers' opinions were inquired about the facilities before and after. The renovation did not decrease the noise exposure of the teachers. However, the majority preferred the facilities after the renovation. The Finnish code of conduct is not sufficient for facilities where loud instruments are played, or band practise. Good facilities can be designed but they must be specified at the designing stage for their intended use.

  19. Reconfigurable Advanced Receiver Design and Implementation

    NASA Technical Reports Server (NTRS)

    Xu, Jianjing

    2005-01-01

    While the demand for real-time broadband information access has grown and continues to grow at a rapid Pace, the need for a reconfigurable receiver system has increased. To achieve the goal to communicate with multiple shuttles at a time, a filter bank in polyphase structure is introduced. This paper presents the design and implementation for high-speed, high-performance, and fixed-point polyphase filter banks. The polyphase filter structure is designed such that the use of a fixed-point system has minimum impact on the performance of the filter. The final hardware implementation is done on a Xilinx FPGA chip.

  20. IMPLEMENTING THE SAFEGUARDS-BY-DESIGN PROCESS

    SciTech Connect

    Whitaker, J Michael; McGinnis, Brent; Laughter, Mark D; Morgan, Jim; Bjornard, Trond; Bean, Robert; Durst, Phillip; Hockert, John; DeMuth, Scott; Lockwood, Dunbar

    2010-01-01

    The Safeguards-by-Design (SBD) approach incorporates safeguards into the design and construction of nuclear facilities at the very beginning of the design process. It is a systematic and structured approach for fully integrating international and national safeguards for material control and accountability (MC&A), physical protection, and other proliferation barriers into the design and construction process for nuclear facilities. Implementing SBD is primarily a project management or project coordination challenge. This paper focuses specifically on the design process; the planning, definition, organization, coordination, scheduling and interaction of the safeguards experts and stakeholders as they participate in the design and construction of a nuclear facility. It delineates the steps in a nuclear facility design and construction project in order to provide the project context within which the safeguards design activities take place, describes the involvement of the safeguards experts in the design process, the nature of their analyses, interactions and decisions, and describes the documents created and how they are used. This report highlights the project context of safeguards activities, and identifies the safeguards community (nuclear facility operator, designer/builder, state regulator, SSAC and IAEA) must accomplish in order to implement SBD within the project.

  1. Veterinary oncology clinical trials: design and implementation.

    PubMed

    Thamm, Douglas H; Vail, David M

    2015-08-01

    There has been a recent increase in interest among veterinarians and the larger biomedical community in the evaluation of novel cancer therapies in client-owned (pet) animals with spontaneous cancer. This includes novel drugs designed to be veterinary therapeutics, as well as agents for which data generated in animals with tumors may inform human clinical trial design and implementation. An understanding of the process involved in moving a therapeutic agent through the stages of clinical evaluation is critical to the successful implementation of clinical investigations, as well as interpretation of the veterinary oncology literature. This review outlines considerations in the design and conduct of the various phases of oncology clinical trials, along with recent adaptations/modifications of these basic designs that can enhance the generation of timely and meaningful clinical data. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. The design and development of an acoustic test section for the ARA transonic wind tunnel

    NASA Astrophysics Data System (ADS)

    Wood, M. E.; Newman, D. A.

    1988-11-01

    The structural, aerodynamic and acoustic design of a lined test section necessary to produce a sufficiently reflection-free environment for noise tests in the Aircraft Research Association (ARA) tunnel at Mach numbers up to 0.85 are described. The aerodynamic design was aided by computational fluid dynamics methods and the acoustic design by a ray-theory model. Results of the aerodynamic calibration of the liner and preliminary acoustic and performance tests on two model propellers are presented. Development work carried out to improve the liner acoustically and aerodynamically is described.

  3. Design Issues of a Mind Snaps Implementation

    DTIC Science & Technology

    2009-05-01

    AFRL-RI-RS-TR-2009-141 Final Technical Report May 2009 DESIGN ISSUES OF A MIND SNAPS IMPLEMENTATION SET Corporation...REPORT DATE (DD-MM-YYYY) MAY 09 2. REPORT TYPE Final 3. DATES COVERED (From - To) Jul 08 – Jan 09 4. TITLE AND SUBTITLE DESIGN ISSUES OF A MIND ...which are referred to as Mind Snaps. We have completed a short (approximately six months) seedling to explore the Mind Snaps concept, focusing on

  4. Mechanical design and vibro-acoustic testing of ultrathin carbon foils for a spacecraft instrument

    SciTech Connect

    Bernardin, John D; Baca, Allen G

    2009-01-01

    IBEX-Hi is an electrostatic analyzer spacecraft instrument designed to measure the energy and flux distribution of energetic neutral atoms (ENAs) emanating from the interaction zone between the Earth's solar system and the Milky Way galaxy. A key element to this electro-optic instrument is an array of fourteen carbon foils that are used to ionize the ENAs. The foils are comprised of an ultrathin (50-100 {angstrom} thick) layer of carbon suspended across the surface of an electroformed Nickel wire screen, which in turn is held taught by a metal frame holder. The electro formed orthogonal screen has square wire elements, 12.7 {micro}m thick, with a pitch of 131.1 wires/cm. Each foil holder has an open aperture approximately 5 cm by 2.5 cm. Designing and implementing foil holders with such a large surface area has not been attempted for spaceflight in the past and has proven to be extremely challenging. The delicate carbon foils are subject to fatigue failure from the large acoustic and vibration loads that they will be exposed to during launch of the spacecraft. This paper describes the evolution of the foil holder design from previous space instrument applications to a flight-like IBEX-Hi prototype. Vibro-acoustic qualification tests of the IBEX-Hi prototype instrument and the resulting failure of several foils are summarized. This is followed by a discussion of iterative foil holder design modifications and laser vibrometer modal testing to support future fatigue failure analyses, along with additional acoustic testing of the IBEX-Hi prototype instrument. The results of these design and testing activities are merged and the resulting flight-like foil holder assembly is proposed.

  5. Design and Implementation of an Anomaly Detector

    SciTech Connect

    Bagherjeiran, A; Cantu-Paz, E; Kamath, C

    2005-07-11

    This paper describes the design and implementation of a general-purpose anomaly detector for streaming data. Based on a survey of similar work from the literature, a basic anomaly detector builds a model on normal data, compares this model to incoming data, and uses a threshold to determine when the incoming data represent an anomaly. Models compactly represent the data but still allow for effective comparison. Comparison methods determine the distance between two models of data or the distance between a model and a point. Threshold selection is a largely neglected problem in the literature, but the current implementation includes two methods to estimate thresholds from normal data. With these components, a user can construct a variety of anomaly detection schemes. The implementation contains several methods from the literature. Three separate experiments tested the performance of the components on two well-known and one completely artificial dataset. The results indicate that the implementation works and can reproduce results from previous experiments.

  6. Design and Implementation of an Intranet Dashboard

    PubMed Central

    Wolpin, SE

    2005-01-01

    Healthcare organizations are complex systems and well served by efficient feedback mechanisms. Many organizations have invested in data warehouses; however there are few tools for automatically extracting and delivering relevant measures to decision makers. This research study resulted in the design and implementation of an intranet dashboard linked to a data warehouse PMID:16779440

  7. Design and Implementation of Collaborative Research Approaches

    NASA Technical Reports Server (NTRS)

    Venti, Mike W.; Berger, David E.

    2009-01-01

    This poster reviews the collarborative research approaches that NASA has been designing and implementing for the Integrated Vehicle Health Management (IVHM) Project. The inputs for the technical plan are reviewed, the Research Test and Integration Plan (RTIP) WIKI, is used to create and propose a multi-themed and multi-partner research testing opportunities. The outputs are testing opportunities.

  8. Design, Implementation and Deployment of PAIRwise

    ERIC Educational Resources Information Center

    Knight, Allan; Almeroth, Kevin; Bimber, Bruce

    2008-01-01

    Increased access to the Internet has dramatically increased the sources from which students can deliberately or accidentally copy information. This article discusses our motivation to design, implement, and deploy an Internet based plagiarism detection system, called PAIRwise, to address this growing problem. We give details as to how we detect…

  9. Design and Implementation of Instructional Computer Systems.

    ERIC Educational Resources Information Center

    Graczyk, Sandra L.

    1989-01-01

    Presents an input-process-output (IPO) model that can facilitate the design and implementation of instructional micro and minicomputer systems in school districts. A national survey of school districts with outstanding computer systems is described, a systems approach to develop the model is explained, and evaluation of the system is discussed.…

  10. Physical Science Day: Design, Implementation, and Assessment

    ERIC Educational Resources Information Center

    Zeng, Liang; Cunningham, Mark A.; Tidrow, Steven C.; Smith, K. Christopher; Contreras, Jerry

    2016-01-01

    Physical Science Day at The University of Texas--Pan American (UTPA), in collaboration with the Edinburg Consolidated Independent School District, has been designed, developed and implemented to address an identified fundamental shortcoming in our educational process within this primarily (90+%) Hispanic serving border region. Physical Science Day…

  11. Physical Science Day: Design, Implementation, and Assessment

    ERIC Educational Resources Information Center

    Zeng, Liang; Cunningham, Mark A.; Tidrow, Steven C.; Smith, K. Christopher; Contreras, Jerry

    2016-01-01

    Physical Science Day at The University of Texas--Pan American (UTPA), in collaboration with the Edinburg Consolidated Independent School District, has been designed, developed and implemented to address an identified fundamental shortcoming in our educational process within this primarily (90+%) Hispanic serving border region. Physical Science Day…

  12. Implementing XML Schema Naming and Design Rules

    SciTech Connect

    Lubell, Joshua; Kulvatunyou, Boonserm; Morris, Katherine; Harvey, Betty

    2006-08-01

    We are building a methodology and tool kit for encoding XML schema Naming and Design Rules (NDRs) in a computer-interpretable fashion, enabling automated rule enforcement and improving schema quality. Through our experience implementing rules from various NDR specifications, we discuss some issues and offer practical guidance to organizations grappling with NDR development.

  13. Designing and Implementing Multicultural Initiatives: Guiding Principles

    ERIC Educational Resources Information Center

    Watt, Sherry K.

    2013-01-01

    This chapter provides guiding principles for designing and implementing successful multicultural initiatives. A rationale for why these elements transcend both higher education and student affairs settings is presented. In addition to providing guiding principles, this chapter includes advice for socially and politically conscious-minded…

  14. Changing space and sound: Parametric design and variable acoustics

    NASA Astrophysics Data System (ADS)

    Norton, Christopher William

    This thesis examines the potential for parametric design software to create performance based design using acoustic metrics as the design criteria. A former soundstage at the University of Southern California used by the Thornton School of Music is used as a case study for a multiuse space for orchestral, percussion, master class and recital use. The criteria used for each programmatic use include reverberation time, bass ratio, and the early energy ratios of the clarity index and objective support. Using a panelized ceiling as a design element to vary the parameters of volume, panel orientation and type of absorptive material, the relationships between these parameters and the design criteria are explored. These relationships and subsequently derived equations are applied to Grasshopper parametric modeling software for Rhino 3D (a NURBS modeling software). Using the target reverberation time and bass ratio for each programmatic use as input for the parametric model, the genomic optimization function of Grasshopper - Galapagos - is run to identify the optimum ceiling geometry and material distribution.

  15. Vibro-acoustic performance of newly designed tram track structures

    NASA Astrophysics Data System (ADS)

    Haladin, Ivo; Lakušić, Stjepan; Ahac, Maja

    2017-09-01

    Rail vehicles in interaction with a railway structure induce vibrations that are propagating to surrounding structures and cause noise disturbance in the surrounding areas. Since tram tracks in urban areas often share the running surface with road vehicles one of top priorities is to achieve low maintenance and long lasting structure. Research conducted in scope of this paper gives an overview of newly designed tram track structures designated for use on Zagreb tram network and their performance in terms of noise and vibration mitigation. Research has been conducted on a 150 m long test section consisted of three tram track types: standard tram track structure commonly used on tram lines in Zagreb, optimized tram structure for better noise and vibration mitigation and a slab track with double sleepers embedded in a concrete slab, which presents an entirely new approach of tram track construction in Zagreb. Track has been instrumented with acceleration sensors, strain gauges and revision shafts for inspection. Relative deformations give an insight into track structure dynamic load distribution through the exploitation period. Further the paper describes vibro-acoustic measurements conducted at the test site. To evaluate the track performance from the vibro-acoustical standpoint, detailed analysis of track decay rate has been analysed. Opposed to measurement technique using impact hammer for track decay rate measurements, newly developed measuring technique using vehicle pass by vibrations as a source of excitation has been proposed and analysed. Paper gives overview of the method, it’s benefits compared to standard method of track decay rate measurements and method evaluation based on noise measurements of the vehicle pass by.

  16. A Requirements-Driven Optimization Method for Acoustic Treatment Design

    NASA Technical Reports Server (NTRS)

    Berton, Jeffrey J.

    2016-01-01

    Acoustic treatment designers have long been able to target specific noise sources inside turbofan engines. Facesheet porosity and cavity depth are key design variables of perforate-over-honeycomb liners that determine levels of noise suppression as well as the frequencies at which suppression occurs. Layers of these structures can be combined to create a robust attenuation spectrum that covers a wide range of frequencies. Looking to the future, rapidly-emerging additive manufacturing technologies are enabling new liners with multiple degrees of freedom, and new adaptive liners with variable impedance are showing promise. More than ever, there is greater flexibility and freedom in liner design. Subject to practical considerations, liner design variables may be manipulated to achieve a target attenuation spectrum. But characteristics of the ideal attenuation spectrum can be difficult to know. Many multidisciplinary system effects govern how engine noise sources contribute to community noise. Given a hardwall fan noise source to be suppressed, and using an analytical certification noise model to compute a community noise measure of merit, the optimal attenuation spectrum can be derived using multidisciplinary systems analysis methods. The subject of this paper is an analytical method that derives the ideal target attenuation spectrum that minimizes noise perceived by observers on the ground.

  17. Designing theoretically-informed implementation interventions.

    PubMed

    2006-02-23

    Clinical and health services research is continually producing new findings that may contribute to effective and efficient patient care. However, the transfer of research findings into practice is unpredictable and can be a slow and haphazard process. Ideally, the choice of implementation strategies would be based upon evidence from randomised controlled trials or systematic reviews of a given implementation strategy. Unfortunately, reviews of implementation strategies consistently report effectiveness some, but not all of the time; possible causes of this variation are seldom reported or measured by the investigators in the original studies. Thus, any attempts to extrapolate from study settings to the real world are hampered by a lack of understanding of the effects of key elements of individuals, interventions, and the settings in which they were trialled. The explicit use of theory offers a way of addressing these issues and has a number of advantages, such as providing: a generalisable framework within which to represent the dimensions that implementation studies address, a process by which to inform the development and delivery of interventions, a guide when evaluating, and a way to allow for an exploration of potential causal mechanisms. However, the use of theory in designing implementation interventions is methodologically challenging for a number of reasons, including choosing between theories and faithfully translating theoretical constructs into interventions. The explicit use of theory offers potential advantages in terms of facilitating a better understanding of the generalisability and replicability of implementation interventions. However, this is a relatively unexplored methodological area.

  18. ITS detector testbed system design and implementation

    NASA Astrophysics Data System (ADS)

    Chang, Edmond C. P.

    1999-03-01

    Intelligent Transportation Systems (ITS) implemented all over the world, has become an important and practical traffic management technique. Among all ITS subsystems, the detection system plays an integral element that provides all the necessary environmental information to the ITS infrastructure. This paper describes the ITS Detector testbed design, currently being implemented with these potential ITS applications on the State Highway 6 in College Station, Texas to provide a multi-sensor, multi-source fusion environment that utilizes both multi-sensor and distributed sensor system testing environment.

  19. Design of acoustic metamaterials using the covariance matrix adaptation evolutionary strategy

    NASA Astrophysics Data System (ADS)

    Huang, Bei; Cheng, Qiang; Song, Gang Yong; Cui, Tie Jun

    2017-03-01

    Acoustic metamaterials can manipulate sound waves in surprising ways, including the focusing, cloaking, and extraordinary transmitting of sound waves. With the increasing requirements for acoustic metamaterials with extreme parameters, we propose the design of acoustic meta-atoms with a large refraction index using the covariance matrix adaptation evolutionary optimization strategy. To validate the procedure, we propose an optimized metamaterial to construct an acoustic deflection lens. The full-wave simulation results are consistent with the theoretical predictions, showing the efficacy and accuracy of the proposed method, and indicating that the optimization algorithm is a powerful tool for designing meta-atoms with excellent applications.

  20. Design of fluid-loaded piezoelectric transducers for acoustic power considerations

    NASA Astrophysics Data System (ADS)

    Grosh, Karl; Lin, Yuan; Nelli Silva, Emilio C.; Kikuchi, Noboru

    1998-07-01

    In this paper, a design methodology for enhancing the acoustic power radiated from fluid-loaded piezoelectric transducers at a particular operating frequency is developed. For many applications the operating frequency is fixed by the absorption of the material and the desired depth of penetration (e.g., therapeutic ultrasound). For therapeutic ultrasound and other industrial applications, the acoustic power is the critical figure of merit. The acoustic power radiated from the transducer system is computed from a finite element formulation of the coupled acoustic, elastic, piezoelectric equations of motion. The sensitivities of the acoustic power to two design variables: the length of the piezoelectric element and the thickness of the matching layer, are derived. Using these sensitivities, a novel design methodology in which remeshing is avoided is developed and the effectiveness of the method is studied. Results from the application of this framework for transducer design demonstrate the dramatic increase in radiated power possible from this two member design space.

  1. Design and implementation of spherical ultrasonic motor.

    PubMed

    Mashimo, Tomoaki; Toyama, Shigeki; Ishida, Hiroshi

    2009-11-01

    We present a mechanical design and implementation of spherical ultrasonic motor (SUSM) that is an actuator with multiple rotational degrees of freedom (multi-DOF). The motor is constructed of 3 annular stators and a spherical rotor and is much smaller and simpler than conventional multi-DOF mechanisms such as gimbals using servomotors. We designed a novel SUSM using experimental data from a single annular stator and a finite element method. The SUSM using a spherical rotor of diameter 20 mm without any reduction gear has demonstrated advantages of high responsiveness, good accuracy, and high torque at low speed. The dynamic implementation of SUSM was consistent with the driving model of SUSM based on a friction drive.

  2. Multifolded torus chaotic attractors: Design and implementation

    NASA Astrophysics Data System (ADS)

    Yu, Simin; Lu, Jinhu; Chen, Guanrong

    2007-03-01

    This paper proposes a systematic methodology for creating multifolded torus chaotic attractors from a simple three-dimensional piecewise-linear system. Theoretical analysis shows that the multifolded torus chaotic attractors can be generated via alternative switchings between two basic linear systems. The theoretical design principle and the underlying dynamic mechanism are then further investigated by analyzing the emerging bifurcation and the stable and unstable subspaces of the two basic linear systems. A novel block circuit diagram is also designed for hardware implementation of 3-, 5-, 7-, 9-folded torus chaotic attractors via switching the corresponding switches. This is the first time a 9-folded torus chaotic attractor generated by an analog circuit has been verified experimentally. Furthermore, some recursive formulas of system parameters are rigorously derived, which is useful for improving hardware implementation.

  3. Developmental design, fabrication, and test of acoustic suppressors for fans of high bypass turbofan engines

    NASA Technical Reports Server (NTRS)

    Tucker, R. H.; Nelsen, M. D.; Gregg, G. E.; Palmer, F. I.

    1974-01-01

    An analysis procedure was developed for design of acoustically treated nacelles for high bypass turbofan engines. The plan was applied to the conceptual design of a nacelle for the quiet engine typical of a 707/DC-8 airplane installation. The resultant design was modified to a test nacelle design for the NASA Lewis quiet fan. The acoustic design goal was a 10 db reduction in effective perceived fan noise levels during takoff and approach. Detailed nacelle designs were subsequently developed for both the quiet engine and the quiet fan. The acoustic design goal for each nacelle was 15 db reductions in perceived fan noise levels from the inlet and fan duct. Acoustically treated nacelles were fabricated for the quiet engine and quiet fan for testing. Performance of selected inlet and fan duct lining configurations was experimentally evaluated in a flow duct. Results of the tests show that the linings perform as designed.

  4. Designing and Implementing a Clinician Workstation

    PubMed Central

    Tape, Thomas G.; Campbell, James R.

    1993-01-01

    We describe a simple approach to designing and quickly implementing a clinician workstation that helps practitioners access a variety of information resources. Using easy-to-use graphical tools, we installed a pilot workstation in our clinics. We were able to accommodate most of our users' needs and have a functional workstation installed in two months. This is the first step of an evolutionary process moving from separate tasks to full application integration.

  5. The NOAO NVO Portal: Overall Design & Implementation

    NASA Astrophysics Data System (ADS)

    Fuentes, E.; Miller, C. J.; Gasson, D.

    2007-10-01

    We present an overview and design of the NOAO National Virtual Observatory (NVO) Portal. This is a web application providing one-stop discovery, analysis, and access to VO-compliant imaging data and services. It strictly follows the Model-View-Controller (MVC) design pattern and relies heavily on Asynchronous Javascript And XML (AJAX) in the browser. Because of the heavy use of AJAX, the relatively simple database schemas, and, most importantly, the rapid development/iteration schedule, Ruby-on-Rails (RoR) was chosen as the implementation language and PostgreSQL as the database engine.

  6. Swarming Robot Design, Construction and Software Implementation

    NASA Technical Reports Server (NTRS)

    Stolleis, Karl A.

    2014-01-01

    In this paper is presented an overview of the hardware design, construction overview, software design and software implementation for a small, low-cost robot to be used for swarming robot development. In addition to the work done on the robot, a full simulation of the robotic system was developed using Robot Operating System (ROS) and its associated simulation. The eventual use of the robots will be exploration of evolving behaviors via genetic algorithms and builds on the work done at the University of New Mexico Biological Computation Lab.

  7. Combining COMSOL modeling with acoustic pressure maps to design sono-reactors.

    PubMed

    Wei, Zongsu; Weavers, Linda K

    2016-07-01

    Scaled-up and economically viable sonochemical systems are critical for increased use of ultrasound in environmental and chemical processing applications. In this study, computational simulations and acoustic pressure maps were used to design a larger-scale sono-reactor containing a multi-stepped ultrasonic horn. Simulations in COMSOL Multiphysics showed ultrasonic waves emitted from the horn neck and tip, generating multiple regions of high acoustic pressure. The volume of these regions surrounding the horn neck were larger compared with those below the horn tip. The simulated acoustic field was verified by acoustic pressure contour maps generated from hydrophone measurements in a plexiglass box filled with water. These acoustic pressure contour maps revealed an asymmetric and discrete distribution of acoustic pressure due to acoustic cavitation, wave interaction, and water movement by ultrasonic irradiation. The acoustic pressure contour maps were consistent with simulation results in terms of the effective scale of cavitation zones (∼ 10 cm and <5 cm above and below horn tip, respectively). With the mapped acoustic field and identified cavitation location, a cylindrically-shaped sono-reactor with a conical bottom was designed to evaluate the treatment capacity (∼ 5 L) for the multi-stepped horn using COMSOL simulations. In this study, verification of simulation results with experiments demonstrates that coupling of COMSOL simulations with hydrophone measurements is a simple, effective and reliable scientific method to evaluate reactor designs of ultrasonic systems.

  8. Implementation of distributed feedback fiber laser sensor for acoustic measurements in hydraulic fracturing

    NASA Astrophysics Data System (ADS)

    Chen, Rongzhang; Yan, Aidong; Zaghloul, Mohamed A. S.; Lu, Guanyi; Bunger, Andrew P.; Miller, Gary A.; Cranch, Geoffrey A.; Chen, Kevin P.

    2016-09-01

    A distributed feedback (DFB) fiber laser strain sensor was implemented to measure acoustic emission induced by the hydraulic fracturing process. A study of practical sensor mounting configurations and their characteristics was carried out to find a practical solution. Combining the suitable mounting configuration and ultrahigh strain sensitivity of the DFB fiber laser, the evolution of the hydraulic fracturing process was well monitored. This study shows that fiber lasers can be useful alternatives to piezoelectric sensors in the field of hydraulic fracturing for gas and oil extraction.

  9. Analytic Formulation and Numerical Implementation of an Acoustic Pressure Gradient Prediction

    NASA Technical Reports Server (NTRS)

    Lee, Seongkyu; Brentner, Kenneth S.; Farassat, F.; Morris, Philip J.

    2008-01-01

    Two new analytical formulations of the acoustic pressure gradient have been developed and implemented in the PSU-WOPWOP rotor noise prediction code. The pressure gradient can be used to solve the boundary condition for scattering problems and it is a key aspect to solve acoustic scattering problems. The first formulation is derived from the gradient of the Ffowcs Williams-Hawkings (FW-H) equation. This formulation has a form involving the observer time differentiation outside the integrals. In the second formulation, the time differentiation is taken inside the integrals analytically. This formulation avoids the numerical time differentiation with respect to the observer time, which is computationally more efficient. The acoustic pressure gradient predicted by these new formulations is validated through comparison with available exact solutions for a stationary and moving monopole sources. The agreement between the predictions and exact solutions is excellent. The formulations are applied to the rotor noise problems for two model rotors. A purely numerical approach is compared with the analytical formulations. The agreement between the analytical formulations and the numerical method is excellent for both stationary and moving observer cases.

  10. A novel approach for design of acoustical enclosure of projectors

    NASA Astrophysics Data System (ADS)

    Panahkhahi, Sara

    To create a quiet environment inside buildings, it is necessary to decrease the noise level, which partly originates from electromechanical devices. This study explored a method for designing an acoustic enclosure for projectors that generate noises in a wide band frequency range. The source of noise in projectors is their fans, which cause the structure borne and airborne noise. Fans are required in projectors that use lamps as an illumination source to dissipate the heat emitted from their lamps. Sound measurements were performed to determine the frequency range that is generated by the projector. Based on the data obtained from the measurements, the sound level of the projector and the design of the enclosure were studied. Another aspect of this project was to find a way to cool down the projector while it was operating in a completely sealed enclosure. Based on the information about the power consumption of the projector and the temperature range that the projector can safely operates under, the cooling system was proposed. Finally the sound and temperature measurements were performed on the fabricated prototype of the enclosure to evaluate its functionality.

  11. Design for Aplanatic Fresnel Acoustic Lens for Underwater Imaging

    NASA Astrophysics Data System (ADS)

    Sato, Yuji; Mizutani, Koichi; Wakatsuki, Naoto; Nakamura, Toshiaki

    2009-07-01

    We designed several shapes of aplanatic Fresnel acoustic lenses to correct spherical and coma aberrations. These lenses were made of room temperature vulcanizable (RTV) silicone rubber, and were designed by combining several aplanatic lenses. The converged sound pressure fields of these lenses were calculated numerically with the two-dimensional finite difference time domain (2D FDTD) method. The focal sound pressures of these lenses were 8-9 dB larger than those of aplanatic biconvex lenses. Comparing several aplanatic Fresnel lenses, the best convergence was achieved by the lens having the smoothest first surface. We assumed the reason for this advantage was the smooth first surface itself. Thus to smooth the first surface and to enlarge the focal sound pressure, small steps on the first surface were removed by two methods. The first method approximates the first surface to a polynomial equation. The second method changes the curvature of the aplanatic lenses to minimize the small steps; this method is called bending. The evaluation of the lenses made by the two methods showed that the resolutions of these lenses were higher than 1°. The lens made by bending showed higher sound pressure than the lens made by the approximated surface.

  12. On the acoustic wedge design and simulation of anechoic chamber

    NASA Astrophysics Data System (ADS)

    Jiang, Changyong; Zhang, Shangyu; Huang, Lixi

    2016-10-01

    This study proposes an alternative to the classic wedge design for anechoic chambers, which is the uniform-then-gradient, flat-wall (UGFW) structure. The working mechanisms of the proposed structure and the traditional wedge are analyzed. It is found that their absorption patterns are different. The parameters of both structures are optimized for achieving minimum absorber depth, under the condition of absorbing 99% of normal incident sound energy. It is found that, the UGFW structure achieves a smaller total depth for the cut-off frequencies ranging from 100 Hz to 250 Hz. This paper also proposes a modification for the complex source image (CSI) model for the empirical simulation of anechoic chambers, originally proposed by Bonfiglio et al. [J. Acoust. Soc. Am. 134 (1), 285-291 (2013)]. The modified CSI model considers the non-locally reactive effect of absorbers at oblique incidence, and the improvement is verified by a full, finite-element simulation of a small chamber. With the modified CSI model, the performance of both decorations with the optimized parameters in a large chamber is simulated. The simulation results are analyzed and checked against the tolerance of 1.5 dB deviation from the inverse square law, stipulated in the ISO standard 3745(2003). In terms of the total decoration depth and anechoic chamber performance, the UGFW structure is better than the classic wedge design.

  13. Multiple Acoustical Matching Layer Design of Ultrasonic Transducer for Medical Application

    NASA Astrophysics Data System (ADS)

    Chen, Yeong-Chin; Wu, Sean

    2002-10-01

    Ultrasonic diagnostic equipment is widely used due to its merit of being a noninvasive technique as well as because it provides a clear real-time display of body tissue. Our focus is on the design of low-loss (high transmitting power) and wide-band transducers for ultrasonic diagnosis. The approach we have used consists of impedance matching the front face of the piezoelectric transducer to the propagating medium with a quarter wavelength impedance matching layer and inserting an unmatching quarter wavelength acoustical layer between the rear face and backing material. By tuning the acoustical impedance of the matching layer, transducers with wide-band characteristics and high transmitting power can be obtained. For the backing at the rear surface, a soft backing demonstrating a better impedance matching result which can improve the bandwidth, but exhibiting a longer duration impulse response should be used. A heavy backing would degrade the wide-band phenomena, but show a shorter time duration (<0.5 μS) for image application. To obtain the optimal solution to a specific design formulation, PSPICE (Personal Simulation Program with Integrated Circuit Emphasis) programming techniques can be applied. The PSPICE code of the Mason model is implemented to precisely predict the performance of the matched transducers such as impedance, insertion loss, bandwidth and duration of the impulse response. Good agreement between the simulation results and experimental results has been achieved.

  14. Design and fabrication of an augmentor wing model for acoustic tests

    NASA Technical Reports Server (NTRS)

    Jackson, J.; Schedin, R. W.; Campbell, J. M.

    1973-01-01

    The design and fabrication of a full-scale section of an augmentor wing to be used for acoustic testing at the Lewis Research Center are discussed. This hardware will be used primarily to investigate scaling effects of acoustic data obtained during the Boeing-run model tests. Typical model test data is shown in the report, together with predictions on both performance and acoustics that can be expected from the full-scale section to be built. Areas covered include: the aerodynamic and acoustic criteria of the flap system and nozzles, detailed discussion of the hardware, test system operation procedure, and stress analysis of the entire test system.

  15. FPGA design and implementation of Gaussian filter

    NASA Astrophysics Data System (ADS)

    Yang, Zhihui; Zhou, Gang

    2015-12-01

    In this paper , we choose four different variances of 1,3,6 and 12 to conduct FPGA design with three kinds of Gaussian filtering algorithm ,they are implementing Gaussian filter with a Gaussian filter template, Gaussian filter approximation with mean filtering and Gaussian filter approximation with IIR filtering. By waveform simulation and synthesis, we get the processing results on the experimental image and the consumption of FPGA resources of the three methods. We set the result of Gaussian filter used in matlab as standard to get the result error. By comparing the FPGA resources and the error of FPGA implementation methods, we get the best FPGA design to achieve a Gaussian filter. Conclusions can be drawn based on the results we have already got. When the variance is small, the FPGA resources is enough for the algorithm to implement Gaussian filter with a Gaussian filter template which is the best choice. But when the variance is so large that there is no more FPGA resources, we can chose the mean to approximate Gaussian filter with IIR filtering.

  16. Design of acoustic beam aperture modifier using gradient-index phononic crystals

    NASA Astrophysics Data System (ADS)

    Lin, Sz-Chin Steven; Tittmann, Bernhard R.; Huang, Tony Jun

    2012-06-01

    This article reports the design concept of a novel acoustic beam aperture modifier using butt-jointed gradient-index phononic crystals (GRIN PCs) consisting of steel cylinders embedded in a homogeneous epoxy background. By gradually tuning the period of a GRIN PC, the propagating direction of acoustic waves can be continuously bent to follow a sinusoidal trajectory in the structure. The aperture of an acoustic beam can therefore be shrunk or expanded through change of the gradient refractive index profiles of the butt-jointed GRIN PCs. Our computational results elucidate the effectiveness of the proposed acoustic beam aperture modifier. Such an acoustic device can be fabricated through a simple process and will be valuable in applications, such as biomedical imaging and surgery, nondestructive evaluation, communication, and acoustic absorbers.

  17. Experimental verification of the sparse design of a square partial discharge acoustic emission array sensor

    NASA Astrophysics Data System (ADS)

    Xie, Qing; Liu, Xiong; Tao, Junhan; Li, Tong; Cheng, Shuyi; Lu, Fangcheng

    2015-04-01

    This study experimentally verified the sparse design of a square partial discharge (PD) acoustic emission array sensor proposed in Xie et al (2014 Meas. Sci. Technol. 25 035102). Firstly, this study developed a square PD acoustic emission array sensor and determined the material, centre frequency, thickness, radius, etc of the element of this array sensor through analysis and comparison with others. Moreover, in combination with a sound-absorbing backing and a matching layer, a single acoustic emission array sensor element was designed, which laid the basis for the experimental verification of the ensuing sparse design. On this basis, the assembly of the square acoustic emission array sensor was designed. It realised the plug-and-play ability of the array elements and formed the basis for the experimental study of the following sparse design. Subsequently, this study established and introduced an experimental system and methods for PD positioning. Finally, it experimentally investigated the sparse design of a square PD acoustic emission array sensor. The 9-element square PD acoustic emission array sensor was used as an example to study the positioning effects on PD using the acoustic emission array sensor in optimum and random sparse structures respectively. The results suggested that: (1) the PD acoustic emission array sensor and corresponding experimental system were effective in detecting and positioning the PD; (2) the square PD acoustic emission array sensor proposed in Xie et al (2014 Meas. Sci. Technol. 25 035102) was feasible. Using this array sensor, it was possible to optimise the sparse distribution structure of this acoustic emission array sensor.

  18. Real-time implementations of acoustic signal enhancement techniques for aerial based surveillance and rescue applications

    NASA Astrophysics Data System (ADS)

    Ramos, Antonio L. L.; Shao, Zhili; Holthe, Aleksander; Sandli, Mathias F.

    2017-05-01

    The introduction of the System-on-Chip (SoC) technology has brought exciting new opportunities for the development of smart low cost embedded systems spanning a wide range of applications. Currently available SoC devices are capable of performing high speed digital signal processing tasks in software while featuring relatively low development costs and reduced time-to-market. Unmanned aerial vehicles (UAV) are an application example that has shown tremendous potential in an increasing number of scenarios, ranging from leisure to surveillance as well as in search and rescue missions. Video capturing from UAV platforms is a relatively straightforward task that requires almost no preprocessing. However, that does not apply to audio signals, especially in cases where the data is to be used to support real-time decision making. In fact, the enormous amount of acoustic interference from the surroundings, including the noise from the UAVs propellers, becomes a huge problem. This paper discusses a real-time implementation of the NLMS adaptive filtering algorithm applied to enhancing acoustic signals captured from UAV platforms. The model relies on a combination of acoustic sensors and a computational inexpensive algorithm running on a digital signal processor. Given its simplicity, this solution can be incorporated into the main processing system of an UAV using the SoC technology, and run concurrently with other required tasks, such as flight control and communications. Simulations and real-time DSP-based implementations have shown significant signal enhancement results by efficiently mitigating the interference from the noise generated by the UAVs propellers as well as from other external noise sources.

  19. Numerical investigation of implementation of air-earth boundary by acoustic-elastic boundary approach

    USGS Publications Warehouse

    Xu, Y.; Xia, J.; Miller, R.D.

    2007-01-01

    The need for incorporating the traction-free condition at the air-earth boundary for finite-difference modeling of seismic wave propagation has been discussed widely. A new implementation has been developed for simulating elastic wave propagation in which the free-surface condition is replaced by an explicit acoustic-elastic boundary. Detailed comparisons of seismograms with different implementations for the air-earth boundary were undertaken using the (2,2) (the finite-difference operators are second order in time and space) and the (2,6) (second order in time and sixth order in space) standard staggered-grid (SSG) schemes. Methods used in these comparisons to define the air-earth boundary included the stress image method (SIM), the heterogeneous approach, the scheme of modifying material properties based on transversely isotropic medium approach, the acoustic-elastic boundary approach, and an analytical approach. The method proposed achieves the same or higher accuracy of modeled body waves relative to the SIM. Rayleigh waves calculated using the explicit acoustic-elastic boundary approach differ slightly from those calculated using the SIM. Numerical results indicate that when using the (2,2) SSG scheme for SIM and our new method, a spatial step of 16 points per minimum wavelength is sufficient to achieve 90% accuracy; 32 points per minimum wavelength achieves 95% accuracy in modeled Rayleigh waves. When using the (2,6) SSG scheme for the two methods, a spatial step of eight points per minimum wavelength achieves 95% accuracy in modeled Rayleigh waves. Our proposed method is physically reasonable and, based on dispersive analysis of simulated seismographs from a layered half-space model, is highly accurate. As a bonus, our proposed method is easy to program and slightly faster than the SIM. ?? 2007 Society of Exploration Geophysicists.

  20. Towards optimal design of locally resonant acoustic metamaterials

    NASA Astrophysics Data System (ADS)

    Krushynska, A. O.; Kouznetsova, V. G.; Geers, M. G. D.

    2014-11-01

    The paper presents an in-depth analysis of solid locally resonant acoustic metamaterials (LRAMs) consisting of rubber-coated inclusions. Dispersion properties of two-dimensional LRAMs are studied by means of finite-element modal analysis. For an incompressible rubber, only one practically important spectral band gap is found for in-plane modes in a low-frequency range. This result is in striking contrast with the compressible coating case, previously studied in the literature. For inclusions with a circular cross-section, the lower bound of the band gap can be evaluated exactly by means of the derived analytical solution, which is also valid for compressible coatings and can therefore be used to determine lower bounds of higher band gaps as well. The influence of geometric and material parameters, filling fraction and inclusion shape on the width of the lowest band gap is investigated in detail. Based on the results of this analysis, an optimal microstructure of LRAMs yielding the widest low-frequency band gap is proposed. To achieve the band gap at the lowest possible frequencies in LRAMs suitable for practical applications, the use of the tungsten core material is advised, as a safe and economically viable alternative to commonly considered lead and gold. Two configurations of LRAM with various sizes of coated tungsten cylindrical inclusions with circular cross-section are considered. The evolution of dispersion spectra due to the presence of different inclusions is investigated, and the parameters for optimal design of LRAMs are determined.

  1. Advanced Avionics Breadboard Executive Design and Implementation

    NASA Technical Reports Server (NTRS)

    Adams, L. R.

    1972-01-01

    The advanced avionics breadboard (AAB) executive evolved from an effort to design and develop an avionics system. This executive is unique in that it supervises a triple redundant avionics computer system. Three IBM System 4 Pi/CP computers, operating synchronously and executing identical software, comprise the central processors which route data to and from a data bus via an input/output controller. The executive's basic function is to provide application programs with an efficient software structure within which to perform specific avionics application tasks. Although implemented in a triplex data management system, the AAB executive contains the flexibility to be adapted to other systems with minimal change.

  2. Case study of restaurant successfully designed, constructed, and operated for excellent dining acoustics

    NASA Astrophysics Data System (ADS)

    Bollard, Paul; Des Jardins, Stephen

    2005-09-01

    Prior to the construction of La Provence Restaurant in Roseville, California in 2004, the owner, Stephen Des Jardins, traveled with his cook, architect, and engineer to the Provence Region of France to study the cuisine, architecture, and acoustics of the local restaurants. This information was incorporated into the design, construction, and operation of his restaurant, with acoustical design assistance provided by the author, Paul Bollard. The result of the owner's painstaking attention to detail is a restaurant which has received very positive reviews for its architecture, quality of food, service, and acoustic ambience. This paper documents the measures included in the construction of the restaurant to ensure that the building acoustics enhance the dining experience, rather than detract from it. Photographs of acoustic treatments are included, as are reverberation time (RT60) test results and ambient noise level measurement results.

  3. A preliminary design study on an acoustic muffler for the laminar flow transition research apparatus

    NASA Technical Reports Server (NTRS)

    Abrahamson, A. L.

    1984-01-01

    An acoustic muffler design of a research tool for studying laminar flow and the mechanisms of transition, the Laminar Flow and Transition Research Apparatus (LFTRA) is investigated. Since the presence of acoustic pressure fluctuations is known to affect transition, low background noise levels in the test section of the LFTRA are mandatory. The difficulties and tradeoffs of various muffler design concepts are discussed and the most promising candidates are emphasized.

  4. Design of acoustic logging signal source of imitation based on field programmable gate array

    NASA Astrophysics Data System (ADS)

    Zhang, K.; Ju, X. D.; Lu, J. Q.; Men, B. Y.

    2014-08-01

    An acoustic logging signal source of imitation is designed and realized, based on the Field Programmable Gate Array (FPGA), to improve the efficiency of examining and repairing acoustic logging tools during research and field application, and to inspect and verify acoustic receiving circuits and corresponding algorithms. The design of this signal source contains hardware design and software design,and the hardware design uses an FPGA as the control core. Four signals are made first by reading the Random Access Memory (RAM) data which are inside the FPGA, then dealing with the data by digital to analog conversion, amplification, smoothing and so on. Software design uses VHDL, a kind of hardware description language, to program the FPGA. Experiments illustrate that the ratio of signal to noise for the signal source is high, the waveforms are stable, and also its functions of amplitude adjustment, frequency adjustment and delay adjustment are in accord with the characteristics of real acoustic logging waveforms. These adjustments can be used to imitate influences on sonic logging received waveforms caused by many kinds of factors such as spacing and span of acoustic tools, sonic speeds of different layers and fluids, and acoustic attenuations of different cementation planes.

  5. Design and Implementation of Embedded RFID Middleware

    NASA Astrophysics Data System (ADS)

    Zhen-xiang, Li.; Yu-xiang, Zhang

    An embedded RFID (Radio Frequency Identification) middleware based on ARM Linux operating system and S3C2410 hardware platform was designed and implemented. The system architecture and platform of software and hardware of this middleware were introduced. The key technology applied in some device management and tag data processing and the application of SQLite were specialized. Since its rich standard interfaces offered by the hardware platform, the middleware can connect with different kind of readers from different manufacturers without cosidering the diversity and complexity of RFID bottom layer hardware. So, it can supply upper layer application of system with a powerful, uniform platform, and lay a broader, richer foundation for the application of RFID.

  6. Design optimization of composite structures operating in acoustic environments

    NASA Astrophysics Data System (ADS)

    Chronopoulos, D.

    2015-10-01

    The optimal mechanical and geometric characteristics for layered composite structures subject to vibroacoustic excitations are derived. A Finite Element description coupled to Periodic Structure Theory is employed for the considered layered panel. Structures of arbitrary anisotropy as well as geometric complexity can thus be modelled by the presented approach. Damping can also be incorporated in the calculations. Initially, a numerical continuum-discrete approach for computing the sensitivity of the acoustic wave characteristics propagating within the modelled periodic composite structure is exhibited. The first- and second-order sensitivities of the acoustic transmission coefficient expressed within a Statistical Energy Analysis context are subsequently derived as a function of the computed acoustic wave characteristics. Having formulated the gradient vector as well as the Hessian matrix, the optimal mechanical and geometric characteristics satisfying the considered mass, stiffness and vibroacoustic performance criteria are sought by employing Newton's optimization method.

  7. Implementation of Surface Acoustic Wave Vapor Sensor Using Complementary Metal-Oxide-Semiconductor Amplifiers

    NASA Astrophysics Data System (ADS)

    Chiu, Chia-Sung; Chang, Ching-Chun; Ku, Chia-Lin; Peng, Kang-Ming; Jeng, Erik S.; Chen, Wen-Lin; Huang, Guo-Wei; Wu, Lin-Kun

    2009-04-01

    A surface acoustic wave (SAW) vapor sensor is presented in this work. A SAW delay line oscillator on quartz substrate with the high gain complementary metal-oxide-semiconductor (CMOS) amplifier using a two-poly-two-metal (2P2M) 0.35 µm process was designed. The gain of the CMOS amplifier and its total power consumption are 20 dB and 70 mW, respectively. The achieved phase noise of this SAW oscillator is -150 dBc/Hz at 100 kHz offset. The sensing is successfully demonstrated by a thin poly(epichlorohydrin) (PECH) polymer film on a SAW oscillator with alcohol vapor. This two-in-one sensor unit includes the SAW device and the CMOS amplifier provides designers with comprehensive model for using these components for sensor circuit fabrication. Furthermore it will be promising for future chemical and biological sensing applications.

  8. Design and implementation of the CAPS receiver

    NASA Astrophysics Data System (ADS)

    Hu, Yonghui; Hua, Yu; Hou, Lei; Wei, Jingfa; Wu, Jianfeng

    2009-03-01

    In this paper, based on analyses of the Chinese Area Positioning System (CAPS) satellite (GEO satellite) resources and signal properties, the signal power at the port of the receiver antenna is estimated, and the implementation projects are presented for a switching band C to band L CAPS C/A code receiver integrated with GPS receiver suite and for a CAPS dual frequency P code receiver. A microstrip receiving antenna is designed with high sensitivity and wide beam orientation, the RF front end of the C/A code and P code receivers, and a processor is designed for the navigation baseband. A single frequency CAPS C/A code receiver and a CAPS dual frequency P code receiver are built at the same time. A software process flow is provided, and research on relatively key techniques is also conducted, such as signal searching, code loop and carrier loop algorithms, a height assistant algorithm, a dual frequency difference speed measurement technique, a speed measurement technique using a single frequency source with frequency assistance, and a CAPS time correcting algorithm, according to the design frame of the receiver hardware. Research results show that the static plane positioning accuracy of the CAPS C/A code receiver is 20.5-24.6 m, height accuracy is 1.2-12.8 m, speed measurement accuracy is 0.13-0.3 m/s, dynamic plane positioning accuracy is 24.4 m, height accuracy is 3.0 m, and speed measurement accuracy is 0.24 m/s. In the case of C/A code, the timing accuracy is 200 ns, and it is also shown that the positioning accuracy of the CAPS precise code receiver (1 σ) is 5 m from south to north, and 0.8 m from east to west. Finally, research on positioning accuracy is also conducted.

  9. Acoustic broadband metacouplers

    NASA Astrophysics Data System (ADS)

    Li, Kun; Liang, Bin; Yang, Jing; Yang, Jun; Cheng, Jian-chun

    2017-05-01

    We present the concept of acoustic metacoupler for broadband impedance match between two media with different impedances and cross sections. An implementation is demonstrated that produces spatial gradient of effective acoustic impedance by utilizing helical-like structure with continuously varying pitch instead of changing the cross-section or employing multiple layers. Numerical results verify the effectiveness of our design in achieving near-unity coupling efficiency in a broad band. We anticipate the proposed metacoupler with capability and flexibility to open route to broadband impedance matching and to have a wide realm of potential applications such as transducer design, acoustic imaging and energy harvesting.

  10. An Ultra-Low Power and Flexible Acoustic Modem Design to Develop Energy-Efficient Underwater Sensor Networks

    PubMed Central

    Sánchez, Antonio; Blanc, Sara; Yuste, Pedro; Perles, Angel; Serrano, Juan José

    2012-01-01

    This paper is focused on the description of the physical layer of a new acoustic modem called ITACA. The modem architecture includes as a major novelty an ultra-low power asynchronous wake-up system implementation for underwater acoustic transmission that is based on a low-cost off-the-shelf RFID peripheral integrated circuit. This feature enables a reduced power dissipation of 10 μW in stand-by mode and registers very low power values during reception and transmission. The modem also incorporates clear channel assessment (CCA) to support CSMA-based medium access control (MAC) layer protocols. The design is part of a compact platform for a long-life short/medium range underwater wireless sensor network. PMID:22969324

  11. An ultra-low power and flexible acoustic modem design to develop energy-efficient underwater sensor networks.

    PubMed

    Sánchez, Antonio; Blanc, Sara; Yuste, Pedro; Perles, Angel; Serrano, Juan José

    2012-01-01

    This paper is focused on the description of the physical layer of a new acoustic modem called ITACA. The modem architecture includes as a major novelty an ultra-low power asynchronous wake-up system implementation for underwater acoustic transmission that is based on a low-cost off-the-shelf RFID peripheral integrated circuit. This feature enables a reduced power dissipation of 10 μW in stand-by mode and registers very low power values during reception and transmission. The modem also incorporates clear channel assessment (CCA) to support CSMA-based medium access control (MAC) layer protocols. The design is part of a compact platform for a long-life short/medium range underwater wireless sensor network.

  12. Characterization of HIFU transducers designed for sonochemistry application: Acoustic streaming.

    PubMed

    Hallez, L; Touyeras, F; Hihn, J-Y; Bailly, Y

    2016-03-01

    Cavitation distribution in a High Intensity Focused Ultrasound sonoreactors (HIFU) has been extensively described in the recent literature, including quantification by an optical method (Sonochemiluminescence SCL). The present paper provides complementary measurements through the study of acoustic streaming generated by the same kind of HIFU transducers. To this end, results of mass transfer measurements (electrodiffusional method) were compared to optical method ones (Particle Image Velocimetry). This last one was used in various configurations: with or without an electrode in the acoustic field in order to have the same perturbation of the wave propagation. Results show that the maximum velocity is not located at the focal but shifted near the transducer, and that this shift is greater for high powers. The two cavitation modes (stationary and moving bubbles) are greatly affect the hydrodynamic behavior of our sonoreactors: acoustic streaming and the fluid generated by bubble motion. The results obtained by electrochemical measurements show the same low hydrodynamic activity in the transducer vicinity, the same shift of the active focal toward the transducer, and the same absence of activity in the post-focal axial zone. The comparison with theoretical Eckart's velocities (acoustic streaming in non-cavitating media) confirms a very high activity at the "sonochemical focal", accounted for by wave distortion, which induced greater absorption coefficients. Moreover, the equivalent liquid velocities are one order of magnitude larger than the ones measured by PIV, confirming the enhancement of mass transfer by bubbles oscillation and collapse close to the surface, rather than from a pure streaming effect.

  13. AST Launch Vehicle Acoustics

    NASA Technical Reports Server (NTRS)

    Houston, Janice; Counter, D.; Giacomoni, D.

    2015-01-01

    The liftoff phase induces acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are then used in the prediction of internal vibration responses of the vehicle and components which result in the qualification levels. Thus, predicting these liftoff acoustic (LOA) environments is critical to the design requirements of any launch vehicle. If there is a significant amount of uncertainty in the predictions or if acoustic mitigation options must be implemented, a subscale acoustic test is a feasible pre-launch test option to verify the LOA environments. The NASA Space Launch System (SLS) program initiated the Scale Model Acoustic Test (SMAT) to verify the predicted SLS LOA environments and to determine the acoustic reduction with an above deck water sound suppression system. The SMAT was conducted at Marshall Space Flight Center and the test article included a 5% scale SLS vehicle model, tower and Mobile Launcher. Acoustic and pressure data were measured by approximately 250 instruments. The SMAT liftoff acoustic results are presented, findings are discussed and a comparison is shown to the Ares I Scale Model Acoustic Test (ASMAT) results.

  14. Acoustics in Research Facilities--Control of Wanted and Unwanted Sound. Laboratory Design Notes.

    ERIC Educational Resources Information Center

    Newman, Robert B.

    Common and special acoustics problems are discussed in relation to the design and construction of research facilities. Following a brief examination of design criteria for the control of wanted and unwanted sound, the technology for achieving desired results is discussed. Emphasis is given to various design procedures and materials for the control…

  15. DIRSIG 5: core design and implementation

    NASA Astrophysics Data System (ADS)

    Goodenough, Adam A.; Brown, Scott D.

    2012-06-01

    The Digital Imaging and Remote Sensing Image Generation (DIRSIG) model has been developed at the Rochester Institute of Technology (RIT) for over two decades. The last major update of the model, DIRSIG 4, built on an established, first-principles, multi- and hyper-spectral scene simulation tool. It introduced a modern and flexible software architecture to support new sensor modalities and more complex and dynamic scenes. Since that time, the needs of the user community have grown and diversified in tandem with the computational capabilities of modern hardware. Faced with a desire to model more complex, multi-component systems that are beyond the original intent and capabilities of an aging software design, a new version of DIRSIG, version 5, is being introduced to the community. This paper describes the core of DIRSIG 5 that is responsible for linking the disparate sensor, scene, and environmental models together, spatially, temporally, and parametrically. The spatial relationships are governed by a planet-centric universe model encompassing a whole globe digital elevation and optical property model, the scene model(s), globally varying atmospheric models, and a space model. Temporal relationships are driven by a formal modeling and simulation architecture based on approaches used in engineering and biological sciences to model highly dynamic and interactive systems. Finally, the parametric interfaces are described by a universal data model that facilitates scripting, inter-dependent properties and user interface construction. The design of these components will be presented along with specific module implementation details. These simulation tools will be used to demonstrate some of the new capabilities and applications of DIRSIG 5.

  16. Design and implementation of multisteerable matched filters.

    PubMed

    Mühlich, Matthias; Friedrich, David; Aach, Til

    2012-02-01

    Image analysis problems such as feature tracking, edge detection, image enhancement, or texture analysis require thedetection of multi-oriented patterns which can appear at arbitrary orientations. Direct rotated matched filtering for feature detection is computationally expensive, but can be sped up with steerable filters. So far, steerable filter approaches were limited to only one direction. Many important low-level image features are, however, characterized by more than a single orientation. We therefore present here a framework for efficiently detecting specific multi-oriented patterns with arbitrary orientations in grayscale images. The core idea is to construct multisteerable filters by appropriate combinations of single-steerable filters. We exploit that steerable filters are closed under addition and multiplication. This allows to derive a design guide for multisteerable filters by means of multivariate polynomials. Furthermore, we describe an efficient implementation scheme and discuss the use of weighting functions to reduce angular oscillations. Applications in camera calibration, junction analysis of images from plant roots, and the discrimination of L, T, and X-junctions demonstrate the potential of this approach.

  17. Design and Implementation of Replicated Object Layer

    NASA Technical Reports Server (NTRS)

    Koka, Sudhir

    1996-01-01

    One of the widely used techniques for construction of fault tolerant applications is the replication of resources so that if one copy fails sufficient copies may still remain operational to allow the application to continue to function. This thesis involves the design and implementation of an object oriented framework for replicating data on multiple sites and across different platforms. Our approach, called the Replicated Object Layer (ROL) provides a mechanism for consistent replication of data over dynamic networks. ROL uses the Reliable Multicast Protocol (RMP) as a communication protocol that provides for reliable delivery, serialization and fault tolerance. Besides providing type registration, this layer facilitates distributed atomic transactions on replicated data. A novel algorithm called the RMP Commit Protocol, which commits transactions efficiently in reliable multicast environment is presented. ROL provides recovery procedures to ensure that site and communication failures do not corrupt persistent data, and male the system fault tolerant to network partitions. ROL will facilitate building distributed fault tolerant applications by performing the burdensome details of replica consistency operations, and making it completely transparent to the application.Replicated databases are a major class of applications which could be built on top of ROL.

  18. The Testing Behind The Test Facility: The Acoustic Design of the NASA Glenn Research Center's World-Class Reverberant Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    Hughes, William O.; McNelis, Mark E.; McNelis, Anne M.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is leading the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC?s Plum Brook Station in Sandusky, Ohio, USA. Benham Companies, LLC is currently constructing modal, base-shake sine and reverberant acoustic test facilities to support the future testing needs of NASA?s space exploration program. T he large Reverberant Acoustic Test Facility (RATF) will be approximately 101,000 ft3 in volume and capable of achieving an empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world?s known active reverberant acoustic test facilities. The key to achieving the expected acoustic test spectra for a range of many NASA space flight environments in the RATF is the knowledge gained from a series of ground acoustic tests. Data was obtained from several NASA-sponsored test programs, including testing performed at the National Research Council of Canada?s acoustic test facility in Ottawa, Ontario, Canada, and at the Redstone Technical Test Center acoustic test facility in Huntsville, Alabama, USA. The majority of these tests were performed to characterize the acoustic performance of the modulators (noise generators) and representative horns that would be required to meet the desired spectra, as well as to evaluate possible supplemental gas jet noise sources. The knowledge obtained in each of these test programs enabled the design of the RATF sound generation system to confidently advance to its final acoustic de-sign and subsequent on-going construction.

  19. The Testing Behind the Test Facility: the Acoustic Design of the NASA Glenn Research Center's World-Class Reverberant Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    Hughes, William O.; McNelis, Mark E.; Hozman, Aron D.; McNelis, Anne M.

    2010-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is leading the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC s Plum Brook Station in Sandusky, Ohio, U.S.A. Benham Companies, LLC is currently constructing modal, base-shake sine and reverberant acoustic test facilities to support the future testing needs of NASA s space exploration program. The large Reverberant Acoustic Test Facility (RATF) will be approximately 101,000 ft3 in volume and capable of achieving an empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world s known active reverberant acoustic test facilities. The key to achieving the expected acoustic test spectra for a range of many NASA space flight environments in the RATF is the knowledge gained from a series of ground acoustic tests. Data was obtained from several NASA-sponsored test programs, including testing performed at the National Research Council of Canada s acoustic test facility in Ottawa, Ontario, Canada, and at the Redstone Technical Test Center acoustic test facility in Huntsville, Alabama, U.S.A. The majority of these tests were performed to characterize the acoustic performance of the modulators (noise generators) and representative horns that would be required to meet the desired spectra, as well as to evaluate possible supplemental gas jet noise sources. The knowledge obtained in each of these test programs enabled the design of the RATF sound generation system to confidently advance to its final acoustic design and subsequent ongoing construction.

  20. The Testing Behind The Test Facility: The Acoustic Design of the NASA Glenn Research Center's World-Class Reverberant Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    Hozman, Aron D.; Hughes, William O.; McNelis, Mark E.; McNelis, Anne M.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is leading the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC's Plum Brook Station in Sandusky, Ohio, USA. Benham Companies, LLC is currently constructing modal, base-shake sine and reverberant acoustic test facilities to support the future testing needs of NASA's space exploration program. The large Reverberant Acoustic Test Facility (RATF) will be approximately 101,000 cu ft in volume and capable of achieving an empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world's known active reverberant acoustic test facilities. The key to achieving the expected acoustic test spectra for a range of many NASA space flight environments in the RATF is the knowledge gained from a series of ground acoustic tests. Data was obtained from several NASA-sponsored test programs, including testing performed at the National Research Council of Canada's acoustic test facility in Ottawa, Ontario, Canada, and at the Redstone Technical Test Center acoustic test facility in Huntsville, Alabama, USA. The majority of these tests were performed to characterize the acoustic performance of the modulators (noise generators) and representative horns that would be required to meet the desired spectra, as well as to evaluate possible supplemental gas jet noise sources. The knowledge obtained in each of these test programs enabled the design of the RATF sound generation system to confidently advance to its final acoustic design and subsequent on-going construction.

  1. Feasibility of acoustic neutrino detection in ice: Design and performance of the South Pole Acoustic Test Setup (SPATS)

    NASA Astrophysics Data System (ADS)

    Böser, S.; Bohm, C.; Descamps, F.; Fischer, J.; Hallgren, A.; Heller, R.; Hundertmark, S.; Krieger, K.; Nahnhauer, R.; Pohl, M.; Price, P.B.; Sulanke, K.-H.; Tosi, D.; Vandenbroucke, J.

    The South Pole Acoustic Test Setup (SPATS) has been built to evaluate the acoustic characteristics of the Antarctic ice in the 10 to 100 kHz frequency range so that the feasibility and specific design of an acoustic neutrino detection array at South Pole can be evaluated. SPATS consists of three vertical strings that have been deployed in the upper 400 meter of the Antarctic ice cap in January 2007, using the upper part of IceCube holes. The strings form a triangular array with a longest baseline of 422 meters. Each of them has 7 stages with one transmitter and one sensor module. Both are equipped with piezoelectric ceramic elements in order to produce or detect sound. Analog signals are brought to the surface on electric cables where they are digitized by a PCbased data acquisition system. Connected through dedicated wire pairs in the IceCube surface cables, the data from all three strings is then collected on a MasterPC in a central facility, from which they are sent to the northern hemisphere via a satellite link or locally stored on tape. A full technical overview of the SPATS detector and its performance will be presented.

  2. Implementation of a self-sensing piezoelectric actuator for vibro-acoustic active control

    NASA Astrophysics Data System (ADS)

    Pelletier, Anik; Micheau, Philippe; Berry, Alain

    2014-04-01

    Significant reduction of airplane interior noise may be obtained by active structural acoustic control (ASAC) of fuselage panels. This requires to accurately measure the vibrations of the aircraft panels while injecting anti-vibrations. Co-located piezoelectric sensors and actuators, spatially distributed on the structure, are an interesting avenue since they can lead to the implementation of distributed virtual impedances. When the same piezoelectric device is used to simultaneously measure and actuate, it is called a self-sensing piezoelectric actuator (SSPA). When a SSPA is submitted to a voltage, the measured current is the sum of the electric current due to the capacitive effect of the transducer plus the mechanical current induced by the strain of the structure. The latter is an order of magnitude smaller than the total current measured. Provided the measured current is digitized with sufficient accuracy, adequate numerical processing can subtract the capacitive current from the total measured current. A similar processing can also be used to subtract from the sensor information, near-field vibrations induced by the collocated actuator. Hence, information related to the global, vibrational flexural modes of the plate is extracted without complicated electronics. The numerical method of current separation has been programmed and validated with MATLAB/SimulinkR® and implemented on Speedgoat hardware. A shunt resistor is used to measure the current simultaneously with the voltage measurement. Strain-induced current has been successfully extracted from SSPA signal with this method. Numerical simulations show good agreement with experimental data.

  3. High-frequency, high-sensitivity acoustic sensor implemented on ALN/Si substrate

    NASA Astrophysics Data System (ADS)

    Caliendo, C.; Imperatori, P.

    2003-08-01

    AlN films, 1.6-6.3 μm thick, were sputtered at 200 °C on Si(100) and Si(111) substrates. The films were crack-free, uniform, and c-axis oriented. The experimental phase velocities of surface acoustic waves (SAW) propagating in the AlN/Si structures were estimated and showed only a small discrepancy (20-40 m/s) compared to the calculated theoretical values. A SAW resonator (SAWR)-based chemical sensor, operating at about 700 MHz, was implemented on AlN/Si. The SAWR surface was covered with a polymer film sensitive to relative humidity (RH) changes, already tested for RH sensing in previous works on SAW delay lines implemented on AlN/Si and ZnO/Si and operating at about 130 MHz. The RH mass sensitivity and the detection limit of the SAWR sensor improved by 38% and by one order of magnitude, respectively, compared to the delay line-based sensors previously tested.

  4. SU-E-CAMPUS-T-02: Exploring Radiation Acoustics CT Dosimeter Design Aspects for Proton Therapy

    SciTech Connect

    Alsanea, F; Moskvin, V; Stantz, K

    2014-06-15

    Purpose: Investigate the design aspects and imaging dose capabilities of the Radiation Acoustics Computed Tomography (RA CT) dosimeter for Proton induced acoustics, with the objective to characterize a pulsed pencil proton beam. The focus includes scanner geometry, transducer array, and transducer bandwidth on image quality. Methods: The geometry of the dosimeter is a cylindrical water phantom (length 40cm, radius 15cm) with 71 ultrasound transducers placed along the length and end of the cylinder to achieve a weighted set of projections with spherical sampling. A 3D filtered backprojection algorithm was used to reconstruct the dosimetric images and compared to MC dose distribution. First, 3D Monte Carlo (MC) Dose distributions for proton beam energies (range of 12cm, 16cm, 20cm, and 27cm) were used to simulate the acoustic pressure signal within this scanner for a pulsed proton beam of 1.8x107 protons, with a pulse width of 1 microsecond and a rise time of 0.1 microseconds. Dose comparison within the Bragg peak and distal edge were compared to MC analysis, where the integrated Gaussian was used to locate the 50% dose of the distal edge. To evaluate spatial fidelity, a set of point sources within the scanner field of view (15×15×15cm3) were simulated implementing a low-pass bandwidth response function (0 to 1MHz) equivalent to a multiple frequency transducer array, and the FWHM of the point-spread-function determined. Results: From the reconstructed images, RACT and MC range values are within 0.5mm, and the average variation of the dose within the Bragg peak are within 2%. The spatial resolution tracked with transducer bandwidth and projection angle sampling, and can be kept at 1.5mm. Conclusion: This design is ready for fabrication to start acquiring measurements. The 15 cm FOV is an optimum size for imaging dosimetry. Currently, simulations comparing transducer sensitivity, bandwidth, and proton beam parameters are being evaluated to assess signal-to-noise.

  5. Acoustical design economic trade off for transport aircraft

    NASA Astrophysics Data System (ADS)

    Benito, A.

    The effects of ICAO fixed certification limits and local ordinances on acoustic emissions from jets on commercial transport aircraft and costs of operations are explored. The regulations effectively ban some aircraft from operation over populated areas, impose curfews on airports and, in conjunction with local civil aviation rules, levy extra taxes and quotas on noisier equipment. Jet engine manufacturers have attempted to increase the flow laminarity, decrease the exhaust speed and develop acoustic liners for selected duct areas. Retrofits are, however, not usually cost effective due to increased operational costs, e.g., fuel consumption can increase after engine modification because of increased weight. Finally, an attempt is made to assess, monetarily, the costs of noise pollution, wherein fines are levied for noisy aircraft and the money is spent insulating homes from noise.

  6. Design and Analysis of Underwater Acoustic Networks with Reflected Links

    NASA Astrophysics Data System (ADS)

    Emokpae, Lloyd

    Underwater acoustic networks (UWANs) have applications in environmental state monitoring, oceanic profile measurements, leak detection in oil fields, distributed surveillance, and navigation. For these applications, sets of nodes are employed to collaboratively monitor an area of interest and track certain events or phenomena. In addition, it is common to find autonomous underwater vehicles (AUVs) acting as mobile sensor nodes that perform search-and-rescue missions, reconnaissance in combat zones, and coastal patrol. These AUVs are to work cooperatively to achieve a desired goal and thus need to be able to, in an ad-hoc manner, establish and sustain communication links in order to ensure some desired level of quality of service. Therefore, each node is required to adapt to environmental changes and be able to overcome broken communication links caused by external noise affecting the communication channel due to node mobility. In addition, since radio waves are quickly absorbed in the water medium, it is common for most underwater applications to rely on acoustic (or sound) rather than radio channels for mid-to-long range communications. However, acoustic channels pose multiple challenging issues, most notably the high transmission delay due to slow signal propagation and the limited channel bandwidth due to high frequency attenuation. Moreover, the inhomogeneous property of the water medium affects the sound speed profile while the signal surface and bottom reflections leads to multipath effects. In this dissertation, we address these networking challenges by developing protocols that take into consideration the underwater physical layer dynamics. We begin by introducing a novel surface-based reflection scheme (SBR), which takes advantage of the multipath effects of the acoustic channel. SBR works by using reflections from the water surface, and bottom, to establish non-line-of-sight (NLOS) communication links. SBR makes it possible to incorporate both line

  7. Architectural acoustics to non acousticians: Prediction auralization in design and consulting

    NASA Astrophysics Data System (ADS)

    Ciao, Quinsan

    2003-04-01

    Acoustic theories and principals are not necessarily familiar to most of the parties closely related to architectural acoustic issues. For example, architects involved in building designs, occupant communicates involved in space improvements are often the clients of architectural acoustic consultants. On one hand they are responsible to make knowledgeable decisions, on the other hand they do not have time or interest to be systematically trained in acoustics principals and theories. Properly educating such clients is one of the challenges constantly faced by architectural acoustic consultants. Traditionally, consultants are tormented between two different approaches. One is to deeply educate clients in architectural acoustics. The other is to convince the clients to trust and leave the matter to experts. Neither has been satisfactory. The former is insufficient and inefficient to establish appreciation of practical results, while the lattter is resisted for lack of transparency. Thanks to the latest development of computing technologies, a new approach is available, which is to demonstrate the acoustic effects in audible media through auralization and prediction in conjunction with explanation of simple principles. This paper discusses this approach of client education in practices with case study examples.

  8. Optimum acoustic design of free-running low speed propellers

    NASA Technical Reports Server (NTRS)

    Ormsbee, A. I.; Woan, C. J.

    1977-01-01

    A theoretical analysis is conducted concerning the effect of blade loading on the noise output of a free-running propeller in axial motion. The minimization of the mean square sound pressure at a point in space is considered, taking into account constraints on propeller thrust and torque. Attention is given to aerodynamic equations, acoustic equations, the expansion of the aerodynamic variables, and the nonlinear programming formulation.

  9. Design and performance of the South Pole Acoustic Test Setup

    NASA Astrophysics Data System (ADS)

    Abdou, Y.; Becker, K.-H.; Berdermann, J.; Bissok, M.; Bohm, C.; Böser, S.; Bothe, M.; Carson, M.; Descamps, F.; Fischer-Wolfarth, J.-H.; Gustafsson, L.; Hallgren, A.; Heinen, D.; Helbing, K.; Heller, R.; Hundertmark, S.; Karg, T.; Krieger, K.; Laihem, K.; Meures, T.; Nahnhauer, R.; Naumann, U.; Oberson, F.; Paul, L.; Pohl, M.; Price, B.; Ribordy, M.; Ryckbosch, D.; Schunck, M.; Semburg, B.; Stegmaier, J.; Sulanke, K.-H.; Tosi, D.; Vandenbroucke, J.; Wiebusch, C.

    2012-08-01

    The South Pole Acoustic Test Setup (SPATS) was built to evaluate the acoustic characteristics of the South Pole ice in the 10-100 kHz frequency range, for the purpose of assessing the feasibility of an acoustic neutrino detection array at the South Pole. The SPATS hardware consists of four vertical strings deployed in the upper 500 m of the South Pole ice cap. The strings form a trapezoidal array with a maximum baseline of 543 m. Each string has seven stages equipped with one transmitter and one sensor module (glaciophone). Sound is detected or generated by piezoelectric ceramic elements inside the modules. Analogue signals are sent to the surface on electric cables where they are digitized by a PC-based data acquisition system. The data from all strings are collected on a central computer in the IceCube Laboratory from where they are sent to a central data storage facility via a satellite link or stored locally on tape. A technical overview of SPATS and its performance is presented.

  10. A design of complex square root for FPGA implementation

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Ercegovac, Milos D.

    2009-08-01

    We present a design for FPGA implementation of a complex square root algorithm for fixed-point operands in radix-4 representation. The design consists of (i) argument prescaling, (ii) residual recurrence, and (iii) result postscaling. These parts share logic resources and optimize the use of resources on FPGA devices used for implementation. Table building methods for prescaling and postscaling are analyzed and efficient designs approaches are discussed. The design is implemented in Altera Stratix-II FPGA for several argument precisions and compared in cost, latency and power with a design with an IP-based design. The results show advantages of the proposed design in cost, delay, and power.

  11. Mobile health units. Design and implementation considerations.

    PubMed

    Murphy, D C; Klinghoffer, I; Fernandez-Wilson, J B; Rosenberg, L

    2000-11-01

    The decision to provide health care services with a mobile van is one which educational and service facilities are increasingly pursuing. The benefits include: The potential to increase the availability of services to underserved populations where access to care is perceived to be one reason for underuse of available services. The opportunity to increase and broaden the educational experiences of students in a training program. The opportunity to develop a sense of social responsibility in the health care provider. The process of deciding to pursue a van purchase is complicated, and administrators may best be served by obtaining experienced consultants to help them fully comprehend the issues involved. After the decision to purchase a mobile unit is made, it is necessary to focus on van requirements and design to meet federal, state, and city codes concerning motor vehicles and health requirements. Some modifications of one's standard practices are needed because of these codes. Being aware of them in advance will allow a smooth project completion. This article provides information about some of the steps required to implement a mobile unit. The approximate time from initial concept to van delivery was 1 year, with one fully dedicated project coordinator working to assure the project's success in such a short time frame. Seeing the gratified personnel and students who serve the children on the "Smiling Faces, Going Places" Mobile Dental Van of the NYUCD (see Figure 2), and knowing the children would otherwise not have received such services, allows the health care professionals involved to feel the development of this van is an exciting mechanism for delivery of health care to individuals who would otherwise go without.

  12. Harnessing fluid-structure interactions to design self-regulating acoustic metamaterials

    NASA Astrophysics Data System (ADS)

    Casadei, Filippo; Bertoldi, Katia

    2014-01-01

    The design of phononic crystals and acoustic metamaterials with tunable and adaptive wave properties remains one of the outstanding challenges for the development of next generation acoustic devices. We report on the numerical and experimental demonstration of a locally resonant acoustic metamaterial with dispersion characteristics, which autonomously adapt in response to changes of an incident aerodynamic flow. The metamaterial consists of a slender beam featuring a periodic array or airfoil-shaped masses supported by a linear and torsional springs. The resonance characteristics of the airfoils lead to strong attenuation at frequencies defined by the properties of the airfoils and the speed on the incident fluid. The proposed concept expands the ability of existing acoustic bandgap materials to autonomously adapt their dispersion properties through fluid-structure interactions, and has the potential to dramatically impact a variety of applications, such as robotics, civil infrastructures, and defense systems.

  13. A procedure for combining acoustically induced and mechanically induced loads (first passage failure design criterion)

    NASA Technical Reports Server (NTRS)

    Crowe, D. R.; Henricks, W.

    1983-01-01

    The combined load statistics are developed by taking the acoustically induced load to be a random population, assumed to be stationary. Each element of this ensemble of acoustically induced loads is assumed to have the same power spectral density (PSD), obtained previously from a random response analysis employing the given acoustic field in the STS cargo bay as a stationary random excitation. The mechanically induced load is treated as either (1) a known deterministic transient, or (2) a nonstationary random variable of known first and second statistical moments which vary with time. A method is then shown for determining the probability that the combined load would, at any time, have a value equal to or less than a certain level. Having obtained a statistical representation of how the acoustic and mechanical loads are expected to combine, an analytical approximation for defining design levels for these loads is presented using the First Passage failure criterion.

  14. Harnessing fluid-structure interactions to design self-regulating acoustic metamaterials

    SciTech Connect

    Casadei, Filippo; Bertoldi, Katia

    2014-01-21

    The design of phononic crystals and acoustic metamaterials with tunable and adaptive wave properties remains one of the outstanding challenges for the development of next generation acoustic devices. We report on the numerical and experimental demonstration of a locally resonant acoustic metamaterial with dispersion characteristics, which autonomously adapt in response to changes of an incident aerodynamic flow. The metamaterial consists of a slender beam featuring a periodic array or airfoil-shaped masses supported by a linear and torsional springs. The resonance characteristics of the airfoils lead to strong attenuation at frequencies defined by the properties of the airfoils and the speed on the incident fluid. The proposed concept expands the ability of existing acoustic bandgap materials to autonomously adapt their dispersion properties through fluid-structure interactions, and has the potential to dramatically impact a variety of applications, such as robotics, civil infrastructures, and defense systems.

  15. The Design and Implementation of Persistence in the Annex System

    DTIC Science & Technology

    2009-08-01

    design. Amongst these we can count the Annex software system developed at DSTO. In this technical note we consider the design and implementation of...location moves from the address space in which it was created).” [Booch 1994] A software system is said to implement persistence if all its objects are...projects, have implemented orthogonal persistence as an essential part of their design. Among these is the Annex software system developed at DSTO. In

  16. Optimal acoustical design of commercial meeting and teleconference rooms

    NASA Astrophysics Data System (ADS)

    Campanella, Angelo

    2002-05-01

    Along with a quiet NC-25 environment, speech communication among multiple individuals in a conference room, especially for teleconferencing, should be enhanced. Conferees are often located around a table and along the room perimeter. Speech propagation among all is enhanced by a flat ceiling reflector placed as low as practical over the table and the seated participants. This reinforces direct sound with a first-bounce reflection between all parties and microphones. Ceiling perimeter, 50%-75% of the ceiling area, is absorptive. This arrangement works for a speaker-phone and for microphones placed on the ceiling reflector avoiding paper shuffling noise. In the latter case, loudspeakers are placed on the absorbing perimeter acoustical tile. Absorption must be placed on the sidewalls to avoid flutter echoes. Uneven absorber distribution among surfaces is evaluated with the Fitzroy reverberation time [D. Fitzroy, J. Acoust. Soc. Am. 31, 893-897 (1959)]. It was found that this RT at 500 Hz should be [1+log(V)]/10 (about 1/2 s) to avoid a ``hollow'' timbre in purveyed speech. Examples of good and troublesome teleconference rooms are discussed.

  17. Radiometric and photometric design for an Acoustic Containerless Experiment System. [for space processing

    NASA Technical Reports Server (NTRS)

    Glavich, T. A.

    1981-01-01

    The design of an optical system for a high temperature Acoustic Containerless Experiment System is examined. The optical system provides two-axis video, cine and infrared images of an acoustically positioned sample over a temperature range of 20 to 1200 C. Emphasis is placed on the radiometric and photometric characterization of the elements in the optical system and the oven to assist image data determination. Sample visibility due to wall radiance is investigated along with visibility due to strobe radiance. The optical system is designed for operation in Spacelab, and is used for a variety of materials processing experiments.

  18. The acoustic design of the Centro Nacional de las Artes in Mexico City

    NASA Astrophysics Data System (ADS)

    Cooper, Rusell

    2002-11-01

    In this paper the acoustic design of the separate buildings housing the school of music, school of drama, and school of dance that opened in 1996 will be described. Spaces that JHA designed included practice rooms, studios, rehearsal rooms, black box, and concert hall. Details of room acoustic treatments, sound isolation measures, and venturi air flow will be illustrated. An overview of the entire project will also include the 500 seat multipurpose theater (with variable absorption systems) and the Alla Magna. Differences between the American and Mexican styles of consulting, importing of materials, installation, and commissioning will also be discussed.

  19. A Design Process for the Acoustical System of an Enclosed Space Colony

    NASA Technical Reports Server (NTRS)

    Hawke, Joanne

    1981-01-01

    Sounds of Silence. Using a general systems approach, factors and components of the acoustical design process for an isolated, confined space community in a torus space enclosure are considered. These components include the following: organizational structure and its effect on alternatives; problem definition and limits; criteria and priorities; methods of data gathering; modelling and measurement of the whole system and its components; decision methods; and design scenario of the acoustics of the complex, socio-technical space community system with emphasis on the human factors.

  20. Radiometric and photometric design for an Acoustic Containerless Experiment System. [for space processing

    NASA Technical Reports Server (NTRS)

    Glavich, T. A.

    1981-01-01

    The design of an optical system for a high temperature Acoustic Containerless Experiment System is examined. The optical system provides two-axis video, cine and infrared images of an acoustically positioned sample over a temperature range of 20 to 1200 C. Emphasis is placed on the radiometric and photometric characterization of the elements in the optical system and the oven to assist image data determination. Sample visibility due to wall radiance is investigated along with visibility due to strobe radiance. The optical system is designed for operation in Spacelab, and is used for a variety of materials processing experiments.

  1. A Design Process for the Acoustical System of an Enclosed Space Colony

    NASA Technical Reports Server (NTRS)

    Hawke, Joanne

    1981-01-01

    Sounds of Silence. Using a general systems approach, factors and components of the acoustical design process for an isolated, confined space community in a torus space enclosure are considered. These components include the following: organizational structure and its effect on alternatives; problem definition and limits; criteria and priorities; methods of data gathering; modelling and measurement of the whole system and its components; decision methods; and design scenario of the acoustics of the complex, socio-technical space community system with emphasis on the human factors.

  2. Implementation of dispersion-free slow acoustic wave propagation and phase engineering with helical-structured metamaterials

    PubMed Central

    Zhu, Xuefeng; Li, Kun; Zhang, Peng; Zhu, Jie; Zhang, Jintao; Tian, Chao; Liu, Shengchun

    2016-01-01

    The ability to slow down wave propagation in materials has attracted significant research interest. A successful solution will give rise to manageable enhanced wave–matter interaction, freewheeling phase engineering and spatial compression of wave signals. The existing methods are typically associated with constructing dispersive materials or structures with local resonators, thus resulting in unavoidable distortion of waveforms. Here we show that, with helical-structured acoustic metamaterials, it is now possible to implement dispersion-free sound deceleration. The helical-structured metamaterials present a non-dispersive high effective refractive index that is tunable through adjusting the helicity of structures, while the wavefront revolution plays a dominant role in reducing the group velocity. Finally, we numerically and experimentally demonstrate that the helical-structured metamaterials with designed inhomogeneous unit cells can turn a normally incident plane wave into a self-accelerating beam on the prescribed parabolic trajectory. The helical-structured metamaterials will have profound impact to applications in explorations of slow wave physics. PMID:27198887

  3. Implementation of dispersion-free slow acoustic wave propagation and phase engineering with helical-structured metamaterials.

    PubMed

    Zhu, Xuefeng; Li, Kun; Zhang, Peng; Zhu, Jie; Zhang, Jintao; Tian, Chao; Liu, Shengchun

    2016-05-20

    The ability to slow down wave propagation in materials has attracted significant research interest. A successful solution will give rise to manageable enhanced wave-matter interaction, freewheeling phase engineering and spatial compression of wave signals. The existing methods are typically associated with constructing dispersive materials or structures with local resonators, thus resulting in unavoidable distortion of waveforms. Here we show that, with helical-structured acoustic metamaterials, it is now possible to implement dispersion-free sound deceleration. The helical-structured metamaterials present a non-dispersive high effective refractive index that is tunable through adjusting the helicity of structures, while the wavefront revolution plays a dominant role in reducing the group velocity. Finally, we numerically and experimentally demonstrate that the helical-structured metamaterials with designed inhomogeneous unit cells can turn a normally incident plane wave into a self-accelerating beam on the prescribed parabolic trajectory. The helical-structured metamaterials will have profound impact to applications in explorations of slow wave physics.

  4. Acoustic Treatment Design Scaling Methods. Volume 3; Test Plans, Hardware, Results, and Evaluation

    NASA Technical Reports Server (NTRS)

    Yu, J.; Kwan, H. W.; Echternach, D. K.; Kraft, R. E.; Syed, A. A.

    1999-01-01

    The ability to design, build, and test miniaturized acoustic treatment panels on scale-model fan rigs representative of the full-scale engine provides not only a cost-savings, but an opportunity to optimize the treatment by allowing tests of different designs. To be able to use scale model treatment as a full-scale design tool, it is necessary that the designer be able to reliably translate the scale model design and performance to an equivalent full-scale design. The primary objective of the study presented in this volume of the final report was to conduct laboratory tests to evaluate liner acoustic properties and validate advanced treatment impedance models. These laboratory tests include DC flow resistance measurements, normal incidence impedance measurements, DC flow and impedance measurements in the presence of grazing flow, and in-duct liner attenuation as well as modal measurements. Test panels were fabricated at three different scale factors (i.e., full-scale, half-scale, and one-fifth scale) to support laboratory acoustic testing. The panel configurations include single-degree-of-freedom (SDOF) perforated sandwich panels, SDOF linear (wire mesh) liners, and double-degree-of-freedom (DDOF) linear acoustic panels.

  5. Design, construction, activation, and operation of a high intensity acoustic test chamber

    NASA Technical Reports Server (NTRS)

    Kamel, L. T.

    1986-01-01

    The design philosophy, construction, integration, and activation of the high intensity acoustic test chamber for production acceptance testing of satellites are discussed. The 32,000 cubic-foot acoustic test cell consists of a steel reinforced concrete chamber with six electropneumatic noise generators. One of the innovative features of the chamber is a unique quarter horn assembly that acoustically couples the noise generators to the chamber. Design concepts, model testing, and evaluation results are presented. Considerations such as nitrogen versus compressed air source, digital closed loop spectrum control versus manual equalizers, and microprocessor based interlock systems are included. Construction difficulties, anomalies encountered, and their resolution are also discussed. Results of the readiness testing are highlighted.

  6. Design, construction, activation, and operation of a high intensity acoustic test chamber

    NASA Technical Reports Server (NTRS)

    Kamel, L. T.

    1986-01-01

    The design philosophy, construction, integration, and activation of the high intensity acoustic test chamber for production acceptance testing of satellites are discussed. The 32,000 cubic-foot acoustic test cell consists of a steel reinforced concrete chamber with six electropneumatic noise generators. One of the innovative features of the chamber is a unique quarter horn assembly that acoustically couples the noise generators to the chamber. Design concepts, model testing, and evaluation results are presented. Considerations such as nitrogen versus compressed air source, digital closed loop spectrum control versus manual equalizers, and microprocessor based interlock systems are included. Construction difficulties, anomalies encountered, and their resolution are also discussed. Results of the readiness testing are highlighted.

  7. An acoustic head simulator for hearing protector evaluation. I: Design and construction.

    PubMed

    Kunov, H; Giguère, C

    1989-03-01

    As an alternative to subjective methods, an acoustic head simulator was constructed for hearing protector evaluation. The primary purpose of the device is for hearing protector testing and research under high-level steady-state and impulse noise environments. The design is based on the KEMAR manikin and therefore approximates the physical dimensions and the acoustical eardrum impedance of the median human adult. The head simulator includes a mechanical reproduction of the human circumaural and intraaural tissues with a silicone rubber material. A compliant head-neck system was constructed to approximate the vibrational characteristics of the human head in a sound field in order to simulate the inertia effect of earmuffs. The bone-conducted sounds are not mechanically reproduced in the design. Applications for the device are reported in a companion article [C. Giguère and H. Kunov, J. Acoust. Soc. Am. 85, 1197-1205 (1989)].

  8. Design Based Research: The Way of Developing and Implementing

    ERIC Educational Resources Information Center

    Štemberger, Tina; Cencic, Majda

    2016-01-01

    The appropriate implementation of innovation is a crucial factor in improving educational practice. In the implementation process, there is, however, often a lack of interaction between designers and practitioners that would enable the latter to become competent enough to implement theoretical knowledge into practice and to have an ongoing support…

  9. The Heart of Implementation Fidelity: Instructional Design and Intent

    ERIC Educational Resources Information Center

    Kulo, Violet A.; Cates, Ward Mitchell

    2013-01-01

    Given that there is no universal way to measure implementation fidelity, instructional designers developing instructional innovations may find themselves faced with the challenge of determining the extent to which teachers' implementation of an instructional model is faithful. This article contends that a faithful implementation is one in…

  10. The Heart of Implementation Fidelity: Instructional Design and Intent

    ERIC Educational Resources Information Center

    Kulo, Violet A.; Cates, Ward Mitchell

    2013-01-01

    Given that there is no universal way to measure implementation fidelity, instructional designers developing instructional innovations may find themselves faced with the challenge of determining the extent to which teachers' implementation of an instructional model is faithful. This article contends that a faithful implementation is one in…

  11. Qualitative Research Designs: Selection and Implementation

    ERIC Educational Resources Information Center

    Creswell, John W.; Hanson, William E.; Plano Clark, Vicki L.; Morales, Alejandro

    2007-01-01

    Counseling psychologists face many approaches from which to choose when they conduct a qualitative research study. This article focuses on the processes of selecting, contrasting, and implementing five different qualitative approaches. Based on an extended example related to test interpretation by counselors, clients, and communities, this article…

  12. Qualitative Research Designs: Selection and Implementation

    ERIC Educational Resources Information Center

    Creswell, John W.; Hanson, William E.; Plano Clark, Vicki L.; Morales, Alejandro

    2007-01-01

    Counseling psychologists face many approaches from which to choose when they conduct a qualitative research study. This article focuses on the processes of selecting, contrasting, and implementing five different qualitative approaches. Based on an extended example related to test interpretation by counselors, clients, and communities, this article…

  13. Extension Sustainability Camp: Design, Implementation, and Evaluation

    ERIC Educational Resources Information Center

    Brain, Roslynn; Upton, Sally; Tingey, Brett

    2015-01-01

    Sustainability Camps provide an opportunity for Extension educators to be in the forefront of sustainability outreach and to meet the growing demand for sustainability education. This article shares development, implementation, and evaluation of an Extension Sustainability Camp for youth, grades 4-6. Camp impact was measured via daily pre-and…

  14. Design and Implementation Skills for Social Innovation.

    ERIC Educational Resources Information Center

    Tornatzky, Louis G.; Fairweather, George W.

    New models of research and training combined with dissemination techniques can contribute to relevant social change. The Ecological Psychology Program at Michigan State University, a graduate training program which focuses on model building and implementation research, offers ideas on the plausability of social programming. The process would…

  15. Extension Sustainability Camp: Design, Implementation, and Evaluation

    ERIC Educational Resources Information Center

    Brain, Roslynn; Upton, Sally; Tingey, Brett

    2015-01-01

    Sustainability Camps provide an opportunity for Extension educators to be in the forefront of sustainability outreach and to meet the growing demand for sustainability education. This article shares development, implementation, and evaluation of an Extension Sustainability Camp for youth, grades 4-6. Camp impact was measured via daily pre-and…

  16. An integrated optimum design approach for high speed prop-rotors including acoustic constraints

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Aditi; Wells, Valana; Mccarthy, Thomas; Han, Arris

    1993-01-01

    The objective of this research is to develop optimization procedures to provide design trends in high speed prop-rotors. The necessary disciplinary couplings are all considered within a closed loop multilevel decomposition optimization process. The procedures involve the consideration of blade-aeroelastic aerodynamic performance, structural-dynamic design requirements, and acoustics. Further, since the design involves consideration of several different objective functions, multiobjective function formulation techniques are developed.

  17. SLS Scale Model Acoustic Test Liftoff Results and Comparisons

    NASA Technical Reports Server (NTRS)

    Houston, Janice; Counter, Douglas; Giacomoni, Clothilde

    2015-01-01

    The liftoff phase induces acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are then used in the prediction of internal vibration responses of the vehicle and components which result in the qualification levels. Thus, predicting these liftoff acoustic (LOA) environments is critical to the design requirements of any launch vehicle. If there is a significant amount of uncertainty in the predictions or if acoustic mitigation options must be implemented, a subscale acoustic test is a feasible design phase test option to verify the LOA environments. The NASA Space Launch System (SLS) program initiated the Scale Model Acoustic Test (SMAT) to verify the predicted SLS LOA environments.

  18. Parallel optimization algorithms and their implementation in VLSI design

    NASA Technical Reports Server (NTRS)

    Lee, G.; Feeley, J. J.

    1991-01-01

    Two new parallel optimization algorithms based on the simplex method are described. They may be executed by a SIMD parallel processor architecture and be implemented in VLSI design. Several VLSI design implementations are introduced. An application example is reported to demonstrate that the algorithms are effective.

  19. The design and implementation of the LLNL gigabit testbed

    SciTech Connect

    Garcia, D.

    1994-12-01

    This paper will look at the design and implementation of the LLNL Gigabit testbed (LGTB), where various high speed networking products, can be tested in one environment. The paper will discuss the philosophy behind the design of and the need for the testbed, the tests that are performed in the testbed, and the tools used to implement those tests.

  20. Implementing E-Learning Designed Courses in General Education

    ERIC Educational Resources Information Center

    Nuangchalerm, Prasart; Sakkumduang, Krissada; Uhwha, Suleepornn; Chansirisira, Pacharawit

    2014-01-01

    The aim of this study is to implement e-learning designed course for general education. The study employed 3 phases for developing e-learning course: contextual study, designing, and implementing. Two courses general education, 217 undergraduate students are participated the study. Research tool consisted of interview about e-learning form and…

  1. Designing and implementing a state quality award

    NASA Astrophysics Data System (ADS)

    Dobson, E. N.

    1993-02-01

    To remain competitive in today's global economy, businesses need to ensure customer satisfaction by offering high-quality products and services. Governors and state governments can play a critical role in ensuring the economic health of the business in their state by encouraging the adoption of quality practices and recognizing successful efforts by firms to improve quality and productivity. The manual is intended to help state government officials and other individuals implement a state quality award program.

  2. Scale Model Acoustic Test Overview

    NASA Technical Reports Server (NTRS)

    Counter, Douglas D.; Houston, Janice D.

    2012-01-01

    Launch environments, such as liftoff acoustic (LOA) and ignition overpressure (IOP), are important design factors for any vehicle and are dependent upon the design of both the vehicle and the ground systems. LOA environments are used directly in the development of vehicle vibro-acoustic environments and IOP is used in the loads assessment. The Scale Model Acoustic Test (SMAT) program was implemented to verify the Space Launch Systems LOA and IOP environments for the vehicle and ground systems including the Mobile Launcher (ML) and tower. The SMAT is currently in the design and fabrication phase. The SMAT program is described in this presentation.

  3. Design of a Blended Learning Environment: Considerations and Implementation Issues

    ERIC Educational Resources Information Center

    Gedik, Nuray; Kiraz, Ercan; Ozden, M. Yasar

    2013-01-01

    This study identified critical issues in the design of a blended learning environment by examining basic design considerations and implementation issues. Following a design-based research approach with the phenomenological tradition of qualitative research, the study investigated instructor experiences relating to the design, development, and…

  4. Single stage, low noise advanced technology fan. Volume 3: Acoustic design

    NASA Technical Reports Server (NTRS)

    Kazin, S. B.; Mishler, R. B.

    1976-01-01

    The acoustic design for a half-scale fan vehicle, which would have application on an advanced transport aircraft, is described. The single stage advanced technology fan was designed to a pressure ratio of 1.8 at a tip speed of 503 m/sec (1,650 ft/sec). The two basic approaches taken in the acoustic design were: (1) minimization of noise at the source, and (2) suppression of the generated noise in the inlet and bypass exhaust duct. Suppression of the generated noise is accomplished in the inlet through use of the hybrid concept (wall acoustic treatment plus airflow acceleration suppression) and in the exhaust duct with extensive acoustic treatment including a splitter. The goal of the design was attainment of twenty effective perceived noise decibels (20 EPNdB) below current Federal Air Regulation noise standards for a full-scale fan at the takeoff, cutback, and approach conditions. Predicted unsuppressed and suppressed fore and aft maximum perceived noise levels indicate that the cutback condition is the most critical with respect to the goal, which is probably unattainable for that condition. This is also true for aft radiated noise in the approach condition.

  5. Designing an Acoustic Suspension Speaker System in the General Physics Laboratory: A Divergent experiment

    ERIC Educational Resources Information Center

    Horton, Philip B.

    1969-01-01

    Describes a student laboratory project involving the design of an "acoustic suspension speaker system. The characteristics of the loudspeaker used are measured as an extension of the inertia-balance experiment. The experiment may be extended to a study of Stelmholtz resonators, coupled oscillators, electromagnetic forces, thermodynamics and…

  6. Designing an Acoustic Suspension Speaker System in the General Physics Laboratory: A Divergent experiment

    ERIC Educational Resources Information Center

    Horton, Philip B.

    1969-01-01

    Describes a student laboratory project involving the design of an "acoustic suspension speaker system. The characteristics of the loudspeaker used are measured as an extension of the inertia-balance experiment. The experiment may be extended to a study of Stelmholtz resonators, coupled oscillators, electromagnetic forces, thermodynamics and…

  7. Integrated Language Design and Implementation Process

    DTIC Science & Technology

    2000-03-28

    and Technology PO Box 91000 Portland, OR 97291 DISTRIBUTION STATEMENT A 20000403 154 Approved for Public Release Distribution Unlimited Software Design...Experimental Software Engineering Science and Technology Sauerwiesen 6 P.O. Box 91000 D-67661 Kaiserslautern, Germany Portland, OR 97291-1000 USA widen...the language technology of the target (MSL) [28] developed as part of the Software Design for environment. Reliability and Reuse (SDRR) project [4

  8. Design of acoustic cell settler for filtering and recycling microbial cells.

    PubMed

    Hwang, Sung-Ho; Koo, Yoon-Mo

    2003-02-01

    An acoustic cell settler (ACS) using ultrasound at cells of 3 MHz was used to recycle Saccharomyces cerevisiae in a fermenter. The locations of both the inlet and outlet in the acoustic cell settler, which have a relatively long distance between the transducer and reflector, were optimized. A tilted settler was designed to make up for the defect in the horizontal ACS, which has a low recovery ratio. The tilted ACS gave a recovery ratio of yeast cells of about 5 during the most period of operation, which was twice that of the horizontal ACS.

  9. MEMS acoustic emission transducers designed with high aspect ratio geometry

    NASA Astrophysics Data System (ADS)

    Saboonchi, H.; Ozevin, D.

    2013-09-01

    In this paper, micro-electro-mechanic systems (MEMS) acoustic emission (AE) transducers are manufactured using an electroplating technique. The transducers use a capacitance change as their transduction principle, and are tuned to the range 50-200 kHz. Through the electroplating technique, a thick metal layer (20 μm nickel + 0.5 μm gold) is used to form a freely moving microstructure layer. The presence of the gold layer reduces the potential corrosion of the nickel layer. A dielectric layer is deposited between the two electrodes, thus preventing the stiction phenomenon. The transducers have a measured quality factor in the range 15-30 at atmospheric pressure and are functional without vacuum packaging. The transducers are characterized using electrical and mechanical tests to identify the capacitance, resonance frequency and damping. Ultrasonic wave generation using a Q-switched laser shows the directivity of the transducer sensitivity. The comparison of the MEMS transducers with similar frequency piezoelectric transducers shows that the MEMS AE transducers have better response characteristics and sensitivity at the resonance frequency and well-defined waveform signatures (rise time and decay time) due to pure resonance behavior in the out-of-plane direction. The transducers are sensitive to a unique wave direction, which can be utilized to increase the accuracy of source localization by selecting the correct wave velocity at the structures.

  10. Conceptual design study of advanced acoustic-composite nacelles

    NASA Technical Reports Server (NTRS)

    Nordstrom, K. E.; Marsh, A. H.; Sargisson, D. F.

    1975-01-01

    Conceptual studies were conducted to assess the impact of incorporating advanced technologies in the nacelles of a current wide-bodied transport and an advanced technology transport. The improvement possible in the areas of fuel consumption, flyover noise levels, airplane weight, manufacturing costs, and airplane operating cost were evaluated for short and long-duct nacelles. Use of composite structures for acoustic duct linings in the fan inlet and exhaust ducts was considered as well as for other nacelle components. For the wide-bodied transport, the use of a long-duct nacelle with an internal mixer nozzle in the primary exhaust showed significant improvement in installed specific fuel consumption and airplane direct operating costs compared to the current short-duct nacelle. The long-duct mixed-flow nacelle is expected to achieve significant reductions in jet noise during takeoff and in turbo-machinery noise during landing approach. Recommendations were made of the technology development needed to achieve the potential fuel conservation and noise reduction benefits.

  11. Design of non-reciprocal acoustic waveguides by indirect interband transitions

    NASA Astrophysics Data System (ADS)

    Ishikawa, Atsushi; Tsuruta, Kenji

    2017-07-01

    We numerically demonstrate a non-reciprocal acoustic waveguide by utilizing the indirect interband transition between two guided modes. The waveguide, consisting of a water core sandwiched between parallel steel plates, is designed to support symmetric and asymmetric guided modes with different frequencies and wavevectors. Dynamic mode conversion is then achieved by applying spatio-temporal density modulation in the core of the waveguide to induce both frequency and wavevector shifts of the incident guided wave. Numerical simulations prove that the phase matching condition is satisfied only for the forward propagation, not for the backward one, thus realizing the non-reciprocal acoustic waveguide. Our approach based on a linear dynamic system may achieve wide-band tunable operation with a low-energy consumption, paving the way toward the sophisticated acoustic diode applications.

  12. Analytical models for use in fan inflow control structure design. Inflow distortion and acoustic transmission models

    NASA Technical Reports Server (NTRS)

    Gedge, M. R.

    1979-01-01

    Analytical models were developed to study the effect of flow contraction and screening on inflow distortions to identify qualitative design criteria. Results of the study are that: (1) static testing distortions are due to atmospheric turbulence, nacelle boundary layer, exhaust flow reingestion, flow over stand, ground plane, and engine casing; (2) flow contraction suppresses, initially, turbulent axial velocity distortions and magnifies turbulent transverse velocity distortions; (3) perforated plate and gauze screens suppress axial components of velocity distortions to a degree determined by the screen pressure loss coefficient; (4) honeycomb screen suppress transverse components of velocity distortions to a degree determined by the length to diameter ratio of the honeycomb; (5) acoustic transmission loss of perforated plate is controlled by the reactance of its acoustic impedance; (6) acoustic transmission loss of honeycomb screens is negligible; and (7) a model for the direction change due to a corner between honeycomb panels compares favorably with measured data.

  13. Designing and implementing an interdependent resilience culture.

    PubMed

    Knapp, Henry Patrick

    Once an emergency occurs, companies find themselves competing for diminishing resources. Companies mired in confusion and debate often fail to obtain the resources necessary for a speedy recovery and fail to meet the expectations of their various interested parties. Unfortunately, it is during these emergencies that the firm is judged. Unfavourable evaluations of a company by customers, the government and/or the general public result in lost future revenue through contracts that are either not renewed or cancelled, as well as disqualification from tenders and lost bids. This paper discusses how an oil field services company implemented an interdependent resilience culture. Development of this culture included paring down complex concepts and theories into simple rules that are continually introduced and reinforced to the company's leadership. After years of effort, employees from the well head to the corporate boardroom are aligned and aware of everyone's roles when an incident occurs. In short, because each person can count on the others, the company quickly adapts and overcomes significant issues, adding to its competitiveness. As a reader, you will understand that the results of implementing this new culture come down to a single metric: speed. Responses become faster, decisions faster, communication and the transfer of knowledge faster. Emergencies are dynamic and ever-changing. Information quickly becomes stale and outdated. Installing this culture creates a more nimble company which reacts in a manner that allows for extra time, so all the unplanned delays, pitfalls and breakdowns can occur with little to no meaningful impact.

  14. Acoustic sounder system design for measurement of optical turbulence and wind profiles

    NASA Astrophysics Data System (ADS)

    Miller, Judith E.; Eaton, Frank D.; Stokes, Sheldon S.

    2000-07-01

    An Acoustic Sounder System has been installed on the side of the cliff at North Oscura Peak, WSMR to provide important refractive index structure parameter, Cn2 data for laser propagation tests. The acoustic sounder system records echo information that is used to provide 3D wind and optical turbulence profiles. The received signal is the product of the interaction of the transmitted acoustic pulse with the small scale atmospheric temperature variations. This information is displayed as a time-height display of the signal intensity. The frequency of the received signals are processed and converted into time histories of the horizontal wind field. The data from the Acoustic Sounder is calibrated with the hot-wire anemometer temperature structure parameter (Ct2) data, and meteorological data measured locally to produce the Cn2 profile. The design and location of the Acoustic Sounder System will be discussed along with the methodology of extracting the turbulence. Many days of data have been collected and representative data will be shown.

  15. Acoustic fatigue and sound transmission characteristics of a ram composite panel design

    NASA Technical Reports Server (NTRS)

    Cockburn, J. A.; Chang, K. Y.; Kao, G. C.

    1972-01-01

    An experimental study to determine the acoustic fatigue characteristics of a flat multi-layered structural panel is described. The test panel represented a proposed design for the outer skin of a research application module to be housed within the space shuttle orbiter vehicle. The test specimen was mounted in one wall of the Wyle 100,000 cu ft reverberation room and exposed to a broadband acoustic environment having an overall level of 145 db. The test panel was exposed to nine separate applications of the acoustic environment, each application consisting of 250 seconds duration. Upon completion of the ninth test run, the specimen was exposed to a simulated micrometeoroid impact near the panel center. One additional test run of 250 seconds duration was then performed to complete the overall simulation of 50 flight missions. The experimental results show that no significant fatigue damage occurred until the test specimen was exposed to a simulated micrometeoroid impact. The intermediate foam layer forming the core of the test specimen suffered considerable damage due to this impact, causing a marked variation in the dynamic characteristics of the overall test panel. During the final application of the acoustic environment, the strain and acceleration response spectra showed considerable variation from those spectra obtained prior to impact of the panel. Fatigue damage from acoustic loading however, was limited to partial de-bonding around the edges of the composite panel.

  16. Acoustic Analysis and Design of the E-STA MSA Simulator

    NASA Technical Reports Server (NTRS)

    Bittinger, Samantha A.

    2016-01-01

    The Orion European Service Module Structural Test Article (E-STA) Acoustic Test was completed in May 2016 to verify that the European Service Module (ESM) can withstand qualification acoustic environments. The test article required an aft closeout to simulate the Multi-Purpose Crew Vehicle (MPCV) Stage Adapter (MSA) cavity, however, the flight MSA design was too cost-prohibitive to build. NASA Glenn Research Center (GRC) had 6 months to design an MSA Simulator that could recreate the qualification prediction MSA cavity sound pressure level to within a reasonable tolerance. This paper summarizes the design and analysis process to arrive at a design for the MSA Simulator, and then compares its performance to the final prediction models created prior to test.

  17. Design and Integration of a Rotor Alone Nacelle for Acoustic Fan Testing

    NASA Technical Reports Server (NTRS)

    Shook, Tony D.; Hughes, Christoper E.; Thompson, William K.; Tavernelli, Paul F.; Cunningham, Cameron C.; Shah, Ashwin

    2001-01-01

    A brief summary of the design, integration and testing of a rotor alone nacelle (RAN) in NASA Glenn's 9'x 15' Low Speed Wind Tunnel (LSWT) is presented. The purpose of the RAN system was to provide an "acoustically clean" flow path within the nacelle to isolate that portion of the total engine system acoustic signature attributed to fan noise. The RAN design accomplished this by removing the stators that provided internal support to the nacelle. In its place, two external struts mounted to a two-axis positioning table located behind the tunnel wall provided the support. Nacelle-mounted lasers and a closed-loop control system provided the input to the table to maintain nacelle to fan concentricity as thermal and thrust loads displaced the strut-mounted fan. This unique design required extensive analysis and verification testing to ensure the safety of the fan model, propulsion simulator drive rig, and facility, along with experimental consistency of acoustic data obtained while using the RAN system. Initial testing was used to optimize the positioning system and resulted in concentricity errors of +/- 0.0031 in. in the horizontal direction and +0.0035/-0.0013 in, in the vertical direction. As a result of successful testing, the RAN system will be transitioned into other acoustic research programs at NASA Glenn Research Center.

  18. Designing and Implementing Teacher Selection Systems.

    ERIC Educational Resources Information Center

    Smith, Mary C.; Knab, Karen M.

    1996-01-01

    Tools from industrial psychology and business can be designed to help schools select the best teachers. Hiring systems should identify and screen for desirable attitudes, behaviors, and skills; validate the selection process to predict excellence; ensure legal compliance; and eliminate unproductive paperwork. A five-stage application, testing,…

  19. The Design and Implementation of INGRES.

    ERIC Educational Resources Information Center

    Stonebraker, Michael; And Others

    The currently operational version of the INGRES data base management system gives a relational view of data, supports two high level, non-procedural data sublanguages, and runs as a collection of user processes on top of a UNIX operating system. The authors stress the design decisions and tradeoffs in relation to (1) structuring the system into…

  20. Design and Implementation Issues in Longitudinal Research

    ERIC Educational Resources Information Center

    Ludlow, Larry H.; Pedulla, Joseph; Reagan, Emile Mitescu; Enterline, Sarah; Cannady, Mac; Chappe, Stephanie

    2011-01-01

    To meet demands for accountability, most schools and departments of education at institutions of higher education (IHEs) gather information on their current students and graduates. This paper describes issues to consider when designing a longitudinal data collection and management system, drawing on seven years' experience developing such a…

  1. Longwave hyperspectral imaging spectrometer design and implementation

    NASA Astrophysics Data System (ADS)

    Miller, Harold, Jr.; Yokoyama, Karen E.; Rasmussen, Kent; Engler, Tom; Rupert, Jim; Flegal, Bruce; Jarecke, Peter J.

    2003-12-01

    Northrop Grumman Space Technology (NGST), using internal funding, has designed, built and is testing a Long Wave Hyperspectral Imaging Spectrometer (LWHIS) that operates in the 8 to 12.5 micron band. This instrument was designed to be compatible with aircraft platforms so that flight data in this wavelength band can be used for phenomenological analysis. The instrument provides up to 256 contiguous spectral channels with 17 nm of dispersion per pixel (pixels are binned in normal operation to provide 128 spectral channels). The entrance aperture is 3.5 cm and feeds a F2/5 reflective triplet front end. The focal plane is a 256 x 256 array of 40 micron pixels which can be binned to form an 80 micron superpixel. With a fixed frame rate of 60 Hz, the instrument provides a ground sample distance of 1m at 1.1km altitude. This paper describes the physical characteristics of the design and presents the predicted performance based on NGST internal models. Design trades and test data will be presented. A more detailed look at the characterization and calibration of this instrument will be presented in a companion paper "Long Wave Hyperspectral Imaging Spectrometer -- System Characterization and Calibration."

  2. Longwave hyperspectral imaging spectrometer design and implementation

    NASA Astrophysics Data System (ADS)

    Miller, Harold, Jr.; Yokoyama, Karen E.; Rasmussen, Kent; Engler, Tom; Rupert, Jim; Flegal, Bruce; Jarecke, Peter J.

    2004-01-01

    Northrop Grumman Space Technology (NGST), using internal funding, has designed, built and is testing a Long Wave Hyperspectral Imaging Spectrometer (LWHIS) that operates in the 8 to 12.5 micron band. This instrument was designed to be compatible with aircraft platforms so that flight data in this wavelength band can be used for phenomenological analysis. The instrument provides up to 256 contiguous spectral channels with 17 nm of dispersion per pixel (pixels are binned in normal operation to provide 128 spectral channels). The entrance aperture is 3.5 cm and feeds a F2/5 reflective triplet front end. The focal plane is a 256 x 256 array of 40 micron pixels which can be binned to form an 80 micron superpixel. With a fixed frame rate of 60 Hz, the instrument provides a ground sample distance of 1m at 1.1km altitude. This paper describes the physical characteristics of the design and presents the predicted performance based on NGST internal models. Design trades and test data will be presented. A more detailed look at the characterization and calibration of this instrument will be presented in a companion paper "Long Wave Hyperspectral Imaging Spectrometer -- System Characterization and Calibration."

  3. Design and Implementation of Therapist Online Counseling

    ERIC Educational Resources Information Center

    Thomas, Aaron O.; Lee, Geoff; Ess, Brian

    2015-01-01

    The following paper describes the rationale for creating an online therapy program of cognitive behavioral therapy, or CBT, for students at the University of Florida who are struggling with stress and anxiety. In addition, the paper discusses the unique challenges of the instructional design process of creating psychoeducational materials through…

  4. Genetic Parallel Programming: design and implementation.

    PubMed

    Cheang, Sin Man; Leung, Kwong Sak; Lee, Kin Hong

    2006-01-01

    This paper presents a novel Genetic Parallel Programming (GPP) paradigm for evolving parallel programs running on a Multi-Arithmetic-Logic-Unit (Multi-ALU) Processor (MAP). The MAP is a Multiple Instruction-streams, Multiple Data-streams (MIMD), general-purpose register machine that can be implemented on modern Very Large-Scale Integrated Circuits (VLSIs) in order to evaluate genetic programs at high speed. For human programmers, writing parallel programs is more difficult than writing sequential programs. However, experimental results show that GPP evolves parallel programs with less computational effort than that of their sequential counterparts. It creates a new approach to evolving a feasible problem solution in parallel program form and then serializes it into a sequential program if required. The effectiveness and efficiency of GPP are investigated using a suite of 14 well-studied benchmark problems. Experimental results show that GPP speeds up evolution substantially.

  5. Introducing passive acoustic filter in acoustic based condition monitoring: Motor bike piston-bore fault identification

    NASA Astrophysics Data System (ADS)

    Jena, D. P.; Panigrahi, S. N.

    2016-03-01

    Requirement of designing a sophisticated digital band-pass filter in acoustic based condition monitoring has been eliminated by introducing a passive acoustic filter in the present work. So far, no one has attempted to explore the possibility of implementing passive acoustic filters in acoustic based condition monitoring as a pre-conditioner. In order to enhance the acoustic based condition monitoring, a passive acoustic band-pass filter has been designed and deployed. Towards achieving an efficient band-pass acoustic filter, a generalized design methodology has been proposed to design and optimize the desired acoustic filter using multiple filter components in series. An appropriate objective function has been identified for genetic algorithm (GA) based optimization technique with multiple design constraints. In addition, the sturdiness of the proposed method has been demonstrated in designing a band-pass filter by using an n-branch Quincke tube, a high pass filter and multiple Helmholtz resonators. The performance of the designed acoustic band-pass filter has been shown by investigating the piston-bore defect of a motor-bike using engine noise signature. On the introducing a passive acoustic filter in acoustic based condition monitoring reveals the enhancement in machine learning based fault identification practice significantly. This is also a first attempt of its own kind.

  6. Design and Implementation of an Intelligence Database.

    DTIC Science & Technology

    1984-12-01

    allocation are finalized in this phasE. .[ Parameters regarding data volume, application proce~ssng . frequency, and sequence of operations in aplication ...database. 1. The 2 ! 2f S M In designing SDM, many database aplications were analyzed in order to determine the structures that cc. i:r and recur in them...accoriine to the information in the WRC record. vr ,’w UFI ’ U II SELECT UVI1DUE PDAY 2 FROM A;REC, PIREC 3 mHERE .R&NGE ;8000 4 AND ALSS 3 OO00- S

  7. Theoretical design of acoustic treatment for cabin noise control of a light aircraft

    NASA Technical Reports Server (NTRS)

    Vaicaitis, R.; Mixson, J. S.

    1984-01-01

    An analytical procedure has been used to design an acoustic treatment for cabin noise control of a light aircraft. Using this approach acoustic add-on treatments capable of reducing the average noise levels in the cabin by about 17 dB from the untreated condition are developed. The added weight of the noise control package is about 2 percent of the total gross take-off weight of the aircraft. The analytical model uses modal solutions wherein the structural modes of the sidewall and the acoustic modes of the receiving space are accounted for. The additional noise losses due to add-on treatments are calculated by the impedance transfer method. The input noise spectral levels are selected utilizing experimental flight data. The add-on treatments considered for cabin noise control include aluminum honeycomb panels, constrained layer damping tape, porous acoustic materials, noise barriers and limp trim panels. To reduce the noise transmitted through the double wall aircraft windows to acceptable levels, changes in the design of the aircraft window are recommended.

  8. Acoustical features of two Mayan monuments at Chichen Itza: Accident or design?

    NASA Astrophysics Data System (ADS)

    Lubman, David

    2002-11-01

    Chichen Itza dominated the early postclassic Maya world, ca. 900-1200 C.E. Two of its colossal monuments, the Great Ball Court and the temple of Kukulkan, reflect the sophisticated, hybrid culture of a Mexicanized Maya civilization. The architecture seems intended for ceremony and ritual drama. Deducing ritual practices will advance the understanding of a lost civilization, but what took place there is largely unknown. Perhaps acoustical science can add value. Unexpected and unusual acoustical features can be interpreted as intriguing clues or irrelevant accidents. Acoustical advocates believe that, when combined with an understanding of the Maya worldview, acoustical features can provide unique insights into how the Maya designed and used theater spaces. At Chichen Itza's monuments, sound reinforcement features improve rulers and priests ability to address large crowds, and Ball Court whispering galleries permit speech communication over unexpectedly large distances. Handclaps at Kukulkan stimulate chirps that mimic a revered bird (''Kukul''), thus reinforcing cultic beliefs. A ball striking playing field wall stimulates flutter echoes at the Great Ball Court; their strength and duration arguably had dramatic, mythic, and practical significance. Interpretations of the possible mythic, magic, and political significance of sound phenomena at these Maya monuments strongly suggests intentional design.

  9. Experimental validation of systematically designed acoustic hyperbolic meta material slab exhibiting negative refraction

    NASA Astrophysics Data System (ADS)

    Christiansen, Rasmus E.; Sigmund, Ole

    2016-09-01

    This Letter reports on the experimental validation of a two-dimensional acoustic hyperbolic metamaterial slab optimized to exhibit negative refractive behavior. The slab was designed using a topology optimization based systematic design method allowing for tailoring the refractive behavior. The experimental results confirm the predicted refractive capability as well as the predicted transmission at an interface. The study simultaneously provides an estimate of the attenuation inside the slab stemming from the boundary layer effects—insight which can be utilized in the further design of the metamaterial slabs. The capability of tailoring the refractive behavior opens possibilities for different applications. For instance, a slab exhibiting zero refraction across a wide angular range is capable of funneling acoustic energy through it, while a material exhibiting the negative refractive behavior across a wide angular range provides lensing and collimating capabilities.

  10. Two stage low noise advanced technology fan. 1: Aerodynamic, structural, and acoustic design

    NASA Technical Reports Server (NTRS)

    Messenger, H. E.; Ruschak, J. T.; Sofrin, T. G.

    1974-01-01

    A two-stage fan was designed to reduce noise 20 db below current requirements. The first-stage rotor has a design tip speed of 365.8 m/sec and a hub/tip ratio of 0.4. The fan was designed to deliver a pressure ratio of 1.9 with an adiabatic efficiency of 85.3 percent at a specific inlet corrected flow of 209.2kg/sec/sq m. Noise reduction devices include acoustically treated casing walls, a flowpath exit acoustic splitter, a translating centerbody sonic inlet device, widely spaced blade rows, and the proper ratio of blades and vanes. Multiple-circular-arc rotor airfoils, resettable stators, split outer casings, and capability to go to close blade-row spacing are also included.

  11. Large interactive database: design and implementation

    NASA Astrophysics Data System (ADS)

    Peralta-Fabi, Ricardo; Peralta, Alejandro; Vicente, Esau; Prado, Jorge M.; Diaz, C.

    1992-04-01

    A database system is being integrated in order to store and interactively retrieve information from a several hundred Gbytes optical memory. The low cost, high reliability requirements for the development and maintenance phase of the system suggested a modular design based on a network server, optical server, and some 40 (80386 based) viewing consoles with touch screens, but no keyboard or other controls since they are exposed to use by the general public. Optical disks store graphics, video, stills, text, animation, and audio which are accessed through hypertext and interactive graphics while a somewhat simple expert analyzes and records data on various aspects of the user, such as general interests, common questions, sociological-educational, background, etc. This information is in turn used to adapt several parameters of information display: rate of flow, language style, number and type of control buttons, degree of detail, and others. The large quantity of video, still images, and different graphics formats, has made it necessary to optimize the information contained via reduction of colors/resolution, compression techniques, and recursive use of a basic set of displays and video segments. The paper presents the design in some detail, with general examples of system capabilities, growth, and applications.

  12. Design and implementation of land reservation system

    NASA Astrophysics Data System (ADS)

    Gao, Yurong; Gao, Qingqiang

    2009-10-01

    Land reservation is defined as a land management policy for insuring the government to control primary land market. It requires the government to obtain the land first, according to plan, by purchase, confiscation and exchanging, and then exploit and consolidate the land for reservation. Underlying this policy, it is possible for the government to satisfy and manipulate the needs of land for urban development. The author designs and develops "Land Reservation System for Eastern Lake Development District" (LRSELDD), which deals with the realistic land requirement problems in Wuhan Eastern Lake Development Districts. The LRSELDD utilizes modern technologies and solutions of computer science and GIS to process multiple source data related with land. Based on experiments on the system, this paper will first analyze workflow land reservation system and design the system structure based on its principles, then illustrate the approach of organization and management of spatial data, describe the system functions according to the characteristics of land reservation and consolidation finally. The system is running to serve for current work in Eastern Lake Development Districts. It is able to scientifically manage both current and planning land information, as well as the information about land supplying. We use the LRSELDD in our routine work, and with such information, decisions on land confiscation and allocation will be made wisely and scientifically.

  13. Real-time monitoring of focused ultrasound blood-brain barrier opening via subharmonic acoustic emission detection: implementation of confocal dual-frequency piezoelectric transducers

    NASA Astrophysics Data System (ADS)

    Tsai, Chih-Hung; Zhang, Jia-Wei; Liao, Yi-Yi; Liu, Hao-Li

    2016-04-01

    Burst-tone focused ultrasound exposure in the presence of microbubbles has been demonstrated to be effective at inducing temporal and local opening of the blood-brain barrier (BBB), which promises significant clinical potential to deliver therapeutic molecules into the central nervous system (CNS). Traditional contrast-enhanced imaging confirmation after focused ultrasound (FUS) exposure serves as a post-operative indicator of the effectiveness of FUS-BBB opening, however, an indicator that can concurrently report the BBB status and BBB-opening effectiveness is required to provide effective feedback to implement this treatment clinically. In this study, we demonstrate the use of subharmonic acoustic emission detection with implementation on a confocal dual-frequency piezoelectric ceramic structure to perform real-time monitoring of FUS-BBB opening. A confocal dual-frequency (0.55 MHz/1.1 MHz) focused ultrasound transducer was designed. The 1.1 MHz spherically-curved ceramic was employed to deliver FUS exposure to induce BBB-opening, whereas the outer-ring 0.55 MHz ceramic was employed to detect the subharmonic acoustic emissions originating from the target position. In stage-1 experiments, we employed spectral analysis and performed an energy spectrum density (ESD) calculation. An optimized 0.55 MHz ESD level change was shown to effectively discriminate the occurrence of BBB-opening. Wideband acoustic emissions received from 0.55 MHz ceramics were also analyzed to evaluate its correlations with erythrocyte extravasations. In stage-2 real-time monitoring experiments, we applied the predetermined ESD change as a detection threshold in PC-controlled algorithm to predict the FUS exposure intra-operatively. In stage-1 experiment, we showed that subharmonic ESD presents distinguishable dynamics between intact BBB and opened BBB, and therefore a threshold ESD change level (5.5 dB) can be identified for BBB-opening prediction. Using this ESD change threshold detection as a

  14. Real-time monitoring of focused ultrasound blood-brain barrier opening via subharmonic acoustic emission detection: implementation of confocal dual-frequency piezoelectric transducers.

    PubMed

    Tsai, Chih-Hung; Zhang, Jia-Wei; Liao, Yi-Yi; Liu, Hao-Li

    2016-04-07

    Burst-tone focused ultrasound exposure in the presence of microbubbles has been demonstrated to be effective at inducing temporal and local opening of the blood-brain barrier (BBB), which promises significant clinical potential to deliver therapeutic molecules into the central nervous system (CNS). Traditional contrast-enhanced imaging confirmation after focused ultrasound (FUS) exposure serves as a post-operative indicator of the effectiveness of FUS-BBB opening, however, an indicator that can concurrently report the BBB status and BBB-opening effectiveness is required to provide effective feedback to implement this treatment clinically. In this study, we demonstrate the use of subharmonic acoustic emission detection with implementation on a confocal dual-frequency piezoelectric ceramic structure to perform real-time monitoring of FUS-BBB opening. A confocal dual-frequency (0.55 MHz/1.1 MHz) focused ultrasound transducer was designed. The 1.1 MHz spherically-curved ceramic was employed to deliver FUS exposure to induce BBB-opening, whereas the outer-ring 0.55 MHz ceramic was employed to detect the subharmonic acoustic emissions originating from the target position. In stage-1 experiments, we employed spectral analysis and performed an energy spectrum density (ESD) calculation. An optimized 0.55 MHz ESD level change was shown to effectively discriminate the occurrence of BBB-opening. Wideband acoustic emissions received from 0.55 MHz ceramics were also analyzed to evaluate its correlations with erythrocyte extravasations. In stage-2 real-time monitoring experiments, we applied the predetermined ESD change as a detection threshold in PC-controlled algorithm to predict the FUS exposure intra-operatively. In stage-1 experiment, we showed that subharmonic ESD presents distinguishable dynamics between intact BBB and opened BBB, and therefore a threshold ESD change level (5.5 dB) can be identified for BBB-opening prediction. Using this ESD change threshold detection as a

  15. Acoustic Treatment Design Scaling Methods. Volume 1; Overview, Results, and Recommendations

    NASA Technical Reports Server (NTRS)

    Kraft, R. E.; Yu, J.

    1999-01-01

    Scale model fan rigs that simulate new generation ultra-high-bypass engines at about 1/5-scale are achieving increased importance as development vehicles for the design of low-noise aircraft engines. Testing at small scale allows the tests to be performed in existing anechoic wind tunnels, which provides an accurate simulation of the important effects of aircraft forward motion on the noise generation. The ability to design, build, and test miniaturized acoustic treatment panels on scale model fan rigs representative of the fullscale engine provides not only a cost-savings, but an opportunity to optimize the treatment by allowing tests of different designs. The primary objective of this study was to develop methods that will allow scale model fan rigs to be successfully used as acoustic treatment design tools. The study focuses on finding methods to extend the upper limit of the frequency range of impedance prediction models and acoustic impedance measurement methods for subscale treatment liner designs, and confirm the predictions by correlation with measured data. This phase of the program had as a goal doubling the upper limit of impedance measurement from 6 kHz to 12 kHz. The program utilizes combined analytical and experimental methods to achieve the objectives.

  16. A Framework for Promoting Learning in IS Design and Implementation

    ERIC Educational Resources Information Center

    Small, Adrian; Sice, Petia; Venus, Tony

    2008-01-01

    Purpose: The purpose of this paper is to set out an argument for a way to design, implement and manage IS with an emphasis on first, the learning that can be created through undertaking the approach, and second, the learning that may be created through using the IS that was implemented. The paper proposes joining two areas of research namely,…

  17. A Framework for Promoting Learning in IS Design and Implementation

    ERIC Educational Resources Information Center

    Small, Adrian; Sice, Petia; Venus, Tony

    2008-01-01

    Purpose: The purpose of this paper is to set out an argument for a way to design, implement and manage IS with an emphasis on first, the learning that can be created through undertaking the approach, and second, the learning that may be created through using the IS that was implemented. The paper proposes joining two areas of research namely,…

  18. Learning from the Implementers in a Design Experiment

    ERIC Educational Resources Information Center

    Toh, Tin Lam; Dindyal, Jaguthsing; Tay, Eng Guan

    2013-01-01

    In a design experiment, the feedback from the teacher-implementer is crucial to the success of the innovation simply because the teacher is finally the one that brings the innovation to life in front of the students. We describe in this paper the feedback made by the teacher-implementer after teaching one cycle of the problem solving module in a…

  19. On the implementation of an automated acoustic output optimization algorithm for subharmonic aided pressure estimation

    PubMed Central

    Dave, J. K.; Halldorsdottir, V. G.; Eisenbrey, J. R.; Merton, D. A.; Liu, J. B.; Machado, P.; Zhao, H.; Park, S.; Dianis, S.; Chalek, C. L.; Thomenius, K. E.; Brown, D. B.; Forsberg, F.

    2013-01-01

    Incident acoustic output (IAO) dependent subharmonic signal amplitudes from ultrasound contrast agents can be categorized into occurrence, growth or saturation stages. Subharmonic aided pressure estimation (SHAPE) is a technique that utilizes growth stage subharmonic signal amplitudes for hydrostatic pressure estimation. In this study, we developed an automated IAO optimization algorithm to identify the IAO level eliciting growth stage subharmonic signals and also studied the effect of pulse length on SHAPE. This approach may help eliminate the problems of acquiring and analyzing the data offline at all IAO levels as was done in previous studies and thus, pave the way for real-time clinical pressure monitoring applications. The IAO optimization algorithm was implemented on a Logiq 9 (GE Healthcare, Milwaukee, WI) scanner interfaced with a computer. The optimization algorithm stepped the ultrasound scanner from 0 to 100 % IAO. A logistic equation fitting function was applied with the criterion of minimum least squared error between the fitted subharmonic amplitudes and the measured subharmonic amplitudes as a function of the IAO levels and the optimum IAO level was chosen corresponding to the inflection point calculated from the fitted data. The efficacy of the optimum IAO level was investigated for in vivo SHAPE to monitor portal vein (PV) pressures in 5 canines and was compared with the performance of IAO levels, below and above the optimum IAO level, for 4, 8 and 16 transmit cycles. The canines received a continuous infusion of Sonazoid microbubbles (1.5 μl/kg/min; GE Healthcare, Oslo, Norway). PV pressures were obtained using a surgically introduced pressure catheter (Millar Instruments, Inc., Houston, TX) and were recorded before and after increasing PV pressures. The experiments showed that optimum IAO levels for SHAPE in the canines ranged from 6 to 40 %. The best correlation between changes in PV pressures and in subharmonic amplitudes (r = -0.76; p = 0

  20. Design and Implementation of Volitional Control Support in Mathematics Courses

    ERIC Educational Resources Information Center

    Kim, ChanMin; Bennekin, Kimberly N.

    2013-01-01

    We designed support for volitional control with four stages for "goal initiation" ("Want it"), "goal formation" ("Plan for it"), "action control" ("Do it"), and "emotion control" ("Finish it") based on theories and models of volition. We implemented the support in…

  1. Lunar Fission Surface Power System Design and Implementation Concept

    SciTech Connect

    Elliott, John O.; Reh, Kim; MacPherson, Duncan

    2006-01-20

    At the request of NASA's Exploration Systems Mission Directorate (ESMD) in May of 2005, a team was assembled within the Prometheus Project to investigate lunar surface nuclear power architectures and provide design and implementation concept inputs to NASA's Exploration Systems Architecture 60-day Study (ESAS) team. System engineering tasks were undertaken to investigate the design and implementation of a Fission Surface Power System (FSPS) that could be launched as early as 2019 as part of a possible initial Lunar Base architecture. As a result of this activity, the Prometheus team evaluated a number of design and implementation concepts as well as a significant number of trades associated with lunar surface power, all culminating in a recommended approach. This paper presents the results of that study, including a recommended FSPS design and implementation concept.

  2. Design and Implementation of Volitional Control Support in Mathematics Courses

    ERIC Educational Resources Information Center

    Kim, ChanMin; Bennekin, Kimberly N.

    2013-01-01

    We designed support for volitional control with four stages for "goal initiation" ("Want it"), "goal formation" ("Plan for it"), "action control" ("Do it"), and "emotion control" ("Finish it") based on theories and models of volition. We implemented the support in…

  3. Lunar Fission Surface Power System Design and Implementation Concept

    NASA Astrophysics Data System (ADS)

    Elliott, John O.; Reh, Kim; MacPherson, Duncan

    2006-01-01

    At the request of NASA's Exploration Systems Mission Directorate (ESMD) in May of 2005, a team was assembled within the Prometheus Project to investigate lunar surface nuclear power architectures and provide design and implementation concept inputs to NASA's Exploration Systems Architecture 60-day Study (ESAS) team. System engineering tasks were undertaken to investigate the design and implementation of a Fission Surface Power System (FSPS) that could be launched as early as 2019 as part of a possible initial Lunar Base architecture. As a result of this activity, the Prometheus team evaluated a number of design and implementation concepts as well as a significant number of trades associated with lunar surface power, all culminating in a recommended approach. This paper presents the results of that study, including a recommended FSPS design and implementation concept.

  4. Lunar fission surface power system design and implementation concept

    NASA Technical Reports Server (NTRS)

    Elliott, John O.; Reh, Kim; MacPherson, Duncan

    2006-01-01

    The request of NASA's Exploration Systems Mission Directorate (ESMD) in May of 2005, a team was assembled within the Prometheus Project to investigate lunar surface nuclear power architectures and provide design and implementation concept inputs to NASA's Exploration Systems Architecture 60-day Study (ESAS) team. System engineering tasks were undertaken to investigate the design and implementation of a Fission Surface Power System (FSPS) that could be launched as early as 2019 as part of a possible initial Lunar Base architecture. As a result of this activity, the Prometheus team evaluated a number of design and implementation concepts as well as a significant number of trades associated with lunar surface power, all culminating in a recommended approach. This paper presents the results of that study, including a recommended FSPS design and implementation concept.

  5. The Agway Management Development Program: Design and Implementation

    ERIC Educational Resources Information Center

    Barth, Anthony L.; Engfer, Robert T.

    1977-01-01

    Focus is on the Agway (a farm supply and food marketing cooperative) retail store system in this informational case history and how-to approach for designing, developing, and implementing a formal corporate management program. (Editor/TA)

  6. Lunar fission surface power system design and implementation concept

    NASA Technical Reports Server (NTRS)

    Elliott, John O.; Reh, Kim; MacPherson, Duncan

    2006-01-01

    The request of NASA's Exploration Systems Mission Directorate (ESMD) in May of 2005, a team was assembled within the Prometheus Project to investigate lunar surface nuclear power architectures and provide design and implementation concept inputs to NASA's Exploration Systems Architecture 60-day Study (ESAS) team. System engineering tasks were undertaken to investigate the design and implementation of a Fission Surface Power System (FSPS) that could be launched as early as 2019 as part of a possible initial Lunar Base architecture. As a result of this activity, the Prometheus team evaluated a number of design and implementation concepts as well as a significant number of trades associated with lunar surface power, all culminating in a recommended approach. This paper presents the results of that study, including a recommended FSPS design and implementation concept.

  7. Sulfur Dioxide Designations and Implementation Modeling Guidance and Assistance

    EPA Pesticide Factsheets

    The information and links here are intended to help inform and assist Regional, State, Local, and Tribal modelers with respect to designation and implementation modeling for the 1-hour SO2 NAAQS that became effective on June 2, 2010.

  8. Design and implementation of Kyongju VR theatre

    NASA Astrophysics Data System (ADS)

    Park, ChangHoon; Kim, Ig-Jae; Ahn, Sang Chul; Ko, HeeDong; Kwon, Yong-Moo; Kim, Hyoung-Gon

    2003-04-01

    Recently we have built the largest Virtual Reality (VR) theatre in the world of the Kyongju World Culture EXPO 2000. Unlike single user VR systems, the VR theatre is characterized by a single shared screen and controlled by several hundreds of people in the audience. The large computer-generated stereo images displayed by the huge cylindrical screen provide the feeling of immersion into 3D virtual environment that is augmented by the physical theatre space. In addition to the visual immersion, the theatre provides 3D audio, vibration and olfactory display as well as keypads for each and everyone in the audience in their seats interactively control the virtual environment. This paper introduces the issues raised and addressed during the design of making the VR theatre, production process and presentation techniques using the versatile display and interaction capabilities of the theatre.

  9. Design and implementation air quality monitoring robot

    NASA Astrophysics Data System (ADS)

    Chen, Yuanhua; Li, Jie; Qi, Chunxue

    2017-01-01

    Robot applied in environmental protection can break through the limitations in working environment, scope and mode of the existing environmental monitoring and pollution abatement equipments, which undertake the innovation and improvement in the basin, atmosphere, emergency and pollution treatment facilities. Actually, the relevant technology is backward with limited research and investment. Though the device companies have achieved some results in the study on the water quality monitoring, pipeline monitoring and sewage disposal, this technological progress on the whole is still much slow, and the mature product has not been formed. As a result, the market urges a demand of a new type of device which is more suitable for environmental protection on the basis of robot successfully applied in other fields. This paper designs and realizes a tracked mobile robot of air quality monitoring, which can be used to monitor air quality for the pollution accident in industrial parks and regular management.

  10. Education in acoustics in Argentina

    NASA Astrophysics Data System (ADS)

    Miyara, Federico

    2002-11-01

    Over the last decades, education in acoustics (EA) in Argentina has experienced ups and downs due to economic and political issues interfering with long term projects. Unlike other countries, like Chile, where EA has reached maturity in spite of the acoustical industry having shown little development, Argentina has several well-established manufacturers of acoustic materials and equipment but no specific career with a major in acoustics. At the university level, acoustics is taught as a complementary--often elective--course for careers such as architecture, communication engineering, or music. In spite of this there are several research centers with programs covering environmental and community noise, effects of noise on man, acoustic signal processing, musical acoustics and acoustic emission, and several national and international meetings are held each year in which results are communicated and discussed. Several books on a variety of topics such as sound system, architectural acoustics, and noise control have been published as well. Another chapter in EA is technical and vocational education, ranging between secondary and postsecondary levels, with technical training on sound system operation or design. Over the last years there have been several attempts to implement master degrees in acoustics or audio engineering, with little or no success.

  11. Design and Implementation of a Multimedia DBMS: Modification and Deletion

    DTIC Science & Technology

    1991-09-01

    process data are discussed. This thesis concentrates on the design and implementation operations for deletion and modification of formatted and...of this thesis , only the create, insert, and retrieve options were available. The system, as it is now, performs media data processing by means of...AD-A246 080 NAVAL POSTGRADUATE SCHOOL Monterey, California DTIC ELECTE FEB 20 199211 .S D THESIS DESIGN AND IMPLEMENTATION OF A MULTIMEDIA DBMS

  12. INCEPTION, DESIGN AND IMPLEMENTATION OF A MANAGEMENT INFORMATION SYSTEM.

    DTIC Science & Technology

    The purpose of this paper is to develop a uniform systematic approach to the design and implementation of a management information system . In recent...directed towards the design of a management information system . To this end - the creaction of such a document - is this paper dedicated. The...inception to successful implementation of a management information system . Many factors must be considered while applying this procedure, e.g., complexity

  13. Design and implementation of an audio indicator

    NASA Astrophysics Data System (ADS)

    Zheng, Shiyong; Li, Zhao; Li, Biqing

    2017-04-01

    This page proposed an audio indicator which designed by using C9014, LED by operational amplifier level indicator, the decimal count/distributor of CD4017. The experimental can control audibly neon and holiday lights through the signal. Input audio signal after C9014 composed of operational amplifier for power amplifier, the adjust potentiometer extraction amplification signal input voltage CD4017 distributors make its drive to count, then connect the LED display running situation of the circuit. This simple audio indicator just use only U1 and can produce two colors LED with the audio signal tandem come pursuit of the running effect, from LED display the running of the situation takes can understand the general audio signal. The variation in the audio and the frequency of the signal and the corresponding level size. In this light can achieve jump to change, slowly, atlas, lighting four forms, used in home, hotel, discos, theater, advertising and other fields, and a wide range of USES, rU1h life in a modern society.

  14. Designing and implementing a balanced scorecard: lessons learned in nonprofit implementation.

    PubMed

    Gumbus, Andra; Wilson, Tom

    2004-01-01

    The balanced scorecard has been referred to as the management innovation of the century, and extensive articles have been written using case studies of organizations that use this performance measurement system. This article addresses the key issues of design and implementation with a step-by-step guide to how to design a balanced scorecard and lessons to avoid implementation problems in government and nonprofit settings.

  15. HETDEX tracker control system design and implementation

    NASA Astrophysics Data System (ADS)

    Beno, Joseph H.; Hayes, Richard; Leck, Ron; Penney, Charles; Soukup, Ian

    2012-09-01

    To enable the Hobby-Eberly Telescope Dark Energy Experiment, The University of Texas at Austin Center for Electromechanics and McDonald Observatory developed a precision tracker and control system - an 18,000 kg robot to position a 3,100 kg payload within 10 microns of a desired dynamic track. Performance requirements to meet science needs and safety requirements that emerged from detailed Failure Modes and Effects Analysis resulted in a system of 13 precision controlled actuators and 100 additional analog and digital devices (primarily sensors and safety limit switches). Due to this complexity, demanding accuracy requirements, and stringent safety requirements, two independent control systems were developed. First, a versatile and easily configurable centralized control system that links with modeling and simulation tools during the hardware and software design process was deemed essential for normal operation including motion control. A second, parallel, control system, the Hardware Fault Controller (HFC) provides independent monitoring and fault control through a dedicated microcontroller to force a safe, controlled shutdown of the entire system in the event a fault is detected. Motion controls were developed in a Matlab-Simulink simulation environment, and coupled with dSPACE controller hardware. The dSPACE real-time operating system collects sensor information; motor commands are transmitted over a PROFIBUS network to servo amplifiers and drive motor status is received over the same network. To interface the dSPACE controller directly to absolute Heidenhain sensors with EnDat 2.2 protocol, a custom communication board was developed. This paper covers details of operational control software, the HFC, algorithms, tuning, debugging, testing, and lessons learned.

  16. Rotating rake design for unique measurement of fan-generated spinning acoustic modes

    NASA Technical Reports Server (NTRS)

    Konno, Kevin E.; Hausmann, Clifford R.

    1993-01-01

    In light of the current emphasis on noise reduction in subsonic aircraft design, NASA has been actively studying the source of and propagation of noise generated by subsonic fan engines. NASA/LeRC has developed and tested a unique method of accurately measuring these spinning acoustic modes generated by an experimental fan. This mode measuring method is based on the use of a rotating microphone rake. Testing was conducted in the 9 x 15 Low-speed Wind Tunnel. The rotating rake was tested with the Advanced Ducted Propeller (ADP) model. This memorandum discusses the design and performance of the motor/drive system for the fan-synchronized rotating acoustic rake. This novel motor/drive design approach is now being adapted for additional acoustic mode studies in new test rigs as baseline data for the future design of active noise control for subsonic fan engines. Included in this memorandum are the research requirements, motor/drive specifications, test performance results, and a description of the controls and software involved.

  17. Design and implementation of scalable tape archiver

    NASA Technical Reports Server (NTRS)

    Nemoto, Toshihiro; Kitsuregawa, Masaru; Takagi, Mikio

    1996-01-01

    In order to reduce costs, computer manufacturers try to use commodity parts as much as possible. Mainframes using proprietary processors are being replaced by high performance RISC microprocessor-based workstations, which are further being replaced by the commodity microprocessor used in personal computers. Highly reliable disks for mainframes are also being replaced by disk arrays, which are complexes of disk drives. In this paper we try to clarify the feasibility of a large scale tertiary storage system composed of 8-mm tape archivers utilizing robotics. In the near future, the 8-mm tape archiver will be widely used and become a commodity part, since recent rapid growth of multimedia applications requires much larger storage than disk drives can provide. We designed a scalable tape archiver which connects as many 8-mm tape archivers (element archivers) as possible. In the scalable archiver, robotics can exchange a cassette tape between two adjacent element archivers mechanically. Thus, we can build a large scalable archiver inexpensively. In addition, a sophisticated migration mechanism distributes frequently accessed tapes (hot tapes) evenly among all of the element archivers, which improves the throughput considerably. Even with the failures of some tape drives, the system dynamically redistributes hot tapes to the other element archivers which have live tape drives. Several kinds of specially tailored huge archivers are on the market, however, the 8-mm tape scalable archiver could replace them. To maintain high performance in spite of high access locality when a large number of archivers are attached to the scalable archiver, it is necessary to scatter frequently accessed cassettes among the element archivers and to use the tape drives efficiently. For this purpose, we introduce two cassette migration algorithms, foreground migration and background migration. Background migration transfers cassettes between element archivers to redistribute frequently accessed

  18. Acoustic resonators for noise control in enclosures: Modelling, design and optimization

    NASA Astrophysics Data System (ADS)

    Yu, Ganghua

    This work systematically investigates the acoustic interaction between an enclosure and resonators, and establishes systematic design tools based upon the interaction theory to optimize the physical characteristics and the locations of resonators. A general theoretical model is first established to predict the acoustic performance of multiple resonators placed in an acoustic enclosure of arbitrary shape. Analytical solutions for the sound pressure inside the enclosure are obtained when a single resonator is installed, which provide insight into the physics of the acoustic interaction between the enclosure and resonators. The theoretical model is experimentally validated, showing the effectiveness and reliability of the theoretical model. Using the validated acoustic interaction model and the analytical solutions, the internal resistance of a resonator is optimized to improve its performance in a frequency band enclosing acoustic resonances. An energy reduction index is defined to conduct the optimization. The dual process of the energy dissipation and radiation of the resonator is quantified. Optimal resistance and its physical effect on the enclosure-resonator interaction are numerically evaluated and categorized in terms of frequency bandwidths. Predictions on the resonator performance are confirmed by experiments. Comparisons with existing models based on different optimization criteria are also performed. It is shown that the proposed model serves as an effective design tool to determine the optimal internal-resistance of the resonator in a chosen frequency band. Due to the multi-modal coupling, the resonator performance is also affected by its location besides its physical characteristics. When multiple resonators are used, the mutual interaction among resonators leads to the requirement of a systematic optimization tool to determine their locations. In the present work, different optimization methodologies are explored. These include a sequential design

  19. A Power Analysis and Recommended Study Design to Directly Detect Population Level Consequences of Acoustic Disturbance

    DTIC Science & Technology

    2015-09-30

    quantify potential human impacts on the health of beaked whale populations ?” (i.e, what is a recommended study design for doing this?). Quantifying...effectiveness of Navy funds for monitoring population health of beaked whales and human impacts thereon. RELATED PROJECTS Moretti, David...Detect Population -Level Consequences of Acoustic Disturbance Jeffrey Moore NOAA Southwest Fisheries Science Center 8901 La Jolla Shores Drive

  20. Acoustic characteristics and the design of two-layered soundproof plates

    NASA Astrophysics Data System (ADS)

    Chonan, S.; Kugo, Y.

    1989-03-01

    This paper presents exact solutions for the coincidence frequency and the sound transmission loss of two-layered infinite plates excited by a plane acoustic wave. The problem is studied based on the two-dimensional elasticity theory wih the use of the Lame potential functions . A simple design method for a soundproof sheet with high transmission loss and high coincidence frequency is presented and illustrated with some examples. The results obtained are also compared with those from the thick plate theory.

  1. Teacher Educators' Design and Implementation of Group Learning Activities

    ERIC Educational Resources Information Center

    De Hei, Miranda S. A.; Sjoer, Ellen; Admiraal, Wilfried; Strijbos, Jan-Willem

    2016-01-01

    The aim of this study was to describe how teacher educators design and implement group learning activities (GLAs). We used the Group Learning Activities Instructional Design (GLAID) framework to analyse their descriptions. The GLAID framework includes eight components: (1) interaction, (2) learning objectives and outcomes, (3) assessment, (4) task…

  2. Teacher Educators' Design and Implementation of Group Learning Activities

    ERIC Educational Resources Information Center

    De Hei, Miranda S. A.; Sjoer, Ellen; Admiraal, Wilfried; Strijbos, Jan-Willem

    2016-01-01

    The aim of this study was to describe how teacher educators design and implement group learning activities (GLAs). We used the Group Learning Activities Instructional Design (GLAID) framework to analyse their descriptions. The GLAID framework includes eight components: (1) interaction, (2) learning objectives and outcomes, (3) assessment, (4) task…

  3. Spectrally Efficient Underwater Acoustic Communications: Channel Characterization and Design Aspects for OFDM

    NASA Astrophysics Data System (ADS)

    Radosevic, Andreja

    In this dissertation, we consider design aspects of spectrally efficient underwater acoustic (UWA) communications. In particular, we first focus on statistical characterization and capacity evaluation of shallow water acoustic communications channels. Wideband single-carrier and multi-carrier probe signals are employed during the Kauai Acoustic Communications MURI 2008 (KAM08) and 2011 (KAM11) experiments, to measure the time-varying channel response, and to estimate its statistical properties and capacity that play an important role in the design of spectrally efficient communication systems. Besides the capacity analysis for unconstrained inputs, we determine new bounds on the achievable information rate for discrete-time Gaussian channels with inter-symbol interference and independent and uniformly distributed channel input symbols drawn from finite-order modulation alphabets. Specifically, we derived new bounds on the achievable rates for sparse channels with long memory. Furthermore, we explore design aspects of adaptive modulation based on orthogonal frequency division multiplexing (OFDM) for UWA communications, and study its performance using real-time at-sea experiments. Lastly, we investigate a channel estimation (CE) method for improving the spectral efficiency of UWA communications. Specifically, we determine the performance of a selective decision directed (DD) CE method for UWA OFDM-based communications.

  4. Optimal Design and Purposeful Sampling: Complementary Methodologies for Implementation Research.

    PubMed

    Duan, Naihua; Bhaumik, Dulal K; Palinkas, Lawrence A; Hoagwood, Kimberly

    2015-09-01

    Optimal design has been an under-utilized methodology. However, it has significant real-world applications, particularly in mixed methods implementation research. We review the concept and demonstrate how it can be used to assess the sensitivity of design decisions and balance competing needs. For observational studies, this methodology enables selection of the most informative study units. For experimental studies, it entails selecting and assigning study units to intervention conditions in the most informative manner. We blend optimal design methods with purposeful sampling to show how these two concepts balance competing needs when there are multiple study aims, a common situation in implementation research.

  5. Optimal Design and Purposeful Sampling: Complementary Methodologies for Implementation Research

    PubMed Central

    Duan, Naihua; Bhaumik, Dulal K.; Palinkas, Lawrence A.; Hoagwood, Kimberly

    2015-01-01

    Optimal design has been an under-utilized methodology. However, it has significant real-world applications, particularly in mixed methods implementation research. We review the concept and demonstrate how it can be used to assess the sensitivity of design decisions and balance competing needs. For observational studies, this methodology enables selection of the most informative study units. For experimental studies, it entails selecting and assigning study units to intervention conditions in the most informative manner. We blend optimal design methods with purposeful sampling to show how these two concepts balance competing needs when there are multiple study aims, a common situation in implementation research. PMID:25491200

  6. Design technologies for DSP algorithm implementation on heterogeneous architectures

    NASA Astrophysics Data System (ADS)

    McAllister, John; Yi, Ying; Woods, Roger F.; Walke, Richard L.; Reilly, Darren; Colgan, Kevin

    2003-12-01

    Computationally intensive digital signal processing (DSP) systems sometimes have real time requirements beyond that which programmable processor platform solutions, consisting of RISC and DSP processors, can achieve. The addition of Field Programmable Gate Array (FPGA) components to these platforms provides a configurable hardware resource where increased parallelism levels allow very large computational rates. Techniques to implement circuit architectures from signal flow graph (SFG) algorithm expression can produce highly efficient processor implementations. Applying folding transformations produces implementations where hardware resource usage is reduced at the possible expense of throughput. In this paper a new development methodology is presented which analyses the SFG algorithm to suggest appropriate folding techniques. By characterizing different folding techniques, a template circuit architecture can be created early in the design process which does not alter throughout the remainder of the implementation process. Retiming techniques applied to the algorithm SFG produces the properly timed implementation from the template. By applying this methodology, architectural exploration can be quickly and efficiently performed to generate a set of implementations (an 'implementation space") to best meet the constraints of the system. When applied to a Normalised Lattice Filter design example, the results demonstrate high savings on FPGA resource usage, with little reduction in real time performance, demonstrating the implementation advantage of employing this methodology.

  7. Wind-tunnel acoustic results of two rotor models with several tip designs

    NASA Technical Reports Server (NTRS)

    Martin, R. M.; Connor, A. B.

    1986-01-01

    A three-phase research program has been undertaken to study the acoustic signals due to the aerodynamic interaction of rotorcraft main rotors and tail rotors. During the first phase, two different rotor models with several interchangeable tips were tested in the Langley 4- by 7-Meter Tunnel on the U.S. Army rotor model system. An extensive acoustic data base was acquired, with special emphasis on blade-vortex interaction (BVI) noise. The details of the experimental procedure, acoustic data acquisition, and reduction are documented. The overall sound pressure level (OASPL) of the high-twist rotor systems is relatively insensitive to flight speed but generally increases with rotor tip-path-plane angle. The OASPL of the high-twist rotors is dominated by acoustic energy in the low-frequency harmonics. The OASPL of the low-twist rotor systems shows more dependence on flight speed than the high-twist rotors, in addition to being quite sensitive to tip-path-plane angle. An integrated band-limited sound pressure level, limited by 500 to 3000 Hz, is a useful metric to quantify the occurrence of BVI noise. The OASPL of the low-twist rotors is strongly influenced by the band-limited sound levels, indicating that the blade-vortex impulsive noise is a dominant noise source for this rotor design. The midfrequency acoustic levels for both rotors show a very strong dependence on rotor tip-path-plane angle. The tip-path-plane angle at which the maximum midfrequency sound level occurs consistently decreases with increasing flight speed. The maximum midfrequency sound level measured at a given location is constant regardless of the flight speed.

  8. Acoustical Testing Laboratory Developed to Support the Low-Noise Design of Microgravity Space Flight Hardware

    NASA Technical Reports Server (NTRS)

    Cooper, Beth A.

    2001-01-01

    The NASA John H. Glenn Research Center at Lewis Field has designed and constructed an Acoustical Testing Laboratory to support the low-noise design of microgravity space flight hardware. This new laboratory will provide acoustic emissions testing and noise control services for a variety of customers, particularly for microgravity space flight hardware that must meet International Space Station limits on noise emissions. These limits have been imposed by the space station to support hearing conservation, speech communication, and safety goals as well as to prevent noise-induced vibrations that could impact microgravity research data. The Acoustical Testing Laboratory consists of a 23 by 27 by 20 ft (height) convertible hemi/anechoic chamber and separate sound-attenuating test support enclosure. Absorptive 34-in. fiberglass wedges in the test chamber provide an anechoic environment down to 100 Hz. A spring-isolated floor system affords vibration isolation above 3 Hz. These criteria, along with very low design background levels, will enable the acquisition of accurate and repeatable acoustical measurements on test articles, up to a full space station rack in size, that produce very little noise. Removable floor wedges will allow the test chamber to operate in either a hemi/anechoic or anechoic configuration, depending on the size of the test article and the specific test being conducted. The test support enclosure functions as a control room during normal operations but, alternatively, may be used as a noise-control enclosure for test articles that require the operation of noise-generating test support equipment.

  9. Design and Analysis of Advanced Materials in a Thermal/Acoustic Environment. Delivery Order 0007: Volume 1 - Structural Health Monitoring

    DTIC Science & Technology

    2010-03-01

    AFRL-RB-WP-TR-2010-3028 DESIGN AND ANALYSIS OF ADVANCED MATERIALS IN A THERMAL/ACOUSTIC ENVIRONMENT Delivery Order 0007: Volume 1‒Structural...Final 15 July 2005 – 30 March 2010 4. TITLE AND SUBTITLE DESIGN AND ANALYSIS OF ADVANCED MATERIALS IN A THERMAL/ACOUSTIC ENVIRONMENT Delivery...ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER Wright State University Department of Mechanical and Materials

  10. Implementation of a Distributed Time Based Simulation of Underwater Acoustic Networking Using Java

    DTIC Science & Technology

    2006-09-01

    submarine. The first submarine was a mere toy compared to the machines of today. Although William Bourne first drew plans for one in 1578, it was...dynamic environment. Currently, shortcuts are being taken, by both sides , which make the validity of their results questionable. For underwater...offered by the computer scientist. However, several validation attempts have been made at the edges. 11 Two examples on the acoustic side are the Navy

  11. Acoustic and social design of schools-ways to improve the school listening environment

    NASA Astrophysics Data System (ADS)

    Hagen, Mechthild

    2005-04-01

    Results of noise research indicate that communication, and as a result, teaching, learning and the social atmosphere are impeded by noise in schools. The development of strategies to reduce noise levels has often not been effective. A more promising approach seems to be to pro-actively support the ability to listen and to understand. The presentation describes the approach to an acoustic and social school design developed and explored within the project ``GanzOhrSein'' by the Education Department of the Ludwig-Maximilians-University of Munich. The scope includes an analysis of the current ``school soundscape,'' an introduction to the concept of the project to improve individual listening abilities and the conditions for listening, as well as practical examples and relevant research results. We conclude that an acoustic school design should combine acoustic changes in classrooms with educational activities to support listening at schools and thus contribute to improving individual learning conditions and to reducing stress on both pupils and teachers.

  12. Towards multifocal ultrasonic neural stimulation II: design considerations for an acoustic retinal prosthesis

    NASA Astrophysics Data System (ADS)

    Naor, Omer; Hertzberg, Yoni; Zemel, Esther; Kimmel, Eitan; Shoham, Shy

    2012-04-01

    Ultrasound waves, widely used as a non-invasive diagnostic modality, were recently shown to stimulate neuronal activity. Functionally meaningful stimulation, as is required in order to form a unified percept, requires the dynamic generation of simultaneous stimulation patterns. In this paper, we examine the general feasibility and properties of an acoustic retinal prosthesis, a new vision restoration strategy that will combine ultrasonic neuro-stimulation and ultrasonic field sculpting technology towards non-invasive artificial stimulation of surviving neurons in a degenerating retina. We explain the conceptual framework for such a device, study its feasibility in an in vivo ultrasonic retinal stimulation study and discuss the associated design considerations and tradeoffs. Finally, we simulate and experimentally validate a new holographic method—the angular spectrum-GSW—for efficient generation of uniform and accurate continuous ultrasound patterns. This method provides a powerful, flexible solution to the problem of projecting complex acoustic images onto structures like the retina.

  13. Design and Analyses of High Aspect Ratio Nozzles for Distributed Propulsion Acoustic Measurements

    NASA Technical Reports Server (NTRS)

    Dippold, Vance F., III

    2016-01-01

    A series of three convergent round-to-rectangular high-aspect ratio nozzles were designed for acoustics measurements. The nozzles have exit area aspect ratios of 8:1, 12:1, and 16:1. With septa inserts, these nozzles will mimic an array of distributed propulsion system nozzles, as found on hybrid wing-body aircraft concepts. Analyses were performed for the three nozzle designs and showed that the flow through the nozzles was free of separated flow and shocks. The exit flow was mostly uniform with the exception of a pair of vortices at each span-wise end of the nozzle.

  14. Design, Implementation, and Verification of the Reliable Multicast Protocol. Thesis

    NASA Technical Reports Server (NTRS)

    Montgomery, Todd L.

    1995-01-01

    This document describes the Reliable Multicast Protocol (RMP) design, first implementation, and formal verification. RMP provides a totally ordered, reliable, atomic multicast service on top of an unreliable multicast datagram service. RMP is fully and symmetrically distributed so that no site bears an undue portion of the communications load. RMP provides a wide range of guarantees, from unreliable delivery to totally ordered delivery, to K-resilient, majority resilient, and totally resilient atomic delivery. These guarantees are selectable on a per message basis. RMP provides many communication options, including virtual synchrony, a publisher/subscriber model of message delivery, a client/server model of delivery, mutually exclusive handlers for messages, and mutually exclusive locks. It has been commonly believed that total ordering of messages can only be achieved at great performance expense. RMP discounts this. The first implementation of RMP has been shown to provide high throughput performance on Local Area Networks (LAN). For two or more destinations a single LAN, RMP provides higher throughput than any other protocol that does not use multicast or broadcast technology. The design, implementation, and verification activities of RMP have occurred concurrently. This has allowed the verification to maintain a high fidelity between design model, implementation model, and the verification model. The restrictions of implementation have influenced the design earlier than in normal sequential approaches. The protocol as a whole has matured smoother by the inclusion of several different perspectives into the product development.

  15. GENERAL: Design and FPGA Implementation of a new hyperchaotic system

    NASA Astrophysics Data System (ADS)

    Wang, Guang-Yi; Bao, Xu-Lei; Wang, Zhong-Lin

    2008-10-01

    In this paper, a new four-dimensional autonomous hyperchaotic system is designed for generating complex chaotic signals. In the design, its parameters are selected according to the requirements for chaos and hyperchaos. The hyperchaotic Nature is verified theoretically by using the bifurcation analysis and demonstrated experimentally by the implementation of an analogue electronic circuit. Moreover, the Field Programmable Gate Array (FPGA) technology is applied to implementing a continuous system in a digital form by using a chip of Altera Cyclone II EP2C35F484C8. The digital sequence generated from the FPGA device is observed in our experimental setup.

  16. Implementing and testing a panel-based method for modeling acoustic scattering from CFD input

    NASA Astrophysics Data System (ADS)

    Swift, S. Hales

    Exposure of sailors to high levels of noise in the aircraft carrier deck environment is a problem that has serious human and economic consequences. A variety of approaches to quieting exhausting jets from high-performance aircraft are undergoing development. However, testing of noise abatement solutions at full-scale may be prohibitively costly when many possible nozzle treatments are under consideration. A relatively efficient and accurate means of predicting the noise levels resulting from engine-quieting technologies at personnel locations is needed. This is complicated by the need to model both the direct and the scattered sound field in order to determine the resultant spectrum and levels. While the direct sound field may be obtained using CFD plus surface integral methods such as the Ffowcs-Williams Hawkings method, the scattered sound field is complicated by its dependence on the geometry of the scattering surface--the aircraft carrier deck, aircraft control surfaces and other nearby structures. In this work, a time-domain boundary element method, or TD-BEM, (sometimes referred to in terms of source panels) is proposed and developed that takes advantage of and offers beneficial effects for the substantial planar components of the aircraft carrier deck environment and uses pressure gradients as its input. This method is applied to and compared with analytical results for planar surfaces, corners and spherical surfaces using an analytic point source as input. The method can also accept input from CFD data on an acoustic data surface by using the G1A pressure gradient formulation to obtain pressure gradients on the surface from the flow variables contained on the acoustic data surface. The method is also applied to a planar scattering surface characteristic of an aircraft carrier flight deck with an acoustic data surface from a supersonic jet large eddy simulation, or LES, as input to the scattering model. In this way, the process for modeling the complete

  17. Improving the design of acoustic and midwater trawl surveys through stratification, with an application to Lake Michigan prey fishes

    USGS Publications Warehouse

    Adams, J.V.; Argyle, R.L.; Fleischer, G.W.; Curtis, G.L.; Stickel, R.G.

    2006-01-01

    Reliable estimates of fish biomass are vital to the management of aquatic ecosystems and their associated fisheries. Acoustic and midwater trawl surveys are an efficient sampling method for estimating fish biomass in large bodies of water. To improve the precision of biomass estimates from combined acoustic and midwater trawl surveys, sampling effort should be optimally allocated within each stage of the survey design. Based on information collected during fish surveys, we developed an approach to improve the design of combined acoustic and midwater trawl surveys through stratification. Geographic strata for acoustic surveying and depth strata for midwater trawling were defined using neighbor-restricted cluster analysis, and the optimal allocation of sampling effort for each was then determined. As an example, we applied this survey stratification approach to data from lakewide acoustic and midwater trawl surveys of Lake Michigan prey fishes. Precision of biomass estimates from surveys with and without geographic stratification was compared through resampling. Use of geographic stratification with optimal sampling allocation reduced the variance of Lake Michigan acoustic biomass estimates by 77%. Stratification and optimal allocation at each stage of an acoustic and midwater trawl survey should serve to reduce the variance of the resulting biomass estimates.

  18. Design and Implementation of a Multimedia DBMS: Complex Query Processing

    DTIC Science & Technology

    1991-09-01

    IMPLEMENTATION OF A MULTIMEDIA DBMS: COMPLEX QUERY PROCESSING by Huseyin Aygun September 1991 Thesis Advisor Vincent Y. Lum Approved for public release...type "trace in <function name>. 31 IV. DESIGN OF COMPLEX QUERY PROCESSING In Chapter II of this thesis the general architecture of the MDBMS...data to display. More detailed information about the modification can be found in the next chapter of this thesis . Because the design for the process

  19. A Parameterized Design Framework for Hardware Implementation of Particle Filters

    DTIC Science & Technology

    2008-03-01

    explore differ- ent design options for implementing two different particle filtering applications on field-programmable gate arrays ( FPGAs ), and we present...associated results on trade-offs between area ( FPGA resource requirements) and execution speed. Index Terms — Field programmable gate arrays, Parallel...programmable gate arrays ( FPGAs ) is proposed to enable comprehensive design space exploration of the whole system with attention to the interaction

  20. Implementation Of Simulink Controller Design On IRIS+ Quadrotor

    DTIC Science & Technology

    2015-09-01

    Instead of the PID controller used in this thesis, alternatives to the controller design (e.g. LQR ) can be implemented on the Iris+ quadrotor to...at AIAA InfoTech@Aerospace Conf., Washington, DC, 2005. [29] S. Bouabdallah, A. Noth and R. Siegwart, “PID vs LQR control techniques applied to...SIMULINK CONTROLLER DESIGN ON IRIS+ QUADROTOR by Wei Zhong Fum September 2015 Thesis Advisor: Vladimir Dobrokhodov Second Reader: Noel

  1. Design and Instrumentation of a Measurement and Calibration System for an Acoustic Telemetry System

    PubMed Central

    Deng, Zhiqun; Weiland, Mark; Carlson, Thomas; Eppard, M. Brad

    2010-01-01

    The Juvenile Salmon Acoustic Telemetry System (JSATS) is an active sensing technology developed by the U.S. Army Corps of Engineers, Portland District, for detecting and tracking small fish. It is used primarily for evaluating behavior and survival of juvenile salmonids migrating through the Federal Columbia River Power System to the Pacific Ocean. It provides critical data for salmon protection and development of more “fish-friendly” hydroelectric facilities. The objective of this study was to design and build a Measurement and Calibration System (MCS) for evaluating the JSATS components, because the JSATS requires comprehensive acceptance and performance testing in a controlled environment before it is deployed in the field. The MCS consists of a reference transducer, a water test tank lined with anechoic material, a motion control unit, a reference receiver, a signal conditioner and amplifier unit, a data acquisition board, MATLAB control and analysis interface, and a computer. The fully integrated MCS has been evaluated successfully at various simulated distances and using different encoded signals at frequencies within the bandwidth of the JSATS transmitter. The MCS provides accurate acoustic mapping capability in a controlled environment and automates the process that allows real-time measurements and evaluation of the piezoelectric transducers, sensors, or the acoustic fields. The MCS has been in use since 2009 for acceptance and performance testing of, and further improvements to, the JSATS. PMID:22319288

  2. Design and Instrumentation of a Measurement and Calibration System for an Acoustic Telemetry System

    SciTech Connect

    Deng, Zhiqun; Weiland, Mark A.; Carlson, Thomas J.; Eppard, M. B.

    2010-03-31

    The Juvenile Salmon Acoustic Telemetry System (JSATS) is an active sensing technology developed by Portland District, the U.S. Army Corps of Engineers for detecting and tracking small fish. It is used at hydroelectric projects and in the laboratory for evaluating behavior and survival of juvenile salmonids migrating through the Federal Columbia River Power System to the Pacific Ocean. It provides critical data for salmon protection and development of more “fish-friendly” hydroelectric facilities. The objective of this study was to design and build a measurement and calibration system for evaluating the JSATS component, because the JSATS requires comprehensive acceptance and performance testing in a controlled environment before it is deployed in the field. The system consists of a reference transducer, a water test tank lined with anechoic material, a motion control unit, a reference receiver, a signal conditioner and amplifier unit, a data acquisition board, MATLAB control and analysis interface, and a computer. The fully integrated system has been evaluated successfully at various simulated distances and using different encoded signals at frequencies within the bandwidth of the JSATS transmitter. It provides accurate acoustic mapping capability in a controlled environment and automates the process that allows real-time measurements and evaluation of the piezoelectric transducers, sensors, or the acoustic fields. The measurement and calibration system has been in use since 2009 for acceptance and performance testing of, and further improvements to, the JSATS.

  3. Design and instrumentation of a measurement and calibration system for an acoustic telemetry system.

    PubMed

    Deng, Zhiqun; Weiland, Mark; Carlson, Thomas; Eppard, M Brad

    2010-01-01

    The Juvenile Salmon Acoustic Telemetry System (JSATS) is an active sensing technology developed by the U.S. Army Corps of Engineers, Portland District, for detecting and tracking small fish. It is used primarily for evaluating behavior and survival of juvenile salmonids migrating through the Federal Columbia River Power System to the Pacific Ocean. It provides critical data for salmon protection and development of more "fish-friendly" hydroelectric facilities. The objective of this study was to design and build a Measurement and Calibration System (MCS) for evaluating the JSATS components, because the JSATS requires comprehensive acceptance and performance testing in a controlled environment before it is deployed in the field. The MCS consists of a reference transducer, a water test tank lined with anechoic material, a motion control unit, a reference receiver, a signal conditioner and amplifier unit, a data acquisition board, MATLAB control and analysis interface, and a computer. The fully integrated MCS has been evaluated successfully at various simulated distances and using different encoded signals at frequencies within the bandwidth of the JSATS transmitter. The MCS provides accurate acoustic mapping capability in a controlled environment and automates the process that allows real-time measurements and evaluation of the piezoelectric transducers, sensors, or the acoustic fields. The MCS has been in use since 2009 for acceptance and performance testing of, and further improvements to, the JSATS.

  4. Design and Analyses of High Aspect Ratio Nozzles for Distributed Propulsion Acoustic Measurements

    NASA Technical Reports Server (NTRS)

    Dippold, Vance F., III

    2016-01-01

    A series of three convergent, round-to-rectangular high aspect ratio (HAR) nozzles were designed for acoustic testing at the NASA Glenn Research Center Nozzle Acoustic Test Rig (NATR). The HAR nozzles had exit area aspect ratios of 8:1, 12:1, and 16:1. The nozzles were designed to mimic a distributed propulsion system array with a slot nozzle. The nozzle designs were screened using Reynolds-Averaged Navier-Stokes (RANS) simulations. In addition to meeting the geometric constraints required for testing in the NATR, the HAR nozzles were designed to be free of flow features that would produce unwanted noise (e.g., flow separations) and to have uniform flow at the nozzle exit. Multiple methods were used to generate HAR nozzle designs. The final HAR nozzle designs were generated in segments using a computer code that parameterized each segment. RANS screening simulations showed that intermediate nozzle designs suffered flow separation, a normal shockwave at the nozzle exit (caused by an aerodynamic throat produced by boundary layer growth), and non-uniform flow at the nozzle exit. The RANS simulations showed that the final HAR nozzle designs were free of flow separations, but were not entirely successful at producing a fully uniform flow at the nozzle exit. The final designs suffered a pair of counter-rotating vortices along the outboard walls of the nozzle. The 16:1 aspect ratio HAR nozzle had the least uniform flow at the exit plane; the 8:1 aspect ratio HAR nozzles had a fairly uniform flow at the nozzle exit plane.

  5. Design, fabrication and acoustic tests of a 36 inch (0.914 meter) statorless turbotip fan

    NASA Technical Reports Server (NTRS)

    Smith, E. G.; Stempert, D. L.; Uhl, W. R.

    1975-01-01

    The LF336/E is a 36 inch (0.914 meter) diameter fan designed to operate in a rotor-alone configuration. Design features required for modification of the existing LF336/A rotor-stator fan into the LF336/E statorless fan configuration are discussed. Tests of the statorless fan identified an aerodynamic performance deficiency due to inaccurate accounting of the fan exit swirl during the aerodynamic design. This performance deficiency, related to fan exit static pressure levels, produced about a 20 percent thrust loss. A study was then conducted for further evaluation of the fan exit flow fields typical of statorless fan systems. This study showed that through proper selection of fan design variables such as pressure ratio, radius ratio, and swirl distributions, performance of a statorless fan configuration could be improved with levels of thrust approaching the conventional rotor-stator fan system. Acoustic measurements were taken for the statorless fan system at both GE and NASA, and when compared to other lift fan systems, showed noise levels comparable to the quietest lift fan configuration which included rotor-stator spacing and acoustic treatment. The statorless fan system was also used to determine effects of rotor leading edge serrations on noise generations. A cascade test program identified the serration geometry based on minimum pressure losses, wake turbulence levels and noise generations.

  6. Design of a low power hybrid HIFU applicator for haemostasis based on acoustic propagation modelling.

    PubMed

    Martínez-Valdez, Raquel; Ramos Fernández, Antonio; Vera Hernandez, Arturo; Leija Salas, Lorenzo

    2016-01-01

    The aim of this study was to design an applicator for haemostasis usage needing lower acoustic intensities (<880 W/cm(2)) than in previous devices intended for it, which is based on ultrasound propagation FEM modelling using a 2-MHz HIFU transducer. Acoustic field characterisation and numerical simulations in water were performed with and without the proposed applicator. Parameters such as form factor, ellipsoidal shape ratio, and Euclidean distance were used (among others) to compare simulated data with transducer measurements without applicator. A low density polyethylene cone was manufactured from geometries validated from acoustic field modelling. The hollow cone was filled with 10% polyacrylamide gel as a coupling medium with liver phantom or chicken liver. Focal temperature was measured with a thermocouple embedded in the phantom for 1-20 W driving powers for 120 s. Standing wave ratios (SWR) were used as coupling indexes. Ex vivo experimentation in chicken liver was made at 10-20 W. Simulated acoustic patterns showed good concordance with measurements. Experimental focal distance was 20.72 ± 0.24 mm, while the simulated was 19.79 mm (≈4% error). SWR at low power were: 2.01 with transducer emitting in air, 1.53 at applicator tip, and 1.35 after phantom placement. Average SWR at high power was 1.31. Similarity of percentages for data comparison in focal plane was over 60%. Maximum temperature measured at focus was 88.7 °C with 20 W after 85 s. Temperatures reached at focus suggest that this applicator has good efficiency, which notably reduces the power typically needed for haemostasis effect.

  7. Supporting Middle School Teachers' Implementation of STEM Design Challenges

    ERIC Educational Resources Information Center

    Lesseig, Kristin; Nelson, Tamara Holmlund; Slavit, David; Seidel, Ryan August

    2016-01-01

    We describe and analyze a professional development (PD) model that involved a partnership among science, mathematics and education university faculty, science and mathematics coordinators, and middle school administrators, teachers, and students. The overarching project goal involved the implementation of interdisciplinary STEM Design Challenges…

  8. Empowering Students as Active Participants in Curriculum Design and Implementation

    ERIC Educational Resources Information Center

    Jagersma, John

    2010-01-01

    Curriculum is constructed with the learner as its central focus. Yet the voice of the learner is largely excluded from the curriculum design and implementation process. The author is both an educator and administrator and the intent of this paper is to provide other educators with a deeper understanding of the potential for increased learning when…

  9. Design and Implementation of an Undergraduate Laboratory Course in Psychophysiology

    ERIC Educational Resources Information Center

    Thibodeau, Ryan

    2011-01-01

    Most psychology curricula require the completion of coursework on the physiological bases of behavior. However, delivery of this critical content in a laboratory format is somewhat rare at the undergraduate level. To fill this gap, this article describes the design and implementation of an undergraduate laboratory course in psychophysiology at a…

  10. Empowering Design-Based Implementation Research: The Need for Infrastructure

    ERIC Educational Resources Information Center

    Sabelli, Nora; Dede, Chris

    2013-01-01

    This chapter discusses frameworks and conceptual lenses that help orient design-based implementation research (DBIR) work to the types of infrastructure required for success, while contributing to theories about the processes of educational improvement. Such infrastructures can be conceived as a framework: a set of interconnected elements that…

  11. Designing, Implementing, and Evaluating a Group Therapy for Underserved Populations

    ERIC Educational Resources Information Center

    Waltman, Scott H.; Hetrick, Holly; Tasker, Tamara E.

    2012-01-01

    This article presents the case of a mindfulness-based group therapy that was implemented in a residential treatment facility. The case presented comprised a group of adolescent males with disruptive behavior disorders. The group was designed to be appropriate for the unique demographics of the clients, with the intent to help the clients enhance…

  12. Supporting Middle School Teachers' Implementation of STEM Design Challenges

    ERIC Educational Resources Information Center

    Lesseig, Kristin; Nelson, Tamara Holmlund; Slavit, David; Seidel, Ryan August

    2016-01-01

    We describe and analyze a professional development (PD) model that involved a partnership among science, mathematics and education university faculty, science and mathematics coordinators, and middle school administrators, teachers, and students. The overarching project goal involved the implementation of interdisciplinary STEM Design Challenges…

  13. Designing, Implementing, and Evaluating a Group Therapy for Underserved Populations

    ERIC Educational Resources Information Center

    Waltman, Scott H.; Hetrick, Holly; Tasker, Tamara E.

    2012-01-01

    This article presents the case of a mindfulness-based group therapy that was implemented in a residential treatment facility. The case presented comprised a group of adolescent males with disruptive behavior disorders. The group was designed to be appropriate for the unique demographics of the clients, with the intent to help the clients enhance…

  14. Designing and Implementing a Family of Intrusion Detection Systems

    DTIC Science & Technology

    2004-11-01

    Designing and Implementing a Family of Intrusion Detection Systems Richard A. Kemmerer Reliable Software Group Department of Computer Science ...Reliable Software Group Department of Computer Science University of California, Santa Barbara Santa Barbara, CA 93106 USA 8. PERFORMING ORGANIZATION...Systems Richard A. Kemmerer Reliable Software Group Computer Science Department University of California Santa Barbara, CA 93106, USA http

  15. Design and Implementation Considerations for Alternative Teacher Compensation Programs

    ERIC Educational Resources Information Center

    Brodsky, Andrew; DeCesare, Dale; Kramer-Wine, Jennifer

    2010-01-01

    Over the past decade, educators and policymakers have used a variety of approaches to designing and implementing teacher compensation programs. These approaches include federal incentive funds, state-level programs, and district initiatives. This article reviews 6 such programs in order to identify themes and draw conclusions relevant to…

  16. The Design and Implementation of a Read Prediction Buffer

    DTIC Science & Technology

    1992-12-01

    distribution is unlimited THE DESIGN AND IMPLEMENTATION OF A READ PREDICTION BUFFER by Gary Joseph Nowicki Lieutenant, United States Navy B.S.E.E., University...EMAT >000000000000:AMWR >1 I II I00I II0I0:ERO >000000000000:DVA >000000000000:AMWR >000000000000:CAR >00000000: ODV >000000000000:PAMR >000000000000:SUB

  17. Design and Implementation of a Learning Analytics Toolkit for Teachers

    ERIC Educational Resources Information Center

    Dyckhoff, Anna Lea; Zielke, Dennis; Bultmann, Mareike; Chatti, Mohamed Amine; Schroeder, Ulrik

    2012-01-01

    Learning Analytics can provide powerful tools for teachers in order to support them in the iterative process of improving the effectiveness of their courses and to collaterally enhance their students' performance. In this paper, we present the theoretical background, design, implementation, and evaluation details of eLAT, a Learning Analytics…

  18. Design and Implementation of a Learning Analytics Toolkit for Teachers

    ERIC Educational Resources Information Center

    Dyckhoff, Anna Lea; Zielke, Dennis; Bultmann, Mareike; Chatti, Mohamed Amine; Schroeder, Ulrik

    2012-01-01

    Learning Analytics can provide powerful tools for teachers in order to support them in the iterative process of improving the effectiveness of their courses and to collaterally enhance their students' performance. In this paper, we present the theoretical background, design, implementation, and evaluation details of eLAT, a Learning Analytics…

  19. Designing and Implementing Effective Adapted Physical Education Programs

    ERIC Educational Resources Information Center

    Kelly, Luke E.

    2011-01-01

    "Designing and Implementing Effective Adapted Physical Education Programs" was written to assist adapted and general physical educators who are dedicated to ensuring that the physical and motor needs of all their students are addressed in physical education. While it is anticipated that adapted physical educators, where available, will typically…

  20. Design and Implementation Issues for Modern Remote Laboratories

    ERIC Educational Resources Information Center

    Guimaraes, E. G.; Cardozo, E.; Moraes, D. H.; Coelho, P. R.

    2011-01-01

    The design and implementation of remote laboratories present different levels of complexity according to the nature of the equipments operated by the remote laboratory, the requirements imposed on the accessing computers, the network linking the user to the laboratory, and the type of experiments the laboratory supports. This paper addresses the…

  1. Design and implementation of underwater wireless electromagnetic communication system

    NASA Astrophysics Data System (ADS)

    Wu, Xiangshang; Xue, Wei; Shu, Xin

    2017-08-01

    This paper introduces the design and implementation of the underwater wireless electromagnetic communication system based on the current field theory. The system realizes the wireless transmission of underwater voice signal, and has a good application prospect in underwater short-range wireless communication.

  2. Design and Implementation Issues for Modern Remote Laboratories

    ERIC Educational Resources Information Center

    Guimaraes, E. G.; Cardozo, E.; Moraes, D. H.; Coelho, P. R.

    2011-01-01

    The design and implementation of remote laboratories present different levels of complexity according to the nature of the equipments operated by the remote laboratory, the requirements imposed on the accessing computers, the network linking the user to the laboratory, and the type of experiments the laboratory supports. This paper addresses the…

  3. Empowering Design-Based Implementation Research: The Need for Infrastructure

    ERIC Educational Resources Information Center

    Sabelli, Nora; Dede, Chris

    2013-01-01

    This chapter discusses frameworks and conceptual lenses that help orient design-based implementation research (DBIR) work to the types of infrastructure required for success, while contributing to theories about the processes of educational improvement. Such infrastructures can be conceived as a framework: a set of interconnected elements that…

  4. Designing and Implementing a Mainstream Course for Regular Early Educators.

    ERIC Educational Resources Information Center

    Wolf, Judith M.

    The University of Minnesota and the Minnesota State Department of Education joined forces to design and implement a course to prepare regular educators to work with handicapped children. The purposes of the course were to present a rationale and philosophy for integrating special needs children into mainstream settings and to offer a variety of…

  5. Designing and Implementing a Successful Merit Pay Program for Teachers.

    ERIC Educational Resources Information Center

    Farnsworth, Briant; And Others

    1991-01-01

    In 1984, a Salt Lake City school district began developing a merit pay program to cover all certified teachers. A committee of teachers designed an assessment method called AIM. Implementation involved developing measurement criteria, establishing evaluation procedures, providing feedback, creating a merit pay plan tied to career development, and…

  6. Design and Implementation of an Undergraduate Laboratory Course in Psychophysiology

    ERIC Educational Resources Information Center

    Thibodeau, Ryan

    2011-01-01

    Most psychology curricula require the completion of coursework on the physiological bases of behavior. However, delivery of this critical content in a laboratory format is somewhat rare at the undergraduate level. To fill this gap, this article describes the design and implementation of an undergraduate laboratory course in psychophysiology at a…

  7. Design and implementation of an underwater sound recording device.

    PubMed

    Martinez, Jayson J; Myers, Josh R; Carlson, Thomas J; Deng, Z Daniel; Rohrer, John S; Caviggia, Kurt A; Woodley, Christa M; Weiland, Mark A

    2011-01-01

    To monitor the underwater sound and pressure waves generated by anthropogenic activities such as underwater blasting and pile driving, an autonomous system was designed to record underwater acoustic signals. The underwater sound recording device (USR) allows for connections of two hydrophones or other dynamic pressure sensors, filters high frequency noise out of the collected signals, has a gain that can be independently set for each sensor, and allows for 2 h of data collection. Two versions of the USR were created: a submersible model deployable to a maximum depth of 300 m, and a watertight but not fully submersible model. Tests were performed on the USR in the laboratory using a data acquisition system to send single-frequency sinusoidal voltages directly to each component. These tests verified that the device operates as designed and performs as well as larger commercially available data acquisition systems, which are not suited for field use. On average, the designed gain values differed from the actual measured gain values by about 0.35 dB. A prototype of the device was used in a case study to measure blast pressures while investigating the effect of underwater rock blasting on juvenile Chinook salmon and rainbow trout. In the case study, maximum positive pressure from the blast was found to be significantly correlated with frequency of injury for individual fish. The case study also demonstrated that the device withstood operation in harsh environments, making it a valuable tool for collecting field measurements.

  8. Design and Implementation of an Underwater Sound Recording Device

    PubMed Central

    Martinez, Jayson J.; Myers, Josh R.; Carlson, Thomas J.; Deng, Z. Daniel; Rohrer, John S.; Caviggia, Kurt A.; Woodley, Christa M.; Weiland, Mark A.

    2011-01-01

    To monitor the underwater sound and pressure waves generated by anthropogenic activities such as underwater blasting and pile driving, an autonomous system was designed to record underwater acoustic signals. The underwater sound recording device (USR) allows for connections of two hydrophones or other dynamic pressure sensors, filters high frequency noise out of the collected signals, has a gain that can be independently set for each sensor, and allows for 2 h of data collection. Two versions of the USR were created: a submersible model deployable to a maximum depth of 300 m, and a watertight but not fully submersible model. Tests were performed on the USR in the laboratory using a data acquisition system to send single-frequency sinusoidal voltages directly to each component. These tests verified that the device operates as designed and performs as well as larger commercially available data acquisition systems, which are not suited for field use. On average, the designed gain values differed from the actual measured gain values by about 0.35 dB. A prototype of the device was used in a case study to measure blast pressures while investigating the effect of underwater rock blasting on juvenile Chinook salmon and rainbow trout. In the case study, maximum positive pressure from the blast was found to be significantly correlated with frequency of injury for individual fish. The case study also demonstrated that the device withstood operation in harsh environments, making it a valuable tool for collecting field measurements. PMID:22164089

  9. Optimization of Capacitive Acoustic Resonant Sensor Using Numerical Simulation and Design of Experiment

    PubMed Central

    Haque, Rubaiyet Iftekharul; Loussert, Christophe; Sergent, Michelle; Benaben, Patrick; Boddaert, Xavier

    2015-01-01

    Optimization of the acoustic resonant sensor requires a clear understanding of how the output responses of the sensor are affected by the variation of different factors. During this work, output responses of a capacitive acoustic transducer, such as membrane displacement, quality factor, and capacitance variation, are considered to evaluate the sensor design. The six device parameters taken into consideration are membrane radius, backplate radius, cavity height, air gap, membrane tension, and membrane thickness. The effects of factors on the output responses of the transducer are investigated using an integrated methodology that combines numerical simulation and design of experiments (DOE). A series of numerical experiments are conducted to obtain output responses for different combinations of device parameters using finite element methods (FEM). Response surface method is used to identify the significant factors and to develop the empirical models for the output responses. Finally, these results are utilized to calculate the optimum device parameters using multi-criteria optimization with desirability function. Thereafter, the validating experiments are designed and deployed using the numerical simulation to crosscheck the responses. PMID:25894937

  10. Acoustic Performance Of New Designs Of Traffic Noise Barriers: Full Scale Tests

    NASA Astrophysics Data System (ADS)

    Watts, G. R.; Crombie, D. H.; Hothersall, D. C.

    1994-10-01

    Full scale tests of acoustical performance are reported on a range of promising traffic noise barrier shapes which had previously been identified by mathematical and scale modelling work. The designs chosen for testing were T-shaped, multiple edge barriers and double barriers. A test facility was established at the Transport Research Laboratory (TRL) in order to examine effectiveness under full scale conditions. This consisted of a 20 m length of noise barrier with interchangeable barrier panels, a large flat asphalt surface and a transportable speaker system capable of sufficient output to represent typical traffic noise. Screening performance was measured up to 80 m behind the barriers over a flat grassland area and at heights above the ground of 1·5 and 4·5 m. It was concluded that the average increase in acoustic screening of 2 m high T-shaped, multiple edge and double barriers compared with a simple plane reflecting barrier of identical overall height ranged from 1·4 to 3·6dB(A) depending on detailed design. It was suggested that a full scale test of a promising design should be carried out at a suitable highway location in order to validate fully these test results.

  11. Design and implementation of highly parallel pipelined VLSI systems

    NASA Astrophysics Data System (ADS)

    Delange, Alphonsus Anthonius Jozef

    A methodology and its realization as a prototype CAD (Computer Aided Design) system for the design and analysis of complex multiprocessor systems is presented. The design is an iterative process in which the behavioral specifications of the system components are refined into structural descriptions consisting of interconnections and lower level components etc. A model for the representation and analysis of multiprocessor systems at several levels of abstraction and an implementation of a CAD system based on this model are described. A high level design language, an object oriented development kit for tool design, a design data management system, and design and analysis tools such as a high level simulator and graphics design interface which are integrated into the prototype system and graphics interface are described. Procedures for the synthesis of semiregular processor arrays, and to compute the switching of input/output signals, memory management and control of processor array, and sequencing and segmentation of input/output data streams due to partitioning and clustering of the processor array during the subsequent synthesis steps, are described. The architecture and control of a parallel system is designed and each component mapped to a module or module generator in a symbolic layout library, compacted for design rules of VLSI (Very Large Scale Integration) technology. An example of the design of a processor that is a useful building block for highly parallel pipelined systems in the signal/image processing domains is given.

  12. Acceptance testing for PACS: from methodology to design to implementation

    NASA Astrophysics Data System (ADS)

    Liu, Brent J.; Huang, H. K.

    2004-04-01

    Acceptance Testing (AT) is a crucial step in the implementation process of a PACS within a clinical environment. AT determines whether the PACS is ready for clinical use and marks the official sign off of the PACS product. Most PACS vendors have Acceptance Testing (AT) plans, however, these plans do not provide a complete and robust evaluation of the full system. In addition, different sites will have different special requirements that vendor AT plans do not cover. The purpose of this paper is to introduce a protocol for AT design and present case studies of AT performed on clinical PACS. A methodology is presented that includes identifying testing components within PACS, quality assurance for both functionality and performance, and technical testing focusing on key single points-of-failure within the PACS product. Tools and resources that provide assistance in performing AT are discussed. In addition, implementation of the AT within the clinical environment and the overall implementation timeline of the PACS process are presented. Finally, case studies of actual AT of clinical PACS performed in the healthcare environment will be reviewed. The methodology for designing and implementing a robust AT plan for PACS was documented and has been used in PACS acceptance tests in several sites. This methodology can be applied to any PACS and can be used as a validation for the PACS product being acquired by radiology departments and hospitals. A methodology for AT design and implementation was presented that can be applied to future PACS installations. A robust AT plan for a PACS installation can increase both the utilization and satisfaction of a successful implementation of a PACS product that benefits both vendor and customer.

  13. Award 1 Title: Acoustic Communications 2011 Experiment: Deployment Support and Post Experiment Data Handling and Analysis. Award 2 Title: Exploiting Structured Dependencies in the Design of Adaptive Algorithms for Underwater Communication Award. 3 Title: Coupled Research in Ocean Acoustics and Signal Processing for the Next Generation of Underwater Acoustic Communication Systems

    DTIC Science & Technology

    2015-09-30

    Award #1 Title Acoustic Communications 2011 Experiment: Deployment Support and Post Experiment Data Handling and Analysis Award #2 Title...Exploiting Structured Dependencies in the Design of Adaptive Algorithms for Underwater Communication Award #3 Title Coupled Research in Ocean Acoustics...and Signal Processing for theNext Generation of Underwater Acoustic Communication Systems James Preisig Woods Hole Oceanographic Institution

  14. Implementation of an acoustic emission proximity detector for use in generating glass optics

    SciTech Connect

    Blaedel, K.L.; Piscotty, M.A.; Taylor, J.S.

    1996-11-11

    We are using the approach acoustic emission (AE) signal during a grinding operation to detect the proximity of the grinding wheel relative to a brittle material workpiece and are using this detection as a feed- back control signal in our CNC. The repeatability of the AE signal during the wheel approach is the key that allows AE to be used as a proximity detector and is demonstrated at LLNL to be about mm. We noted significant changes of the AE signal as process parameters are modified, but conclude that with a quick CNC calibration routine and holding the parameters constant during a given operation, the AE system can be successfully used to sense pre- contact wheel- to- workpiece separation. Additionally, the AE sensing system allows real- time monitoring during grinding to provide in- process information. The first prototype of an AE system on a commercially available generator is currently be tested at the Center for Optics Manufacturing.

  15. Design & implementation of distributed spatial computing node based on WPS

    NASA Astrophysics Data System (ADS)

    Liu, Liping; Li, Guoqing; Xie, Jibo

    2014-03-01

    Currently, the research work of SIG (Spatial Information Grid) technology mostly emphasizes on the spatial data sharing in grid environment, while the importance of spatial computing resources is ignored. In order to implement the sharing and cooperation of spatial computing resources in grid environment, this paper does a systematical research of the key technologies to construct Spatial Computing Node based on the WPS (Web Processing Service) specification by OGC (Open Geospatial Consortium). And a framework of Spatial Computing Node is designed according to the features of spatial computing resources. Finally, a prototype of Spatial Computing Node is implemented and the relevant verification work under the environment is completed.

  16. Effect of synergism in the mechanics of multilayer designs. 2. synthesis of optimal acoustic systems

    NASA Astrophysics Data System (ADS)

    Urzhumtsev, Yu. S.; Babe, G. D.; Gusev, E. L.

    1985-07-01

    Use of the synergism effect in the mechanics of inhomogeneous systems, and algorithms constructed on the basis of the theory of optimal control makes it possible to synthesize multilayer designs that are optimum in terms of weight capacity, thermal stability, sound conduction, and sound insulation. The proposed approach to solution of the problem of the optimal design of multilayer acoustic systems makes it possible firstly to develop a rather effective method on the basis of this approach; this method reduces to a solution that is optimal in terms of the physical parameters of the layer materials, the layer thicknesses, and the number of layers; and, secondly, to establish a number of qualitative attributes of the parameters of optimal multilayer structures. This approach is also promising for the development of methods for the optimization of multilayer foundations and systems that dampen vibrational loadings, earthquake-resistant designs, and armor protection.

  17. A wireless sensor network design and implementation for vehicle detection, classification, and tracking

    NASA Astrophysics Data System (ADS)

    Aljaafreh, A.; Al Assaf, A.

    2013-05-01

    Vehicle intrusion is considered a significant threat for critical zones specially the militarized zones and therefore vehicles monitoring has a great importance. In this paper a small wireless sensor network for vehicle intrusion monitoring consists of a five inexpensive sensor nodes distributed over a small area and connected with a gateway using star topology has been designed and implemented. The system is able to detect a passage of an intrusive vehicle, classify it either wheeled or tracked, and track the direction of its movement. The approach is based on Vehicle's ground vibrations for detection, vehicle's acoustic signature for classification and the Energy- based target localization for tracking. Detection and classification are implemented by using different algorithms and techniques including Analog to Digital Conversion, Fast Fourier Transformation (FFT) and Neural Network .All of these algorithms and techniques are implemented locally in the sensor node using Microchip dsPIC digital signal controller. Results are sent from the sensor node to the gateway using ZigBee technology and then from the gateway to a web server using GPRS technology.

  18. Design and implementation of an underwater sound recording device

    SciTech Connect

    Martinez, Jayson J.; Myers, Joshua R.; Carlson, Thomas J.; Deng, Zhiqun; Rohrer, John S.; Caviggia, Kurt A.; Woodley, Christa M.; Weiland, Mark A.

    2011-09-01

    To monitor the underwater sound and pressure waves generated by activities such as underwater blasting and pile driving, an autonomous system used to record underwater acoustic signals was designed. The device designed allows two hydrophones or other dynamic pressure sensors to be connected, filters out high frequency noise, has a gain that can be independently set for each sensor, and allows two hours of data to be collected. Two versions of the USR were created; one is submersible to a maximum depth of 300 m, and the other, although watertight, is not intended to be fully submersed. Tests were performed in the laboratory using a data acquisition system to send single-frequency sinusoidal voltages directly to the each component. These tests verified that the device performs as well as larger commercially available data acquisition systems, which are not suited for field use. A prototype of the device was used in a case study to investigate the effect of underwater rock blasting on juvenile Chinook salmon and rainbow trout. The case study demonstrated that the device was able to tolerate being operated in harsh environments, making it a valuable tool for collecting field measurements.

  19. Design of a Hydro-Turbine Blade for Acoustic and Performance Validation Studies

    NASA Astrophysics Data System (ADS)

    Johnson, E.; Barone, M.

    2011-12-01

    To meet the growing, global energy demands governments and industry have recently begun to focus on marine hydrokinetic (MHK) devices as an additional form of power generation. Water turbines have become a popular design choice since they are able to leverage experience from the decades-old wind industry in the hope of decreasing time-to-market. However, the difference in environments poses challenges that need to be addressed. In particular, little research has addressed the acoustic effects of common aerofoils in a marine setting. This has both a potential impact on marine life and may cause early fatigue by exciting new structural modes. An initial blade design is presented, which has been used to begin characterization of any structural and acoustic issues that may arise from a direct one-to-one swap of wind technologies into MHK devices. The blade was optimized for performance using blade-element momentum theory while requiring that it not exceed the allowable stress under a specified extreme operating design condition. This limited the maximum power generated, while ensuring a realizable blade. A stress analysis within ANSYS was performed to validate the structural integrity of the design. Additionally, predictions of the radiated noise from the MHK rotor will be made using boundary element modeling based on flow results from ANSYS CFX, a computational fluid dynamics (CFD) code. The FEA and CFD results demonstrate good comparison to the expected design. Determining a range for the anticipated noise produced from a MHK turbine provides a look at the environmental impact these devices will have. Future efforts will focus on the design constraints noise generation places on MHK devices.

  20. Implementation of an Expert System for Instructional Design, Phase 3. Design Document and Technical Report.

    ERIC Educational Resources Information Center

    Merrill, M. David; Li, Zhongmin

    Instructional Design Expert (ID Expert) is a prototype instructional design expert system which supports the instructional design phase of instructional system development. Phase 2 of ID Expert was implemented using S.1 expert system language on the VAX computer. The user interface was text-based, consisting of a question/answer dialogue primarily…

  1. The FEYNMAN tools for quantum information processing: Design and implementation

    NASA Astrophysics Data System (ADS)

    Fritzsche, S.

    2014-06-01

    The FEYNMAN tools have been re-designed with the goal to establish and implement a high-level (computer) language that is capable to deal with the physics of finite, n-qubit systems, from frequently required computations to mathematically advanced tasks in quantum information processing. In particular, emphasis has been placed to introduce a small but powerful set of keystring-driven commands in order to support both, symbolic and numerical computations. Though the current design is implemented again within the framework of MAPLE, it is general and flexible enough to be utilized and combined with other languages and computational environments. The present implementation facilitates a large number of computational tasks, including the definition, manipulation and parametrization of quantum states, the evaluation of quantum measures and quantum operations, the evolution of quantum noise in discrete models, quantum measurements and state estimation, and several others. The design is based on a few high-level commands, with a syntax close to the mathematical notation and its use in the literature, and which can be generalized quite readily in order to solve computational tasks at even higher degree of complexity. In this work, I present and discuss the (re-design of the) FEYNMAN tools and make major parts of the code available for public use. Moreover, a few selected examples are shown and demonstrate possible application of this toolbox. The FEYNMAN tools are provided as MAPLE library and can hence be used on all platforms on which this computer-algebra system is accessible.

  2. Comparison between design and installed acoustic characteristics of NASA Lewis 9- by 15-foot low-speed wind tunnel acoustic treatment

    NASA Technical Reports Server (NTRS)

    Dahl, Milo D.; Woodward, Richard P.

    1990-01-01

    The test section of the NASA Lewis 9- by 15-Foot Low-Speed Wind Tunnel was acoustically treated to allow the measurement of sound under simulated free-field conditions. The treatment was designed for high sound absorption at frequencies above 250 Hz and for withstanding the environmental conditions in the test section. In order to achieve the design requirements, a fibrous, bulk-absorber material was packed into removable panel sections. Each section was divided into two equal-depth layers packed with material to different bulk densities. The lower density was next to the facing of the treatment. The facing consisted of a perforated plate and screening material layered together. Sample tests for normal-incidence acoustic absorption were also conducted in an impedance tube to provide data to aid in the treatment design. Tests with no airflow, involving the measurement of the absorptive properties of the treatment installed in the 9- by 15-foot wind tunnel test section, combined the use of time-delay spectrometry with a previously established free-field measurement method. This new application of time-delay spectrometry enabled these free-field measurements to be made in nonanechoic conditions. The results showed that the installed acoustic treatment had absorption coefficients greater than 0.95 over the frequency range 250 Hz to 4 kHz. The measurements in the wind tunnel were in good agreement with both the analytical prediction and the impedance tube test data.

  3. Design and Implementation of an Innovative Residential PV System

    NASA Astrophysics Data System (ADS)

    Najm, Elie Michel

    This work focuses on the design and implementation of an innovative residential PV system. In chapter one, after an introduction related to the rapid growth of solar systems' installations, the most commonly used state of the art solar power electronics' configurations are discussed, which leads to introducing the proposed DC/DC parallel configuration. The advantages and disadvantages of each of the power electronics' configurations are deliberated. The scope of work in the power electronics is defined in this chapter to be related to the panel side DC/DC converter. System integration and mechanical proposals are also within the scope of work and are discussed in later chapters. Operation principle of a novel low cost PV converter is proposed in chapter 2. The proposal is based on an innovative, simplified analog implementation of a master/slave methodology resulting in an efficient, soft-switched interleaved variable frequency flybacks, operating in the boundary conduction mode (BCM). The scheme concept and circuit configuration, operation principle and theoretical waveforms, design equations, and design considerations are presented. Furthermore, design examples are also given, illustrating the significance of the newly derived frequency equation for flybacks operating in BCM. In chapters 3, 4, and 5, the design implementation and optimization of the novel DC/DC converter illustrated in chapter 2 are discussed. In chapter 3, a detailed variable frequency BCM flyback design model leading to optimizing the component selections and transformer design, detailed in chapter 4, is presented. Furthermore, in chapter 4, the method enabling the use of lower voltage rating switching devices is also discussed. In chapter 5, circuitry related to Start-UP, drive for the main switching devices, zero-voltage-switching (ZVS) as well as turn OFF soft switching and interleaving control are fully detailed. The experimental results of the proposed DC/DC converter are presented in

  4. Effect of fan outlet guide vane on the acoustic treatment design in aeroengine nacelle

    NASA Astrophysics Data System (ADS)

    Sun, X.; Yang, Z.; Wang, X.

    2007-04-01

    The main objective of this study is to clarify the effect of the outlet guide vane (OGV) on the acoustic treatment design in aeroengine nacelle, which received less attention previously. A model of sound propagation through a lining section and a blade row is developed to investigate the interaction between sound sources of blade rows and liners in a channel of parallel walls containing uniform mean flow. The present method makes it possible to evaluate the performance of liner while a blade row is inserted in the channel and the sound attenuation in a duct with both liner section and cascade. Various numerical results show that the effect of the cascade may have diverse effects on sound attenuation of the liner under different conditions, but the existence of the OGV always enhances the total sound attenuation in the duct due to energy dissipation caused by vortex shedding from the tailing edge of the OGV. To pursue a better design of acoustic liner in aeroengine nacelle, it is thus necessary to include the effect of OGV on the sound attenuation.

  5. Design guidelines for avoiding thermo-acoustic oscillations in helium piping systems

    SciTech Connect

    Gupta, Prabhat Kumar; Rabehl, Roger

    2015-04-02

    Thermo-acoustic oscillations are a commonly observed phenomenon in helium cryogenic systems, especially in tubes connecting hot and cold areas. The open ends of these tubes are connected to the lower temperature (typically at 4.5 K), and the closed ends of these tubes are connected to the high temperature (300 K). Cryogenic instrumentation installations provide ideal conditions for these oscillations to occur due to the steep temperature gradient along the tubing. These oscillations create errors in measurements as well as an undesirable heat load to the system. The work presented here develops engineering guidelines to design oscillation-free helium piping. This work also studies the effect of different piping inserts and shows how the proper geometrical combinations have to be chosen to avoid thermo-acoustic oscillations. The effect of an 80 K intercept is also studied and shows that thermo-oscillations can be dampened by placing the intercept at an appropriate location. As a result, the design of helium piping based on the present work is also verified with the experimental results available in open literature.

  6. Acoustic Characteristics of Various Treatment Panel Designs Specific to HSCT Mixer-Ejector Application

    NASA Technical Reports Server (NTRS)

    Salikuddin, M.; Kinzie, K.; Vu, D. D.; Langenbrunner, L. E.; Szczepkowski, G. T.

    2006-01-01

    The development process of liner design methodology is described in several reports. The results of the initial effort of concept development, screening, laboratory testing of various liner concepts, and preliminary correlation (generic data) are presented in a report Acoustic Characteristics of Various Treatment Panel Designs for HSCT Ejector Liner Acoustic Technology Development Program. The second phase of laboratory test results of more practical concepts and their data correlations are presented in this report (product specific). In particular, this report contains normal incidence impedance measurements of several liner types in both a static rig and in a high temperature flow duct rig. The flow duct rig allows for temperatures up to 400 F with a grazing flow up to Mach 0.8. Measurements of impedance, DC flow resistance, and in the flow rig cases, impact of the liner on boundary layer profiles are documented. In addition to liner rig tests, a limited number of tests were made on liners installed in a mixer-Ejector nozzle to confirm the performance of the liner prediction in an installed configuration.

  7. Design guidelines for avoiding thermo-acoustic oscillations in helium piping systems

    DOE PAGES

    Gupta, Prabhat Kumar; Rabehl, Roger

    2015-04-02

    Thermo-acoustic oscillations are a commonly observed phenomenon in helium cryogenic systems, especially in tubes connecting hot and cold areas. The open ends of these tubes are connected to the lower temperature (typically at 4.5 K), and the closed ends of these tubes are connected to the high temperature (300 K). Cryogenic instrumentation installations provide ideal conditions for these oscillations to occur due to the steep temperature gradient along the tubing. These oscillations create errors in measurements as well as an undesirable heat load to the system. The work presented here develops engineering guidelines to design oscillation-free helium piping. This workmore » also studies the effect of different piping inserts and shows how the proper geometrical combinations have to be chosen to avoid thermo-acoustic oscillations. The effect of an 80 K intercept is also studied and shows that thermo-oscillations can be dampened by placing the intercept at an appropriate location. As a result, the design of helium piping based on the present work is also verified with the experimental results available in open literature.« less

  8. Canonical Acoustics and Its Application to Surface Acoustic Wave on Acoustic Metamaterials

    NASA Astrophysics Data System (ADS)

    Shen, Jian Qi

    2016-08-01

    In a conventional formalism of acoustics, acoustic pressure p and velocity field u are used for characterizing acoustic waves propagating inside elastic/acoustic materials. We shall treat some fundamental problems relevant to acoustic wave propagation alternatively by using canonical acoustics (a more concise and compact formalism of acoustic dynamics), in which an acoustic scalar potential and an acoustic vector potential (Φ ,V), instead of the conventional acoustic field quantities such as acoustic pressure and velocity field (p,u) for characterizing acoustic waves, have been defined as the fundamental variables. The canonical formalism of the acoustic energy-momentum tensor is derived in terms of the acoustic potentials. Both the acoustic Hamiltonian density and the acoustic Lagrangian density have been defined, and based on this formulation, the acoustic wave quantization in a fluid is also developed. Such a formalism of acoustic potentials is employed to the problem of negative-mass-density assisted surface acoustic wave that is a highly localized surface bound state (an eigenstate of the acoustic wave equations). Since such a surface acoustic wave can be strongly confined to an interface between an acoustic metamaterial (e.g., fluid-solid composite structures with a negative dynamical mass density) and an ordinary material (with a positive mass density), it will give rise to an effect of acoustic field enhancement on the acoustic interface, and would have potential applications in acoustic device design for acoustic wave control.

  9. Design, implementation, and extension of thermal invisibility cloaks

    NASA Astrophysics Data System (ADS)

    Zhang, Youming; Xu, Hongyi; Zhang, Baile

    2015-05-01

    A thermal invisibility cloak, as inspired by optical invisibility cloaks, is a device which can steer the conductive heat flux around an isolated object without changing the ambient temperature distribution so that the object can be "invisible" to external thermal environment. While designs of thermal invisibility cloaks inherit previous theories from optical cloaks, the uniqueness of heat diffusion leads to more achievable implementations. Thermal invisibility cloaks, as well as the variations including thermal concentrator, rotator, and illusion devices, have potentials to be applied in thermal management, sensing and imaging applications. Here, we review the current knowledge of thermal invisibility cloaks in terms of their design and implementation in cloaking studies, and their extension as other functional devices.

  10. Advanced Control Design for Wind Turbines; Part I: Control Design, Implementation, and Initial Tests

    SciTech Connect

    Wright, A. D.; Fingersh, L. J.

    2008-03-01

    The purpose of this report is to give wind turbine engineers information and examples of the design, testing through simulation, field implementation, and field testing of advanced wind turbine controls.

  11. Application of acoustic surface wave filter-beam lead component technology to deep space multimission hardware design

    NASA Technical Reports Server (NTRS)

    Kermode, A. W.; Boreham, J. F.

    1974-01-01

    This paper discusses the utilization of acoustic surface wave filters, beam lead components, and thin film metallized ceramic substrate technology as applied to the design of deep space, long-life, multimission transponder. The specific design to be presented is for a second mixer local oscillator module, operating at frequencies as high as 249 MHz.

  12. Design and optimization of a noise reduction system for infrasonic measurements using elements with low acoustic impedance.

    PubMed

    Alcoverro, Benoit; Le Pichon, Alexis

    2005-04-01

    The implementation of the infrasound network of the International Monitoring System (IMS) for the enforcement of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) increases the effort in the design of suitable noise reducer systems. In this paper we present a new design consisting of low impedance elements. The dimensioning and the optimization of this discrete mechanical system are based on numerical simulations, including a complete electroacoustical modeling and a realistic wind-noise model. The frequency response and the noise reduction obtained for a given wind speed are compared to statistical noise measurements in the [0.02-4] Hz frequency band. The effects of the constructive parameters-the length of the pipes, inner diameters, summing volume, and number of air inlets-are investigated through a parametric study. The studied system consists of 32 air inlets distributed along an overall diameter of 16 m. Its frequency response is flat up to 4 Hz. For a 2 m/s wind speed, the maximal noise reduction obtained is 15 dB between 0.5 and 4 Hz. At lower frequencies, the noise reduction is improved by the use of a system of larger diameter. The main drawback is the high-frequency limitation introduced by acoustical resonances inside the pipes.

  13. Design and Implementation of Telemedicine based on Java Media Framework

    NASA Astrophysics Data System (ADS)

    Xiong, Fengguang; Jia, Zhiyan

    According to analyze the importance and problem of telemedicine in this paper, a telemedicine system based on JMF is proposed to design and implement capturing, compression, storage, transmission, reception and play of a medical audio and video. The telemedicine system can solve existing problems that medical information is not shared, platform-dependent is high, software is incompatibilities and so on. Experimental data prove that the system has low hardware cost, and is easy to transmission and storage, and is portable and powerful.

  14. Design and Implementation of a Group Membership Protocol

    DTIC Science & Technology

    1992-09-01

    AD’-A257 442 NAVAL POSTfGRADUATE SCHOOL 09 Monterey, California DTICJ~SELECTE f NOV23 199213 A ’ THESIS DESIGN AND IMPLEMENTATION OF A GROUP...MEMBERSHIP PROTOCOL by DEVALLA RAGHURAM September, 1992 Thesis Advisor: Shridhar B. Shukia Second Reader: Douglas J. Fouts Approved for public release...Year. Month, Day) 15. PAGE COUNT Master’s Thesis FROM 09/90 TO 09/92 . September 1992 127 16. SUPPLEMENTARY NOTATION The views expressed in this

  15. Design and implementation of active members for precision space structures

    NASA Technical Reports Server (NTRS)

    Webster, M. S.; Fanson, J. L.; Lurie, B. J.; O'Brien, J. F.

    1992-01-01

    This paper describes the development and implementation of an active member in a precision truss structure. The active member utilizes a piezoelectric actuator motor imbedded in a steel case with built-in displacement sensor. This active member is used in structural quieting. Collocated active damping control loops are designed in order to impedance match piezoelectric active members to the structure. Results from application of these controllers and actuators to the JPL Phase B testbed are given.

  16. Design and implementation of distributed information retrieval system

    NASA Astrophysics Data System (ADS)

    Liu, Haishu

    2013-07-01

    For the lack of robustness and scalability in the existing centralized search engine implementation, this paper presents a distributed information retrieval service system model based on search engine technology. This model can real-t imely monitor the specified information source to collect the latest informat ion in the first time and process it, for users to search, and the design is distributed, can make the system have good robustness and scalability through mutual cooperation of background nodes.

  17. Design and Implementation of the MSL Cruise Propulsion Tank Heaters

    NASA Technical Reports Server (NTRS)

    Krylo, Robert; Mikhaylov, Rebecca; Cucullu, Gordon; Watkins, Brenda

    2008-01-01

    This slide presentation reviews the design and the implementation of the heaters for the Mars Science Laboratory (MSL). The pressurized tanks store hydrazine that freezes at 2 C, this means that heaters are required to keep the hydrazine and the helium at 36 C for the trip to Mars. Using the TMG software the heat loss was analyzed, and a thermal model simulates a half full tank which yielded a 13W heating requirement for each hemisphere. Views of the design, and the heater are included.

  18. Design Principles, Implementation And Evaluation For Inquiry-Based Astronomy:

    NASA Astrophysics Data System (ADS)

    Fitzgerald, Michael

    2015-09-01

    This thesis is situated in the context of an Australian high school level astronomy intervention project which aimed to enable students to undertake real science with professional grade 2-metre class telescopes. The thesis explores the context and background within which the project was situated and the main blocking factors preventing successful implementation culminating in an outline of the education design used in, and the evaluation of, the project. This work has illustrated that with careful design and sufficient teacher training and support, inquiry-based astronomy can feasibly be undertaken in the high-school classroom.

  19. Design and implementation of Skype USB user gateway software

    NASA Astrophysics Data System (ADS)

    Qi, Yang

    2017-08-01

    With the widespread application of VoIP, the client with private protocol becomes more and more popular. Skype is one of the representatives. How to connect Skype with PSTN just by Skype client has gradually become hot. This paper design and implement the software based on a kind of USB User Gateway. With the software Skype user can freely communicate with PSTN phone. FSM is designed as the core of the software, and Skype control is separated by the USB Gateway control. In this way, the communication becomes more flexible and efficient. In the actual user testing, the software obtains good results.

  20. A formulation of metamodel implementation processes for complex systems design

    NASA Astrophysics Data System (ADS)

    Daberkow, Debora Daniela

    Complex systems design poses an interesting as well as demanding information management problem for system level integration and design. The high interconnectivity of disciplines combined with the specific knowledge and expertise in each of these calls for a system level view that is broad, as in spanning across all disciplines, while at the same time detailed enough to do the disciplinary knowledge justice. The treatment of this requires highly evolved information management and decision approaches, which result in design methodologies that can handle this high degree of complexity. The solution is to create models within the design process, which predict meaningful metrics representative of the various disciplinary analyses that can be quickly evaluated and thus serve in system level decision making and optimization. Such models approximate the physics-based analysis codes used in each of the disciplines and are called metamodels since effectively, they model the (physics-based) models on which the disciplinary analysis codes are based. The thesis formulates a new metamodel implementation process to be used in complex systems design, utilizing a Gaussian Process prediction method. It is based on a Bayesian probability and inference approach and as such returns a variance prediction along with the most likely value, thus giving an estimate also for the confidence in the prediction. Within this thesis, the applicability and appropriateness at the theoretical as well as practical level are investigated, and proof-of-concept implementations at the disciplinary and system levels are provided.

  1. Design and Experimental Validation of a USBL Underwater Acoustic Positioning System.

    PubMed

    Reis, Joel; Morgado, Marco; Batista, Pedro; Oliveira, Paulo; Silvestre, Carlos

    2016-09-14

    This paper presents the steps for developing a low-cost POrtableNavigation Tool for Underwater Scenarios (PONTUS) to be used as a localization device for subsea targets. PONTUS consists of an integrated ultra-short baseline acoustic positioning system aided by an inertial navigation system. Built on a practical design, it can be mounted on an underwater robotic vehicle or be operated by a scuba diver. It also features a graphical user interface that provides information on the tracking of the designated target, in addition to some details on the physical properties inside PONTUS. A full disclosure of the architecture of the tool is first presented, followed by thorough technical descriptions of the hardware components ensemble and the software development process. A series of experiments was carried out to validate the developed prototype, and the results are presented herein, which allow assessing its overall performance.

  2. Design and Experimental Validation of a USBL Underwater Acoustic Positioning System

    PubMed Central

    Reis, Joel; Morgado, Marco; Batista, Pedro; Oliveira, Paulo; Silvestre, Carlos

    2016-01-01

    This paper presents the steps for developing a low-cost POrtableNavigation Tool for Underwater Scenarios (PONTUS) to be used as a localization device for subsea targets. PONTUS consists of an integrated ultra-short baseline acoustic positioning system aided by an inertial navigation system. Built on a practical design, it can be mounted on an underwater robotic vehicle or be operated by a scuba diver. It also features a graphical user interface that provides information on the tracking of the designated target, in addition to some details on the physical properties inside PONTUS. A full disclosure of the architecture of the tool is first presented, followed by thorough technical descriptions of the hardware components ensemble and the software development process. A series of experiments was carried out to validate the developed prototype, and the results are presented herein, which allow assessing its overall performance. PMID:27649181

  3. The design and flight test of an engine inlet bulk acoustic liner

    NASA Technical Reports Server (NTRS)

    Lester, H. C.; Preisser, J. S.; Parrott, T. L.

    1983-01-01

    This paper summarizes the design, fabrication and flight evaluation of a Kevlar acoustic liner configuration for a JT15D turbofan engine. The liner was designed to suppress, by a measurable amount, a dominant (13,0) BPF tone. This tone or spinning mode was produced for research purposes by installing 41 circumferentially distributed small diameter rods upstream of the 28 fan blades. Duct liner attenuations calculated by a finite element procedure were compared to far field power (insertion) losses deduced from flight data. The finite element program modeled the variable geometry of the JT15D inlet and used a uniform flow with a boundary layer roll-off to model the inlet flow field. Calculated liner losses were generally conservative. That is, measured far field power losses were generally greater than attenuations calculated by the finite element computer program.

  4. Implementing an online pharmaceutical service using design science research.

    PubMed

    Lapão, Luís Velez; da Silva, Miguel Mira; Gregório, João

    2017-03-27

    The rising prevalence of chronic diseases is pressing health systems to introduce reforms. Primary healthcare and multidisciplinary models have been suggested as approaches to deal with this challenge, with new roles for nurses and pharmacists being advocated. More recently, implementing healthcare based on information systems and technologies (e.g. eHealth) has been proposed as a way to improve health services. However, implementing online pharmaceutical services, including their adoption by pharmacists and patients, is still an open research question. In this paper we present ePharmacare, a new online pharmaceutical service implemented using Design Science Research. The Design Science Research Methodology (DSRM) was chosen to implement this online service for chronic diseases management. In the paper, DSRM's different activities are explained, from the definition of the problem to the evaluation of the artifact. During the design and development activities, surveys, observations, focus groups, and eye-tracking glasses were used to validate pharmacists' and patients' requirements. During the demonstration and evaluation activities the new service was used with real-world pharmacists and patients. The results show the contribution of DSRM in the implementation of online services for pharmacies. We found that pharmacists spend only 50% of their time interacting with patients, uncovering a clear opportunity to implement online pharmaceutical care services. On the other hand, patients that regularly visit the same pharmacy recognize the value in patient follow-up demanding to use channels such as the Internet for their pharmacy interactions. Limitations were identified regarding the high workload of pharmacists, but particularly their lack of know-how and experience in dealing with information systems (IST) for the provision of pharmaceutical services. This paper summarizes a research project in which an online pharmaceutical service was proposed, designed, developed

  5. A microfluidic-based hydrodynamic trap: design and implementation.

    PubMed

    Tanyeri, Melikhan; Ranka, Mikhil; Sittipolkul, Natawan; Schroeder, Charles M

    2011-05-21

    We report an integrated microfluidic device for fine-scale manipulation and confinement of micro- and nanoscale particles in free-solution. Using this device, single particles are trapped in a stagnation point flow at the junction of two intersecting microchannels. The hydrodynamic trap is based on active flow control at a fluid stagnation point using an integrated on-chip valve in a monolithic PDMS-based microfluidic device. In this work, we characterize device design parameters enabling precise control of stagnation point position for efficient trap performance. The microfluidic-based hydrodynamic trap facilitates particle trapping using the sole action of fluid flow and provides a viable alternative to existing confinement and manipulation techniques based on electric, optical, magnetic or acoustic force fields. Overall, the hydrodynamic trap enables non-contact confinement of fluorescent and non-fluorescent particles for extended times and provides a new platform for fundamental studies in biology, biotechnology and materials science. © The Royal Society of Chemistry 2011

  6. Design flow for implementing image processing in FPGAs

    NASA Astrophysics Data System (ADS)

    Trakalo, M.; Giles, G.

    2007-04-01

    A design flow for implementing a dynamic gamma algorithm in an FPGA is described. Real-time video processing makes enormous demands on processing resources. An FPGA solution offers some advantages over commercial video chip and DSP implementation alternatives. The traditional approach to FPGA development involves a system engineer designing, modeling and verifying an algorithm and writing a specification. A hardware engineer uses the specification as a basis for coding in VHDL and testing the algorithm in the FPGA with supporting electronics. This process is work intensive and the verification of the image processing algorithm executing on the FPGA does not occur until late in the program. The described design process allows the system engineer to design and verify a true VHDL version of the algorithm, executing in an FPGA. This process yields reduced risk and development time. The process is achieved by using Xilinx System Generator in conjunction with Simulink® from The MathWorks. System Generator is a tool that bridges the gap between the high level modeling environment and the digital world of the FPGA. System Generator is used to develop the dynamic gamma algorithm for the contrast enhancement of a candidate display product. The results of this effort are to increase the dynamic range of the displayed video, resulting in a more useful image for the user.

  7. Implementation of an acoustic emission proximity detector for use in generating glass optics

    SciTech Connect

    Piscotty, M.A.; Taylor, J.S.; Blaedel, K.L.

    1996-12-31

    The use acoustic emission (AE) sensing as a method to monitor proximity between a grinding wheel and a brittle material workpiece is being developed at Lawrence Livermore National Laboratory (LLNL) and the Center for Optics Manufacturing (COM) in Rochester, NY. Significantly reducing the amount of expensive {open_quote}air-grinding{close_quote} is one of the primary motivations behind this effort, along with lessening the chances of a crash which could damage the wheel, part and machine tool. AE sensing is well developed and routinely used in the metal working industry for {open_quote}initial contact{close_quote} sensing or tool breakage, for example, and in monitoring diamond turning and grinding processes. However, using AE sensing to switch from a rapid to a final in-feed rate at the detection of initial-contact between the grinding wheel and a brittle material workpiece, such as an optical glass, is often unacceptable during fine grinding (less than 10 {mu}m grit wheels) which produce surfaces with roughness values of 100 {Angstrom} rms or less. In the approach taken here, the authors are sensing the AE prior to contact between the workpiece and the tool. The coolant between the workpiece and the grinding wheel is used as an AE medium to transfer AE signals generated by the relative motions of the coolant, workpiece and wheel. Capitalizing on the repeatability of the AE approach signal, the authors have developed a system to detect the proximity of the grinding wheel relative to the workpiece prior to initial contact.

  8. Preliminary vibration, acoustic, and shock design and test criteria for components on the Lightweight External Tank (LWT)

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The Space Shuttle LWT is divided into zones and subzones. Zones are designated primarily to assist in determining the applicable specifications. A subzone (general Specification) is available for use when the location of the component is known but component design and weight are not well defined. When the location, weight, and mounting configuration of the component are known, specifications for appropriate subzone weight ranges are available. Along with the specifications are vibration, acoustic, shock, transportation, handling, and acceptance test requirements and procedures. A method of selecting applicable vibration, acoustic, and shock specifications is presented.

  9. Virtual sensors for active noise control in acoustic-structural coupled enclosures using structural sensing: robust virtual sensor design.

    PubMed

    Halim, Dunant; Cheng, Li; Su, Zhongqing

    2011-03-01

    The work was aimed to develop a robust virtual sensing design methodology for sensing and active control applications of vibro-acoustic systems. The proposed virtual sensor was designed to estimate a broadband acoustic interior sound pressure using structural sensors, with robustness against certain dynamic uncertainties occurring in an acoustic-structural coupled enclosure. A convex combination of Kalman sub-filters was used during the design, accommodating different sets of perturbed dynamic model of the vibro-acoustic enclosure. A minimax optimization problem was set up to determine an optimal convex combination of Kalman sub-filters, ensuring an optimal worst-case virtual sensing performance. The virtual sensing and active noise control performance was numerically investigated on a rectangular panel-cavity system. It was demonstrated that the proposed virtual sensor could accurately estimate the interior sound pressure, particularly the one dominated by cavity-controlled modes, by using a structural sensor. With such a virtual sensing technique, effective active noise control performance was also obtained even for the worst-case dynamics. © 2011 Acoustical Society of America

  10. Design and analysis of air acoustic vector-sensor configurations for two-dimensional geometry.

    PubMed

    Wajid, Mohd; Kumar, Arun; Bahl, Rajendar

    2016-05-01

    Acoustic vector-sensors (AVS) have been designed using the P-P method for different microphone configurations. These configurations have been used to project the acoustic intensity on the orthogonal axes through which the direction of arrival (DoA) of a sound source has been estimated. The analytical expressions for the DoA for different microphone configurations have been derived for two-dimensional geometry. Finite element method simulation using COMSOL-Multiphysics has been performed, where the microphone signals for AVS configurations have been recorded in free field conditions. The performance of all the configurations has been evaluated with respect to angular error and root-mean-square angular error. The simulation results obtained with ideal geometry for different configurations have been corroborated experimentally with prototype AVS realizations and also compared with microphone-array method, viz., Multiple Signal Classification and Generalized Cross Correlation. Experiments have been performed in an anechoic room using different prototype AVS configurations made from small size microphones. The DoA performance using analytical expressions, simulation studies, and experiments with prototype AVS in anechoic chamber are presented in the paper. The square and delta configurations are found to perform better in the absence and presence of noise, respectively.

  11. Effect of design changes on aerodynamic and acoustic performance of translating-centerbody sonic inlets

    NASA Technical Reports Server (NTRS)

    Miller, B. A.

    1978-01-01

    An experimental investigation was conducted to determine the effect of design changes on the aerodynamic and acoustic performance of translating centerbody sonic inlets. Scale model inlets were tested in the Lewis Research Center's V/STOL wind tunnel. The effects of centerbody position, entry lip contraction ratio, diffuser length, and diffuser area ratio on inlet total pressure recovery, distortion, and noise suppression were investigated at static conditions and at forward velocity and angle of attack. With the centerbody in the takeoff position (retracted), good aerodynamic and acoustic performance was attained at static conditions and at forward velocity. At 0 deg incidence angle with a sound pressure level reduction of 20 dB, the total pressure recovery was 0.986. Pressure recovery at 50 deg was 0.981. With the centerbody in the approach position (extended), diffuser flow separation occurred at an incidence angle of approximately 20 deg. However, good performance was attained at lower angles. With the centerbody in the takeoff position the ability of the inlet to tolerate high incidence angles was improved by increasing the lip contraction ratio. However, at static conditions with the centerbody in the approach position, an optimum lip contraction ratio appears to exist, with both thinner and thicker lips yielding reduced performance.

  12. Design of a robust underwater acoustic communication system over multipath fading channels

    NASA Astrophysics Data System (ADS)

    Kim, Jangeun; Shim, Taebo

    2012-11-01

    Due to the surface and bottom constraints of the underwater acoustic channel (UAC) in shallow waters, multipath fading occurs and causes degradation of the signal for the UAC system. To overcome these problems, a robust underwater acoustic communication system was designed over multipath fading channels by employing both decision feedback equalization with the RLS algorithm and convolutional coding with interleaving+shuffling block data sequence. The dual use of these two methods simultaneously can reduce the intersymbol interference (ISI) and the adjacent bit and burst errors. The system will retransmit the same signal if the system fails to estimate the channel due to severe multipath fading. To verify the performance of the system, the transmission of an image was tested using a 524,288bit gray-scaled image through the multipath fading channel. The test results showed that the number of bit errors was reduced from 86,824 to 5,106 when the reference SNR was 12 dB.

  13. Acoustic specifications for the design of jet engine test facilities on an airbase

    SciTech Connect

    Strumpf, F.M.

    1982-01-01

    The use of engine run up test arrangements was common in Israeli air-bases since the forties, when engines for the Mustang, Mosquito, Harward and other propellor powered planes were used. The era of jet engine propulsion boosted the noise levels, and the use of fighters with afterburners in the new engines of the 80's brought it up to unbearable levels. Thus, the growth of the Israeli Air Force demanded the use of efficient noise suppression devices. These were divided into engine run-up noise suppressors, and aircraft noise suppessors (Hush Houses). For both of the bove ground arrangements, acoustic specifications had to be given. They were, as well as design goals for the manufacturers, also needed to restrict noise levels on the air-base as well as its surroundings. The acoustic specifications discussed are based on measured data, and permitted noise levels in the homes on the base being as far as 2500 meters from the engine exhaust silencer. For the special air-base discussed, various criteria were tested, including US Military Specifications, none of which were acceptable, and a special specification was therefore prepared.

  14. Design and implementation of a web-enabled haematological system.

    PubMed

    Gortzis, Lefteris; Koubias, Stavros; Nikiforidis, George

    2004-09-01

    This paper describes the design and the implementation of a web-enabled integrated haematological system, named e-HS. The proposed system runs on a set of distributed network nodes providing useful haematological services. These services include patient-oriented data management, digitized histopathological slides (DHS) acquisition, teleconsulting facilities, etc. The objective of e-HS is to supply web-enabled services according to haematological requirements, implement a distributed storage scheme for DHS, and provide a common database containing all haematological laboratory results by using eXtensible Markup Language (XML) and web technologies. Our implementation can be accessible to every authorized physician at the distributed nodes without any additional software. The only software required for the user is the widely used browser (e.g. MS Internet Explorer v 3.02 or higher). Besides, by using a self-explaining user interfaces and HTML-techniques, such as hyperlinks, the necessary amount of training at the physicians-side is reduced to a minimum. A first implementation of the e-HS, has been established at the Medical Physics Department of the University of Patras (master node of the system), and has been tested with success by the medical staff of the Hospital Departments of the University of Patras and Thessalonica that served as distributed nodes of the system.

  15. Design and implementation of robust controllers for a gait trainer.

    PubMed

    Wang, F C; Yu, C H; Chou, T Y

    2009-08-01

    This paper applies robust algorithms to control an active gait trainer for children with walking disabilities. Compared with traditional rehabilitation procedures, in which two or three trainers are required to assist the patient, a motor-driven mechanism was constructed to improve the efficiency of the procedures. First, a six-bar mechanism was designed and constructed to mimic the trajectory of children's ankles in walking. Second, system identification techniques were applied to obtain system transfer functions at different operating points by experiments. Third, robust control algorithms were used to design Hinfinity robust controllers for the system. Finally, the designed controllers were implemented to verify experimentally the system performance. From the results, the proposed robust control strategies are shown to be effective.

  16. A Components Database Design and Implementation for Accelerators and Detectors

    SciTech Connect

    Chan, A.; Meyer, S.; /SLAC

    2011-08-31

    Many accelerator and detector systems being fabricated for the PEP-II Accelerator and BABAR Detector needed configuration control and calibration measurements tracked for their components. Instead of building a database for each distinct system, a Components Database was designed and implemented that can encompass any type of component and any type of measurement. In this paper we describe this database design that is especially suited for the engineering and fabrication processes of the accelerator and detector environments where there are thousands of unique component types. We give examples of information stored in the Components Database, which includes accelerator configuration, calibration measurements, fabrication history, design specifications, inventory, etc. The World Wide Web interface is used to access the data, and templates are available for international collaborations to collect data off-line.

  17. Design and implementation of fishery rescue data mart system

    NASA Astrophysics Data System (ADS)

    Pan, Jun; Huang, Haiguang; Liu, Yousong

    A novel data mart based system for fishery rescue field was designed and implemented. The system runs ETL process to deal with original data from various databases and data warehouses, and then reorganized the data into the fishery rescue data mart. Next, online analytical processing (OLAP) are carried out and statistical reports are generated automatically. Particularly, quick configuration schemes are designed to configure query dimensions and OLAP data sets. The configuration file will be transformed into statistic interfaces automatically through a wizard-style process. The system provides various forms of reporting files, including crystal reports, flash graphical reports, and two-dimensional data grids. In addition, a wizard style interface was designed to guide users customizing inquiry processes, making it possible for nontechnical staffs to access customized reports. Characterized by quick configuration, safeness and flexibility, the system has been successfully applied in city fishery rescue department.

  18. Piezoelectric actuator design for MR elastography: implementation and vibration issues.

    PubMed

    Tse, Zion Tsz Ho; Chan, Yum Ji; Janssen, Henning; Hamed, Abbi; Young, Ian; Lamperth, Michael

    2011-09-01

    MR elastography (MRE) is an emerging technique for tumor diagnosis. MRE actuation devices require precise mechanical design and radiofrequency engineering to achieve the required mechanical vibration performance and MR compatibility. A method of designing a general-purpose, compact and inexpensive MRE actuator is presented. It comprises piezoelectric bimorphs arranged in a resonant structure designed to operate at its resonant frequency for maximum vibration amplitude. An analytical model was established to understand the device vibration characteristics. The model-predicted performance was validated in experiments, showing its accuracy in predicting the actuator resonant frequency with an error < 4%. The device MRI compatibility was shown to cause minimal interference to a 1.5 tesla MRI scanner, with maximum signal-to-noise ratio reduction of 7.8% and generated artefact of 7.9 mm in MR images. A piezoelectric MRE actuator is proposed, and its implementation, vibration issues and future work are discussed. Copyright © 2011 John Wiley & Sons, Ltd.

  19. Integrated Design and Implementation of Embedded Control Systems with Scilab.

    PubMed

    Ma, Longhua; Xia, Feng; Peng, Zhe

    2008-09-05

    Embedded systems are playing an increasingly important role in control engineering. Despite their popularity, embedded systems are generally subject to resource constraints and it is therefore difficult to build complex control systems on embedded platforms. Traditionally, the design and implementation of control systems are often separated, which causes the development of embedded control systems to be highly timeconsuming and costly. To address these problems, this paper presents a low-cost, reusable, reconfigurable platform that enables integrated design and implementation of embedded control systems. To minimize the cost, free and open source software packages such as Linux and Scilab are used. Scilab is ported to the embedded ARM-Linux system. The drivers for interfacing Scilab with several communication protocols including serial, Ethernet, and Modbus are developed. Experiments are conducted to test the developed embedded platform. The use of Scilab enables implementation of complex control algorithms on embedded platforms. With the developed platform, it is possible to perform all phases of the development cycle of embedded control systems in a unified environment, thus facilitating the reduction of development time and cost.

  20. Integrated Design and Implementation of Embedded Control Systems with Scilab

    PubMed Central

    Ma, Longhua; Xia, Feng; Peng, Zhe

    2008-01-01

    Embedded systems are playing an increasingly important role in control engineering. Despite their popularity, embedded systems are generally subject to resource constraints and it is therefore difficult to build complex control systems on embedded platforms. Traditionally, the design and implementation of control systems are often separated, which causes the development of embedded control systems to be highly time-consuming and costly. To address these problems, this paper presents a low-cost, reusable, reconfigurable platform that enables integrated design and implementation of embedded control systems. To minimize the cost, free and open source software packages such as Linux and Scilab are used. Scilab is ported to the embedded ARM-Linux system. The drivers for interfacing Scilab with several communication protocols including serial, Ethernet, and Modbus are developed. Experiments are conducted to test the developed embedded platform. The use of Scilab enables implementation of complex control algorithms on embedded platforms. With the developed platform, it is possible to perform all phases of the development cycle of embedded control systems in a unified environment, thus facilitating the reduction of development time and cost. PMID:27873827

  1. Design and implementation of a multi-institution immunization registry.

    PubMed

    Jenders, R A; Dasgupta, B; Mercedes, D; Clayton, P D

    1998-01-01

    One of every four children in the USA is underimmunized. Surveys of children in New York City have documented rates of appropriate immunization as low as 37% in certain populations in northern Manhattan. In response to this, government and private agencies have undertaken efforts to improve immunization rates. As part of one such multiinstitution effort in northern Manhattan, we have begun implementation of a computer-based immunization registry. Key features of this registry system include adaptation of legacy software in order to perform initial capture of data in electronic format; design of a user interface using a World Wide Web server that provides data review and capture functions with appropriate security; implementation of a registry database with links to the server, communication links between hospital registration systems, a Master Patient Index, community providers and the central registry; and integration of decision support in the form of Medical Logic Modules encoded in the Arden Syntax. We discuss our design of this multi-institution immunization registry and implementation efforts to date.

  2. Design and Implementation of a Project-Based Active/Cooperative Engineering Design Course for Freshmen

    ERIC Educational Resources Information Center

    Abdulaal, R. M.; Al-Bahi, A. M.; Soliman, A. Y.; Iskanderani, F. I.

    2011-01-01

    A project-based active/cooperative design course is planned, implemented, assessed and evaluated to achieve several desired engineering outcomes. The course allows freshman-level students to gain professional hands-on engineering design experience through an opportunity to practise teamwork, quality principles, communication skills, life-long…

  3. Design and Implementation of a Project-Based Active/Cooperative Engineering Design Course for Freshmen

    ERIC Educational Resources Information Center

    Abdulaal, R. M.; Al-Bahi, A. M.; Soliman, A. Y.; Iskanderani, F. I.

    2011-01-01

    A project-based active/cooperative design course is planned, implemented, assessed and evaluated to achieve several desired engineering outcomes. The course allows freshman-level students to gain professional hands-on engineering design experience through an opportunity to practise teamwork, quality principles, communication skills, life-long…

  4. Implementation and Comparison of Acoustic Travel-Time Measurement Procedures for the Helioseismic and Magnetic Imager Time-Distance Helioseismology Pipeline

    NASA Technical Reports Server (NTRS)

    Couvidat, S.; Zhao, J.; Birch, A. C.; Kosovichev, A. G.; Duvall, T. L., Jr.; Parchevsky, K.; Scherrer, P. H.

    2009-01-01

    The Helioseismic and Magnetic Imager (HMI) instrument on board the Solar Dynamics Observatory (SDO) satellite is designed to produce high-resolution Doppler velocity maps of oscillations at the solar surface with high temporal cadence. To take advantage of these high-quality oscillation data, a time-distance helioseismology pipeline has been implemented at the Joint Science Operations Center (JSOC) at Stanford University. The aim of this pipeline is to generate maps of acoustic travel times from oscillations on the solar surface, and to infer subsurface 3D flow velocities and sound-speed perturbations. The wave travel times are measured from cross covariances of the observed solar oscillation signals. For implementation into the pipeline we have investigated three different travel-time definitions developed in time-distance helioseismology: a Gabor wavelet fitting (Kosovichev and Duvall, 1997), a minimization relative to a reference cross-covariance function (Gizon and Birch, 2002), and a linearized version of the minimization method (Gizon and Birch, 2004). Using Doppler velocity data from the Michelson Doppler Imager (MDI) instrument on board SOHO, we tested and compared these definitions for the mean and difference travel-time perturbations measured from reciprocal signals. Although all three procedures return similar travel times in a quiet Sun region, the method of Gizon and Birch (2004) gives travel times that are significantly different from the others in a magnetic (active) region. Thus, for the pipeline implementation we chose the procedures of Kosovichev and Duvall (1997) and Gizon and Birch (2002). We investigated the relationships among these three travel-time definitions, their sensitivities to fitting parameters, and estimated the random errors they produce

  5. Implementation and Comparison of Acoustic Travel-Time Measurement Procedures for the Solar Dynamics Observatory/Helioseismic and Magnetic Imager Time - Distance Helioseismology Pipeline

    NASA Astrophysics Data System (ADS)

    Couvidat, S.; Zhao, J.; Birch, A. C.; Kosovichev, A. G.; Duvall, T. L.; Parchevsky, K.; Scherrer, P. H.

    2012-01-01

    The Helioseismic and Magnetic Imager (HMI) instrument onboard the Solar Dynamics Observatory (SDO) satellite is designed to produce high-resolution Doppler-velocity maps of oscillations at the solar surface with high temporal cadence. To take advantage of these high-quality oscillation data, a time - distance helioseismology pipeline (Zhao et al., Solar Phys. submitted, 2010) has been implemented at the Joint Science Operations Center (JSOC) at Stanford University. The aim of this pipeline is to generate maps of acoustic travel times from oscillations on the solar surface, and to infer subsurface 3D flow velocities and sound-speed perturbations. The wave travel times are measured from cross-covariances of the observed solar oscillation signals. For implementation into the pipeline we have investigated three different travel-time definitions developed in time - distance helioseismology: a Gabor-wavelet fitting (Kosovichev and Duvall, SCORE’96: Solar Convection and Oscillations and Their Relationship, ASSL, Dordrecht, 241, 1997), a minimization relative to a reference cross-covariance function (Gizon and Birch, Astrophys. J. 571, 966, 2002), and a linearized version of the minimization method (Gizon and Birch, Astrophys. J. 614, 472, 2004). Using Doppler-velocity data from the Michelson Doppler Imager (MDI) instrument onboard SOHO, we tested and compared these definitions for the mean and difference travel-time perturbations measured from reciprocal signals. Although all three procedures return similar travel times in a quiet-Sun region, the method of Gizon and Birch ( Astrophys. J. 614, 472, 2004) gives travel times that are significantly different from the others in a magnetic (active) region. Thus, for the pipeline implementation we chose the procedures of Kosovichev and Duvall ( SCORE’96: Solar Convection and Oscillations and Their Relationship, ASSL, Dordrecht, 241, 1997) and Gizon and Birch ( Astrophys. J. 571, 966, 2002). We investigated the relationships

  6. Implementation and Comparison of Acoustic Travel-Time Measurement Procedures for the Solar Dynamics Observatory-Helioseismic and Magnetic Imager Time-Distance Helioseismology Pipeline

    NASA Technical Reports Server (NTRS)

    Couvidat, S.; Zhao, J.; Birch, A. C.; Kosovichev, A. G.; Duvall, Thomas L., Jr.; Parchevsky, K.; Scherrer, P. H.

    2010-01-01

    The Helioseismic and Magnetic Imager (HMI) instrument onboard the Solar Dynamics Observatory (SDO) satellite is designed to produce high-resolution Doppler-velocity maps of oscillations at the solar surface with high temporal cadence. To take advantage of these high-quality oscillation data, a time - distance helioseismology pipeline (Zhao et al., Solar Phys. submitted, 2010) has been implemented at the Joint Science Operations Center (JSOC) at Stanford University. The aim of this pipeline is to generate maps of acoustic travel times from oscillations on the solar surface, and to infer subsurface 3D flow velocities and sound-speed perturbations. The wave travel times are measured from cross-covariances of the observed solar oscillation signals. For implementation into the pipeline we have investigated three different travel-time definitions developed in time - distance helioseismology: a Gabor-wavelet fitting (Kosovichev and Duvall, SCORE'96: Solar Convection and Oscillations and Their Relationship, ASSL, Dordrecht, 241, 1997), a minimization relative to a reference cross-covariance function (Gizon and Birch, Astrophys. J. 571, 966, 2002), and a linearized version of the minimization method (Gizon and Birch, Astrophys. J. 614, 472, 2004). Using Doppler-velocity data from the Michelson Doppler Imager (MDI) instrument onboard SOHO, we tested and compared these definitions for the mean and difference traveltime perturbations measured from reciprocal signals. Although all three procedures return similar travel times in a quiet-Sun region, the method of Gizon and Birch (Astrophys. J. 614, 472, 2004) gives travel times that are significantly different from the others in a magnetic (active) region. Thus, for the pipeline implementation we chose the procedures of Kosovichev and Duvall (SCORE'96: Solar Convection and Oscillations and Their Relationship, ASSL, Dordrecht, 241, 1997) and Gizon and Birch (Astrophys. J. 571, 966, 2002). We investigated the relationships among

  7. Implementation and Comparison of Acoustic Travel-Time Measurement Procedures for the Helioseismic and Magnetic Imager Time-Distance Helioseismology Pipeline

    NASA Technical Reports Server (NTRS)

    Couvidat, S.; Zhao, J.; Birch, A. C.; Kosovichev, A. G.; Duvall, T. L., Jr.; Parchevsky, K.; Scherrer, P. H.

    2009-01-01

    The Helioseismic and Magnetic Imager (HMI) instrument on board the Solar Dynamics Observatory (SDO) satellite is designed to produce high-resolution Doppler velocity maps of oscillations at the solar surface with high temporal cadence. To take advantage of these high-quality oscillation data, a time-distance helioseismology pipeline has been implemented at the Joint Science Operations Center (JSOC) at Stanford University. The aim of this pipeline is to generate maps of acoustic travel times from oscillations on the solar surface, and to infer subsurface 3D flow velocities and sound-speed perturbations. The wave travel times are measured from cross covariances of the observed solar oscillation signals. For implementation into the pipeline we have investigated three different travel-time definitions developed in time-distance helioseismology: a Gabor wavelet fitting (Kosovichev and Duvall, 1997), a minimization relative to a reference cross-covariance function (Gizon and Birch, 2002), and a linearized version of the minimization method (Gizon and Birch, 2004). Using Doppler velocity data from the Michelson Doppler Imager (MDI) instrument on board SOHO, we tested and compared these definitions for the mean and difference travel-time perturbations measured from reciprocal signals. Although all three procedures return similar travel times in a quiet Sun region, the method of Gizon and Birch (2004) gives travel times that are significantly different from the others in a magnetic (active) region. Thus, for the pipeline implementation we chose the procedures of Kosovichev and Duvall (1997) and Gizon and Birch (2002). We investigated the relationships among these three travel-time definitions, their sensitivities to fitting parameters, and estimated the random errors they produce

  8. Design considerations for the acoustic emission testing of large composite specimens

    NASA Astrophysics Data System (ADS)

    Scholey, Jonathan J.; Wilcox, Paul D.; Wisnom, Michael R.; Friswell, Mike I.

    2009-03-01

    Acoustic emission (AE) testing is a sensitive technique capable of detecting many types of defect with a sparse sensor array making it an attractive structural health monitoring technology. The widespread application of the technology is limited by a lack of predictive modelling and in part, the lack of quantitative source characteristics. The vast majority of current laboratory AE testing is conducted on small coupons which cannot be used to generate quantitative source characteristics since reflected wave energy from the specimen edges influences the received waveforms. An alternative approach is to test on large specimens where the modal properties of propagating waves can be examined with no influence from reflected wave energy. However, the design and testing of large specimens is not trivial. The work in this paper discusses the design of large fibre reinforced composite (FRC) specimens which are suitable for making quantitative source measurements. The design considerations include the minimum plate dimensions and placement of sensors. A novel technique, referred to as the location-time plot technique, is described which links propagation characteristics, specimen dimensions and sensor locations to map the dispersion of elastic waves in plates. The technique is demonstrated in the design of a simple AE experiment on a highly anisotropic plate. The technique is then used in the design of a practical AE testing arrangement for monitoring delamination from artificial defects in a large FRC plate. Experimental waveforms, recorded using this AE testing arrangement, are presented and are shown to be in agreement with the location-time plot technique.

  9. A debugging system for azimuthally acoustic logging tools based on modular and hierarchical design ideas

    NASA Astrophysics Data System (ADS)

    Zhang, K.; Ju, X. D.; Lu, J. Q.; Men, B. Y.

    2016-08-01

    On the basis of modular and hierarchical design ideas, this study presents a debugging system for an azimuthally sensitive acoustic bond tool (AABT). The debugging system includes three parts: a personal computer (PC), embedded front-end machine and function expansion boards. Modular and hierarchical design ideas are conducted in all design and debug processes. The PC communicates with the front-end machine via the Internet, and the front-end machine and function expansion boards connect each other by the extended parallel bus. In this method, the three parts of the debugging system form stable and high-speed data communication. This study not only introduces the system-level debugging and sub-system level debugging of the tool but also the debugging of the analogue signal processing board, which is important and greatly used in logging tools. Experiments illustrate that the debugging system can greatly improve AABT verification and calibration efficiency and that, board-level debugging can examine and improve analogue signal processing boards. The design thinking is clear and the design structure is reasonable, thus making it easy to extend and upgrade the debugging system.

  10. Design and implementation of spaceborne high resolution infrared touch screen

    NASA Astrophysics Data System (ADS)

    Li, Tai-guo; Li, Wen-xin; Dong, Yi-peng; Ma, Wen; Xia, Jia-gao

    2015-10-01

    For the consideration of the special application environment of the electronic products used in aerospace and to further more improve the human-computer interaction of the manned aerospace area. The research is based on the design and implementation way of the high resolution spaceborne infrared touch screen on the basis of FPGA and DSP frame structure. Beside the introduction of the whole structure for the high resolution spaceborne infrared touch screen system, this essay also gives the detail information about design of hardware for the high resolution spaceborne infrared touch screen system, FPGA design, GUI design and DSP algorithm design based on Lagrange interpolation. What is more, the easy makes a comprehensive research of the reliability design for the high resolution spaceborne infrared touch screen for the special purpose of it. Besides, the system test is done after installation of spaceborne infrared touch screen. The test result shows that the system is simple and reliable enough, which has a stable running environment and high resolution, which certainly can meet the special requirement of the manned aerospace instrument products.

  11. Design and implementation of MPI on Puma portals

    SciTech Connect

    Brightwell, R.; Shuler, L.

    1996-07-01

    As the successor to SUNMOS [8], the Puma operating system provides a flexible, lightweight, high performance message passing environment for massively parallel computers. Message passing in Puma is accomplished through the use of a new mechanism known as a portal. Puma is currently running on the Intel Paragon and is being developed for the Intel TeraFLOPS machine. In this paper we discuss issues regarding the development of the Argonne National Laboratory/Mississippi State University implementation of the Message Passing Interface standard on top of portals. Included is a description of the design and implementation for both MPI point-to- point and collective communications, and MPI-2 one-sided communications.

  12. In-flight acoustic results from an advanced-design propeller at Mach numbers to 0.8

    NASA Technical Reports Server (NTRS)

    Mackall, K. G.; Lasagna, P. L.; Walsh, K.; Dittmar, J. H.

    1982-01-01

    Acoustic data for the advanced-design SR-3 propeller at Mach numbers to 0.8 and helical tip Mach numbers to 1.14 are presented. Several advanced-design propellers, previously tested in wind tunnels at the Lewis Research Center, are being tested in flight at the Dryden Flight Research Facility. The flight-test propellers are mounted on a pylon on the top of the fuselage of a JetStar airplane. Instrumentation provides near-field acoustic data for the SR-3. Acoustic data for the SR-3 propeller at Mach numbers up to 0.8, for propeller helical tip Mach numbers up to 1.14, and comparison of wind tunnel to flight data are included. Flowfield profiles measured in the area adjacent to the propeller are also included.

  13. On the design and implementation of linear differential microphone arrays.

    PubMed

    Chen, Jingdong; Benesty, Jacob; Pan, Chao

    2014-12-01

    Differential microphone array (DMA), a particular kind of sensor array that is responsive to the differential sound pressure field, has a broad range of applications in sound recording, noise reduction, signal separation, dereverberation, etc. Traditionally, an Nth-order DMA is formed by combining, in a linear manner, the outputs of a number of DMAs up to (including) the order of N - 1. This method, though simple and easy to implement, suffers from a number of drawbacks and practical limitations. This paper presents an approach to the design of linear DMAs. The proposed technique first transforms the microphone array signals into the short-time Fourier transform (STFT) domain and then converts the DMA beamforming design to simple linear systems to solve. It is shown that this approach is much more flexible as compared to the traditional methods in the design of different directivity patterns. Methods are also presented to deal with the white noise amplification problem that is considered to be the biggest hurdle for DMAs, particularly higher-order implementations.

  14. Optimization of Infobutton Design and Implementation: A Systematic Review.

    PubMed

    Teixeira, Miguel; Cook, David A; Heale, Bret S E; Del Fiol, Guilherme

    2017-08-21

    Infobuttons are clinical decision tools embedded in the electronic health record that attempt to link clinical data with context sensitive knowledge resources. We systematically reviewed technical approaches that contribute to improved infobutton design, implementation and functionality. We searched databases including MEDLINE, EMBASE, and the Cochrane Library database from inception to March 1, 2016 for studies describing the use of infobuttons. We selected full review comparative studies, usability studies, and qualitative studies examining infobutton design and implementation. We abstracted usability measures such as user satisfaction, impact, and efficiency, as well as prediction accuracy of infobutton content retrieval algorithms and infobutton adoption/interoperability. We found 82 original research studies on infobuttons. Twelve studies met criteria for detailed abstraction. These studies investigated infobutton interoperability (1 study); tools to help tailor infobutton functionality (1 study); interventions to improve user experience (7 studies); and interventions to improve content retrieval by improving prediction of relevant knowledge resources and information needs (3 studies). In-depth interviews with implementers showed the Health Level Seven (HL7) Infobutton standard to be simple and easy to implement. A usability study demonstrated the feasibility of a tool to help medical librarians tailor infobutton functionality. User experience studies showed that access to resources with which users are familiar increased user satisfaction ratings; and that links to specific subsections of drug monographs increased information seeking efficiency. However, none of the user experience improvements led to increased usage uptake. Recommender systems based on machine learning algorithms outperformed hand-crafted rules in the prediction of relevant resources and clinicians' information needs in a laboratory setting, but no studies were found using these techniques

  15. Design Guidelines for Avoiding Thermo-Acoustic Oscillations in Helium Piping Systems

    SciTech Connect

    Gupta, Prabhat Kumar; Rabehl, Roger

    2014-01-01

    Thermo-acoustic oscillations are a commonly observed phenomenon in helium cryogenic systems, especially in tubes connecting hot and cold areas. The open ends of these tubes are connected to the lower temperature (typically at 4.2 K), and the closed ends of these tubes are connected to the high temperature (300K). Cryogenic instrumentation installations provide ideal conditions for these oscillations to occur due to the steep temperature gradient along the tubing. These oscillations create errors in measurements as well as an undesirable heat load to the system. The work presented here develops engineering guidelines to design oscillation-free helium piping. This work also studies the effect of different piping inserts and shows how the proper geometrical combinations have to be chosen to avoid thermo-oscillations. The effect of an 80 K intercept is also studied and shows that thermo-oscillations can be dampened by placing the intercept at an appropriate location.

  16. Design, characterization, and experimental use of the second generation MEMS acoustic emission device

    NASA Astrophysics Data System (ADS)

    Ozevin, Didem; Greve, David W.; Oppenheim, Irving J.; Pessiki, Stephen

    2005-05-01

    We describe the design, fabrication, testing and application (in structural experiments) of our 2004 (second generation) MEMS device, designed for acoustic emission sensing based upon experiments with our 2002 (first generation) device. Both devices feature a suite of resonant-type transducers in the frequency range between 100 kHz and 1 MHz. The 2002 device was designed to operate in an evacuated housing because of high squeeze film damping, as confirmed in our earlier experiments. In additional studies involving the 2002 device, experimental simulation of acoustic emissions in a steel plate, using pencil lead break or ball impact loading, showed that the transducers in the frequency range of 100 kHz-500 kHz presented clearer output signals than the transducers with frequencies higher than 500 kHz. Using the knowledge gained from the 2002 device, we designed and fabricated our second generation device in 2004 using the multi-user polysilicon surface micromachining (MUMPs) process. The 2004 device has 7 independent capacitive type transducers, compared to 18 independent transducers in the 2002 device, including 6 piston type transducers in the frequency range of 100 kHz to 500 kHz and 1 piston type transducer at 1 MHz to capture high frequency information. Piston type transducers developed in our research have two uncoupled modes so that twofold information can be acquired from a single transducer. In addition, the piston shape helps to reduce residual stress effect of surface micromachining process. The center to center distance between etch holes in the vibrating plate was reduced from 30 μm to 13 μm, in order to reduce squeeze film damping. As a result, the Q factor under atmospheric pressure for the 100 kHz transducer was increased to 2.37 from 0.18, and therefore the vacuum housing has been eliminated from the 2004 device. Sensitivities of transducers were also increased, by enlarging transducer area, in order to capture significant small amplitude acoustic

  17. Design and Implementation of an Enterprise Internet of Things

    NASA Astrophysics Data System (ADS)

    Sun, Jing; Zhao, Huiqun; Wang, Ka; Zhang, Houyong; Hu, Gongzhu

    Since the notion of "Internet of Things" (IoT) introduced about 10 years ago, most IoT research has focused on higher level issues, such as strategies, architectures, standardization, and enabling technologies, but studies of real cases of IoT are still lacking. In this paper, a real case of Internet of Things called ZB IoT is introduced. It combines the Service Oriented Architecture (SOA) with EPC global standards in the system design, and focuses on the security and extensibility of IoT in its implementation.

  18. CleanFleet. Volume 2, Project Design and Implementation

    SciTech Connect

    1995-12-01

    The CleanFleet alternative fuels demonstration project evaluated five alternative motorfuels in commercial fleet service over a two-year period. The five fuels were compressed natural gas, propane gas, California Phase 2 reformulated gasoline (RFG), M-85 (85 percent methanol and 15 percent RFG), and electric vans. Eight-four vans were operated on the alternative fuels and 27 vans were operated on gasoline as baseline controls. Throughout the demonstration information was collected on fleet operations, vehicle emissions, and fleet economics. In this volume of the CleanFleet findings, the design and implementation of the project are summarized.

  19. Pharmacology Goes Concept-Based: Course Design, Implementation, and Evaluation.

    PubMed

    Lanz, Amelia; Davis, Rebecca G

    Although concept-based curricula are frequently discussed in the nursing education literature, little information exists to guide the development of a concept-based pharmacology course. Traditionally, nursing pharmacology courses are taught with an emphasis on drug class where a prototype drug serves as an exemplar. When transitioning pharmacology to a concept-based course, special considerations are in order. How can educators successfully integrate essential pharmacological content into a curriculum structured around nursing concepts? This article presents one approach to the design and implementation of a concept-based undergraduate pharmacology course. Planning methods, supportive teaching strategies, and course evaluation procedures are discussed.

  20. Design and Implementation of Campus Application APP Based on Android

    NASA Astrophysics Data System (ADS)

    dongxu, Zhu; yabin, liu; xian lei, PI; weixiang, Zhou; meng, Huang

    2017-07-01

    In this paper, "Internet + campus" as the entrance of the Android technology based on the application of campus design and implementation of Application program. Based on GIS(Geographic Information System) spatial database, GIS spatial analysis technology, Java development technology and Android development technology, this system server adopts the Model View Controller architectue to realize the efficient use of campus information and provide real-time information of all kinds of learning and life for campus student at the same time. "Fingertips on the Institute of Disaster Prevention Science and Technology" release for the campus students of all grades of life, learning, entertainment provides a convenient.

  1. Implementation of Sensor and Control Designs for Bioregenerative Systems

    NASA Technical Reports Server (NTRS)

    Rodriguez, Pedro R. (Editor)

    1990-01-01

    The goal of the Spring 1990 EGM 4001 Design class was to design, fabricate, and test sensors and control systems for a closed loop life support system (CLLSS). The designs investigated were to contribute to the development of NASA's Controlled Ecological Life Support System (CELSS) at Kennedy Space Center (KSC). Designs included a seed moisture content sensor, a porous medium wetness sensor, a plant health sensor, and a neural network control system. The seed group focused on the design and implementation of a sensor that could detect the moisture content of a seed batch. The porous medium wetness group concentrated on the development of a sensor to monitor the amount of nutrient solution within a porous plate incorporating either infrared reflectance or thermal conductance properties. The plant health group examined the possibility of remotely monitoring the health of the plants within the Biomass Production Chamber (BPC) using infrared reflectance properties. Finally, the neural network group concentrated on the ability to use parallel processing in order to control a robot arm and analyze the data from the health sensor to detect regions of a plant.

  2. Design and implementation of dynamic hybrid Honeypot network

    NASA Astrophysics Data System (ADS)

    Qiao, Peili; Hu, Shan-Shan; Zhai, Ji-Qiang

    2013-05-01

    The method of constructing a dynamic and self-adaptive virtual network is suggested to puzzle adversaries, delay and divert attacks, exhaust attacker resources and collect attacking information. The concepts of Honeypot and Honeyd, which is the frame of virtual Honeypot are introduced. The techniques of network scanning including active fingerprint recognition are analyzed. Dynamic virtual network system is designed and implemented. A virtual network similar to real network topology is built according to the collected messages from real environments in this system. By doing this, the system can perplex the attackers when Hackers attack and can further analyze and research the attacks. The tests to this system prove that this design can successfully simulate real network environment and can be used in network security analysis.

  3. Modular implementation of a digital hardware design automation system

    NASA Astrophysics Data System (ADS)

    Masud, M.

    An automation system based on AHPL (A Hardware Programming Language) was developed. The project may be divided into three distinct phases: (1) Upgrading of AHPL to make it more universally applicable; (2) Implementation of a compiler for the language; and (3) illustration of how the compiler may be used to support several phases of design activities. Several new features were added to AHPL. These include: application-dependent parameters, mutliple clocks, asynchronous results, functional registers and primitive functions. The new language, called Universal AHPL, has been defined rigorously. The compiler design is modular. The parsing is done by an automatic parser generated from the SLR(1)BNF grammar of the language. The compiler produces two data bases from the AHPL description of a circuit. The first one is a tabular representation of the circuit, and the second one is a detailed interconnection linked list. The two data bases provide a means to interface the compiler to application-dependent CAD systems.

  4. The SEASAT-A synthetic aperture radar design and implementation

    NASA Technical Reports Server (NTRS)

    Jordan, R. L.

    1978-01-01

    The SEASAT-A synthetic aperture imaging radar system is the first imaging radar system intended to be used as a scientific instrument designed for orbital use. The requirement of the radar system is to generate continuous radar imagery with a 100 kilometer swath with 25 meter resolution from an orbital altitude of 800 kilometers. These requirements impose unique system design problems and a description of the implementation is given. The end-to-end system is described, including interactions of the spacecraft, antenna, sensor, telemetry link, recording subsystem, and data processor. Some of the factors leading to the selection of critical system parameters are listed. The expected error sources leading to degradation of image quality are reported as well as estimate given of the expected performance from data obtained during a ground testing of the completed subsystems.

  5. Design and Development of a Deep Acoustic Lining for the 40-by 80-Foot Wind Tunnel Test Section

    NASA Technical Reports Server (NTRS)

    Soderman, Paul T.; Schmitz, Fredric H.; Allen, Christopher S.; Jaeger, Stephen M.; Sacco, Joe N.; Mosher, Marianne; Hayes, Julie A.

    2002-01-01

    The work described in this report has made effective use of design teams to build a state-of-the-art anechoic wind-tunnel facility. Many potential design solutions were evaluated using engineering analysis, and computational tools. Design alternatives were then evaluated using specially developed testing techniques, Large-scale coupon testing was then performed to develop confidence that the preferred design would meet the acoustic, aerodynamic, and structural objectives of the project. Finally, designs were frozen and the final product was installed in the wind tunnel. The result of this technically ambitious project has been the creation of a unique acoustic wind tunnel. Its large test section (39 ft x 79 ft x SO ft), potentially near-anechoic environment, and medium subsonic speed capability (M = 0.45) will support a full range of aeroacoustic testing-from rotorcraft and other vertical takeoff and landing aircraft to the take-off/landing configurations of both subsonic and supersonic transports.

  6. Design and implementation of the NPOI database and website

    NASA Astrophysics Data System (ADS)

    Newman, K.; Jorgensen, A. M.; Landavazo, M.; Sun, B.; Hutter, D. J.; Armstrong, J. T.; Mozurkewich, David; Elias, N.; van Belle, G. T.; Schmitt, H. R.; Baines, E. K.

    2014-07-01

    The Navy Precision Optical Interferometer (NPOI) has been recording astronomical observations for nearly two decades, at this point with hundreds of thousands of individual observations recorded to date for a total data volume of many terabytes. To make maximum use of the NPOI data it is necessary to organize them in an easily searchable manner and be able to extract essential diagnostic information from the data to allow users to quickly gauge data quality and suitability for a specific science investigation. This sets the motivation for creating a comprehensive database of observation metadata as well as, at least, reduced data products. The NPOI database is implemented in MySQL using standard database tools and interfaces. The use of standard database tools allows us to focus on top-level database and interface implementation and take advantage of standard features such as backup, remote access, mirroring, and complex queries which would otherwise be time-consuming to implement. A website was created in order to give scientists a user friendly interface for searching the database. It allows the user to select various metadata to search for and also allows them to decide how and what results are displayed. This streamlines the searches, making it easier and quicker for scientists to find the information they are looking for. The website has multiple browser and device support. In this paper we present the design of the NPOI database and website, and give examples of its use.

  7. Design and implementation of a high performance network security processor

    NASA Astrophysics Data System (ADS)

    Wang, Haixin; Bai, Guoqiang; Chen, Hongyi

    2010-03-01

    The last few years have seen many significant progresses in the field of application-specific processors. One example is network security processors (NSPs) that perform various cryptographic operations specified by network security protocols and help to offload the computation intensive burdens from network processors (NPs). This article presents a high performance NSP system architecture implementation intended for both internet protocol security (IPSec) and secure socket layer (SSL) protocol acceleration, which are widely employed in virtual private network (VPN) and e-commerce applications. The efficient dual one-way pipelined data transfer skeleton and optimised integration scheme of the heterogenous parallel crypto engine arrays lead to a Gbps rate NSP, which is programmable with domain specific descriptor-based instructions. The descriptor-based control flow fragments large data packets and distributes them to the crypto engine arrays, which fully utilises the parallel computation resources and improves the overall system data throughput. A prototyping platform for this NSP design is implemented with a Xilinx XC3S5000 based FPGA chip set. Results show that the design gives a peak throughput for the IPSec ESP tunnel mode of 2.85 Gbps with over 2100 full SSL handshakes per second at a clock rate of 95 MHz.

  8. A design and implementation methodology for diagnostic systems

    NASA Technical Reports Server (NTRS)

    Williams, Linda J. F.

    1988-01-01

    A methodology for design and implementation of diagnostic systems is presented. Also discussed are the advantages of embedding a diagnostic system in a host system environment. The methodology utilizes an architecture for diagnostic system development that is hierarchical and makes use of object-oriented representation techniques. Additionally, qualitative models are used to describe the host system components and their behavior. The methodology architecture includes a diagnostic engine that utilizes a combination of heuristic knowledge to control the sequence of diagnostic reasoning. The methodology provides an integrated approach to development of diagnostic system requirements that is more rigorous than standard systems engineering techniques. The advantages of using this methodology during various life cycle phases of the host systems (e.g., National Aerospace Plane (NASP)) include: the capability to analyze diagnostic instrumentation requirements during the host system design phase, a ready software architecture for implementation of diagnostics in the host system, and the opportunity to analyze instrumentation for failure coverage in safety critical host system operations.

  9. Design and implementation of a generalized laboratory data model

    PubMed Central

    Wendl, Michael C; Smith, Scott; Pohl, Craig S; Dooling, David J; Chinwalla, Asif T; Crouse, Kevin; Hepler, Todd; Leong, Shin; Carmichael, Lynn; Nhan, Mike; Oberkfell, Benjamin J; Mardis, Elaine R; Hillier, LaDeana W; Wilson, Richard K

    2007-01-01

    Background Investigators in the biological sciences continue to exploit laboratory automation methods and have dramatically increased the rates at which they can generate data. In many environments, the methods themselves also evolve in a rapid and fluid manner. These observations point to the importance of robust information management systems in the modern laboratory. Designing and implementing such systems is non-trivial and it appears that in many cases a database project ultimately proves unserviceable. Results We describe a general modeling framework for laboratory data and its implementation as an information management system. The model utilizes several abstraction techniques, focusing especially on the concepts of inheritance and meta-data. Traditional approaches commingle event-oriented data with regular entity data in ad hoc ways. Instead, we define distinct regular entity and event schemas, but fully integrate these via a standardized interface. The design allows straightforward definition of a "processing pipeline" as a sequence of events, obviating the need for separate workflow management systems. A layer above the event-oriented schema integrates events into a workflow by defining "processing directives", which act as automated project managers of items in the system. Directives can be added or modified in an almost trivial fashion, i.e., without the need for schema modification or re-certification of applications. Association between regular entities and events is managed via simple "many-to-many" relationships. We describe the programming interface, as well as techniques for handling input/output, process control, and state transitions. Conclusion The implementation described here has served as the Washington University Genome Sequencing Center's primary information system for several years. It handles all transactions underlying a throughput rate of about 9 million sequencing reactions of various kinds per month and has handily weathered a number

  10. Design and implementation of a mechanically heterogeneous robot group

    NASA Astrophysics Data System (ADS)

    Sukhatme, Gaurav S.; Montgomery, James F.; Mataric, Maja J.

    1999-08-01

    This paper describes the design and construction of a cooperative, heterogeneous robot group comprised of one semi-autonomous aerial robot and two autonomous ground robots. The robots are designed to perform automated surveillance and reconnaissance of an urban outdoor area using onboard sensing. The ground vehicles have GPS, sonar for obstacle detection and avoidance, and a simple color- based vision system. Navigation is performed using an optimal mixture of odometry and GPS. The helicopter is equipped with a GPS/INS system, a camera, and a framegrabber. Each robot has an embedded 486 PC/104 processor running the QNX real-time operating system. Individual robot controllers are behavior-based and decentralized. We describe a control strategy and architecture that coordinates the robots with minimal top- down planning. The overall system is controlled at high level by a single human operator using a specially designed control unit. The operator is able to task the group with a mission using a minimal amount of training. The group can re-task itself based on sensor inputs and can also be re- tasked by the operator. We describe a particular reconnaissance mission that the robots have been tested with, and lessons learned during the design and implementation. Our initial results with these experiments are encouraging given the challenging mechanics of the aerial robot. We conclude the paper with a discussion of ongoing and future work.

  11. Laser fiber source implemented with a resonator Sagnac for fiber optic acoustic sensor

    NASA Astrophysics Data System (ADS)

    Sandoval-Romero, G. E.; Pinzón-Escobar, E. F.

    2013-11-01

    Two innovative laser scanning prototypes have been developed at ENEA for diagnostics of large surfaces relevant to monumental cultural heritage. The first, based on amplitude modulation technique in the visible, is a trichromatic (Red /Green /Blue) imaging topologic radar (RGB-ITR) specialized to collect high resolution 3D models. After proper color calibration, it allows for hyper-realistic rendering of colored features on painted surfaces and for precise localization of irregularities. The second is a line scanning system, working either in reflectance or laser induced fluorescence mode, capable of fast 2D monochromatic images acquisition on up to 90 different spectral channels in the visible/UV range, which was developed to investigate the presence of different substances onto the painted surface. Data collected during former field campaigns on frescos by means each scanning system will be reported and discussed extracting information of interest to conservators by means of specific data processing methodologies and respective software tools. Recent results relevant to paints of the Assumption on slate and canvas by Scipione Pulzone named "il Gaetano" collected in two churches in Rome (San Silvestro al Quirinale, Bandini chapel; Santa Caterina dei Funari, Solano della Vetera Chapel) from the late XVI century are presented in order to demonstrate the increased diagnostic capabilities coming from data integration. From combination of reflectance data from both instruments, the first true remote differential colorimetry has been implemented, giving a chance to test the color quality in the future from the archived images.

  12. Design and aero-acoustic analysis of a counter-rotating wind turbine

    NASA Astrophysics Data System (ADS)

    Agrawal, Vineesh V.

    Wind turbines have become an integral part of the energy business because they are one of the most economical and reliable sources of renewable energy. Conventional wind turbines are capable of capturing less than half of the energy present in the wind. Hence, to make the wind turbines more efficient, it is important to increase their performance. A horizontal axis wind turbine with multiple rotors is one concept that can achieve a higher power conversion rate. Also, a concern for wind energy is the noise generated by wind turbines. Hence, an investigation into the acoustic behavior of a multi-rotor horizontal axis wind turbine is required. In response to the need of a wind turbine design with higher power coefficient, a unique design of a counter-rotating horizontal axis wind turbine (CR-HAWT) is proposed. The Blade Element Momentum (BEM) theory is used to aerodynamically design the blades of the two rotors. Modifications are made to the BEM theory to accommodate the interaction of the two rotors. The tower effect on the noise generation of the downwind rotor is investigated. Predictions are made for the total noise generated by the wind turbine at its design operating conditions. A total power coefficient of 65.2% is predicted for the proposed CR-HAWT design. A low tip speed ratio is chosen to minimize the noise generation. The aeroacoustic analysis of the CR-HAWT shows that the noise generated at its design operating conditions is within an acceptable range. Thus, the CR-HAWT is predicted to be a quiet wind turbine with a high power coefficient, making it highly desirable for small wind turbine applications.

  13. The Acoustic Model Evaluation Committee (AMEC) Reports. Volume 1. Model Evaluation Methodology and Implementation

    DTIC Science & Technology

    1982-09-01

    acknowledge the valuable con- tributions of Dr. F. R. DiNapoli of the Naval Under- water Systems Center, New London, Conn., while he was chairman of the Panel...request. loss ( RIPL ), range depeadent propagation The test cases will be designed to eval- loss (RDPL), directional ambient noise uate the model’s...source, 1 shot per 10 nm Range over which Environment Is Range Independent: 0-240 nm water Depth: 1500 fathoms mnax (2750 m) 1420 fathoms min (2600 m

  14. Implementation Science and Employer Disability Practices: Embedding Implementation Factors in Research Designs.

    PubMed

    Main, Chris J; Nicholas, Michael K; Shaw, William S; Tetrick, Lois E; Ehrhart, Mark G; Pransky, Glenn

    2016-12-01

    Purpose For work disability research to have an impact on employer policies and practices it is important for such research to acknowledge and incorporate relevant aspects of the workplace. The goal of this article is to summarize recent theoretical and methodological advances in the field of Implementation Science, relate these to research of employer disability management practices, and recommend future research priorities. Methods The authors participated in a year-long collaboration culminating in an invited 3-day conference, "Improving Research of Employer Practices to Prevent Disability", held October 14-16, 2015, in Hopkinton, MA, USA. The collaboration included a topical review of the literature, group conference calls to identify key areas and challenges, drafting of initial documents, review of industry publications, and a conference presentation that included feedback from peer researchers and a question/answer session with a special panel of knowledge experts with direct employer experience. Results A 4-phase implementation model including both outer and inner contexts was adopted as the most appropriate conceptual framework, and aligned well with the set of process evaluation factors described in both the work disability prevention literature and the grey literature. Innovative interventions involving disability risk screening and psychologically-based interventions have been slow to gain traction among employers and insurers. Research recommendations to address this are : (1) to assess organizational culture and readiness for change in addition to individual factors; (2) to conduct process evaluations alongside controlled trials; (3) to analyze decision-making factors among stakeholders; and (4 ) to solicit input from employers and insurers during early phases of study design. Conclusions Future research interventions involving workplace support and involvement to prevent disability may be more feasible for implementation if organizational decision

  15. Design and Implementation of Alkali Activated Cement For Sustainable Development

    NASA Astrophysics Data System (ADS)

    Moseson, Alexander James

    Herein, progress is presented on the design and implementation of technology for sustainable development in general and international development in particular. Necessarily interdisciplinary, the work draws upon the tools and techniques of Mechanical, Materials, and Civil Engineering; and History & Politics. The work was conducted along two paths, the first being the theory and methodology of sustainable development. A flexible design and dissemination framework was developed, Technology Seeding, defined as: development by the transfer and participatory adaptation of appropriate proven conceptual designs. The methodology was developed in part through two case studies which implemented, respectively, wood-turning lathes in Tanzania and upland rice planters in Thailand. The second path is the design and investigation of alkali-activated cements (AACs) for practical use. Those developed herein, for US markets, comprise ground granulated blast furnace slag, soda ash (sodium carbonate), and up to 68 wt.% granular limestone. Mixture Design of Experiment (DOE) was utilized to guide empirical and theoretical analysis of performance (e.g. compressive strength), economic & ecological aspects (e.g. cost, CO2 production, energy consumption), and chemistry (e.g. Rietveld analysis of x-ray diffractograms). Models were derived to understand the impact of mix design on performance and for optimization. Successful formulations are hydraulic and cure at room temperature, with strengths as high as 41 MPa at 3 days and 65 MPa at 28 days. Some of these formulations, compared to OPC, are competitive in performance, reduce cost by up to 40%, and reduce both CO2 production and energy consumption by up to 97%. Major chemical products include calcium silicate hydrates / calcium aluminum silicate hydrates (C-(A)-S-H), gaylussite, and calcite (both newly formed and remaining from limestone). Calcite/dolomite and C-(A)-S-H both contribute to strength. A fraction of the limestone is consumed

  16. Analytical and numerical calculations of optimum design frequency for focused ultrasound therapy and acoustic radiation force.

    PubMed

    Ergün, A Sanlı

    2011-10-01

    Focused ultrasound therapy relies on acoustic power absorption by tissue. The stronger the absorption the higher the temperature increase is. However, strong acoustic absorption also means faster attenuation and limited penetration depth. Hence, there is a trade-off between heat generation efficacy and penetration depth. In this paper, we formulated the acoustic power absorption as a function of frequency and attenuation coefficient, and defined two figures of merit to measure the power absorption: spatial peak of the acoustic power absorption density, and the acoustic power absorbed within the focal area. Then, we derived "rule of thumb" expressions for the optimum frequencies that maximized these figures of merit given the target depth and homogeneous tissue type. We also formulated a method to calculate the optimum frequency for inhomogeneous tissue given the tissue composition for situations where the tissue structure can be assumed to be made of parallel layers of homogeneous tissue. We checked the validity of the rules using linear acoustic field simulations. For a one-dimensional array of 4cm acoustic aperture, and for a two-dimensional array of 4×4cm(2) acoustic aperture, we found that the power absorbed within the focal area is maximized at 0.86MHz, and 0.79MHz, respectively, when the target depth is 4cm in muscle tissue. The rules on the other hand predicted the optimum frequencies for acoustic power absorption as 0.9MHz and 0.86MHz, respectively for the 1D and 2D array case, which are within 6% and 9% of the field simulation results. Because radiation force generated by an acoustic wave in a lossy propagation medium is approximately proportional to the acoustic power absorption, these rules can be used to maximize acoustic radiation force generated in tissue as well.

  17. Preliminary design and implementation for HSOS data archive system

    NASA Astrophysics Data System (ADS)

    Lin, Ganghua

    2002-12-01

    Video Vector Magnetograph at Huairou Solar Observing Station, in Beijing of China is the primary instrument designed to simultaneously measure the solar 2-dimension magnetic field and velocity field with different spectral lines in the world. In order to satisfy needs from various users, raw data, received from the observations system is processed into CD-ROMs for archive and distribution to the Co-Investigators, and summary data is generated for viewing at the HSOS Web site (http://sun.bao.ac.cn) The data archive is designed to store in two parts for the sake of safe, one part is located at the local, the other is at headquarter of National Astronomical Center of Observatories. The data archive system is setup here. This paper presents a preliminary design and preliminary implement of the data archive system. The goal of this project is to provide a high efficient, fast speed and extensible software that is characterized by lower cost and high performance and a desire to create high quality software system. The article will encompass a wide variety of experiments associated with the inception and prototype stages to its current state of maturity of the database system, its relative integrality of the means and tools employed on a series of implement steps on operating system, database management system, and server end scripting language, etc. The solution offers significant performance improvements over some existing methods in similar system. The gained experiments all are in Linux system of PC. Everyone, who follows along with the steps described herein, must build a good online database server in a short time.

  18. Development and implementation of rotorcraft preliminary design methodology using multidisciplinary design optimization

    NASA Astrophysics Data System (ADS)

    Khalid, Adeel Syed

    Rotorcraft's evolution has lagged behind that of fixed-wing aircraft. One of the reasons for this gap is the absence of a formal methodology to accomplish a complete conceptual and preliminary design. Traditional rotorcraft methodologies are not only time consuming and expensive but also yield sub-optimal designs. Rotorcraft design is an excellent example of a multidisciplinary complex environment where several interdependent disciplines are involved. A formal framework is developed and implemented in this research for preliminary rotorcraft design using IPPD methodology. The design methodology consists of the product and process development cycles. In the product development loop, all the technical aspects of design are considered including the vehicle engineering, dynamic analysis, stability and control, aerodynamic performance, propulsion, transmission design, weight and balance, noise analysis and economic analysis. The design loop starts with a detailed analysis of requirements. A baseline is selected and upgrade targets are identified depending on the mission requirements. An Overall Evaluation Criterion (OEC) is developed that is used to measure the goodness of the design or to compare the design with competitors. The requirements analysis and baseline upgrade targets lead to the initial sizing and performance estimation of the new design. The digital information is then passed to disciplinary experts. This is where the detailed disciplinary analyses are performed. Information is transferred from one discipline to another as the design loop is iterated. To coordinate all the disciplines in the product development cycle, Multidisciplinary Design Optimization (MDO) techniques e.g. All At Once (AAO) and Collaborative Optimization (CO) are suggested. The methodology is implemented on a Light Turbine Training Helicopter (LTTH) design. Detailed disciplinary analyses are integrated through a common platform for efficient and centralized transfer of design

  19. Implementing Inclusive Design for Learning in an introductory geology laboratory

    NASA Astrophysics Data System (ADS)

    Robert, G.; Merriman, J. D.; Ceylan, G. M.

    2013-12-01

    As an expansion of universal design for learning, IDL provides a framework for opening up and adapting classroom interaction systems, minimizing barriers through promoting perception, engagement, expression, and accommodation for diverse learners. We implemented an introductory-level laboratory for communicating the concept of magma viscosity using the guidelines and principles of IDL. We developed the lab as a mini-implementation project for an IDL course offered by the University of Missouri (MU) Graduate School. The laboratory was subsequently taught during the summer session of Principles of Geology in our Department of Geological Sciences. Traditional geology laboratories rely heavily on visual aids, either physical (rocks and minerals) or representative (idealized cartoons of processes, videos), with very few alternative representations and descriptions made available to the students. Our main focus for this new lab was to diversify the means of representation available to the students (and instructor) to make the lab as equitable and flexible as possible. We considered potential barriers to learning arising from the physical lab environment, from the means of representation, engagement and expression, and tried to minimize them upfront. We centred the laboratory on the link between volcano shape and viscosity as an applied way to convey that viscosity is the resistance to flow. The learning goal was to have the students observe that more viscous eruptives resulted in steeper-sided volcanoes through experimentation. Students built their own volcanoes by erupting lava (foods of various viscosities) onto the Earth's surface (a piece of sturdy cardboard with a hole for the 'vent') through a conduit (pastry bag). Such a hands on lab exercise allows students to gain a tactile and visual, i.e., physical representation of an abstract concept. This specific exercise was supported by other, more traditional, means of representation (e.g., lecture, videos, cartoons, 3D

  20. The Scientific Uplink System for SIRTF: Design to Implementation

    NASA Astrophysics Data System (ADS)

    Dodd, Suzanne R.; Heinrichsen, Ingolf

    The Space Infrared Telescope Facility (SIRTF) is the last of NASA's Great Observatory missions, scheduled for launch in July 2002. SIRTF will perform an extended series of science observations at wavelengths ranging from 20 to 160 microns for five years or more. The California Institute of Technology is the home for the SIRTF Science Center (SSC). The SSC is responsible for supporting the scientific community with observation design and scheduling, and production and archiving of data products. The SIRTF ground segment design is driven by the requirement to provide strong support to the entire astronomical community, while automating several functions in order to save operations costs. In the past year, the ground segment software has evolved from an early development system into an operational system, currently supporting both SIRTF Legacy Teams and Guaranteed Time Observers. This paper describes the Uplink Segment software developed at the SIRTF Science Center, addresses the remaining development work to be completed this winter, and gives a brief list of lessons learned during the transition from system design to system implementation. This work was performed at the California Institute of Technology under contract to the National Aeronautics and Space Administration.

  1. Holistic design and implementation of pressure actuated cellular structures

    NASA Astrophysics Data System (ADS)

    Gramüller, B.; Köke, H.; Hühne, C.

    2015-12-01

    Providing the possibility to develop energy-efficient, lightweight adaptive components, pressure-actuated cellular structures (PACS) are primarily conceived for aeronautics applications. The realization of shape-variable flaps and even airfoils provides the potential to safe weight, increase aerodynamic efficiency and enhance agility. The herein presented holistic design process points out and describes the necessary steps for designing a real-life PACS structure, from the computation of truss geometry to the manufacturing and assembly. The already published methods for the form finding of PACS are adjusted and extended for the exemplary application of a variable-camber wing. The transfer of the form-finding truss model to a cross-sectional design is discussed. The end cap and sealing concept is described together with the implementation of the integral fluid flow. Conceptual limitations due to the manufacturing and assembly processes are discussed. The method’s efficiency is evaluated by finite element method. In order to verify the underlying methods and summarize the presented work a modular real-life demonstrator is experimentally characterized and validates the numerical investigations.

  2. Design and implementation of SMO for a nonlinear MIMO AHRS

    NASA Astrophysics Data System (ADS)

    Doostdar, Parisa; Keighobadi, Jafar

    2012-10-01

    In a low-cost attitude heading reference system (AHRS), the measurements made by MEMS inertial and magnetic sensors are affected by large parameter uncertainties, stochastic noises and unknown disturbances. In this paper, considering the robustness of the sliding mode observers (SMO) against both structured and unstructured uncertainties as well as exogenous inputs, the process of design and implementation of a nonlinear SMO is proposed for a low-cost AHRS. For simultaneous estimation of orientation variables and calibration biases of gyroscopes, a nonlinear and non-affine model of the AHRS is considered. Therefore, based on the Lie-algebraic method, the estimation algorithm is designed for a general class of non-affine nonlinear MIMO systems. In the proposed observer, owing to decreasing the required assumptions for coordinate transformation in recent literatures, the design process of the SMO is simplified. The gain matrices of the proposed SMO are obtained through ensuring the stability and the convergence of estimation errors based on Lyapunov's direct method. The expected tracking performance of the robust state and parameter estimation algorithm compared to that of the extended Kalman filter (EKF) is evaluated through simulations and real experiments of a strapped AHRS on a ground vehicle.

  3. Designing and implementing full immersion simulation as a research tool.

    PubMed

    Munroe, Belinda; Buckley, Thomas; Curtis, Kate; Morris, Richard

    2016-05-01

    Simulation is a valuable research tool used to evaluate the clinical performance of devices, people and systems. The simulated setting may address concerns unique to complex clinical environments such as the Emergency Department, which make the conduct of research challenging. There is limited evidence available to inform the development of simulated clinical scenarios for the purpose of evaluating practice in research studies, with the majority of literature focused on designing simulated clinical scenarios for education and training. Distinct differences exist in scenario design when implemented in education compared with use in clinical research studies. Simulated scenarios used to assess practice in clinical research must not comprise of any purposeful or planned teaching and be developed with a high degree of validity and reliability. A new scenario design template was devised to develop two standardised simulated clinical scenarios for the evaluation of a new assessment framework for emergency nurses. The scenario development and validation processes undertaken are described and provide an evidence-informed guide to scenario development for future clinical research studies.

  4. SSV Launch Monitoring Strategies: HGDS Design Implementation Through System Maturity

    NASA Technical Reports Server (NTRS)

    Shoemaker, Marc D.; Crimi, Thomas

    2010-01-01

    With over 500,000 gallons of liquid hydrogen and liquid oxygen, it is of vital importance to monitor the space shuttle vehicle (SSV) from external tank (ET) load through launch. The Hazardous Gas Detection System (HGDS) was installed as the primary system responsible for monitoring fuel leaks within the orbiter and ET. The HGDS was designed to obtain the lowest possible detection limits with the best resolution while monitoring the SSV for any hydrogen, helium, oxygen, or argon as the main requirement. The HGDS is a redundant mass spectrometer used for real-time monitoring during Power Reactant Storage and Distribution (PRSD) load and ET load through launch or scrub. This system also performs SSV processing leak checks of the Tail Service Mast (TSM) umbilical quick disconnects (QD's), Ground Umbilical Carrier Plate (GUCP) QD's and supports auxiliary power unit (APU) system tests. From design to initial implementation and operations, the HGDS has evolved into a mature and reliable launch support system. This paper will discuss the operational challenges and lessons learned from facing design deficiencies, validation and maintenance efforts, life cycle issues, and evolving requirements

  5. Generation of acoustic helical wavefronts using metasurfaces

    NASA Astrophysics Data System (ADS)

    Esfahlani, Hussein; Lissek, Herve; Mosig, Juan R.

    2017-01-01

    It has been shown that acoustic waves with helical wavefronts can carry angular momentum, which can be transmitted towards a propagating medium. Such a wave field can be achieved by using a planar array of electroacoustic transducers, forming a given spatial distribution of phased sound sources which produce the desired helical wavefronts. Here, we introduce a technique to generate acoustic vortices, based on the passive acoustic metasurface concept. The proposed metasurface is composed of space-coiled cylindrical unit cells transmitting sound pressure with a controllable phase shift, which are arranged in a discretized circular configuration, and thus passively transforming an incident plane wavefront into the desired helical wavefront. This method presents the advantage of overcoming the restrictions on using many acoustic sources, and it is implemented with a transmitting metasurface which can be easily three-dimensionally printed. The proposed straightforward design principle can be adopted for easy production of acoustic angular momentum with minimum complexity and using a single source.

  6. FPGA design and implementation for EIT data acquisition.

    PubMed

    Yue, Xicai; McLeod, Chris

    2008-10-01

    OXBACT-5 was designed to meet the challenges involved in working in the intensive care hospital environment focussed particularly on thoracic imaging of patients with respiratory distress and chronic heart failure (CHF). The FPGA-based wireless LAN linked multi-channel EIT data acquisition system (DAS) providing 16 programmable excitation current channels and 64 voltage measurement channels is presented. It contains function modules of a PCI bus interface, direct digital synthesizers, dual-port memory blocks, digital demodulation and all the command and control logic in the FPGA. The whole EIT data acquisition system is fully programmable and reconfigurable from the host PC. The excitation frequency, excitation patterns, the measuring sequence and the gain of each measurement channel can be set from the host PC before each measurement. The demodulation is implemented in the FPGA chip to reduce the data rate between the DAS and the host PC. In addition, measurement process management is achieved in this FPGA chip. Complemented by analogue devices such as ADCs, DACs, analogue buffers and analogue multiplexers, the new FPGA-based EIT DAS system is implemented in a very compact way for bedside use in intensive care units of hospitals. It is intended for applications such as continuous respiration monitoring with data collection at 25 frames per second. Image reconstruction times depend on the choice of 2D or 3D imaging algorithms and the available processing power.

  7. Design and Implementation of the Retinoblastoma Collaborative Laboratory.

    PubMed

    Qaiser, Seemi; Limo, Alice; Gichana, Josiah; Kimani, Kahaki; Githanga, Jessie; Waweru, Wairimu; Dimba, Elizabeth A O; Dimaras, Helen

    2017-01-01

    The purpose of this work was to describe the design and implementation of a digital pathology laboratory, the Retinoblastoma Collaborative Laboratory (RbCoLab) in Kenya. The RbCoLab is a central lab in Nairobi that receives retinoblastoma specimens from all over Kenya. Specimens were processed using evidence-based standard operating procedures. Images were produced by a digital scanner, and pathology reports were disseminated online. The lab implemented standard operating procedures aimed at improving the accuracy, completeness, and timeliness of pathology reports, enhancing the care of Kenyan retinoblastoma patients. Integration of digital technology to support pathology services supported knowledge transfer and skills transfer. A bidirectional educational network of local pathologists and other clinicians in the circle of care of the patients emerged and served to emphasize the clinical importance of cancer pathology at multiple levels of care. A 'Robin Hood' business model of health care service delivery was developed to support sustainability and scale-up of cancer pathology services. The application of evidence-based protocols, comprehensive training, and collaboration were essential to bring improvements to the care of retinoblastoma patients in Kenya. When embraced as an integrated component of retinoblastoma care, digital pathology offers the opportunity for frequent connection and consultation for development of expertise over time.

  8. Design and Implementation of the Retinoblastoma Collaborative Laboratory

    PubMed Central

    Qaiser, Seemi; Limo, Alice; Gichana, Josiah; Kimani, Kahaki; Githanga, Jessie; Waweru, Wairimu; Dimba, Elizabeth A.O.; Dimaras, Helen

    2017-01-01

    Purpose The purpose of this work was to describe the design and implementation of a digital pathology laboratory, the Retinoblastoma Collaborative Laboratory (RbCoLab) in Kenya. Method The RbCoLab is a central lab in Nairobi that receives retinoblastoma specimens from all over Kenya. Specimens were processed using evidence-based standard operating procedures. Images were produced by a digital scanner, and pathology reports were disseminated online. Results The lab implemented standard operating procedures aimed at improving the accuracy, completeness, and timeliness of pathology reports, enhancing the care of Kenyan retinoblastoma patients. Integration of digital technology to support pathology services supported knowledge transfer and skills transfer. A bidirectional educational network of local pathologists and other clinicians in the circle of care of the patients emerged and served to emphasize the clinical importance of cancer pathology at multiple levels of care. A ‘Robin Hood’ business model of health care service delivery was developed to support sustainability and scale-up of cancer pathology services. Discussion The application of evidence-based protocols, comprehensive training, and collaboration were essential to bring improvements to the care of retinoblastoma patients in Kenya. When embraced as an integrated component of retinoblastoma care, digital pathology offers the opportunity for frequent connection and consultation for development of expertise over time. PMID:28275608

  9. Design and Implementation of PACS at Georgetown University Hospital

    NASA Astrophysics Data System (ADS)

    Mun, S. K.; Benson, H.. R.; Choyke, P.; Fahey, F. H.; Wang, P. C.; Zeman, R. K...; Elliott, L. P.

    1985-09-01

    During the preparation and planning phase of the PACS project at Georgetown University Hospital it was realized that PACS requires truly the state of the art technology in data communication, image processing and man machine interfacing. It was also realized that un-like many other technology intensive devices used in radiology, PACS cannot be seen as an independent system that will provide well defined services. PACS will be the backbone of the department operation in clinical, educational and managerial functions. It will indeed be the nerve center of the radiologic services affecting every aspect of the department. PACS will have to be designed to perform in a cost-effective manner to widely varying needs within the radiology departments. The integration of ever changing complex technology that will impact every aspect of a radiology service is not a trivial matter. This transition period going from current manual film based PACS to Digital PACS can be long, expansive and disruptive unless careful planning preceeds the implementation. PACS is still an emerging technology at its infancy. Performance monitoring and evaluation of diversified functions have to be also established so that improvement to the system can be efficiently implemented. Thus the evaluation criteria should be also established as early as possible.

  10. Optimal design and evaluation criteria for acoustic emission pulse signature analysis

    NASA Technical Reports Server (NTRS)

    Houghton, J. R.; Townsend, M. A.; Packman, P. F.

    1977-01-01

    Successful pulse recording and evaluation is strongly dependent on the instrumentation system selected and the method of analyzing the pulse signature. The paper studies system design, signal analysis techniques, and interdependences with a view toward defining optimal approaches to pulse signal analysis. For this purpose, the instrumentation system is modeled, and analytical pulses, representative of the types of acoustic emissions to be distinguished are passed through the system. Particular attention is given to comparing frequency spectrum analysis and deconvolution referred to as time domain reconstruction of the pulse or pulse train. The possibility of optimal transducer-filter system parameters is investigated. Deconvolution of a pulse is shown to be a superior approach for transient pulse analysis. Reshaping of a transducer output back to the original input pulse is possible and gives an accurate representation of the generating pulse in the time domain. Any definable transducer and filter system can be used for measurement of pulses by means of the deconvolution method. Selection of design variables for general usage is discussed.

  11. Optimal design and evaluation criteria for acoustic emission pulse signature analysis

    NASA Technical Reports Server (NTRS)

    Houghton, J. R.; Townsend, M. A.; Packman, P. F.

    1977-01-01

    Successful pulse recording and evaluation is strongly dependent on the instrumentation system selected and the method of analyzing the pulse signature. The paper studies system design, signal analysis techniques, and interdependences with a view toward defining optimal approaches to pulse signal analysis. For this purpose, the instrumentation system is modeled, and analytical pulses, representative of the types of acoustic emissions to be distinguished are passed through the system. Particular attention is given to comparing frequency spectrum analysis and deconvolution referred to as time domain reconstruction of the pulse or pulse train. The possibility of optimal transducer-filter system parameters is investigated. Deconvolution of a pulse is shown to be a superior approach for transient pulse analysis. Reshaping of a transducer output back to the original input pulse is possible and gives an accurate representation of the generating pulse in the time domain. Any definable transducer and filter system can be used for measurement of pulses by means of the deconvolution method. Selection of design variables for general usage is discussed.

  12. Acoustic Treatment Design Scaling Methods. Volume 2; Advanced Treatment Impedance Models for High Frequency Ranges

    NASA Technical Reports Server (NTRS)

    Kraft, R. E.; Yu, J.; Kwan, H. W.

    1999-01-01

    The primary purpose of this study is to develop improved models for the acoustic impedance of treatment panels at high frequencies, for application to subscale treatment designs. Effects that cause significant deviation of the impedance from simple geometric scaling are examined in detail, an improved high-frequency impedance model is developed, and the improved model is correlated with high-frequency impedance measurements. Only single-degree-of-freedom honeycomb sandwich resonator panels with either perforated sheet or "linear" wiremesh faceplates are considered. The objective is to understand those effects that cause the simple single-degree-of- freedom resonator panels to deviate at the higher-scaled frequency from the impedance that would be obtained at the corresponding full-scale frequency. This will allow the subscale panel to be designed to achieve a specified impedance spectrum over at least a limited range of frequencies. An advanced impedance prediction model has been developed that accounts for some of the known effects at high frequency that have previously been ignored as a small source of error for full-scale frequency ranges.

  13. Design factors of intravascular dual frequency transducers for super-harmonic contrast imaging and acoustic angiography

    NASA Astrophysics Data System (ADS)

    Ma, Jianguo; Martin, K. Heath; Li, Yang; Dayton, Paul A.; Shung, K. Kirk; Zhou, Qifa; Jiang, Xiaoning

    2015-05-01

    Imaging of coronary vasa vasorum may lead to assessment of the vulnerable plaque development in diagnosis of atherosclerosis diseases. Dual frequency transducers capable of detection of microbubble super-harmonics have shown promise as a new contrast-enhanced intravascular ultrasound (CE-IVUS) platform with the capability of vasa vasorum imaging. Contrast-to-tissue ratio (CTR) in CE-IVUS imaging can be closely associated with low frequency transmitter performance. In this paper, transducer designs encompassing different transducer layouts, transmitting frequencies, and transducer materials are compared for optimization of imaging performance. In the layout selection, the stacked configuration showed superior super-harmonic imaging compared with the interleaved configuration. In the transmitter frequency selection, a decrease in frequency from 6.5 MHz to 5 MHz resulted in an increase of CTR from 15 dB to 22 dB when receiving frequency was kept constant at 30 MHz. In the material selection, the dual frequency transducer with the lead magnesium niobate-lead titanate (PMN-PT) 1-3 composite transmitter yielded higher axial resolution compared to single crystal transmitters (70 μm compared to 150 μm pulse length). These comparisons provide guidelines for the design of intravascular acoustic angiography transducers.

  14. A new electromagnetic acoustic transducer design for generating torsional guided wave modes for pipe inspections

    NASA Astrophysics Data System (ADS)

    Hill, Samuel; Dixon, Steve; Sri Harsha Reddy, K.; Rajagopal, Prabhu; Balasubramaniam, Krishnan

    2017-02-01

    Guided waves inspection is a well-established method for the long-range ultrasonic inspection of pipes. Guided waves, used in a pulse-echo arrangement, can inspect a large range of the pipe from a single point as the pipe structure carries the waves over a large distance due to the relatively low attenuation of the wave modes. However, the complexity of the dispersion characteristics of these pipe guided wave modes are well known, and can lead to diffculty interpreting the obtained results. The torsional family of guided wave modes are generally considered to have much simpler dispersion characteristics; especially the fundamental T(0,1) mode, which is nominally non-dispersive, making it particularly useful for guided wave inspection. Torsional waves have been generated by a circumferential ring of transducers to approximate an axi-symmetric load to excite this T(0, 1) mode. Presented here is a new design of Electromagnetic Acoustic Transducer (EMAT) that can generate a T(0, 1) as a single transducer, rather than a circumferential array of transducers that all need to be excited in order to generate an axisymmetric force. The EMAT consists of a periodic permanent magnet array and a single meander coil, meaning that the excitation of the torsional mode is greatly simplified. The design parameters of this new EMAT are explored, and the ability to detect notch defects on a pipe is demonstrated.

  15. Design factors of intravascular dual frequency transducers for super-harmonic contrast imaging and acoustic angiography

    PubMed Central

    Ma, Jianguo; Martin, K. Heath; Li, Yang; Dayton, Paul A.; Shung, K. Kirk; Zhou, Qifa; Jiang, Xiaoning

    2015-01-01

    Imaging of coronary vasa vasorum may lead to assessment of the vulnerable plaque development in diagnosis of atherosclerosis diseases. Dual frequency transducers capable of detection of microbubble super-harmonics have shown promise as a new contrast-enhanced intravascular ultrasound (CE-IVUS) platform with the capability of vasa vasorum imaging. Contrast-to-tissue ratio (CTR) in CE-IVUS imaging can be closely associated with the low frequency transmitter performance. In this paper, transducer designs encompassing different transducer layouts, transmitting frequencies, and transducer materials are compared for optimization of imaging performance. In the layout selection, the stacked configuration showed superior super-harmonic imaging compared with the interleaved configuration. In the transmitter frequency selection, a decrease in frequency from 6.5 MHz to 5 MHz resulted in an increase of CTR from 15 dB to 22 dB when receiving frequency was kept constant at 30 MHz. In the material selection, the dual frequency transducer with the lead magnesium niobate-lead titanate (PMN-PT) 1-3 composite transmitter yielded higher axial resolution compared to single crystal transmitters (70 μm compared to 150 μm pulse length). These comparisons provide guidelines for design of intravascular acoustic angiography transducers. PMID:25856384

  16. Design and implementation of a fuzzy logic yaw controller

    NASA Astrophysics Data System (ADS)

    Wu, Kung C.; Swift, Andrew H.; Craver, W. Lionel, Jr.; Chang, Yi-Chieh

    1993-08-01

    This paper describes a fuzzy logic controller (FLC) designed and implemented to control the yaw angle of a 10 kW fixed speed teetered-rotor wind turbine presently being commissioned at the University of Texas at El Paso. The technical challenge of this project is that the wind turbine represents a highly stochastic nonlinear system. The problems associated with the wind turbine yaw control are of a similar nature as those experienced with position control of high inertia equipment like tracking antenna, gun turrets, and overhead cranes. Furthermore, the wind turbine yaw controller must be extremely cost-effective and highly reliable in order to be economically viable compared to the fossil fueled power generators.

  17. The AARTFAAC All-Sky Monitor: System Design and Implementation

    NASA Astrophysics Data System (ADS)

    Prasad, Peeyush; Huizinga, Folkert; Kooistra, Eric; van der Schuur, Daniel; Gunst, Andre; Romein, John; Kuiack, Mark; Molenaar, Gijs; Rowlinson, Antonia; Swinbank, John D.; Wijers, Ralph A. M. J.

    The Amsterdam-ASTRON Radio Transients Facility and Analysis Center (AARTFAAC) all-sky monitor is a sensitive, real-time transient detector based on the Low Frequency Array (LOFAR). It generates images of the low frequency radio sky with spatial resolution of tens of arcmin, MHz bandwidths, and a time cadence of a few seconds, while simultaneously but independently observing with LOFAR. The image timeseries is then monitored for short and bright radio transients. On detection of a transient, a low latency trigger will be generated for LOFAR, which can interrupt its schedule to carry out follow-up observations of the trigger location at high sensitivity and resolutions. In this paper, we describe our heterogeneous, hierarchical design to manage the 259Gbps raw data rate and large scale computing to produce real-time images with minimum latency. We discuss the implementation of the instrumentation, its performance and scalability.

  18. Design and implementation of artistic gymnastics training guidance system

    NASA Astrophysics Data System (ADS)

    Cai, Limin; Luo, Lin

    2017-04-01

    Artistic gymnastics (AG) has developed into a favorite sports activity among many university students; recent years saw not only the increase of AG learners, but also the emergence of more and more problems in the training. Based on surveys in different forms, students' physical quality and their performance in the AG training were analyzed and summarized; and with the aid of the computer technology, Artistic Gymnastics Training Guidance System was designed and implemented to meet the students' needs for personalized training schemes and improve AG teaching quality. The System can provide convenient ways for scientific training in a targeted and oriented manner on the basis of the differences in physical quality. Also, it can provide teachers with detailed data about the students' physical quality and their AG training; through the visualization of valuable statistical data, it is able to provide a powerful basis for decision makers of teaching departments and thus facilitate the perfection of AG teaching methods.

  19. Designing and implementing the objective structured clinical examination in anesthesiology.

    PubMed

    Hastie, Maya Jalbout; Spellman, Jessica L; Pagano, Parwane P; Hastie, Jonathan; Egan, Brian J

    2014-01-01

    Since its description in 1974, the Objective Structured Clinical Examination (OSCE) has gained popularity as an objective assessment tool of medical students, residents, and trainees. With the development of the anesthesiology residents' milestones and the preparation for the Next Accreditation System, there is an increased interest in OSCE as an evaluation tool of the six core competencies and the corresponding milestones proposed by the Accreditation Council for Graduate Medical Education.In this article the authors review the history of OSCE and its current application in medical education and in different medical and surgical specialties. They also review the use of OSCE by anesthesiology programs and certification boards in the United States and internationally. In addition, they discuss the psychometrics of test design and implementation with emphasis on reliability and validity measures as they relate to OSCE.

  20. The Palomar-Quest Survey Archive: Design and Implementation

    NASA Astrophysics Data System (ADS)

    Graham, Matthew; Djorgovski, S. G.; Mahabal, A.; Drake, A.; Williams, R.; Glikman, E.; Donalek, C.; Baltay, C.; Rabinowitz, D.; PQ Survey Team

    2009-01-01

    The Palomar-Quest (PQ) Synoptic Sky Survey is the first of the next generation of sky surveys devoted to transient astronomy. With the emphasis placed on repeated observations of astronomical objects rather than just single observations, different constraints are imposed on how the data are archived and accessed than with a conventional survey, such as 2MASS. For example, Terabyte-scale catalogs regularly need to be crossmatched to construct groupings of observations corresponding to time histories of astronomical objects. In this paper, we will review the design and implementation of the PQ Survey Archive, which now holds more than five years' worth of data consisting of 3.5 billion observations (5 times greater than SDSS DR6) over 15,500 sq. deg. (twice the coverage of SDSS). We will also describe user interfaces to the archive which rely heavily on VO technologies such as SIAP and CasJobs.

  1. Issues in the design and implementation of psychoneuroimmunology research.

    PubMed

    Robinson, F Patrick; Mathews, Herbert L; Witek-Janusek, Linda

    2002-04-01

    Research that uses a psychoneuroimmunology (PNI) framework seeks to determine whether valid associations exist among stress, immune function, and health. These associations are difficult to conclusively determine due to the fact that PNI research is fraught with methodological difficulties. These difficulties arise from the multifaceted and complex nature of the neuro-endocrine-immune network that is the phenomenon of interest in PNI. This article discusses multiple issues of which investigators should be aware when designing and implementing PNI research including (1) the control of potentially immunomodulating variables related to demographics, behavior, and lifestyle; (2) the manner in which stress, endocrine function, immunity, and health outcomes are measured in consideration of the theoretical relevance to the research question, population, or disease entity understudy; (3) the way physiological specimens are procured and stored; and (4) the methods by which assays are performed.

  2. Design and Implementation of High-Throughput Screening Assays.

    PubMed

    Powell, David J; Hertzberg, Robert P; Macarrόn, Ricardo

    2016-01-01

    HTS remains at the core of the drug discovery process, and so it is critical to design and implement HTS assays in a comprehensive fashion involving scientists from the disciplines of biology, chemistry, engineering, and informatics. This requires careful consideration of many options and variables, starting with the choice of screening strategy and ending with the discovery of lead compounds. At every step in this process, there are decisions to be made that can greatly impact the outcome of the HTS effort, to the point of making it a success or a failure. Although specific guidelines should be established to ensure that the screening assay reaches an acceptable level of quality, many choices require pragmatism and the ability to compromise opposing forces.

  3. Jet A fuel recovery using micellar flooding: Design and implementation.

    PubMed

    Kostarelos, Konstantinos; Lenschow, Søren R; Stylianou, Marinos A; de Blanc, Phillip C; Mygind, Mette Marie; Christensen, Anders G

    2016-09-01

    Surfactants offer two mechanisms for recovering NAPLs: 1) to mobilize NAPL by reducing NAPL/water interfacial tension, and; 2) to increase the NAPL's aqueous solubility-called solubilization-as an enhancement to pump & treat. The second approach has been well-studied and applied successfully in several pilot-scale and a few full-scale tests within the last 15years, known as Surfactant Enhanced Aquifer Remediation (SEAR). A useful source of information for this second approach is the "Surfactant-enhanced aquifer remediation (SEAR) design manual" from the U.S. Navy Facilities Engineering Command. Few attempts, however, have been made at recovering NAPLs using the mobilization approach presented in this paper. Now, a full-scale field implementation of the mobilization approach is planned to recover an LNAPL (Jet A fuel) from a surficial sand aquifer located in Denmark using a smaller amount of surfactant solution and fewer PVs of throughput compared with the SEAR approach. The approach will rely on mobilizing the LNAPL so that it is recovered ahead of the surfactant microemulsion, also known as a micellar flood. This paper will review the laboratory work performed as part of the design for a full-scale implementation of a micellar flood. Completed lab work includes screening of surfactants, phase behavior and detailed salinity scans of the most promising formulations, and generating a ternary diagram to be used for the numerical simulations of the field application. The site owners and regulators were able to make crucial decisions such as the anticipated field results based on this work. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. A new sparse design method on phased array-based acoustic emission sensor for partial discharge detection

    NASA Astrophysics Data System (ADS)

    Xie, Qing; Cheng, Shuyi; Lü, Fangcheng; Li, Yanqing

    2014-03-01

    The acoustic detecting performance of a partial discharge (PD) ultrasonic sensor array can be improved by increasing the number of array elements. However, it will increase the complexity and cost of the PD detection system. Therefore, a sparse sensor with an optimization design can be chosen to ensure good acoustic performance. In this paper, first, a quantitative method is proposed for evaluating the acoustic performance of a square PD ultrasonic array sensor. Second, a method of sparse design is presented to combine the evaluation method with the chaotic monkey algorithm. Third, an optimal sparse structure of a 3 × 3 square PD ultrasonic array sensor is deduced. It is found that, under different sparseness and sparse structure, the main beam width of the directivity function shows a small variation, while the sidelobe amplitude shows a bigger variation. For a specific sparseness, the acoustic performance under the optimal sparse structure is close to that using a full array. Finally, some simulations based on the above method show that, for certain sparseness, the sensor with the optimal sparse structure exhibits superior positioning accuracy compared to that with a stochastic one. The sensor array structure may be chosen according to the actual requirements for an actual engineering application.

  5. Towards a reference cavitating vessel Part III—design and acoustic pressure characterization of a multi-frequency sonoreactor

    NASA Astrophysics Data System (ADS)

    Wang, Lian; Memoli, Gianluca; Hodnett, Mark; Butterworth, Ian; Sarno, Dan; Zeqiri, Bajram

    2015-08-01

    A multi-frequency cavitation vessel (RV-multi) has been commissioned at the National Physical Laboratory (NPL, UK), with the aim of establishing a standard source of acoustic cavitation in water, with reference to which details of the cavitation process can be studied and cavitation measurement techniques evaluated. The vessel is a cylindrical cavity with a maximum capacity up to 17 L, and is designed to work at six frequency ranges, from 21 kHz to 136 kHz, under controlled temperature conditions. This paper discusses the design of RV-multi and reports experiments carried out to establish the reproducibility of the acoustic pressure field established within the vessel and its operating envelope, including sensitivity to aspects such as water depth and temperature. The acoustic field distribution was determined along the radial and depth directions within the vessel using a miniature hydrophone, for two input voltage levels under low power transducer excitation conditions (e.g. below the cavitation threshold). Particular care was taken in determining peak acoustic pressure locations, as these are critical for accompanying cavitation studies. Perturbations of the vessel by the measuring hydrophone were also monitored with a bottom-mounted pressure sensor.

  6. Preliminary vibration, acoustic, and shock design and test criteria for components on the SRB, ET, and SSME

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Specifications for vibration, acoustic and shock design for components and subassemblies on the External Tank (ET), Solid Rocket Booster (SRB), and Space Shuttle Main Engine (SSME). Included are vibration, acoustic, shock, transportation, handling, and acceptance test requirements and procedures. The space shuttle ET, SRB, and SSME have been divided into zones and subzones. Zones are designated primarily to assist in determining the applicable specifications. A subzone (General Specification) is available for use when the location of the component is known but component design and weight are not well defined. When the location, weight, and mounting configuration of the component are known, specifications for appropriate subzone weight ranges are available. Criteria for some specific components are also presented.

  7. The design of Helmholtz resonator based acoustic lenses by using the symmetric Multi-Level Wave Based Method and genetic algorithms

    NASA Astrophysics Data System (ADS)

    Atak, Onur; Huybrechs, Daan; Pluymers, Bert; Desmet, Wim

    2014-07-01

    Sonic crystals can be used as acoustic lenses in certain frequencies and the design of such systems by creating vacancies and using genetic algorithms has been proven to be an effective method. So far, rigid cylinders have been used to create such acoustic lens designs. On the other hand, it has been proven that Helmholtz resonators can be used to construct acoustic lenses with higher refraction index as compared to rigid cylinders, especially in low frequencies by utilizing their local resonances. In this paper, these two concepts are combined to design acoustic lenses that are based on Helmholtz resonators. The Multi-Level Wave Based Method is used as the prediction method. The benefits of the method in the context of design procedure are demonstrated. In addition, symmetric boundary conditions are derived for more efficient calculations. The acoustic lens designs that use Helmholtz resonators are compared with the acoustic lens designs that use rigid cylinders. It is shown that using Helmholtz resonator based sonic crystals leads to better acoustic lens designs, especially at the low frequencies where the local resonances are pronounced.

  8. Design and implementation of the mobility assessment tool: software description

    PubMed Central

    2013-01-01

    Background In previous work, we described the development of an 81-item video-animated tool for assessing mobility. In response to criticism levied during a pilot study of this tool, we sought to develop a new version built upon a flexible framework for designing and administering the instrument. Results Rather than constructing a self-contained software application with a hard-coded instrument, we designed an XML schema capable of describing a variety of psychometric instruments. The new version of our video-animated assessment tool was then defined fully within the context of a compliant XML document. Two software applications—one built in Java, the other in Objective-C for the Apple iPad—were then built that could present the instrument described in the XML document and collect participants’ responses. Separating the instrument’s definition from the software application implementing it allowed for rapid iteration and easy, reliable definition of variations. Conclusions Defining instruments in a software-independent XML document simplifies the process of defining instruments and variations and allows a single instrument to be deployed on as many platforms as there are software applications capable of interpreting the instrument, thereby broadening the potential target audience for the instrument. Continued work will be done to further specify and refine this type of instrument specification with a focus on spurring adoption by researchers in gerontology and geriatric medicine. PMID:23879716

  9. Design and implementation of the mobility assessment tool: software description.

    PubMed

    Barnard, Ryan T; Marsh, Anthony P; Rejeski, Walter Jack; Pecorella, Anthony; Ip, Edward H

    2013-07-23

    In previous work, we described the development of an 81-item video-animated tool for assessing mobility. In response to criticism levied during a pilot study of this tool, we sought to develop a new version built upon a flexible framework for designing and administering the instrument. Rather than constructing a self-contained software application with a hard-coded instrument, we designed an XML schema capable of describing a variety of psychometric instruments. The new version of our video-animated assessment tool was then defined fully within the context of a compliant XML document. Two software applications--one built in Java, the other in Objective-C for the Apple iPad--were then built that could present the instrument described in the XML document and collect participants' responses. Separating the instrument's definition from the software application implementing it allowed for rapid iteration and easy, reliable definition of variations. Defining instruments in a software-independent XML document simplifies the process of defining instruments and variations and allows a single instrument to be deployed on as many platforms as there are software applications capable of interpreting the instrument, thereby broadening the potential target audience for the instrument. Continued work will be done to further specify and refine this type of instrument specification with a focus on spurring adoption by researchers in gerontology and geriatric medicine.

  10. Design, modelling, implementation, and intelligent fuzzy control of a hovercraft

    NASA Astrophysics Data System (ADS)

    El-khatib, M. M.; Hussein, W. M.

    2011-05-01

    A Hovercraft is an amphibious vehicle that hovers just above the ground or water by air cushion. The concept of air cushion vehicle can be traced back to 1719. However, the practical form of hovercraft nowadays is traced back to 1955. The objective of the paper is to design, simulate and implement an autonomous model of a small hovercraft equipped with a mine detector that can travel over any terrains. A real time layered fuzzy navigator for a hovercraft in a dynamic environment is proposed. The system consists of a Takagi-Sugenotype fuzzy motion planner and a modified proportional navigation based fuzzy controller. The system philosophy is inspired by human routing when moving between obstacles based on visual information including the right and left views from which he makes his next step towards the goal in the free space. It intelligently combines two behaviours to cope with obstacle avoidance as well as approaching a goal using a proportional navigation path accounting for hovercraft kinematics. MATLAB/Simulink software tool is used to design and verify the proposed algorithm.

  11. Design and implementation of an optical Gaussian noise generator

    NASA Astrophysics Data System (ADS)

    Za~O, Leonardo; Loss, Gustavo; Coelho, Rosângela

    2009-08-01

    A design of a fast and accurate optical Gaussian noise generator is proposed and demonstrated. The noise sample generation is based on the Box-Muller algorithm. The functions implementation was performed on a high-speed Altera Stratix EP1S25 field-programmable gate array (FPGA) development kit. It enabled the generation of 150 million 16-bit noise samples per second. The Gaussian noise generator required only 7.4% of the FPGA logic elements, 1.2% of the RAM memory, 0.04% of the ROM memory, and a laser source. The optical pulses were generated by a laser source externally modulated by the data bit samples using the frequency-shift keying technique. The accuracy of the noise samples was evaluated for different sequences size and confidence intervals. The noise sample pattern was validated by the Bhattacharyya distance (Bd) and the autocorrelation function. The results showed that the proposed design of the optical Gaussian noise generator is very promising to evaluate the performance of optical communications channels with very low bit-error-rate values.

  12. Design, Implementation, and Assessment Approaches Within a Pharmacogenomics Course

    PubMed Central

    Remsberg, Connie M.; Bray, Brenda S.; Wright, Susan K.; Ashmore, Joe; Kabasenche, William; Wang, Shuwen; Lazarus, Philip

    2017-01-01

    Objective. To design and implement a pharmacogenomics course that focuses on analysis and integration of pharmacogenomic data into clinical practice and to explore how participation in the course influences student self-confidence. Design. The Basic and Clinical Pharmacogenomics course content was divided into three modules: genetic-based didactic sessions, genomic techniques and self-genotype/phenotype laboratory exercise, and clinical-based case studies. Student learning assessment included knowledge- and application-based tests and performance on a group project. Assessment. Effectiveness of the course was evaluated using results of student performance on coded test questions, student perceptions on pre- and post-course self-assessments, performance on a group project, and course evaluation results. Student pharmacists successfully demonstrated competency in pharmacogenomics knowledge-based learning, demonstrated their abilities to apply learned skills in clinical-based scenarios, and reported improved confidence in analyzing patient-based genomic testing results. Conclusions. This course appears to have contributed to student learning and positively influenced student self-confidence in pharmacogenomics. PMID:28289301

  13. Numerical implementation of generalized Coddington equations for ophthalmic lens design

    NASA Astrophysics Data System (ADS)

    Rojo, P.; Royo, S.; Ramírez, J.; Madariaga, I.

    2014-02-01

    A method for general implementation in any software platform of the generalized Coddington equations is presented, developed, and validated within a Matlab environment. The ophthalmic lens design strategy is presented thoroughly, and the basic concepts of generalized ray tracing are introduced. The methodology for ray tracing is shown to include two inter-related processes. Firstly, finite ray tracing is used to provide the main direction of propagation of the considered ray at the incidence point of interest. Afterwards, generalized ray tracing provides the principal curvatures of the local wavefront at that point, and its orientation after being refracted by the lens. The curvature values of the local wavefront are interpreted as the sagital and tangential powers of the lens at the point of interest. The proposed approach is validated using a double-check of the calculated lens performance in the spherical lens case: while finite ray tracing is validated using a commercial ray tracing software, generalized ray tracing is validated using a software application for ophthalmic lens design based on the classical version of Coddington equations. Equations of the complete tracing process are developed in detail for the case of generic astigmatic ophthalmic lenses as an example. Three-dimensional representation of the sagital and tangential powers of the ophthalmic lens at all directions of gaze then becomes possible, and results are presented for lenses with different geometries.

  14. Design, Implementation, and Assessment Approaches Within a Pharmacogenomics Course.

    PubMed

    Remsberg, Connie M; Bray, Brenda S; Wright, Susan K; Ashmore, Joe; Kabasenche, William; Wang, Shuwen; Lazarus, Philip; Daoud, Sayed S

    2017-02-25

    Objective. To design and implement a pharmacogenomics course that focuses on analysis and integration of pharmacogenomic data into clinical practice and to explore how participation in the course influences student self-confidence. Design. The Basic and Clinical Pharmacogenomics course content was divided into three modules: genetic-based didactic sessions, genomic techniques and self-genotype/phenotype laboratory exercise, and clinical-based case studies. Student learning assessment included knowledge- and application-based tests and performance on a group project. Assessment. Effectiveness of the course was evaluated using results of student performance on coded test questions, student perceptions on pre- and post-course self-assessments, performance on a group project, and course evaluation results. Student pharmacists successfully demonstrated competency in pharmacogenomics knowledge-based learning, demonstrated their abilities to apply learned skills in clinical-based scenarios, and reported improved confidence in analyzing patient-based genomic testing results. Conclusions. This course appears to have contributed to student learning and positively influenced student self-confidence in pharmacogenomics.

  15. Translational illusion of acoustic sources by transformation acoustics.

    PubMed

    Sun, Fei; Li, Shichao; He, Sailing

    2017-09-01

    An acoustic illusion of creating a translated acoustic source is designed by utilizing transformation acoustics. An acoustic source shifter (ASS) composed of layered acoustic metamaterials is designed to achieve such an illusion. A practical example where the ASS is made with naturally available materials is also given. Numerical simulations verify the performance of the proposed device. The designed ASS may have some applications in, e.g., anti-sonar detection.

  16. Challenges of implementation and implementation research: Learning from an intervention study designed to improve tumor registry reporting

    PubMed Central

    McAlearney, Ann Scheck; Walker, Daniel M; Livaudais-Toman, Jennifer; Parides, Michael; Bickell, Nina A

    2016-01-01

    Objectives: Implementation of interventions designed to improve the quality of medical care often proceeds differently from what is planned. Improving existing conceptual models to better understand the sources of these differences can help future projects avoid these pitfalls and achieve desired effectiveness. To inform an adaptation of an existing theoretical model, we examined unanticipated changes that occurred in an intervention designed to improve reporting of adjuvant therapies for breast cancer patients at a large, urban academic medical center. Methods: Guided by the complex innovation implementation conceptual framework, our study team observed and evaluated the implementation of an intervention designed to improve reporting to a tumor registry. Findings were assessed against the conceptual framework to identify boundary conditions and modifications that could improve implementation effectiveness. Results: The intervention successfully increased identification of the managing medical oncologist and treatment reporting. During implementation, however, unexpected external challenges including hospital acquisitions of community practices and practices’ responses to government incentives to purchase electronic medical record systems led to unanticipated changes and associated threats to implementation. We present a revised conceptual model that incorporates the sources of these unanticipated challenges. Conclusion: This report of our experience highlights the importance of monitoring implementation over time and accounting for changes that affect both implementation and measurement of intervention impact. In this article, we use our study to examine the challenges of implementation research in health care, and our experience can help future implementation efforts. PMID:27635248

  17. Design, implementation and control of a magnetic levitation device

    NASA Astrophysics Data System (ADS)

    Shameli, Ehsan

    levitation system, the feedback linearization controller has the shortest settling time and is capable of reducing the positioning error to RMS value of 11.56mum. The force model was also utilized in the design of a model reference adaptive feedback linearization (MRAFL) controller for the z direction. For this case, the levitated object is a small microrobot equipped with a remote controlled gripper weighting approximately 28(gr). Experimental results showed that the MRAFL controller enables the micro-robot to pick up and transport a payload as heavy as 30% of its own weight without a considerable effect on its positioning accuracy. In the presence of the payload, the MRAFL controller resulted in a RMS positioning error of 8microm compared with 27.9mum of the regular feedback linearization controller. For the horizontal position control of the system, a mathematical formula for distributing the electric currents to the multiple electromagnets of the system was proposed and a PID control approach was implemented to control the position of the levitated object in the xy-plane. The control system was experimentally tested in tracking circular and spiral trajectories with overall positioning accuracy of 60mum. Also, a new mathematical approach is presented for the prediction of magnetic field distribution in the horizontal direction. The proposed approach is named the pivot point method and is capable of predicting the two dimensional position of the levitated object in a given vertical plane for an arbitrary current distribution in the electromagnets of the levitation system. Experimental results showed that the proposed method is capable of predicting the location of the levitated object with less than 10% error.

  18. Ultra-high-resolution turbulence, flux, and wind profiles using new acoustic profiler designs

    NASA Astrophysics Data System (ADS)

    Bradley, S. G.; von Hünerbein, S.

    2009-09-01

    We give an overview of new developments in acoustic remote sensing of the lowest 150m of the atmosphere. These developments are driven by requirements for higher resolution continuous profiling in more demanding environments than traditionally addressed by SODARs. In wind energy applications there is a need for more accurate wind measurement for wind turbine monitoring, and measurements in a shear environment for wind farm site evaluation in complex terrain. More accurate wind measurement requires better specification on instrument design as well as accounting for spatial coherence variations between the sampling volumes used to derive the wind vector components at each height. These requirements give rise to new hardware and software approaches. A new bi-static design overcomes problems arising in complex terrain due to spatial variation in the wind components between sampling volumes in conventional SODARs. In studies of urban environments, profiling must be done at high spatial resolution, starting within a few meters of the ground and extending to around 100m, so that the structure within the street canyon canopy and the transition to the overlying boundary layers can be sampled. We describe extensions of the bi-static SODAR development for this purpose and the upcoming UK field campaigns in London. As a third example, we describe the exciting outcomes of the European/Australian SNODAR/PLATO high resolution astronomy at Dome C in the Antarctic, in which very high quality optical imaging is supported by 1m resolution turbulence measurements in the lowest 50m. Finally, we discuss new methodologies for obtaining continuous flux profiles from a bi-static design.

  19. DICE Mission Design, Development, and Implementation: Success and Challenges

    NASA Astrophysics Data System (ADS)

    Stromberg, E.; Swenson, C.; Fish, C. S.; Crowley, G.; Barjatya, A.; Petersen, J.

    2012-12-01

    Funded by the NSF CubeSat and NASA ELaNa programs, the Dynamic Ionosphere CubeSat Experiment (DICE) mission consists of two 1.5U CubeSats which were launched into an eccentric low Earth orbit on October 28, 2011. Each identical spacecraft carries two Langmuir probes to measure ionospheric in-situ plasma densities, electric field probes to measure in-situ DC and AC electric fields, and a magnetometer to measure in-situ DC and AC magnetic fields. Given the tight integration of these multiple sensors with the CubeSat platforms, each of the DICE spacecraft is effectively a "sensor-sat" capable of comprehensive ionospheric diagnostics. Over time, the sensor-sats will separate relative to each other due to differences in the ejection velocity and enable accurate identification of geospace storm-time features, such as the geomagnetic Storm Enhanced Density (SED) bulge and plume. The use of two identical sensor-sats permits the de-convolution of spatial and temporal ambiguities in the observations of the ionosphere from a moving platform. In addition to demonstrating nanosat constellation science, the DICE mission downlink communications system is operating at 3 Mbit/s. To our knowledge, this transmission rate is a factor of 100 or more greater than previous CubeSat missions to date. This paper will focus on the DICE mission design, implementation, and on-orbit operations successes as well as the challenges faced in implementing a high-return science mission with limited resources. Specifically, it will focus on the lessons learned in integrating, calibrating, and managing a small constellation of sensor-sats for global science measurements.

  20. Acoustic neuroma

    MedlinePlus

    Vestibular schwannoma; Tumor - acoustic; Cerebellopontine angle tumor; Angle tumor; Hearing loss - acoustic; Tinnitus - acoustic ... Acoustic neuromas have been linked with the genetic disorder neurofibromatosis type 2 (NF2). Acoustic neuromas are uncommon.

  1. Modeling, design, packing and experimental analysis of liquid-phase shear-horizontal surface acoustic wave sensors

    NASA Astrophysics Data System (ADS)

    Pollard, Thomas B

    Recent advances in microbiology, computational capabilities, and microelectromechanical-system fabrication techniques permit modeling, design, and fabrication of low-cost, miniature, sensitive and selective liquid-phase sensors and lab-on-a-chip systems. Such devices are expected to replace expensive, time-consuming, and bulky laboratory-based testing equipment. Potential applications for devices include: fluid characterization for material science and industry; chemical analysis in medicine and pharmacology; study of biological processes; food analysis; chemical kinetics analysis; and environmental monitoring. When combined with liquid-phase packaging, sensors based on surface-acoustic-wave (SAW) technology are considered strong candidates. For this reason such devices are focused on in this work; emphasis placed on device modeling and packaging for liquid-phase operation. Regarding modeling, topics considered include mode excitation efficiency of transducers; mode sensitivity based on guiding structure materials/geometries; and use of new piezoelectric materials. On packaging, topics considered include package interfacing with SAW devices, and minimization of packaging effects on device performance. In this work novel numerical models are theoretically developed and implemented to study propagation and transduction characteristics of sensor designs using wave/constitutive equations, Green's functions, and boundary/finite element methods. Using developed simulation tools that consider finite-thickness of all device electrodes, transduction efficiency for SAW transducers with neighboring uniform or periodic guiding electrodes is reported for the first time. Results indicate finite electrode thickness strongly affects efficiency. Using dense electrodes, efficiency is shown to approach 92% and 100% for uniform and periodic electrode guiding, respectively; yielding improved sensor detection limits. A numerical sensitivity analysis is presented targeting viscosity

  2. Design of a semi-implantable hearing device for direct acoustic cochlear stimulation.

    PubMed

    Bernhard, Hans; Stieger, Christof; Perriard, Yves

    2011-02-01

    A new hearing therapy based on direct acoustic cochlear stimulation was developed for the treatment of severe to profound mixed hearing loss. The device efficacy was validated in an initial clinical trial with four patients. This semi-implantable investigational device consists of an externally worn audio processor, a percutaneous connector, and an implantable microactuator. The actuator is placed in the mastoid bone, right behind the external auditory canal. It generates vibrations that are directly coupled to the inner ear fluids and that, therefore, bypass the external and the middle ear. The system is able to provide an equivalent sound pressure level of 125 dB over the frequency range between 125 and 8000 Hz. The hermetically sealed actuator is designed to provide maximal output power by keeping its dimensions small enough to enable implantation. A network model is used to simulate the dynamic characteristics of the actuator to adjust its transfer function to the characteristics of the middle ear. The geometry of the different actuator components is optimized using finite-element modeling.

  3. Mass sensitivity analysis and designing of surface acoustic wave resonators for chemical sensors

    NASA Astrophysics Data System (ADS)

    Kshetrimayum, Roshan; Yadava, R. D. S.; Tandon, R. P.

    2009-05-01

    The sensitivity of surface acoustic wave (SAW) chemical sensors depends on several factors such as the frequency and phase point of SAW device operation, sensitivity of the SAW velocity to surface mass loading, sensitivity of the SAW oscillator resonance to the loop phase shift, film thickness and oscillator electronics. This paper analyzes the influence of the phase point of operation in SAW oscillator sensors based on two-port resonator devices. It is found that the mass sensitivity will be enhanced if the SAW device has a nonlinear dependence on the frequency (delay ~ frequency-1). This requires the device to generate and operate in a ωτg(ω) = const region in the device passband, where ω denotes the angular frequency of oscillation and τg(ω) denotes the phase slope of the SAW resonator device. A SAW coupled resonator filter (CRF) that take advantage of mode coupling is considered in realizing such a device to help in shaping the phase transfer characteristics of a high mass sensitivity sensor. The device design and simulation results are presented within the coupling-of-modes formalism.

  4. Design requirements for SRB production control system. Volume 4: Implementation

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The implementation plan which is presented was developed to provide the means for the successful implementation of the automated production control system. There are three factors which the implementation plan encompasses: detailed planning; phased implementation; and user involvement. The plan is detailed to the task level in terms of necessary activities as the system is developed, refined, installed, and tested. These tasks are scheduled, on a preliminary basis, over a two-and-one-half-year time frame.

  5. Quasi-experimental designs in practice-based research settings: design and implementation considerations.

    PubMed

    Handley, Margaret A; Schillinger, Dean; Shiboski, Stephen

    2011-01-01

    Although randomized controlled trials are often a gold standard for determining intervention effects, in the area of practice-based research (PBR), there are many situations in which individual randomization is not possible. Alternative approaches to evaluating interventions have received increased attention, particularly those that can retain elements of randomization such that they can be considered "controlled" trials. Methodological design elements and practical implementation considerations for two quasi-experimental design approaches that have considerable promise in PBR settings--the stepped-wedge design, and a variant of this design, a wait-list cross-over design, are presented along with a case study from a recent PBR intervention for patients with diabetes. PBR-relevant design features include: creation of a cohort over time that collects control data but allows all participants (clusters or patients) to receive the intervention; staggered introduction of clusters; multiple data collection points; and one-way cross-over into the intervention arm. Practical considerations include: randomization versus stratification, training run in phases; and extended time period for overall study completion. Several design features of practice based research studies can be adapted to local circumstances yet retain elements to improve methodological rigor. Studies that utilize these methods, such as the stepped-wedge design and the wait-list cross-over design, can increase the evidence base for controlled studies conducted within the complex environment of PBR.

  6. Space Launch System, Core Stage, Structural Test Design and Implementation

    NASA Technical Reports Server (NTRS)

    Shaughnessy, Ray

    2017-01-01

    As part of the National Aeronautics and Space Administration's (NASA) Space Launch System (SLS) Program, engineers at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Alabama are working to design, develop and implement the SLS Core Stage structural testing. The SLS will have the capability to return humans to the Moon and beyond and its first launch is scheduled for December of 2017. The SLS Core Stage consist of five major elements; Forward Skirt, Liquid Oxygen (LOX) tank, Intertank (IT), Liquid Hydrogen (LH2) tank and the Engine Section (ES). Structural Test Articles (STA) for each of these elements are being designed and produced by Boeing at Michoud Assembly Facility located in New Orleans, La. The structural test for the Core Stage STAs (LH2, LOX, IT and ES) are to be conducted by the MSFC Test Laboratory. Additionally, the MSFC Test Laboratory manages the Structural Test Equipment (STE) design and development to support the STAs. It was decided early (April 2012) in the project life that the LH2 and LOX tank STAs would require new test stands and the Engine Section and Intertank would be tested in existing facilities. This decision impacted schedules immediately because the new facilities would require Construction of Facilities (C of F) funds that require congressional approval and long lead times. The Engine Section and Intertank structural test are to be conducted in existing facilities which will limit lead times required to support the first launch of SLS. With a SLS launch date of December, 2017 Boeing had a need date for testing to be complete by September of 2017 to support flight certification requirements. The test facilities were required to be ready by October of 2016 to support test article delivery. The race was on to get the stands ready before Test Article delivery and meet the test complete date of September 2017. This paper documents the past and current design and development phases and the supporting processes, tools, and

  7. Electromagnetic acoustic imaging.

    PubMed

    Emerson, Jane F; Chang, David B; McNaughton, Stuart; Jeong, Jong Seob; Shung, K K; Cerwin, Stephen A

    2013-02-01

    Electromagnetic acoustic imaging (EMAI) is a new imaging technique that uses long-wavelength RF electromagnetic (EM) waves to induce ultrasound emission. Signal intensity and image contrast have been found to depend on spatially varying electrical conductivity of the medium in addition to conventional acoustic properties. The resultant conductivity- weighted ultrasound data may enhance the diagnostic performance of medical ultrasound in cancer and cardiovascular applications because of the known changes in conductivity of malignancy and blood-filled spaces. EMAI has a potential advantage over other related imaging techniques because it combines the high resolution associated with ultrasound detection with the generation of the ultrasound signals directly related to physiologically important electrical properties of the tissues. Here, we report the theoretical development of EMAI, implementation of a dual-mode EMAI/ultrasound apparatus, and successful demonstrations of EMAI in various phantoms designed to establish feasibility of the approach for eventual medical applications.

  8. Acoustic Suppression Systems and Related Methods

    NASA Technical Reports Server (NTRS)

    Kolaini, Ali R. (Inventor); Kern, Dennis L. (Inventor)

    2013-01-01

    An acoustic suppression system for absorbing and/or scattering acoustic energy comprising a plurality of acoustic targets in a containment is described, the acoustic targets configured to have resonance frequencies allowing the targets to be excited by incoming acoustic waves, the resonance frequencies being adjustable to suppress acoustic energy in a set frequency range. Methods for fabricating and implementing the acoustic suppression system are also provided.

  9. Acoustic evaluation and adjustment of an open-plan office through architectural design and noise control.

    PubMed

    Passero, Carolina Reich Marcon; Zannin, Paulo Henrique Trombetta

    2012-11-01

    Arranging office space into a single open room offers advantages in terms of easy exchange of information and interaction among coworkers, but reduces privacy and acoustic comfort. Thus, the purpose of this work was to evaluate the acoustic quality of a real open-plan office and to propose changes in the room to improve the acoustic conditioning of this office. The computational model of the office under study was calibrated based on RT and STI measurements. Predictions were made of the RT and STI, which generated the radius of distraction r(D), and the rate of spatial decay of sound pressure levels per distance doubling DL(2) in the real conditions of the office and after modifications of the room. The insertion of dividers between work stations and an increase in the ceiling's sound absorption improved the acoustic conditions in the office under study. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  10. Design and evaluation of a compound acoustic lens for photoacoustic computed tomography.

    PubMed

    Yang, Shirui; Qin, Wei; Guo, Heng; Jin, Tian; Huang, Na; He, Ming; Xi, Lei

    2017-05-01

    In photoacoustic computed tomography, the limited directivity of the detectors may cause deformation of off-center targets and lead to an imbalanced resolution in the imaging area. To improve the directivity of the acoustic detectors, several negative acoustic lenses have been proposed. In this study, we develop a new compound acoustic lens fabricated by integrating a concave polydimethylsiloxane (PDMS) lens and a convex epoxy lens. Both theoretical simulations and experimental evaluations demonstrate that the compound lens provides a larger directivity compared to single lenses made of PDMS, epoxy, and liquid. The measured acceptance angles of a 6-mm piezoelectric acoustic transducer equipped with the compound, epoxy, liquid, and PDMS lenses are 55°, 36°, 25°, and 20°, respectively. No deformation is observed in the off-center targets by using compound lens. However, serious deformation appears in the cases using single lenses.

  11. A research program to reduce interior noise in general aviation airplanes. Design of an acoustic panel test facility

    NASA Technical Reports Server (NTRS)

    Roskam, J.; Muirhead, V. U.; Smith, H. W.; Henderson, T. D.

    1977-01-01

    The design, construction, and costs of a test facility for determining the sound transmission loss characteristics of various panels and panel treatments are described. The pressurization system and electronic equipment used in experimental testing are discussed as well as the reliability of the facility and the data gathered. Tests results are compared to pertinent acoustical theories for panel behavior and minor anomalies in the data are examined. A method for predicting panel behavior in the stiffness region is also presented.

  12. New specimen design for studying the growth of small fatigue cracks with surface acoustic waves

    NASA Astrophysics Data System (ADS)

    London, Blair

    1985-08-01

    The study of small surface fatigue cracks in AISI 4140 quenched and tempered steel by a nondestructive surface acoustic wave technique is summarized. A novel cantilevered bending, plate-type fatigue specimen is described that is compatible with the acoustic method. Small cracks are initiated from a 25-μm deep surface pit produced by an electrospark machine. The importance of studying these cracks which closely approximate naturally occurring fatigue cracks is briefly discussed.

  13. The Design and Implementation of the Swim Integrated Plasma Simulator

    SciTech Connect

    Elwasif, Wael R; Bernholdt, David E; Shet, Aniruddha G; Foley, Samantha S; Bramley, Randall B; Batchelor, Donald B; Berry, Lee A

    2010-01-01

    As computing capabilities have increased, the coupling of computational models has become an increasingly viable and therefore important way of improving the physical fidelity of simulations. Applications currently using some form of multicode or multi-component coupling include climate modeling, rocket simulations, and chemistry. In recent years, the plasma physics community has also begun to pursue integrated multiphysics simulations for space weather and fusion energy applications. Such model coupling generally exposes new issues in the physical, mathematical, and computational aspects of the problem. This paper focuses on the computational aspects of one such effort, detailing the design, and implementation of the Integrated Plasma Simulator (IPS) for the Center for Simulation of Wave Interactions with Magnetohydrodynamics (SWIM). The IPS framework focuses on maximizing flexibility for the creators of loosely-coupled component-based simulations, and provides services for execution coordination, resource management, data management, and inter-component communication. It also serves as a proving ground for a concurrent 'multi-tasking' execution model to improve resource utilization, and application-level fault tolerance. We also briefly describe how the IPS has been applied to several problems of interest to the fusion community.

  14. Design and implementation of a telecare information platform.

    PubMed

    Li, Shing-Han; Wang, Ching-Yao; Lu, Wen-Hui; Lin, Yuan-Yuan; Yen, David C

    2012-06-01

    For the aging population and for people with dominant chronic diseases, countries all over the world are promoting an "Aging in Place" program with its primary focus on the implementation of telecare. In 2009, Taiwan held a "Health Care Value-Added Platinum Program" with the goal of promoting the development of "Telecare" services by integrating medical treatment, healthcare, information communication, medical equipment and materials and by linking related cross-discipline professions to enable people to familiarize themselves with preventive healthcare services offered in their household and community environments. In addition, this program can be utilized to effectively provide diversified healthcare service benefitting society as a whole. This study aims to promote a diversified telecare service network in Taiwan's household and community environments, establish telecare information platforms, build an internal network of various healthcare service modes, standardize externally interfacing telecare information networks, effectively utilize related healthcare service resources, and complete reasonable service resource links forming an up-to-date health information exchange network. To this end, the telecare information platform based on service oriented architecture (SOA) is designed to promote an open telecare information interface and sharing environment to assist in such tasks as developing healthcare information exchange services, integrating service resources among various different healthcare service modes, accessing externally complex community affairs information, supporting remote physiological information transmissions, and providing diversified remote innovative services. Information system architecture and system monitoring indices of various types of healthcare service modes are used for system integrations for future development and/or expansions.

  15. Design and implementation of the BESIII detector-control system

    NASA Astrophysics Data System (ADS)

    Chen, Xihui; Xie, Xiaoxi; Gao, Cuishan; Zhang, Yinhong; Min, Jian; Nie, Zhendong; Xie, Song; Liu, Guoming; Li, Xiaonan

    2008-07-01

    In the upgrade project of the Beijing Electron-Positron Collider (BEPCII), a novel Detector-Control System (DCS) for the Beijing Spectrometer (BESIII) has been built and started its successful operation for the BESIII Commissioning. The main task of the DCS is to monitor and control the status of the BESIII detector and to guarantee a safe operation of the detector. The DCS must provide a uniform and coherent interface to detector operators even though there are a large number of distributed I/O channels from a large variety of equipments. For this reason, the DCS is hierarchically organized and divided into three layers: front-end layer (FEL), local control layer (LCL) and global control layer (GCL). In the FEL, devices ranging from simple sensors up to complex computer-based devices like embedded systems and programmable logical controllers (PLC) are utilized. A LabVIEW-based software framework has been developed for the LCL. Network communication and web server technologies have been used for the GCL. This paper will give a detailed introduction to the design and implementation of the DCS. Its performance and reliability will also be discussed.

  16. Design and Implementation of a Modern Automatic Deformation Monitoring System

    NASA Astrophysics Data System (ADS)

    Engel, Philipp; Schweimler, Björn

    2016-03-01

    The deformation monitoring of structures and buildings is an important task field of modern engineering surveying, ensuring the standing and reliability of supervised objects over a long period. Several commercial hardware and software solutions for the realization of such monitoring measurements are available on the market. In addition to them, a research team at the University of Applied Sciences in Neubrandenburg (NUAS) is actively developing a software package for monitoring purposes in geodesy and geotechnics, which is distributed under an open source licence and free of charge. The task of managing an open source project is well-known in computer science, but it is fairly new in a geodetic context. This paper contributes to that issue by detailing applications, frameworks, and interfaces for the design and implementation of open hardware and software solutions for sensor control, sensor networks, and data management in automatic deformation monitoring. It will be discussed how the development effort of networked applications can be reduced by using free programming tools, cloud computing technologies, and rapid prototyping methods.

  17. The IXV Ground Segment design, implementation and operations

    NASA Astrophysics Data System (ADS)

    Martucci di Scarfizzi, Giovanni; Bellomo, Alessandro; Musso, Ivano; Bussi, Diego; Rabaioli, Massimo; Santoro, Gianfranco; Billig, Gerhard; Gallego Sanz, José María

    2016-07-01

    The Intermediate eXperimental Vehicle (IXV) is an ESA re-entry demonstrator that performed, on the 11th February of 2015, a successful re-entry demonstration mission. The project objectives were the design, development, manufacturing and on ground and in flight verification of an autonomous European lifting and aerodynamically controlled re-entry system. For the IXV mission a dedicated Ground Segment was provided. The main subsystems of the IXV Ground Segment were: IXV Mission Control Center (MCC), from where monitoring of the vehicle was performed, as well as support during pre-launch and recovery phases; IXV Ground Stations, used to cover IXV mission by receiving spacecraft telemetry and forwarding it toward the MCC; the IXV Communication Network, deployed to support the operations of the IXV mission by interconnecting all remote sites with MCC, supporting data, voice and video exchange. This paper describes the concept, architecture, development, implementation and operations of the ESA Intermediate Experimental Vehicle (IXV) Ground Segment and outlines the main operations and lessons learned during the preparation and successful execution of the IXV Mission.

  18. Design and implementation of digital airborne multispectral camera system

    NASA Astrophysics Data System (ADS)

    Lin, Zhaorong; Zhang, Xuguo; Wang, Li; Pan, Deai

    2012-10-01

    The multispectral imaging equipment is a kind of new generation remote sensor, which can obtain the target image and the spectra information simultaneously. A digital airborne multispectral camera system using discrete filter method had been designed and implemented for unmanned aerial vehicle (UAV) and manned aircraft platforms. The digital airborne multispectral camera system has the advantages of larger frame, higher resolution, panchromatic and multispectral imaging. It also has great potential applications in the fields of environmental and agricultural monitoring and target detection and discrimination. In order to enhance the measurement precision and accuracy of position and orientation, Inertial Measurement Unit (IMU) is integrated in the digital airborne multispectral camera. Meanwhile, the Temperature Control Unit (TCU) guarantees that the camera can operate in the normal state in different altitudes to avoid the window fogging and frosting which will degrade the imaging quality greatly. Finally, Flying experiments were conducted to demonstrate the functionality and performance of the digital airborne multispectral camera. The resolution capability, positioning accuracy and classification and recognition ability were validated.

  19. Design and implementation of automatic color information collection system

    NASA Astrophysics Data System (ADS)

    Ci, Wenjie; Xie, Kai; Li, Tong

    2015-12-01

    In liquid crystal display (LCD) colorimetric characterization, it needs to convert RGB the device-dependent color space to CIEXYZ or CIELab the device-independent color space. Namely establishing the relationship between RGB and CIE using the data of device color and the corresponding data of CIE. Thus a color automatic message acquisition software is designed. We use openGL to fulfill the full screen display function, write c++ program and call the Eyeone equipment library functions to accomplish the equipment calibration, set the sample types, and realize functions such as sampling and preservation. The software can drive monitors or projectors display the set of sample colors automatically and collect the corresponding CIE values. The sample color of RGB values and the acquisition of CIE values can be stored in a text document, which is convenient for future extraction and analysis. Taking the cubic polynomial as an example, each channel is sampled of 17 sets using this system. And 100 sets of test data are also sampled. Using the least square method we can get the model. The average of color differences are around 2.4874, which is much lower than the CIE2000 commonly required level of 6.00.The successful implementation of the system saves the time of sample color data acquisition, and improves the efficiency of LCD colorimetric characterization.

  20. Design and implementation of GGEarth spatial data service application system

    NASA Astrophysics Data System (ADS)

    Chen, Jianhua; Miao, Fang; Wang, Weihong; Wang, Huajun

    2009-06-01

    The digital earth concept has aroused strong repercussions and been arousing researches boom both at home and abroad once it is proposed. Many digital earth prototype systems have been researched and distributed in worldwide, and the Google Earth is more typical. The booming development of digital earth's research and its prototype's development bring about G/S mode timely, a novel spatial information distributing access, and organization software architecture mode. Based on native GML spatial database system and Google Earth, with G/S mode as its architecture, and combination with GML/KML compressive transport and transformation, this paper proposed and designed the software architecture of GGEarth spatial data service application system, the research content and key implementation technologies were given. This system provides functions of data presentation, query, update and spatial analysis, which uses native GML spatial database (and GML, KML documents) as the standard data center, and the client based on Google Earth COM API as the front-end. This system can be applied in fields of digital city, digital tourism and traditional Web GIS. The authors developed the GGEarth experimental system and ran it with the data of '5.12' Wenchuan earthquake timing and the model data of digital Jiuzhaigou virtual tourism. Some running screenshots are also given.

  1. Design and Implementation of a Modern Automatic Deformation Monitoring System

    NASA Astrophysics Data System (ADS)

    Engel, Philipp; Schweimler, Björn

    2016-03-01

    The deformation monitoring of structures and buildings is an important task field of modern engineering surveying, ensuring the standing and reliability of supervised objects over a long period. Several commercial hardware and software solutions for the realization of such monitoring measurements are available on the market. In addition to them, a research team at the University of Applied Sciences in Neubrandenburg (NUAS) is actively developing a software package for monitoring purposes in geodesy and geotechnics, which is distributed under an open source licence and free of charge. The task of managing an open source project is well-known in computer science, but it is fairly new in a geodetic context. This paper contributes to that issue by detailing applications, frameworks, and interfaces for the design and implementation of open hardware and software solutions for sensor control, sensor networks, and data management in automatic deformation monitoring. It will be discussed how the development effort of networked applications can be reduced by using free programming tools, cloud computing technologies, and rapid prototyping methods.

  2. Design and implementation of a real-time positron imager

    NASA Astrophysics Data System (ADS)

    Naik, Pranab S.; Beling, Christopher D.; Fung, Stevenson

    2004-05-01

    In this paper we are going to present the first real-time S-parameter positron imager. This is a useful tool in solid state technology for mapping the lateral defect types and concentrations on a material sample. This technology has been developed for two major categories of researchers, the first being those that have a focused low energy positron beam and second those that do not. Here we describe the design and implementation of a real-time automated scanning system that rasters a sample surface with a 0.5mm diameter positron source (or beam focus) so as to give an S-parameter image of a sample. The source (or beam) rasters across a region of a semiconductor sample in rectilinear motion while gamma ray energies Eγ are processed using a standard HP Ge spectroscopy system and a 14 bit nuclear ADC. Two other ADCs are used to obtain the x, y coordinate data corresponding to each event by storing voltage pulses from the x & y stepper motor drives (or saddle coil currents) gated with the event pulses. Using these event data triplets (x, y, Eγ) the S-parameter is computed in real time for each pixel region and is used to refresh a color image display on the screen coordinates. Optimal use is made of processing time and the system resources. This user-friendly system is efficient for producing high resolution S-parameter images of the sample. (patent pending 2003)

  3. Design and implementation of an intelligent belt system using accelerometer.

    PubMed

    Liu, Botong; Wang, Duo; Li, Sha; Nie, Xuhui; Xu, Shan; Jiao, Bingli; Duan, Xiaohui; Huang, Anpeng

    2015-01-01

    Activity monitor systems are increasing used recently. They are important for athletes and casual users to manage physical activity during daily exercises. In this paper, we use a triaxial accelerometer to design and implement an intelligent belt system, which can detect the user's step and flapping motion. In our system, a wearable intelligent belt is worn on the user's waist to collect activity acceleration signals. We present a step detection algorithm to detect real-time human step, which has high accuracy and low complexity. In our system, an Android App is developed to manage the intelligent belt. We also propose a protocol, which can guarantee data transmission between smartphones and wearable belt effectively and efficiently. In addition, when users flap the belt in emergency, the smartphone will receive alarm signal sending by the belt, and then notifies the emergency contact person, which can be really helpful for users in danger. Our experiment results show our system can detect physical activities with high accuracy (overall accuracy of our algorithm is above 95%) and has an effective alarm subsystem, which is significant for the practical use.

  4. Designing and implementing the Army Nursing Leader Academy.

    PubMed

    Dunemn, Kathleen; Hopkins-Chadwick, Denise L; Connally, Tina; Bramley, Kelly

    2011-01-01

    In 2008, the Chief of the Army Nurse Corps directed a thorough review of existing training programs available to and provided for Army Nursing personnel for the development of full-spectrum leaders for Army Nursing. The review provided the gap analysis necessary to restructure courses provided by the Department of Nursing Science at the Army Medical Department Center and School. This new grouping of courses is referred to as the Army Nursing Leader Academy. The Army Nursing Leader Academy is the first of its kind in that it addresses career-long learning of all Army Nursing by focusing on building skills, knowledge, and behaviors to produce sustainable, full-spectrum leaders. The Nursing Leader Academy consists of a series of sequential nurse leader development courses combined with a web based resource center. Grounded in the Patient CaringTouch System, guided by nurse competencies, and gauged by the Leader Capabilities Map, the Nursing Leader Academy provides learning that is relevant and timely designed to reinforce enterprise values and culture to ensure readiness for successive roles and positions. Full implementation of the Nursing Leader Academy will include the evidence-based elements of formal schooling, coaching, self-development, functional/technical (competency attainment), and professional experiences.

  5. Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface.

    PubMed

    Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A

    2014-11-24

    Metasurfaces are a family of novel wavefront-shaping devices with planar profile and subwavelength thickness. Acoustic metasurfaces with ultralow profile yet extraordinary wave manipulating properties would be highly desirable for improving the performance of many acoustic wave-based applications. However, designing acoustic metasurfaces with similar functionality to their electromagnetic counterparts remains challenging with traditional metamaterial design approaches. Here we present a design and realization of an acoustic metasurface based on tapered labyrinthine metamaterials. The demonstrated metasurface can not only steer an acoustic beam as expected from the generalized Snell's law, but also exhibits various unique properties such as conversion from propagating wave to surface mode, extraordinary beam-steering and apparent negative refraction through higher-order diffraction. Such designer acoustic metasurfaces provide a new design methodology for acoustic signal modulation devices and may be useful for applications such as acoustic imaging, beam steering, ultrasound lens design and acoustic surface wave-based applications.

  6. Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface

    NASA Astrophysics Data System (ADS)

    Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A.

    2014-11-01

    Metasurfaces are a family of novel wavefront-shaping devices with planar profile and subwavelength thickness. Acoustic metasurfaces with ultralow profile yet extraordinary wave manipulating properties would be highly desirable for improving the performance of many acoustic wave-based applications. However, designing acoustic metasurfaces with similar functionality to their electromagnetic counterparts remains challenging with traditional metamaterial design approaches. Here we present a design and realization of an acoustic metasurface based on tapered labyrinthine metamaterials. The demonstrated metasurface can not only steer an acoustic beam as expected from the generalized Snell’s law, but also exhibits various unique properties such as conversion from propagating wave to surface mode, extraordinary beam-steering and apparent negative refraction through higher-order diffraction. Such designer acoustic metasurfaces provide a new design methodology for acoustic signal modulation devices and may be useful for applications such as acoustic imaging, beam steering, ultrasound lens design and acoustic surface wave-based applications.

  7. Structural-acoustic modal analysis of cylindrical shells: application to MRI scanner systems.

    PubMed

    Li, Gemin; Mechefske, Chris K

    2009-12-01

    The acoustic noise in a magnetic resonance imaging (MRI) scanner bore is mainly introduced by the vibration of gradient coils. The interaction between acoustic modes in the scanner bore and structure modes in the coil structure leads to structural-acoustic coupling. In order to implement quiet MRI design, the structural-acoustic coupling mechanism in MRI machines needs to be fully investigated. Structural analysis was first implemented using Love's classical shell theory. The concept of a "virtually closed cavity" was used in the acoustic modal analysis of the gradient coil duct. The dispersion curves and the number of modes per frequency band were used to reveal modal distribution properties for both structural modes and acoustic modes. Structural-acoustic coupling modes were identified by superposition of the dispersion diagrams of the structural waves and acoustic waves. Experimental validation was implemented separately for the structural analysis and acoustic analysis. Independent structural modes and acoustic modes and their distribution patterns were calculated up to 3000Hz with various boundary conditions. Coupling modes were clearly revealed using the analysis procedures presented in this paper and were found to be in agreement with the ones identified from experimental measurements. These methods are effective for coupled and uncoupled modal analysis of MRI scanner systems and can be used for quiet MRI design or sound absorber design for existing MRI systems.

  8. Vibration, acoustic, and shock design and test criteria for components on the Solid Rocket Boosters (SRB), Lightweight External Tank (LWT), and Space Shuttle Main Engines (SSME)

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The vibration, acoustics, and shock design and test criteria for components and subassemblies on the space shuttle solid rocket booster (SRB), lightweight tank (LWT), and main engines (SSME) are presented. Specifications for transportation, handling, and acceptance testing are also provided.

  9. Fault tolerant high-performance PACS network design and implementation

    NASA Astrophysics Data System (ADS)

    Chimiak, William J.; Boehme, Johannes M.

    1998-07-01

    The Wake Forest University School of Medicine and the Wake Forest University/Baptist Medical Center (WFUBMC) are implementing a second generation PACS. The first generation PACS provided helpful information about the functional and temporal requirements of the system. It highlighted the importance of image retrieval speed, system availability, RIS/HIS integration, the ability to rapidly view images on any PACS workstation, network bandwidth, equipment redundancy, and the ability for the system to evolve using standards-based components. This paper deals with the network design and implementation of the PACS. The physical layout of the hospital areas served by the PACS, the choice of network equipment and installation issues encountered are addressed. Efforts to optimize fault tolerance are discussed. The PACS network is a gigabit, mixed-media network based on LAN emulation over ATM (LANE) with a rapid migration from LANE to Multiple Protocols Over ATM (MPOA) planned. Two fault-tolerant backbone ATM switches serve to distribute network accesses with two load-balancing 622 megabit per second (Mbps) OC-12 interconnections. The switch was sized to be upgradable to provide a 2.54 Gbps OC-48 interconnection with an OC-12 interconnection as a load-balancing backup. Modalities connect with legacy network interface cards to a switched-ethernet device. This device has two 155 Mbps OC-3 load-balancing uplinks to each of the backbone ATM switches of the PACS. This provides a fault-tolerant logical connection to the modality servers which pass verified DICOM images to the PACS servers and proper PACS diagnostic workstations. Where fiber pulls were prohibitively expensive, edge ATM switches were installed with an OC-12 uplink to a backbone ATM switches. The PACS and data base servers are fault-tolerant, hot-swappable Sun Enterprise Servers with an OC-12 connection to a backbone ATM switch and a fast-ethernet connection to a back-up network. The workstations come with 10

  10. Effective design, implementation and management of change in healthcare.

    PubMed

    Allen, Belinda

    2016-09-14

    Changes in healthcare organisations are common, and their implementation is often complex and challenging. Change is often implemented suboptimally, and can have several negative effects on staff turnover, patient care and budget targets. To minimise and avoid negative outcomes, a systematic three-stage change process that comprises preparing for change, implementing change, and evaluating and sustaining change can be followed. In the first stage, before commencing any change activities, time and attention should be given to conducting detailed analyses and preparatory work to establish the foundation for the implementation phase. In the second stage, a clear set of multiple implementation tactics are used to ensure the change process is effective. In the final stage, an evaluation of the success of the change is undertaken and measures are put in place to ensure it is sustained over time. It is only by following a methodical change process such as this that changes can be implemented effectively in healthcare organisations.

  11. A rail system for circular synthetic aperture sonar imaging and acoustic target strength measurements: design/operation/preliminary results.

    PubMed

    Kennedy, J L; Marston, T M; Lee, K; Lopes, J L; Lim, R

    2014-01-01

    A 22 m diameter circular rail, outfitted with a mobile sonar tower trolley, was designed, fabricated, instrumented with underwater acoustic transducers, and assembled on a 1.5 m thick sand layer at the bottom of a large freshwater pool to carry out sonar design and target scattering response studies. The mobile sonar tower translates along the rail via a drive motor controlled by customized LabVIEW software. The rail system is modular and assembly consists of separately deploying eight circular arc sections, measuring a nominal center radius of 11 m and 8.64 m arc length each, and having divers connect them together in the underwater environment. The system enables full scale measurements on targets of interest with 0.1° angular resolution over a complete 360° aperture, without disrupting target setup, and affording a level of control over target environment conditions and noise sources unachievable in standard field measurements. In recent use, the mobile cart carrying an instrumented sonar tower was translated along the rail in 720 equal position increments and acoustic backscatter data were acquired at each position. In addition, this system can accommodate both broadband monostatic and bistatic scattering measurements on targets of interest, allowing capture of target signature phenomena under diverse configurations to address current scientific and technical issues encountered in mine countermeasure and unexploded ordnance applications. In the work discussed here, the circular rail apparatus is used for acoustic backscatter testing, but this system also has the capacity to facilitate the acquisition of magnetic and optical sensor data from targets of interest. A brief description of the system design and operation will be presented along with preliminary processed results for data acquired from acoustic measurements conducted at the Naval Surface Warfare Center, Panama City Division Test Pond Facility. [Work Supported by the U.S. Office of Naval Research and

  12. A rail system for circular synthetic aperture sonar imaging and acoustic target strength measurements: Design/operation/preliminary results

    NASA Astrophysics Data System (ADS)

    Kennedy, J. L.; Marston, T. M.; Lee, K.; Lopes, J. L.; Lim, R.

    2014-01-01

    A 22 m diameter circular rail, outfitted with a mobile sonar tower trolley, was designed, fabricated, instrumented with underwater acoustic transducers, and assembled on a 1.5 m thick sand layer at the bottom of a large freshwater pool to carry out sonar design and target scattering response studies. The mobile sonar tower translates along the rail via a drive motor controlled by customized LabVIEW software. The rail system is modular and assembly consists of separately deploying eight circular arc sections, measuring a nominal center radius of 11 m and 8.64 m arc length each, and having divers connect them together in the underwater environment. The system enables full scale measurements on targets of interest with 0.1° angular resolution over a complete 360° aperture, without disrupting target setup, and affording a level of control over target environment conditions and noise sources unachievable in standard field measurements. In recent use, the mobile cart carrying an instrumented sonar tower was translated along the rail in 720 equal position increments and acoustic backscatter data were acquired at each position. In addition, this system can accommodate both broadband monostatic and bistatic scattering measurements on targets of interest, allowing capture of target signature phenomena under diverse configurations to address current scientific and technical issues encountered in mine countermeasure and unexploded ordnance applications. In the work discussed here, the circular rail apparatus is used for acoustic backscatter testing, but this system also has the capacity to facilitate the acquisition of magnetic and optical sensor data from targets of interest. A brief description of the system design and operation will be presented along with preliminary processed results for data acquired from acoustic measurements conducted at the Naval Surface Warfare Center, Panama City Division Test Pond Facility. [Work Supported by the U.S. Office of Naval Research and

  13. Design and implementation of a laboratory-based drug design and synthesis advanced pharmacy practice experience.

    PubMed

    Philip, Ashok; Stephens, Mark; Mitchell, Sheila L; Watkins, E Blake

    2015-04-25

    To provide students with an opportunity to participate in medicinal chemistry research within the doctor of pharmacy (PharmD) curriculum. We designed and implemented a 3-course sequence in drug design or drug synthesis for pharmacy students consisting of a 1-month advanced elective followed by two 1-month research advanced pharmacy practice experiences (APPEs). To maximize student involvement, this 3-course sequence was offered to third-year and fourth-year students twice per calendar year. Students were evaluated based on their commitment to the project's success, productivity, and professionalism. Students also evaluated the course sequence using a 14-item course evaluation rubric. Student feedback was overwhelmingly positive. Students found the experience to be a valuable component of their pharmacy curriculum. We successfully designed and implemented a 3-course research sequence that allows PharmD students in the traditional 4-year program to participate in drug design and synthesis research. Students report the sequence enhanced their critical-thinking and problem-solving skills and helped them develop as independent learners. Based on the success achieved with this sequence, efforts are underway to develop research APPEs in other areas of the pharmaceutical sciences.

  14. Relational Programming: Design and Implementation of a Prototype Interpreter.

    DTIC Science & Technology

    1985-06-01

    are dis- cussed. Also several appendices are provided which include the grammar , the relational operators implemented, and the documented LISP code...Information and Policy ences 3 * ~* * * %V% % %. ABSTRACT Relational programming is a methodology which combines the advantages of funtional programming...include the grammar , the relational operators implemented, and the documented LISP code. 4 TABLE OF CONTENTS i. . . . . . . . . . . . . . . . I. BHY Lp

  15. The Design and Implementation of an Alternative High School.

    ERIC Educational Resources Information Center

    Kritek, William J.

    The analysis of the planning for an implementation of an alternative high school in a large urban school system is the focus of this study. Interview data are used. This investigation draws on, and compliments, the previous literature on implementation. While most of the earlier studies look at failures, this one is based on an instance of…

  16. Functional relevance of acoustic tracheal design in directional hearing in crickets.

    PubMed

    Schmidt, Arne K D; Römer, Heiner

    2016-10-15

    Internally coupled ears (ICEs) allow small animals to reliably determine the direction of a sound source. ICEs are found in a variety of taxa, but crickets have evolved the most complex arrangement of coupled ears: an acoustic tracheal system composed of a large cross-body trachea that connects two entry points for sound in the thorax with the leg trachea of both ears. The key structure that allows for the tuned directionality of the ear is a tracheal inflation (acoustic vesicle) in the midline of the cross-body trachea holding a thin membrane (septum). Crickets are known to display a wide variety of acoustic tracheal morphologies, most importantly with respect to the presence of a single or double acoustic vesicle. However, the functional relevance of this variation is still not known. In this study, we investigated the peripheral directionality of three co-occurring, closely related cricket species of the subfamily Gryllinae. No support could be found for the hypothesis that a double vesicle should be regarded as an evolutionary innovation to (1) increase interaural directional cues, (2) increase the selectivity of the directional filter or (3) provide a better match between directional and sensitivity tuning. Nonetheless, by manipulating the double acoustic vesicle in the rainforest cricket Paroecanthus podagrosus, selectively eliminating the sound-transmitting pathways, we revealed that these pathways contribute almost equally to the total amount of interaural intensity differences, emphasizing their functional relevance in the system. © 2016. Published by The Company of Biologists Ltd.

  17. Preliminary vibration, acoustic, and shock design and test criteria for components on the HEAO-A spacecraft

    NASA Technical Reports Server (NTRS)

    1975-01-01

    These vibration, acoustic, and shock specifications provide the qualification test criteria for spacecraft components and subassemblies and for the High Energy Astronomy Observatory (HEAO-A) experiments. The HEAO-A was divided into zones and subzones to obtain simple component groupings. Zones are designated primarily to assist in determining the applicable specification. A Subzone is available for use when the location of the component is known but component design and weight are not well defined. When the location, weight, and mounting configuration of the component are known, the appropriate Subzone weight ranges are available. Experiment and specific component specifications are available.

  18. Preliminary vibration, acoustic, and shock design and test criteria for components on the HEAO-C spacecraft

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The vibration, acoustic, and shock specification test criteria for spacecraft components and subassemblies and for the high Energy Astronomy Observatory (HEAO-C) experiments are presented. The HEAO-C was divided into zones and subzones to obtain simple component groupings. Zones are designated primarily to assist in determining the applicable specification. A subzone (general specification) is available for use when the location of the component is known but component design and weight are not well defined. When the location, weight, and mounting configuration of the component are known, the appropriate subzone weight ranges (-A, -B, etc. ) are available. Experiment and specific component specifications are available.

  19. Noise testing of an advanced design propeller in the Boeing transonic wind tunnel with and without test section acoustic treatment

    NASA Astrophysics Data System (ADS)

    Glover, B. M., Jr.; Plunkett, E. I.; Simcox, C. D.

    1984-10-01

    Noise tests using the NASA SR-6 advanced design propeller in the Boeing Transonic Wind Tunnel have recently been completed. Measurements were taken both with and without an acoustically treated test section. A wide range of helical tip speeds and power loadings were explored. Noise test techniques, previously not applied to advanced design propeller testing, have shown results indicating an increased level of confidence in the measured signatures. Typical results are presented along with recommendations for future noise tests and elementary empirical prediction methods for the SR-6.

  20. Design study of Software-Implemented Fault-Tolerance (SIFT) computer

    NASA Technical Reports Server (NTRS)

    Wensley, J. H.; Goldberg, J.; Green, M. W.; Kutz, W. H.; Levitt, K. N.; Mills, M. E.; Shostak, R. E.; Whiting-Okeefe, P. M.; Zeidler, H. M.

    1982-01-01

    Software-implemented fault tolerant (SIFT) computer design for commercial aviation is reported. A SIFT design concept is addressed. Alternate strategies for physical implementation are considered. Hardware and software design correctness is addressed. System modeling and effectiveness evaluation are considered from a fault-tolerant point of view.