Analyzing Radio-Frequency Coverage for the ISS

NASA Technical Reports Server (NTRS)

Bolen, Steven M.; Sham, Catherine C.

2007-01-01

The Interactive Coverage Analysis Tool (iCAT) is an interactive desktop computer program serving to (1) support planning of coverage, and management of usage of frequencies, of current and proposed radio communication systems on and near the International Space Station (ISS) and (2) enable definition of requirements for development of future such systems. The iCAT can also be used in design trade studies for other (both outer-space and terrestrial) communication systems. A user can enter the parameters of a communication-system link budget in a table in a worksheet. The nominal (onaxis) link values for the bit-to-noise-energy ratio, received isotropic power (RIP), carrier-to-noise ratio (C/N), power flux density (PFD), and link margin of the system are calculated and displayed in the table. Plots of field gradients for the RIP, C/N, PFD, and link margin are constructed in an ISS coordinate system, at a specified link range, for both the forward and return link parameters, and are displayed in worksheets. The forward and reverse link antenna gain patterns are also constructed and displayed. Line-of-sight (LOS) obstructions can be both incorporated into the gradient plots and displayed on separate plots.

High-speed optical feeder-link system using adaptive optics

NASA Astrophysics Data System (ADS)

Arimoto, Yoshinori; Hayano, Yutaka; Klaus, Werner

1997-05-01

We propose a satellite laser communication system between a ground station and a geostationary satellite, named high- speed optical feeder link system. It is based on the application of (a) high-speed optical devices, which have been developed for ground-based high-speed fiber-optic communications, and (b) the adaptive optics which compensates wavefront distortions due to atmospheric turbulences using a real time feedback control. A link budget study shows that a system with 10-Gbps bit-rate are available assuming the state-of-the-art device performance of the Er-doped fiber amplifier. We further discuss preliminary measurement results of the atmospheric turbulence at the telescope site in Tokyo, and present current study on the design of the key components for the feeder-link laser transceiver.

Current driven transition from Abrikosov-Josephson to Josephson-like vortex in mesoscopic lateral S/S’/S superconducting weak links

PubMed Central

Carapella, G.; Sabatino, P.; Barone, C.; Pagano, S.; Gombos, M.

2016-01-01

Vortices are topological defects accounting for many important effects in superconductivity, superfluidity, and magnetism. Here we address the stability of a small number of such excitations driven by strong external forces. We focus on Abrikosov-Josephson vortex that appears in lateral superconducting S/S’/S weak links with suppressed superconductivity in S’. In such a system the vortex is nucleated and confined in the narrow S’ region by means of a small magnetic field and moves under the effect of a force proportional to an applied electrical current with a velocity proportional to the measured voltage. Our numerical simulations show that when a slow moving Abrikosov-Josephson vortex is driven by a strong constant current it becomes unstable with respect to a faster moving excitation: the Josephon-like vortex. Such a current-driven transition explains the structured dissipative branches that we observe in the voltage-current curve of the weak link. When vortex matter is strongly confined phenomena as magnetoresistance oscillations and reentrance of superconductivity can possibly occur. We experimentally observe these phenomena in our weak links. PMID:27752137

Next-Generation Telemetry Workstation

NASA Technical Reports Server (NTRS)

2008-01-01

A next-generation telemetry workstation has been developed to replace the one currently used to test and control Range Safety systems. Improving upon the performance of the original system, the new telemetry workstation uses dual-channel telemetry boards for better synchronization of the two uplink telemetry streams. The new workstation also includes an Interrange Instrumentation Group/Global Positioning System (IRIG/GPS) time code receiver board for independent, local time stamping of return-link data. The next-generation system will also record and play back return-link data for postlaunch analysis.

Study of the generator/motor operation of induction machines in a high frequency link space power system

NASA Technical Reports Server (NTRS)

Lipo, Thomas A.; Sood, Pradeep K.

1987-01-01

Static power conversion systems have traditionally utilized dc current or voltage source links for converting power from one ac or dc form to another since it readily achieves the temporary energy storage required to decouple the input from the output. Such links, however, result in bulky dc capacitors and/or inductors and lead to relatively high losses in the converters due to stresses on the semiconductor switches. The feasibility of utilizing a high frequency sinusoidal voltage link to accomplish the energy storage and decoupling function is examined. In particular, a type of resonant six pulse bridge interface converter is proposed which utilizes zero voltage switching principles to minimize switching losses and uses an easy to implement technique for pulse density modulation to control the amplitude, frequency, and the waveshape of the synthesized low frequency voltage or current. Adaptation of the proposed topology for power conversion to single-phase ac and dc voltage or current outputs is shown to be straight forward. The feasibility of the proposed power circuit and control technique for both active and passive loads are verified by means of simulation and experiment.

Power Management Based Current Control Technique for Photovoltaic-Battery Assisted Wind-Hydro Hybrid System

NASA Astrophysics Data System (ADS)

Ram Prabhakar, J.; Ragavan, K.

2013-07-01

This article proposes new power management based current control strategy for integrated wind-solar-hydro system equipped with battery storage mechanism. In this control technique, an indirect estimation of load current is done, through energy balance model, DC-link voltage control and droop control. This system features simpler energy management strategy and necessitates few power electronic converters, thereby minimizing the cost of the system. The generation-demand (G-D) management diagram is formulated based on the stochastic weather conditions and demand, which would likely moderate the gap between both. The features of management strategy deploying energy balance model include (1) regulating DC-link voltage within specified tolerances, (2) isolated operation without relying on external electric power transmission network, (3) indirect current control of hydro turbine driven induction generator and (4) seamless transition between grid-connected and off-grid operation modes. Furthermore, structuring of the hybrid system with appropriate selection of control variables enables power sharing among each energy conversion systems and battery storage mechanism. By addressing these intricacies, it is viable to regulate the frequency and voltage of the remote network at load end. The performance of the proposed composite scheme is demonstrated through time-domain simulation in MATLAB/Simulink environment.

Design of a video teleconference facility for a synchronous satellite communications link

NASA Technical Reports Server (NTRS)

Richardson, M. D.

1979-01-01

The system requirements, design tradeoffs, and final design of a video teleconference facility are discussed, including proper lighting, graphics transmission, and picture aesthetics. Methods currently accepted in the television broadcast industry are used in the design. The unique problems associated with using an audio channel with a synchronous satellite communications link are discussed, and a final audio system design is presented.

System Thinking Tutorial and Reef Link Database Fact Sheets

EPA Science Inventory

The sustainable well-being of communities is inextricably linked to both the health of the earth’s ecosystems and the health of humans living in the community. Currently, many policy and management decisions are made without considering the goods and services humans derive from ...

Link Analysis of High Throughput Spacecraft Communication Systems for Future Science Missions

NASA Technical Reports Server (NTRS)

Simons, Rainee N.

2015-01-01

NASA's plan to launch several spacecrafts into low Earth Orbit (LEO) to support science missions in the next ten years and beyond requires down link throughput on the order of several terabits per day. The ability to handle such a large volume of data far exceeds the capabilities of current systems. This paper proposes two solutions, first, a high data rate link between the LEO spacecraft and ground via relay satellites in geostationary orbit (GEO). Second, a high data rate direct to ground link from LEO. Next, the paper presents results from computer simulations carried out for both types of links taking into consideration spacecraft transmitter frequency, EIRP, and waveform; elevation angle dependent path loss through Earths atmosphere, and ground station receiver GT.

Link Analysis of High Throughput Spacecraft Communication Systems for Future Science Missions

NASA Technical Reports Server (NTRS)

Simons, Rainee N.

2015-01-01

NASA's plan to launch several spacecraft into low Earth Orbit (LEO) to support science missions in the next ten years and beyond requires down link throughput on the order of several terabits per day. The ability to handle such a large volume of data far exceeds the capabilities of current systems. This paper proposes two solutions, first, a high data rate link between the LEO spacecraft and ground via relay satellites in geostationary orbit (GEO). Second, a high data rate direct to ground link from LEO. Next, the paper presents results from computer simulations carried out for both types of links taking into consideration spacecraft transmitter frequency, EIRP, and waveform; elevation angle dependent path loss through Earths atmosphere, and ground station receiver GT.

Autonomic and inflammatory consequences of posttraumatic stress disorder and the link to cardiovascular disease.

PubMed

Brudey, Chevelle; Park, Jeanie; Wiaderkiewicz, Jan; Kobayashi, Ihori; Mellman, Thomas A; Marvar, Paul J

2015-08-15

Stress- and anxiety-related disorders are on the rise in both military and general populations. Over the next decade, it is predicted that treatment of these conditions, in particular, posttraumatic stress disorder (PTSD), along with its associated long-term comorbidities, will challenge the health care system. Multiple organ systems are adversely affected by PTSD, and PTSD is linked to cancer, arthritis, digestive disease, and cardiovascular disease. Evidence for a strong link between PTSD and cardiovascular disease is compelling, and this review describes current clinical data linking PTSD to cardiovascular disease, via inflammation, autonomic dysfunction, and the renin-angiotensin system. Recent clinical and preclinical evidence regarding the role of the renin-angiotensin system in the extinction of fear memory and relevance in PTSD-related immune and autonomic dysfunction is also addressed. Copyright © 2015 the American Physiological Society.

Epipelagic and mesopelagic fishes in the southern California Current System: Ecological interactions and oceanographic influences on their abundance

NASA Astrophysics Data System (ADS)

Koslow, J. Anthony; Davison, Peter; Lara-Lopez, Ana; Ohman, Mark D.

2014-10-01

We use zooplankton and ichthyoplankton data from the ~ 60-year CalCOFI time series to examine relationships of mesopelagic (i.e. midwater) fishes in the California Current System with midwater predators, potential competitors (epipelagic planktivorous fishes) and zooplankton prey, within the context of local and basin-scale oceanography. Equilibrium-based near-steady state models and the “wasp-waist” paradigm for eastern boundary currents predict tightly-coupled trophic interactions, with negative correlations between the abundance of planktivorous competitors and between dominant planktivores and their prey. Testing these hypotheses with the CalCOFI time series, we found them to be generally invalid. Potential competitors within the mesopelagic community (planktivorous vertical migrators (VMs) and non-migrators (NMs)) were highly positively correlated, as were these groups with the mesopelagic piscivores (e.g. dragonfishes) that prey on them. In addition, the abundance of VMs was mostly positively correlated with that of epipelagic planktivores, such as anchovy, mackerels and hake. The VMs and epipelagic planktivores were negatively correlated with key potential planktonic prey groups, indicating a lack of bottom-up forcing. However, neither do these negative correlations appear to signify top-down forcing, since they seem to be mediated through correlations with key environmental drivers, such as the Pacific Decadal Oscillation (PDO), sea surface temperature, and the relative strength of the California Current. We suggest that the web of correlations linking key meso- and epipelagic planktivores, their predators and prey is mediated through common links with basin-scale oceanographic drivers, such as the PDO and ENSO cycles. Thus, the abundance of mesopelagic fishes in the California Current is closely tied to variation in the oxygen minimum zone, whose dynamics have been linked to the PDO. The PDO and other drivers are also linked to the transport of the California Current System, which influences the abundance of many dominant taxa off southern California that have broad biogeographic distributions linked to water masses that extend to the north (Transition Zone/sub-Arctic faunas) or the south (tropical/subtropical faunas).

Regulatory behavior and frontal activity: Considering the role of revised-BIS in relative right frontal asymmetry.

PubMed

Gable, Philip A; Neal, Lauren B; Threadgill, A Hunter

2018-01-01

Essential to human behavior are three core personality systems: approach, avoidance, and a regulatory system governing the two motivational systems. Decades of research has linked approach motivation with greater relative left frontal-cortical asymmetry. Other research has linked avoidance motivation with greater relative right frontal-cortical asymmetry. However, past work linking withdrawal motivation with greater relative right frontal asymmetry has been mixed. The current article reviews evidence suggesting that activation of the regulatory system (revised Behavioral Inhibition System [r-BIS]) may be more strongly related to greater relative right frontal asymmetry than withdrawal motivation. Specifically, research suggests that greater activation of the r-BIS is associated with greater relative right frontal activity, and reduced r-BIS activation is associated with reduced right frontal activity (greater relative left frontal activity). We review evidence examining trait and state frontal activity using EEG, source localization, lesion studies, neuronal stimulation, and fMRI supporting the idea that r-BIS may be the core personality system related to greater relative right frontal activity. In addition, the current review seeks to disentangle avoidance motivation and r-BIS as substrates of relative right frontal asymmetry. © 2017 Society for Psychophysiological Research.

Power Quality Improvement by Unified Power Quality Conditioner Based on CSC Topology Using Synchronous Reference Frame Theory

PubMed Central

Dharmalingam, Rajasekaran; Dash, Subhransu Sekhar; Senthilnathan, Karthikrajan; Mayilvaganan, Arun Bhaskar; Chinnamuthu, Subramani

2014-01-01

This paper deals with the performance of unified power quality conditioner (UPQC) based on current source converter (CSC) topology. UPQC is used to mitigate the power quality problems like harmonics and sag. The shunt and series active filter performs the simultaneous elimination of current and voltage problems. The power fed is linked through common DC link and maintains constant real power exchange. The DC link is connected through the reactor. The real power supply is given by the photovoltaic system for the compensation of power quality problems. The reference current and voltage generation for shunt and series converter is based on phase locked loop and synchronous reference frame theory. The proposed UPQC-CSC design has superior performance for mitigating the power quality problems. PMID:25013854

Power quality improvement by unified power quality conditioner based on CSC topology using synchronous reference frame theory.

PubMed

Dharmalingam, Rajasekaran; Dash, Subhransu Sekhar; Senthilnathan, Karthikrajan; Mayilvaganan, Arun Bhaskar; Chinnamuthu, Subramani

2014-01-01

This paper deals with the performance of unified power quality conditioner (UPQC) based on current source converter (CSC) topology. UPQC is used to mitigate the power quality problems like harmonics and sag. The shunt and series active filter performs the simultaneous elimination of current and voltage problems. The power fed is linked through common DC link and maintains constant real power exchange. The DC link is connected through the reactor. The real power supply is given by the photovoltaic system for the compensation of power quality problems. The reference current and voltage generation for shunt and series converter is based on phase locked loop and synchronous reference frame theory. The proposed UPQC-CSC design has superior performance for mitigating the power quality problems.

Design of A Grid Integrated PV System with MPPT Control and Voltage Oriented Controller using MATLAB/PLECES

NASA Astrophysics Data System (ADS)

Soreng, Bineeta; Behera, Pradyumna; Pradhan, Raseswari

2017-08-01

This paper presents model of a grid-integrated photovoltaic array with Maximum Power Point Tracker (MPPT) and voltage oriented controller. The MPPT of the PV array is usually an essential part of PV system as MPPT helps the operating point of the solar array to align its maximum power point. In this model, the MPPT along with a DC-DC converter lets a PV generator to produce continuous power, despite of the measurement conditions. The neutral-point-clamped converter (NPC) with a boost converter raises the voltage from the panels to the DC-link. An LCL-filter smoothens the current ripple caused by the PWM modulation of the grid-side inverter. In addition to the MPPT, the system has two more two controllers, such as voltage controller and a current controller. The voltage control has a PI controller to regulate the PV voltage to optimal level by controlling the amount of current injected into the boost stage. Here, the grid-side converter transfers the power from the DC-link into the grid and maintains the DC-link voltage. Three-phase PV inverters are used for off-grid or designed to create utility frequency AC. The PV system can be connected in series or parallel to get the desired output power. To justify the working of this model, the grid-integrated PV system has been designed in MATLAB/PLECS. The simulation shows the P-V curve of implemented PV Array consisting 4 X 20 modules, reactive, real power, grid voltage and current.

Using Linked Data to Drive Education and Training Improvement

ERIC Educational Resources Information Center

Data Quality Campaign, 2010

2010-01-01

To address key policy and programmatic questions and help improve student and system performance, states must work to link data across the early childhood, postsecondary and workforce (P-20/workforce) spectrum and share this information with appropriate stakeholders. This issue brief highlights current efforts in California, Florida, Indiana, and…

FELIX: The new detector readout system for the ATLAS experiment

NASA Astrophysics Data System (ADS)

Ryu, Soo; ATLAS TDAQ Collaboration

2017-10-01

After the Phase-I upgrades (2019) of the ATLAS experiment, the Front-End Link eXchange (FELIX) system will be the interface between the data acquisition system and the detector front-end and trigger electronics. FELIX will function as a router between custom serial links and a commodity switch network using standard technologies (Ethernet or Infiniband) to communicate with commercial data collecting and processing components. The system architecture of FELIX will be described and the status of the firmware implementation and hardware development currently in progress will be presented.

Lightning Discharges, Cosmic Rays and Climate

NASA Astrophysics Data System (ADS)

Kumar, Sanjay; Siingh, Devendraa; Singh, R. P.; Singh, A. K.; Kamra, A. K.

2018-03-01

The entirety of the Earth's climate system is continuously bombarded by cosmic rays and exhibits about 2000 thunderstorms active at any time of the day all over the globe. Any linkage among these vast systems should have global consequences. Numerous studies done in the past deal with partial links between some selected aspects of this grand linkage. Results of these studies vary from weakly to strongly significant and are not yet complete enough to justify the physical mechanism proposed to explain such links. This review is aimed at presenting the current understanding, based on the past studies on the link between cosmic ray, lightning and climate. The deficiencies in some proposed links are pointed out. Impacts of cosmic rays on engineering systems and the possible effects of cosmic rays on human health are also briefly discussed. Also enumerated are some problems for future work which may help in developing the grand linkage among these three vast systems.

AIDS is an exception to bus system's offer of lower fares.

PubMed

1997-05-02

The American Civil Liberties Union (ACLU) sued the Metro Link bus system in Rock Island, IL on behalf of [name removed]. The suit claims that the bus system explicitly excludes people with AIDS from a reduced-rate fare program for riders with disabilities. Currently, Metro Link offers a discount to senior citizens or people with disabilities who have documentation. The application for the discount specifically rules out people whose sole disability is AIDS. [Name removed] asked Metro Link to eliminate the exclusion. When the request was refused, the ACLU sued, alleging a violation of the Americans with Disabilities Act (ADA), the Rehabilitation Act, and [name removed]'s constitutional right to equal protection under the law.

Linking turbidity current triggers to flow power, frequency and runout distances

NASA Astrophysics Data System (ADS)

Hizzett, J. L.; Hughes Clarke, J. E.; Cartigny, M.; Talling, P.; Sumner, E.; Clare, M. A.

2017-12-01

Submarine turbidity currents and terrestrial river systems are the two main processes for moving sediment across our planet, and it is important to understand how they are linked. Turbidity currents form thick deposits, burying large amounts of organic carbon, and posing a hazard to seabed pipelines and cables. It is essential to understand which initial trigger mechanisms produce the most frequent, powerful and longest runout turbidity currents, as these flows pose the greatest hazard for seafloor infrastructure (Cooper et al., 2013). Here were re-analyse the most detailed time-lapse mapping of a turbidity current system, which comprises 93 near-daily surveys collected by Hughes Clarke at Squamish Delta, British Columbia. It enables us to link different trigger mechanisms to flow properties such as runout distance. Turbidity currents at Squamish Delta are either triggered by submarine landslides or by sediment settling out from the river plume. Previously it was inferred that turbidity currents were most commonly triggered at river mouths by underwater landslides, or plunging (hyperpycnal) river discharge. However, here we show that turbidity currents are most commonly triggered by what we infer to be sediment settling from surface plumes (Hughes Clarke et al., 2014). We go on to show that turbidity currents initiated by settling from surface plumes can be as erosive and travel as far as landslide-triggered flows. We also find no relationship between submarine landslide volume and turbidity current runout. This is surprising because larger volume subaerial landslides tend to runout longer distances. We therefore show that the most hazardous turbidity currents at Squamish, which have the biggest impact on the seafloor, are initiated by sediment settling out from surface plumes, and not by large landslides as was previously expected.

Development of an air ground data exchange concept: Flight deck perspective

NASA Technical Reports Server (NTRS)

Flathers, G. W., II

1987-01-01

The planned modernization of the U.S. National Airspace System (NAS) includes the development and use of a digital data link as a means to exchange information between aircraft and ground-based facilities. This report presents an operationally-oriented concept on how data link could be used for applications related directly to air traffic control. The specific goal is to establish the role that data link could play in the air-ground communications. Due regard is given to the unique characteristics of data link and voice communications, current principles of air traffic control, operational procedures, human factors/man-machine interfaces, and the integration of data link with other air and ground systems. The resulting concept is illustrated in the form of a paper-and-pencil simulation in which data link and voice communications during the course of a hypothetical flight are described.

Toward a Pedagogy of Transformative Teacher Education: World Educational Links

ERIC Educational Resources Information Center

Reed, Judith; Black, Deborah J.

2006-01-01

By describing an innovative model for teacher education, these authors hope to contribute to an interrogation of teacher education, class, and culture within the current political and economic system. Inaugurated at Keene State College in New Hampshire in May 2002, World Educational Links (WEL) prepares future educators for anti-oppressive…

Simulation of Controller Pilot Data Link Communications over VHF Digital Link Mode 3

NASA Technical Reports Server (NTRS)

Bretmersky, Steven C.; Murawski, Robert; Nguyen, Thanh C.; Raghavan, Rajesh S.

2004-01-01

The Federal Aviation Administration (FAA) has established an operational plan for the future Air Traffic Management (ATM) system, in which the Controller Pilot Data Link Communications (CPDLC) is envisioned to evolve into digital messaging that will take on an ever increasing role in controller to pilot communications, significantly changing the way the National Airspace System (NAS) is operating. According to FAA, CPDLC represents the first phase of the transition from the current analog voice system to an International Civil Aviation Organization (ICAO) compliant system in which digital communication becomes the alternate and perhaps primary method of routine communication. The CPDLC application is an Air Traffic Service (ATS) application in which pilots and controllers exchange messages via an addressed data link. CPDLC includes a set of clearance, information, and request message elements that correspond to existing phraseology employed by current Air Traffic Control (ATC) procedures. These message elements encompass altitude assignments, crossing constraints, lateral deviations, route changes and clearances, speed assignments, radio frequency assignments, and various requests for information. The pilot is provided with the capability to respond to messages, to request clearances and information, to report information, and to declare/rescind an emergency. A 'free text' capability is also provided to exchange information not conforming to defined formats. This paper presents simulated results of the aeronautical telecommunication application Controller Pilot Data Link Communications over VHF Digital Link Mode 3 (VDL Mode 3). The objective of this simulation study was to determine the impact of CPDLC traffic loads, in terms of timely message delivery and capacity of the VDL Mode 3 subnetwork. The traffic model is based on and is used for generating air/ground messages with different priorities. Communication is modeled for the en route domain of the Cleveland Center air traffic (ZOB ARTCC).

Performance Evaluation of Peer-to-Peer Progressive Download in Broadband Access Networks

NASA Astrophysics Data System (ADS)

Shibuya, Megumi; Ogishi, Tomohiko; Yamamoto, Shu

P2P (Peer-to-Peer) file sharing architectures have scalable and cost-effective features. Hence, the application of P2P architectures to media streaming is attractive and expected to be an alternative to the current video streaming using IP multicast or content delivery systems because the current systems require expensive network infrastructures and large scale centralized cache storage systems. In this paper, we investigate the P2P progressive download enabling Internet video streaming services. We demonstrated the capability of the P2P progressive download in both laboratory test network as well as in the Internet. Through the experiments, we clarified the contribution of the FTTH links to the P2P progressive download in the heterogeneous access networks consisting of FTTH and ADSL links. We analyzed the cause of some download performance degradation occurred in the experiment and discussed about the effective methods to provide the video streaming service using P2P progressive download in the current heterogeneous networks.

A Hybrid Satellite-Terrestrial Approach to Aeronautical Communication Networks

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Chomos, Gerald J.; Griner, James H.; Mainger, Steven W.; Martzaklis, Konstantinos S.; Kachmar, Brian A.

2000-01-01

Rapid growth in air travel has been projected to continue for the foreseeable future. To maintain a safe and efficient national and global aviation system, significant advances in communications systems supporting aviation are required. Satellites will increasingly play a critical role in the aeronautical communications network. At the same time, current ground-based communications links, primarily very high frequency (VHF), will continue to be employed due to cost advantages and legacy issues. Hence a hybrid satellite-terrestrial network, or group of networks, will emerge. The increased complexity of future aeronautical communications networks dictates that system-level modeling be employed to obtain an optimal system fulfilling a majority of user needs. The NASA Glenn Research Center is investigating the current and potential future state of aeronautical communications, and is developing a simulation and modeling program to research future communications architectures for national and global aeronautical needs. This paper describes the primary requirements, the current infrastructure, and emerging trends of aeronautical communications, including a growing role for satellite communications. The need for a hybrid communications system architecture approach including both satellite and ground-based communications links is explained. Future aeronautical communication network topologies and key issues in simulation and modeling of future aeronautical communications systems are described.

Is the Annual Confidential Report system effective? A study of the government appraisal system in Gujarat, India.

PubMed

Purohit, Bhaskar; Martineau, Tim

2016-06-02

Effective performance appraisal systems can not only motivate employees to improve performance but also be important for the performance of organizations. However, the appraisal systems in civil services called the Annual Confidential Report (ACR) systems can be ineffective and do not contribute to employees' learning and development. With this background, the current study aimed at understanding the ACR system and assessing its effectiveness. The research aims to contribute in filling the knowledge gap in the existing literature on the need as to why the ACR system in civil services is an important human resource management (HRM) function. The analysis is based on policy review to understand the extant appraisal-related rules and policies. Nineteen in-depth interviews with medical officers (MOs) working with the government health department of Gujarat, India, were conducted. The main objective of the research was to assess the effectiveness of the actual appraisal system called or referred to as the ACR as perceived by MOs. Thematic framework approach was used to analyze qualitative data using NVIVO 9. Themes were built around five features of an effective appraisal system, i.e., purpose, source, feedback quality, link of the ACR system with other human resource functions, and administrative effectiveness. The five features of the effective appraisal system studied in the current research (purpose, source, feedback quality, link of ACR system with other HRM functions, and administrative effectiveness) indicate that the overall appraisal system is ineffective. The overall appraisal system was perceived to be subjective and one directional in character by the study respondents. Furthermore, respondents perceived the appraisal system to be a ritual and where MOs hardly got to know about their performance, especially good performance. Hence, the feedback loop, an important feature for an effective appraisal system, was absent. The overall ACR system functions in isolation with no link to other HRM functions such as training and counselling, and a weak link with salary administration and promotion. Addressing the five features or domains of an effective appraisal system can lead to improved perceived fairness MOs have on the current appraisal system which may further influence the satisfaction and motivation positively. Improved motivation and satisfaction with the appraisal system can influence two important human resource for health-related outcomes, i.e., performance and retention.

Toroidal magnet system

DOEpatents

Ohkawa, Tihiro; Baker, Charles C.

1981-01-01

In a plasma device having a toroidal plasma containment vessel, a toroidal field-generating coil system includes fixed linking coils each formed of first and second sections with the first section passing through a central opening through the containment vessel and the second section completing the linking coil to link the containment vessel. A plurality of removable unlinked coils are each formed of first and second C-shaped sections joined to each other at their open ends with their bights spaced apart. The second C-shaped section of each movable coil is removably mounted adjacent the second section of a linking coil, with the containment vessel disposed between the open ends of the first and second C-shaped sections. Electric current is passed through the linking and removable coils in opposite sense in the respective adjacent second sections to produce a net toroidal field.

Cross-disciplinary links in environmental systems science: Current state and claimed needs identified in a meta-review of process models.

PubMed

Ayllón, Daniel; Grimm, Volker; Attinger, Sabine; Hauhs, Michael; Simmer, Clemens; Vereecken, Harry; Lischeid, Gunnar

2018-05-01

Terrestrial environmental systems are characterised by numerous feedback links between their different compartments. However, scientific research is organized into disciplines that focus on processes within the respective compartments rather than on interdisciplinary links. Major feedback mechanisms between compartments might therefore have been systematically overlooked so far. Without identifying these gaps, initiatives on future comprehensive environmental monitoring schemes and experimental platforms might fail. We performed a comprehensive overview of feedbacks between compartments currently represented in environmental sciences and explores to what degree missing links have already been acknowledged in the literature. We focused on process models as they can be regarded as repositories of scientific knowledge that compile findings of numerous single studies. In total, 118 simulation models from 23 model types were analysed. Missing processes linking different environmental compartments were identified based on a meta-review of 346 published reviews, model intercomparison studies, and model descriptions. Eight disciplines of environmental sciences were considered and 396 linking processes were identified and ascribed to the physical, chemical or biological domain. There were significant differences between model types and scientific disciplines regarding implemented interdisciplinary links. The most wide-spread interdisciplinary links were between physical processes in meteorology, hydrology and soil science that drive or set the boundary conditions for other processes (e.g., ecological processes). In contrast, most chemical and biological processes were restricted to links within the same compartment. Integration of multiple environmental compartments and interdisciplinary knowledge was scarce in most model types. There was a strong bias of suggested future research foci and model extensions towards reinforcing existing interdisciplinary knowledge rather than to open up new interdisciplinary pathways. No clear pattern across disciplines exists with respect to suggested future research efforts. There is no evidence that environmental research would clearly converge towards more integrated approaches or towards an overarching environmental systems theory. Copyright © 2017 Elsevier B.V. All rights reserved.

Integrated Airport Surface Operations

NASA Technical Reports Server (NTRS)

Koczo, S.

1998-01-01

The current air traffic environment in airport terminal areas experiences substantial delays when weather conditions deteriorate to Instrument Meteorological Conditions (IMC). Research activity at NASA has culminated in the development, flight test and demonstration of a prototype Low Visibility Landing and Surface Operations (LVLASO) system. A NASA led industry team and the FAA developed the system which integrated airport surface surveillance systems, aeronautical data links, DGPS navigation, automation systems, and controller and flight deck displays. The LVLASO system was demonstrated at the Hartsfield-Atlanta International Airport using a Boeing 757-200 aircraft during August, 1997. This report documents the contractors role in this testing particularly in the area of data link and DGPS navigation.

US HealthLink: a national information resource for health care professionals.

PubMed

Yasnoff, W A

1992-06-01

US HealthLink is a new, comprehensive online medical information system designed specifically for health care professionals. Available to individuals for a fixed fee, it includes literature, news, diagnostic decision support, drug interactions, electronic mail, and bulletin boards. It also provides user-specific current awareness via clipping service, and fax delivery of both clipping and electronic mail information. US HealthLink can now be utilized to access a wide variety of medical information sources inexpensively.

Ka-Band Phased Array System Characterization

NASA Technical Reports Server (NTRS)

Acosta, R.; Johnson, S.; Sands, O.; Lambert, K.

2001-01-01

Phased Array Antennas (PAAs) using patch-radiating elements are projected to transmit data at rates several orders of magnitude higher than currently offered with reflector-based systems. However, there are a number of potential sources of degradation in the Bit Error Rate (BER) performance of the communications link that are unique to PAA-based links. Short spacing of radiating elements can induce mutual coupling between radiating elements, long spacing can induce grating lobes, modulo 2 pi phase errors can add to Inter Symbol Interference (ISI), phase shifters and power divider network introduce losses into the system. This paper describes efforts underway to test and evaluate the effects of the performance degrading features of phased-array antennas when used in a high data rate modulation link. The tests and evaluations described here uncover the interaction between the electrical characteristics of a PAA and the BER performance of a communication link.

Performance of unified power quality conditioner (UPQC) based on fuzzy controller for attenuating of voltage and current harmonics

NASA Astrophysics Data System (ADS)

Milood Almelian, Mohamad; Mohd, Izzeldin I.; Asghaiyer Omran, Mohamed; Ullah Sheikh, Usman

2018-04-01

Power quality-related issues such as current and voltage distortions can adversely affect home and industrial appliances. Although several conventional techniques such as the use of passive and active filters have been developed to increase power quality standards, these methods have challenges and are inadequate due to the increasing number of applications. The Unified Power Quality Conditioner (UPQC) is a modern strategy towards correcting the imperfections of voltage and load current supply. A UPQC is a combination of both series and shunt active power filters in a back-to-back manner with a common DC link capacitor. The control of the voltage of the DC link capacitor is important in achieving a desired UPQC performance. In this paper, the UPQC with a Fuzzy logic controller (FLC) was used to precisely eliminate the imperfections of voltage and current harmonics. The results of the simulation studies using MATLAB/Simulink and Simpower system programming for R-L load associated through an uncontrolled bridge rectifier was used to assess the execution process. The UPQC with FLC was simulated for a system with distorted load current and a system with distorted source voltage and load current. The outcome of the comparison of %THD in the load current and source voltage before and after using UPQC for the two cases was presented.

Modulation and coding for throughput-efficient optical free-space links

NASA Technical Reports Server (NTRS)

Georghiades, Costas N.

1993-01-01

Optical direct-detection systems are currently being considered for some high-speed inter-satellite links, where data-rates of a few hundred megabits per second are evisioned under power and pulsewidth constraints. In this paper we investigate the capacity, cutoff-rate and error-probability performance of uncoded and trellis-coded systems for various modulation schemes and under various throughput and power constraints. Modulation schemes considered are on-off keying (OOK), pulse-position modulation (PPM), overlapping PPM (OPPM) and multi-pulse (combinatorial) PPM (MPPM).

Control and Non-Payload Communications (CNPC) Prototype Radio - Generation 2 Security Architecture Lab Test Report

NASA Technical Reports Server (NTRS)

Iannicca, Dennis C.; McKim, James H.; Stewart, David H.; Thadhani, Suresh K.; Young, Daniel P.

2015-01-01

NASA Glenn Research Center, in cooperation with Rockwell Collins, is working to develop a prototype Control and Non-Payload Communications (CNPC) radio platform as part of NASA Integrated Systems Research Program's (ISRP) Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) project. A primary focus of the project is to work with the FAA and industry standards bodies to build and demonstrate a safe, secure, and efficient CNPC architecture that can be used by industry to evaluate the feasibility of deploying a system using these technologies in an operational capacity. GRC has been working in conjunction with these groups to assess threats, identify security requirements, and to develop a system of standards-based security controls that can be applied to the current GRC prototype CNPC architecture as a demonstration platform. The security controls were integrated into a lab test bed mock-up of the Mobile IPv6 architecture currently being used for NASA flight testing, and a series of network tests were conducted to evaluate the security overhead of the controls compared to the baseline CNPC link without any security. The aim of testing was to evaluate the performance impact of the additional security control overhead when added to the Mobile IPv6 architecture in various modes of operation. The statistics collected included packet captures at points along the path to gauge packet size as the sample data traversed the CNPC network, round trip latency, jitter, and throughput. The effort involved a series of tests of the baseline link, a link with Robust Header Compression (ROHC) and without security controls, a link with security controls and without ROHC, and finally a link with both ROHC and security controls enabled. The effort demonstrated that ROHC is both desirable and necessary to offset the additional expected overhead of applying security controls to the CNPC link.

Open loop model for WDM links

NASA Astrophysics Data System (ADS)

D, Meena; Francis, Fredy; T, Sarath K.; E, Dipin; Srinivas, T.; K, Jayasree V.

2014-10-01

Wavelength Division Multiplexing (WDM) techniques overfibrelinks helps to exploit the high bandwidth capacity of single mode fibres. A typical WDM link consisting of laser source, multiplexer/demultiplexer, amplifier and detectoris considered for obtaining the open loop gain model of the link. The methodology used here is to obtain individual component models using mathematical and different curve fitting techniques. These individual models are then combined to obtain the WDM link model. The objective is to deduce a single variable model for the WDM link in terms of input current to system. Thus it provides a black box solution for a link. The Root Mean Square Error (RMSE) associated with each of the approximated models is given for comparison. This will help the designer to select the suitable WDM link model during a complex link design.

The reliability-quality relationship for quality systems and quality risk management.

PubMed

Claycamp, H Gregg; Rahaman, Faiad; Urban, Jason M

2012-01-01

Engineering reliability typically refers to the probability that a system, or any of its components, will perform a required function for a stated period of time and under specified operating conditions. As such, reliability is inextricably linked with time-dependent quality concepts, such as maintaining a state of control and predicting the chances of losses from failures for quality risk management. Two popular current good manufacturing practice (cGMP) and quality risk management tools, failure mode and effects analysis (FMEA) and root cause analysis (RCA) are examples of engineering reliability evaluations that link reliability with quality and risk. Current concepts in pharmaceutical quality and quality management systems call for more predictive systems for maintaining quality; yet, the current pharmaceutical manufacturing literature and guidelines are curiously silent on engineering quality. This commentary discusses the meaning of engineering reliability while linking the concept to quality systems and quality risk management. The essay also discusses the difference between engineering reliability and statistical (assay) reliability. The assurance of quality in a pharmaceutical product is no longer measured only "after the fact" of manufacturing. Rather, concepts of quality systems and quality risk management call for designing quality assurance into all stages of the pharmaceutical product life cycle. Interestingly, most assays for quality are essentially static and inform product quality over the life cycle only by being repeated over time. Engineering process reliability is the fundamental concept that is meant to anticipate quality failures over the life cycle of the product. Reliability is a well-developed theory and practice for other types of manufactured products and manufacturing processes. Thus, it is well known to be an appropriate index of manufactured product quality. This essay discusses the meaning of reliability and its linkages with quality systems and quality risk management.

Flight tests show potential benefits of data link as primary communication medium

NASA Technical Reports Server (NTRS)

Scanlon, Charles H.; Knox, Charles E.

1991-01-01

Message exchange for air traffic control (ATC) purposes via data link offers the potential benefits of increasing the airspace system safety and efficiency. This is accomplished by reducing communication errors and relieving the overloaded ATC radio frequencies, which hamper efficient message exchanges during peak traffic periods in many busy terminal areas. However, the many uses and advantages of data link create additional questions concerning the interface among the human-users and the cockpit and ground systems. A flight test was conducted in the NASA Langley B-737 airplane to contrast flight operations using current voice communications with the use of data link for transmitting both strategic and tactical ATC clearances during a typical commercial airline flight from takeoff to landing. Commercial airplane pilots were used as test subjects.

Prediction in complex systems: The case of the international trade network

NASA Astrophysics Data System (ADS)

Vidmer, Alexandre; Zeng, An; Medo, Matúš; Zhang, Yi-Cheng

2015-10-01

Predicting the future evolution of complex systems is one of the main challenges in complexity science. Based on a current snapshot of a network, link prediction algorithms aim to predict its future evolution. We apply here link prediction algorithms to data on the international trade between countries. This data can be represented as a complex network where links connect countries with the products that they export. Link prediction techniques based on heat and mass diffusion processes are employed to obtain predictions for products exported in the future. These baseline predictions are improved using a recent metric of country fitness and product similarity. The overall best results are achieved with a newly developed metric of product similarity which takes advantage of causality in the network evolution.

A flight investigation of simulated data link communications during single-pilot IFR flight

NASA Technical Reports Server (NTRS)

Parker, J. F.; Duffy, J. W.; Christensen, D. G.

1983-01-01

A Flight Data Console (FDC) was developed to allow simulation of a digital communications link to replace the current voice communication system used in air traffic control (ATC). The voice system requires manipulation of radio equipment, read-back of clearances, and mental storage of critical information items, all contributing to high workload, particularly during single-pilot operations. This was an inflight study to determine how a digital communications system might reduce cockpit workload, improve flight proficiency, and be accepted by general aviation pilots. Results show that instrument flight, including approach and landing, can be accomplished quite effectively using a digital data link system for ATC communications. All pilots expressed a need for a back-up voice channel. When included, this channel was used sparingly and principally to confirm any item of information about which there might be uncertainty.

Flight tests with a data link used for air traffic control information exchange

NASA Technical Reports Server (NTRS)

Knox, Charles E.; Scanlon, Charles H.

1991-01-01

Previous studies showed that air traffic control (ATC) message exchange with a data link offers the potential benefits of increased airspace system safety and efficiency. To accomplish these benefits, data link can be used to reduce communication errors and relieve overloaded ATC voice radio frequencies, which hamper efficient message exchange during peak traffic periods. Flight tests with commercial airline pilots as test subjects were conducted in the NASA Transport Systems Research Vehicle Boeing 737 airplane to contrast flight operations that used current voice communications with flight operations that used data link to transmit both strategic and tactical ATC clearances during a typical commercial airflight from takeoff to landing. The results of these tests that used data link as the primary communication source with ATC showed flight crew acceptance, a perceived reduction in crew work load, and a reduction in crew communication errors.

High Precision Ranging and Range-Rate Measurements over Free-Space-Laser Communication Link

NASA Technical Reports Server (NTRS)

Yang, Guangning; Lu, Wei; Krainak, Michael; Sun, Xiaoli

2016-01-01

We present a high-precision ranging and range-rate measurement system via an optical-ranging or combined ranging-communication link. A complete bench-top optical communication system was built. It included a ground terminal and a space terminal. Ranging and range rate tests were conducted in two configurations. In the communication configuration with 622 data rate, we achieved a two-way range-rate error of 2 microns/s, or a modified Allan deviation of 9 x 10 (exp -15) with 10 second averaging time. Ranging and range-rate as a function of Bit Error Rate of the communication link is reported. They are not sensitive to the link error rate. In the single-frequency amplitude modulation mode, we report a two-way range rate error of 0.8 microns/s, or a modified Allan deviation of 2.6 x 10 (exp -15) with 10 second averaging time. We identified the major noise sources in the current system as the transmitter modulation injected noise and receiver electronics generated noise. A new improved system will be constructed to further improve the system performance for both operating modes.

Scoreboards for Schools: ASCD Special Report.

ERIC Educational Resources Information Center

Betts, Frank

1997-01-01

A program developed by the Association for Curriculum and Supervision Development and Group Decisions Support Systems, Inc., aims to enhance accountability and improve school district/community communication. Scoreboards for Schools addresses inadequacies of current financial reporting systems by providing tightly linked planning strategies for…

Discovering disease-disease associations by fusing systems-level molecular data

PubMed Central

Žitnik, Marinka; Janjić, Vuk; Larminie, Chris; Zupan, Blaž; Pržulj, Nataša

2013-01-01

The advent of genome-scale genetic and genomic studies allows new insight into disease classification. Recently, a shift was made from linking diseases simply based on their shared genes towards systems-level integration of molecular data. Here, we aim to find relationships between diseases based on evidence from fusing all available molecular interaction and ontology data. We propose a multi-level hierarchy of disease classes that significantly overlaps with existing disease classification. In it, we find 14 disease-disease associations currently not present in Disease Ontology and provide evidence for their relationships through comorbidity data and literature curation. Interestingly, even though the number of known human genetic interactions is currently very small, we find they are the most important predictor of a link between diseases. Finally, we show that omission of any one of the included data sources reduces prediction quality, further highlighting the importance in the paradigm shift towards systems-level data fusion. PMID:24232732

Epilepsy and the immune system: is there a link?

PubMed

Billiau, An D; Wouters, Carine H; Lagae, Lieven G

2005-01-01

The concept that the immune system plays a role in the epileptogenic process of some epileptic syndromes was first proposed more than 20 years ago. Since then, numerous studies have reported on the existence of a variety of immunological alterations in epileptic patients, on the observation of favourable responses of refractory epilepsy syndromes to immunomodulatory treatment, and on the association of certain well-known immune-mediated disease states with epilepsy. This review comprehensively recapitulates the currently available evidence supporting or arguing against the possible involvement of the immune system in the pathogenesis of certain types of epilepsy. It is concluded that an abundance of facts is in support of this concept and that further studies should be directed at substantiating the pathogenic significance of (auto)immune responses in certain types of epilepsy. Current progress in the functional and molecular immunological research techniques will indisputably contribute to the elucidation of this link.

Discovering disease-disease associations by fusing systems-level molecular data.

PubMed

Žitnik, Marinka; Janjić, Vuk; Larminie, Chris; Zupan, Blaž; Pržulj, Nataša

2013-11-15

The advent of genome-scale genetic and genomic studies allows new insight into disease classification. Recently, a shift was made from linking diseases simply based on their shared genes towards systems-level integration of molecular data. Here, we aim to find relationships between diseases based on evidence from fusing all available molecular interaction and ontology data. We propose a multi-level hierarchy of disease classes that significantly overlaps with existing disease classification. In it, we find 14 disease-disease associations currently not present in Disease Ontology and provide evidence for their relationships through comorbidity data and literature curation. Interestingly, even though the number of known human genetic interactions is currently very small, we find they are the most important predictor of a link between diseases. Finally, we show that omission of any one of the included data sources reduces prediction quality, further highlighting the importance in the paradigm shift towards systems-level data fusion.

Millimeter Wave Systems for Airports and Short-Range Aviation Communications: A Survey of the Current Channel Models at mmWave Frequencies

NASA Technical Reports Server (NTRS)

Khatun, Mahfuza; Mehrpouyan, Hani; Matolak, David; Guvenc, Ismail

2017-01-01

Millimeter-wave (mmWave) communications will play a key role in enhancing the throughput, reliability, and security of next generation wireless networks. These advancements are achieved through the large bandwidth available in this band and through the use of highly directional links that will be used to overcome the large pathloss at these frequencies. Although the terrestrial application of mmWave systems is advancing at a rapid pace, the use of mmWave communication systems in aviation systems or airports is still in its infancy. This can be attributed to the challenges related to radio technology and lack of development, and characterization of mmWave wireless channels for the aviation field and the airport environment. Consequently, one of our goals is to develop methodologies that support mmWave air to ground links, and various links at airports, by applying new localization schemes that allow for application of highly directional links that can be deployed over longer distances despite the high path loss at mmWave frequencies. However, a very thorough understanding of the mmWave channel models are needed to enable such new applications. To this end, in this paper, we present a survey of the current channel models in the mmWave band. The 3-dimensional statistical channel model is also reviewed and its parameters and typical characteristics for this model are identified and computed through simulation for the Boise metropolitan area.

Digital teleprotection units; A technology overview

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, D.; Madge, R.

1992-10-01

Over the past several years, there have been major technological advances in the area of fibre optics links and digital communication systems. This opens the possibility for digital teleprotection systems which are both faster and more reliable than current analogue ones. This paper presents a description of a generic Digital Teleprotection Unit (DTU) followed by a discussion on the technical characteristics of current commercial systems. A comparison is made between DTUs and their analogue counterparts in the area of transfer trip delay. Finally, a direct transfer trip system utilizing redundant DTUs is proposed.

The NIF LinkOut broker: a web resource to facilitate federated data integration using NCBI identifiers.

PubMed

Marenco, Luis; Ascoli, Giorgio A; Martone, Maryann E; Shepherd, Gordon M; Miller, Perry L

2008-09-01

This paper describes the NIF LinkOut Broker (NLB) that has been built as part of the Neuroscience Information Framework (NIF) project. The NLB is designed to coordinate the assembly of links to neuroscience information items (e.g., experimental data, knowledge bases, and software tools) that are (1) accessible via the Web, and (2) related to entries in the National Center for Biotechnology Information's (NCBI's) Entrez system. The NLB collects these links from each resource and passes them to the NCBI which incorporates them into its Entrez LinkOut service. In this way, an Entrez user looking at a specific Entrez entry can LinkOut directly to related neuroscience information. The information stored in the NLB can also be utilized in other ways. A second approach, which is operational on a pilot basis, is for the NLB Web server to create dynamically its own Web page of LinkOut links for each NCBI identifier in the NLB database. This approach can allow other resources (in addition to the NCBI Entrez) to LinkOut to related neuroscience information. The paper describes the current NLB system and discusses certain design issues that arose during its implementation.

Towards Improved Linkage of Disaster Risk Reduction and Climate Change Adaptation in Health: A Review.

PubMed

Banwell, Nicola; Rutherford, Shannon; Mackey, Brendan; Chu, Cordia

2018-04-18

Climate change and climate-sensitive disasters significantly impact health. Linking Disaster Risk Reduction (DRR) and Climate Change Adaptation (CCA) is essential for addressing these ever present, complex and increasing risks. Recent calls have been made to build these links in health. However, there is a need to clearly articulate why linking DRR and CCA is important in health. Furthermore, little is known about how DRR and CCA should be linked in health. By extensively examining relevant literature, this review presents the current state of knowledge of linking DRR and CCA in health. This includes the potential for maximising conceptual synergies such as building resilience, and reducing vulnerability and risk. Additionally, technical and operational synergies are identified to link DRR and CCA in health, including: policy, Early Warning Systems, vulnerability and risk assessment, health systems strengthening, infrastructure resilience, disaster preparedness and response, and health impact pathways. Public health actors have a central role in building these links due to their expertise, work functions, and experience in addressing complex health risks. The review concludes with recommendations for future research, including how to better link DRR and CCA in health; and the opportunities, challenges and enablers to build and sustain these links.

The NIF LinkOut Broker: A Web Resource to Facilitate Federated Data Integration using NCBI Identifiers

PubMed Central

Ascoli, Giorgio A.; Martone, Maryann E.; Shepherd, Gordon M.; Miller, Perry L.

2009-01-01

This paper describes the NIF LinkOut Broker (NLB) that has been built as part of the Neuroscience Information Framework (NIF) project. The NLB is designed to coordinate the assembly of links to neuroscience information items (e.g., experimental data, knowledge bases, and software tools) that are (1) accessible via the Web, and (2) related to entries in the National Center for Biotechnology Information’s (NCBI’s) Entrez system. The NLB collects these links from each resource and passes them to the NCBI which incorporates them into its Entrez LinkOut service. In this way, an Entrez user looking at a specific Entrez entry can LinkOut directly to related neuroscience information. The information stored in the NLB can also be utilized in other ways. A second approach, which is operational on a pilot basis, is for the NLB Web server to create dynamically its own Web page of LinkOut links for each NCBI identifier in the NLB database. This approach can allow other resources (in addition to the NCBI Entrez) to LinkOut to related neuroscience information. The paper describes the current NLB system and discusses certain design issues that arose during its implementation. PMID:18975149

Real-Time Reconnaissance-A Systems Look At Advanced Technology

NASA Astrophysics Data System (ADS)

Lapp, Henry

1981-12-01

An important role for reconnaissance is the location and identification of targets in real time. Current technology has been compartmented into sensors, automatic target recognizers, data links, ground exploitation and finally dissemination. In the days of bring home film recce, this segmentation of functions was appropriate. With the current emphasis on real time decision making from outputs of high resolution sensors this thinking has to be re-analyzed. A total systems approach to data management must be employed using the constraints imposed by technology as well as the atmosphere, survivable flight profiles, and the human workload. This paper will analyze the target acquisition through exploitation tasks and discuss the current advanced development technology that are applicable. A philosophy of processing data to get information as early as possible in the data handling chain is examined in the context of ground exploitation and dissemination needs. Examples of how the various real time sensors (screeners and processors), jam resistant data links and near real time ground data handling systems fit into this scenario are discussed. Specific DoD programs will be used to illustrate the credibility of this integrated approach.

A Power-Efficient Wireless Capacitor Charging System Through an Inductive Link

PubMed Central

Lee, Hyung-Min; Ghovanloo, Maysam

2014-01-01

A power-efficient wireless capacitor charging system for inductively powered applications has been presented. A bank of capacitors can be directly charged from an ac source by generating a current through a series charge injection capacitor and a capacitor charger circuit. The fixed charging current reduces energy loss in switches, while maximizing the charging efficiency. An adaptive capacitor tuner compensates for the resonant capacitance variations during charging to keep the amplitude of the ac input voltage at its peak. We have fabricated the capacitor charging system prototype in a 0.35-μm 4-metal 2-poly standard CMOS process in 2.1 mm2 of chip area. It can charge four pairs of capacitors sequentially. While receiving 2.7-V peak ac input through a 2-MHz inductive link, the capacitor charging system can charge each pair of 1 μF capacitors up to ±2 V in 420 μs, achieving a high measured charging efficiency of 82%. PMID:24678284

A Power-Efficient Wireless Capacitor Charging System Through an Inductive Link.

PubMed

Lee, Hyung-Min; Ghovanloo, Maysam

2013-10-01

A power-efficient wireless capacitor charging system for inductively powered applications has been presented. A bank of capacitors can be directly charged from an ac source by generating a current through a series charge injection capacitor and a capacitor charger circuit. The fixed charging current reduces energy loss in switches, while maximizing the charging efficiency. An adaptive capacitor tuner compensates for the resonant capacitance variations during charging to keep the amplitude of the ac input voltage at its peak. We have fabricated the capacitor charging system prototype in a 0.35- μ m 4-metal 2-poly standard CMOS process in 2.1 mm 2 of chip area. It can charge four pairs of capacitors sequentially. While receiving 2.7-V peak ac input through a 2-MHz inductive link, the capacitor charging system can charge each pair of 1 μ F capacitors up to ±2 V in 420 μ s, achieving a high measured charging efficiency of 82%.

Analysis of a novel autonomous marine hybrid power generation/energy storage system with a high-voltage direct current link

NASA Astrophysics Data System (ADS)

Wang, Li; Lee, Dong-Jing; Lee, Wei-Jen; Chen, Zhe

This paper presents both time-domain and frequency-domain simulated results of a novel marine hybrid renewable-energy power generation/energy storage system (PG/ESS) feeding isolated loads through an high-voltage direct current (HVDC) link. The studied marine PG subsystems comprise both offshore wind turbines and Wells turbines to respectively capture wind energy and wave energy from marine wind and ocean wave. In addition to wind-turbine generators (WTGs) and wave-energy turbine generators (WETGs) employed in the studied system, diesel-engine generators (DEGs) and an aqua electrolyzer (AE) absorbing a part of generated energy from WTGs and WETGs to generate available hydrogen for fuel cells (FCs) are also included in the PG subsystems. The ES subsystems consist of a flywheel energy storage system (FESS) and a compressed air energy storage (CAES) system to balance the required energy in the hybrid PG/ESS. It can be concluded from the simulation results that the proposed hybrid marine PG/ESS feeding isolated loads can stably operate to achieve system power-frequency balance condition.

Modeling of NASA's 30/20 GHz satellite communications system

NASA Technical Reports Server (NTRS)

Kwatra, S. C.; Maples, B. W.; Stevens, G. A.

1984-01-01

NASA is in the process of developing technology for a 30/20 GHz satellite communications link. Currently hardware is being assembled for a test transponder. A simulation package is being developed to study the link performance in the presence of interference and noise. This requires developing models for the components of the system. This paper describes techniques used to model the components for which data is available. Results of experiments performed using these models are described. A brief overview of NASA's 30/20 GHz communications satellite program is also included.

System and component design and test of a 10 hp, 18,000 rpm AC dynamometer utilizing a high frequency AC voltage link, part 1

NASA Technical Reports Server (NTRS)

Lipo, Thomas A.; Alan, Irfan

1991-01-01

Hard and soft switching test results conducted with one of the samples of first generation MOS-controlled thyristor (MCTs) and similar test results with several different samples of second generation MCT's are reported. A simple chopper circuit is used to investigate the basic switching characteristics of MCT under hard switching and various types of resonant circuits are used to determine soft switching characteristics of MCT under both zero voltage and zero current switching. Next, operation principles of a pulse density modulated converter (PDMC) for three phase (3F) to 3F two-step power conversion via parallel resonant high frequency (HF) AC link are reviewed. The details for the selection of power switches and other power components required for the construction of the power circuit for the second generation 3F to 3F converter system are discussed. The problems encountered in the first generation system are considered. Design and performance of the first generation 3F to 3F power converter system and field oriented induction moter drive based upon a 3 kVA, 20 kHz parallel resonant HF AC link are described. Low harmonic current at the input and output, unity power factor operation of input, and bidirectional flow capability of the system are shown via both computer and experimental results. The work completed on the construction and testing of the second generation converter and field oriented induction motor drive based upon specifications for a 10 hp squirrel cage dynamometer and a 20 kHz parallel resonant HF AC link is discussed. The induction machine is designed to deliver 10 hp or 7.46 kW when operated as an AC-dynamo with power fed back to the source through the converter. Results presented reveal that the proposed power level requires additional energy storage elements to overcome difficulties with a peak link voltage variation problem that limits reaching to the desired power level. The power level test of the second generation converter after the addition of extra energy storage elements to the HF link are described. The importance of the source voltage level to achieve a better current regulation for the source side PDMC is also briefly discussed. The power levels achieved in the motoring mode of operation show that the proposed power levels achieved in the generating mode of operation can also be easily achieved provided that no mechanical speed limitation were present to drive the induction machine at the proposed power level.

I(CES)-cubes: a modular self-reconfigurable bipartite robotic system

NASA Astrophysics Data System (ADS)

Unsal, Cem; Kiliccote, Han; Khosla, Pradeep K.

1999-08-01

In this manuscript, we introduce I(CES)-Cubes, a class of 3D modular robotic system that is capable of reconfiguring itself in order to adapt to its environment. This is a bipartite system, i.e. a collection of (i) active elements capable of actuation, and (ii) passive elements acting as connectors between actuated elements. Active elements, called links, are 3-DOF manipulators that are capable of attaching/detaching themselves to/from the passive elements. The cubes can then be positioned and oriented using links, which are independent mechatronic elements. Self- reconfiguration property enables the system to performed locomotion tasks over difficult terrain. For example, the system would be capable of moving over obstacles and climbing stairs. These task are performed by positing and orienting cubes and links to form a 3D network with required shape and position. This paper describes the design of the passive and active elements, the attachment mechanics, and several reconfiguration scenarios. Specifics of the hardware implementation and result of experiments with current prototypes are also given.

Physical Samples Linked Data in Action

NASA Astrophysics Data System (ADS)

Ji, P.; Arko, R. A.; Lehnert, K.; Bristol, S.

2017-12-01

Most data and metadata related to physical samples currently reside in isolated relational databases driven by diverse data models. How to approach the challenge for sharing, interchanging and integrating data from these difference relational databases motivated us to publish Linked Open Data for collections of physical samples, using Semantic Web technologies including the Resource Description Framework (RDF), RDF Query Language (SPARQL), and Web Ontology Language (OWL). In last few years, we have released four knowledge graphs concentrated on physical samples, including System for Earth Sample Registration (SESAR), USGS National Geochemical Database (NGDC), Ocean Biogeographic Information System (OBIS), and Earthchem Database. Currently the four knowledge graphs contain over 12 million facets (triples) about objects of interest to the geoscience domain. Choosing appropriate domain ontologies for representing context of data is the core of the whole work. Geolink ontology developed by Earthcube Geolink project was used as top level to represent common concepts like person, organization, cruise, etc. Physical sample ontology developed by Interdisciplinary Earth Data Alliance (IEDA) and Darwin Core vocabulary were used as second level to describe details about geological samples and biological diversity. We also focused on finding and building best tool chains to support the whole life cycle of publishing linked data we have, including information retrieval, linked data browsing and data visualization. Currently, Morph, Virtuoso Server, LodView, LodLive, and YASGUI were employed for converting, storing, representing, and querying data in a knowledge base (RDF triplestore). Persistent digital identifier is another main point we concentrated on. Open Researcher & Contributor IDs (ORCIDs), International Geo Sample Numbers (IGSNs), Global Research Identifier Database (GRID) and other persistent identifiers were used to link different resources from various graphs with person, sample, organization, cruise, etc. This work is supported by the EarthCube "GeoLink" project (NSF# ICER14-40221 and others) and the "USGS-IEDA Partnership to Support a Data Lifecycle Framework and Tools" project (USGS# G13AC00381).

High performance 3-coil wireless power transfer system for the 512-electrode epiretinal prosthesis.

PubMed

Zhao, Yu; Nandra, Mandheerej; Yu, Chia-Chen; Tai, Yu-chong

2012-01-01

The next-generation retinal prostheses feature high image resolution and chronic implantation. These features demand the delivery of power as high as 100 mW to be wireless and efficient. A common solution is the 2-coil inductive power link, used by current retinal prostheses. This power link tends to include a larger-size extraocular receiver coil coupled to the external transmitter coil, and the receiver coil is connected to the intraocular electrodes through a trans-sclera trans-choroid cable. In the long-term implantation of the device, the cable may cause hypotony (low intraocular pressure) and infection. However, when a 2-coil system is constructed from a small-size intraocular receiver coil, the efficiency drops drastically which may induce over heat dissipation and electromagnetic field exposure. Our previous 2-coil system achieved only 7% power transfer. This paper presents a fully intraocular and highly efficient wireless power transfer system, by introducing another inductive coupling link to bypass the trans-sclera trans-choroid cable. With the specific equivalent load of our customized 512-electrode stimulator, the current 3-coil inductive link was measured to have the overall power transfer efficiency around 36%, with 1-inch separation in saline. The high efficiency will favorably reduce the heat dissipation and electromagnetic field exposure to surrounding human tissues. The effect of the eyeball rotation on the power transfer efficiency was investigated as well. The efficiency can still maintain 14.7% with left and right deflection of 30 degree during normal use. The surgical procedure for the coils' implantation into the porcine eye was also demonstrated.

Merit Pay and the Music Teacher

ERIC Educational Resources Information Center

Elpus, Kenneth

2011-01-01

Current proponents of education reform are at present seeking to fundamentally change the system of teacher compensation by eliminating the traditional single salary schedule and instituting a merit pay system that directly links teacher pay to student achievement. To date, the scholarly literature in music education has been silent on the subject…

SpEnD: Linked Data SPARQL Endpoints Discovery Using Search Engines

NASA Astrophysics Data System (ADS)

Yumusak, Semih; Dogdu, Erdogan; Kodaz, Halife; Kamilaris, Andreas; Vandenbussche, Pierre-Yves

In this study, a novel metacrawling method is proposed for discovering and monitoring linked data sources on the Web. We implemented the method in a prototype system, named SPARQL Endpoints Discovery (SpEnD). SpEnD starts with a "search keyword" discovery process for finding relevant keywords for the linked data domain and specifically SPARQL endpoints. Then, these search keywords are utilized to find linked data sources via popular search engines (Google, Bing, Yahoo, Yandex). By using this method, most of the currently listed SPARQL endpoints in existing endpoint repositories, as well as a significant number of new SPARQL endpoints, have been discovered. Finally, we have developed a new SPARQL endpoint crawler (SpEC) for crawling and link analysis.

State of the science: chronic periodontitis and systemic health.

PubMed

Otomo-Corgel, Joan; Pucher, Jeffery J; Rethman, Michael P; Reynolds, Mark A

2012-09-01

Inflammatory periodontal diseases exhibit an association with multiple systemic conditions. Currently, there is a lack of consensus among experts on the nature of these associations and confusion among health care providers and the public on how to interpret this rapidly growing body of science. This article overviews the current evidence linking periodontal diseases to diabetes, cardiovascular disease, osteoporosis, preterm low birth weight babies, respiratory diseases, and rheumatoid arthritis. Evidence was taken from systematic reviews, clinical trials, and mechanistic studies retrieved in searches of the PubMed electronic database. The available data provide the basis for applied practical clinical recommendations. Evidence is summarized and critically reviewed from systematic reviews, primary clinical trials, and mechanistic studies Surrogate markers for chronic periodontitis, such as tooth loss, show relatively consistent but weak associations with multiple systemic conditions. Despite biological plausibility, shorter-term interventional trials have generally not supported unambiguous cause-and-effect relationships. Nevertheless, the effective treatment of periodontal infections is important to achieve oral health goals, as well as to reduce the systemic risks of chronic local inflammation and bacteremias. Inflammatory periodontal diseases exhibit an association with multiple systemic conditions. With pregnancy as a possible exception, the local and systemic effects of periodontal infections and inflammation are usually exerted for many years, typically among those who are middle-aged or older. It follows that numerous epidemiological associations linking chronic periodontitis to age-associated and biologically complex conditions such as diabetes, cardiovascular disease, osteoporosis, respiratory diseases, rheumatoid arthritis, certain cancers, erectile dysfunction, kidney disease and dementia, have been reported. In the coming years, it seems likely that additional associations will be reported, despite adjustments for known genetic, behavioral and environmental confounders. Determining cause-and-effect mechanisms is more complicated, especially in circumstances where systemic effects may be subtle. Currently, however, there is a lack of consensus among experts on the nature of these associations and confusion among health care providers and the public on how to interpret this rapidly growing body of science. This article overviews the current evidence linking periodontal diseases to diabetes, cardiovascular disease, osteoporosis, preterm/low birth weight babies, respiratory diseases, and rheumatoid arthritis. Copyright © 2012 Elsevier Inc. All rights reserved.

The CCSDS return all frames Space Link Extension service

NASA Technical Reports Server (NTRS)

Uhrig, Hans; Pietras, John; Stoloff, Michael

1994-01-01

Existing Consultative Committee for Space Data Systems (CCSDS) Recommendations for Telemetry Channel Coding, Packet Telemetry, Advanced Orbiting Systems, and Telecommand have facilitated cross-support between Agencies by standardizing the link between spacecraft and ground terminal. CCSDS is currently defining a set of Space Link Extension (SLE) services that will enable remote science and mission operations facilities to access the ground termination of the Space Link services in a standard manner. The first SLE service to be defined is the Return All Frames (RAF) service. The RAF service delivers all CCSDS link-layer frames received on a single space link physical channel. The service provides both on-line and off-line data transfer modes to accommodate the variety of access methods typical of space mission operations. This paper describes the RAF service as of the Summer of 1994. It characterizes the behavior of the service as seen across the interface between the user and the service and gives an overview of the interactions involved in setting up and operating the service in a cross-support environment.

Towards Improved Linkage of Disaster Risk Reduction and Climate Change Adaptation in Health: A Review

PubMed Central

Banwell, Nicola; Rutherford, Shannon; Mackey, Brendan; Chu, Cordia

2018-01-01

Climate change and climate-sensitive disasters significantly impact health. Linking Disaster Risk Reduction (DRR) and Climate Change Adaptation (CCA) is essential for addressing these ever present, complex and increasing risks. Recent calls have been made to build these links in health. However, there is a need to clearly articulate why linking DRR and CCA is important in health. Furthermore, little is known about how DRR and CCA should be linked in health. By extensively examining relevant literature, this review presents the current state of knowledge of linking DRR and CCA in health. This includes the potential for maximising conceptual synergies such as building resilience, and reducing vulnerability and risk. Additionally, technical and operational synergies are identified to link DRR and CCA in health, including: policy, Early Warning Systems, vulnerability and risk assessment, health systems strengthening, infrastructure resilience, disaster preparedness and response, and health impact pathways. Public health actors have a central role in building these links due to their expertise, work functions, and experience in addressing complex health risks. The review concludes with recommendations for future research, including how to better link DRR and CCA in health; and the opportunities, challenges and enablers to build and sustain these links. PMID:29670057

Numerical analysis of nonminimum phase zero for nonuniform link design

NASA Technical Reports Server (NTRS)

Girvin, Douglas L.; Book, Wayne J.

1991-01-01

As the demand for light-weight robots that can operate in a large workspace increases, the structural flexibility of the links becomes more of an issue in control. When the objective is to accurately position the tip while the robot is actuated at the base, the system is nonminimum phase. One important characteristic of nonminimum phase systems is system zeros in the right half of the Laplace plane. The ability to pick the location of these nonminimum phase zeros would give the designer a new freedom similar to pole placement. This research targets a single-link manipulator operating in the horizontal plane and modeled as a Euler-Bernoulli beam with pinned-free end conditions. Using transfer matrix theory, one can consider link designs that have variable cross-sections along the length of the beam. A FORTRAN program was developed to determine the location of poles and zeros given the system model. The program was used to confirm previous research on nonminimum phase systems, and develop a relationship for designing linearly tapered links. The method allows the designer to choose the location of the first pole and zero and then defines the appropriate taper to match the desired locations. With the pole and zero location fixed, the designer can independently change the link's moment of inertia about its axis of rotation by adjusting the height of the beam. These results can be applied to the inverse dynamic algorithms that are currently under development.

Numerical analysis of nonminimum phase zero for nonuniform link design

NASA Astrophysics Data System (ADS)

Girvin, Douglas L.; Book, Wayne J.

1991-11-01

As the demand for light-weight robots that can operate in a large workspace increases, the structural flexibility of the links becomes more of an issue in control. When the objective is to accurately position the tip while the robot is actuated at the base, the system is nonminimum phase. One important characteristic of nonminimum phase systems is system zeros in the right half of the Laplace plane. The ability to pick the location of these nonminimum phase zeros would give the designer a new freedom similar to pole placement. This research targets a single-link manipulator operating in the horizontal plane and modeled as a Euler-Bernoulli beam with pinned-free end conditions. Using transfer matrix theory, one can consider link designs that have variable cross-sections along the length of the beam. A FORTRAN program was developed to determine the location of poles and zeros given the system model. The program was used to confirm previous research on nonminimum phase systems, and develop a relationship for designing linearly tapered links. The method allows the designer to choose the location of the first pole and zero and then defines the appropriate taper to match the desired locations. With the pole and zero location fixed, the designer can independently change the link's moment of inertia about its axis of rotation by adjusting the height of the beam. These results can be applied to the inverse dynamic algorithms that are currently under development.

Frequency Spectrum for New Aviation Data Links: Initial Study Results

NASA Technical Reports Server (NTRS)

Matolak, David W.; Branstetter, James R.

2004-01-01

We describe results from an initial study to assess the suitability of various spectral bands for supporting the deployment of new aviation data links (ADL). The study focused on systems and spectral bands that can deliver VHF data link (VDL)-or-higher data rates in a two-way communication setting, including air-ground, ground-air, and air-air modes of operation. In the first part of our paper, we briefly discuss the current situation regarding communications, navigation, and surveillance (CNS) links and existing spectrum, and the well-known need for new aviation data links. We next provide an overview of related systems, and discuss key factors involved in the use of spectrum in various bands for any future integrated CNS data link, addressing primarily the lower few layers of the communications protocol stack. Desired attributes of a new ADL system are discussed, and the beneficial aspects of a particular transmission technique spread spectrum are summarized. We also provide a short list of several example potential spectral regions, and note that while none of the existing systems will likely meet the full range of desired features of a new ADL, several systems and spectral regions offer promise in terms of one or more characteristics. A detailed discussion and evaluation of these spectral regions is proposed as future work. We include a few brief examples to illustrate initial technical results regarding spread spectrum overlay, also a subject for future work.

Fuzzy logic, PSO based fuzzy logic algorithm and current controls comparative for grid-connected hybrid system

NASA Astrophysics Data System (ADS)

Borni, A.; Abdelkrim, T.; Zaghba, L.; Bouchakour, A.; Lakhdari, A.; Zarour, L.

2017-02-01

In this paper the model of a grid connected hybrid system is presented. The hybrid system includes a variable speed wind turbine controlled by aFuzzy MPPT control, and a photovoltaic generator controlled with PSO Fuzzy MPPT control to compensate the power fluctuations caused by the wind in a short and long term, the inverter currents injected to the grid is controlled by a decoupled PI current control. In the first phase, we start by modeling of the conversion system components; the wind system is consisted of a turbine coupled to a gearless permanent magnet generator (PMG), the AC/DC and DC-DC (Boost) converter are responsible to feed the electric energy produced by the PMG to the DC-link. The solar system consists of a photovoltaic generator (GPV) connected to a DC/DC boost converter controlled by a PSO fuzzy MPPT control to extract at any moment the maximum available power at the GPV terminals, the system is based on maximum utilization of both of sources because of their complementary. At the end. The active power reached to the DC-link is injected to the grid through a DC/AC inverter, this function is achieved by controlling the DC bus voltage to keep it constant and close to its reference value, The simulation studies have been performed using Matlab/Simulink. It can be concluded that a good control system performance can be achieved.

Automatic speech recognition in air-ground data link

NASA Technical Reports Server (NTRS)

Armstrong, Herbert B.

1989-01-01

In the present air traffic system, information presented to the transport aircraft cockpit crew may originate from a variety of sources and may be presented to the crew in visual or aural form, either through cockpit instrument displays or, most often, through voice communication. Voice radio communications are the most error prone method for air-ground data link. Voice messages can be misstated or misunderstood and radio frequency congestion can delay or obscure important messages. To prevent proliferation, a multiplexed data link display can be designed to present information from multiple data link sources on a shared cockpit display unit (CDU) or multi-function display (MFD) or some future combination of flight management and data link information. An aural data link which incorporates an automatic speech recognition (ASR) system for crew response offers several advantages over visual displays. The possibility of applying ASR to the air-ground data link was investigated. The first step was to review current efforts in ASR applications in the cockpit and in air traffic control and evaluated their possible data line application. Next, a series of preliminary research questions is to be developed for possible future collaboration.

Technology Candidates for Air-to-Air and Air-to-Ground Data Exchange

NASA Technical Reports Server (NTRS)

Haynes, Brian D.

2015-01-01

Technology Candidates for Air-to-Air and Air-to-Ground Data Exchange is a two-year research effort to visualize the U. S. aviation industry at a point 50 years in the future, and to define potential communication solutions to meet those future data exchange needs. The research team, led by XCELAR, was tasked with identifying future National Airspace System (NAS) scenarios, determining requirements and functions (including gaps), investigating technical and business issues for air, ground, & air-to-ground interactions, and reporting on the results. The project was conducted under technical direction from NASA and in collaboration with XCELAR's partner, National Institute of Aerospace, and NASA technical representatives. Parallel efforts were initiated to define the information exchange functional needs of the future NAS, and specific communication link technologies to potentially serve those needs. Those efforts converged with the mapping of each identified future NAS function to potential enabling communication solutions; those solutions were then compared with, and ranked relative to, each other on a technical basis in a structured analysis process. The technical solutions emerging from that process were then assessed from a business case perspective to determine their viability from a real-world adoption and deployment standpoint. The results of that analysis produced a proposed set of future solutions and most promising candidate technologies. Gap analyses were conducted at two points in the process, the first examining technical factors, and the second as part of the business case analysis. In each case, no gaps or unmet needs were identified in applying the solutions evaluated to the requirements identified. The future communication solutions identified in the research comprise both specific link technologies and two enabling technologies that apply to most or all specific links. As a result, the research resulted in a new analysis approach, viewing the underlying architecture of ground-air and air-air communications as a whole, rather than as simple "link to function" paired solutions. For the business case analysis, a number of "reference architectures" were developed for both the future technologies and the current systems, based on three typical configurations of current aircraft. Current and future costs were assigned, and various comparisons made between the current and future architectures. In general, it was assumed that if a future architecture offers lower cost than the current typical architecture, while delivering equivalent or better performance, it is likely that the future solution will gain industry acceptance. Conversely, future architectures presenting higher costs than their current counterparts must present a compelling benefit case in other areas or risk a lack of industry acceptance. The business case analysis consistently indicated lower costs for the proposed future architectures, and in most cases, significantly so. The proposed future solutions were found to offer significantly greater functionality, flexibility, and growth potential over time, at lower cost, than current systems. This was true for overall, fleet-wide equipage for domestic and oceanic air carriers, as well as for single, General Aviation (GA) aircraft. The overall research results indicate that all identified requirements can be met by the proposed solutions with significant capacity for future growth. Results also illustrate that the majority of the future communication needs can be met using currently allocated aviation RF spectrum, if used in more effective ways than it is today. A combination of such optimized aviation-specific links and commercial communication systems meets all identified needs for the 50-year future and beyond, with the caveat that a new, overall function will be needed to manage all information exchange, individual links, security, cost, and other factors. This function was labeled "Delivery Manager" (DM) within this research. DM employs a distributed client/server architecture, for both airborne and ground communications architectures. Final research results included identifying the most promising candidate technologies for the future system, conclusions and recommendations, and identifying areas where further research should be considered.

Link Winds: A visual data analysis system and its application to the atmospheric ozone depletion problem

NASA Technical Reports Server (NTRS)

Jacobson, Allan S.; Berkin, Andrew L.

1995-01-01

The Linked Windows Interactive Data System (LinkWinds) is a prototype visual data exploration system resulting from a NASA Jet Propulsion Laboratory (JPL) program of research into the application of graphical methods for rapidly accessing, displaying, and analyzing large multi variate multidisciplinary data sets. Running under UNIX it is an integrated multi-application executing environment using a data-linking paradigm to dynamically interconnect and control multiple windows containing a variety of displays and manipulators. This paradigm, resulting in a system similar to a graphical spreadsheet, is not only a powerful method for organizing large amounts of data for analysis, but leads to a highly intuitive, easy-to-learn user interface. It provides great flexibility in rapidly interacting with large masses of complex data to detect trends, correlations, and anomalies. The system, containing an expanding suite of non-domain-specific applications, provides for the ingestion of a variety of data base formats and hard -copy output of all displays. Remote networked workstations running LinkWinds may be interconnected, providing a multiuser science environment (MUSE) for collaborative data exploration by a distributed science team. The system is being developed in close collaboration with investigators in a variety of science disciplines using both archived and real-time data. It is currently being used to support the Microwave Limb Sounder (MLS) in orbit aboard the Upper Atmosphere Research Satellite (UARS). This paper describes the application of LinkWinds to this data to rapidly detect features, such as the ozone hole configuration, and to analyze correlations between chemical constituents of the atmosphere.

Ultra-wideband microwave photonic link based on single-sideband modulation

NASA Astrophysics Data System (ADS)

Li, Jingnan; Wang, Yunxin; Wang, Dayong; Zhou, Tao; Zhong, Xin; Xu, Jiahao; Yang, Dengcai; Rong, Lu

2017-10-01

Comparing with the conventional double-sideband (DSB) modulation in communication system, single-sideband (SSB) modulation only demands half bandwidth of DSB in transmission. Two common ways are employed to implement SSB modulation by using optical filter (OF) or electrical 90° phase shift, respectively. However, the bandwidth of above methods is limited by characteristics of current OF and electrical phase shift. To overcome this problem, an ultra-wideband microwave photonic link based on SSB modulation is proposed and demonstrated. The radio frequency (RF) signal modulates a single-drive dual-parallel Mach-Zehnder modulator, and the SSB modulation is realized by combining an electrical 90° hybrid coupler and an optical bandpass filter. The experimental results indicate that the system can achieve SSB modulation for RF signal from 2 to 40 GHz. The proposed microwave photonic link provides an ultra-wideband approach based on SSB modulation for radio-over-fiber system.

A Modular PV System Using Chain-Link-Type Multilevel Converter

NASA Astrophysics Data System (ADS)

Hatano, Nobuhiko; Ise, Toshifumi

This paper presents a modular photovoltaic system (MPVS) that uses a chain-link-type multilevel converter (CLMC). In large-scale PV generating systems, the DC power supply is generally composed of a large number of PV panels. Hence, losses are caused by differences in the maximum power point at each PV panel. An MPVS has been proposed to address the above mentioned problem. It helps improve the photoelectric conversion efficiency by applying maximum power point tracking (MPPT) control to each group of PV panels. In addition, if a CLMC is used in an MPVS, a high voltage can be output from the AC side and transmission losses can be decreased. However, with this circuit configuration, the current output from the AC side may be unbalanced. Therefore, we propose a method to output balanced current from the AC side, even if the output of the DC power supply is unbalanced. The validity of the proposed method is examined by digital simulation.

Payment models to support population health management.

PubMed

Huerta, Timothy R; Hefner, Jennifer L; McAlearney, Ann Scheck

2014-01-01

To survey the policy-driven financial controls currently being used to drive physician change in the care of populations. This paper offers a review of current health care payment models and discusses the impact of each on the potential success of PHM initiatives. We present the benefits of a multi-part model, combining visit-based fee-for-service reimbursement with a monthly "care coordination payment" and a performance-based payment system. A multi-part model removes volume-based incentives and promotes efficiency. However, it is predicated on a pay-for-performance framework that requires standardized measurement. Application of this model is limited due to the current lack of standardized measurement of quality goals that are linked to payment incentives. Financial models dictated by health system payers are inextricably linked to the organization and management of health care. There is a need for better measurements and realistic targets as part of a comprehensive system of measurement assessment that focuses on practice redesign, with the goal of standardizing measurement of the structure and process of redesign. Payment reform is a necessary component of an accurate measure of the associations between practice transformation and outcomes important to both patients and society.

The deep-sea hub of the ANTARES neutrino telescope

NASA Astrophysics Data System (ADS)

Anghinolfi, M.; Calzas, A.; Dinkespiler, B.; Cuneo, S.; Favard, S.; Hallewell, G.; Jaquet, M.; Musumeci, M.; Papaleo, R.; Raia, G.; Valdy, P.; Vernin, P.

2006-11-01

The ANTARES neutrino telescope, currently under construction at 2500 m depth off the French Mediterranean coast, will contain 12 detection lines, powered and read out through a deep-sea junction box (JB) hub. Electrical energy from the shore station is distributed through a transformer with multiple secondary windings and a plugboard with 16 deep sea-mateable electro-optic connectors. Connections are made to the JB outputs using manned or remotely operated submersible vehicles. The triply redundant power management and slow control system is based on two identical AC-powered systems, communicating with the shore through 160 Mb/s fibre G-links and a third battery-powered system using a slower link. We describe the power and slow control systems of the underwater hub.

Interface chemistry engineering for stable cycling of reduced GO/SnO2 nanocomposites for lithium ion battery.

PubMed

Wang, Lei; Wang, Dong; Dong, Zhihui; Zhang, Fengxing; Jin, Jian

2013-04-10

From the whole anode electrode of view, we report in this work a system-level strategy of fabrication of reduced graphene oxide (RGO)/SnO2 composite-based anode for lithium ion battery (LIB) to enhance the capacity and cyclic performance of SnO2-based electrode materials. RGO/SnO2 composite was first coated by a nanothick polydopamine (PD) layer and the PD-coated RGO/SnO2 composite was then cross-linked with poly(acrylic acid) (PAA) that was used as a binder to accomplish a whole anode electrode. The cross-link reaction between PAA and PD produced a robust network in the anode system to stabilize the whole anode during cycling. As a result, the designed anode exhibits an outstanding energy capacity up to 718 mAh/g at current density of 100 mA/g after 200 cycles and a good rate performance of 811, 700, 641, and 512 mAh/g at current density of 100, 250, 500, and 1000 mA/g, respectively. Fourier transform IR spectra confirm the formation of cross-link reaction and the stability of the robust network after long-term cycling. Our results indicate the importance of designing interfaces in anode system on achieving improved performance of electrode of LIBs.

Activity-Based Management Accounting for DoD Depot Maintenance

DTIC Science & Technology

1994-08-01

used to establish a management accounting system for the depots is described. The current accounting system does not provide the information to answer...nondirect costs are tied solely to direct labor hours. A possible alternative management accounting system uses Activity-Based Costing (ABC). ABC links...along with its probable benefits and costs. Accounting, Management accounting , Cost analysis, Depot maintenance cost.

A modern diagnostic approach for automobile systems condition monitoring

NASA Astrophysics Data System (ADS)

Selig, M.; Shi, Z.; Ball, A.; Schmidt, K.

2012-05-01

An important topic in automotive research and development is the area of active and passive safety systems. In general, it is grouped in active safety systems to prevent accidents and passive systems to reduce the impact of a crash. An example for an active system is ABS while a seat belt tensioner represents the group of passive systems. Current developments in the automotive industry try to link active with passive system components to enable a complete event sequence, beginning with the warning of the driver about a critical situation till the automatic emergency call after an accident. The cross-linking has an impact on the current diagnostic approach, which is described in this paper. Therefore, this contribution introduces a new diagnostic approach for automotive mechatronic systems. The concept is based on monitoring the messages which are exchanged via the automotive communication systems, e.g. the CAN bus. According to the authors' assumption, the messages on the bus are changing between faultless and faulty vehicle condition. The transmitted messages of the sensors and control units are different depending on the condition of the car. First experiments are carried and in addition, the hardware design of a suitable diagnostic interface is presented. Finally, first results will be presented and discussed.

Organizational Climate, Services, and Outcomes in Child Welfare Systems

ERIC Educational Resources Information Center

Glisson, Charles; Green, Philip

2011-01-01

Objective: This study examines the association of organizational climate, casework services, and youth outcomes in child welfare systems. Building on preliminary findings linking organizational climate to youth outcomes over a 3-year follow-up period, the current study extends the follow-up period to 7 years and tests main, moderating and…

The Renin Angiotensin Aldosterone System in Obesity and Hypertension: Roles in the Cardiorenal Metabolic Syndrome.

PubMed

Cabandugama, Peminda K; Gardner, Michael J; Sowers, James R

2017-01-01

In the United States, more than 50 million people have blood pressure at or above 120/80 mm Hg. All components of cardiorenal metabolic syndrome (CRS) are linked to metabolic abnormalities and obesity. A major driver for CRS is obesity. Current estimates show that many of those with hypertension and CRS show some degree of systemic and cardiovascular insulin resistance. Several pathophysiologic factors participate in the link between hypertension and CRS. This article updates recent literature with a focus on the function of insulin resistance, obesity, and renin angiotensin aldosterone system-mediated oxidative stress on endothelial dysfunction and the pathogenesis of hypertension. Copyright © 2016 Elsevier Inc. All rights reserved.

Revisiting competition in a classic model system using formal links between theory and data.

PubMed

Hart, Simon P; Burgin, Jacqueline R; Marshall, Dustin J

2012-09-01

Formal links between theory and data are a critical goal for ecology. However, while our current understanding of competition provides the foundation for solving many derived ecological problems, this understanding is fractured because competition theory and data are rarely unified. Conclusions from seminal studies in space-limited benthic marine systems, in particular, have been very influential for our general understanding of competition, but rely on traditional empirical methods with limited inferential power and compatibility with theory. Here we explicitly link mathematical theory with experimental field data to provide a more sophisticated understanding of competition in this classic model system. In contrast to predictions from conceptual models, our estimates of competition coefficients show that a dominant space competitor can be equally affected by interspecific competition with a poor competitor (traditionally defined) as it is by intraspecific competition. More generally, the often-invoked competitive hierarchies and intransitivities in this system might be usefully revisited using more sophisticated empirical and analytical approaches.

Providing the full DDF link protection for bus-connected SIEPON based system architecture

NASA Astrophysics Data System (ADS)

Hwang, I.-Shyan; Pakpahan, Andrew Fernando; Liem, Andrew Tanny; Nikoukar, AliAkbar

2016-09-01

Currently a massive amount of traffic per second is delivered through EPON systems, one of the prominent access network technologies for delivering the next generation network. Therefore, it is vital to keep the EPON optical distribution network (ODN) working by providing the necessity protection mechanism in the deployed devices; otherwise, when failures occur it will cause a great loss for both network operators and business customers. In this paper, we propose a bus-connected architecture to protect and recover distribution drop fiber (DDF) link faults or transceiver failures at ONU(s) in SIEPON system. The proposed architecture provides a cost-effective architecture, which delivers the high fault-tolerance in handling multiple DDF faults, while also providing flexibility in choosing the backup ONU assignments. Simulation results show that the proposed architecture provides the reliability and maintains quality of service (QoS) performance in terms of mean packet delay, system throughput, packet loss and EF jitter when DDF link failures occur.

Numerical analysis of right-half plane zeros for a single-link manipulator. M.S. Thesis

NASA Technical Reports Server (NTRS)

Girvin, Douglas Lynn

1992-01-01

The purpose of this research is to further develop an understanding of how nonminimum phase zero location is affected by structural link design. As the demand for light-weight robots that can operate in a large workspace increases, the structural flexibility of the links become more of an issue in controls problems. When the objective is to accurately position the tip while the robot is actuated at the base, the system is nonminimum phase. One important characteristic of nonminimum phase systems is system zeros in the right half of the Laplace plane. The ability to pick the location of these nonminimum phase zeros would give the designer a new freedom similar to pole placement. The research targets a single-link manipulator operating in the horizontal plane and modeled as a Euler-Bernoulli beam with pinned-free end conditions. Using transfer matrix theory, one can consider link designs that have variable cross-sections along the length of the beam. A FORTRAN program was developed to determine the location of poles and zeros given the system model. The program was used to confirm previous research on nonminimum phase systems, and develop a relationship for designing linearly tapered links. The method allows the designer to choose the location of the first pole and zero and then defines the appropriate taper to match the desired locations. With the pole and zero location fixes, the designer can independently change the link's moment of inertia about its axis of rotation by adjusting the height of the beam. These results can be applied to inverse dynamic algorithms currently under development at Georgia Tech.

A multidisciplinary approach to the development of low-cost high-performance lightwave networks

NASA Technical Reports Server (NTRS)

Maitan, Jacek; Harwit, Alex

1991-01-01

Our research focuses on high-speed distributed systems. We anticipate that our results will allow the fabrication of low-cost networks employing multi-gigabit-per-second data links for space and military applications. The recent development of high-speed low-cost photonic components and new generations of microprocessors creates an opportunity to develop advanced large-scale distributed information systems. These systems currently involve hundreds of thousands of nodes and are made up of components and communications links that may fail during operation. In order to realize these systems, research is needed into technologies that foster adaptability and scaleability. Self-organizing mechanisms are needed to integrate a working fabric of large-scale distributed systems. The challenge is to fuse theory, technology, and development methodologies to construct a cost-effective, efficient, large-scale system.

Control and Non-Payload Communications Links for Integrated Unmanned Aircraft Operations

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Griner, James H.

2012-01-01

Technology for unmanned aircraft has advanced so rapidly in recent years that many new applications to public and commercial use are being proposed and implemented. In many countries, emphasis is now being placed on developing the means to allow unmanned aircraft to operate within non-segregated airspace along with commercial, cargo and other piloted and passenger-carrying aircraft.In the U.S., Congress has mandated that the Federal Aviation Administration reduce and remove restrictions on unmanned aircraft operations in a relatively short time frame. To accomplish this, a number of technical and regulatory hurdles must be overcome. A key hurdle involve the communications link connecting the remote pilot located at a ground control station with the aircraft in the airspace, referred to as the Control and Non-Payload Communications (CNPC) link. This link represents a safety critical communications link, and thus requires dedicated and protected aviation spectrum as well as national and international standards defining the operational requirements the CNPC system. The CNPC link must provide line-of-site (LOS) communications, primarily through a ground-based communication system, and beyond-line-of-sight (BLOS) communication achieved using satellite communications. In the U.S., the National Aeronautics and Space Administration (NASA) is charged with providing the technical body of evidence to support spectrum allocation requirements and national and international standards development for the CNPC link. This paper provides a description of the CNPC system, an overview of NASA's CNPC project, and current results in technology assessment, air-ground propagation characterization, and supporting system studies and analyses will be presented.

Current developments in the French engineering education system

NASA Astrophysics Data System (ADS)

Lemaître, Denis

2017-03-01

The French engineering education system has been established in quite a different way from others in Europe, such as the German and British systems, for instance. Due to both the whole state system and the private initiatives during the industrial revolution, the engineering education system today is composed of a large number (nearly 200) of rather small and specialised institutions, which have historically mostly developed outside universities. In the last decades, this system has had to face a powerful internationalisation movement. This has had major consequences on the curricula design, regarding foreign language teaching, international exchanges, and links with research. Currently, the French engineering education system is facing new challenges, regarding innovation and environmental and social issues, in a very competitive higher education context.

Supporting Instruction By Defining Conceptual Relevance Of Materials: Alignment Of Resources To An Earth Systems Framework

NASA Astrophysics Data System (ADS)

Menicucci, A. J.; Bean, J. R.

2017-12-01

Environmental, geological, and climatological sciences are important facets of physical science education. However, it is often difficult for educators to acquire the necessary resources to facilitate content explanations, and demonstration of the conceptual links between individual lessons. The Understanding Global Change (UGC) Project at the University of California Museum of Paleontology (UCMP) at UC Berkeley is aligning new and existing Earth systems educational resources that are high-quality, interactive and inquiry based. Learning resources are organized by the UGC framework topics (Causes of Change, How the Earth System Works, and Measurable Changes), and focus on exploring topic relationships. Resources are currently aligned with both the UGC framework and the Next Generation Science Standards (NGSS), facilitating broad utility among K-16 educators. The overarching goal of the UGC Project is to provide the necessary resources that guide the construction of coherent, interdisciplinary instructional units. These units can be reinforced through system models, providing visual learning scaffolds for assessments of student content knowledge. Utilizing the central framework of UGC alleviates the long-standing problem of creating coherent instructional units from multiple learning resources, each organized and categorized independently across multiple platforms that may not provide explicit connections among Earth science subjects UGC topic cross listing of learning modules establishes conceptual links. Each resource is linked across several Earth system components, facilitating exploration of relationships and feedbacks between processes. Cross listed topics are therefore useful for development of broad picture learning goals via targeted instructional units. We also anticipate cultivating summaries of the explicit conceptual links explored in each resource from both current teachers and content specialists. Insructional units currated and aligned under the UGC framework therefore have the potential for users to develop and impliment inderdisciplinary lesson plans, including multi-segmented units designed to function as independent educational segments, that combine to provide broader subject exploration and deeper understanding of Earth system relationships.

Proposed Development of NASA Glenn Research Center's Aeronautical Network Research Simulator

NASA Technical Reports Server (NTRS)

Nguyen, Thanh C.; Kerczewski, Robert J.; Wargo, Chris A.; Kocin, Michael J.; Garcia, Manuel L.

2004-01-01

Accurate knowledge and understanding of data link traffic loads that will have an impact on the underlying communications infrastructure within the National Airspace System (NAS) is of paramount importance for planning, development and fielding of future airborne and ground-based communications systems. Attempting to better understand this impact, NASA Glenn Research Center (GRC), through its contractor Computer Networks & Software, Inc. (CNS, Inc.), has developed an emulation and test facility known as the Virtual Aircraft and Controller (VAC) to study data link interactions and the capacity of the NAS to support Controller Pilot Data Link Communications (CPDLC) traffic. The drawback of the current VAC test bed is that it does not allow the test personnel and researchers to present a real world RF environment to a complex airborne or ground system. Fortunately, the United States Air Force and Navy Avionics Test Commands, through its contractor ViaSat, Inc., have developed the Joint Communications Simulator (JCS) to provide communications band test and simulation capability for the RF spectrum through 18 GHz including Communications, Navigation, and Identification and Surveillance functions. In this paper, we are proposing the development of a new and robust test bed that will leverage on the existing NASA GRC's VAC and the Air Force and Navy Commands JCS systems capabilities and functionalities. The proposed NASA Glenn Research Center's Aeronautical Networks Research Simulator (ANRS) will combine current Air Traffic Control applications and physical RF stimulation into an integrated system capable of emulating data transmission behaviors including propagation delay, physical protocol delay, transmission failure and channel interference. The ANRS will provide a simulation/stimulation tool and test bed environment that allow the researcher to predict the performance of various aeronautical network protocol standards and their associated waveforms under varying density conditions. The system allows the user to define human-interactive and scripted aircraft and controller models of various standards, such as (but not limited to) Very High Frequency Digital Link (VDL) of various modes.

Comparison of Centralized-Manual, Centralized-Computerized, and Decentralized-Computerized Order and Management Information Models for the Turkish Air Force Logistics System.

DTIC Science & Technology

1986-09-01

differentiation between the systems. This study will investigate an appropriate Order Processing and Management Information System (OP&MIS) to link base-level...methodology: 1. Reviewed the current order processing and information model of the TUAF Logistics System. (centralized-manual model) 2. Described the...RDS program’s order processing and information system. (centralized-computerized model) 3. Described the order irocessing and information system of

An Optimal Schedule for Urban Road Network Repair Based on the Greedy Algorithm

PubMed Central

Lu, Guangquan; Xiong, Ying; Wang, Yunpeng

2016-01-01

The schedule of urban road network recovery caused by rainstorms, snow, and other bad weather conditions, traffic incidents, and other daily events is essential. However, limited studies have been conducted to investigate this problem. We fill this research gap by proposing an optimal schedule for urban road network repair with limited repair resources based on the greedy algorithm. Critical links will be given priority in repair according to the basic concept of the greedy algorithm. In this study, the link whose restoration produces the ratio of the system-wide travel time of the current network to the worst network is the minimum. We define such a link as the critical link for the current network. We will re-evaluate the importance of damaged links after each repair process is completed. That is, the critical link ranking will be changed along with the repair process because of the interaction among links. We repair the most critical link for the specific network state based on the greedy algorithm to obtain the optimal schedule. The algorithm can still quickly obtain an optimal schedule even if the scale of the road network is large because the greedy algorithm can reduce computational complexity. We prove that the problem can obtain the optimal solution using the greedy algorithm in theory. The algorithm is also demonstrated in the Sioux Falls network. The problem discussed in this paper is highly significant in dealing with urban road network restoration. PMID:27768732

GPS-Squitter capacity analysis

NASA Astrophysics Data System (ADS)

Orlando, Vincent A.; Harman, William H.

1994-05-01

GPS-Squitter is a system concept that merges the capabilities of Automatic Dependent Surveillance (ADS) and the Mode S beacon radar. The result is an integrated concept for seamless surveillance and data link that permits equipped aircraft to participate in ADS and/or beacon ground environments. This concept offers many possibilities for transition from a beacon to an ADS-based environment. This report provides the details of the techniques used to estimate GPS-Squitter surveillance and data link capacity. Surveillance capacity of airborne aircraft is calculated for the omni and six-sector ground stations. Next, the capacity of GPS-Squitter for surface traffic is estimated. The interaction between airborne and surface operations is addressed to show the independence of these systems. Air ground data link capacity for GPS-Squitter is estimated, together with an estimate of the use of the Mode S link to support other ground surveillance and data link activities as well as TCAS operation. The analysis indicates the low transponder occupancy resulting from the total effect of these activities. Low occupancy is a key requirement in avoiding interference with the operation of the current ATCRBS and future Mode S interrogators.

Evaluation of 5 different labeled polymer immunohistochemical detection systems.

PubMed

Skaland, Ivar; Nordhus, Marit; Gudlaugsson, Einar; Klos, Jan; Kjellevold, Kjell H; Janssen, Emiel A M; Baak, Jan P A

2010-01-01

Immunohistochemical staining is important for diagnosis and therapeutic decision making but the results may vary when different detection systems are used. To analyze this, 5 different labeled polymer immunohistochemical detection systems, REAL EnVision, EnVision Flex, EnVision Flex+ (Dako, Glostrup, Denmark), NovoLink (Novocastra Laboratories Ltd, Newcastle Upon Tyne, UK) and UltraVision ONE (Thermo Fisher Scientific, Fremont, CA) were tested using 12 different, widely used mouse and rabbit primary antibodies, detecting nuclear, cytoplasmic, and membrane antigens. Serial sections of multitissue blocks containing 4% formaldehyde fixed paraffin embedded material were selected for their weak, moderate, and strong staining for each antibody. Specificity and sensitivity were evaluated by subjective scoring and digital image analysis. At optimal primary antibody dilution, digital image analysis showed that EnVision Flex+ was the most sensitive system (P < 0.005), with means of 8.3, 13.4, 20.2, and 41.8 gray scale values stronger staining than REAL EnVision, EnVision Flex, NovoLink, and UltraVision ONE, respectively. NovoLink was the second most sensitive system for mouse antibodies, but showed low sensitivity for rabbit antibodies. Due to low sensitivity, 2 cases with UltraVision ONE and 1 case with NovoLink stained false negatively. None of the detection systems showed any distinct false positivity, but UltraVision ONE and NovoLink consistently showed weak background staining both in negative controls and at optimal primary antibody dilution. We conclude that there are significant differences in sensitivity, specificity, costs, and total assay time in the immunohistochemical detection systems currently in use.

Optimization of naltrexone diclofenac codrugs for sustained drug delivery across microneedle-treated skin.

PubMed

Ghosh, Priyanka; Lee, DoMin; Kim, Kyung Bo; Stinchcomb, Audra L

2014-01-01

The purpose of this work was to optimize the structure of codrugs for extended delivery across microneedle treated skin. Naltrexone, the model compound was linked with diclofenac, a nonspecific cyclooxygenase inhibitor to enhance the pore lifetime following microneedle treatment and develop a 7 day transdermal system for naltrexone. Four different codrugs of naltrexone and diclofenac were compared in terms of stability and solubility. Transdermal flux, permeability and skin concentration of both parent drugs and codrugs were quantified to form a structure permeability relationship. The results indicated that all codrugs bioconverted in the skin. The degree of conversion was dependent on the structure, phenol linked codrugs were less stable compared to the secondary alcohol linked structures. The flux of naltrexone across microneedle treated skin and the skin concentration of diclofenac were higher for the phenol linked codrugs. The polyethylene glycol link enhanced solubility of the codrugs, which translated into flux enhancement. The current studies indicated that formulation stability of codrugs and the flux of naltrexone can be enhanced via structure design optimization. The polyethylene glycol linked naltrexone diclofenac codrug is better suited for a 7 day drug delivery system both in terms of stability and drug delivery.

A novel transient rotor current control scheme of a doubly-fed induction generator equipped with superconducting magnetic energy storage for voltage and frequency support

NASA Astrophysics Data System (ADS)

Shen, Yang-Wu; Ke, De-Ping; Sun, Yuan-Zhang; Daniel, Kirschen; Wang, Yi-Shen; Hu, Yuan-Chao

2015-07-01

A novel transient rotor current control scheme is proposed in this paper for a doubly-fed induction generator (DFIG) equipped with a superconducting magnetic energy storage (SMES) device to enhance its transient voltage and frequency support capacity during grid faults. The SMES connected to the DC-link capacitor of the DFIG is controlled to regulate the transient dc-link voltage so that the whole capacity of the grid side converter (GSC) is dedicated to injecting reactive power to the grid for the transient voltage support. However, the rotor-side converter (RSC) has different control tasks for different periods of the grid fault. Firstly, for Period I, the RSC injects the demagnetizing current to ensure the controllability of the rotor voltage. Then, since the dc stator flux degenerates rapidly in Period II, the required demagnetizing current is low in Period II and the RSC uses the spare capacity to additionally generate the reactive (priority) and active current so that the transient voltage capability is corroborated and the DFIG also positively responds to the system frequency dynamic at the earliest time. Finally, a small amount of demagnetizing current is provided after the fault clearance. Most of the RSC capacity is used to inject the active current to further support the frequency recovery of the system. Simulations are carried out on a simple power system with a wind farm. Comparisons with other commonly used control methods are performed to validate the proposed control method. Project supported by the National Natural Science Foundation of China (Grant No. 51307124) and the Major Program of the National Natural Science Foundation of China (Grant No. 51190105).

Getting beyond the Facts: Reforming California School Finance. Issue Brief

ERIC Educational Resources Information Center

Bersin, Alan; Kirst, Michael W.; Liu, Goodwin

2008-01-01

California's school finance system is long overdue for reform. The authors propose a new system that is more rational, more equitable, and, they believe, politically feasible. At its core, their proposal aims to link district revenue to student needs and regional costs while ensuring that all districts are held harmless at current funding levels.…

Space vehicle onboard command encoder

NASA Technical Reports Server (NTRS)

1975-01-01

A flexible onboard encoder system was designed for the space shuttle. The following areas were covered: (1) implementation of the encoder design into hardware to demonstrate the various encoding algorithms/code formats, (2) modulation techniques in a single hardware package to maintain comparable reliability and link integrity of the existing link systems and to integrate the various techniques into a single design using current technology. The primary function of the command encoder is to accept input commands, generated either locally onboard the space shuttle or remotely from the ground, format and encode the commands in accordance with the payload input requirements and appropriately modulate a subcarrier for transmission by the baseband RF modulator. The following information was provided: command encoder system design, brassboard hardware design, test set hardware and system packaging, and software.

Smart transducer with radiomodem

NASA Astrophysics Data System (ADS)

Pugach, V. N.; Voronin, E. L.

2018-04-01

Systems for measuring different parameters enabling metering and wireless data transmission are an urgent problem in the industry. One of the most promising solutions is the developments of metering instruments enabling radio-link and GSM data transmission. The article describes a transducer operating with temperature sensors of different types as well as with the sensors of other physical values with the output signal represented as current or voltage with subsequent measurement data transmission from the transducer to the computer via radio-link. The article provides transducer measurement accuracy check. The work confirmed the claimed temperature measurement accuracy, noted a stable data transmission via radio link and convenience of work with the transducer and software.

A review of the scientific rationale and methods used in the search for other planetary systems

NASA Technical Reports Server (NTRS)

Black, D. C.

1985-01-01

Planetary systems appear to be one of the crucial links in the chain leading from simple molecules to living systems, particularly complex (intelligent?) living systems. Although there is currently no observational proof of the existence of any planetary system other than our own, techniques are now being developed which will permit a comprehensive search for other planetary systems. The scientific rationale for and methods used in such a search effort are reviewed here.

[From microdosimetry to nanodosimetry--the link between radiobiology and radiation physics].

PubMed

Fu, Yuchuan; Li, Ping

2014-06-01

The link between micro- and macro-parameters for radiation interactions that take place in living biological systems is described in this paper. Meanwhile recent progress and development in microdosimetry and nanodosimetry are introduced, including the methods to measure and calculate these micro- or nano-parameters. The relationship between radiobiology and physical quantities in microdosimetry and nanodosimetry was presented. Both the current problems on their applications in radiation protection and radiotherapy and the future development direction are proposed.

Global Power Requires a Global, Persistent Air-to-Air Capability

DTIC Science & Technology

2010-01-01

anywhere on the high seas, and in most coastal waters as well, and sink them if necessary by using guns, missiles, or tor- pedoes . Current Air Force...apparently a number of so-far-undisclosed challenges remain, perhaps including the air refuel- ing of an RPA and maintaining the data link with it in...will remain relatively short- range systems.31 With regard to the data link , a remote pi- lot flies the Predator—our primary opera- tional, fighter-sized

Development and Operation of the Astrophysics Data System

NASA Technical Reports Server (NTRS)

Murray, Stephen S.

1997-01-01

The Astrophysics Data System (ADS) provides access to astronomical bibliographic information, including references, abstracts, and full journal articles, as well as links to other on-line information sources like on-line electronic journals and on-line data. This section will first provide a brief history of the ADS, a general introduction of the current system, and a more detailed description of some of the parts of the ADS.

Weather data dissemination to aircraft

NASA Technical Reports Server (NTRS)

Mcfarland, Richard H.; Parker, Craig B.

1990-01-01

Documentation exists that shows weather to be responsible for approximately 40 percent of all general aviation accidents with fatalities. Weather data products available on the ground are becoming more sophisticated and greater in number. Although many of these data are critical to aircraft safety, they currently must be transmitted verbally to the aircraft. This process is labor intensive and provides a low rate of information transfer. Consequently, the pilot is often forced to make life-critical decisions based on incomplete and outdated information. Automated transmission of weather data from the ground to the aircraft can provide the aircrew with accurate data in near-real time. The current National Airspace System Plan calls for such an uplink capability to be provided by the Mode S Beacon System data link. Although this system has a very advanced data link capability, it will not be capable of providing adequate weather data to all airspace users in its planned configuration. This paper delineates some of the important weather data uplink system requirements, and describes a system which is capable of meeting these requirements. The proposed system utilizes a run-length coding technique for image data compression and a hybrid phase and amplitude modulation technique for the transmission of both voice and weather data on existing aeronautical Very High Frequency (VHF) voice communication channels.

Developing Systems Engineering Skills Through NASA Summer Intern Project

NASA Technical Reports Server (NTRS)

Bhasin, Kul; Barritt, Brian; Golden, Bert; Knoblock, Eric; Matthews, Seth; Warner, Joe

2010-01-01

During the Formulation phases of the NASA Project Life Cycle, communication systems engineers are responsible for designing space communication links and analyzing their performance to ensure that the proposed communication architecture is capable of satisfying high-level mission requirements. Senior engineers with extensive experience in communications systems perform these activities. However, the increasing complexity of space systems coupled with the current shortage of communications systems engineers has led to an urgent need for expedited training of new systems engineers. A pilot program, in which college-bound high school and undergraduate students studying various engineering disciplines are immersed in NASA s systems engineering practices, was conceived out of this need. This rapid summerlong training approach is feasible because of the availability of advanced software and technology tools and the students inherent ability to operate such tools. During this pilot internship program, a team of college-level and recently-hired engineers configured and utilized various software applications in the design and analysis of communication links for a plausible lunar sortie mission. The approach taken was to first design the direct-to-Earth communication links for the lunar mission elements, then to design the links between lunar surface and lunar orbital elements. Based on the data obtained from these software applications, an integrated communication system design was realized and the students gained valuable systems engineering knowledge. This paper describes this approach to rapidly training college-bound high school and undergraduate engineering students from various disciplines in NASA s systems engineering practices and tools. A summary of the potential use of NASA s emerging systems engineering internship program in broader applications is also described.

COPD and stroke: are systemic inflammation and oxidative stress the missing links?

PubMed Central

Austin, Victoria; Crack, Peter J.; Bozinovski, Steven; Miller, Alyson A.

2016-01-01

Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation and loss of lung function, and is currently the third largest cause of death in the world. It is now well established that cardiovascular-related comorbidities such as stroke contribute to morbidity and mortality in COPD. The mechanisms linking COPD and stroke remain to be fully defined but are likely to be interconnected. The association between COPD and stroke may be largely dependent on shared risk factors such as aging and smoking, or the association of COPD with traditional stroke risk factors. In addition, we propose that COPD-related systemic inflammation and oxidative stress may play important roles by promoting cerebral vascular dysfunction and platelet hyperactivity. In this review, we briefly discuss the pathogenesis of COPD, acute exacerbations of COPD (AECOPD) and cardiovascular comorbidities associated with COPD, in particular stroke. We also highlight and discuss the potential mechanisms underpinning the link between COPD and stroke, with a particular focus on the roles of systemic inflammation and oxidative stress. PMID:27215677

Single- and double-ion type cross-linked polysiloxane solid electrolytes for lithium cells

NASA Astrophysics Data System (ADS)

Tsutsumi, Hiromori; Yamamoto, Masahiro; Morita, Masayuki; Matsuda, Yoshiharu; Nakamura, Takashi; Asai, Hiroyuki

Polymeric solid electrolytes, that have poly(dimethylsiloxane) (PMS) backbone and cross-linked network, were applied to a rechargeable lithium battery system. Single- (PMS-Li) and double-ion type (PMS-LiClO 4) electrolytes were prepared from the same prepolymers. Lithium electrode in the both electrolytes showed reversible stripping and deposition of lithium. Intercalation and deintercalation processes of lithium ion between lithium-manganese composite oxide (Li xMnO 2) electrode and the electrolytes were also confirmed by cyclic voltammetry, however, peak current decreased with several cycles in both cases. The model cell, Li/PMS-Li/Li xMnO 2 cell had 1.4 mA h g -1 (per 1 g of active material, current density: 3.77 μA cm -2), and the Li/PMS-LiClO 4/Li xMnO 2 cell had 1.6 mA h g -1 (current density: 75.3 μA cm -2).

Concrete pavement quality control testing requirements needed for the super air meter : final report.

DOT National Transportation Integrated Search

2016-10-01

Concrete freeze-thaw durability is prominently linked to the air void system within the concrete. : Concrete pavements in Kansas undergo repetitive freeze-thaw cycles. Total air content measurements : currently used on fresh concrete do not provide a...

A synthesis of the "state-of-the-practice for advancing planning and operations integration opportunities within transportation agencies".

DOT National Transportation Integrated Search

2014-12-01

Linking Planning and Operations is vital to improving transportation decision-making and overall : efficiency of transportation systems management. This synthesis summarizes current state of : knowledge and practices in Planning and Operations Integr...

Concrete pavement quality control testing requirements needed for the super air meter : technical summary.

DOT National Transportation Integrated Search

2016-10-01

Concrete freeze-thaw durability is prominently linked to the air void system : within the concrete. Concrete pavements in Kansas undergo repetitive : freeze-thaw cycles. Total air content measurements currently used on fresh : concrete do not provide...

Training for a Changing Society. A Report on Current Vocational Education and Training Research in Europe. Reference Document.

ERIC Educational Resources Information Center

Tessaring, Manfred

This report describes the background and links among education, training, labor market, economy, and society. Part 1 deals with the statutory, institutional, and political background to vocational education and training (VET), steering of VET systems, funding, and performance of VET systems and the European context. Part 2 discusses research on…

The Transcription Factor EB Links Cellular Stress to the Immune Response



PubMed Central

Nabar, Neel R.; Kehrl, John H.

2017-01-01

The transcription factor EB (TFEB) is the master transcriptional regulator of autophagy and lysosome biogenesis. Recent advances have led to a paradigm shift in our understanding of lysosomes from a housekeeping cellular waste bin to a dynamically regulated pathway that is efficiently turned up or down based on cellular needs. TFEB coordinates the cellular response to nutrient deprivation and other forms of cell stress through the lysosome system, and regulates a myriad of cellular processes associated with this system including endocytosis, phagocytosis, autophagy, and lysosomal exocytosis. Autophagy and the endolysosomal system are critical to both the innate and adaptive arms of the immune system, with functions in effector cell priming and direct pathogen clearance. Recent studies have linked TFEB to the regulation of the immune response through the endolysosmal pathway and by direct transcriptional activation of immune related genes. In this review, we discuss the current understanding of TFEB’s function and the molecular mechanisms behind TFEB activation. Finally, we discuss recent advances linking TFEB to the immune response that positions lysosomal signaling as a potential target for immune modulation. PMID:28656016

The Transcription Factor EB Links Cellular Stress to the Immune Response

.

PubMed

Nabar, Neel R; Kehrl, John H

2017-06-01

The transcription factor EB (TFEB) is the master transcriptional regulator of autophagy and lysosome biogenesis. Recent advances have led to a paradigm shift in our understanding of lysosomes from a housekeeping cellular waste bin to a dynamically regulated pathway that is efficiently turned up or down based on cellular needs. TFEB coordinates the cellular response to nutrient deprivation and other forms of cell stress through the lysosome system, and regulates a myriad of cellular processes associated with this system including endocytosis, phagocytosis, autophagy, and lysosomal exocytosis. Autophagy and the endolysosomal system are critical to both the innate and adaptive arms of the immune system, with functions in effector cell priming and direct pathogen clearance. Recent studies have linked TFEB to the regulation of the immune response through the endolysosmal pathway and by direct transcriptional activation of immune related genes. In this review, we discuss the current understanding of TFEB's function and the molecular mechanisms behind TFEB activation. Finally, we discuss recent advances linking TFEB to the immune response that positions lysosomal signaling as a potential target for immune modulation.

Charlie, Development of a Light-Weight, Virtual Reality Trainer for the LSO Community: Time to Make the Leap Toward Immersive VR

DTIC Science & Technology

2015-09-01

Training System ARB Aircraft Recovery Bulletins AR Augmented Reality CAG Carrier Air Group CATCC Carrier Air Traffic Control Center COTS...in integration of an optical lens systems into the aircraft carrier. The current generation of optical lens systems integrated into aircraft ...The use of MOVLAS on an aircraft carrier represents a direct communication link between the LSO and pilot. As a backup landing aid system to

Can an employer-based health insurance system be just?

PubMed

Jecker, N S

1993-01-01

It is America's distinctive practice to tie private health insurance to employment, and recent proposals have tried to retain this link through mandating that all employers provide health insurance to their employees. My primary approach to these issues is neither economic, nor historical, nor political but ethical. After a brief historical overview, I outline a general approach to evaluating the ethical significance of linking the distributions of distinct goods. I examine whether an unjust distribution of jobs spoils justice in the distribution of health insurance, taking as a central example gender inequities in employment and exploring their impact on job-based health insurance. Second, I explore the possibility that justly awarding jobs guarantees justice in employment-sponsored insurance. However, linking the distributions of different goods remains problematic, because such links inevitably undermine equality by enabling the same individuals to enjoy advantages in many different distributive areas. Finally, I examine recent proposals to reform America's health care system by requiring all employers to provide health insurance to their employees. I argue that such proposals lend themselves to the same ethical problems that the current system does and urge greater attention to alternative reform options.

A control approach for robots with flexible links and rigid end-effectors

NASA Technical Reports Server (NTRS)

Barbieri, Enrique; Ozguner, Umit

1989-01-01

Multiarm flexible robots with dexterous end effectors are currently being considered in such tasks as satellite retrieval, servicing and repair where a two phase problem can be identified: Phase 1, robot positioning in space; Phase 2, object retrieval. Some issues in Phase 1 regarding modelling and control strategies for a robotic system comprised of along flexible arm and a rigid three-link end effector are presented. The control objective is to maintain the last (rigid) link stationary in space in the presence of an additive disturbance caused by the flexible energy in the first link after a positioning maneuver has been accomplished. Several configuration strategies can be considered, and optimal decentralized servocompensators can be designed. Preliminary computer simulations are included for a simple proportional controller to illustrate the approach.

Conceptual design study: Forest Fire Advanced System Technology (FFAST)

NASA Technical Reports Server (NTRS)

Nichols, J. D.; Warren, J. R.

1986-01-01

An integrated forest fire detection and mapping system that will be based upon technology available in the 1990s was defined. Uncertainties in emerging and advanced technologies related to the conceptual design were identified and recommended for inclusion as preferred system components. System component technologies identified for an end-to-end system include thermal infrared, linear array detectors, automatic georeferencing and signal processing, geosynchronous satellite communication links, and advanced data integration and display. Potential system configuration options were developed and examined for possible inclusion in the preferred system configuration. The preferred system configuration will provide increased performance and be cost effective over the system currently in use. Forest fire management user requirements and the system component emerging technologies were the basis for the system configuration design. A preferred system configuration was defined that warrants continued refinement and development, examined economic aspects of the current and preferred system, and provided preliminary cost estimates for follow-on system prototype development.

User Interaction with the CNPC Link

NASA Technical Reports Server (NTRS)

Hobbs, Alan; Lyall, Elizabeth A.

2014-01-01

As part of NASAs UAS in the NAS project, human factor guidelines are being developed for the ground control station of unmanned aircraft systems. A critical task for the pilot of a UAS is the management and control of the terrestrial radio links used to provide control of the vehicle and relay communications with air traffic control. An analysis of the task of the UAS pilot has been conducted to identify areas where guidelines are required. This analysis has identified a set of information requirements that must be supported by the radio equipment used to provide Control and Non-payload Communication (CNPC). Key requirements include the need for an alert when the link is lost, information on the current quality and latency of the link, and information to enable the future quality of the link to be anticipated as the aircraft changes location. These identified requirements can assist in the development of minimum operational performance standards for CNPC equipment.

World Wide Web Metaphors for Search Mission Data

NASA Technical Reports Server (NTRS)

Norris, Jeffrey S.; Wallick, Michael N.; Joswig, Joseph C.; Powell, Mark W.; Torres, Recaredo J.; Mittman, David S.; Abramyan, Lucy; Crockett, Thomas M.; Shams, Khawaja S.; Fox, Jason M.;

Flow networks for Ocean currents

NASA Astrophysics Data System (ADS)

Tupikina, Liubov; Molkenthin, Nora; Marwan, Norbert; Kurths, Jürgen

2014-05-01

Complex networks have been successfully applied to various systems such as society, technology, and recently climate. Links in a climate network are defined between two geographical locations if the correlation between the time series of some climate variable is higher than a threshold. Therefore, network links are considered to imply heat exchange. However, the relationship between the oceanic and atmospheric flows and the climate network's structure is still unclear. Recently, a theoretical approach verifying the correlation between ocean currents and surface air temperature networks has been introduced, where the Pearson correlation networks were constructed from advection-diffusion dynamics on an underlying flow. Since the continuous approach has its limitations, i.e., by its high computational complexity, we here introduce a new, discrete construction of flow-networks, which is then applied to static and dynamic velocity fields. Analyzing the flow-networks of prototypical flows we find that our approach can highlight the zones of high velocity by degree and transition zones by betweenness, while the combination of these network measures can uncover how the flow propagates within time. We also apply the method to time series data of the Equatorial Pacific Ocean Current and the Gulf Stream ocean current for the changing velocity fields, which could not been done before, and analyse the properties of the dynamical system. Flow-networks can be powerful tools to theoretically understand the step from system's dynamics to network's topology that can be analyzed using network measures and is used for shading light on different climatic phenomena.

The Role of Margin in Link Design and Optimization

NASA Technical Reports Server (NTRS)

Cheung, K.

2015-01-01

Link analysis is a system engineering process in the design, development, and operation of communication systems and networks. Link models that are mathematical abstractions representing the useful signal power and the undesirable noise and attenuation effects (including weather effects if the signal path transverses through the atmosphere) that are integrated into the link budget calculation that provides the estimates of signal power and noise power at the receiver. Then the link margin is applied which attempts to counteract the fluctuations of the signal and noise power to ensure reliable data delivery from transmitter to receiver. (Link margin is dictated by the link margin policy or requirements.) A simple link budgeting approach assumes link parameters to be deterministic values typically adopted a rule-of-thumb policy of 3 dB link margin. This policy works for most S- and X-band links due to their insensitivity to weather effects. But for higher frequency links like Ka-band, Ku-band, and optical communication links, it is unclear if a 3 dB link margin would guarantee link closure. Statistical link analysis that adopted the 2-sigma or 3-sigma link margin incorporates link uncertainties in the sigma calculation. (The Deep Space Network (DSN) link margin policies are 2-sigma for downlink and 3-sigma for uplink.) The link reliability can therefore be quantified statistically even for higher frequency links. However in the current statistical link analysis approach, link reliability is only expressed as the likelihood of exceeding the signal-to-noise ratio (SNR) threshold that corresponds to a given bit-error-rate (BER) or frame-error-rate (FER) requirement. The method does not provide the true BER or FER estimate of the link with margin, or the required signalto-noise ratio (SNR) that would meet the BER or FER requirement in the statistical sense. In this paper, we perform in-depth analysis on the relationship between BER/FER requirement, operating SNR, and coding performance curve, in the case when the channel coherence time of link fluctuation is comparable or larger than the time duration of a codeword. We compute the "true" SNR design point that would meet the BER/FER requirement by taking into account the fluctuation of signal power and noise power at the receiver, and the shape of the coding performance curve. This analysis yields a number of valuable insights on the design choices of coding scheme and link margin for the reliable data delivery of a communication system - space and ground. We illustrate the aforementioned analysis using a number of standard NASA error-correcting codes.

APPLICATION OF BIAS AND ADJUSTMENT TECHNIQUES TO THE ETA-CMAQ AIR QUALITY FORECAST

EPA Science Inventory

The current air quality forecast system, based on linking NOAA's Eta meteorological model with EPA's Community Multiscale Air Quality (CMAQ) model, consistently overpredicts surface ozone concentrations, but simulates its day-to-day variability quite well. The ability of bias cor...

The changing global carbon cycle: Linking plant-soil carbon dynamics to global consequences

USGS Publications Warehouse

Chapin, F. S.; McFarland, J.; McGuire, David A.; Euskirchen, E.S.; Ruess, Roger W.; Kielland, K.

2009-01-01

Synthesis. Current climate systems models that include only NPP and HR are inadequate under conditions of rapid change. Many of the recent advances in biogeochemical understanding are sufficiently mature to substantially improve representation of ecosystem C dynamics in these models.

Shedding Light on Fiber Optics.

ERIC Educational Resources Information Center

Bunch, Robert M.

1994-01-01

Explains the principles of fiber optics as a medium for light-wave communication. Current uses of fiber systems on college campuses include voice, video, and local area network applications. A group of seven school districts in Minnesota are linked via fiber-optic cables. Other uses are discussed. (MLF)

Cumulative Development of Attentional Theory.

ERIC Educational Resources Information Center

Posner, Michael I.

1982-01-01

Describes current work in selective attention within a framework of research conducted over the past century. Presents evidence that findings at the level of performance, subjective experience, and neural systems can be linked, even though these findings are not yet reducible to a single theory. (Author/GC)

Impute DC link (IDCL) cell based power converters and control thereof

DOEpatents

Divan, Deepakraj M.; Prasai, Anish; Hernendez, Jorge; Moghe, Rohit; Iyer, Amrit; Kandula, Rajendra Prasad

2016-04-26

Power flow controllers based on Imputed DC Link (IDCL) cells are provided. The IDCL cell is a self-contained power electronic building block (PEBB). The IDCL cell may be stacked in series and parallel to achieve power flow control at higher voltage and current levels. Each IDCL cell may comprise a gate drive, a voltage sharing module, and a thermal management component in order to facilitate easy integration of the cell into a variety of applications. By providing direct AC conversion, the IDCL cell based AC/AC converters reduce device count, eliminate the use of electrolytic capacitors that have life and reliability issues, and improve system efficiency compared with similarly rated back-to-back inverter system.

The Goodrich 3rd generation DB-110 system: operational on tactical and unmanned aircraft

NASA Astrophysics Data System (ADS)

Iyengar, Mrinal; Lange, Davis

2006-05-01

Goodrich's DB-110 Reconnaissance Airborne Pod for TORnado (RAPTOR) and Data Link Ground Station (DLGS) have been used operationally for several years by the Royal Air Force (RAF). A variant of the RAPTOR DB-110 Sensor System is currently being used by the Japan Maritime Self Defense Force (JMSDF). Recently, the DB-110 system was flown on the Predator B Unmanned Aerial Vehicle (UAV), demonstrating the DB-110 system's utility on unmanned reconnaissance aircraft. The DB-110 is a dual-band EO and IR imaging capability for long, medium, and short standoff ranges, including oblique and over-flight imaging, in a single sensor package. The DB-110 system has also proven performance for real-time high bandwidth data link imagery transmission. Goodrich has leveraged this operational experience in building a 3rd Generation DB-110 system including new Reconnaissance Airborne Pod and Ground System, to be first used by the Polish Air Force. This 3rd Generation system maintains all the capability of the current 2nd Generation DB-110 system and adds several new features. The 3rd Generation system upgrades include an increase in resolution via new focal planes, addition of a third ("super-wide") field of view, and new avionics. This paper summarizes the Goodrich DB-110 3rd Generation System in terms of its basic design and capabilities. Recent demonstration of the DB-110 on the Predator B UAV is overviewed including sample imagery.

Application of AirCell Cellular AMPS Network and Iridium Satellite System Dual Mode Service to Air Traffic Management

NASA Technical Reports Server (NTRS)

Shamma, Mohammed A.

2004-01-01

The AirCell/Iridium dual mode service is evaluated for potential applications to Air Traffic Management (ATM) communication needs. The AirCell system which is largely based on the Advanced Mobile Phone System (AMPS) technology, and the Iridium FDMA/TDMA system largely based on the Global System for Mobile Communications(GSM) technology, can both provide communication relief for existing or future aeronautical communication links. Both have a potential to serve as experimental platforms for future technologies via a cost effective approach. The two systems are well established in the entire CONUS and globally hence making it feasible to utilize in all regions, for all altitudes, and all classes of aircraft. Both systems have been certified for air usage. The paper summarizes the specifications of the AirCell/Iridium system, as well as the ATM current and future links, and application specifications. the paper highlights the scenarios, applications, and conditions under which the AirCell/Iridium technology can be suited for ATM Communication.

Serotonin affects association of aversive outcomes to past actions.

PubMed

Tanaka, Saori C; Shishida, Kazuhiro; Schweighofer, Nicolas; Okamoto, Yasumasa; Yamawaki, Shigeto; Doya, Kenji

2009-12-16

Impairment in the serotonergic system has been linked to action choices that are less advantageous in a long run. Such impulsive choices can be caused by a deficit in linking a given reward or punishment with past actions. Here, we tested the effect of manipulation of the serotonergic system by tryptophan depletion and loading on learning the association of current rewards and punishments with past actions. We observed slower associative learning when actions were followed by a delayed punishment in the low serotonergic condition. Furthermore, a model-based analysis revealed a positive correlation between the length of the memory trace for aversive choices and subjects' blood tryptophan concentration. Our results suggest that the serotonergic system regulates the time scale of retrospective association of punishments to past actions.

An Update on the CCSDS Optical Communications Working Group

NASA Technical Reports Server (NTRS)

Edwards, Bernard L.; Schulz, Klaus-Juergen; Hamkins, Jonathan; Robinson, Bryan; Alliss, Randall; Daddato, Robert; Schmidt, Christopher; Giggebach, Dirk; Braatz, Lena

2017-01-01

International space agencies around the world are currently developing optical communication systems for Near Earth and Deep Space applications for both robotic and human rated spacecraft. These applications include both links between spacecraft and links between spacecraft and ground. The Interagency Operation Advisory Group (IOAG) has stated that there is a strong business case for international cross support of spacecraft optical links. It further concluded that in order to enable cross support the links must be standardized. This paper will overview the history and structure of the space communications international standards body, the Consultative Committee for Space Data Systems (CCSDS), that will develop the standards and provide an update on the proceedings of the Optical Communications Working Group within CCSDS. This paper will also describe the set of optical communications standards being developed and outline some of the issues that must be addressed in the next few years. The paper will address in particular the ongoing work on application scenarios for deep space to ground called High Photon Efficiency, for LEO to ground called Low Complexity, for inter-satellite and near Earth to ground called High Data Rate, as well as associated atmospheric measurement techniques and link operations concepts.

Constructing and decoding unconventional ubiquitin chains.

PubMed

Behrends, Christian; Harper, J Wade

2011-05-01

One of the most notable discoveries in the ubiquitin system during the past decade is the extensive use of diverse chain linkages to control signaling networks. Although the utility of Lys48- and Lys63-linked chains in protein turnover and molecular assembly, respectively, are well known, we are only beginning to understand how unconventional chain linkages are formed on target proteins and how such linkages are decoded by specific binding proteins. In this review, we summarize recent efforts to elucidate the machinery and mechanisms controlling assembly of Lys11-linked and linear (or Met1-linked) ubiquitin chains, and describe current models for how these chain types function in immune signaling and cell-cycle control.

Adding HDLC Framing to CCSDS Recommendations

NASA Technical Reports Server (NTRS)

Hogie, Keith; Criscuolo, Ed; Parise, Ron

2004-01-01

Current Space IP missions use High-Level Data Link Control (HDLC) framing to provide standard serial link interfaces over a space link. HDLC is the standard framing technique used by all routers over clock and data serial lines and is also the basic framing used in all Frame Relay services which are widely deployed in national and international communication networks. In late 2003 a presentation was made to CCSDS committees to initiate discussion on including HDLC in the CCSDS recommendations for space systems. This presentation will summarize the differences between variable length HDLC frames and fixed length CCSDS frames. It will also discuss where and how HDLC framing would fit into the overall CCSDS structures.

Evolution of auroral acceleration region field-aligned current systems, plasma, and potentials observed by Cluster during substorms

NASA Astrophysics Data System (ADS)

Hull, A. J.; Chaston, C. C.; Fillingim, M. O.; Frey, H. U.; Goldstein, M. L.; Bonnell, J. W.; Mozer, F.

2015-12-01

The auroral acceleration region is an integral link in the chain of events that transpire during substorms, and the currents, plasma and electric fields undergo significant changes driven by complex dynamical processes deep in the magnetotail. The acceleration processes that occur therein accelerate and heat the plasma that ultimately leads to some of the most intense global substorm auroral displays. Though this region has garnered considerable attention, the temporal evolution of field-aligned current systems, associated acceleration processes, and resultant changes in the plasma constituents that occur during key stages of substorm development remain unclear. In this study we present a survey of Cluster traversals within and just above the auroral acceleration region (≤3 Re altitude) during substorms. Particular emphasis is on the spatial morphology and developmental sequence of auroral acceleration current systems, potentials and plasma constituents, with the aim of identifying controlling factors, and assessing auroral emmission consequences. Exploiting multi-point measurements from Cluster in combination with auroral imaging, we reveal the injection powered, Alfvenic nature of both the substorm onset and expansion of auroral particle acceleration. We show evidence that indicates substorm onsets are characterized by the gross-intensification and filamentation/striation of pre-existing large-scale current systems to smaller/dispersive scale Alfven waves. Such an evolutionary sequence has been suggested in theoretical models or single spacecraft data, but has not been demonstrated or characterized in multispacecraft observations until now. It is also shown how the Alfvenic variations over time may dissipate to form large-scale inverted-V structures characteristic of the quasi-static aurora. These findings suggest that, in addition to playing active roles in driving substorm aurora, inverted-V and Alfvenic acceleration processes are causally linked. Key elements of substorm current spatial structure and temporal development, relationship to electric fields/potentials, plasma moment and distribution features, causal linkages to auroral emission features, and other properties will be discussed.

Data Link Performance Analysis for LVLASO Experiments

NASA Technical Reports Server (NTRS)

Mukkamala, Ravi

1998-01-01

Low-visibility Landing and Surface Operations System (LVLASO) is currently being prototyped and tested at NASA Langley Research Center. Since the main objective of the system is to maintain the aircraft landings and take-offs even during low-visibility conditions, timely exchange of positional and other information between the aircraft and the ground control is critical. For safety and reliability reasons, there are several redundant sources on the ground (e.g., ASDE, AMASS) that collect and disseminate information about the environment to the aircrafts. The data link subsystem of LVLASO is responsible for supporting the timely transfer of information between the aircrafts and the ground controllers. In fact, if not properly designed, the data link subsystem could become a bottleneck in the proper functioning of LVLASO. Currently, the other components of the system are being designed assuming that the data link has adequate capacity and is capable of delivering the information in a timely manner. During August 1-28, 1997, several flight experiments were conducted to test the prototypes of subsystems developed under LVLASO project, The back-round and details of the tests are described in the next section. The test results have been collected in two CDs by FAA and Rockwell-Collins. Under the current grant, we have analyzed the data and evaluated the performance of the Mode S datalink. In this report, we summarize the results of our analysis. Much of the results are shown in terms of graphs or histograms. The test date (or experiment number) was often taken as the X-axis and the Y-axis denotes whatever metric of focus in that chart. In interpreting these charts, one need to take into account the vehicular traffic during a particular experiment. In general, the performance of the data link was found to be quite satisfactory in terms of delivering long and short Mode S squitters from the vehicles to the ground receiver, Similarly, its performance in delivering control messages from the ground control to the vehicles (aircrafts) was also satisfactory. The report is organized as follows. In Section 2, we describe the background information for the LVLASO and the system flight experiments. Section 3 contains formats of the performance data that was analyzed during our research. Section 4 describes different experiments flight experiments and their setup. Section 5 analyzes each of the graphs produced in this report. Finally, Section 6 has a summary of observations that we make based on our research.

An investigation of the role of current and future remote sensing data systems in numerical meteorology

NASA Technical Reports Server (NTRS)

Diak, George R.; Smith, William L.

1992-01-01

A flexible system for performing observing system simulation experiments which made contributions to meteorology across all elements of the observing system simulation experiment (OSSE) components was developed. Future work will seek better understanding of the links between satellite-measured radiation and radiative transfer in the clear, cloudy and precipitating atmosphere and investigate how that understanding might be applied to improve the depiction of the initial state and the treatment of physical processes in forecast models of the atmosphere.

Optical Phased Array Antennas using Coupled Vertical Cavity Surface Emitting Lasers

NASA Technical Reports Server (NTRS)

Mueller, Carl H.; Rojas, Roberto A.; Nessel, James A.; Miranda, Felix A.

2007-01-01

High data rate communication links are needed to meet the needs of NASA as well as other organizations to develop space-based optical communication systems. These systems must be robust to high radiation environments, reliable, and operate over a wide temperature range. Highly desirable features include beam steering capability, reconfigurability, low power consumption, and small aperture size. Optical communication links, using coupled vertical cavity surface emitting laser radiating elements are promising candidates for the transmit portion of these communication links. In this talk we describe a mission scenario, and how the antenna requirements are derived from the mission needs. We describe a potential architecture for this type of antenna, and outline the advantages and drawbacks of this approach relative to competing technologies. The technology we are proposing used coupled arrays of 1550 nm vertical cavity surface emitting lasers for transmission. The feasibility of coupling these arrays together, to form coherent high-power beams that can be modulated at data rates exceeding 1 Gbps, will be explored. We will propose an architecture that enables electronic beam steering, thus mitigating the need for ancillary acquisition, tracking and beam pointing equipment such as needed for current optical communicatin systems. The beam-steering capability we are proposing also opens the possibility of using this technology for inter-satellite communicatin links, and satellite-to-surface links.

Buddhism as a Support System for Southeast Asian Refugees.

ERIC Educational Resources Information Center

Canda, Edward R.; Phaobtong, Thitiya

1992-01-01

Used ethnographic participant-observation research methodology to determine human services available through three Buddhist mutual assistance associations for Southeast Asian refugees living in Midwest. Found that Buddhism was linked to both traditional lifestyle and current efforts to overcome effects of war and trauma. Identified physical,…

Testing the Carcinogenic Potential of Water Disinfectant Byproducts in a Human Colon Mucosal Culture System

EPA Science Inventory

Epidemiological studies have linked the consumption of disinfected surface waters to an increased risk of colorectal cancer. Approximately 600 disinfection byproducts (DBPs) have been identified for a number of disinfectants currently in use. An in-depth mechanism-based structure...

Recording emergency situations occurring in thermal power plant transformer station automatic control systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Senyagin, Yu.V.; Sop'yanik, V.Kh.; Oreshkin, Yu.A.

1982-11-01

Increasing the operational reliability of power generating equipment is linked to the storage and systematization of objective information pertaining to the causes and progress of emergencies occurring in the equipment. Current methods for receiving such information at thermal power plants are discussed.

Ten Years of Entrepreneurship Education at Chinese Universities: Evolution, Problems, and System Building

ERIC Educational Resources Information Center

Weiming, Li; Chunyan, Li; Xiaohua, Du

2016-01-01

Entrepreneurship education has experienced four stages of development in Chinese universities, shifting from entrepreneurship show to entrepreneurship education, from teacher training to student education, from classroom teaching to multimodal teaching, and from imparting knowledge to cultivating skills. Currently, the weak links in…

Software and Systems Producibility Collaboration and Experimentation Environment (SPRUCE)

DTIC Science & Technology

2014-04-01

represent course materials and assignments from Vanderbilt University’s Dr . Gokhale’s courses. 3.2.4. Communities of Interest Current list of...blogging platforms of Twitter, Facebook and LinkedIn today, these user interactions represent low-effort means for users to start getting involved. A

Modular, Cost-Effective, Extensible Avionics Architecture for Secure, Mobile Communications

NASA Technical Reports Server (NTRS)

Ivancic, William D.

2006-01-01

Current onboard communication architectures are based upon an all-in-one communications management unit. This unit and associated radio systems has regularly been designed as a one-off, proprietary system. As such, it lacks flexibility and cannot adapt easily to new technology, new communication protocols, and new communication links. This paper describes the current avionics communication architecture and provides a historical perspective of the evolution of this system. A new onboard architecture is proposed that allows full use of commercial-off-the-shelf technologies to be integrated in a modular approach thereby enabling a flexible, cost-effective and fully deployable design that can take advantage of ongoing advances in the computer, cryptography, and telecommunications industries.

Modular, Cost-Effective, Extensible Avionics Architecture for Secure, Mobile Communications

NASA Technical Reports Server (NTRS)

Ivancic, William D.

2007-01-01

Current onboard communication architectures are based upon an all-in-one communications management unit. This unit and associated radio systems has regularly been designed as a one-off, proprietary system. As such, it lacks flexibility and cannot adapt easily to new technology, new communication protocols, and new communication links. This paper describes the current avionics communication architecture and provides a historical perspective of the evolution of this system. A new onboard architecture is proposed that allows full use of commercial-off-the-shelf technologies to be integrated in a modular approach thereby enabling a flexible, cost-effective and fully deployable design that can take advantage of ongoing advances in the computer, cryptography, and telecommunications industries.

Genetic algorithm optimization of transcutaneous energy transmission systems for implantable ventricular assist devices.

PubMed

Byron, Kelly; Bluvshtein, Vlad; Lucke, Lori

2013-01-01

Transcutaneous energy transmission systems (TETS) wirelessly transmit power through the skin. TETS is particularly desirable for ventricular assist devices (VAD), which currently require cables through the skin to power the implanted pump. Optimizing the inductive link of the TET system is a multi-parameter problem. Most current techniques to optimize the design simplify the problem by combining parameters leading to sub-optimal solutions. In this paper we present an optimization method using a genetic algorithm to handle a larger set of parameters, which leads to a more optimal design. Using this approach, we were able to increase efficiency while also reducing power variability in a prototype, compared to a traditional manual design method.

Progress in American Superconductor's HTS wire and optimization for fault current limiting systems

NASA Astrophysics Data System (ADS)

Malozemoff, Alexis P.

2016-11-01

American Superconductor has developed composite coated conductor tape-shaped wires using high temperature superconductor (HTS) on a flexible substrate with laminated metal stabilizer. Such wires enable many applications, each requiring specific optimization. For example, coils for HTS rotating machinery require increased current density J at 25-50 K. A collaboration with Argonne, Brookhaven and Los Alamos National Laboratories and several universities has increased J using an optimized combination of precipitates and ion irradiation defects in the HTS. Major commercial opportunities also exist to enhance electric power grid resiliency by linking substations with distribution-voltage HTS power cables [10]. Such links provide alternative power sources if one substation's transmission-voltage power is compromised. But they must also limit fault currents which would otherwise be increased by such distribution-level links. This can be done in an HTS cable, exploiting the superconductor-to-resistive transition when current exceeds the wires' critical J. A key insight is that such transitions are usually nonuniform; so the wire must be designed to prevent localized hot spots from damaging the wire or even generating gas bubbles in the cable causing dielectric breakdown. Analysis shows that local heating can be minimized by increasing the composite tape's total thickness, decreasing its total resistance in the normal state and decreasing its critical J. This conflicts with other desirable wire characteristics. Optimization of these conflicting requirements is discussed.

A Single-Phase Current Source Solar Inverter with Constant Instantaneous Power, Improved Reliability, and Reduced-Size DC-Link Filter

NASA Astrophysics Data System (ADS)

Bush, Craig R.

This dissertation presents a novel current source converter topology that is primarily intended for single-phase photovoltaic (PV) applications. In comparison with the existing PV inverter technology, the salient features of the proposed topology are: a) the low frequency (double of line frequency) ripple that is common to single-phase inverters is greatly reduced; b) the absence of low frequency ripple enables significantly reduced size pass components to achieve necessary DC-link stiffness and c) improved maximum power point tracking (MPPT) performance is readily achieved due to the tightened current ripple even with reduced-size passive components. The proposed topology does not utilize any electrolytic capacitors. Instead an inductor is used as the DC-link filter and reliable AC film capacitors are utilized for the filter and auxiliary capacitor. The proposed topology has a life expectancy on par with PV panels. The proposed modulation technique can be used for any current source inverter where an unbalanced three-phase operation is desires such as active filters and power controllers. The proposed topology is ready for the next phase of microgrid and power system controllers in that it accepts reactive power commands. This work presents the proposed topology and its working principle supported by with numerical verifications and hardware results. Conclusions and future work are also presented.

Linearized Optically Phase-Modulated Fiber Optic Links for Microwave Signal Transport

DTIC Science & Technology

2009-03-03

detectors (with internal 50- Ohm resistors) capable of 40-mA dc current per detector. With this link, the linearized SFDR would improve to 133 dB/Hz4/5...the IF) limitation on the signal. All calculations consider the 3dB power loss from the hybrid combiner and 6dB loss from parallel 50- Ohm resistors...283. [25] M. Nazarathy, J. Berger, A. Ley , I. Levi, and Y. Kagan, “Externally Modulated 80 Channel Am Catv Fiber-to-feeder Distribution System Over

Data compression for full motion video transmission

NASA Technical Reports Server (NTRS)

Whyte, Wayne A., Jr.; Sayood, Khalid

1991-01-01

Clearly transmission of visual information will be a major, if not dominant, factor in determining the requirements for, and assessing the performance of the Space Exploration Initiative (SEI) communications systems. Projected image/video requirements which are currently anticipated for SEI mission scenarios are presented. Based on this information and projected link performance figures, the image/video data compression requirements which would allow link closure are identified. Finally several approaches which could satisfy some of the compression requirements are presented and possible future approaches which show promise for more substantial compression performance improvement are discussed.

An Information NEXUS: The NASA Global Hawk Link Module

NASA Technical Reports Server (NTRS)

Sullivan, D. V.

2012-01-01

The Link Module described in this paper was first developed for the NASA Global Hawk Pacific Mission (GloPAC), four flights of 30 hour duration, supporting the Aura Validation Experiment (AVE). Its second use was during the Genesis and Rapid Intensification Processes (GRIP) experiment, a NASA Earth Science field experiment to better understand how tropical storms form and develop into major hurricanes. In these missions, the Link module negotiated all communication over the high bandwidth Ku satellite link, archived al the science data from onboard experiments in a spatially enable database, routed command and control of the instruments from the Global Hawk Operations Center, and retransmitted select data sets directly to experimenters control and analysis systems. The availability of aggregated information from collections of sensors, and remote control capabilities, in real-time, is revolutionizing the way Airborne Science is being conducted. Also described is the next generation Link Module now being designed and tested to support the NASA Earth Venture missions, the Hurricane and Severe Storm Sentinel (HS3) mission, and Airborne Tropical Tropopause Experiment (ATTREX) mission. Advanced data fusion technologies being developed will further advance the Scientific productivity, flexibility and robustness of these systems. Historically, the Link module evolved from the instrument and communication interface controller used by NASA's Pathfinder and Pathfinder plus solar powered UAS's in the late 1990's. It later was expanded for use in the AIRDAS four channel scanner flown on the NASA Altus UAS, and then again to a module in the AMS twelve channel multispectral scanner flying on the NASA (Predator-b) Ikhana UAS. The current system is the next step in the evolution, a multi board system packaged in a Curtiss Wright MIL-spec, flight qualified enclosure.

A validation study of an alternate state science assessment: Alignment of the Pennsylvania Alternate System of Assessment (PASA) science assessment

NASA Astrophysics Data System (ADS)

Heh, Peter

The current study examined the validation and alignment of the PASA-Science by determining whether the alternate science assessment anchors linked to the regular education science anchors; whether the PASA-Science assessment items are science; whether the PASA-Science assessment items linked to the alternate science eligible content, and what PASA-Science assessment content was considered important by parents and teachers. Special education and science education university faculty determined all but one alternate science assessment anchor linked to the regular science assessment anchors. Special education and science education teachers determined that the PASA-Science assessment items are indeed science and linked to the alternate science eligible content. Finally, parents and teachers indicated the most important science content assessed in the PASA-Science involved safety and independence.

Air traffic management system design using satellite based geo-positioning and communications assets

NASA Technical Reports Server (NTRS)

Horkin, Phil

1995-01-01

The current FAA and ICAO FANS vision of Air Traffic Management will transition the functions of Communications, Navigation, and Surveillance to satellite based assets in the 21st century. Fundamental to widespread acceptance of this vision is a geo-positioning system that can provide worldwide access with best case differential GPS performance, but without the associated problems. A robust communications capability linking-up aircraft and towers to meet the voice and data requirements is also essential. The current GPS constellation does not provide continuous global coverage with a sufficient number of satellites to meet the precision landing requirements as set by the world community. Periodic loss of the minimum number of satellites in view creates an integrity problem, which prevents GPS from becoming the primary system for navigation. Furthermore, there is reluctance on the part of many countries to depend on assets like GPS and GLONASS which are controlled by military communities. This paper addresses these concerns and provides a system solving the key issues associated with navigation, automatic dependent surveillance, and flexible communications. It contains an independent GPS-like navigation system with 27 satellites providing global coverage with a minimum of six in view at all times. Robust communications is provided by a network of TDMA/FDMA communications payloads contained on these satellites. This network can support simultaneous communications for up to 30,000 links, nearly enough to simultaneously support three times the current global fleet of jumbo air passenger aircraft. All of the required hardware is directly traceable to existing designs.

NASA 60 GHz intersatellite communication link definition study. Baseline document

NASA Technical Reports Server (NTRS)

1986-01-01

The overall system and component concepts for a 60 GHz intersatellite communications link system (ICLS) are described. The ICLS was designed to augment the capabilities of the current Tracking and Data Relay Satellite System (TDRSS), providing a data rate capacity large enough to accommodate the expected rates for user satellites (USAT's) in the post-1995 timeframe. The use of 60 GHz for the anticipated successor to TDRSS, the Tracking and Data Acquisition System (TDAS), was selected because of current technology development that will enable multigigibit data rates. Additionally, the attenuation of the earth's atmosphere at 60 GHz means that there is virtually no possibility of terrestrially generated interference (intentional or accidental) or terrestrially based intercept. The ICLS includes the following functional areas: (1) the ICLS payload package on the GEO TDAS satellite that communicates simultaneously with up to five LEO USAT's; (2) the payload package on the USAT that communicates with the TDAS satellite; and (3) the crosslink payload package on the TDAS satellite that communicates with another TDAS satellite. Two methods of data relay on-board the TDAS spacecraft were addressed. One is a complete baseband system (demod and remod) with a bi-directional 2 Gbps data stream; the other is a channelized system wherein some of the channels are baseband and others are merely frequency translated before re-transmission. Descriptions of the TDAS antenna, transmitter, receiver, and mechanical designs are presented.

Growth of the shallow Mekong clinoform and the impact of seasonal variability in fluvial and shelf processes

NASA Astrophysics Data System (ADS)

Eidam, E.; Nittrouer, C.; Ogston, A. S.; Liu, P.; DeMaster, D. J.; Nguyen, T. T.

2016-02-01

Like many large rivers, the Mekong River has built a compound delta (with subaqueous and subaerial segments) during Holocene sea-level transgression. Unlike many other deltas, the subaqueous part of the Mekong Delta (the clinoform) builds into shallow water in an epicontinental sea. The shallow depths of the Mekong clinoform (rollover at 5 m) may provide additional controls on sediment convergence and deposition through wave and current effects. Knowledge of the shelf dynamics is a key to understanding the total evolution of the Mekong, given that subaqueous and subaerial deltaic growth/erosion are intimately linked. To understand sediment transfer patterns and hydrodynamic controls better, we deployed boundary-layer sensor systems and collected kasten cores offshore of the southernmost Mekong distributary in Sep 2014 and Mar 2015 (high and low river discharge/low and high wave climate, respectively). Sediment accumulates rapidly on the foreset at rates of cm/yr, and sediment fines downslope until merging with relict transgressive sands on the bottomset - as expected for a clinoform system. However, tidal currents are competent to transport silt at all depths on the foreset, and added wave energy during seasonal monsoons creates the capacity to mobilize sand at most (or all) depths on the foreset. During high-flow periods, intense sediment delivery and dominantly shore-perpendicular currents likely drive cross-shelf sediment transfer. During low-flow periods, shoreward- and southwestward-dominant currents compress the sediment-dispersal system against the coast, maintaining a shallow topset while elongating the feature southwestward. These results suggest that for the Mekong, clinoform growth is linked to seasonal changes in shelf currents and in river discharge.

A Missing Link? Contemporary Insights into Principal Preparation and Training in Russia

ERIC Educational Resources Information Center

Bysik, Nadezhda; Evstigneeva, Nadezhda; Isaeva, Natalia; Kukso, Katsiaryna; Harris, Alma; Jones, Michelle

2015-01-01

Over the last decade, the Russian education system has undergone significant transformation that has radically changed the expectations placed upon the school principals. This current reform process has placed far greater responsibilities and accountabilities upon principals to secure school effectiveness and improved student learning outcomes.…

Measuring nitrification inhibition by metals in wastewater treatment systems: Current state of science and fundamental research needs

EPA Science Inventory

Wastewater treatment is an important step within the water continuum as it reduces the risks associated with microorganisms as well as organic and inorganic compounds. From a chemical standpoint, treatment effectiveness is linked to carbon and nitrogen removal, although phosphate...

Creating Educational Opportunities for Engineers with Communication Technologies.

ERIC Educational Resources Information Center

Baldwin, Lionel V.

The large number and known career patterns of engineers make them an important target population for the use of videotechnology in programs of continuing professional education. Currently, universities use videobased instruction with engineering students on and off campus. A variety of signal delivery systems are used to link job sites to…

Design of the Digital Satellite Link Interface for a System That Detects the Precursory Electromagnetic Emissions Associated with Earthquakes

DTIC Science & Technology

1986-12-01

earthquake that is likely to occur in a given louality [Ref. 8:p. 1082]. The accumulation law of seismotectonic movement relates the amount of...mechanism - fault creep anomaly - seismic wave velocity - geomagnetic field - telluric (earth) currents - electromagnetic emissions - resistivity of

Embedded C Programming: A Practical Course Introducing Programmable Microprocessors

ERIC Educational Resources Information Center

Laverty, David M.; Milliken, Jonny; Milford, Matthew; Cregan, Michael

2012-01-01

This paper presents a new laboratory-based module for embedded systems teaching, which addresses the current lack of consideration for the link between hardware development, software implementation, course content and student evaluation in a laboratory environment. The course introduces second year undergraduate students to the interface between…

Library and Information Networks: Centralization and Decentralization.

ERIC Educational Resources Information Center

Segal, JoAnn S.

1988-01-01

Describes the development of centralized library networks and the current factors that make library sharing on a smaller scale feasible. The discussion covers the need to decide the level at which library cooperation should occur and the possibility of linking via the Open System Interface Reference Model. (37 references) (CLB)

Publication, discovery and interoperability of Clinical Decision Support Systems: A Linked Data approach.

PubMed

Marco-Ruiz, Luis; Pedrinaci, Carlos; Maldonado, J A; Panziera, Luca; Chen, Rong; Bellika, J Gustav

2016-08-01

The high costs involved in the development of Clinical Decision Support Systems (CDSS) make it necessary to share their functionality across different systems and organizations. Service Oriented Architectures (SOA) have been proposed to allow reusing CDSS by encapsulating them in a Web service. However, strong barriers in sharing CDS functionality are still present as a consequence of lack of expressiveness of services' interfaces. Linked Services are the evolution of the Semantic Web Services paradigm to process Linked Data. They aim to provide semantic descriptions over SOA implementations to overcome the limitations derived from the syntactic nature of Web services technologies. To facilitate the publication, discovery and interoperability of CDS services by evolving them into Linked Services that expose their interfaces as Linked Data. We developed methods and models to enhance CDS SOA as Linked Services that define a rich semantic layer based on machine interpretable ontologies that powers their interoperability and reuse. These ontologies provided unambiguous descriptions of CDS services properties to expose them to the Web of Data. We developed models compliant with Linked Data principles to create a semantic representation of the components that compose CDS services. To evaluate our approach we implemented a set of CDS Linked Services using a Web service definition ontology. The definitions of Web services were linked to the models developed in order to attach unambiguous semantics to the service components. All models were bound to SNOMED-CT and public ontologies (e.g. Dublin Core) in order to count on a lingua franca to explore them. Discovery and analysis of CDS services based on machine interpretable models was performed reasoning over the ontologies built. Linked Services can be used effectively to expose CDS services to the Web of Data by building on current CDS standards. This allows building shared Linked Knowledge Bases to provide machine interpretable semantics to the CDS service description alleviating the challenges on interoperability and reuse. Linked Services allow for building 'digital libraries' of distributed CDS services that can be hosted and maintained in different organizations. Copyright © 2016 Elsevier Inc. All rights reserved.

Proceedings Papers of the AFSC (Air Force Systems Command) Avionics Standardization Conference (2nd) Held at Dayton, Ohio on 30 November-2 December 1982. Volume 1.

DTIC Science & Technology

1982-11-01

Avionic Systems Integration Facilities, Mark van den Broek 1113 and Paul M. Vicen, AFLC/LOE Planning of Operational Software Implementation Tool...classified as software tools, including: * o" Operating System " Language Processors (compilers, assem’blers, link editors) o Source Editors " Debug Systems ...o Data Base Systems o Utilities o Etc . This talk addresses itself to the current set of tools provided JOVIAL iJ73 1750A application programmners by

FNDC5/irisin, a molecular target for boosting reward-related learning and motivation.

PubMed

Zsuga, Judit; Tajti, Gabor; Papp, Csaba; Juhasz, Bela; Gesztelyi, Rudolf

2016-05-01

Interventions focusing on the prevention and treatment of chronic non-communicable diseases are on rise. In the current article, we propose that dysfunction of the mesocortico-limbic reward system contributes to the emergence of the WHO-identified risk behaviors (tobacco use, unhealthy diet, physical inactivity and harmful use of alcohol), behaviors that underlie the evolution of major non-communicable diseases (e.g. cardiovascular diseases, cancer, diabetes and chronic respiratory diseases). Given that dopaminergic neurons of the mesocortico-limbic system are tightly associated with reward-related processes and motivation, their dysfunction may fundamentally influence behavior. While nicotine and alcohol alter dopamine neuron function by influencing some receptors, mesocortico-limbic system dysfunction was associated with elevation of metabolic set-point leading to hedonic over-eating. Although there is some empirical evidence, precise molecular mechanism for linking physical inactivity and mesocortico-limbic dysfunction per se seems to be missing; identification of which may contribute to higher success rates for interventions targeting lifestyle changes pertaining to physical activity. In the current article, we compile evidence in support of a link between exercise and the mesocortico-limbic system by elucidating interactions on the axis of muscle - irisin - brain derived neurotrophic factor (BDNF) - and dopaminergic function of the midbrain. Irisin is a contraction-regulated myokine formed primarily in skeletal muscle but also in the brain. Irisin stirred considerable interest, when its ability to induce browning of white adipose tissue parallel to increasing thermogenesis was discovered. Furthermore, it may also play a role in the regulation of behavior given it readily enters the central nervous system, where it induces BDNF expression in several brain areas linked to reward processing, e.g. the ventral tegmental area and the hippocampus. BDNF is a neurotropic factor that increases neuronal dopamine content, modulates dopamine release relevant for neuronal plasticity and increased neuronal survival as well as learning and memory. Further linking BDNF to dopaminergic function is BDNF's ability to activate tropomyosin-related kinase B receptor that shares signalization with presynaptic dopamine-3 receptors in the ventral tegmental area. Summarizing, we propose that the skeletal muscle derived irisin may be the link between physical activity and reward-related processes and motivation. Moreover alteration of this axis may contribute to sedentary lifestyle and subsequent non-communicable diseases. Preclinical and clinical experimental models to test this hypothesis are also proposed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Utilizing the ISS Mission as a Testbed to Develop Cognitive Communications Systems

NASA Technical Reports Server (NTRS)

Jackson, Dan

2016-01-01

The ISS provides an excellent opportunity for pioneering artificial intelligence software to meet the challenges of real-time communications (comm) link management. This opportunity empowers the ISS Program to forge a testbed for developing cognitive communications systems for the benefit of the ISS mission, manned Low Earth Orbit (LEO) science programs and future planetary exploration programs. In November, 1998, the Flight Operations Directorate (FOD) started the ISS Antenna Manager (IAM) project to develop a single processor supporting multiple comm satellite tracking for two different antenna systems. Further, the processor was developed to be highly adaptable as it supported the ISS mission through all assembly stages. The ISS mission mandated communications specialists with complete knowledge of when the ISS was about to lose or gain comm link service. The current specialty mandated cognizance of large sun-tracking solar arrays and thermal management panels in addition to the highly-dynamic satellite service schedules and rise/set tables. This mission requirement makes the ISS the ideal communications management analogue for future LEO space station and long-duration planetary exploration missions. Future missions, with their precision-pointed, dynamic, laser-based comm links, require complete autonomy for managing high-data rate communications systems. Development of cognitive communications management systems that permit any crew member or payload science specialist, regardless of experience level, to control communications is one of the greater benefits the ISS can offer new space exploration programs. The IAM project met a new mission requirement never previously levied against US space-born communications systems management: process and display the orientation of large solar arrays and thermal control panels based on real-time joint angle telemetry. However, IAM leaves the actual communications availability assessment to human judgement, which introduces unwanted variability because each specialist has a different core of experience with comm link performance. Because the ISS utilizes two different frequency bands, dynamic structure can be occasionally translucent at one frequency while it can completely interdict service at the other frequency. The impact of articulating structure on the comm link can depend on its orientation at the time it impinges on the link. It can become easy for a human specialist to cross-associate experience at one frequency with experience at the other frequency. Additionally, the specialist's experience is incremental, occurring one nine-hour shift at a time. Only the IAM processor experiences the complete 24x7x365 communications link performance for both communications links but, it has no "learning capability." If the IAM processor could be endowed with a cognitive ability to remember past structure-induced comm link outages, based on its knowledge of the ISS position, attitude, communications gear, array joint angles and tracking accuracy, it could convey such experience to the human operator. It could also use its learned communications link behaviors to accurately convey the availability of future communications sessions. Further, the tool could remember how accurately or inaccurately it predicted availability and correct future predictions based on past performance. The IAM tool could learn frequency-specific impacts due to spacecraft structures and pass that information along as "experience." Such development would provide a single artificial intelligence processor that could provide two different experience bases. If it also "knew" the satellite service schedule, it could distinguish structure blockage from schedule or planet blockage and then quickly switch to another satellite. Alternatively, just as a human operator could judge, a cognizant comm system based on the IAM model could "know" that the blockage is not going to last very long and continue tracking a comm satellite, waiting for it to track away from structure. Ultimately, once this capability was fully developed and tested in the Mission Control Center, it could be transferred on-orbit to support development of operations concepts that include more advanced cognitive communications systems. Future applications of this capability are easily foreseen because even more dynamic satellite constellations with more nodes and greater capability are coming. Currently, the ISS fully employs its high-data-rate return link for harvesting payload science. In the coming months, it will double that data rate and is forecast to fully utilize that capability. Already there is talk of an upgrade that quadruples the current data rate allocated to ISS payload science before the end of its mission and laser comm links have already been tested from the ISS. Every data rate upgrade mandates more complicated and sensitive communications equipment which implies greater expertise invested in the human operator. Future on-orbit cognizant comm systems will be needed to meet greater performance demands aboard larger, far more complicated spacecraft. In the LEO environment, the old-style one-satellite-per-spacecraft operations concept will give way to a new concept of a single customer spacecraft simultaneously using multiple comm satellites. Much more highly-dynamic manned LEO missions with decades of crew members potentially increase the demand for communications link performance. A cognizant on-board communications system will meet advanced communications demands from future LEO missions and future planetary missions. The ISS has fledgling components of future exploration programs, both LEO and planetary. Further, the Flight Operations Directorate, through the IAM project, has already begun to develop a communications management system that attempts to solve advanced problems ideally represented by dynamic structure impacting scheduled satellite service. With an earnest project to integrate artificial intelligence into the IAM processor, the ISS Program could develop a cognizant communications system that could be adapted and transferred to future on-orbit avionics designs.

Common neighbours and the local-community-paradigm for topological link prediction in bipartite networks

NASA Astrophysics Data System (ADS)

Daminelli, Simone; Thomas, Josephine Maria; Durán, Claudio; Vittorio Cannistraci, Carlo

2015-11-01

Bipartite networks are powerful descriptions of complex systems characterized by two different classes of nodes and connections allowed only across but not within the two classes. Unveiling physical principles, building theories and suggesting physical models to predict bipartite links such as product-consumer connections in recommendation systems or drug-target interactions in molecular networks can provide priceless information to improve e-commerce or to accelerate pharmaceutical research. The prediction of nonobserved connections starting from those already present in the topology of a network is known as the link-prediction problem. It represents an important subject both in many-body interaction theory in physics and in new algorithms for applied tools in computer science. The rationale is that the existing connectivity structure of a network can suggest where new connections can appear with higher likelihood in an evolving network, or where nonobserved connections are missing in a partially known network. Surprisingly, current complex network theory presents a theoretical bottle-neck: a general framework for local-based link prediction directly in the bipartite domain is missing. Here, we overcome this theoretical obstacle and present a formal definition of common neighbour index and local-community-paradigm (LCP) for bipartite networks. As a consequence, we are able to introduce the first node-neighbourhood-based and LCP-based models for topological link prediction that utilize the bipartite domain. We performed link prediction evaluations in several networks of different size and of disparate origin, including technological, social and biological systems. Our models significantly improve topological prediction in many bipartite networks because they exploit local physical driving-forces that participate in the formation and organization of many real-world bipartite networks. Furthermore, we present a local-based formalism that allows to intuitively implement neighbourhood-based link prediction entirely in the bipartite domain.

COPD and stroke: are systemic inflammation and oxidative stress the missing links?

PubMed

Austin, Victoria; Crack, Peter J; Bozinovski, Steven; Miller, Alyson A; Vlahos, Ross

2016-07-01

Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation and loss of lung function, and is currently the third largest cause of death in the world. It is now well established that cardiovascular-related comorbidities such as stroke contribute to morbidity and mortality in COPD. The mechanisms linking COPD and stroke remain to be fully defined but are likely to be interconnected. The association between COPD and stroke may be largely dependent on shared risk factors such as aging and smoking, or the association of COPD with traditional stroke risk factors. In addition, we propose that COPD-related systemic inflammation and oxidative stress may play important roles by promoting cerebral vascular dysfunction and platelet hyperactivity. In this review, we briefly discuss the pathogenesis of COPD, acute exacerbations of COPD (AECOPD) and cardiovascular comorbidities associated with COPD, in particular stroke. We also highlight and discuss the potential mechanisms underpinning the link between COPD and stroke, with a particular focus on the roles of systemic inflammation and oxidative stress. © 2016 The Author(s).

Evaluation of Mixed-Mode Data-Link Communications for NextGen 4DT and Equivalent Visual Surface Operations

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III; Shelton, Kevin J.; Jones, Denise R.; Allamandola, Angela S.; Arthur, Jarvis, J., III; Bailey, Randall E.

2010-01-01

By 2025, U.S. air traffic is predicted to increase 3-fold and may strain the current air traffic management system, which may not be able to accommodate this growth. In response to this challenge, a revolutionary new concept has been proposed for U.S. aviation operations, termed the Next Generation Air Transportation System or NextGen. Many key capabilities are being identified to enable NextGen, including the use of data-link communications. Because NextGen represents a radically different approach to air traffic management and requires a dramatic shift in the tasks, roles, and responsibilities for the flight deck, there are numerous research issues and challenges that must be overcome to ensure a safe, sustainable air transportation system. Flight deck display and crew-vehicle interaction concepts are being developed that proactively investigate and overcome potential technology and safety barriers that might otherwise constrain the full realization of NextGen. The paper describes simulation research examining data-link communications during 4DT and equivalent visual surface operations.

Remote Neural Pendants In A Welding-Control System

NASA Technical Reports Server (NTRS)

Venable, Richard A.; Bucher, Joseph H.

1995-01-01

Neural network integrated circuits enhance functionalities of both remote terminals (called "pendants") and communication links, without necessitating installation of additional wires in links. Makes possible to incorporate many features into pendant, including real-time display of critical welding parameters and other process information, capability for communication between technician at pendant and host computer or technician elsewhere in system, and switches and potentiometers through which technician at pendant exerts remote control over such critical aspects of welding process as current, voltage, rate of travel, flow of gas, starting, and stopping. Other potential manufacturing applications include control of spray coating and of curing of composite materials. Potential nonmanufacturing uses include remote control of heating, air conditioning, and lighting in electrically noisy and otherwise hostile environments.

Development of simulation techniques suitable for the analysis of air traffic control situations and instrumentation

NASA Technical Reports Server (NTRS)

1972-01-01

A terminal area simulation is described which permits analysis and synthesis of current and advanced air traffic management system configurations including ground and airborne instrumentation and new and modified aircraft characteristics. Ground elements in the simulation include navigation aids, surveillance radars, communication links, air-route structuring, ATC procedures, airport geometries and runway handling constraints. Airborne elements include traffic samples with individual aircraft performance and operating characteristics and aircraft navigation equipment. The simulation also contains algorithms for conflict detection, conflict resolution, sequencing and pilot-controller data links. The simulation model is used to determine the sensitivities of terminal area traffic flow, safety and congestion to aircraft performance characteristics, avionics systems, and other ATC elements.

Intrahemispheric white matter asymmetries: the missing link between brain structure and functional lateralization?

PubMed

Ocklenburg, Sebastian; Friedrich, Patrick; Güntürkün, Onur; Genç, Erhan

2016-07-01

Hemispheric asymmetries are a central principle of nervous system architecture and shape the functional organization of most cognitive systems. Structural gray matter asymmetries and callosal interactions have been identified as contributing neural factors but always fell short to constitute a full explanans. Meanwhile, recent advances in in vivo white matter tractography have unrevealed the asymmetrical organization of many intrahemispheric white matter pathways, which might serve as the missing link to explain the substrate of functional lateralization. By taking into account callosal interactions, gray matter asymmetries and asymmetrical interhemispheric pathways, we opt for a new triadic model that has the potential to explain many observations which cannot be elucidated within the current frameworks of lateralized cognition.

A comparison of superconductor and manganin technology for electronic links used in space mission applications

NASA Technical Reports Server (NTRS)

Caton, R.; Selim, R.; Buoncristiani, A. M.

1992-01-01

The electronic link connecting cryogenically cooled radiation detectors to data acquisition and signal processing electronics at higher temperatures contributes significantly to the total heat load on spacecraft cooling systems that use combined mechanical and cryogenic liquid cooling. Using high transition temperature superconductors for this link has been proposed to increase the lifetime of space missions. Herein, several YBCO (YBa2Cu3O7) superconductor-substrate combinations were examined and total heat loads were compared to manganin wire technology in current use. Using numerical solutions to the heat-flow equations, it is shown that replacing manganin technology with YBCO thick film technology can extend a 7-year mission by up to 1 year.

Biomine: predicting links between biological entities using network models of heterogeneous databases.

PubMed

Eronen, Lauri; Toivonen, Hannu

2012-06-06

Biological databases contain large amounts of data concerning the functions and associations of genes and proteins. Integration of data from several such databases into a single repository can aid the discovery of previously unknown connections spanning multiple types of relationships and databases. Biomine is a system that integrates cross-references from several biological databases into a graph model with multiple types of edges, such as protein interactions, gene-disease associations and gene ontology annotations. Edges are weighted based on their type, reliability, and informativeness. We present Biomine and evaluate its performance in link prediction, where the goal is to predict pairs of nodes that will be connected in the future, based on current data. In particular, we formulate protein interaction prediction and disease gene prioritization tasks as instances of link prediction. The predictions are based on a proximity measure computed on the integrated graph. We consider and experiment with several such measures, and perform a parameter optimization procedure where different edge types are weighted to optimize link prediction accuracy. We also propose a novel method for disease-gene prioritization, defined as finding a subset of candidate genes that cluster together in the graph. We experimentally evaluate Biomine by predicting future annotations in the source databases and prioritizing lists of putative disease genes. The experimental results show that Biomine has strong potential for predicting links when a set of selected candidate links is available. The predictions obtained using the entire Biomine dataset are shown to clearly outperform ones obtained using any single source of data alone, when different types of links are suitably weighted. In the gene prioritization task, an established reference set of disease-associated genes is useful, but the results show that under favorable conditions, Biomine can also perform well when no such information is available.The Biomine system is a proof of concept. Its current version contains 1.1 million entities and 8.1 million relations between them, with focus on human genetics. Some of its functionalities are available in a public query interface at http://biomine.cs.helsinki.fi, allowing searching for and visualizing connections between given biological entities.

Stability, performance and sensitivity analysis of I.I.D. jump linear systems

NASA Astrophysics Data System (ADS)

Chávez Fuentes, Jorge R.; González, Oscar R.; Gray, W. Steven

2018-06-01

This paper presents a symmetric Kronecker product analysis of independent and identically distributed jump linear systems to develop new, lower dimensional equations for the stability and performance analysis of this type of systems than what is currently available. In addition, new closed form expressions characterising multi-parameter relative sensitivity functions for performance metrics are introduced. The analysis technique is illustrated with a distributed fault-tolerant flight control example where the communication links are allowed to fail randomly.

Sensorless Sinusoidal Drives for Fan and Pump Motors by V/f Control

NASA Astrophysics Data System (ADS)

Kiuchi, Mitsuyuki; Ohnishi, Tokuo

This paper proposes sensorless sinusoidal driving methods of permanent magnet synchronous motors for fans and pumps by V/f control. The proposed methods are simple methods that control the motor peak current constant by voltage or frequency control, and are characterized by DC link current detection using a single shunt resistor at carrier wave signal bottom timing. As a result of the dumping factor from square torque load characteristics of fan and pump motors, it is possible to control stable starting and stable steady state by V/f control. In general, pressure losses as a result of the fluid pass of fan and pump systems are nearly constant; therefore, the flow rate and motor torque are determined by revolutions. Accordingly, high efficiency driving is possible by setting corresponding currents to q-axis currents (torque currents) at target revolutions. Because of the simple current detection and motor control methods, the proposed methods are optimum for fan and pump motor driving systems of home appliances.

Radio Science from an Optical Communications Signal

NASA Technical Reports Server (NTRS)

Moision, Bruce; Asmar, Sami; Oudrhiri, Kamal

2013-01-01

NASA is currently developing the capability to deploy deep space optical communications links. This creates the opportunity to utilize the optical link to obtain range, doppler, and signal intensity estimates. These may, in turn, be used to complement or extend the capabilities of current radio science. In this paper we illustrate the achievable precision in estimating range, doppler, and received signal intensity of an non-coherent optical link (the current state-of-the-art for a deep-space link). We provide a joint estimation algorithm with performance close to the bound. We draw comparisons to estimates based on a coherent radio frequency signal, illustrating that large gains in either precision or observation time are possible with an optical link.

Practical application of thermoreversibly Cross-linked rubber products

NASA Astrophysics Data System (ADS)

Polgar, L. M.; Picchioni, F.; de Ruiter, E.; van Duin, M.

2017-07-01

Currently, rubber products cannot simply be reprocessed after their product life, due to the irreversible cross-linking methods traditionally applied. The purpose of this work is to investigate how thermoreversible cross-linking of rubbers via Diels Alder chemistry can be used for the development of recyclable rubber products. Unfortunately, the applicability of the thermoreversible EPM-g-furan/BM system appears to be limited to room temperature applications, because of the rapid deterioration of the compression set at elevated temperatures compared to irreversibly cross-linked EPM. However, the use of EPM rubber modified with thiophene or cyclopentadiene moieties may extend the temperature application range and results in rubber products with acceptable properties. Finally, rubber products generally comprise fillers such as silica, carbon black or fibers. In this context, the reinforcing effect of short cut aramid fibers on the material properties of the newly developed thermoreversibly cross-linked EPM rubbers was also studied. The material properties of the resulting products were found to be comparable to those of a fiber reinforced, peroxide cured reference sample.

An imaging system based on laser optical feedback for fog vision applications

NASA Astrophysics Data System (ADS)

Belin, E.; Boucher, V.

2008-08-01

The Laboratoire Régional des Ponts et Chaussées d'Angers - LRPC of Angers is currently studying the feasability of applying an optical technique based on the principle of the laser optical feedback to long distance fog vision. Optical feedback set up allows the creation of images on roadsigns. To create artificial fog conditions we used a vibrating cell that produces a micro-spray of water according to the principle of acoustic cavitation. To scale the sensitivity of the system under duplicatible conditions we also used optical densities linked to first-sight visibility distances. The current system produces, in a few seconds, 200 × 200 pixel images of a roadsign seen through dense artificial fog.

Defining the ATC Controller Interface for Data Link Clearances

NASA Technical Reports Server (NTRS)

Rankin, James

1998-01-01

The Controller Interface (CI) is the primary method for Air Traffic Controllers to communicate with aircraft via Controller-Pilot Data Link Communications (CPDLC). The controller, wearing a microphone/headset, aurally gives instructions to aircraft as he/she would with today's voice radio systems. The CI's voice recognition system converts the instructions to digitized messages that are formatted according to the RTCA DO-219 Operational Performance Standards for ATC Two-Way Data Link Communications. The DO-219 messages are transferred via RS-232 to the ATIDS system for uplink using a Mode-S datalink. Pilot acknowledgments of controller messages are downlinked to the ATIDS system and transferred to the Cl. A computer monitor is used to convey information to the controller. Aircraft data from the ARTS database are displayed on flight strips. The flight strips are electronic versions of the strips currently used in the ATC system. Outgoing controller messages cause the respective strip to change color to indicate an unacknowledged transmission. The message text is shown on the flight strips for reference. When the pilot acknowledges the message, the strip returns to its normal color. A map of the airport can also be displayed on the monitor. In addition to voice recognition, the controller can enter messages using the monitor's touch screen or by mouse/keyboard.

Optical data communication for Earth observation satellite systems

NASA Astrophysics Data System (ADS)

Fischer, J.; Loecherbach, E.

1991-10-01

The current development status of optical communication engineering in comparison to the conventional microwave systems and the different configurations of the optical data communication for Earth observation satellite systems are described. An outlook to future optical communication satellite systems is given. During the last decade Earth observation became more and more important for the extension of the knowledge about our planet and the human influence on nature. Today pictures taken by satellites are used, for example, to discover mineral resources or to predict harvest, crops, climate, and environment variations and their influence on the population. A new and up to date application for Earth observation satellites can be the verification of disarmament arrangements and the control of crises areas. To solve these tasks a system of Earth observing satellites with sensors tailored to the envisaged mission is necessary. Besides these low Earth orbiting satellites, a global Earth observation system consists of at least two data relay satellites. The communication between the satellites will be established via Inter-Satellite Links (ISL) and Inter-Orbit Links (IOL). On these links, bitrates up to 1 Gbit/s must be taken into account. Due to the increasing scarcity of suitable frequencies, higher carrier frequencies must probably be considered, and possible interference with terrestrial radio relay systems are two main problems for a realization in microwave technique. One important step to tackle these problems is the use of optical frequencies for IOL's and ISL's.

MiniX-STR multiplex system population study in Japan and application to degraded DNA analysis.

PubMed

Asamura, H; Sakai, H; Kobayashi, K; Ota, M; Fukushima, H

2006-05-01

We sought to evaluate a more effective system for analyzing X-chromosomal short tandem repeats (X-STRs) in highly degraded DNA. To generate smaller amplicon lengths, we designed new polymerase chain reaction (PCR) primers for DXS7423, DXS6789, DXS101, GATA31E08, DXS8378, DXS7133, DXS7424, and GATA165B12 at X-linked short tandem repeat (STR) loci, devising two miniX-multiplex PCR systems. Among 333 Japanese individuals, these X-linked loci were detected in amplification products ranging in length from 76 to 169 bp, and statistical analyses of the eight loci indicated a high usefulness for the Japanese forensic practice. Results of tests on highly degraded DNA indicated the miniX-STR multiplex strategies to be an effective system for analyzing degraded DNA. We conclude that analysis by the current miniX-STR multiplex systems offers high effectiveness for personal identification from degraded DNA samples.

Design of video interface conversion system based on FPGA

NASA Astrophysics Data System (ADS)

Zhao, Heng; Wang, Xiang-jun

2014-11-01

This paper presents a FPGA based video interface conversion system that enables the inter-conversion between digital and analog video. Cyclone IV series EP4CE22F17C chip from Altera Corporation is used as the main video processing chip, and single-chip is used as the information interaction control unit between FPGA and PC. The system is able to encode/decode messages from the PC. Technologies including video decoding/encoding circuits, bus communication protocol, data stream de-interleaving and de-interlacing, color space conversion and the Camera Link timing generator module of FPGA are introduced. The system converts Composite Video Broadcast Signal (CVBS) from the CCD camera into Low Voltage Differential Signaling (LVDS), which will be collected by the video processing unit with Camera Link interface. The processed video signals will then be inputted to system output board and displayed on the monitor.The current experiment shows that it can achieve high-quality video conversion with minimum board size.

Tree species effects on topsoil properties in an old tropical plantation

NASA Astrophysics Data System (ADS)

Bauters, Marijn; Boeckx, Pascal; Ampoorter, Evy; Verbeeck, Hans; Döetterl, Sebastian; Baert, Geert; Verheyen, Kris

2016-04-01

Forest biogeochemistry is strongly linked to the functional strategies of the tree community and the topsoil. Research has long documented that tree species affect soil properties in forests. Our current understanding on this interaction is mainly based on common garden experiments in temperate forest and needs to be extended to other ecosystems if we want to understand this interaction in natural forests worldwide. Using a 77-year-old tropical experimental plantation from central Africa, we examined the relationship between canopy and litter chemical traits and topsoil properties. By the current diversity in this site, the unique setup allowed us to extend the current knowledge from temperate and simplified systems to near-natural tropical forests, and thus bridge the gap between planted monocultures in common gardens, and correlative studies in natural systems. We linked the species-specific leaf and litter chemical traits to the topsoil cation composition, acidity, pH and soil organic matter. We found that average canopy trait values were a better predictor for the topsoil than the litter chemistry. Canopy base cation content positively affected topsoil pH and negatively affected acidity. These, in turn strongly determined the soil organic carbon contents of the topsoil, which ranged a tree-fold in the experiment.

Vocational Education at the Crossroads. The Case of Taiwan.

ERIC Educational Resources Information Center

Chen, Gerald C.; Shih, Mingfa

Programs and curricula in vocational education in Taiwan have traditionally been linked to the nation's priority of economic development. The current vocational education system originated in the 1950s. In the 1970s, public free education was extended from 6 years of elementary school education to include an additional 3 years of junior high…

Staffing for Success: Linking Teacher Evaluation and School Personnel Management in Practice

ERIC Educational Resources Information Center

Master, Benjamin

2014-01-01

Teacher evaluation is at the center of current education policy reform. Most evaluation systems rely at least in part on principals' assessments of teachers, and their discretionary judgments carry substantial weight. However, we know relatively little about what they value when determining evaluations and high stakes personnel decisions.…

A Multilevel Latent Growth Curve Approach to Predicting Student Proficiency

ERIC Educational Resources Information Center

Choi, Kilchan; Goldschmidt, Pete

2012-01-01

Value-added models and growth-based accountability aim to evaluate school's performance based on student growth in learning. The current focus is on linking the results from value-added models to the ones from growth-based accountability systems including Adequate Yearly Progress decisions mandated by No Child Left Behind. We present a new…

Religion and Education: A Human Rights Dilemma Illustrated by the Recent "Headscarf Cases"

ERIC Educational Resources Information Center

Smith, Rhona K. M.

2007-01-01

Education and religion are indelibly linked: cultural precepts underpin education policies within the formal State education system, while education has a clear role to play in promoting tolerance. Clashes between religious beliefs and secular education pose problems for states as the current array of jurisprudence, particularly on Islamic dress…

Teacher Effects on Student Achievement and Height: A Cautionary Tale

ERIC Educational Resources Information Center

Bitler, Marianne P.; Corcoran, Sean P.; Domina, Thurston; Penner, Emily K.

2014-01-01

The growing availability of data linking students to classroom teachers has made it possible to estimate the contribution teachers make to student achievement. While there is a growing consensus that teacher quality is important and current evaluation systems are inadequate, many have expressed concerns over the use of value-added measures (VAMs)…

A Bowen Family Systems Model of Generalized Anxiety Disorder and Romantic Relationship Distress.

PubMed

Priest, Jacob B

2015-07-01

Many individuals with generalized anxiety disorder (GAD) do not respond well to currently available treatments. Moreover, treatments are less effective when GAD is accompanied by romantic relationship distress. In order to develop effective treatments for GAD and relationship distress, it is necessary to conduct theory-based research to identify links common to both GAD and romantic relationship distress. Drawing on Bowen's family systems theory, the roles of family abuse/violence and differentiation in GAD and romantic relationship distress were examined using existing data from the National Comorbidity Survey Replication (n = 2,312; 2005). As predicted, family abuse/violence was directly linked to both GAD and romantic relationship distress. Differentiation mediated the relationship between family abuse/violence and GAD, and partially mediated the relationship between family abuse/violence and romantic relationship distress. Findings suggest that current and past relationship processes may help maintain chronic anxiety and that Bowen's theory may be a useful framework for developing couple therapy treatment of GAD and romantic relationship distress. © 2013 American Association for Marriage and Family Therapy.

A solid phase enzyme-linked immunosorbent assay for the antigenic detection of Legionella pneumophila (serogroup 1): A compliment for the space station diagnostic capability

NASA Technical Reports Server (NTRS)

Hejtmancik, Kelly E.

1987-01-01

It is necessary that an adequate microbiology capability be provided as part of the Health Maintenance Facility (HMF) to support expected microbial disease events and environmental monitoring during long periods of space flight. The application of morphological and biochemical studies to confirm the presence of certain bacterial and fungal disease agents are currently available and under consideration. This confirmation would be facilitated through employment of serological methods to aid in the identification of bacterial, fungal, and viral agents. A number of serological approaches are currently being considered, including the use of Enzyme Linked Immunosorbent Assay (ELISA) technology, which could be utilized during microgravity conditions. A solid phase, membrane supported ELISA for the detection of Legionella pneumophila, an expected disease agent, was developed to show a potential model system that would meet the HMF requirements and specifications for the future space station. These studies demonstrate the capability of membrane supported ELISA systems for identification of expected microbial disease agents as part of the HMF.

Prospects for detecting decreasing exoplanet frequency with main-sequence age using PLATO

NASA Astrophysics Data System (ADS)

Veras, Dimitri; Brown, David J. A.; Mustill, Alexander J.; Pollacco, Don

2015-10-01

The space mission PLATO will usher in a new era of exoplanetary science by expanding our current inventory of transiting systems and constraining host star ages, which are currently highly uncertain. This capability might allow PLATO to detect changes in planetary system architecture with time, particularly because planetary scattering due to Lagrange instability may be triggered long after the system was formed. Here, we utilize previously published instability time-scale prescriptions to determine PLATO's capability to detect a trend of decreasing planet frequency with age for systems with equal-mass planets. For two-planet systems, our results demonstrate that PLATO may detect a trend for planet masses which are at least as massive as super-Earths. For systems with three or more planets, we link their initial compactness to potentially detectable frequency trends in order to aid future investigations when these populations will be better characterized.

Prospects for detecting decreasing exoplanet frequency with main-sequence age using PLATO

NASA Astrophysics Data System (ADS)

Veras, D.; Brown, D. J. A.; Mustill, A. J.; Pollacco, D.

2017-09-01

The space mission PLATO will usher in a new era of exoplanetary science by expanding our current inventory of transiting systems and constraining host star ages, which are currently highly uncertain. This capability might allow PLATO to detect changes in planetary system architecture with time, particularly because planetary scattering due to Lagrange instability may be triggered long after the system was formed. Here, we utilize previously published instability time-scale prescriptions to determine PLATO's capability to detect a trend of decreasing planet frequency with age for systems with equal- mass planets. For two-planet systems, our results demonstrate that PLATO may detect a trend for planet masses which are at least as massive as super-Earths. For systems with three or more planets, we link their initial compactness to potentially detectable frequency trends in order to aid future investigations when these populations will be better characterized.

Missile telemetry systems for flight tests and EMC tests on EED's

NASA Astrophysics Data System (ADS)

Freymann, D.

1985-06-01

This paper describes telemetry systems developed for use in the 'Roland', 'MLRS AT2' and 'Kormoran' missiles. The main design effort required to obtain a high performance of telemetry data acquisition and transmission under extreme environmental conditions are discussed, along with test results. Considered are different types of PCM telemetry systems where the data is either transmitted directly to the ground via an RF or fiber optic link or stored in an onboard solid-state memory. The safety of EEDs in the presence of unwanted electromagnetic fields or currents is very important in weapon-systems. Therefore another type of telemetry system is reported here allowing the measurement of extremely small DC- and RF-currents induced on EEDs during EMC ground-tests. These telemetry signals are transmitted via fiber optics, to avoid additional coupling. Finally, there is a brief commentary on the future design philosophy of missile telemetry systems.

Performance Evaluation of Solar Blind NLOS Ultraviolet Communication Systems

DTIC Science & Technology

2008-12-01

noise and signal count statistical distributions . Then we further link key system parameters such as path loss and communication bit error rate (BER... quantum noise limited photon-counting detection. These benefits can now begin to be realized based on technological advances in both miniaturized...multiplication gain of 105~107, high responsivity of 62 A/W, large detection area of a few cm2, reasonable quantum efficiency of 15%, and low dark current

Health care informatics.

PubMed

Siau, Keng

2003-03-01

The health care industry is currently experiencing a fundamental change. Health care organizations are reorganizing their processes to reduce costs, be more competitive, and provide better and more personalized customer care. This new business strategy requires health care organizations to implement new technologies, such as Internet applications, enterprise systems, and mobile technologies in order to achieve their desired business changes. This article offers a conceptual model for implementing new information systems, integrating internal data, and linking suppliers and patients.

Experimental demonstration of real-time adaptively modulated DDO-OFDM systems with a high spectral efficiency up to 5.76bit/s/Hz transmission over SMF links.

PubMed

Chen, Ming; He, Jing; Tang, Jin; Wu, Xian; Chen, Lin

2014-07-28

In this paper, a FPGAs-based real-time adaptively modulated 256/64/16QAM-encoded base-band OFDM transceiver with a high spectral efficiency up to 5.76bit/s/Hz is successfully developed, and experimentally demonstrated in a simple intensity-modulated direct-detection optical communication system. Experimental results show that it is feasible to transmit a raw signal bit rate of 7.19Gbps adaptively modulated real-time optical OFDM signal over 20km and 50km single mode fibers (SMFs). The performance comparison between real-time and off-line digital signal processing is performed, and the results show that there is a negligible power penalty. In addition, to obtain the best transmission performance, direct-current (DC) bias voltage for MZM and launch power into optical fiber links are explored in the real-time optical OFDM systems.

Design and Development of a Linked Open Data-Based Health Information Representation and Visualization System: Potentials and Preliminary Evaluation

PubMed Central

Kauppinen, Tomi; Keßler, Carsten; Fritz, Fleur

2014-01-01

Background Healthcare organizations around the world are challenged by pressures to reduce cost, improve coordination and outcome, and provide more with less. This requires effective planning and evidence-based practice by generating important information from available data. Thus, flexible and user-friendly ways to represent, query, and visualize health data becomes increasingly important. International organizations such as the World Health Organization (WHO) regularly publish vital data on priority health topics that can be utilized for public health policy and health service development. However, the data in most portals is displayed in either Excel or PDF formats, which makes information discovery and reuse difficult. Linked Open Data (LOD)—a new Semantic Web set of best practice of standards to publish and link heterogeneous data—can be applied to the representation and management of public level health data to alleviate such challenges. However, the technologies behind building LOD systems and their effectiveness for health data are yet to be assessed. Objective The objective of this study is to evaluate whether Linked Data technologies are potential options for health information representation, visualization, and retrieval systems development and to identify the available tools and methodologies to build Linked Data-based health information systems. Methods We used the Resource Description Framework (RDF) for data representation, Fuseki triple store for data storage, and Sgvizler for information visualization. Additionally, we integrated SPARQL query interface for interacting with the data. We primarily use the WHO health observatory dataset to test the system. All the data were represented using RDF and interlinked with other related datasets on the Web of Data using Silk—a link discovery framework for Web of Data. A preliminary usability assessment was conducted following the System Usability Scale (SUS) method. Results We developed an LOD-based health information representation, querying, and visualization system by using Linked Data tools. We imported more than 20,000 HIV-related data elements on mortality, prevalence, incidence, and related variables, which are freely available from the WHO global health observatory database. Additionally, we automatically linked 5312 data elements from DBpedia, Bio2RDF, and LinkedCT using the Silk framework. The system users can retrieve and visualize health information according to their interests. For users who are not familiar with SPARQL queries, we integrated a Linked Data search engine interface to search and browse the data. We used the system to represent and store the data, facilitating flexible queries and different kinds of visualizations. The preliminary user evaluation score by public health data managers and users was 82 on the SUS usability measurement scale. The need to write queries in the interface was the main reported difficulty of LOD-based systems to the end user. Conclusions The system introduced in this article shows that current LOD technologies are a promising alternative to represent heterogeneous health data in a flexible and reusable manner so that they can serve intelligent queries, and ultimately support decision-making. However, the development of advanced text-based search engines is necessary to increase its usability especially for nontechnical users. Further research with large datasets is recommended in the future to unfold the potential of Linked Data and Semantic Web for future health information systems development. PMID:25601195

Design and development of a linked open data-based health information representation and visualization system: potentials and preliminary evaluation.

PubMed

Tilahun, Binyam; Kauppinen, Tomi; Keßler, Carsten; Fritz, Fleur

2014-10-25

Healthcare organizations around the world are challenged by pressures to reduce cost, improve coordination and outcome, and provide more with less. This requires effective planning and evidence-based practice by generating important information from available data. Thus, flexible and user-friendly ways to represent, query, and visualize health data becomes increasingly important. International organizations such as the World Health Organization (WHO) regularly publish vital data on priority health topics that can be utilized for public health policy and health service development. However, the data in most portals is displayed in either Excel or PDF formats, which makes information discovery and reuse difficult. Linked Open Data (LOD)-a new Semantic Web set of best practice of standards to publish and link heterogeneous data-can be applied to the representation and management of public level health data to alleviate such challenges. However, the technologies behind building LOD systems and their effectiveness for health data are yet to be assessed. The objective of this study is to evaluate whether Linked Data technologies are potential options for health information representation, visualization, and retrieval systems development and to identify the available tools and methodologies to build Linked Data-based health information systems. We used the Resource Description Framework (RDF) for data representation, Fuseki triple store for data storage, and Sgvizler for information visualization. Additionally, we integrated SPARQL query interface for interacting with the data. We primarily use the WHO health observatory dataset to test the system. All the data were represented using RDF and interlinked with other related datasets on the Web of Data using Silk-a link discovery framework for Web of Data. A preliminary usability assessment was conducted following the System Usability Scale (SUS) method. We developed an LOD-based health information representation, querying, and visualization system by using Linked Data tools. We imported more than 20,000 HIV-related data elements on mortality, prevalence, incidence, and related variables, which are freely available from the WHO global health observatory database. Additionally, we automatically linked 5312 data elements from DBpedia, Bio2RDF, and LinkedCT using the Silk framework. The system users can retrieve and visualize health information according to their interests. For users who are not familiar with SPARQL queries, we integrated a Linked Data search engine interface to search and browse the data. We used the system to represent and store the data, facilitating flexible queries and different kinds of visualizations. The preliminary user evaluation score by public health data managers and users was 82 on the SUS usability measurement scale. The need to write queries in the interface was the main reported difficulty of LOD-based systems to the end user. The system introduced in this article shows that current LOD technologies are a promising alternative to represent heterogeneous health data in a flexible and reusable manner so that they can serve intelligent queries, and ultimately support decision-making. However, the development of advanced text-based search engines is necessary to increase its usability especially for nontechnical users. Further research with large datasets is recommended in the future to unfold the potential of Linked Data and Semantic Web for future health information systems development.

Internet over the VDL-2 Subnetwork: the VDL-2/IP Aviation Datalink System

NASA Technical Reports Server (NTRS)

Grappel, R. D.

2000-01-01

This report describes the design to operate the standard Internet communications protocols (IP) over the VHF aviation Data Link Mode 2 (VDL-2) subnetwork. The VDL-2/IP system specified in this report can operate transparently with the current aviation users of VDL-2 (Airline Communications and Reporting System, ACARS and Aeronautical Telecommunications Network, ATN) and proposed users (Flight Information Service via Broadcast, FIS-B). The VDL-2/IP system provides a straightforward mechanisms to utilize inexpensive, commercial off-the-shelf (COTS) communications packages developed for the Internet as part of the aviation datalink system.

Influence of basin- and local-scale environmental conditions on nearshore production in the northeast Pacific Ocean

USGS Publications Warehouse

von Biela, Vanessa R.; Zimmerman, Christian E.; Kruse, Gordon H.; Mueter, Franz J.; Black, Bryan A.; Douglas, David C.; Bodkin, James L.

2016-01-01

Nearshore marine habitats are productive and vulnerable owing to their connections to pelagic and terrestrial landscapes. To understand how ocean basin- and local-scale conditions may influence nearshore species, we developed an annual index of nearshore production (spanning the period 1972–2010) from growth increments recorded in otoliths of representative pelagic-feeding (Black Rockfish Sebastes melanops) and benthic-feeding (Kelp Greenling Hexagrammos decagrammus) nearshore-resident fishes at nine sites in the California Current and Alaska Coastal Current systems. We explored the influence of basin- and local-scale conditions across all seasons at lags of up to 2 years to represent changes in prey quantity (1- or 2-year time lags) and quality (within-year relationships). Relationships linking fish growth to basin-scale (Pacific Decadal Oscillation, North Pacific Gyre Oscillation, and multivariate El Niño–Southern Oscillation index) and local-scale (sea surface temperature, sea surface height anomalies, upwelling index, photosynthetically active radiation, and freshwater discharge) environmental conditions varied by species and current system. Growth of Black Rockfish increased with cool basin-scale conditions in the California Current and warm local-scale conditions in the Alaska Coastal Current, consistent with existing hypotheses linking climate to pelagic production on continental shelves in the respective regions. Relationships for Kelp Greenlings in the California Current were complex, with faster growth related to within-year warm conditions and lagged-year cool conditions. These opposing, lag-dependent relationships may reflect differences in conditions that promote quantity versus quality of benthic invertebrate prey in the California Current. Thus, we hypothesize that benthic production is maximized by alternating cool and warm years, as benthic invertebrate recruitment is food limited during warm years while growth is temperature limited by cool years in the California Current. On the other hand, Kelp Greenlings grew faster during and subsequent to warm conditions at basin and local scales in the Alaska Coastal Current.

An ALS-Associated Mutant SOD1 Rapidly Suppresses KCNT1 (Slack) Na+-Activated K+ Channels in Aplysia Neurons.

PubMed

Zhang, Yalan; Ni, Weiming; Horwich, Arthur L; Kaczmarek, Leonard K

2017-02-22

Mutations that alter levels of Slack (KCNT1) Na + -activated K + current produce devastating effects on neuronal development and neuronal function. We now find that Slack currents are rapidly suppressed by oligomers of mutant human Cu/Zn superoxide dismutase 1 (SOD1), which are associated with motor neuron toxicity in an inherited form of amyotrophic lateral sclerosis (ALS). We recorded from bag cell neurons of Aplysia californica , a model system to study neuronal excitability. We found that injection of fluorescent wild-type SOD1 (wt SOD1YFP) or monomeric mutant G85R SOD1YFP had no effect on net ionic currents measured under voltage clamp. In contrast, outward potassium currents were significantly reduced by microinjection of mutant G85R SOD1YFP that had been preincubated at 37°C or of cross-linked dimers of G85R SOD1YFP. Reduction of potassium current was also seen with multimeric G85R SOD1YFP of ∼300 kDa or >300 kDa that had been cross-linked. In current clamp recordings, microinjection of cross-linked 300 kDa increased excitability by depolarizing the resting membrane potential, and decreasing the latency of action potentials triggered by depolarization. The effect of cross-linked 300 kDa on potassium current was reduced by removing Na + from the bath solution, or by knocking down levels of Slack using siRNA. It was also prevented by pharmacological inhibition of ASK1 (apoptosis signal-regulating kinase 1) or of c-Jun N-terminal kinase, but not by an inhibitor of p38 mitogen-activated protein kinase. These results suggest that soluble mutant SOD1 oligomers rapidly trigger a kinase pathway that regulates the activity of Na + -activated K + channels in neurons. SIGNIFICANCE STATEMENT Slack Na + -activated K + channels (KCNT1, K Na 1.1) regulate neuronal excitability but are also linked to cytoplasmic signaling pathways that control neuronal protein translation. Mutations that alter the amplitude of these currents have devastating effects on neuronal development and function. We find that injection of oligomers of mutant superoxide dismutase 1 (SOD1) into the cytoplasm of invertebrate neurons rapidly suppresses these Na + -activated K + currents and that this effect is mediated by a MAP kinase cascade, including ASK1 and c-Jun N-terminal kinase. Because amyotrophic lateral sclerosis is a fatal adult-onset neurodegenerative disease produced by mutations in SOD1 that cause the enzyme to form toxic oligomers, our findings suggest that suppression of Slack channels may be an early step in the progression of the disease. Copyright © 2017 the authors 0270-6474/17/372258-08$15.00/0.

Proposal for implementation of CCSDS standards for use with spacecraft engineering/housekeeping data

NASA Technical Reports Server (NTRS)

Welch, Dave

1994-01-01

Many of today's low earth orbiting spacecraft are using the Consultative Committee for Space Data Systems (CCSDS) protocol for better optimization of down link RF bandwidth and onboard storage space. However, most of the associated housekeeping data has continued to be generated and down linked in a synchronous, Time Division Multiplexed (TDM) fashion. There are many economies that the CCSDS protocol will allow to better utilize the available bandwidth and storage space in order to optimize the housekeeping data for use in operational trending and analysis work. By only outputting what is currently important or of interest, finer resolution of critical items can be obtained. This can be accomplished by better utilizing the normally allocated housekeeping data down link and storage areas rather than taking space reserved for science.

Proposal for implementation of CCSDS standards for use with spacecraft engineering/housekeeping data

NASA Astrophysics Data System (ADS)

Welch, Dave

1994-11-01

Many of today's low earth orbiting spacecraft are using the Consultative Committee for Space Data Systems (CCSDS) protocol for better optimization of down link RF bandwidth and onboard storage space. However, most of the associated housekeeping data has continued to be generated and down linked in a synchronous, Time Division Multiplexed (TDM) fashion. There are many economies that the CCSDS protocol will allow to better utilize the available bandwidth and storage space in order to optimize the housekeeping data for use in operational trending and analysis work. By only outputting what is currently important or of interest, finer resolution of critical items can be obtained. This can be accomplished by better utilizing the normally allocated housekeeping data down link and storage areas rather than taking space reserved for science.

Epigenetics studies of fetal alcohol spectrum disorder: where are we now?

PubMed

Lussier, Alexandre A; Weinberg, Joanne; Kobor, Michael S

2017-03-01

Adverse in utero events can alter the development and function of numerous physiological systems, giving rise to lasting neurodevelopmental deficits. In particular, data have shown that prenatal alcohol exposure can reprogram neurobiological systems, altering developmental trajectories and resulting in increased vulnerability to adverse neurobiological, behavioral and health outcomes. Increasing evidence suggests that epigenetic mechanisms are potential mediators for the reprogramming of neurobiological systems, as they may provide a link between the genome, environmental conditions and neurodevelopmental outcomes. This review outlines the current state of epigenetic research in fetal alcohol spectrum disorder, highlighting the role of epigenetic mechanisms in the reprogramming of neurobiological systems by alcohol and as potential diagnostic tools for fetal alcohol spectrum disorder. We also present an assessment of the current limitations in studies of prenatal alcohol exposure, and highlight the future steps needed in the field.

The Trouble with Triplets in Biodiversity Informatics: A Data-Driven Case against Current Identifier Practices

PubMed Central

Guralnick, Robert; Conlin, Tom; Deck, John; Stucky, Brian J.; Cellinese, Nico

2014-01-01

The biodiversity informatics community has discussed aspirations and approaches for assigning globally unique identifiers (GUIDs) to biocollections for nearly a decade. During that time, and despite misgivings, the de facto standard identifier has become the “Darwin Core Triplet”, which is a concatenation of values for institution code, collection code, and catalog number associated with biocollections material. Our aim is not to rehash the challenging discussions regarding which GUID system in theory best supports the biodiversity informatics use case of discovering and linking digital data across the Internet, but how well we can link those data together at this moment, utilizing the current identifier schemes that have already been deployed. We gathered Darwin Core Triplets from a subset of VertNet records, along with vertebrate records from GenBank and the Barcode of Life Data System, in order to determine how Darwin Core Triplets are deployed “in the wild”. We asked if those triplets follow the recommended structure and whether they provide an easy and unambiguous means to track from specimen records to genetic sequence records. We show that Darwin Core Triplets are often riddled with semantic and syntactic errors when deployed and curated in practice, despite specifications about how to construct them. Our results strongly suggest that Darwin Core Triplets that have not been carefully curated are not currently serving a useful role for relinking data. We briefly consider needed next steps to overcome current limitations. PMID:25470125

Linking User Identities Across the DataONE Federation of Data Repositories

NASA Astrophysics Data System (ADS)

Jones, M. B.; Mecum, B.; Leinfelder, B.; Jones, C. S.; Walker, L.

2016-12-01

DataONE provides services for identifying, authenticating, and authorizing researchers to access and contribute data to repositories within the DataONE federation. In the earth sciences, thousands of institutional and disciplinary repositories have created their own user identity and authentication systems with their own user directory based on a database or web content management systems. Thus, researchers have many identities that are neither linked nor interoperable, making it difficult to reference the identity of these users across systems. Key user information is hidden, and only a non-disambiguated name is often available. From a sample of 160,000 data sets within DataONE, a super-majority of references to the data creators lack even an email address. In an attempt to disambiguate these people via the GeoLink project, we conservatively estimate they represent at least 57,000 unique identities, but without a clear user identifier, there could be as many as 223,000. Interoperability among repositories is critical to improving the scope of scientific synthesis and capabilities for research collaboration. While many have focused on the convenience of Single Sign-On (SSO), we have found that sharing user identifiers is far more useful for interoperability. With an unambiguous user identity in incoming metadata, DataONE has built user-profiles that present that user's data across repositories, that link users and their organizational affiliations, and that allow users to work collaboratively in private groups that span repository systems. DataONE's user identity solution leverages existing systems such as InCommon, CILogon, Google, and ORCID to not further proliferate user identities. DataONE provides a core service allowing users to link their multiple identities so that authenticating with one identity (e.g., ORCID) can authorize access to data protected via another identity (e.g., InCommon). Currently, DataONE is using ORCID identities to link and identify users, but challenges must still be overcome to support historical records for which ORCIDs can not be used because the associated people are unavailable to confirm their identity. DataONE's identity systems facilitate crosslinking between user identities and scientific metadata to accelerate collaboration and synthesis.

Implementation of a MFAC based position sensorless drive for high speed BLDC motors with nonideal back EMF.

PubMed

Li, Haitao; Ning, Xin; Li, Wenzhuo

2017-03-01

In order to improve the reliability and reduce power consumption of the high speed BLDC motor system, this paper presents a model free adaptive control (MFAC) based position sensorless drive with only a dc-link current sensor. The initial commutation points are obtained by detecting the phase of EMF zero-crossing point and then delaying 30 electrical degrees. According to the commutation error caused by the low pass filter (LPF) and other factors, the relationship between commutation error angle and dc-link current is analyzed, a corresponding MFAC based control method is proposed, and the commutation error can be corrected by the controller in real time. Both the simulation and experimental results show that the proposed correction method can achieve ideal commutation effect within the entire operating speed range. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Free-Space Quantum Key Distribution using Polarization Entangled Photons

NASA Astrophysics Data System (ADS)

Kurtsiefer, Christian

2007-06-01

We report on a complete experimental implementation of a quantum key distribution protocol through a free space link using polarization-entangled photon pairs from a compact parametric down-conversion source [1]. Based on a BB84-equivalent protocol, we generated without interruption over 10 hours a secret key free-space optical link distance of 1.5 km with a rate up to 950 bits per second after error correction and privacy amplification. Our system is based on two time stamp units and relies on no specific hardware channel for coincidence identification besides an IP link. For that, initial clock synchronization with an accuracy of better than 2 ns is achieved, based on a conventional NTP protocol and a tiered cross correlation of time tags on both sides. Time tags are used to servo a local clock, allowing a streamed measurement on correctly identified photon pairs. Contrary to the majority of quantum key distribution systems, this approach does not require a trusted large-bandwidth random number generator, but integrates that into the physical key generation process. We discuss our current progress of implementing a key distribution via an atmospherical link during daylight conditions, and possible attack scenarios on a physical timing information side channel to a entanglement-based key distribution system. [1] I. Marcikic, A. Lamas-Linares, C. Kurtsiefer, Appl. Phys. Lett. 89, 101122 (2006).

Hospital accreditation, reimbursement and case mix: links and insights for contractual systems.

PubMed

Ammar, Walid; Khalife, Jade; El-Jardali, Fadi; Romanos, Jenny; Harb, Hilda; Hamadeh, Ghassan; Dimassi, Hani

2013-12-05

Resource consumption is a widely used proxy for severity of illness, and is often measured through a case-mix index (CMI) based on Diagnosis Related Groups (DRGs), which is commonly linked to payment. For countries that do not have DRGs it has been suggested to use CMIs derived from International Classification of Diseases (ICD). Our research objective was to use ICD-derived case-mix to evaluate whether or not the current accreditation-based hospital reimbursement system in Lebanon is appropriate. Our study population included medical admissions to 122 hospitals contracted with the Lebanese Ministry of Public Health (MoPH) between June 2011 and May 2012. Applying ICD-derived CMI on principal diagnosis cost (CMI-ICDC) using weighing similar to that used in Medicare DRG CMI, analyses were made by hospital accreditation, ownership and size. We examined two measures of 30-day re-admission rate. Further analysis was done to examine correlation between principal diagnosis CMI and surgical procedure cost CMI (CMI-CPTC), and three proxy measures on surgical complexity, case complexity and surgical proportion. Hospitals belonging to the highest accreditation category had a higher CMI than others, but no difference was found in CMI among the three other categories. Private hospitals had a higher CMI than public hospitals, and those more than 100 beds had a higher CMI than smaller hospitals. Re-admissions rates were higher in accreditation category C hospitals than category D hospitals. CMI-ICDC was fairly correlated with CMI-CPTC, and somehow correlated with the proposed proxies. Our results indicate that the current link between accreditation and reimbursement rate is not appropriate, and leads to unfairness and inefficiency in the system. Some proxy measures are correlated with case-mix but are not good substitutes for it. Policy implications of our findings propose the necessity for changing the current reimbursement system by including case mix and outcome indicators in addition to accreditation in hospital contracting. Proxies developed may be used to detect miss-use and provider adverse behavior. Research using ICD-derived case mix is limited and our findings may be useful to inform similar initiatives and other limited-setting countries in the region.

Modeling of the Mode S tracking system in support of aircraft safety research

NASA Technical Reports Server (NTRS)

Sorensen, J. A.; Goka, T.

1982-01-01

This report collects, documents, and models data relating the expected accuracies of tracking variables to be obtained from the FAA's Mode S Secondary Surveillance Radar system. The data include measured range and azimuth to the tracked aircraft plus the encoded altitude transmitted via the Mode S data link. A brief summary is made of the Mode S system status and its potential applications for aircraft safety improvement including accident analysis. FAA flight test results are presented demonstrating Mode S range and azimuth accuracy and error characteristics and comparing Mode S to the current ATCRBS radar tracking system. Data are also presented that describe the expected accuracy and error characteristics of encoded altitude. These data are used to formulate mathematical error models of the Mode S variables and encoded altitude. A brief analytical assessment is made of the real-time tracking accuracy available from using Mode S and how it could be improved with down-linked velocity.

International short-term medical missions: a systematic review of recommended practices.

PubMed

Roche, Stephanie D; Ketheeswaran, Pavinarmatha; Wirtz, Veronika J

2017-01-01

To identify practices for conducting international short-term medical missions (STMMs) recommended in the literature and examine how these link STMMs to recipient countries' existing health systems. Systematic review of PubMed-indexed articles on STMMs and their bibliographies using preferred reporting items for systematic reviews and meta-analyses guidelines. Recommendations were organized using the World Health Organization Health Systems Framework. In 92 publications, 67 % offered at least one recommendation that would link STMMs to the recipient country's health system. Among these recommendations, most focused on service delivery and few on health financing and governance. There is a lack of consensus around a proper standard of care, patient selection, and trip duration. Comprehensive global standards are needed for STMM work to ensure that services are beneficial both to patients and to the broader healthcare systems of recipient countries. By providing an overview of the current recommendations and important gaps where practice recommendations are needed, this study can provide relevant input into the development of global standards for STMMs.

How Do Astronomers Share Data? Reliability and Persistence of Datasets Linked in AAS Publications and a Qualitative Study of Data Practices among US Astronomers

PubMed Central

Pepe, Alberto; Goodman, Alyssa; Muench, August; Crosas, Merce; Erdmann, Christopher

2014-01-01

We analyze data sharing practices of astronomers over the past fifteen years. An analysis of URL links embedded in papers published by the American Astronomical Society reveals that the total number of links included in the literature rose dramatically from 1997 until 2005, when it leveled off at around 1500 per year. The analysis also shows that the availability of linked material decays with time: in 2011, 44% of links published a decade earlier, in 2001, were broken. A rough analysis of link types reveals that links to data hosted on astronomers' personal websites become unreachable much faster than links to datasets on curated institutional sites. To gauge astronomers' current data sharing practices and preferences further, we performed in-depth interviews with 12 scientists and online surveys with 173 scientists, all at a large astrophysical research institute in the United States: the Harvard-Smithsonian Center for Astrophysics, in Cambridge, MA. Both the in-depth interviews and the online survey indicate that, in principle, there is no philosophical objection to data-sharing among astronomers at this institution. Key reasons that more data are not presently shared more efficiently in astronomy include: the difficulty of sharing large data sets; over reliance on non-robust, non-reproducible mechanisms for sharing data (e.g. emailing it); unfamiliarity with options that make data-sharing easier (faster) and/or more robust; and, lastly, a sense that other researchers would not want the data to be shared. We conclude with a short discussion of a new effort to implement an easy-to-use, robust, system for data sharing in astronomy, at theastrodata.org, and we analyze the uptake of that system to-date. PMID:25165807

How do astronomers share data? Reliability and persistence of datasets linked in AAS publications and a qualitative study of data practices among US astronomers.

PubMed

Pepe, Alberto; Goodman, Alyssa; Muench, August; Crosas, Merce; Erdmann, Christopher

2014-01-01

We analyze data sharing practices of astronomers over the past fifteen years. An analysis of URL links embedded in papers published by the American Astronomical Society reveals that the total number of links included in the literature rose dramatically from 1997 until 2005, when it leveled off at around 1500 per year. The analysis also shows that the availability of linked material decays with time: in 2011, 44% of links published a decade earlier, in 2001, were broken. A rough analysis of link types reveals that links to data hosted on astronomers' personal websites become unreachable much faster than links to datasets on curated institutional sites. To gauge astronomers' current data sharing practices and preferences further, we performed in-depth interviews with 12 scientists and online surveys with 173 scientists, all at a large astrophysical research institute in the United States: the Harvard-Smithsonian Center for Astrophysics, in Cambridge, MA. Both the in-depth interviews and the online survey indicate that, in principle, there is no philosophical objection to data-sharing among astronomers at this institution. Key reasons that more data are not presently shared more efficiently in astronomy include: the difficulty of sharing large data sets; over reliance on non-robust, non-reproducible mechanisms for sharing data (e.g. emailing it); unfamiliarity with options that make data-sharing easier (faster) and/or more robust; and, lastly, a sense that other researchers would not want the data to be shared. We conclude with a short discussion of a new effort to implement an easy-to-use, robust, system for data sharing in astronomy, at theastrodata.org, and we analyze the uptake of that system to-date.

How Do Astronomers Share Data? Reliability and Persistence of Datasets Linked in AAS Publications and a Qualitative Study of Data Practices among US Astronomers

NASA Astrophysics Data System (ADS)

Pepe, Alberto; Goodman, Alyssa; Muench, August; Crosas, Merce; Erdmann, Christopher

2014-08-01

We analyze data sharing practices of astronomers over the past fifteen years. An analysis of URL links embedded in papers published by the American Astronomical Society reveals that the total number of links included in the literature rose dramatically from 1997 until 2005, when it leveled off at around 1500 per year. The analysis also shows that the availability of linked material decays with time: in 2011, 44% of links published a decade earlier, in 2001, were broken. A rough analysis of link types reveals that links to data hosted on astronomers' personal websites become unreachable much faster than links to datasets on curated institutional sites. To gauge astronomers' current data sharing practices and preferences further, we performed in-depth interviews with 12 scientists and online surveys with 173 scientists, all at a large astrophysical research institute in the United States: the Harvard-Smithsonian Center for Astrophysics, in Cambridge, MA. Both the in-depth interviews and the online survey indicate that, in principle, there is no philosophical objection to data-sharing among astronomers at this institution. Key reasons that more data are not presently shared more efficiently in astronomy include: the difficulty of sharing large data sets; over reliance on non-robust, non-reproducible mechanisms for sharing data (e.g. emailing it); unfamiliarity with options that make data-sharing easier (faster) and/or more robust; and, lastly, a sense that other researchers would not want the data to be shared. We conclude with a short discussion of a new effort to implement an easy-to-use, robust, system for data sharing in astronomy, at theastrodata.org, and we analyze the uptake of that system to-date.

Open source data logger for low-cost environmental monitoring

PubMed Central

2014-01-01

Abstract The increasing transformation of biodiversity into a data-intensive science has seen numerous independent systems linked and aggregated into the current landscape of biodiversity informatics. This paper outlines how we can move forward with this programme, incorporating real time environmental monitoring into our methodology using low-power and low-cost computing platforms. PMID:24855446

77 FR 24952 - Staff Technical Conference on Geomagnetic Disturbances to the Bulk-Power System; Technical...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-26

... risks and impacts from geomagnetically induced currents to transformers and other equipment on the Bulk... this event in the Calendar. The event will contain a link to the webcast. The Capitol Connection... for a fee. If you have any questions, visit www.CapitolConnection.org or call 703-993-3100. Commission...

Myth Busting: Using Data Mining to Refute Link between Transfer Students and Retention Risk

ERIC Educational Resources Information Center

McAleer, Brenda; Szakas, Joseph S.

2010-01-01

In the past few years, universities have become much more involved in outcomes assessment. Outside of the classroom analysis of learning outcomes, an investigation is performed into the use of current data mining tools to assess the issue of student retention within the Computer Information Systems (CIS) department. Utilizing both a historical…

Thermal Protection System Imagery Inspection Management System -TIIMS

NASA Technical Reports Server (NTRS)

Goza, Sharon; Melendrez, David L.; Henningan, Marsha; LaBasse, Daniel; Smith, Daniel J.

2011-01-01

TIIMS is used during the inspection phases of every mission to provide quick visual feedback, detailed inspection data, and determination to the mission management team. This system consists of a visual Web page interface, an SQL database, and a graphical image generator. These combine to allow a user to ascertain quickly the status of the inspection process, and current determination of any problem zones. The TIIMS system allows inspection engineers to enter their determinations into a database and to link pertinent images and video to those database entries. The database then assigns criteria to each zone and tile, and via query, sends the information to a graphical image generation program. Using the official TIPS database tile positions and sizes, the graphical image generation program creates images of the current status of the orbiter, coloring zones, and tiles based on a predefined key code. These images are then displayed on a Web page using customized JAVA scripts to display the appropriate zone of the orbiter based on the location of the user's cursor. The close-up graphic and database entry for that particular zone can then be seen by selecting the zone. This page contains links into the database to access the images used by the inspection engineer when they make the determination entered into the database. Status for the inspection zones changes as determinations are refined and shown by the appropriate color code.

A Well-Controlled Nucleus Pulposus Tissue Culture System with Injection Port for Evaluating Regenerative Therapies.

PubMed

Arkesteijn, Irene T M; Mouser, Vivian H M; Mwale, Fackson; van Dijk, Bart G M; Ito, Keita

2016-05-01

In vitro evaluation of nucleus pulposus (NP) tissue regeneration would be useful, but current systems for NP culture are not ideal for injections. The aim of this study was to develop a long-term culture system for NP tissue that allows injections of regenerative agents. Bovine caudal NPs were harvested and placed in the newly designed culture system. After equilibration of the tissue to 0.3 MPa the volume was fixed and the tissue was cultured for 28 days. The cell viability and extracellular matrix composition remained unchanged during the culture period and gene expression profiles were similar to those obtained in earlier studies. Furthermore, to test the responsiveness of bovine caudal NPs in the system, samples were cultured for 4 days and injected twice (day 1 and 3) with (1) PBS, (2) Link-N, for regeneration, and (3) TNF-α, for degeneration. It was shown that TNF-α increased COX2 gene expression, whereas no effect of Link-N was detected. In conclusion, the newly designed system allows long-term culture of NP tissue, wherein tissue reactions to injected stimulants can be observed.

Polyvinyl alcohol hydrogels for iontohporesis

NASA Astrophysics Data System (ADS)

Bera, Prasanta; Alam, Asif Ali; Arora, Neha; Tibarewala, Dewaki Nandan; Basak, Piyali

2013-06-01

Transdermal therapeutic systems propound controlled release of active ingredients through the skin into the systemic circulation in a predictive manner. Drugs administered through these systems escape first-pass metabolism and maintain a steady state scenario similar to a continuous intravenous infusion for up to several days. The iontophoresis deal with the systemic delivery of the bioactive agents (drug) by applying an electric current. It is basically an injection without the needle. The iontophoretic system requires a gel-based matrix to accommodate the bioactive agent. Hydrogels have been used by many investigators in controlled-release drug delivery systems because of their good tissue compatibility and easy manipulation of swelling level and, thereby, solute permeability. In this work we have prepared polyvinyl alcohol (PVA) hydrogel. We have cross linked polyvinyl alcohol chemically with Glutaraldehyde with different wt%. FTIR study reveals the chemical changes during cross linking. Swelling in water, is done to have an idea about drug loading and drug release from the membrane. After drug loading to the hydrogels, we have studied the drug release property of the hydrogels using salicylic acid as a model drug.

An Evaluation of Spacecraft Pointing Requirements for Optically Linked Satellite Systems

NASA Astrophysics Data System (ADS)

Gunter, B. C.; Dahl, T.

2017-12-01

Free space optical (laser) communications can offer certain advantages for many remote sensing applications, due primarily to the high data rates (Gb/s) and energy efficiences possible from such systems. An orbiting network of crosslinked satellites could potentially relay imagery and other high-volume data at near real-time intervals. To achieve this would require satellites actively tracking one or more satellites, as well as ground terminals. The narrow laser beam width utilized by the transmitting satellites pose technical challenges due to the higher pointing accuracy required for effective signal transmission, in particular if small satellites are involved. To better understand what it would take to realize such a small-satellite laser communication network, this study investigates the pointing requirements needed to support optical data links. A general method for characterizing pointing tolerance, angle rates and accelerations for line of site vectors is devised and applied to various case studies. Comparisons with state-of-the-art small satellite attitude control systems are also made to assess what is possible using current technology. The results help refine the trade space for designs for optically linked networks from the hardware aboard each satellite to the design of the satellite constellation itself.

Integration of offshore wind farms through high voltage direct current networks

NASA Astrophysics Data System (ADS)

Livermore, Luke

The integration of offshore wind farms through Multi Terminal DC (MTDC) networks into the GB network was investigated. The ability of Voltage Source Converter (VSC) High Voltage Direct Current (HVDC) to damp Subsynchronous Resonance (SSR) and ride through onshore AC faults was studied. Due to increased levels of wind generation in Scotland, substantial onshore and offshore reinforcements to the GB transmission network are proposed. Possible inland reinforcements include the use of series compensation through fixed capacitors. This potentially can lead to SSR. Offshore reinforcements are proposed by two HVDC links. In addition to its primary functions of bulk power transmission, a HVDC link can be used to provide damping against SSR, and this function has been modelled. Simulation studies have been carried out in PSCAD. In addition, a real-time hardware-in-the-loop HVDC test rig has been used to implement and validate the proposed damping scheme on an experimental platform. When faults occur within AC onshore networks, offshore MTDC networks are vulnerable to DC overvoltages, potentially damaging the DC plant and cables. Power reduction and power dissipation control systems were investigated to ride through onshore AC faults. These methods do not require dedicated fast communication systems. Simulations and laboratory experiments are carried out to evaluate the control systems, with the results from the two platforms compared..

Gastritis: the histology report.

PubMed

Rugge, Massimo; Pennelli, Gianmaria; Pilozzi, Emanuela; Fassan, Matteo; Ingravallo, Giuseppe; Russo, Valentina M; Di Mario, Francesco

2011-03-01

Gastritis is defined as inflammation of the gastric mucosa. In histological terms, it is distinguishable into two main categories, i.e. non-atrophic and atrophic. In the gastric mucosa, atrophy is defined as the loss of appropriate glands. There are several etiological types of gastritis, their different etiology being related to different clinical manifestations and pathological features. Atrophic gastritis (resulting mainly from long-standing Helicobacter pylori infection) is a major risk factor for the onset of (intestinal type) gastric cancer. The extent and site of the atrophic changes correlate significantly with the cancer risk. The current format for histology reporting in cases of gastritis fails to establish an immediate link between gastritis phenotype and risk of malignancy. Building on current knowledge of the biology of gastritis, an international group of pathologists [Operative Link for Gastritis Assessment (OLGA)] has proposed a system for reporting gastritis in terms of its stage (the OLGA Staging System): this system places the histological phenotypes of gastritis on a scale of progressively increasing gastric cancer risk, from the lowest (Stage 0) to the highest (Stage IV). The aim of this tutorial is to provide unequivocal information on how to standardize histology reports on gastritis in diagnostic practice. Copyright © 2011 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd.. All rights reserved.

Use of Persistent Identifiers to link Heterogeneous Data Systems in the Integrated Earth Data Applications (IEDA) Facility

NASA Astrophysics Data System (ADS)

Hsu, L.; Lehnert, K. A.; Carbotte, S. M.; Arko, R. A.; Ferrini, V.; O'hara, S. H.; Walker, J. D.

2012-12-01

The Integrated Earth Data Applications (IEDA) facility maintains multiple data systems with a wide range of solid earth data types from the marine, terrestrial, and polar environments. Examples of the different data types include syntheses of ultra-high resolution seafloor bathymetry collected on large collaborative cruises and analytical geochemistry measurements collected by single investigators in small, unique projects. These different data types have historically been channeled into separate, discipline-specific databases with search and retrieval tailored for the specific data type. However, a current major goal is to integrate data from different systems to allow interdisciplinary data discovery and scientific analysis. To increase discovery and access across these heterogeneous systems, IEDA employs several unique IDs, including sample IDs (International Geo Sample Number, IGSN), person IDs (GeoPass ID), funding award IDs (NSF Award Number), cruise IDs (from the Marine Geoscience Data System Expedition Metadata Catalog), dataset IDs (DOIs), and publication IDs (DOIs). These IDs allow linking of a sample registry (System for Earth SAmple Registration), data libraries and repositories (e.g. Geochemical Research Library, Marine Geoscience Data System), integrated synthesis databases (e.g. EarthChem Portal, PetDB), and investigator services (IEDA Data Compliance Tool). The linked systems allow efficient discovery of related data across different levels of granularity. In addition, IEDA data systems maintain links with several external data systems, including digital journal publishers. Links have been established between the EarthChem Portal and ScienceDirect through publication DOIs, returning sample-level objects and geochemical analyses for a particular publication. Linking IEDA-hosted data to digital publications with IGSNs at the sample level and with IEDA-allocated dataset DOIs are under development. As an example, an individual investigator could sign up for a GeoPass account ID, write a proposal to NSF and create a data plan using the IEDA Data Management Plan Tool. Having received the grant, the investigator then collects rock samples on a scientific cruise from dredges and registers the samples with IGSNs. The investigator then performs analytical geochemistry on the samples, and submits the full dataset to the Geochemical Resource Library for a dataset DOI. Finally, the investigator writes an article that is published in Science Direct. Knowing any of the following IDs: Investigator GeoPass ID, NSF Award Number, Cruise ID, Sample IGSNs, dataset DOI, or publication DOI, a user would be able to navigate to all samples, datasets, and publications in IEDA and external systems. Use of persistent identifiers to link heterogeneous data systems in IEDA thus increases access, discovery, and proper citation of hard-earned investigator datasets.

The Role of the NASA Global Hawk Link Module as an Information Nexus For Atmospheric Mapping Missions

NASA Technical Reports Server (NTRS)

Sullivan, D. V.

2015-01-01

The Link Module described in this paper was developed for the NASA Uninhabited Aerial System (UAS) Global Hawk Pacific Mission (GloPAC) Airborne Science Campaign; four flights of 30 hour duration, supporting the Aura Validation Experiment (AVE). It was used again during the Genesis and Rapid Intensification Processes (GRIP) experiment, a NASA Earth Science field experiment to better understand how tropical storms form and develop into major hurricanes. In these missions, the Link Module negotiated all communication over the high bandwidth Ku satellite link, archived all the science data from onboard experiments in a spatially enabled database, routed command and control of the instruments from the Global Hawk Operations Center, and re-transmitted select data sets directly to experimenters control and analysis systems. The availability of aggregated information from collections of sensors, and remote control capabilities, in real-time, is revolutionizing the way Airborne Science is being conducted. The Link Module NG now being flown in support of the NASA Earth Venture missions, the Hurricane and Severe Storm Sentinel (HS3) mission, and Airborne Tropical Tropopause Experiment (A TTREX) mission, has advanced data fusion technologies that are further advancing the Scientific productivity, flexibility and robustness of these systems. On-the-fly traffic shaping has been developed to allow the high definition video, used for critical flight control segments, to dynamically allocate variable bandwidth on demand. Historically, the Link Module evolved from the instrument and communication interface controller used by NASA's Pathfinder and Pathfinder plus solar powered UAS's in the late 1990' s. It later was expanded for use in the AIRDAS four channel scanner flown on the NASA Altus UAS, and then again to a module in the AMS twelve channel multispectral scanner flying on the NASA (Predator-b) Ikhana UAS. The current system is the answer to the challenges imposed by extremely long duration UASs, with on-board multi-instrument (>= 12) Sensor Webs.

Type II toxin: antitoxin systems. More than small selfish entities?

PubMed

Rocker, Andrea; Meinhart, Anton

2016-05-01

Toxin-antitoxin (TA) modules regulate metabolism and viability of bacteria and archaea. In type II TA systems these functions are generally thought to be performed by two small proteins. However, evidence is increasing that the toxins are much more diverse and can form multi-domain proteins. Recently, we published a novel type II TA system in which toxin and antitoxin are covalently linked into a single polypeptide chain. In this review we summarize the current knowledge on these elongated toxin homologs and provide perspectives for future study.

Microwave systems applications in deep space telecommunications and navigation - Space Exploration Initiative architectures

NASA Technical Reports Server (NTRS)

Hall, Justin R.; Hastrup, Rolf C.; Bell, David J.

1992-01-01

The general support requirements of a typical SEI mission set, along with the mission operations objectives and related telecommunications, navigation, and information management (TNIM) support infrastructure options are described. Responsive system architectures and designs are proposed, including a Mars orbiting communications relay satellite system and a Mars-centered navigation capability for servicing all Mars missions. With the TNIM architecture as a basis, key elements of the microwave link design are proposed. The needed new technologies which enable these designs are identified, and current maturity is assessed.

Microwave systems applications in deep space telecommunications and navigation - Space Exploration Initiative architectures

NASA Astrophysics Data System (ADS)

Hall, Justin R.; Hastrup, Rolf C.; Bell, David J.

1992-06-01

The general support requirements of a typical SEI mission set, along with the mission operations objectives and related telecommunications, navigation, and information management (TNIM) support infrastructure options are described. Responsive system architectures and designs are proposed, including a Mars orbiting communications relay satellite system and a Mars-centered navigation capability for servicing all Mars missions. With the TNIM architecture as a basis, key elements of the microwave link design are proposed. The needed new technologies which enable these designs are identified, and current maturity is assessed.

Sharing and reusing cardiovascular anatomical models over the Web: a step towards the implementation of the virtual physiological human project.

PubMed

Gianni, Daniele; McKeever, Steve; Yu, Tommy; Britten, Randall; Delingette, Hervé; Frangi, Alejandro; Hunter, Peter; Smith, Nicolas

2010-06-28

Sharing and reusing anatomical models over the Web offers a significant opportunity to progress the investigation of cardiovascular diseases. However, the current sharing methodology suffers from the limitations of static model delivery (i.e. embedding static links to the models within Web pages) and of a disaggregated view of the model metadata produced by publications and cardiac simulations in isolation. In the context of euHeart--a research project targeting the description and representation of cardiovascular models for disease diagnosis and treatment purposes--we aim to overcome the above limitations with the introduction of euHeartDB, a Web-enabled database for anatomical models of the heart. The database implements a dynamic sharing methodology by managing data access and by tracing all applications. In addition to this, euHeartDB establishes a knowledge link with the physiome model repository by linking geometries to CellML models embedded in the simulation of cardiac behaviour. Furthermore, euHeartDB uses the exFormat--a preliminary version of the interoperable FieldML data format--to effectively promote reuse of anatomical models, and currently incorporates Continuum Mechanics, Image Analysis, Signal Processing and System Identification Graphical User Interface (CMGUI), a rendering engine, to provide three-dimensional graphical views of the models populating the database. Currently, euHeartDB stores 11 cardiac geometries developed within the euHeart project consortium.

Geoscience Australia's enterprise application of provenance standards and systems for physical and digital objects

NASA Astrophysics Data System (ADS)

Kemp, C.; Car, N. J.

2016-12-01

Geoscience Australia (GA) is a government agency that provides advice on the geology and geography of Australia. It is the custodian of many digital and physical datasets of national significance. For several years GA has been implementing an enterprise approach to provenance management. The goal for transparency and reproducibility for all of GA's information products; an objective supported at the highest levels and explicitly listed in its Science Principles. Currently GA is finalising a set of enterprise tools to assist with provenance management and rolling out provenance reporting to different science areas. GA has adopted or developed: provenance storage systems; provenance collection code libraries (for use within automated systems); reporting interfaces (for manual use) and provenance representation capability within legacy catalogues. Using these tools within GA's science areas involves modelling the scenario first and then assessing whether the area has its data managed in such a way that allows links to data within provenance to be resolvable in perpetuity. We don't just want to represent provenance (demonstrating transparency), we want to access data via provenance (allowing for reproducibility). A subtask of GA's current work is to link physical samples to information products (datasets, reports, papers) by uniquely and persistently identifying samples using International GeoSample Numbers and then modelling automated & manual laboratory workflows and associated tasks, such as data delivery to corporate databases using the W3C's PROV Data Model. We use PROV DM throughout our modelling and systems. We are also moving to deliver all sample and digital dataset metadata across the agency in the Web Ontology Language (OWL) and exposing it via Linked Data methods in order to allow Semantic Web querying of multiple systems allowing provenance to be leveraged using as a single method and query point. Through the Science First Transformation Program GA is undergoing a significant rethinking of its data architecture, curation and access to support the Digital Science capability for which Provenance management is an output.

Developing critical consciousness or justifying the system? A qualitative analysis of attributions for poverty and wealth among low-income racial/ethnic minority and immigrant women

PubMed Central

Godfrey, Erin B.; Wolf, Sharon

2015-01-01

Objectives Economic inequality is a growing concern in the United States and globally. The current study uses qualitative techniques to (1) explore the attributions low-income racial/ethnic minority and immigrant women make for poverty and wealth in the U.S., and (2) clarify important links between attributions, critical consciousness development and system justification theory. Methods In-depth interview transcripts from 19 low-income immigrant Dominican and Mexican and native African-American mothers in a large Northeastern city were analyzed using open coding techniques. Interview topics included perceptions of current economic inequality and mobility and experiences of daily economic hardships. Results Almost all respondents attributed economic inequality to individual factors (character flaws, lack of hard work). Structural explanations for poverty and wealth were expressed by less than half the sample and almost always paired with individual explanations. Moreover, individual attributions included system-justifying beliefs such as the belief in meritocracy and equality of opportunity and structural attributions represented varying levels of critical consciousness. Conclusions Our analysis sheds new light on how and why individuals simultaneously hold individual and structural attributions and highlights key links between system justification and critical consciousness. It shows that critical consciousness and system justification do not represent opposite stances along a single underlying continuum, but are distinct belief systems and motivations. It also suggests that the motive to justify the system is a key psychological process impeding the development of critical consciousness. Implications for scholarship and intervention are discussed. PMID:25915116

Developing critical consciousness or justifying the system? A qualitative analysis of attributions for poverty and wealth among low-income racial/ethnic minority and immigrant women.

PubMed

Godfrey, Erin B; Wolf, Sharon

2016-01-01

Economic inequality is a growing concern in the United States and globally. The current study uses qualitative techniques to (a) explore the attributions low-income racial/ethnic minority and immigrant women make for poverty and wealth in the U.S., and (b) clarify important links between attributions, critical consciousness development, and system justification theory. In-depth interview transcripts from 19 low-income immigrant Dominican and Mexican and native African American mothers in a large Northeastern city were analyzed using open coding techniques. Interview topics included perceptions of current economic inequality and mobility and experiences of daily economic hardships. Almost all respondents attributed economic inequality to individual factors (character flaws, lack of hard work). Structural explanations for poverty and wealth were expressed by fewer than half the sample and almost always paired with individual explanations. Moreover, individual attributions included system-justifying beliefs such as the belief in meritocracy and equality of opportunity and structural attributions represented varying levels of critical consciousness. Our analysis sheds new light on how and why individuals simultaneously hold individual and structural attributions and highlights key links between system justification and critical consciousness. It shows that critical consciousness and system justification do not represent opposite stances along a single underlying continuum, but are distinct belief systems and motivations. It also suggests that the motive to justify the system is a key psychological process impeding the development of critical consciousness. Implications for scholarship and intervention are discussed. (c) 2016 APA, all rights reserved).

Multiple access techniques and spectrum utilization of the GLOBALSTAR mobile satellite system

NASA Astrophysics Data System (ADS)

Louie, Ming; Cohen, Michel; Rouffet, Denis; Gilhousen, Klein S.

The GLOBALSTAR System is a Low Earth Orbit (LEO) satellite-based mobile communications system that is interoperable with the current and future Public Land Mobile Network (PLMN). The GLOBALSTAR System concept is based upon technological advancement in two key areas: (1) the advancement in LEO satellite technology; (2) the advancement in cellular telephone technology, including the commercial applications of Code Division Multiple Access (CDMA) technologies, and of the most recent progress in Time Division Multiple Access technologies. The GLOBALSTAR System uses elements of CDMA, Frequency Division Multiple Access (FDMA), and Time Division Multiple Access (TDMA) technology, combining with satellite Multiple Beam Antenna (MBA) technology, to arrive at one of the most efficient modulation and multiple access system ever proposed for a satellite communications system. The technology used in GLOBALSTAR exploits the following techniques in obtaining high spectral efficiency and affordable cost per channel, with minimum coordination among different systems: power control, in open and closed loops, voice activation, spot beam satellite antenna for frequency reuse, weighted satellite antenna gain, multiple satellite coverage, and handoff between satellites. The GLOBALSTAR system design will use the following frequency bands: 1610-1626.5 MHz for up-link and 2483.5-2500 MHz for down-link.

Powering the High-Luminosity Triplets

NASA Astrophysics Data System (ADS)

Ballarino, A.; Burnet, J. P.

The powering of the magnets in the LHC High-Luminosity Triplets requires production and transfer of more than 150 kA of DC current. High precision power converters will be adopted, and novel High Temperature Superconducting (HTS) current leads and MgB2 based transfer lines will provide the electrical link between the power converters and the magnets. This chapter gives an overview of the systems conceived in the framework of the LHC High-Luminosity upgrade for feeding the superconducting magnet circuits. The focus is on requirements, challenges and novel developments.

Assessment of the importance of the current-wave coupling in the shelf ocean forecasts

NASA Astrophysics Data System (ADS)

Jordà, G.; Bolaños, R.; Espino, M.; Sánchez-Arcilla, A.

2006-10-01

The effects of wave-current interactions on shelf ocean forecasts is investigated in the framework of the MFSTEP (Mediterranean Forecasting System Project Towards Enviromental Predictions) project. A one way sequential coupling approach is adopted to link the wave model (WAM) to the circulation model (SYMPHONIE). The coupling of waves and currents has been done considering four main processes: wave refraction due to currents, surface wind drag and bo€ttom drag modifications due to waves, and the wave induced mass flux. The coupled modelling system is implemented in the southern Catalan shelf (NW Mediterranean), a region with characteristics similar to most of the Mediterranean shelves. The sensitivity experiments are run in a typical operational configuration. The wave refraction by currents seems to be not very relevant in a microtidal context such as the western Mediterranean. The main effect of waves on current forecasts is through the modification of the wind drag. The Stokes drift also plays a significant role due to its spatial and temporal characteristics. Finally, the enhanced bottom friction is just noticeable in the inner shelf.

Review on enzyme-linked immunosorbent assays for sulfonamide residues in edible animal products.

PubMed

Zhang, Hongyan; Wang, Shuo

2009-10-31

The current status of enzyme-linked immunosorbent assays (ELISAs) for sulfonamides in edible animal products is reviewed. The attention was focused on the design and synthesis of haptens, conjugation to carrier protein, production of antibody, application of homologous and heterologous systems, as well as the molecular modeling of the haptens and sulfonamides. Researches have shown that sulfonamides seem to be particularly resistant to attempts to produce broad specificity antibodies. By summarizing the available research on sulfonamide ELISAs, it is hoped that it can be considered as a basis for further investigation aimed at developing the most efficient approaches for detection.

Predicting the performance of linear optical detectors in free space laser communication links

NASA Astrophysics Data System (ADS)

Farrell, Thomas C.

2018-05-01

While the fundamental performance limit for optical communications is set by the quantum nature of light, in practical systems background light, dark current, and thermal noise of the electronics also degrade performance. In this paper, we derive a set of equations predicting the performance of PIN diodes and linear mode avalanche photo diodes (APDs) in the presence of such noise sources. Electrons generated by signal, background, and dark current shot noise are well modeled in PIN diodes as Poissonian statistical processes. In APDs, on the other hand, the amplifying effects of the device result in statistics that are distinctly non-Poissonian. Thermal noise is well modeled as Gaussian. In this paper, we appeal to the central limit theorem and treat both the variability of the signal and the sum of noise sources as Gaussian. Comparison against Monte-Carlo simulation of PIN diode performance (where we do model shot noise with draws from a Poissonian distribution) validates the legitimacy of this approximation. On-off keying, M-ary pulse position, and binary differential phase shift keying modulation are modeled. We conclude with examples showing how the equations may be used in a link budget to estimate the performance of optical links using linear receivers.

Bone as an ion exchange system: evidence for a link between mechanotransduction and metabolic needs.

PubMed

Rubinacci, A; Covini, M; Bisogni, C; Villa, I; Galli, M; Palumbo, C; Ferretti, M; Muglia, M A; Marotti, G

2002-04-01

To detect whether the mutual interaction occurring between the osteocytes-bone lining cells system (OBLCS) and the bone extracellular fluid (BECF) is affected by load through a modification of the BECF-extracellular fluid (ECF; systemic extracellular fluid) gradient, mice metatarsal bones immersed in ECF were subjected ex vivo to a 2-min cyclic axial load of different amplitudes and frequencies. The electric (ionic) currents at the bone surface were measured by a vibrating probe after having exposed BECF to ECF through a transcortical hole. The application of different loads and different frequencies increased the ionic current in a dose-dependent manner. The postload current density subsequently decayed following an exponential pattern. Postload increment's amplitude and decay were dependent on bone viability. Dummy and static loads did not induce current density modifications. Because BECF is perturbed by loading, it is conceivable that OBLCS tends to restore BECF preload conditions by controlling ion fluxes at the bone-plasma interface to fulfill metabolic needs. Because the electric current reflects the integrated activity of OBLCS, its evaluation in transgenic mice engineered to possess genetic lesions in channels or matrix constituents could be helpful in the characterization of the mechanical and metabolic functions of bone.

Investigating the effect of plate-mantle interaction in basin creation and associated drainage systems: insights from the North West Shelf of Australia

NASA Astrophysics Data System (ADS)

Morón, S.; Gallagher, S. J.; Moresi, L. N.; Salles, T.; Rey, P. F.; Payenberg, T.

2016-12-01

The effect of plate-mantle dynamics on surface topography has increasingly being recognized. This concept is particularly useful for the understanding of the links between plate-mantle dynamics, continental break up and the creation of sedimentary basins and their associated drainage systems. To unravel these links back in time we present an approach that uses numerical models and the geological record. The sedimentary basins of the North West Shelf (NWS) of Australia contain an exceptional record of the Permian to early Cretaceous polyphased rifting of Australia from Greater India, which is in turn associated with the breakup of Gondwana. This record and the relative tectonic quiescence of the Australian Continent since the Late Cretaceous make the NWS a great natural laboratory for investigating the interaction between mantle dynamics, plate tectonics and drainage patterns. Furthermore, as a result of the extensive petroleum exploration and production in the area a uniquely large dataset containing seismic, lithologic, biostratigraphic and detrital zircon information is already available. This study will first focus on augmenting zircon datasets to refine the current conceptual models of paleodrainage systems associated with the NWS. Current conceptual models of drainage patterns suggest the previous existance of large transcontinental rivers that transported sediments from Antarctica and India, rather than from more proximal Australian sources. From a mass-balance point of view this model seems reasonable, as large transcontinental rivers would be required to transport the significant volume of sediments that are deposited in the thick (15km) sedimentary sequences of the NWS. Coupling of geodynamic (Underworld) and landscape-dynamics (Badlands) models will allow us to numerically test the likelihood of this conceptual model and also to present and integrated approach to investigate the link between deep Earth processes and surficial processes.

Antidepressant medications and osteoporosis.

PubMed

Rizzoli, R; Cooper, C; Reginster, J-Y; Abrahamsen, B; Adachi, J D; Brandi, M L; Bruyère, O; Compston, J; Ducy, P; Ferrari, S; Harvey, N C; Kanis, J A; Karsenty, G; Laslop, A; Rabenda, V; Vestergaard, P

2012-09-01

Use of antidepressant medications that act on the serotonin system has been linked to detrimental impacts on bone mineral density (BMD), and to osteoporosis. This article reviews current evidence for such effects, and identifies themes for future research. Serotonin receptors are found in all major types of bone cell (osteoblasts, osteocytes, and osteoclasts), indicating an important role of the neuroendocrine system in bone. Observational studies indicate a complex relationship between depression, antidepressants, and fracture. First, the presence of depression itself increases fracture risk, in relation with decreased BMD and an increase in falls. A range of aspects of depression may operate, including behavioral factors (e.g., smoking and nutrition), biological changes, and confounders (e.g., comorbidities and concomitant medications). A substantial proportion of depressed patients receive antidepressants, mostly selective serotonin reuptake inhibitors (SSRIs). Some of these have been linked to decreased BMD (SSRIs) and increased fracture risk (SSRIs and tricyclic agents). Current use of SSRIs and tricyclics increases fracture risk by as much as twofold versus nonusers, even after adjustment for potential confounders. While there is a dose-response relationship for SSRIs, the effect does not appear to be homogeneous across the whole class of drugs and may be linked to affinity for the serotonin transporter system. The increase in risk is the greatest in the early stages of treatment, with a dramatic increase after initiation, reaching a peak within 1 month for tricyclics and 8 months for SSRIs. Treatment-associated increased risk diminishes towards baseline in the year following discontinuation. The body of evidence suggests that SSRIs should be considered in the list of medications that are risk factors for osteoporotic fractures. Copyright © 2012 Elsevier Inc. All rights reserved.

Potential of glyburide to reduce intracerebral edema in brain metastases.

PubMed

Boggs, Drexell Hunter; Simard, J Marc; Steven, Andrew; Mehta, Minesh P

2014-04-01

Metastatic disease to the brain results in significant morbidity because of edema in the central nervous system. Current anti-edema therapies are either expensive or result in unwanted long-term side effects. Sulfonylurea receptor 1 (Sur1) is a transmembrane protein that, when activated in the central nervous system, allows for unregulated sodium influx into cells, a process that has been linked to cytotoxic edema formation in ischemic stroke, subarachnoid hemorrhage, spinal cord injury, traumatic brain injury, and, most recently, brain metastases. In this focused review, we explore preclinical data linking Sur1 channel formation to development of edema and reference evidence suggesting that the antidiabetic sulfonylurea drug glyburide (a Sur1 inhibitor) is an inexpensive and well-tolerated agent that can be clinically tested to reduce or prevent malignancy and/or treatment-associated edema.

20-meter underwater wireless optical communication link with 1.5 Gbps data rate.

PubMed

Shen, Chao; Guo, Yujian; Oubei, Hassan M; Ng, Tien Khee; Liu, Guangyu; Park, Ki-Hong; Ho, Kang-Ting; Alouini, Mohamed-Slim; Ooi, Boon S

2016-10-31

The video streaming, data transmission, and remote control in underwater call for high speed (Gbps) communication link with a long channel length (~10 meters). We present a compact and low power consumption underwater wireless optical communication (UWOC) system utilizing a 450-nm laser diode (LD) and a Si avalanche photodetector. With the LD operating at a driving current of 80 mA with an optical power of 51.3 mW, we demonstrated a high-speed UWOC link offering a data rate up to 2 Gbps over a 12-meter-long, and 1.5 Gbps over a record 20-meter-long underwater channel. The measured bit-error rate (BER) are 2.8 × 10^-5, and 3.0 × 10^-3, respectively, which pass well the forward error correction (FEC) criterion.

The Airspace Concepts Evaluation System Architecture and System Plant

NASA Technical Reports Server (NTRS)

Windhorst, Robert; Meyn, Larry; Manikonda, Vikram; Carlos, Patrick; Capozzi, Brian

2006-01-01

The Airspace Concepts Evaluation System is a simulation of the National Airspace System. It includes models of flights, airports, airspaces, air traffic controls, traffic flow managements, and airline operation centers operating throughout the United States. It is used to predict system delays in response to future capacity and demand scenarios and perform benefits assessments of current and future airspace technologies and operational concepts. Facilitation of these studies requires that the simulation architecture supports plug and play of different air traffic control, traffic flow management, and airline operation center models and multi-fidelity modeling of flights, airports, and airspaces. The simulation is divided into two parts that are named, borrowing from classical control theory terminology, control and plant. The control consists of air traffic control, traffic flow management, and airline operation center models, and the plant consists of flight, airport, and airspace models. The plant can run open loop, in the absence of the control. However, undesired affects, such as conflicts and over congestions in the airspaces and airports, can occur. Different controls are applied, "plug and played", to the plant. A particular control is evaluated by analyzing how well it managed conflicts and congestions. Furthermore, the terminal area plants consist of models of airports and terminal airspaces. Each model consists of a set of nodes and links which are connected by the user to form a network. Nodes model runways, fixes, taxi intersections, gates, and/or other points of interest, and links model taxiways, departure paths, and arrival paths. Metering, flow distribution, and sequencing functions can be applied at nodes. Different fidelity model of how a flight transits are can be used by links. The fidelity of the model can be adjusted by the user by either changing the complexity of the node/link network-or the way that the link models how the flights transit from one node to the other.

Optoelectronics research for communication programs at the Goddard Space Flight Center

NASA Technical Reports Server (NTRS)

Krainak, Michael A.

1991-01-01

Current optoelectronics research and development of high-power, high-bandwidth laser transmitters, high-bandwidth, high-sensitivity optical receivers, pointing, acquisition and tracking components, and experimental and theoretical system modeling at the NASA Goddard Space Flight Center is reviewed. Program hardware and space flight milestones are presented. It is believed that these experiments will pave the way for intersatellite optical communications links for both the NASA Advanced Tracking and Data Relay Satellite System and commercial users in the 21st century.

Epigenetics studies of fetal alcohol spectrum disorder: where are we now?

PubMed Central

Lussier, Alexandre A; Weinberg, Joanne; Kobor, Michael S

2017-01-01

Adverse in utero events can alter the development and function of numerous physiological systems, giving rise to lasting neurodevelopmental deficits. In particular, data have shown that prenatal alcohol exposure can reprogram neurobiological systems, altering developmental trajectories and resulting in increased vulnerability to adverse neurobiological, behavioral and health outcomes. Increasing evidence suggests that epigenetic mechanisms are potential mediators for the reprogramming of neurobiological systems, as they may provide a link between the genome, environmental conditions and neurodevelopmental outcomes. This review outlines the current state of epigenetic research in fetal alcohol spectrum disorder, highlighting the role of epigenetic mechanisms in the reprogramming of neurobiological systems by alcohol and as potential diagnostic tools for fetal alcohol spectrum disorder. We also present an assessment of the current limitations in studies of prenatal alcohol exposure, and highlight the future steps needed in the field. PMID:28234026

System for estimating fatigue damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

LeMonds, Jeffrey; Guzzo, Judith Ann; Liu, Shaopeng

In one aspect, a system for estimating fatigue damage in a riser string is provided. The system includes a plurality of accelerometers which can be deployed along a riser string and a communications link to transmit accelerometer data from the plurality of accelerometers to one or more data processors in real time. With data from a limited number of accelerometers located at sensor locations, the system estimates an optimized current profile along the entire length of the riser including riser locations where no accelerometer is present. The optimized current profile is then used to estimate damage rates to individual risermore » components and to update a total accumulated damage to individual riser components. The number of sensor locations is small relative to the length of a deepwater riser string, and a riser string several miles long can be reliably monitored along its entire length by fewer than twenty sensor locations.« less

Progress and challenges to the global waste management system.

PubMed

Singh, Jagdeep; Laurenti, Rafael; Sinha, Rajib; Frostell, Björn

2014-09-01

Rapid economic growth, urbanization and increasing population have caused (materially intensive) resource consumption to increase, and consequently the release of large amounts of waste to the environment. From a global perspective, current waste and resource management lacks a holistic approach covering the whole chain of product design, raw material extraction, production, consumption, recycling and waste management. In this article, progress and different sustainability challenges facing the global waste management system are presented and discussed. The study leads to the conclusion that the current, rather isolated efforts, in different systems for waste management, waste reduction and resource management are indeed not sufficient in a long term sustainability perspective. In the future, to manage resources and wastes sustainably, waste management requires a more systems-oriented approach that addresses the root causes for the problems. A specific issue to address is the development of improved feedback information (statistics) on how waste generation is linked to consumption. © The Author(s) 2014.

Development of Shunt-Type Three-Phase Active Power Filter with Novel Adaptive Control for Wind Generators

PubMed Central

2015-01-01

This paper proposes a new adaptive filter for wind generators that combines instantaneous reactive power compensation technology and current prediction controller, and therefore this system is characterized by low harmonic distortion, high power factor, and small DC-link voltage variations during load disturbances. The performance of the system was first simulated using MATLAB/Simulink, and the possibility of an adaptive digital low-pass filter eliminating current harmonics was confirmed in steady and transient states. Subsequently, a digital signal processor was used to implement an active power filter. The experimental results indicate, that for the rated operation of 2 kVA, the system has a total harmonic distortion of current less than 5.0% and a power factor of 1.0 on the utility side. Thus, the transient performance of the adaptive filter is superior to the traditional digital low-pass filter and is more economical because of its short computation time compared with other types of adaptive filters. PMID:26451391

Development of Shunt-Type Three-Phase Active Power Filter with Novel Adaptive Control for Wind Generators.

PubMed

Chen, Ming-Hung

2015-01-01

This paper proposes a new adaptive filter for wind generators that combines instantaneous reactive power compensation technology and current prediction controller, and therefore this system is characterized by low harmonic distortion, high power factor, and small DC-link voltage variations during load disturbances. The performance of the system was first simulated using MATLAB/Simulink, and the possibility of an adaptive digital low-pass filter eliminating current harmonics was confirmed in steady and transient states. Subsequently, a digital signal processor was used to implement an active power filter. The experimental results indicate, that for the rated operation of 2 kVA, the system has a total harmonic distortion of current less than 5.0% and a power factor of 1.0 on the utility side. Thus, the transient performance of the adaptive filter is superior to the traditional digital low-pass filter and is more economical because of its short computation time compared with other types of adaptive filters.

Design and optimisation of low heat load liquid helium cryostat to house cryogenic current comparator in antiproton decelerator at CERN

NASA Astrophysics Data System (ADS)

Lees, A.; Koettig, T.; Fernandes, M.; Tan, J.

2017-02-01

The Cryogenic Current Comparator (CCC) is installed in the low-energy Antiproton Decelerator (AD) at CERN to make an absolute measurement of the beam intensity. Operating below 4.2 K, it is based on a superconducting quantum interference device (SQUID) and employs a superconducting niobium shield to supress magnetic field components not linked to the beam current. The AD contains no permanent cryogenic infrastructure so the local continuous liquefaction of helium using a pulse-tube is required; limiting the available cooling power to 0.69 W at 4.2K. Due to the sensitivity of the SQUID to variations in magnetic fields, the CCC is highly sensitive to mechanical vibration which is limited to a minimum by the support systems of the cryostat. This article presents the cooling system of the cryostat and discusses the design challenges overcome to minimise the transmission of vibration to the CCC while operating within the cryogenic limits imposed by the cooling system.

Rising CO2, Climate Change, and Public Health: Exploring the Links to Plant Biology

PubMed Central

Ziska, Lewis H.; Epstein, Paul R.; Schlesinger, William H.

2009-01-01

Background Although the issue of anthropogenic climate forcing and public health is widely recognized, one fundamental aspect has remained underappreciated: the impact of climatic change on plant biology and the well-being of human systems. Objectives We aimed to critically evaluate the extant and probable links between plant function and human health, drawing on the pertinent literature. Discussion Here we provide a number of critical examples that range over various health concerns related to plant biology and climate change, including aerobiology, contact dermatitis, pharmacology, toxicology, and pesticide use. Conclusions There are a number of clear links among climate change, plant biology, and public health that remain underappreciated by both plant scientists and health care providers. We demonstrate the importance of such links in our understanding of climate change impacts and provide a list of key questions that will help to integrate plant biology into the current paradigm regarding climate change and human health. PMID:19270781

Effect of Joule heating and current crowding on electromigration in mobile technology

NASA Astrophysics Data System (ADS)

Tu, K. N.; Liu, Yingxia; Li, Menglu

2017-03-01

In the present era of big data and internet of things, the use of microelectronic products in all aspects of our life is manifested by the ubiquitous presence of mobile devices as i-phones and wearable i-products. These devices are facing the need for higher power and greater functionality applications such as in i-health, yet they are limited by physical size. At the moment, software (Apps) is much ahead of hardware in mobile technology. To advance hardware, the end of Moore's law in two-dimensional integrated circuits can be extended by three-dimensional integrated circuits (3D ICs). The concept of 3D ICs has been with us for more than ten years. The challenge in 3D IC technology is dense packing by using both vertical and horizontal interconnections. Mass production of 3D IC devices is behind schedule due to cost because of low yield and uncertain reliability. Joule heating is serious in a dense structure because of heat generation and dissipation. A change of reliability paradigm has advanced from failure at a specific circuit component to failure at a system level weak-link. Currently, the electronic industry is introducing 3D IC devices in mainframe computers, where cost is not an issue, for the purpose of collecting field data of failure, especially the effect of Joule heating and current crowding on electromigration. This review will concentrate on the positive feedback between Joule heating and electromigration, resulting in an accelerated system level weak-link failure. A new driving force of electromigration, the electric potential gradient force due to current crowding, will be reviewed critically. The induced failure tends to occur in the low current density region.

The Institutional Design for Continuing Education in the "National Medium- and Long-Term Educational Reform and Development Guideline (2010-20)"

ERIC Educational Resources Information Center

Mingming, Ji

2012-01-01

The cause of continuing education has gained significant strides in China after the advent of Reform and Opening Up, but it is still the weakest link in the current system of education. The "National Medium- and Long-Term Educational Reform and Development Guideline (2010-20)" (hereafter abbreviated as the "Guideline") has…

A New England Land-Grant Network; A Study of the Feasibility of Establishing Educational Information Links Between the Six Land-Grant Universities in New England.

ERIC Educational Resources Information Center

Bardwell, John D.

This study sought to identify physical facilities needed to connect the six New England land-grant universities. Criteria were time (use of current technology), cost (regular operating budgets of participating institutions), minimal personnel requirements, flexibility, and compatibility. The telephone system, an existing microwave network, a…

A Missing Link in Suggestibility Research: What Is Known About the Behavior of Field Interviewers in Unstructured Interviews With Young Children?

ERIC Educational Resources Information Center

Gilstrap, Livia L.

2004-01-01

Despite suggestibility researchers' focus on adult behaviors that distort children's reports, whether behaviors examined in experimental work are used in the field is unknown. The current study presents a mutually exclusive and exhaustive hierarchical coding system that reflects interview questioning behaviors of concern in experimental work. The…

Redesigning School Finance Systems: Lessons from CPRE Research. CPRE Policy Briefs. RB-50

ERIC Educational Resources Information Center

Odden, Allan

2007-01-01

This policy brief describes how the Consortium for Policy Research in Education (CPRE) has approached the objectives of educational equity and adequacy over the past decade and a half, and reveals how their current finance research has begun to explicitly link the level and use of resources with strategies that districts and schools can deploy to…

Relate@IU>>>Share@IU: A New and Different Computer-Based Communications Paradigm.

ERIC Educational Resources Information Center

Frick, Theodore W.; Roberto, Joseph; Korkmaz, Ali; Oh, Jeong-En; Twal, Riad

The purpose of this study was to examine problems with the current computer-based electronic communication systems and to initially test and revise a new and different paradigm for e-collaboration, Relate@IU. Understanding the concept of sending links to resources, rather than sending the resource itself, is at the core of how Relate@IU differs…

VehiHealth: An Emergency Routing Protocol for Vehicular Ad Hoc Network to Support Healthcare System.

PubMed

Bhoi, S K; Khilar, P M

2016-03-01

Survival of a patient depends on effective data communication in healthcare system. In this paper, an emergency routing protocol for Vehicular Ad hoc Network (VANET) is proposed to quickly forward the current patient status information from the ambulance to the hospital to provide pre-medical treatment. As the ambulance takes time to reach the hospital, ambulance doctor can provide sudden treatment to the patient in emergency by sending patient status information to the hospital through the vehicles using vehicular communication. Secondly, the experienced doctors respond to the information by quickly sending a treatment information to the ambulance. In this protocol, data is forwarded through that path which has less link breakage problem between the vehicles. This is done by calculating an intersection value I v a l u e for the neighboring intersections by using the current traffic information. Then the data is forwarded through that intersection which has minimum I v a l u e . Simulation results show VehiHealth performs better than P-GEDIR, GyTAR, A-STAR and GSR routing protocols in terms of average end-to-end delay, number of link breakage, path length, and average response time.

Building a biomedical semantic network in Wikipedia with Semantic Wiki Links

PubMed Central

Good, Benjamin M.; Clarke, Erik L.; Loguercio, Salvatore; Su, Andrew I.

2012-01-01

Wikipedia is increasingly used as a platform for collaborative data curation, but its current technical implementation has significant limitations that hinder its use in biocuration applications. Specifically, while editors can easily link between two articles in Wikipedia to indicate a relationship, there is no way to indicate the nature of that relationship in a way that is computationally accessible to the system or to external developers. For example, in addition to noting a relationship between a gene and a disease, it would be useful to differentiate the cases where genetic mutation or altered expression causes the disease. Here, we introduce a straightforward method that allows Wikipedia editors to embed computable semantic relations directly in the context of current Wikipedia articles. In addition, we demonstrate two novel applications enabled by the presence of these new relationships. The first is a dynamically generated information box that can be rendered on all semantically enhanced Wikipedia articles. The second is a prototype gene annotation system that draws its content from the gene-centric articles on Wikipedia and exposes the new semantic relationships to enable previously impossible, user-defined queries. Database URL: http://en.wikipedia.org/wiki/Portal:Gene_Wiki PMID:22434829

Building a biomedical semantic network in Wikipedia with Semantic Wiki Links.

PubMed

Good, Benjamin M; Clarke, Erik L; Loguercio, Salvatore; Su, Andrew I

2012-01-01

Wikipedia is increasingly used as a platform for collaborative data curation, but its current technical implementation has significant limitations that hinder its use in biocuration applications. Specifically, while editors can easily link between two articles in Wikipedia to indicate a relationship, there is no way to indicate the nature of that relationship in a way that is computationally accessible to the system or to external developers. For example, in addition to noting a relationship between a gene and a disease, it would be useful to differentiate the cases where genetic mutation or altered expression causes the disease. Here, we introduce a straightforward method that allows Wikipedia editors to embed computable semantic relations directly in the context of current Wikipedia articles. In addition, we demonstrate two novel applications enabled by the presence of these new relationships. The first is a dynamically generated information box that can be rendered on all semantically enhanced Wikipedia articles. The second is a prototype gene annotation system that draws its content from the gene-centric articles on Wikipedia and exposes the new semantic relationships to enable previously impossible, user-defined queries. DATABASE URL: http://en.wikipedia.org/wiki/Portal:Gene_Wiki.

Towards full band colorless reception with coherent balanced receivers.

PubMed

Zhang, Bo; Malouin, Christian; Schmidt, Theodore J

2012-04-23

In addition to linear compensation of fiber channel impairments, coherent receivers also provide colorless selection of any desired data channel within multitude of incident wavelengths, without the need of a channel selecting filter. In this paper, we investigate the design requirements for colorless reception using a coherent balanced receiver, considering both the optical front end (OFE) and the transimpedance amplifier (TIA). We develop analytical models to predict the system performance as a function of receiver design parameters and show good agreement against numerical simulations. At low input signal power, an optimum local oscillator (LO) power is shown to exist where the thermal noise is balanced with the residual LO-RIN beat noise. At high input signal power, we show the dominant noise effect is the residual self-beat noise from the out of band (OOB) channels, which scales not only with the number of OOB channels and the common mode rejection ratio (CMRR) of the OFE, but also depends on the link residual chromatic dispersion (CD) and the orientation of the polarization tributaries relative to the receiver. This residual self-beat noise from OOB channels sets the lower bound for the LO power. We also investigate the limitations imposed by overload in the TIA, showing analytically that the DC current scales only with the number of OOB channels, while the differential AC current scales only with the link residual CD, which induces high peak-to-average power ratio (PAPR). Both DC and AC currents at the input to the TIA set the upper bounds for the LO power. Considering both the OFE noise limit and the TIA overload limit, we show that the receiver operating range is notably narrowed for dispersion unmanaged links, as compared to dispersion managed links. © 2012 Optical Society of America

UAS CNPC Satellite Link Performance - Sharing Spectrum with Terrestrial Systems

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Wilson, Jeffrey D.; Bishop, William D.

2016-01-01

In order to provide for the safe integration of unmanned aircraft systems into the National Airspace System, the control and non-payload communications (CNPC) link connecting the ground-based pilot with the unmanned aircraft must be highly reliable. A specific requirement is that it must operate using aviation safety radiofrequency spectrum. The 2012 World Radiocommunication Conference (WRC-12) provided a potentially suitable allocation for radio line-of-sight (LOS), terrestrial based CNPC link at 5030-5091 MHz. For a beyond radio line-of-sight (BLOS), satellite-based CNPC link, aviation safety spectrum allocations are currently inadequate. Therefore, the 2015 WRC will consider the use of Fixed Satellite Service (FSS) bands to provide BLOS CNPC under Agenda Item 1.5. This agenda item requires studies to be conducted to allow for the consideration of how unmanned aircraft can employ FSS for BLOS CNPC while maintaining existing systems. Since there are terrestrial Fixed Service systems also using the same frequency bands under consideration in Agenda Item 1.5 one of the studies required considered spectrum sharing between earth stations on-board unmanned aircraft and Fixed Service station receivers. Studies carried out by NASA have concluded that such sharing is possible under parameters previously established by the International Telecommunications Union. As the preparation for WRC-15 has progressed, additional study parameters Agenda Item 1.5 have been proposed, and some studies using these parameters have been added. This paper examines the study results for the original parameters as well as results considering some of the more recently proposed parameters to provide insight into the complicated process of resolving WRC-15 Agenda Item 1.5 and achieving a solution for BLOS CNPC for unmanned aircraft.

Optimization of a Two Stage Pulse Tube Refrigerator for the Integrated Current Lead System

NASA Astrophysics Data System (ADS)

Maekawa, R.; Matsubara, Y.; Okada, A.; Takami, S.; Konno, M.; Tomioka, A.; Imayoshi, T.; Hayashi, H.; Mito, T.

2008-03-01

Implementation of a conventional current lead with a pulse tube refrigerator has been validated to be working as an Integrated Current Lead (ICL) system for the Superconducting Magnetic Energy Storage (SMES). Realization of the system is primarily accounted for the flexibility of a pulse tube refrigerator, which does not posses any mechanical piston and/or displacer. As for an ultimate version of the ICL system, a High Temperature Superconducting (HTS) lead links a superconducting coil with a conventional copper lead. To ensure the minimization of heat loads to the superconducting coil, a pulse tube refrigerator has been upgraded to have a second cooling stage. This arrangement reduces not only the heat loads to the superconducting coil but also the operating cost for a SMES system. A prototype two-stage pulse tube refrigerator, series connected arrangement, was designed and fabricated to satisfy the requirements for the ICL system. Operation of the first stage refrigerator is a four-valve mode, while the second stage utilizes a double inlet configuration to ensure its confined geometry. The paper discusses the optimization of second stage cooling to validate the conceptual design

UDE-based control of variable-speed wind turbine systems

NASA Astrophysics Data System (ADS)

Ren, Beibei; Wang, Yeqin; Zhong, Qing-Chang

2017-01-01

In this paper, the control of a PMSG (permanent magnet synchronous generator)-based variable-speed wind turbine system with a back-to-back converter is considered. The uncertainty and disturbance estimator (UDE)-based control approach is applied to the regulation of the DC-link voltage and the control of the RSC (rotor-side converter) and the GSC (grid-side converter). For the rotor-side controller, the UDE-based vector control is developed for the RSC with PMSG control to facilitate the application of the MPPT (maximum power point tracking) algorithm for the maximum wind energy capture. For the grid-side controller, the UDE-based vector control is developed to control the GSC with the power reference generated by a UDE-based DC-link voltage controller. Compared with the conventional vector control, the UDE-based vector control can achieve reliable current decoupling control with fast response. Moreover, the UDE-based DC-link voltage regulation can achieve stable DC-link voltage under model uncertainties and external disturbances, e.g. wind speed variations. The effectiveness of the proposed UDE-based control approach is demonstrated through extensive simulation studies in the presence of coupled dynamics, model uncertainties and external disturbances under varying wind speeds. The UDE-based control is able to generate more energy, e.g. by 5% for the wind profile tested.

Modified Perfect Harmonics Cancellation Control of a Grid Interfaced SPV Power Generation

NASA Astrophysics Data System (ADS)

Singh, B.; Shahani, D. T.; Verma, A. K.

2015-03-01

This paper deals with a grid interfaced solar photo voltaic (SPV) power generating system with modified perfect harmonic cancellation (MPHC) control for power quality improvement in terms of mitigation of the current harmonics, power factor correction, control of point of common coupling (PCC) voltage with reactive power compensation and load balancing in a three phase distribution system. The proposed grid interfaced SPV system consists of a SPV array, a dc-dc boost converter and a voltage source converter (VSC) used for the compensation of other connected linear and nonlinear loads at PCC. The reference grid currents are estimated using MPHC method and control signals are derived by using pulse width modulation (PWM) current controller of VSC. The SPV power is fed to the common dc bus of VSC and dc-dc boost converter using maximum power point tracking (MPPT). The dc link voltage of VSC is regulated by using dc voltage proportional integral (PI) controller. The analysis of the proposed SPV power generating system is carried out under dc/ac short circuit and severe SPV-SX and SPV-TX intrusion.

Sliding mode observers for automotive alternator

NASA Astrophysics Data System (ADS)

Chen, De-Shiou

Estimator development for synchronous rectification of the automotive alternator is a desirable approach for estimating alternator's back electromotive forces (EMFs) without a direct mechanical sensor of the rotor position. Recent theoretical studies show that estimation of the back EMF may be observed based on system's phase current model by sensing electrical variables (AC phase currents and DC bus voltage) of the synchronous rectifier. Observer design of the back EMF estimation has been developed for constant engine speed. In this work, we are interested in nonlinear observer design of the back EMF estimation for the real case of variable engine speed. Initial back EMF estimate can be obtained from a first-order sliding mode observer (SMO) based on the phase current model. A fourth-order nonlinear asymptotic observer (NAO), complemented by the dynamics of the back EMF with time-varying frequency and amplitude, is then incorporated into the observer design for chattering reduction. Since the cost of required phase current sensors may be prohibitive, the most applicable approach in real implementation by measuring DC current of the synchronous rectifier is carried out in the dissertation. It is shown that the DC link current consists of sequential "windows" with partial information of the phase currents, hence, the cascaded NAO is responsible not only for the purpose of chattering reduction but also for necessarily accomplishing the process of estimation. Stability analyses of the proposed estimators are considered for most linear and time-varying cases. The stability of the NAO without speed information is substantiated by both numerical and experimental results. Prospective estimation algorithms for the case of battery current measurements are investigated. Theoretical study indicates that the convergence of the proposed LAO may be provided by high gain inputs. Since the order of the LAO/NAO for the battery current case is one order higher than that of the link current measurements, it is hard to find moderate values of the input gains for the real-time sampled-data systems. Technical difficulties in implementation of such high order discrete-time nonlinear estimators have been discussed. Directions of further investigations have been provided.

The NASA Astrophysics Data System: Capabilities and Roadmap for the 2020s

NASA Astrophysics Data System (ADS)

Accomazzi, Alberto; ADS Team

2018-06-01

The NASA Astrophysics Data System (ADS) is used daily by researchers and curators as a discovery platform for the Astronomy literature. Over the past several years, the ADS has been adding to the breadth and depth of its contents. Scholarly astronomy articles are now indexed as full-text documents, allowing for complete and accurate literature searches. High-level data products, data links, and software used in refereed astronomy papers are now also being ingested and indexed in our database. All the search functionality exposed in the new ADS interface is also available via its API, which we are continuing to develop and enhance. In this talk I will describe the current system, our current roadmap, and solicit input from the community regarding what additional data, services, and discovery capabilities the ADS should support.

Secure Network-Centric Aviation Communication (SNAC)

NASA Technical Reports Server (NTRS)

Nelson, Paul H.; Muha, Mark A.; Sheehe, Charles J.

2017-01-01

The existing National Airspace System (NAS) communications capabilities are largely unsecured, are not designed for efficient use of spectrum and collectively are not capable of servicing the future needs of the NAS with the inclusion of new operators in Unmanned Aviation Systems (UAS) or On Demand Mobility (ODM). SNAC will provide a ubiquitous secure, network-based communications architecture that will provide new service capabilities and allow for the migration of current communications to SNAC over time. The necessary change in communication technologies to digital domains will allow for the adoption of security mechanisms, sharing of link technologies, large increase in spectrum utilization, new forms of resilience and redundancy and the possibly of spectrum reuse. SNAC consists of a long term open architectural approach with increasingly capable designs used to steer research and development and enable operating capabilities that run in parallel with current NAS systems.

How to engage end-users in smart energy behaviour?

NASA Astrophysics Data System (ADS)

Valkering, Pieter; Laes, Erik; Kessels, Kris; Uyterlinde, Matthijs; Straver, Koen

2014-12-01

End users will play a crucial role in up-coming smart grids that aim to link end-users and energy providers in a better balanced and more efficient electricity system. Within this context, this paper aims to deliver a coherent view on current good practice in end-user engagement in smart grid projects. It draws from a recent review of theoretical insights from sustainable consumption behaviour, social marketing and innovation systems and empirical insights from recent smart grid projects to create an inventory of common motivators, enablers and barriers of behavioural change, and the end-user engagement principles that can be derived from that. We conclude with identifying current research challenges as input for a research agenda on end-user engagement in smart grids.

Integrating Engineering Data Systems for NASA Spaceflight Projects

NASA Technical Reports Server (NTRS)

Carvalho, Robert E.; Tollinger, Irene; Bell, David G.; Berrios, Daniel C.

2012-01-01

NASA has a large range of custom-built and commercial data systems to support spaceflight programs. Some of the systems are re-used by many programs and projects over time. Management and systems engineering processes require integration of data across many of these systems, a difficult problem given the widely diverse nature of system interfaces and data models. This paper describes an ongoing project to use a central data model with a web services architecture to support the integration and access of linked data across engineering functions for multiple NASA programs. The work involves the implementation of a web service-based middleware system called Data Aggregator to bring together data from a variety of systems to support space exploration. Data Aggregator includes a central data model registry for storing and managing links between the data in disparate systems. Initially developed for NASA's Constellation Program needs, Data Aggregator is currently being repurposed to support the International Space Station Program and new NASA projects with processes that involve significant aggregating and linking of data. This change in user needs led to development of a more streamlined data model registry for Data Aggregator in order to simplify adding new project application data as well as standardization of the Data Aggregator query syntax to facilitate cross-application querying by client applications. This paper documents the approach from a set of stand-alone engineering systems from which data are manually retrieved and integrated, to a web of engineering data systems from which the latest data are automatically retrieved and more quickly and accurately integrated. This paper includes the lessons learned through these efforts, including the design and development of a service-oriented architecture and the evolution of the data model registry approaches as the effort continues to evolve and adapt to support multiple NASA programs and priorities.

Implementation of a Multichannel Serial Data Streaming Algorithm using the Xilinx Serial RapidIO Solution

NASA Technical Reports Server (NTRS)

Doxley, Charles A.

2016-01-01

In the current world of applications that use reconfigurable technology implemented on field programmable gate arrays (FPGAs), there is a need for flexible architectures that can grow as the systems evolve. A project has limited resources and a fixed set of requirements that development efforts are tasked to meet. Designers must develop robust solutions that practically meet the current customer demands and also have the ability to grow for future performance. This paper describes the development of a high speed serial data streaming algorithm that allows for transmission of multiple data channels over a single serial link. The technique has the ability to change to meet new applications developed for future design considerations. This approach uses the Xilinx Serial RapidIO LOGICORE Solution to implement a flexible infrastructure to meet the current project requirements with the ability to adapt future system designs.

Surface Map Traffic Intent Displays and Net-Centric Data-link Communications for NextGen

NASA Technical Reports Server (NTRS)

Shelton, Kevin J.; Prinzel, Lawrence J., III; Jones, Denise R.; Allamandola, Angela S.; Arthur, Jarvis J., III; Bailey, Randall E.

2009-01-01

By 2025, U.S. air traffic is predicted to increase three fold and may strain the current air traffic management system, which may not be able to accommodate this growth. In response to this challenge, a revolutionary new concept has been proposed for U.S. aviation operations, termed the Next Generation Air Transportation System or "NextGen". Many key capabilities are being identified to enable NextGen, including the use of data-link communications. Because NextGen represents a radically different approach to air traffic management and requires a dramatic shift in the tasks, roles, and responsibilities for the flight deck, there are numerous research issues and challenges that must be overcome to ensure a safe, sustainable air transportation system. Flight deck display and crew-vehicle interaction concepts are being developed that proactively investigate and overcome potential technology and safety barriers that might otherwise constrain the full realization of NextGen. The paper describes simulation research, conducted at National Aeronautics and Space Administration (NASA) Langley Research Center, examining data-link communications and traffic intent data during envisioned four-dimensional trajectory (4DT)-based and equivalent visual (EV) surface operations. Overall, the results suggest that controller pilot data-link communications (CPDLC) with the use of mandatory pilot read-back of all clearances significantly enhanced situation awareness for 4DT and EV surface operations. The depiction of graphical traffic state and intent information on the surface map display further enhanced off-nominal detection and pilot qualitative reports of safety and awareness.

Telecommunications and navigation systems design for manned Mars exploration missions

NASA Astrophysics Data System (ADS)

Hall, Justin R.; Hastrup, Rolf C.

1989-06-01

This paper discusses typical manned Mars exploration needs for telecommunications, including preliminary navigation support functions. It is a brief progress report on an ongoing study program within the current NASA JPL Deep Space Network (DSN) activities. A typical Mars exploration case is defined, and support approaches comparing microwave and optical frequency performance for both local in situ and Mars-earth links are described. Optical telecommunication and navigation technology development opportunities in a Mars exploration program are also identified. A local Mars system telecommunication relay and navigation capability for service support of all Mars missions has been proposed as part of an overall solar system communications network. The effects of light-time delay and occultations on real-time mission decision-making are discussed; the availability of increased local mass data storage may be more important than increasing peak data rates to earth. The long-term frequency use plan will most likely include a mix of microwave, millimeter-wave and optical link capabilities to meet a variety of deep space mission needs.

Telecommunications and navigation systems design for manned Mars exploration missions

NASA Technical Reports Server (NTRS)

Hall, Justin R.; Hastrup, Rolf C.

1989-01-01

This paper discusses typical manned Mars exploration needs for telecommunications, including preliminary navigation support functions. It is a brief progress report on an ongoing study program within the current NASA JPL Deep Space Network (DSN) activities. A typical Mars exploration case is defined, and support approaches comparing microwave and optical frequency performance for both local in situ and Mars-earth links are described. Optical telecommunication and navigation technology development opportunities in a Mars exploration program are also identified. A local Mars system telecommunication relay and navigation capability for service support of all Mars missions has been proposed as part of an overall solar system communications network. The effects of light-time delay and occultations on real-time mission decision-making are discussed; the availability of increased local mass data storage may be more important than increasing peak data rates to earth. The long-term frequency use plan will most likely include a mix of microwave, millimeter-wave and optical link capabilities to meet a variety of deep space mission needs.

Forty and 80 GHz technology assessment and forecast including executive summary

NASA Technical Reports Server (NTRS)

Mazur, D. G.; Mackey, R. J., Jr.; Tanner, S. G.; Altman, F. J.; Nicholas, J. J., Jr.; Duchaine, K. A.

1976-01-01

The results of a survey to determine current demand and to forecast growth in demand for use of the 40 and 80 GHz bands during the 1980-2000 time period are given. The current state-of-the-art is presented, as well as the technology requirements of current and projected services. Potential developments were identified, and a forecast is made. The impacts of atmospheric attenuation in the 40 and 80 GHz bands were estimated for both with and without diversity. Three services for the 1980-2000 time period -- interactive television, high quality three stereo pair audio, and 30 MB data -- are given with system requirements and up and down-link calculations.

SHARP: A multi-mission artificial intelligence system for spacecraft telemetry monitoring and diagnosis

NASA Technical Reports Server (NTRS)

Lawson, Denise L.; James, Mark L.

1989-01-01

The Spacecraft Health Automated Reasoning Prototype (SHARP) is a system designed to demonstrate automated health and status analysis for multi-mission spacecraft and ground data systems operations. Telecommunications link analysis of the Voyager 2 spacecraft is the initial focus for the SHARP system demonstration which will occur during Voyager's encounter with the planet Neptune in August, 1989, in parallel with real time Voyager operations. The SHARP system combines conventional computer science methodologies with artificial intelligence techniques to produce an effective method for detecting and analyzing potential spacecraft and ground systems problems. The system performs real time analysis of spacecraft and other related telemetry, and is also capable of examining data in historical context. A brief introduction is given to the spacecraft and ground systems monitoring process at the Jet Propulsion Laboratory. The current method of operation for monitoring the Voyager Telecommunications subsystem is described, and the difficulties associated with the existing technology are highlighted. The approach taken in the SHARP system to overcome the current limitations is also described, as well as both the conventional and artificial intelligence solutions developed in SHARP.

SHARP: A multi-mission AI system for spacecraft telemetry monitoring and diagnosis

NASA Technical Reports Server (NTRS)

Lawson, Denise L.; James, Mark L.

1989-01-01

The Spacecraft Health Automated Reasoning Prototype (SHARP) is a system designed to demonstrate automated health and status analysis for multi-mission spacecraft and ground data systems operations. Telecommunications link analysis of the Voyager II spacecraft is the initial focus for the SHARP system demonstration which will occur during Voyager's encounter with the planet Neptune in August, 1989, in parallel with real-time Voyager operations. The SHARP system combines conventional computer science methodologies with artificial intelligence techniques to produce an effective method for detecting and analyzing potential spacecraft and ground systems problems. The system performs real-time analysis of spacecraft and other related telemetry, and is also capable of examining data in historical context. A brief introduction is given to the spacecraft and ground systems monitoring process at the Jet Propulsion Laboratory. The current method of operation for monitoring the Voyager Telecommunications subsystem is described, and the difficulties associated with the existing technology are highlighted. The approach taken in the SHARP system to overcome the current limitations is also described, as well as both the conventional and artificial intelligence solutions developed in SHARP.

Breast cancer treatment across health care systems: linking electronic medical records and state registry data to enable outcomes research.

PubMed

Kurian, Allison W; Mitani, Aya; Desai, Manisha; Yu, Peter P; Seto, Tina; Weber, Susan C; Olson, Cliff; Kenkare, Pragati; Gomez, Scarlett L; de Bruin, Monique A; Horst, Kathleen; Belkora, Jeffrey; May, Suepattra G; Frosch, Dominick L; Blayney, Douglas W; Luft, Harold S; Das, Amar K

2014-01-01

Understanding of cancer outcomes is limited by data fragmentation. In the current study, the authors analyzed the information yielded by integrating breast cancer data from 3 sources: electronic medical records (EMRs) from 2 health care systems and the state registry. Diagnostic test and treatment data were extracted from the EMRs of all patients with breast cancer treated between 2000 and 2010 in 2 independent California institutions: a community-based practice (Palo Alto Medical Foundation; "Community") and an academic medical center (Stanford University; "University"). The authors incorporated records from the population-based California Cancer Registry and then linked EMR-California Cancer Registry data sets of Community and University patients. The authors initially identified 8210 University patients and 5770 Community patients; linked data sets revealed a 16% patient overlap, yielding 12,109 unique patients. The percentage of all Community patients, but not University patients, treated at both institutions increased with worsening cancer prognostic factors. Before linking the data sets, Community patients appeared to receive less intervention than University patients (mastectomy: 37.6% vs 43.2%; chemotherapy: 35% vs 41.7%; magnetic resonance imaging: 10% vs 29.3%; and genetic testing: 2.5% vs 9.2%). Linked Community and University data sets revealed that patients treated at both institutions received substantially more interventions (mastectomy: 55.8%; chemotherapy: 47.2%; magnetic resonance imaging: 38.9%; and genetic testing: 10.9% [P < .001 for each 3-way institutional comparison]). Data linkage identified 16% of patients who were treated in 2 health care systems and who, despite comparable prognostic factors, received far more intensive treatment than others. By integrating complementary data from EMRs and population-based registries, a more comprehensive understanding of breast cancer care and factors that drive treatment use was obtained. © 2013 American Cancer Society.

Modeling and real time simulation of an HVDC inverter feeding a weak AC system based on commutation failure study.

PubMed

Mankour, Mohamed; Khiat, Mounir; Ghomri, Leila; Chaker, Abdelkader; Bessalah, Mourad

2018-06-01

This paper presents modeling and study of 12-pulse HVDC (High Voltage Direct Current) based on real time simulation where the HVDC inverter is connected to a weak AC system. In goal to study the dynamic performance of the HVDC link, two serious kind of disturbance are applied at HVDC converters where the first one is the single phase to ground AC fault and the second one is the DC link to ground fault. The study is based on two different mode of analysis, which the first is to test the performance of the DC control and the second is focalized to study the effect of the protection function on the system behavior. This real time simulation considers the strength of the AC system to witch is connected and his relativity with the capacity of the DC link. The results obtained are validated by means of RT-lab platform using digital Real time simulator Hypersim (OP-5600), the results carried out show the effect of the DC control and the influence of the protection function to reduce the probability of commutation failures and also for helping inverter to take out from commutation failure even while the DC control fails to eliminate them. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

TDRSS Onboard Navigation System (TONS) flight qualification experiment

NASA Technical Reports Server (NTRS)

Gramling, C. J.; Hart, R. C.; Folta, D. C.; Long, A. C.

1994-01-01

The National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) is currently developing an operational Tracking and Data Relay Satellite (TDRS) System (TDRSS) Onboard Navigation System (TONS) to provide realtime, autonomous, high-accuracy navigation products to users of TDRSS. A TONS experiment was implemented on the Explorer Platform/Extreme Ultraviolet Explorer (EP/EUVE) spacecraft, launched June 7, 1992, to flight qualify the TONS operational system using TDRSS forward-link communications services. This paper provides a detailed evaluation of the flight hardware, an ultrastable oscillator (USO) and Doppler extractor (DE) card in one of the TDRSS user transponders and the ground-based prototype flight software performance, based on the 1 year of TONS experiment operation. The TONS experiment results are used to project the expected performance of the TONS 1 operational system. TONS 1 processes Doppler data derived from scheduled forward-link S-band services using a sequential estimation algorithm enhanced by a sophisticated process noise model to provide onboard orbit and frequency determination and time maintenance. TONS 1 will be the prime navigation system on the Earth Observing System (EOS)-AM1 spacecraft, currently scheduled for launch in 1998. Inflight evaluation of the USO and DE short-term and long-term stability indicates that the performance is excellent. Analysis of the TONS prototype flight software performance indicates that realtime onboard position accuracies of better than 25 meters root-mean-square are achievable with one tracking contact every one to two orbits for the EP/EUVE 525-kilometer altitude, 28.5 degree inclination orbit. The success of the TONS experiment demonstrates the flight readiness of TONS to support the EOS-AM1 mission.

Current limiting behavior in three-phase transformer-type SFCLs using an iron core according to variety of fault

NASA Astrophysics Data System (ADS)

Cho, Yong-Sun; Jung, Byung-Ik; Ha, Kyoung-Hun; Choi, Soo-Geun; Park, Hyoung-Min; Choi, Hyo-Sang

To apply the superconducting fault current limiter (SFCL) to the power system, the reliability of the fault-current-limiting operation must be ensured in diverse fault conditions. The SFCL must also be linked to the operation of the high-speed recloser in the power system. In this study, a three-phase transformer-type SFCL, which has a neutral line to improve the simultaneous quench characteristics of superconducting elements, was manufactured to analyze the fault-current-limiting characteristic according to the single, double, and triple line-to-ground faults. The transformer-type SFCL, wherein three-phase windings are connected to one iron core, reduced the burden on the superconducting element as the superconducting element on the sound phase was also quenched in the case of the single line-to-ground fault. In the case of double or triple line-to-ground faults, the flux from the faulted phase winding was interlinked with other faulted or sound phase windings, and the fault-current-limiting rate decreased because the windings of three phases were inductively connected by one iron core.

Electronic properties of a molecular system with Platinum

NASA Astrophysics Data System (ADS)

Ojeda, J. H.; Medina, F. G.; Becerra-Alonso, David

2017-10-01

The electronic properties are studied using a finite homogeneous molecule called Trans-platinum-linked oligo(tetraethenylethenes). This system is composed of individual molecules such as benzene rings, platinum, Phosphore and Sulfur. The mechanism for the study of the electron transport through this system is based on placing the molecule between metal contacts to control the current through the molecular system. We study this molecule based on the tight-binding approach for the calculation of the transport properties using the Landauer-Büttiker formalism and the Fischer-Lee relationship, based on a semi-analytic Green's function method within a real-space renormalization approach. Our results show a significant agreement with experimental measurements.

Serotonin transporter genotype (5-HTTLPR) and electrocortical responses indicating the sensitivity to negative emotional cues.

PubMed

Papousek, Ilona; Reiser, Eva M; Schulter, Günter; Fink, Andreas; Holmes, Emily A; Niederstätter, Harald; Nagl, Simone; Parson, Walther; Weiss, Elisabeth M

2013-12-01

Growing literature indicates that emotional reactivity and regulation are strongly linked to genetic modulation of serotonergic neurotransmission. However, until now, most studies have focused on the relationship between genotypic markers, in particular the serotonin transporter-linked polymorphic region (5-HTTLPR), and neural structures using MRI. The current study aimed to bridge the gap between the relevant MRI literature on the effects of the 5-HTTLPR genotype and the research tradition focusing on transient lateralized changes of electrocortical activity in the prefrontal cortex using electroencephalography (EEG). Lateral shifts of EEG alpha asymmetry in response to an aversive film consisting of scenes of real injury and death were assessed in healthy participants (n = 165). To evaluate the specificity of the 5-HTTLPR effect, participants were also tested for the COMT Val158Met polymorphism which is linked to dopamine inactivation. While viewing the film, individuals homozygous for the 5-HTTLPR short allele displayed a clear lateral shift of dorsolateral frontal activity to the right, which was virtually absent in participants carrying the long allele. The heightened electrocortical response to the aversive stimulation and its direction indicates a greater propensity of s/s homozygotes to experience withdrawal oriented affect in response to negative emotion cues in the environment. Moreover, together with previous research the findings support the notion of a link between the serotonergic system and self-regulation related to avoidance motivation, and a link between the dopaminergic system and self-regulation related to approach motivation.

Exploring the future with anticipatory networks

NASA Astrophysics Data System (ADS)

Skulimowski, A. M. J.

2013-01-01

This paper presents a theory of anticipatory networks that originates from anticipatory models of consequences in multicriteria decision problems. When making a decision, the decision maker takes into account the anticipated outcomes of each future decision problem linked by the causal relations with the present one. In a network of linked decision problems, the causal relations are defined between time-ordered nodes. The scenarios of future consequences of each decision are modeled by multiple vertices starting from an appropriate node. The network is supplemented by one or more relations of anticipation, or future feedback, which describe a situation where decision makers take into account the anticipated results of some future optimization problems while making their choice. So arises a multigraph of decision problems linked causally and by one or more anticipation relation, termed here the anticipatory network. We will present the properties of anticipatory networks and propose a method of reducing, transforming and using them to solve current decision problems. Furthermore, it will be shown that most anticipatory networks can be regarded as superanticipatory systems, i.e. systems that are anticipatory in the Rosen sense and contain a future model of at least one other anticipatory system. The anticipatory networks can also be applied to filter the set of future scenarios in a foresight exercise.

The effects of mixotrophy on the stability and dynamics of a simple planktonic food web

USGS Publications Warehouse

Jost, Christian; Lawrence, Cathryn A.; Campolongo, Francesca; Wouter, van de Bund; Hill, Sheryl; DeAngelis, Donald L.

2004-01-01

Recognition of the microbial loop as an important part of aquatic ecosystems disrupted the notion of simple linear food chains. However, current research suggests that even the microbial loop paradigm is a gross simplification of microbial interactions due to the presence of mixotrophs—organisms that both photosynthesize and graze. We present a simple food web model with four trophic species, three of them arranged in a food chain (nutrients–autotrophs–herbivores) and the fourth as a mixotroph with links to both the nutrients and the autotrophs. This model is used to study the general implications of inclusion of the mixotrophic link in microbial food webs and the specific predictions for a parameterization that describes open ocean mixed layer plankton dynamics. The analysis indicates that the system parameters reside in a region of the parameter space where the dynamics converge to a stable equilibrium rather than displaying periodic or chaotic solutions. However, convergence requires weeks to months, suggesting that the system would never reach equilibrium in the ocean due to alteration of the physical forcing regime. Most importantly, the mixotrophic grazing link seems to stabilize the system in this region of the parameter space, particularly when nutrient recycling feedback loops are included.

Exploring Bim for Operational Integrated Asset Management - a Preliminary Study Utilising Real-World Infrastructure Data

NASA Astrophysics Data System (ADS)

Boyes, G. A.; Ellul, C.; Irwin, D.

2017-10-01

The use of 3D information models within collaborative working environments and the practice of Building Information Modelling (BIM) are becoming more commonplace within infrastructure projects. Currently used predominantly during the design and construction phase, the use of BIM is capable in theory of providing the information at handover that will satisfy the Asset Information Requirements (AIRs) of the future Infrastructure Manager (IM). One particular challenge is establishing a link between existing construction-centric information and the asset-centric information needed for future operations. Crossrail, a project to build a new high-frequency railway underneath London, is handling many such challenges as they prepare to handover their digital information to the future operator, in particular the need to provide a two-way link between a federated 3D CAD model and an object-relational Asset Information Management System (AIMS). This paper focusses on the potential for improved Asset Management (AM) by integrating BIM and GIS systems and practices, and makes a preliminary report on how 3D spatial queries can be used to establish a two-way relational link between two information systems (3D geometry and asset lists), as well as the challenges being overcome to transform the data to be suitable for AM.

When should acute exacerbations of COPD be treated with systemic corticosteroids and antibiotics in primary care: a systematic review of current COPD guidelines.

PubMed

Laue, Johanna; Reierth, Eirik; Melbye, Hasse

2015-02-19

Not all patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) benefit from treatment with systemic corticosteroids and antibiotics. The aim of the study was to identify criteria recommended in current COPD guidelines for treating acute exacerbations with systemic corticosteroids and antibiotics and to assess the underlying evidence. Current COPD guidelines were identified by a systematic literature search. The most recent guidelines as per country/organisation containing recommendations about treating acute exacerbations of COPD were included. Guideline development and criteria for treating acute exacerbations with systemic corticosteroids and antibiotics were appraised. Randomised controlled trials directly referred to in context with the recommendations were evaluated in terms of study design, setting, and study population. A total of 19 COPD guidelines were included. Systemic corticosteroids were often universally recommended to all patients with acute exacerbations. Criteria for treatment with antibiotics were mainly an increase in respiratory symptoms. Objective diagnostic tests or clinical examination were only rarely recommended. Only few criteria were directly linked to underlying evidence, and the trial patients represented a highly specific group of COPD patients. Current COPD guidelines are of little help in primary care to identify patients with acute exacerbations probably benefitting from treatment with systemic corticosteroids and antibiotics in primary care, and might contribute to overuse or inappropriate use of either treatment.

Wireless local area networking for linking a PC reporting system and PACS: clinical feasibility in emergency reporting.

PubMed

Yoshihiro, Akiko; Nakata, Norio; Harada, Junta; Tada, Shimpei

2002-01-01

Although local area networks (LANs) are commonplace in hospital-based radiology departments today, wireless LANs are still relatively unknown and untried. A linked wireless reporting system was developed to improve work throughput and efficiency. It allows radiologists, physicians, and technologists to review current radiology reports and images and instantly compare them with reports and images from previous examinations. This reporting system also facilitates creation of teaching files quickly, easily, and accurately. It consists of a Digital Imaging and Communications in Medicine 3.0-based picture archiving and communication system (PACS), a diagnostic report server, and portable laptop computers. The PACS interfaces with magnetic resonance imagers, computed tomographic scanners, and computed radiography equipment. The same kind of functionality is achievable with a wireless LAN as with a wired LAN, with comparable bandwidth but with less cabling infrastructure required. This wireless system is presently incorporated into the operations of the emergency and radiology departments, with future plans calling for applications in operating rooms, outpatient departments, all hospital wards, and intensive care units. No major problems have been encountered with the system, which is in constant use and appears to be quite successful. Copyright RSNA, 2002

The science of complexity and the role of mathematics

NASA Astrophysics Data System (ADS)

Bountis, T.; Johnson, J.; Provata, A.; Tsironis, G.

2016-09-01

In the middle of the second decade of the 21st century, Complexity Science has reached a turning point. Its rapid advancement over the last 30 years has led to remarkable new concepts, methods and techniques, whose applications to complex systems of the physical, biological and social sciences has produced a great number of exciting results. The approach has so far depended almost exclusively on the solution of a wide variety of mathematical models by sophisticated numerical techniques and extensive simulations that have inspired a new generation of researchers interested in complex systems. Still, the impact of Complexity beyond the natural sciences, its applications to Medicine, Technology, Economics, Society and Policy are only now beginning to be explored. Furthermore, its basic principles and methods have so far remained within the realm of high level research institutions, out of reach of society's urgent need for practical applications. To address these issues, evaluate the current situation and bring Complexity Science closer to university students, a series of Ph.D. Schools on Mathematical Modeling of Complex Systems was launched, starting in July 2011 at the University of Patras, Greece (see http://www.math.upatras.gr/˜phdsch11). These Schools lasted two weeks each and included, beyond introductory lectures, a conference component of 2-3 days where students were exposed to recent results mainly presented by young researchers. The Ph.D. Schools continued successfully, the 2nd one taking place at Pescara, Italy (2012), (see http://www.nodycosy.unich.it), the 3d one at Heraklion, Crete, Greece (2013) (see http://nlsconf2013.physics.uoc.gr) and the 4th one in Athens, Greece (2014) (see http://nlsconf2014.physics.uoc.gr) (2014). This Special Theme volume contains the proceedings of the 5th Ph.D. School-Conference of this series held at the University of Patras, Greece, 20 30 July, 2015 (see http://www.math.upatras.gr/˜phdsch15) and includes many of the introductory lectures and research talks presented at this event. The primary concern of all those that participated in these events was to emphasize the role of mathematics, modeling and numerical simulation, which are indispensable for understanding what we call complex behavior of physical, biological, technological and socio - economical systems. In the discussions that took place, a great number of participants expressed the need to formulate a unifying theory of complex systems based on the main conclusions that have been reached so far in the science of Complexity. As Guest Editors of this volume, we also feel that it is important to reach some fundamental conclusions concerning common phenomena, theories and methodologies that arise in Complexity. We should all work to explore common rules and approaches, particularly in view of the remarkable challenges that face us all regarding complex social problems that threaten present day society and civilization as we know them.

[National system of protection against electromagnetic fields 0 Hz-300 GHz in the light of current legal regulations].

PubMed

Aniołczyk, Halina

2006-01-01

Exposure to electromagnetic fields (EMF) occurs when man is exposed to the effect of electric, magnetic and electromagnetic fields and contact currents different from those resulting from physiological processes in the organism or other natural phenomena. In Poland, the system of protection against EMF has been functioning for over 35 years. In 2001, when the Minister of Labor and Social Policy issued the regulation introducing the maximum admissible intensities (MAI) for electromagnetic fields and radiation within the range of 0 Hz-300 GHz, the system was directed mainly towards evaluation of exposure to EMF occurring in the occupational environment. The system is linked via MAI values with human protection in the natural environment. In this paper, the background, principles and the range of the national system of protection against EMF and its monitoring are presented. The project of implementation of EU directives, following Poland's accession to the European Union is also discussed.

Dewey Redux: Virtual Dewey Resources Deliver Trusted, Familiar 21st-Century Information

ERIC Educational Resources Information Center

Adamich, Tom

2013-01-01

Where do school librarians go to find out the latest on how the Dewey Decimal Classification (DDC) system is being used (and will be used) in the 21st-century virtual-knowledge world? The answer is two great websites containing: (1) the most current information on both Dewey and linked data at ; (2) Dewey here-and-now…

The Link between Competitive Sport Participation and Self-Concept in Early Adolescence: A Consideration of Gender and Sport Orientation

ERIC Educational Resources Information Center

Findlay, Leanne C.; Bowker, Anne

2009-01-01

The current study explored specific aspects of sports and individuals on 4 domains of the self-system (physical competence and physical appearance self-concept, global physical and general self-esteem). Participants were 351 adolescents (M[subscript age] = 13.45, SD = 1.25 years, males n = 132) recruited from elite sports and regular school…

The rainbow: from ancient Greece to modern optics.

PubMed

Schwab, Ivan R; Lee, W Barry; Bisno, David

2009-01-01

We provide a historical perspective on the rainbow, with a review of early research and observations regarding the rainbow's origin and a discussion of some of the major contributors to our current understanding of what the rainbow represents. An overview of the various types of rainbows is undertaken. We conclude with a discussion of the rainbow's link to refraction, light, the visual system, and perception.

Closing the Missing Links and Opening the Relationships among the Factors: A Literature Review on the Use of Clicker Technology Using the 3P Model

ERIC Educational Resources Information Center

Han, Jae Hoon

2014-01-01

Clicker technology is one of the most widely adopted communication systems in college classroom environments. Previous literature reviews on clicker technology have identified and thoroughly documented the advantages, disadvantages, and implications of the use of this technology; the current review is intended to synthesize those earlier findings…

Air quality and future energy system planning

NASA Astrophysics Data System (ADS)

Sobral Mourao, Zenaida; Konadu, Dennis; Lupton, Rick

2016-04-01

Ambient air pollution has been linked to an increasing number of premature deaths throughout the world. Projected increases in demand for food, energy resources and manufactured products will likely contribute to exacerbate air pollution with an increasing impact on human health, agricultural productivity and climate change. Current events such as tampering emissions tests by VW car manufacturers, failure to comply with EU Air Quality directives and WHO guidelines by many EU countries, the problem of smog in Chinese cities and new industrial emissions regulations represent unique challenges but also opportunities for regulators, local authorities and industry. However current models and practices of energy and resource use do not consider ambient air impacts as an integral part of the planing process. Furthermore the analysis of drivers, sources and impacts of air pollution is often fragmented, difficult to understand and lacks effective visualization tools that bring all of these components together. This work aims to develop a model that links impacts of air quality on human health and ecosystems to current and future developments in the energy system, industrial and agricultural activity and patterns of land use. The model will be added to the ForeseerTM tool, which is an integrated resource analysis platform that has been developed at the University of Cambridge initially with funding from BP and more recently through the EPSRC funded Whole Systems Energy Modeling (WholeSEM) project. The basis of the tool is a set of linked physical models for energy, water and land, including the technologies that are used to transform these resources into final services such as housing, food, transport and household goods. The new air quality model will explore different feedback effects between energy, land and atmospheric systems with the overarching goal of supporting better communication about the drivers of air quality and to incorporate concerns about air quality into energy system planning. Some example applications of this work are: (1) to discover conflicts and synergies between air quality regulations and future developments in the energy system and land use change; (2) to show the drivers of air quality in a given spatial context; (3) to explore effective ways to visualize impacts of different energy, land use and emissions control policies on air quality. An initial test case for the Bay Area in California will be presented, extending the scope of the existing California ForeseerTM tool to identify impacts of different policies within the water-energy-land nexus on local air quality.

Advances in Ka-Band Communication System for CubeSats and SmallSats

NASA Technical Reports Server (NTRS)

Kegege, Obadiah; Wong, Yen F.; Altunc, Serhat

2016-01-01

A study was performed that evaluated the feasibility of Ka-band communication system to provide CubeSat/SmallSat high rate science data downlink with ground antennas ranging from the small portable 1.2m/2.4m to apertures 5.4M, 7.3M, 11M, and 18M, for Low Earth Orbit (LEO) to Lunar CubeSat missions. This study included link analysis to determine the data rate requirement, based on the current TRL of Ka-band flight hardware and ground support infrastructure. Recent advances in Ka-band transceivers and antennas, options of portable ground stations, and various coverage distances were included in the analysis. The link/coverage analysis results show that Cubesat/Smallsat missions communication requirements including frequencies and data rates can be met by utilizing Near Earth Network (NEN) Ka-band support with 2 W and high gain (>6 dBi) antennas.

The role of foundations: Rockefeller Foundation.

PubMed

Rockefeller, David

The consequences of climate change and the impacts of human activity on the environment have made it clearer than ever before that we must evolve our current model of public health to better account for the inextricable link between human health and the natural systems on which it depends-creating a "public health 2.0" that builds on the innovations of the twentieth century to account for a world where humans have bypassed planetary boundaries to achieve well-being. First coined at the Rockefeller Foundation's Centennial gathering in Beijing in 2013, "Planetary Health" will factor in future health and environmental harms over present-day gains, particularly those that disproportionately affect the poor and those in developing nations. To build this new field, foundations must address the challenge of information, increasing support for research to bridge knowledge gaps on the links between economic development, natural systems, and human health.

Prizes for innovation of new medicines and vaccines.

PubMed

Love, James; Hubbard, Tim

2009-01-01

This article argues that prizes can help stimulate medical innovation, control costs and ensure greater access to new medicines and vaccines. The authors explore four increasingly ambitious prize options to reward medical innovation, each addressing flaws in the current patent system. The first option promotes innovation through a large prize fund linked to the impact on health outcomes; the second option rewards the sharing of knowledge, data, and technology with open source dividends; the third option awards prizes for interim benchmarks and discrete technical problems; and the final option removes the exclusive right to use patented inventions in upstream research in favor of prizes. The authors conclude that a system of prizes to reward drug development would break the link between R&D incentives and product prices, and that such a reform is needed to improve innovation and access to new medicines and vaccines.

The Second Brain: Is the Gut Microbiota a Link Between Obesity and Central Nervous System Disorders?

PubMed Central

Ochoa-Repáraz, Javier; Kasper, Lloyd H.

2016-01-01

The gut-brain axis is a bi-directional integrated system composed by immune, endocrine and neuronal components by which the gap between the gut microbiota and the brain is significantly impacted. An increasing number of different gut microbial species are now postulated to regulate brain function in health and disease. The westernized diet is hypothesized to be the cause of the current obesity levels in many countries, a major socio-economical health problem. Experimental and epidemiological evidence suggest that the gut microbiota is responsible for significant immunologic, neuronal and endocrine changes that lead to obesity. We hypothesize that the gut microbiota, and changes associated with diet, affect the gut-brain axis and may possibly contribute to the development of mental illness. In this review, we discuss the links between diet, gut dysbiosis, obesity, and immunologic and neurologic diseases that impact brain function and behavior. PMID:26865085

The Second Brain: Is the Gut Microbiota a Link Between Obesity and Central Nervous System Disorders?

PubMed

Ochoa-Repáraz, Javier; Kasper, Lloyd H

2016-03-01

The gut-brain axis is a bi-directional integrated system composed by immune, endocrine, and neuronal components by which the gap between the gut microbiota and the brain is significantly impacted. An increasing number of different gut microbial species are now postulated to regulate brain function in health and disease. The westernized diet is hypothesized to be the cause of the current obesity levels in many countries, a major socio-economical health problem. Experimental and epidemiological evidence suggest that the gut microbiota is responsible for significant immunologic, neuronal, and endocrine changes that lead to obesity. We hypothesize that the gut microbiota, and changes associated with diet, affect the gut-brain axis and may possibly contribute to the development of mental illness. In this review, we discuss the links between diet, gut dysbiosis, obesity, and immunologic and neurologic diseases that impact brain function and behavior.

Phase slips in superconducting weak links

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimmel, Gregory; Glatz, Andreas; Aranson, Igor S.

2017-01-01

Superconducting vortices and phase slips are primary mechanisms of dissipation in superconducting, superfluid, and cold-atom systems. While the dynamics of vortices is fairly well described, phase slips occurring in quasi-one- dimensional superconducting wires still elude understanding. The main reason is that phase slips are strongly nonlinear time-dependent phenomena that cannot be cast in terms of small perturbations of the superconducting state. Here we study phase slips occurring in superconducting weak links. Thanks to partial suppression of superconductivity in weak links, we employ a weakly nonlinear approximation for dynamic phase slips. This approximation is not valid for homogeneous superconducting wires andmore » slabs. Using the numerical solution of the time-dependent Ginzburg-Landau equation and bifurcation analysis of stationary solutions, we show that the onset of phase slips occurs via an infinite period bifurcation, which is manifested in a specific voltage-current dependence. Our analytical results are in good agreement with simulations.« less

Lipids, adiposity and tendinopathy: is there a mechanistic link? Critical review

PubMed Central

Scott, Alex; Zwerver, Johannes; Grewal, Navi; de Sa, Agnetha; Alktebi, Thuraya; Granville, David J; Hart, David A

2015-01-01

Being overweight or obese is associated with an elevated risk of tendon pathology. However, for sportspeople the epidemiological data linking weight or adiposity on one hand, and risk of tendon pathology on the other, are less consistent. Indeed, the mechanistic links between diet, adiposity and tendon pathology remain largely unexamined. Recent studies have begun to examine the effects of dietary interventions on outcomes such as tendon biomechanics or pain. Oxidised low-density lipoprotein has been shown to (A) accumulate in the tendon tissues of mice that eat a fatty diet and (B) induce a pathological phenotype in human tendon cells. This paper addresses the current debate: is excessive body mass index (causing increased load and strain on tendon tissue) per se the underlying mechanism? Or do local or systemic influences of fat on tendons predispose to tendon pathology? This narrative review argues that excessive blood lipids may be an important avenue for clinical investigations. PMID:25488953

Properties of Bread Dough with Added Fiber Polysaccharides and Phenolic Antioxidants: A Review

PubMed Central

Sivam, Anusooya S; Sun-Waterhouse, Dongxiao; Quek, SiewYoung; Perera, Conrad O

2010-01-01

During breadmaking, different ingredients are used to ensure the development of a continuous protein network that is essential for bread quality. Interests in incorporating bioactive ingredients such as dietary fiber (DF) and phenolic antioxidants into popular foods such as bread have grown rapidly, due to the increased consumer health awareness. The added bioactive ingredients may or may not promote the protein cross-links. Appropriate cross-links among wheat proteins, fiber polysaccharides, and phenolic antioxidants could be the most critical factor for bread dough enhanced with DF and phenolic antioxidants. Such cross-links may influence the structure and properties of a bread system during baking. This article presents a brief overview of our current knowledge of the fate of the key components (wheat proteins, fibers, and phenolic antioxidants) and how they might interact during bread dough development and baking. PMID:21535512

Linked-List-Based Multibody Dynamics (MBDyn) Engine

NASA Technical Reports Server (NTRS)

MacLean, John; Brain, Thomas; Wuiocho, Leslie; Huynh, An; Ghosh, Tushar

2012-01-01

This new release of MBDyn is a software engine that calculates the dynamics states of kinematic, rigid, or flexible multibody systems. An MBDyn multibody system may consist of multiple groups of articulated chains, trees, or closed-loop topologies. Transient topologies are handled through conservation of energy and momentum. The solution for rigid-body systems is exact, and several configurable levels of nonlinear term fidelity are available for flexible dynamics systems. The algorithms have been optimized for efficiency and can be used for both non-real-time (NRT) and real-time (RT) simulations. Interfaces are currently compatible with NASA's Trick Simulation Environment. This new release represents a significant advance in capability and ease of use. The two most significant new additions are an application programming interface (API) that clarifies and simplifies use of MBDyn, and a link-list infrastructure that allows a single MBDyn instance to propagate an arbitrary number of interacting groups of multibody top ologies. MBDyn calculates state and state derivative vectors for integration using an external integration routine. A Trickcompatible interface is provided for initialization, data logging, integration, and input/output.

Mechanism-based Pharmacovigilance over the Life Sciences Linked Open Data Cloud.

PubMed

Kamdar, Maulik R; Musen, Mark A

2017-01-01

Adverse drug reactions (ADR) result in significant morbidity and mortality in patients, and a substantial proportion of these ADRs are caused by drug-drug interactions (DDIs). Pharmacovigilance methods are used to detect unanticipated DDIs and ADRs by mining Spontaneous Reporting Systems, such as the US FDA Adverse Event Reporting System (FAERS). However, these methods do not provide mechanistic explanations for the discovered drug-ADR associations in a systematic manner. In this paper, we present a systems pharmacology-based approach to perform mechanism-based pharmacovigilance. We integrate data and knowledge from four different sources using Semantic Web Technologies and Linked Data principles to generate a systems network. We present a network-based Apriori algorithm for association mining in FAERS reports. We evaluate our method against existing pharmacovigilance methods for three different validation sets. Our method has AUROC statistics of 0.7-0.8, similar to current methods, and event-specific thresholds generate AUROC statistics greater than 0.75 for certain ADRs. Finally, we discuss the benefits of using Semantic Web technologies to attain the objectives for mechanism-based pharmacovigilance.

Indigenous Māori perspectives on urban transport patterns linked to health and wellbeing.

PubMed

Raerino Ngāti Awa Te Arawa, K; Macmillan, Alex K; Jones Ngāti Kahungunu, Rhys G

2013-09-01

There is a growing body of research linking urban transport systems to inequities in health. However, there is a lack of research providing evidence of the effect of transport systems on indigenous family wellbeing. We examined the connections between urban transport and the health and wellbeing of Māori, the indigenous people of New Zealand. We provide an indigenous exploration of current urban transport systems, with a particular focus on the impacts of car dependence and the need for culturally relevant travel. We interviewed nineteen Māori participants utilising qualitative research techniques underpinned by an indigenous research methodology (Kaupapa Māori). The data highlighted the importance of accessing cultural activities and sites relevant to 'being Māori', and issues with affordability and safety of public transport. Understanding the relationship between indigenous wellbeing and transport systems that goes further than limited discourses of inequity is essential to improving transport for indigenous wellbeing. Providing an indigenous voice in transport decision-making will make it more likely that indigenous health and wellbeing is prioritised in transport planning. Copyright © 2013. Published by Elsevier Ltd.

LAILAPS: the plant science search engine.

PubMed

Esch, Maria; Chen, Jinbo; Colmsee, Christian; Klapperstück, Matthias; Grafahrend-Belau, Eva; Scholz, Uwe; Lange, Matthias

2015-01-01

With the number of sequenced plant genomes growing, the number of predicted genes and functional annotations is also increasing. The association between genes and phenotypic traits is currently of great interest. Unfortunately, the information available today is widely scattered over a number of different databases. Information retrieval (IR) has become an all-encompassing bioinformatics methodology for extracting knowledge from complex, heterogeneous and distributed databases, and therefore can be a useful tool for obtaining a comprehensive view of plant genomics, from genes to traits. Here we describe LAILAPS (http://lailaps.ipk-gatersleben.de), an IR system designed to link plant genomic data in the context of phenotypic attributes for a detailed forward genetic research. LAILAPS comprises around 65 million indexed documents, encompassing >13 major life science databases with around 80 million links to plant genomic resources. The LAILAPS search engine allows fuzzy querying for candidate genes linked to specific traits over a loosely integrated system of indexed and interlinked genome databases. Query assistance and an evidence-based annotation system enable time-efficient and comprehensive information retrieval. An artificial neural network incorporating user feedback and behavior tracking allows relevance sorting of results. We fully describe LAILAPS's functionality and capabilities by comparing this system's performance with other widely used systems and by reporting both a validation in maize and a knowledge discovery use-case focusing on candidate genes in barley. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

Security Concepts for Satellite Links

NASA Astrophysics Data System (ADS)

Tobehn, C.; Penné, B.; Rathje, R.; Weigl, A.; Gorecki, Ch.; Michalik, H.

2008-08-01

The high costs to develop, launch and maintain a satellite network makes protecting the assets imperative. Attacks may be passive such as eavesdropping on the payload data. More serious threat are active attacks that try to gain control of the satellite, which may lead to the total lost of the satellite asset. To counter these threats, new satellite and ground systems are using cryptographic technologies to provide a range of services: confidentiality, entity & message authentication, and data integrity. Additionally, key management cryptographic services are required to support these services. This paper describes the key points of current satellite control and operations, that are authentication of the access to the satellite TMTC link and encryption of security relevant TM/TC data. For payload data management the key points are multi-user ground station access and high data rates both requiring frequent updates and uploads of keys with the corresponding key management methods. For secure satellite management authentication & key negotiation algorithms as HMAC-RIPEMD160, EC- DSA and EC-DH are used. Encryption of data uses algorithms as IDEA, AES, Triple-DES, or other. A channel coding and encryption unit for payload data provides download data rates up to Nx250 Mbps. The presented concepts are based on our experience and heritage of the security systems for all German MOD satellite projects (SATCOMBw2, SAR-Lupe multi- satellite system and German-French SAR-Lupe-Helios- II systems inter-operability) as well as for further international (KOMPSAT-II Payload data link system) and ESA activities (TMTC security and GMES).

A Collaborative Analysis Tool for Thermal Protection Systems for Single Stage to Orbit Launch Vehicles

NASA Technical Reports Server (NTRS)

Alexander, Reginald; Stanley, Thomas Troy

2001-01-01

Presented is a design tool and process that connects several disciplines which are needed in the complex and integrated design of high performance reusable single stage to orbit (SSTO) vehicles. Every system is linked to all other systems, as is the case with SSTO vehicles with air breathing propulsion, which is currently being studied by the National Aeronautics and Space Administration (NASA). In particular, the thermal protection system (TPS) is linked directly to almost every major system. The propulsion system pushes the vehicle to velocities on the order of 15 times the speed of sound in the atmosphere before pulling up to go to orbit which results in high temperatures on the external surfaces of the vehicle. Thermal protection systems to maintain the structural integrity of the vehicle must be able to mitigate the heat transfer to the structure and be lightweight. Herein lies the interdependency, in that as the vehicle's speed increases, the TPS requirements are increased. And as TPS masses increase the effect on the propulsion system and all other systems is compounded. To adequately calculate the TPS mass of this type of vehicle several engineering disciplines and analytical tools must be used preferably in an environment that data is easily transferred and multiple iterations are easily facilitated.

The CCSDS Next Generation Space Data Link Protocol (NGSLP)

NASA Technical Reports Server (NTRS)

Kazz, Greg J.; Greenberg, Edward

2014-01-01

The CCSDS space link protocols i.e., Telemetry (TM), Telecommand (TC), Advanced Orbiting Systems (AOS) were developed in the early growth period of the space program. They were designed to meet the needs of the early missions, be compatible with the available technology and focused on the specific link environments. Digital technology was in its infancy and spacecraft power and mass issues enforced severe constraints on flight implementations. Therefore the Telecommand protocol was designed around a simple Bose, Hocquenghem, Chaudhuri (BCH) code that provided little coding gain and limited error detection but was relatively simple to decode on board. The infusion of the concatenated Convolutional and Reed-Solomon codes5 for telemetry was a major milestone and transformed telemetry applications by providing them the ability to more efficiently utilize the telemetry link and its ability to deliver user data. The ability to significantly lower the error rates on the telemetry links enabled the use of packet telemetry and data compression. The infusion of the high performance codes for telemetry was enabled by the advent of digital processing, but it was limited to earth based systems supporting telemetry. The latest CCSDS space link protocol, Proximity-1 was developed in early 2000 to meet the needs of short-range, bi-directional, fixed or mobile radio links characterized by short time delays, moderate but not weak signals, and short independent sessions. Proximity-1 has been successfully deployed on both NASA and ESA missions at Mars and is planned to be utilized by all Mars missions in development. A new age has arisen, one that now provides the means to perform advanced digital processing in spacecraft systems enabling the use of improved transponders, digital correlators, and high performance forward error correcting codes for all communications links. Flight transponders utilizing digital technology have emerged and can efficiently provide the means to make the next leap in performance for space link communications. Field Programmable Gate Arrays (FPGAs) provide the capability to incorporate high performance forward error correcting codes implemented within software transponders providing improved performance in data transfer, ranging, link security, and time correlation. Given these synergistic technological breakthroughs, the time has come to take advantage of them in applying them to both on going (e.g., command, telemetry) and emerging (e.g., space link security, optical communication) space link applications. However one of the constraining factors within the Data Link Layer in realizing these performance gains is the lack of a generic transfer frame format and common supporting services amongst the existing CCSDS link layer protocols. Currently each of the four CCSDS link layer protocols (TM, TC, AOS, and Proximity-1) have unique formats and services which prohibits their reuse across the totality of all space link applications of CCSDS member space agencies. For example, Mars missions. These missions implement their proximity data link layer using the Proximity-1 frame format and the services it supports but is still required to support the direct from Earth (TC) protocols and the Direct To Earth (AOS/TM) protocols. The prime purpose of this paper, is to describe a new general purpose CCSDS Data Link layer protocol, the NGSLP that will provide the required services along with a common transfer frame format for all the CCSDS space links (ground to/from space and space to space links) targeted for emerging missions after a CCSDS agency-wide coordinated date. This paper will also describe related options that can be included for the Coding and Synchronization sub-layer of the Data Link layer to extend the capacities of the link and additionally provide an independence of the transfer frame sub-layer from the coding sublayer. This feature will provide missions the option of running either the currently performed synchronous coding and transfer frame data link or an asynchronous coding/frame data link, in which the transfer frame length is independent of the block size of the code. The benefits from the elimination of this constraint (frame synchronized to the code block) will simplify the interface between the transponder and the data handling equipment and reduce implementation costs and complexities. The benefits include: inclusion of encoders/decoders into transmitters and receivers without regard to data link protocols, providing the ability to insert latency sensitive messages into the link to support launch, landing/docking, telerobotics. and Variable Coded Modulation (VCM). In addition the ability to transfer different sized frames can provide a backup for delivering stored anomaly engineering data simultaneously with real time data, or relaying of frames from various sources onto a trunk line for delivery to Earth.

Minimizing human error in radiopharmaceutical preparation and administration via a bar code-enhanced nuclear pharmacy management system.

PubMed

Hakala, John L; Hung, Joseph C; Mosman, Elton A

2012-09-01

The objective of this project was to ensure correct radiopharmaceutical administration through the use of a bar code system that links patient and drug profiles with on-site information management systems. This new combined system would minimize the amount of manual human manipulation, which has proven to be a primary source of error. The most common reason for dosing errors is improper patient identification when a dose is obtained from the nuclear pharmacy or when a dose is administered. A standardized electronic transfer of information from radiopharmaceutical preparation to injection will further reduce the risk of misadministration. Value stream maps showing the flow of the patient dose information, as well as potential points of human error, were developed. Next, a future-state map was created that included proposed corrections for the most common critical sites of error. Transitioning the current process to the future state will require solutions that address these sites. To optimize the future-state process, a bar code system that links the on-site radiology management system with the nuclear pharmacy management system was proposed. A bar-coded wristband connects the patient directly to the electronic information systems. The bar code-enhanced process linking the patient dose with the electronic information reduces the number of crucial points for human error and provides a framework to ensure that the prepared dose reaches the correct patient. Although the proposed flowchart is designed for a site with an in-house central nuclear pharmacy, much of the framework could be applied by nuclear medicine facilities using unit doses. An electronic connection between information management systems to allow the tracking of a radiopharmaceutical from preparation to administration can be a useful tool in preventing the mistakes that are an unfortunate reality for any facility.

Forest fire advanced system technology (FFAST) conceptual design study

NASA Technical Reports Server (NTRS)

Nichols, J. David; Warren, John R.

1987-01-01

The National Aeronautics and Space Administration's Jet Propulsion Laboratory (JPL) and the U.S. Department of Agriculture (USDA) Forest Service completed a conceptual design study that defined an integrated forest fire detection and mapping system that will be based upon technology available in the 1990s. Potential system configuration options in emerging and advanced technologies related to the conceptual design were identified and recommended for inclusion as preferred system components. System component technologies identified for an end-to-end system include airborne mounted, thermal infrared (IR) linear array detectors, automatic onboard georeferencing and signal processing, geosynchronous satellite communications links, and advanced data integration and display. Potential system configuration options were developed and examined for possible inclusion in the preferred system configuration. The preferred system configuration will provide increased performance and be cost effective over the system currently in use. Forest fire management user requirements and the system component emerging technologies were the basis for the system configuration design. The conceptual design study defined the preferred system configuration that warrants continued refinement and development, examined economic aspects of the current and preferred system, and provided preliminary cost estimates for follow-on system prototype development.

Study on characteristics of the aperture-averaging factor of atmospheric scintillation in terrestrial optical wireless communication

NASA Astrophysics Data System (ADS)

Shen, Hong; Liu, Wen-xing; Zhou, Xue-yun; Zhou, Li-ling; Yu, Long-Kun

2018-02-01

In order to thoroughly understand the characteristics of the aperture-averaging effect of atmospheric scintillation in terrestrial optical wireless communication and provide references for engineering design and performance evaluation of the optics system employed in the atmosphere, we have theoretically deduced the generally analytic expression of the aperture-averaging factor of atmospheric scintillation, and numerically investigated characteristics of the apertureaveraging factor under different propagation conditions. The limitations of the current commonly used approximate calculation formula of aperture-averaging factor have been discussed, and the results showed that the current calculation formula is not applicable for the small receiving aperture under non-uniform turbulence link. Numerical calculation has showed that aperture-averaging factor of atmospheric scintillation presented an exponential decline model for the small receiving aperture under non-uniform turbulent link, and the general expression of the model was given. This model has certain guiding significance for evaluating the aperture-averaging effect in the terrestrial optical wireless communication.

Utilizing the ISS Mission as a Testbed to Develop Cognitive Communications Systems

NASA Technical Reports Server (NTRS)

Jackson, Dan

2016-01-01

The ISS provides an excellent opportunity for pioneering artificial intelligence software to meet the challenges of real-time communications (comm) link management. This opportunity empowers the ISS Program to forge a testbed for developing cognitive communications systems for the benefit of the ISS mission, manned Low Earth Orbit (LEO) science programs and future planetary exploration programs. In November, 1998, the Flight Operations Directorate (FOD) started the ISS Antenna Manager (IAM) project to develop a single processor supporting multiple comm satellite tracking for two different antenna systems. Further, the processor was developed to be highly adaptable as it supported the ISS mission through all assembly stages. The ISS mission mandated communications specialists with complete knowledge of when the ISS was about to lose or gain comm link service. The current specialty mandated cognizance of large sun-tracking solar arrays and thermal management panels in addition to the highly-dynamic satellite service schedules and rise/set tables. This mission requirement makes the ISS the ideal communications management analogue for future LEO space station and long-duration planetary exploration missions. Future missions, with their precision-pointed, dynamic, laser-based comm links, require complete autonomy for managing high-data rate communications systems. Development of cognitive communications management systems that permit any crew member or payload science specialist, regardless of experience level, to control communications is one of the greater benefits the ISS can offer new space exploration programs. The IAM project met a new mission requirement never previously levied against US space-born communications systems management: process and display the orientation of large solar arrays and thermal control panels based on real-time joint angle telemetry. However, IAM leaves the actual communications availability assessment to human judgment, which introduces unwanted variability because each specialist has a different core of experience with comm link performance. Because the ISS utilizes two different frequency bands, dynamic structure can be occasionally translucent at one frequency while it can completely interdict service at the other frequency. The impact of articulating structure on the comm link can depend on its orientation at the time it impinges on the link. It can become easy for a human specialist to cross-associate experience at one frequency with experience at the other frequency. Additionally, the specialist's experience is incremental, occurring one nine-hour shift at a time. Only the IAM processor experiences the complete 24x7x365 communications link performance for both communications links but, it has no "learning capability." If the IAM processor could be endowed with a cognitive ability to remember past structure-induced comm link outages, based on its knowledge of the ISS position, attitude, communications gear, array joint angles and tracking accuracy, it could convey such experience to the human operator. It could also use its learned communications link behaviors to accurately convey the availability of future communications sessions. Further, the tool could remember how accurately or inaccurately it predicted availability and correct future predictions based on past performance. The IAM tool could learn frequency-specific impacts due to spacecraft structures and pass that information along as "experience." Such development would provide a single artificial intelligence processor that could provide two different experience bases. If it also "knew" the satellite service schedule, it could distinguish structure blockage from schedule or planet blockage and then quickly switch to another satellite. Alternatively, just as a human operator could judge, a cognizant comm system based on the IAM model could "know" that the blockage is not going to last very long and continue tracking a comm satellite, waiting for it to track away from structure. Ultimately, once this capability was fully developed and tested in the Mission Control Center, it could be transferred on-orbit to support development of operations concepts that include more advanced cognitive communications systems. Future applications of this capability are easily foreseen because even more dynamic satellite constellations with more nodes and greater capability are coming. Currently, the ISS fully employs a 300 million bit-per-second (Mbps) return link for harvesting payload science. In the coming eighteen months, it will step up to 600 Mbps. Already there is talk of a 1.2 billion bit-per-second (Gbps) upgrade for the ISS and laser comm links have already been tested from the ISS. Every data rate upgrade mandates more complicated and sensitive communications equipment which implies greater expertise invested in the human operator. Future on-orbit cognizant comm systems will be needed to meet greater performance demands aboard larger, far more complicated spacecraft. In the LEO environment, the old-style one-satellite-per-spacecraft operations concept will give way to a new concept of a single customer spacecraft simultaneously using multiple comm satellites. Much more highly-dynamic manned LEO missions with decades of crew members potentially increase the demand for communications link performance. A cognizant on-board communications system will meet advanced communications demands from future LEO missions and future planetary missions. The ISS has fledgling components of future exploration programs, both LEO and planetary. Further, the Flight Operations Directorate, through the IAM project, has already begun to develop a communications management system that attempts to solve advanced problems ideally represented by dynamic structure impacting scheduled satellite service. With an earnest project to integrate artificial intelligence into the IAM processor, the ISS Program could develop a cognizant communications system that could be adapted and transferred to future on-orbit avionics designs.

Teaching topography-based and selection-based verbal behavior to developmentally disabled individuals: Some considerations

PubMed Central

Shafer, Esther

1993-01-01

Augmentative and alternative communication systems are widely recommended for nonvocal developmentally disabled individuals, with selection-based systems becoming increasingly popular. However, theoretical and experimental evidence suggests that topography-based communication systems are easier to learn. This paper discusses research relevant to the ease of acquisition of topography-based and selection-based systems. Additionally, current practices for choosing and designing communication systems are reviewed in order to investigate the extent to which links have been made with available theoretical and experimental knowledge. A stimulus equivalence model is proposed as a clearer direction for practitioners to follow when planning a communication training program. Suggestions for future research are also offered. PMID:22477085

Architecture Studies Done for High-Rate Duplex Direct Data Distribution (D4) Services

NASA Technical Reports Server (NTRS)

2002-01-01

A study was sponsored to investigate a set of end-to-end system concepts for implementing a high-rate duplex direct data distribution (D4) space-to-ground communications link. The NASA Glenn Research Center is investigating these systems (both commercial and Government) as a possible method of providing a D4 communications service between NASA spacecraft in low Earth orbit and the respective principal investigators using or monitoring instruments aboard these spacecraft. Candidate commercial services were assessed regarding their near-term potential to provide a D4 type of service. The candidates included K-band and V-band geostationary orbit and nongeostationary orbit satellite relay services and direct downlink (D3) services. Internet protocol (IP) networking technologies were evaluated to enable the user-directed distribution and delivery of science data. Four realistic, near-future concepts were analyzed: 1) A duplex direct link (uplink plus downlink communication paths) between a low-Earth-orbit spacecraft and a principal-investigator-based autonomous Earth station; 2) A space-based relay using a future K-band nongeosynchronous-orbit system to handle both the uplink and downlink communication paths; 3) A hybrid link using both direct and relay services to achieve full duplex capability; 4) A dual-mode concept consisting of both a duplex direct link and a space relay duplex link operating independently. The concepts were analyzed in terms of contact time between the NASA spacecraft and the communications service and the achievable data throughput. Throughput estimates for the D4 systems were based on the infusion of advanced communications technology products (single and multibeam K-band phased-arrays and digital modems) being developed by Glenn. Cost estimates were also performed using extrapolated information from both terrestrial and current satellite communications providers. The throughput and cost estimates were used to compare the concepts.

Folic acid conjugated cross-linked acrylic polymer (FA-CLAP) hydrogel for site specific delivery of hydrophobic drugs to cancer cells.

PubMed

Pillai, Jisha Jayadevan; Thulasidasan, Arun Kumar Theralikattu; Anto, Ruby John; Chithralekha, Devika Nandan; Narayanan, Ashwanikumar; Kumar, Gopalakrishnapillai Sankaramangalam Vinod

2014-07-15

The hydrogel based system is found to be rarely reported for the delivery of hydrophobic drug due to the incompatibility of hydrophilicity of the polymer network and the hydrophobicity of drug. This problem can be solved by preparing semi-interpenetrating network of cross-linked polymer for tuning the hydrophilicity so as to entrap the hydrophobic drugs. The current study is to develop a folic acid conjugated cross-linked pH sensitive, biocompatible polymeric hydrogel to achieve a site specific drug delivery. For that, we have synthesized a folic acid conjugated PEG cross-linked acrylic polymer (FA-CLAP) hydrogel and investigated its loading and release of curcumin. The formed polymer hydrogel was then conjugated with folic acid for the site specific delivery of curcumin to cancer cells and then further characterized and conducted the cell uptake and cytotoxicity studies on human cervical cancer cell lines (HeLa). In this study, we synthesized folic acid conjugated cross-linked acrylic hydrogel for the delivery of hydrophobic drugs to the cancer site. Poly (ethyleneglycol) (PEG) diacrylate cross-linked acrylic polymer (PAA) was prepared via inverse emulsion polymerization technique and later conjugated it with folic acid (FA-CLAP). Hydrophobic drug curcumin is entrapped into it and investigated the entrapment efficiency. Characterization of synthesized hydogel was done by using Fourier Transform-Infrared spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), Differential Scanning Calorimetry (DSC). Polymerization and folate conjugation was confirmed by FT-IR spectroscopy. The release kinetics of drug from the entrapped form was studied which showed initial burst release followed by sustained release due to swelling and increased cross-linking. In vitro cytotoxicity and cell uptake studies were conducted in human cervical cancer (HeLa) cell lines. Results showed that curcumin entrapped folate conjugated cross-linked acrylic polymer (FA-CLAP) hydrogel showed higher cellular uptake than the non folate conjugated form. So this can be suggested as a better delivery system for site specific release of hydrophobic cancer drugs.

C2-Related Incidents Reported by UAS Pilots

NASA Technical Reports Server (NTRS)

Hobbs, Alan; Cardoza, Colleen; Null, Cynthia

2016-01-01

It has been estimated that aviation accidents are typically preceded by numerous minor incidents arising from the same causal factors that ultimately produced the accident. Accident databases provide in-depth information on a relatively small number of occurrences, however incident databases have the potential to provide insights into the human factors of Remotely Piloted Aircraft System (RPAS) operations based on a larger volume of less-detailed reports. Currently, there is a lack of incident data dealing with the human factors of unmanned aircraft systems. An exploratory study is being conducted to examine the feasibility of collecting voluntary critical incident reports from RPAS pilots. Twenty-three experienced RPAS pilots volunteered to participate in focus groups in which they described critical incidents from their own experience. Participants were asked to recall (1) incidents that revealed a system flaw, or (2) highlighted a case where the human operator contributed to system resilience or mission success. Participants were asked to only report incidents that could be included in a public document. During each focus group session, a note taker produced a de-identified written record of the incident narratives. At the end of the session, participants reviewed each written incident report, and made edits and corrections as necessary. The incidents were later analyzed to identify contributing factors, with a focus on design issues that either hindered or assisted the pilot during the events. A total of 90 incidents were reported. This presentation focuses on incidents that involved the management of the command and control (C2) link. The identified issues include loss of link, interference from undesired transmissions, voice latency, accidental control transfer, and the use of the lost link timer, or lost link OK features.

From Chemical Gardens to Fuel Cells: Generation of Electrical Potential and Current Across Self-Assembling Iron Mineral Membranes.

PubMed

Barge, Laura M; Abedian, Yeghegis; Russell, Michael J; Doloboff, Ivria J; Cartwright, Julyan H E; Kidd, Richard D; Kanik, Isik

2015-07-06

We examine the electrochemical gradients that form across chemical garden membranes and investigate how self-assembling, out-of-equilibrium inorganic precipitates-mimicking in some ways those generated in far-from-equilibrium natural systems-can generate electrochemical energy. Measurements of electrical potential and current were made across membranes precipitated both by injection and solution interface methods in iron-sulfide and iron-hydroxide reaction systems. The battery-like nature of chemical gardens was demonstrated by linking multiple experiments in series which produced sufficient electrical energy to light an external light-emitting diode (LED). This work paves the way for determining relevant properties of geological precipitates that may have played a role in hydrothermal redox chemistry at the origin of life, and materials applications that utilize the electrochemical properties of self-organizing chemical systems. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Postnatal Cardiac Autonomic Nervous Control in Pediatric Congenital Heart Disease

PubMed Central

Nederend, Ineke; Jongbloed, Monique R. M.; de Geus, Eco J. C.; Blom, Nico A.; ten Harkel, Arend D. J.

2016-01-01

Congenital heart disease is the most common congenital defect. During childhood, survival is generally good but, in adulthood, late complications are not uncommon. Abnormal autonomic control in children with congenital heart disease may contribute considerably to the pathophysiology of these long term sequelae. This narrative review of 34 studies aims to summarize current knowledge on function of the autonomic nervous system in children with a congenital heart defect. Large scale studies that measure both branches of the nervous system for prolonged periods of time in well-defined patient cohorts in various phases of childhood and adolescence are currently lacking. Pending such studies, there is not yet a good grasp on the extent and direction of sympathetic and parasympathetic autonomic function in pediatric congenital heart disease. Longitudinal studies in homogenous patient groups linking autonomic nervous system function and clinical outcome are warranted. PMID:29367565

Cigarette smoking and the pathogenesis of systemic lupus erythematosus.

PubMed

Speyer, Cameron B; Costenbader, Karen H

2018-06-01

Systemic lupus erythematosus (SLE) is a multi-system inflammatory autoimmune disease of incompletely understood etiology. It is thought that environmental exposures 'trigger' or accelerate the disease in genetically-predisposed individuals. Areas covered: Substantial epidemiological evidence exists to support the association between cigarette smoking and the risk of incident SLE. Recent evidence points to current smoking as the specific risk factor, with decreasing risk 5 years after smoking cessation, and the greatest risk for disease characterized by the presence of SLE-specific autoantibodies. Research has begun to search for possible explanations for the temporal nature of the relationship between current smoking and autoantibody positive-SLE. Here we review potential biologic mechanisms linking smoking and SLE risk, including effects upon T and B cells, inflammatory cytokines, oxidative stress, and the formation of short-lived DNA adducts. Expert commentary: The directions for future research in this field include studies of gene-environment interactions, epigenetics, metabolomics and putative biologic mechanisms.

Stygoregions – a promising approach to a bioregional classification of groundwater systems

PubMed Central

Stein, Heide; Griebler, Christian; Berkhoff, Sven; Matzke, Dirk; Fuchs, Andreas; Hahn, Hans Jürgen

2012-01-01

Linked to diverse biological processes, groundwater ecosystems deliver essential services to mankind, the most important of which is the provision of drinking water. In contrast to surface waters, ecological aspects of groundwater systems are ignored by the current European Union and national legislation. Groundwater management and protection measures refer exclusively to its good physicochemical and quantitative status. Current initiatives in developing ecologically sound integrative assessment schemes by taking groundwater fauna into account depend on the initial classification of subsurface bioregions. In a large scale survey, the regional and biogeographical distribution patterns of groundwater dwelling invertebrates were examined for many parts of Germany. Following an exploratory approach, our results underline that the distribution patterns of invertebrates in groundwater are not in accordance with any existing bioregional classification system established for surface habitats. In consequence, we propose to develope a new classification scheme for groundwater ecosystems based on stygoregions. PMID:22993698

Persistent Identifiers Implementation in EOSDIS

NASA Technical Reports Server (NTRS)

Ramapriyan, H. K. " Rama"

2016-01-01

This presentation provides the motivation for and status of implementation of persistent identifiers in NASA's Earth Observation System Data and Information System (EOSDIS). The motivation is provided from the point of view of long-term preservation of datasets such that a number of questions raised by current and future users can be answered easily and precisely. A number of artifacts need to be preserved along with datasets to make this possible, especially when the authors of datasets are no longer available to address users questions. The artifacts and datasets need to be uniquely and persistently identified and linked with each other for full traceability, understandability and scientific reproducibility. Current work in the Earth Science Data and Information System (ESDIS) Project and the Distributed Active Archive Centers (DAACs) in assigning Digital Object Identifiers (DOI) is discussed as well as challenges that remain to be addressed in the future.

Power conditioning unit for photovoltaic power systems

NASA Astrophysics Data System (ADS)

Beghin, G.; Nguyen Phuoc, V. T.

Operational features and components of a power conditioning unit for interconnecting solar cell module powers with a utility grid are outlined. The two-stage unit first modifies the voltage to desired levels on an internal dc link, then inverts the current in 2 power transformers connected to a vector summation control to neutralize harmonic distortion up to the 11th harmonic. The system operates in parallel with the grid with extra inductors to absorb line-to-line voltage and phase differences, and permits peak power use from the PV array. Reactive power is gained internally, and a power system controller monitors voltages, frequencies, and currents. A booster preregulator adjusts the input voltage from the array to provide voltage regulation for the inverter, and can commutate 450 amps. A total harmonic distortion of less than 5 percent is claimed, with a rating of 5 kVA, 50/60 Hz, 3-phase, and 4-wire.

Astronomy. Laser telemetry from space.

PubMed

Bland-Hawthorn, Joss; Harwit, Alex; Harwit, Martin

2002-07-26

Space missions currently on the drawing boards are expected to gather data at rates exceeding the transmission capabilities of today's telemetry systems by many orders of magnitude. Even on current missions, onboard data compression techniques are being implemented to compensate for lack of transmission speed. But while data compression can minimize the loss of data, it is no substitute for transmitting all of the data through a faster communications link. The transmission problem will soon reach crisis proportions and will affect astronomical, Earth resources, geophysical, meteorological, planetary and other space science missions. To overcome this communications bottleneck, the authors advocate the implementation of telemetry systems based on near-infrared laser transmission techniques. The fiber-optics communications industry has developed most of the basic components required for signal transmission in this wavelength band, which should make such a system affordable on scales relevant to the cost of anticipated space science missions.

Wireless Channel Characterization in the Airport Surface Environment

NASA Technical Reports Server (NTRS)

Neville, Joshua T.

2004-01-01

Given the anticipated increase in air traffic in the coming years, modernization of the National Airspace System (NAS) is a necessity. Part of this modernization effort will include updating current communication, navigation, and surveillance (CNS) systems to deal with the increased traffic as well as developing advanced CNS technologies for the systems. An example of such technology is the integrated CNS (ICNS) network being developed by the Advanced CNS Architecture and Systems Technology (ACAST) group for use in the airport surface environment. The ICNS network would be used to convey voice/data between users in a secure and reliable manner. The current surface system only supports voice and does so through an obsolete physical infrastructure. The old system is vulnerable to outages and costly to maintain. The proposed ICNS network will include a wireless radio link. To ensure optimal performance, a thorough and accurate characterization of the channel across which the link would operate is necessary. The channel is the path the signal takes from the transmitter to the receiver and is prone to various forms of interference. Channel characterization involves a combination of analysis, simulation, and measurement. My work this summer was divided into four tasks. The first task required compiling and reviewing reference material that dealt with the characterization and modeling of aeronautical channels. The second task involved developing a systematic approach that could be used to group airports into classes, e.g. small airfields, medium airports, large open airports, large cluttered airports, etc. The third task consisted of implementing computer simulations of existing channel models. The fourth task entailed measuring possible interference sources in the airport surface environment via a spectrum analyzer.

[The Mexican health system: does it require a transformation?].

PubMed

Chertorivski Woldenberg, Salomón; Fajardo Dolci, German

2012-01-01

National health systems represent an organized social response that enables countries to improve, maintain and enhance the health status of their citizens. These evolve and are transformed according to changes in the biological, economic, political and social components of health. In Mexico there is currently a segmented health system, consisting of a bismarckian model of social security and a social protection in health model. The latter developed to comply with the fourth constitutional article by which health is no longer described as a right linked to the employment status of the individual. Given this reality at least three alternatives seem to emerge for the future: the permanence of a mixed health system with social security and social protection institutions with a similar weight within the national health system, or its opposite, the extension of social protection as a mechanism for widespread access. Given the challenges we face, it is desirable to establish a unified health system, the aim should be that health care is universally protected, as currently happens, but is guaranteed through a much more efficient and based in primary care health care system.

Socioeconomic influences on brain function: implications for health.

PubMed

Muscatell, Keely A

2018-06-27

Socioeconomic-based disparities in physical health outcomes are well established, with individuals from lower socioeconomic status (SES) backgrounds being more likely to experience chronic disease morbidity and early mortality compared to those from higher SES strata. While numerous studies in recent decades have focused on understanding the contextual, psychosocial, and biological mechanisms linking SES and health, the neural pathways that contribute to this relationship are currently underinvestigated. The present paper reviews and synthesizes the small number of published studies that have explored links between SES and health-relevant neural functioning. Specifically, current knowledge of the relationship between socioeconomic factors and neural systems that may be affected by low SES contexts, including those related to processing threat and stress, responding to reward, and engaging in emotion regulation, is reviewed. Gaps in our knowledge that could be filled by health neuroscience research are emphasized, in an effort to catalyze future studies in this area. Understanding the neural mechanisms linking SES and health is crucial for building comprehensive models of the pathways by which social inequalities become health inequalities and may help identify novel targets for intervention to prevent health disparities. Health neuroscience research has a critical role to play in this important area of research. © 2018 New York Academy of Sciences.

The UK Human Genome Mapping Project online computing service.

PubMed

Rysavy, F R; Bishop, M J; Gibbs, G P; Williams, G W

1992-04-01

This paper presents an overview of computing and networking facilities developed by the Medical Research Council to provide online computing support to the Human Genome Mapping Project (HGMP) in the UK. The facility is connected to a number of other computing facilities in various centres of genetics and molecular biology research excellence, either directly via high-speed links or through national and international wide-area networks. The paper describes the design and implementation of the current system, a 'client/server' network of Sun, IBM, DEC and Apple servers, gateways and workstations. A short outline of online computing services currently delivered by this system to the UK human genetics research community is also provided. More information about the services and their availability could be obtained by a direct approach to the UK HGMP-RC.

Prediction of optical communication link availability: real-time observation of cloud patterns using a ground-based thermal infrared camera

NASA Astrophysics Data System (ADS)

Bertin, Clément; Cros, Sylvain; Saint-Antonin, Laurent; Schmutz, Nicolas

2015-10-01

The growing demand for high-speed broadband communications with low orbital or geostationary satellites is a major challenge. Using an optical link at 1.55 μm is an advantageous solution which potentially can increase the satellite throughput by a factor 10. Nevertheless, cloud cover is an obstacle for this optical frequency. Such communication requires an innovative management system to optimize the optical link availability between a satellite and several Optical Ground Stations (OGS). The Saint-Exupery Technological Research Institute (France) leads the project ALBS (French acronym for BroadBand Satellite Access). This initiative involving small and medium enterprises, industrial groups and research institutions specialized in aeronautics and space industries, is currently developing various solutions to increase the telecommunication satellite bandwidth. This paper presents the development of a preliminary prediction system preventing the cloud blockage of an optical link between a satellite and a given OGS. An infrared thermal camera continuously observes (night and day) the sky vault. Cloud patterns are observed and classified several times a minute. The impact of the detected clouds on the optical beam (obstruction or not) is determined by the retrieval of the cloud optical depth at the wavelength of communication. This retrieval is based on realistic cloud-modelling on libRadtran. Then, using subsequent images, cloud speed and trajectory are estimated. Cloud blockage over an OGS can then be forecast up to 30 minutes ahead. With this information, the preparation of the new link between the satellite and another OGS under a clear sky can be prepared before the link breaks due to cloud blockage.

The Taxiway Navigation and Situation Awareness (T-NASA) System

NASA Technical Reports Server (NTRS)

Foyle, David C.; Sridhar, Banavar (Technical Monitor)

1997-01-01

The goal of NASA's Terminal Area Productivity (TAP) Low-Visibility Landing and Surface Operations (LVLASO) subelement is to improve the efficiency of airport surface operations for commercial aircraft operating in weather conditions to Category IIIB while maintaining a high degree of safety. Currently, surface operations are one of the least technologically sophisticated components of the air transport system, being conducted in the 1990's with the same basic technology as in the 1930's. Pilots are given little or no explicit information about their current position, and routing information is limited to ATC communications and airport charts. In TAP/LVLASO, advanced technologies such as satellite navigation systems, digital data communications, advanced information presentation technology, and ground surveillance systems will be integrated into flight deck displays to enable expeditious and safe traffic movement on the airport surface. The cockpit display suite is called the T-NASA (Taxiway Navigation and Situation Awareness) System. This system has three integrated components: 1) Moving Map track-up airport surface display with own-ship, traffic and graphical route guidance 2) Scene-Linked Symbology - route/taxi information virtually projected via a Head-up Display (HUD) onto the forward scene; and, 3) 3-D Audio Ground Collision Avoidance and Navigation system - spatially-localized auditory traffic and navigation alerts. In the current paper, the design philosophy of the T-NASA system will be presented, and the T-NASA system display components described.

Mitigation of commutation failures in LCC-HVDC systems based on superconducting fault current limiters

NASA Astrophysics Data System (ADS)

Lee, Jong-Geon; Khan, Umer Amir; Lee, Ho-Yun; Lim, Sung-Woo; Lee, Bang-Wook

2016-11-01

Commutation failure in line commutated converter based HVDC systems cause severe damages on the entire power grid system. For LCC-HVDC, thyristor valves are turned on by a firing signal but turn off control is governed by the external applied AC voltage from surrounding network. When the fault occurs in AC system, turn-off control of thyristor valves is unavailable due to the voltage collapse of point of common coupling (PCC), which causes the commutation failure in LCC-HVDC link. Due to the commutation failure, the power transfer interruption, dc voltage drop and severe voltage fluctuation in the AC system could be occurred. In a severe situation, it might cause the protection system to block the valves. In this paper, as a solution to prevent the voltage collapse on PCC and to limit the fault current, the application study of resistive superconducting fault current limiter (SFCL) on LCC-HVDC grid system was performed with mathematical and simulation analyses. The simulation model was designed by Matlab/Simulink considering Haenam-Jeju HVDC power grid in Korea which includes conventional AC system and onshore wind farm and resistive SFCL model. From the result, it was observed that the application of SFCL on LCC-HVDC system is an effective solution to mitigate the commutation failure. And then the process to determine optimum quench resistance of SFCL which enables the recovery of commutation failure was deeply investigated.

Development and Evaluation of an Airborne Separation Assurance System for Autonomous Aircraft Operations

NASA Technical Reports Server (NTRS)

Barhydt, Richard; Palmer, Michael T.; Eischeid, Todd M.

2004-01-01

NASA Langley Research Center is developing an Autonomous Operations Planner (AOP) that functions as an Airborne Separation Assurance System for autonomous flight operations. This development effort supports NASA s Distributed Air-Ground Traffic Management (DAG-TM) operational concept, designed to significantly increase capacity of the national airspace system, while maintaining safety. Autonomous aircraft pilots use the AOP to maintain traffic separation from other autonomous aircraft and managed aircraft flying under today's Instrument Flight Rules, while maintaining traffic flow management constraints assigned by Air Traffic Service Providers. AOP is designed to facilitate eventual implementation through careful modeling of its operational environment, interfaces with other aircraft systems and data links, and conformance with established flight deck conventions and human factors guidelines. AOP uses currently available or anticipated data exchanged over modeled Arinc 429 data buses and an Automatic Dependent Surveillance Broadcast 1090 MHz link. It provides pilots with conflict detection, prevention, and resolution functions and works with the Flight Management System to maintain assigned traffic flow management constraints. The AOP design has been enhanced over the course of several experiments conducted at NASA Langley and is being prepared for an upcoming Joint Air/Ground Simulation with NASA Ames Research Center.

Neuroinflammation, immune system and Alzheimer disease: searching for the missing link.

PubMed

Guerriero, F; Sgarlata, C; Francis, M; Maurizi, N; Faragli, A; Perna, S; Rondanelli, M; Rollone, M; Ricevuti, G

2017-10-01

Due to an increasingly aging population, Alzheimer disease (AD) represents a crucial issue for the healthcare system because of its widespread prevalence and the burden of its care needs. Several hypotheses on AD pathogenesis have been proposed and current therapeutical strategies have shown limited effectiveness. In the last decade, more evidence has supported a role for neuroinflammation and immune system dysregulation in AD. It remains unclear whether astrocytes, microglia and immune cells influence disease onset, progression or both. Amyloid-β peptides that aggregate extracellularly in the typical neuritic plaques generate a constant inflammatory environment. This causes a prolonged activation of microglial and astroglial cells that potentiate neuronal damage and provoke the alteration of the blood brain barrier (BBB), damaging the permeability of blood vessels. Recent data support the role of the BBB as a link between neuroinflammation, the immune system and AD. Hence, a thorough investigation of the neuroinflammatory and immune system pathways that impact neurodegeneration and novel exciting findings such as microglia-derived microvesicles, inflammasomes and signalosomes will ultimately enhance our understanding of the pathological process. Eventually, we should proceed with caution in defining a causal or consequential role of neuroinflammation in AD, but rather focus on identifying its exact pathological contribution.

Operating capability and current status of the reactivated NASA Lewis Research Center Hypersonic Tunnel Facility

NASA Technical Reports Server (NTRS)

Thomas, Scott R.; Trefny, Charles J.; Pack, William D.

1995-01-01

The NASA Lewis Research Center's Hypersonic Tunnel Facility (HTF) is a free-jet, blowdown propulsion test facility that can simulate up to Mach-7 flight conditions with true air composition. Mach-5, -6, and -7 nozzles, each with a 42 inch exit diameter, are available. Previously obtained calibration data indicate that the test flow uniformity of the HTF is good. The facility, without modifications, can accommodate models approximately 10 feet long. The test gas is heated using a graphite core induction heater that generates a nonvitiated flow. The combination of clean-air, large-scale, and Mach-7 capabilities is unique to the HTF and enables an accurate propulsion performance determination. The reactivation of the HTF, in progress since 1990, includes refurbishing the graphite heater, the steam generation plant, the gaseous oxygen system, and all control systems. All systems were checked out and recertified, and environmental systems were upgraded to meet current standards. The data systems were also upgraded to current standards and a communication link with NASA-wide computers was added. In May 1994, the reactivation was complete, and an integrated systems test was conducted to verify facility operability. This paper describes the reactivation, the facility status, the operating capabilities, and specific applications of the HTF.

Orbital Angular Momentum-based Space Division Multiplexing for High-capacity Underwater Optical Communications

DOE PAGES

Ren, Yongxiong; Li, Long; Wang, Zhe; ...

2016-09-12

To increase system capacity of underwater optical communications, we employ the spatial domain to simultaneously transmit multiple orthogonal spatial beams, each carrying an independent data channel. In this paper, we show up to a 40-Gbit/s link by multiplexing and transmitting four green orbital angular momentum (OAM) beams through a single aperture. Moreover, we investigate the degrading effects of scattering/turbidity, water current, and thermal gradient-induced turbulence, and we find that thermal gradients cause the most distortions and turbidity causes the most loss. We show systems results using two different data generation techniques, one at 1064 nm for 10-Gbit/s/beam and one atmore » 520 nm for 1-Gbit/s/beam; we use both techniques since present data-modulation technologies are faster for infrared (IR) than for green. For the 40-Gbit/s link, data is modulated in the IR, and OAM imprinting is performed in the green using a specially-designed metasurface phase mask. For the 4-Gbit/s link, a green laser diode is directly modulated. Lastly, we show that inter-channel crosstalk induced by thermal gradients can be mitigated using multi-channel equalisation processing.« less

Non-nutrient causes of low-grade, systemic inflammation: support for a 'canary in the mineshaft' view of obesity in chronic disease.

PubMed

Egger, G; Dixon, J

2011-05-01

A form of low-grade, systemic inflammation ('metaflammation') is linked to many types of chronic disease. Initially, this was thought to be causally related to weight gain and obesity and a possible explanation of the link between obesity and disease. However, several lifestyle-related inducers of such inflammation, some of which are associated with obesity, but some of which are not, have now been identified. The most common of these have been nutritive related, suggesting that there could still be a relationship, either directly or indirectly, with obesity. Here we provide evidence for non-nutritive inflammatory inducers, providing further support for an earlier suggestion that while obesity, beyond a point, may have a direct link with disease, this may be neither necessary nor sufficient to explain the current epidemic of chronic disease. A more ubiquitous cause encompassing all inflammatory inducers is the modern, post-industrial environment and lifestyles emanating from this. Obesity may thus be more of 'a canary in the mineshaft', warning of bigger global problems, than just a single pathway to modern environmentally driven disease. © 2010 The Authors. obesity reviews © 2010 International Association for the Study of Obesity.

Healthcare quality measurement in orthopaedic surgery: current state of the art.

PubMed

Auerbach, Andrew

2009-10-01

Improving quality of care in arthroplasty is of increasing importance to payors, hospitals, surgeons, and patients. Efforts to compel improvement have traditionally focused measurement and reporting of data describing structural factors, care processes (or 'quality measures'), and clinical outcomes. Reporting structural measures (eg, surgical case volume) has been used with varying degrees of success. Care process measures, exemplified by initiatives such as the Surgical Care Improvement Project measures, are chosen based on the strength of randomized trial evidence linking the process to improved outcomes. However, evidence linking improved performance on Surgical Care Improvement Project measures with improved outcomes is limited. Outcome measures in surgery are of increasing importance as an approach to compel care improvement with prominent examples represented by the National Surgical Quality Improvement Project. Although outcomes-focused approaches are often costly, when linked to active benchmarking and collaborative activities, they may improve care broadly. Moreover, implementation of computerized data systems collecting information formerly collected on paper only will facilitate benchmarking. In the end, care will only be improved if these data are used to define methods for innovating care systems that deliver better outcomes at lower or equivalent costs.

Orbital Angular Momentum-based Space Division Multiplexing for High-capacity Underwater Optical Communications

PubMed Central

Ren, Yongxiong; Li, Long; Wang, Zhe; Kamali, Seyedeh Mahsa; Arbabi, Ehsan; Arbabi, Amir; Zhao, Zhe; Xie, Guodong; Cao, Yinwen; Ahmed, Nisar; Yan, Yan; Liu, Cong; Willner, Asher J.; Ashrafi, Solyman; Tur, Moshe; Faraon, Andrei; Willner, Alan E.

2016-01-01

To increase system capacity of underwater optical communications, we employ the spatial domain to simultaneously transmit multiple orthogonal spatial beams, each carrying an independent data channel. In this paper, we show up to a 40-Gbit/s link by multiplexing and transmitting four green orbital angular momentum (OAM) beams through a single aperture. Moreover, we investigate the degrading effects of scattering/turbidity, water current, and thermal gradient-induced turbulence, and we find that thermal gradients cause the most distortions and turbidity causes the most loss. We show systems results using two different data generation techniques, one at 1064 nm for 10-Gbit/s/beam and one at 520 nm for 1-Gbit/s/beam; we use both techniques since present data-modulation technologies are faster for infrared (IR) than for green. For the 40-Gbit/s link, data is modulated in the IR, and OAM imprinting is performed in the green using a specially-designed metasurface phase mask. For the 4-Gbit/s link, a green laser diode is directly modulated. Finally, we show that inter-channel crosstalk induced by thermal gradients can be mitigated using multi-channel equalisation processing. PMID:27615808

Orbital Angular Momentum-based Space Division Multiplexing for High-capacity Underwater Optical Communications

NASA Astrophysics Data System (ADS)

Ren, Yongxiong; Li, Long; Wang, Zhe; Kamali, Seyedeh Mahsa; Arbabi, Ehsan; Arbabi, Amir; Zhao, Zhe; Xie, Guodong; Cao, Yinwen; Ahmed, Nisar; Yan, Yan; Liu, Cong; Willner, Asher J.; Ashrafi, Solyman; Tur, Moshe; Faraon, Andrei; Willner, Alan E.

2016-09-01

To increase system capacity of underwater optical communications, we employ the spatial domain to simultaneously transmit multiple orthogonal spatial beams, each carrying an independent data channel. In this paper, we show up to a 40-Gbit/s link by multiplexing and transmitting four green orbital angular momentum (OAM) beams through a single aperture. Moreover, we investigate the degrading effects of scattering/turbidity, water current, and thermal gradient-induced turbulence, and we find that thermal gradients cause the most distortions and turbidity causes the most loss. We show systems results using two different data generation techniques, one at 1064 nm for 10-Gbit/s/beam and one at 520 nm for 1-Gbit/s/beam; we use both techniques since present data-modulation technologies are faster for infrared (IR) than for green. For the 40-Gbit/s link, data is modulated in the IR, and OAM imprinting is performed in the green using a specially-designed metasurface phase mask. For the 4-Gbit/s link, a green laser diode is directly modulated. Finally, we show that inter-channel crosstalk induced by thermal gradients can be mitigated using multi-channel equalisation processing.

Orbital Angular Momentum-based Space Division Multiplexing for High-capacity Underwater Optical Communications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ren, Yongxiong; Li, Long; Wang, Zhe

To increase system capacity of underwater optical communications, we employ the spatial domain to simultaneously transmit multiple orthogonal spatial beams, each carrying an independent data channel. In this paper, we show up to a 40-Gbit/s link by multiplexing and transmitting four green orbital angular momentum (OAM) beams through a single aperture. Moreover, we investigate the degrading effects of scattering/turbidity, water current, and thermal gradient-induced turbulence, and we find that thermal gradients cause the most distortions and turbidity causes the most loss. We show systems results using two different data generation techniques, one at 1064 nm for 10-Gbit/s/beam and one atmore » 520 nm for 1-Gbit/s/beam; we use both techniques since present data-modulation technologies are faster for infrared (IR) than for green. For the 40-Gbit/s link, data is modulated in the IR, and OAM imprinting is performed in the green using a specially-designed metasurface phase mask. For the 4-Gbit/s link, a green laser diode is directly modulated. Lastly, we show that inter-channel crosstalk induced by thermal gradients can be mitigated using multi-channel equalisation processing.« less

Orbital Angular Momentum-based Space Division Multiplexing for High-capacity Underwater Optical Communications.

PubMed

Ren, Yongxiong; Li, Long; Wang, Zhe; Kamali, Seyedeh Mahsa; Arbabi, Ehsan; Arbabi, Amir; Zhao, Zhe; Xie, Guodong; Cao, Yinwen; Ahmed, Nisar; Yan, Yan; Liu, Cong; Willner, Asher J; Ashrafi, Solyman; Tur, Moshe; Faraon, Andrei; Willner, Alan E

2016-09-12

To increase system capacity of underwater optical communications, we employ the spatial domain to simultaneously transmit multiple orthogonal spatial beams, each carrying an independent data channel. In this paper, we show up to a 40-Gbit/s link by multiplexing and transmitting four green orbital angular momentum (OAM) beams through a single aperture. Moreover, we investigate the degrading effects of scattering/turbidity, water current, and thermal gradient-induced turbulence, and we find that thermal gradients cause the most distortions and turbidity causes the most loss. We show systems results using two different data generation techniques, one at 1064 nm for 10-Gbit/s/beam and one at 520 nm for 1-Gbit/s/beam; we use both techniques since present data-modulation technologies are faster for infrared (IR) than for green. For the 40-Gbit/s link, data is modulated in the IR, and OAM imprinting is performed in the green using a specially-designed metasurface phase mask. For the 4-Gbit/s link, a green laser diode is directly modulated. Finally, we show that inter-channel crosstalk induced by thermal gradients can be mitigated using multi-channel equalisation processing.

Immunity to human cytomegalovirus measured and compared by complement fixation, indirect fluorescent-antibody, indirect hemagglutination, and enzyme-linked immunosorbent assays.

PubMed Central

Brandt, J A; Kettering, J D; Lewis, J E

1984-01-01

The complement fixation test is currently the test employed most frequently to determine the presence of antibody to human cytomegalovirus. Several other techniques have been adapted for this purpose. A comparison of cytomegalovirus antibody titers was made between the complement fixation test, a commercially available enzyme-linked immunosorbent assay, an indirect immunofluorescent technique, and a modified indirect hemagglutination test. Forty-three serum samples were tested for antibodies by each of the above procedures. The enzyme-linked immunosorbent, immunofluorescent, and indirect hemagglutination assays were in close agreement on all samples tested; the titers obtained with these methods were all equal to or greater than the complement fixation titer for 38 of the 41 samples (92.6%). Two samples were anticomplementary in the complement fixation test but gave readable results in the other tests. The complement fixation test was the least sensitive of the procedures examined. The commercial enzyme-linked immunosorbent assay system was the most practical method and offered the highest degree of sensitivity in detecting antibodies to cytomegalovirus. PMID:6321544

IJS: An Intelligent Junction Selection Based Routing Protocol for VANET to Support ITS Services.

PubMed

Bhoi, Sourav Kumar; Khilar, Pabitra Mohan

2014-01-01

Selecting junctions intelligently for data transmission provides better intelligent transportation system (ITS) services. The main problem in vehicular communication is high disturbances of link connectivity due to mobility and less density of vehicles. If link conditions are predicted earlier, then there is a less chance of performance degradation. In this paper, an intelligent junction selection based routing protocol (IJS) is proposed to transmit the data in a quickest path, in which the vehicles are mostly connected and have less link connectivity problem. In this protocol, a helping vehicle is set at every junction to control the communication by predicting link failures or network gaps in a route. Helping vehicle at the junction produces a score for every neighboring junction to forward the data to the destination by considering the current traffic information and selects that junction which has minimum score. IJS protocol is implemented and compared with GyTAR, A-STAR, and GSR routing protocols. Simulation results show that IJS performs better in terms of average end-to-end delay, network gap encounter, and number of hops.

IJS: An Intelligent Junction Selection Based Routing Protocol for VANET to Support ITS Services

PubMed Central

Khilar, Pabitra Mohan

2014-01-01

Selecting junctions intelligently for data transmission provides better intelligent transportation system (ITS) services. The main problem in vehicular communication is high disturbances of link connectivity due to mobility and less density of vehicles. If link conditions are predicted earlier, then there is a less chance of performance degradation. In this paper, an intelligent junction selection based routing protocol (IJS) is proposed to transmit the data in a quickest path, in which the vehicles are mostly connected and have less link connectivity problem. In this protocol, a helping vehicle is set at every junction to control the communication by predicting link failures or network gaps in a route. Helping vehicle at the junction produces a score for every neighboring junction to forward the data to the destination by considering the current traffic information and selects that junction which has minimum score. IJS protocol is implemented and compared with GyTAR, A-STAR, and GSR routing protocols. Simulation results show that IJS performs better in terms of average end-to-end delay, network gap encounter, and number of hops. PMID:27433485

The sequence measurement system of the IR camera

NASA Astrophysics Data System (ADS)

Geng, Ai-hui; Han, Hong-xia; Zhang, Hai-bo

2011-08-01

Currently, the IR cameras are broadly used in the optic-electronic tracking, optic-electronic measuring, fire control and optic-electronic countermeasure field, but the output sequence of the most presently applied IR cameras in the project is complex and the giving sequence documents from the leave factory are not detailed. Aiming at the requirement that the continuous image transmission and image procession system need the detailed sequence of the IR cameras, the sequence measurement system of the IR camera is designed, and the detailed sequence measurement way of the applied IR camera is carried out. The FPGA programming combined with the SignalTap online observation way has been applied in the sequence measurement system, and the precise sequence of the IR camera's output signal has been achieved, the detailed document of the IR camera has been supplied to the continuous image transmission system, image processing system and etc. The sequence measurement system of the IR camera includes CameraLink input interface part, LVDS input interface part, FPGA part, CameraLink output interface part and etc, thereinto the FPGA part is the key composed part in the sequence measurement system. Both the video signal of the CmaeraLink style and the video signal of LVDS style can be accepted by the sequence measurement system, and because the image processing card and image memory card always use the CameraLink interface as its input interface style, the output signal style of the sequence measurement system has been designed into CameraLink interface. The sequence measurement system does the IR camera's sequence measurement work and meanwhile does the interface transmission work to some cameras. Inside the FPGA of the sequence measurement system, the sequence measurement program, the pixel clock modification, the SignalTap file configuration and the SignalTap online observation has been integrated to realize the precise measurement to the IR camera. Te sequence measurement program written by the verilog language combining the SignalTap tool on line observation can count the line numbers in one frame, pixel numbers in one line and meanwhile account the line offset and row offset of the image. Aiming at the complex sequence of the IR camera's output signal, the sequence measurement system of the IR camera accurately measures the sequence of the project applied camera, supplies the detailed sequence document to the continuous system such as image processing system and image transmission system and gives out the concrete parameters of the fval, lval, pixclk, line offset and row offset. The experiment shows that the sequence measurement system of the IR camera can get the precise sequence measurement result and works stably, laying foundation for the continuous system.

Technologies for Networked Enabled Operations

NASA Technical Reports Server (NTRS)

Glass, B.; Levine, J.

2005-01-01

Current point-to-point data links will not scale to support future integration of surveillance, security, and globally-distributed air traffic data, and already hinders efficiency and capacity. While the FAA and industry focus on a transition to initial system-wide information management (SWIM) capabilities, this paper describes a set of initial studies of NAS network-enabled operations technology gaps targeted for maturity in later SWIM spirals (201 5-2020 timeframe).

Wealth from Health: an incentive program for disease and population management: a 12-year project.

PubMed

Ratner, D; Louria, D; Sheffet, A; Fain, R; Curran, J; Saed, N; Bhaskar, S; Quereshi, M; Cable, G

2001-01-01

The future of healthcare is linked with its ability to face the challenges of consumerism. Disease and population management will represent the dominant style of healthcare delivery in the future. This article describes the Wealth from Health programs which utilize current and future technologies to help the healthcare system become a leader in healthcare delivery and to assist many communities at an affordable cost.

Proof-of-Concept Part Task Trainer for Close Air Support Procedures

DTIC Science & Technology

2016-06-01

TVDL Tactical Video Down Link VE Virtual Environment VR Virtual Reality WTI Weapons and Tactics Instructor xvii ACKNOWLEDGMENTS I would first...in training of USMC pilots for close air support operations? • What is the feasibility of developing a prototype virtual reality (VR) system that...Chapter IV provides a review of virtual reality (VR)/ virtual environment (VE) and part-task trainers currently used in military training

An integrated and highly sensitive ultrafast acoustoelectric imaging system for biomedical applications

NASA Astrophysics Data System (ADS)

Berthon, Beatrice; Dansette, Pierre-Marc; Tanter, Mickaël; Pernot, Mathieu; Provost, Jean

2017-07-01

Direct imaging of the electrical activation of the heart is crucial to better understand and diagnose diseases linked to arrhythmias. This work presents an ultrafast acoustoelectric imaging (UAI) system for direct and non-invasive ultrafast mapping of propagating current densities using the acoustoelectric effect. Acoustoelectric imaging is based on the acoustoelectric effect, the modulation of the medium’s electrical impedance by a propagating ultrasonic wave. UAI triggers this effect with plane wave emissions to image current densities. An ultrasound research platform was fitted with electrodes connected to high common-mode rejection ratio amplifiers and sampled by up to 128 independent channels. The sequences developed allow for both real-time display of acoustoelectric maps and long ultrafast acquisition with fast off-line processing. The system was evaluated by injecting controlled currents into a saline pool via copper wire electrodes. Sensitivity to low current and low acoustic pressure were measured independently. Contrast and spatial resolution were measured for varying numbers of plane waves and compared to line per line acoustoelectric imaging with focused beams at equivalent peak pressure. Temporal resolution was assessed by measuring time-varying current densities associated with sinusoidal currents. Complex intensity distributions were also imaged in 3D. Electrical current densities were detected for injected currents as low as 0.56 mA. UAI outperformed conventional focused acoustoelectric imaging in terms of contrast and spatial resolution when using 3 and 13 plane waves or more, respectively. Neighboring sinusoidal currents with opposed phases were accurately imaged and separated. Time-varying currents were mapped and their frequency accurately measured for imaging frame rates up to 500 Hz. Finally, a 3D image of a complex intensity distribution was obtained. The results demonstrated the high sensitivity of the UAI system proposed. The plane wave based approach provides a highly flexible trade-off between frame rate, resolution and contrast. In conclusion, the UAI system shows promise for non-invasive, direct and accurate real-time imaging of electrical activation in vivo.

Viscosity Measurements of "FeO"-SiO2 Slag in Equilibrium with Metallic Fe

NASA Astrophysics Data System (ADS)

Chen, Mao; Raghunath, Sreekanth; Zhao, Baojun

2013-06-01

The current study delivered the measurements of viscosities in the system "FeO"-SiO2 in equilibrium with metallic Fe in the composition range between 15 and 40 wt pct SiO2. The experiments were carried out in the temperature range of 1473 K to 1773 K (1200 °C to 1500 °C) using a rotational spindle technique. An analysis of the quenched sample by electron probe X-ray microanalysis (EPMA) after the viscosity measurement enables the composition and microstructure of the slag to be directly linked with the viscosity. The current results are compared with available literature data. The significant discrepancies of the viscosity measurements in this system have been clarified. The possible reasons affecting the accuracy of the viscosity measurement have been discussed. The activation energies derived from the experimental data have a sharp increase at about 33 wt pct SiO2, which corresponds to the composition of fayalite (Fe2SiO4). The modified quasi-chemical model was constructed in the system "FeO"-SiO2 to describe the current viscosity data.

An Earth system view on boundaries for human perturbation of the N and P cycles

NASA Astrophysics Data System (ADS)

Cornell, Sarah; de Vries, Wim

2015-04-01

The appropriation and transformation of land, water, and living resources can alter Earth system functioning, and potentially undermine the basis for the sustainability of our societies. Human activities have greatly increased the flows of reactive forms of nitrogen (N) and phosphorus (P) in the Earth system. These non-substitutable nutrient elements play a fundamental role in the human food system. Furthermore, the current mode of social and economic globalization, and its effect on the present-day energy system, also has large effects including large NOx-N emissions through combustion. Until now, this perturbation of N and P cycles has been treated largely as a local/regional issue, and managed in terms of direct impacts (water, land or air pollution). However, anthropogenic N and P cycle changes affect physical Earth system feedbacks (through greenhouse gas and aerosol changes) and biogeochemical feedbacks (via ecosystem changes, links to the carbon cycle, and altered nutrient limitation) with impacts that can be far removed from the direct sources. While some form of N and P management at the global level seems likely to be needed for continued societal development, the current local-level and sectorial management is often problematically simplistic, as seen in the tensions between divergent N management needs for climate change mitigation, air pollution control, food production, and ecosystem conservation. We require a step change in understanding complex biogeochemical, physical and socio-economic interactions in order to analyse these effects together, and inform policy trade-offs to minimize emergent systemic risks. Planetary boundaries for N and P cycle perturbation have recently been proposed. We discuss the current status of these precautionary boundaries and how we may improve on these preliminary assessments. We present an overview of the human perturbation of the global biogeochemical cycles of N and P and its interaction with the functioning of the Earth system. There are various N and P impacts, which vary in space and time and are associated with multiple human drivers. There are multiple possible constraints that need to be considered; for P there is an issue with absolute availability, but not for N. The societal benefits (e.g. food production) and environmental impacts (e.g. eutrophication) are linked through stoichiometry, which differs in terrestrial and aquatic systems, presenting challenges for any global optimization approach. By setting out these features, we can better assess how to apply and improve our current analytic frameworks, models, and data for safer navigation of the biogeochemical complexities of global sustainability.

[Clinical application of super-link system theory in spinal cord injury patients during rehabilitation stage].

PubMed

Chen, Hsiao-Yu

2008-04-01

The purpose of this paper is to introduce Super-Link System Theory, which is a theory of spinal cord injury rehabilitation. This theory has been developed using the grounded theory research method. By explaining the procedure for establishing a super-link system the paper explains the complex structure of this theory. Super-Link System Theory emphasizes that rehabilitation nurses 'build up their interpersonal relationships' with clients, family caregivers, the interdisciplinary team, and the community, and attempt to 'establish links' among them. They know these links have to be made with appropriate 'timing', and must be able to access the appropriate people when necessary. Super-link systems include the following four links: link to client with spinal cord injury, link to family caregiver, link to interdisciplinary rehabilitation team, and link to community. It can enable rehabilitation nurses to provide a better quality of nursing care to clients and their family caregivers, as well as promote their professional position in the interdisciplinary rehabilitation team.

LAHYSTOTRAIN development and evaluation of a complex training system for hysteroscopy.

PubMed

Müller-Wittig, W K; Bisler, A; Bockholt, U; Los Arcos, J L; Oppelt, P; Stähler, J; Voss, G

2001-01-01

Hysteroscopy has already become an irreplaceable method in gynaecoloic diagnosis and therapy. In the diagnostic case the hysteroscope with a 30 degrees optic is insert transvaginally, in the therapeutic case the resectoscope with a 12 degrees optic is used. The endoscopic intervention requires special surgical skills for endoscope handling and remote instrument control. To acquire these skills currently hands-on training in clinical praxis has become standard, which is linked with higher danger for the women. To overcome current drawbacks of traditional training methods the European project LAHYSTOTRAIN was set up, that tries to combine Virtual Reality (VR), Multimedia (MM) technology, and Intelligent Tutoring Systems (ITS) to develop an alternative training system for hysteroscopic interventions. The first prototype of the LAHYSTOTRAIN demonstrator has been shown on several European conferences. An evaluation of the system was performed, with the idea, to collect feedback and impressions, that should be considered in further developments. This paper presents the LAHYSTOTRAIN prototype and the results of these evaluations.

Influence of current pulse shape on directly modulated system performance in metro area optical networks

NASA Astrophysics Data System (ADS)

Campos, Carmina del Rio; Horche, Paloma R.; Martin-Minguez, Alfredo

2011-03-01

Due to the fact that a metro network market is very cost sensitive, direct modulated schemes appear attractive. In this paper a CWDM (Coarse Wavelength Division Multiplexing) system is studied in detail by means of an Optical Communication System Design Software; a detailed study of the modulated current shape (exponential, sine and gaussian) for 2.5 Gb/s CWDM Metropolitan Area Networks is performed to evaluate its tolerance to linear impairments such as signal-to-noise-ratio degradation and dispersion. Point-to-point links are investigated and optimum design parameters are obtained. Through extensive sets of simulation results, it is shown that some of these shape pulses are more tolerant to dispersion when compared with conventional gaussian shape pulses. In order to achieve a low Bit Error Rate (BER), different types of optical transmitters are considered including strongly adiabatic and transient chirp dominated Directly Modulated Lasers (DMLs). We have used fibers with different dispersion characteristics, showing that the system performance depends, strongly, on the chosen DML-fiber couple.

Laser Communication Demonstration System (LCDS) and future mobile satellite services

NASA Technical Reports Server (NTRS)

Chen, Chien-Chung; Wilhelm, Michael D.; Lesh, James R.

1995-01-01

The Laser Communications Demonstration System (LCDS) is a proposed in-orbit demonstration of high data rate laser communications technology conceived jointly by NASA and U.S. industry. The program objectives are to stimulate industry development and to demonstrate the readiness of high data rate optical communications in Earth orbit. For future global satellite communication systems using intersatellite links, laser communications technology can offer reduced mass and power requirements and higher channel bandwidths without regulatory constraints. As currently envisioned, LCDS will consist of one or two orbiting laser communications terminals capable of demonstrating high data rate (greater than 750Mbps) transmission in a dynamic space environment. Two study teams led by Motorola and Ball Aerospace are currently in the process of conducting a Phase A/B mission definition study of LCDS under contracts with JPL/NASA. The studies consist of future application survey, concept and requirements definition, and a point design of the laser communications flight demonstration. It is planned that a single demonstration system will be developed based on the study results. The Phase A/B study is expected to be completed by the coming June, and the current results of the study are presented in this paper.

A machine independent expert system for diagnosing environmentally induced spacecraft anomalies

NASA Technical Reports Server (NTRS)

Rolincik, Mark J.

1991-01-01

A new rule-based, machine independent analytical tool for diagnosing spacecraft anomalies, the EnviroNET expert system, was developed. Expert systems provide an effective method for storing knowledge, allow computers to sift through large amounts of data pinpointing significant parts, and most importantly, use heuristics in addition to algorithms which allow approximate reasoning and inference, and the ability to attack problems not rigidly defines. The EviroNET expert system knowledge base currently contains over two hundred rules, and links to databases which include past environmental data, satellite data, and previous known anomalies. The environmental causes considered are bulk charging, single event upsets (SEU), surface charging, and total radiation dose.

An introduction to web scale discovery systems.

PubMed

Hoy, Matthew B

2012-01-01

This article explores the basic principles of web-scale discovery systems and how they are being implemented in libraries. "Web scale discovery" refers to a class of products that index a vast number of resources in a wide variety formats and allow users to search for content in the physical collection, print and electronic journal collections, and other resources from a single search box. Search results are displayed in a manner similar to Internet searches, in a relevance ranked list with links to online content. The advantages and disadvantages of these systems are discussed, and a list of popular discovery products is provided. A list of library websites with discovery systems currently implemented is also provided.

Utility-Based Link Recommendation in Social Networks

ERIC Educational Resources Information Center

Li, Zhepeng

2013-01-01

Link recommendation, which suggests links to connect currently unlinked users, is a key functionality offered by major online social networking platforms. Salient examples of link recommendation include "people you may know"' on Facebook and "who to follow" on Twitter. A social networking platform has two types of stakeholder:…

Longitudinal Links Between Gambling Participation and Academic Performance in Youth: A Test of Four Models.

PubMed

Vitaro, Frank; Brendgen, Mara; Girard, Alain; Dionne, Ginette; Boivin, Michel

2018-01-11

Gambling participation and low academic performance are related during adolescence, but the causal mechanisms underlying this link are unclear. It is possible that gambling participation impairs academic performance. Alternatively, the link between gambling participation and low academic performance could be explained by common underlying risk factors such as impulsivity and socio-family adversity. It could also be explained by other current correlated problem behaviors such as substance use. The goal of the present study was to examine whether concurrent and longitudinal links between gambling participation and low academic performance exist from age 14 to age 17 years, net of common antecedent factors and current substance use. A convenience sample of 766 adolescents (50.6% males) from a longitudinal twin sample participated in the study. Analyses revealed significant, albeit modest, concurrent links at both ages between gambling participation and academic performance. There was also a longitudinal link between gambling participation at age 14 and academic performance at age 17, which persisted after controlling for age 12 impulsivity and socio-family adversity as well as current substance use. Gambling participation predicts a decrease in academic performance during adolescence, net of concurrent and antecedent personal and familial risk factors.

Integrating free-space optical communication links with existing WiFi (WiFO) network

NASA Astrophysics Data System (ADS)

Liverman, S.; Wang, Q.; Chu, Y.; Duong, T.; Nguyen-Huu, D.; Wang, S.; Nguyen, T.; Wang, A. X.

2016-02-01

Recently, free-space optical (FSO) systems have generated great interest due to their large bandwidth potential and a line-of-sight physical layer of protection. In this paper, we propose WiFO, a novel hybrid system, FSO downlink and WiFi uplink, which will integrate currently available WiFi infrastructure with inexpensive infrared light emitting diodes. This system takes full advantage of the mobility inherent in WiFi networks while increasing the downlink bandwidth available to each end user. We report the results of our preliminary investigation that show the capabilities of our prototype design in terms of bandwidth, bit error rates, delays and transmission distances.

Research on Control System of Three - phase Brushless DC Motor for Electric Vehicle

NASA Astrophysics Data System (ADS)

Wang, Zhiwei; Jin, Hai; Guo, Jie; Su, Jie; Wang, Miao

2017-12-01

In order to study the three-phase brushless motor control system of electric vehicle, Freescale9S12XS128 chip is used as the control core, and the power MOSFET is used as the inverter device. The software is compiled by Codewarrior software. The speed control link adopts open-loop control, and the control chip collects the external sensor signal voltage Change control PWM signal output control three-phase brushless DC motor speed. The whole system consists of Hall position detection module, current detection module, power drive module and voltage detection module. The basic functions of three-phase brushless DC motor drive control are realized.

Ichthyoplankton gut analysis with relevance to prey availability in the waters of Lamon Bay, northeastern Luzon, Philippines

NASA Astrophysics Data System (ADS)

Bollozos, I.; Yniguez, A. T.; Palermo, J. H.; Cabrera, O. C.; Villanoy, C. L.

2013-12-01

The waters in the eastern part of Luzon are highly influenced by the western boundary current system of the western Pacific brought about by the bifurcation of the North Equatorial Current into the Kuroshio and Mindanao Current. Eddies are formed with varying intensities as an effect of the ENSO cycle. Three spatial zones were identified according to prominent current movements and circulations observed during the summer 2011 and 2012 oceanographic cruises. These events also affect the productivity in the surrounding waters. Plankton samples were collected to determine the relative abundances of major groups representing three trophic levels. The abundance and composition of phyto- and zooplankton major groups slightly varied among the zones. Gut analysis of fish larvae was then conducted to determine potential prey preference and linked to the phyto- and zooplankton densities.

Ionospheric refraction effects on orbit determination using the orbit determination error analysis system

NASA Technical Reports Server (NTRS)

Yee, C. P.; Kelbel, D. A.; Lee, T.; Dunham, J. B.; Mistretta, G. D.

1990-01-01

The influence of ionospheric refraction on orbit determination was studied through the use of the Orbit Determination Error Analysis System (ODEAS). The results of a study of the orbital state estimate errors due to the ionospheric refraction corrections, particularly for measurements involving spacecraft-to-spacecraft tracking links, are presented. In current operational practice at the Goddard Space Flight Center (GSFC) Flight Dynamics Facility (FDF), the ionospheric refraction effects on the tracking measurements are modeled in the Goddard Trajectory Determination System (GTDS) using the Bent ionospheric model. While GTDS has the capability of incorporating the ionospheric refraction effects for measurements involving ground-to-spacecraft tracking links, such as those generated by the Ground Spaceflight Tracking and Data Network (GSTDN), it does not have the capability to incorporate the refraction effects for spacecraft-to-spacecraft tracking links for measurements generated by the Tracking and Data Relay Satellite System (TDRSS). The lack of this particular capability in GTDS raised some concern about the achievable accuracy of the estimated orbit for certain classes of spacecraft missions that require high-precision orbits. Using an enhanced research version of GTDS, some efforts have already been made to assess the importance of the spacecraft-to-spacecraft ionospheric refraction corrections in an orbit determination process. While these studies were performed using simulated data or real tracking data in definitive orbit determination modes, the study results presented here were obtained by means of covariance analysis simulating the weighted least-squares method used in orbit determination.

Hybrid Wing Body Planform Design with Vehicle Sketch Pad

NASA Technical Reports Server (NTRS)

Wells, Douglas P.; Olson, Erik D.

2011-01-01

The objective of this paper was to provide an update on NASA s current tools for design and analysis of hybrid wing body (HWB) aircraft with an emphasis on Vehicle Sketch Pad (VSP). NASA started HWB analysis using the Flight Optimization System (FLOPS). That capability is enhanced using Phoenix Integration's ModelCenter(Registered TradeMark). Model Center enables multifidelity analysis tools to be linked as an integrated structure. Two major components are linked to FLOPS as an example; a planform discretization tool and VSP. The planform discretization tool ensures the planform is smooth and continuous. VSP is used to display the output geometry. This example shows that a smooth & continuous HWB planform can be displayed as a three-dimensional model and rapidly sized and analyzed.

Intelsat TDMA and its implementation in Australia

NASA Astrophysics Data System (ADS)

Howe, Stuart

The developmental history and characteristics of the Intelsat digital communications network are surveyed, with a focus on the current implementation status in Australia. Topics addressed include the fundamental principles and advantages of a TDMA system, the hardware required for a TDMA traffic station, and the Intelsat Indian Ocean Primary satellite network. Detailed consideration is given to TDMA test equipment (burst-mode link analyzers, PCM DSI test sets, burst-power meters, burst negators, and reference burst generators), terminal integration with terrestrial and RF links (TWT sharing and equalization), equipment compatibility, and traffic. Plans call for 950 TDMA circuits by the end of 1990, representing about 36.5 percent of the traffic between Australia and Europe, Africa, India and Pakistan, and the Middle East.

Global deformation of the Earth, surface mass anomalies, and the geodetic infrastructure required to study these processes

NASA Astrophysics Data System (ADS)

Kusche, J.; Rietbroek, R.; Gunter, B.; Mark-Willem, J.

2008-12-01

Global deformation of the Earth can be linked to loading caused by mass changes in the atmosphere, the ocean and the terrestrial hydrosphere. World-wide geodetic observation systems like GPS, e.g., the global IGS network, can be used to study the global deformation of the Earth directly and, when other effects are properly modeled, provide information regarding the surface loading mass (e.g., to derive geo-center motion estimates). Vice versa, other observing systems that monitor mass change, either through gravitational changes (GRACE) or through a combination of in-situ and modeled quantities (e.g., the atmosphere, ocean or hydrosphere), can provide indirect information on global deformation. In the framework of the German 'Mass transport and mass distribution' program, we estimate surface mass anomalies at spherical harmonic resolution up to degree and order 30 by linking three complementary data sets in a least squares approach. Our estimates include geo-center motion and the thickness of a spatially uniform layer on top of the ocean surface (that is otherwise estimated from surface fluxes, evaporation and precipitation, and river run-off) as a time-series. As with all current Earth observing systems, each dataset has its own limitations and do not realize homogeneous coverage over the globe. To assess the impact that these limitations might have on current and future deformation and loading mass solutions, a sensitivity study was conducted. Simulated real-case and idealized solutions were explored in which the spatial distribution and quality of GPS, GRACE and OBP data sets were varied. The results show that significant improvements, e.g., over the current GRACE monthly gravity fields, in particular at the low degrees, can be achieved when these solutions are combined with present day GPS and OBP products. Our idealized scenarios also provide quantitative implications on how much surface mass change estimates may improve in the future when improved observing systems become available.

High Capacity Communications From Martian Distances. Part 1; Spacecraft Link Design Analysis

NASA Technical Reports Server (NTRS)

Vyas, Hemali N.; Schuchman, Leonard; Orr, Richard; Williams, Wallace Dan; Collins, Michael; Noreen, Gary

2006-01-01

High capacity space communications has been a desire for Human Exploration and Science missions. Current Mars missions operate at data rates of 120 kbps for telemetry downlink and it is desirable to study high rate communication links in the range of 100 Mbps to 1 Gbps data rates from Martian distances. This paper will present some assumed scenarios along with link design assumptions and link analysis for high capacity communications from Mars. The paper will focus on RF subsystems namely antenna and power for the downlink communication from a relay orbiter at Mars. The relay orbiter will communicate with the low orbit spacecrafts at Mars or any Martian surface elements such as robots, and relay the data back to the ground networks on Earth. The study will dive into the spacecraft downlink system design and communication link analysis between the relay orbiter and ground network on Earth for data rates ranging from 100 Mbps to 1 Gbps based on the assumed scenarios and link assumptions. With high rate links at larger distances, there will be a significant impact on the antenna and power requirements and the link design will make an attempt to minimize the mass of the RF subsystem on the spacecraft. The results of this study will be presented for three data rates 1 Gbps, 500 Mbps and 100 Mbps at maximum Mars to Earth distance of 2.67AU. The design will use a Ka-band downlink with 90% link availability, along with various ground network G/T assumptions and possible bandwidth efficient modulations. The paper will conclude with what types of high rate communication links are feasible from Martian distances and also identify a range of requirements for antenna and power technologies for these high capacity communications from Mars.

Design and implementation of a status at a glance user interface for a power distribution expert system

NASA Technical Reports Server (NTRS)

Liberman, Eugene M.; Manner, David B.; Dolce, James L.; Mellor, Pamela A.

1993-01-01

A user interface to the power distribution expert system for Space Station Freedom is discussed. The importance of features which simplify assessing system status and which minimize navigating through layers of information are examined. Design rationale and implementation choices are also presented. The amalgamation of such design features as message linking arrows, reduced information content screens, high salience anomaly icons, and color choices with failure detection and diagnostic explanation from an expert system is shown to provide an effective status-at-a-glance monitoring system for power distribution. This user interface design offers diagnostic reasoning without compromising the monitoring of current events. The display can convey complex concepts in terms that are clear to its users.

CHANGING OUR DIAGNOSTIC PARADIGM: MOVEMENT SYSTEM DIAGNOSTIC CLASSIFICATION

PubMed Central

Kamonseki, Danilo H.; Staker, Justin L.; Lawrence, Rebekah L.; Braman, Jonathan P.

2017-01-01

Proper diagnosis is a first step in applying best available treatments, and prognosticating outcomes for clients. Currently, the majority of musculoskeletal diagnoses are classified according to pathoanatomy. However, the majority of physical therapy treatments are applied toward movement system impairments or pain. While advocated within the physical therapy profession for over thirty years, diagnostic classification within a movement system framework has not been uniformly developed or adopted. We propose a basic framework and rationale for application of a movement system diagnostic classification for atraumatic shoulder pain conditions, as a case for the broader development of movement system diagnostic labels. Shifting our diagnostic paradigm has potential to enhance communication, improve educational efficiency, facilitate research, directly link to function, improve clinical care, and accelerate preventive interventions. PMID:29158950

Remedial Action Assessment System: A computer-based methodology for conducting feasibility studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, M.K.; Buelt, J.L.; Stottlemyre, J.A.

1991-02-01

Because of the complexity and number of potential waste sites facing the US Department of Energy (DOE) for potential cleanup, DOE is supporting the development of a computer-based methodology to streamline the remedial investigation/feasibility study process. The Remedial Action Assessment System (RAAS), can be used for screening, linking, and evaluating established technology processes in support of conducting feasibility studies. It is also intended to do the same in support of corrective measures studies. The user interface employs menus, windows, help features, and graphical information while RAAS is in operation. Object-oriented programming is used to link unit processes into sets ofmore » compatible processes that form appropriate remedial alternatives. Once the remedial alternatives are formed, the RAAS methodology can evaluate them in terms of effectiveness, implementability, and cost. RAAS will access a user-selected risk assessment code to determine the reduction of risk after remedial action by each recommended alternative. The methodology will also help determine the implementability of the remedial alternatives at a site and access cost estimating tools to provide estimates of capital, operating, and maintenance costs. This paper presents the characteristics of two RAAS prototypes currently being developed. These include the RAAS Technology Information System, which accesses graphical, tabular and textual information about technologies, and the main RAAS methodology, which screens, links, and evaluates remedial technologies. 4 refs., 3 figs., 1 tab.« less

Review Recent progress in identification and characterization of loci associated with sex-linked congenital cataract.

PubMed

Zhang, D D; Du, J Z; Topolewski, J; Wang, X M

2016-07-29

Congenital cataract is a common cause of blindness in children; however, its pathogenesis remains unclear. Genetic factors have been shown to play an important role in the pathogenesis of congenital cataract. The current genetic models of congenital cataract include autosomal dominant, autosomal recessive, and sex-linked inheritance. Sex-linked congenital cataract could be inherited through the X or Y chromosome. Congenital cataract is a symptom associated with several X-linked disorders, including Nance-Horan syndrome, Lowe syndrome, Conradi-Hünermann-Happle syndrome, oculo-facio-cardio-dental syndrome, and Alport syndrome. On the other hand, the mechanism and characteristics of Y-linked congenital cataract remains to be identified. Despite its rarity, sex-linked congenital cataract has been known to seriously affect the quality of life of patients. In this review, we present our current understanding of the genes and loci associated with sex-linked congenital cataract. This could help identify novel approaches for the prevention, early diagnosis, and comprehensive disease treatment.

Intra-Chip Free-Space Optical Interconnect: System, Device, Integration and Prototyping

NASA Astrophysics Data System (ADS)

Ciftcioglu, Berkehan

Currently, on-chip optical interconnect schemes already proposed utilize circuit switching using wavelength division multiplexing (WDM) or all-optical packet switching, all based on planar optical waveguides and related photonic devices such as microrings. These proposed approaches pose significant challenges in latency, energy efficiency, integration, and scalability. This thesis presents a new alternative approach by utilizing free-space optics. This 3-D integrated intra-chip free-space optical interconnect (FSOI) leverages mature photonic devices such as integrated lasers, photodiodes, microlenses and mirrors. It takes full advantages of the latest developments in 3-D integration technologies. This interconnect system provides point-to-point free-space optical links between any two communication nodes to construct an all-to-all intra-chip communication network with little or no arbitration. Therefore, it has significant networking advantages over conventional electrical and waveguide-based optical interconnects. An FSOI system is evaluated based on the real device parameters, predictive technology models and International Roadmap of Semiconductor's predictions. A single FSOI link achieves 10-Gbps data rate with 0.5-pJ/bit energy efficiency and less than 10--12 bit-error-rate (BER). A system using this individual link can provide scalability up to 36 nodes, providing 10-Tbps aggregate bandwidth. A comparison analysis performed between a WDM-based waveguide interconnect system and the proposed FSOI system shows that FSOI achieves better energy efficiency than the WDM one as the technology scales. Similarly, network simulation on a 16-core microprocessor using the proposed FSOI system instead of mesh networks has been shown to speed up the system by 12% and reduce the energy consumption by 33%. As a part of the development of a 3-D integrated FSOI system, operating at 850 nm with a 10-Gbps data rate per optical link, the photonics devices and optical components are individually designed and fabricated. The photodiodes (PDs) are designed to have large area for efficient light coupling and low capacitance to achieve large bandwidth, while achieving reasonably high responsivity. A metal-semiconductor-metal (MSM) structure is chosen over p-i-n ones to reduce parasitic capacitance per area, to allow less stringent microlens-to-PD alignment for efficient light coupling with a large bandwidth. A novel MSM germanium PD is implemented using an amorphous silicon (a-Si) layer on top of the undoped germanium substrate, serving as a barrier enhancement layer, mitigating the low Schottky barrier height for holes due to fermi level pinning and a surface passivation layer, preventing charge accumulation and image force lowering of the barrier. Therefore, the dark current is reduced and low-frequency gain is eliminated. The PDs achieve a 13-GHz bandwidth with a 0.315-A/W responsivity and a 1.7-nAmum² dark current density. The microlenses are fabricated on a fused silica substrate based on the photoresist melt-and-reflow technique, followed by dry etching into fused silica substrate. The measured focal length of a 220-mum aperture size microlens is 350-mum away from the backside of the substrate. The vertical-cavity surface-emitting lasers (VCSELs) are fabricated on a commercial molecular beam epitaxially (MBE) grown GaAs wafer. The fabricated 8-mum aperture size VCSEL can achieve 0.65-mW optical power at a 1.5-mA forward bias current with a threshold current of 0.48 mA and a 0.67-A/W slope efficiency. Three prototypes are implemented via integrating the individually fabricated components using non-conductive epoxy and wirebonding. The first prototype, built on a printed circuit board (PCB) using commercial VCSEL arrays, achieves a 5-dB transmission loss and less than -30-dB crosstalk at 1-cm distance with a small-signal bandwidth of 10 GHz, limited by the VCSEL. The second board-level prototype uses all fabricated components integrated on a PCB. The prototype achieves a 9-dB transmission loss at 3-cm distance and a 4.4-GHz bandwidth. The chip-level prototype is built on a germanium carrier with integrated MSM Ge PDs, microlenses on fused silica and VCSEL chip on GaAs substrates. The prototype achieves 4-dB transmission loss at 1 cm and 3.3-GHz bandwidth, limited by commercial VCSEL bandwidth. (Abstract shortened by UMI.)

Transparent ICD and DRG coding using information technology: linking and associating information sources with the eXtensible Markup Language.

PubMed

Hoelzer, Simon; Schweiger, Ralf K; Dudeck, Joachim

2003-01-01

With the introduction of ICD-10 as the standard for diagnostics, it becomes necessary to develop an electronic representation of its complete content, inherent semantics, and coding rules. The authors' design relates to the current efforts by the CEN/TC 251 to establish a European standard for hierarchical classification systems in health care. The authors have developed an electronic representation of ICD-10 with the eXtensible Markup Language (XML) that facilitates integration into current information systems and coding software, taking different languages and versions into account. In this context, XML provides a complete processing framework of related technologies and standard tools that helps develop interoperable applications. XML provides semantic markup. It allows domain-specific definition of tags and hierarchical document structure. The idea of linking and thus combining information from different sources is a valuable feature of XML. In addition, XML topic maps are used to describe relationships between different sources, or "semantically associated" parts of these sources. The issue of achieving a standardized medical vocabulary becomes more and more important with the stepwise implementation of diagnostically related groups, for example. The aim of the authors' work is to provide a transparent and open infrastructure that can be used to support clinical coding and to develop further software applications. The authors are assuming that a comprehensive representation of the content, structure, inherent semantics, and layout of medical classification systems can be achieved through a document-oriented approach.

Transparent ICD and DRG Coding Using Information Technology: Linking and Associating Information Sources with the eXtensible Markup Language

PubMed Central

Hoelzer, Simon; Schweiger, Ralf K.; Dudeck, Joachim

2003-01-01

With the introduction of ICD-10 as the standard for diagnostics, it becomes necessary to develop an electronic representation of its complete content, inherent semantics, and coding rules. The authors' design relates to the current efforts by the CEN/TC 251 to establish a European standard for hierarchical classification systems in health care. The authors have developed an electronic representation of ICD-10 with the eXtensible Markup Language (XML) that facilitates integration into current information systems and coding software, taking different languages and versions into account. In this context, XML provides a complete processing framework of related technologies and standard tools that helps develop interoperable applications. XML provides semantic markup. It allows domain-specific definition of tags and hierarchical document structure. The idea of linking and thus combining information from different sources is a valuable feature of XML. In addition, XML topic maps are used to describe relationships between different sources, or “semantically associated” parts of these sources. The issue of achieving a standardized medical vocabulary becomes more and more important with the stepwise implementation of diagnostically related groups, for example. The aim of the authors' work is to provide a transparent and open infrastructure that can be used to support clinical coding and to develop further software applications. The authors are assuming that a comprehensive representation of the content, structure, inherent semantics, and layout of medical classification systems can be achieved through a document-oriented approach. PMID:12807813

Imaging of current density distributions with a Nb weak-link scanning nano-SQUID microscope

PubMed Central

Shibata, Yusuke; Nomura, Shintaro; Kashiwaya, Hiromi; Kashiwaya, Satoshi; Ishiguro, Ryosuke; Takayanagi, Hideaki

2015-01-01

Superconducting quantum interference devices (SQUIDs) are accepted as one of the highest magnetic field sensitive probes. There are increasing demands to image local magnetic fields to explore spin properties and current density distributions in a two-dimensional layer of semiconductors or superconductors. Nano-SQUIDs have recently attracting much interest for high spatial resolution measurements in nanometer-scale samples. Whereas weak-link Dayem Josephson junction nano-SQUIDs are suitable to miniaturization, hysteresis in current-voltage (I-V) characteristics that is often observed in Dayem Josephson junction is not desirable for a scanning microscope. Here we report on our development of a weak-link nano-SQUIDs scanning microscope with small hysteresis in I-V curve and on reconstructions of two-dimensional current density vector in two-dimensional electron gas from measured magnetic field. PMID:26459874

Imaging of current density distributions with a Nb weak-link scanning nano-SQUID microscope

NASA Astrophysics Data System (ADS)

Shibata, Yusuke; Nomura, Shintaro; Kashiwaya, Hiromi; Kashiwaya, Satoshi; Ishiguro, Ryosuke; Takayanagi, Hideaki

2015-10-01

Superconducting quantum interference devices (SQUIDs) are accepted as one of the highest magnetic field sensitive probes. There are increasing demands to image local magnetic fields to explore spin properties and current density distributions in a two-dimensional layer of semiconductors or superconductors. Nano-SQUIDs have recently attracting much interest for high spatial resolution measurements in nanometer-scale samples. Whereas weak-link Dayem Josephson junction nano-SQUIDs are suitable to miniaturization, hysteresis in current-voltage (I-V) characteristics that is often observed in Dayem Josephson junction is not desirable for a scanning microscope. Here we report on our development of a weak-link nano-SQUIDs scanning microscope with small hysteresis in I-V curve and on reconstructions of two-dimensional current density vector in two-dimensional electron gas from measured magnetic field.

Looking Back to the Future: Current Issues Facing Nursing Education From the Reflections of a Member of the Silent Generation.

PubMed

Keating, Sarah B

2016-07-01

As a member of the Silent Generation, the author, through her lived experiences, reflects upon the successes and challenges facing nursing education in the mid-20th to 21st centuries. The author looks "back to the future" and reviews current issues that surround four key nursing education milestones. From the early entry-level baccalaureate programs in the 1950s to the current growth of the Doctor of Nursing Practice as entry into advanced practice, milestones in nursing education are linked to the cultural changes and healthcare system demands that took place at the time and their influence on nursing education and the profession. Looking to the future, the author speaks of the implications from the forecasted changes in the healthcare system that will demand interdisciplinary education and practice and the continued need for nursing research to increase the body of scientific knowledge in practice, education, and technology. Keating. © 2015 Wiley Periodicals, Inc.

Multi-modal demands of a smartphone used to place calls and enter addresses during highway driving relative to two embedded systems.

PubMed

Reimer, Bryan; Mehler, Bruce; Reagan, Ian; Kidd, David; Dobres, Jonathan

2016-12-01

There is limited research on trade-offs in demand between manual and voice interfaces of embedded and portable technologies. Mehler et al. identified differences in driving performance, visual engagement and workload between two contrasting embedded vehicle system designs (Chevrolet MyLink and Volvo Sensus). The current study extends this work by comparing these embedded systems with a smartphone (Samsung Galaxy S4). None of the voice interfaces eliminated visual demand. Relative to placing calls manually, both embedded voice interfaces resulted in less eyes-off-road time than the smartphone. Errors were most frequent when calling contacts using the smartphone. The smartphone and MyLink allowed addresses to be entered using compound voice commands resulting in shorter eyes-off-road time compared with the menu-based Sensus but with many more errors. Driving performance and physiological measures indicated increased demand when performing secondary tasks relative to 'just driving', but were not significantly different between the smartphone and embedded systems. Practitioner Summary: The findings show that embedded system and portable device voice interfaces place fewer visual demands on the driver than manual interfaces, but they also underscore how differences in system designs can significantly affect not only the demands placed on drivers, but also the successful completion of tasks.

Ontological Modeling for Integrated Spacecraft Analysis

NASA Technical Reports Server (NTRS)

Wicks, Erica

2011-01-01

Current spacecraft work as a cooperative group of a number of subsystems. Each of these requiresmodeling software for development, testing, and prediction. It is the goal of my team to create anoverarching software architecture called the Integrated Spacecraft Analysis (ISCA) to aid in deploying the discrete subsystems' models. Such a plan has been attempted in the past, and has failed due to the excessive scope of the project. Our goal in this version of ISCA is to use new resources to reduce the scope of the project, including using ontological models to help link the internal interfaces of subsystems' models with the ISCA architecture.I have created an ontology of functions specific to the modeling system of the navigation system of a spacecraft. The resulting ontology not only links, at an architectural level, language specificinstantiations of the modeling system's code, but also is web-viewable and can act as a documentation standard. This ontology is proof of the concept that ontological modeling can aid in the integration necessary for ISCA to work, and can act as the prototype for future ISCA ontologies.

The impact of a prevention delivery system on perceived social capital: the PROSPER project.

PubMed

Chilenski, Sarah M; Ang, Patricia M; Greenberg, Mark T; Feinberg, Mark E; Spoth, Richard

2014-04-01

The current study examined the impact of the PROSPER delivery system for evidence-based prevention programs on multiple indicators of social capital in a rural and semi-rural community sample. Utilizing a randomized blocked design, 317 individuals in 28 communities across two states were interviewed at three time points over the course of 2.5 years. Bridging, linking, and the public life skills forms of social capital were assessed via community members' and leaders' reports on the perceptions of school functioning and the Cooperative Extension System, collaboration among organizations, communication and collaboration around youth problems, and other measures. Longitudinal mixed model results indicate significant improvements in some aspects of bridging and linking social capital in PROSPER intervention communities. Given the strength of the longitudinal and randomized research design, results advance prevention science by suggesting that community collaborative prevention initiatives can significantly impact community social capital in a rural and semi-rural sample. Future research should further investigate changes in social capital in different contexts and how changes in social capital relate to other intervention effects.

Forensic analysis of online marketing for electronic nicotine delivery systems.

PubMed

Cobb, Nathan K; Brookover, Jody; Cobb, Caroline O

2015-03-01

Electronic nicotine delivery systems (ENDS) are growing in awareness and use in the USA. They are currently unregulated as the Food and Drug Administration has yet to assert jurisdiction under its tobacco authority over these products, and a US Court of Appeals held they cannot be regulated as drugs/delivery devices if they are not marketed for a therapeutic purpose. Observation of the current online marketplace suggests ENDS, like some nutraceutical products, are being promoted using affiliate marketing techniques using claims concerning purported health benefits. This study performed a forensic analysis to characterise the relationships between online ENDS affiliate advertisements and ENDS sellers, and evaluated descriptive content on advertisements and websites to inform future policy and regulatory efforts. A purposive sampling strategy was used to identify three forms of ENDS advertising. Web proxy software recorded identifiable objects and their ties to each other. Network analysis of these ties followed, as well as analysis of descriptive content on advertisements and websites identified. The forensic analysis included four ENDS advertisements, two linked affiliate websites, and two linked seller websites, and demonstrated a multilevel relationship between advertisements and sellers with multiple layers of redirection. Descriptive analysis indicated that advertisements and affiliates, but not linked sellers, included smoking cessation claims. Results suggest that ENDS sellers may be trying to distance marketing efforts containing unsubstantiated claims from sales. A separate descriptive analysis of 20 ENDS seller web pages indicated that the use of affiliate marketing by sellers may be widespread. These findings support increased monitoring and regulation of ENDS marketing to prevent deceptive marketing tactics and ensure consumer safety. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Assessing Spectrum Compatibility for Beyond-Line-of-Sight UAS Control and Non-Payload Communications

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Wilson, Jeffrey D.; Bishop, William D.

2014-01-01

In order to provide for the safe integration of unmanned aircraft systems (UAS) into the National Airspace System (NAS), the control and non-payload communications (CNPC) link must be highly reliable. A specific requirement is that it must operate using aviation safety radiofrequency spectrum. Two types of links are required - line-of-sight (LOS) using terrestrial-based communications and beyond-line-of-sight (BLOS) using satellite communications. The 2012 World Radiocommunication Conference (WRC-12) provided a suitable allocation for LOS CNPC spectrum in the 5030 to 5091 MHz band which, when combined with a previously existing allocation fulfills the LOS spectrum requirement. The 5030 to 5091 MHz band is also allocated for BLOS CNPC, but since a significant portion of that band is required for LOS CNPC, additional BLOS spectrum is required. More critically, there are no satellites in operation or in development to provide such services in that band. Hence BLOS CNPC cannot be provided in protected aviation spectrum under current conditions. To fill this gap and enable integration of UAS into the NAS, it has been proposed to allow CNPC to operate over certain Fixed Satellite Service (FSS) bands in which many satellites currently provide commercial services. To enable this, changes in international regulation must be enacted. Agenda Item 1.5 of the 2015 WRC examines the possible regulatory changes needed. As part of the examination process, sharing between potential UAS using satellite communications for BLOS CNPC and other services allocated to the FSS bands being considered must be studied. This paper reviews the technical requirements and approach being undertaken for these sharing studies, with emphasis on study of interference from UAS into digital repeater links operating under the Fixed Service allocation. These studies are being conducted by NASA Glenn Research Center.

Assessing Spectrum Compatibility for Beyond-Line-of-Sight UAS Control and Non-Payload Communications

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Wilson, Jeffrey D.; Bishop, William D.

2014-01-01

In order to provide for the safe integration of unmanned aircraft systems (UAS) into the National Airspace System (NAS), the control and non-payload communications (CNPC) link must be highly reliable. A specific requirement is that it must operate using aviation safety radiofrequency spectrum. Two types of links are required - line-of-sight (LOS) using terrestrial-based communications and beyond-line- of-sight (BLOS) using satellite communications. The 2012 World Radiocommunication Conference (WRC-12) provided a suitable allocation for LOS CNPC spectrum in the 5030-5091 MHz band which, when combined with a previously existing allocation fulfills the LOS spectrum requirement. The 5030- 5091 MHz band is also allocated for BLOS CNPC, but since a significant portion of that band is required for LOS CNPC, additional BLOS spectrum is required. More critically, there are no satellites in operation or in development to provide such services in that band. Hence BLOS CNPC cannot be provided in protected aviation spectrum under current conditions. To fill this gap and enable integration of UAS into the NAS, it has been proposed to allow CNPC to operate over certain Fixed Satellite Service (FSS) bands in which many satellites currently provide commercial services. To enable this, changes in international regulation must be enacted. Agenda Item 1.5 of the 2015 WRC examines the possible regulatory changes needed. As part of the examination process, sharing between potential UAS using satellite communications for BLOS CNPC and other services allocated to the FSS bands being considered must be studied. This paper reviews the technical requirements and approach being undertaken for these sharing studies, with emphasis on study of interference from UAS into digital repeater links operating under the Fixed Service allocation. These studies are being conducted by NASA Glenn Research Center.

Deep-Space Ka-Band Flight Experience

NASA Astrophysics Data System (ADS)

Morabito, D. D.

2017-11-01

Lower frequency bands have become more congested in allocated bandwidth as there is increased competition between flight projects and other entities. Going to higher frequency bands offers significantly more bandwidth, allowing for the use of much higher data rates. However, Ka-band is more susceptible to weather effects than lower frequency bands currently used for most standard downlink telemetry operations. Future or prospective flight projects considering deep-space Ka-band (32-GHz) telemetry data links have expressed an interest in understanding past flight experience with received Ka-band downlink performance. Especially important to these flight projects is gaining a better understanding of weather effects from the experience of current or past missions that operated Ka-band radio systems. We will discuss the historical flight experience of several Ka-band missions starting from Mars Observer in 1993 up to present-day deep-space missions such as Kepler. The study of historical Ka-band flight experience allows one to recommend margin policy for future missions. Of particular interest, we will review previously reported-on flight experience with the Cassini spacecraft Ka-band radio system that has been used for radio science investigations as well as engineering studies from 2004 to 2015, when Cassini was in orbit around the planet Saturn. In this article, we will focus primarily on the Kepler spacecraft Ka-band link, which has been used for operational telemetry downlink from an Earth trailing orbit where the spacecraft resides. We analyzed the received Ka-band signal level data in order to characterize link performance over a wide range of weather conditions and as a function of elevation angle. Based on this analysis of Kepler and Cassini flight data, we found that a 4-dB margin with respect to adverse conditions ensures that we achieve at least a 95 percent data return.

Study of Lateral Misalignment Tolerance of a Symmetric Free-Space Optical Link for Intra International Space Station Communication

NASA Technical Reports Server (NTRS)

Tedder, Sarah A.; Schoenholz, Bryan; Suddath, Shannon N.

2016-01-01

This paper describes the study of lateral misalignment tolerance of a symmetric high-rate free-space optical link (FSOL) for use between International Space Station (ISS) payload sites and the main cabin. The link will enable gigabit per second (Gbps) transmission of data, which is up to three orders of magnitude greater than the current capabilities. This application includes 10-20 meter links and requires minimum size, weight, and power (SWaP). The optical power must not present an eye hazard and must be easily integrated into the existing ISS infrastructure. On the ISS, rapid thermal changes and astronaut movement will cause flexure of the structure which will potentially misalign the free space transmit and receive optics 9 cm laterally and 0.2 degrees angularly. If this misalignment is not accounted for, a loss of the link or degradation of link performance will occur. Power measurements were collected to better understand the effect of various system design parameters on lateral misalignment. Parameters that were varied include: the type of small form pluggable (SFP) transceivers, type of fiber, and transmitted power level. A potential solution was identified that can reach the lateral misalignment tolerance (decenter span) required to create an FSOL on the ISS by using 105 m core fibers, a duplex SFP, two channels of light, and two fiber amplifiers.

Wartime Medical Requirements Models: A Comparison of MPM, MEPES, and LPX-MED.

DTIC Science & Technology

1996-10-01

theater-level models: • Medical Planning Module (MPM) • Medical Planning and Execution System (MEPES) • External Logistics Processor-Medical Module ...current plan is to modify LPX-MED to include a requirements calculator, there is no plan to link the require- ments calculation module and the...simulation module . We believe the simulation module (i.e., today’s LPX-MED) needs reasonable starting values, which a calculator model can pro- vide

A Submersible Holographic Camera for the Undisturbed Characterization of Optically Relevant Particles in Water (HOLOCAM)

DTIC Science & Technology

2012-09-01

how to improve both reconstruction and analytical software during testing of the submersible system. IMPACT AND APPLICATIONS Quality of Life...project (see related projects below). It could also be used for sediment load monitoring and assesment . The HOLOCAM could provide critical data to any...Science Education and Communication Currently the link between the suspended particle field and the bulk scattering properties of natural waters is

JPRS Report, Near East & South Asia

DTIC Science & Technology

1989-04-06

TIMES OF OMAN 2 Mar] 26 QATAR Rise in Shipping Movements Recorded [GULF TIMES 24 Jan] 26 North Field Gas Project Progress Cited [GULF TIMES 23...the eastern province of Saudi Arabia, Bahrain and Qatar . Stage two will link areas in the South Gulf, Oman and the UAE [United Arab Emirates]. In...current to high-frequency and vice versa. While Bahrain, Qatar , Oman and Kuwait use the first system, Saudi Arabia uses the second. The main

Theater Battle Management Core System Systems Engineering Case Study

DTIC Science & Technology

2005-02-17

TOC Army Unit TOCs USMC TACC DASC Data Link Data Link AWACS J-STARS Data Link Data Link Data Link RIVET JOINT COMPASS CALL Theater RECCE/SURV Data...Developer’s Guide ( SDG ), Version 2, 30 August 2001. 11. Air Force Electronic Systems Center, ESC/ACF Program Office, ICWG Charter, November 2003. 12

The Genome Sequencer FLX System--longer reads, more applications, straight forward bioinformatics and more complete data sets.

PubMed

Droege, Marcus; Hill, Brendon

2008-08-31

The Genome Sequencer FLX System (GS FLX), powered by 454 Sequencing, is a next-generation DNA sequencing technology featuring a unique mix of long reads, exceptional accuracy, and ultra-high throughput. It has been proven to be the most versatile of all currently available next-generation sequencing technologies, supporting many high-profile studies in over seven applications categories. GS FLX users have pursued innovative research in de novo sequencing, re-sequencing of whole genomes and target DNA regions, metagenomics, and RNA analysis. 454 Sequencing is a powerful tool for human genetics research, having recently re-sequenced the genome of an individual human, currently re-sequencing the complete human exome and targeted genomic regions using the NimbleGen sequence capture process, and detected low-frequency somatic mutations linked to cancer.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayes, T.; Smith, K.S.; Severino, F.

A critical capability of the new RHIC low level rf (LLRF) system is the ability to synchronize signals across multiple locations. The 'Update Link' provides this functionality. The 'Update Link' is a deterministic serial data link based on the Xilinx RocketIO protocol that is broadcast over fiber optic cable at 1 gigabit per second (Gbps). The link provides timing events and data packets as well as time stamp information for synchronizing diagnostic data from multiple sources. The new RHIC LLRF was designed to be a flexible, modular system. The system is constructed of numerous independent RF Controller chassis. To providemore » synchronization among all of these chassis, the Update Link system was designed. The Update Link system provides a low latency, deterministic data path to broadcast information to all receivers in the system. The Update Link system is based on a central hub, the Update Link Master (ULM), which generates the data stream that is distributed via fiber optic links. Downstream chassis have non-deterministic connections back to the ULM that allow any chassis to provide data that is broadcast globally.« less

Intraformation positioning system

NASA Astrophysics Data System (ADS)

Sheldon, Stuart; Zadzora, Timothy

1996-05-01

The IntraFormation Positioning System is a networked relative navigation system currently being developed for rendezvous, join-up, and formation flight of Air Force helicopters and fixed wing aircraft in instrument meteorological conditions. The system is designed to be integrated into existing aircraft and will display relative positions of all aircraft within a formation, as well as the relative positions of other formations participating in coordinated missions. The system uses a Global Positioning System receiver integrated with the aircraft Inertial Navigation System to generate accurate aircraft position and velocity data. These data are transmitted over a data link to all participating aircraft and displayed as graphic symbols at the relative range and bearing to own aircraft on a situational awareness display format similar to a radar plan position indicator. Flight guidance computation is based on the difference between a desired formation slot position and current aircraft position relative to the formation lead aircraft. This information is presented on the flight director display allowing the pilot to null out position errors. The system is being developed for the Air Force Special Operations Command; however, it is applicable to all aircraft desiring improved formation situational awareness and formation flight coordination.

The hydrological calibration and validation of a complexly-linked watershed reservoir model for the Occoquan watershed, Virginia

NASA Astrophysics Data System (ADS)

Xu, Zhongyan; Godrej, Adil N.; Grizzard, Thomas J.

2007-10-01

SummaryRunoff models such as HSPF and reservoir models such as CE-QUAL-W2 are used to model water quality in watersheds. Most often, the models are independently calibrated to observed data. While this approach can achieve good calibration, it does not replicate the physically-linked nature of the system. When models are linked by using the model output from an upstream model as input to a downstream model, the physical reality of a continuous watershed, where the overland and waterbody portions are parts of the whole, is better represented. There are some additional challenges in the calibration of such linked models, because the aim is to simulate the entire system as a whole, rather than piecemeal. When public entities are charged with model development, one of the driving forces is to use public-domain models. This paper describes the use of two such models, HSPF and CE-QUAL-W2, in the linked modeling of the Occoquan watershed located in northern Virginia, USA. The description of the process is provided, and results from the hydrological calibration and validation are shown. The Occoquan model consists of six HSPF and two CE-QUAL-W2 models, linked in a complex way, to simulate two major reservoirs and the associated drainage areas. The overall linked model was calibrated for a three-year period and validated for a two-year period. The results show that a successful calibration can be achieved using the linked approach, with moderate additional effort. Overall flow balances based on the three-year calibration period at four stream stations showed agreement ranging from -3.95% to +3.21%. Flow balances for the two reservoirs, compared via the daily water surface elevations, also showed good agreement ( R2 values of 0.937 for Lake Manassas and 0.926 for Occoquan Reservoir), when missing (un-monitored) flows were included. Validation of the models ranged from poor to fair for the watershed models and excellent for the waterbody models, thus indicating that the current model can be used to explore waterbody issues, but should be used with appropriate care for watershed issues. The study objective of being able to use the Occoquan model to study the impact of land use changes on hydrodynamics and water quality in the waterbodies, particularly the Occoquan Reservoir, can be met with the current model. However, appropriate judgment should be exercised when using the model for the prediction of watershed runoff. One of the advantages of using the linked approach is to develop a direct linkage between upstream land use changes and downstream water quality. This makes it easier for decision-makers to evaluate alternative watershed management plans and for the public to understand the decision-making process. The successful calibration of hydrology provides a solid base for further model development and application.

Dual control active superconductive devices

DOEpatents

Martens, Jon S.; Beyer, James B.; Nordman, James E.; Hohenwarter, Gert K. G.

1993-07-20

A superconducting active device has dual control inputs and is constructed such that the output of the device is effectively a linear mix of the two input signals. The device is formed of a film of superconducting material on a substrate and has two main conduction channels, each of which includes a weak link region. A first control line extends adjacent to the weak link region in the first channel and a second control line extends adjacent to the weak link region in the second channel. The current flowing from the first channel flows through an internal control line which is also adjacent to the weak link region of the second channel. The weak link regions comprise small links of superconductor, separated by voids, through which the current flows in each channel. Current passed through the control lines causes magnetic flux vortices which propagate across the weak link regions and control the resistance of these regions. The output of the device taken across the input to the main channels and the output of the second main channel and the internal control line will constitute essentially a linear mix of the two input signals imposed on the two control lines. The device is especially suited to microwave applications since it has very low input capacitance, and is well suited to being formed of high temperature superconducting materials since all of the structures may be formed coplanar with one another on a substrate.

A flight test design for studying airborne applications of air to ground duplex data link communications

NASA Technical Reports Server (NTRS)

Scanlon, Charles H.

1988-01-01

The Automatic En Route Air Traffic Control (AERA) and the Advanced Automated System (AAS) of the NAS plan, call for utilization of data links for such items as computer generated flight clearances, enroute minimum safe altitude warnings, sector probes, out of conformance check, automated flight services, and flow management of advisories. A major technical challenge remaining is the integration, flight testing, and validation of data link equipment and procedures in the aircraft cockpit. The flight test organizational chart, was designed to have the airplane side of data link experiments implemented in the NASA Langley Research Center (LaRC) experimental Boeing 737 airplane. This design would enable investigations into implementation of data link equipment and pilot interface, operations, and procedures. The illustrated ground system consists of a work station with links to a national weather database and a data link transceiver system. The data link transceiver system could be a Mode-S transponder, ACARS, AVSAT, or another type of radio system such as the military type HF data link. The airborne system was designed so that a data link transceiver, workstation, and touch panel could be interfaced with an input output processor to the aircraft system bus and thus have communications access to other digital airplane systems.

Securing the Global Airspace System Via Identity-Based Security

NASA Technical Reports Server (NTRS)

Ivancic, William D.

2015-01-01

Current telecommunications systems have very good security architectures that include authentication and authorization as well as accounting. These three features enable an edge system to obtain access into a radio communication network, request specific Quality-of-Service (QoS) requirements and ensure proper billing for service. Furthermore, the links are secure. Widely used telecommunication technologies are Long Term Evolution (LTE) and Worldwide Interoperability for Microwave Access (WiMAX) This paper provides a system-level view of network-centric operations for the global airspace system and the problems and issues with deploying new technologies into the system. The paper then focuses on applying the basic security architectures of commercial telecommunication systems and deployment of federated Authentication, Authorization and Accounting systems to provide a scalable, evolvable reliable and maintainable solution to enable a globally deployable identity-based secure airspace system.

The intestinal microbiome, probiotics and prebiotics in neurogastroenterology

PubMed Central

Saulnier, Delphine M.; Ringel, Yehuda; Heyman, Melvin B.; Foster, Jane A.; Bercik, Premysl; Shulman, Robert J.; Versalovic, James; Verdu, Elena F.; Dinan, Ted G.; Hecht, Gail; Guarner, Francisco

2013-01-01

The brain-gut axis allows bidirectional communication between the central nervous system (CNS) and the enteric nervous system (ENS), linking emotional and cognitive centers of the brain with peripheral intestinal functions. Recent experimental work suggests that the gut microbiota have an impact on the brain-gut axis. A group of experts convened by the International Scientific Association for Probiotics and Prebiotics (ISAPP) discussed the role of gut bacteria on brain functions and the implications for probiotic and prebiotic science. The experts reviewed and discussed current available data on the role of gut microbiota on epithelial cell function, gastrointestinal motility, visceral sensitivity, perception and behavior. Data, mostly gathered from animal studies, suggest interactions of gut microbiota not only with the enteric nervous system but also with the central nervous system via neural, neuroendocrine, neuroimmune and humoral links. Microbial colonization impacts mammalian brain development in early life and subsequent adult behavior. These findings provide novel insights for improved understanding of the potential role of gut microbial communities on psychological disorders, most particularly in the field of psychological comorbidities associated with functional bowel disorders like irritable bowel syndrome (IBS) and should present new opportunity for interventions with pro- and prebiotics. PMID:23202796

Analysis and experiments for a system of two spacecraft paired by means of a flexible link

NASA Astrophysics Data System (ADS)

Sabatini, Marco; Palmerini, Giovanni B.; Gasbarri, Paolo

2016-11-01

A field of current interest in space technology is the on-orbit operation concept, often requiring that a chaser spacecraft captures a target spacecraft. The physical link connecting the two satellites is usually characterized by a high degree of flexibility, because of the special requirements imposed to the space systems, and specifically the constraints on the mass at launch. The focus of this paper is the study of an attitude control of the paired spacecraft system such that the elastic oscillations do not interfere with the attitude dynamics, and the final configuration is reached without residual vibrations. At the scope, a rest-to-rest techniques, that requires an accurate description of the dynamic model of the paired satellites as a flexible multibody setup, is applied. The results of this control are first tested by means of a numerical tool, simulating nominal and non-nominal scenarios. Then the identified control is proved in an experimental test-bed, consisting of two free-floating platforms connected by means of an elastic joint. The performance of the rest-to-rest technique is compared to other classical control laws aiming to minimally excite the system undesired dynamics, showing a promising superiority.

Fast wire per wire X-ray data acquisition system for time-resolved small angle scattering experiments

NASA Astrophysics Data System (ADS)

Epstein, A.; Briquet-Laugier, F.; Sheldon, S.; Boulin, C.

2000-04-01

Most of the X-ray multi-wire gas detectors used at the EMBL Hamburg outstation for time-resolved studies of biological samples are readout, using the delay line method. The main disadvantage of such readout systems is their event rate limitation introduced by the delay line and the required time to digital conversion step. They also lack the possibility to deal with multiple events. To overcome these limitations, a new approach for the complete readout system was introduced. The new linear detection system is based on the wire per wire approach where each individual wire is associated to preamplifier/discriminator/counter electronics channel. High-density, front-end electronics were designed around a fast current sensitive preamplifier. An eight-channel board was designed to include the preamplifiers-discriminators and the differential ECL drivers output stages. The detector front-end consists of 25 boards directly mounted inside the detector assembly. To achieve a time framing resolution as short as 10 /spl mu/s, very fast histogramming is required. The only way to implement this for a high number of channels (200 in our case) is by using a distributed system. The digital part of the system consists of a crate controller, up to 16 acquisition boards (capable of handling fast histogramming for up to 32-channels each) and an optical-link board (based on the Cypress "Hot-Link" chip set). Both the crate controller and the acquisition boards are based on a standard RISC microcontroller (IDT R3081) plug-in board. At present, a dedicated CAMAC module which we developed is used to interface the digital front-end acquisition crate to the host via the optical link.

An Efficient Modulation Strategy for Cascaded Photovoltaic Systems Suffering From Module Mismatch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Cheng; Zhang, Kai; Xiong, Jian

Modular multilevel cascaded converter (MMCC) is a promising technique for medium/high-voltage high-power photovoltaic systems due to its modularity, scalability, and capability of distributed maximum power point tracking (MPPT) etc. However, distributed MPPT under module-mismatch might polarize the distribution of ac output voltages as well as the dc-link voltages among the modules, distort grid currents, and even cause system instability. For the better acceptance in practical applications, such issues need to be well addressed. Based on mismatch degree that is defined to consider both active power distribution and maximum modulation index, this paper presents an efficient modulation strategy for a cascaded-H-bridge-basedmore » MMCC under module mismatch. It can operate in loss-reducing mode or range-extending mode. By properly switching between the two modes, performance indices such as system efficiency, grid current quality, and balance of dc voltages, can be well coordinated. In this way, the MMCC system can maintain high-performance over a wide range of operating conditions. As a result, effectiveness of the proposed modulation strategy is proved with experiments.« less

An Efficient Modulation Strategy for Cascaded Photovoltaic Systems Suffering From Module Mismatch

DOE PAGES

Wang, Cheng; Zhang, Kai; Xiong, Jian; ...

2017-09-26

Modular multilevel cascaded converter (MMCC) is a promising technique for medium/high-voltage high-power photovoltaic systems due to its modularity, scalability, and capability of distributed maximum power point tracking (MPPT) etc. However, distributed MPPT under module-mismatch might polarize the distribution of ac output voltages as well as the dc-link voltages among the modules, distort grid currents, and even cause system instability. For the better acceptance in practical applications, such issues need to be well addressed. Based on mismatch degree that is defined to consider both active power distribution and maximum modulation index, this paper presents an efficient modulation strategy for a cascaded-H-bridge-basedmore » MMCC under module mismatch. It can operate in loss-reducing mode or range-extending mode. By properly switching between the two modes, performance indices such as system efficiency, grid current quality, and balance of dc voltages, can be well coordinated. In this way, the MMCC system can maintain high-performance over a wide range of operating conditions. As a result, effectiveness of the proposed modulation strategy is proved with experiments.« less

[Indicators of the persistent pro-inflammatory activation of the immune system in depression].

PubMed

Cubała, Wiesław Jerzy; Godlewska, Beata; Trzonkowski, Piotr; Landowski, Jerzy

2006-01-01

The aetiology of depression remains tentative. Current hypotheses on the aetiology of the depressive disorder tend to integrate monoaminoergic, neuroendocrine and immunological concepts of depression. A number of research papers emphasise the altered hormonal and immune status of patients with depression with pronounced cytokine level variations. Those studies tend to link the variable course of depression in relation to the altered proinflammatory activity of the immune system. The results of the studies on the activity of the selected elements of the immune system are ambiguous indicating both increased and decreased activities of its selected elements. However, a number of basic and psychopharmacological studies support the hypothesis of the increased proinflammatory activity of the immune system in the course of depression which is the foundation for the immunological hypothesis of depression. The aim of this paper is to review the functional abnormalities that are observed in depression focusing on the monoaminoergic deficiency and increased immune activation as well as endocrine dysregulation. This paper puts together and discusses current studies related to this subject with a detailed insight into interactions involving nervous, endocrine and immune systems.

Real-time access of large volume imagery through low-bandwidth links

NASA Astrophysics Data System (ADS)

Phillips, James; Grohs, Karl; Brower, Bernard; Kelly, Lawrence; Carlisle, Lewis; Pellechia, Matthew

2010-04-01

Providing current, time-sensitive imagery and geospatial information to deployed tactical military forces or first responders continues to be a challenge. This challenge is compounded through rapid increases in sensor collection volumes, both with larger arrays and higher temporal capture rates. Focusing on the needs of these military forces and first responders, ITT developed a system called AGILE (Advanced Geospatial Imagery Library Enterprise) Access as an innovative approach based on standard off-the-shelf techniques to solving this problem. The AGILE Access system is based on commercial software called Image Access Solutions (IAS) and incorporates standard JPEG 2000 processing. Our solution system is implemented in an accredited, deployable form, incorporating a suite of components, including an image database, a web-based search and discovery tool, and several software tools that act in concert to process, store, and disseminate imagery from airborne systems and commercial satellites. Currently, this solution is operational within the U.S. Government tactical infrastructure and supports disadvantaged imagery users in the field. This paper presents the features and benefits of this system to disadvantaged users as demonstrated in real-world operational environments.

Linking Quality and Spending to Measure Value for People with Serious Illness.

PubMed

Ryan, Andrew M; Rodgers, Phillip E

2018-03-01

Healthcare payment is rapidly evolving to reward value by measuring and paying for quality and spending performance. Rewarding value for the care of seriously ill patients presents unique challenges. To evaluate the state of current efforts to measure and reward value for the care of seriously ill patients. We performed a PubMed search of articles related to (1) measures of spending for people with serious illness and (2) linking spending and quality measures and rewarding performance for the care of people with serious illness. We limited our search to U.S.-based studies published in English between January 1, 1960, and March 31, 2017. We supplemented this search by identifying public programs and other known initiatives that linked quality and spending for the seriously ill and extracted key program elements. Our search related to linking spending and quality measures and rewarding performance for the care of people with serious illness yielded 277 articles. We identified three current public programs that currently link measures of quality and spending-or are likely to within the next few years-the Oncology Care Model; the Comprehensive End-Stage Renal Disease Model; and Home Health Value-Based Purchasing. Models that link quality and spending consist of four core components: (1) measuring quality, (2) measuring spending, (3) the payment adjustment model, and (4) the linking/incentive model. We found that current efforts to reward value for seriously ill patients are targeted for specific patient populations, do not broadly encourage the use of palliative care, and have not closely aligned quality and spending measures related to palliative care. We develop recommendations for policymakers and stakeholders about how measures of spending and quality can be balanced in value-based payment programs.

Linking Quality and Spending to Measure Value for People with Serious Illness

PubMed Central

Rodgers, Phillip E.

2018-01-01

Abstract Background: Healthcare payment is rapidly evolving to reward value by measuring and paying for quality and spending performance. Rewarding value for the care of seriously ill patients presents unique challenges. Objective: To evaluate the state of current efforts to measure and reward value for the care of seriously ill patients. Design: We performed a PubMed search of articles related to (1) measures of spending for people with serious illness and (2) linking spending and quality measures and rewarding performance for the care of people with serious illness. We limited our search to U.S.-based studies published in English between January 1, 1960, and March 31, 2017. We supplemented this search by identifying public programs and other known initiatives that linked quality and spending for the seriously ill and extracted key program elements. Results: Our search related to linking spending and quality measures and rewarding performance for the care of people with serious illness yielded 277 articles. We identified three current public programs that currently link measures of quality and spending—or are likely to within the next few years—the Oncology Care Model; the Comprehensive End-Stage Renal Disease Model; and Home Health Value-Based Purchasing. Models that link quality and spending consist of four core components: (1) measuring quality, (2) measuring spending, (3) the payment adjustment model, and (4) the linking/incentive model. We found that current efforts to reward value for seriously ill patients are targeted for specific patient populations, do not broadly encourage the use of palliative care, and have not closely aligned quality and spending measures related to palliative care. Conclusions: We develop recommendations for policymakers and stakeholders about how measures of spending and quality can be balanced in value-based payment programs. PMID:29091529

Systematic review of current efforts to quantify the impacts of climate change on undernutrition.

PubMed

Phalkey, Revati K; Aranda-Jan, Clara; Marx, Sabrina; Höfle, Bernhard; Sauerborn, Rainer

2015-08-18

Malnutrition is a challenge to the health and productivity of populations and is viewed as one of the five largest adverse health impacts of climate change. Nonetheless, systematic evidence quantifying these impacts is currently limited. Our aim was to assess the scientific evidence base for the impact of climate change on childhood undernutrition (particularly stunting) in subsistence farmers in low- and middle-income countries. A systematic review was conducted to identify peer-reviewed and gray full-text documents in English with no limits for year of publication or study design. Fifteen manuscripts were reviewed. Few studies use primary data to investigate the proportion of stunting that can be attributed to climate/weather variability. Although scattered and limited, current evidence suggests a significant but variable link between weather variables, e.g., rainfall, extreme weather events (floods/droughts), seasonality, and temperature, and childhood stunting at the household level (12 of 15 studies, 80%). In addition, we note that agricultural, socioeconomic, and demographic factors at the household and individual levels also play substantial roles in mediating the nutritional impacts. Comparable interdisciplinary studies based on primary data at a household level are urgently required to guide effective adaptation, particularly for rural subsistence farmers. Systemization of data collection at the global level is indispensable and urgent. We need to assimilate data from long-term, high-quality agricultural, environmental, socioeconomic, health, and demographic surveillance systems and develop robust statistical methods to establish and validate causal links, quantify impacts, and make reliable predictions that can guide evidence-based health interventions in the future.

Systematic review of current efforts to quantify the impacts of climate change on undernutrition

PubMed Central

Phalkey, Revati K.; Aranda-Jan, Clara; Marx, Sabrina; Höfle, Bernhard; Sauerborn, Rainer

2015-01-01

Malnutrition is a challenge to the health and productivity of populations and is viewed as one of the five largest adverse health impacts of climate change. Nonetheless, systematic evidence quantifying these impacts is currently limited. Our aim was to assess the scientific evidence base for the impact of climate change on childhood undernutrition (particularly stunting) in subsistence farmers in low- and middle-income countries. A systematic review was conducted to identify peer-reviewed and gray full-text documents in English with no limits for year of publication or study design. Fifteen manuscripts were reviewed. Few studies use primary data to investigate the proportion of stunting that can be attributed to climate/weather variability. Although scattered and limited, current evidence suggests a significant but variable link between weather variables, e.g., rainfall, extreme weather events (floods/droughts), seasonality, and temperature, and childhood stunting at the household level (12 of 15 studies, 80%). In addition, we note that agricultural, socioeconomic, and demographic factors at the household and individual levels also play substantial roles in mediating the nutritional impacts. Comparable interdisciplinary studies based on primary data at a household level are urgently required to guide effective adaptation, particularly for rural subsistence farmers. Systemization of data collection at the global level is indispensable and urgent. We need to assimilate data from long-term, high-quality agricultural, environmental, socioeconomic, health, and demographic surveillance systems and develop robust statistical methods to establish and validate causal links, quantify impacts, and make reliable predictions that can guide evidence-based health interventions in the future. PMID:26216952

0-π phase-controllable thermal Josephson junction

NASA Astrophysics Data System (ADS)

Fornieri, Antonio; Timossi, Giuliano; Virtanen, Pauli; Solinas, Paolo; Giazotto, Francesco

2017-05-01

Two superconductors coupled by a weak link support an equilibrium Josephson electrical current that depends on the phase difference ϕ between the superconducting condensates. Yet, when a temperature gradient is imposed across the junction, the Josephson effect manifests itself through a coherent component of the heat current that flows opposite to the thermal gradient for |ϕ| < π/2 (refs 2-4). The direction of both the Josephson charge and heat currents can be inverted by adding a π shift to ϕ. In the static electrical case, this effect has been obtained in a few systems, for example via a ferromagnetic coupling or a non-equilibrium distribution in the weak link. These structures opened new possibilities for superconducting quantum logic and ultralow-power superconducting computers. Here, we report the first experimental realization of a thermal Josephson junction whose phase bias can be controlled from 0 to π. This is obtained thanks to a superconducting quantum interferometer that allows full control of the direction of the coherent energy transfer through the junction. This possibility, in conjunction with the completely superconducting nature of our system, provides temperature modulations with an unprecedented amplitude of ∼100 mK and transfer coefficients exceeding 1 K per flux quantum at 25 mK. Then, this quantum structure represents a fundamental step towards the realization of caloritronic logic components such as thermal transistors, switches and memory devices. These elements, combined with heat interferometers and diodes, would complete the thermal conversion of the most important phase-coherent electronic devices and benefit cryogenic microcircuits requiring energy management, such as quantum computing architectures and radiation sensors.

The deep-tow marine controlled-source electromagnetic transmitter system for gas hydrate exploration

NASA Astrophysics Data System (ADS)

Wang, Meng; Deng, Ming; Wu, Zhongliang; Luo, Xianhu; Jing, Jianen; Chen, Kai

2017-02-01

The Marine Controlled-Source Electromagnetic (MCSEM) method has been recognized as an important and effective tool to detect electrically resistive structures, such as oil, gas, and gas hydrate. The MCSEM performance is strongly influenced by the transmitter system design. We have developed a deep-tow MCSEM transmitter system. In this paper, some new technical details will be present. A 10,000 m optical-electrical composite cable is used to support high power transmission and fast data transfer; a new clock unit is designed to keep the synchronization between transmitter and receivers, and mark the time stamp into the transmission current full waveform; a data link is established to monitor the real-time altitude of the tail unit; an online insulation measuring instrument is adopted to monitor current leakage from high voltage transformer; a neutrally buoyant dipole antenna of copper cable and flexible electrodes are created to transmit the large power current into seawater; a new design method for the transmitter, which is called "real-time control technology of hardware parallelism", is described to achieve inverting and recording high-power current waveform, controlling functions, and collecting auxiliary information. We use a gas hydrate exploration test to verify the performance of the transmitter system, focusing on more technical details, rather than applications. The test shows that the transmitter can be used for gas hydrate exploration as an effective source.

Link establishment criterion and topology optimization for hybrid GPS satellite communications with laser crosslinks

NASA Astrophysics Data System (ADS)

Li, Lun; Wei, Sixiao; Tian, Xin; Hsieh, Li-Tse; Chen, Zhijiang; Pham, Khanh; Lyke, James; Chen, Genshe

2018-05-01

In the current global positioning system (GPS), the reliability of information transmissions can be enhanced with the aid of inter-satellite links (ISLs) or crosslinks between satellites. Instead of only using conventional radio frequency (RF) crosslinks, the laser crosslinks provide an option to significantly increase the data throughput. The connectivity and robustness of ISL are needed for analysis, especially for GPS constellations with laser crosslinks. In this paper, we first propose a hybrid GPS communication architecture in which uplinks and downlinks are established via RF signals and crosslinks are established via laser links. Then, we design an optical crosslink assignment criteria considering the practical optical communication factors such as optical line- of-sight (LOS) range, link distance, and angular velocity, etc. After that, to further improve the rationality of establishing crosslinks, a topology control algorithm is formulated to optimize GPS crosslink networks at both physical and network layers. The RF transmission features for uplink and downlink and optical transmission features for crosslinks are taken into account as constraints for the optimization problem. Finally, the proposed link establishment criteria are implemented for GPS communication with optical crosslinks. The designs of this paper provide a potential crosslink establishment and topology control algorithm for the next generation GPS.

The physiological functions of central nervous system pericytes and a potential role in pain

PubMed Central

Beazley-Long, Nicholas; Durrant, Alexandra M; Swift, Matthew N; Donaldson, Lucy F

2018-01-01

Central nervous system (CNS) pericytes regulate critical functions of the neurovascular unit in health and disease. CNS pericytes are an attractive pharmacological target for their position within the neurovasculature and for their role in neuroinflammation. Whether the function of CNS pericytes also affects pain states and nociceptive mechanisms is currently not understood. Could it be that pericytes hold the key to pain associated with CNS blood vessel dysfunction? This article reviews recent findings on the important physiological functions of CNS pericytes and highlights how these neurovascular functions could be linked to pain states. PMID:29623199

Space-Based Telemetry and Range Safety (STARS) Study

NASA Technical Reports Server (NTRS)

Hogie, Keith; Crisuolo, Ed; Parise, Ron

2004-01-01

This presentation will describe the design, development, and testing of a system to collect telemetry, format it into UDP/IP packets, and deliver it to a ground test range using standard IP technologies over a TDRSS link. This presentation will discuss the goal of the STARS IP Formatter along with the overall design. It will also present performance results of the current version of the IP formatter. Finally, it will discuss key issues for supporting constant rate telemetry data delivery when using standard components such as PCI/104 processors, the Linux operating system, Internet Protocols, and synchronous serial interfaces.

GAP: yet another image processing system for solar observations.

NASA Astrophysics Data System (ADS)

Keller, C. U.

GAP is a versatile, interactive image processing system for analyzing solar observations, in particular extended time sequences, and for preparing publication quality figures. It consists of an interpreter that is based on a language with a control flow similar to PASCAL and C. The interpreter may be accessed from a command line editor and from user-supplied functions, procedures, and command scripts. GAP is easily expandable via external FORTRAN programs that are linked to the GAP interface routines. The current version of GAP runs on VAX, DECstation, Sun, and Apollo computers. Versions for MS-DOS and OS/2 are in preparation.

System data communication structures for active-control transport aircraft, volume 1

NASA Technical Reports Server (NTRS)

Hopkins, A. L.; Martin, J. H.; Brock, L. D.; Jansson, D. G.; Serben, S.; Smith, T. B.; Hanley, L. D.

1981-01-01

Candidate data communication techniques are identified, including dedicated links, local buses, broadcast buses, multiplex buses, and mesh networks. The design methodology for mesh networks is then discussed, including network topology and node architecture. Several concepts of power distribution are reviewed, including current limiting and mesh networks for power. The technology issues of packaging, transmission media, and lightning are addressed, and, finally, the analysis tools developed to aid in the communication design process are described. There are special tools to analyze the reliability and connectivity of networks and more general reliability analysis tools for all types of systems.

[Human resources for health in the context of the reform of the health system in Mexico: professional training and labor market].

PubMed

Nigenda, Gustavo; Magaña-Valladares, Laura; Ortega-Altamirano, Doris Verónica

2013-01-01

The role that human resources for health should play in future stages of the Mexican Health System reform is discussed. The following dimensions are considered to guide the discussion: the orientation of training, the institutions responsible for training, the mechanisms to link graduates to health institutions and the ways health workers should respond to the current managerial modifications. Changes should be based on a pre-defined strategic planning exercise based on institutional agreements which allow defining common objectives as well as clear procedures to attain those objectives.

The Deep Space Network: An instrument for radio astronomy research

NASA Technical Reports Server (NTRS)

Renzetti, N. A.; Levy, G. S.; Kuiper, T. B. H.; Walken, P. R.; Chandlee, R. C.

1988-01-01

The NASA Deep Space Network operates and maintains the Earth-based two-way communications link for unmanned spacecraft exploring the solar system. It is NASA's policy to also make the Network's facilities available for radio astronomy observations. The Network's microwave communication systems and facilities are being continually upgraded. This revised document, first published in 1982, describes the Network's current radio astronomy capabilities and future capabilities that will be made available by the ongoing Network upgrade. The Bibliography, which includes published papers and articles resulting from radio astronomy observations conducted with Network facilities, has been updated to include papers to May 1987.

Harmonic analysis of spacecraft power systems using a personal computer

NASA Technical Reports Server (NTRS)

Williamson, Frank; Sheble, Gerald B.

1989-01-01

The effects that nonlinear devices such as ac/dc converters, HVDC transmission links, and motor drives have on spacecraft power systems are discussed. The nonsinusoidal currents, along with the corresponding voltages, are calculated by a harmonic power flow which decouples and solves for each harmonic component individually using an iterative Newton-Raphson algorithm. The sparsity of the harmonic equations and the overall Jacobian matrix is used to an advantage in terms of saving computer memory space and in terms of reducing computation time. The algorithm could also be modified to analyze each harmonic separately instead of all at the same time.

Do Helminths cause Epilepsy?

PubMed Central

Wagner, Ryan G; Newton, Charles R

2012-01-01

Both helminthiases and epilepsy occur globally, and are particularly prevalent in developing regions of the world. Studies have suggested an association between epilepsy and helminth infection, but a causal relationship is not established in many helminths, except perhaps with neurocysticercosis. We review the available literature on the global burden of helminths, and the epidemiological evidence linking helminths to epilepsy. We discuss possible routes that helminths affect the central nervous system of humans and the immunological response to helminth infection in the central nervous system, looking at possible mechanisms of epileptogenesis. Finally, we discuss the current gaps in knowledge about the interaction between helminths and epilepsy. PMID:19825109

Vaccine safety monitoring systems in developing countries: an example of the Vietnam model.

PubMed

Ali, Mohammad; Rath, Barbara; Thiem, Vu Dinh

2015-01-01

Only few health intervention programs have been as successful as vaccination programs with respect to preventing morbidity and mortality in developing countries. However, the success of a vaccination program is threatened by rumors and misunderstanding about the risks of vaccines. It is short-sighted to plan the introduction of vaccines into developing countries unless effective vaccine safety monitoring systems are in place. Such systems that track adverse events following immunization (AEFI) is currently lacking in most developing countries. Therefore, any rumor may affect the entire vaccination program. Public health authorities should implement the safety monitoring system of vaccines, and disseminate safety issues in a proactive mode. Effective safety surveillance systems should allow for the conduct of both traditional and alternative epidemiologic studies through the use of prospective data sets. The vaccine safety data link implemented in Vietnam in mid-2002 indicates that it is feasible to establish a vaccine safety monitoring system for the communication of vaccine safety in developing countries. The data link provided the investigators an opportunity to evaluate AEFI related to measles vaccine. Implementing such vaccine safety monitoring system is useful in all developing countries. The system should be able to make objective and clear communication regarding safety issues of vaccines, and the data should be reported to the public on a regular basis for maintaining their confidence in vaccination programs.

Space Communication Artificial Intelligence for Link Evaluation Terminal (SCAILET)

NASA Technical Reports Server (NTRS)

Shahidi, Anoosh K.; Schlegelmilch, Richard F.; Petrik, Edward J.; Walters, Jerry L.

1992-01-01

A software application to assist end-users of the high burst rate (HBR) link evaluation terminal (LET) for satellite communications is being developed. The HBR LET system developed at NASA Lewis Research Center is an element of the Advanced Communications Technology Satellite (ACTS) Project. The HBR LET is divided into seven major subsystems, each with its own expert. Programming scripts, test procedures defined by design engineers, set up the HBR LET system. These programming scripts are cryptic, hard to maintain and require a steep learning curve. These scripts were developed by the system engineers who will not be available for the end-users of the system. To increase end-user productivity a friendly interface needs to be added to the system. One possible solution is to provide the user with adequate documentation to perform the needed tasks. With the complexity of this system the vast amount of documentation needed would be overwhelming and the information would be hard to retrieve. With limited resources, maintenance is another reason for not using this form of documentation. An advanced form of interaction is being explored using current computer techniques. This application, which incorporates a combination of multimedia and artificial intelligence (AI) techniques to provided end-users with an intelligent interface to the HBR LET system, is comprised of an intelligent assistant, intelligent tutoring, and hypermedia documentation. The intelligent assistant and tutoring systems address the critical programming needs of the end-user.

Controlling Hysteresis in Superconducting Weak Links and μ-Superconducting Quantum Interference Devices

NASA Astrophysics Data System (ADS)

Kumar, Nikhil; Winkelmann, C. B.; Biswas, Sourav; Courtois, H.; Gupta, Anjan K.

We have fabricated and studied the current-voltage characteristics of a number of niobium film based weak-link devices and μ-SQUIDs showing a critical current and two re-trapping currents. We have proposed a new understanding for the re-trapping currents in terms of thermal instabilities in different portions of the device. We also find that the superconducting proximity effect and the phase-slip processes play an important role in dictating the temperature dependence of the critical current in the non-hysteretic regime. The proximity effect helps in widening the temperature range of hysteresis-free characteristics. Finally we demonstrate control on temperature-range with hysteresis-free characteristics in two ways: 1) By using a parallel shunt resistor in close vicinity of the device, and 2) by reducing the weak-link width. Thus we get non-hysteretic behavior down to 1.3 K temperature in some of the studied devices. We acknowledge the financial support from CSIR, India as well as CNRS-Institute Neel, Grenoble, France.

Impact of the gut microbiota on inflammation, obesity, and metabolic disease.

PubMed

Boulangé, Claire L; Neves, Ana Luisa; Chilloux, Julien; Nicholson, Jeremy K; Dumas, Marc-Emmanuel

2016-04-20

The human gut harbors more than 100 trillion microbial cells, which have an essential role in human metabolic regulation via their symbiotic interactions with the host. Altered gut microbial ecosystems have been associated with increased metabolic and immune disorders in animals and humans. Molecular interactions linking the gut microbiota with host energy metabolism, lipid accumulation, and immunity have also been identified. However, the exact mechanisms that link specific variations in the composition of the gut microbiota with the development of obesity and metabolic diseases in humans remain obscure owing to the complex etiology of these pathologies. In this review, we discuss current knowledge about the mechanistic interactions between the gut microbiota, host energy metabolism, and the host immune system in the context of obesity and metabolic disease, with a focus on the importance of the axis that links gut microbes and host metabolic inflammation. Finally, we discuss therapeutic approaches aimed at reshaping the gut microbial ecosystem to regulate obesity and related pathologies, as well as the challenges that remain in this area.

Chronic bowel inflammation and inflammatory joint disease: Pathophysiology.

PubMed

Speca, Silvia; Dubuquoy, Laurent

2017-07-01

Bowel inflammation is closely linked to chronic joint inflammation. Research reported in the 1980s demonstrated bowel inflammation with gross and microscopic pathological features identical to those of Crohn's disease in over 60% of patients with spondyloarthritis (SpA). Numerous prospective studies have evidenced joint involvement in patients with chronic inflammatory bowel disease (IBD) and bowel inflammation in patients with SpA. Nevertheless, the interactions of joint disease and chronic bowel inflammation remain incompletely elucidated. Two main hypotheses have been suggested to explain potential links between inflammation of the mucosal immune system and peripheral arthritis: one identifies gut bacteria as potentially implicated in the development of joint inflammation and the other involves the recruitment of gut lymphocytes or activated macrophages to the joints. Pathophysiological investigations have established that HLA-B27 is a pivotal pathogenic factor. Here, we review current data on links between chronic bowel inflammation and inflammatory joint disease. Copyright © 2017 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

Study on rejection characteristic of current loop to the base disturbance of optical communication system

NASA Astrophysics Data System (ADS)

Mao, Yao; Deng, Chao; Liu, Qiong; Cao, Zheng

2016-10-01

As laser has narrow transmitting beam and small divergence angle, the LOS (Line of Sight) stabilization of optical communication system is a primary precondition of laser communication links. Compound axis control is usually adopted in LOS stabilization of optical communication system, in which coarse tracking and fine tracking are included. Rejection against high frequency disturbance mainly depends on fine tracking LOS stabilization platform. Limited by different factors such as mechanical characteristic of the stabilization platform and bandwidth/noise of the sensor, the control bandwidth of LOS stabilization platform is restricted so that effective rejection of high frequency disturbance cannot be achieved as it mainly depends on the isolation characteristic of the platform itself. It is proposed by this paper that current loop may reject the effect of back-EMF. By adopting the method of electric control, high frequency isolation characteristic of the platform can be improved. The improvement effect is similar to increasing passive vibration reduction devices. Adopting the double closed loop control structure of velocity and current with the combining of the rejection effect of back-EMF caused by current loop is equivalent to reducing back-EMF coefficient, which can enhance the isolation ability of the LOS stabilization platform to high frequency disturbance.

Therapeutic Targets for Management of Periodontitis and Diabetes

PubMed Central

Sima, Corneliu; Van Dyke, Thomas E.

2016-01-01

The increasing incidence of diabetes mellitus (DM) and chronic periodontitis (CP) worldwide imposes a rethinking of individualized therapy for patients with both conditions. Central to bidirectional links between DM and CP is deregulated systemic inflammation and dysfunctional immune responses to altered-self and non-self. Control of blood glucose levels and metabolic imbalances associated with hyperglycemia in DM, and disruption of pathogenic subgingival biofilms in CP are currently the main therapeutic approaches for these conditions. Mounting evidence suggests the need to integrate immune modulatory therapeutics in treatment regimens that address the unresolved inflammation associated with DM and CP. The current review discusses the pathogenesis of DM and CP with emphasis on deregulated inflammation, current therapeutic approaches and the novel pro-resolution lipid mediators derived from n-3 polyunsaturated fatty acids. PMID:26881443

Therapeutic Targets for Management of Periodontitis and Diabetes

PubMed Central

Sima, Corneliu; Van Dyke, Thomas E.

2016-01-01

The increasing incidence of diabetes mellitus (DM) and chronic periodontitis (CP) worldwide imposes a rethinking of individualized therapy for patients with both conditions. Central to bidirectional links between DM and CP is deregulated systemic inflammation and dysfunctional immune responses to altered-self and non-self. Control of blood glucose levels and metabolic imbalances associated with hyperglycemia in DM, and disruption of pathogenic subgingival biofilms in CP are currently the main therapeutic approaches for these conditions. Mounting evidence suggests the need to integrate immune modulatory therapeutics in treatment regimens that address the unresolved inflammation associated with DM and CP. The current review discusses the pathogenesis of DM and CP with emphasis on deregulated inflammation, current therapeutic approaches and the novel pro-resolution lipid mediators derived from Ω-3 polyunsaturated fatty acids.

Comment on ''Carrier-concentration dependence of critical superconducting current induced by the proximity effect in silicon''

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kleinsasser, A.W.

1987-06-01

It is pointed out that effect of an applied gate voltage on the critical current observed in a gate-controlled Si-coupled weak link by Nishino, Yamada, and Kawabe (Phy. Rev. B 33, 2042 (1986)) is much larger than that expected from the small change of carrier density in the link.

Design and implementation of a medium speed communications interface and protocol for a low cost, refreshed display computer

NASA Technical Reports Server (NTRS)

Phyne, J. R.; Nelson, M. D.

1975-01-01

The design and implementation of hardware and software systems involved in using a 40,000 bit/second communication line as the connecting link between an IMLAC PDS 1-D display computer and a Univac 1108 computer system were described. The IMLAC consists of two independent processors sharing a common memory. The display processor generates the deflection and beam control currents as it interprets a program contained in the memory; the minicomputer has a general instruction set and is responsible for starting and stopping the display processor and for communicating with the outside world through the keyboard, teletype, light pen, and communication line. The processing time associated with each data byte was minimized by designing the input and output processes as finite state machines which automatically sequence from each state to the next. Several tests of the communication link and the IMLAC software were made using a special low capacity computer grade cable between the IMLAC and the Univac.

[Pregnancy in the context of general adaptation syndrome].

PubMed

Gur'ianov, V A; Pyregov, A V; Tolmachev, G N; Volodin, A V

2007-01-01

Based on their own findings and the data available in the literature on pregnancy including that complicated by gestosis, the authors consider these conditions in the context of Selye's general adaptation syndrome. They identify its basic links (the autonomic nervous and cardiovascular systems) the function of which is affected by all the physiological and pathophysiological processes involved in its development. There is a high likelihood of baseline impaired adaption processes in these links, which may lead to an inability to accommodate (dysadaptation) by the moment of delivery. The paper gives the current interpretation of functional disorders, called Zangemeister'a triad in 1913, from the present-day points of view of the evaluation of pregnancy as the systemic inflammatory response syndrome and, probably, adaptation disease. Based on the results of analyzing the data available in the literature, the authors indicate physiologically the basic trends in the modulation of impaired development processes of the general adaptation syndrome towards the completion of pregnancy and surgical delivery.

The Electronic Astrophysical Journal Letters Project

NASA Astrophysics Data System (ADS)

Dalterio, H. J.; Boyce, P. B.; Biemesderfer, C.; Warnock, A., III; Owens, E.; Fullton, J.

The American Astronomical Society has developed a comprehensive system for the electronic dissemination of refereed astronomical research results. Our current focus is the production of an electronic version of the Astrophysical Journal Letters. With the help of a recent National Science Foundation grant, we have developed a system that includes: LATEX-based manuscript preparation, electronic submission, peer review, production, development of a database of SGML-tagged manuscripts, collection of page charges and other fees, and electronic manuscript storage and delivery. Delivery options include World-Wide Web access through HTML browsers such as Mosaic and Netscape, an email gateway, and a stand-alone client accessible through astronomical software packages such as IRAF. Our goal is to increase the access and usefulness of the journal by providing enhanced features such as faster publication, advanced search capabilities, forward and backward referencing, links to underlying data and links to adjunct materials in a variety of media. We have based our journal on open standards and freely available network tools wherever possible.

The Potential of School-Linked Centers To Promote Adolescent Health and Development. Working Paper.

ERIC Educational Resources Information Center

Millstein, Susan G.

The future of school-linked adolescent health centers cannot be determined without further evaluation. The recent development of school-linked health centers stems from concerns about the special health needs of adolescents. Currently there are 125 school-based and school-linked centers in operation. Characteristics include the following: (1) most…

A medical digital library to support scenario and user-tailored information retrieval.

PubMed

Chu, W W; Johnson, D B; Kangarloo, H

2000-06-01

Current large-scale information sources are designed to support general queries and lack the ability to support scenario-specific information navigation, gathering, and presentation. As a result, users are often unable to obtain desired specific information within a well-defined subject area. Today's information systems do not provide efficient content navigation, incremental appropriate matching, or content correlation. We are developing the following innovative technologies to remedy these problems: 1) scenario-based proxies, enabling the gathering and filtering of information customized for users within a pre-defined domain; 2) context-sensitive navigation and matching, providing approximate matching and similarity links when an exact match to a user's request is unavailable; 3) content correlation of documents, creating semantic links between documents and information sources; and 4) user models for customizing retrieved information and result presentation. A digital medical library is currently being constructed using these technologies to provide customized information for the user. The technologies are general in nature and can provide custom and scenario-specific information in many other domains (e.g., crisis management).

HaloTag Technology: A Versatile Platform for Biomedical Applications

PubMed Central

2015-01-01

Exploration of protein function and interaction is critical for discovering links among genomics, proteomics, and disease state; yet, the immense complexity of proteomics found in biological systems currently limits our investigational capacity. Although affinity and autofluorescent tags are widely employed for protein analysis, these methods have been met with limited success because they lack specificity and require multiple fusion tags and genetic constructs. As an alternative approach, the innovative HaloTag protein fusion platform allows protein function and interaction to be comprehensively analyzed using a single genetic construct with multiple capabilities. This is accomplished using a simplified process, in which a variable HaloTag ligand binds rapidly to the HaloTag protein (usually linked to the protein of interest) with high affinity and specificity. In this review, we examine all current applications of the HaloTag technology platform for biomedical applications, such as the study of protein isolation and purification, protein function, protein–protein and protein–DNA interactions, biological assays, in vitro cellular imaging, and in vivo molecular imaging. In addition, novel uses of the HaloTag platform are briefly discussed along with potential future applications. PMID:25974629

16,000-rpm Interior Permanent Magnet Reluctance Machine with Brushless Field Excitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsu, J.S.; Burress, T.A.; Lee, S.T.

2007-10-31

The reluctance interior permanent magnet (RIPM) motor is currently used by many leading auto manufacturers for hybrid vehicles. The power density for this type of motor is high compared with that of induction motors and switched reluctance motors. The primary drawback of the RIPM motor is the permanent magnet (PM) because during high-speed operation, the fixed PM produces a huge back electromotive force (emf) that must be reduced before the current will pass through the stator windings. This reduction in back-emf is accomplished with a significant direct-axis (d-axis) demagnetization current, which opposes the PM's flux to reduce the flux seenmore » by the stator wires. This may lower the power factor and efficiency of the motor and raise the requirement on the alternate current (ac) power supply; consequently, bigger inverter switching components, thicker motor winding conductors, and heavier cables are required. The direct current (dc) link capacitor is also affected when it must accommodate heavier harmonic currents. It is commonly agreed that, for synchronous machines, the power factor can be optimized by varying the field excitation to minimize the current. The field produced by the PM is fixed and cannot be adjusted. What can be adjusted is reactive current to the d-axis of the stator winding, which consumes reactive power but does not always help to improve the power factor. The objective of this project is to avoid the primary drawbacks of the RIPM motor by introducing brushless field excitation (BFE). This offers both high torque per ampere (A) per core length at low speed by using flux, which is enhanced by increasing current to a fixed excitation coil, and flux, which is weakened at high speed by reducing current to the excitation coil. If field weakening is used, the dc/dc boost converter used in a conventional RIPM motor may be eliminated to reduce system costs. However, BFE supports a drive system with a dc/dc boost converter, because it can further extend the constant power speed range of the drive system and adjust the field for power factor and efficiency gains. Lower core losses at low torque regions, especially at high speeds, are attained by reducing the field excitation. Safety and reliability are increased by weakening the field when a winding short-circuit fault occurs, preventing damage to the motor. For a high-speed motor operating at 16,000-revolutions per minute (rpm), mechanical stress is a challenge. Bridges that link the rotor punching segments together must be thickened for mechanical integrity; consequently, increased rotor flux leakage significantly lowers motor performance. This barrier can be overcome by BFE to ensure sufficient rotor flux when needed.« less

Brain Morphology Links Systemic Inflammation to Cognitive Function in Midlife Adults

PubMed Central

Marsland, Anna L.; Gianaros, Peter J.; Kuan, Dora C-H.; Sheu, Lei K.; Krajina, Katarina; Manuck, Stephen B.

2015-01-01

Background Inflammation is linked to cognitive decline in midlife, but the neural basis for this link is unclear. One possibility is that inflammation associates with adverse changes in brain morphology, which accelerates cognitive aging and later dementia risk. Clear evidence is lacking, however, regarding whether inflammation relates to cognition in midlife via changes in brain morphology. Accordingly, the current study examines whether associations of inflammation with cognitive function are mediated by variation in cortical gray matter volume among midlife adults. Methods Plasma levels of interleukin (IL)-6 and C-reactive protein (CRP), relatively stable markers of peripheral systemic inflammation, were assessed in 408 community volunteers aged 30–54 years. All participants underwent structural neuroimaging to assess global and regional brain morphology and completed neuropsychological tests sensitive to early changes in cognitive function. Measurements of brain morphology (regional tissue volumes and cortical thickness and surface area) were derived using Freesurfer. Results Higher peripheral inflammation was associated with poorer spatial reasoning, short term memory, verbal proficiency, learning and memory, and executive function, as well as lower cortical gray and white matter volumes, hippocampal volume and cortical surface area. Mediation models with age, sex and intracranial volume as covariates showed cortical gray matter volume to partially mediate the association of inflammation with cognitive performance. Exploratory analyses of body mass suggested that adiposity may be a source of the inflammation linking brain morphology to cognition. Conclusions Inflammation and adiposity might relate to cognitive decline via influences on brain morphology. PMID:25882911

Influence of galactose cataract on erythrocytic and lenticular glutathione metabolism in albino rats.

PubMed

Jyothi, M; Sanil, R; Shashidhar, S

2011-01-01

Glutathione depletion has been postulated to be the prime reason for galactose cataract. The current research seeks the prospect of targeting erythrocytes to pursue the lens metabolism by studying the glutathione system. To study the activity of the glutathione-linked scavenger enzyme system in the erythrocyte and lens of rats with cataract. Experiments were conducted in 36 male albino rats weighing 80 ± 20 g of 28 days of age. The rats were divided into two major groups, viz. experimental and control. Six rats in each group were sacrificed every 10 days, for 30 days. Cataract was induced in the experimental group by feeding the rats 30% galactose (w/w). The involvement of reduced glutathione (GSH) and the linked enzymes was studied in the erythrocytes and lens of cataractous as well as control rats. Parametric tests like one-way ANOVA and Student's 't' test were used for comparison. Correlation linear plot was used to compare the erythrocyte and lens metabolism. The concentration of GSH and the activity of linked enzymes were found decreased with the progression of cataract, and also in comparison to the control. The same linear fashion was also observed in the erythrocytes. Depletion of GSH was the prime factor for initiating galactose cataract in the rat model. This depletion may in turn result in enzyme inactivation leading to cross-linking of protein and glycation. The correlation analysis specifies that the biochemical mechanism in the erythrocytes and lens is similar in the rat model.

Evaluation of an operational water cycle prediction system for the Laurentian Great Lakes and St. Lawrence River

NASA Astrophysics Data System (ADS)

Fortin, Vincent; Durnford, Dorothy; Smith, Gregory; Dyck, Sarah; Martinez, Yosvany; Mackay, Murray; Winter, Barbara

2017-04-01

Environment and Climate Change Canada (ECCC) is implementing new numerical guidance products based on fully coupled numerical models to better inform the public as well as specialized users on the current and future state of various components of the water cycle, including stream flow and water levels. Outputs from this new system, named the Water Cycle Prediction System (WCPS), have been available for the Great Lakes and St. Lawrence River watershed since June 2016. WCPS links together ECCC's weather forecasting model, GEM, the 2-D ice model C-ICE, the 3-D lake and ocean model NEMO, and a 2-D hydrological model, WATROUTE. Information concerning the water cycle is passed between the models at intervals varying from a few minutes to one hour. It currently produces two forecasts per day for the next three days of the complete water cycle in the Great Lakes region, the largest freshwater lake system in the world. Products include spatially-varying precipitation, evaporation, river discharge, water level anomalies, surface water temperatures, ice coverage, and surface currents. These new products are of interest to water resources and management authority, flood forecasters, hydroelectricity producers, navigation, environmental disaster managers, search and rescue teams, agriculture, and the general public. This presentation focuses on the evaluation of various elements forecasted by the system, and weighs the advantages and disadvantages of running the system fully coupled.

Modelisation et simulation d'une liaison HVDC de type VSC-MMC

NASA Astrophysics Data System (ADS)

Saad, Hani Aziz

High-voltage direct current transmission systems (HVDC) are rapidly expanding in the world. Two main factors are responsible for this expansion. The first is related to the difficulty of building new overhead lines to ensure the development of high-voltage AC grids, which makes the usage of underground cables more common. However, the use of such cables is limited in length to a few tens of km because of the capacitive current generated by the cable itself. Beyond this length limit, the solution is usually to transmit in DC. The second factor is related to the development of offshore wind power plants that require connecting powers of several hundred of MW to the mainland grid by cables whose lengths can reach several hundreds of km and consequently require HVDC transmission system. Several HVDC projects are currently planned and developed by the French transmission system operator RTE. One of such projects is the INELFE interconnection project, with a capacity of 2,000 MW, between France and Spain. This thesis has been funded by RTE, in order to model and simulate in off-line and real time modes, modern HVDC interconnections. The delivered simulation means are used to examine targeted HVDC system performances and risks of abnormal interactions with surrounding power systems. The particularity of the INELFE HVDC system is the usage of a dedicated control system that will largely determine the dynamic behaviour of the system for both large disturbances (faults on the network) and small perturbations (power step changes). Various VSC topologies, including the conventional two-level, multi-level diode-clamped and floating capacitor multi-level converters, have been proposed and reported in the literature. However, due to the complexity of controls and practical limitations, the VSC-HVDC system installations have been limited to the two-level and three-level diode-clamped converters. Recently, the development of modular technology called MMC (Modular Multilevel Converter [Siemens] - [Alstom]) or CTL (Cascaded Two Level topology [ABB]) has allowed to overcome existing limitations. This topology consists of several sub-modules connected in series. Each sub-module contains two IGBTs with antiparallel diodes and a capacitor that act as energy storage. The control of these IGBTs allows connecting and disconnecting the capacitor on the network. The grouping of several sub-modules in series forms an arm. From the AC side, each phase consists of two arms. Reactors are included in series with each arm in order to limit the fault current. The large number of IGBTs in MMCs creates complicated computation problems in electromagnetic transient type (EMT-type) simulation tools. Detailed MMC models include the representation of thousands of IGBT (Insulated Gate Bipolar Transistor) switches and must use small numerical integration time steps to accurately represent fast and multiple simultaneous switching events. This becomes particularly more complex for performing real-time simulations. The computational burden introduced by such models highlights the need to develop more efficient models. A current trend is based on simplified models capable of delivering sufficient accuracy for EMT-type simulations, however the validity range of such models must be carefully evaluated. The first objective of this thesis is to model HVDC-MMC transmission systems in EMT-type programs for off-line and real-time simulations. To fulfill this objective, different modelling approaches are presented, then the control system used for HVDC-MMC links is developed and finally the implementations of MMC models using both CPU (Central Processing Unit) and FPGA (Field-Programmable Gate Array) technologies for real-time simulations, are presented. The contributions are useful for researchers and engineers using transient simulation tools for modelling and analysis of power systems including HVDC-MMC. The HVDC links currently planned or constructed in France, are embedded in highly meshed networks and may have significant impact on their operations and performance. Therefore, the second objective of this thesis is to perform modal analysis and parametric studies to assess the risks of abnormal interactions between several HVDC links inserted in meshed AC networks.

NASA's K/Ka-Band Broadband Aeronautical Terminal for Duplex Satellite Video Communications

NASA Technical Reports Server (NTRS)

Densmore, A.; Agan, M.

1994-01-01

JPL has recently begun the development of a Broadband Aeronautical Terminal (BAT) for duplex video satellite communications on commercial or business class aircraft. The BAT is designed for use with NASA's K/Ka-band Advanced Communications Technology Satellite (ACTS). The BAT system will provide the systems and technology groundwork for an eventual commercial K/Ka-band aeronautical satellite communication system. With industry/government partnerships, three main goals will be addressed by the BAT task: 1) develop, characterize and demonstrate the performance of an ACTS based high data rate aeronautical communications system; 2) assess the performance of current video compression algorithms in an aeronautical satellite communication link; and 3) characterize the propagation effects of the K/Ka-band channel for aeronautical communications.

Enforcing compatibility and constraint conditions and information retrieval at the design action

NASA Technical Reports Server (NTRS)

Woodruff, George W.

1990-01-01

The design of complex entities is a multidisciplinary process involving several interacting groups and disciplines. There is a need to integrate the data in such environments to enhance the collaboration between these groups and to enforce compatibility between dependent data entities. This paper discusses the implementation of a workstation based CAD system that is integrated with a DBMS and an expert system, CLIPS, (both implemented on a mini computer) to provide such collaborative and compatibility enforcement capabilities. The current implementation allows for a three way link between the CAD system, the DBMS and CLIPS. The engineering design process associated with the design and fabrication of sheet metal housing for computers in a large computer manufacturing facility provides the basis for this prototype system.

The Index to Marine and Lacustrine Geological Samples (IMLGS): Linking Digital Data to Physical Samples for the Marine Community

NASA Astrophysics Data System (ADS)

Stroker, K. J.; Jencks, J. H.; Eakins, B.

2016-12-01

The Index to Marine and Lacustrine Geological Samples (IMLGS) is a community designed and maintained resource enabling researchers to locate and request seafloor and lakebed geologic samples curated by partner institutions. The Index was conceived in the dawn of the digital age by representatives from U.S. academic and government marine core repositories and the NOAA National Geophysical Data Center, now the National Centers for Environmental Information (NCEI), at a 1977 meeting convened by the National Science Foundation (NSF). The Index is based on core concepts of community oversight, common vocabularies, consistent metadata and a shared interface. The Curators Consortium, international in scope, meets biennially to share ideas and discuss best practices. NCEI serves the group by providing database access and maintenance, a list server, digitizing support and long-term archival of sample metadata, data and imagery. Over three decades, participating curators have performed the laborious task of creating and contributing metadata for over 205,000 sea floor and lake-bed cores, grabs, and dredges archived in their collections. Some partners use the Index for primary web access to their collections while others use it to increase exposure of more in-depth institutional systems. The IMLGS has a persistent URL/Digital Object Identifier (DOI), as well as DOIs assigned to partner collections for citation and to provide a persistent link to curator collections. The Index is currently a geospatially-enabled relational database, publicly accessible via Web Feature and Web Map Services, and text- and ArcGIS map-based web interfaces. To provide as much knowledge as possible about each sample, the Index includes curatorial contact information and links to related data, information and images : 1) at participating institutions, 2) in the NCEI archive, and 3) through a Linked Data interface maintained by the Rolling Deck to Repository R2R. Over 43,000 International GeoSample Numbers (IGSNs) linking to the System for Earth Sample Registration (SESAR) are included in anticipation of opportunities for interconnectivity with Integrated Earth Data Applications (IEDA) systems. The paper will discuss the database with a goal to increase the connections and links to related data at partner institutions.

Feeding the world healthily: the challenge of measuring the effects of agriculture on health

PubMed Central

Hawkesworth, Sophie; Dangour, Alan D.; Johnston, Deborah; Lock, Karen; Poole, Nigel; Rushton, Jonathan; Uauy, Ricardo; Waage, Jeff

2010-01-01

Agricultural production, food systems and population health are intimately linked. While there is a strong evidence base to inform our knowledge of what constitutes a healthy human diet, we know little about actual food production or consumption in many populations and how developments in the food and agricultural system will affect dietary intake patterns and health. The paucity of information on food production and consumption is arguably most acute in low- and middle-income countries, where it is most urgently needed to monitor levels of under-nutrition, the health impacts of rapid dietary transition and the increasing ‘double burden’ of nutrition-related disease. Food availability statistics based on food commodity production data are currently widely used as a proxy measure of national-level food consumption, but using data from the UK and Mexico we highlight the potential pitfalls of this approach. Despite limited resources for data collection, better systems of measurement are possible. Important drivers to improve collection systems may include efforts to meet international development goals and partnership with the private sector. A clearer understanding of the links between the agriculture and food system and population health will ensure that health becomes a critical driver of agricultural change. PMID:20713404

DC to DC power converters and methods of controlling the same

DOEpatents

Steigerwald, Robert Louis; Elasser, Ahmed; Sabate, Juan Antonio; Todorovic, Maja Harfman; Agamy, Mohammed

2012-12-11

A power generation system configured to provide direct current (DC) power to a DC link is described. The system includes a first power generation unit configured to output DC power. The system also includes a first DC to DC converter comprising an input section and an output section. The output section of the first DC to DC converter is coupled in series with the first power generation unit. The first DC to DC converter is configured to process a first portion of the DC power output by the first power generation unit and to provide an unprocessed second portion of the DC power output of the first power generation unit to the output section.

Protein O-GlcNAcylation and Cardiovascular (Patho)physiology*

PubMed Central

Marsh, Susan A.; Collins, Helen E.; Chatham, John C.

2014-01-01

Our understanding of the role of protein O-GlcNAcylation in the regulation of the cardiovascular system has increased rapidly in recent years. Studies have linked increased O-GlcNAc levels to glucose toxicity and diabetic complications; conversely, acute activation of O-GlcNAcylation has been shown to be cardioprotective. However, it is also increasingly evident that O-GlcNAc turnover plays a central role in the delicate regulation of the cardiovascular system. Therefore, the goals of this minireview are to summarize our current understanding of how changes in O-GlcNAcylation influence cardiovascular pathophysiology and to highlight the evidence that O-GlcNAc cycling is critical for normal function of the cardiovascular system. PMID:25336635

Lunar and Planetary Science XXXV: Education Programs Demonstrations

NASA Technical Reports Server (NTRS)

2004-01-01

Reports from the session on Education Programs Demonstration include:Hands-On Activities for Exploring the Solar System in K-14; Formal Education and Informal Settings;Making Earth and Space Science and Exploration Accessible; New Thematic Solar System Exploration Products for Scientists and Educators Engaging Students of All Ages with Research-related Activities: Using the Levers of Museum Reach and Media Attention to Current Events; Astronomy Village: Use of Planetary Images in Educational Multimedia; ACUMEN: Astronomy Classes Unleashed: Meaningful Experiences for Neophytes; Unusual Guidebook to Terrestrial Field Work Studies: Microenvironmental Studies by Landers on Planetary Surfaces (New Atlas in the Series of the Solar System Notebooks on E tv s University, Hungary); and The NASA ADS: Searching, Linking and More.

Livestock production systems in developing countries: status, drivers, trends.

PubMed

Steinfeld, H; Wassenaar, T; Jutzi, S

2006-08-01

This paper describes and assesses the current status of livestock production systems, the drivers of global livestock production, and the major trends in such production. The analysis covers the six major livestock species: cattle and buffaloes, goats and sheep, pigs and chickens. Global drivers of the livestock sector include economic growth and income, demographic and land use changes, dietary adjustments and technological change. The rate of change and direction of livestock development vary greatly among world regions, with Asia showing the most rapid growth and structural change. The paper also examines system dynamics, by analysing the ways livestock production has adjusted to external forces. A brief discussion of how these trends link to food safety concludes the paper.

Laser Direct Routing for High Density Interconnects

NASA Astrophysics Data System (ADS)

Moreno, Wilfrido Alejandro

The laser restructuring of electronic circuits fabricated using standard Very Large Scale Integration (VLSI) process techniques, is an excellent alternative that allows low-cost quick turnaround production with full circuit similarity between the Laser Restructured prototype and the customized product for mass production. Laser Restructurable VLSI (LRVLSI) would allow design engineers the capability to interconnect cells that implement generic logic functions and signal processing schemes to achieve a higher level of design complexity. LRVLSI of a particular circuit at the wafer or packaged chip level is accomplished using an integrated computer controlled laser system to create low electrical resistance links between conductors and to cut conductor lines. An infrastructure for rapid prototyping and quick turnaround using Laser Restructuring of VLSI circuits was developed to meet three main parallel objectives: to pursue research on novel interconnect technologies using LRVLSI, to develop the capability of operating in a quick turnaround mode, and to maintain standardization and compatibility with commercially available equipment for feasible technology transfer. The system is to possess a high degree of flexibility, high data quality, total controllability, full documentation, short downtime, a user-friendly operator interface, automation, historical record keeping, and error indication and logging. A specially designed chip "SLINKY" was used as the test vehicle for the complete characterization of the Laser Restructuring system. With the use of Design of Experiment techniques the Lateral Diffused Link (LDL), developed originally at MIT Lincoln Laboratories, was completely characterized and for the first time a set of optimum process parameters was obtained. With the designed infrastructure fully operational, the priority objective was the search for a substitute for the high resistance, high current leakage to substrate, and relatively low density Lateral Diffused Link. A high density Laser Vertical Link with resistance values below 10 ohms was developed, studied and tested using design of experiment methodologies. The vertical link offers excellent advantages in the area of quick prototyping of electronic circuits, but even more important, due to having similar characteristics to a foundry produced via, it gives quick transfer from the prototype system verification stage to the mass production stage.

Integrating cancer survivors' experiences into UK cancer registries: design and development of the ePOCS system (electronic Patient-reported Outcomes from Cancer Survivors)

PubMed Central

Ashley, L; Jones, H; Thomas, J; Forman, D; Newsham, A; Morris, E; Johnson, O; Velikova, G; Wright, P

2011-01-01

Background: Understanding the psychosocial challenges of cancer survivorship, and identifying which patients experience ongoing difficulties, is a key priority. The ePOCS (electronic patient-reported outcomes from cancer survivors) project aims to develop and evaluate a cost-efficient, UK-scalable electronic system for collecting patient-reported outcome measures (PROMs), at regular post-diagnostic timepoints, and linking these with clinical data in cancer registries. Methods: A multidisciplinary team developed the system using agile methods. Design entailed process mapping the system's constituent parts, data flows and involved human activities, and undertaking usability testing. Informatics specialists built new technical components, including a web-based questionnaire tool and tracking database, and established component-connecting data flows. Development challenges were overcome, including patient usability and data linkage and security. Results: We have developed a system in which PROMs are completed online, using a secure questionnaire administration tool, accessed via a public-facing website, and the responses are linked and stored with clinical registry data. Patient monitoring and communications are semiautomated via a tracker database, and patient correspondence is primarily Email-based. The system is currently honed for clinician-led hospital-based patient recruitment. Conclusions: A feasibility test study is underway. Although there are possible challenges to sustaining and scaling up ePOCS, the system has potential to support UK epidemiological PROMs collection and clinical data linkage. PMID:22048035

The Generic Spacecraft Analyst Assistant (GenSAA): A tool for automating spacecraft monitoring with expert systems

NASA Technical Reports Server (NTRS)

Hughes, Peter M.; Luczak, Edward C.

1991-01-01

Flight Operations Analysts (FOAs) in the Payload Operations Control Center (POCC) are responsible for monitoring a satellite's health and safety. As satellites become more complex and data rates increase, FOAs are quickly approaching a level of information saturation. The FOAs in the spacecraft control center for the COBE (Cosmic Background Explorer) satellite are currently using a fault isolation expert system named the Communications Link Expert Assistance Resource (CLEAR), to assist in isolating and correcting communications link faults. Due to the success of CLEAR and several other systems in the control center domain, many other monitoring and fault isolation expert systems will likely be developed to support control center operations during the early 1990s. To facilitate the development of these systems, a project was initiated to develop a domain specific tool, named the Generic Spacecraft Analyst Assistant (GenSAA). GenSAA will enable spacecraft analysts to easily build simple real-time expert systems that perform spacecraft monitoring and fault isolation functions. Lessons learned during the development of several expert systems at Goddard, thereby establishing the foundation of GenSAA's objectives and offering insights in how problems may be avoided in future project, are described. This is followed by a description of the capabilities, architecture, and usage of GenSAA along with a discussion of its application to future NASA missions.

Transactions within the family: Coparenting mediates associations between parents' relationship satisfaction and the parent-child relationship.

PubMed

Peltz, Jack S; Rogge, Ronald D; Sturge-Apple, Melissa L

2018-06-21

In the current study, we examined the potential for transactional relations among parents' marital satisfaction, coparental cooperation and conflict, and parent-child relationship satisfaction in a sample of 249 families with 2-3-year-old children. Using a novel multiwave design with frequent assessments to better capture transactional family processes, mothers and fathers were assessed across 5 waves with 2-month lags; mean age of the target children (53% girls) was 2.8 years ( SD = 0.62) at baseline. Cross-lagged, multilevel structural equation modeling (SEM) analyses using an actor-partner interdependence modeling framework revealed coparental cooperation and conflict as likely mechanisms within the family system. Specifically, marital satisfaction from both parents was reciprocally linked to fathers' coparental cooperation over time, supporting transactional links between those two family subsystems. In addition, there were significant transactional links between both mothers' and fathers' coparental cooperation and father-reported parent-child relationship satisfaction across time, revealing within-parent and cross-parent mediation. Regarding coparental conflict, marital satisfaction from both parents was reciprocally linked to the same parents' reports of coparental conflict across time (i.e., actor effects). Furthermore, father-reported coparental conflict acted as a mediating or intervening mechanism between father-reported marital satisfaction and mother-reported parent-child relationship satisfaction (cross-parent mediation). Taken as a set, the findings supported coparental cooperation and conflict as significant links between marital functioning and the parent-child relationship. Findings build on a growing body of literature addressing the transactional associations embedded within the family system and highlight the importance of modeling the inherent interdependencies between mothers' and fathers' reports of family functioning. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Mapping the Extent and Stability of Montane Wetlands ("Bofedales") in the Andes of Bolivia and Peru using Landsat Imagery, 1980s to Present.

NASA Astrophysics Data System (ADS)

Slayback, D. A.; Hubbard, A. B.; Yager, K.

2017-12-01

Montane wetlands (locally termed "bofedales") in the Andean highlands of Peru and Bolivia provide an important forage resource for camelids (llama and alpaca) in extensive pastoral agriculture systems. For many communities, these systems may provide the only available green forage during the long winter dry season. As a part of a larger project, we are examining the impacts of both current climate change and of socioeconomic drivers on the health and status of these systems. A key part of this analysis requires mapping the current bofedal extent, and observed changes over the recent past, to link to hypothesized drivers. We are therefore mapping bofedal extent using Landsat imagery, from the mid 1980s to present, using a variety of methods (supervised and unsupervised classification, and machine learning). We will present preliminary results from this analysis, showing total regional extent, and observed stability of the bofedales (or lack thereof) over time.

Peptide and low molecular weight proteins based kidney targeted drug delivery systems.

PubMed

Xu, Pengfei; Zhang, Hailiang; Dang, Ruili; Jiang, Pei

2018-05-30

Renal disease is a worldwide public health problem, and unfortunately, the therapeutic index of regular drugs is limited. Thus, it is a great need to develop effective treatment strategies. Among the reported strategies, kidney-targeted drug delivery system is a promising method to increase renal efficacy and reduce extra-renal toxicity. In recent years, working as vehicles for targeted drug delivery, low molecular weight proteins (LMWP) and peptide have received immense attention due to their many advantages, such as selective accumulation in kidney, high drug loading capability, control over routes of biodegradation, convenience in modification at the amino terminus, and good biocompatibility. In this review, we describe the current LMWP and peptide carriers for kidney targeted drug delivery systems. In addition, we discuss different linking strategies between carriers and drugs. Furthermore, we briefly outline the current status and attempt to give an outlook on the further study. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Food Consumption and its impact on Cardiovascular Disease: Importance of Solutions focused on the globalized food system

PubMed Central

Anand, Sonia S.; Hawkes, Corinna; de Souza, Russell J.; Mente, Andrew; Dehghan, Mahshid; Nugent, Rachel; Zulyniak, Michael A.; Weis, Tony; Bernstein, Adam M.; Krauss, Ronald; Kromhout, Daan; Jenkins, David J.A.; Malik, Vasanti; Martinez-Gonzalez, Miguel A.; Mozafarrian, Dariush; Yusuf, Salim; Willett, Walter C.; Popkin, Barry M

2015-01-01

Major scholars in the field, based on a 3-day consensus, created an in-depth review of current knowledge on the role of diet in CVD, the changing global food system and global dietary patterns, and potential policy solutions. Evidence from different countries, age/race/ethnicity/socioeconomic groups suggest the health effects studies of foods, macronutrients, and dietary patterns on CVD appear to be far more consistent though regional knowledge gaps are highlighted. There are large gaps in knowledge about the association of macronutrients to CVD in low- and middle-income countries (LMIC), particularly linked with dietary patterns are reviewed. Our understanding of foods and macronutrients in relationship to CVD is broadly clear; however major gaps exist both in dietary pattern research and ways to change diets and food systems. Based on the current evidence, the traditional Mediterranean-type diet, including plant foods/emphasizing plant protein sources, provides a well-tested healthy dietary pattern to reduce CVD. PMID:26429085

Synthetic Morphogenesis.

PubMed

Teague, Brian P; Guye, Patrick; Weiss, Ron

2016-09-01

Throughout biology, function is intimately linked with form. Across scales ranging from subcellular to multiorganismal, the identity and organization of a biological structure's subunits dictate its properties. The field of molecular morphogenesis has traditionally been concerned with describing these links, decoding the molecular mechanisms that give rise to the shape and structure of cells, tissues, organs, and organisms. Recent advances in synthetic biology promise unprecedented control over these molecular mechanisms; this opens the path to not just probing morphogenesis but directing it. This review explores several frontiers in the nascent field of synthetic morphogenesis, including programmable tissues and organs, synthetic biomaterials and programmable matter, and engineering complex morphogenic systems de novo. We will discuss each frontier's objectives, current approaches, constraints and challenges, and future potential. Copyright © 2016 Cold Spring Harbor Laboratory Press; all rights reserved.

Mechanotransduction current is essential for stability of the transducing stereocilia in mammalian auditory hair cells

PubMed Central

Vélez-Ortega, A Catalina; Freeman, Mary J; Indzhykulian, Artur A; Grossheim, Jonathan M; Frolenkov, Gregory I

2017-01-01

Mechanotransducer channels at the tips of sensory stereocilia of inner ear hair cells are gated by the tension of 'tip links' interconnecting stereocilia. To ensure maximal sensitivity, tip links are tensioned at rest, resulting in a continuous influx of Ca2+ into the cell. Here, we show that this constitutive Ca2+ influx, usually considered as potentially deleterious for hair cells, is in fact essential for stereocilia stability. In the auditory hair cells of young postnatal mice and rats, a reduction in mechanotransducer current, via pharmacological channel blockers or disruption of tip links, leads to stereocilia shape changes and shortening. These effects occur only in stereocilia that harbor mechanotransducer channels, recover upon blocker washout or tip link regeneration and can be replicated by manipulations of extracellular Ca2+ or intracellular Ca2+ buffering. Thus, our data provide the first experimental evidence for the dynamic control of stereocilia morphology by the mechanotransduction current. DOI: http://dx.doi.org/10.7554/eLife.24661.001 PMID:28350294

Process control and recovery in the Link Monitor and Control Operator Assistant

NASA Technical Reports Server (NTRS)

Lee, Lorrine; Hill, Randall W., Jr.

1993-01-01

This paper describes our approach to providing process control and recovery functions in the Link Monitor and Control Operator Assistant (LMCOA). The focus of the LMCOA is to provide semi-automated monitor and control to support station operations in the Deep Space Network. The LMCOA will be demonstrated with precalibration operations for Very Long Baseline Interferometry on a 70-meter antenna. Precalibration, the task of setting up the equipment to support a communications link with a spacecraft, is a manual, time consuming and error-prone process. One problem with the current system is that it does not provide explicit feedback about the effects of control actions. The LMCOA uses a Temporal Dependency Network (TDN) to represent an end-to-end sequence of operational procedures and a Situation Manager (SM) module to provide process control, diagnosis, and recovery functions. The TDN is a directed network representing precedence, parallelism, precondition, and postcondition constraints. The SM maintains an internal model of the expected and actual states of the subsystems in order to determine if each control action executed successfully and to provide feedback to the user. The LMCOA is implemented on a NeXT workstation using Objective C, Interface Builder and the C Language Integrated Production System.

A home-built digital optical MRI console using high-speed serial links.

PubMed

Tang, Weinan; Wang, Weimin; Liu, Wentao; Ma, Yajun; Tang, Xin; Xiao, Liang; Gao, Jia-Hong

2015-08-01

To develop a high performance, cost-effective digital optical console for scalable multichannel MRI. The console system was implemented with flexibility and efficiency based on a modular architecture with distributed pulse sequencers. High-speed serial links were optimally utilized to interconnect the system, providing fast digital communication with a multi-gigabit data rate. The conventional analog radio frequency (RF) chain was replaced with a digital RF manipulation. The acquisition electronics were designed in close proximity to RF coils and preamplifiers, using a digital optical link to transmit the MR signal. A prototype of the console was constructed with a broad frequency range from direct current to 100 MHz. A temporal resolution of 1 μs was achieved for both the RF and gradient operations. The MR signal was digitized in the scanner room with an overall dynamic range between 16 and 24 bits and was transmitted to a master controller over a duplex optic fiber with a high data rate of 3.125 gigabits per second. High-quality phantom and human images were obtained using the prototype on both 0.36T and 1.5T clinical MRI scanners. A homemade digital optical MRI console with high-speed serial interconnection has been developed to better serve imaging research and clinical applications. © 2014 Wiley Periodicals, Inc.

Climate Signals: An On-Line Digital Platform for Mapping Climate Change Impacts in Real Time

NASA Astrophysics Data System (ADS)

Cutting, H.

2016-12-01

Climate Signals is an on-line digital platform for cataloging and mapping the impacts of climate change. The CS platform specifies and details the chains of connections between greenhouse gas emissions and individual climate events. Currently in open-beta release, the platform is designed to to engage and serve the general public, news media, and policy-makers, particularly in real-time during extreme climate events. Climate Signals consists of a curated relational database of events and their links to climate change, a mapping engine, and a gallery of climate change monitors offering real-time data. For each event in the database, an infographic engine provides a custom attribution "tree" that illustrates the connections to climate change. In addition, links to key contextual resources are aggregated and curated for each event. All event records are fully annotated with detailed source citations and corresponding hyper links. The system of attribution used to link events to climate change in real-time is detailed here. This open-beta release is offered for public user testing and engagement. Launched in May 2016, the operation of this platform offers lessons for public engagement in climate change impacts.

Candidate Mission from Planet Earth control and data delivery system architecture

NASA Technical Reports Server (NTRS)

Shapiro, Phillip; Weinstein, Frank C.; Hei, Donald J., Jr.; Todd, Jacqueline

1992-01-01

Using a structured, experienced-based approach, Goddard Space Flight Center (GSFC) has assessed the generic functional requirements for a lunar mission control and data delivery (CDD) system. This analysis was based on lunar mission requirements outlined in GSFC-developed user traffic models. The CDD system will facilitate data transportation among user elements, element operations, and user teams by providing functions such as data management, fault isolation, fault correction, and link acquisition. The CDD system for the lunar missions must not only satisfy lunar requirements but also facilitate and provide early development of data system technologies for Mars. Reuse and evolution of existing data systems can help to maximize system reliability and minimize cost. This paper presents a set of existing and currently planned NASA data systems that provide the basic functionality. Reuse of such systems can have an impact on mission design and significantly reduce CDD and other system development costs.

Propagation Terminal Design and Measurements

NASA Technical Reports Server (NTRS)

Nessel, James

2015-01-01

The NASA propagation terminal has been designed and developed by the Glenn Research Center and is presently deployed at over 5 NASA and partner ground stations worldwide collecting information on the effects of the atmosphere on Ka-band and millimeter wave communications links. This lecture provides an overview of the fundamentals and requirements of the measurement of atmospheric propagation effects and, specifically, the types of hardware and digital signal processing techniques employed by current state-of-the-art propagation terminal systems.

Removal of Direct Current Link Harmonic Ripple in Single Phase Voltage Source Inverter Systems Using Supercapacitors

DTIC Science & Technology

2016-09-01

micro-sources can include sources such as micro- turbines and battery banks. Among the many benefits provided by an EMS is the ability to allow...efficient and reliable sharing of grid loads by several disparate power sources, which allows alternative energy sources such as solar and wind energy to...positions associated with the applicable configuration, with wires and components greyed out when they are not being used. a. SC Bank Disconnected

Roots Withstanding their Environment: Exploiting Root System Architecture Responses to Abiotic Stress to Improve Crop Tolerance

PubMed Central

Koevoets, Iko T.; Venema, Jan Henk; Elzenga, J. Theo. M.; Testerink, Christa

2016-01-01

To face future challenges in crop production dictated by global climate changes, breeders and plant researchers collaborate to develop productive crops that are able to withstand a wide range of biotic and abiotic stresses. However, crop selection is often focused on shoot performance alone, as observation of root properties is more complex and asks for artificial and extensive phenotyping platforms. In addition, most root research focuses on development, while a direct link to the functionality of plasticity in root development for tolerance is often lacking. In this paper we review the currently known root system architecture (RSA) responses in Arabidopsis and a number of crop species to a range of abiotic stresses, including nutrient limitation, drought, salinity, flooding, and extreme temperatures. For each of these stresses, the key molecular and cellular mechanisms underlying the RSA response are highlighted. To explore the relevance for crop selection, we especially review and discuss studies linking root architectural responses to stress tolerance. This will provide a first step toward understanding the relevance of adaptive root development for a plant’s response to its environment. We suggest that functional evidence on the role of root plasticity will support breeders in their efforts to include root properties in their current selection pipeline for abiotic stress tolerance, aimed to improve the robustness of crops. PMID:27630659

Oxytocin and vasopressin: linking pituitary neuropeptides and their receptors to social neurocircuits

PubMed Central

Baribeau, Danielle A.; Anagnostou, Evdokia

2015-01-01

Oxytocin and vasopressin are pituitary neuropeptides that have been shown to affect social processes in mammals. There is growing interest in these molecules and their receptors as potential precipitants of, and/or treatments for, social deficits in neurodevelopmental disorders, including autism spectrum disorder. Numerous behavioral-genetic studies suggest that there is an association between these peptides and individual social abilities; however, an explanatory model that links hormonal activity at the receptor level to complex human behavior remains elusive. The following review summarizes the known associations between the oxytocin and vasopressin neuropeptide systems and social neurocircuits in the brain. Following a micro- to macro- level trajectory, current literature on the synthesis and secretion of these peptides, and the structure, function and distribution of their respective receptors is first surveyed. Next, current models regarding the mechanism of action of these peptides on microcircuitry and other neurotransmitter systems are discussed. Functional neuroimaging evidence on the acute effects of exogenous administration of these peptides on brain activity is then reviewed. Overall, a model in which the local neuromodulatory effects of pituitary neuropeptides on brainstem and basal forebrain regions strengthen signaling within social neurocircuits proves appealing. However, these findings are derived from animal models; more research is needed to clarify the relevance of these mechanisms to human behavior and treatment of social deficits in neuropsychiatric disorders. PMID:26441508

Oxytocin and vasopressin: linking pituitary neuropeptides and their receptors to social neurocircuits.

PubMed

Baribeau, Danielle A; Anagnostou, Evdokia

2015-01-01

Oxytocin and vasopressin are pituitary neuropeptides that have been shown to affect social processes in mammals. There is growing interest in these molecules and their receptors as potential precipitants of, and/or treatments for, social deficits in neurodevelopmental disorders, including autism spectrum disorder. Numerous behavioral-genetic studies suggest that there is an association between these peptides and individual social abilities; however, an explanatory model that links hormonal activity at the receptor level to complex human behavior remains elusive. The following review summarizes the known associations between the oxytocin and vasopressin neuropeptide systems and social neurocircuits in the brain. Following a micro- to macro- level trajectory, current literature on the synthesis and secretion of these peptides, and the structure, function and distribution of their respective receptors is first surveyed. Next, current models regarding the mechanism of action of these peptides on microcircuitry and other neurotransmitter systems are discussed. Functional neuroimaging evidence on the acute effects of exogenous administration of these peptides on brain activity is then reviewed. Overall, a model in which the local neuromodulatory effects of pituitary neuropeptides on brainstem and basal forebrain regions strengthen signaling within social neurocircuits proves appealing. However, these findings are derived from animal models; more research is needed to clarify the relevance of these mechanisms to human behavior and treatment of social deficits in neuropsychiatric disorders.

Networking seismological data exchange in Europe

NASA Astrophysics Data System (ADS)

Sleeman, Reinoud; van Eck, Torild; van den Hazel, Gert-Jan; Trani, Luca; Spinuso, Alessandro

2010-05-01

The mission of the ORFEUS Data Centre (ODC) is to collect and archive high-quality seismic broadband waveform data from European-Mediterranean organizations and to provide open access to this data for monitoring and research purposes by the scientific community. The core activity of the ODC is to run an automatic, sustainable system to achieve this mission. Our 4 key operations are: data exchange protocols, quality control procedures, data management and data services. All these activities at the ODC benefit from developments within the EC Infrastructure (I3) project NERIES (Network of Research Infrastructure for European Seismology). For the data acquisition the ODC uses different standard, real-time data exchange protocols (e.g. Antelope, SeedLink, Scream) to ensure a very high data availability from stations in the Virtual European Broadband Seismic Network (VEBSN), which currently exists of about 500 BB stations. Within the data services a number of tools (e.g. Wilber II, NetDC, BreqFast, AutoDRM and webforms) are in place to serve the scientific community. These are currently being complemented by webservices and an integrated portal. The data management part relies on a simple flat file structure and a MySQL data management system on which both ArcLink and the Generic Data Interface (GDI) operate. In this presentation we will present an overview of the different aspects concerning data acquisition, services and management at ODC.

Time Transfer Methodologies for International Atomic Time (TAI)

DTIC Science & Technology

2007-01-01

International Atomic Time (TAI) and Coordinated Universal Time (UTC) involve either GPS or Two Way Satellite Time and Frequency Transfer ( TWSTFT ). This paper...NRCan, provide real-time carrier-phase based time transfer as well [3,4] Beginning in 2000, time-transfer links using TWSTFT replaced some GPS...links as the primary operational link, and currently over half the clocks used for TAI-generation are linked to other sites via a direct TWSTFT link

Modeling the Association between Lifecourse Socioeconomic Disadvantage and Systemic Inflammation in Healthy Adults: The Role of Self-Control

PubMed Central

Hostinar, Camelia E.; Ross, Kharah M.; Chen, Edith; Miller, Gregory E.

2015-01-01

Objective We sought to identify pathways connecting lifecourse socioeconomic status (SES) with chronic, low-grade inflammation, focusing on the explanatory roles of self-control, abdominal adiposity, and health practices. Methods Participants were 360 adults aged 15 - 55 who were free of chronic medical conditions. They were roughly equally divided between low and high current SES, with each group further divided between low and high early-life SES. Structural Equation Modeling (SEM) was used to identify direct and indirect pathways linking early-life and current SES with low-grade, chronic inflammation in adulthood, as manifest by serum interleukin-6 and C-reactive protein. Low SES was hypothesized to relate to inflammation by reducing self-control, which in turn was hypothesized to facilitate lifestyle factors that potentiate inflammation (smoking, alcohol use, sedentary behavior, and weight gain). Results Analyses revealed that self-control was pivotal in linking both early-life and current SES to inflammation. Low early-life SES was related to a harsher family climate, and in turn lower adult self-control, over and above the effects of current SES. Controlling for early-life SES, low current SES was associated with perceived stress, and in turn diminished self-control. Results showed that lower self-control primarily operated through higher abdominal adiposity to associate with greater inflammation. Conclusions The findings suggest a mechanistic scenario wherein low SES in early-life or adulthood depletes self-control and in turn fosters adiposity and inflammation. These pathways should be studied longitudinally to elucidate and potentially ameliorate socioeconomic disparities in health. PMID:25110854

Analysis of InP-based QCLs designed for application in optical transmitter of free-space optics

NASA Astrophysics Data System (ADS)

Pierscinski, Kamil; Mikołajczyk, Janusz; Szabra, Dariusz; Pierścińska, Dorota; Gutowski, Piotr; Bielecki, Zbigniew; Bugajski, Maciej

2017-10-01

In this paper, the study of AlInAs/InGaAs/InP Quantum Cascade Lasers application in Free Space Optical data link is performed. Implementation of such FSO link operated in long-wavelength infrared (LWIR: 8-12 μm) will be unique for construction of so-called RF/FSO hybrid communication system. The range of longer wavelengths provides better data transfer performance in the case of severe weather conditions, especially, fog, low haze or air turbulence. In the frame of this work, series of QCLs for application in FSO system were examined. They are characterized by different geometries and constructions towards best performance in optical link systems operated in the wavelength range of 8-12 μm. The preliminary test of QCLs included electrical measurements of pulsed light-current-voltage characteristics and time-resolved spectra. The obtained results made it possible to determine operation point for FSO. Their modulation performances were tested using the laboratory laser drivers. Based on measurements, both power and time parameters of QCLs pulses were investigated. These results defined critical values for FSO system. The second part of the analysis concerned the spatial parameters of QCLs radiation. Knowledge of spatial characteristics of emission is vital for FSO optics construction. To characterize spatial properties of beams, far-field patterns of emission were registered. Finally, the obtained results made it possible to optimize the optical transmitter construction and further performance of FSO laboratory model. This research was supported by The Polish National Centre for Research and Development grant DOB-BIO8/01/01/2016.

ICE-Based Custom Full-Mesh Network for the CHIME High Bandwidth Radio Astronomy Correlator

NASA Astrophysics Data System (ADS)

Bandura, K.; Cliche, J. F.; Dobbs, M. A.; Gilbert, A. J.; Ittah, D.; Mena Parra, J.; Smecher, G.

2016-03-01

New generation radio interferometers encode signals from thousands of antenna feeds across large bandwidth. Channelizing and correlating this data requires networking capabilities that can handle unprecedented data rates with reasonable cost. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) correlator processes 8-bits from N=2,048 digitizer inputs across 400MHz of bandwidth. Measured in N2× bandwidth, it is the largest radio correlator that is currently commissioning. Its digital back-end must exchange and reorganize the 6.6terabit/s produced by its 128 digitizing and channelizing nodes, and feed it to the 256 graphics processing unit (GPU) node spatial correlator in a way that each node obtains data from all digitizer inputs but across a small fraction of the bandwidth (i.e. ‘corner-turn’). In order to maximize performance and reliability of the corner-turn system while minimizing cost, a custom networking solution has been implemented. The system makes use of Field Programmable Gate Array (FPGA) transceivers to implement direct, passive copper, full-mesh, high speed serial connections between sixteen circuit boards in a crate, to exchange data between crates, and to offload the data to a cluster of 256 GPU nodes using standard 10Gbit/s Ethernet links. The GPU nodes complete the corner-turn by combining data from all crates and then computing visibilities. Eye diagrams and frame error counters confirm error-free operation of the corner-turn network in both the currently operating CHIME Pathfinder telescope (a prototype for the full CHIME telescope) and a representative fraction of the full CHIME hardware providing an end-to-end system validation. An analysis of an equivalent corner-turn system built with Ethernet switches instead of custom passive data links is provided.

Can we estimate plasma density in ICP driver through electrical parameters in RF circuit?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bandyopadhyay, M., E-mail: mainak@iter-india.org; Sudhir, Dass, E-mail: dass.sudhir@iter-india.org; Chakraborty, A., E-mail: arunkc@iter-india.org

2015-04-08

To avoid regular maintenance, invasive plasma diagnostics with probes are not included in the inductively coupled plasma (ICP) based ITER Neutral Beam (NB) source design. Even non-invasive probes like optical emission spectroscopic diagnostics are also not included in the present ITER NB design due to overall system design and interface issues. As a result, negative ion beam current through the extraction system in the ITER NB negative ion source is the only measurement which indicates plasma condition inside the ion source. However, beam current not only depends on the plasma condition near the extraction region but also on the perveancemore » condition of the ion extractor system and negative ion stripping. Nevertheless, inductively coupled plasma production region (RF driver region) is placed at distance (∼ 30cm) from the extraction region. Due to that, some uncertainties are expected to be involved if one tries to link beam current with plasma properties inside the RF driver. Plasma characterization in source RF driver region is utmost necessary to maintain the optimum condition for source operation. In this paper, a method of plasma density estimation is described, based on density dependent plasma load calculation.« less

Weak links in high critical temperature superconductors

NASA Astrophysics Data System (ADS)

Tafuri, Francesco; Kirtley, John R.

2005-11-01

The traditional distinction between tunnel and highly transmissive barriers does not currently hold for high critical temperature superconducting Josephson junctions, both because of complicated materials issues and the intrinsic properties of high temperature superconductors (HTS). An intermediate regime, typical of both artificial superconductor-barrier-superconductor structures and of grain boundaries, spans several orders of magnitude in the critical current density and specific resistivity. The physics taking place at HTS surfaces and interfaces is rich, primarily because of phenomena associated with d-wave order parameter (OP) symmetry. These phenomena include Andreev bound states, the presence of the second harmonic in the critical current versus phase relation, a doubly degenerate state, time reversal symmetry breaking and the possible presence of an imaginary component of the OP. All these effects are regulated by a series of transport mechanisms, whose rules of interplay and relative activation are unknown. Some transport mechanisms probably have common roots, which are not completely clear and possibly related to the intrinsic nature of high-TC superconductivity. The d-wave OP symmetry gives unique properties to HTS weak links, which do not have any analogy with systems based on other superconductors. Even if the HTS structures are not optimal, compared with low critical temperature superconductor Josephson junctions, the state of the art allows the realization of weak links with unexpectedly high quality quantum properties, which open interesting perspectives for the future. The observation of macroscopic quantum tunnelling and the qubit proposals represent significant achievements in this direction. In this review we attempt to encompass all the above aspects, attached to a solid experimental basis of junction concepts and basic properties, along with a flexible phenomenological background, which collects ideas on the Josephson effect in the presence of d-wave pairing for different types of barriers.

Design Concepts for a Small Space-Based GEO Relay Satellite for Missions Between Low Earth and near Earth Orbits

NASA Technical Reports Server (NTRS)

Bhasin, Kul B.; Warner, Joseph D.; Oleson, Steven; Schier, James

2014-01-01

The main purpose of the Small Space-Based Geosynchronous Earth orbiting (GEO) satellite is to provide a space link to the user mission spacecraft for relaying data through ground networks to user Mission Control Centers. The Small Space Based Satellite (SSBS) will provide services comparable to those of a NASA Tracking Data Relay Satellite (TDRS) for the same type of links. The SSBS services will keep the user burden the same or lower than for TDRS and will support the same or higher data rates than those currently supported by TDRS. At present, TDRSS provides links and coverage below GEO; however, SSBS links and coverage capability to above GEO missions are being considered for the future, especially for Human Space Flight Missions (HSF). There is also a rising need for the capability to support high data rate links (exceeding 1 Gbps) for imaging applications. The communication payload on the SSBS will provide S/Ka-band single access links to the mission and a Ku-band link to the ground, with an optical communication payload as an option. To design the communication payload, various link budgets were analyzed and many possible operational scenarios examined. To reduce user burden, using a larger-sized antenna than is currently in use by TDRS was considered. Because of the SSBS design size, it was found that a SpaceX Falcon 9 rocket could deliver three SSBSs to GEO. This will greatly reduce the launch costs per satellite. Using electric propulsion was also evaluated versus using chemical propulsion; the power system size and time to orbit for various power systems were also considered. This paper will describe how the SSBS will meet future service requirements, concept of operations, and the design to meet NASA users' needs for below and above GEO missions. These users' needs not only address the observational mission requirements but also possible HSF missions to the year 2030. We will provide the trade-off analysis of the communication payload design in terms of the number of links looking above and below GEO; the detailed design of a GEO SSBS spacecraft bus and its accommodation of the communication payload, and a summary of the trade study that resulted in the selection of the Falcon 9 launch vehicle to deploy the SSBS and its impact on cost reductions per satellite. ======================================================================== Several initiatives have taken place within NASA1 and international space agencies2 to create a human exploration strategy for expanding human presence into the solar system; these initiatives have been driven by multiple factors to benefit Earth. Of the many elements in the strategy one stands out: to send robotic and human missions to destinations beyond Low Earth Orbit (LEO), including cis-lunar space, Near-Earth Asteroids (NEAs), the Moon, and Mars and its moons.3, 4 The time frame for human exploration to various destinations, based on the public information available,1,4 is shown in Figure 1. Advance planning is needed to define how future space communications services will be provided in the new budget environment to meet future space communications needs. The spacecraft for these missions can be dispersed anywhere from below LEO to beyond GEO, and to various destinations within the solar system. NASA's Space Communications and Navigation (SCaN) program office provides communication and tracking services to space missions during launch, in-orbit testing, and operation phases. Currently, SCaN's space networking relay satellites mainly provide services to users below GEO, at Near Earth Orbit (NEO), below LEO, and in deep space. The potential exists for using a space-based relay satellite, located in the vicinity of various solar system destinations, to provide communication space links to missions both below and above its orbit. Such relays can meet the needs of human exploration missions for maximum connectivity to Earth locations and for reduced latency. In the past, several studies assessed the ability of satellite-based relays working above GEO in conjunction with Earth ground stations. Many of these focused on the trade between space relay and direct-to-Earth station links5,6,7. Several others focused on top-level architecture based on relays at various destinations8,9,10,11,12. Much has changed in terms of microwave and optical technology since the publication of the referenced papers; Ka-band communication systems are being deployed, optical communication is being demonstrated, and spacecraft buses are becoming increasingly more functional and operational. A design concept study was undertaken to access the potential for deploying a Small Space-Based Satellite (SSBS) relay capable of serving missions between LEO and NEO. The needs of future human exploration missions were analyzed, and a notional relay-based architecture concept was generated as shown in Fig. 1. Relay satellites in Earth through cis-Lunar orbits are normally located in stable orbits requiring low fuel consumption. Relay satellites for Mars orbit are normally selected based on the mission requirement and projected fuel consumption. Relay satellites have extreme commonalities of functions between them, differing only in the redundancy and frequencies used; therefore, the relay satellite in GEO was selected for further analysis since it will be the first step in achieving a relay-based architecture for human exploration missions (see Fig.Figure 2). The mission design methodology developed by the Collaborative Modeling for Parametric Assessment of Space Systems (COMPASS) team13 was used to produce the satellite relay design and to perform various design trades. At the start of the activity, the team was provided with the detailed concept of the notional architecture and the system and communication payload drivers.

Simulating the Agulhas system in global ocean models - nesting vs. multi-resolution unstructured meshes

NASA Astrophysics Data System (ADS)

Biastoch, Arne; Sein, Dmitry; Durgadoo, Jonathan V.; Wang, Qiang; Danilov, Sergey

2018-01-01

Many questions in ocean and climate modelling require the combined use of high resolution, global coverage and multi-decadal integration length. For this combination, even modern resources limit the use of traditional structured-mesh grids. Here we compare two approaches: A high-resolution grid nested into a global model at coarser resolution (NEMO with AGRIF) and an unstructured-mesh grid (FESOM) which allows to variably enhance resolution where desired. The Agulhas system around South Africa is used as a testcase, providing an energetic interplay of a strong western boundary current and mesoscale dynamics. Its open setting into the horizontal and global overturning circulations also requires global coverage. Both model configurations simulate a reasonable large-scale circulation. Distribution and temporal variability of the wind-driven circulation are quite comparable due to the same atmospheric forcing. However, the overturning circulation differs, owing each model's ability to represent formation and spreading of deep water masses. In terms of regional, high-resolution dynamics, all elements of the Agulhas system are well represented. Owing to the strong nonlinearity in the system, Agulhas Current transports of both configurations and in comparison with observations differ in strength and temporal variability. Similar decadal trends in Agulhas Current transport and Agulhas leakage are linked to the trends in wind forcing.

The TSS-1R Electrodynamic Tether Experiment: Scientific and Technological Results

NASA Technical Reports Server (NTRS)

Stone, Nobie H.; Raitt, John

1998-01-01

The bi-national, US-Italian, Tethered Satellite System (TSS) program was designed to provide a unique opportunity to explore certain space plasma- electrodynamic processes and the orbital mechanics of a gravity-gradient stabilized system of two satellites linked by a long conducting tether. The second flight, TSS-LR, was launched February 22, 1996 on STS-75 and satellite deployment began at MET 3/00:27. A unique data set was obtained over the next five hours, as the tether was deployed to a length of 19695 meters, which has allowed significant science to be accomplished. This presentation will focus on electrodynamic processes generated by the tether--in particular, the collection of electrical current from the ionospheric plasma. Of particular significance is an apparent transition of the physics of current collection when the potential of the collecting body becomes greater than the ram energy of the ionospheric atomic oxygen ions. Previous theoretical models of current collection were electrostatic--assuming that the orbital motion of the system, which is highly subsonic with respect to electron thermal motion, was un- important. This may still be acceptable for the case of relatively slow-moving sounding rockets. However, the TSS-LR results show that motion relative to the plasma must be accounted for in orbiting systems.

Optoelectronic retinal prosthesis: system design and performance

NASA Astrophysics Data System (ADS)

Loudin, J. D.; Simanovskii, D. M.; Vijayraghavan, K.; Sramek, C. K.; Butterwick, A. F.; Huie, P.; McLean, G. Y.; Palanker, D. V.

2007-03-01

The design of high-resolution retinal prostheses presents many unique engineering and biological challenges. Ever smaller electrodes must inject enough charge to stimulate nerve cells, within electrochemically safe voltage limits. Stimulation sites should be placed within an electrode diameter from the target cells to prevent 'blurring' and minimize current. Signals must be delivered wirelessly from an external source to a large number of electrodes, and visual information should, ideally, maintain its natural link to eye movements. Finally, a good system must have a wide range of stimulation currents, external control of image processing and the option of either anodic-first or cathodic-first pulses. This paper discusses these challenges and presents solutions to them for a system based on a photodiode array implant. Video frames are processed and imaged onto the retinal implant by a head-mounted near-to-eye projection system operating at near-infrared wavelengths. Photodiodes convert light into pulsed electric current, with charge injection maximized by applying a common biphasic bias waveform. The resulting prosthesis will provide stimulation with a frame rate of up to 50 Hz in a central 10° visual field, with a full 30° field accessible via eye movements. Pixel sizes are scalable from 100 to 25 µm, corresponding to 640-10 000 pixels on an implant 3 mm in diameter.

Analysis of Mesh Distribution Systems Considering Load Models and Load Growth Impact with Loops on System Performance

NASA Astrophysics Data System (ADS)

Kumar Sharma, A.; Murty, V. V. S. N.

2014-12-01

The distribution system is the final link between bulk power system and consumer end. A distinctive load flow solution method is used for analysis of the load flow of radial and weakly meshed network based on Kirchhoff's Current Law (KCL) and KVL. This method has excellent convergence characteristics for both radial as well as weakly meshed structure and is based on bus injection to branch current and branch-current to bus-voltage matrix. The main contribution of the paper is: (i) an analysis has been carried out for a weekly mesh network considering number of loops addition and its impact on the losses, kW and kVAr requirements from a system, and voltage profile, (ii) different load models, realistic ZIP load model and load growth impact on losses, voltage profile, kVA and kVAr requirements, (iii) impact of addition of loops on losses, voltage profile, kVA and kVAr requirements from substation, and (iv) comparison of system performance with radial distribution system. Voltage stability is a major concern in planning and operation of power systems. This paper also includes identifying the closeness critical bus which is the most sensitive to the voltage collapse in radial distribution networks. Node having minimum value of voltage stability index is the most sensitive node. Voltage stability index values are computed for meshed network with number of loops added in the system. The results have been obtained for IEEE 33 and 69 bus test system. The results have also been obtained for radial distribution system for comparison.

Non-linear control of the output stage of a solar microinverter

NASA Astrophysics Data System (ADS)

Lopez-Santos, Oswaldo; Garcia, Germain; Martinez-Salamero, Luis; Avila-Martinez, Juan C.; Seguier, Lionel

2017-01-01

This paper presents a proposal to control the output stage of a two-stage solar microinverter to inject real power into the grid. The input stage of the microinverter is used to extract the maximum available power of a photovoltaic module enforcing a power source behavior in the DC-link to feed the output stage. The work here reported is devoted to control a grid-connected power source inverter with a high power quality level at the grid side ensuring the power balance of the microinverter regulating the voltage of the DC-link. The proposed control is composed of a sinusoidal current reference generator and a cascade type controller composed by a current tracking loop and a voltage regulation loop. The current reference is obtained using a synchronized generator based on phase locked loop (PLL) which gives the shape, the frequency and phase of the current signal. The amplitude of the reference is obtained from a simple controller regulating the DC-link voltage. The tracking of the current reference is accomplished by means of a first-order sliding mode control law. The solution takes advantage of the rapidity and inherent robustness of the sliding mode current controller allowing a robust behavior in the regulation of the DC-link using a simple linear controller. The analytical expression to determine the power quality indicators of the micro-inverter's output is theoretically solved giving expressions relating the converter parameters. The theoretical approach is validated using simulation and experimental results.

Secure scalable disaster electronic medical record and tracking system.

PubMed

Demers, Gerard; Kahn, Christopher; Johansson, Per; Buono, Colleen; Chipara, Octav; Griswold, William; Chan, Theodore

2013-10-01

Electronic medical records (EMRs) are considered superior in documentation of care for medical practice. Current disaster medical response involves paper tracking systems and radio communication for mass-casualty incidents (MCIs). These systems are prone to errors, may be compromised by local conditions, and are labor intensive. Communication infrastructure may be impacted, overwhelmed by call volume, or destroyed by the disaster, making self-contained and secure EMR response a critical capability. Report As the prehospital disaster EMR allows for more robust content including protected health information (PHI), security measures must be instituted to safeguard these data. The Wireless Internet Information System for medicAl Response in Disasters (WIISARD) Research Group developed a handheld, linked, wireless EMR system utilizing current technology platforms. Smart phones connected to radio frequency identification (RFID) readers may be utilized to efficiently track casualties resulting from the incident. Medical information may be transmitted on an encrypted network to fellow prehospital team members, medical dispatch, and receiving medical centers. This system has been field tested in a number of exercises with excellent results, and future iterations will incorporate robust security measures. A secure prehospital triage EMR improves documentation quality during disaster drills.

Safety Case Development as an Information Modelling Problem

NASA Astrophysics Data System (ADS)

Lewis, Robert

This paper considers the benefits from applying information modelling as the basis for creating an electronically-based safety case. It highlights the current difficulties of developing and managing large document-based safety cases for complex systems such as those found in Air Traffic Control systems. After a review of current tools and related literature on this subject, the paper proceeds to examine the many relationships between entities that can exist within a large safety case. The paper considers the benefits to both safety case writers and readers from the future development of an ideal safety case tool that is able to exploit these information models. The paper also introduces the idea that the safety case has formal relationships between entities that directly support the safety case argument using a methodology such as GSN, and informal relationships that provide links to direct and backing evidence and to supporting information.

C3 System Performance Simulation and User Manual. Getting Started: Guidelines for Users

NASA Technical Reports Server (NTRS)

2006-01-01

This document is a User's Manual describing the C3 Simulation capabilities. The subject work was designed to simulate the communications involved in the flight of a Remotely Operated Aircraft (ROA) using the Opnet software. Opnet provides a comprehensive development environment supporting the modeling of communication networks and distributed systems. It has tools for model design, simulation, data collection, and data analysis. Opnet models are hierarchical -- consisting of a project which contains node models which in turn contain process models. Nodes can be fixed, mobile, or satellite. Links between nodes can be physical or wireless. Communications are packet based. The model is very generic in its current form. Attributes such as frequency and bandwidth can easily be modified to better reflect a specific platform. The model is not fully developed at this stage -- there are still more enhancements to be added. Current issues are documented throughout this guide.

Unified computational model of transport in metal-insulating oxide-metal systems

NASA Astrophysics Data System (ADS)

Tierney, B. D.; Hjalmarson, H. P.; Jacobs-Gedrim, R. B.; Agarwal, Sapan; James, C. D.; Marinella, M. J.

2018-04-01

A unified physics-based model of electron transport in metal-insulator-metal (MIM) systems is presented. In this model, transport through metal-oxide interfaces occurs by electron tunneling between the metal electrodes and oxide defect states. Transport in the oxide bulk is dominated by hopping, modeled as a series of tunneling events that alter the electron occupancy of defect states. Electron transport in the oxide conduction band is treated by the drift-diffusion formalism and defect chemistry reactions link all the various transport mechanisms. It is shown that the current-limiting effect of the interface band offsets is a function of the defect vacancy concentration. These results provide insight into the underlying physical mechanisms of leakage currents in oxide-based capacitors and steady-state electron transport in resistive random access memory (ReRAM) MIM devices. Finally, an explanation of ReRAM bipolar switching behavior based on these results is proposed.

Tobacco against Ebola virus disease.

PubMed

Budzianowski, Jaromir

2015-01-01

The Ebola virus disease (EVD), formerly known as a hemorrhagic fever and discovered in 1976, is dangerous, highly infectious disease with very high mortality. There are no licensed therapeutics against EVD, although a range of medicines and therapies are currently being evaluated. During the 2014 Ebola outbreak, an experimental drug named ZMapp was administered on an emergency basis to seven patients of which five were recovered. Currently, since February 2015, ZMapp is tested in clinical trials. ZMapp is a mixture (named a cocktail) of three chimaeric monoclonal antibodies (mAbs) of IgG class, which bind to three different epitopes on Ebola surface glycoprotein (GP). ZMapp was created by systematic selection of antibodies from two other three-component cocktails--MB-003 and ZMab the components of which were produced by rapid transient expression method in tobacco species of Australian origin--Nicotiana benthamiana. The ZMapp antibodies of pharmaceutical grade are manufactured in green-house grown N.benthamiana according to the cGMP (current Good Manufacturing Practice), using RAMP platform (Rapid Antibody Manufacturing Platform) and MagnICON system, which utilizes transient expression by magnifection method using viral vectors delivered to plant tissue by a bacterium--Agrobacterium tumefaciens. The applied glycosylation mutant of N.benthamiana (delta XTFT) synthesizes human-like, biantennary N-glycans, with terminal N-acetylglucoseamine and without typical of plants, immunogenic sugar epitopes-beta1,2-linked xylose and alpha1,3-linked fucose. Due to an absence of fucose on N-glycans attached to the Fc domains, the plant-produced anti-Ebola mAbs elicited significantly stronger antibody-dependent cellular cytotoxicity (ADCC) than the analogous anti-Ebola mAbs with fucosylated (alpha1,6-linked fucose) N-glycans produced in a mammalian CHO cell line--the basic expression system for the industrial production of recombinant therapeutical glycoproteins. As far as a vaccine against Ebola virus disease is considered, so-called Ebola Immunogenic Complex (EIC) consisting of assembled molecules of a humanized IgG mAb--6D8 specific for Ebola GPI with GP1 fused to the C-terminus of the heavy chains, was obtained by transient expression in N. benthamiana.