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Sample records for ka-band link management

  1. Deep Space Ka-band Link Management and the MRO Demonstration: Long-term Weather Statistics Versus Forecasting

    Science.gov (United States)

    Davarian, Faramaz; Shambayati, Shervin; Slobin, Stephen

    2004-01-01

    During the last 40 years, deep space radio communication systems have experienced a move toward shorter wavelengths. In the 1960s a transition from L- to S-band occurred which was followed by a transition from S- to X-band in the 1970s. Both these transitions provided deep space links with wider bandwidths and improved radio metrics capability. Now, in the 2000s, a new change is taking place, namely a move to the Ka-band region of the radio frequency spectrum. Ka-band will soon replace X-band as the frequency of choice for deep space communications providing ample spectrum for the high data rate requirements of future missions. The low-noise receivers of deep space networks have a great need for link management techniques that can mitigate weather effects. In this paper, three approaches for managing Ka-band Earth-space links are investigated. The first approach uses aggregate annual statistics, the second one uses monthly statistics, and the third is based on the short-term forecasting of the local weather. An example of weather forecasting for Ka-band link performance prediction is presented. Furthermore, spacecraft commanding schemes suitable for Ka-band link management are investigated. Theses schemes will be demonstrated using NASA's Mars Reconnaissance Orbiter (MRO) spacecraft in the 2007 to 2008 time period, and the demonstration findings will be reported in a future publication.

  2. DVB-RCS return link radio resource management for broadband satellite systems using fade mitigation techniques at ka band

    OpenAIRE

    2008-01-01

    Current Broadband Satellite systems supporting DVB-RCS at Ku band have static physical layer in order not to complicate their implementation. However at Ka band frequencies and above an adaptive physical layer wherein the physical layer parameters are dynamically modified on a per user basis is necessary to counteract atmospheric attenuation. Satellite Radio Resource Management (RRM) at the Medium Access Control (MAC) layer has become an important issue given the emphasis placed on Quality...

  3. Experimental radio frequency link for Ka-band communications applications

    Science.gov (United States)

    Fujikawa, Gene; Conray, Martin J.; Saunders, Alan L.; Pope, Dale E.

    1988-01-01

    An experimental radio frequency link has been demonstrated to provide two-way communication between a remote user ground terminal and a ground-based Ka-band transponder. Bit-error-rate performance and radio frequency characteristics of the communication link were investigated.

  4. A Ka-band (32 GHz) beacon link experiment (KABLE) with Mars Observer

    Science.gov (United States)

    Riley, A. L.; Hansen, D. M.; Mileant, A.; Hartop, R. W.

    1987-02-01

    A proposal for a Ka-Band (32 GHz) Link Experiment (KABLE) with the Mars Observer mission was submitted to NASA. The experiment will rely on the fourth harmonic of the spacecraft X-band transmitter to generate a 33.6 GHz signal. The experiment will rely also on the Deep Space Network (DSN) receiving station equipped to simultaneously receive X- and Ka-band signals. The experiment will accurately measure the spacecraft-to-Earth telecommunication link performance at Ka-band and X-band (8.4 GHz).

  5. The Mars Global Surveyor Ka-Band Link Experiment (MGS/KaBLE-II)

    Science.gov (United States)

    Morabito, D.; Butman, S.; Shambayati, S.

    1999-01-01

    The Mars Global Surveyor (MGS) spacecraft, launched on November 7, 1996, carries an experimental space-to-ground telecommunications link at Ka-band (32 GHz) along with the primary X-band (8.4-GHz) downlink. The signals are simultaneously transmitted from a 1.5-m-diameter parabolic antenna on MGS and received by a beam-waveguide (BWG) research and development (R&D) 34-meter a ntenna located in NASA's Goldstone Deep Space Network (DSN) complex near Barstow, California. This Ka-band link experiment (KaBLE-II) allows the performances of the Ka-band and X-band signals to be compared under nearly identical conditions. The two signals have been regularly tracked during the past 2 years. This article presents carrier-signal-level data (P_c/N_o) for both X-band and Ka-band acquired over a wide range of station elevation angles, weather conditions, and solar elongation angles. The cruise phase of the mission covered the period from launch (November 7, 1996) to Mars orbit capture (September 12, 1997). Since September 12, 1997, MGS has been in orbit around Mars. The measurements confirm that Ka-band could increase data capacity by at least a factor of three (5 dB) as compared with X-band. During May 1998, the solar corona experiment, in which the effects of solar plasma on the X-band and Ka-band links were studied, was conducted. In addition, frequency and difference frequency (f_x - f_(Ka)/3.8), ranging, and telemetry data results are presented. MGS/KaBLE-II measured signal strengths (for 54 percent of the experiments conducted) that were in reasonable agreement with predicted values based on preflight knowledge, and frequency residuals that agreed between bands and whose statistics were consistent with expected noise sources. For passes in which measured signal strengths disagreed with predicted values, the problems were traced to known deficiencies, for example, equipment operating under certain conditions, such as a cold Ka-band solid-state power amplifier (SSPA

  6. Deep-Space Ka-Band Link Priority Data Protection: Pre-Emptive Retransmission vs. Margin

    Science.gov (United States)

    Shambayati, Shervin

    2009-01-01

    In this paper the performance of two preemptive retransmission schemes for protection of priority data over deep-space Ka-band links is evaluated. The first scheme merges the correctly received bit from each transmission to create the most complete set of priority data for each pass (bit merge). The second scheme (symbol combining) combines the soft symbols received from each transmission of the priority data to increase the priority data's signal to noise ratio (SNR), thus increasing the liklihood of the correct reception.

  7. User RF requirements for a Ka-band data relay satellite link

    Science.gov (United States)

    Copeland, David J.; Aleman, Roberto M.

    1989-01-01

    The user G/T and EIRP requirements were determined for a data relay satellite link consisting of a forward link to 360 Mbps at 23 GHz and a return link to 2 Gbps at 26.5 GHz. Hardware for this data link would be a modular expansion to the NASA Data Link Module. Calculations were based on a data relay satellite model of predetermined characteristics patterned after the NASA Tracking and Data Relay Satellite (TDRS). The desired data rates could be achieved with a G/T of 21.7 dB/deg K (forward link) and an EIRP of 68.2 dBW (return link) for the user satellite. Hardware configurations meeting these requirements are discussed in terms of RF performance, efficiency, reliability, and modular flexibility. A planar array configuration emerges as the logical candidate for most NASA missions. Pertinent Ka-band technology and certain ongoing research efforts are reviewed. Areas of particular interest include new power device families, 0.25-micron low-noise HEMT technology, and fiber optic distribution and control of RF arrays.

  8. Improvement of Ka-band satellite link availability for real-time IP-based video contribution

    Directory of Open Access Journals (Sweden)

    G. Berretta

    2017-09-01

    Full Text Available New High Throughput Satellite (HTS systems allow high throughput IP uplinks/contribution at Ka-band frequencies for relatively lower costs when compared to broadcasting satellite uplinks at Ku band. This technology offers an advantage for live video contribution from remote areas, where the terrestrial infrastructure may not be adequate. On the other hand, the Ka-band is more subject to impairments due to rain or bad weather. This paper addresses the target system specification and provides an optimized approach for the transmission of IP-based video flows through HTS commercial services operating at Ka-band frequencies. In particular, the focus of this study is on the service requirements and the propagation analysis that provide a reference architecture to improve the overall link availability. The approach proposed herein leads to the introduction of a new concept of live service contribution using pairs of small satellite antennas and cheap satellite terminals.

  9. Analysis and Mitigation of Tropospheric Effects on Ka Band Satellite Signals and Estimation of Ergodic Capacity and Outage Probability for Terrestrial Links

    OpenAIRE

    Enserink, Scott Warren

    2012-01-01

    The first part of this work covers the effect of the troposphere onKa band (20-30 GHz) satellite signals. The second part deals withthe estimation of the capacity and outage probability forterrestrial links when constrained to quadrature amplitudemodulations.The desire for higher data rates and the need for availablebandwidth has pushed satellite communications into the Ka band(20-30 GHz). At these higher carrier frequencies the effects ofscintillation and rain attenuation are increased. In...

  10. Ka-Band Link Study and Analysis for a Mars Hybrid RF/Optical Software Defined Radio

    Science.gov (United States)

    Zeleznikar, Daniel J.; Nappier, Jennifer M.; Downey, Joseph A.

    2014-01-01

    The integrated radio and optical communications (iROC) project at the NASA Glenn Research Center (GRC) is investigating the feasibility of a hybrid RF and optical communication subsystem for future deep space missions. The hybrid communications subsystem enables the advancement of optical communications while simultaneously mitigating the risk of infusion by combining an experimental optical transmitter and telescope with a reliable Ka-band RF transmitter and antenna. The iROC communications subsystem seeks to maximize the total data return over the course of a potential 2-year mission in Mars orbit beginning in 2021. Although optical communication by itself offers potential for greater data return over RF, the reliable Ka-band link is also being designed for high data return capability in this hybrid system. A daily analysis of the RF link budget over the 2-year span is performed to optimize and provide detailed estimates of the RF data return. In particular, the bandwidth dependence of these data return estimates is analyzed for candidate waveforms. In this effort, a data return modeling tool was created to analyze candidate RF modulation and coding schemes with respect to their spectral efficiency, amplifier output power back-off, required digital to analog conversion (DAC) sampling rates, and support by ground receivers. A set of RF waveforms is recommended for use on the iROC platform.

  11. Fade Mitigation Techniques at Ka-Band

    Science.gov (United States)

    Dissanayake, Asoka (Editor)

    1996-01-01

    Rain fading is the dominant propagation impairment affecting Ka-band satellite links and rain fade mitigation is a key element in the design of Ka-band satellite networks. Some of the common fade mitigation techniques include: power control, diversity, adaptive coding, and resource sharing. The Advanced Communications Technology Satellite (ACTS) provides an excellent opportunity to develop and test Ka-band rain impairment amelioration techniques. Up-link power control and diversity are discussed in this paper.

  12. Hardware-in-the-loop simulation of the dynamic characteristics of rain fading channel for satellite-to-Earth links at Ka-band

    Science.gov (United States)

    Yao, Hongchao; Wang, Huali

    2007-11-01

    Modeling of rain fading channel dynamics is essential to the real-time prediction of link availability for Ka-band satellite communication system under rain attenuation impairment, and can validate fade mitigation techniques (FMT) such as adaptive transmission and diversity. The mechanism of dynamic rain attenuation model based on time-series generator is firstly concerned in this paper. We further provide a scheme and implementation of real-time simulator for dynamic rain fading channels based on Hardware-in-the-loop (HIL) simulation method and general Field Programmable Logic Array (FPGA) device. Finally, the impact of adaptive modulation fade countermeasures (AMFC) in the different state of rain attenuation is evaluated with simulation results.

  13. Aeronautical applications of steerable K/Ka-band antennas

    Science.gov (United States)

    Helmken, Henry; Prather, Horton

    1995-01-01

    The expected growth of wideband data and video transmission via satellite will press existing satellite Ku-band services and push development of the Ka-band region. Isolated ground based K/Ka-band terminals can experience severe fading due to rain and weather phenomena. However, since aircraft generally fly above the severe weather, they are attractive platforms for developing commercial K/Ka-band communication links.

  14. Ka-band MMIC microstrip array for high rate communications

    Science.gov (United States)

    Lee, R. Q.; Raquet, C. A.; Tolleson, J. B.; Sanzgiri, S. M.

    1991-01-01

    In a recent technology assessment of alternative communication systems for the space exploration initiative (SEI), Ka-band (18 to 40 GHz) communication technology was identified to meet the mission requirements of telecommunication, navigation, and information management. Compared to the lower frequency bands, Ka-band antennas offer higher gain and broader bandwidths; thus, they are more suitable for high data rate communications. Over the years, NASA has played an important role in monolithic microwave integrated circuit (MMIC) phased array technology development, and currently, has an ongoing contract with Texas Instrument (TI) to develop a modular Ka-band MMIC microstrip subarray (NAS3-25718). The TI contract emphasizes MMIC integration technology development and stipulates using existing MMIC devices to minimize the array development cost. The objective of this paper is to present array component technologies and integration techniques used to construct the subarray modules.

  15. Studying NASA's Transition to Ka-Band Communications for Low Earth Orbit

    Science.gov (United States)

    Chelmins, David; Reinhart, Richard; Mortensen, Dale; Welch, Bryan; Downey, Joseph; Evans, Mike

    2014-01-01

    As the S-band spectrum becomes crowded, future space missions will need to consider moving command and telemetry services to Ka-band. NASAs Space Communications and Navigation (SCaN) Testbed provides a software-defined radio (SDR) platform that is capable of supporting investigation of this service transition. The testbed contains two S-band SDRs and one Ka-band SDR. Over the past year, SCaN Testbed has demonstrated Ka-band communications capabilities with NASAs Tracking and Data Relay Satellite System (TDRSS) using both open- and closed-loop antenna tracking profiles. A number of technical areas need to be addressed for successful transition to Ka-band. The smaller antenna beamwidth at Ka-band increases the criticality of antenna pointing, necessitating closed loop tracking algorithms and new techniques for received power estimation. Additionally, the antenna pointing routines require enhanced knowledge of spacecraft position and attitude for initial acquisition, versus an S-band antenna. Ka-band provides a number of technical advantages for bulk data transfer. Unlike at S-band, a larger bandwidth may be available for space missions, allowing increased data rates. The potential for high rate data transfer can also be extended for direct-to-ground links through use of variable or adaptive coding and modulation. Specific examples of Ka-band research from SCaN Testbeds first year of operation will be cited, such as communications link performance with TDRSS, and the effects of truss flexure on antenna pointing.

  16. REAL-TIME FADE MITIGATION USING RADIOMETRIC MEASUREMENTS FOR FUTURE KA-BAND SERVICES AT DLR.

    OpenAIRE

    2009-01-01

    Due to the congestion of popular C- and Ku-band frequencies, the satellite communication systems are rapidly moving toward the higher frequencies. Most of the commercial communication satellites in the near future will operate Ka-band transponders. One of the inevitable part of such systems are ground stations which support In-Orbit-testing and the traffic routine for the satellites. The main problem at Ka-band link planning is the link availability reduction due to rain fade and scintillatio...

  17. Mars Global Surveyor Ka-Band Frequency Data Analysis

    Science.gov (United States)

    Morabito, D.; Butman, S.; Shambayati, S.

    2000-01-01

    The Mars Global Surveyor (MGS) spacecraft, launched on November 7, 1996, carries an experimental space-to-ground telecommunications link at Ka-band (32 GHz) along with the primary X-band (8.4 GHz) downlink. The signals are simultaneously transmitted from a 1.5-in diameter parabolic high gain antenna (HGA) on MGS and received by a beam-waveguide (BWG) R&D 34-meter antenna located in NASA's Goldstone Deep Space Network (DSN) complex near Barstow, California. The projected 5-dB link advantage of Ka-band relative to X-band was confirmed in previous reports using measurements of MGS signal strength data acquired during the first two years of the link experiment from December 1996 to December 1998. Analysis of X-band and Ka-band frequency data and difference frequency (fx-fka)/3.8 data will be presented here. On board the spacecraft, a low-power sample of the X-band downlink from the transponder is upconverted to 32 GHz, the Ka-band frequency, amplified to I-W using a Solid State Power Amplifier, and radiated from the dual X/Ka HGA. The X-band signal is amplified by one of two 25 W TWTAs. An upconverter first downconverts the 8.42 GHz X-band signal to 8 GHz and then multiplies using a X4 multiplier producing the 32 GHz Ka-band frequency. The frequency source selection is performed by an RF switch which can be commanded to select a VCO (Voltage Controlled Oscillator) or USO (Ultra-Stable Oscillator) reference. The Ka-band frequency can be either coherent with the X-band downlink reference or a hybrid combination of the USO and VCO derived frequencies. The data in this study were chosen such that the Ka-band signal is purely coherent with the X-band signal, that is the downconverter is driven by the same frequency source as the X-band downlink). The ground station used to acquire the data is DSS-13, a 34-meter BWG antenna which incorporates a series of mirrors inside beam waveguide tubes which guide the energy to a subterranean pedestal room, providing a stable environment

  18. Modulation transfer functions at Ka band

    Science.gov (United States)

    Hesany, Vahid; Sistani, Bita; Salam, Asif; Haimov, Samuel; Gogineni, Prasad; Moore, Richard K.

    The modulation transfer function (MTF) is often used to describe the modulation of the radar signal by the long waves. MTFs were measured at 35 GHz (Ka band) with a switched-beam vector slope gauge/scatterometer on the research platform NORDSEE as part of the SAXON-FPN experiment. Three independent measurements of the scattering were available for each height measurement. This provided the opportunity to average the time series to reduce the effects of fading noise and sea spikes, or, alternatively, to append the time series to achieve more degrees of freedom in the spectral estimates. For upwind measurements, the phase of the VV-polarized Ka-band MTF was always positive, which implies that the maximum of the radar return originates from the forward face of the long-scale waves. This phase increases with increasing wind speed. The magnitude of the MTF decreases with increasing wind speed.

  19. Advances in Ka-Band Communication System for CubeSats and SmallSats

    Science.gov (United States)

    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.

  20. Design and Validation of High Date Rate Ka-Band Software Defined Radio for Small Satellite

    Science.gov (United States)

    Xia, Tian

    2016-01-01

    The Design and Validation of High Date Rate Ka- Band Software Defined Radio for Small Satellite project will develop a novel Ka-band software defined radio (SDR) that is capable of establishing high data rate inter-satellite links with a throughput of 500 megabits per second (Mb/s) and providing millimeter ranging precision. The system will be designed to operate with high performance and reliability that is robust against various interference effects and network anomalies. The Ka-band radio resulting from this work will improve upon state of the art Ka-band radios in terms of dimensional size, mass and power dissipation, which limit their use in small satellites.

  1. Ka-band waveguide rotary joint

    KAUST Repository

    Yevdokymov, Anatoliy

    2013-04-11

    The authors present a design of a waveguide rotary joint operating in Ka-band with central frequency of 33 GHz, which also acts as an antenna mount. The main unit consists of two flanges with a clearance between them; one of the flanges has three circular choke grooves. Utilisation of three choke grooves allows larger operating clearance. Two prototypes of the rotary joint have been manufactured and experimentally studied. The observed loss is from 0.4 to 0.8 dB in 1.5 GHz band.

  2. High Efficiency Ka-Band Spatial Combiner

    Directory of Open Access Journals (Sweden)

    D. Passi

    2014-12-01

    Full Text Available A Ka-Band, High Efficiency, Small Size Spatial Combiner (SPC is proposed in this paper, which uses an innovatively matched quadruple Fin Lines to microstrip (FLuS transitions. At the date of this paper and at the Author's best knowledge no such FLuS innovative transitions have been reported in literature before. These transitions are inserted into a WR28 waveguide T-junction, in order to allow the integration of 16 Monolithic Microwave Integrated Circuit (MMIC Solid State Power Amplifiers (SSPA's. A computational electromagnetic model using the finite elements method has been implemented. A mean insertion loss of 2 dB is achieved with a return loss better the 10 dB in the 31-37 GHz bandwidth.

  3. High power Ka band TWT amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Golkowski, C.; Ivers, J.D.; Nation, J.A.; Wang, P.; Schachter, L.

    1999-07-01

    Two high power 35 GHz TWT amplifiers driven by a relativistic pencil, 850 kV, 200A electron beam have been assembled and tested. The first had a dielectric slow wave structure and was primarily used to develop diagnostics, and to gain experience in working with high power systems in Ka band. The source of the input power for the amplifier was a magnetron producing a 30 kW, 200ns long pulse of which 10 kW as delivered to the experiment. The 30 cm long dielectric (Teflon) amplifier produced output power levels of about 1 MW with a gain of about 23 dB. These results are consistent with expectations from PIC code simulations for this arrangement. The second amplifier, which is a single stage disk loaded slow wave structure, has been designed. It consists of one hundred uniform cells with two sets of ten tapered calls at the ends to lower the reflection coefficient. The phase advance per cell is {pi}/2. The amplifier passband extends from 28 to 40 GHz. It is designed to increase the output power to about 20 MW. The amplifier is in construction and will be tested in the near future. Details of the design of both systems will be provided and initial results from the new amplifier presented.

  4. Overview of Ka-band communications technology requirements for the space exploration initiative

    Science.gov (United States)

    Miller, Edward F.

    1991-12-01

    In the Space Exploration Initiative, Ka-band frequencies are likely to carry the bulk of the communications traffic both in the vicinity of and on the return links from the moon and Mars. The four exploration architectures identified by the Synthesis Group are examined and Ka-band technology requirements to meet the data traffic needs and schedule are identified. Specific Ka-band technology requirements identified are: transmitters - 0.5 to 200 W with high efficiency; antennas - 5m and 9m diameter, with multiple beams and/or scanning beams; and spacecraft receivers - noise figure of 2 dB. For each component, the current state of technology is assessed and needed technology development programs are identified. It is concluded that to meet the schedules of lunar and Mars precursor missions beginning in approximately the year 2000, aggressive technology development and advanced development programs are required immediately for Ka-band communications systems components. Additionally, the greater data transmission rates for the cargo and piloted phases of the exploration program require further Ka-band communications technology developments targeted for operations beginning in about 2010.

  5. Mars Reconnaissance Orbiter: Ka Band Radio Science Experiments and the Effect of the Troposphere

    Science.gov (United States)

    Asmar, Sami W.; Morabito, David

    2006-01-01

    This viewgraph presentation reviews the possibilities of utilizing the telecommunication links between spacecraft and Earth to examine changes in the phase/frequency, amplitude, and polarization of radio signals to investigate, specifically for the Mars Reconnaissance Orbiter (MRO)mission utilizes X-band coherent (uplink and downlink) carrier Doppler and range for its gravity investigation Gravity team will also take advantage of Ka-band downlink signal Tropospheric calibration data from Advanced Water Vapor Radiometer (AWVR) will be used. The calibration of the received Ka band signal for the effect of the troposphere is discussed.

  6. Mars Reconnaissance Orbiter: Ka Band Radio Science Experiments and the Effect of the Troposphere

    Science.gov (United States)

    Asmar, Sami W.; Morabito, David

    2006-01-01

    This viewgraph presentation reviews the possibilities of utilizing the telecommunication links between spacecraft and Earth to examine changes in the phase/frequency, amplitude, and polarization of radio signals to investigate, specifically for the Mars Reconnaissance Orbiter (MRO)mission utilizes X-band coherent (uplink and downlink) carrier Doppler and range for its gravity investigation Gravity team will also take advantage of Ka-band downlink signal Tropospheric calibration data from Advanced Water Vapor Radiometer (AWVR) will be used. The calibration of the received Ka band signal for the effect of the troposphere is discussed.

  7. Results from Two Years of Ka-Band Propagation Characterization at Svalbard, Norway

    Science.gov (United States)

    Nessel, James A.; Morse, Jacquelynne Rose; Zemba, Michael

    2014-01-01

    Over the several years, NASA plans to launch several earth science missions which are expected to achieve data throughputs of 5-40 terabits per day transmitted from low earth orbiting spacecraft to ground stations. The current S-band and X-band frequency allocations in use by NASA, however, are incapable of supporting the data rates required to meet this demand. As such, NASA is in the planning stages to upgrade its existing Near Earth Network (NEN) Polar ground stations to support Ka-band (25.5-27 GHz) operations. Consequently, it becomes imperative that characterization of propagation effects at these NEN sites is conducted to determine expected system performance, particularly at low elevation angles ((is) less than 10 deg) where spacecraft signal acquisition typically occurs. Since May 2011, NASA Glenn Research Center has installed and operated a Ka-band radiometer at the NEN site located in Svalbard, Norway. The Ka-band radiometer monitors the water vapor line, as well as 6 frequencies around 26.5 GHz at multiple elevation angles: 45 deg, 20 deg, and 10 deg. Two year data collection results indicate comparable performance to previously characterized northern latitude sites in the United States, i.e., Fairbanks, Alaska. It is observed that cloud cover at the Svalbard site remains the dominant loss mechanism for Ka-band links, resulting in a margin requirement of 4.1 dB to maintain link availability of 99% at 10 deg elevation.

  8. Ka-Band MMIC T/R Module Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is specifically written to address the need for improved Ka-band T/R modules. The solicitation calls for investigation and development of core...

  9. Ka-Band MMIC T/R Module Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase II proposal is presented as the follow on to the Phase I SBIR contract number NNC06CB21C entitled "Ka-band MMIC T/R Module" For active microwave...

  10. A comparative study of RADAR Ka-band backscatter

    Science.gov (United States)

    Mapelli, D.; Pierdicca, N.; Guerriero, L.; Ferrazzoli, Paolo; Calleja, Eduardo; Rommen, B.; Giudici, D.; Monti Guarnieri, A.

    2014-10-01

    Ka-band RADAR frequency range has not yet been used for Synthetic Aperture Radar (SAR) from space so far, although this technology may lead to important applications for the next generation of SAR space sensors. Therefore, feasibility studies regarding a Ka-band SAR instrument have been started [1][2], for the next generation of SAR space sensors. In spite of this, the lack of trusted references on backscatter at Ka-band revealed to be the main limitation for the investigation of the potentialities of this technology. In the framework of the ESA project "Ka-band SAR backscatter analysis in support of future applications", this paper is aimed at the study of wave interaction at Ka-band for a wide range of targets in order to define a set of well calibrated and reliable Ka-band backscatter coefficients for different kinds of targets. We propose several examples of backscatter data resulting from a critical survey of available datasets at Ka-band, focusing on the most interesting cases and addressing both correspondences and differences. The reliability of the results will be assessed via a preliminary comparison with ElectroMagnetic (EM) theoretical models. Furthermore, in support of future technological applications, we have designed a prototypal software acting as a "library" of earth surface radar response. In our intention, the output of the study shall contribute to answer to the need of a trustworthy Ka-Band backscatter reference. It will be of great value for future technological applications, such as support to instrument analysis, design and requirements' definition (e.g.: Signal to Noise Ratio, Noise Equivalent Sigma Zero).

  11. SYSTEM MODELLING OF DTH BROADCASTING AT KA BAND MULTIBEAM SATELLITE SYSTEM OVER INDIA

    Directory of Open Access Journals (Sweden)

    Swastik Sahoo

    2015-12-01

    Full Text Available A major application of satellite is broadcasting and in India this is done at Ku band. But with the increase of demand of number of channels Ku band is getting saturated. So, to satisfy this requirement an approach is to go to higher frequency band, i.e. Ka band. As India is allocated with seven fixed GEO locations, so the purpose is to calculate what is the suitable satellite position for India at Ka band, what is the best EIRP available at that position and what will be the smallest ground antenna diameter and satellite antenna diameter at Ka band. Broadcasting is done at 20GHz Ka band downlink frequency. At this frequency, as the signal will face lots of impairments during propagation, so the attenuation caused by variety of factors are discussed here. To overcome the attenuation maximum EIRP is given. The link equation is taken as a reference to calculate quality of the signal, G/T ratio and EIRP of the satellite. The extreme west region of India is being taken as earth station and after some brief calculations all the results are discussed. Out of seven allocated GEO locations, 74⁰E gives best output in terms of minimum loss & small antenna diameters.

  12. Results from Three Years of Ka-Band Propagation Characterization at Svalbard, Norway

    Science.gov (United States)

    Nessel, James; Zemba, Michael; Morse, Jacquelynne

    2015-01-01

    Over the next several years, NASA plans to launch several earth science missions which are expected to achieve data throughputs of 5-40 terabits per day transmitted from low earth orbiting spacecraft to ground stations. The current S-band and X-band frequency allocations in use by NASA, however, are incapable of supporting the data rates required to meet this demand. As such, NASA is in the planning stages to upgrade its existing Near Earth Network (NEN) polar ground stations to support Ka-band (25.5-27 GHz) operations. Consequently, it installed and operated a Ka-band radiometer at the Svalbard site. Svalbard was chosen as the appropriate site for two primary reasons: (1) Svalbard will be the first site to be upgraded to Ka-band operations within the NEN Polar Network enhancement plan, and (2) there exists a complete lack of Ka-band propagation data at this site (as opposed to the Fairbanks, AK NEN site, which has 5 years of characterization collected during the Advanced Communications Technology becomes imperative that characterization of propagation effects at these NEN sites is conducted to determine expected system Satellite (ACTS) campaign). processing and provide the Herein, we discuss the data three-year measurement results performance, particularly at low elevation angles ((is) less than 10 deg) from the ongoing Ka-band propagation characterization where spacecraft signal acquisition typically occurs. Since May 2011, NASA Glenn Research Center has installed and operated a Ka-band radiometer at the NEN site located in Svalbard, Norway. The Ka-band radiometer monitors the water vapor line, as well as 4 frequencies around 26.5 GHz at a fixed 10 deg elevation angle. Three-year data collection results indicate good campaign at Svalbard, Norway. Comparison of these results with the ITU models and existing ERA profile data indicates very good agreement when the 2010 rain maps and cloud statistics are used. Finally, the Svalbard data is used to derive the expected

  13. Rain Fade Compensation for Ka-Band Communications Satellites

    Science.gov (United States)

    Mitchell, W. Carl; Nguyen, Lan; Dissanayake, Asoka; Markey, Brian; Le, Anh

    1997-01-01

    This report provides a review and evaluation of rain fade measurement and compensation techniques for Ka-band satellite systems. This report includes a description of and cost estimates for performing three rain fade measurement and compensation experiments. The first experiment deals with rain fade measurement techniques while the second one covers the rain fade compensation techniques. The third experiment addresses a feedback flow control technique for the ABR service (for ATM-based traffic). The following conclusions were observed in this report; a sufficient system signal margin should be allocated for all carriers in a network, that is a fixed clear-sky margin should be typically in the range of 4-5 dB and should be more like 15 dB in the up link for moderate and heavy rain zones; to obtain a higher system margin it is desirable to combine the uplink power control technique with the technique that implements the source information rate and FEC code rate changes resulting in a 4-5 dB increase in the dynamic part of the system margin. The experiments would assess the feasibility of the fade measurements and compensation techniques, and ABR feedback control technique.

  14. Ka-Band Phased Array System Characterization

    Science.gov (United States)

    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.

  15. X-/Ka-band dichroic plate noise temperature reduction

    Science.gov (United States)

    Veruttipong, W.; Lee, P.

    1994-11-01

    The X-/Ka-band (8.4 GHz/32.0 GHz) dichroic plate installed as DSS 13 contributes an estimated 3 K to the system noise temperature at 32.0 GHz. Approximately 1 percent of the Ka-band incident field is reflected by the plate into the 300-K environment of the DSS-13 pedestal room. A low-cost, easily implemented method of reducing the noise temperature is presented. Using a curved reflector, the reflected field can be re-focused into an 80-K cold load, reducing the noise temperature contribution of the dichroic plate by about 2 K.

  16. Ka-band MMIC subarray technology program (Ka-Mist)

    Science.gov (United States)

    Pottinger, W.

    1995-09-01

    Ka-band monolithic microwave integrated circuit (MMIC) arrays have been considered as having high potential for increasing the capability of space, aircraft, and land mobile communication systems in terms of scan performance, data rate, link margin, and flexibility while offering a significant reduction in size, weight, and power consumption. Insertion of MMIC technology into antenna systems, particularly at millimeter wave frequencies using low power and low noise amplifiers in closed proximity to the radiating elements, offers a significant improvement in the array transmit efficiency, receive system noise figure, and overall array reliability. Application of active array technology also leads to the use of advanced beamforming techniques that can improve beam agility, diversity, and adaptivity to complex signal environments. The objective of this program was to demonstrate the technical feasibility of the 'tile' array packaging architecture at EHF via the insertion of 1990 MMIC technology into a functional tile array or subarray module. The means test of this objective was to demonstrate and deliver to NASA a minimum of two 4 x 4 (16 radiating element) subarray modules operating in a transmit mode at 29.6 GHz. Available (1990) MMIC technology was chosen to focus the program effort on the novel interconnect schemes and packaging requirements rather than focusing on MMIC development. Major technical achievements of this program include the successful integration of two 4 x 4 subarray modules into a single antenna array. This 32 element array demonstrates a transmit EIRP of over 300 watts yielding an effective directive power gain in excess of 55 dB at 29.63 GHz. The array has been actively used as the transmit link in airborne/terrestrial mobile communication experiments accomplished via the ACTS satellite launched in August 1993.

  17. Reconfigurable phased antenna array for extending cubesat operations to Ka-band: Design and feasibility

    Science.gov (United States)

    Buttazzoni, G.; Comisso, M.; Cuttin, A.; Fragiacomo, M.; Vescovo, R.; Vincenti Gatti, R.

    2017-08-01

    Started as educational tools, CubeSats have immediately encountered the favor of the scientific community, subsequently becoming viable platforms for research and commercial applications. To ensure competitive data rates, some pioneers have started to explore the usage of the Ka-band beside the conventional amateur radio frequencies. In this context, this study proposes a phased antenna array design for Ka-band downlink operations consisting of 8×8 circularly polarized subarrays of microstrip patches filling one face of a single CubeSat unit. The conceived structure is developed to support 1.5 GHz bandwidth and dual-task missions, whose feasibility is verified by proper link budgets. The dual-task operations are enabled by a low-complexity phase-only control algorithm that provides pattern reconfigurability in order to satisfy both orbiting and intersatellite missions, while remaining adherent to the cost-effective CubeSat paradigm.

  18. Additive manufacturing of Ka-band antennas for wireless communications

    DEFF Research Database (Denmark)

    Armendariz, Unai; Rommel, Simon; Rodríguez Páez, Juan Sebastián

    2016-01-01

    This paper presents the design and fabrication of WR-28 waveguide horn antennas operating in the Ka-band frequency range between 26.5 GHz and 40 GHz through 3D printing. Three different antennas are fabricated from polylactide acid filaments in conductive and non-conductive variants; the latter...

  19. Analysis of Standards Efficiency in Digital Television Via Satellite at Ku and Ka Bands

    Directory of Open Access Journals (Sweden)

    Landeros-Ayala Salvador

    2013-06-01

    Full Text Available In this paper, an analysis on the main technical features of digital television standards for satellite transmission is carried out. Based on simulations and link budgets, the standard with the best operational performance is defined, based on simulations and link budget analysis, as well as a comparative efficiency analysis is conducted for the Ku and Ka bands for both transparent and regenerative transponders in terms of power, bandwidth, information rate and link margin, including clear sky, uplink rain, downlink rain and rain in both.

  20. Rain Fade Compensation Alternatives for Ka Band Communication Satellites

    Science.gov (United States)

    Acosta, Roberto J.

    1997-01-01

    Future satellite communications systems operating in Ka-band frequency band are subject to degradation produced by the troposphere which is much more severe than those found at lower frequency bands. These impairments include signal absorption by rain, clouds and gases, and amplitude scintillation's arising from refractive index irregularities. For example, rain attenuation at 20 GHz is almost three times that at 11 GHz. Although some of these impairments can be overcome by oversizing the ground station antennas and high power amplifiers, the current trend is using small (less than 20 inches apertures), low-cost ground stations (less than $1000) that can be easily deployed at user premises. As a consequence, most Ka-band systems are expected to employ different forms of fade mitigation that can be implemented relatively easily and at modest cost. The rain fade mitigation approaches are defined by three types of Ka-band communications systems - a low service rate (less than 1.5 Mb/s), a moderate service rate (1.5 to 6 Mb/s) system and a high service rate (greater than 43 Mb/s) system. The ACTS VSAT network, which includes an adaptive rain fade technique, is an example of a moderate service rate.

  1. Evaluation of Deep Space Ka-Band Data Transfer using Radiometeorological Forecasts and Radiometer Measurements

    Science.gov (United States)

    Montopoli, Mario; Marzano, Frank S.; Biscarini, Marianna; Milani, Luca; Cimini, Domenico; De Sanctis, Klaide; Di Fabio, Saverio

    2016-04-01

    Deep space exploration is aimed at acquiring information about the solar system. In this scenario, telecommunications links between Earth ground receiving stations and extra-terrestrial satellite platforms have to be designed in order to ensure the optimal transfer of the acquired scientific data back to the Earth. A significant communication capacity has to be planned when very large distances, as those characterising deep space links, are involved thus fostering more ambitious scientific mission requirements. At the current state of the art, two microwave channel frequencies are used to perform the deep space data transfer: X band (~ 8.4 GHz) and Ka band (~ 32 GHz) channel. Ka-band transmission can offer an advantage over X-band in terms of antenna performance with the same antenna effective area and an available data transfer bandwidth (50 times higher at Ka band than X band). However, Earth troposphere-related impairments can affects the space-to-Earth carrier signals at frequencies higher than 10 GHz by degrading its integrity and thus reducing the deep space channel temporal availability. Such atmospheric impairments, especially in terms of path attenuation, their statistic and the possibility to forecast them in the next 24H at the Earth's receiving station would allow a more accurate design of the deep space link, promoting the mitigation of the detrimental effects on the link availability. To pursue this aim, meteorological forecast models and in situ measurements need to be considered in order to characterise the troposphere in terms of signal path attenuation at current and future time. In this work, we want to show how the synergistic use of meteorological forecasts, radiative transfer simulations and in situ measurements such as microwave radiometry observations, rain gauges and radiosoundings, can aid the optimisation of a deep space link at Ka band and improve its performance with respect to usual practices. The outcomes of the study are in the

  2. Design of High Power Density Amplifiers: Application to Ka Band

    Science.gov (United States)

    Passi, Davide; Leggieri, Alberto; Di Paolo, Franco; Bartocci, Marco; Tafuto, Antonio

    2017-06-01

    Recent developments in the design of high-power-high-frequency amplifiers are assessed in this paper by the analysis and measurements of a high power density amplifier operating in the Ka Band. Design procedure is presented and a technical investigation is reported. The proposed device has shown over 23% of useful frequency bandwidth. It is an ensemble of 16 monolithic solid state power amplifiers that employees mixed technologies as spatial and planar combiners. Test performed have given maximum delivered power of 47.2 dBm.

  3. NASA SCaN Overview and Ka-Band Actvities

    Science.gov (United States)

    Stegeman, James D.; Midon, Marco Mario; Davarian, Faramaz; Geldzahler, Barry

    2014-01-01

    The Ka- and Broadband Communications Conference is an international forum attended by worldwide experts in the area of Ka-Band Propagation and satellite communications. Since its inception, NASA has taken the initiative of organizing and leading technical sections on RF Propagation and satellite communications, solidifying its worldwide leadership in the aforementioned areas. Consequently, participation in this conference through the contributions described below will maintain NASA leadership in Ka- and above RF Propagation as it relates to enhancing current and future satellite communication systems supporting space exploration.

  4. Ka-Band ARM Zenith Radar (KAZR) Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Widener, K; Bharadwaj, N; Johnson, K

    2012-03-06

    The Ka-band ARM zenith radar (KAZR) is a zenith-pointing Doppler cloud radar operating at approximately 35 GHz. The KAZR is an evolutionary follow-on radar to ARM's widely successful millimeter-wavelength cloud radar (MMCR). The main purpose of the KAZR is to provide vertical profiles of clouds by measuring the first three Doppler moments: reflectivity, radial Doppler velocity, and spectra width. At the sites where the dual-polarization measurements are made, the Doppler moments for the cross-polarization channel are also available. In addition to the moments, velocity spectra are also continuously recorded for each range gate.

  5. Ka-Band Site Characterization of the NASA Near Earth Network in Svalbard, Norway

    Science.gov (United States)

    Acosta, R.; Morse, J.; Nessel, J.; Zemba, M.; Tuttle, K.; Caroglanian, A.; Younes, B.; Pedersen, Sten-Chirstian

    2011-01-01

    Critical to NASA s rapid migration toward Ka-Band is the comprehensive characterization of the communication channels at NASA's ground sites to determine the effects of the atmosphere on signal propagation and the network's ability to support various classes of users in different orbits. Accordingly, NASA has initiated a number of studies involving the ground sites of its Near Earth and Deep Space Networks. Recently, NASA concluded a memorandum of agreement (MOA) with the Norwegian Space Centre of the Kingdom of Norway and began a joint site characterization study to determine the atmospheric effects on Ka-Band links at the Svalbard Satellite Station in Norway, which remains a critical component of NASA s Near Earth Communication Network (NEN). System planning and design for Ka-band links at the Svalbard site cannot be optimally achieved unless measured attenuation statistics (e.g. cumulative distribution functions (CDF)) are obtained. In general, the CDF will determine the necessary system margin and overall system availability due to the atmospheric effects. To statistically characterize the attenuation statistics at the Svalbard site, NASA has constructed a ground-based monitoring station consisting of a multi-channel total power radiometer (25.5 - 26.5 GHz) and a weather monitoring station to continuously measure (at 1 second intervals) attenuation and excess noise (brightness temperature). These instruments have been tested in a laboratory environment as well as in an analogous outdoor climate (i.e. winter in Northeast Ohio), and the station was deployed in Svalbard, Norway in May 2011. The measurement campaign is planned to last a minimum of 3 years but not exceeding a maximum of 5 years.

  6. Proposal for a Joint NASA/KSAT Ka-band RF Propagation Terminal at Svalbard, Norway

    Science.gov (United States)

    Volosin, Jeffrey; Acosta, Roberto; Nessel, James; McCarthy, Kevin; Caroglanian, Armen

    2010-01-01

    This slide presentation discusses the placement of a Ka-band RF Propagation Terminal at Svalbard, Norway. The Near Earth Network (NEN) station would be managed by Kongsberg Satellite Services (KSAT) and would benefit NASA and KSAT. There are details of the proposed NASA/KSAT campaign, and the responsibilities each would agree to. There are several reasons for the placement, a primary reason is comparison with the Alaska site, Based on climatological similarities/differences with Alaska, Svalbard site expected to have good radiometer/beacon agreement approximately 99% of time.

  7. A CDMA architecture for a Ka-band Personal Access Satellite System

    Science.gov (United States)

    Motamedi, Masoud; Sue, Miles K.

    1990-01-01

    A Code Division Multiple Access (CDMA) architecture is currently being studied for use in a Ka-band Personal Access Satellite System (PASS). The complete architecture consisting of block diagrams of the user terminal, the supplier station, the network management center, and the satellite is described along with the access methods and frequency/time plans. The complexity of developing this system using the CDMA architecture is compared to that of a Frequency Division Multiple Access (FDMA) architecture. The inherent advantages and disadvantages of the two architectures are compared and their respective capacities are discussed.

  8. Ka-Band Atmospheric Phase Stability Measurements in Goldstone, CA; White Sands, NM; and Guam

    Science.gov (United States)

    Zemba, Michael J.; Morse, Jacquelynne Rose; Nessel, James A.

    2014-01-01

    As spacecraft communication links are driven to higher frequencies (e.g. Ka-band) both by spectrum congestion and the appeal of higher data rates, the propagation phenomena at these frequencies must be well characterized for effective system design. In particular, the phase stability of a site at a given frequency will govern whether or not the site is a practical location for an antenna array, particularly if uplink capabilities are desired. Propagation studies to characterize such phenomena must be done on a site-by-site basis due to the wide variety of climates and weather conditions at each ground terminal. Accordingly, in order to statistically characterize the atmospheric effects on Ka-Band links, site test interferometers (STIs) have been deployed at three of NASA's operational sites to directly measure each site's tropospheric phase stability. Using three years of results from these experiments, this paper will statistically characterize the simultaneous atmospheric phase noise measurements recorded by the STIs deployed at the following ground station sites: the Goldstone Deep Space Communications Complex near Barstow, CA; the White Sands Ground Terminal near Las Cruces, NM; and the Guam Remote Ground Terminal on the island of Guam.

  9. Ka-Band Transponder for Deep-Space Radio Science

    Science.gov (United States)

    Dennis, Matthew S.; Mysoor, Narayan R.; Folkner, William M.; Mendoza, Ricardo; Venkatesan, Jaikrishna

    2008-01-01

    A one-page document describes a Ka-band transponder being developed for use in deep-space radio science. The transponder receives in the Deep Space Network (DSN) uplink frequency band of 34.2 to 34.7 GHz, transmits in the 31.8- to 32.3 GHz DSN downlink band, and performs regenerative ranging on a DSN standard 4-MHz ranging tone subcarrier phase-modulated onto the uplink carrier signal. A primary consideration in this development is reduction in size, relative to other such transponders. The transponder design is all-analog, chosen to minimize not only the size but also the number of parts and the design time and, thus, the cost. The receiver features two stages of frequency down-conversion. The receiver locks onto the uplink carrier signal. The exciter signal for the transmitter is derived from the same source as that used to generate the first-stage local-oscillator signal. The ranging-tone subcarrier is down-converted along with the carrier to the second intermediate frequency, where the 4-MHz tone is demodulated from the composite signal and fed into a ranging-tone-tracking loop, which regenerates the tone. The regenerated tone is linearly phase-modulated onto the downlink carrier.

  10. Design of Ka-band antipodal finline mixer and detector

    Institute of Scientific and Technical Information of China (English)

    Yao Changfei; Xu Jinping; Chen Mo

    2009-01-01

    This paper mainly discusses the analysis and design of a finline single-ended mixer and detector. In the circuit, for the purpose of eliminating high-order resonant modes and improving transition loss, metallic via holes are implemented along the mounting edge of the substrate embedded in the split-block of the WG-finline-microstrip transition. Meanwhile, a Ka band slow-wave and bandstop filter, which represents a reactive termination, is designed for the utilization of idle frequencies and operation frequencies energy. Full-wave analysis is carried out to optimize the input matching network of the mixer and the detector circuit using lumped elements to model the nonlinear diode. The exported S-matrix of the optimized circuit is used for conversion loss and voltage sensitivity analysis.The lowest measured conversion loss is 3.52 dB at 32.2 GHz; the conversion loss is flat and less than 5.68 dB in the frequency band of 29-34 GHz. The highest measured zero-bias voltage sensitivity is 1450 mV/mW at 38.6 GHz,and the sensitivity is better than 1000 mV/mW in the frequency band of 38-40 GHz.

  11. Simultaneous Ka-Band Site Characterization: Goldstone, CA, White Sands, NM, and Guam, USA

    Science.gov (United States)

    Acosta, Roberto; Morse, Jacquelynne; Zemba, Michael; Nessel, James; Morabito, David; Caroglanian, Armen

    2011-01-01

    To statistically characterize atmospheric effects on Ka-band links at NASA operational sites, NASA has constructed site test interferometers (STI s) which directly measure the tropospheric phase stability and rain attenuation. These instruments observe an unmodulated beacon signal broadcast from a geostationary satellite (e.g., Anik F2) and measure the phase difference between the signals received by the two antennas and its signal attenuation. Three STI s have been deployed so far: the first one at the NASA Deep Space Network Tracking Complex in Goldstone, California (May 2007); the second at the NASA White Sands Complex, in Las Cruses, New Mexico (February 2009); and the third at the NASA Tracking and Data Relay Satellite (TDRS) Remote Ground Terminal (GRGT) complex in Guam (May 2010). Two station-years of simultaneous atmospheric phase fluctuation data have been collected at Goldstone and White Sands, while one year of data has been collected in Guam. With identical instruments operating simultaneously, we can directly compare the phase stability and rain attenuation at the three sites. Phase stability is analyzed statistically in terms of the root-mean-square (rms) of the tropospheric induced time delay fluctuations over 10 minute blocks. For two years, the time delay fluctuations at the DSN site in Goldstone, CA, have been better than 2.5 picoseconds (ps) for 90% of the time (with reference to zenith), meanwhile at the White Sands, New Mexico site, the time delay fluctuations have been better than 2.2 ps with reference to zenith) for 90% of time. For Guam, the time delay fluctuations have been better than 12 ps (reference to zenith) at 90% of the time, the higher fluctuations are as expected from a high humidity tropical rain zone. This type of data analysis, as well as many other site quality characteristics (e.g., rain attenuation, infrastructure, etc.) will be used to determine the suitability of all the sites for NASA s future communication services at Ka-band.

  12. A Novel Ku-Band/Ka-Band and Ka-Band/E-Band Multimode Waveguide Couplers for Power Measurement of Traveling-Wave Tube Amplifier Harmonic Frequencies

    Science.gov (United States)

    Wintucky, Edwin G.; Simons, Rainee N.

    2015-01-01

    This paper presents the design, fabrication and test results for a novel waveguide multimode directional coupler (MDC). The coupler, fabricated from two dissimilar frequency band waveguides, is capable of isolating power at the second harmonic frequency from the fundamental power at the output port of a traveling-wave tube (TWT) amplifier. Test results from proof-of-concept demonstrations are presented for a Ku-band/Ka-band MDC and a Ka-band/E-band MDC. In addition to power measurements at harmonic frequencies, a potential application of the MDC is in the design of a satellite borne beacon source for atmospheric propagation studies at millimeter-wave (mm-wave) frequencies (Ka-band and E-band).

  13. High Performance Ka-band Phase Shifters for Space Telecommunications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a novel MEMS-based digital phase shifter targeted for Ka-band operation, but scalable down to X-band and up to W-band. This novel phase shifter will...

  14. MMIC for High-Efficiency Ka-BAnd GaN Power Amplifiers (2007043) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses the need for high-efficiency, high-output power amplifiers operating in the Ka-band frequencies. For space communications, the power...

  15. Solid State KA-Band, Solid State W-Band and TWT Amplifiers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Phase I of the proposal describes plans to develop a state of the art transmitter for the W-Band and KA -Band Cloud Radar system. Our focus will be concentrated in...

  16. High Performance Ka Band Power Amplifiers for Future EVA Radio Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, AlphaSense, Inc. and the University of Washington detail the development of a novel, high performance Ka band power amplifier for EVA radio...

  17. High-power X- and Ka-band Gallium Nitride Amplifiers with Exceptional Efficiency Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Achieving very high-power amplification with maximum efficiency at X- and Ka-band is challenging using solid-state technology. Gallium Arsenide (GaAs) has been the...

  18. Ka Band Parabolic Deployable Antenna (KaPDA) for Interplanetary CubeSat Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ka Band Parabolic Deployable Antenna (KaPDA) for Interplanetary CubeSat Communications allowing moving up from UHF, S or X to get higher gain for a given diameter.

  19. NASA's Evolution to Ka-Band Space Communications for Near-Earth Spacecraft

    Science.gov (United States)

    McCarthy, Kevin; Stocklin, Frank; Geldzahler, Barry; Friedman, Daniel; Celeste, Peter

    2010-01-01

    This slide presentation reviews the exploration of NASA using a Ka-band system for spacecraft communications in Near-Earth orbits. The reasons for changing to Ka-band are the higher data rates, and the current (X-band spectrum) is becoming crowded. This will require some modification to the current ground station antennas systems. The results of a Request for Information (RFI) are discussed, and the recommended solution is reviewed.

  20. The Potential for a Ka-band (32 GHz) Worldwide VLBI Network

    Science.gov (United States)

    Jacobs, C. S.; Bach, U.; Colomer, F.; Garcia-Miro, C.; Gomez-Gonzalez, J.; Gulyaev, S.; Horiuchi, S.; Ichikawa, R.; Kraus, A.; Kronschnabl, G.; Lopez-Fernandez, J. A.; Lovell, J.; Majid, W.; Natusch, T.; Neidhardt, A.; Phillips, C.; Porcas, R.; Romero-Wolf, A.; Saldana, L.; Schreiber, U.; Sotuela, I.; Takeuchi, H.; Trinh, J.; Tzioumis, A.; deVincente, P.

    2012-01-01

    Ka-band (32 GHz, 9mm) Very Long Baseline Interferometric (VLBI) networking has now begun and has tremendous potential for expansion over the next few years. Ka-band VLBI astrometry from NASA's Deep Space Network has already developed a catalog of 470 observable sources with highly accurate positions. Now, several antennas worldwide are planning or are considering adding Ka-band VLBI capability. Thus, there is now an opportunity to create a worldwide Ka-band network with potential for high resolution imaging and astrometry. With baselines approaching a Giga-lambda, a Ka-band network would be able to probe source structure at the nano-radian (200 as) level ( 100X better than Hubble) and thus gain insight into the astrophysics of the most compact regions of emission in active galactic nuclei. We discuss the advantages of Ka-band, show the known sources and candidates, simulate projected baseline (uv) coverage, and discuss potential radio frequency feeds. The combination of these elements demonstrates the feasibility of a worldwide Ka network within the next few years!

  1. A Ka-band Celestial Reference Frame with Applications to Deep Space Navigation

    Science.gov (United States)

    Jacobs, Christopher S.; Clark, J. E.; García-Miró, C.; Horiuchi, S.; Sotuela, I.

    2011-10-01

    The Ka-band radio spectrum is now being used for a wide variety of applications. This paper highlights the use of Ka-band as a frequency for precise deep space navigation based on a set of reference beacons provided by extragalactic quasars which emit broadband noise at Ka-band. This quasar-based celestial reference frame is constructed using X/Ka-band (8.4/32 GHz) from fifty-five 24-hour sessions with the Deep Space Network antennas in California, Australia, and Spain. We report on observations which have detected 464 sources covering the full 24 hours of Right Ascension and declinations down to -45 deg. Comparison of this X/Ka-band frame to the international standard S/X-band (2.3/8.4 GHz) ICRF2 shows wRMS agreement of ~200 micro-arcsec (μas) in α cos δ and ~300 μas in δ. There is evidence for systematic errors at the 100 μas level. Known errors include limited SNR, lack of instrumental phase calibration, tropospheric refraction mis-modeling, and limited southern geometry. The motivation for extending the celestial reference frame to frequencies above 8 GHz is to access more compact source morphology for improved frame stability and to support spacecraft navigation for Ka-band based NASA missions.

  2. A Ka-Band Celestial Reference Frame with Applications to Deep Space Navigation

    Science.gov (United States)

    Jacobs, Christopher S.; Clark, J. Eric; Garcia-Miro, Cristina; Horiuchi, Shinji; Sotuela, Ioana

    2011-01-01

    The Ka-band radio spectrum is now being used for a wide variety of applications. This paper highlights the use of Ka-band as a frequency for precise deep space navigation based on a set of reference beacons provided by extragalactic quasars which emit broadband noise at Ka-band. This quasar-based celestial reference frame is constructed using X/Ka-band (8.4/32 GHz) from fifty-five 24-hour sessions with the Deep Space Network antennas in California, Australia, and Spain. We report on observations which have detected 464 sources covering the full 24 hours of Right Ascension and declinations down to -45 deg. Comparison of this X/Ka-band frame to the international standard S/X-band (2.3/8.4 GHz) ICRF2 shows wRMS agreement of approximately 200 micro-arcsec in alpha cos(delta) and approximately 300 micro-arcsec in delta. There is evidence for systematic errors at the 100 micro-arcsec level. Known errors include limited SNR, lack of instrumental phase calibration, tropospheric refraction mis-modeling, and limited southern geometry. The motivation for extending the celestial reference frame to frequencies above 8 GHz is to access more compact source morphology for improved frame stability and to support spacecraft navigation for Ka-band based NASA missions.

  3. The Potential for a Ka-band (32 GHz) Worldwide VLBI Network

    Science.gov (United States)

    Jacobs, C. S.; Bach, U.; Colomer, F.; Garcia-Miro, C.; Gomez-Gonzalez, J.; Gulyaev, S.; Horiuchi, S.; Ichikawa, R.; Kraus, A.; Kronschnabl, G.; hide

    2012-01-01

    Ka-band (32 GHz, 9mm) Very Long Baseline Interferometric (VLBI) networking has now begun and has tremendous potential for expansion over the next few years. Ka-band VLBI astrometry from NASA's Deep Space Network has already developed a catalog of 470 observable sources with highly accurate positions. Now, several antennas worldwide are planning or are considering adding Ka-band VLBI capability. Thus, there is now an opportunity to create a worldwide Ka-band network with potential for high resolution imaging and astrometry. With baselines approaching a Giga-lambda, a Ka-band network would be able to probe source structure at the nano-radian (200 as) level ( 100X better than Hubble) and thus gain insight into the astrophysics of the most compact regions of emission in active galactic nuclei. We discuss the advantages of Ka-band, show the known sources and candidates, simulate projected baseline (uv) coverage, and discuss potential radio frequency feeds. The combination of these elements demonstrates the feasibility of a worldwide Ka network within the next few years!

  4. Ka-band Technologies for Small Spacecraft Communications via Relays and Direct Data Downlink

    Science.gov (United States)

    Budinger, James M.; Niederhaus, Charles; Reinhart, Richard; Downey, Joe; Roberts, Anthony

    2016-01-01

    As the scientific capabilities and number of small spacecraft missions in the near Earth region increase, standard yet configurable user spacecraft terminals operating in Ka-band are needed to lower mission cost and risk and enable significantly higher data return than current UHF or S-band terminals. These compact Ka-band terminals are intended to operate with both the current and next generation of Ka-band relay satellites and via direct data communications with near Earth tracking terminals. This presentation provides an overview of emerging NASA-sponsored and commercially provided technologies in software defined radios (SDRs), transceivers, and electronically steered antennas that will enable data rates from hundreds of kbps to over 1 Gbps and operate in multiple frequency bands (such as S- and X-bands) and expand the use of NASA's common Ka-bands frequencies: 22.55-23.15 GHz for forward data or uplink; and 25.5-27.0 GHz for return data or downlink. Reductions in mass, power and volume come from integration of multiple radio functions, operations in Ka-band, high efficiency amplifiers and receivers, and compact, flat and vibration free electronically steered narrow beam antennas for up to + 60 degrees field of regard. The software defined near Earth space transceiver (SD-NEST) described in the presentation is intended to be compliant with NASA's space telecommunications radio system (STRS) standard for communications waveforms and hardware interoperability.

  5. Fabrication of band-pass filter using YBCO film at Ka-band frequency; YBCO hakumaku wo mochiita Ka-band taiiki tsuka fuiruta no sakusei

    Energy Technology Data Exchange (ETDEWEB)

    Yoshitake, T.; Hattori, W.; Murakami, S.; Suzuki, S. [NEC Corp., Tokyo (Japan)

    1999-11-10

    In this report, Ka band microstrip band pass filter was produced experimentally using an YBCO system high temperature superconductivity thin film as examination initial stage high temperature superconductivity a thin film superscription communication element. With it, the following were examined: Evaluation method and frequency characteristics of the filter. Especially, the examination on structure of the package and system of measurement using refrigerating machine becomes important in order to evaluate the filter with the high frequency. (NEDO)

  6. Weather Forecasting for Ka-band Operations: Initial Study Results

    Science.gov (United States)

    Morabito, D.; Wu, L.; Slobin, S.

    2016-08-01

    As lower frequency bands (e.g., 2.3 GHz and 8.4 GHz) have become oversubscribed during the past several decades, NASA has become interested in using higher frequency bands (e.g., 26 GHz and 32 GHz) for telemetry, thus making use of the available wider bandwidth. However, these bands are more susceptible to atmospheric degradation. Currently, flight projects tend to be conservative in preparing their communications links by using worst-case or conservative assumptions. Such assumptions result in nonoptimum data return. We explore the use of weather forecasting for Goldstone and Madrid for different weather condition scenarios to determine more optimal values of atmospheric attenuation and atmospheric noise temperature for use in telecommunication link design. We find that the use of weather forecasting can provide up to 2 dB or more of increased data return when more favorable conditions are forecast. Future plans involve further developing the technique for operational scenarios with interested flight projects.

  7. Design of a Ka-Band Propagation Terminal for Atmospheric Measurements in Polar Regions

    Science.gov (United States)

    Houts, Jacquelynne R.; Nessel, James A.; Zemba, Michael J.

    2016-01-01

    This paper describes the design and performance of a Ka-Band beacon receiver developed at NASA Glenn Research Center (GRC) that will be installed alongside an existing Ka-Band Radiometer [2] located at the east end of the Svalbard Near Earth Network (NEN) complex. The goal of this experiment is to characterize rain fade attenuation to improve the performance of existing statistical rain attenuation models. The ground terminal developed by NASA GRC utilizes an FFT-based frequency estimation [3] receiver capable of characterizing total path attenuation effects due to gaseous absorption, clouds, rain, and scintillation by directly measuring the propagated signal from the satellite Thor 7.

  8. Design of a Ka-band Propagation Terminal for Atmospheric Measurements in Polar Regions

    Science.gov (United States)

    Houts, Jacquelynne R.; Nessel, James A.; Zemba, Michael J.

    2016-01-01

    This paper describes the design and performance of a Ka-Band beacon receiver developed at NASA Glenn Research Center (GRC) that will be installed alongside an existing Ka-Band Radiometer located at the east end of the Svalbard Near Earth Network (NEN) complex. The goal of this experiment is to characterize rain fade attenuation to improve the performance of existing statistical rain attenuation models. The ground terminal developed by NASA GRC utilizes an FFT-based frequency estimation receiver capable of characterizing total path attenuation effects due to gaseous absorption, clouds, rain, and scintillation by directly measuring the propagated signal from the satellite Thor 7.

  9. Computer Aided Design of Ka-Band Waveguide Power Combining Architectures for Interplanetary Spacecraft

    Science.gov (United States)

    Vaden, Karl R.

    2006-01-01

    Communication systems for future NASA interplanetary spacecraft require transmitter power ranging from several hundred watts to kilowatts. Several hybrid junctions are considered as elements within a corporate combining architecture for high power Ka-band space traveling-wave tube amplifiers (TWTAs). This report presents the simulated transmission characteristics of several hybrid junctions designed for a low loss, high power waveguide based power combiner.

  10. Steerable K/Ka-Band Antenna For Land-Mobile Satellite Applications

    Science.gov (United States)

    Densmore, Arthur; Jamnejad, Vahraz; Woo, Kenneth

    1994-01-01

    Prototype steerable microwave antenna tracks and communicates with geostationary satellite. Designed to mount on roof of vehicle and only 10 cm tall. K/Ka-band antenna rugged and compact to suit rooftop mobile operating environment. More-delicate signal-processing and control equipment located inside vehicle.

  11. Evaluation and Performance Analysis of 3D Printing Technique for Ka-Band Antenna Production

    DEFF Research Database (Denmark)

    Armendariz, Unai; Rommel, Simon; Rodríguez Páez, Juan Sebastián

    2016-01-01

    This paper presents the design and fabrication of 3D printed WR-28 waveguide horn antennas operating in the Ka-band frequency range between 26.5GHz and 40GHz. Three antennas are fabricated from polylactide acid filaments in conductive and non-conductive variants; the latter is covered...

  12. Design of a Ka-band gyro-TWT amplifier for broadband operation

    Energy Technology Data Exchange (ETDEWEB)

    Alaria, Mukesh Kumar; Sinha, A. K. [Microwave Tubes Area, CSIR-Central Electronics Engineering Research Institute, Pilani 333031 (India); Choyal, Y. [Department of Physics, Devi Ahilya Vishwavidyalaya, Indore (India)

    2013-07-15

    In this paper, the design of a Ka-band periodically ceramic loaded gyro-TWT amplifier has been carried out. The design predict that the interaction structure can produce more than 80 kW output power, 50 dB saturated gain, and 3 dB bandwidth for 65 kV and 5 A electron beam with velocity ratio (α) of 1.2. This paper describes the design and simulation of a high performance 35 GHz TE{sub 01} mode gyro-TWT that applies the same technique of employing a periodic dielectric loaded interaction structure to achieve stability and wide bandwidth. The design of input coupler with loaded interaction structure for Ka-band Gyro-TWT has been carried out using Ansoft hfss. The return loss (S{sub 11}) and transmission loss (S{sub 21}) of the Ka-band gyro-TWT input coupler have been found to be −27.3 dB and −0.05 dB, respectively. The design of output window for Ka-band Gyro-TWT has been carried out using cst microwave studio.

  13. High Power High Efficiency Ka-Band Power Combiners for Solid-State Devices

    Science.gov (United States)

    Freeman, Jon C.; Wintucky, Edwin G.; Chevalier, Christine T.

    2006-01-01

    Wide-band power combining units for Ka-band are simulated for use as MMIC amplifier applications. Short-slot couplers as well as magic-tees are the basic elements for the combiners. Wide bandwidth (5 GHz) and low insertion (approx.0.2 dB) and high combining efficiencies (approx.90 percent) are obtained.

  14. Performance of a Ka-band transponder breadboard for deep-space applications

    Science.gov (United States)

    Mysoor, N. R.; Lane, J. P.; Kayalar, S.; Kermode, A. W.

    1995-08-01

    This article summarizes the design concepts applied in the development of and advanced Ka-band (34.4 GHz/32 GHz) transponder breadboard for the next generation of space communications systems applications. The selected architecture upgrades the X-band (7.2 GHz/8.4 GHz) deep-space transponder (DST) to provide Da-band up/Ka- and X-band down capability. The Ka-band transponder breadboard incorporates several state-of-the-art components, including sampling mixers, a Ka-band dielectric resonator oscillator, and microwave monolithic integrated circuits (MMICs). The MMICs that were tested in the breadboard include upconverters, downconverters, automatic gain control circuits, mixers, phase modulators, and amplifiers. The measured receiver dynamic range, tracking range, acquisition rate, static phase error, and phase jitter characteristics of the Ka-band breadboard interfaced to the advanced engineering model X-band DST are in good agreement with the expected performance. The results show a receiver tracking threshold of -149 dBm with a dynamic range of 80 dB and a downlink phase jitter of 7 deg rms. The analytical results of phase noise and Allan standard deviation are in good agreement with the experimental results.

  15. Ka-Band PAA for Satellite Telemetry System for RLVs & Aircraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed antenna is a Radial-Waveguide Array (RWA) that will operate at Ka band, 25.5-27.5 GHz in transmit and receive for left-hand, right-hand. This Phase I...

  16. Dichroic Filter for Separating W-Band and Ka-Band

    Science.gov (United States)

    Epp, Larry W.; Durden, Stephen L.; Jamnejad, Vahraz; Long, Ezra M.; Sosnowski, John B.; Higuera, Raymond J.; Chen, Jacqueline C.

    2012-01-01

    The proposed Aerosol/Cloud/Ecosystems (ACEs) mission development would advance cloud profiling radar from that used in CloudSat by adding a 35-GHz (Ka-band) channel to the 94-GHz (W-band) channel used in CloudSat. In order to illuminate a single antenna, and use CloudSat-like quasi-optical transmission lines, a spatial diplexer is needed to add the Ka-band channel. A dichroic filter separates Ka-band from W-band by employing advances in electrical discharge machining (EDM) and mode-matching analysis techniques developed and validated for designing dichroics for the Deep Space Network (DSN), to develop a preliminary design that both met the requirements of frequency separation and mechanical strength. First, a mechanical prototype was built using an approximately 102-micron-diameter EDM process, and tolerances of the hole dimensions, wall thickness, radius, and dichroic filter thickness measured. The prototype validated the manufacturing needed to design a dichroic filter for a higher-frequency usage than previously used in the DSN. The initial design was based on a Ka-band design, but thicker walls are required for mechanical rigidity than one obtains by simply scaling the Ka-band dichroic filter. The resulting trade of hole dimensions for mechanical rigidity (wall thickness) required electrical redesign of the hole dimensions. Updates to existing codes in the linear solver decreased the analysis time using mode-matching, enabling the electrical design to be realized quickly. This work is applicable to missions and instruments that seek to extend W-band cloud profiling measurements to other frequencies. By demonstrating a dichroic filter that passes W-band, but reflects a lower frequency, this opens up the development of instruments that both compare to and enhance CloudSat.

  17. Study of rain attenuation in Ka band for satellite communication in South Korea

    Science.gov (United States)

    Shrestha, Sujan; Choi, Dong-You

    2016-10-01

    The important factor to be considered in the link budget estimation for satellite communication systems, operating at frequencies above 10 GHz is the rain attenuation. Scattering and absorption are the main concern for system designers at these frequency bands. This has resulted in the need for suitable prediction models that can best provide estimates of attenuation due to rain with available information of rain attenuation data. Researchers have developed models that can be used to estimate 1-min rainfall attenuation distribution for earth space link but there is still some confusion with regard to choosing the right model to predict attenuation for the location of interest. In this context, the existing prediction models need to be tested against the measured results. This paper presents studies on rain attenuation at 19.8 GHz, which specifies the performance parameters for Ka-Band under earth space communication system. It presents the experimental result of rain rates and rain-induced attenuation in 19.8 and 20.73 GHz for vertical and circular polarization respectively. The received signal data for rain attenuation and rain rate were collected at 10 s intervals over a three year periods from 2013 to 2015. The data highlights the impact of clear air variation and rain fade loss. Rain rate data was measured through OTT Parsivel. During the observation period, rain rates of about 50 mm/h and attenuation values of 11.6 dB for 0.01% of the time were noted. The experimental link was set up at Korea Radio Promotion Association, Mokdong, Seoul. Out of several models, this paper present discussion and comparison of ITU-R P.618-12, Unified Method, Dissanayake Allnutt and Haidara (DAH), Simple Attenuation (SAM), Crane Global and Ramachandran and Kumar models. The relative error margin of 27.51, 89.84,72.46% and 67.24, 130.84, 166.48% are obtained for 0.1%, 0.01% and 0.001% of the time for 19.8 and 20.73 GHz under vertical and circular polarization respectively from ITU

  18. Linked data management

    CERN Document Server

    Hose, Katja; Schenkel, Ralf

    2014-01-01

    Linked Data Management presents techniques for querying and managing Linked Data that is available on today’s Web. The book shows how the abundance of Linked Data can serve as fertile ground for research and commercial applications. The text focuses on aspects of managing large-scale collections of Linked Data. It offers a detailed introduction to Linked Data and related standards, including the main principles distinguishing Linked Data from standard database technology. Chapters also describe how to generate links between datasets and explain the overall architecture of data integration systems based on Linked Data. A large part of the text is devoted to query processing in different setups. After presenting methods to publish relational data as Linked Data and efficient centralized processing, the book explores lookup-based, distributed, and parallel solutions. It then addresses advanced topics, such as reasoning, and discusses work related to read-write Linked Data for system interoperation. Desp...

  19. Experimental characterization of negative refractive index material NRM at Ka band

    CERN Document Server

    Chatterjee, Sougata

    2016-01-01

    In this paper, we discuss the experimental characterization of a negative refractive material NRM at Ka band using LR labyrinth Ring and wire array WA. We describe in detail the the LR and wire array characterization separately, and after that the combined experimental results, for NRM are reported. The LRs analytical and simulation study is not new but design in Ka band and different experimental procedure for the characterization of the negative refractive index is the novelty of this paper. For performing a negative refractive index experiment we made prism of 150 Prism angle . We get enhanced transmittance of more than 20 dB from background, at a negative angle of refraction. The values of the negative refractive index in a band of about 1 G Hz around 31 GHz are retrieved from the experimental data.

  20. DESIGN, FABRICATION AND RF CHARACTERIZATION OF KA-BAND SILICON IMPATT DIODE

    Directory of Open Access Journals (Sweden)

    TAPAS KUMAR PAL,

    2010-09-01

    Full Text Available A silicon (p+nn+ SDR IMPATT diode for Ka-band operation has been designed by using a double iterative DC and Small signal simulation which involves simultaneous solution of Poisson’s equation and Carrier continuity equation, satisfying appropriate boundary conditions in the depletion layer edges. Using the design parameters,silicon epitaxial n/n+ wafers of appropriate thickness and resistivity of the epitaxial layer have been selected for fabrication of (p+nn+ SDR IMPATT diode for Ka-band operation. The (p+nn+ SDR IMPATT diode has been fabricated through diffusion technique. The optimized process steps of fabrication, starting from wafer cleaningto packaging have been described in details. The DC V-I and RF characteristics of fabricated IMPATT diode have been measured by using an integrated heat sink cum resonant cap waveguide cavity.

  1. Ka-band InSAR Imaging and Analysis Based on IMU Data

    Directory of Open Access Journals (Sweden)

    Shi Jun

    2014-02-01

    Full Text Available Compared with other bands, the millimeter wave Interferometric Synthetic Aperture Radar (InSAR has high accuracy and small size, which is a hot topic in InSAR research. On the other hand, shorter wavelength causes difficulties in 2D imaging and interferometric phase extraction. In this study, the imaging and phase performance of the streaming Back Projection (BP method combined with IMU data are analyzed and discussed on the basis of actual Ka-band InSAR data. It is found that because the wavelength of the Ka-band is short, it is more sensitive to the antenna phase-center history. To ensure the phase-preserving capacity, the IMU data must be used with accurate motion error compensation. Furthermore, during data processing, we verify the flat-earth-removing capacity of the BP algorithm that calculates and compensates the master and slave antenna phase centers individually.

  2. A satellite system for multimedia personal communications at Ka-band and beyond

    Science.gov (United States)

    Vatalaro, F.; Losquadro, G.

    1995-01-01

    The main characteristics of the satellite extremely high frequency (EHF) communication of multimedia mobile services (SECOMS) system are given and the results of the preliminary analysis are included. The SECOMS provides a first generation Ka band system with coverage over Western Europe, in order to satisfy business user needs of very large bandwidths and terminal mobility. The satellite system also provides a second generation EHF enhanced system with increased capacity and enlarged coverage, to serve all of Europe and the nearby countries.

  3. A K/Ka band radiating element for Tx/Rx phased array

    KAUST Repository

    Sandhu, Ali Imran

    2017-01-20

    The paper presents a K/Ka band radiating element for TX/RX phased arrays. Dual band operations is obtained using a single radiating surface: a novel radiator is adopted and placed in a configuration in which dual band and single band elements are interleaved. The array elements are optimized to scan the beam in excess of 50° in both bands. A subarray with 49 Rx elements and 105 Tx elements was built and measured confirming the results obtained in simulations.

  4. Calibration of the KA Band Tracking of the Bepi-Colombo Spacecraft (more Experiment)

    Science.gov (United States)

    Barriot, J.; Serafini, J.; Sichoix, L.

    2013-12-01

    The radiosciences Bepi-Colombo MORE experiment will use X/X, X/Ka and Ka/Ka band radio links to make accurate measurements of the spacecraft range and range rate. Tropospheric zenith wet delays range from 1.5 cm to 10 cm, with high variability (less than 1000 s) and will impair these accurate measurements. Conditions vary from summer (worse) to winter (better), from day (worse) to night (better). These wet delays cannot be estimated from ground weather measurements and alternative calibration methods should be used in order to cope with the MORE requirements (no more than 3 mm at 1000 s). Due to the Mercury orbit, MORE measurements will be performed by daylight and more frequently in summer than in winter (from Northern hemisphere). Two systems have been considered to calibrate this wet delay: Water Vapor Radiometers (WVRs) and GPS receivers. The Jet Propulsion Laboratory has developed a new class of WVRs reaching a 5 percent accuracy for the wet delay calibration (0.75 mm to 5 mm), but these WVRs are expensive to build and operate. GPS receivers are also routinely used for the calibration of data from NASA Deep Space probes, but several studies have shown that GPS receivers can give good calibration (through wet delay mapping functions) for long time variations, but are not accurate enough for short time variations (100 to 1000 s), and that WVRs must be used to efficiently calibrate the wet troposphere delays over such time spans. We think that such a calibration could be done by assimilating data from all the GNSS constellations (GPS, GLONASS, Galileo, Beidou and IRNSS) that will be available at the time of the Bepi-Colombo arrival at Mercury (2021), provided that the underlying physics of the turbulent atmosphere and evapotranspiration processes are properly taken into account at such time scales. This implies to do a tomographic image of the troposphere overlying each Deep Space tracking station at time scales of less than 1000 s. For this purpose, we have

  5. Miniaturized UHF, S-, and Ka-band RF MEMS Filters for Small Form Factor, High Performance EVA Radio Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In Phase II of this SBIR, Harmonic Devices (HDI) proposes to develop miniaturized MEMS filters at UHF, S-band and Ka-band to address the requirements of NASA's...

  6. High-Efficiency, Ka-band Solid-State Power Amplifier Utilizing GaN Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — QuinStar Technology proposes to develop an efficient, solid-state power amplifier (SSPA), operating at Ka-band frequencies, for high data rate, long range space...

  7. Ka-band Dielectric Waveguide Antenna Array for Millimeter Wave Active Imaging System

    Science.gov (United States)

    Fang, Weihai; Fei, Peng; Nian, Feng; Yang, Yujie; Feng, Keming

    2014-11-01

    Ka-band compact dielectric waveguide antenna array for active imaging system is given. Antenna array with WR28 metal waveguide direct feeding is specially designed with small size, high gain, good radiation pattern, easy realization, low insertion loss and low mutual coupling. One practical antenna array for 3-D active imaging system is shown with theoretic analysis and experimental results. The mutual coupling of transmitting and receiving units is less than -30dB, the gain from 26.5GHz to 40GHz is (12-16) dB. The results in this paper provide guidelines for the designing of millimeter wave dielectric waveguide antenna array.

  8. Particle simulation of a ka-band gyrotron traveling wave amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Xu Shouxi; Liu Pukun; Zhang Shichang; Du Chaohai; Xue Qianzhong; Geng Zhihui; Su Yinong [Key Laboratory of High Power Microwave Sources and Technologies, Institute of Electronics, Chinese Academy of Sciences, P.O. Box 2652, Beijing 100190 (China)

    2011-08-15

    The design of a ka-band gyrotron traveling wave (gyro-TWT) amplifier is presented. The gyro-TWT amplifier with a severed structure operates in the fundamental harmonic TE{sub 01} circular electric mode. The beam-wave interaction is studied by using a particle-in-cell (PIC) code. The simulations predict that the amplifier can produce an output peak power of over 155 kW, 22% efficiency, 23 dB gain, and a 3 dB bandwidth of 2 GHz for a 70 kV, 10 A electron beam with an axial velocity spread {Delta}v{sub z}/v{sub z}=5%.

  9. Ka Band Phase Locked Loop Oscillator Dielectric Resonator Oscillator for Satellite EHF Band Receiver

    Directory of Open Access Journals (Sweden)

    S. Coco

    2008-01-01

    Full Text Available This paper describes the design and fabrication of a Ka Band PLL DRO having a fundamental oscillation frequency of 19.250 GHz, used as local oscillator in the low-noise block of a down converter (LNB for an EHF band receiver. Apposite circuital models have been created to describe the behaviour of the dielectric resonator and of the active component used in the oscillator core. The DRO characterization and measurements have shown very good agreement with simulation results. A good phase noise performance is obtained by using a very high Q dielectric resonator.

  10. Sea surface Ka-band radar cross-section from field observations in the Black Sea

    Science.gov (United States)

    Yurovsky, Yury; Kudryavtsev, Vladimir; Grodsky, Semyon; Chapron, Bertrand

    2016-04-01

    An interest in Ka-band radar backscattering from the ocean surface is growing due to better spatial resolution and more accurate Doppler anomaly estimate. But, available empirical models of Ka-band cross-section are quite scarce and sometime controversial. Here we present multi-year (2009-2015) field measurements of Ka-band co-polarized (VV and HH) sea surface normalized radar cross-section (NRCS) from research platform in the Black sea collected in a wide range of observation and sea state conditions. The data are fitted by polynomial function of incidence angle, azimuth and wind speed with accounting for measured radar antenna pattern. This empirical NRCS is compared with published Ka- and Ku-band data. Our Ka-band NRCS is close to Ku-band, but is 5-7 dB higher than 'pioneer' measurements by Masuko et al. (1986). Following the two-scale Bragg paradigm, the NRCS is split into polarized (Bragg) and non-polarized components and analyzed in terms of polarization ratio (VV/HH) and polarization difference (VV-HH) to estimate wave spectra at the Bragg wave number. Non-polarized component dominates at low incidence angles 60°) NRCS azimuth dependency is unimodal (upwind peak) for HH and bimodal (with up- and downwind peaks) for VV polarization. This again can be attributed to different backscattering mechanisms for VV and HH polarizations. With decreasing of incidence angle, up- to downwind ratio tends to 1, and under light wind conditions (4-6 m/s) can be less than 1. The same situation is observed for polarization difference, which reflects Bragg backscattering properties only. This effect can be explained by enhanced roughness on upwind (windward) face of the tilting wave. Retrieval of Bragg roughness properties shows that omni-directional saturation spectra at ~1000 rad/m are 2-3 times higher (0.01 at 10 m/s wind speed) than the spectra obtained from optical measurements of regular sea surface without wave breaking. This suggests that observed difference can arise

  11. Simulation and measurement of a Ka-band HTS MMIC Josephson junction mixer

    Science.gov (United States)

    Zhang, Ting; Pegrum, Colin; Du, Jia; Guo, Yingjie Jay

    2017-01-01

    We report modeling and simulation results for a Ka band high-temperature superconducting (HTS) monolithic microwave integrated circuit (MMIC) Josephson junction mixer. A Verilog-A model of a Josephson junction is established and imported into the system simulator to realize a full HTS MMIC circuit simulation containing the HTS passive circuit models. Impedance matching optimization between the junction and passive devices is investigated. Junction DC I-V characteristics, current and local oscillator bias conditions and mixing performance are simulated and compared with the experimental results. Good agreement is obtained between the simulation and measurement results.

  12. Ka Band Phase Locked Loop Oscillator Dielectric Resonator Oscillator for Satellite EHF Band Receiver

    OpenAIRE

    Coco, S; Di Maggio, F.; A. Laudani; I. Pomona

    2008-01-01

    This paper describes the design and fabrication of a Ka Band PLL DRO having a fundamental oscillation frequency of 19.250 GHz, used as local oscillator in the low-noise block of a down converter (LNB) for an EHF band receiver. Apposite circuital models have been created to describe the behaviour of the dielectric resonator and of the active component used in the oscillator core. The DRO characterization and measurements have shown very good agreement with simulation results. A good phase nois...

  13. Modeling and Measurement of Phase Noise in GaAs HBT Ka-Band Oscillators

    OpenAIRE

    Lenk, Friedrich; Schott, Matthias; Heinrich, Wolfgang

    2001-01-01

    Accurate oscillator phase-noise simulation is a key problem in MMIC design, which is not solved satisfactory so far and needs further investigation. In this paper, a Ka-band MMIC oscillator with GaInP/GaAs HBT and on-chip resonator is treated as an example. Measured phase noise reaches -90 dBc/Hz and below at 100 kHz offset. To evaluate phase-noise predic-tion, the circuit is simulated using different commercial simulation tools and HBT models. Con-siderable differences in simulation results ...

  14. FERROELECTRIC SWITCH FOR A HIGH-POWER Ka-BAND ACTIVE PULSE COMPRESSOR

    Energy Technology Data Exchange (ETDEWEB)

    Hirshfield, Jay L. [Omega-P, Inc.

    2013-12-18

    Results are presented for design of a high-power microwave switch for operation at 34.3 GHz, intended for use in an active RF pulse compressor. The active element in the switch is a ring of ferroelectric material, whose dielectric constant can be rapidly changed by application of a high-voltage pulse. As envisioned, two of these switches would be built into a pair of delay lines, as in SLED-II at SLAC, so as to allow 30-MW μs-length Ka-band pulses to be compressed in time by a factor-of-9 and multiplied in amplitude to generate 200 MW peak power pulses. Such high-power pulses could be used for testing and evaluation of high-gradient mm-wave accelerator structures, for example. Evaluation of the switch design was carried out with an X-band (11.43 GHz) prototype, built to incorporate all the features required for the Ka-band version.

  15. A Ka-band 22 dBm GaN amplifier MMIC

    Institute of Scientific and Technical Information of China (English)

    Wang Dongfang; Chen Xiaojuan; Yuan Tingting; Wei Ke; Liu Xinyu

    2011-01-01

    A Ka-band GaN amplifier MMIC has been designed in CPW technology,and fabricated with a domestic GaN epitaxial wafer and process.This is,to the best of our knowledge,the first demonstration of domestic Kaband GaN amplifier MMICs.The single stage CPW MMIC utilizes an AIGaN/GaN HEMT with a gate-length of 0.25 μm and a gate-width of 2 × 75 μm.Under Vds =10 V,continuous-wave operating conditions,the amplifier has a 1.5 GHz operating bandwidth.It exhibits a linear gain of 6.3 dB,a maximum output power of 22 dBm and a peak PAE of 9.5% at 26.5 GHz.The output power density of the AIGaN/GaN HEMT in the MMIC reaches 1 W/mm at Ka-band under the condition of Vds =10 V.

  16. A novel Ka-band coaxial transit-time oscillator with a four-gap buncher

    Energy Technology Data Exchange (ETDEWEB)

    Song, Lili; He, Juntao; Ling, Junpu [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2015-05-15

    A novel Ka-band coaxial transit-time oscillator (TTO) with a four-gap buncher is proposed and investigated. Simulation results show that an output power of 1.27 GW and a frequency of 26.18 GHz can be achieved with a diode voltage of 447 kV and a beam current of 7.4 kA. The corresponding power efficiency is 38.5%, and the guiding magnetic field is 0.6 T. Studies and analysis indicate that a buncher with four gaps can modulate the electron beam better than the three-gap buncher in such a Ka-band TTO. Moreover, power efficiency increases with the coupling coefficient between the buncher and the extractor. Further simulation demonstrates that power efficiency can reach higher than 30% with a guiding magnetic field of above 0.5 T. Besides, the power efficiency exceeds 30% in a relatively large range of diode voltage from 375 kV to 495 kV.

  17. Electromagnetic Properties of Graphene-like Films in Ka-Band

    Directory of Open Access Journals (Sweden)

    Sofia Voronovich

    2014-05-01

    Full Text Available We studied electromagnetic properties of pyrolytic carbon (PyC films with thicknesses from 9 nm to 110 nm. The PyC films consisted of randomly oriented and intertwined graphene flakes with a typical size of a few nanometers were synthesized by chemical vapor deposition (CVD at 1100 °C on a quartz substrate. The reflectance and transmittance of these films in Ka-band, 26–37 GHz, were studied both experimentally and theoretically. The discovered remarkably high absorption loss of up to 50% of incident power, along with chemical stability, makes PyC films attractive for electromagnetic (EM interference shielding in space and airspace communication systems, as well as in portable electronic devices occupying this frequency slot. Since, in practical applications, the PyC film should be employed for coating of dielectric surfaces, two important issues to be addressed are: (i which side (front or back of the substrate should be covered to ensure maximum absorption losses; and (ii the frequency dependence of absorbance/transmittance/reflectance of binary PyC/quartz structures in the Ka-band.

  18. Ferroelectric switch for a high-power Ka-band active pulse compressor

    Energy Technology Data Exchange (ETDEWEB)

    Hirshfield, Jay L. [Omega-P, Inc., New Haven, CT (United States)

    2013-12-18

    Results are presented for design of a high-power microwave switch for operation at 34.3 GHz, intended for use in an active RF pulse compressor. The active element in the switch is a ring of ferroelectric material, whose dielectric constant can be rapidly changed by application of a high-voltage pulse. As envisioned, two of these switches would be built into a pair of delay lines, as in SLED-II at SLAC, so as to allow 30-MW μs-length Ka-band pulses to be compressed in time by a factor-of-9 and multiplied in amplitude to generate 200 MW peak power pulses. Such high-power pulses could be used for testing and evaluation of high-gradient mm-wave accelerator structures, for example. Evaluation of the switch design was carried out with an X-band (11.43 GHz) prototype, built to incorporate all the features required for the Ka-band version.

  19. On the Design of Laser Structured Ka Band Multi-Chip Module

    Directory of Open Access Journals (Sweden)

    Ghulam Mehdi

    2013-09-01

    Full Text Available The rapid prototyping of millimeter wave (MMW multi-chip module (MCM on low-cost ceramic-polymer composite substrate using laser ablation process is presented. A Ka band MCM front-end receiver is designed, fabricated and tested. The complete front-end receiver module except the IF and power distribution sections is realized on the single prescribed substrate. The measured receiver gain, noise figure and image rejection is 37 dB, 4.25 dB and 40 dB respectively. However, it deduced from the experimental results of the two front-end modules that the complex permittivity characteristics of the substrate are altered after the laser ablation process. The effective permittivity alteration phenomenon is further validated through the characterization and comparison of various laser ablated and chemically etched Ka band parallel-coupled band-pass filters. A simple and experimentally verified method is worked out to utilize the laser ablation structuring process on the prescribed substrate. It is anticipated that the proposed method can be applied to other laminated substrates as well with the prescribed manufacturing process.

  20. Thermal Deformation and RF Performance Analyses for the SWOT Large Deployable Ka-Band Reflectarray

    Science.gov (United States)

    Fang, H.; Sunada, E.; Chaubell, J.; Esteban-Fernandez, D.; Thomson, M.; Nicaise, F.

    2010-01-01

    A large deployable antenna technology for the NASA Surface Water and Ocean Topography (SWOT) Mission is currently being developed by JPL in response to NRC Earth Science Tier 2 Decadal Survey recommendations. This technology is required to enable the SWOT mission due to the fact that no currently available antenna is capable of meeting SWOT's demanding Ka-Band remote sensing requirements. One of the key aspects of this antenna development is to minimize the effect of the on-orbit thermal distortion to the antenna RF performance. An analysis process which includes: 1) the on-orbit thermal analysis to obtain the temperature distribution; 2) structural deformation analysis to get the geometry of the antenna surface; and 3) the RF performance with the given deformed antenna surface has been developed to accommodate the development of this antenna technology. The detailed analysis process and some analysis results will be presented and discussed by this paper.

  1. Dual Ka-band radar field campaign for GPM/DPR algorithm development

    Science.gov (United States)

    Nakagawa, K.; Nishikawa, M.; Nakamura, K.; Komachi, K.; Hanado, H.; Kawamura, S.; Sugitani, S.; Minda, H.; Shimizu, S.; Oki, R.

    2012-04-01

    The Global Precipitation Measurement (GPM) mission is an expanded follow-on mission to TRMM (Tropical Rainfall Measuring Mission) and a GPM core satellite will carry dual frequency precipitation radar (DPR) and a GPM Microwave Imager on board. The DPR, which is being developed by National Institute of Information and Communications Technology (NICT) and Japan Aerospace Exploration Agency (JAXA), consists of two radars; Ku-band precipitation radar (KuPR) and Ka-band radar (KaPR). The DPR is expected to advance precipitation science by expanding the coverage of observations to higher latitudes than those of the TRMM/PR, measuring snow and light rain by the KaPR, and providing drop size distribution information based on the differential attenuation of echoes at two frequencies. In order to secure the quality of precipitation estimates, ground validation (GV) of satellite data and retrieval algorithms is essential. Since end-to-end comparisons between instantaneous precipitation data observed by satellite and ground-based instruments is not enough to improve the algorithms. The error of various physical parameters in the precipitation retrieval algorithms (e.g. attenuation factor, drop size distribution, terminal velocity, density of the snow particles, etc.) will be estimated by the comparison with the ground-based observation data. A dual Ka-band radar system is developed by the JAXA for the GPM/DPR algorithm development. The dual Ka-radar system which consists of two identical Ka-band radars can measure both the specific attenuation and the equivalent radar reflectivity at Ka-band. Those parameters are important particularly for snow measurement. Using the dual Ka-radar system along with other instruments, such as a polarimetric precipitation radar, a wind-profiler radar, ground-based precipitation measurement systems, the uncertainties of the parameters in the DPR algorithm can be reduced. The verification of improvement of rain retrieval with the DPR algorithm is

  2. Analysis of a Novel Ka-band Folded Waveguide Amplifier for Traveling-Wave Tubes

    Institute of Scientific and Technical Information of China (English)

    LIAO Ming-Liang; WEI Yan-Yu; HE Jun; GONG Yu-Bin; WANG Wen-Xiang; Gun-Sik Park

    2009-01-01

    A novel Ka-band folded waveguide (FW) amplifier for traveling wave tubes (TWT) is investigated. The dispersion curve and interaction impedance are obtained and compared to the normal FW circuit by numerical simulation. The interaction impedance is higher than a normal circuit through the whole band. We also study the beam-wave interaction in this novel circuit, and the nonlinear large-signal performance is analyzed by a 3-D particle-in-cell code MACIC3D. A much higher continuous-wave (CW) output power with a considerably shorter circuit compared to a normal circuit is predicted by our simulation. Moreover, the novel FW even has a broader 3-dB bandwidth. It therefore will be useful in designing a miniature but high-power and broadband millimeter-wave TWT.

  3. A new low-cost 10 ns pulsed Ka-band radar

    Science.gov (United States)

    Eskelinen, Pekka; Ylinen, Juhana

    2011-07-01

    Two Gunn oscillators, conventional intermediate frequency building blocks, and a modified GaAs diode detector are combined to form a portable monostatic 10 ns instrumentation radar for outdoor Ka-band radar cross section measurements. At 37.8 GHz the radar gives +20 dBm output power and its tangential sensitivity is -76 dBm. Processing bandwidth is 125 MHz, which also allows for some frequency drift in the Gunn devices. Intra-pulse frequency chirp is less than 15 MHz. All functions are steered by a microcontroller. First measurements convince that the construction has a reasonable ability to reduce close-to-ground surface clutter and gives an effective way of resolving target detail. This is beneficial especially when amplitude fluctuations disturb measurements with longer pulses. The new unit operates on 12 V dc, draws a current of less than 3 A, and weighs 5 kg.

  4. Performance Analyses of the Radio Orbital Angular Momentum Steering Technique Based on Ka-Band Antenna

    Directory of Open Access Journals (Sweden)

    Mingtuan Lin

    2017-01-01

    Full Text Available The misalignment in the orbital angular momentum- (OAM- based system would distort the radiation patterns of twisted beams carrying OAM, consequently making the OAM-based communication infeasible. To tackle the misalignment problem, a radio OAM steering technique based on a uniform circular array (UCA is illustrated. Subsequently, simulations are conducted to explore the influence of the OAM steering on the OAM mode quality and transmission performance. Furthermore, UCAs working at Ka-band with formulated feeding networks are designed and fabricated to analyze the performance of the OAM steering. The influences of OAM steering on mode quality and orthogonality are then evaluated in the experiment. Overall, the analyses of OAM steering technique are beneficial for the development of radio OAM study.

  5. Thermal Deformation and RF Performance Analyses for the SWOT Large Deployable Ka-Band Reflectarray

    Science.gov (United States)

    Fang, H.; Sunada, E.; Chaubell, J.; Esteban-Fernandez, D.; Thomson, M.; Nicaise, F.

    2010-01-01

    A large deployable antenna technology for the NASA Surface Water and Ocean Topography (SWOT) Mission is currently being developed by JPL in response to NRC Earth Science Tier 2 Decadal Survey recommendations. This technology is required to enable the SWOT mission due to the fact that no currently available antenna is capable of meeting SWOT's demanding Ka-Band remote sensing requirements. One of the key aspects of this antenna development is to minimize the effect of the on-orbit thermal distortion to the antenna RF performance. An analysis process which includes: 1) the on-orbit thermal analysis to obtain the temperature distribution; 2) structural deformation analysis to get the geometry of the antenna surface; and 3) the RF performance with the given deformed antenna surface has been developed to accommodate the development of this antenna technology. The detailed analysis process and some analysis results will be presented and discussed by this paper.

  6. Enhancing End-to-End Performance of Information Services Over Ka-Band Global Satellite Networks

    Science.gov (United States)

    Bhasin, Kul B.; Glover, Daniel R.; Ivancic, William D.; vonDeak, Thomas C.

    1997-01-01

    The Internet has been growing at a rapid rate as the key medium to provide information services such as e-mail, WWW and multimedia etc., however its global reach is limited. Ka-band communication satellite networks are being developed to increase the accessibility of information services via the Internet at global scale. There is need to assess satellite networks in their ability to provide these services and interconnect seamlessly with existing and proposed terrestrial telecommunication networks. In this paper the significant issues and requirements in providing end-to-end high performance for the delivery of information services over satellite networks based on various layers in the OSI reference model are identified. Key experiments have been performed to evaluate the performance of digital video and Internet over satellite-like testbeds. The results of the early developments in ATM and TCP protocols over satellite networks are summarized.

  7. Ka-Band SiGe Receiver Front-End MMIC for Transponder Applications

    Science.gov (United States)

    Venkatesan, Jaikrishna; Mysoor, Narayan R.; Hashemi, Hassein; Aflatouni, Firooz

    2010-01-01

    A fully integrated, front-end Ka-band monolithic microwave integrated circuit (MMIC) was developed that houses an LNA (low noise amplifier) stage, a down-conversion stage, and output buffer amplifiers. The MMIC design employs a two-step quadrature down-conversion architecture, illustrated in the figure, which results in improved quality of the down-converted IF quadrature signals. This is due to the improved sensitivity of this architecture to amplitude and phase mismatches in the quadrature down-conversion process. Current sharing results in reduced power consumption, while 3D-coupled inductors reduce the chip area. Improved noise figure is expected over previous SiGe-based, frontend designs

  8. Cryo-Cooled Sapphire Oscillator for the Cassini Ka-Band Experiment

    Science.gov (United States)

    Wang, Rabi T.; Dick, G. John

    1997-01-01

    We present features for an ultra-stable sapphire cryogenic oscillator which has been designed to support the Cassini Ka-band Radio Science experiment. The design of this standard is new in several respects. It is cooled by a commercial cryocooler instead of liquid cryogens to increase operating time, and it uses a technology to adjust the temperature turn-over point to extend the upper operating temperature limit and to enable construction of multiple units with uniform operating characteristics. Objectives are 3 x 10(exp -15) stability for measuring times 1 second less than or equal to (tau) less than or equal to 100 seconds, phase noise of -85 dBc/Hz from offset frequencies of 1 Hz to 1000 Hz at 10 GHz carrier frequency, and a one year continuous operating period.

  9. Low phase noise GaAs HBT VCO in Ka-band

    Science.gov (United States)

    Ting, Yan; Yuming, Zhang; Hongliang, Lü; Yimen, Zhang; Yue, Wu; Yifeng, Liu

    2015-02-01

    Design and fabrication of a Ka-band voltage-controlled oscillator (VCO) using commercially available 1-μm GaAs heterojunction bipolar transistor technology is presented. A fully differential common-emitter configuration with a symmetric capacitance with a symmetric inductance tank structure is employed to reduce the phase noise of the VCO, and a novel π-feedback network is applied to compensate for the 180° phase shift. The on-wafer test shows that the VCO exhibits a phase noise of -96.47 dBc/Hz at a 1 MHz offset and presents a tuning range from 28.312 to 28.695 GHz. The overall dc current consumption of the VCO is 18 mA with a supply voltage of -6 V The chip area of the VCO is 0.7 × 0.7 mm2.

  10. Design of a Cryocooled Sapphire Oscillator for the Cassini Ka-Band Experiment

    Science.gov (United States)

    Dick, G. J.; Wang, R. T.

    1998-04-01

    We present design aspects of a cryogenic sapphire oscillator that is being developed for ultra-high short-term stability and low phase noise in support of the Cassini Ka-band (32-GHz) radio science experiment. With cooling provided by a commercial cryocooler instead of liquid helium, this standard is designed to operate continuously for periods of a year or more. Performance targets are a stability of 3 x 10^(-15) (1 second ≤ τ ≤ 100 seconds) and a phase noise of -73 dBc/Hz at 1 Hz measured at 34 GHz. Test results are reported for several subsystems, including the cryocooler, vibration isolation system, and ruby compensating element.

  11. Radiating Elements for Shared Aperture Tx/Rx Phased Arrays at K/Ka Band

    KAUST Repository

    Sandhu, A.I.

    2016-04-11

    A dual band, Tx/Rx, self-diplexing phased array is presented. The antenna has been designed to cover Tx/Rx satellite communications at K/Ka band with a frequency ratio 1.5:1. To obtain dual band operations with a single radiating surface, a novel dual band radiator is adopted and placed in a configuration in which dual band and single band elements are interleaved. The proposed configuration reduces the number of radiating elements required by other solutions while avoiding the insurgence of grating lobes. The tightly packed arrangement of the elements poses many integration issues, which are solved with a novel integration technique. The array elements are optimized to scan the beam in excess of ° in both bands. A subarray with 49 Rx elements and 105 Tx elements was built and measured confirming the results obtained in simulations.

  12. High-Efficiency Ka-Band Waveguide Two-Way Asymmetric Power Combiner

    Science.gov (United States)

    Wintucky, E. G.; Simons, R. N.; Freeman, J. C.; Chevalier, C. T.

    2011-01-01

    NASA is planning a number of Space Exploration, Earth Observation and Space Science missions where Ka-band solid-state power amplifiers (SSPAs) could have a role. Monolithic microwave integrated circuit (MMIC) based SSPAs with output powers on the order of 10 W at Ka-band frequencies would be adequate to satisfy the data transmission rate requirements at the distances involved. MMICs are a type of integrated circuit fabricated on a GaAs wafer, which operates at micro wave frequencies and performs the function of signal amplification. The highest power Ka-band (31.8 to 32.3 GHz) SSPA to have flown in space had an output power of 2.6 W with an overall efficiency of 14.3 percent. This SSPA was built around discrete GaAs pHEMT (high electron mobility transistor) devices and flew aboard the Deep Space One spacecraft. State-of-the-art GaAs pHEMT-based MMIC power amplifiers (PAs) can deliver RF power at Ka-band frequencies anywhere from 3 W with a power added efficiency (PAE) of 32 percent to 6 W with a PAE of 26 percent. However, to achieve power levels higher than 6 W, the output of several MMIC PAs would need to be combined using a high-efficiency power combiner. Conventional binary waveguide power combiners, based on short-slot and magic-T circuits, require MMIC PAs with identical amplitude and phase characteristics for high combining efficiency. However, due to manufacturing process variations, the output powers of the MMIC PAs tend to be unequal, and hence the need to develop unequal power combiners. A two-way asymmetric magic-T based power combiner for MMIC power amplifiers, which can take in unequal inputs, has been successfully designed, fabricated, and characterized over NASA s Deep Space Network (DSN) frequency range of 31.8 to 32.3 GHz. The figure is a transparent view of the a sym - metric combiner that shows the 4-port configuration and the internal structure. The rod, post, and iris are positioned by design to achieve the desired asymmetric power ratio

  13. Ka-band bistatic ground-based SAR using noise signals

    Science.gov (United States)

    Lukin, K.; Mogyla, A.; Vyplavin, P.; Palamarchuk, V.; Zemlyaniy, O.; Tarasenko, V.; Zaets, N.; Skretsanov, V.; Shubniy, A.; Glamazdin, V.; Natarov, M.; Nechayev, O.

    2008-01-01

    Currently, one of the actual problems is remote monitoring of technical state of large objects. Different methods can be used for that purpose. The most promising of them relies on application of ground based synthetic aperture radars (SAR) and differential interferometry. We have designed and tested Ground Based Noise Waveform SAR based on noise radar technology [1] and synthetic aperture antennas [2]. It enabled to build an instrument for precise all-weather monitoring of large objects in real-time. We describe main performance of ground-based interferometric SAR which uses continuous Ka-band noise waveform as a probe signal. Besides, results of laboratory trials and evaluation of its main performance are presented as well.

  14. High Efficiency Ka-Band Solid State Power Amplifier Waveguide Power Combiner

    Science.gov (United States)

    Wintucky, Edwin G.; Simons, Rainee N.; Chevalier, Christine T.; Freeman, Jon C.

    2010-01-01

    A novel Ka-band high efficiency asymmetric waveguide four-port combiner for coherent combining of two Monolithic Microwave Integrated Circuit (MMIC) Solid State Power Amplifiers (SSPAs) having unequal outputs has been successfully designed, fabricated and characterized over the NASA deep space frequency band from 31.8 to 32.3 GHz. The measured combiner efficiency is greater than 90 percent, the return loss greater than 18 dB and input port isolation greater than 22 dB. The manufactured combiner was designed for an input power ratio of 2:1 but can be custom designed for any arbitrary power ratio. Applications considered are NASA s space communications systems needing 6 to 10 W of radio frequency (RF) power. This Technical Memorandum (TM) is an expanded version of the article recently published in Institute of Engineering and Technology (IET) Electronics Letters.

  15. First Airswot Ka-Band Radar Backscatter Returns over a Complex California Wetland

    Science.gov (United States)

    Baney, O. N.; Smith, L. C.; Pitcher, L. H.; Gleason, C. J.; Chu, V. W.; Bennett, M. M.; Pavelsky, T.; Sadowy, G. A.

    2014-12-01

    In anticipation of the launch of the NASA Surface Water Ocean Topography (SWOT) mission, this project was conducted around the Piute Ponds of Edwards Air Force Base within the Mojave Desert, California to characterize ground conditions simultaneously with two AirSWOT flights collected May 14th, 2014. Both SWOT and AirSWOT employ a Ka-band interferometer to map water surface elevations and extent, but the ability of Ka-band radar to discriminate shorelines and flooded vegetation is not well known. Presumed bright returns from moist soils surrounding surface water bodies have also been speculated to confound interpretation of SWOT/AirSWOT data. The Piute Ponds are a dynamic area of constantly changing water conditions, providing a convenient test site for field studies to assess open water, dry shorelines, vegetation edges, islands, flooded vegetation and soil moisture in conjunction with AirSWOT backscatter and visible/near-infrared camera imagery. Islands were characterized into dry islands and flooded vegetation stands including species such as bulrush (Scripus acutus) and tamarisk (Tammarix ramosissima). Results demonstrate that full water extent can be determined by near-range backscatter returns which are strong for both open water and flooded vegetation. Far-range backscatter returns over open water were unreliable for flooded extent. Comparing near-range and far-range backscatter results to the soil moisture transect shows correlation, however as soil moisture increases, discriminating between wet sediment and water becomes difficult. In sum, first results suggest near-return backscatter results prove most useful in distinguishing open water from non-water, with a strong correlation between soil moisture and backscatter returns.

  16. Design and ImpIementation of Ka-Band Up-Converer%Ka频段上变频器的设计与实现

    Institute of Scientific and Technical Information of China (English)

    王启; 陈小忠

    2015-01-01

    阐述了一种Ka频段卫星通信上变频器的实现方案,采用一次变频方案将中频信号上变频至Ka频段射频信号,在实现一定增益的同时能够保证设备的杂散、相位噪声以及幅频特性等指标。该设计方法与调试技巧能够广泛应用于卫星通信地球站的上行链路。%Describes an achievement to design a kind of Ka-band up-converter, which converts S-band IF signal to Ka-band RF signal by once frequency conversion. The some gain can be achieved as well as the output spurious, phase noise and amplitude –frequency characteristics. The design and debug method can be used in up-link of satellite communications.

  17. A Ka-Band Backscatter Model Function and an Algorithm for Measurement of the Wind Vector Over the Sea Surface

    NARCIS (Netherlands)

    Nekrasov, A.; Hoogeboom, P.

    2005-01-01

    A Ka-band backscatter model and an algorithm for measurement of the wind speed and direction over the sea surface by a frequency-modulated continous-wave radar demonstrator system operated in scatterometer mode have been developed. To evaluate the proposed algorithm, a simulation of the wind vector

  18. A New Blind Pointing Model Improves Large Reflector Antennas Precision Pointing at Ka-Band (32 GHz)

    Science.gov (United States)

    Rochblatt, David J.

    2009-01-01

    The National Aeronautics and Space Administration (NASA), Jet Propulsion Laboratory (JPL)-Deep Space Network (DSN) subnet of 34-m Beam Waveguide (BWG) Antennas was recently upgraded with Ka-Band (32-GHz) frequency feeds for space research and communication. For normal telemetry tracking a Ka-Band monopulse system is used, which typically yields 1.6-mdeg mean radial error (MRE) pointing accuracy on the 34-m diameter antennas. However, for the monopulse to be able to acquire and lock, for special radio science applications where monopulse cannot be used, or as a back-up for the monopulse, high-precision open-loop blind pointing is required. This paper describes a new 4th order pointing model and calibration technique, which was developed and applied to the DSN 34-m BWG antennas yielding 1.8 to 3.0-mdeg MRE pointing accuracy and amplitude stability of 0.2 dB, at Ka-Band, and successfully used for the CASSINI spacecraft occultation experiment at Saturn and Titan. In addition, the new 4th order pointing model was used during a telemetry experiment at Ka-Band (32 GHz) utilizing the Mars Reconnaissance Orbiter (MRO) spacecraft while at a distance of 0.225 astronomical units (AU) from Earth and communicating with a DSN 34-m BWG antenna at a record high rate of 6-megabits per second (Mb/s).

  19. Design and Analysis of a 34 dBm Ka-Band GaN High Power Amplifier MMIC

    NARCIS (Netherlands)

    Heijningen, M. van; Vliet, F.E. van; Quay, R.; Raay, F. van; Seelmann-Eggebert, M.

    2006-01-01

    This paper presents the design and analysis issues related to the use of recent GaN technologies for realizing high power millimeter wave MMICs. Two GaN Ka-band amplifier MMICs have been designed, fabricated and characterized. The small-signal and power measurement results are presented for both amp

  20. Robust AlGaN/GaN low noise amplifier MMICs for C-, Ku- and Ka-band space applications

    NARCIS (Netherlands)

    Suijker, E.M.; Rodenburg, M.; Hoogland, J.A.; Heijningen, M. van; Seelmann-Eggebert, M.; Quay, R.; Brückner, P.; Vliet, F.E. van

    2009-01-01

    The high power capabilities in combination with the low noise performance of Gallium Nitride (GaN) makes this technology an excellent choice for robust receivers. This paper presents the design and measured results of three different LNAs, which operate in C-, Ku-, and Ka-band. The designs are reali

  1. Ka-Band Slot-Microstrip-Covered and Waveguide-Cavity-Backed Monopulse Antenna Array

    Directory of Open Access Journals (Sweden)

    Li-Ming Si

    2014-01-01

    Full Text Available A slot-microstrip-covered and waveguide-cavity-backed monopulse antenna array is proposed for high-resolution tracking applications at Ka-band. The monopulse antenna array is designed with a microstrip with 2×32 slots, a waveguide cavity, and a waveguide monopulse comparator, to make the structure simple, reduce the feeding network loss, and increase the frequency bandwidth. The 2×32 slot-microstrip elements are formed by a metal clad dielectric substrate and slots etched in the metal using the standard printed circuit board (PCB process with dimensions of 230 mm  ×  10 mm. The proposed monopulse antenna array not only maintains the advantages of the traditional waveguide slot antenna array, but also has the characteristics of wide bandwidth, high consistence, easy of fabrication, and low cost. From the measured results, it exhibits good monopulse characteristics, including the following: the maximum gains of sum pattern are greater than 24 dB, the 3 dB beamwidth of sum pattern is about 2.2 degrees, the sidelobe levels of the sum pattern are less than −18 dB, and the null depths of the difference pattern are less than −25 dB within the operating bandwidth between 33.65 GHz and 34.35 GHz for VSWR ≤ 2.

  2. Onboard Interferometric SAR Processor for the Ka-Band Radar Interferometer (KaRIn)

    Science.gov (United States)

    Esteban-Fernandez, Daniel; Rodriquez, Ernesto; Peral, Eva; Clark, Duane I.; Wu, Xiaoqing

    2011-01-01

    An interferometric synthetic aperture radar (SAR) onboard processor concept and algorithm has been developed for the Ka-band radar interferometer (KaRIn) instrument on the Surface and Ocean Topography (SWOT) mission. This is a mission- critical subsystem that will perform interferometric SAR processing and multi-look averaging over the oceans to decrease the data rate by three orders of magnitude, and therefore enable the downlink of the radar data to the ground. The onboard processor performs demodulation, range compression, coregistration, and re-sampling, and forms nine azimuth squinted beams. For each of them, an interferogram is generated, including common-band spectral filtering to improve correlation, followed by averaging to the final 1 1-km ground resolution pixel. The onboard processor has been prototyped on a custom FPGA-based cPCI board, which will be part of the radar s digital subsystem. The level of complexity of this technology, dictated by the implementation of interferometric SAR processing at high resolution, the extremely tight level of accuracy required, and its implementation on FPGAs are unprecedented at the time of this reporting for an onboard processor for flight applications.

  3. Automated rain rate estimates using the Ka-band ARM Zenith Radar (KAZR

    Directory of Open Access Journals (Sweden)

    A. Chandra

    2014-02-01

    Full Text Available The use of millimeter wavelength radars for probing precipitation has recently gained interest. However, estimation of precipitation variables is not straightforward due to strong attenuation, radar receiver saturation, antenna wet radome effects and natural microphysical variability. Here, an automated algorithm is developed for routinely retrieving rain rates from profiling Ka-band (35-GHz ARM zenith radars (KAZR. A 1-D simple, steady state microphysical model is used to estimate the impact of microphysical processes and attenuation on the profiles of the radar observables at 35-GHz and thus provide criteria for identifying when attenuation or microphysical processes dominate KAZR observations. KAZR observations are also screened for saturation and wet radome effects. The proposed algorithm is implemented in two steps: high rain rates are retrieved by using the amount of attenuation in rain layers, while lower rain rates by the Ze–R (reflectivity-rain rate relation is implemented. Observations collected by the KAZR, disdrometer and scanning weather radars during the DYNAMO/AMIE field campaign at Gan Island of the tropical Indian Ocean are used to validate the proposed approach. The results indicate that the proposed algorithm can be used to derive robust statistics of rain rates in the tropics from KAZR observations.

  4. Automated rain rate estimates using the Ka-band ARM zenith radar (KAZR)

    Science.gov (United States)

    Chandra, A.; Zhang, C.; Kollias, P.; Matrosov, S.; Szyrmer, W.

    2015-09-01

    The use of millimeter wavelength radars for probing precipitation has recently gained interest. However, estimation of precipitation variables is not straightforward due to strong signal attenuation, radar receiver saturation, antenna wet radome effects and natural microphysical variability. Here, an automated algorithm is developed for routinely retrieving rain rates from the profiling Ka-band (35-GHz) ARM (Atmospheric Radiation Measurement) zenith radars (KAZR). A 1-dimensional, simple, steady state microphysical model is used to estimate impacts of microphysical processes and attenuation on the profiles of radar observables at 35-GHz and thus provide criteria for identifying situations when attenuation or microphysical processes dominate KAZR observations. KAZR observations are also screened for signal saturation and wet radome effects. The algorithm is implemented in two steps: high rain rates are retrieved by using the amount of attenuation in rain layers, while low rain rates are retrieved from the reflectivity-rain rate (Ze-R) relation. Observations collected by the KAZR, rain gauge, disdrometer and scanning precipitating radars during the DYNAMO/AMIE field campaign at the Gan Island of the tropical Indian Ocean are used to validate the proposed approach. The differences in the rain accumulation from the proposed algorithm are quantified. The results indicate that the proposed algorithm has a potential for deriving continuous rain rate statistics in the tropics.

  5. AltiKa: a Ka-band Altimetry Payload and System for Operational Altimetry during the GMES Period

    Science.gov (United States)

    Vincent, Patrick; Steunou, Nathalie; Caubet, Eric; Phalippou, Laurent; Rey, Laurent; Thouvenot, Eric; Verron, Jacques

    2006-01-01

    This paper describes the Ka-band altimetry payload and system that has been studied for several years by CNES, ALCATEL SPACE and some science laboratories. Altimetry is one of the major elements of the ocean observing system to be made sustainable through the GEOSS (Global Earth Observation System of Systems) and GMES (Global Monitoring of the Environment and Security) programs. A short review of some mission objectives to be fulfilled in terms of mesoscale oceanography in the frame of the GEOSS and GMES programs is performed. To answer the corresponding requirements, the approach consisting in a constellation of nadir altimeter is discussed. A coupled Ka-band altimeter-radiometer payload is then described; technical items are detailed to explain how this payload shall meet the science and operational requirements, and expected performances are displayed. The current status of the payload development and flight perspectives are given.

  6. Frequency Tracking Performance Using a Hyperbolic Digital-Phase Locked Loop for Ka-Band Communication in Rain Fading Channels

    Science.gov (United States)

    Sithamparanathan, Kandeepan; Piesiewicz, Radoslaw

    In this paper we study and present some results on the performances of frequency tracking for Ka-band satellite communications in rain fading channels. The carrier frequency is tracked using a 2nd order hyperbolic phase detector based digital-phase locked loop (D-PLL). The hyperbolic D-PLL has the capability of extending the tracking range compared to the other D-PLL and hence can be designed such that to achieve low phase jitter performance for improved carrier tracking. We present the design and analysis of the D-PLL and show some simulation results on the frequency tracking performance for Ka-band rain fading channel. The results are compared with the non-fading noise only case and comparative analyses are made.

  7. Ka-Band TWT High-Efficiency Power Combiner for High-Rate Data Transmission

    Science.gov (United States)

    Wintucky, Edwin G.; Simons, Rainee; Vaden, Karl R.; Lesny, Gary G.; Glass, Jeffrey L.

    2007-01-01

    A four-port magic-T hybrid waveguide junction serves as the central component of a high-efficiency two-way power combiner circuit for transmitting a high-rate phase-modulated digital signal at a carrier frequency in the Ka-band (between 27 and 40 GHz). This power combiner was developed to satisfy a specific requirement to efficiently combine the coherent outputs of two traveling-wavetube (TWT) amplifiers that are typically characterized by power levels on the order of 100 W or more. In this application, the use of a waveguide-based power combiner (instead of a coaxial-cable- or microstrip-based power combiner, for example) is dictated by requirements for low loss, high power-handling capability, and broadband response. Combiner efficiencies were typically 90 percent or more over both the linear and saturated output power regions of operation of the TWTs . Figure 1 depicts the basic configuration of the magic-T hybrid junction. The coherent outputs of the two TWTs enter through ports 1 and 4. As a result of the orientations of the electromagnetic fields, which also provides a needed high port-to-port isolation, of these two input signals and the interior design of the magic-T junction, the input powers are divided so as to add in phase at one output port (port 2), and to be opposite in phase and hence cancel each other at the opposite coplanar output port (port 3). The net result is that the output power at port 2 is essentially double that of the output of one TWT, minus the power lost in the magic-T hybrid junction. Optimum performance as a high-efficiency power combiner thus requires a balance of both power and phase at the input ports of the magic-T. Replicas of this two-way combiner can be arranged in a binary configuration to obtain a 2n-way (where n is an integer) combiner. For example, Figure 2 illustrates the use of three two-way combiners to combine the outputs of four TWTs.

  8. A Novel Low-cost, Ka-band, High Altitude, Multi-Baseline Unmanned Aerial Vehicle Sensor for Surface Water Ocean Topography Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal presents the Ka-band SWOT Phenomenology Airborne Radar (KaSPAR) to support the surface water ocean topography (SWOT) mission for science and algorithm...

  9. Coherent summation of Ka-band microwave beams produced by sub-gigawatt superradiance backward wave oscillators

    Science.gov (United States)

    Sharypov, K. A.; El'chaninov, A. A.; Mesyats, G. A.; Pedos, M. S.; Romancheko, I. V.; Rostov, V. V.; Rukin, S. N.; Shpak, V. G.; Shunailov, S. A.; Ul'masculov, M. R.; Yalandin, M. I.

    2013-09-01

    Coherent summation of microwave beams has been demonstrated for two superradiance Ka-band backward wave oscillators producing over 700 MW of power. The explosive emission cathodes of the e-beam injectors were powered by stable splitted voltage pulses produced by an all-solid-state modulator. The voltage fronts were shortened to 300 ps in controlled delay shock-excited ferrite lines. The standard deviation of the phase difference between the microwave pulses was less than 2% of the oscillations period. The power flux density of the summarized radiation was the same as that of a single generator producing an output power of ˜3 GW.

  10. Low cost low phase noise PLL controlled push-push VCOs in k- and ka- bands, stabilized by cavity resonator

    OpenAIRE

    Tsvelykh, I. S.; B. A. Kotserzhynskyi

    2016-01-01

    This work demonstrates push-push VCOs in K-band (with second harmonic output at 24 GHz) and in Ka-band (with third harmonic output at 36 GHz), and PLL synthesizers on their basis. Oscillators are stabilized by a rectangular resonant metallic cavity. Output signal power within the frequency tuning range changes in the limits of -11,5 -7,6 dBm and -11,8 -10,9 dBm for 24 GHz and 36 GHz oscillators respectively. Single sideband (SSB) phase noise spectral densities of -91 dBc/Hz for 24 GHz oscilla...

  11. Phase Noise Enhancement of the GaAs High Electron Mobility Transistors Using Micromachined Cavity Resonators at Ka-band

    Science.gov (United States)

    Song, Insang; Kim, Chungwoo; Kwon, Youngwoo; Cheon, Changyul; Song, Cimoo

    1999-06-01

    We introduce a new structure of the micromachined cavity resonator coupled GaAs-based oscillator to enhance the phase noise and the frequency stability. The oscillator and the cavity are designed for Ka-band applications. Compared to the free running oscillator, the cavity resonator coupled oscillator showed the phase noise enhancement of about 20 dB. The phase noises of about -110 and -85 dBc/Hz are obtained at 1 MHz and 100 kHz offset frequency, respectively. The frequency pushing for the gate bias of the cavity coupled oscillator is about two order of magnitude less than that of the free running oscillator.

  12. A Frequency Transfer and Cleanup System for Ultra-High Stability at Both Long and Short Times for the Cassini Ka-Band Experiment

    Science.gov (United States)

    Calhoun, M. D.; Dick, G. J.; Wang, R. T.

    1999-01-01

    New radio science experiments, including a gravitational wave search and several atmospheric occultation studies, are planned for the Cassini Ka-band experiment. These experiments are made possible by reduced solar-induced phase fluctuations at the high-frequency (32 GHZ) of the radio link between the earth and the spacecraft. In order to match the improved link performance, a significant upgrade is under way to improve the frequency stability capabilities of NASA's Deep Space Network (DSN). Significant improvements are being undertaken in many areas, including antenna vibration and (wet) tropospheric calibration, in addition to frequency generation and distribution. We describe here the design and development of a system to provide a reference signal with the highest possible frequency stability for both long-term, short-term, and phase noise, at an antenna (DSS 25) that is remote from the frequency standards room at SPC-10 at the Goldstone site. The new technologies were developed in order to meet the very tight requirements. They are: 1) a Stabilized Fiber-Optic Distribution Assembly (SFODA) that includes active compensation of thermal variations to transfer long-term stability over 16 km of ordinary fiber-optic cable, and 2) a Compensated Sapphire Oscillator (CSO) that provides short-term performance in a cryocooled sapphire oscillator with ultra-high short-term stability and low phase noise.

  13. Installing the earth station of Ka-band satellite frequency in Malaysia: conceptual framework for site decision

    Science.gov (United States)

    Mahmud, M. R.; Reba, M. N. M.; Jaw, S. W.; Arsyad, A.; Ibrahim, M. A. M.

    2017-05-01

    This paper developed a conceptual framework in determining the suitable location in installing the earth station for Ka-band satellite communication in Malaysia. This current evolution of high throughput satellites experienced major challenge due to Malaysian climate. Because Ka-band frequency is highly attenuated by the rainfall; it is an enormous challenge to define the most appropriate site for the static communication. Site diversity, a measure to anticipate this conflict by choosing less attenuated region and geographically change the transmission strategy on season basis require accurate spatio-temporal information on the geographical, environmental and hydro-climatology at local scale. Prior to that request, this study developed a conceptual framework to cater the needs. By using the digital spatial data, acquired from site measurement and remote sensing, the proposed framework applied a multiple criteria analysis to perform the tasks of site selection. With the advancement of high resolution remotely sensed data, site determination can be conducted as in Malaysia; accommodating a new, fast, and effective satellite communication. The output of this study is one of the pioneer contributions to create a high tech-society.

  14. Lunar Noise-Temperature Increase Measurements at S-Band, X-Band, and Ka-Band Using a 34-Meter-Diameter Beam-Waveguide Antenna

    Science.gov (United States)

    Morabito, D. D.

    2006-08-01

    The Moon radiates energy at infrared and microwave wavelengths, in addition to reflecting sunlight at optical wavelengths. As a result, an antenna pointed at or near the Moon will cause an increase in receiver noise temperature that needs to be accounted for in telemetry, radio science, or ranging link budgets. The Deep Space Network may be required to use its antennas in future lunar robotic or human missions, and thus it is important to understand the nature of this temperature increase as a function of observing frequency, lunar phase, and angular offset of the antenna beam from the center of the lunar disk. This article quantifies such a set of measurements acquired at DSS 13, a 34-m-diameter research and development beam-waveguide antenna located at Goldstone, California, at three different telecommunication frequencies, S-band (2.3 GHz), X-band (8.4 GHz), and Ka-band (32 GHz), over a wide range of lunar phase, for both disk-centered and limb-centered positions of the antenna beam.

  15. Synchronization of radiation in an oversized coaxial Ka-band backward wave oscillator using two-dimensional Bragg structure

    Directory of Open Access Journals (Sweden)

    N. S. Ginzburg

    2015-12-01

    Full Text Available A coaxial Ka-band backward wave oscillator with a two-dimensional Bragg structure located at the output of the interaction space has been studied. This structure has a double-period corrugation and provides azimuthal electromagnetic energy fluxes, which act on the synchronized radiation of an oversized tubular electron beam. Proof-of-principle experiments were conducted based on the Saturn thermionic accelerator (300  keV/200  A/2  μs. In accordance with simulations, narrow-band generation was obtained at a frequency of 30 GHz and a power level of 1.5–2 MW. As a result, the possibility of using a two-dimensional distributed feedback mechanism in oscillators of the Cherenkov type has been demonstrated.

  16. Performance Analysis of Ultra-Wideband Channel for Short-Range Monopulse Radar at Ka-Band

    Directory of Open Access Journals (Sweden)

    Naohiko Iwakiri

    2012-01-01

    Full Text Available High-range resolution is inherently provided with Ka-band ultra-wideband (UWB vehicular radars. The authors have developed a prototype UWB monopulse radar equipped with a two-element receiving antenna array and reported its measurement results. In this paper, a more detailed verification using these measurements is presented. The measurements were analyzed employing matched filtering and eigendecomposition, and then multipath components were extracted to examine the behavior of received UWB monopulse signals. Next, conventional direction finding algorithms based on narrowband assumption were evaluated using the extracted multipath components, resulting in acceptable angle-of-arrival (AOA from the UWB monopulse signal regardless of wideband signals. Performance degradation due to a number of averaging the received monopulses was also examined to design suitable radar's waveforms.

  17. Fine resolution topographic mapping of the Jovian moons: a Ka-band high resolution topographic mapping interferometric synthetic aperture radar

    Science.gov (United States)

    Madsen, Soren N.; Carsey, Frank D.; Turtle, Elizabeth P.

    2003-01-01

    The topographic data set obtained by MOLA has provided an unprecedented level of information about Mars' geologic features. The proposed flight of JIMO provides an opportunity to accomplish a similar mapping of and comparable scientific discovery for the Jovian moons through us of an interferometric imaging radar analogous to the Shuttle radar that recently generated a new topographic map of Earth. A Ka-band single pass across-track synthetic aperture radar (SAR) interferometer can provide very high resolution surface elevation maps. The concept would use two antennas mounted at the ends of a deployable boom (similar to the Shuttle Radar Topographic Mapper) extended orthogonal to the direction of flight. Assuming an orbit altitude of approximately 100 km and a ground velocity of approximately 1.5 km/sec, horizontal resolutions at the 10 meter level and vertical resolutions at the sub-meter level are possible.

  18. Current status of Dual Ka-band radar field campaign in Japan for GPM/DPR mission

    Science.gov (United States)

    Kaneko, Yuki; Nakagawa, Katsuhiro; Nishikawa, Masanori; Nakamura, Kenji; Fujiyoshi, Yasushi; Hanado, Hiroshi; Minda, Haruya; Yamamoto, Kazuhide; Oki, Riko; Furukawa, Kinji

    2013-04-01

    The Global Precipitation Measurement (GPM) mission is an expanded follow-on mission to TRMM (Tropical Rainfall Measuring Mission) and a GPM core satellite will carry dual frequency precipitation radar (DPR) and a GPM Microwave Imager on board. The DPR, which is being developed by National Institute of Information and Communications Technology (NICT) and Japan Aerospace Exploration Agency (JAXA), consists of two radars; Ku-band precipitation radar (KuPR) and Ka-band radar (KaPR). The DPR is expected to advance precipitation science by expanding the coverage of observations to higher latitudes than those of the TRMM/PR, measuring snow and light rain by the KaPR, and providing drop size distribution information based on the differential attenuation of echoes at two frequencies. In order to secure the quality of precipitation estimates, ground validation (GV) of satellite data and retrieval algorithms is essential. Since end-to-end comparisons between instantaneous precipitation data observed by satellite and ground-based instruments is not enough to improve the algorithms. The error of various physical parameters in the precipitation retrieval algorithms (e.g. attenuation factor, drop size distribution, terminal velocity, density of the snow particles, etc.) will be estimated by the comparison with the ground-based observation data. A dual Ka-band radar system is developed by the JAXA for the GPM/DPR algorithm development. The dual Ka-radar system which consists of two identical Ka-band radars can measure both the specific attenuation and the equivalent radar reflectivity at Ka-band. Those parameters are important particularly for snow measurement. Using the dual Ka-radar system along with other instruments, such as a polarimetric precipitation radar, a wind-profiler radar, ground-based precipitation measurement systems, the uncertainties of the parameters in the DPR algorithm can be reduced. The verification of improvement of rain retrieval with the DPR algorithm is

  19. A comparison of MESFET and HEMT MMIC technologies using a compact Ka-band voltage-controlled oscillator

    Science.gov (United States)

    Swirhun, S.; Geddes, J.; Sokolov, Vladimir; Bosch, D.; Gawronski, M.; Anholt, R.

    1991-07-01

    To compare the capability of MESFET and HEMT technologies for monolithic microwave integrated circuit (MMIC) implementation we have fabricated and tested discrete field-effect transistors (FETs) and a novel Ka-band monolithic voltage controlled oscillator (VCO). We implemented the circuit with three different active devices: moderate- and high-doped ion-implanted MESFETs (metal-semiconductor FETs) and AlGaAs/GaAs HEMTs (high electron mobility transistors). A comparison of the measured oscillator phase-noise and an independent comparison of the temperature dependence of MESFET and HEMT RF equivalent circuits yields two general guidelines: MESFETs are preferred over HEMTs for applications requiring low phase-noise and temperature insensitive operation.

  20. A Ka-band monolithic low phase noise coplanar waveguide oscillator using InAlAs/InGaAs HBT

    Science.gov (United States)

    Cui, Delong; Hsu, Shawn; Pavlidis, Dimitris; Chin, Patrick; Block, Tom

    2002-02-01

    A Ka-band oscillator has been designed, fabricated and tested using InAlAs/InGaAs HBTs. Coplanar waveguide technology has been employed to improve the Q-factor of the circuit. An output power of 2.6 dBm with DC to RF conversion efficiency of 7.8% was measured at 31.7 GHz. Low phase noise of -87 and -112 dBc/Hz were achieved at an offset frequency of 100 kHz and 1 MHz respectively. These low phase noise values can be attributed to the low 1/ f noise of the InAlAs/InGaAs HBT devices and the coplanar design used for the circuit.

  1. Ka-band and X-band observations of the solar corona acquired during the Cassini 2001 superior conjunction

    Science.gov (United States)

    Morabito, D. D.

    2002-01-01

    Simultaneous dual-frequency Ka-band (32 GHz) and X-band (8.4 GHz) carrier signal data have been acquired during the superior conjunction of the Cassini spacecraft June 2001, using the NASA Deep Space Network's facilities located in Goldstone, California. The solar elongation angle of the observations varied from -4.1 degrees (-16 solar radii) to -0.6 degrees (-2.3 solar radii). The observed coronal and solar effects on the signals include spectral broadening, amplitude scintillation, phase scintillation, and increased noise. The measurements were generally consistent with existing solar models, except during solar transient events when the signatures of the measurements were observed to increase significantly above the quiet background levels. This is the second solar conjunction of Cassini for which simultaneous X/Ka data were acquired. Both solar conjunctions, conducted in May 2000 and June 2001, occurred near the peak of the current 11 year solar cycle.

  2. AltiKa: a Ka-band Altimetry Payload and System for Operational Altimetry during the GMES Period

    Directory of Open Access Journals (Sweden)

    Jacques Verron

    2006-03-01

    Full Text Available This paper describes the Ka-band altimetry payload and system that has beenstudied for several years by CNES, ALCATEL SPACE and some science laboratories.Altimetry is one of the major elements of the ocean observing system to be madesustainable through the GEOSS (Global Earth Observation System of Systems and GMES(Global Monitoring of the Environment and Security programs. A short review of somemission objectives to be fulfilled in terms of mesoscale oceanography in the frame of theGEOSS and GMES programs is performed. To answer the corresponding requirements, theapproach consisting in a constellation of nadir altimeter is discussed. A coupled Ka-bandaltimeter-radiometer payload is then described; technical items are detailed to explain howthis payload shall meet the science and operational requirements, and expectedperformances are displayed. The current status of the payload development and flightperspectives are given.

  3. Sensitivity of S- and Ka-band matched dual-wavelength radar system for detecting nonprecipitating cloud

    Science.gov (United States)

    Vivekanandan, J.; Politovich, Marcia; Rilling, Robert; Ellis, Scott; Pratte, Frank

    2004-12-01

    Remote detection of cloud phase in either liquid, ice or mixed form a key microphysical observation. Evolution of a cloud system and associated radiative properties depend on microphysical characteristics. Polarization radars rely on the shape of the particle to delineate the regions of liquid and ice. For specified transmitter and receiver characteristics, it is easier to detect a high concentrations of larger atmospheric particles than a low concentration of small particles. However, the radar cross-section of a given hydrometeor increases as the transmit frequency of the radar increases. Thus, in spite of a low transmit power, the sensitivity of a millimeter-wave radar might be better than high powered centimeter-wave radars. Also, ground clutter echoes and receiver system noise powers are sensitive functions of radar transmit frequency. For example, ground clutter in centimeter-wave radar sample volumes might mask non-precipitating or lightly precipitating clouds. An optimal clutter filter or signal processing technique can be used to suppress clutter masking its effects and/or enhanced weak cloud echoes that have significantly different Doppler characteristics than stationary ground targets. In practice, it is imperative to investigate the actual performance of S and Ka-band radar systems to detect small-scale, weak cloud reflectivity. This paper describes radar characteristics and the sensitivity of the new system in non-precipitating conditions. Recently, a dual-wavelength S and Ka-band radar system with matched resolution volume and sensitivity was built to remotely detect supercooled liquid droplets. The detection of liquid water content was based on the fact that the shorter of the two wavelengths is more strongly attenuated by liquid water. The radar system was deployed during the Winter Icing Storms Project 2004 (WISP04) near Boulder, Colorado to detect and estimate liquid water content. Observations by dual-wavelength radar were collected in both non

  4. Managing Your Team's Weakest Link.

    Science.gov (United States)

    Hills, Laura

    2015-01-01

    Do you have a poor-performing employee on your medical practice team? If so, you're not alone. Unfortunately, this is a problem that many medical practice managers face. This article describes the best strategies for managing your team's weakest link. It explores common yet very difficult circumstances that cause low employee performance and that test the patience, heart, and skills of a practice manager. It guides readers through a process of self-discovery to determine whether their negative biases or grudges may be causing employees to perform poorly. It suggests several possible other reasons for weak employee performance, including problems with the job, practice, leadership, communication, and fit between the employee and the job. This article also suggests the best strategy for communicating concerns about performance to the weakest-link employee. It offers guidance to practice managers about protecting their time and energy when handling a poor performer. It provides a simple formula for calculating the cost of a low-performing employee, 10 possible personal reasons for the employee's poor work performance, specific questions to ask to uncover the reasons for poor performance, and an eight-rule strategy for confronting poor performance effectively. Finally, this article offers practice managers a practical strategy for handling resistance from their weakest link, illustrated with a sample dialogue.

  5. Ka-Band Parabolic Deployable Antenna (KaPDA) Enabling High Speed Data Communication for CubeSats

    Science.gov (United States)

    Sauder, Jonathan F.; Chahat, Nacer; Hodges, Richard; Thomson, Mark W.; Rahmat-Samii, Yahya

    2015-01-01

    CubeSats are at a very exciting point as their mission capabilities and launch opportunities are increasing. But as instruments become more advanced and operational distances between CubeSats and earth increase communication data rate becomes a mission-limiting factor. Improving data rate has become critical enough for NASA to sponsor the Cube Quest Centennial Challenge when: one of the key metrics is transmitting as much data as possible from the moon and beyond Currently, many CubeSats communicate on UHF bands and those that have high data rate abilities use S-band or X-band patch antennas. The CubeSat Aneas, which was launched in September 2012, pushed the envelope with a half-meter S-band dish which could achieve 100x the data rate of patch antennas. A half-meter parabolic antenna operating at Ka-band would increase data rates by over 100x that of the AMOS antenM and 10,000 that of X-band patch antennas.

  6. A low-noise K-Ka band oscillator using AlGaAs/GaAs heterojunction bipolar transistors

    Science.gov (United States)

    Madihian, Mohammad; Takahashi, Hideki

    1991-01-01

    The design considerations, fabrication process, and performance of the first K-Ka-band oscillator implemented using a self-aligned AlGaAs/GaAs heterojunction bipolar transistor (HBT) are described. A large-signal time-domain-based design approach has been used which applies a SPICE-F simulator for optimization of the oscillator circuit parameters for maximum output power. The oscillator employs a 2 x 10 sq mm emitter AlGaAs/GaAs HBT that was fabricated using a pattern inversion technology. The HBT has a base current 1/f noise power density lower than 1 x 10 to the -20th sq A/Hz at 1 kHz and lower than 1 x 10 to the -22nd sq A/Hz at 100 kHz for a collector current of 1 mA. The oscillator, which is composed of only low-Q microstrip transmission lines, has a phase noise of -80 dBc/Hz at 100 kHz off carrier when operated at 26.6 GHz. These results indicate the applicability of the HBTs to low-phase-noise monolithic oscillators at microwave and millimeter-wave frequencies, where both Si bipolar transistors and GaAs FETs are absent.

  7. Design on a Ka-band Up-converter Module%Ka频段上变频模块设计

    Institute of Scientific and Technical Information of China (English)

    陈焕东

    2011-01-01

    A new Ka-band Up-converter module is described in this paper.How to achieve low spurious and low phase noise performance is studied,and then the feasible scheme is designed.The filter is co-simulated by Ansoft Designer and HFSS software and is realized with thin film technique.High spurious suppression is obtained by the filter.A 27 GHz local oscillator with very low phase noise is realized by sampling phase-locked technique.The waveguide to micro-strip transition is simulated.Finally the module is tested,and the design objective is satisfied.%论述一种Ka频段上变频模块设计,对模块的杂散和相位噪声性能做了分析,根据分析结果,设计出合理的变频方案。滤波器采用Ansoft Designer和HFSS软件协同仿真,薄膜工艺制作,获得足够的杂散抑制度从而实现低杂散。应用取样锁相技术合成了相位噪声极低的27 GHz本振。对波导—微带过渡结构进行仿真,并给出仿真结果。从测试结果表明,模块设计实现了低杂散和低相位噪声。

  8. Design of Ka band MMIC VCO%Ka波段单片压控振荡器的设计

    Institute of Scientific and Technical Information of China (English)

    李鹏亮; 马伟

    2014-01-01

    基于0.25μm GaAs pHEMT工艺设计了Ka波段单片压控振荡器,该压控振荡器采用源极正反馈结构,变容管采用源极和漏极接地的pHEMT管。通过优化输出匹配网络和谐振网络以改善输出功率和相位噪声性能,使用蒙特卡洛成品率分析对本设计的成品率进行分析和改进。版图仿真结果显示:芯片输出频率为24.6~26.3 GHz,输出功率为(10±1)dBm,谐波抑制大于19 dB,芯片尺寸为1.5 mm×1 mm。%A Ka-band MMIC VCO was designed with 0.25 μm GaAs pHEMT process. The source electrode positive feed-back structure is adopted for VCO. The pHEMT whose source electrode and drain electrode are connected to the ground is used for the varactor. The resonance network and the matching network are optimized to improve the output power and the phase noise performance. The yield of the VCO is analyzed and improved by the Monte-Carlo method. The simulation data shows the typical output power of VCO is 10±1 dBm,the output frequency of VCO is 24.6~26.3 GHz,the harmonic suppression is better than 19 dB. The chip size of the MMIC VCO is 1.5 mm×1 mm.

  9. An FSS-Backed 20/30 GHz Circularly Polarized Reflectarray for a Shared Aperture L- and Ka-Band Satellite Communication Antenna

    DEFF Research Database (Denmark)

    Smith, Thomas Gunst; Gothelf, Ulrich; Kim, Oleksiy S.

    2014-01-01

    A shared aperture antenna for simultaneous operation at L- (1525 to 1661 MHz) and Ka-band (19.7 to 20.2 GHz and 29.5 to 30.0 GHz) is demonstrated. This stacked antenna consists of a Ka-band reflectarray antenna with a frequency selective surface (FSS) ground-plane above an L-band patch array...... antenna. The reflectarray is based on the concentric dual split-loop element backed by a concentric dual-loop FSS element. The reflectarray comprises 80 × 80 elements and it is printed on a 40 ×40 cm2 Rogers 5880 substrate, while the L-band antenna is a 2 × 2 patch array. The reflectarray antenna has been...

  10. Feasibility Study on Acquisition, Tracking, and Pointing Using Earth Thermal Images for Deep-Space Ka-Band and Optical Communications

    Science.gov (United States)

    Lee, S.; Ortiz, G. G.; Roberts, W. T.; Alexander, J. W.

    2003-11-01

    The feasibility of using long-wavelength Earth thermal (infrared) images for antenna/ telescope tracking/pointing applications for both deep-space Ka-band (18 to 35 GHz) and free-space optical communications has been investigated and is reported on here. The advantage of this technology rests on using full Earth images in this band that yield more accurate estimates of geometric centroids than those of Earth images in the visible band. Furthermore, these images are nearly independent of Earth phase angle. The results of the study show that, at a Mars range with currently available sensors, a noise equivalent angle of 10 to 150 nrad and a bias error of better than 80 nrad can be obtained. This would enable precise pointing of both the optical and Ka-band communications beams.

  11. Analysis of Dual-Frequency Ocean Backscatter Measurements at Ku- and Ka-Bands Using Near-Nadir Incidence GPM Radar Data

    OpenAIRE

    NOUGUIER, Frederic; Mouche, Alexis; Rascle, Nicolas; Chapron, Bertrand; Vandemark, Douglas

    2016-01-01

    Global colocalized ocean surface measurements using the Global Precipitation Measurement near-nadir dual-frequency Ku- and Ka-band microwave measurements are analyzed and compared. Focusing on the Ka and Ku cross-sections fall-off with incidence angles, the contemporaneous measurements enable to more precisely document differing ocean scattering characteristics for both microwave frequencies. Sensitivity with wind speed and significant wave height is further reported using global comparisons ...

  12. Investigation of Ka-Band CW 250 W TWT%Ka波段250W连续波行波管的研制

    Institute of Scientific and Technical Information of China (English)

    冯晨; 杨明华; 黄拓朴

    2011-01-01

    本文介绍了一种Ka波段连续波250 W螺旋线行波管研制的主要技术方案.介绍了这种行波管的研究现状和研制成果.%This paper presents the main technology scheme of a CW 250 W Ka-band helix TWT. The current situation of this TWT and the research achievements are introduced.

  13. Analysis of Fade Detection and Compensation Experimental Results in a Ka-Band Satellite System. Degree awarded by Akron Univ., May 2000

    Science.gov (United States)

    Johnson, Sandra

    2001-01-01

    The frequency bands being used for new satellite communication systems are constantly increasing to accommodate the requirements for additional capacity. At these higher frequencies, propagation impairments that did not significantly affect the signal at lower frequencies begin to have considerable impact. In Ka-band, the next logical commercial frequency band to be used for satellite communication, attenuation of the signal due to rain is a primary concern. An experimental satellite built by NASA, the Advanced Communication Technology Satellite (ACTS), launched in September 1993, is the first US communication satellite operating in the Ka-band. In addition to higher carrier frequencies, a number of other new technologies, including onboard baseband processing, multiple beam antennas, and rain fade detection and compensation techniques, were designed into the ACTS. Verification experiments have been conducted since the launch to characterize the new technologies. The focus of this thesis is to describe and validate the method used by the ACTS Very Small Aperture Terminal (VSAT) ground stations in detecting the presence of fade in the communication signal and to adaptively compensate for it by the addition of burst rate reduction and forward error correction. Measured data obtained from the ACTS program is used to validate the compensation technique. In this thesis, models in MATLAB are developed to statistically characterize the increased availability achieved by the compensation techniques in terms of the bit error rate time enhancement factor. Several improvements to the ACTS technique are discussed and possible implementations for future Ka-band systems are also presented.

  14. High Efficiency Traveling-Wave Tube Power Amplifier for Ka-Band Software Defined Radio on International Space Station-A Platform for Communications Technology Development

    Science.gov (United States)

    Simons, Rainee N.; Force, Dale A.; Kacpura, Thomas J.

    2013-01-01

    The design, fabrication and RF performance of the output traveling-wave tube amplifier (TWTA) for a space based Ka-band software defined radio (SDR) is presented. The TWTA, the SDR and the supporting avionics are integrated to forms a testbed, which is currently located on an exterior truss of the International Space Station (ISS). The SDR in the testbed communicates at Ka-band frequencies through a high-gain antenna directed to NASA s Tracking and Data Relay Satellite System (TDRSS), which communicates to the ground station located at White Sands Complex. The application of the testbed is for demonstrating new waveforms and software designed to enhance data delivery from scientific spacecraft and, the waveforms and software can be upgraded and reconfigured from the ground. The construction and the salient features of the Ka-band SDR are discussed. The testbed is currently undergoing on-orbit checkout and commissioning and is expected to operate for 3 to 5 years in space.

  15. Fan tomography of the tropospheric water vapor for the calibration of the Ka band tracking of the Bepi-Colombo spacecraft (MORE experiment).

    Science.gov (United States)

    Barriot, Jean-Pierre; Serafini, Jonathan; Sichoix, Lydie

    2012-07-01

    The radiosciences Bepi-Colombo MORE experiment will use X/X, X/Ka and Ka/Ka band radio links to make accurate measurements of the spacecraft range and range rate. Tropospheric zenith wet delays range from 1.5 cm to 10 cm, with high variability (less than 1000 s) and will impair these accurate measurements. Conditions vary from summer (worse) to winter (better), from day (worse) to night (better). These wet delays cannot be estimated from ground weather measurements and alternative calibration methods should be used in order to cope with the MORE requirements (no more than 3 mm at 1000 s). Due to the Mercury orbit, MORE measurements will be performed by daylight and more frequently in summer than in winter (from Northern hemisphere). Two systems have been considered to calibrate this wet delay: Water Vapour Radiometers (WVRs) and GPS receivers. The Jet Propulsion Laboratory has developed a new class of WVRs reaching a 5 percent accuracy for the wet delay calibration (0.75 mm to 5 mm), but these WVRs are expensive to build and operate. GPS receivers are also routinely used for the calibration of data from NASA Deep Space probes, but several studies have shown that GPS receivers can give good calibration (through wet delay mapping functions) for long time variations, but are not accurate enough for short time variations (100 to 1000 s), and that WVRs must be used to efficiently calibrate the wet troposphere delays over such time spans. We think that such a calibration could be done by assimilating data from all the GNSS constellations (GPS, GLONASS, Galileo, Beidou and IRNSS) that will be available at the time of the Bepi-Colombo arrival at Mercury (2021), provided that the underlying physics of the turbulent atmosphere and evapotranspiration processes are properly taken into account at such time scales. This implies to do a tomographic image of the troposphere overlying each Deep Space tracking station at time scales of less than 1000 s. For this purpose, we have

  16. Ka-Band Wide-Bandgap Solid-State Power Amplifier: Prototype Combiner Spurious Mode Suppression and Power Constraints

    Science.gov (United States)

    Khan, P.; Epp, L.

    2006-01-01

    Results of prototype hardware activities related to a 120-W, 32-GHz (Ka-band) solid-state power amplifier (SSPA) architecture study are presented. Spurious mode suppression and the power-handling capability of a prototype 24-way radial combiner and a prototype 2-way septum binary combiner were investigated. Experimental data indicate that a commercial absorptive filter, designed to pass the circular TE01 mode, effectively suppressed the higher-order modes generated by a narrowband, flower-petal-type mode transducer. However, the same filter was not effective in suppressing higher-order modes generated by the broadband Marie mode transducer that is used in the prototype waveguide radial combiner. Should greater filtering be required by a particular SSPA application, a broadband mode filter that can suppress specifically those higher-order modes that are generated by the Marie transducer will need to be developed. A back-to-back configuration of the prototype radial combiner was tested with drive power up to approximately 50 W. No anomalous behavior was observed. Power measurements of the septum combiner indicate that up to 10-W radio frequency (RF) can be dissipated in the integrated resistive element before a permanent performance shift is observed. Thus, a given adder (a single-stage, 2-way combiner) can safely combine two 20-W sources, and the adder will not be damaged in the event of a source failure. This result is used to calculate the maximum source power that can be safely combined as a function of the number of sources combined and the number of source failures allowed in a multi-stage combiner. The analysis shows that SSPA power >140 W can be generated by power combining 16 sources producing 10 W each. In this configuration, up to three sources could fail with the guarantee that the combiner would not be damaged. Finally, a modified prototype septum combiner design was verified. The improved design reduced the assembly time from over 2 hours to about 15

  17. Global Ka Band Broadband Satellite Services Overview (1)%全球Ka波段宽带卫星业务的现状和发展(一)

    Institute of Scientific and Technical Information of China (English)

    陈强; 赵庆锁; 李涛

    2014-01-01

    本文简要回顾了全球卫星通信从C/Ku波段到Ka波段,从话音、广播电视到互联网应用的轨迹;对目前Ka波段HTS卫星网络的架构、地面系统情况以及采用的新技术进行了概述;列出了目前全球Ka波段在轨HTS卫星、建造的HTS卫星的容量、运营公司、使用的地面系统等;介绍了美国Ka波段宽带卫星业务的发展情况。%This article is retrospected the trajectory of global satellite telecommunication industry from C/Ku band to Ka band and from Voice/TV to Internet. The article is listed in HTS satellites which are in orbit and in construction, the capacity , the operators and the ground system. The Ka band broadband satellite business in USA is also introduced.

  18. Global Ka Band Broadband Satellite Services Overview (2)%全球Ka波段宽带卫星业务的现状和发展(二)

    Institute of Scientific and Technical Information of China (English)

    陈强; 赵庆锁; 李涛

    2014-01-01

    本文简要回顾了全球卫星通信从C/Ku波段到Ka波段,从话音、广播电视到互联网应用的轨迹;对目前Ka波段HTS卫星网络的架构、地面系统情况以及采用的新技术进行了概述;并列出了目前全球Ka波段在轨HTS卫星、建造的HTS卫星的容量、运营公司、使用的地面系统等;并介绍了美国Ka波段宽带卫星业务的发展情况。%This article is retrospected the trajectory of global satellite telecommunication industry from C/Ku band to Ka band and from Voice/TV to Internet. The article is listed in HTS satellites which are in orbit and in construction, the capacity , the operators and the ground system. The Ka band broadband satellite business in USA is also introduced.

  19. Thickness and Composition Tailoring of K- and Ka-Band Microwave Absorption of BaCo x Ti x Fe(12-2 x)O19 Ferrites

    Science.gov (United States)

    Narang, Sukhleen Bindra; Pubby, Kunal; Singh, Charanjeet

    2017-02-01

    The goal of this research is to investigate the electromagnetic and microwave absorption properties of M-type barium hexaferrites with chemical formula BaCo x Ti x Fe(12-2 x)O19 ( x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) in K and Ka band. Characterization techniques such as x-ray diffraction analysis and scanning electron microscopy were applied to confirm ferrite formation. The frequency dependence of the complex permittivity and complex permeability was studied for prepared ferrite samples in the frequency range from 18 GHz to 40 GHz. Factors such as the quarter-wavelength condition, impedance matching, high dielectric-magnetic losses, as well as ferromagnetic resonance were investigated to determine their contribution to the absorption characteristics. It was found that the quarter-wavelength ( λ/4) model could be successfully applied to predict and understand the position as well as number of reflection peaks in the microwave absorption spectrum. The origin of the reflection loss peaks is explained and verified based on calculations of input impedance, loss tangent, and ferromagnetic resonance. Reflection loss analysis revealed that all six compositions exhibited reflection loss peaks (absorption >90%) at their matching thicknesses and frequencies. Therefore, these ferrites are potential candidates for use in electromagnetic shielding applications requiring low reflectivity in K and Ka band.

  20. Link-Net : improving railcar fleet management

    Energy Technology Data Exchange (ETDEWEB)

    Mancini, G.; Partington, M. [Procor Limited, Oakville, ON (Canada)

    1997-12-31

    Information about Link-Net, a new rail car information facility available on Netscape, was presented. Link-Net was developed by Ontario`s Procor Limited. It can be used to find a comprehensive list of data on rail fleet management, down to details about the status of single cars. 6 figs.

  1. A Ka-Band Transmitter for Deep Space Communication%深空通信Ka频段数传发射机的研究

    Institute of Scientific and Technical Information of China (English)

    梁显锋; 张津舟; 谢春坚; 熊蔚明; 安军社; 陈晓敏; 孙辉先

    2012-01-01

    Design of a Ka-band telemetry transmitter is proposed to meet requirements of future deep space missions. Key output characteristics results of the Ka-band transmitter are given. Integrated design and digital technologies are used to develop a light, compact and high efficiency transmitter. Based on CCSDS (Consultative Committee for Space Data Systems) recommendations, a concatenated error-control code in channel coding is used for improved performance and different code rate ranges are separately chosen for PCM/BPSK/PM (Pulse Code Modulation/ Quadrature Phase Shift Keying/Phase Modulation), NRZ (Non-Return to Zero)/BPSK and SRRC (Square Root Raised Cosine)-QPSK (Quadrature Phase Shift Keying) modulation. Equipped with an SSPA (Solid State Power Amplifier), the Ka-band transmitter provides an output power of 2. 0 W 31. 84 GHz center frequency. The supported data rate is up to 2. 0 Mbit/s with QPSK modulation.%针对我国今后深空探测任务的发展需求,提出了应用于深空通信的Ka频段数传发射机技术设计方案,给出了整机关键输出特性结果.采用一体化设计和数字化技术,Ka频段数传发射机实现了轻小型化和高效率.基于CCSDS(空间数据系统咨询委员会)的相关建议标准,信道编码采用级联纠错编码技术和低、中、高速率数传码分段对应选择PCM/BPSK/PM(脉冲编码调制/二相相移键控/调相)、NRZ/BPSK(非归零/二相相移键控)和SRRC-QPSK(平方根升余弦-四相相移键控)的数据调制模式.Ka频段发射机采用KaSSPA(Ka频段固态功率放大器)实现了在31.84 GHz中心频率输出信号功率大于2.0W,QPSK(四相相移键控)调制时支持最大码率2 Mbit/s.

  2. On Solving TM0n Modal Excitation in a Ka-Band Overmoded Circular Waveguide by the Conservation of Complex Power Technique

    Institute of Scientific and Technical Information of China (English)

    Feng Lan; Xi Gao; Zong-Jun Shi

    2009-01-01

    To measure the radiation properties of relativistic diffraction generator (RDG) in Ka-band, a TM0n modal excitation model is established, which consists of an overmoded circular waveguide and a coaxial line feeding probe. Using the transverse E-field mode matching and the conservation of complex power technique (CCPT), we deduce the scattering matrix at coaxial line to coaxial line and coaxial line to circular waveguide junctions. Then using the overall cascaded junction scattering matrix, the numerical results for the reflection coefficient of the coaxial line and the power distribution of TM0n multi-modal are presented. The numerical results are in agreement with HFSS simulation results and experimental results. The analysis shows that by choosing the appropriate position of coaxial line probe, the power proportion of the device operating mode excited in circular waveguide could be the largest.

  3. A portable Ka-band front-end test package for beam-waveguide antenna performance evaluation. Part 1: Design and ground tests

    Science.gov (United States)

    Otoshi, T. Y.; Stewart, S. R.; Franco, M. M.

    1991-01-01

    A unique experimental method was used to test the beam waveguide (BWG) antenna at Deep Space Station (DDS) 13 in the Goldstone Deep Space Communications Complex near Barstow, California. The methodology involved the use of portable test packages to make measurements of operating noise temperatures and antenna efficiencies (as functions of antenna pointing angles) at the Cassegrain focal point and the final focal point located in a subterranean pedestal room. Degradations caused by the BWG mirror systems were determined by making comparisons of the measured parameters at the two focal points of the antenna. Previous articles were concerned with the design, performance characteristics, and test results obtained with an X-band test package operating at 32 GHz. Noise temperature measurement results are presented for the Ka-band test package in an on-the-ground test configuration.

  4. The Electron Gun's Design with High Performance for Ka-Band TWT%Ka波段行波管高性能电子枪设计

    Institute of Scientific and Technical Information of China (English)

    赵国庆; 王文祥; 宫玉彬; 魏彦玉; 黄民智

    2012-01-01

    The initial structure parameters of the electron gun for Ka-band TWT can be obtained by the synthesis iteration proposed by Vaughan, and then, the modifications for electron gun's structure are performed by stimulation and optimization with the TAU. With comparison of the uniformity electron's emission density of the cathode surface, the influence of trajectories for different thermal emission angles of e-lectrons, the trajectory's laminar and the radial current density distribution near the electron beam's waist, the final structure of the electron gun is got. The test result is in agreement with the optimized design for Ka-band TWT electron gun.%利用学者Vaughan等提出的皮尔斯电子枪设计综合迭代法计算得到某Ka波段行波管电子枪的基本结构参数;在此基础上,采用电子光学数值模拟软件Tau进行模拟优化进一步修改电子枪各结构尺寸;在模拟优化过程中,通过量化比较、判断阴极表面电子发射密度的均匀性,比较阴极表面部分热初速电子非垂直发射时对电子注轨迹的影响程度,比较注腰位置附近电子注层流性及径向密度分布均匀性等,最后得到优化的电子枪结构设计.对装配有此优化设计电子枪的行波管进行了实验研究,测试结果达到设计要求.

  5. Linking ecosystem processes to sustainable wetland management

    Science.gov (United States)

    Euliss, Ned H.; Smith, Loren M.; Wilcox, Douglas A.; Browne, Bryant A.

    2009-01-01

    As a result of concern over problems associated with the future of managed wetlands in North America, nearly two dozen wetland scientists and managers met in February 2006 at Bosque del Apache National Wildlife Refuge in New Mexico and discussed a sustainable approach to wetland management. This approach links science with management by focusing on underlying wetland processes. From that meeting, several papers were developed and published in Wetlands to address these concerns (Euliss et al. 2008, Smith et al. 2008, Wilcox 2008). This article summarizes our first paper, Euliss et al. (2008), and a future Newsletter article will summarize Smith et al. (2008). Realization of the role that complex interactions play in maintaining ecosystems, coupled with increasing demands of humans for ecosystem services, has prompted much interest in ecosystem management. Not surprisingly, sustainability of ecosystems has become an explicitly stated goal of many natural resource agencies and, in some cases, has been legislatively mandated to ensure provision of resources for future generations. However, examples of sustainable ecosystem management are uncommon because management goals often focus on specific deliverables rather than processes that sustain ecosystems. This paper has three sections: (1) perspectives in which we provide a bit of history, (2), ecological consequences of a static view, and (3) suggestions to aid wetland managers link management goals with critical ecosystem processes responsible for provision of wetland services.

  6. A Mobile Communications Space Link Between the Space Shuttle Orbiter and the Advanced Communications Technology Satellite

    Science.gov (United States)

    Fink, Patrick; Arndt, G. D.; Bondyopadhyay, P.; Shaw, Roland

    1994-01-01

    A communications experiment is described as a link between the Space Shuttle Orbiter (SSO) and the Advanced Communications Technology Satellite (ACTS). Breadboarding for this experiment has led to two items with potential for commercial application: a 1-Watt Ka-band amplifier and a Ka-band, circularly polarized microstrip antenna. Results of the hybrid Ka-band amplifier show gain at 30 dB and a saturated output power of 28.5 dBm. A second version comprised of MMIC amplifiers is discussed. Test results of the microstrip antenna subarray show a gain of approximately 13 dB and excellent circular polarization.

  7. A High Efficiency, Miniaturized Ka Band Traveling Wave Tube Based on a Novel Finned Ladder RF Circuit Design

    Science.gov (United States)

    Wintucky, E. G.; Wilson, J. D.; Vaden, K. R.; Force, D. A.; Freeman, J. C.; Lesny, G. G.; Kory, C. L.; Chevalier, C. T.; Ebihara, B.; Dayton, J. A.; Williams, W. D. (Technical Monitor)

    2001-01-01

    Space communications architectures are being planned to meet the high rate data distribution requirements of future NASA Enterprise missions. These will require the use of traveling wave tube amplifiers (TWTAs) to provide the high frequency, RF (radio frequency) power and efficiency needed for many of the communications links. A program addressing these requirements is currently underway at NASA Glenn Research Center (GRC) for the development of a high efficiency, 20 watt, 32 GHz TWT of reduced size and weight that is based on a novel high gain n circuit design, termed the 'finned ladder'.

  8. Ka波段螺旋波纹波导回旋行波管%Linear calculation of Ka-band gyro-TWT with helical waveguide

    Institute of Scientific and Technical Information of China (English)

    薛智浩; 刘濮鲲; 杜朝海

    2012-01-01

    螺旋波纹波导回旋行波管与采用圆波导的回旋行波管相比,有较大的带宽.介绍了它的线性注波互作用理论,并用该理论计算了不同的磁场与波导表面微扰幅度对Ka波段螺旋波纹波导回旋行渡管线性增益的影响.计算结果与已报道的实验结果基本符合,说明该理论可以初步确定螺旋波纹波导回旋行波管的各项参数.%Gyrotron traveling-wave tube (gyro-TWT) with helical waveguide has wider instantaneous frequency bandwidth than that with smooth waveguide. This paper introduces the linear theory of its beam-wave interaction, and calculates the influence on linear gain of Ka-band gyro-TWT caused by changing the applied magnetic field and the amplitude of the groove. The results accord with those reported, indicating that the theory can be used to preliminarily determine the parameters of gyro-TWT assembly.

  9. A Compact Ka-Band PHEMT MMIC Voltage Controlled Oscillator%紧凑型Ka波段PHEMT微波单片集成VCO

    Institute of Scientific and Technical Information of China (English)

    余稳; 孙晓玮; 钱蓉; 张义门

    2005-01-01

    设计并流片制作了基于GaAs PHEMT工艺的Ka波段微波单片集成压控振荡器(MMIC VCO).该VCO具有紧凑、宽电调谐带宽及高输出功率的特点.提出了缩小芯片面积及增大调谐带宽的方法,同时还给出了设计MMIC VCO的基本步骤.该方法设计并流片制做的MMIC VCO的测量结果为:振荡频率为36±1.2GHz,输出功率为10士1dBm,芯片面积为1.3mm×1.0mm.%A compact Ka-band monolithic microwave integrated circuit(MMIC) voltage controlled oscillator (VCO)with wide tuning range and high output power, which is based on GaAs PHEMT process,is presented. A method is introduced to reduce the chip size and to increase the bandwidth of operation. The procedure to design a MMIC VCO is also described here. The measured oscillating frequency of the MMIC VCO is 36±1.2GHz and the output power is 10±1dBm. The fabricated MMIC chip size is 1.3mm× 1.0mm.

  10. Application of Synthetic Storm Technique for Diurnal and Seasonal Variation of Slant Path Ka-Band Rain Attenuation Time Series over a Subtropical Location in South Africa

    Directory of Open Access Journals (Sweden)

    J. S. Ojo

    2015-01-01

    Full Text Available As technology advances and more demands are on satellite services, rain-induced attenuation still creates one of the most damaging effects of the atmosphere on the quality of radio communication signals, especially those operating above 10 GHz. System designers therefore require statistical information on rain-induced attenuation over the coverage area in order to determine the appropriate transmitter and receiver characteristics to be adopted. This paper presents results on the time-varying rain characterization and diurnal variation of slant path rain attenuation in the Ka-band frequency simulated with synthetic storm techniques over a subtropical location in South Africa using 10-year rain rate time-series data. The analysis is based on the CDF of one-minute rain rate; time-series seasonal variation of rain rate observed over four time intervals: 00:00–06:00, 06:00–12:00, 12:00–18:00, and 18:00–24:00; diurnal fades margin; and diurnal variation of rain attenuation. Comparison was also made between the synthesized values and measured attenuation data. The predicted statistics are in good agreement with those obtained from the propagation beacon measurement in the area. The overall results will be needed for an acceptable planning that can effectively reduce the fade margin to a very low value for an optimum data communication over this area.

  11. Volcanic Ash Cloud Observation using Ground-based Ka-band Radar and Near-Infrared Lidar Ceilometer during the Eyjafjallajökull eruption

    Directory of Open Access Journals (Sweden)

    Frank S. Marzano

    2015-03-01

    Full Text Available Active remote sensing techniques can probe volcanic ash plumes, but their sensitivity at a given distance depends upon the sensor transmitted power, wavelength and polarization capability. Building on a previous numerical study at centimeter wavelength, this work aims at i simulating the distal ash particles polarimetric response of millimeter-wave radar and multi-wavelength optical lidar; ii developing and applying a model-based statistical retrieval scheme using a multi-sensor approach. The microphysical electromagnetic forward model of volcanic ash particle distribution, previously set up at microwaves, is extended to include non-spherical particle shapes, vesicular composition, silicate content and orientation phenomena for both millimeter and optical bands. Monte Carlo generation of radar and lidar signatures are driven by random variability of volcanic particle main parameters, using constraints from available data and experimental evidences. The considered case study is related to the ground-based observation of the Eyjafjallajökull (Iceland volcanic ash plume on May 15, 2010, carried out by the Atmospheric Research Station at Mace Head (Ireland with a 35-GHz Ka-band Doppler cloud radar and a 1064-nm ceilometer lidar. The detection and estimation of ash layer presence and composition is carried out using a Bayesian approach, which is trained by the Monte Carlo model-based dataset. Retrieval results are corroborated exploiting auxiliary data such as those from a ground-based microwave radiometer also positioned at Mace Head.

  12. Review of the Airborne Ku and Ka-band Satellite Communication System%机载Ku、Ka频段卫星通信系统综述

    Institute of Scientific and Technical Information of China (English)

    艾文光; 赵大勇; 邓军

    2011-01-01

    叙述了Ku频段和Ka频段机载卫星通信系统的国内外发展现状,列举了几个典型的卫星通信系统技术指标,并简述了研制机载卫星通信系统应注意的事项和技术途径,其中包括选择天线系统形式,合理分配系统指标,消除多普勒效应的影响等。%This paper reviews the Ku-band and Ka-band airborne satellite communication system both at home and abroad,cites a few typical satellite communication system specifications,and outlines matters that deserve our attention and some technical approaches in the development of airborne satellite communications systems,including choosing the form of antenna system,reasonably allocating system indicators,and eliminating the impact of the Doppler effect.

  13. A low-phase-noise Ka-band push-push voltage-controlled oscillator using CMOS/glass-integrated passive device technologies.

    Science.gov (United States)

    Wang, Sen

    2014-09-01

    In this paper, a Ka-band CMOS push-push voltage- controlled oscillator (VCO) integrated into a glass-integrated passive device (GIPD) process is presented. The transformer, λ/4 transmission line, and inductors of the VCO are realized in the GIPD process, achieving superior performances, and therefore improve the phase noise of the VCO. Moreover, the transformer-based VCO is a differential Hartley topology to further reduce the phase noise and chip area. Operating at 1.8 V supply voltage, the VCO core consumes merely 3.8 mW of dc power. The measured phase noise is -109.18 dBc/Hz at 1 MHz offset from the 30.84 GHz oscillation frequency. The push-push VCO also demonstrates a 24.5 dB fundamental rejection, and exhibits an 8.4% tuning range. Compared with recently published CMOS-based VCOs, it is observed that the proposed VCO exhibits excellent performance under low power consumption.

  14. Design of a Novel Ka-band Circular Polarization Microstrip Antenna%一种新型Ka频段圆极化微带天线设计

    Institute of Scientific and Technical Information of China (English)

    刘洋; 王昕; 董涛

    2012-01-01

    A novel Ka band circular-polarization microstrip antenna is proposed.The antenna is coupled-fed by L-shaped apertures in the ground plane to realize circular-polarization.The antenna array is analyzed and optimized,then the array is made and measured.Simulated and measured results show the feasibility of the proposed design.Simulated results of the relative impedance bandwidth and axial-ratio bandwidth are 3.9% and 2% respectively,and measured results are 4.2% and 3.5%.With good circular polarization performance,the antenna can be used in satellite communication.%提出了一种Ka频段圆极化微带天线的新设计,采用缝隙耦合馈电方式,通过在接地板开L型缝隙实现天线的圆极化工作。对天线阵列进行了仿真优化和加工实测,仿真和测试结果表明了设计的可行性。天线仿真和实测的相对阻抗带宽分别为3.9%和4.2%,仿真和实测的轴比相对带宽分别为2%和3.5%。天线具有良好的圆极化特性,可应用在卫星通信中。

  15. Ka频段遥感卫星数据接收系统跟踪性能测试新方法%A New Tracking Performance Test Method for Ka-band Remote Sensing Satellite Data Receiving System

    Institute of Scientific and Technical Information of China (English)

    朱维祥; 穆伟; 王万玉; 冯旭祥; 王永华

    2015-01-01

    To solve the problems in the tracking performance test of Ka-band Low Earth Orbit( LEO) re-mote sensing satellite data receiving system,a new method is proposed. Simulation data is generated by u-sing Ka-band LEO satellite,and dynamic target tracking is simulated with the method of tracking Ka-band beacon on the calibration tower by rotating the third axis of antenna. A verification test on tracking per-formance of receiving system is carried out in the developed prototype system. The proposed method pro-vides a reference for acceptance test for Ka-band LEO satellite data receiving system.%针对Ka频段低轨遥感卫星数据接收系统跟踪性能测试中的问题,提出了一种新的测试方法。利用设计的Ka频段低轨卫星动态目标模拟数据,采用转动第三轴跟踪标校塔Ka频段信标的方式模拟动态目标的跟踪,在研制的原型系统中开展了接收系统跟踪性能的测试验证。该测试方法可为Ka频段低轨卫星数据接收系统跟踪性能的测试验收提供参考。

  16. 一种Ka波段低噪声下变频器组件%Novel Ka-band low-noise down-converter assembly

    Institute of Scientific and Technical Information of China (English)

    李鸣; 李兴国

    2006-01-01

    An efficient way to design a down-converter assembly for the Ka-band millimeter system is presented, in which dielectric resonators (DR's) are adopted in the Schottky barrier diode image recovery mixer and the local oscillator (LO). DR structures guarantee high frequency stability with an acceptable volume. The configurations of low noise amplifier, mixer and oscillator in the assembly are described and fabricated to estimate the chain performance. According to the verification results, the assembly exhibits the noise figure of less than 5 dB over 1 GHz frequency range, and the single-sideband phase noise (200 kHz offset from carrier frequency) of - 70 dBc/Hz. Utilizing the DR structure, the frequency stability of the local oscillator is less than 60 × 10-6/℃.%介绍了一种用于毫米波系统的下变频器,其中混频器采用了肖特基二极管镜频回收混频结构,振荡器采用了DRO(dielectric resonator oscillator)结构以提高系统性能,以保证在合适的体积内实现较高的频率稳定度.描述了系统中低噪声放大器、混频器、振荡器的性能,用于评估系统链路性能,最后合并制作在单个基片上.根据测试结果,该下变频器的噪声系数在35 GHz处1 GHz频率范围内小于5 dB,单边带相位噪声系数在偏离载波200 kHz处达到-70 dBc/Hz.由于采用了介质谐振结构,本振的频率稳定度小于60×10-6/℃.

  17. Linking integrated water resources management and integrated coastal zone management.

    Science.gov (United States)

    Rasch, P S; Ipsen, N; Malmgren-Hansen, A; Mogensen, B

    2005-01-01

    Some of the world's most valuable aquatic ecosystems such as deltas, lagoons and estuaries are located in the coastal zone. However, the coastal zone and its aquatic ecosystems are in many places under environmental stress from human activities. About 50% of the human population lives within 200 km of the coastline, and the population density is increasing every day. In addition, the majority of urban centres are located in the coastal zone. It is commonly known that there are important linkages between the activities in the upstream river basins and the environment conditions in the downstream coastal zones. Changes in river flows, e.g. caused by irrigation, hydropower and water supply, have changed salinity in estuaries and lagoons. Land use changes, such as intensified agricultural activities and urban and industrial development, cause increasing loads of nutrients and a variety of chemicals resulting in considerable adverse impacts in the coastal zones. It is recognised that the solution to such problems calls for an integrated approach. Therefore, the terms Integrated Water Resources Management (IWRM) and Integrated Coastal Zone Management (ICZM) are increasingly in focus on the international agenda. Unfortunately, the concepts of IWRM and ICZM are mostly being developed independently from each other by separate management bodies using their own individual approaches and tools. The present paper describes how modelling tools can be used to link IWRM and ICZM. It draws a line from the traditional sectoral use of models for the Istanbul Master Planning and assessment of the water quality and ecological impact in the Bosphorus Strait and the Black Sea 10 years ago, to the most recent use of models in a Water Framework Directive (WFD) context for one of the selected Pilot River Basins in Denmark used for testing of the WFD Guidance Documents.

  18. Linking soil biodiversity and agricultural soil management

    NARCIS (Netherlands)

    Thiele-Bruhn, S.; Bloem, J.; Vries, de F.T.; Kalbitz, K.; Wagg, C.

    2012-01-01

    Soil biodiversity vastly exceeds aboveground biodiversity, and is prerequisite for ecosystem stability and services. This review presents recent findings in soil biodiversity research focused on interrelations with agricultural soil management. Richness and community structure of soil biota depend o

  19. Linking soil biodiversity and agricultural soil management

    NARCIS (Netherlands)

    Thiele-Bruhn, S.; Bloem, J.; de Vries, F.T.; Kalbitz, K.; Wagg, C.

    2012-01-01

    Soil biodiversity vastly exceeds aboveground biodiversity, and is prerequisite for ecosystem stability and services. This review presents recent findings in soil biodiversity research focused on interrelations with agricultural soil management. Richness and community structure of soil biota depend

  20. The XML approach to implementing space link extension service management

    Science.gov (United States)

    Tai, W.; Welz, G. A.; Theis, G.; Yamada, T.

    2001-01-01

    A feasibility study has been conducted at JPL, ESOC, and ISAS to assess the possible applications of the eXtensible Mark-up Language (XML) capabilities to the implementation of the CCSDS Space Link Extension (SLE) Service Management function.

  1. Linking case management and community development.

    Science.gov (United States)

    Austin, Carol D; McClelland, Robert W; Gursansky, Di

    2006-01-01

    Case management, in various forms, is now institutionalized as a core part of policy and programs designed to deliver home- and community-based services to older adults. The case management role, in theory, requires attention to both client and system goals, although in practice the system goals that have received most attention have been gatekeeping and resource allocation. While case managers have been admonished to find and develop resources in the community, this has primarily taken the form of including informal services in individual client care plans. What has been missing is focused attention to the potential of the community as a nurturing environment with the capacity to support older adults and their caregivers. Sustainable care for older adults cannot be achieved by formal service and family support alone. This article proposes the creation of linkages between case managers, who build the service arrangements for older people, and community developers, who are responsible for building community capacity and social capital. It is argued that this linkage is essential for establishing the foundations of a caring community with the capacity to support older people.

  2. Design and study on the dual-band radome with FSS operation at Ku-/Ka-band%Ku/Ka波段双通带频率选择表面雷达罩设计研究

    Institute of Scientific and Technical Information of China (English)

    王秀芝; 高劲松; 徐念喜

    2013-01-01

    In order to meet the multi-band and integration requirements of the communication apparatus, the coupling and resonance mecha-nism can be exploited to design a frequency selective surface (FSS), with two pass-bands at Ku-band and Ka-band, which is composed of three metallic layers and fabricated on a flat substrate equivalent to a solid wall radome or an A-sandwiched radome. According to the physical structure of the FSS, an equivalent circuit model is established to analyze the filtering mechanism, and the transmission characteristics of the radomes with FSS are obtained by using a full-wave analysis software. The first pass-band at Ku-band with miniaturization property can be achieved by coupling the electric and magnetic field of the three surfaces, while the second pass-band at Ka-band can be achieved by the resonance of the square loop slots embedded in the capacitive surfaces. The transmissions of the solid wall radome and A-sandwiched radome with FSS are 89%and 94.7%at Ku-band, and 88.2%and 93.7%at Ka-band, respectively. When the incident angle is varied from normal to 60◦, the frequency response characteristics of the two pass-bands are stable. Finally, the experimental results of the prototype with a solid substrate measured in free-space environment are in good agreement with the simulated values. The proposed radome structure with FSS, which is based on the coupling and resonance mechanism, can achieve two stable pass-bands at Ku-/Ka-band. This may provide some theoretical and experimental assistance for the study of the multi-band and wide band spacing FSS.%为了满足现代通信设备多频带及集成化要求,基于耦合机理和谐振机理,在实心半波壁雷达罩和A夹层雷达罩等效平板基底上设计了一种由容性表面(内嵌谐振单元)-感性表面-容性表面(内嵌谐振单元)-等效基底级联而成的Ku/Ka波段双通带频率选择表面结构.根据FSS的物理结构建立了等效电路模型,分析了滤波机

  3. Ka-BAND MICROSTRIP INTEGRATED LOCAL-OSCILLATOR-MIXER ASSEMBLY USED IN PROJECTILE SENSORS%用于抛掷敏感器的Ka-波段微带集成本振-混频组件

    Institute of Scientific and Technical Information of China (English)

    蒋金水; 李兴国; 吴文; 娄国伟

    2001-01-01

    A compact Ka-band microstrip integrated local-oscillator-mixer assembly used in projectile sensors was introduced. The overall configuration of microstrip circuit of this assembly was given. The functions of each component were described. The environment and reliability tests performed on this assembly were explored in detail, which include vibration, shock and temperature. The Ka-band local-oscillator-mixer assembly exhibits a 3.4~4.2-dB double side band (DSB) noise figure over a 2-GHz RF bandwidth. LO-to-RF isolation is greater than 27dB over the range of operating frequencies. The frequency stability of local oscillator with dielectric resonator used is less than 60ppm/℃.%介绍一种用于抛掷敏感器的结构紧凑的Ka-波段微带集成本振-混频组件,给出了该组件的微带电路结构,叙述了其中每一部件的功能.对该组件仔细做了环境和可靠性实验,其中包括震动,冲击和温度.在2GHz射频带宽内,该组件的双边带噪声系数是3.4~4.2dB,在其工作频带内本振到射频的隔离度大于27dB.由于使用了介质谐振器,本振的频率稳定度小于60ppm/℃.

  4. Model and Implementation of Communication Link Management Supporting High Availability

    Institute of Scientific and Technical Information of China (English)

    Luo Juan; Cao Yang; He Zheng; Li Feng

    2004-01-01

    Despite the rapid evolution in all aspects of computer technology, both the computer hardware and software are prone to numerous failure conditions. In this paper, we analyzed the characteristic of a computer system and the methods of constructing a system , proposed a communication link management model supporting high availability for network applications, Which will greatly increase the high availability of network applications. Then we elaborated on heartbeat or service detect, fail-over, service take-over, switchback and error recovery process of the model. In the process of constructing the communication link, we implemented the link management and service take-over with high availability requirement, and discussed the state and the state transition of building the communication link between the hosts, depicted the message transfer and the start of timer. At Last, we applied the designed high availability system to a network billing system, and showed how the system was constructed and implemented, which perfectly satisfied the system requirements.

  5. Airborne Field Campaign Results of Ka-band Precipitation Measuring Radar in China%我国Ka频段降水测量雷达机载校飞试验结果

    Institute of Scientific and Technical Information of China (English)

    商建; 郭杨; 吴琼; 杨虎; 尹红刚

    2011-01-01

    2010年6-10月在天津与江苏地区开展了国内首次Ku/Ka频段星载降水测量雷达机载校飞试验.此次校飞试验获得了宝贵的机载雷达观测数据和地面、海面同步观测数据,目前已开展了外定标、数据对比与衰减订正等工作.该文给出了天津校飞试验中Ka频段降水测量雷达实测结果,对Ka频段降水测量雷达资料与天津地区S波段地基多普勒雷达资料进行了详细的对比分析,有利于更好地了解Ka频段降水测量雷达仪器本身的性能及其探测降水的能力;利用由GPS探空资料、地基多通道微波辐射计观测亮温结合微波辐射传输模式得到的雷达路径积分衰减量,对Ka频段降水测量雷达进行了衰减订正,为继续开展降水反演工作奠定了基础.%Spaceborne precipitation measuring radar can measure precipitation quantitatively, observe the vertical distribution and provide three dimensional precipitation structures. Spaceborne precipitation measuring radar is an important instrument on FY-3 meteorological satellite constellation. As a possible future member of the Global Precipitation Measurement(GPM) , this satellite will carry dual-frequency precipitation radar operating at Ku and Ka bands to provide scientific data for dual-frequency retrieval algorithm. Its two prototype devices, Ku-band and Ka-band radars have already been developed under the support of National Defense Science and Industry Bureau. Field campaign of Ku/Ka-band airborne precipitation measuring radar is carried out by National Satellite Meteorological Center of China Meteorological Administration combining several groups from June to October in 2010 in Tianjin and Jiangsu, called BH-RM 2010 and JS-RM 2010, respectively. This is the first time that China carries out airborne precipitation measuring radar field campaign. The purposes of this field campaign are to validate the correctness of internal and external calibration scheme under airborne

  6. Mechanisms linking advanced airway management and cardiac arrest outcomes.

    Science.gov (United States)

    Benoit, Justin L; Prince, David K; Wang, Henry E

    2015-08-01

    Advanced airway management--such as endotracheal intubation (ETI) or supraglottic airway (SGA) insertion--is one of the most prominent interventions in out-of-hospital cardiac arrest (OHCA) resuscitation. While randomized controlled trials are currently in progress to identify the best advanced airway technique in OHCA, the mechanisms by which airway management may influence OHCA outcomes remain unknown. We provide a conceptual model describing potential mechanisms linking advanced airway management with OHCA outcomes. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Urban Land Use Classifcation Linked to Planning Management

    Institute of Scientific and Technical Information of China (English)

    QI Dongjin; ZHOU Jianyun; SHI Ke

    2012-01-01

    By analyzing the applicability of the new Code for Classification of Urban Land Use and Planning Standards of Development Land from the angle of planning management,this paper points out the conflicts between the planning and land use management institutions.Referring to the experience of land use control in the US and the UK through zoning and case law respectively,this paper puts forward that the urban land use classification should take into consideration the characteristics of the actual urban planning system and the possibility of mixed land use due to the uncertainty of urban development,and be linked to the institutions of planning and land supply management.

  8. Calculation of attenuation by rain using the DAH model and diameter of antennas for the Ka Band in Mexico; Calculo de atenuacion por lluvia usando el modelo DAH y diametro de antena para Banda Ka en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Landeros-Ayala, S.; Neri-Vela, R; Cruz-Sanchez, H.; Hernandez-Bautista, H. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2002-03-01

    In the last years, the peak in the demand of satellite communication service has caused the saturation in the use of the frequencies corresponding to the band, Cand Ku. Due to this, the engineers have looked for viable alternatives, in order to satisfy the current requisition, as well as the future demand, for which a considerable increment is expected. One of these alternatives is the use of the Ka Band (20Hz/30Hz), that is why the importance of studying the propagation effects that are experienced at these frequencies, especially the attenuation effect by rain, as in this case, where it is significant. The present article has the purpose to describe the use of the Modelo DAH (whose authors are Asoka Dissanayake, Jeremy Allnutt and Fatim Haidara), mixed with the global maps of distribution of rain by Crane, for the calculation of the attenuation by rain in satellite communication systems operated in the Ka Band. Besides, antenna diameters for the systems of communications in Ka Band in different locations of the Mexican Republic, using for it the attenuation margins for rain obtained through the Modelo DAH, and using as references the characteristics of the ANIK F2 satellite and a terrestrial station VSAT, are proposed. [Spanish] En los ultimos anos, el auge en la demanda de servicios de comunicacion por satelite ha provocado la saturacion en los uso de la frecuencia correspondientes a las bandas C y Ku. Debido a esta razon, se han buscado alternativas viables para poder satisfacer la demanda actual, asi como la demanda futura, para la cual se espera un incremento considerable. Una de estas alternativas es el uso de Banda Ka (20Hz/30Hz), de ahi la importancia del estudio sobre los efectos de programacion que se experimentan a esta frecuencia, en especial, el efecto de atencion por lluvias, ya que sen este caso resulta ser significativa. El presente articulo tiene como finalidad describir el uso del Modelo DAH (cuyos autores son Asoka Dissanayake, Jeremy Allnutt y

  9. Demonstration of Multi-Gbps Data Rates at Ka-Band Using Software-Defined Modem and Broadband High Power Amplifier for Space Communications

    Science.gov (United States)

    Simons, Rainee N.; Wintucky, Edwin G.; Landon, David G.; Sun, Jun Y.; Winn, James S.; Laraway, Stephen; McIntire, William K.; Metz, John L.; Smith, Francis J.

    2011-01-01

    The paper presents the first ever research and experimental results regarding the combination of a software-defined multi-Gbps modem and a broadband high power space amplifier when tested with an extended form of the industry standard DVB-S2 and LDPC rate 9/10 FEC codec. The modem supports waveforms including QPSK, 8-PSK, 16-APSK, 32-APSK, 64-APSK, and 128-QAM. The broadband high power amplifier is a space qualified traveling-wave tube (TWT), which has a passband greater than 3 GHz at 33 GHz, output power of 200 W and efficiency greater than 60 percent. The modem and the TWTA together enabled an unprecedented data rate at 20 Gbps with low BER of 10(exp -9). The presented results include a plot of the received waveform constellation, BER vs. E(sub b)/N(sub 0) and implementation loss for each of the modulation types tested. The above results when included in an RF link budget analysis show that NASA s payload data rate can be increased by at least an order of magnitude (greater than 10X) over current state-of-practice, limited only by the spacecraft EIRP, ground receiver G/T, range, and available spectrum or bandwidth.

  10. Improved fiber nonlinearity mitigation in dispersion managed optical OFDM links

    Science.gov (United States)

    Tamilarasan, Ilavarasan; Saminathan, Brindha; Murugappan, Meenakshi

    2017-02-01

    Fiber nonlinearity is seen as a capacity limiting factor in OFDM based dispersion managed links since the Four Wave Mixing effects become enhanced due to the high PAPR. In this paper, the authors have compared the linear and nonlinear PAPR reduction techniques for fiber nonlinearity mitigation in OFDM based dispersion managed links. In the existing optical systems, linear transform techniques such as SLM and PTS have been implemented to reduce nonlinear effects. In the proposed study, superior performance of the L2-by-3 nonlinear transform technique is demonstrated for PAPR reduction to mitigate fiber nonlinearities. The performance evaluation is carried out by interfacing multiple simulators. The results of both linear and nonlinear transform techniques have been compared and the results show that nonlinear transform technique outperforms the linear transform in terms of nonlinearity mitigation and improved BER performance.

  11. Disease management strategy: initiative links pharmaceutical and mental health data.

    Science.gov (United States)

    Docherty, J P

    1996-02-01

    The emphasis in healthcare is shifting to practical applications of medical knowledge for the provision of more cost-effective care. This requires greater linkages among clinical information systems across multiple organizations. This article describes new initiatives in disease management to link the traditionally separate data systems fo pharmaceutical, behavioral and general medical care. The potential for improved patient care is highlighted. The author is an expert consultant for a large pharmaceutical manufacturer's disease state management initiative, and has an extensive leadership background in many segments of the behavioral healthcare industry.

  12. Ka频段陶瓷基板微带带通滤波器设计分析%Design of Ka-band Microstrip Bandpass Filter on Ceramic Substrate

    Institute of Scientific and Technical Information of China (English)

    赵飞; 党元兰; 王璇

    2012-01-01

    为满足微波电路小型化的发展要求,基于陶瓷基板设计了一款Ka频段的微带带通滤波器。分析了滤波器的电路设计原理及工艺设计方案,采用电路优化和三维全波仿真结合的方法对电路进行仿真。在优化后的版图基础上,通过改善膜层附着力、提高加工精度等方式对滤波器的加工进行控制。测试结果满足使用要求,证明了电路及工艺设计方案的正确性。%A Ka-band microstrip bandpass filter using ceramic substrate is designed to meet the requirement of microwave IC miniaturization.The circuit design principle and technology design scheme are analyzed.The circuit is simulated by combining the circuit optimization and 3D full-wave simulation.Based on the optimized layout,the processing of filter is controlled by improving the adhesion of the film and increasing the processing accuracy.The test result proves the validity of the microstrip bandpass filter and its design method.

  13. Is road safety management linked to road safety performance?

    Science.gov (United States)

    Papadimitriou, Eleonora; Yannis, George

    2013-10-01

    This research aims to explore the relationship between road safety management and road safety performance at country level. For that purpose, an appropriate theoretical framework is selected, namely the 'SUNflower' pyramid, which describes road safety management systems in terms of a five-level hierarchy: (i) structure and culture, (ii) programmes and measures, (iii) 'intermediate' outcomes'--safety performance indicators (SPIs), (iv) final outcomes--fatalities and injuries, and (v) social costs. For each layer of the pyramid, a composite indicator is implemented, on the basis of data for 30 European countries. Especially as regards road safety management indicators, these are estimated on the basis of Categorical Principal Component Analysis upon the responses of a dedicated road safety management questionnaire, jointly created and dispatched by the ETSC/PIN group and the 'DaCoTA' research project. Then, quasi-Poisson models and Beta regression models are developed for linking road safety management indicators and other indicators (i.e. background characteristics, SPIs) with road safety performance. In this context, different indicators of road safety performance are explored: mortality and fatality rates, percentage reduction in fatalities over a given period, a composite indicator of road safety final outcomes, and a composite indicator of 'intermediate' outcomes (SPIs). The results of the analyses suggest that road safety management can be described on the basis of three composite indicators: "vision and strategy", "budget, evaluation and reporting", and "measurement of road user attitudes and behaviours". Moreover, no direct statistical relationship could be established between road safety management indicators and final outcomes. However, a statistical relationship was found between road safety management and 'intermediate' outcomes, which were in turn found to affect 'final' outcomes, confirming the SUNflower approach on the consecutive effect of each layer.

  14. Ka波段DMTL移相器用RF MEMS电容式并联开关研制%Development of RF MEMS Capacitive Shunt Switch for Ka-Band DMTL Phase Shifter

    Institute of Scientific and Technical Information of China (English)

    高杨; 贾小慧; 秦燃; 官承秋

    2012-01-01

    A MEMS capacitive shunt switch for Ka-band 5-bit distributed MEMS transmission line (DMTL) phase shifter was presented in this paper.The structural dimensions of MEMS capacitive shunt switch were roughly defined by theoretical calculation and engineering experience.The 3D electromagnetic model of the switch was established,and the structural dimensions were optimized by using HFSS software.Simulation results show that the insertion loss of the switch was lower than 0.15 dB and the isolation loss was higher than 15 dB in Ka-band.The driving voltage of the switch was 2.1 V,which was obtained from the simulation of electromechanical coupling by using CoventorWare software.After several modifications of device layout and fabrication process according to the surface micro-machining process restriction of the foundry,preliminary MEMS capacitive shunt switch process sample was obtained.Dynamic characteristics of a single MEMS switch were tested.The results show that the height pulled down by microbridge was about 2 μm with 36 V driving voltage applied.There was a big difference between the tested driving voltage 36 V and the originally designed value 2.1 V,due to the temporary structural design modification according to the process restriction of the foundry.The modifications mainly involve increasing the microbridge height,and increasing the initial distance between the microbridge (top electrode) and the bottom electrode.%本文设计并制作了一种用于Ka波段分布式MEMS传输线(DMTL)移相器的MEMS电容式并联开关.通过理论计算和工程经验,大致定义了开关的结构尺寸.采用HFSS软件建立了开关的三维电磁场模型并优化了关键结构参数.仿真表明:开关在Ka波段插入损耗小于0.15 dB,回波损耗大于15 dB.采用CoventorWare软件进行了开关的机电耦合仿真,得出其驱动电压为2.1V.为了满足流片单位表面微加工工艺的约束,对开关的设计版图和微加工工艺进行了多轮改进,

  15. 一种Ka频段海上卫星通信抗雨衰编码方案%An anti-rain attenuation encoding solution for sea Ka-band satellite communication

    Institute of Scientific and Technical Information of China (English)

    高化猛; 李智

    2011-01-01

    The mechanism of rain attenuation in satellite communication and it's affection to Ka-band satellite communication are analyzed. CCSDS( 15,1/6)standard convolution code is recommended as channel code to anti-rain attenuation the performance of CCSDS( 15,1/6) standard convolution code is researched. The encoding efficiency is found by simulating encoding system in C translation environment. The decoding performance and encoding gain are found by simulating decoding system in BPSK modulation, ACWN channel, viterbi decoding algorithm. Simulation research demonstrates that the CCSDS (15, 1/6 ) standard convolution code is a good channel encoding solution for anti-rain attenuation in satellite communication on the sea because of high encoding velocity, high decoding performance and high encoding gain.%分析卫星通信雨衰现象的产生机制和对Ka频段卫星通信的影响,提出采用CCSDS标准卷积码作为抗雨衰编码方案.研究CCSDS(15,1/6)卷积码编译码性能:使用C语言编译环境,仿真CCSDS(15,1/6)编码系统,得出编码效率;使用二进制相移键控调制、加性高斯白噪声信道、维特比译码,仿真CCSDS(15,1/6)译码系统,得出译码性能和编码增益.仿真计算表明,CCSDS(15,1/6)具有编码速度快,译码性能好,编码增益高的特点,是一种好的海上卫星通信抗雨衰编码方案.

  16. Benefits of Linked Data for Interoperability during Crisis Management

    Science.gov (United States)

    Roller, R.; Roes, J.; Verbree, E.

    2015-08-01

    Floodings represent a permanent risk to the Netherlands in general and to her power supply in particular. Data sharing is essential within this crisis scenario as a power cut affects a great variety of interdependant sectors. Currently used data sharing systems have been shown to hamper interoperability between stakeholders since they lack flexibility and there is no consensus in term definitions and interpretations. The study presented in this paper addresses these challenges by proposing a new data sharing solution based on Linked Data, a method of interlinking data points in a structured way on the web. A conceptual model for two data sharing parties in a flood-caused power cut crisis management scenario was developed to which relevant data were linked. The analysis revealed that the presented data sharing solution burderns its user with extra costs in the short run, but saves resources in the long run by overcoming interoperability problems of the legacy systems. The more stakeholders adopt Linked Data the stronger its benefits for data sharing will become.

  17. BENEFITS OF LINKED DATA FOR INTEROPERABILITY DURING CRISIS MANAGEMENT

    Directory of Open Access Journals (Sweden)

    R. Roller

    2015-08-01

    Full Text Available Floodings represent a permanent risk to the Netherlands in general and to her power supply in particular. Data sharing is essential within this crisis scenario as a power cut affects a great variety of interdependant sectors. Currently used data sharing systems have been shown to hamper interoperability between stakeholders since they lack flexibility and there is no consensus in term definitions and interpretations. The study presented in this paper addresses these challenges by proposing a new data sharing solution based on Linked Data, a method of interlinking data points in a structured way on the web. A conceptual model for two data sharing parties in a flood-caused power cut crisis management scenario was developed to which relevant data were linked. The analysis revealed that the presented data sharing solution burderns its user with extra costs in the short run, but saves resources in the long run by overcoming interoperability problems of the legacy systems. The more stakeholders adopt Linked Data the stronger its benefits for data sharing will become.

  18. Linked Data Methodologies for Managing Information about Television Content

    Directory of Open Access Journals (Sweden)

    José Luis Redondo-García

    2012-09-01

    Full Text Available OntoTV is a television information management system designed for improving the quality and quantity of the information available in the current television platforms. In order to achieve this objective, OntoTV (1 collects the information offered by the broadcasters, (2 integrates it into a ontology-based data structure, (3 extracts extra data from alternative television sources, and (4 makes possible for the user to perform queries over the stored information.This document shows the way Linked Data methodologies have been applied in OntoTV system, and the improvements in the data consumption and publication processes that have been obtained as result. On the one hand, the possibility of accessing to information available in the Web of Data has made possible to offer more complete descriptions about the programs, as well as more detailed guides than those obtained by using classic collection methods. On the other hand, as the information of the television programs and channels is published according to the Linked Data philosophy, it becomes available not only for OntoTV clients, but also for other agents able to access Linked Data resources, who could offer the viewer more fresh and innovative features.

  19. Linking denitrification and infiltration rates during managed groundwater recharge.

    Science.gov (United States)

    Schmidt, Calla M; Fisher, Andrew T; Racz, Andrew J; Lockwood, Brian S; Huertos, Marc Los

    2011-11-15

    We quantify relations between rates of in situ denitrification and saturated infiltration through shallow, sandy soils during managed groundwater recharge. We used thermal methods to determine time series of point-specific flow rates, and chemical and isotopic methods to assess denitrification progress. Zero order denitrification rates between 3 and 300 μmol L(-1) d(-1) were measured during infiltration. Denitrification was not detected at times and locations where the infiltration rate exceeded a threshold of 0.7 ± 0.2 m d(-1). Pore water profiles of oxygen and nitrate concentration indicated a deepening of the redoxocline at high flow rates, which reduced the thickness of the zone favorable for denitrification. Denitrification rates were positively correlated with infiltration rates below the infiltration threshold, suggesting that for a given set of sediment characteristics, there is an optimal infiltration rate for achieving maximum nitrate load reduction and improvements to water supply during managed groundwater recharge. The extent to which results from this study may be extended to other managed and natural hydrologic settings remains to be determined, but the approach taken in this study should be broadly applicable, and provides a quantitative link between shallow hydrologic and biogeochemical processes.

  20. LINKING PROJECTS TO BUSINESS STRATEGY THROUGH PROJECT PORTFOLIO MANAGEMENT

    Directory of Open Access Journals (Sweden)

    A.J. Buys

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: In many organisations, a chasm exists between the development of strategy and its successful implementation. Failure to cross this chasm may ultimately result in strategy failure and the loss of competitive advantage, profits, and employment. Project Portfolio Management (PPM is theorised as a management methodology that links a portfolio of projects to the business strategy. However, current literature lacks empirical evidence of the levels of employment, functionality, and success of the Project Portfolio Management approach in South Africa. A survey of respondents in 32 technology organisations was used to analyze the reasons for the following: strategy implementation and project delivery failure in South African technology organisations; the South African situation regarding the chasm that exists in many organisations between strategy development and successful strategy implementation; and the extent to which – and with what success – Project Portfolio Management is employed in South African technology organisations.

    AFRIKAANSE OPSOMMING: In baie organisasies bestaan daar ’n gaping tussen strategie-ontwikkeling en suksesvolle strategie-implementering. Die onvermoë om die gaping te oorbrug sal uiteindelik lei tot strategiefaling en die verlies van mededingende voordeel, winste, en werksgeleenthede. Projekportefeuljebestuur (PPB word voorgehou as ’n bestuursmetodologie wat ’n portefeulje van projekte koppel aan die besigheidstrategie. Bestaande literatuur gaan egter mank aan empiriese bewyse ten opsigte van die vlakke van indiensneming, funksionaliteit, en sukses van die Projekportefeuljebestuursbenadering in Suid-Afrika. ’n Opname van respondente in 32 tegnologie-organisasies is gebruik om die volgende aspekte te ondersoek: die redes vir falings in strategie-implementering en projekaflewering in Suid-Afrikaanse tegnologie-organisasies; die Suid-Afrikaanse situasie rakende die gaping wat bestaan tussen

  1. Design of a Ka-band 10 W Adaptive RF Predistortion Linearization Power Amplifier%Ka频段10W自适应射频预失真线性化固态功放研制

    Institute of Scientific and Technical Information of China (English)

    李凯; 张科; 张能波

    2014-01-01

    The characteristic of radio frequency power amplifier ( RFPA) will change with the channel switching,environment temperature,working conditions and other factors. In order to guarantee the steady operation of the predistortion RFPA,the predistortion system with adaptive performance is very important. This paper proposes a detection method of adaptive feedback,and uses the multidirectional search algorithm to minimize the amplitude distortion and phase distortion of the RFPA′s output signal to optimize the pre-distortion system,to make the system operate in optimum state all the time. An adaptive RF predistortion linearization solid-state power amplifier operating at the Ka-band is developed. In 3 GHz operation fre-quency band,the three-order intermodulation of the developed RFPA is effectively enhanced to be better than -32 dBc at -40℃ ~ 60℃. The test results show that the power amplifier has the characteristics of wide operation frequency band and wide temperature adaptability.%射频功率放大器的特性会随信道切换、环境温度、工作状态等多种因素发生变化,为了保证功率放大器的优良工作特性,具有自适应性能的预失真系统就显得非常重要。提出了一种自适应反馈检测方法,以减小放大器输出信号的幅度失真和相位失真作为系统自适应的优化目标,采用多方向搜索优化算法对预失真系统进行优化调整,使系统始终处于最优工作状态。研制了工作于 Ka 频段10 W自适应射频预失真线性化固态功放原理样机,当工作温度为-40℃~+60℃时,在3 GHz的工作带宽内,三阶交调指标优于-32 dBc。测试结果表明该功放具有工作频带宽、温度适应性广等特点。

  2. [Experience with the reference manager EndNote-EndLink].

    Science.gov (United States)

    Reiss, M; Reiss, G

    1998-09-01

    A good reference management program should make it easy to record the elements of a reference: author's name, year of publication, title of article, etc. It should offer tools that let you find and retrieve references quickly, and it should be able to produce the bibliography in the format required for a particular publication. There are many computer programs, but very few stand out as truly useful, time saving, and work enhancing. One of them is EndNote-EndLink. We want to report our experience with this database manager. The functions and the use of the software package EndNote 2.3 for Windows are described. You can create your database or you can download batches of references from one of the popular searching services (e.g. MEDLINE). When you want to cite a reference you simply paste the reference wherever you want your in-text citation to appear. To prepare the bibliography, EndNote scans your article, replaces the place holders with citations and prints the list of references at the end of the manuscript, according with the style that you have chosen. Altogether EndNote provides an excellent combination of features and ease of use.

  3. Tools for Reducing and Managing Link Rot in LibGuides

    Directory of Open Access Journals (Sweden)

    Wilhelmina Randtke

    2012-06-01

    Full Text Available While creating content in LibGuides in quite easy, link maintenance is troublesome, and the built-in link checker offers only a partial solution. The authors describe a method of using PURLs and a third-party link checker to effectively manage links within LibGuides.

  4. Natural hazard management and sustainable development: a questionable link

    Directory of Open Access Journals (Sweden)

    Lauren Andres

    2009-03-01

    Full Text Available This article examines the nature of the possible link between natural hazards and sustainable development through a study of the area to the south of Grenoble in the French Alps, a zone subject to two major natural hazards: the extensive landslide known as the "Séchilienne Ruins" and flooding from the Romanche and Drac rivers. More specifically, the study analyzes the assumed transition from the management of natural hazards to the sustainable management of an area subject to natural hazards and is divided into three stages. Thus the link between natural hazards and sustainability is considered as: 1 an association that is entirely relative, 2 one that is logical but limited in the field, 3 one that is above all indirect. The interactions identified between risk and sustainability, in legislative as well as ideal and operational terms, are found to be complex and not necessarily explicit. They depend in particular on the juxtaposition of multiple territorial scales or spatial boundaries (national to local that bring into conflict the different strategies of the actors involved – from decision-makers to technical specialists.Cet article questionne la nature du lien envisageable entre risque naturel et développement durable à travers l’étude du territoire du sud grenoblois, soumis notamment à deux aléas naturels majeurs : le mouvement de terrain de grande ampleur dit des « Ruines de Séchilienne » et les probables crues de la Romanche et du Drac. Trois étapes structurent cette réflexion questionnant la transition supposée entre une gestion des risques naturels et une gestion durable des territoires soumis aux risques naturels : une association toute relative, un lien logique mais limité sur le terrain, une relation surtout indirecte. Les interactions identifiées, en termes législatifs mais aussi idéels et opérationnels, entre risque et durabilité se révèlent ainsi complexes et ne sont pas forcément explicites ; elles d

  5. Linking better shiftwork arrangements with safety and health management systems

    Directory of Open Access Journals (Sweden)

    Kazutaka Kogi

    2004-12-01

    Full Text Available OBJECTIVE: Various support measures useful for promoting joint change approaches to the improvement of both shiftworking arrangements and safety and health management systems were reviewed. A particular focus was placed on enterprise-level risk reduction measures linking working hours and management systems. METHODS: Voluntary industry-based guidelines on night and shift work for department stores and the chemical, automobile and electrical equipment industries were examined. Survey results that had led to the compilation of practicable measures to be included in these guidelines were also examined. The common support measures were then compared with ergonomic checkpoints for plant maintenance work involving irregular nightshifts. On the basis of this analysis, a new night and shift work checklist was designed. RESULTS: Both the guidelines and the plant maintenance work checkpoints were found to commonly cover multiple issues including work schedules and various job-related risks. This close link between shiftwork arrangements and risk management was important as shiftworkers in these industries considered teamwork and welfare services to be essential for managing risks associated with night and shift work. Four areas found suitable for participatory improvement by managers and workers were work schedules, ergonomic work tasks, work environment and training. The checklist designed to facilitate participatory change processes covered all these areas. CONCLUSIONS: The checklist developed to describe feasible workplace actions was suitable for integration with comprehensive safety and health management systems and offered valuable opportunities for improving working time arrangements and job content together.OBJETIVOS: Foram revisados diversas medidas de apoio úteis para incentivar abordagens conjuntas para a melhoria na organização do trabalho por turnos e os processos de gestão de saúde e segurança. As medidas para redução de risco em n

  6. Linking Leadership Studies to Corporate Brand Management: A Review

    OpenAIRE

    Zullina H. Shaari; Amzairi Amar; M. Radzi Zainol; Azamudin Badri Harun

    2015-01-01

    Two models of corporate brand or reputation management include ¡°leadership and success¡± as a dimension that influences reactions of multiple stakeholders to organisations. Primary groups of stakeholders such as shareholders/investors, employees, and customers, often associate leadership of organisations with Chief Executive Officers (CEOs) or managing directors. This paper proposes that if CEOs are to be capitalised as part of corporate brand management, their leadership should be projected...

  7. Educational Leadership and Organizational Management: Linking Theories to Practice

    Science.gov (United States)

    Wang, Victor C. X.; Bain, Bernice; Hope, John; Hansman, Catherine A.

    2016-01-01

    This book is intended for students, leaders and managers who wish to explore the personal relevance and conceptual bases of educational leadership and organizational management and to develop their expertise in this field. It is a book written for both scholars and practitioners. The general public will also appreciate the accessible language in…

  8. Measuring success : metrics that link supply chain management to aircraft readiness

    OpenAIRE

    McDoniel, Patrick S.; Balestreri, William G.

    2002-01-01

    Approved for public release; distribution is unlimited. This thesis evaluates and analyzes current strategic management planning methods that develop performance metrics linking supply chain management to aircraft readiness. Our primary focus is the Marine Aviation Logistics Squadron. Utilizing the Logistics Management Institute's DoD Supply Chain Implementation Guide and adapted SCOR model, we applied the six step process for developing a strategic logistics management plan for implementi...

  9. The Link between Self-Managed Work Teams and Learning Organisations Using Performance Indicators

    Science.gov (United States)

    Power, Joe; Waddell, Di

    2004-01-01

    Both the learning organization literature and the self-managed work team literature have alluded to the potential links between teamwork and learning. However, as yet the link between these two concepts remains undeveloped. This study uses a survey of a random sample of 200 Australian organizations to empirically examine the relationships between…

  10. Effective Supply Chain Management Strategy for Food Products: An Insight to Linked Partnerships

    OpenAIRE

    Witaya Krajaysri

    2010-01-01

    This paper explores and extends the supply chain management strategy for food products effectively and efficiently through analysis of insights to linked partnerships within the supply chain due to the possibility of a global food crisis. The required solution is a collaboration of all parties in the supply chain since an effective supply chain management strategy (ESCMS) for food products is through proper insight between linked partnerships, including customer satisfaction through service q...

  11. Knowledge Management Systems: Linking Contribution, Refinement and Use

    Science.gov (United States)

    Chung, Ting-ting

    2009-01-01

    Electronic knowledge repositories represent one of the fundamental tools for knowledge management (KM) initiatives. Existing research, however, has largely focused on supply-side driven research questions, such as employee motivation to contribute knowledge to a repository. This research turns attention to the dynamic relationship between the…

  12. Linked Heritage: a collaborative terminology management platform for a network of multilingual thesauri and controlled vocabularies

    Directory of Open Access Journals (Sweden)

    Marie-Veronique Leroi

    2013-01-01

    Full Text Available Terminology and multilingualism have been one of the main focuses of the Athena Project. Linked Heritage as a legacy of this project also deals with terminology and bring theory to practice applying the recommendations given in the Athena Project. Linked Heritage as a direct follow-up of these recommendations on terminology and multilingualism is currently working on the development of a Terminology Management Platform (TMP. This platform will allow any cultural institution to register, SKOSify and manage its terminology in a collaborative way. This Terminology Management Platform will provide a network of multilingual and cross-domain terminologies.

  13. Gi2MO: Interoperability, Linking and Filtering in Idea Management Systems

    OpenAIRE

    Westerski, Adam

    2011-01-01

    This thesis proposes how to apply the Semantic Web tech- nologies for the Idea Management Systems to deliver a solution to knowl- edge management and information over ow problems. Firstly, the aim is to present a model that introduces rich metadata annotations and their usage in the domain of Idea Management Systems. Furthermore, the the- sis shall investigate how to link innovation data with information from other systems and use it to categorize and lter out the most valuable elements....

  14. Science priorities for seamounts: research links to conservation and management.

    Directory of Open Access Journals (Sweden)

    Malcolm R Clark

    Full Text Available Seamounts shape the topography of all ocean basins and can be hotspots of biological activity in the deep sea. The Census of Marine Life on Seamounts (CenSeam was a field program that examined seamounts as part of the global Census of Marine Life (CoML initiative from 2005 to 2010. CenSeam progressed seamount science by collating historical data, collecting new data, undertaking regional and global analyses of seamount biodiversity, mapping species and habitat distributions, challenging established paradigms of seamount ecology, developing new hypotheses, and documenting the impacts of human activities on seamounts. However, because of the large number of seamounts globally, much about the structure, function and connectivity of seamount ecosystems remains unexplored and unknown. Continual, and potentially increasing, threats to seamount resources from fishing and seabed mining are creating a pressing demand for research to inform conservation and management strategies. To meet this need, intensive science effort in the following areas will be needed: 1 Improved physical and biological data; of particular importance is information on seamount location, physical characteristics (e.g. habitat heterogeneity and complexity, more complete and intensive biodiversity inventories, and increased understanding of seamount connectivity and faunal dispersal; 2 New human impact data; these shall encompass better studies on the effects of human activities on seamount ecosystems, as well as monitoring long-term changes in seamount assemblages following impacts (e.g. recovery; 3 Global data repositories; there is a pressing need for more comprehensive fisheries catch and effort data, especially on the high seas, and compilation or maintenance of geological and biodiversity databases that underpin regional and global analyses; 4 Application of support tools in a data-poor environment; conservation and management will have to increasingly rely on predictive

  15. Science priorities for seamounts: research links to conservation and management.

    Science.gov (United States)

    Clark, Malcolm R; Schlacher, Thomas A; Rowden, Ashley A; Stocks, Karen I; Consalvey, Mireille

    2012-01-01

    Seamounts shape the topography of all ocean basins and can be hotspots of biological activity in the deep sea. The Census of Marine Life on Seamounts (CenSeam) was a field program that examined seamounts as part of the global Census of Marine Life (CoML) initiative from 2005 to 2010. CenSeam progressed seamount science by collating historical data, collecting new data, undertaking regional and global analyses of seamount biodiversity, mapping species and habitat distributions, challenging established paradigms of seamount ecology, developing new hypotheses, and documenting the impacts of human activities on seamounts. However, because of the large number of seamounts globally, much about the structure, function and connectivity of seamount ecosystems remains unexplored and unknown. Continual, and potentially increasing, threats to seamount resources from fishing and seabed mining are creating a pressing demand for research to inform conservation and management strategies. To meet this need, intensive science effort in the following areas will be needed: 1) Improved physical and biological data; of particular importance is information on seamount location, physical characteristics (e.g. habitat heterogeneity and complexity), more complete and intensive biodiversity inventories, and increased understanding of seamount connectivity and faunal dispersal; 2) New human impact data; these shall encompass better studies on the effects of human activities on seamount ecosystems, as well as monitoring long-term changes in seamount assemblages following impacts (e.g. recovery); 3) Global data repositories; there is a pressing need for more comprehensive fisheries catch and effort data, especially on the high seas, and compilation or maintenance of geological and biodiversity databases that underpin regional and global analyses; 4) Application of support tools in a data-poor environment; conservation and management will have to increasingly rely on predictive modelling

  16. Linked Heritage: a collaborative terminology management platform for a network of multilingual thesauri and controlled vocabularies

    OpenAIRE

    Marie-Veronique Leroi

    2013-01-01

    Terminology and multilingualism have been one of the main focuses of the Athena Project. Linked Heritage as a legacy of this project also deals with terminology and bring theory to practice applying the recommendations given in the Athena Project. Linked Heritage as a direct follow-up of these recommendations on terminology and multilingualism is currently working on the development of a Terminology Management Platform (TMP). This platform will allow any cultural institution to register, SKOS...

  17. Impression Management in Social Media: The Example of LinkedIn

    Directory of Open Access Journals (Sweden)

    Joanna Paliszkiewicz

    2016-09-01

    Full Text Available Nowadays, the relationships are often initiated and maintained in online environments, the formation and management of online impressions have gained importance and become the subject of numerous studies. The impression management is a conscious process in which people attempt to influence the perceptions of their image. They do it by controlling and managing information presented in social media. The presentation of identity is the key to success or failure for example in business life. In the article, the critical literature review related to impression management in social media is described. The example of the way of self-presentation in LinkedIn is presented. The future directions are indicated.

  18. Exploring the link between meteorological drought and streamflow to inform water resource management

    Science.gov (United States)

    Lennard, Amy; Macdonald, Neil; Hooke, Janet

    2015-04-01

    Drought indicators are an under-used metric in UK drought management. Standardised drought indicators offer a potential monitoring and management tool for operational water resource management. However, the use of these metrics needs further investigation. This work uses statistical analysis of the climatological drought signal based on meteorological drought indicators and observed streamflow data to explore the link between meteorological drought and hydrological drought to inform water resource management for a single water resource region. The region, covering 21,000 km2 of the English Midlands and central Wales, includes a variety of landscapes and climatological conditions. Analysis of the links between meteorological drought and hydrological drought performed using streamflow data from 'natural' catchments indicates a close positive relationship between meteorological drought indicators and streamflow, enhancing confidence in the application of drought indicators for monitoring and management. However, many of the catchments in the region are subject to modification through impoundments, abstractions and discharge. Therefore, it is beneficial to explore how climatological drought signal propagates into managed hydrological systems. Using a longitudinal study of catchments and sub-catchments that include natural and modified river reaches the relationship between meteorological and hydrological drought is explored. Initial statistical analysis of meteorological drought indicators and streamflow data from modified catchments shows a significantly weakened statistical relationship and reveals how anthropogenic activities may alter hydrological drought characteristics in modified catchments. Exploring how meteorological drought indicators link to streamflow across the water supply region helps build an understanding of their utility for operational water resource management.

  19. Intelligent On/Off Dynamic Link Management for On-Chip Networks

    Directory of Open Access Journals (Sweden)

    Andreas G. Savva

    2012-01-01

    Full Text Available Networks-on-chips (NoCs provide scalable on-chip communication and are expected to be the dominant interconnection architectures in multicore and manycore systems. Power consumption, however, is a major limitation in NoCs today, and researchers have been constantly working on reducing both dynamic and static power. Among the NoC components, links that connect the NoC routers are the most power-hungry components. Several attempts have been made to reduce the link power consumption at both the circuit level and the system level. Most past research efforts have proposed selective on/off link state switching based on system-level information based on link utilization levels. Most of these proposed algorithms focus on a pessimistic and simple static threshold mechanism which determines whether or not a link should be turned on/off. This paper presents an intelligent dynamic power management policy for NoCs with improved predictive abilities based on supervised online learning of the system status (i.e., expected future utilization link levels, where links are turned off and on via the use of a small and scalable neural network. Simulation results with various synthetic traffic models over various network topologies show that the proposed work can reach up to 13% power savings when compared to a trivial threshold computation, at very low (<4% hardware overheads.

  20. Linking Human Resource Management and Knowledge Management via Commitment to Safety

    Directory of Open Access Journals (Sweden)

    Kuimet Karin

    2015-11-01

    Full Text Available This paper contributes to the development of the human resource management (HRM, organisational (safety culture and knowledge management literature through developing the linkage and relationship among them. The article suggests that the HRM concepts and frameworks could play an important role in the safety knowledge exchange within the organisation. The research method includes exploratory case studies, interviews and evaluation questionnaires in order to clarify how HRM practices are adopted for safety management systems.

  1. Linking the spare parts management with the total costs of ownership: An agenda for future research

    Directory of Open Access Journals (Sweden)

    Orlando Duran

    2016-12-01

    Full Text Available Purpose: This manuscript explores the link between Spare Parts Management and Total Costs of Ownership or Life Cycle Costs (LCC. Design/methodology/approach: First, this work enumerates the different managerial decisions instances in spare parts management that are present during the life cycle of a physical asset. Second, we analyse how those decision instances could affect the TCO of a physical asset (from the economic point of view. Finally, we propose a conceptual framework for incorporating the spare parts management into a TCO model. Findings: The recent literature lacks discussions on the integration of spare parts management with the Total Costs of Ownership (TCO. Based in an extensive literature revision we can declare that the computation of costs related to spare parts management has been neglected by TCO models. Originality/value: The contribution of this paper is twofold. First, a literature review and identification of a series of spare parts management decision instances and its relationship with TCOs is presented in this paper. Second, a conceptual framework is suggested for linking those decisions instances to a total cost of ownership perspective. Some research questions and future research challenges are presented at the end of this work.

  2. Analysis and Optimization of the Performance of a Convolutionally Encoded Deep-Space Link in the Presence of Spacecraft Oscillator Phase Noise

    Science.gov (United States)

    Shambayati, S.

    1999-10-01

    In order to reduce the cost of deep-space missions, NASA is exploring the possibility of using new, cheaper technologies. Among these is the possibility of replacing ultra-stable oscillators (USOs) onboard the spacecraft with oscillators with measurable phase noise. In addition, it is proposed that these spacecraft use higher 32-GHz (Ka-band) radio frequencies in order to save mass. In this article, the performance of a convolutionally encoded deep-space link using non-USO-type oscillators onboard the spacecraft at Ka-band is analyzed. It is shown that the ground-receiver tracking-loop bandwidth settings need to be optimized and that, by selecting an oscillator with good phase-noise characteristics, the minimum required power onboard the spacecraft could be reduced by as much as 10 dB.

  3. Linking departmental priorities to knowledge management: the experiences of Santa Cruz County's Human Services Department.

    Science.gov (United States)

    Lindberg, Arley

    2012-01-01

    Federal welfare reform, local service collaborations, and the evolution of statewide information systems inspired agency interest in evidence-informed practice and knowledge sharing systems. Four agency leaders, including the Director, Deputy Director, Director of Planning and Evaluation, and Staff Development Program Manager championed the development of a learning organization based on knowledge management throughout the agency. Internal department restructuring helped to strengthen the Planning and Evaluation, Staff Development, and Personnel units, which have become central to supporting knowledge sharing activities. The Four Pillars of Knowledge framework was designed to capture agency directions in relationship to future knowledge management goals. Featuring People, Practice, Technology and Budget, the framework links the agency's services, mission and goals to the process of becoming a learning organization. Built through an iterative process, the framework was created by observing existing activities in each department rather than being designed from the top down. Knowledge management can help the department to fulfill its mission despite reduced resources.

  4. Links between environmental management and the company's other management systems especially the quality mangement system

    DEFF Research Database (Denmark)

    Bjarnø, Ole-Christian; Larsen, Lars Bjørn

    1999-01-01

    Based on a literature survey and case material from several companies, this paper try to highlight some of the difficulties related to the integration of environmental management, as well as some of the advantages and disadvantages of the integration....

  5. 'The link between practices of Human Resource Management and Supply Chain Management'

    OpenAIRE

    Kouali, Marianthi

    2013-01-01

    The scope of this study is to establish the significance of human resource practices in reaching high levels of supply chain management performance through the comparison of two companies that belong in the telecommunications industry in the Republic of Cyprus. For the purposes of this study, a literature review was undertaken which was divided in three parts. The first part includes aspects related to Supply Chain Management, the second part includes the best practice of Human Resource Ma...

  6. Links between environmental management and the company's other management systems especially the quality mangement system

    DEFF Research Database (Denmark)

    Bjarnø, Ole-Christian; Larsen, Lars Bjørn

    1999-01-01

    Based on a literature survey and case material from several companies, this paper try to highlight some of the difficulties related to the integration of environmental management, as well as some of the advantages and disadvantages of the integration.......Based on a literature survey and case material from several companies, this paper try to highlight some of the difficulties related to the integration of environmental management, as well as some of the advantages and disadvantages of the integration....

  7. Mixing Methods in Innovation Research: Studying the Process-Culture-Link in Innovation Management

    Directory of Open Access Journals (Sweden)

    Jens O. Meissner

    2010-09-01

    Full Text Available Two trends in innovation management have influenced the basic idea of this paper. The first trend shows increased attempts by managers to utilize linear innovation processes derived from literature and from practice. The second trend is an increasing acceptance of the dynamics created in an "innovation culture," as being one of the key drivers of innovation. Both approaches partially contrast each other. Researching the literature in more detail, we found that studies explaining the link between innovation culture and innovation project management are rare. Indeed there is a study by Shona BROWN and Kathleen EISENHARDT (1995 which gives an excellent overview of innovation management research, but again the issue of "culture" was lacking. This missing link between innovation process design and innovation culture at the firm-level provides the theoretical framework of this paper. Behind the scenes of innovation management studies, we realized a methodological gap existed between the research of innovation cultures and their impact upon an organization's innovation processes. Thus, we applied a methodological mix of problem-centered interviews, structural analyses, and context analyses to study the phenomenon. We conducted an interview-based single case study in a Swiss telecommunications company. From these methodologies we created a themed landscape comprising relational topics of the innovation dynamics within an innovation project in the company (one year duration and briefly described each topic. The main finding in our study is the dynamic role-model that innovation managers in large service firms have to apply to succeed in their innovation management work. Thus, our methodological mix proved to be helpful, although some weaknesses remain to be solved in the future. URN: urn:nbn:de:0114-fqs1003134

  8. Coherent resonant Ka-band photonic microwave receiver

    CERN Document Server

    Ilchenko, Vladimir S; Savchenkov, Anatoliy A; Seidel, David; Matsko, Andrey B; Maleki, Lute

    2008-01-01

    We propose theoretically and demonstrate experimentally a coherent microwave photonic receiver operating at 35 GHz carrier frequency. The device is based on a lithium niobate or lithium tantalate optical whispering gallery mode resonator coupled to a microwave strip line resonator. Microwave local oscillator is fed into the microwave resonator along with the microwave signal. We show that the sensitivity of this receiver significantly exceeds the sensitivity of the incoherent quadratic receiver based on the same technology. The coherent receiver can possess a dynamic range in excess of 100 dB in 5 MHz band if a low noise laser is utilized.

  9. High-Power Ka-Band Window and Resonant Ring

    Energy Technology Data Exchange (ETDEWEB)

    Jay L. Hirshfield

    2006-11-29

    A stand-alone 200 MW rf test station is needed for carrying out development of accelerator structures and components for a future high-gradient multi-TeV collider, such as CLIC. A high-power rf window is needed to isolate the test station from a structure element under test. This project aimed to develop such a window for use at a frequency in the range 30-35 GHz, and to also develop a high-power resonant ring for testing the window. During Phase I, successful conceptual designs were completed for the window and the resonant ring, and cold tests of each were carried out that confirmed the designs.

  10. Miniature Ka-band Automated Swath Mapper (KASM) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal discusses the development and demonstration of a swath-based airborne instrument suite intended as a calibration and validation with relevance to the...

  11. Frequency-Agile Monolithic Ka-Band Filter

    Science.gov (United States)

    2012-10-18

    Watts, (v) low power consumption in the device and control circuit, (vi) fast switching speed, and (vii) temperature stability. The Phase II...nGimat 5. FABRICATION/TESTING nGimat/GT 6. OPTIMIZE FERRITE FILMS nGimat 7. FERRITE FILTERS nGimat/GT 8...Optimize Ferrite Films 60% 7. Ferrite Filters 35% 8. Prototyping 90% 9. Scale-up 80% 10. Customer Relations 70% 11. Report 100%

  12. Technology Issues for Mobile Ka-band Communications

    Science.gov (United States)

    Satorius, E.; Jedrey, T.; Davarian, F.; Divsalar, D.

    1993-01-01

    The key to success of any future telecommunications System is its ability to provide many users with a diversity of services in a cost-effective manner. An important consideration is system capacity which is requred to suport a large pool of users and their varied demands.

  13. Ka-Band Reliability Improvement. Part I. Volume III. Ka-Band SATCOM Set Analysis. Appendix C

    Science.gov (United States)

    1978-09-01

    SECURIT L S1 ICATION OF THIS PAGE flWbon flati Frtir-d NO ADDRESS ( IBFORE COLEING FRORMTTS 2. OW ACIESIOr REA E WO’S CAT MBER IS DISTA RII BITA T Y...wYwI 4 - # .1. z I op W 1 0 . . . ..a, I 𔃾*1 4l I c, . 4g c co n . ......... %%C C CoCs. 4 3’. 1 .I4 ." . . . ., 11 *1 Ir %, I -’ulx - I. . .,Z. 4 1. r

  14. Analysis of the solid waste management practices in Chinhoyi: bridging the missing link

    Directory of Open Access Journals (Sweden)

    Ishumael SANGO

    2010-12-01

    Full Text Available Over the years, there has been noticeable and steady mismatch between urban population growth and capacity for managing the corresponding increases in solid wastes. The local community is greatly concerned because it is aware of the clear link between poorly managed waste and the potential for the spread of diseases. This study was carried out to examine the solid waste management practices in Chinhoyi urban area and assess the impacts on the environment and human health. The study combined quantitative and qualitative data collected through fieldwork, questionnaires, interviews and document reviews. The population of Chinhoyi stands at about 60 000 generating more than 100 tons of waste per day. Results of the study include high percentage of uncollected waste, high levels of health and safety related problems such as lacerations, contusions, strain/sprains, and illness as well as noticeable deterioration of facilities and the environment. Issues affecting the effective management of waste are discussed. Recommendations based on the sustainable principle of integrated solid waste management are suggested. Sustainability requires the system to be environmentally effective, economically affordable, and socially acceptable.

  15. Ocean acidification: Linking science to management solutions using the Great Barrier Reef as a case study.

    Science.gov (United States)

    Albright, Rebecca; Anthony, Kenneth R N; Baird, Mark; Beeden, Roger; Byrne, Maria; Collier, Catherine; Dove, Sophie; Fabricius, Katharina; Hoegh-Guldberg, Ove; Kelly, Ryan P; Lough, Janice; Mongin, Mathieu; Munday, Philip L; Pears, Rachel J; Russell, Bayden D; Tilbrook, Bronte; Abal, Eva

    2016-11-01

    Coral reefs are one of the most vulnerable ecosystems to ocean acidification. While our understanding of the potential impacts of ocean acidification on coral reef ecosystems is growing, gaps remain that limit our ability to translate scientific knowledge into management action. To guide solution-based research, we review the current knowledge of ocean acidification impacts on coral reefs alongside management needs and priorities. We use the world's largest continuous reef system, Australia's Great Barrier Reef (GBR), as a case study. We integrate scientific knowledge gained from a variety of approaches (e.g., laboratory studies, field observations, and ecosystem modelling) and scales (e.g., cell, organism, ecosystem) that underpin a systems-level understanding of how ocean acidification is likely to impact the GBR and associated goods and services. We then discuss local and regional management options that may be effective to help mitigate the effects of ocean acidification on the GBR, with likely application to other coral reef systems. We develop a research framework for linking solution-based ocean acidification research to practical management options. The framework assists in identifying effective and cost-efficient options for supporting ecosystem resilience. The framework enables on-the-ground OA management to be the focus, while not losing sight of CO2 mitigation as the ultimate solution.

  16. Relay Forward-Link File Management Services (MaROS Phase 2)

    Science.gov (United States)

    Allard, Daniel A.; Wallick, Michael N.; Hy, Franklin H.; Gladden, Roy E.

    2013-01-01

    This software provides the service-level functionality to manage the delivery of files from a lander mission repository to an orbiter mission repository for eventual spacelink relay by the orbiter asset on a specific communications pass. It provides further functions to deliver and track a set of mission-defined messages detailing lander authorization instructions and orbiter data delivery state. All of the information concerning these transactions is persisted in a database providing a high level of accountability of the forward-link relay process.

  17. Links between osteoarthritis and diabetes: implications for management from a physical activity perspective.

    Science.gov (United States)

    Piva, Sara R; Susko, Allyn M; Khoja, Samannaaz S; Josbeno, Deborah A; Fitzgerald, G Kelley; Toledo, Frederico G S

    2015-02-01

    Osteoarthritis (OA) and type 2 diabetes mellitus (T2DM) often coexist in older adults. Those with T2DM are more susceptible to developing arthritis, which has been traditionally attributed to common risk factors, namely, age and obesity. Alterations in lipid metabolism and hyperglycemia might directly impact cartilage health and subchondral bone, contributing to the development/progression of OA. Adequate management of older persons with both conditions benefits from a comprehensive understanding of the associated risk factors. We discuss common risk factors and emerging links between OA and T2DM, emphasizing the importance of physical activity and the implications of safe and effective physical activity.

  18. [Subjectiveness and management: exploring psychosocial links on managerial and health work].

    Science.gov (United States)

    Sá, Marilene de Castilho; Azevedo, Creuza da Silva

    2010-08-01

    This paper presents our theoretical perspective over health management, particularly on managerial and health work. To face the complex problems related to public health services management and health care quality - important challenges of Brazilian Sanitary Reform - we study the group/inter-subjective and unconscious characteristic of organizational processes, which has important effects over health services dynamics and their quality. For this purpose, we attempt to articulate three theoretical perspectives:(1) the French Psycho sociology approach on organizations and contemporary society; (2) the psychoanalytical theory on inter-subjective and group processes; and (3) the Work Psychodynamics, which focuses the relations between pleasure and suffering in work processes. Through this research process, we explore links and mediations among psychic, inter-subjective, group and social realities that are present in health organizations, managerial work and health work. Also, limits and possibilities these mediations set to leadership, cooperation, collective projects and health care quality are identified.

  19. Linking river management to species conservation using dynamic landscape scale models

    Science.gov (United States)

    Freeman, Mary C.; Buell, Gary R.; Hay, Lauren E.; Hughes, W. Brian; Jacobson, Robert B.; Jones, John W.; Jones, S.A.; LaFontaine, Jacob H.; Odom, Kenneth R.; Peterson, James T.; Riley, Jeffrey W.; Schindler, J. Stephen; Shea, C.; Weaver, J.D.

    2013-01-01

    Efforts to conserve stream and river biota could benefit from tools that allow managers to evaluate landscape-scale changes in species distributions in response to water management decisions. We present a framework and methods for integrating hydrology, geographic context and metapopulation processes to simulate effects of changes in streamflow on fish occupancy dynamics across a landscape of interconnected stream segments. We illustrate this approach using a 482 km2 catchment in the southeastern US supporting 50 or more stream fish species. A spatially distributed, deterministic and physically based hydrologic model is used to simulate daily streamflow for sub-basins composing the catchment. We use geographic data to characterize stream segments with respect to channel size, confinement, position and connectedness within the stream network. Simulated streamflow dynamics are then applied to model fish metapopulation dynamics in stream segments, using hypothesized effects of streamflow magnitude and variability on population processes, conditioned by channel characteristics. The resulting time series simulate spatially explicit, annual changes in species occurrences or assemblage metrics (e.g. species richness) across the catchment as outcomes of management scenarios. Sensitivity analyses using alternative, plausible links between streamflow components and metapopulation processes, or allowing for alternative modes of fish dispersal, demonstrate large effects of ecological uncertainty on model outcomes and highlight needed research and monitoring. Nonetheless, with uncertainties explicitly acknowledged, dynamic, landscape-scale simulations may prove useful for quantitatively comparing river management alternatives with respect to species conservation.

  20. Linking Ecological and Perceptual Assessments for Environmental Management: a Coral Reef Case Study

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Dinsdale

    2009-12-01

    Full Text Available Integrating information from a range of community members in environmental management provides a more complete assessment of the problem and a diversification of management options, but is difficult to achieve. To investigate the relationship between different environmental interpretations, I compared three distinct measures of anchor damage on coral reefs: ecological measures, perceptual meanings, and subjective health judgments. The ecological measures identified an increase in the number of overturned corals and a reduction in coral cover, the perceptual meanings identified a loss of visual quality, and the health judgments identified a reduction in the health of the coral reef sites associated with high levels of anchoring. Combining the perceptual meanings and health judgments identified that the judgment of environmental health was a key feature that both scientific and lay participants used to describe the environment. Some participants in the survey were familiar with the coral reef environment, and others were not. However, they provided consistent judgment of a healthy coral reef, suggesting that these judgments were not linked to present-day experiences. By combining subjective judgments and ecological measures, the point at which the environment is deemed to lose visual quality was identified; for these coral reefs, if the level of damage rose above 10.3% and the cover of branching corals dropped below 17.1%, the reefs were described as unhealthy. Therefore, by combining the information, a management agency can involve the community in identifying when remedial action is required or when management policies are effectively maintaining a healthy ecosystem.

  1. Linking knowledge with action in the pursuit of sustainable water-resources management.

    Science.gov (United States)

    Jacobs, Katharine; Lebel, Louis; Buizer, James; Addams, Lee; Matson, Pamela; McCullough, Ellen; Garden, Po; Saliba, George; Finan, Timothy

    2016-04-26

    Managing water for sustainable use and economic development is both a technical and a governance challenge in which knowledge production and sharing play a central role. This article evaluates and compares the role of participatory governance and scientific information in decision-making in four basins in Brazil, Mexico, Thailand, and the United States. Water management institutions in each of the basins have evolved during the last 10-20 years from a relatively centralized water-management structure at the state or national level to a decision structure that involves engaging water users within the basins and the development of participatory processes. This change is consistent with global trends in which states increasingly are expected to gain public acceptance for larger water projects and policy changes. In each case, expanded citizen engagement in identifying options and in decision-making processes has resulted in more complexity but also has expanded the culture of integrated learning. International funding for water infrastructure has been linked to requirements for participatory management processes, but, ironically, this study finds that participatory processes appear to work better in the context of decisions that are short-term and easily adjusted, such as water-allocation decisions, and do not work so well for longer-term, high-stakes decisions regarding infrastructure. A second important observation is that the costs of capacity building to allow meaningful stakeholder engagement in water-management decision processes are not widely recognized. Failure to appreciate the associated costs and complexities may contribute to the lack of successful engagement of citizens in decisions regarding infrastructure.

  2. Development of conceptual ecological models linking management of the Missouri River to pallid sturgeon population dynamics

    Science.gov (United States)

    Jacobson, Robert B.; Parsley, Michael J.; Annis, Mandy L.; Colvin, Michael E.; Welker, Timothy L.; James, Daniel A.

    2015-01-01

    This report documents the process of developing and refining conceptual ecological models (CEMs) for linking river management to pallid sturgeon (Scaphirhynchus albus) population dynamics in the Missouri River. The refined CEMs are being used in the Missouri River Pallid Sturgeon Effects Analysis to organize, document, and formalize an understanding of pallid sturgeon population responses to past and future management alternatives. The general form of the CEMs, represented by a population-level model and component life-stage models, was determined in workshops held in the summer of 2013. Subsequently, the Missouri River Pallid Sturgeon Effects Analysis team designed a general hierarchical structure for the component models, refined the graphical structure, and reconciled variation among the components and between models developed for the upper river (Upper Missouri & Yellowstone Rivers) and the lower river (Missouri River downstream from Gavins Point Dam). Importance scores attributed to the relations between primary biotic characteristics and survival were used to define a candidate set of working dominant hypotheses about pallid sturgeon population dynamics. These CEMs are intended to guide research and adaptive-management actions to benefit pallid sturgeon populations in the Missouri River.

  3. Dispersion management for nonlinearity mitigation in two-span 28 GBaud QPSK phase-sensitive amplifier links.

    Science.gov (United States)

    Astra, Egon; Olsson, Samuel L I; Eliasson, Henrik; Andrekson, Peter A

    2017-06-12

    We present an investigation of dispersion map optimization for two-span single-channel 28 GBaud QPSK transmission systems with phase-sensitive amplifiers (PSAs). In experiments, when the PSA link is operated in a highly nonlinear regime, a 1.4 dB error vector magnitude (EVM) improvement is achieved compared to a one-span optimized dispersion map link due to improved nonlinearity mitigation. The two-span optimized dispersion map of a PSA link differs from the optimized dispersion map of a dispersion managed phase-insensitive amplifier (PIA) link. Simulations show that the performance of the two-span dispersion map optimized PSA link does not improve by residual dispersion optimization. Further, by using the two-span optimized dispersion maps repeatedly in a long-haul PSA link instead of one-span optimized maps, the maximum transmission reach can be improved 1.5 times.

  4. Quick Link Selection Method by Using Pricing Strategy Based on User Equilibrium for Implementing an Effective Urban Travel Demand Management

    Directory of Open Access Journals (Sweden)

    Shahriar Afandizadeh Zargari

    2016-12-01

    Full Text Available This paper presents a two-stage model of optimization as a quick method to choose the best potential links for implementing urban travel demand management (UTDM strategy like road pricing. The model is optimized by minimizing the hidden cost of congestion based on user equilibrium (MHCCUE. It forecasts the exact amount of flows and tolls for links in user equilibrium condition to determine the hidden cost for each link to optimize the link selection based on the network congestion priority. The results show that not only the amount of total cost is decreased, but also the number of selected links for pricing is reduced as compared with the previous toll minimization methods. Moreover, as this model just uses the traffic assignment data for calculation, it could be considered as a quick and optimum solution for choosing the potential links.

  5. Understanding Organizational Learning via Knowledge Management in Government-Link Companies in Malaysia

    Science.gov (United States)

    Helmi, Asleena; Ahmad, Zainal Ariffin; Hung, Daisy Kee Mui

    The knowledge management or KM discipline conjures a host of understanding and impact upon the global business community albeit commercially or socially. Regardless of the different approach to KM, it has inarguably brought about changes in viewing the knowledge capabilities and capacities of organizations. Peter Drucker (1998) argued that knowledge has become the key economic resource and the only source of competitive advantage. Hence organizational learning is an integral part of KM initiatives and has been widely practiced in many large organizations and across nations such as Europe, North America and Asia Pacific. Thus, this paper explores the KM initiatives of government link companies (GLCs) in Malaysia via synergizing knowledge strategy and capabilities in order to achieve competitive advantage.

  6. Concept for linking de-identified biomedical research data using a study participant management system.

    Science.gov (United States)

    Stahmann, Alexander; Bauer, Christian R K D; Schwanke, Jens

    2014-01-01

    Biomedical research projects show an increasing demand of large numbers of participants from different recruiting centers to achieve statistically significant results. The collected types of data are stored in distributed databases and are linked to the participant by different non-resolvable identifiers (layered pseudonyms) for de-identification. To ensure the quality of the gathered data, regular quality assurance analyses are required at each local center. Because of the distributed databases and layered pseudonyms the analyses can only be achieved manually. Therefore, the process is error-prone and laborious. The objective of this paper is to propose a solution concept to automate the manual process by using a local study participant management system. It orchestrates the process and enables the quality assurance analyses within a clinical data warehouse.

  7. Linking geodiversity and biodiversity in protected area management: developing a more integrated approach

    Science.gov (United States)

    Gordon, John

    2014-05-01

    The ecosystem approach is now a key driver for conservation policy globally. By definition an ecosystem includes both abiotic and biotic components interacting as a functional unit. However, the role of geodiversity generally remains poorly recognised both at a policy level and in the practical management of protected areas. This presentation examines key links between geodiversity and biodiversity, and demonstrates the benefits of better integration both to enhance conservation of geoheritage and the role of geodiversity in ecosystem management. Geodiversity contributes essentially to most of the ecosystem services recognised in the Millennium Ecosystem Assessment. It underpins biodiversity from micro- to macro-scales through the influence of factors such as lithology, topography, sediments, soils and hydrology. Most habitats and species depend on the abiotic 'stage' on which they exist. Active geological processes also help to determine the heterogeneity of the physical environment, creating mosaics of landforms, surface deposits and dynamic environments that support a range of biodiversity. In the face of climate change and other human pressures, maintaining and enhancing geodiversity should help to 'future-proof' biodiversity in the longer term. Learning from the past through palaeoenvironmental records can also enable better understanding of ecosystem dynamics. As well as recognising the value of geoheritage in its own right, a more integrated approach to conservation in protected areas would benefit both biodiversity and geodiversity, incorporating the concept of 'conserving the stage' (Anderson & Ferree, 2010) and the maintenance of natural processes. As part of developing the scientific framework of geodiversity, this requires geoscience engagement in the ecosystem approach, including evidence-based interdisciplinary research on the functional links between geodiversity and biodiversity across a range of spatial and temporal scales both to inform policy and

  8. The Energy-Water Nexus: Managing the Links between Energy and Water for a Sustainable Future

    Science.gov (United States)

    Hussey, Karen; Petit, Carine

    2010-05-01

    Water and energy are both indispensable inputs to modern economies but currently both resources are under threat owing to the impacts of an ever-increasing population and associated demand, unsustainable practices in agriculture and manufacturing, and the implications of a changing climate. However, it is where water and energy rely on each other that pose the most complex challenges for policy-makers. Water is needed for mining coal, drilling oil, refining gasoline, and generating and distributing electricity; and, conversely, vast amounts of energy are needed to pump, transport, treat and distribute water, particularly in the production of potable water through the use of desalination plants and waste water treatment plants. Despite the links, and the urgency in both sectors for security of supply, in existing policy frameworks energy and water policies are developed largely in isolation from one another. Worse still, some policies designed to encourage alternative energy supplies give little thought to the resultant consequences on water resources, and, similarly, policies designed to secure water supplies pay little attention to the resultant consequences on energy use. The development of new technologies presents both opportunities and challenges for managing the energy-water nexus but a better understanding of the links between energy and water is essential in any attempt to formulate policies for more resilient and adaptable societies. The energy-water nexus must be adequately integrated into policy and decision-making or governments run the risk of contradicting their efforts, and therefore failing in their objectives, in both sectors. A series of COST Exploratory Workshops, drawing on on-going research in the energy-water nexus from a number of international teams, identified the implications of the energy-water nexus on the development of (i) energy policies (ii) water resource management policies and (iii) climate adaptation and mitigation policies. A

  9. Economic analysis of linking operating room scheduling and hospital material management information systems for just-in-time inventory control.

    Science.gov (United States)

    Epstein, R H; Dexter, F

    2000-08-01

    Operating room (OR) scheduling information systems can decrease perioperative labor costs. Material management information systems can decrease perioperative inventory costs. We used computer simulation to investigate whether using the OR schedule to trigger purchasing of perioperative supplies is likely to further decrease perioperative inventory costs, as compared with using sophisticated, stand-alone material management inventory control. Although we designed the simulations to favor financially linking the information systems, we found that this strategy would be expected to decrease inventory costs substantively only for items of high price ($1000 each) and volume (>1000 used each year). Because expensive items typically have different models and sizes, each of which is used by a hospital less often than this, for almost all items there will be no benefit to making daily adjustments to the order volume based on booked cases. We conclude that, in a hospital with a sophisticated material management information system, OR managers will probably achieve greater cost reductions from focusing on negotiating less expensive purchase prices for items than on trying to link the OR information system with the hospital's material management information system to achieve just-in-time inventory control. In a hospital with a sophisticated material management information system, operating room managers will probably achieve greater cost reductions from focusing on negotiating less expensive purchase prices for items than on trying to link the operating room information system with the hospital's material management information system to achieve just-in-time inventory control.

  10. Using Private Rights to Manage Natural Resources: Is Stewardship Linked to Ownership?

    Directory of Open Access Journals (Sweden)

    Peter D. Dwyer

    2012-09-01

    Full Text Available There is increasing interest in privatizing natural resource systems to promote sustainability and conservation goals. Though economic theory suggests owners of private property rights have an incentive to act as resource stewards, few studies have tested this empirically. This paper asks whether private rights-owners were more conservative with respect to their management opinions than nonrights-owners in five Australian abalone (Haliotis spp. fisheries. Multiple regression analyses were used to link opinions to demographic, economic, and attitudinal variables. In contrast to standard economic assumptions, nonrights-owners suggested more conservative catch limits than did rights-owners, confirming qualitative observations of behavior in management workshops. Differing views about the condition of the resource and differing levels of experience contributed to these results. The first of its kind, this study directly demonstrates that private rights do not necessarily promote the greatest level of stewardship. This has substantial implications for how natural resources are governed globally, but also warns against applying simplistic behavioral assumptions to complex social-ecological systems.

  11. Evaluating the link between human resource management decisions and patient satisfaction with quality of care.

    Science.gov (United States)

    Oppel, Eva-Maria; Winter, Vera; Schreyögg, Jonas

    Patient satisfaction with quality of care is becoming increasingly important in the competitive hospital market. Simultaneously, the growing shortage of clinical staff poses a considerable challenge to ensuring a high quality of care. In this context, a question emerges regarding whether and how human resource management (HRM) might serve as a means to reduce staff shortage problems and to increase patient satisfaction. Although considerable efforts have been devoted to understanding the concepts of patient satisfaction and HRM, little is known about the interrelationships between these concepts or about the link between staff shortage problems and patients' satisfaction with quality of care. The aim of this study was to investigate the relationship between strategic human resource management (SHRM), staff shortage problems, and patients' satisfaction with care. Furthermore, we analyze how the HRM decision to fill short-term vacancies through temporary staffing affects patient satisfaction. We differentiate between physicians and nurses. We develop and empirically test a theoretical model. The data (n = 165) are derived from a survey on SHRM that was sent to 732 German hospitals and from a survey on patient satisfaction that comprises 436,848 patient satisfaction ratings. We use a structural equation modeling approach to test the model. The results indicate that SHRM significantly reduces staff shortage problems for both occupational groups. Having fewer physician shortage problems is significantly associated with higher levels of patient satisfaction, whereas this effect is not significant for nurses. Furthermore, the use of temporary staffing considerably reduces patients' satisfaction with care. Hospital managers are advised to consider the effects of HRM decisions on patients' satisfaction with care. In particular, investments in SHRM targeted at physicians have significantly positive effects on patient satisfaction, whereas the temporary staffing of physicians

  12. Equipment Management for Sensor Networks: Linking Physical Infrastructure and Actions to Observational Data

    Science.gov (United States)

    Jones, A. S.; Horsburgh, J. S.; Matos, M.; Caraballo, J.

    2015-12-01

    Networks conducting long term monitoring using in situ sensors need the functionality to track physical equipment as well as deployments, calibrations, and other actions related to site and equipment maintenance. The observational data being generated by sensors are enhanced if direct linkages to equipment details and actions can be made. This type of information is typically recorded in field notebooks or in static files, which are rarely linked to observations in a way that could be used to interpret results. However, the record of field activities is often relevant to analysis or post-processing of the observational data. We have developed an underlying database schema and deployed a web interface for recording and retrieving information on physical infrastructure and related actions for observational networks. The database schema for equipment was designed as an extension to the Observations Data Model 2 (ODM2), a community-developed information model for spatially discrete, feature based earth observations. The core entities of ODM2 describe location, observed variable, and timing of observations, and the equipment extension contains entities to provide additional metadata specific to the inventory of physical infrastructure and associated actions. The schema is implemented in a relational database system for storage and management with an associated web interface. We designed the web-based tools for technicians to enter and query information on the physical equipment and actions such as site visits, equipment deployments, maintenance, and calibrations. These tools were implemented for the iUTAH (innovative Urban Transitions and Aridregion Hydrosustainability) ecohydrologic observatory, and we anticipate that they will be useful for similar large-scale monitoring networks desiring to link observing infrastructure to observational data to increase the quality of sensor-based data products.

  13. Linking Theory with Practice: Undergraduate Project Management with School-Age Children.

    Science.gov (United States)

    Falkenberg, Loren; Russell, Randy; Ricker, Lynne

    2000-01-01

    Management students taught basic business concepts to sixth graders and managed business projects with them. The management students applied knowledge of marketing, human resources, and operations management and developed reflective learning skills through project reports and coaching sessions. (SK)

  14. The Management of “Coats' Response” in a Patient with X-Linked Retinitis Pigmentosa—A Case Report

    OpenAIRE

    Shveta Bansal; Niladri Saha; Woon, W. H.

    2011-01-01

    The management of exudative retinal detachment in Coats disease can be very difficult with variable results. A case is presented of a 12 year old boy who was diagnosed with X-linked retinitis pigmentosa with an associated “Coat's Response”. The patient had a marked reduction in his left visual acuity due to intragel and subhyaloid haemorrhage as well as exudative retinal detachment. This was managed successfully with vitrectomy and endolaser, resulting in clearance of the haemorrhage and flat...

  15. Management concept to promote biodiversity-linked ecosystem services in vineyards (Project PromESSinG)

    Science.gov (United States)

    Griesser, Michaela; Schlossnikel, Bettina; Pingel, Martin; Uzman, Deniz; Steiner, Magdalena; Reineke, Annette; Bacher, Sven; van Helden, Maarten; Giffard, Brice; Tolle, Pauline; Preda, Cristina; Forneck, Astrid; Leyer, Ilona

    2016-04-01

    Although vineyards are intensive used agro-ecosystem with high economic importance worldwide the efforts to establish a sustainable viticulture system have been increased dramatically. In accordance with these efforts knowledge about the ecosystem vineyard and the influencing factors is highly needed. In a three years project the question whether and how biodiversity can support ecosystem services is addressed in five European countries, representing temperate vine-growing regions. Vineyards can provide high levels of biodiversity inside the cropped area, which cannot be found in annual cropping systems. Our research will have a strong focus on the biodiversity in the soil, analyzing microorganisms as well as the meso- und macrofauna. These parameters will be linked with different ecosystem services of the soil, like organic matter degradation, provision of water and nutrients, influences on the soil structure and the interaction of beneficial and phytopathogenic microorganisms and insects. In order to find options for promoting biodiversity and ecosystem services we study three different types of vineyard soil management: bare ground, complete vegetation cover, and both types arranged in alternating alleys. Further treatments of green manure and species rich seed mixtures are investigated in single countries. The second influencing factor analyzed is the surrounding landscape structure, as it is known that a high density of semi-natural habitats can provide biodiversity and ecosystem services for agricultural fields. Therefore vineyards with a different density of hedges, woodlands, and grasslands were selected for the study. The project started 2015 and first results concerning the influence of the soil management system on the degradation of the soil organic matter and the abundance of the macrofauna showed already first responsive effects in Austrian vineyards.

  16. A Linked Simulation-Optimization (LSO) Model for Conjunctive Irrigation Management using Clonal Selection Algorithm

    Science.gov (United States)

    Islam, Sirajul; Talukdar, Bipul

    2016-09-01

    A Linked Simulation-Optimization (LSO) model based on a Clonal Selection Algorithm (CSA) was formulated for application in conjunctive irrigation management. A series of measures were considered for reducing the computational burden associated with the LSO approach. Certain modifications were incurred to the formulated CSA, so as to decrease the number of function evaluations. In addition, a simple problem specific code for a two dimensional groundwater flow simulation model was developed. The flow model was further simplified by a novel approach of area reduction, in order to save computational time in simulation. The LSO model was applied in the irrigation command of the Pagladiya Dam Project in Assam, India. With a view to evaluate the performance of the CSA, a Genetic Algorithm (GA) was used as a comparison base. The results from the CSA compared well with those from the GA. In fact, the CSA was found to consume less computational time than the GA while converging to the optimal solution, due to the modifications incurred in it.

  17. "Advances in Linked Air Quality, Farm Management and Biogeochemistry Models to Address Bidrectional Ammonia Flux in CMAQ"

    Science.gov (United States)

    Recent increases in anthropogenic inputs of nitrogen to air, land and water media pose a growing threat to human health and ecosystems. Modeling of air-surface N flux is one area in need of improvement. Implementation of a linked air quality and cropland management system is de...

  18. Advances in Linked Air Quality, Farm Management and Biogeochemistry Models to Address Bidirectional Ammonia Flux in CMAQ

    Science.gov (United States)

    Recent increases in anthropogenic inputs of nitrogen to air, land and water media pose a growing threat to human health and ecosystems. Modeling of air-surface N flux is one area in need of improvement. Implementation of a linked air quality and cropland management system is de...

  19. Self-management support interventions that are clinically linked and technology enabled: can they successfully prevent and treat diabetes?

    Science.gov (United States)

    Kaufman, Neal D; Woodley, Paula D Patnoe

    2011-05-01

    Patients with diabetes need a complex set of services and supports. The challenge of integrating these services into the diabetes regimen can be successfully overcome through self-management support interventions that are clinically linked and technology enabled: self-management support because patients need help mastering the knowledge, attitudes, skills, and behaviors so necessary for good outcomes; interventions because comprehensive theory-based, evidence-proven, long-term, longitudinal interventions work better than direct-to-consumer or nonplanned health promotion approaches; clinically linked because patients are more likely to adopt new behaviors when the approach is in the context of a trusted therapeutic relationship and within an effective medical care system; and technology enabled because capitalizing on the amazing power of information technology leads to the delivery of cost-effective, scalable, engaging solutions that prevent and manage diabetes.

  20. ANALYSIS OF LINK STATE RESOURCE RESERVATION PROTOCOL FOR CONGESTION MANAGEMENT IN SMART WEB HOTSPOT ENVIRONMENTS

    Directory of Open Access Journals (Sweden)

    Anulika Okoye Joy1

    2016-06-01

    Full Text Available With the wide spread of WiFi hotspots, concentrated traffic workload on Smart Web (SW can slow down the network performance. This paper presents a congestion management strategy considering real time activities in today’s smart web. With the SW context, cooperative packet recovery using resource reservation procedure for TCP flows was adapted for mitigating packet losses. This is to maintain data consistency between various access points of smart web hotspot. Using a real world scenario, it was confirmed that generic TCP cannot handle traffic congestion in a SW hotspot network. With TCP in scalable workload environments, continuous packet drops at the event of congestion remains obvious. This is unacceptable for mission critical domains. An enhanced Link State Resource Reservation Protocol (LSRSVP which serves as dynamic feedback mechanism in smart web hotspots is presented. The contextual behaviour was contrasted with the generic TCP model. For the LS-RSVP, a simulation experiment for TCP connection between servers at the remote core layer and the access layer was carried out while using selected benchmark metrics. From the results, under realistic workloads, a steady-state throughput response was achieved by TCP LS-RSVP to about 3650Bits/secs compared with generic TCP plots in a previous study. Considering network service availability, this was found to be dependent on fault-tolerance of the hotspot network. From study, a high peak threshold of 0.009 (i.e. 90% was observed. This shows fairly acceptable service availability behaviour compared with the existing TCP schemes. For packet drop effects, an analysis on the network behaviour with respect to the LS-RSVP yielded a drop response of about 0.000106 bits/sec which is much lower compared with the case with generic TCP with over 0.38 bits/sec. The latency profile of average FTP download response was found to be 0.030secs, but with that of FTP pload response, this yielded about 0.028 sec. The

  1. Developing Managerial Talent: Exploring the Link between Management Talent and Perceived Performance in Multinational Corporations (MNCs)

    Science.gov (United States)

    Sheehan, Maura

    2012-01-01

    Purpose: To examine the association between talent management (TM) and perceived subsidiary performance. Focus is given to the development of one key talent group--line managers--in subsidiaries of multinational corporations (MNCs). Specifically, the paper examines: whether there is a positive relationship between Management Development (MD) and…

  2. A Linked Fusion of Things, Services, and Data to Support a Collaborative Data Management Facility

    Energy Technology Data Exchange (ETDEWEB)

    Stephan, Eric G.; Elsethagen, Todd O.; Wynne, Adam S.; Sivaraman, Chitra; Macduff, Matt C.; Berg, Larry K.; Shaw, William J.

    2013-09-30

    The purpose of this paper is to illustrate the use of semantic technologies and approaches to seamlessly link things, services, and data in the proposed design of a scientific offshore wind energy research for the U.S. Department of Energy Wind and Water Technology Office of the Office of Energy Efficiency and Renewable Energy (EERE). By adapting linked community best practices, we were able to design a collaborative facility supporting both operational staff and end users that incorporates off-the-shelf components and overcome traditional barriers between devices, resulting data, and processing services. This was made largely possible through complementary advances in the Internet of Things (IoT), semantic web, Linked Services, and Linked Data communities, which provide the foundation for our design.

  3. Linking knowledge with action in the pursuit of sustainable water-resources management

    OpenAIRE

    Jacobs, Katharine; Lebel, Louis; De Buizer, James; Addams, Lee; Matson, Pamela; McCullough, Ellen; Garden, Po; Saliba, George; Finan, Timothy

    2010-01-01

    Managing water for sustainable use and economic development is both a technical and a governance challenge in which knowledge production and sharing play a central role. This article evaluates and compares the role of participatory governance and scientific information in decision-making in four basins in Brazil, Mexico, Thailand, and the United States. Water management institutions in each of the basins have evolved during the last 10–20 years from a relatively centralized water-management s...

  4. The Moderating Role of Performance in the Link From Interactional Justice Climate to Mutual Trust Between Managers and Team Members.

    Science.gov (United States)

    Martínez-Tur, Vicente; Gracia, Esther; Moliner, Carolina; Molina, Agustín; Kuster, Inés; Vila, Natalia; Ramos, José

    2016-06-01

    The main goal of this study was to examine the interaction between team members' performance and interactional justice climate in predicting mutual trust between managers and team members. A total of 93 small centers devoted to the attention of people with intellectual disability participated in the study. In each center, the manager (N = 93) and a group of team members (N = 746) were surveyed. On average, team members were 36.2 years old (SD = 9.3), whereas managers were 41.2 years old (SD = 8.8). The interaction between interactional justice climate and performance was statistically significant. Team members' performance strengthened the link from interactional justice climate to mutual trust. © The Author(s) 2016.

  5. Linking local vulnerability to climatic hazard damage assessment for integrated river basin management

    Science.gov (United States)

    Hung, Hung-Chih; Liu, Yi-Chung; Chien, Sung-Ying

    2015-04-01

    1. Background Major portions of areas in Asia are expected to increase exposure and vulnerability to climate change and weather extremes due to rapid urbanization and overdevelopment in hazard-prone areas. To prepare and confront the potential impacts of climate change and related hazard risk, many countries have implemented programs of integrated river basin management. This has led to an impending challenge for the police-makers in many developing countries to build effective mechanism to assess how the vulnerability distributes over river basins, and to understand how the local vulnerability links to climatic (climate-related) hazard damages and risks. However, the related studies have received relatively little attention. This study aims to examine whether geographic localities characterized by high vulnerability experience significantly more damages owing to onset weather extreme events at the river basin level, and to explain what vulnerability factors influence these damages or losses. 2. Methods and data An indicator-based assessment framework is constructed with the goal of identifying composite indicators (including exposure, biophysical, socioeconomic, land-use and adaptive capacity factors) that could serve as proxies for attributes of local vulnerability. This framework is applied by combining geographical information system (GIS) techniques with multicriteria decision analysis (MCDA) to evaluate and map integrated vulnerability to climatic hazards across river basins. Furthermore, to explain the relationship between vulnerability factors and disaster damages, we develop a disaster damage model (DDM) based on existing disaster impact theory. We then synthesize a Zero-Inflated Poisson regression model with a Tobit regression analysis to identify and examine how the disaster impacts and vulnerability factors connect to typhoon disaster damages and losses. To illustrate the proposed methodology, the study collects data on the vulnerability attributes of

  6. Linking Management Actions to Interactive Ecosystem Report Cards via an Ontology

    Science.gov (United States)

    Alabri, A.; Newman, A.; Abal, E.; van Ingen, C.; Hunter, J.

    2008-12-01

    IINTRODUCTION The Health-e-Waterways Project is a three way collaboration between the University of Queensland, Microsoft Research and the Healthy Waterways Partnership (SEQ-HWP)(over 60 local government, state agency, universities, community and environmental organizations). The project is developing a highly innovative framework and set of services to enable streamlined access to an integrated collection of real- time, near-real-time and static datasets acquired through ecosystem monitoring programs in South East Queensland. Using a novel combination of semantic web technologies, scientific data servers, web services, GIS visualization interfaces and scientific workflows, we are enabling the sharing and integration of high quality data and models, through a combined integrated water information management system and Web portal. DYNAMIC GENERATION OF ECOSYSTEM HEALTH REPORT CARDS SEQ-HWP is responsible for the Ecosystem Health Monitoring Program (EHMP) in South East Queensland. This currently involves sampling 30 freshwater indicators at 100 sites twice a year and 250 estuarine/marine sites every month. The EHMP data sets are statistically aggregated and standardized to produce ecosystem health grades that are published annually in hard copy EHMP Report Cards. Politicians and planners use the report cards to make decisions with respect to land use, water quality, allocations and investments in water recycling plants etc. To date, these report cards have been largely produced manually, by calculating standardized scores (0-1) across 5 indicators and 16 indices (physical, chemical, nutrients, ecosystem processes, acquatic macroinvertebrates and fish) and grades from A-F for each catchment and season (spring and autumn). Currently this process takes about 5 months. For the past 6 months, we have been working with the SEQ-HWP staff, developing software services that will enable the report cards to be generated dynamically via a Web-based Map interface to an underlying

  7. Linking Farmer Weed Management Behavior with Weed Pressure: More than Just Technology

    NARCIS (Netherlands)

    Riemens, M.M.; Groeneveld, R.M.W.; Kropff, M.J.; Lotz, L.A.P.; Renes, R.J.; Sukkel, W.; Weide, van der R.Y.

    2010-01-01

    Most studies on weed population dynamics in farming systems have focused on the effects of different weed control strategies. Those studies usually assume that farmers, operating within a particular system, have a uniform management style. However, it is likely that weed management decision making

  8. Linking a Medical User Survey to Management for Library Effectiveness: II, A Checkland Soft Systems Study.

    Science.gov (United States)

    Brember, V. L.

    1985-01-01

    Presents Checkland's soft systems methodology, discusses it in terms of the systems approach, and illustrates how it was used to relate evidence of user survey to practical problems of library management. Difficulties in using methodology are described and implications for library management and information science research are presented. (8…

  9. Anger management and the process mediating the link between witnessing violence between parents and partner violence.

    Science.gov (United States)

    Turcotte-Seabury, Catherine A

    2010-01-01

    Multinomial logistic regression was used on a sample of 14,252 students to determine the extent to which the relationship between witnessing interparental violence and the perpetration of violence is mediated by limited anger management ability, and to determine whether anger management is a mediator for women as well as men. Both males and females who witnessed interparental violence had higher levels of violence perpetration, and those who disclosed witnessing interparental violence had more limited anger management abilites. These limited anger management abilities were associated with increased levels of violence perpetration. This study is consistent with others finding a relationship between witnessing interparental violence and the perpetration of violence but also shows that the relationship between these two variables is mediated by limited anger management abilities.

  10. Communities of practice : Finally a link between individual and organizational learning in management development programs

    NARCIS (Netherlands)

    Ropes, D.C.; Thölke, J.M.

    2010-01-01

    This paper is about helping human resource development professionals to understand how community of practice theory can inform the design of learning-based programs in order to link individual and organizational learning better. Learning is often considered a major contributor to the success or

  11. Managing coopetition through horizontal supply chain relations : Linking dyadic and network levels of analysis

    NARCIS (Netherlands)

    Wilhelm, Miriam M.

    2011-01-01

    A growing research stream has expanded the level of analysis beyond single buyer-supplier relations to the network, including supplier-supplier relations. These supplier-supplier relations may constitute a missing link between the traditional analysis of the dyadic and the network level of analysis

  12. Linked open data on its way into next generation library management and discovery solutions

    Directory of Open Access Journals (Sweden)

    Axel Kaschte

    2013-01-01

    Full Text Available Library Linked Data Model is an important topic for librarianship and it is equally of interest to the many organizations that provide products and services to that community. Ex Libris, as one of those organizations, frequently gets asked: “Where do we see it fitting into our plans?”. In order to be able to answer questions like this, we need to ask: “What exactly are the problems being solved for the profession by this technology that can only be solved with the Library Linked Data model?” What most developers/providers of products analyzing the potential of library linked data would see is that at this stage, this technology is very much in the research stage. The presentation talks about the research ExLibris is involved in and how this can be utilized by innovative libraries to help defining the actual use cases in which the potential of the Library Linked Data Modell is indeed exploited.

  13. Managing coopetition through horizontal supply chain relations : Linking dyadic and network levels of analysis

    NARCIS (Netherlands)

    Wilhelm, Miriam M.

    2011-01-01

    A growing research stream has expanded the level of analysis beyond single buyer-supplier relations to the network, including supplier-supplier relations. These supplier-supplier relations may constitute a missing link between the traditional analysis of the dyadic and the network level of analysis

  14. Communities of practice : Finally a link between individual and organizational learning in management development programs

    NARCIS (Netherlands)

    Ropes, D.C.; Thölke, J.M.

    2010-01-01

    This paper is about helping human resource development professionals to understand how community of practice theory can inform the design of learning-based programs in order to link individual and organizational learning better. Learning is often considered a major contributor to the success or fail

  15. Communities of Practice : Finally a link between individual and organizational learning in management development programs

    NARCIS (Netherlands)

    Thölke, Jürg; Ropes, Donald

    2010-01-01

    This paper is about helping human resource development professionals to understand how community of practice theory can inform the design of learning-based programs in order to link individual and organizational learning better. Learning is often considered a major contributor to the success or fail

  16. Ecological perspective: linking ecology, GIS, and remote sensing to ecosystem management

    Science.gov (United States)

    Allen, C. D.

    1994-01-01

    Awareness of significant human impacts on the ecology of Earth's landscapes is not new (Thomas 1956). Over the past decade (Forman and Godron 1986, Urban et a1. 1987) applications of geographic information systems (GIS) and remote sensing technologies have supported a rapid rise in landscape.stale research. The heightened recognition within the research community of the ecological linkages between local sites and larger spatial scales has spawned increasing calls for more holistic management of landscapes (Noss 1983, Harris 1984, Risser 1985, Norse et al. 1986, Agee and Johnson 1988, Franklin 1989, Brooks and Grant 1992, Endangered Species Update-Special Issue 1993, Crow 1994, Grumbine 1994). As a result agencies such as the U.S. Forest Service, U.S. Fish and Wildlife Service, and National Park Service are now converging on "ecosystem management" as a new paradigm to sustainably manage wildlands and maintain biodiversity. However, as this transition occurs, several impediments to implementation of this new paradigm persist, including (1) significant uncenainty among many land managers about the definition and goals of ecosystem management, (2) inadequate ecological information on the past and present processes and structural conditions of target ecosystems, (3) insufficient experience on the part of land managers with the rapidly diversifying array of GIS and remote sensing tools to effectively use them to support ecology-based land management, and (4) a paucity of intimate, long-term relationships between people (including land managers) and the particular landscape communities to which they belong. This chapter provides an ecological perspective on these issues as applied to ecosystem management in a southwestern U.S. landscape.

  17. PROJECT MANAGEMENT OFFICE – LINK BETWEEN ORGANIZATIONAL STRATEGIC AND OPERATIONAL: A CASE STUDY

    Directory of Open Access Journals (Sweden)

    Mario Manzini Cianfanelli

    2014-12-01

    Full Text Available The objective of this work is to demonstrate the organizational integration achieved through the implementation of a project management office (PMO, created to combat the loss of water distribution in one of the business units of Basic Sanitation Company of the State of São Paulo – Sabesp. The methodology used to achieve this goal was the study of a single case in which the information was obtained through documentary research and semi-structured interviews. The results showed how this integration was achieved with the adoption of a standard methodology in project management, control based on information technology and the spread of the organization's strategy in the sectors below. This work concluded that with this implantation of the project management office it was possible to improve the planning and the control of the activities of the projects through a pattern methodology in managing projects that gave possibilities to create a new culture focusing in solving problems.

  18. Ecological Forestry in the Longleaf Pine Ecosystem: Linking Research, Adaptive Management, and Outreach for Conservation

    OpenAIRE

    McIntyre, Kevin; Jack, Steven B.; Robert J. Mitchell

    2009-01-01

    The integration of scientific understanding, conservation values, and silvicultural systems is critical to ecologically sustainable forest management. The longleaf pine ecosystem is one of the rarest forest types in North America and, until recently, one of the least well understood in terms of its basic ecology. Models of management based on natural disturbance that utilize single tree selection are unique in their ability to maintain the conservation values of the longleaf ecosystem while g...

  19. Intricacies in Drought Management Policy, Crisis Response and Preparedness: Linking the Interface

    Science.gov (United States)

    Prakash, P.; Harter, T.

    2016-12-01

    Drought per se is often misrepresented as mere water scarcity issue overlooking the complexities associated with it. In many parts of the world, the drought management policy prescriptions are often driven by crisis management rather than preventive approach. As a result, the economic, social and environmental impact of droughts continues to increase even to this day. To overcome this calamity, nations should encourage coordinated effort at both national and regional scale. An integrated approach on open data sharing, technical advancement in monitoring and robust early warning system to deliver timely information to decision makers, drought projection through high performance mathematical model and effective impact assessment procedure, implementing proactive risk management measures and preparedness with effective emergency response programs plans, will certainly increase the likelihood of drought coping capabilities. The present study focuses on knowledge augmentation for better policy framework and action for all countries that suffer from droughts. A comprehensive database at the global scale has been compiled giving information on existing drought management policies/practices and the major challenges faced by major drought distressed countries. Plausible solution is suggested towards integrating the water management policy, response and preparedness, that has been garnered through the lessons from success/failure stories of nations with effective drought management policies

  20. Reflexive Land and Water Management in Iran: Linking Technology, Governance and Culture. Part 1: Land and Water Management Paradigms

    NARCIS (Netherlands)

    Balali, M.R.; Keulartz, F.W.J.; Korthals, M.J.J.A.A.

    2011-01-01

    In order to examine the possibilities for sustainable land and water management in Iran, this research was carried out with two types of research and their combinations, i.e. theoretical and empirical research during 2005- 2009. In the theoretical part, which is the scope of this paper, the co-evolu

  1. Reflexive Land and Water Management in Iran: Linking Technology, Governance and Culture. Part 1: Land and Water Management Paradigms

    NARCIS (Netherlands)

    Balali, M.R.; Keulartz, F.W.J.; Korthals, M.J.J.A.A.

    2011-01-01

    In order to examine the possibilities for sustainable land and water management in Iran, this research was carried out with two types of research and their combinations, i.e. theoretical and empirical research during 2005- 2009. In the theoretical part, which is the scope of this paper, the

  2. USA Nutrient managment forecasting via the "Fertilizer Forecaster": linking surface runnof, nutrient application and ecohydrology.

    Science.gov (United States)

    Drohan, Patrick; Buda, Anthony; Kleinman, Peter; Miller, Douglas; Lin, Henry; Beegle, Douglas; Knight, Paul

    2017-04-01

    USA and state nutrient management planning offers strategic guidance that strives to educate farmers and those involved in nutrient management to make wise management decisions. A goal of such programs is to manage hotspots of water quality degradation that threaten human and ecosystem health, water and food security. The guidance provided by nutrient management plans does not provide the day-to-day support necessary to make operational decisions, particularly when and where to apply nutrients over the short term. These short-term decisions on when and where to apply nutrients often make the difference between whether the nutrients impact water quality or are efficiently utilized by crops. Infiltrating rainfall events occurring shortly after broadcast nutrient applications are beneficial, given they will wash soluble nutrients into the soil where they are used by crops. Rainfall events that generate runoff shortly after nutrients are broadcast may wash off applied nutrients, and produce substantial nutrient losses from that site. We are developing a model and data based support tool for nutrient management, the Fertilizer Forecaster, which identifies the relative probability of runoff or infiltrating events in Pennsylvania (PA) landscapes in order to improve water quality. This tool will support field specific decisions by farmers and land managers on when and where to apply fertilizers and manures over 24, 48 and 72 hour periods. Our objectives are to: (1) monitor agricultural hillslopes in watersheds representing four of the five Physiographic Provinces of the Chesapeake Bay basin; (2) validate a high resolution mapping model that identifies soils prone to runoff; (3) develop an empirically based approach to relate state-of-the-art weather forecast variables to site-specific rainfall infiltration or runoff occurrence; (4) test the empirical forecasting model against alternative approaches to forecasting runoff occurrence; and (5) recruit farmers from the four

  3. Managing E-mail Interactions with Patients: A Discussion with Clinicians in Evaluating the Personal Health Link Project.

    Science.gov (United States)

    Serrato, Carl A; Retecki, Sally

    2004-01-01

    One software feature in the Personal Health Link (PHL) Project allows members of Kaiser Permanente to send secure e-mail messages to clinicians and staff. As an early step in the PHL evaluation process, a group of primary care physicians met to discuss their opinions and experiences with e-mail interactions with patients and to suggest strategies for effectively managing these e-mail interactions. Most clinicians spoke from their experience with e-mail interactions with patients in a conventional e-mail environment; only one clinician in the group was using PHL.

  4. Management of pediatric keratoconus – Evolving role of corneal collagen cross-linking: An update

    Science.gov (United States)

    Kankariya, Vardhaman P; Kymionis, George D; Diakonis, Vasilios F; Yoo, Sonia H

    2013-01-01

    Pediatric keratoconus demonstrates several distinctive management issues in comparison with adult keratoconus with respect to under-diagnosis, poor compliance and modifications in treatment patterns. The major concerns comprise of the accelerated progression of the disease in the pediatric age group and management of co-morbidities such as vernal keratoconjuntivitis. Visual impairment in pediatric patients may affect social and educational development and overall negatively impact their quality of life. The treatment algorithm between adults and pediatric keratoconus has been similar; comprising mainly of visual rehabilitation with spectacles, contacts lenses (soft or rigid) and keratoplasty (lamellar or penetrating) depending on the stage of the disease. There is a paradigm shift in the management of keratoconus, a new treatment modality, corneal collagen crosslinking (CXL), has been utilized in adult keratoconic patients halting the progression of the disease. CXL has been utilized for over a 10 year period and based on the evidence of efficacy and safety in the adult population; this treatment has been recently utilized in management of pediatric keratoconus. This article will present an update about current management of pediatric keratoconus with special focus on CXL in this age group. PMID:23925333

  5. Simulation-Based Learning Environments to Teach Complexity: The Missing Link in Teaching Sustainable Public Management

    Directory of Open Access Journals (Sweden)

    Michael Deegan

    2014-05-01

    Full Text Available While public-sector management problems are steeped in positivistic and socially constructed complexity, public management education in the management of complexity lags behind that of business schools, particularly in the application of simulation-based learning. This paper describes a Simulation-Based Learning Environment for public management education that includes a coupled case study and System Dynamics simulation surrounding flood protection, a domain where stewardship decisions regarding public infrastructure and investment have direct and indirect effects on businesses and the public. The Pointe Claire case and CoastalProtectSIM simulation provide a platform for policy experimentation under conditions of exogenous uncertainty (weather and climate change as well as endogenous effects generated by structure. We discuss the model in some detail, and present teaching materials developed to date to support the use of our work in public administration curricula. Our experience with this case demonstrates the potential of this approach to motivate sustainable learning about complexity in public management settings and enhance learners’ competency to deal with complex dynamic problems.

  6. Management of pediatric keratoconus - Evolving role of corneal collagen cross-linking: An update

    Directory of Open Access Journals (Sweden)

    Vardhaman P Kankariya

    2013-01-01

    Full Text Available Pediatric keratoconus demonstrates several distinctive management issues in comparison with adult keratoconus with respect to under-diagnosis, poor compliance and modifications in treatment patterns. The major concerns comprise of the accelerated progression of the disease in the pediatric age group and management of co-morbidities such as vernal keratoconjuntivitis. Visual impairment in pediatric patients may affect social and educational development and overall negatively impact their quality of life. The treatment algorithm between adults and pediatric keratoconus has been similar; comprising mainly of visual rehabilitation with spectacles, contacts lenses (soft or rigid and keratoplasty (lamellar or penetrating depending on the stage of the disease. There is a paradigm shift in the management of keratoconus, a new treatment modality, corneal collagen crosslinking (CXL, has been utilized in adult keratoconic patients halting the progression of the disease. CXL has been utilized for over a 10 year period and based on the evidence of efficacy and safety in the adult population; this treatment has been recently utilized in management of pediatric keratoconus. This article will present an update about current management of pediatric keratoconus with special focus on CXL in this age group.

  7. Are managers also ‘crafting leaders’? The link between organizational rank, autonomy, and job crafting

    Directory of Open Access Journals (Sweden)

    Roczniewska Marta Anna

    2017-06-01

    Full Text Available Although research has examined the role leaders may play in shaping job re-design behaviors among their subordinates, little is known about the way managers craft their jobs as compared to other employees. In two crosssectional studies we tested whether organizational rank affects the frequency of job crafting (H1, and to what extent this relationship is mediated via perceived autonomy (H2. Study 1 (N = 267 demonstrated that managers craft their jobs more frequently than non-managers by increasing structural job resources and seeking challenges at work. We also showed that autonomy explains the relationship between organizational rank and the frequency of increasing structural and social job demands, as well as seeking challenges. However, managers did not craft their jobs by decreasing job demands more often than regular employees. In Study 2 (N = 262 we replicated this pattern of results, subsequently demonstrating that managers with shorter tenure use their autonomy to craft their jobs via decreasing job demands. We discuss the contributions and potential implications of these results.

  8. A Fast linking approach for CMYK to CMYK conversion preserving black separation in ICC color management system

    Science.gov (United States)

    Zeng, Huanzhao

    2003-12-01

    In the linking step of the standard ICC color management workflow for CMYK to CMYK conversion, a CMM takes an AToBn tag (n = 0, 1, or 2) from a source ICC profile to convert a color from the source color space to PCS (profile connection space), and then takes a BToAn tag from the destination ICC profile to convert the color from PCS to the destination color space. This approach may give satisfactory result perceptually or colorimetrically. However, it does not preserve the K channel for CMYK to CMYK conversion, which is often required in graphic art"s market. The problem is that the structure of a BtoAn tag is designed to convert colors from PCS to a device color space ignoring the K values from the source color space. Different approaches have been developed to control K in CMYK to CMYK printing, yet none of them well fits into the "Profile - PCS - Profile" model in the ICC color management system. A traditional approach is to transform the source CMYK to the destination CMYK by 1-D TRC curves and GCR/UCR tables. This method is so simple that it cannot accurately transform colors perceptually or colorimetrically. Another method is to build a 4-D CMYK to CMYK closed-loop lookup table (LUT) (or a deviceLink ICC profile) for the color transformation. However, this approach does not fit into opened color management workflows for it ties the source and the destination color spaces in the color characterization step. A specialized CMM may preserve K for a limit number of colors by mapping those CMYK colors to some carefully chosen PCS colors in both the AToBi tag and the BToAi tag. A more complete solution is to move to smart linking in which gamut mapping is performed in the real-time linking at a CMM. This method seems to solve all problems existed in the CMYK to CMYK conversion. However, it introduces new problems: 1) gamut mapping at real-time linking is often unacceptable slow; 2) gamut mapping may not be optimized or may be unreliable; 3) manual adjustment for

  9. The missing link to success: using a business process management system to automate and manage process improvement.

    Science.gov (United States)

    Hess, Ray

    2009-01-01

    Healthcare continues to face many significant challenges in its quest to provide optimal patient care. Many hospitals have instituted various process improvement methodologies to address these challenges. The outcome of these efforts still produces a large volume of manual tasks that must be addressed by the caregiver. The Chester County Hospital employed a Business Process Management (BPM) engine to automate and manage several of these processes. A BPM engine can perform key tasks and interact with the clinician to decrease the manual requirements of a process. The result is reduced workloads and improved outcomes. The Chester County Hospital has been able to demonstrate significant decreases in hospital acquired MRSA infections and compliance with several CMS core measures. There are multiple items to evaluate before attempting to use a BPM engine. This paper reviews the work at Chester County, its outcomes and the considerations that were important for achieving success.

  10. Depression in systemic sclerosis: Review of the neuro-immunologic link and pharmacological management

    Directory of Open Access Journals (Sweden)

    Aditya Somani

    2016-01-01

    Full Text Available Depression is a common neuropsychiatric condition associated with systemic sclerosis. The association of depression and systemic sclerosis is the result of multiple mechanisms such as autoimmune, significant morbidity due to multi-system involvement, distorted self-image due to disfigurement, chronic disability, and iatrogenic. The prevalence of depression in systemic sclerosis is as high as 65% as found in several clinical studies. Early diagnosis and appropriate intervention of depression in systemic sclerosis through integrated multidisciplinary team approach is more likely to improve the global outcome of illness. Hence, multidisciplinary management approach is highly recommended for the management of depression in systemic sclerosis.

  11. Hospital financial management: what is the link between revenue cycle management, profitability, and not-for-profit hospitals' ability to grow equity?

    Science.gov (United States)

    Singh, Simone Rauscher; Wheeler, John

    2012-01-01

    Effective revenue cycle management--from appointment scheduling and patient registration at the front end of the revenue cycle to billing and cash collections at the back end--plays a crucial role in hospitals' efforts to improve their financial performance. Using data for 1,397 bond-issuing, not-for-profit US hospitals for 2000 to 2007, this study analyzed the relationship between hospitals' performance at managing the revenue cycle and their profitability and ability to build equity capital. Hospital-level fixed effects regression analysis was used to model four different measures of profitability and equity capital as functions of two key financial indicators of revenue cycle management--amount of patient revenue and speed of revenue collection. The results indicated that higher amounts of patient revenue in relation to a hospital's assets were associated with statistically significant increases in operating and total profit margins, free cash flow, and equity capital (p revenue per dollar of assets invested reported improved financial performance. Likewise, a statistically significant link existed between lower revenue collection periods and all four indicators of hospital financial performance (p revenue reported higher profit margins and larger equity values. For revenue cycle managers, these findings represent good news: Streamlining a hospital's management of the patient revenue cycle can advance the organization's financial viability by improving profitability and enabling equity growth.

  12. Reorienting land degradation towards sustainable land management: linking sustainable livelihoods with ecosystem services in rangeland systems.

    Science.gov (United States)

    Reed, M S; Stringer, L C; Dougill, A J; Perkins, J S; Atlhopheng, J R; Mulale, K; Favretto, N

    2015-03-15

    This paper identifies new ways of moving from land degradation towards sustainable land management through the development of economic mechanisms. It identifies new mechanisms to tackle land degradation based on retaining critical levels of natural capital whilst basing livelihoods on a wider range of ecosystem services. This is achieved through a case study analysis of the Kalahari rangelands in southwest Botswana. The paper first describes the socio-economic and ecological characteristics of the Kalahari rangelands and the types of land degradation taking place. It then focuses on bush encroachment as a way of exploring new economic instruments (e.g. Payments for Ecosystem Services) designed to enhance the flow of ecosystem services that support livelihoods in rangeland systems. It does this by evaluating the likely impacts of bush encroachment, one of the key forms of rangeland degradation, on a range of ecosystem services in three land tenure types (private fenced ranches, communal grazing areas and Wildlife Management Areas), before considering options for more sustainable land management in these systems. We argue that with adequate policy support, economic mechanisms could help reorient degraded rangelands towards more sustainable land management.

  13. Self-Management Skills: An Important Link to Successful Special Education Postsecondary Transition Planning

    Science.gov (United States)

    Carter, Sharon D.

    2013-01-01

    This qualitative case study investigated the process of teaching the self-management strategies, self-determination, and self-monitoring to chronically misbehaved students from the perspective of a secondary special education teacher. The investigation used a purposeful sample to select an urban high school setting and a tenured special education…

  14. Towards reflexive land and water management in Iran : linking technology, governance and culture

    NARCIS (Netherlands)

    Balali, M.R.

    2009-01-01

    Key words: Qanat, land and water, sustainability, Industrial and reflexive modernity This PhD thesis is concerned with the causes and consequences of the environmental crisis and explores possible trajectories towards sustainable land and water management in Iran and other countries of the Middle

  15. The weak link in waste management in tropical Asia? Solid waste collection in Bali

    NARCIS (Netherlands)

    MacRae, Graeme; Rodic-Wiersma, Ljiljana

    2015-01-01

    This article builds on earlier work that examined waste processing options on the island of Bali, which can be seen as a useful "laboratory" for the study of solid waste management (SWM) problems and solutions in tropical Asia. The research reported here examines the challenges of waste

  16. The weak link in waste management in tropical Asia? Solid waste collection in Bali

    NARCIS (Netherlands)

    MacRae, Graeme; Rodic-Wiersma, Ljiljana

    2015-01-01

    This article builds on earlier work that examined waste processing options on the island of Bali, which can be seen as a useful "laboratory" for the study of solid waste management (SWM) problems and solutions in tropical Asia. The research reported here examines the challenges of waste collectio

  17. Linking people management and extra-role behaviour : Results of a longitudinal study

    NARCIS (Netherlands)

    Knies, Eva; Leisink, Peter

    2014-01-01

    This article examines the validity of the assumption that employees' perceptions of those people management activities of their supervisor that impact on employees' abilities, motivation and opportunities to perform influence employee extra-role behaviour. The results of a longitudinal survey with d

  18. Towards reflexive land and water management in Iran : linking technology, governance and culture

    NARCIS (Netherlands)

    Balali, M.R.

    2009-01-01

    Key words: Qanat, land and water, sustainability, Industrial and reflexive modernity This PhD thesis is concerned with the causes and consequences of the environmental crisis and explores possible trajectories towards sustainable land and water management in Iran and other countries of the Middle

  19. Managing Abandoned Farmland: The Need to Link Biological and Sociological Aspects

    Science.gov (United States)

    Benjamin, Karyne; Bouchard, André; Domon, Gérald

    2008-10-01

    The lack of a particular use associated with abandoned farmland provides real opportunities with respect to the various land-use pressures occurring in productive territories. These environments remain generally poorly known and, because of this, require in-depth studies on the feasibility of management options, on biological as well as social grounds. This study, based on research on the biophysical potential and the perceptions by the owners of abandoned farmlands, analyzes the feasibility of silvicultural management options to improve forestry potential. Using a questionnaire, we surveyed abandoned farmland owners on different aspects of the status of their abandoned farmland in order to determine their willingness toward the management of these private lands. The land owners were also asked to express their interests and their constraints toward various types of interventions, with an emphasis on silvicultural work. The data were analyzed using multivariate methods to establish relationships between the questionnaire data and the characteristics of the land owners (socioeconomic profile and value system toward the environment). The results show that, in general, abandoned farmland is an unwanted space, is generally little used, is poorly known, and has little importance in the plans of its owners. We have found three types of owner profiles; the owners with a farmer’s profile are those who are the most interested in managing their abandoned farmland, whether for agriculture or silviculture. The desire to improve abandoned farmland seems less important to owners with an ecocentric profile (high awareness of the environment) and to older owners. Finally, by associating the type of abandoned farmland owned and the characteristics of the owners, it is possible to propose different management options that reconcile the wishes of the owners as well as the biophysical potential of their abandoned farmland.

  20. Linking Ecosystem Health Indicators and Collaborative Management: a Systematic Framework to Evaluate Ecological and Social Outcomes

    Directory of Open Access Journals (Sweden)

    Tischa A. Muñoz-Erickson

    2007-12-01

    Full Text Available Collaborative management has gained popularity across the United States as a means of addressing the sustainability of mixed-ownership landscapes and resolving persistent conflicts in public lands management. At the same time, it has generated skepticism because its ecological and social outcomes are seldom measured. Evaluating the success of collaborative efforts is difficult because frameworks to assess on-the-ground outcomes are poorly developed or altogether lacking. Ecosystem health indicators are valuable tools for evaluating site-specific outcomes of collaboration based on the effects of collaboration on ecological and socioeconomic conditions. We present the holistic ecosystem health indicator, a promising framework for evaluating the outcomes of collaborative processes, which uses ecological, social, and interactive indicators to monitor conditions through time. Finally, we draw upon our experience working with the Diablo Trust, a community-based collaborative group in northern Arizona, USA, to illustrate the development of an indicator selection model generated through a stakeholder-driven process.

  1. Linking an agency strategic review to increase knowledge management: San Francisco County Human Service Agency.

    Science.gov (United States)

    Harrison, Lindsay

    2012-01-01

    Led by the agency director, the agency engaged in a Strategic Review, based on a comprehensive assessment of agency performance that identified strategies to improve organizational effectiveness through increased data-informed practice and knowledge management. The Strategic Review gathered information on staff perceptions, perceptions of external stakeholders, changing citywide and neighborhood demographics, policy mandates, and budget and workload issues. The need for the review was based upon multiple, substantial changes not addressed in the 2000 Strategic Plan, including the 2004 merger of the Department of Human Services and the Department of Aging and Adult Services, changes among the executive management team, transitions among key political entities, new policy mandates and changing budget allocations. This case study describes the Strategic Review process and content, summarizing key challenges and lessons related to addressing workload demands, fostering positive staff attitudes, balancing internal and external information needs, and integrating data use and planning processes across the agency. Copyright © Taylor & Francis Group, LLC

  2. Linking climate change mitigation and coastal eutrophication management through biogas technology

    DEFF Research Database (Denmark)

    Kaspersen, Bjarke Stoltze; Christensen, Thomas Budde; Fredenslund, Anders Michael

    2016-01-01

    and phosphorous loads to Køge Bay are estimated to be reduced by approx. 63tyr.-1 and 9tyr.-1, respectively, contributing to the achievement of more than 70% of the nutrient reduction target set for Køge Bay in the first WFD river basin management plan. This study shows that anaerobic co-digestion of the specific......The interest in sustainable bioenergy solutions has gained great importance in Europe due to the need to reduce GHG emissions and to meet environmental policy targets, not least for the protection of groundwater and surface water quality. In the Municipality of Solrød in Denmark, a novel bioenergy...... concept for anaerobic co-digestion of food industry residues, manure and beach-cast seaweed has been developed and tested in order to quantify the potential for synergies between climate change mitigation and coastal eutrophication management in the Køge Bay catchment. The biogas plant, currently under...

  3. Oil terrorism-militancy link: Mediating role of moral disengagement in emergency and crisis management.

    Science.gov (United States)

    Mafimisebi, Oluwasoye Patrick; Thorne, Sara

    2015-01-01

    The controversial issues of terrorism and militancy have generated contemporary interests and different interpretations have emerged on how to combat and manage these dangerous events. This study widens understanding of moral disengagement mechanism application in the perpetuation of inhumanities within the context of oil terrorist and militant behaviors. The research findings and model are explicit on how people form moral evaluations of agents who are forced to make morally relevant decisions over times in context of crisis situations. Quite crucially, understanding the context of terrorism and militancy provides policymakers, emergency and crisis managers better analysis and response to such events. The research fundamental purpose was to investigate the mediating role of moral disengagement on delinquency of oil terrorism and militancy; and considered implications for emergency and crisis management practices. The study found that situational-induced crises such as oil terrorism and militancy were sufficient to account for an individual's misdeeds and unethical or inhumane decisions made under frustration and agitation may be perceived as less indicative of one's fundamental character. Findings suggest that more repugnant delinquencies could have been committed in the name of justice than in the name of injustice, avenues for future research. In context, the result of the moral disengagement scale shows that morality of delinquency (oil terrorism and militancy) is accomplished by cognitively redefining the morality of such acts. The main finding is that people in resistance movements are rational actors making rational choices. The authors argue that theorists, policymakers, and practitioners must give meaningful attention to understanding the multidimensional nature of emergency, crisis and disaster management for better strength of synthesis between theory and practice. The research is concluded by thorough examination of the implication and limitations for

  4. The link between 'green' and economic success: environmental management as the crucial trigger between environmental and economic performance.

    Science.gov (United States)

    Schaltegger, Stefan; Synnestvedt, Terje

    2002-08-01

    The link between environmental and economic performance has been widely debated in the literature for the last ten to fifteen years. One view is that improved environmental performance mainly causes extra costs for the firm and thus reduces profitability. However, also the opposite has been argued for: improved environmental performance would induce cost savings and increase sales and thus improve economic performance. Theoretical and empirical research have provided arguments for both positions and have not been conclusive so far. This article discusses reasons for the different views and the differences in empirical research and presents a theoretical framework to explain the coexistence of the conflicting views. It is argued that not merely the level of environmental performance, but mainly the kind of environmental management with which a certain level is achieved, influences the economic outcome. The model presented provides implications for both empirical research and company management in practice. Research and business practice should focus less on general correlations and more on causal relationships of eco-efficiency, i.e. the effect of different environmental management approaches on economic performance.

  5. SIMULATION OF QUALITY GOALS: A MISSING LINK BETWEEN CORPORATE STRATEGY AND BUSINESS PROCESS MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Zora Arsovski

    2009-12-01

    Full Text Available This paper describes design methodology for quality goals simulation model as a supporting tool for quality goal-directed decision-making at strategic management level. The paper presents such an integrated, system (MIS/DES and draw attention to the essential role of simulation based strategic quality goal-directed decision-making within it. With proposed approach it is possible to converge, or focus, comprehensive but static MIS knowledge in dynamic simulation models and to fully utilize prediction power of simulation for effective and integrated quality goal-directed strategic decision making. Importance of modeling in field of control, equality of knowledge and models, dynamic nature and complexity of models and real systems from viewpoint of modern cybernetic science are also presented in the paper. The final goal is a purposeful decision-making simulation system that guides in the right direction strategically focused management action promising implementation of strategic plans and achievement of related quality goals. In its experimental section the paper describes a quality goals model designed for concrete environment. Overall model structure, components structure, components relations, mathematical models, and other elements of modeling approach are also given in this section. Finally, an example of successfully designed simulation solution is given. The approach presented in the paper gives verbal and mathematical problem description, builds ontology of quality goals problem domain, uses Extended Petri Nets as modeling tools in order to obtain faithful model which easily can be replicated in object oriented class and object hierarchy.

  6. Supply chain knowledge management: A linked data-based approach using SKOS

    Directory of Open Access Journals (Sweden)

    Cristian Aarón Rodríguez-Enríquez

    2015-01-01

    Full Text Available Hoy en día, el conocimiento es una poderosa herramienta para obtener beneficios en cualquier organización. Especialmente cuando las tecnologías de la Web semántica son adaptadas a los requerimientos de las empresas. En este sentido, el sistema simple de organización de conocimiento (SKOS es un área de trabajo que ha desarrollado especificaciones y estándares para trabajar con sistemas de organización de conocimiento. Tomando esto en cuenta, en los últimos años SKOS se ha convertido en uno de los puntos clave en el ecosistema de Linked Data (LD. En este artículo, proponemos un enfoque basado en LD usando SKOS, con la finalidad de administrar el conocimiento en las cadenas de suministro. Adicionalmente este artículo cubre como SKOS puede ser enriquecido por ontologías y LD para mejorar la semántica en la administración del conocimiento. Esto se debe a que la literatura de cadenas de suministro se enfoca en los recursos, los datos y la información que se intercambian entre los socios de la cadena de suministro, a pesar del hecho que para mejorar la integración y colaboración entre socios requiere del desarrollo de características complejas de “saber-hacer” y conocimiento.

  7. Dynamically linking economic models to ecological condition for coastal zone management: Application to sustainable tourism planning.

    Science.gov (United States)

    Dvarskas, Anthony

    2017-03-01

    While the development of the tourism industry can bring economic benefits to an area, it is important to consider the long-run impact of the industry on a given location. Particularly when the tourism industry relies upon a certain ecological state, those weighing different development options need to consider the long-run impacts of increased tourist numbers upon measures of ecological condition. This paper presents one approach for linking a model of recreational visitor behavior with an ecological model that estimates the impact of the increased visitors upon the environment. Two simulations were run for the model using initial parameters available from survey data and water quality data for beach locations in Croatia. Results suggest that the resilience of a given tourist location to the changes brought by increasing tourism numbers is important in determining its long-run sustainability. Further work should investigate additional model components, including the tourism industry, refinement of the relationships assumed by the model, and application of the proposed model in additional areas. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Corneal Collagen Cross-Linking in the Management of Keratoconus in Canada: A Cost-Effectiveness Analysis.

    Science.gov (United States)

    Leung, Victoria C; Pechlivanoglou, Petros; Chew, Hall F; Hatch, Wendy

    2017-08-01

    To use patient-level microsimulation models to evaluate the comparative cost-effectiveness of early corneal cross-linking (CXL) and conventional management with penetrating keratoplasty (PKP) when indicated in managing keratoconus in Canada. Cost-utility analysis using individual-based, state-transition microsimulation models. Simulated cohorts of 100 000 individuals with keratoconus who entered each treatment arm at 25 years of age. Fellow eyes were modeled separately. Simulated individuals lived up to a maximum of 110 years. We developed 2 state-transition microsimulation models to reflect the natural history of keratoconus progression and the impact of conventional management with PKP versus CXL. We collected data from the published literature to inform model parameters. We used realistic parameters that maximized the potential costs and complications of CXL, while minimizing those associated with PKP. In each treatment arm, we allowed simulated individuals to move through health states in monthly cycles from diagnosis until death. For each treatment strategy, we calculated the total cost and number of quality-adjusted life years (QALYs) gained. Costs were measured in Canadian dollars. Costs and QALYs were discounted at 5%, converting future costs and QALYs into present values. We used an incremental cost-effectiveness ratio (ICER = difference in lifetime costs/difference in lifetime health outcomes) to compare the cost-effectiveness of CXL versus conventional management with PKP. Lifetime costs and QALYs for CXL were estimated to be Can$5530 (Can$4512, discounted) and 50.12 QALYs (16.42 QALYs, discounted). Lifetime costs and QALYs for conventional management with PKP were Can$2675 (Can$1508, discounted) and 48.93 QALYs (16.09 QALYs, discounted). The discounted ICER comparing CXL to conventional management was Can$9090/QALY gained. Sensitivity analyses revealed that in general, parameter variations did not influence the cost-effectiveness of CXL. CXL is

  9. Exploring the link between institutional pressures and environmental management systems effectiveness: An empirical study.

    Science.gov (United States)

    Daddi, Tiberio; Testa, Francesco; Frey, Marco; Iraldo, Fabio

    2016-12-01

    Institutional theory has been widely debated by scholars. A part of literature examines how institutional pressures act on company choices regarding proactive environmental strategies. However, the institutional perspective has still not completely clarified the influence of these pressures on the effectiveness of environmental management systems (EMSs) in achieving goals in terms of eco-innovation, competitiveness and corporate reputation. This paper analyses the role played by coercive, mimetic and normative forces in stimulating innovative and competitive responses by firms with an environmental certification. Using the results of a survey on 242 European EMAS-registered organisations, the paper highlights the more positive influence of mimetic and normative pressures than coercive ones. The paper contributes to the literature debate on EMSs analysed through the lens of institutional theory. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Knowledge apartheid in disaster risk management discourse: Is marrying indigenous and scientific knowledge the missing link?

    Directory of Open Access Journals (Sweden)

    Mukundi Mutasa

    2015-02-01

    Full Text Available Indigenous knowledge (IK is a key component of disaster risk management (DRM and development planning, yet it is often overlooked, with practitioners preferring to use scientific knowledge. Critics of IK have termed it archaic, primitive, a constraint to development and inferior to scientific knowledge, which has contributed to its widespread marginalisation. However, smallholder farmers in rural Zimbabwe have utilised IK for generations, especially in predicting rainfall patterns and managing drought conditions, showing that IK can be a useful tool in DRM. This article presents findings from research on drought vulnerability and coping conducted in Zimbabwe’s Buhera and Chikomba districts in 2009, particularly relating to utilisation of IK in smallholder farming communities, and argues that unless IK is documented and preserved, its marginalisation will persist. The research followed a mixed-methods approach whereby both quantitative and qualitative data were collected and analysed. Whilst smallholder respondents were randomly selected for household surveys, snowball sampling was employed for key informant interviews. Respondents indicated that they utilised some indigenous rainfall pattern predictions gained from observing and interpreting plant and animal behaviour. Some cultural practices that were critical to development and utilisation of certain IK were also threatened with extinction. The article argues for ’marrying’ IK and scientific knowledge, in the hope that the two will offset each other’s weaknesses, resulting in some kind of hybrid knowledge that will be critical for promoting sustainable agricultural production in Zimbabwe. However, this is not for disregard the challenges associated with knowledge hybridisation, as these two types of knowledge are grounded on differing foundations.

  11. RISK MANAGEMENT AND EXPERTISE: Biotechnology Risk Regulation in Europe: Linking Precaution with Sustainable Development

    Directory of Open Access Journals (Sweden)

    Levidow Les

    2000-07-01

    Full Text Available In the risk debate over genetically modified (GM crops, their status as ‘‘environmentally-friendly products’’ has been controversial. The 1990 precautionary legislation of the European Union was designed to anticipate potential harm from GMOs in advance. Yet the acceptability of harm - or even its definition - has been contentious in evaluating commercial products. The legislation has been interpreted in ways which implicitly link concepts of precaution and ‘‘sustainable development’’. In the mid-1990s risk regulation, the European Union framed ‘‘risk’’ within a commitment to intensive agriculture. Its familiar hazards were accepted as a normal baseline for evaluating the effects of GM crops. The regulatory procedure regarded choices of crop protection measures as irrelevant or interchangeable, and therefore regarded some future options as dispensible, regardless of whether they would be environmentally preferable. At least implicitly, safety claims presupposed environmental advantages of GM crops in reducing agrochemical usage. That risk-framing came under challenge from widespread protest and expert disagreements. In response, some governments applied more precautionary measures. They broadened the definition of the ‘‘adverse effects’’ which must be avoided, devised market-stage precautions for such effects, and increased the burden of evidence for demonstrating safety. Soon the EU-wide procedure began to formalize such approaches. In the contested definitions of relevant harm, there are deeper issues about the sort of environment which should be protected, sustained or created. Thus GM crops have become a test case for environmental norms, within a broader debate about how to construct a sustainable agriculture.

  12. X-linked adrenoleukodystrophy (X-ALD: clinical presentation and guidelines for diagnosis, follow-up and management

    Directory of Open Access Journals (Sweden)

    Engelen Marc

    2012-08-01

    Full Text Available Abstract X-linked adrenoleukodystrophy (X-ALD is the most common peroxisomal disorder. The disease is caused by mutations in the ABCD1 gene that encodes the peroxisomal membrane protein ALDP which is involved in the transmembrane transport of very long-chain fatty acids (VLCFA; ≥C22. A defect in ALDP results in elevated levels of VLCFA in plasma and tissues. The clinical spectrum in males with X-ALD ranges from isolated adrenocortical insufficiency and slowly progressive myelopathy to devastating cerebral demyelination. The majority of heterozygous females will develop symptoms by the age of 60 years. In individual patients the disease course remains unpredictable. This review focuses on the diagnosis and management of patients with X-ALD and provides a guideline for clinicians that encounter patients with this highly complex disorder.

  13. Systematic review of the links between human resource management practices and performance.

    Science.gov (United States)

    Patterson, M; Rick, J; Wood, S; Carroll, C; Balain, S; Booth, A

    2010-10-01

    In recent years human resource management (HRM) has been seen as an important factor in the successful realisation of organisational change programmes. The UK NHS is undergoing substantial organisational change and there is a need to establish which human resource (HR) initiatives may be most effective. To assess the results from a wide-ranging series of systematic reviews of the evidence on HRM and performance. The first part assesses evidence on use of HRM in the UK and fidelity of practice implemented. The second part considers evidence for the impact of HRM practices on intermediate outcomes, which can impact on final outcomes, such as organisational performance or patient care. The following databases were searched: Applied Social Sciences Index and Abstracts (ASSIA), British Nursing Index (BNI), Business Source Premier, Campbell Collaboration, Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews (CDSR), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Database of Abstracts of Reviews of Effectiveness (DARE), DH-Data, EMBASE, Health Management Information Consortium (HMIC), International Bibliography of the Social Sciences (IBSS), King's Fund database, MEDLINE, NHS Economic Evaluation Database (NHS EED), National Research Register (NRR), PREMEDLINE, PsycINFO, ReFeR, Social Sciences Citation Index (SSCI) and Science Citation Index (SCI). The searches were conducted in May/June 2006. Broad categories of HRM interventions and intermediate outcomes were generated: 10 HRM categories and 12 intermediate outcome categories. Seven patient final outcomes were derived from the NHS Performance Indicators and the NHS Improvement Plan. The quality criteria used to select papers incorporated a longitudinal study design filter to provide evidence of the causal direction of relationships between HRM and relevant outcomes. Single HRM practices were considered. Within the health-specific literature, focus was on the

  14. 中高职贯通视域中的课程管理%On Curriculum Management from the Perspective of Secondary and Higher Vocational Education Linking

    Institute of Scientific and Technical Information of China (English)

    刘磊; 张爱芹; 李钰

    2015-01-01

    To effectively achieve talent training mode linking secondary and higher vocational education, it is necessary to break out inherent course systems of secondary and higher vocational education and reconstruct integrated curriculum system, in which strengthening curriculum management is necessary. Therefore, it is critical to straighten out the rights and responsibilities of secondary and higher vocational schools in linked curriculum development by curriculum development management, lead logical architecture of secondary and higher vocational linked curriculum by curriculum design management, embody the real implication of secondary and higher vocational linked curriculum by curriculum implementation management, and guarantee the effectiveness of secondary and higher vocational linked curriculum by course evaluation management.%中高职贯通人才培养模式的有效实现,需要打破中职、高职固有课程体系,重构一体化课程体系,这一过程必须加强课程管理。为此,要以课程开发管理理顺中高职贯通课程开发的权与责,以课程设计管理统领中高职贯通课程的逻辑架构,以课程实施管理体现中高职贯通课程真正意蕴,以课程评价管理保障中高职贯通课程的有效性。

  15. Oceans and Human Health: Linking Ocean, Organism, and Human Health for Sustainable Management of Coastal Ecosystems

    Science.gov (United States)

    Sandifer, P. A.; Trtanj, J.; Collier, T. K.

    2012-12-01

    Scientists and policy-makers are increasingly recognizing that sustainable coastal communities depend on healthy and resilient economies, ecosystems, and people, and that the condition or "health" of the coastal ocean and humans are intimately and inextricably connected. A wealth of ecosystem services provided by ocean and coastal environments are crucial for human survival and well being. Nonetheless, the health of coastal communities, their economies, connected ecosystems and ecosystem services, and people are under increasing threats from health risks associated with environmental degradation, climate change, and unwise land use practices, all of which contribute to growing burdens of naturally-occurring and introduced pathogens, noxious algae, and chemical contaminants. The occurrence, frequency, intensity, geographic range, and number and kinds of ocean health threats are increasing, with concomitant health and economic effects and eroding public confidence in the safety and wholesomeness of coastal environments and resources. Concerns in the research and public health communities, many summarized in the seminal 1999 NRC Report, From Monsoons to Microbes and the 2004 final report of the US Commission on Ocean Policy, resulted in establishment of a new "meta-discipline" known as Oceans and Human Health (OHH). OHH brings together practitioners in oceanography, marine biology, ecology, biomedical science, medicine, economics and other social sciences, epidemiology, environmental management, and public health to focus on water- and food-borne causes of human and animal illnesses associated with ocean and coastal systems and on health benefits of seafood and other marine products. It integrates information across multiple disciplines to increase knowledge of ocean health risks and benefits and communicate such information to enhance public safety. Recognizing the need for a comprehensive approach to ocean health threats and benefits, Congress passed the Oceans and

  16. Transition Phase Nutrition Recommendations: A Missing Link in the Nutrition Management of Preterm Infants

    Science.gov (United States)

    Brennan, Ann-Marie; Fenton, Sarah; Murphy, Brendan P; Kiely, Mairead E

    2017-03-01

    Despite the availability of international nutrition recommendations, preterm infants remain vulnerable to suboptimal nutrition. The standard approach of assessing nutrient intakes chronologically may make it difficult to identify the origin of nutrient deficits and/or excesses. To develop a "nutrition phase" approach to evaluating nutrition support, enabling analysis of nutrient intakes during the period of weaning from parenteral nutrition (PN) to enteral nutrition (EN), called the transition (TN) phase, and compare the data with those analyzed using the standard "chronological age" approach to assess whether the identification of nutrient deficits and/or excesses can be improved. Analysis of a comprehensive nutrition database developed using actual nutrient intake data collected on an hourly basis in 59 preterm infants (birth weight ≤1500 g, gestation phase analysis approach revealed substantial macronutrient and energy deficits during the TN phase. In particular, deficits were identified as maximal during the EN-dominant TN phase (enteral feeds ≥80 mL/kg/d) of the infant's nutrition course. In contrast, the chronological age analysis approach did not reveal a corresponding pattern of deficit occurrence but rather intakes that approximated or exceeded recommendations. Actual intakes of nutrients, analyzed using a nutrition phase approach to evaluating nutrition support, enabled a more infant-driven rather than age-driven application of nutrition recommendations. This approach unmasked nutrient deficits occurring during the transition phase. Overcoming nutrient deficits in this nutrition phase should be prioritized to improve the nutrition management of preterm infants.

  17. Linking outcomes management and practice improvement. Structured care methodologies: evolution and use in patient care delivery.

    Science.gov (United States)

    Cole, L; Houston, S

    1999-01-01

    Structured care methodologies are tools that provide a comprehensive approach to patient care delivery. These tools have evolved in their application and purpose over the years. In many situations, multiple tools are needed to obtain the best outcomes for a patient. The presence of a SCM does not preclude clinical judgment. On the contrary, the fundamental purpose of any SCM is to assist practitioners in implementing practice patterns associated with good clinical judgment, research-based interventions, and improved patient outcomes. These tools support smooth operation and appropriate use of resources, establish a means of patient management across the continuum of care, facilitate collaboration among disciplines, reflect patient outcomes, and provide outcomes data. Data from SCMs permit benchmarking, comparison of pre-implementation and post-implementation outcomes, development of action plans for quality enhancement, identification of high-risk patients, identification of issues and problems in the system that require interventions, and the development of research protocols and studies. Structured care methodology development and implementation can be challenging, rewarding, and at times frustrating. When used appropriately, these tools can have a major impact on the standardization of care and the achievement of desired outcomes. However, individual patient needs may supersede adherence to a tool. The challenge then becomes one of balancing the unique needs of each patient and appropriate use of SCMs. Change comes slowly, but persistence pays off.

  18. Ecohydrology of managed ecosystems: Linking rainfall unpredictability, agronomic performance, and sustainable water use

    Science.gov (United States)

    Vico, Giulia; Porporato, Amilcare

    2014-05-01

    The field of ecohydrology, traditionally focusing on natural ecosystems, can offer the necessary quantitative tools to assess and compare the sustainability of agriculture across climates, soil types, crops, and irrigation strategies, including rainfall unpredictability. In particular, irrigation is one of the main strategies to enhance and stabilize agricultural productivity, but represents a cost in terms of often scarce water resources. Here, the sustainability of irrigated and rainfed agriculture is assessed by means of water productivity (defined as the ratio between yield and total supplied water), yields, water requirements, and their variability. These indicators are quantified using a probabilistic description of the soil water balance and crop development. Employing this framework, we interpret changes in water productivity as total water input is altered, in two staple crops (maize and wheat) grown under different soils, climates, and irrigation strategies. Climate change scenarios are explored by using the same approach and altering the rainfall statistics. For a given irrigation strategy, intermediate rainfall inputs leads to the highest variability in yield and irrigation water requirement - it is under these conditions that water management is most problematic. When considering the contrasting needs of limiting water requirements while ensuring adequate yields, micro-irrigation emerges as the most sustainable strategy at the field level, although consideration should be given to its profitability and long-term environmental implications.

  19. Investigating Controls on Denitrification Rates During Managed Aquifer Recharge: Linking Field and Laboratory Column Experiments

    Science.gov (United States)

    Gorski, G.; Beganskas, S.; Weir, W. B.; Karim, P.; Saltikov, C.; Hernandez, J.; Fisher, A. T.

    2016-12-01

    We present initial results from a series of laboratory column experiments aimed at elucidating the underlying controls on water quality improvement during managed aquifer recharge (MAR). During field infiltration experiments, we have observed decreases in nitrate (NO3-) concentrations of up to 20% at infiltration rates as high as 15 m/day in the presence of woodchips, but no nitrate removal in the absence of woodchips at slower infiltration rates. These results suggest that the extent of nitrate removal is strongly influenced by the rate of infiltrating water and the presence of a carbon amendment in the form of redwood chips or biochar, which facilitates microbial processing. We probe these relationships at a finer spatial scale with laboratory flow-through column experiments. The columns are constructed as analogues to field experiments, with fluid and substrate sampled directly from field sites. Each day, we sample fluid along the length of the column during experiments to analyze for nitrate, dissolved oxygen, and dissolved organic carbon, in order to track changes in redox conditions and biogeochemistry. The experimental setup allows us to finely control the fluid flow rate and fluid residence time, in order to quantify the relationship between nitrate removal rate and total infiltration rate over a wider range of conditions than is possible during field studies. To determine how the addition of reactive media might increase nitrate removal rates, we conduct side-by-side comparisons of native soil and soil amended with a carbon source. We also analyze changes in nitrate isotope enrichment and microbial ecology to gain a better understanding of the microbial processes and communities responsible for nitrate removal. These field and lab experiments are helping us learn how fluid flow rate, soil type, and availability of carbon sources influences nitrate removal during infiltration for MAR, which can improve the quality of MAR water resources.

  20. LINKING HUMAN RESOURCES STRATEGY WITH KNOWLEDGE MANAGEMENT STRATEGY TO DRIVE MEASURABLE RESULTS

    Directory of Open Access Journals (Sweden)

    Otilia‐Maria\tBORDEIANU

    2015-06-01

    Full Text Available Today the human resources are seen as a very valuable asset to achieve long-term performance. Today we understand that every employee is required to learn throughout life, so to acquire new knowledge, to process such knowledge and possibly disseminate expertise with other members of the organization. The theory on human resources in various organizations has changed over time; recommendations have become more numerous, but there is no consensus on the subject. In other words, the permanent change which defines the competitive environment of business remains a type of constant when analysing the efficiency of human resources within companies; inter-individual relations (formal and informal and the values to which each employee relates remains crucial for any theoretical construction in this area. Principles and strategies applied by organizations yesterday could prove their inefficiency today; human resource strategies in organizations today should include a separate subcomponent, we believe, i.e. knowledge management (KM strategy. This is because the competitive advantage obtained or maintained by the company depends today, in large proportion, on the type, quality and value of knowledge possessed by the organization. Therefore, organizational strategy and thus the strategy of acquisition, developing and rewarding of human resources (HR should take into account this reality from the global environment. Moreover, in the current knowledge-driven economy, organizations must know how to develop and implement knowledge-based strategies to drive measurable business results. The goal of this paper is to describe a potential relation between the overall company strategy, HR strategy and KM strategy.

  1. Linking measurements of biodegradability, thermal stability and chemical composition to evaluate the effects of management on soil organic matter

    Science.gov (United States)

    Gregorich, Ed; Gillespie, Adam; Beare, Mike; Curtin, Denis; Sanei, Hamed; Yanni, Sandra

    2015-04-01

    The stability of soil organic matter (SOM) as it relates to resistance to microbial degradation has important implications for nutrient cycling, emission of greenhouse gases, and C sequestration. Hence, there is interest in developing new ways to accurately quantify and characterise the labile and stable forms of soil organic C. Our objectives in this study were to evaluate and describe relationships among the biodegradability, thermal stability and chemistry of SOM in soil under widely contrasting management regimes. Samples from the same soil under permanent pasture, an arable cropping rotation, and chemical fallow were fractionated (sand: 2000-50 μm; silt: 50-5 μm, and clay: managements and that sand-associated organic matter was significantly more susceptible than that in the silt or clay fractions. Analysis by XANES showed accumulation of carboxylates and strong depletion of amides (protein) and aromatics in the fallow whole soil. Moreover, protein depletion was most significant in the sand fraction of the fallow soil. Sand fractions in fallow and cropped soils were, however, enriched in plant-derived phenols, aromatics and carboxylates compared to the sand fraction of pasture soils. In contrast, ketones, which have been identified as products of microbially-processed organic matter, were slightly enriched in the silt fraction of the pasture soil. These data suggest reduced inputs and cropping restrict the decomposition of plant residues and, without supplemental N additions, protein-N in native SOM is significantly mineralized in fallow systems to meet microbial C mineralization demands. Analytical pyrolysis showed distinct differences in the thermal stability of SOM among the size fractions and management treatments; it also showed that the loss of SOM generally involved dehydrogenation. The temperature at which half of the C was pyrolyzed showed strong correlation with mineralizable C and thus provides solid evidence for a link between the biological and

  2. Co-word analysis: a study on the links and boundaries between information and knowledge management according to iranian press authors

    OpenAIRE

    Hamid Ahmadi; Morteza Kokabi

    2015-01-01

    Information and knowledge management has emerged as major tools for collecting and regulating available data to spread over an entire organ.The present study is to identify the links and boundaries between the two management systems. Co-word analysis method is obtained as research method since along with other scientometric techniques is a parameter for content analysis. Articles accepted for domestic journals and conferences constitute the population of this study. The current research findi...

  3. Medical managers' managerial self-efficacy and role clarity: How do they bridge the budgetary participation-performance link?

    Science.gov (United States)

    Macinati, Manuela S; Cantaluppi, Gabriele; Rizzo, Marco Giovanni

    2017-02-01

    This study explains the process ''how'' organizational accounting practices, such as budgetary participation, influence medical doctors' perceptions and beliefs associated with their hybrid role and what the consequences are on their performance. Building on social cognitive theory, we hypothesize a structural model in which managerial self-efficacy and role clarity mediate the effects of budgetary participation on performance. The data were collected by a survey conducted in an Italian hospital. The research hypotheses were tested employing a path model. The results suggest that role clarity and managerial self-efficacy fully mediate the link between budgetary participation and performance. From a managerial viewpoint results suggest that organizations that invest in budgetary participation will also affect individual beliefs about the perceived benefits of participation itself, since an information-rich internal environment allows employees to experience a clearer sense of direction through organizational goals. According to our results, organizations that seek self-directed employees should pay attention to the experience the medical managers acquire through budgetary participation. In fact, this event influences the employees' mental states-and specifically provides them with information needed to perform in the role and enhance their judgment of their own capabilities to organize and execute the required course of actions-which take on internal psychological motivation to reach performance levels.

  4. A Wide-band, Ka-band Amplifier and Radar System for Precipitation Retrievals Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is committed to measuring precipitation on a global scale. In 1997, NASA launched the Tropical Rain Measuring Mission which carried the first spaceborne...

  5. Solid state Ka-band pulse oscillator with frequency electronic switching

    Directory of Open Access Journals (Sweden)

    Dvornichenko V. P.

    2015-08-01

    Full Text Available Transmitting devices for small radars in the millimeter wavelength range with high resolution on range and noise immunity. The work presents the results of research and development of compact pulse oscillators with digital frequency switching from pulse to pulse. The oscillator consists of a frequency synthesizer and a synchronized amplifier on the IMPATT diode. Reference oscillator of synthesizer is synchronized by crystal oscillator with digital PLL system and contains a frequency multiplier and an amplifier operating in pulse mode. Small-sized frequency synthesizer of 8 mm wave lengths provides an output power of ~1.2 W per pulse with a frequency stability of no worse than 2•10–6. Radiation frequency is controlled by three-digit binary code in OOL levels. Synchronized amplifier made on IMPATT diodes provides microwave power up to 20 W in oscillator output with microwave pulse duration of 100—300 ns in an operating band. The oscillator can be used as a driving source for the synchronization of semiconductor and electro-vacuum devices of pulsed mode, and also as a transmitting device for small-sized radar of millimeter wave range.

  6. High-Power, High-Efficiency Ka-Band Space Traveling-Wave Tube

    Science.gov (United States)

    Krawczyk, Richard; Wilson, Jeffrey; Simons, Rainee; Williams, Wallace; Bhasin, Kul; Robbins, Neal; Dibb, Daniel; Menninger, William; Zhai, Xiaoling; Benton, Robert; Burdette, James

    2007-01-01

    The L-3 Communications Model 999H traveling-wave tube (TWT) has been demonstrated to generate an output power of 144 W at 60-percent overall efficiency in continuous-wave operation over the frequency band from 31.8 to 32.3 GHz. The best TWT heretofore commercially available for operation in the affected frequency band is characterized by an output power of only 35 W and an efficiency of 50 percent. Moreover, whereas prior TWTs are limited to single output power levels, it has been shown that the output power of the Model 999H can be varied from 54 to 144 W. A TWT is a vacuum electronic device used to amplify microwave signals. TWTs are typically used in free-space communication systems because they are capable of operating at power and efficiency levels significantly higher than those of solid-state devices. In a TWT, an electron beam is generated by an electron gun consisting of a cathode, focusing electrodes, and an anode. The electrons pass through a hole in the anode and are focused into a cylindrical beam by a stack of periodic permanent magnets and travel along the axis of an electrically conductive helix, along which propagates an electromagnetic wave that has been launched by an input signal that is to be amplified. The beam travels within the helix at a velocity close to the phase velocity of the electromagnetic wave. The electromagnetic field decelerates some of the electrons and accelerates others, causing the beam to become formed into electron bunches, which further interact with the electromagnetic wave in such a manner as to surrender kinetic energy to the wave, thereby amplifying the wave. The net result is to amplify the input signal by a factor of about 100,000. After the electrons have passed along the helix, they impinge on electrodes in a collector. The collector decelerates the electrons in such a manner as to recover most of the remaining kinetic energy and thereby significantly increase the power efficiency of the TWT.

  7. Ka-Band PAA for Satellite Telemetry System for RLVs & Aircraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The development and implementation of passive phased array antennas (PAAs) offers significant performance benefits over the current active arrays. The keys to...

  8. Superradiant Ka-band Cherenkov oscillator with 2-GW peak power

    Science.gov (United States)

    Rostov, V. V.; Romanchenko, I. V.; Pedos, M. S.; Rukin, S. N.; Sharypov, K. A.; Shpak, V. G.; Shunailov, S. A.; Ul'masculov, M. R.; Yalandin, M. I.

    2016-09-01

    The generation of a 2-GW microwave superradiance (SR) pulses has been demonstrated at 29-GHz using a single-mode relativistic backward-wave oscillator possessing the beam-to-wave power conversion factor no worse than 100%. A record-breaking radiation power density in the slow-wave structure (SWS) of ˜1.5 GW/cm2 required the use of high guiding magnetic field (7 T) decreasing the beam losses to the SWS in strong rf fields. Despite the field strength at the SWS wall of 2 MV/cm, a single-pass transmission mode of a short SR pulse in the SWS allows one to obtain extremely high power density in subnanosecond time scale due to time delay in the development of the breakdown phenomena.

  9. SWIFT-HPX - High Data Rate Ka-band Commications for Small Satellites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Leveraging TUI's SWIFT software defined radio (SDR) architecture, we propose to develop a 100 Mbps downlink and intersatellite crosslink capability with ranging and...

  10. Design and Performance of Ka-Band Fiber-Optic Delay Lines

    Science.gov (United States)

    2012-12-28

    usually erbium-doped fiber amplifiers ( EDFAs ). Laser RIN is a major concern in analog photonics. Laser noise at the RF carrier frequency as well as...amplification will be required in long FODLs to maintain the signal level. The optical amplifier of choice is the EDFA . A classical work on EDFAs is provided...introduction to EDFA noise and the concept of EDFA noise penalty is applied to FODL design in Section 3. Shown in Fig. 12 is a data set for an EDFA

  11. Design of an optically controlled Ka-band GaAs MMIC phased-array antenna

    Science.gov (United States)

    Kunath, Richard R.; Bhasin, Kul B.; Claspy, Paul C.; Richard, Mark A.

    1990-06-01

    Phased array antennas long were investigated to support the agile, multibeam radiating apertures with rapid reconfigurability needs of radar and communications. With the development of the Monolithic Microwave Integrated Circuit (MMIC), phased array antennas having the stated characteristics are becoming realizable. However, at K-band frequencies (20 to 40 GHz) and higher, the problem of controlling the MMICs using conventional techniques either severely limits the array size or becomes insurmountable due to the close spacing of the radiating elements necessary to achieve the desired antenna performance. Investigations were made that indicate using fiber optics as a transmission line for control information for the MMICs provides a potential solution. By adding an optical interface circuit to pre-existing MMIC designs, it is possible to take advantage of the small size, lightweight, mechanical flexibility and RFI/EMI resistant characteristics of fiber optics to distribute MMIC control signals. The architecture, circuit development, testing and integration of optically controlled K-band MMIC phased array antennas are described.

  12. Design of an optically controlled Ka-band GaAs MMIC phased-array antenna

    Science.gov (United States)

    Kunath, Richard R.; Bhasin, Kul B.; Claspy, Paul C.; Richard, Mark A.

    1990-01-01

    Phased array antennas long were investigated to support the agile, multibeam radiating apertures with rapid reconfigurability needs of radar and communications. With the development of the Monolithic Microwave Integrated Circuit (MMIC), phased array antennas having the stated characteristics are becoming realizable. However, at K-band frequencies (20 to 40 GHz) and higher, the problem of controlling the MMICs using conventional techniques either severely limits the array size or becomes insurmountable due to the close spacing of the radiating elements necessary to achieve the desired antenna performance. Investigations were made that indicate using fiber optics as a transmission line for control information for the MMICs provides a potential solution. By adding an optical interface circuit to pre-existing MMIC designs, it is possible to take advantage of the small size, lightweight, mechanical flexibility and RFI/EMI resistant characteristics of fiber optics to distribute MMIC control signals. The architecture, circuit development, testing and integration of optically controlled K-band MMIC phased array antennas are described.

  13. Ka-Band AlGaN/GaN HEMT high power and driver amplifier MMICs

    NARCIS (Netherlands)

    Heijningen, M. van; Vliet, F.E. van; Quay, R.; Raay, F. van; Kiefer, R.; Mueller, S.; Krausse, D.; Seelmann-Eggebert, M.; Mikulla, M.; Schlechtweg, M.

    2005-01-01

    In this paper the MMIC technology, design and characterization of a high power amplifier and driver amplifier MMIC at 30 GHz in AlGaN/GaN HEMT technology are presented. The MMICs are designed using CPW technology on a 390 μm thick SiC substrate. The measured small-signal gain of the driver is 14 dB

  14. Design, Analysis, and Verification of Ka-Band Pattern Reconfigurable Patch Antenna Using RF MEMS Switches

    Directory of Open Access Journals (Sweden)

    Zhongliang Deng

    2016-08-01

    Full Text Available This paper proposes a radiating pattern reconfigurable antenna by employing RF Micro-electromechanical Systems (RF MEMS switches. The antenna has a low profile and small size of 4 mm × 5 mm × 0.4 mm, and mainly consists of one main patch, two assistant patches, and two RF MEMS switches. By changing the RF MEMS switches operating modes, the proposed antenna can switch among three radiating patterns (with main lobe directions of approximately −17.0°, 0° and +17.0° at 35 GHz. The far-field vector addition model is applied to analyse the pattern. Comparing the measured results with analytical and simulated results, good agreements are obtained.

  15. a KA-BAND Chirped-Pulse Fourier Transform Microwave Spectrometer.

    Science.gov (United States)

    Zaleski, Daniel P.; Neill, Justin L.; Muckle, Matthew T.; Pate, Brooks H.; Carroll, P. Brandon; Weaver, Susanna L. Widicus

    2010-06-01

    The design and performance of a new chirped-pulse Fourier transform microwave (CP-FTMW) spectrometer operating from 25-40 GHz will be discussed. A 10.5-3 GHz linear frequency sweep, generated by a 24 GS/s arbitrary waveform generator, is upconverted by a 23.00 GHz phase-locked oscillator, then fed into an active doubler to create a 25-40 GHz chirped pulse. After amplification with a 60-80 W pulsed traveling wave tube amplifier, the pulse is broadcast across a molecular beam chamber where it interacts with a molecular sample. The molecular FID signal is downconverted with the 23 GHz oscillator so that it can be digitized on a 50 GS/s oscilloscope with 16 GHz hardware bandwidth. The sensitivity and phase stability of this spectrometer is comparable to that of the previously reported 6.5-18.5 CP-FTMW spectrometer. On propyne (μ=0.78 D), a single-shot signal to noise ratio of approximately 200:1 is observed on the J=2-1 rotational transition at 34183 MHz when the full bandwidth is swept; optimal excitation is observed for this transition with a 250 MHz bandwidth sweep. The emission has a T_2 lifetime of 4 μs. Early results from this spectrometer, particularly in the study of species of astrochemical interest, will be presented. G.G. Brown et al., Rev. Sci. Instrum. 79 (2008) 053103.

  16. Ka-Band Monopulse Antenna Pointing Calibration Using Wideband Radio Sources

    Science.gov (United States)

    Buu, C.; Calvo, J.; Cheng, T.-H.; Vazquez, M.

    2010-08-01

    A new method of performing a system end-to-end monopulse antenna calibration using widely available wideband astronomical radio sources is presented as an alternative to the current method of using a spacecraft signal. Current monopulse calibration requires a spacecraft carrier signal to measure amplitude and phase differences in the monopulse feed and low-noise amplifiers (LNAs). The alternative method presented here will allow the ground station to perform monopulse calibrations during maintenance periods instead of spacecraft track time, and provide an end-to-end system check-out capability without requiring a spacecraft signal. In this article, we give an overview of the current calibration approach, describe a new method for calibrating with radio sources, and present results from field testing of this new method.

  17. Two stage dual gate MESFET monolithic gain control amplifier for Ka-band

    Science.gov (United States)

    Sokolov, V.; Geddes, J.; Contolatis, A.

    A monolithic two stage gain control amplifier has been developed using submicron gate length dual gate MESFETs fabricated on ion implanted material. The amplifier has a gain of 12 dB at 30 GHz with a gain control range of over 30 dB. This ion implanted monolithic IC is readily integrable with other phased array receiver functions such as low noise amplifiers and phase shifters.

  18. A statistical rain attenuation prediction model with application to the advanced communication technology satellite project. 3: A stochastic rain fade control algorithm for satellite link power via non linear Markow filtering theory

    Science.gov (United States)

    Manning, Robert M.

    1991-01-01

    The dynamic and composite nature of propagation impairments that are incurred on Earth-space communications links at frequencies in and above 30/20 GHz Ka band, i.e., rain attenuation, cloud and/or clear air scintillation, etc., combined with the need to counter such degradations after the small link margins have been exceeded, necessitate the use of dynamic statistical identification and prediction processing of the fading signal in order to optimally estimate and predict the levels of each of the deleterious attenuation components. Such requirements are being met in NASA's Advanced Communications Technology Satellite (ACTS) Project by the implementation of optimal processing schemes derived through the use of the Rain Attenuation Prediction Model and nonlinear Markov filtering theory.

  19. From microbes to water districts: Linking observations across scales to uncover the implications of riparian and channel management on water quality in an irrigated agricultural landscape

    Science.gov (United States)

    Webster, A.; Cadenasso, M. L.

    2016-12-01

    Interactions among runoff, riparian and stream ecosystems, and water quality remain uncertain in many settings, particularly those heavily impacted by human activities. For example, waterways in the irrigated agricultural landscape of California's Central Valley are seasonally disconnected from groundwater tables and are extensively modified by infrastructure and management. These conditions make the impact of riparian and channel management difficult to predict across scales, which hinders efforts to promote best management practices to improve water quality. We seek to link observations across catchment, reach, and patch scales to understand patterns of nitrate and turbidity in waterways draining irrigated cropland. Data was collected on 80 reaches spanning two water management districts. At the catchment scale, water districts implemented waterway and riparian management differently: one water district had a decentralized approach, allowing individual land owners to manage their waterway channels and banks, while the other had a centralized approach, in which land owners defer management to a district-run program. At the reach scale, riparian and waterway vegetation, geomorphic complexity, and flow conditions were quantified. Reach-scale management such as riparian planting projects and channel dredging frequency were also considered. At the patch scale, denitrification potential and organic matter were measured in riparian toe-slope soils and channel sediments, along with associated vegetation and geomorphic features. All factors were tested for their ability to predict water quality using generalized linear mixed effects models and the consistency of predictors within and across scales was evaluated. A hierarchy of predictors emerges: catchment-scale management regimes predict reach-scale geomorphic and vegetation complexity, which in turn predicts sediment denitrification potential - the patch-scale factor most associated with low nitrate. Similarly

  20. Coordination of short-term and long-term mitigation measures of hydro-meteorological risks: the importance of establishing a link between emergency management and spatial planning

    Science.gov (United States)

    Prenger-Berninghoff, Kathrin; Cortes, V. Juliette; Aye, Zar Chi; Sprague, Teresa

    2013-04-01

    The management of natural hazards involves, as generally known, the four stages of the risk management cycle: Prevention, preparedness, response and recovery. Accordingly, the mitigation of disasters can be performed in terms of short-term and long-term purposes. Whereas emergency management or civil protection helps to strengthen a community's capacity to be better prepared for natural hazards and to better respond in case a disaster strikes, thus addressing the short-term perspective, spatial planning serves long-term planning goals and can therefore implement long-term prevention measures. A purposefully applied risk mitigation strategy requires coordination of short-term and long-term mitigation measures and thus an effective coordination of emergency management and spatial planning. Several actors are involved in risk management and should consequently be linked throughout the whole risk management cycle. However, these actors, partly because of a historically fragmented administrative system, are hardly connected to each other, with spatial planning only having a negligible role compared to other actors1, a problem to which Young (2002) referred to as the "problem of interplay". In contrast, information transfer and decision-taking happen at the same time and are not coordinated among different actors. This applies to the prevention and preparedness phase as well as to the recovery phase, which basically constitutes the prevention phase for the next disaster2. Since investments in both risk prevention and emergency preparedness and response are considered necessary, a better coordination of the two approaches is required. In this regard, Decision Support Systems (DSS) can be useful in order to provide support in the decision-making aspect of risk management. The research work currently undertaken examines the problem of interplay in the four case study areas of the Marie Curie ITN, CHANGES3. The link between different risk management actors will be explored

  1. Applying Bayesian network modelling to understand the links between on-farm biosecurity practice during the 2007 equine influenza outbreak and horse managers' perceptions of a subsequent outbreak.

    Science.gov (United States)

    Firestone, Simon M; Lewis, Fraser I; Schemann, Kathrin; Ward, Michael P; Toribio, Jenny-Ann L M L; Taylor, Melanie R; Dhand, Navneet K

    2014-10-01

    Australia experienced its first ever outbreak of equine influenza in August 2007. Horses on 9359 premises were infected over a period of 5 months before the disease was successfully eradicated through the combination of horse movement controls, on-farm biosecurity and vaccination. In a previous premises-level case-control study of the 2007 equine influenza outbreak in Australia, the protective effect of several variables representing on-farm biosecurity practices were identified. Separately, factors associated with horse managers' perceptions of the effectiveness of biosecurity measures have been identified. In this analysis we applied additive Bayesian network modelling to describe the complex web of associations linking variables representing on-farm human behaviours during the 2007 equine influenza outbreak (compliance or lack thereof with advised personal biosecurity measures) and horse managers' perceptions of the effectiveness of such measures in the event of a subsequent outbreak. Heuristic structure discovery enabled identification of a robust statistical model for 31 variables representing biosecurity practices and perceptions of the owners and managers of 148 premises. The Bayesian graphical network model we present statistically describes the associations linking horse managers' on-farm biosecurity practices during an at-risk period in the 2007 outbreak and their perceptions of whether such measures will be effective in a future outbreak. Practice of barrier infection control measures were associated with a heightened perception of preparedness, whereas horse managers that considered their on-farm biosecurity to be more stringent during the outbreak period than normal practices had a heightened perception of the effectiveness of other measures such as controlling access to the premises. Past performance in an outbreak setting may indeed be a reliable predictor of future perceptions, and should be considered when targeting infection control guidance to

  2. Science framework for conservation and restoration of the sagebrush biome: Linking the Department of the Interior’s Integrated Rangeland Fire Management Strategy to long-term strategic conservation actions

    Science.gov (United States)

    J.C. Chambers; J.L. Beck; J.B. Bradford; J. Bybee; S. Campbell; J. Carlson; T.J. Christiansen; K.J. Clause; G. Collins; M.R. Crist; J.B. Dinkins; K.E. Doherty; F. Edwards; S. Espinosa; K.A. Griffin; P. Griffin; J.R. Haas; S.E. Hanser; D.W. Havlina; K.F. Henke; J.D. Hennig; L.A. Joyce; F.M. Kilkenny; S.M. Kulpa; L.L. Kurth; J.D. Maestas; M. Manning; K.E. Mayer; B.A. Mealor; C. McCarthy; M. Pellant; M.A. Perea; K.L. Prentice; D.A. Pyke; L.A. Wiechman; A. Wuenschel

    2017-01-01

    The Science Framework is intended to link the Department of the Interior’s Integrated Rangeland Fire Management Strategy with long-term strategic conservation actions in the sagebrush biome. The Science Framework provides a multiscale approach for prioritizing areas for management and determining effective management strategies within the sagebrush biome. The emphasis...

  3. Impairment assessment of orthogonal frequency division multiplexing over dispersion-managed links in backbone and backhaul networks

    Science.gov (United States)

    Tamilarasan, Ilavarasan; Saminathan, Brindha; Murugappan, Meenakshi

    2016-04-01

    The past decade has seen the phenomenal usage of orthogonal frequency division multiplexing (OFDM) in the wired as well as wireless communication domains, and it is also proposed in the literature as a future proof technique for the implementation of flexible resource allocation in cognitive optical networks. Fiber impairment assessment and adaptive compensation becomes critical in such implementations. A comprehensive analytical model for impairments in OFDM-based fiber links is developed. The proposed model includes the combined impact of laser phase fluctuations, fiber dispersion, self phase modulation, cross phase modulation, four-wave mixing, the nonlinear phase noise due to the interaction of amplified spontaneous emission with fiber nonlinearities, and the photodetector noises. The bit error rate expression for the proposed model is derived based on error vector magnitude estimation. The performance analysis of the proposed model is presented and compared for dispersion compensated and uncompensated backbone/backhaul links. The results suggest that OFDM would perform better for uncompensated links than the compensated links due to the negligible FWM effects and there is a need for flexible compensation. The proposed model can be employed in cognitive optical networks for accurate assessment of fiber-related impairments.

  4. Quantifying Carbon Consequences of Recent Land Management and Disturbances in the Greater Yellowstone Ecosystems (GYE) by linking inventory data, remote sensing and carbon modeling

    Science.gov (United States)

    Zhao, F.; Huang, C.; Healey, S. P.; McCarter, J. B.; Garrard, C.; Zhu, Z.

    2015-12-01

    Natural disturbances and land management directly change C stored in biomass and soil pools, and can have indirect impacts on long-term C balance. The Greater Yellowstone Ecosystem (GYE), located in Central Rocky Mountains of United States, is of different land ownerships within similar environmental settings, making it an ideal site to examine the impacts of management and disturbances on regional carbon dynamics. Recent advances in the remote sensing of vegetation condition and change, along with new techniques linking remote sensing with inventory records, have allowed investigations that are much more tightly constrained to actual landscape environment, instead of hypothetical or generalized conditions. These new capabilities are built into the Forest Carbon Management Framework (ForCaMF), which is being used by the National Forest System to not only model, but to monitor across very specific management units, the impact of different kinds of disturbance on carbon storage. In this study, we used the ForCaMF approach to evaluate carbon effects of natural disturbances (e.g. wildfire) and land management (e.g. harvests) in GYE National Parks, Wilderness Area and National Forests. As might be expected, wildfire has been the dominant disturbance factor in the carbon cycle of GYE's administratively protected areas since the mid-1980s, while harvests have dominated storage trends on the managed land in the region's National Forests. Moving beyond this monitoring result but maintaining the same fidelity to historical vegetation patterns, we are also able to simulate alternative disturbance scenarios to provide landscape-specific insights to forest managers. We can estimate likely carbon storage impacts in GYE protected areas, for example, if more active fire suppression had been pursued since the mid-1980s. Likewise, we can identify differences in current carbon storage on managed lands if high harvest rates during the same period had been moderated. We discuss

  5. Development of working hypotheses linking management of the Missouri River to population dynamics of Scaphirhynchus albus (pallid sturgeon)

    Science.gov (United States)

    Jacobson, Robert B.; Parsley, Michael J.; Annis, Mandy L.; Colvin, Michael E.; Welker, Timothy L.; James, Daniel A.

    2016-01-20

    This report documents a process of filtering of hypotheses that relate Missouri River Scaphirhynchus albus (pallid sturgeon) population dynamics to management actions including flow alterations, channel reconfigurations, and pallid sturgeon population augmentation. The filtering process was a partnership among U.S. Geological Survey, U.S. Army Corps of Engineers, and U.S. Fish and Wildlife Service to contribute to the Missouri River Recovery Management Plan process. The objective of the filtering process was to produce a set of hypotheses with high relevance to pallid sturgeon population dynamics and decision making on the Missouri River. The Missouri River Pallid Sturgeon Effects Analysis team filtered hundreds of potential hypotheses implicit in conceptual ecological models to develop a set of 40 candidate dominant hypotheses that were identified by experts as being important in pallid sturgeon population dynamics. Using a modified Delphi process and additional expert opinion, the team reduced this set of hypotheses to 23 working dominant hypotheses. We then matched the 23 hypotheses with management actions that could influence the biotic outcomes, resulting in as many as 176 potential effects between management actions and pallid sturgeon in the Missouri River. This number was consolidated to a candidate set of 53 working management hypotheses because some management actions applied to multiple life stages of the pallid sturgeon. We used an additional round of expert surveys to identify a set of 30 working management hypotheses. Finally, the set of working management hypotheses was filtered by the U.S. Army Corps of Engineers, Missouri River Recovery Program for actions that were within the agency’s authority and jurisdiction. This round resulted in a set of 21 hypotheses for initial modeling of linkages from management to pallid sturgeon population responses.

  6. Scandinavian links

    DEFF Research Database (Denmark)

    Matthiessen, Christian Wichmann; Knowles, Richard D.

    2014-01-01

    centres, one joins more thinly populated regions, and the last one links peripheral areas. Two of them (The Great Belt Link and the Oresund Link) have been constructed and are in full operation. The third (the Fehmarnbelt Link) has been decided 2008 on bilateral government level. The three links...

  7. Understanding the links between resilience and type-2 diabetes self-management: a qualitative study in South Australia.

    Science.gov (United States)

    Wilson, A L; McNaughton, D; Meyer, S B; Ward, P R

    2017-01-01

    Research conducted by Ward, Muller, Tsourtos, et al. (Soc Sci Med 72(7):1140-1148, 2011) has led to the development of the psycho-social interactive model of resilience, which reveals the interaction between individual resilience factors (i.e. coping, confidence and self esteem) and external resilience environments (i.e. employment, supportive family environments and health promoting policies) in facilitating the development of resilience. This present study explored the utility of this model of resilience for understanding how people self-manage type-2 diabetes. Data were collected via 14 semi-structured life-history interviews with women and men living with type-2 diabetes mellitus (T2DM). Participants varied according to socio-demographics (gender, age, education level, income) and were recruited based on their self-reported management (or lack thereof) of T2DM. The inter-play of internal traits and external resources with additive and subtractive resilience strategies were consistent with the psycho-social interactive model of resilience. Self-management was influenced by life history. Differences in self-management and material disadvantage were also identified. Alongside increased disadvantage are higher levels of external barriers to self-management practices. This paper supports the concepts of additive and subtractive resilience strategies for use with diabetes populations; providing health professionals and policy makers with an increased understanding of how to recognize and foster patient resilience for the improvement of self-care, disease management and ultimately health outcomes.

  8. The link in Linking

    Science.gov (United States)

    Caldwell, Jane C; Chiale, Pablo A; Gonzalez, Mario D; Baranchuk, Adrian

    2013-01-01

    We present 2 cases of the slow-fast form of AVNRT with initially narrow QRS complexes followed by sudden unexpected transition to persistently wide QRS complexes due to aberrant intraventricular conduction. Introduction of a properly timed extrastimulus in one case and critical oscillations in cycle length due to short-long coupling in the second case set the stage for the initial bundle branch block. However, persistence of the aberrancy pattern once the initial event abated was maintained by the "linking" phenomenon. Delayed, retrograde concealed activation from the contralateral bundle branch perpetuated the initial bundle branch block. PMID:23840106

  9. Changing Use Patterns, Changing Feedback Links: Implications for Reorganization of Coastal Fisheries Management in the Stockholm Archipelago, Sweden

    Directory of Open Access Journals (Sweden)

    Maria Åqvist Almlöv

    2006-12-01

    Full Text Available Property rights are important institutions for regulating the use of valuable natural resources from coastal ecosystems. In this case study, we identify and analyze property rights and user patterns related to small-scale coastal fisheries in the Stockholm Archipelago, Sweden. User patterns and user groups have changed significantly over the last century, as commercial fishing has been increasingly replaced by recreational activities. Interviews with local resource users and owners of water properties in two different areas, Möja and Ornö parishes within the Stockholm Archipelago, revealed a very diverse pattern of property and user rights, with a large number of water and fishing rights owners. Recreational fisheries, including both sport and household fishing, seem to predominate in both areas, but ownership differs. In Möja, most waters are collectively owned, whereas in Ornö, individual ownership predominates. Very few examples of local influence on fisheries management were found in either area, although the social structure for joint management does exist in Möja. Instead, larger-scale institutions at the regional, national, or international level regulate fisheries, often not addressing local conditions and fish populations. The ongoing shift in resource use has created a heterogeneous user group, and the limitations of centralized management authorities in dealing with the diversity in the coastal ecosystem have created mismatches within the social-ecological system. Combined with a large-scale decline in coastal fish stocks, these mismatches challenge the existing local property rights arrangements as well as the more centralized regulatory management structure. A key issue for fisheries management is how to develop and stimulate appropriate distribution of management functions at different geographical scales and organizational levels. The complexity and diversity in archipelago fisheries call for multilevel arrangements and cross

  10. Accurate Navigation of Deep Space Probes using Multifrequency Links: the Cassini Breakthrough during Solar Conjunction Experiments

    Science.gov (United States)

    Tortora, P.; Iess, L.; Ekelund, J. E.

    2002-01-01

    (1) transponders, used for both range and range-rate estimation. These devices are characterized by a frequency stability (measured by the Allan deviation) whose typical value never falls below the limit of 10-13, which broadly reflects in a range rate accuracy of about 15.10-4 cm/s. Moreover, for missions in the ecliptic plane, a critical phase is represented by the solar conjunctions which, depending on the spacecraft trajectory, can last up to two weeks. In such conditions the radio data are inherently corrupted by solar plasma noise, which causes a dramatic decay of the obtainable navigation accuracy. As a matter of fact, in the orbit determination process, radio data collected when the line of sight falls within 40 solar radii are usually discarded, leading to long time spans during which navigation cannot rely on actual data. and 2001 solar conjunctions were removed for navigation purposes. While this strategy is widely acceptable and proven during the cruise flight, it is not recommended during critical mission phases, when frequent ground-commanded maneuvers are executed. maneuver, scheduled on July 1st 2004, a few days before a solar conjunction. A significant improvement of the navigation accuracy would be achieved using, for the Orbit Determination process, all radio data collected up to the SOI. science experiments (RSE). The on-board configuration is based on a X/X transponder, which generates a reference signal to the Ka-Band Exciter (KEX) for the X/Ka link; furthermore a coherent frequency translator (KaT) is used for the Ka/Ka link. With this configuration, the sky frequencies in the three bands (X/X, X/Ka, Ka/Ka) can be coherently combined to remove the effects of the solar plasma, the major noise source in the Doppler observable. plasma calibration scheme, has shown an improvement of a factor of 8 over the noise of the bare Ka/Ka observable and a factor of 100 over X/X data. At an impact parameter of about 25 solar radii, the Allan deviation is as

  11. Protocols for vegetation and habitat monitoring with unmanned aerial vehicles: linking research to management on US public lands

    Science.gov (United States)

    Background/Question/Methods: Monitoring of the condition and trend of natural resources is critical for determining effectiveness of management actions and understanding ecosystem responses to broad-scale processes like climate change. While broad-scale remote sensing has generally improved the abi...

  12. You Are Not Logged In: Context and Interpersonal Meaning of Instructions and Links in a typical Learning Management System

    Directory of Open Access Journals (Sweden)

    Hakeem Olafemi Ogunmuyiwa

    2016-11-01

    Full Text Available It is common knowledge that the incorporation of Learning Management Systems (LMS in ESL/EFL instruction has enhanced learners understanding of the language just as it has helped teachers in monitoring students’ progress. However, the use of these eLearning platforms can be quite challenging for EFL learners who are yet to be proficient in the English language. This is because all course information and instructions are offered in the language. Following the notion of context and language metafunctions by Halliday (1985 and his followers, analysis of some linguistic expressions in typical learning management systems is conducted. I show how context and interpersonal meanings are established, and how they can enhance learners’ comprehension of information and instructions. The linguistic expressions used as data are sourced from student-specific pages of the web-based Learning Management System (Blackboard and the Modular Object-Oriented Dynamic Learning Environment (Moodle as adapted in colleges and institutes in Saudi Arabia. Keywords: Systemic Functional Linguistics, Interpersonal Meaning, Mood, Context, Learning Management Systems

  13. Peer-Based Control in Self-Managing Teams: Linking Rational and Normative Influence with Individual and Group Performance

    Science.gov (United States)

    Stewart, Greg L.; Courtright, Stephen H.; Barrick, Murray R.

    2012-01-01

    The authors use a multilevel framework to introduce peer-based control as a motivational state that emerges in self-managing teams. The authors specifically describe how "peer-based rational control", which is defined as team members perceiving the distribution of economic rewards as dependent on input from teammates, extends and interacts with…

  14. Peer-Based Control in Self-Managing Teams: Linking Rational and Normative Influence with Individual and Group Performance

    Science.gov (United States)

    Stewart, Greg L.; Courtright, Stephen H.; Barrick, Murray R.

    2012-01-01

    The authors use a multilevel framework to introduce peer-based control as a motivational state that emerges in self-managing teams. The authors specifically describe how "peer-based rational control", which is defined as team members perceiving the distribution of economic rewards as dependent on input from teammates, extends and…

  15. Challenges of linking scientific knowledge to river basin management policy: AquaTerra as a case study

    NARCIS (Netherlands)

    Slob, A.; Rijnveld, M.

    2007-01-01

    The EU Project AquaTerra generates knowledge about the river-soil-sediment-groundwater system and delivers scientific information of value for river basin management. In this article, the use and ignorance of scientific knowledge in decision making is explored by a theoretical review. We elaborate o

  16. Peer-Based Control in Self-Managing Teams: Linking Rational and Normative Influence with Individual and Group Performance

    Science.gov (United States)

    Stewart, Greg L.; Courtright, Stephen H.; Barrick, Murray R.

    2012-01-01

    The authors use a multilevel framework to introduce peer-based control as a motivational state that emerges in self-managing teams. The authors specifically describe how "peer-based rational control", which is defined as team members perceiving the distribution of economic rewards as dependent on input from teammates, extends and…

  17. Linking noninvasive genetic sampling and traditional monitoring to aid management of a trans-border carnivore population.

    Science.gov (United States)

    Bischof, Richard; Swenson, Jon E

    2012-01-01

    Noninvasive genetic sampling has been embraced by wildlife managers and ecologists, especially those charged with monitoring rare and elusive species over large areas. Challenges arise when desired population measures are not directly attainable from genetic data and when monitoring targets trans-border populations. Norwegian management authorities count individual brown bears (Ursus arctos) using noninvasive genetic sampling but express management goals in the annual number of bear reproductions (females that produce cubs), a measure that is not directly available from genetic data. We combine noninvasive genetic sampling data with information obtained from a long-term intensive monitoring study in neighboring Sweden to estimate the number of annual reproductions by females detected within Norway. Most female brown bears in Norway occur near the border with neighboring countries (Sweden, Finland, and Russia) and their potential reproduction can therefore only partially be credited to Norway. Our model includes a simulation-based method that corrects census data to account for this. We estimated that 4.3 and 5.7 reproductions can be credited to females detected with noninvasive genetic sampling in Norway in 2008 and 2009, respectively. These numbers fall substantially short of the national target (15 annual reproductions). Ignoring the potential for home ranges to extend beyond Norway's borders leads to an increase in the estimate of the number of reproductions by -30%. Our study shows that combining noninvasive genetic sampling with information obtained from traditional intensive/invasive monitoring can help answer contemporary management questions in the currency desired by managers and policy makers. Furthermore, combining methodologies and thereby accounting for space use increases the accuracy of the information on which decisions are based. It is important that the information derived from multiple approaches is applicable to the same focal population and

  18. Targeting and valuing conservation investments in support of a water fund: linking upstream land management with downstream services in the Upper Tana catchment, Kenya

    Science.gov (United States)

    Bryant, B. P.; Droogers, P.; Hunink, J.; Vogl, A.; Wolny, S.

    2014-12-01

    We apply an integrated modeling framework to both target and value watershed management interventions in the Upper Tana watershed, which provides municipal water, irrigation water, and hydropower services to Nairobi and surrounding areas. The analysis begins by applying an index model approach that incorporates existing land use and land surface characteristics to prioritize the type and location of conservation investments in different subbasins, subject to budget constraints and stakeholder concerns (Resource Investment Optimization System -- RIOS). We then run the Soil and Water Assessment Tool (SWAT) using the RIOS-identified investment scenarios to produce spatially explicit scenarios that simulate changes in water yield and suspended sediment. Finally, we link those biophysical outputs to monetary and non-monetary human well-being metrics for multiple benefit streams, including: Reduced water treatment costs, increased hydropower production, and crop yield benefits for upstream farmers in the conservation area. The viability of a payment for watershed services scheme is discussed, with attention to the various components of value assessed and to dependencies on water management approaches. While other studies have examined links between land use and the provision of hydrologic services, this study is novel in that it presents an integrated analysis that targets interventions in a decision context and then relies on calibrated, process-based, biophysical models to demonstrate the return on those investments considering multiple (and sometimes competing) hydrological services, doing so at a sub-annual time-scale.

  19. Randomised controlled trial of an automated, interactive telephone intervention to improve type 2 diabetes self-management (Telephone-Linked Care Diabetes Project: study protocol

    Directory of Open Access Journals (Sweden)

    Scuffham Paul A

    2010-10-01

    Full Text Available Abstract Background An estimated 285 million people worldwide have diabetes and its prevalence is predicted to increase to 439 million by 2030. For the year 2010, it is estimated that 3.96 million excess deaths in the age group 20-79 years are attributable to diabetes around the world. Self-management is recognised as an integral part of diabetes care. This paper describes the protocol of a randomised controlled trial of an automated interactive telephone system aiming to improve the uptake and maintenance of essential diabetes self-management behaviours. Methods/Design A total of 340 individuals with type 2 diabetes will be randomised, either to the routine care arm, or to the intervention arm in which participants receive the Telephone-Linked Care (TLC Diabetes program in addition to their routine care. The intervention requires the participants to telephone the TLC Diabetes phone system weekly for 6 months. They receive the study handbook and a glucose meter linked to a data uploading device. The TLC system consists of a computer with software designed to provide monitoring, tailored feedback and education on key aspects of diabetes self-management, based on answers voiced or entered during the current or previous conversations. Data collection is conducted at baseline (Time 1, 6-month follow-up (Time 2, and 12-month follow-up (Time 3. The primary outcomes are glycaemic control (HbA1c and quality of life (Short Form-36 Health Survey version 2. Secondary outcomes include anthropometric measures, blood pressure, blood lipid profile, psychosocial measures as well as measures of diet, physical activity, blood glucose monitoring, foot care and medication taking. Information on utilisation of healthcare services including hospital admissions, medication use and costs is collected. An economic evaluation is also planned. Discussion Outcomes will provide evidence concerning the efficacy of a telephone-linked care intervention for self-management of

  20. Fisheries conservation on the high seas: linking conservation physiology and fisheries ecology for the management of large pelagic fishes.

    Science.gov (United States)

    Horodysky, Andrij Z; Cooke, Steven J; Graves, John E; Brill, Richard W

    2016-01-01

    Populations of tunas, billfishes and pelagic sharks are fished at or over capacity in many regions of the world. They are captured by directed commercial and recreational fisheries (the latter of which often promote catch and release) or as incidental catch or bycatch in commercial fisheries. Population assessments of pelagic fishes typically incorporate catch-per-unit-effort time-series data from commercial and recreational fisheries; however, there have been notable changes in target species, areas fished and depth-specific gear deployments over the years that may have affected catchability. Some regional fisheries management organizations take into account the effects of time- and area-specific changes in the behaviours of fish and fishers, as well as fishing gear, to standardize catch-per-unit-effort indices and refine population estimates. However, estimates of changes in stock size over time may be very sensitive to underlying assumptions of the effects of oceanographic conditions and prey distribution on the horizontal and vertical movement patterns and distribution of pelagic fishes. Effective management and successful conservation of pelagic fishes requires a mechanistic understanding of their physiological and behavioural responses to environmental variability, potential for interaction with commercial and recreational fishing gear, and the capture process. The interdisciplinary field of conservation physiology can provide insights into pelagic fish demography and ecology (including environmental relationships and interspecific interactions) by uniting the complementary expertise and skills of fish physiologists and fisheries scientists. The iterative testing by one discipline of hypotheses generated by the other can span the fundamental-applied science continuum, leading to the development of robust insights supporting informed management. The resulting species-specific understanding of physiological abilities and tolerances can help to improve stock

  1. Evaluating environmental impacts of alternative construction waste management approaches using supply-chain-linked life-cycle analysis.

    Science.gov (United States)

    Kucukvar, Murat; Egilmez, Gokhan; Tatari, Omer

    2014-06-01

    Waste management in construction is critical for the sustainable treatment of building-related construction and demolition (C&D) waste materials, and recycling of these wastes has been considered as one of the best strategies in minimization of C&D debris. However, recycling of C&D materials may not always be a feasible strategy for every waste type and therefore recycling and other waste treatment strategies should be supported by robust decision-making models. With the aim of assessing the net carbon, energy, and water footprints of C&D recycling and other waste management alternatives, a comprehensive economic input-output-based hybrid life-cycle assessment model is developed by tracing all of the economy-wide supply-chain impacts of three waste management strategies: recycling, landfilling, and incineration. Analysis results showed that only the recycling of construction materials provided positive environmental footprint savings in terms of carbon, energy, and water footprints. Incineration is a better option as a secondary strategy after recycling for water and energy footprint categories, whereas landfilling is found to be as slightly better strategy when carbon footprint is considered as the main focus of comparison. In terms of construction materials' environmental footprint, nonferrous metals are found to have a significant environmental footprint reduction potential if recycled.

  2. A proposed ecosystem-based management system for marine waters: linking the theory of environmental policy to the practice of environmental management

    Directory of Open Access Journals (Sweden)

    Rafael Sardà

    2014-12-01

    Full Text Available New coastal and marine management strategies have recently been developed in many countries and regions. From an ecosystem approach perspective, the aim of such strategies is the maintenance of ecosystem integrity while enabling the sustainable use of ecosystem goods and services. There is, however, a need for harmonized definitions and standardized processes to deal not only with the interjurisdictional and multidisciplinary complexities that are associated with such strategies but also with the extensive timelines and resources implicated in the planning and implementation of these strategies. The ecosystem-based management system proposed here is based on three pillars that facilitate the integration of an ecosystem approach to coastal and oceans policy development, regardless of the ecosystem or administrative scales. The managerial pillar is based on classical risk-management systems that incorporate environmental considerations and objectives within a continuous improvement cycle of adaptive management. The managerial pillar is supported by governance structures that provide oversight and thereby ensure that planning and implementation activities adhere to modern environmental principles. The information pillar ensures that data and scientific advice are based on current knowledge, and the participation pillar brings together communication and consultation requirements as indicated by the principles of the ecosystem approach.

  3. Construction of a multisite DataLink using electronic health records for the identification, surveillance, prevention, and management of diabetes mellitus: the SUPREME-DM project.

    Science.gov (United States)

    Nichols, Gregory A; Desai, Jay; Elston Lafata, Jennifer; Lawrence, Jean M; O'Connor, Patrick J; Pathak, Ram D; Raebel, Marsha A; Reid, Robert J; Selby, Joseph V; Silverman, Barbara G; Steiner, John F; Stewart, W F; Vupputuri, Suma; Waitzfelder, Beth

    2012-01-01

    Electronic health record (EHR) data enhance opportunities for conducting surveillance of diabetes. The objective of this study was to identify the number of people with diabetes from a diabetes DataLink developed as part of the SUPREME-DM (SUrveillance, PREvention, and ManagEment of Diabetes Mellitus) project, a consortium of 11 integrated health systems that use comprehensive EHR data for research. We identified all members of 11 health care systems who had any enrollment from January 2005 through December 2009. For these members, we searched inpatient and outpatient diagnosis codes, laboratory test results, and pharmaceutical dispensings from January 2000 through December 2009 to create indicator variables that could potentially identify a person with diabetes. Using this information, we estimated the number of people with diabetes and among them, the number of incident cases, defined as indication of diabetes after at least 2 years of continuous health system enrollment. The 11 health systems contributed 15,765,529 unique members, of whom 1,085,947 (6.9%) met 1 or more study criteria for diabetes. The nonstandardized proportion meeting study criteria for diabetes ranged from 4.2% to 12.4% across sites. Most members with diabetes (88%) met multiple criteria. Of the members with diabetes, 428,349 (39.4%) were incident cases. The SUPREME-DM DataLink is a unique resource that provides an opportunity to conduct comparative effectiveness research, epidemiologic surveillance including longitudinal analyses, and population-based care management studies of people with diabetes. It also provides a useful data source for pragmatic clinical trials of prevention or treatment interventions.

  4. Linking River Basin Modifications and Rural Soil and Water Management Practices in Tropical Deltas to Sea Level Rise Vulnerability

    Science.gov (United States)

    Rogers, K. G.; Brondizio, E.; Roy, K.; Syvitski, J. P.

    2015-12-01

    The increased vulnerability of deltaic communities to coastal flooding as a result of upstream engineering has been acknowledged for decades. What has received less attention is the sensitivity of deltas to the interactions between river basin modifications and local scale cultivation and irrigation. Combined with reduced river and sediment discharge, soil and water management practices in coastal areas may exacerbate the risk of tidal flooding, erosion of arable land, and salinization of soils and groundwater associated with sea level rise. This represents a cruel irony to smallholder subsistence farmers whose priorities are food, water and economic security, rather than sustainability of the environment. Such issues challenge disciplinary approaches and require integrated social-biophysical models able to understand and diagnose these complex relationships. This study applies a new conceptual framework to define the relevant social and physical units operating on the common pool resources of climate, water and sediment in the Bengal Delta (Bangladesh). The new framework will inform development of a nested geospatial analysis and a coupled model to identify multi-scale social-biophysical feedbacks associated with smallholder soil and water management practices, coastal dynamics, basin modification, and climate vulnerability in tropical deltas. The framework was used to create household surveys for collecting data on climate perceptions, land and water management, and governance. Test surveys were administered to rural farmers in 14 villages during a reconnaissance visit to coastal Bangladesh. Initial results demonstrate complexity and heterogeneity at the local scale in both biophysical conditions and decision-making. More importantly, the results illuminate how national and geopolitical-level policies scale down to impact local-level environmental and social stability in communities already vulnerable to coastal flooding. Here, we will discuss components of the

  5. Linking Environmental Magnetism to Geochemical Studies and Management of Trace Metals. Examples from Fluvial, Estuarine and Marine Systems

    Directory of Open Access Journals (Sweden)

    Michael Scoullos

    2014-07-01

    Full Text Available Among the diverse research fields and wide range of studies encompassed by environmental magnetism, the present work elaborates on critical aspects of the geochemistry of trace metals that emerged through years of original research in a variety of environmental compartments. This review aims at sharing the insights gained on (a tracing metal pollution sources; and (b identifying processes and transport pathways from sources to depositional environments. Case studies on the Elefsis Gulf (Greece and the Gulf of Lions (France demonstrate the potential of combined magnetic measurements and chemical analysis to trace pollution signals resulting from land-based sources and atmospheric deposition. Case studies on estuarine environments, namely the Louros, Acheloos, and Asopos Estuaries (Greece, address modes of trace metal behavior under the influence of different hydrological regimes and elucidate in situ processes within the transitional estuarine zone, that define their ultimate fate. As sources, transport pathways, and processes of trace metals are fundamental in environmental management assessments, the involvement of magnetic measurements in the policy cycle could facilitate the development and implementation of appropriate regulatory measures for the integrated management of river basins, coastal, and marine areas.

  6. Stigma management? The links between enacted stigma and teen pregnancy trends among gay, lesbian, and bisexual students in British Columbia

    Science.gov (United States)

    Saewyc, Elizabeth M.; Poon, Colleen S.; Homma, Yuko; Skay, Carol L.

    2008-01-01

    Over the past decade, several large-scale school-based studies of adolescents in Canada and the U.S. have documented health disparities for lesbian, gay and bisexual teens compared to their heterosexual peers, such as higher rates of suicide attempts, homelessness, and substance use. Many of these disparities have been linked to “enacted stigma,” or the higher rates of harassment, discrimination, and sexual or physical violence that sexual minority youth experience at home, at school, and in the community. An unexpected health disparity for lesbia n, gay and bisexual youth is their significantly higher risk of teen pregnancy involvement (between two and seven times the rate of their heterosexual peers), especially in light of declining trends in teen pregnancy across North America since the early 1990s. What is behind this higher risk? Is it getting better or worse? Using the province-wide cluster-stratified British Columbia Adolescent Health Surveys from 1992, 1998, and 2003, this paper explores the trends in pregnancy involvement, related sexual behaviours, and exposure to forms of enacted stigma that may help explain this particular health disparity for gay, lesbian and bisexual youth in Canada. PMID:19293941

  7. An approach to link water resource management with landscape art to enhance its aesthetic appeal, ecological utility and social benefits

    Science.gov (United States)

    Mukherjee, Anita; Sen, Somnath; Paul, Saikat Kumar

    2017-04-01

    Landscape art or land art is the discourse of scientific application of artistic skill to integrate man-made structures with the natural landscape for planning, design, management, preservation and rehabilitation of natural and built environment. It does beautification of the landscape enhancing its utility for habitats. Availability of water with acceptable quality is crucial for economic growth, social peace and equality and of course for environmental sustainability. Development of new and growth of existing urban and suburban units are obvious. It postulates the increase of population density and percent of the impervious area in an urban unit. The demand for water is increasing with progressive concentration of population, the volume and velocity of surface runoff increase and the travel time decreases. At the same time, an increase in the volume of gray water not only contaminate water bodies, it also reduces the quantity of available freshwater transforming a portion of blue and green water to gray one and would intensify the pressure on water resources of the area. Therefore, to meet the incremental pressure of demand for and pollution of water collection, treatment and reuse of wastewater, both sewage and storm water, are on the requirement to improve urban water security. People must be concerned not to stifle urban lives with concrete; rather must provide all basic amenities for achieving a higher standard of life than the previous one with the essence of natural green spaces. The objective of the study is to propose a conceptual design and planning guidelines for developing urban and suburban drainage network and reuse of surface runoff and sewage water utilizing less used natural water bodies, such as paleo-channels or lakes or moribund channels as retention or detention basin. In addition to wastewater management, the proposal serves to promote the aesthetics of environmental engagement, ecological utility and restoration of moribund channels

  8. Customer Relationship Management System (CRM and Information Ethics in Call Centres - 'You are the Weakest Link. Goodbye!'

    Directory of Open Access Journals (Sweden)

    Helen Richardson

    2002-05-01

    Full Text Available This paper catalogues the rise and rise of call centres in the North West of England, UK and their use of CRM systems. CRM systems often imply new technologies and new ways of working. However, in this account we explore the historical development of the telegraph and work in early telephone exchanges and find the same old story. Our consideration of the ethics of CRM system use and some inherent contradictions are in terms of privacy, communication richness, management methods and computer ethics in an organizational context. Call centres today are viewed by some as offering satisfying employment of intrinsic value, for others, they are the 'new sweatshops of the 21st century' (Belt et al 2000. Our interpretative field study makes a contribution to this debate.

  9. Linking ecological sensitivity to hydrological information in perspective of flow-ecology compliance status and water management

    Science.gov (United States)

    Lathouri, Maria; Klaar, Megan; Hannah, David; Dunbar, Mike; Futter, Alison; England, Judy; Warren, Mark

    2016-04-01

    Increasing pressures and climate change effects on water resources suggest that we may need to re-consider flow regulations in the context of river ecological sensitivity to abstraction, and how this can be better integrated into flow standards. An increasing number of ecosystems have been identified as vulnerable to hydrological change. Different flow pressures, especially very low flows, can be can be very destructive to aquatic biodiversity. However, although this vulnerability is recognized, knowledge is lacking regarding the most ecologically sensitive regimes to hydrology and associated water stress and habitat disturbance. In addition, any interaction between hydromorphology and river ecology is still generally poorly understood - particularly in quantitative terms. To further understand the relationships between hydrology and ecology and to help us protect the long term future of the water environment for water resources management, the present study is focused on underpinning different aspects of flow pressures on ecology and establishing quantitative relationships between physicochemical factors, hydrological pressures and biological indicators. This includes carrying-out a review of existing typology approaches to grouping water bodies on the basis of similar ecological sensitivity to flow and therefore to evaluate the ecological impacts of the flow regime alterations. Explicitly generalised additive models are applied to demonstrate a relationship between ecology (macroinvertebrate) scores and flow pressure data, including geographical, geological and physical habitat conditions. This evidence base will to be used to further recommend ecologically appropriate flow regimes in rivers to help provide efficient flow management practices and support the classification of the ecological status under the Water Framework Directive.

  10. Diet, Gut Microbiome and Epigenetics: Emerging Links with Inflammatory Bowel Diseases and Prospects for Management and Prevention

    Directory of Open Access Journals (Sweden)

    Krasimira Aleksandrova

    2017-08-01

    Full Text Available Inflammatory bowel diseases (IBD represent a growing public health concern due to increasing incidence worldwide. The current notion on the pathogenesis of IBD is that genetically susceptible individuals develop intolerance to dysregulated gut microflora (dysbiosis and chronic inflammation develops as a result of environmental triggers. Among the environmental factors associated with IBD, diet plays an important role in modulating the gut microbiome, influencing epigenetic changes, and, therefore, could be applied as a therapeutic tool to improve the disease course. Nevertheless, the current dietary recommendations for disease prevention and management are scarce and have weak evidence. This review summarises the current knowledge on the complex interactions between diet, microbiome and epigenetics in IBD. Whereas an overabundance of calories and some macronutrients increase gut inflammation, several micronutrients have the potential to modulate it. Immunonutrition has emerged as a new concept putting forward the importance of vitamins such as vitamins A, C, E, and D, folic acid, beta carotene and trace elements such as zinc, selenium, manganese and iron. However, when assessed in clinical trials, specific micronutrients exerted a limited benefit. Beyond nutrients, an anti-inflammatory dietary pattern as a complex intervention approach has become popular in recent years. Hence, exclusive enteral nutrition in paediatric Crohn’s disease is the only nutritional intervention currently recommended as a first-line therapy. Other nutritional interventions or specific diets including the Specific Carbohydrate Diet (SCD, the low fermentable oligosaccharides, disaccharides, monosaccharides, and polyol (FODMAP diet and, most recently, the Mediterranean diet have shown strong anti-inflammatory properties and show promise for improving disease symptoms. More work is required to evaluate the role of individual food compounds and complex nutritional

  11. Beyond the Dams: Linking Rural Smallholder Soil and Water Management Practices in Tropical Deltas to Sea Level Rise Vulnerability

    Science.gov (United States)

    Rogers, K. G.; Syvitski, J. P.; Brondizio, E. S.

    2014-12-01

    The increased vulnerability of deltaic communities to coastal flooding as a result of upstream engineering has been acknowledged for decades. What has received less attention is the sensitivity of deltas to the interactions of river basin modifications and cultivation and irrigation in their coastal regions, particularly in tropical deltas. Embanking, tilling, and crop or stock choice all affect the movement of sediment and water on deltas. Combined with reduced river and sediment discharge, soil and water management practices in coastal areas may in fact exacerbate the risk of tidal flooding, erosion of arable land, and salinization of soils and groundwater associated with sea level rise. Thus exists a cruel irony to smallholder subsistence farmers whose priorities are food, water and economic security, rather than sustainability of the regional environment. Such issues challenge disciplinary approaches and require integrated social-biophysical models able to understand and diagnose these complex relationships. The complementary Institutional Analysis and Development and SocioEcological Systems frameworks are applied to the southwestern Bengal Delta (Bangladesh). The method helps to define the relevant social and physical units operating on the common pool of environmental resources, those of climate, water and sediment. The conceptual frameworks are designed to inform development of a nested geospatial analysis and a dynamic coupled model to identify the social-biophysical feedbacks associated with smallholder soil and water management practices, coastal dynamics, and climate vulnerability in rural Bangladesh. Our presentation will discuss components of the conceptual frameworks and will introduce a bi-directional pilot study designed for obtaining and disseminating information about environmental change to farmers in southwest Bangladesh with potential application to rural farming communities in other tropical deltas.

  12. Linking fishery management and conservation in a tropical estuarine lagoon: biological and physical effects of an artisanal fishing gear

    Science.gov (United States)

    Rueda, M.; Defeo, O.

    2003-04-01

    Information coming from fishery monitoring, surveys and experimental fishing with participation of fishers was employed to determine the impact of an artisanal gear, 'boliche', on the biodiversity of the Ciénaga Grande de Santa Marta (CGSM), an estuarine lagoon on the Caribbean coast of Colombia. Fishery monitoring (catch data) included landings before (1968 and 1978) and after (1994-1996) the introduction of the boliche in the CGSM (1985), whereas surveys were conducted seasonally during 1993-1994. Fishing experiments involved evaluating different mesh sizes and the short-term effect of physical disturbance by the boliche. Monitoring suggested potential trophic effects of this fishing gear: the catch of large, long-lived, carnivorous species declined after the introduction of the boliche in the CGSM, whereas catch rates of smaller, shorter-lived, and lower trophic level species increased. Surveys revealed that the boliche retained 41 species. The by-catch made up 62% of the total catch and the remaining 38% involved the three target species Eugerres plumieri, Mugil incilis and Cathorops spixii. Selectivity experiments showed that 2.5 in. stretched mesh size gill nets caught more species than the 3.0-in. mesh. The smaller mesh also increased the risk of a critical reduction in the spawning stock of target species (notably E. plumieri); a situation that could affect the fish community if mesh sizes lower than 2.5 in. were intensively used. Suspended particulate matter significantly increased after fishing activity, with higher resuspension on mud-shells and mud substrata, whereas dissolved oxygen showed no appreciable changes after fishing operations. Notwithstanding, the activity of the boliche would generate sediment resuspension between 382 and 470 t day -1, which could lead to potential cascade impacts on water quality. We propose a framework of redundancy in management measures in order to simultaneously reach management and conservation goals.

  13. Linking climate change mitigation and coastal eutrophication management through biogas technology: Evidence from a new Danish bioenergy concept.

    Science.gov (United States)

    Kaspersen, Bjarke Stoltze; Christensen, Thomas Budde; Fredenslund, Anders Michael; Møller, Henrik Bjarne; Butts, Michael Brian; Jensen, Niels H; Kjaer, Tyge

    2016-01-15

    The interest in sustainable bioenergy solutions has gained great importance in Europe due to the need to reduce GHG emissions and to meet environmental policy targets, not least for the protection of groundwater and surface water quality. In the Municipality of Solrød in Denmark, a novel bioenergy concept for anaerobic co-digestion of food industry residues, manure and beach-cast seaweed has been developed and tested in order to quantify the potential for synergies between climate change mitigation and coastal eutrophication management in the Køge Bay catchment. The biogas plant, currently under construction, was designed to handle an annual input of up to 200,000 t of biomass based on four main fractions: pectin wastes, carrageenan wastes, manure and beach-cast seaweed. This paper describes how this bioenergy concept can contribute to strengthening the linkages between climate change mitigation strategies and Water Framework Directive (WFD) action planning. Our assessments of the projected biogas plant indicate an annual reduction of GHG emissions of approx. 40,000 t CO2 equivalents, corresponding to approx. 1/3 of current total GHG emissions in the Municipality of Solrød. In addition, nitrogen and phosphorous loads to Køge Bay are estimated to be reduced by approx. 63 t yr.(-1) and 9 tyr.(-1), respectively, contributing to the achievement of more than 70% of the nutrient reduction target set for Køge Bay in the first WFD river basin management plan. This study shows that anaerobic co-digestion of the specific food industry residues, pig manure and beach-cast seaweed is feasible and that there is a very significant, cost-effective GHG and nutrient loading mitigation potential for this bioenergy concept. Our research demonstrates how an integrated planning process where considerations about the total environment are integrated into the design and decision processes can support the development of this kind of holistic bioenergy solutions.

  14. Linking the spatial patterns of organisms and abiotic factors to ecosystem function and management: insights from semi-arid environments

    Directory of Open Access Journals (Sweden)

    F. T. Maestre

    2006-12-01

    Full Text Available Numerous theoretical and modeling studies have demonstrated the ecological significance of the spatial patterning of organisms on ecosystem functioning and dynamics. However, there is a paucity of empirical evidence that quantitatively shows how changes in the spatial patterns of the organisms forming biotic communities are directly related to ecosystem structure and functioning. In this article, I review a series of experiments and observational studies conducted in semi-arid environments from Spain (degraded calcareous shrubland, steppes dominated by Stipa tenacissima, and gypsum shrublands to: 1 evaluate whether the spatial patterns of the dominant biotic elements in the community are linked to ecosystem structure and functioning, and 2 test if these patterns, and those of abiotic factors, can be used to improve ecosystem restoration. In the semiarid steppes we found a significant positive relationship between the spatial pattern of the perennial plant community and: i the water status of S. tenacissima and ii perennial species richness and diversity. Experimental plantings conducted in these steppes showed that S. tenacissima facilitated the establishment of shrub seedlings, albeit the magnitude and direction of this effect was dependent on rainfall conditions during the first yr after planting. In the gypsum shrubland, a significant, direct relationship between the spatial pattern of the biological soil crusts and surrogates of ecosystem functioning (soil bulk density and respiration was found. In a degraded shrubland with very low vegetation cover, the survival of an introduced population of the shrub Pistacia lentiscus showed marked spatial patterns, which were related to the spatial patterns of soil properties such as soil compaction and sand content. These results provide empirical evidence on the importance of spatial patterns for maintaining ecosystem structure and functioning in semi-arid ecosystems

  15. Impact of a chronic disease self-management program on health care utilization in rural communities: a retrospective cohort study using linked administrative data.

    Science.gov (United States)

    Jaglal, Susan B; Guilcher, Sara J T; Hawker, Gillian; Lou, Wendy; Salbach, Nancy M; Manno, Michael; Zwarenstein, Merrick

    2014-05-01

    Internationally, chronic disease self-management programs (CDSMPs) have been widely promoted with the assumption that confident, knowledgeable patients practicing self-management behavior will experience improved health and utilize fewer healthcare resources. However, there is a paucity of published data supporting this claim and the majority of the evidence is based on self-report. We used a retrospective cohort study using linked administrative health data. Data from 104 tele-CDSMP participants from 13 rural and remote communities in the province of Ontario, Canada were linked to administrative databases containing emergency department (ED) and physician visits and hospitalizations. Patterns of health care utilization prior to and after participation in the tele-CDSMP were compared. Poisson Generalized Estimating Equations regression was used to examine the impact of the tele-CDSMP on health care utilization after adjusting for covariates. There were no differences in patterns of health care utilization before and after participating in the tele-CDSMP. Among participants ≤ 66 years, however, there was a 34% increase in physician visits in the 12 months following the program (OR = 1.34, 95% CI 1.11-1.61) and a trend for decreased ED visits in those >66 years (OR = 0.59, 95% CI 0.33-1.06). This is the first study to examine health care use following participation in the CDSMP in a Canadian population and to use administrative data to measure health care utilization. Similar to other studies that used self-report measures to evaluate health care use we found no differences in health care utilization before and after participation in the CDSMP. Future research needs to confirm our findings and examine the impact of the CDSMP on health care utilization in different age groups to help to determine whether these interventions are more effective with select population groups.

  16. Linking the actors and policies throughout the disaster management cycle by "Agreement on Objectives" – a new output-oriented management approach

    Directory of Open Access Journals (Sweden)

    S. Greiving

    2012-04-01

    Full Text Available Current management of disaster risks is often fragmented due to a lack of coordination between involved actors, i.e. civil protection and spatial planning – a phenomenon which is known as the "problem of interplay". This paper presents an output-oriented risk management approach ("parametric governance". Here, the modality of the achievement of objectives remains in the hands of the given addressees. This implies a shift from a top-down to a more collaborative, process-oriented form of decision-making. The approach has been successfully applied in two hazard cases and three administrative contexts: (a the City of Dortmund (Germany facing flash floods, (b East Attica region (Greece facing forest fires, and (c Lazio Region (Italy also facing forest fires. As proved by the applications of the concept, a dialogue among experts, stakeholders, and decision-makers is indispensable in order to guarantee inclusion of all diverse and competing values, opinions, and claims. Moreover, a structured communication path is needed to meet the requirements of a risk governance process. Finally, a win-win-situation among the involved actors has to be created to reach an agreement on common goals and actions to achieve them in due time.

  17. Earthwatch and the HSBC Climate Partnership: Linking climate change and forests management one citizen scientist at a time

    Science.gov (United States)

    Stover, D. B.; Jones, A.; Kusek, K.; Bebber, D.; Phillips, R.; Campbell, J.

    2010-12-01

    Earthwatch has engaged more than 90,000 citizen scientists in long-term research studies since its founding in 1971. One of its newer research and engagement programs is the HSBC Climate Partnership, a five-year global program on climate change to inspire action by individuals, businesses and governments (2007-2012). In this unique NGO-business partnership, Earthwatch has implemented five forest research-focused climate centers in the US, UK, Brazil, India and China. At each center, a team of scientists—supported by HSBC banking employees and local citizen scientists—is gathering data to determine how temperate and tropical forests are affected by changes in climate and human activity. Results are establishing baseline data to empower forest managers, conservationists and communities with the information they need to better manage forests within a changing climate. A critical component of the program is the engagement of 2,200 corporate HSBC employees who spend two weeks out of the office at one of the regional climate centers. They work alongside leading scientists to perform forest research by day, and participate each evening in an interactive education program on the ecological and socioeconomic impacts of climate change—including how climate change impacts HSBC’s bottom line. Program participants are empowered and have successfully developed sustainability projects they implement back in their office, homes and communities that furthers corporate and public commitment to sustainability and combating the effects of climate change. In addition to the corporate engagement model, Earthwatch has successfully engaged scores of local community stakeholders in the HSBC Climate Partnership, including teachers who report back to their classrooms “live from the field,” reporters and other business/NGO leaders in modified one week versions of the field program. New models of citizen science engagement are currently under development, with best practices and

  18. The role of trade-offs in biodiversity conservation planning: linking local management, regional planning and global conservation efforts

    Indian Academy of Sciences (India)

    Daniel P Faith; P A Walker

    2002-07-01

    Biodiversity conservation planning requires trade-offs, given the realities of limited resources and the competing demands of society. If net benefits for society are important, biodiversity assessment cannot occur without other sectoral factors ``on the table”. In trade-offs approaches, the biodiversity value of a given area is expressed in terms of the species or other components of biodiversity that it has that are additional to the components protected elsewhere. That ``marginal gain” is called the complementarity value of the area. A recent whole-country planning study for Papua New Guinea illustrates the importance of complementarity-based trade-offs in determining priority areas for biodiversity conservation, and for designing economic instruments such as biodiversity levies and offsets. Two international biodiversity programs provide important new opportunities for biodiversity trade-offs taking complementarity into account. Both the Millennium Ecosystem Assessment and the Critical Ecosystems or ``hotspots” programs can benefit from an explicit framework that incorporates trade-offs, in which a balance is achieved not only by land-use allocation among areas, but also by the crediting of partial protection of biodiversity provided by sympathetic management within areas. For both international programs, our trade-offs framework can provide a natural linkage between local, regional and global planning levels.

  19. The future of monitoring in clinical research - a holistic approach: linking risk-based monitoring with quality management principles.

    Science.gov (United States)

    Ansmann, Eva B; Hecht, Arthur; Henn, Doris K; Leptien, Sabine; Stelzer, Hans Günther

    2013-01-01

    Since several years risk-based monitoring is the new "magic bullet" for improvement in clinical research. Lots of authors in clinical research ranging from industry and academia to authorities are keen on demonstrating better monitoring-efficiency by reducing monitoring visits, monitoring time on site, monitoring costs and so on, always arguing with the use of risk-based monitoring principles. Mostly forgotten is the fact, that the use of risk-based monitoring is only adequate if all mandatory prerequisites at site and for the monitor and the sponsor are fulfilled.Based on the relevant chapter in ICH GCP (International Conference on Harmonisation of technical requirements for registration of pharmaceuticals for human use - Good Clinical Practice) this publication takes a holistic approach by identifying and describing the requirements for future monitoring and the use of risk-based monitoring. As the authors are operational managers as well as QA (Quality Assurance) experts, both aspects are represented to come up with efficient and qualitative ways of future monitoring according to ICH GCP.

  20. Lessons learned from the management of a national outbreak of Salmonella ohio linked to pork meat processing and distribution.

    Science.gov (United States)

    Bertrand, Sophie; Dierick, Katelijne; Heylen, Kim; De Baere, Thierry; Pochet, Brigitte; Robesyn, Emmanuel; Lokietek, Sophie; Van Meervenne, Eva; Imberechts, Hein; De Zutter, Lieven; Collard, Jean-Marc

    2010-03-01

    During the summer of 2005, an increase in reports of human cases of Salmonella enterica serovar Ohio infection was observed in Belgium. During 11 weeks, between 1 July and 13 September, 60 cases of laboratory-confirmed Salmonella Ohio infection were reported to the National Reference Centre for Salmonella, with a peak onset of symptoms in the third week of July. All clinical isolates caused self-limiting gastroenteritis; both genders (32 males and 28 females) and all age groups (three children 65 years of age) were affected. The isolates were distributed throughout Belgium but a cluster of several cases was observed around Brussels. At the same time, an increase in the incidence of this serovar was observed in the Salmonella isolates originating from the official surveillance campaign conducted by the Federal Agency for the Safety of the Food Chain, which identified pork as a likely source of the outbreak strain. Pulsed-field gel electrophoresis typing confirmed the clonal relationship between the human isolates, the isolates from samples collected in the cutting plants, and the isolates from pork meat in distribution. Further epidemiological investigations indicated that one particular slaughterhouse was involved. In that slaughterhouse, the carcasses were contaminated during the evisceration process because of contaminated equipment and uncontrolled environmental conditions. This study highlights the importance of a centralized surveillance laboratory in the management of outbreaks and the need of strict implementation of hygienic rules to avoid this type of outbreak.

  1. Effect of Home Blood Pressure Telemonitoring and Pharmacist Management On Blood Pressure Control: The HyperLink Cluster Randomized Trial

    Science.gov (United States)

    Margolis, Karen L.; Asche, Stephen E.; Bergdall, Anna R.; Dehmer, Steven P.; Groen, Sarah E.; Kadrmas, Holly M.; Kerby, Tessa J.; Klotzle, Krissa J.; Maciosek, Michael V.; Michels, Ryan D.; O'Connor, Patrick J.; Pritchard, Rachel A.; Sekenski, Jaime L.; Sperl-Hillen, JoAnn M.; Trower, Nicole K.

    2015-01-01

    Context Patients with high blood pressure (BP) visit a physician 4 times or more per year on average in the U.S., yet BP is controlled in only about half. Practical, robust and sustainable models are needed to improve BP control in patients with uncontrolled hypertension. Objectives To determine whether an intervention combining home BP telemonitoring with pharmacist case management improves BP control compared with usual care and to determine whether BP control is maintained after the intervention stops. Design A clinic-randomized trial with 12 months of intervention and 6 months of post-intervention follow-up. Patients and Setting 450 adults with uncontrolled BP recruited from 14,692 patients with electronic medical records across sixteen primary care clinics in an integrated health system in Minneapolis-St. Paul, MN. Interventions Eight clinics were randomized to provide usual care to their patients (n = 222) and 8 were randomized to provide the telemonitoring intervention (n = 228). Intervention patients received home BP telemonitors and transmitted BP data to pharmacists who adjusted antihypertensive therapy accordingly. Main Outcome Measures BP control to Telemonitoring Intervention patients and 30.0% (95% CI, 23.2% - 37.8%) of Usual Care patients, P=0.001. At 6 months, BP was controlled in 71.8 % (95% CI, 65.6% - 77.3%) of Telemonitoring Intervention patients and 45.2% (95% CI, 39.2% - 51.3%) of Usual Care patients, PTelemonitoring Intervention patients and 52.8% (95% CI, 45.4% - 60.2%) of Usual Care patients, P=0.005; and at 18 months BP was controlled in 71.8% (95% CI, 65.0% - 77.8%) of Telemonitoring Intervention patients and 57.1% (95% CI, 51.5% - 62.6%) of Usual Care patients, P=0.003. Systolic BP decreased from baseline more among Telemonitoring Intervention than Usual Care patients by 10.7 mm Hg (95% CI, 7.3-14.3) at 6 months, 9.7 mm Hg (95% CI, 6.0-13.4) at 12 months, and 6.6 mm Hg (95% CI, 2.5-10.7) at 18 months, all PTelemonitoring Intervention

  2. 光链路检测系统在网管中的设计与实现%Optical Link Detection System in Network Management Design and Implementation

    Institute of Scientific and Technical Information of China (English)

    吴向成; 徐艳芬

    2012-01-01

    The network design and implementation of integrated OTDR board OLT equipment management is used in this paper, achieves the purpose of monitoring and management of the optical link. The scheme has automatic and manual detection function, a graphical interface can display the real-time testing and diagnosis. The detection process is more simple, acquisition method is more perfect, the test result is more accurate, with strong real-time and practicality.%主要利用网管设计实现对集成了光时域反射仪(OTDR)板卡的OLT设备进行管理,达到监控管理光链路状况的目的.该方案具有自动检测和手动检测的功能,图形化的界面能实时显示测试与诊断结果.检测过程更简单,采集手段更完善,测试结论更准确,具有很强的实时性和实用性.

  3. Gains from trans-boundary water quality management in linked catchment and coastal socio-ecological systems: a case study for the Minho region

    Science.gov (United States)

    Roebeling, P. C.; Brito, A. G.; Rocha, J.; Alves, H.; Mamede, J.

    2012-04-01

    Worldwide, aquatic and coastal ecosystems are affected by point and diffuse source water pollution originating from rural, urban and industrial land uses in catchments, even though these ecosystems are of vital importance from an environmental and economic perspective. Integrated Catchment and Coastal Zone Management (ICCZM) specifically takes into account this inherent relationship between terrestrial land use, surface and ground water pollution, aquatic and coastal ecosystem state, and associated environmental values. To warrant sustainable regional economic development, we need to balance the marginal costs from terrestrial water pollution abatement and the associated marginal benefits from aquatic and coastal resource appreciation. In doing so, however, we need to differentiate between intra- and trans-boundary catchments because benefactors and beneficiaries from water quality improvement are not one and the same. In trans-boundary catchments, private (national) welfare maximizing rates of water quality improvement differ across nations as benefits from water quality improvement generally accrue to one nation while the costs are paid by multiple nations. While approaches for water quality management in linked catchment and coastal socio-ecological systems are fairly recent though existent, water quality management in trans-boundary catchments poses additional challenges. The objective of this paper is to develop and apply a deterministic optimal control approach that allows us to explore private and social welfare maximizing rates of water pollution abatement in linked catchment and coastal socio-ecological systems. For a case study of the Minho region in the Iberian Peninsula, we estimate nation-specific water pollution abatement cost (based on management practice adoption) and benefit (based on aquatic and coastal environmental values) functions, to determine as well as compare private (national) and social (trans-national) welfare maximizing rates of water

  4. Landslide risk assessment and landslide disaster risk management: on the missing link between scientific knowledge, decision making and practice (Sergey Soloviev Medal Lecture)

    Science.gov (United States)

    Alcántara-Ayala, Irasema

    2016-04-01

    Different investigations have been developed to address the uncertainty and quality evaluations leading to improve landslide hazard and risk assessment. With no doubt, and by using a wide range of scientific and technical approaches, they have contributed to a major extent to the understanding of the dynamics of landslide processes at different scales. Nonetheless, in a similar fashion than other hazards, it has been rather difficult to assess in a precise manner the multi-dimensions of their associated vulnerability and what is more, to effectively link risk assessments with disaster risk management. Owing to the double-character of landslide events, as natural and socio-natural hazards, mass movements turn out to be very complex processes, as their occurrence is also enhanced by population growth, socio-economic inequality, urbanization processes, land-degradation, unsustainable practices and mounting hazard exposure. Disaster Risk Management rope in the actions to attain Disaster Risk Reduction. The latter aims at decreasing existing hazard, vulnerability, and exposure, in addition to strengthening resilience, and very importantly, avoiding the construction of future disaster risk (UNISDR, 2015a). More specifically, and along the same line of ideas, the new-fangled Sendai Framework for Disaster Risk Reduction (SFDRR) 2015-2030 (UNISDR, 2015b) points towards reducing disaster risk and losses by engaging in a series of actions at local, national and global levels. Among them and of utterly significance are those initiatives related to the need of moving from risk assessment into disaster risk management. Consequently, and beyond championing scientific and technical capacity to strengthen landslide knowledge to assess vulnerability, hazard exposure and disaster risks, the challenge remains in the realm of promoting and improving permanent communication, dialogue and partnership among the science and technology communities, policymakers and other stakeholders

  5. Communication Links

    OpenAIRE

    2003-01-01

    This interactive tutorial helps learners to: Identify key upward, lateral, downward, and informal communication links in their organizations. , Reflect on the benefits, control, satisfaction, information filters, and feedback mechanism of various communication links in the organizations. OCL1000 Communicating Change in Complex Organizations

  6. Operative links

    DEFF Research Database (Denmark)

    Wistoft, Karen

    2010-01-01

    as networks: second, a semantic perspective on discourses and concepts of health, and, third, a health pedagogical perspective on participation, intervention, and roles. This paper argues for the importance of 'operative links' between different levels in health strategies. It is proposed that such links...

  7. Linking environmental and stakeholder management

    DEFF Research Database (Denmark)

    Madsen, Henning; Ulhøi, John Parm

    1999-01-01

    Regulation has been an important instrument in pushing the business community towards a more sustainable way of conduct. But recently an increasing pressure from a growing number of stakeholders including employees, customers, neighbours, NGO's etc has been observed. The purpose of this paper...

  8. Link managers for grey literature

    CERN Document Server

    Lodi-Rizzini, E; Vigen, Jens

    1999-01-01

    In the self service area of the library reading rooms it is required to organise the collections in the simplest way possible. This is an important feature for readers making it possible to a get direct access to the material without necessarily having to go via the library catalogue to retrieve the call number. A typical example will be that a collection is organised so that a reader easily can get directly from an article reference to the article itself in a library where the journal collection simply is organised alphabetically. This requirement seems to have been forgotten by many of the most important actors in the digital library, both by the commercial publishers and many of the bodies producing grey literature. How are the users supposed to get directly to Report XXX without having to navigate through n different web pages? This is on top happening in "The Library" which is intended to be close up to 100 based on self service! CERN Library has developed a mechanism, "Go direct", which handles the prob...

  9. Links, Exchanges, Sharing.

    Science.gov (United States)

    Shearer, James

    1992-01-01

    Describes the international activities of the Thames Valley University's Department of Information Management, including formal academic links with overseas institutions, development of short courses for practitioners, discussion meetings, staff and student visits, and enrollment of international students. Topics addressed include personnel,…

  10. Link Analysis

    Science.gov (United States)

    Donoho, Steve

    Link analysis is a collection of techniques that operate on data that can be represented as nodes and links. This chapter surveys a variety of techniques including subgraph matching, finding cliques and K-plexes, maximizing spread of influence, visualization, finding hubs and authorities, and combining with traditional techniques (classification, clustering, etc). It also surveys applications including social network analysis, viral marketing, Internet search, fraud detection, and crime prevention.

  11. Science framework for conservation and restoration of the sagebrush biome: Linking the Department of the Interior’s Integrated Rangeland Fire Management Strategy to long-term strategic conservation actions, Part 1. Science basis and applications

    Science.gov (United States)

    Chambers, Jeanne C.; Beck, Jeffrey L.; Bradford, John B.; Bybee, Jared; Campbell, Steve; Carlson, John; Christiansen, Thomas J; Clause, Karen J.; Collins, Gail; Crist, Michele R.; Dinkins, Jonathan B.; Doherty, Kevin E; Edwards, Fred; Espinosa, Shawn; Griffin, Kathleen A.; Griffin, Paul; Haas, Jessica R.; Hanser, Steve; Havlina, Douglas W.; Henke, Kenneth F.; Hennig, Jacob D.; Joyce, Linda A; Kilkenny, Francis F.; Kulpa, Sarah M; Kurth, Laurie L; Maestas, Jeremy D; Manning, Mary; Mayer, Kenneth E.; Mealor, Brian A.; McCarthy, Clinton; Pellant, Mike; Perea, Marco A.; Prentice, Karen L.; Pyke, David A.; Wiechman , Lief A.; Wuenschel, Amarina

    2017-01-01

    The Science Framework is intended to link the Department of the Interior’s Integrated Rangeland Fire Management Strategy with long-term strategic conservation actions in the sagebrush biome. The Science Framework provides a multiscale approach for prioritizing areas for management and determining effective management strategies within the sagebrush biome. The emphasis is on sagebrush (Artemisia spp.) ecosystems and Greater sage-grouse (Centrocercus urophasianus). The approach provided in the Science Framework links sagebrush ecosystem resilience to disturbance and resistance to nonnative, invasive plant species to species habitat information based on the distribution and abundance of focal species. A geospatial process is presented that overlays information on ecosystem resilience and resistance, species habitats, and predominant threats and that can be used at the mid-scale to prioritize areas for management. A resilience and resistance habitat matrix is provided that can help decisionmakers evaluate risks and determine appropriate management strategies. Prioritized areas and management strategies can be refined by managers and stakeholders at the local scale based on higher resolution data and local knowledge. Decision tools are discussed for determining appropriate management actions for areas that are prioritized for management. Geospatial data, maps, and models are provided through the U.S. Geological Survey (USGS) ScienceBase and Bureau of Land Management (BLM) Landscape Approach Data Portal. The Science Framework is intended to be adaptive and will be updated as additional data become available on other values and species at risk. It is anticipated that the Science Framework will be widely used to: (1) inform emerging strategies to conserve sagebrush ecosystems, sagebrush dependent species, and human uses of the sagebrush system, and (2) assist managers in prioritizing and planning on-the-ground restoration and mitigation actions across the sagebrush biome.

  12. Regional Approach for Managing for Resilience Linking Ecosystem Services and Livelihood Strategies for Agro-Pastoral Communities in the Mongolian Steppe Ecosystem

    Science.gov (United States)

    Ojima, D. S.; Togtohyn, C.; Qi, J.; Galvin, K.

    2011-12-01

    Dramatic changes due to climate and land use dynamics in the Mongolian Plateau are affecting ecosystem services and agro-pastoral livelihoods in Mongolia and China. Recently, evaluation of pastoral systems, where humans depend on livestock and grassland ecosystem services, have demonstrated the vulnerability of the social-ecological system to climate change. Current social-ecological changes in ecosystem services are affecting land productivity and carrying capacity, land-atmosphere interactions, water resources, and livelihood strategies. Regional dust events, changes in hydrological cycle, and land use changes contribute to changing interactions between ecosystem and landscape processes which then affect social-ecological systems. The general trend involves greater intensification of resource exploitation at the expense of traditional patterns of extensive range utilization. Thus we expect climate-land use-land cover relationships to be crucially modified by the socio-economic forces. The analysis incorporates information of the socio-economic transitions taking place in the region which affect land-use, food security, and ecosystem dynamics. The region of study extends from the Mongolian plateau in Mongolia and China to the fertile northeast China plain. Sustainability of agro-pastoral systems in the region needs to integrate the impact of climate change on ecosystem services with socio-economic changes shaping the livelihood strategies of pastoral systems in the region. Adaptation strategies which incorporate landscape management provides a potential framework to link ecosystem services across space and time more effectively to meet the needs of agro-pastoral land use, herd quality, and herder's living standards. Under appropriate adaptation strategies agro-pastoralists will have the opportunity to utilize seasonal resources and enhance their ability to process and manufacture products from the available ecosystem services in these dynamic social

  13. Study of LEO-SAT microwave link for broad-band mobile satellite communication system

    Science.gov (United States)

    Fujise, Masayuki; Chujo, Wataru; Chiba, Isamu; Furuhama, Yoji; Kawabata, Kazuaki; Konishi, Yoshihiko

    1993-01-01

    In the field of mobile satellite communications, a system based on low-earth-orbit satellites (LEO-SAT's) such as the Iridium system has been proposed. The LEO-SAT system is able to offer mobile telecommunication services in high-latitude areas. Rain degradation, fading and shadowing are also expected to be decreased when the system is operated at a high elevation angle. Furthermore, the propagation delay generated in the LEO-SAT system is less pronounced than that in the geostationary orbit satellite (GEO-SAT) system and, in voice services, the effect of the delay is almost negligible. We proposed a concept of a broad-band mobile satellite communication system with LEO-SAT's and Optical ISL. In that system, a fixed L-band (1.6/1.5 GHz) multibeam is used to offer narrow band service to the mobile terminals in the entire area covered by a LEO-SAT and steerable Ka-band (30/20 GHz) spot beams are used for the wide band service. In this paper, we present results of a study of LEO-SAT microwave link between a satellite and a mobile terminal for a broad-band mobile satellite communication system. First, the results of link budget calculations are presented and the antennas mounted on satellites are shown. For a future mobile antenna technology, we also show digital beamforming (DBF) techniques. DBF, together with modulation and/or demodulation, is becoming a key technique for mobile antennas with advanced functions such as antenna pattern calibration, correction, and radio interference suppression. In this paper, efficient DBF techniques for transmitting and receiving are presented. Furthermore, an adaptive array antenna system suitable for this LEO-SAT is presented.

  14. URL攻击防范和细粒度权限管理的安全链接方法%Secure link method for preventing URL attack and fine granularity rights management

    Institute of Scientific and Technical Information of China (English)

    杜恩宽

    2009-01-01

    针对URL攻击提出了一种安全链接的生成和验证方法,能有效防止URL篡改而防范攻击;并融合权限管理需要,加入了细粒度的权限管理;最后,结合J2EE实际应用环境,介绍了安全链接方法的实施细节和注意事项.%For preventing URL attack, this paper proposed a secure link method, which could be used to check out the modification of URL efficiently. Then it illustrated how to generate and certify the secure link, and expanded the method to rights management in mini granularity level; at last, introduced the detail of implementation of the secure link method in a J2EE project was introduced.

  15. Modeling groundwater-surface water interactions in an operational setting by linking object- oriented river basin management model (RiverWare) with 3-D finite-difference groundwater model (MODFLOW).

    Science.gov (United States)

    Valerio, A.; Rajaram, H.; Zagona, E.

    2007-12-01

    Accurate representation of groundwater-surface water interactions is critical to modeling low river flow periods in riparian environments in the semi-arid southwestern United States. As an example, over-appropriation of human water use in the Middle Rio Grande region adversely impacts the habitat of the endangered Rio Grande silvery minnow. Improved management practices during low flow conditions could prevent channel desiccation and habitat destruction. We present a modeling tool with significant potential for improved decision-making in stream reaches influenced by significant surface-groundwater interactions. While river basin management models typically represent operational complexities such as human elements of water demand and consumption with a high degree of sophistication, they often represent groundwater-surface water interactions semi-empirically or at coarse resolution. In contrast, distributed groundwater models, with an adequately fine grid represent groundwater-surface water interactions accurately, but seldom incorporate complex details of water rights and user demands. To best exploit the strengths of both classes of models, we have developed a link between the object-oriented river management software package RiverWare and the USGS groundwater modeling program MODFLOW. An interactive time stepping approach is used in the linked model. RiverWare and MODFLOW run in parallel exchanging data after each time-step. This linked framework incorporates several features critical to modeling groundwater-surface interactions in riparian zones, including riparian ET, localized variations in seepage rates and rule-based water allocations to users and/or environmental flows, and is expected to be an improved tool for modeling groundwater-surface water interaction in regions where groundwater storage repose to changing river conditions is rapid. The performance of the linked model is illustrated through applications on the Rio Grande in the vicinity of

  16. Study of fade and inter-fade durations in Ku- and Ka- band frequencies using OLYMPUS satellite beacons

    OpenAIRE

    Ajaz, Haroon

    1993-01-01

    Fade and inter-fade duration data obtained from the three beacons at 12, 20, and 30 GHz aboard the OLYMPUS satellite were analyzed. The different types of signal impairments and their causes were highlighted and a literature survey conducted. Twelve months of fade and inter-fade data were analyzed and the results of these statistics are presented in the form of tables and figures. The analysis was done on both the monthly and annual data. These tables and figures show that at t...

  17. Radiation Hard Multichannel AlN/GaN HEMT for High Efficiency X- and Ka-Band Power Amplifiers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project is directed to the development of low-loss, high power-density Aluminum Nitride (AlN)/Gallium Nitride (GaN) heterostructure based transistors for...

  18. KARIN: The Ka-Band Radar Interferometer for the Proposed Surface Water and Ocean Topography (SWOT) Mission

    Science.gov (United States)

    Esteban-Fernandez, Daniel; Peral, Eva; McWatters, Dalia; Pollard, Brian; Rodriguez, Ernesto; Hughes, Richard

    2013-01-01

    Over the last two decades, several nadir profiling radar altimeters have provided our first global look at the ocean basin-scale circulation and the ocean mesoscale at wavelengths longer than 100 km. Due to sampling limitations, nadir altimetry is unable to resolve the small wavelength ocean mesoscale and sub-mesoscale that are responsible for the vertical mixing of ocean heat and gases and the dissipation of kinetic energy from large to small scales. The proposed Surface Water and Ocean Topography (SWOT) mission would be a partnership between NASA, CNES (Centre National d'Etudes Spaciales) and the Canadian Space Agency, and would have as one of its main goals the measurement of ocean topography with kilometer-scale spatial resolution and centimeter scale accuracy. In this paper, we provide an overview of all ocean error sources that would contribute to the SWOT mission.

  19. Self-Biased Radiation Hardened Ka-Band Circulators for Size, Weight and Power Restricted Long Range Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ferrite control components including circulators and isolators are fundamental building blocks of Transmit/Receive modules (TRM) utilized in high data rate active...

  20. Self-Biased Radiation Hardened Ka-Band Circulators for Size, Weight and Power Restricted Long Range Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ferrite control components including circulators and isolators are fundamental building blocks of Transmit/Receive modules (TRM) utilized in high data rate active...

  1. Over the horizon Ka Band Radio Wave Propagation Studies in the Coastal South Australian Spencer Gulf Region (PREPRINT)

    Science.gov (United States)

    2014-10-09

    of four vertically distributed 35 GHz continuous wave (CW) carrier transmitters and four vertically distributed receivers at a distance of 26 km. An...transmissions, each of ~45 dBm effective radiated power ( ERP ) at 35.002, 35.004 and 35.006 GHz, were directed towards the receiver site at Point Lowly...Equivalent Radiated Powers ( ERP ) of these sources are similar as are the distributed receiver sensitivities. Invariant of the height location of each

  2. Ku/Ka-band electrically-scanned line array for tri-band cloud and precipitation radar applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A spaceborne radar system that operates simultaneously at multiple frequency bands from microwave through millimeter-wave frequencies can exploit the largely varying...

  3. A new airborne Ka-band double-antenna microwave radiometer for cloud liquid water content measurement

    Science.gov (United States)

    Sun, Jian; Zhao, Kai; Jiang, Tao; Gu, Lingjia

    2013-09-01

    A new type upward-looking airborne double-antenna microwave radiometer (ADAMR) system intended for detecting atmospheric cloud liquid water content (LWC) is developed in this paper. The frequency of this radiometer is 31.65 GHz. For the antenna elevation angle, one is 30°and the other is 90°. In order to detect the signals with low effective noise temperature (antenna ports respectively, the technique can elevate the small input noise signal power to the detectable range of the square-law detector and thus realize the weak signal detection. Moreover, in order to eliminate the impacts of the system gain fluctuations and obtain a higher sensitivity, an auto-gain compensation method based on the analog-to-digital converter, microcontroller and host computer software techniques is also proposed. Compared with the traditional radiometers, the radiometer topology is greatly simplified and the gain fluctuations can be readily realtime compensated using the compensation method. The laboratory test results show that radiometric sensitivity is better than 0.2 K for 300ms integration time and the instrument is conforming to specifications. Finally, the flight observation experiment results are presented to prove that the designed instrument is able to detect small changes of noise signal in a wide effective range of noise temperature (10-350K) and is a powerful tool for LWC measurement.

  4. Antennas Designed for Advanced Communications for Air Traffic Management (AC/ATM) Project

    Science.gov (United States)

    Zakrajsek, Robert J.

    2000-01-01

    The goal of the Advanced Communications for Air Traffic Management (AC/ATM) Project at the NASA Glenn Research Center at Lewis Field is to enable a communications infrastructure that provides the capacity, efficiency, and flexibility necessary to realize a mature free-flight environment. The technical thrust of the AC/ATM Project is targeted at the design, development, integration, test, and demonstration of enabling technologies for global broadband aeronautical communications. Since Ku-band facilities and equipment are readily available, one of the near-term demonstrations involves a link through a Kuband communications satellite. Two conformally mounted antennas will support the initial AC/ATM communications links. Both of these are steered electronically through monolithic microwave integrated circuit (MMIC) amplifiers and phase shifters. This link will be asymmetrical with the downlink to the aircraft (mobile vehicle) at a throughput rate of greater than 1.5 megabits per second (Mbps), whereas the throughput rate of the uplink from the aircraft will be greater than 100 kilobits per second (kbps). The data on the downlink can be narrow-band, wide-band, or a combination of both, depending on the requirements of the experiment. The AC/ATM project is purchasing a phased-array Ku-band transmitting antenna for the uplink from the test vehicle. Many Ku-band receiving antennas have been built, and one will be borrowed for a short time to perform the initial experiments at the NASA Glenn Research Center at Lewis Field. The Ku-band transmitting antenna is a 254-element MMIC phased-array antenna being built by Boeing Phantom Works. Each element can radiate 100 mW. The antenna is approximately 43-cm high by 24-cm wide by 3.3-cm thick. It can be steered beyond 60 from broadside. The beamwidth varies from 6 at broadside to 12 degrees at 60 degrees, which is typical of phased-array antennas. When the antenna is steered to 60 degrees, the beamwidth will illuminate

  5. Transatlantic link

    Science.gov (United States)

    (left) European Geophysical Society (EGS) President Rolf Meissner at AGU Headquarters with (center) Executive Director Fred Spilhaus and (right) Foreign Secretary Juan Roederer. Meissner attended the meeting of AGU's Committee on International Participation (CIP) on February 26, 1988. At that meeting, specific ways of fostering close links between AGU and EGS were discussed.A few weeks later, Roederer and AGU staff, working with EGS Secretary-General Arne Richter at the EGS meeting in Bologna, Italy, March 21-25, planned details of the establishment of an AGU office in Europe. The Copernicus Gesellschaft, a new entity located on the premises of the Max Planck Institute for Aeronomy in Lindau, Federal Republic of Germany, will provide the administrative staff and handle logistics.

  6. Data cleaning and management protocols for linked perinatal research data: a good practice example from the Smoking MUMS (Maternal Use of Medications and Safety) Study.

    Science.gov (United States)

    Tran, Duong Thuy; Havard, Alys; Jorm, Louisa R

    2017-07-11

    Data cleaning is an important quality assurance in data linkage research studies. This paper presents the data cleaning and preparation process for a large-scale cross-jurisdictional Australian study (the Smoking MUMS Study) to evaluate the utilisation and safety of smoking cessation pharmacotherapies during pregnancy. Perinatal records for all deliveries (2003-2012) in the States of New South Wales (NSW) and Western Australia were linked to State-based data collections including hospital separation, emergency department and death data (mothers and babies) and congenital defect notifications (babies in NSW) by State-based data linkage units. A national data linkage unit linked pharmaceutical dispensing data for the mothers. All linkages were probabilistic. Twenty two steps assessed the uniqueness of records and consistency of items within and across data sources, resolved discrepancies in the linkages between units, and identified women having records in both States. State-based linkages yielded a cohort of 783,471 mothers and 1,232,440 babies. Likely false positive links relating to 3703 mothers were identified. Corrections of baby's date of birth and age, and parity were made for 43,578 records while 1996 records were flagged as duplicates. Checks for the uniqueness of the matches between State and national linkages detected 3404 ID clusters, suggestive of missed links in the State linkages, and identified 1986 women who had records in both States. Analysis of content data can identify inaccurate links that cannot be detected by data linkage units that have access to personal identifiers only. Perinatal researchers are encouraged to adopt the methods presented to ensure quality and consistency among studies using linked administrative data.

  7. Linked Ocean Data

    Science.gov (United States)

    Leadbetter, Adam; Arko, Robert; Chandler, Cynthia; Shepherd, Adam

    2014-05-01

    "Linked Data" is a term used in Computer Science to encapsulate a methodology for publishing data and metadata in a structured format so that links may be created and exploited between objects. Berners-Lee (2006) outlines the following four design principles of a Linked Data system: Use Uniform Resource Identifiers (URIs) as names for things. Use HyperText Transfer Protocol (HTTP) URIs so that people can look up those names. When someone looks up a URI, provide useful information, using the standards (Resource Description Framework [RDF] and the RDF query language [SPARQL]). Include links to other URIs so that they can discover more things. In 2010, Berners-Lee revisited his original design plan for Linked Data to encourage data owners along a path to "good Linked Data". This revision involved the creation of a five star rating system for Linked Data outlined below. One star: Available on the web (in any format). Two stars: Available as machine-readable structured data (e.g. An Excel spreadsheet instead of an image scan of a table). Three stars: As two stars plus the use of a non-proprietary format (e.g. Comma Separated Values instead of Excel). Four stars: As three stars plus the use of open standards from the World Wide Web Commission (W3C) (i.e. RDF and SPARQL) to identify things, so that people can point to your data and metadata. Five stars: All the above plus link your data to other people's data to provide context Here we present work building on the SeaDataNet common vocabularies served by the NERC Vocabulary Server, connecting projects such as the Rolling Deck to Repository (R2R) and the Biological and Chemical Oceanography Data Management Office (BCO-DMO) and other vocabularies such as the Marine Metadata Interoperability Ontology Register and Repository and the NASA Global Change Master Directory to create a Linked Ocean Data cloud. Publishing the vocabularies and metadata in standard RDF XML and exposing SPARQL endpoints renders them five-star Linked

  8. The regulatory aspects linked to wastes management. The fundamental safety rules; Les aspects reglementaires lies a la gestion des dechets. Les regles fondamentales de surete

    Energy Technology Data Exchange (ETDEWEB)

    Viala, M. [CEA Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire

    2001-07-01

    The radioactive waste management implies a well-established legislative frame. That is that frame that is discussed here, general principles, official authorities, wastes classification, high level radioactive waste management, regulation relative to storage, to uranium ore processing. (N.C.)

  9. Linking Project-Based Interdisciplinary Learning and Recommended Professional Competencies with Business Management, Digital Media, Distance Learning, Engineering Technology, and English

    Science.gov (United States)

    Bender, Melinda; Fulwider, Miles; Stemkoski, Michael J.

    2008-01-01

    This paper encourages the investigation of real world problems by students and faculty and links recommended student competencies with project based learning. In addition to the traditional course objectives, project-based learning (PBL) uses real world problems for classroom instruction and fieldwork to connect students, instructors, and industry…

  10. Operative Links

    DEFF Research Database (Denmark)

    Wistoft, Karen; Højlund, Holger

    2012-01-01

    Aim: The subject of investigation is the ways in which the Danish municipalities organize prevention and health-promotion efforts for children and adolescents. The aim is to examine how health managerial ideas have been combined with health professional ideals concerning different health educatio......Aim: The subject of investigation is the ways in which the Danish municipalities organize prevention and health-promotion efforts for children and adolescents. The aim is to examine how health managerial ideas have been combined with health professional ideals concerning different health...... educational approaches. Methods: Mixed qualitative design: survey based on telephone interviews with health managers (n=72), personal and focus group interviews with health professionals (n=84) and pupils (n=108) from 18 school classes, and comparative case studies in five selected municipalities of various...... size and geographical location. The theoretical framework has three positions combining a public management perspective with a pedagogical perspective on health promotion. Results: The municipalities give high priority to prevention and health promotion directed toward children and adolescents and face...

  11. Dancing links

    CERN Document Server

    Knuth, Donald E

    2009-01-01

    The author presents two tricks to accelerate depth-first search algorithms for a class of combinatorial puzzle problems, such as tiling a tray by a fixed set of polyominoes. The first trick is to implement each assumption of the search with reversible local operations on doubly linked lists. By this trick, every step of the search affects the data incrementally. The second trick is to add a ghost square that represents the identity of each polyomino. Thus puts the rule that each polyomino be used once on the same footing as the rule that each square be covered once. The coding simplifies to a more abstract form which is equivalent to 0-1 integer programming. More significantly for the total computation time, the search can naturally switch between placing a fixed polyomino or covering a fixed square at different stages, according to a combined heuristic. Finally the author reports excellent performance for his algorithm for some familiar puzzles. These include tiling a hexagon by 19 hexiamonds and the N queen...

  12. Several Important Links of Management in University's Infrastructure Construction%做好高校基建管理的几个重要环节

    Institute of Scientific and Technical Information of China (English)

    杨海勇; 宓林

    2011-01-01

    The management of university infrastructure project has its own characteristics. This paper discusses some important aspects of the system construction, management in design stage, tendering and bidding management, project management, building energy-saving applications, informatization and so on, to expect to get some good views.%高校基建项目管理有其自身的特点,文中从制度建设、设计阶段管理、招投标管理、项目管理、建筑节能应用、信息化建设等几个重要环节入手做了一些研究讨论,以期抛砖引玉.

  13. Operative Links

    DEFF Research Database (Denmark)

    Wistoft, Karen; Højlund, Holger

    2012-01-01

    The article combines a public management perspective with a pedagogical perspective on health promotion. Our aim is to look into recent reforms in Denmark on health promotion in order to see how managerial ideas have been combined with welfare professional ideals concerning broad, positive...... and have been the object of great expectations concerning the ability to incorporate health concerns into every welfare area through health promotion strategies. The paper draws on results and analyses of a collective research project funded by the Danish National Research Council and carried out...... by researchers from Copenhagen Business School and The Danish School of Education (1.9.2007 -31.12.2009). The data have been obtained in four separate empirical studies on the basis of a mixed qualitative design including a survey, personal and focus group interviews and comparative case studies. The theoretical...

  14. Operative Links

    DEFF Research Database (Denmark)

    Wistoft, Karen; Højlund, Holger

    2012-01-01

    The article combines a public management perspective with a pedagogical perspective on health promotion. Our aim is to look into recent reforms in Denmark on health promotion in order to see how managerial ideas have been combined with welfare professional ideals concerning broad, positive...... and have been the object of great expectations concerning the ability to incorporate health concerns into every welfare area through health promotion strategies. The paper draws on results and analyses of a collective research project funded by the Danish National Research Council and carried out...... by researchers from Copenhagen Business School and The Danish School of Education (1.9.2007 -31.12.2009). The data have been obtained in four separate empirical studies on the basis of a mixed qualitative design including a survey, personal and focus group interviews and comparative case studies. The theoretical...

  15. Sex-linked dominant

    Science.gov (United States)

    Inheritance - sex-linked dominant; Genetics - sex-linked dominant; X-linked dominant; Y-linked dominant ... can be either an autosomal chromosome or a sex chromosome. It also depends on whether the trait ...

  16. Reflexive Land and Water Management in Iran: Linking Technology, Governance and Culture, Part 2: Stakeholders'Attitudes and the Key Elements of Reflexive Framework

    NARCIS (Netherlands)

    Balali, M.R.; Keulartz, F.W.J.; Korthals, M.J.J.A.A.

    2011-01-01

    In order to get a better grasp of the opportunities and constraints of transition to sustainable land and water management in Iran, four large-scale qualitative–quantitative surveys were designed to find out the attitudes, interests, and values of land and water stakeholders including farmers,

  17. Application of link quality control in whole process management of disposal of medical waste%环节质量控制对医疗废物处置的全过程管理

    Institute of Scientific and Technical Information of China (English)

    许玉冰; 郭俊艳; 赵江河; 杨金燕; 臧妍; 郭光昂; 邢玉斌

    2015-01-01

    OBJECTIVE To explore the whole process management and supervision of disposal of medical waste in a general hospital and guide the healthcare workers for correct classification of the medical waste so as to safeguard the healthcare workers .METHODS The whole process management was started from the link quality control in 2012 ,the whole process management of disposal of medical waste was intensified ,the management system was made perfect ,the responsibility was made clear to all levels ,the process of disposal of medical waste was made standardized ,the development of hardware and software for management of medical waste was strengthened .The professional staff of the infection control department needed to change the working idea ,intensified the supervision and inspection of the key sites and departments ,stepped deep into the department irregularly and inspected the whole process of disposal of medical waste involving the classification ,collection ,transportation ,registration ,and handover ,and made great efforts to the implementation of the link quality control so as to earnestly achieve the whole-process ,orderly management .RESULTS The link quality control has improved the healthcare workers awareness of correct classification ,collection ,and disposal of medical waste and reduced the occasions of blind placement and secondary classified disposal so as to achieve a standardized and smooth whole process management of disposal of medical waste and reduce the possibility of recontamination and re‐damage .CONCLUSION The healthcare workers pay great attention to the standardized operations including the classification ,disposal ,and transportation of medical waste and make all the management meet the national standards so as to protect the healthcare workers and the environment .%目的:探讨综合性医院如何做好医疗废物处置全过程管理和监督,指导医护人员对医疗废物的正确分类,以保护医护人员安全。方法于2012

  18. Linking River Management-Induced Perturbations of Hydrologic and Sediment Regimes to Geomorphic Processes Along a Highly-Dynamic Gravel-Bed River: Snake River, WY.

    Science.gov (United States)

    Leonard, C.; Legleiter, C. J.

    2015-12-01

    Encroachment of human development onto river floodplains creates a need to stabilize rivers and provide flood protection. Structural interventions, such as levees, often perturb hydrologic and sediment regimes and thus can initiate morphological responses. An understanding of how human activities affect river morphodynamics and trigger channel change is needed to anticipate future river responses and facilitate effective restoration. This study examines approximately 66 km of the Snake River, WY, USA, and links sediment transport processes to channel form and behavior by developing a morphological sediment budget that spans both a natural, unconfined reach and a reach confined by artificial levees. Sediment transport rates are inferred from the morphological sediment budget and a bed mobility study is used to estimate entrainment thresholds that allow us to link the hydrological regime during the sediment budget period to the observed channel changes. Results indicate that lateral constriction by levees triggers a positive feedback mechanism by incising the bed, focusing flow energy, thus increasing transport capacity, and leading to armoring of the bed. In other systems, armoring promotes widening of the channel but in this case levees prevent widening and the channel instead migrates across the braidplain rapidly, producing further erosion of bars and vegetated islands that is expressed as negative net volumetric changes and increased sediment transport rates. Furthermore, decreased slopes and reduced discharges due to dam regulation in the upstream unconfined reach cause gravel sheets to stall on bars and in other areas of storage, creating a spatial discontinuity in sediment conveyance downstream, and thus contributing to the sediment deficit within the leveed reach.

  19. Self-management support using an Internet-linked tablet computer (the EDGE platform)-based intervention in chronic obstructive pulmonary disease: protocol for the EDGE-COPD randomised controlled trial.

    Science.gov (United States)

    Farmer, Andrew; Toms, Christy; Hardinge, Maxine; Williams, Veronika; Rutter, Heather; Tarassenko, Lionel

    2014-01-08

    The potential for telehealth-based interventions to provide remote support, education and improve self-management for long-term conditions is increasingly recognised. This trial aims to determine whether an intervention delivered through an easy-to-use tablet computer can improve the quality of life of patients with chronic obstructive pulmonary disease (COPD) by providing personalised self-management information and education. The EDGE (sElf management anD support proGrammE) for COPD is a multicentre, randomised controlled trial designed to assess the efficacy of an Internet-linked tablet computer-based intervention (the EDGE platform) in improving quality of life in patients with moderate to very severe COPD compared with usual care. Eligible patients are randomly allocated to receive the tablet computer-based intervention or usual care in a 2:1 ratio using a web-based randomisation system. Participants are recruited from respiratory outpatient clinics and pulmonary rehabilitation courses as well as from those recently discharged from hospital with a COPD-related admission and from primary care clinics. Participants allocated to the tablet computer-based intervention complete a daily symptom diary and record clinical symptoms using a Bluetooth-linked pulse oximeter. Participants allocated to receive usual care are provided with all the information given to those allocated to the intervention but without the use of the tablet computer or the facility to monitor their symptoms or physiological variables. The primary outcome of quality of life is measured using the St George's Respiratory Questionnaire for COPD patients (SGRQ-C) baseline, 6 and 12 months. Secondary outcome measures are recorded at these intervals in addition to 3 months. The Research Ethics Committee for Berkshire-South Central has provided ethical approval for the conduct of the study in the recruiting regions. The results of the study will be disseminated through peer review publications and

  20. Advanced solderless flexible thermal link

    Science.gov (United States)

    Williams, Brian G.; Jensen, Scott M.; Batty, J. Clair

    1996-10-01

    Flexible thermal links play an important role int he thermal management of cryogenically cooled components. The purpose of these links is to provide a means of transferring heat from a cooled component to a cooler reservoir with little increase in temperature. The standard soldered approach although effective proves to be time consuming and contributes to added thermal impedances which degrade the performance of the link. For system with little tolerance for temperature differences between cooled components and a cooling source this is undesirable. The authors of this paper have developed a technique by which thin metal foil or braided wire can be attached to metal end blocks without any solder using the swaging process. Swaging provides a fast, simple method for providing a low thermal impedance between the foils and blocks. This paper describes the characteristics of these thermal links in terms of length, mass, thermal resistance, flexibility, and survivability.

  1. Inter-satellite links: A versatile tool for geodesy and planetary and interplanetary navigation

    Science.gov (United States)

    Schlicht, Anja; Hugentobler, Urs; Hauk, Markus; Murböck, Michael; Pail, Roland

    2016-07-01

    With the use of low-low satellite-to-satellite tracking gravity field recovery made a big step forward. Based on this technique the Gravity Recovery And Climate Experiment (GRACE) mission delivers monthly gravity field with high precision, allowing to measure effects in Earth water storage basins and variations in ice mass in Greenland and Antarctica from space. GRACE is using a Ka-band inter-satellite ranging technique, GRACE Follow-On will in addition test optical ranging. In fundamental physics high-precision optical inter-satellite tracking will be used to detect gravitational waves in space, as a first step LISA Pathfinder was launched recently. Inter-satellite links are not only used for ranging, also data transfer in space is based on such links. ESA's European Data Relay System will be established in up-coming years to collect data from the low orbiting Sentinel satellites and transfer the high data rate to ground. The same link may be used for ranging, data transfer and time transfer, a functionality that is discussed for next generation Galileo satellites. But to exploit this synergy a common concept for all three tasks has to be developed. In this paper we show that with inter-satellite ranging techniques with µm accuracy the limited accuracy of GNSS based orbit determination of low Earth orbiters (LEO), which is due to the limitations of one-way microwave tracking (unsynchronized clocks, phase center variations and offsets of the sending and receiving antennas) can be overcome. In the ESA study GETRIS the following question is answered: How can a highly accurate and precise GEO-based two-way ranging method support GNSS tracking? The reduction of systematic errors in LEO precise orbit determination (POD) by exploiting the synergy between ranging, data- and time-transfer is assessed in a concept consisting of precise two-way GEO-LEO tracking (as used for data transfer) and an ultra-stable oscillator on-board of the geostationary satellite (GEO

  2. Linked alternating forms and linked symplectic Grassmannians

    CERN Document Server

    Osserman, Brian

    2011-01-01

    Motivated by applications to higher-rank Brill-Noether theory and the Bertram-Feinberg-Mukai conjecture, we introduce the concepts of linked alternating and linked symplectic forms on a chain of vector bundles, and show that the linked symplectic Grassmannians parametrizing chains of subbundles isotropic for a given linked symplectic form has good dimensional behavior analogous to that of the classical symplectic Grassmannian.

  3. 浅谈基层体委体育产业经营开发的基本环节%Simple Discussions about the Basic Links of Management and Development of Physical Training Estate of Primary Phyical Education Committee

    Institute of Scientific and Technical Information of China (English)

    杨海龙

    2001-01-01

    According to Document Material Law, and my personal investigation. The article points out that under the condition of the market economy system, the management and development of primary physical training estate is at the preliminary stage. Combined with the case of primary physical education committee, the article analyses both internal and external causes of management and develpoment of physical training estate, advancing the basic links of management and development of primary P.E. Committee%通过实地走访和文献资料法,发现在市场经济体制条件下,基层体育产业经营开发正处在起步阶段,结合基层体委的实际情况,分析体育产业经营开发的内外因,提出基层体委体育产业经营开发的基本环节。

  4. Sustainable use of veterinary pharmaceuticals on the territory (Sust-PHarm): Linking available database of manure management and environmental fate models.

    Science.gov (United States)

    Di Guardo, Andrea; Finizio, Antonio

    2017-01-01

    Analogously to the evolution of the EU legislation on pesticides, there is an increasing need of strategies aiming to reach a "sustainable use of veterinary pharmaceuticals". To this end, it is essential to develop tools, such as supporting information systems (SIS), for managing the environmental risks of veterinary pharmaceuticals on a territorial scale. In this context, we propose Sust-PHarm (SUSTainable use of veterinary Pharmaceuticals), a SIS useful to identify groundwater vulnerable areas to veterinary pharmaceuticals at both local and regional scale. As background, Sust-PHarm follows the schemes of SIS for pesticides. The latter are based on the integration of predictive models in GIS. The proposed approach goes a step forward by integrating also data on the typologies of livestock farm, their spatial distribution and manure management techniques. This information allows to identify the potential environmental loads of veterinary pharmaceuticals. In this paper, we discuss the innovative elements characterizing Sust-PHarm through a comparison with the SIS currently used for pesticides. The advantages of Sust-PHarm are discussed using Lombardia Region (Northern Italy) as a case study. Simulations were made on 12 veterinary pharmaceuticals characterized by different physical-chemical properties. Results are compared with the current guidelines for the evaluation of veterinary pharmaceuticals leaching highlighting some substantial differences when realistic data are utilized making our approach more accurate than guidelines one.

  5. Link analysis and management strategies of 132 cases medication errors in second-class hospitals%二级医院132例给药差错环节分析及管理对策

    Institute of Scientific and Technical Information of China (English)

    潘秀红; 顾建芳

    2013-01-01

    目的:分析给药差错各环节中存在的关键风险点,为护理管理者制定防范给药差错的管理措施提供依据.方法:收集上海郊区8家二级医院2009年1月至2011年6月主动上报的给药差错,分析各环节发生差错的原因.结果:共收集到132例给药差错,其中发生在用药环节的差错最多,占56.06%;发生在配置环节的差错占25.00%;发生在转录环节的差错占18.94%.结论:在给药流程的各环节中,始终存在给药差错的风险,护理管理者应根据可预见的风险,梳理给药过程各环节的风险要素,加强给药环节管理,从多元素、多角度着手,管理和防范关键风险点.%Objective: To analyze the key risks of medication errors to provide evidences for nurse managers to develop some strategies to prevent medication errors. Methods: The data of medication errors were collected from 8 second-class hospitals in Shanghai suburbs from January 2009 to June 2011, and analyzed the reasons. Results: One hundred and thirty-two cases of medication errors were reviewed. Most errors occurred at the use of medication administration link (74 cases, 56.06%), 33 cases (25.00%) occurred at the configuration link, and 25 cases (18.94%) occurred at the transcriptional link. Conclusion: Many steps of medication process are at risk of error. Nurse managers should review the foreseeable risk of medication error, recognize the key points, and strengthen the comprehensive management of medication process to reduce the risk of error.

  6. 环节质量管理模式在肿瘤病人PICC置管中安全性的研究%Study on link quality management mode for improving safety of cancer patients after PICC

    Institute of Scientific and Technical Information of China (English)

    范祖燕; 吴丹纯; 林金香

    2016-01-01

    [目的]探讨环节质量管理对提高肿瘤病人PICC置管后安全性的效果。[方法]选择2014年7月—2015年7月在我科行静脉化疗留置PICC导管的肿瘤病人256例,按置管时间先后,将2014年7月—2015年1月置管的126例病人作为对照组,将2015年2月—2015年7月置管的130例病人作为观察组。对照组采用常规护理;观察组采用环节质量管理进行护理,比较两组病人PICC置管后并发症的发生情况。[结果]观察组PICC置管后并发症发生率显著低于对照组(χ2=30.7,P<0.05)。[结论]紧抓环节质量管理的护理方法,可以显著提高肿瘤病人PICC置管后的安全性。%Objective:To probe into the effect of link quality management for improving safety after PICC in pa-tients with cancer.Methods:A total of 256 cancer patients with intravenous chemotherapy indwelling peripheral-ly inserted central catheter(PICC)were selected from July 2014 to July 2015 in our department.Based on cathe-terization time successively,126 patients receiving PICC from July 2014 to January 2015 were selected as control group,130 cases of PICC patients from February 2015 to July 2015 were selected as the observation group.Rou-tine nursing care was used in control group,the link quality management was used in observation group,to compare the incidence of PICC complications between the two groups.Results:The incidence of complications af-ter PICC observation group was significantly lower than that in control group (χ2=30.7,P<0.05).Conclusion:Clutching nursing method of link quality management could significantly improve the safety of patients with cancer after PICC .

  7. Arctic Risk Management (ARMNet) Network: Linking Risk Management Practitioners and Researchers Across the Arctic Regions of Canada and Alaska To Improve Risk, Emergency and Disaster Preparedness and Mitigation Through Comparative Analysis and Applied Research

    Science.gov (United States)

    Garland, A.

    2015-12-01

    The Arctic Risk Management Network (ARMNet) was conceived as a trans-disciplinary hub to encourage and facilitate greater cooperation, communication and exchange among American and Canadian academics and practitioners actively engaged in the research, management and mitigation of risks, emergencies and disasters in the Arctic regions. Its aim is to assist regional decision-makers through the sharing of applied research and best practices and to support greater inter-operability and bilateral collaboration through improved networking, joint exercises, workshops, teleconferences, radio programs, and virtual communications (eg. webinars). Most importantly, ARMNet is a clearinghouse for all information related to the management of the frequent hazards of Arctic climate and geography in North America, including new and emerging challenges arising from climate change, increased maritime polar traffic and expanding economic development in the region. ARMNet is an outcome of the Arctic Observing Network (AON) for Long Term Observations, Governance, and Management Discussions, www.arcus.org/search-program. The AON goals continue with CRIOS (www.ariesnonprofit.com/ARIESprojects.php) and coastal erosion research (www.ariesnonprofit.com/webinarCoastalErosion.php) led by the North Slope Borough Risk Management Office with assistance from ARIES (Applied Research in Environmental Sciences Nonprofit, Inc.). The constituency for ARMNet will include all northern academics and researchers, Arctic-based corporations, First Responders (FRs), Emergency Management Offices (EMOs) and Risk Management Offices (RMOs), military, Coast Guard, northern police forces, Search and Rescue (SAR) associations, boroughs, territories and communities throughout the Arctic. This presentation will be of interest to all those engaged in Arctic affairs, describe the genesis of ARMNet and present the results of stakeholder meetings and webinars designed to guide the next stages of the Project.

  8. The critical role of conflict resolution in teams: a close look at the links between conflict type, conflict management strategies, and team outcomes.

    Science.gov (United States)

    Behfar, Kristin J; Peterson, Randall S; Mannix, Elizabeth A; Trochim, William M K

    2008-01-01

    This article explores the linkages between strategies for managing different types of conflict and group performance and satisfaction. Results from a qualitative study of 57 autonomous teams suggest that groups that improve or maintain top performance over time share 3 conflict resolution tendencies: (a) focusing on the content of interpersonal interactions rather than delivery style, (b) explicitly discussing reasons behind any decisions reached in accepting and distributing work assignments, and (c) assigning work to members who have the relevant task expertise rather than assigning by other common means such as volunteering, default, or convenience. The authors' results also suggest that teams that are successful over time are likely to be both proactive in anticipating the need for conflict resolution and pluralistic in developing conflict resolution strategies that apply to all group members. 2008 APA

  9. Quality Control of the Key Link of Safety Management of Blood%血液安全管理关键环节质量控制

    Institute of Scientific and Technical Information of China (English)

    贺许华

    2013-01-01

    输血是临床抢救和治疗病人不可缺少的重要手段,同时输血安全也日益受到重视,已成为一个重要的公共安全问题。加强血液安全管理,保证输血安全关键环节包括:科学判断献血者资格,严格血液采集;加强实验室管理,构建血液检测安全屏障;建立疫情报告制度,屏蔽不合格献血者;严格成分血液制备,确保贮存运输条件;科学评估输血指征,合理有效输血;做好输血前检查,保证输血安全有效;核对输血相关信息,填写输血记录。影响输血安全的因素很多,关键因素是“人”,只有牢固树立血液质量理念,建立输血质量管理体系,人人牢记质量,个个关注质量,不断完善血液从采集到输注(即血管到血管)整个流程的质量管理,血站和临床紧密结合,环环相扣,树立输血存在风险意识,科学合理用血,提高输血技术水平,才能保障临床用血安全有效。%Blood transfusion is an important means for clinical treatment and patients indispensable, and blood transfusion safety has received increasing attention, has become an important issue of public safety. strengthen the blood safety management, ensure the safety of blood transfusion: including key scientific judgment donors qualification, strict blood collection; strengthen the management of the laboratory, construction of blood safety barrier; establish the epidemic reporting system, shielding the unqualified blood donors; strict blood component preparation, ensure storage and transportation conditions;scientific evaluation of the indications for transfusion, reasonable and effective blood transfusion; do the examination before the blood transfusion, ensure blood transfusion is safe and effective; check the transfusion related information, fill in the record of the transfusion. Many factors influence the safety of blood transfusion, the key factor is "people", only to

  10. The Transboundary Aquifer Management Challenge: Linking Landscape Patterns and Groundwater Nitrate Concentrations in the Abbotsford-Sumas Aquifer, USA/Canada

    Science.gov (United States)

    Gallagher, T.; Gergel, S. E.

    2015-12-01

    Changes in land use and landscape pattern can have an array of impacts on aquatic systems, including impacts which span international waters and borders. Globally, agricultural land use patterns and practices are among the factors responsible for elevated nitrate concentrations in groundwater aquifers. Coordination of landscape monitoring across trans-boundary aquifers is needed to monitor and address contamination issues as landscape patterns can vary widely among different political jurisdictions. Landscape indicators, which quantify the amount and arrangement of land cover (such as proportion and abundance of land cover types), are one such way to improve our understanding of cross-border aquatic system interactions. In Western North America, the Abbotsford-Sumas Aquifer (ASA) spans the US-Canada border and provides drinking water for over 100,000 people. Intensive agriculture combined with high precipitation and well-drained soils make this aquifer susceptible to nitrate leaching. To understand how landscape patterns influence nitrate concentrations, we ask: Which landscape indicators correlate most strongly with elevated nitrate concentrations? A seamless cross-border land cover mosaic was created by harmonizing a variety of US and Canadian geodata. Auxiliary high spatial resolution imagery (e.g., 5m RapidEye and historical Google Earth) were used to quantify fine-scale landscape features (such as number of farm field renovations) with suspected mechanistic links to nitrate sources. We examined groundwater nitrate concentrations in shallow wells (screens Washington State Department of Ecology and Environment Canada. Surrounding each well, terrestrial zones of influence (aligned with the directional flow of groundwater) were delineated within which landscape patterns were characterized. Multiple regression was used to compare the strength of relationships between land use practices and nitrate concentrations. Preliminary results show strong positive

  11. ICU压疮全程衔接预防管理效果%The effect of the whole process link-up model on the management of pressure ulcer prevention in ICU

    Institute of Scientific and Technical Information of China (English)

    杜俊; 李佳佳; 骆金铠; 张会芝

    2013-01-01

    Objective:To apply the model of pressure ulcer prevention management to reduce pressure ulcer incidence among ICU patients. Methods:We began to infuse nurses with the idea of"prevention ifrst"in 2011, and set the link-up model among different departments in 2012. Results:Patients' APACHE II scores in 2010, 2011 and 2012 had no signiifcant difference (P>0.05). However, their pressure ulcer incidences were signiifcantly different (P﹤0.01). Conclusions:Prevention idea is key in pressure ulcer management in ICU. The link-up model can effectively reduce pressure ulcer incidence among ICU patients.%目的:探讨危重患者压疮预防管理模式,有效降低危重患者压疮发生率。方法:2011年开始采用植入预防为主的压疮管理理念,2012年建立多科合作模式。结果:2011年至2012年与2010年相比,在收治患者危重程度没有降低的情况下(P>0.05),2011年、2012年压疮发生率下降(P<0.01)。结论:危重患者压疮管理重在预防,建立住院期间多科合作模式可有效降低危重患者压疮发生率。

  12. Paradigm Shift in Transboundary Water Management Policy: Linking Water Environment Energy and Food (weef) to Catchment Hydropolitics - Needs, Scope and Benefits

    Science.gov (United States)

    RAI, S.; Wolf, A.; Sharma, N.; Tiwari, H.

    2015-12-01

    The incessant use of water due to rapid growth of population, enhanced agricultural and industrial activities, degraded environment and ecology will in the coming decades constrain the socioeconomic development of humans. To add on to the precarious situation, political boundaries rarely embrace hydrological boundaries of lakes, rivers, aquifers etc. Hydropolitics relate to the ability of geopolitical institutions to manage shared water resources in a politically sustainable manner, i.e., without tensions or conflict between political entities. Riparian hydropolitics caters to differing objectives, needs and requirements of states making it difficult to administer the catchment. The diverse riparian objectives can be merged to form a holistic catchment objective of sustainable water resources development and management. It can be proposed to make a paradigm shift in the present-day transboundary water policy from riparian hydropolitics (in which the focal point of water resources use is hinged on state's need) to catchment hydropolitics (in which the interest of the basin inhabitants are accorded primacy holistically over state interests) and specifically wherein the water, environment, energy and food (WEEF) demands of the catchment are a priority and not of the states in particular. The demands of the basin pertaining to water, food and energy have to be fulfilled, keeping the environment and ecology healthy in a cooperative political framework; the need for which is overwhelming. In the present scenario, the policy for water resources development of a basin is segmented into independent uncoordinated parts controlled by various riparians; whereas in catchment hydropolitics the whole basin should be considered as a unit. The riparians should compromise a part of national interest and work in collaboration on a joint objective which works on the principle of the whole as against the part. Catchment hydropolitics may find greater interest in the more than 250

  13. Impact of Ca-amendments and soil management in physical properties linked to soil-water relationship in degraded Ultisols from South-Europe

    Science.gov (United States)

    Mariscal-Sancho, I.; Gonzalez-Fernandez, P.; León, P.; Gómez-Paccard, C.; Benito, M.; Espejo, R.

    2012-04-01

    Cañamerós raña formation in western Spain was cleared for cropping in 1940´s. Its highly weathered acidic soils (Ultisols) were deeply affected by tillage. The soil organic matter (SOM) content and specially the particulate organic matter (POM), a labile fraction, were drastically reduced, and most of their chemical and physical soil properties related to its quality were negatively affected. The extraction of Ca through the harvest and the release of Al retained in organic-Al complexes resulted in a lower Ca/Al ratio which increased the Al toxicity. These effects led to a drastic yield reduction and the abandon of many degraded fields after 20-70 years of unsustainable managements. On these degraded soils we studied the effect of different soil management strategies (no-till with wild pasture (WP) and no-till with an improved pasture (IP)), and amendment applications (sugar foam waste (SF), and SF + Phosphogypsum (PH) versus control (C)). One of the objectives of this work was to evaluate the efficiency of these practices to recover soil quality parameters, especially those related to soil-water relationship. A Split-plot experiment was established in a degraded field. We evaluated the changes in superficial infiltration, bulk density, and content of water-stable aggregates per 100 g of soil before the Ca-amendment applications and pasture establishments, and after 4.5 years. We also measured the changes in SOM and POM contents which are closely related with the previous parameters. The Ca applications reduced Al toxicity, improved the pasture yield and increased organic matter inputs to soil. The results showed a significant increase of POM in all treatment compared with the POM content at the beginning of this experiment. However the "SOM minus POM" which could be classified as recalcitrant organic matter did not show significant increments. The increase of POM had a positive effect on the content of water-stable aggregates per 100 g of soil and the water

  14. Modelling in forest management

    Science.gov (United States)

    Mark J. Twery

    2004-01-01

    Forest management has traditionally been considered management of trees for timber. It really includes vegetation management and land management and people management as multiple objectives. As such, forest management is intimately linked with other topics in this volume, most especially those chapters on ecological modelling and human dimensions. The key to...

  15. The management of cornea blindness from severe corneal scarring, with the Athens Protocol (transepithelial topography-guided PRK therapeutic remodeling, combined with same-day, collagen cross-linking

    Directory of Open Access Journals (Sweden)

    Kanellopoulos AJ

    2012-02-01

    Full Text Available Anastasios John KanellopoulosLaservision.gr Institute, Athens, Greece; Manhattan Eye, Ear and Throat Hospital, New York, NY, USA; New York University Medical School, New York, NY, USAPurpose: To evaluate the safety and efficacy of combined transepithelial topography-guided photorefractive keratectomy (PRK therapeutic remodeling, combined with same-day, collagen cross-linking (CXL. This protocol was used for the management of cornea blindness due to severe corneal scarring.Methods: A 57-year-old man had severe corneal blindness in both eyes. Both corneas had significant central scars attributed to a firework explosion 45 years ago, when the patient was 12 years old. Corrected distance visual acuity (CDVA was 20/100 both eyes (OU with refraction: +4.00, –4.50 at 135° in the right eye and +3.50, –1.00 at 55° in the left. Respective keratometries were: 42.3, 60.4 at 17° and 35.8, 39.1 at 151.3°. Cornea transplantation was the recommendation by multiple cornea specialists as the treatment of choice. We decided prior to considering a transplant to employ the Athens Protocol (combined topography-guided partial PRK and CXL in the right eye in February 2010 and in the left eye in September 2010. The treatment plan for both eyes was designed on the topography-guided wavelight excimer laser platform.Results: Fifteen months after the right eye treatment, the right cornea had improved translucency and was topographically stable with uncorrected distance visual acuity (UDVA 20/50 and CDVA 20/40 with refraction +0.50, –2.00 at 5°. We noted a similar outcome after similar treatment applied in the left eye with UDVA 20/50 and CDVA 20/40 with –0.50, –2.00 at 170° at the 8-month follow-up.Conclusion: In this case, the introduction of successful management of severe cornea abnormalities and scarring with the Athens Protocol may provide an effective alternative to other existing surgical or medical options.Keywords: Athens Protocol, collagen cross-linking

  16. 环节管理在NICU医疗器械性压疮预防中的应用效果%Application effect of link management in prevention of medical device related pressure ulcers in NICU

    Institute of Scientific and Technical Information of China (English)

    郑翠霞; 王秀萍; 纪进华; 徐娟; 牛双

    2016-01-01

    Objective To explore the link management of medical device related pressure ulcers in neonatal intensive care unit ( NICU) , and reduce the incidence of NICU medical device related pressure ulcers through various link management. Methods From June 2012 to May 2014, 726 cases of patients in our department were selected as the control group and received commonly used preventive measures and conventional pressure ulcer grading nursing care. From June 2014 to May 2016, another 869 patients in our department was selected as the observation group, and they received link intervention based on the routine nursing method which includes the establishment of pressure ulcer steering group, developing nursing measures of common medical device related pressure ulcers, establishing management principles of prevention and management of medical devices related pressure ulcers and strengthening personnel training and development of all levels of responsibility.The incidence rate of NICU medical device related pressure ulcers was observed. Results There were 28 cases of medical device related pressure ulcers in the control group, and the incidence rate was 3. 9%( 28/726);while there were 7 cases of medical instrument pressure ulcers in the observation group, and the incidence rate was 0.8% (7/869). The severity of pressure ulcer in the control group was significantly higher than that in the observation group; the cure rate of the wound was significantly lower than that of the observation group (U=-2.001,P<0.05). The score of nursing staff on the knowledge of medical device related pressure ulcers was (26. 2±1.7) after training, which was higher than that before training (17.6± 0. 8) (t=-6.04,P<0.01).Conclusions Through the link management of medical device related pressure ulcers, incidence rate of pressure ulcers is reduced;the quality of nursing is improved; the use of medical equipment is standardized;and the new concept of medical device related pressure ulcers is updated.%目

  17. Materializing the web of linked data

    CERN Document Server

    Konstantinou, Nikolaos

    2015-01-01

    This book explains the Linked Data domain by adopting a bottom-up approach: it introduces the fundamental Semantic Web technologies and building blocks, which are then combined into methodologies and end-to-end examples for publishing datasets as Linked Data, and use cases that harness scholarly information and sensor data. It presents how Linked Data is used for web-scale data integration, information management and search. Special emphasis is given to the publication of Linked Data from relational databases as well as from real-time sensor data streams. The authors also trace the transformation from the document-based World Wide Web into a Web of Data. Materializing the Web of Linked Data is addressed to researchers and professionals studying software technologies, tools and approaches that drive the Linked Data ecosystem, and the Web in general.

  18. Weierstrass polynomials for links

    DEFF Research Database (Denmark)

    Hansen, Vagn Lundsgaard

    1997-01-01

    There is a natural way of identifying links in3-space with polynomial covering spaces over thecircle. Thereby any link in 3-space can be definedby a Weierstrass polynomial over the circle. Theequivalence relation for covering spaces over thecircle is, however, completely different from...... that for links in 3-space. This paper initiates a study of the connections between polynomial covering spaces over the circle and links in 3-space....

  19. [Hospitals as vital links].

    Science.gov (United States)

    Klink, A

    2013-01-01

    The reform of the system in 2006 aimed at reducing waiting lists in an efficient manner. Performance-linked funding and regulated competition did indeed lead to improved efficiency. The other side of the coin is overtreatment, and expensive and not infrequently damaging growth in volume. In order to control costs, three strategies have been determined: agreements with an annual cap on volume; (b) collaboration of regional health-care providers with the mission of improving results in health care (with profit-sharing if costs fall); and (c) fusions reducing the number of hospitals which reduces the burden of injuries (supply no longer creates its own demand). This article comments on these strategies. The author argues for a fourth approach: if the quality of health care improves, the number of complications will fall, overtreatment will decline and the outcome will be a decrease in burden of injuries. This requires the health care insurers to modify the way they manage their contracts and methods of payment, and stimulates competition based on quality.

  20. Using PDCA Method to Control the Quality of Medical Record Link, Strengthen the Process Control Management%运用PDCA法进行病案环节质量控制,加强全程监控管理

    Institute of Scientific and Technical Information of China (English)

    王晨

    2014-01-01

    为了提高病案书写质质量,建立严密的病案质量全程监控管理系统,实行病案质量自我控质、监督控制和终末控制,运用PDCA法做到逐级负责,把监控结果以质量简报的形式反馈到院级网络和所有科室,并同时在院周会上通报。使病案质量重心从终末质量转移到环节质监控上来。%In order to improve the quality of the medical record writing quality, the establishment of strict medical record quality control management system, implementation of the medical record quality self control, supervision and control and terminal control, using the method of PDCA to chase class to be in charge, the monitoring results feedback to the school level network and all the departments to the quality of briefings, and at the same time was reported to be in weekly. The medical record quality center of gravity from the final quality transfer to link quality monitoring.

  1. Collagen cross linking: Current perspectives

    Directory of Open Access Journals (Sweden)

    Srinivas K Rao

    2013-01-01

    Full Text Available Keratoconus is a common ectatic disorder occurring in more than 1 in 1,000 individuals. The condition typically starts in adolescence and early adulthood. It is a disease with an uncertain cause and its progression is unpredictable, but in extreme cases, vision deteriorates and can require corneal transplant surgery. Corneal collagen cross-linking (CCL with riboflavin (C3R is a recent treatment option that can enhance the rigidity of the cornea and prevent disease progression. Since its inception, the procedure has evolved with newer instrumentation, surgical techniques, and is also now performed for expanded indications other than keratoconus. With increasing experience, newer guidelines regarding optimization of patient selection, the spectrum of complications and their management, and combination procedures are being described. This article in conjunction with the others in this issue, will try and explore the uses of collagen cross-linking (CXL in its current form.

  2. Subjetividade e gestão: explorando as articulações psicossociais no trabalho gerencial e no trabalho em saúde Subjectiveness and management: exploring psychosocial links on managerial and health work

    Directory of Open Access Journals (Sweden)

    Marilene de Castilho Sá

    2010-08-01

    Full Text Available Este artigo apresenta a perspectiva teórica com a qual abordamos a gestão em saúde e, particularmente, o trabalho gerencial e o trabalho em saúde. Para fazer face à complexidade dos problemas relacionados à gestão dos serviços públicos de saúde e à qualidade do cuidado - importantes desafios da reforma sanitária brasileira - as autoras têm estudado a característica grupal/intersubjetiva e inconsciente dos processos organizacionais, que apresenta um impacto importante na dinâmica dos serviços de saúde e em sua qualidade. Para este propósito, procura-se articular três eixos de pensamento: (1 a abordagem da psicossociologia francesa sobre as organizações e a sociedade contemporânea; (2 a abordagem psicanalítica sobre os processos intersubjetivos e grupais; e (3 a psicodinâmica do trabalho, que focaliza as relações entre prazer e sofrimento no trabalho. Neste caminho de investigação, temos explorado as mediações entre as realidades psíquicas, intersubjetivas, grupais e sociais, nas organizações de saúde, no trabalho gerencial e no trabalho em saúde, identificando os limites e possibilidades que elas estabelecem para o exercício da liderança, para a cooperação e construção de projetos coletivos e para a qualidade do cuidado em saúde.This paper presents our theoretical perspective over health management, particularly on managerial and health work. To face the complex problems related to public health services management and health care quality - important challenges of Brazilian Sanitary Reform - we study the group/inter-subjective and unconscious characteristic of organizational processes, which has important effects over health services dynamics and their quality. For this purpose, we attempt to articulate three theoretical perspectives:(1 the French Psycho sociology approach on organizations and contemporary society; (2 the psychoanalytical theory on inter-subjective and group processes; and (3 the Work

  3. Linking open vocabularies

    CERN Document Server

    Greifender, Elke; Seadle, Michael

    2013-01-01

    Linked Data (LD), Linked Open Data (LOD) and generating a web of data, present the new knowledge sharing frontier. In a philosophical context, LD is an evolving environment that reflects humankinds' desire to understand the world by drawing on the latest technologies and capabilities of the time. LD, while seemingly a new phenomenon did not emerge overnight; rather it represents the natural progression by which knowledge structures are developed, used, and shared. Linked Open Vocabularies is a significant trajectory of LD. Linked Open Vocabularies targets vocabularies that have traditionally b

  4. MANAGING CHANGE WHEN IMPLEMENTING BUSINESS PROCESS MANAGEMENT

    OpenAIRE

    VLAD BÃLÃNESCU

    2012-01-01

    In this paper I attempted to establish the link between business process management and change management. After the introduction, in the second chapter I made a short presentation of business process management, what the concept entails and prospects. The third chapter contains a definition of change management and types of changes that can occur in an organization when implementing Business Process Management. The fourth part of this paper contains two models for change and present how they...

  5. Let's "Downscale" Linked Data

    NARCIS (Netherlands)

    Gueret, Christophe; de Boer, Victor; Schlobach, Stefan

    2014-01-01

    Open data policies and linked data publication are powerful tools for increasing transparency, participatory governance, and accountability. A closer look at linked data technologies, however, proves that their design and deployment exclude the majority of the world’s population. It will take small

  6. Typed links in Webvise

    DEFF Research Database (Denmark)

    1999-01-01

    We extended the Webvise open hypermedia system with support for typed links.  The ECDL'99 paper describes these extensions.......We extended the Webvise open hypermedia system with support for typed links.  The ECDL'99 paper describes these extensions....

  7. Il progetto Linked Heritage

    Directory of Open Access Journals (Sweden)

    Marzia Piccininno

    2013-03-01

    Full Text Available ItLinked Heritage è uno dei progetti di punta finanziati dalla Commissione europea per alimentare Europeana, il portale dei contenuti culturali digitali europei. Linked Heritage raccoglie, sotto il coordinamento dell’ICCU, un consorzio molto vasto i cui partner provengono da quasi tutti i paesi dell’Unione più Russia e Israele; essi forniranno a Europeana ben 3 milioni di risorse digitali. Oltre al tema dell’aggregazione di contenuti culturali digitali, Linked Heritage sta esplorando altri temi fondamentali per Europeana come il multilinguismo, i linked data e il rapporto con possibili partner commerciali. Linked Heritage è l’ultimo in ordine di tempo di una serie di iniziative progettuali avviate da un consorzio europeo di istituzioni che opera insieme da oltre dieci anni nell’ambito del patrimonio culturale digitale.EnLinked Heritage is one of the flagship projects funded by the European commission to feed Europeana, the portal of the European digital cultural content. Linked Heritage has a very large partnership, coordinated by ICCU, whose members come from many European countries, Russia and Israel; they will supply Europeana with 3 million digital resources. Beyond the aggregation of digital cultural content, Linked Heritage is exploring other topics which are essential for Europeana, like multilingualism, linked data and the relationship with the commercial partners. Linked Heritage is the last one in time of a series of projects made up by a European consortium of institutions that has been working for over ten years in the field of digital cultural heritage.

  8. A Novel Low-cost, Ka-band, High Altitude, Multi-Baseline Unmanned Aerial Vehicle Sensor for Surface Water Ocean Topography Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The NRC Decadal Survey recommended the Surface Water Ocean Topography (SWOT) satellite mission to address terrestrial fresh water hydrology and physical oceanography...

  9. Design and experimental verification of near-field Ka-band probe based on wideband OMJ with minimum higher-order spherical mode content

    DEFF Research Database (Denmark)

    Foged, L. J.; Giacomini, A.; Morbidini, R;

    2012-01-01

    A desired feature of modern field probes is that the useable bandwidth should exceed that of the Antenna Under Test (AUT) [1]. Recent developments in probe and orthomode junctions (OMJ) technology has shown that bandwidths of up to 4:1 are achievable [2-5]. The probes are based on inverted ridge...... technology capable of maintaining the same high performance standards of traditional probes However, in typical Spherical Near Field (SNF) measurement scenarios, the applicable frequency range of the single probe can also be limited by the content of μ≠1 spherical modes in the probe pattern [6...

  10. Ka-band reliable and compact 3-bit true-time-delay phase shifter using MEMS single-pole-eight-throw switching networks

    Science.gov (United States)

    Koul, Shiban K.; Dey, Sukomal; Poddar, Ajay K.; Rohde, Ulrich L.

    2016-10-01

    This paper presents a radio frequency micro-electromechanical system (RF MEMS) based 3-bit phase shifter using MEMS single-pole-eight-throw (SP8T) switches. Devices are fabricated on 635 µm alumina substrate utilizing on the coplanar waveguide (CPW) transmission line. Single switch dimensions are 0.14  ×  0.23 mm2 which is much smaller than Si-on-insulator switches. The symmetric and compact SP8T switch is the primary building block of the 3-bit phase shifter. The SP8T switch results in isolation levels of 31-15 dB, return loss of 33-18 dB and insertion loss of 0.6-1.9 dB, respectively, at 26-40 GHz. Later, two SP8T switches are connected back to back to develop the 3-bit phase shifter using different delay lines at 35 GHz. Finally, the phase shifter provides average return loss of better than 14 dB and average insertion loss of 4.4 dB over the 34.75-35.25 GHz. Measured average phase error is less than 0.98° at 35 GHz. The total area of the fabricated 3-bit phase shifter is 5.95 mm2. SP8T switches are capable of handling 0.1-1 W of power up to 100 million cycles which is sufficient power handling capability for wireless communication systems. Reliability of the phase shifter is extensively characterized with different incident RF powers at room temperature (25°C) and discussed in detail. To the best of the authors’ knowledge, this is the first reported MEMS 3-bit phase shifter in the literature that has used a minimum number of switching elements per phase state.

  11. 高隔离度Ka波段平面魔T的设计%Design of High Isolated Ka Band Planar Magic-T

    Institute of Scientific and Technical Information of China (English)

    高艳红; 徐军; 吴洪江; 王绍东; 胡召宇

    2011-01-01

    A high isolated planar Magic-T was presented which was appropriate for MIC. This structure belonged to a novel 180° planar hybrids configuration. It was designed based on the traditional principle of microstrip hybrid ring and introduces microstrip-slotline tee junction. The 180° phase shift of the two ports was realized by the transition of microstrip-slotline which the isolation of output ports was realized. A multisection impedance transformation network was used to increase the operating bandwidth and minimize the parasitic coupling around the microstrip-slotline tee junction. The design implemented a small microstrip-slotline tee junctions with minimumsized slotline terminations to reduce radiation loss. Derived equivalent circuit models were used efficiently for the design of the planar Magic-T. The λg/4 impedance transformer and the impedance matching of the microstrip - slotline tee junctions were simulated and optimized by CST to achieve higher isolation. The experimental results show that the structure provides the isolation of 20 dB with the insertion loss of 1 dB in the bandwidth of 34 - 36 GHz. The return loss is got less than 18 dB at input put.%提出了一种适合于毫米波微波集成电路(MIC)的高隔离度平面魔T结构,该结构属于一种新型的180°平面型混合网络.基于传统的微带混合环原理,引入了微带-槽线过渡的结构,两个端口之间的180°相移通过微带-槽线转换结构实现,从而实现了输出端口的隔离.该结构采用多节阻抗匹配网络,增加了工作带宽,使微带-槽线过渡结的寄生耦合最小化.通过设计可实现得到最小尺寸的槽线终端,降低了微带-槽线过渡结的辐射损耗.引入的等效电路模型有效地提高了平面魔T的设计.借助CST软件,仿真优化了λg/4变换器以及微带-槽线转换结构的阻抗匹配,提高了隔离度.实验结果表明:在工作带宽(34~36 GHz)内,该结构输出端口2和3的隔离度达20 dB,输入端口回波损耗低于18 dB,插入损耗1 dB.

  12. Ka波段高功率合成放大技术的研究*%Ka-band High Power Amplification Technology

    Institute of Scientific and Technical Information of China (English)

    程光伟; 孔祥丽

    2015-01-01

    This paper introduces a kind of Ka‐band high‐gain solid state power amplifier device based on wavequide .It uses waveguide microstrip line to transite power output ,also design effectively microstrip dielectric substrate and cavity structure ,inhibition of self‐excited resulting from high gain ,and makes it have a compact in the partial circuit and the char‐acteristics of good heat dissipation .The production of ka‐band and high power signal is completed .The input is low power signal and power amplifier preheating pulse modulation of 34 .4GHz ,and the output is high power (20W) emission signal .%论文介绍了一种基于波导的Ka波段高增益固态功率放大器件,它运用波导‐微带线过渡输出功率,有效地进行了微带介质基片和腔体结构的设计,抑制由于高增益所产生的自激,并且使其具有紧凑的偏里电路以及良好的散热特性。完成Ka波段高功率发射信号的产生,输入为34.4GHz已调制低功率发射信号和功放预热脉冲,输出为高功率(20W)发射信号。

  13. High-Efficiency, High-Power Ka-Band Elliptic-Beam Traveling-Wave-Tube Amplifier for Long-Range Space RF Telecommunications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space telecommunications require amplifiers that are efficient, high-power, wideband, small, lightweight, and highly reliable. Currently, helix traveling wave tube...

  14. Characterization and Modeling of DHBT in InP/GaAsSb Technology for the Design and Fabrication of a Ka Band MMIC Oscillator

    OpenAIRE

    Laurent, S.; Nallatamby, J. C.; PRIGENT, M.; Riet, M.; Nodjiadjim, V.

    2012-01-01

    This paper presents the design of an MMIC oscillator operating at a 38 GHz frequency. This circuit was fabricated by the III–V Lab with the new InP/GaAsSb Double Heterojunction Bipolar Transistor (DHBT) submicronic technology (We=700 nm). The transistor used in the circuit has a 15 μm long two-finger emitter. This paper describes the complete nonlinear modeling of this DHBT, including the cyclostationary modeling of its low frequency (LF) noise sources. The specific interest of the methodolog...

  15. Characterization and Modeling of DHBT in InP/GaAsSb Technology for the Design and Fabrication of a Ka Band MMIC Oscillator

    Directory of Open Access Journals (Sweden)

    S. Laurent

    2012-01-01

    Full Text Available This paper presents the design of an MMIC oscillator operating at a 38 GHz frequency. This circuit was fabricated by the III–V Lab with the new InP/GaAsSb Double Heterojunction Bipolar Transistor (DHBT submicronic technology (We=700 nm. The transistor used in the circuit has a 15 μm long two-finger emitter. This paper describes the complete nonlinear modeling of this DHBT, including the cyclostationary modeling of its low frequency (LF noise sources. The specific interest of the methodology used to design this oscillator resides in being able to choose a nonlinear operating condition of the transistor from an analysis in amplifier mode. The oscillator simulation and measurement results are compared. A 38 GHz oscillation frequency with 8.6 dBm output power and a phase noise of −80 dBc/Hz at 100 KHz offset from carrier have been measured.

  16. Dynamical fat link fermions

    CERN Document Server

    Kamleh, W; Williams, A G; Kamleh, Waseem; Leinweber, Derek B.; Williams, Anthony G.; 10.1016/j.nuclphysbps.2003.12.058

    2004-01-01

    The use of APE smearing or other blocking techniques in fermion actions can provide many advantages. There are many variants of these fat link actions in lattice QCD currently, such as FLIC fermions. Frequently, fat link actions make use of the APE blocking technique in combination with a projection of the blocked links back into the special unitary group. This reunitarisation is often performed using an iterative maximisation of a gauge invariant measure. This technique is not differentiable with respect to the gauge field and thus prevents the use of standard Hybrid Monte Carlo simulation algorithms. The use of an alternative projection technique circumvents this difficulty and allows the simulation of dynamical fat link fermions with standard HMC and its variants.

  17. Link to paper

    Data.gov (United States)

    U.S. Environmental Protection Agency — Link to the paper. This dataset is associated with the following publication: Naile, J., A.W. Garrison, J. Avants, and J. Washington. Isomers/enantiomers of...

  18. Latest Research: Genetic Links

    Science.gov (United States)

    ... Current Issue Past Issues Feature: Vision Latest Research: Genetic Links Past Issues / Summer 2008 Table of Contents ... inside the eye is a risk factor for glaucoma. Summer 2008 Issue: Volume 3 Number 3 Page ...

  19. Development Issues on Linked Data Weblog Enrichment

    Science.gov (United States)

    Ruiz-Rube, Iván; Cornejo, Carlos M.; Dodero, Juan Manuel; García, Vicente M.

    In this paper, we describe the issues found during the development of LinkedBlog, a Linked Data extension for WordPress blogs. This extension enables to enrich text-based and video information contained in blog entries with RDF triples that are suitable to be stored, managed and exploited by other web-based applications. The issues have to do with the generality, usability, tracking, depth, security, trustiness and performance of the linked data enrichment process. The presented annotation approach aims at maintaining web-based contents independent from the underlying ontological model, by providing a loosely coupled RDFa-based approach in the linked data application. Finally, we detail how the performance of annotations can be improved through a semantic reasoner.

  20. Managing Networks

    DEFF Research Database (Denmark)

    Jørgensen, Heidi; Vintergaard, Christian

    isprovided, that the relation between a company's strategy, structure and processesin fact have a considerable influence on its pattern of network behaviour. Threecase studies from the Danish biotech industry exemplify and illustrate how acompany's strategy is directly correlated with how it manages its...... of networkbehaviour, knowing how to manage this relation becomes essential, especiallyduring the development of new strategies.......Logically it seems that companies pursuing different business strategies wouldalso manage their relationships with other firms accordingly. Nevertheless, due tothe lack of research in the field of network strategies, this link still remainsinadequately examined. Based on the well-known framework...

  1. Linked data for libraries, archives and museums how to clean, link and publish your metadata

    CERN Document Server

    Hooland, Seth van

    2014-01-01

    This highly practical handbook teaches you how to unlock the value of your existing metadata through cleaning, reconciliation, enrichment and linking and how to streamline the process of new metadata creation. Libraries, archives and museums are facing up to the challenge of providing access to fast growing collections whilst managing cuts to budgets. Key to this is the creation, linking and publishing of good quality metadata as Linked Data that will allow their collections to be discovered, accessed and disseminated in a sustainable manner. This highly practical handbook teaches you how to unlock the value of your existing metadata through cleaning, reconciliation, enrichment and linking and how to streamline the process of new metadata creation. Metadata experts Seth van Hooland and Ruben Verborgh introduce the key concepts of metadata standards and Linked Data and how they can be practically applied to existing metadata, giving readers the tools and understanding to achieve maximum results with limited re...

  2. Ecosystem Management. A Management View

    DEFF Research Database (Denmark)

    Ravn-Jonsen, Lars

    The need for management of the marine ecosystem using a broad perspective has been recommended under a variety of names. This paper uses the term Ecosystem Management, which is seen as a convergence between the ecological idea of an organisational hierarchy and the idea of strategic planning...... with a planning hierarchy---with the ecosystem being the strategic planning level. Management planning requires, in order to establish a quantifiable means and ends chain, that the goals at the ecosystem level can be linked to operational levels; ecosystem properties must therefore be reducible to lower...

  3. Change Management

    Directory of Open Access Journals (Sweden)

    Motab Raja Aljohani

    2015-08-01

    Full Text Available Managing change within organizations is a core challenge for the HR professionals as any change concerns people working within the organization. The study of Human Resource Management is based on achievement of goals through corporate strategy and effective management of change within the organization. Change can be successful when it links people job satisfaction and productivity within an organization. Effective change management can result in greater productivity higher work life quality and improved readiness for future changes. Most HR professionals are regularly being asked for developing attitudes and personal skills for change implementation as technical understanding of applying the tools for managing change. This article will outline the challenges faced by Human Resource managers in change implementation. The well-known theories and literature will also be discussed to share light on the importance and change management for HR. Also recommendations and suggestion will be provided for improving change management process within an organizational context. Keywords Change Management Human Resource Management

  4. Organizational Knowledge Management Structure

    Science.gov (United States)

    Walczak, Steven

    2005-01-01

    Purpose: To propose and evaluate a novel management structure that encourages knowledge sharing across an organization. Design/methodology/approach: The extant literature on the impact of organizational culture and its link to management structure is examined and used to develop a new knowledge sharing management structure. Roadblocks to…

  5. Organic farming, soil health, and food quality: considering possible links

    Science.gov (United States)

    That the health of soils, plants, animals and people are linked is an ancient idea that still resonates. It is well known that soil nutrient deficiencies and toxicities can adversely impact plant and animal health. Growing evidence also supports the idea of positive links between farm management, so...

  6. Response model parameter linking

    NARCIS (Netherlands)

    Barrett, Michelle Derbenwick

    2015-01-01

    With a few exceptions, the problem of linking item response model parameters from different item calibrations has been conceptualized as an instance of the problem of equating observed scores on different test forms. This thesis argues, however, that the use of item response models does not require

  7. Linking Literacy and Movement

    Science.gov (United States)

    Pica, Rae

    2010-01-01

    There are many links between literacy and movement. Movement and language are both forms of communication and self-expression. Rhythm is an essential component of both language and movement. While people may think of rhythm primarily in musical terms, there is a rhythm to words and sentences as well. Individuals develop an internal rhythm when…

  8. Linking place and mind

    DEFF Research Database (Denmark)

    Jensen, Marie Møller

    2016-01-01

    This paper investigates the salience of vernacular Tyneside forms on the basis of theories of enregisterment and exemplar processing. On one level, exemplar theory provides a psycholinguistic account of how the link between social value and linguistic features is possible. Conversely, integrating...

  9. Link Influence Entropy

    Science.gov (United States)

    Singh, Priti; Chakraborty, Abhishek; Manoj, B. S.

    2017-01-01

    In this paper we propose a new metric, Link Influence Entropy (LInE), which describes importance of each node based on the influence of each link present in a network. Influence of a link can neither be effectively estimated using betweenness centrality nor using degree based probability measures. The proposed LInE metric which provides an effective way to estimate the influence of a link in the network and incorporates this influence to identify nodal characteristics, performs better compared to degree based entropy. We found that LInE can differentiate various network types which degree-based or betweenness centrality based node influence metrics cannot. Our findings show that spatial wireless networks and regular grid networks, respectively, have lowest and highest LInE values. Finally, performance analysis of LInE is carried out on a real-world network as well as on a wireless mesh network testbed to study the influence of our metric as well as influence stability of nodes in dynamic networks.

  10. Secure Link Middleware

    Science.gov (United States)

    2008-08-01

    Secure Link middleware as specified by the circled ‘sld’, sld . Using a network traffic analyzer (e.g., tcpdump) at router bulldog and tiger, ARL...or nfs (remote accessing file systems) to be securely operated and used among networked computer systems without any bulldog (router3) bear (router2

  11. Energy care in relation to your management system. Linking lists between the Reference Energy Care and ISO 14001, ISO 9001 and HACCP; Energiezorg in relatie tot uw zorgsysteem. Linking lists tussen de Referentie Energiezorg en ISO 14001, ISO 9001 en HACCP

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Several so-called care systems are in use at institutes and companies. For efficiency reasons it makes sense to integrate an energy care system to the existing care system. For the so-called Reference Energy Care, developed by the Netherlands Agency for Energy and the Environment (Novem) links to three of the most important care systems have been elaborated: environmental care according to ISO 14001, the quality care system ISO 9001:2000 and the food safety system Hazard Analysis Critical Control Points (HACCP). The elaboration resulted in three tables, indicating the connections ('linking lists') between each of those care systems and the Reference Energy Care system and how energy care can be integrated into those systems. [Dutch] Bij instellingen en bedrijven zijn diverse zorgsystemen in gebruik. Het is zinvol om energiezorg - waar mogelijk - in een dergelijk bestaand systeem op te nemen. Meerdere zorgsystemen naast elkaar in stand houden is minder efficient dan de systemen integreren tot een systeem. Novem heeft daarom voor haar Referentie Energiezorg de link laten uitwerken naar drie van de meest voorkomende systemen: milieuzorg volgens ISO 14001, het kwaliteitszorgsysteem ISO 9001:2000 en het voedselveiligheidssysteem HACCP (Hazard Analysis Critical Control Points). Hieruit zijn drie tabellen voortgekomen, die aangeven welke verbanden er zijn tussen elk van deze zorgsystemen en de Referentie Energiezorg en hoe u energiezorg kunt integreren in elk van deze systemen. Deze tabellen worden aangeduid als 'linking lists' en u kunt ze gebruiken als hulpmiddel bij het integreren van energiezorg in uw eigen zorgsysteem. U vindt ze in deze brochure.

  12. Creating Intelligent Linking for Information Threading in Knowledge Networks

    CERN Document Server

    Nair, Dr T R Gopalakrishnan; 10.1109/INDCON.2011.6139335

    2012-01-01

    Informledge System (ILS) is a knowledge network with autonomous nodes and intelligent links that integrate and structure the pieces of knowledge. In this paper, we aim to put forward the link dynamics involved in intelligent processing of information in ILS. There has been advancement in knowledge management field which involve managing information in databases from a single domain. ILS works with information from multiple domains stored in distributed way in the autonomous nodes termed as Knowledge Network Node (KNN). Along with the concept under consideration, KNNs store the processed information linking concepts and processors leading to the appropriate processing of information.

  13. Volumes of chain links

    CERN Document Server

    Kaiser, James; Rollins, Clint

    2011-01-01

    Agol has conjectured that minimally twisted n-chain links are the smallest volume hyperbolic manifolds with n cusps, for n at most 10. In his thesis, Venzke mentions that these cannot be smallest volume for n at least 11, but does not provide a proof. In this paper, we give a proof of Venzke's statement. The proof for n at least 60 is completely rigorous. The proof for n between 11 and 59 uses a computer calculation, and can be made rigorous for manifolds of small enough complexity, using methods of Moser and Milley. Finally, we prove that the n-chain link with 2m or 2m+1 half-twists cannot be the minimal volume hyperbolic manifold with n cusps, provided n is at least 60 or |m| is at least 8, and we give computational data indicating this remains true for smaller n and |m|.

  14. Urban rainfall estimation employing commercial microwave links

    Science.gov (United States)

    Overeem, Aart; Leijnse, Hidde; Uijlenhoet, Remko; ten Veldhuis, Marie-claire

    2015-04-01

    Urban areas often lack rainfall information. To increase the number of rainfall observations in cities, microwave links from operational cellular telecommunication networks may be employed. Although this new potential source of rainfall information has been shown to be promising, its quality needs to be demonstrated more extensively. In the Rain Sense kickstart project of the Amsterdam Institute for Advanced Metropolitan Solutions (AMS), sensors and citizens are preparing Amsterdam for future weather. Part of this project is rainfall estimation using new measurement techniques. Innovative sensing techniques will be utilized such as rainfall estimation from microwave links, umbrellas for weather sensing, low-cost sensors at lamp posts and in drainage pipes for water level observation. These will be combined with information provided by citizens in an active way through smartphone apps and in a passive way through social media posts (Twitter, Flickr etc.). Sensor information will be integrated, visualized and made accessible to citizens to help raise citizen awareness of urban water management challenges and promote resilience by providing information on how citizens can contribute in addressing these. Moreover, citizens and businesses can benefit from reliable weather information in planning their social and commercial activities. In the end city-wide high-resolution rainfall maps will be derived, blending rainfall information from microwave links and weather radars. This information will be used for urban water management. This presentation focuses on rainfall estimation from commercial microwave links. Received signal levels from tens of microwave links within the Amsterdam region (roughly 1 million inhabitants) in the Netherlands are utilized to estimate rainfall with high spatial and temporal resolution. Rainfall maps will be presented and compared to a gauge-adjusted radar rainfall data set. Rainfall time series from gauge(s), radars and links will be compared.

  15. Linking assumptions in amblyopia

    Science.gov (United States)

    LEVI, DENNIS M.

    2017-01-01

    Over the last 35 years or so, there has been substantial progress in revealing and characterizing the many interesting and sometimes mysterious sensory abnormalities that accompany amblyopia. A goal of many of the studies has been to try to make the link between the sensory losses and the underlying neural losses, resulting in several hypotheses about the site, nature, and cause of amblyopia. This article reviews some of these hypotheses, and the assumptions that link the sensory losses to specific physiological alterations in the brain. Despite intensive study, it turns out to be quite difficult to make a simple linking hypothesis, at least at the level of single neurons, and the locus of the sensory loss remains elusive. It is now clear that the simplest notion—that reduced contrast sensitivity of neurons in cortical area V1 explains the reduction in contrast sensitivity—is too simplistic. Considerations of noise, noise correlations, pooling, and the weighting of information also play a critically important role in making perceptual decisions, and our current models of amblyopia do not adequately take these into account. Indeed, although the reduction of contrast sensitivity is generally considered to reflect “early” neural changes, it seems plausible that it reflects changes at many stages of visual processing. PMID:23879956

  16. Collaboratively Patching Linked Data

    CERN Document Server

    Knuth, Magnus; Sack, Harald

    2012-01-01

    Today's Web of Data is noisy. Linked Data often needs extensive preprocessing to enable efficient use of heterogeneous resources. While consistent and valid data provides the key to efficient data processing and aggregation we are facing two main challenges: (1st) Identification of erroneous facts and tracking their origins in dynamically connected datasets is a difficult task, and (2nd) efforts in the curation of deficient facts in Linked Data are exchanged rather rarely. Since erroneous data often is duplicated and (re-)distributed by mashup applications it is not only the responsibility of a few original publishers to keep their data tidy, but progresses to be a mission for all distributers and consumers of Linked Data too. We present a new approach to expose and to reuse patches on erroneous data to enhance and to add quality information to the Web of Data. The feasibility of our approach is demonstrated by example of a collaborative game that patches statements in DBpedia data and provides notifications ...

  17. X linked mental retardation.

    Science.gov (United States)

    Rejeb, Imen; Ben Jemaa, Lamia; Chaabouni, Habiba

    2009-05-01

    Mental retardation (MR) is a group of heterogeneous clinical conditions. There are more than 900 genetic disorders associated with MR and it affects around 3% of the general population. Many MR conditions described are syndromic, fragile X syndrome being the most common clinical entity among them. X linked mental retardation (XLMR) is subdivided in two categories: syndromic XLMR (MRXS) when MR is associated with clinical features and non-syndromic XLMR (MRX) when MR is isolated. The aim of this systematic review of the literature was to join together the results of several studies related to X linked mental retardation and to present various genes implicated in this disease. In this review, focus has been given on genes implicated in mental retardation, the clinical data and on phenotype-genotype correlations. An exhaustive electronic and library research of the recent literature was carried out on the Web sites "Science Direct" and "Interscience Wiley". The key words used were "mental retardation", "X chromosome", "gene", "syndromic mental retardation", "non-syndromic mental retardation". In this review a number of X linked genes, the clinical features associated with the gene abnormality, and the prevalence of the disease gene are discussed. We classified these genes by order of their first implication in MR. A table presented on the XLMR Update Web site who list the 82 known XLMR genes is available as XLMR Genes and corresponding proteins.

  18. 多链路接入的流量控制及在校园网中的应用%TrafficManagement for Multi_link Acess and Its Application in the Campus Network

    Institute of Scientific and Technical Information of China (English)

    王冠宇; 蔡大鹏; 秦爱梅

    2012-01-01

    校园网的出口是网络规划和建设中需要重点考虑的问题,它关系到校园网用户对Internet访问的速度,本文就校园网的多链路接入方法进行了分析,介绍了采用先进成熟的流量管理设备LinkProof实现多链路接入的解决方案,并和传统的多链路接入方案进行了分析对比。该方案充分整合了CERNET及本地ISP的优势资源,并作到多链路负载均衡,在高校校园网中进行了实际应用,是行之有效的校园网出口瓶颈及链路负载均衡的解决办法。%The campus network exit is the key issue needs to be taken into full consideration in network planning and construction,which is directly connected with the speed to Internet.The solution to implement multi_link access with the advanced trafficmanager_LinkProof is introduced and compared with traditional solutions in this paper.To expand bandwidth and balance the load of export-links,the solution makes use of all available resource provided by CERNET and local ISP,its' a good way in the similar situation.

  19. LinkedIn Marketing An Hour a Day

    CERN Document Server

    von Rosen, Viveka

    2012-01-01

    A step-by-step guide for succeeding on the for ''business'' social media network LinkedIn Marketing: An Hour a Day helps you create, customize, and optimize a presence on LinkedIn, the world's largest social network for professionals. In this detailed, step-by-step book, LinkedIn expert Viveka von Rosen reveals how to use this powerful platform to ensure that you or your company get noticed by the right audience. Discover previously undocumented tips and tricks for community growth and management, including how to best use Groups, events, and other LinkedIn features and applications. Offers a

  20. Link Analysis in the Mission Planning Lab

    Science.gov (United States)

    McCarthy, Jessica A.; Cervantes, Benjamin W.; Daugherty, Sarah C.; Arroyo, Felipe; Mago, Divyang

    2011-01-01

    The legacy communications link analysis software currently used at Wallops Flight Facility involves processes that are different for command destruct, radar, and telemetry. There is a clear advantage to developing an easy-to-use tool that combines all the processes in one application. Link Analysis in the Mission Planning Lab (MPL) uses custom software and algorithms integrated with Analytical Graphics Inc. Satellite Toolkit (AGI STK). The MPL link analysis tool uses pre/post-mission data to conduct a dynamic link analysis between ground assets and the launch vehicle. Just as the legacy methods do, the MPL link analysis tool calculates signal strength and signal- to-noise according to the accepted processes for command destruct, radar, and telemetry assets. Graphs and other custom data are generated rapidly in formats for reports and presentations. STK is used for analysis as well as to depict plume angles and antenna gain patterns in 3D. The MPL has developed two interfaces with the STK software (see figure). The first interface is an HTML utility, which was developed in Visual Basic to enhance analysis for plume modeling and to offer a more user friendly, flexible tool. A graphical user interface (GUI) written in MATLAB (see figure upper right-hand corner) is also used to quickly depict link budget information for multiple ground assets. This new method yields a dramatic decrease in the time it takes to provide launch managers with the required link budgets to make critical pre-mission decisions. The software code used for these two custom utilities is a product of NASA's MPL.

  1. Integrated Space Asset Management Database and Modeling

    Science.gov (United States)

    Gagliano, L.; MacLeod, T.; Mason, S.; Percy, T.; Prescott, J.

    Phased Array of Widely Separated Antennas: Steps Toward a Verifiable Real-Time Atmospheric Phase Fluctuation Correction for a High Resolution Radar System Barry Geldzahler, NASA- HQ NASA is pursuing a demonstration of coherent uplink arraying at 7.145-7.190 GHz (X-band) and 30-31 GHz (Ka-band) at using three 12m diameter COTS antennas separated by 60m at the Kennedy Space Center in Florida. In addition, we have used up to three 34m antennas separated by ~250m at the Goldstone Deep Space Communication Complex in California and at X-band 7.1 GHz incorporating real-time correction for tropospheric phase fluctuations. Such a demonstration would then enable NASA to establish a high power, high resolution, 24/7 availability radar system for (a) tracking and characterizing observations of Near Earth Objects, (b) tracking, characterizing and determining the statistics of small-scale (?10cm) orbital debris, (c) incorporating the capability into its space communication and navigation tracking stations for emergency spacecraft commanding in the Ka band era which NASA is entering, and (d) fielding capabilities of interest to other US government agencies. We present herein the results of our phased array uplink combining at near 7.17 and 8.3 GHz using widely separated antennas demonstrations at both locales, the results of a study to upgrade from a communication to a radar system, and our vision for going forward. Operations Analysis of Australian-based Systems for Surveillance of Space Mark Graham, Defence Science and Technology Group, Department of Defence Due to increasing dependence on space-based capabilities, in recent years Australia has committed to making a greater contribution to generating space situational awareness (SSA). A natural first step has been to acknowledge Australia's privileged geolocation and accept US invitations to host and jointly operate elements of the Space Surveillance Network (SSN), in particular a C-Band tracking radar to help maintain the Low Earth

  2. Knots and links

    CERN Document Server

    Rolfsen, Dale

    2003-01-01

    Rolfsen's beautiful book on knots and links can be read by anyone, from beginner to expert, who wants to learn about knot theory. Beginners with a basic background find an inviting introduction to the elements of topology, emphasizing the tools needed for understanding knots, the fundamental group and van Kampen's theorem, for example, which are then applied to concrete problems, such as computing knot groups. For experts, Rolfsen explains advanced topics, such as the connections between knot theory and surgery and how they are useful to understanding three-manifolds. Besides providing a guide

  3. The weakest link

    Energy Technology Data Exchange (ETDEWEB)

    Lumley, G. [GBI Consulting, Qld. (Australia)

    2005-08-01

    In part seven of his series on dragline productivity, the author tackles the subject of the dump rope, the weakest link in the operation of the dragline, is traded. Five factors have been identified as critical to dump life: ratio of dump block to dump rope diameter; excessive loads in dumps rope; rope abrasion against dump block; rope abrasion against bucket; dump rope construction. These factors are considered in the article. The author comments that in the drive to increase dragline productivity, rope life has been sacrificed. 4 figs., 1 tab.

  4. Linking consumer experiences

    DEFF Research Database (Denmark)

    Smed, Karina Madsen

    Consumers consume products in various ways serving a number of purposes. Much attention has been paid to experiences attached to consumption, sometimes very explicitly, e.g. in tourism, the essence of which is experiences of various sorts, but often also implicitly as internalised experiences...... become part of the individual self, worldview, and behaviour. This paper seeks to explore links between consumer experiences through the exploration of narrative sequences in travel blogs. Findings indicate that non-consumption is a central element to the bloggers and also indicative of a community...

  5. EEE Links. Volume 5

    Science.gov (United States)

    Humphrey, Robert (Editor)

    1999-01-01

    The EEE Links Newsletter is a quarterly publication produced by Code 562 in support of the NASA HQ funded NASA Electronic Parts and Packaging (NEPP) Program. The newsletter is produced as an electronic format deliverable made available via the referenced www site administered by Code 562, The newsletter publishes brief articles on topics of interest to NASA programs and projects in the area of electronic parts and packaging. The newsletter does not provide information pertaining to patented or proprietary information. The information provided is at the level of that produced by industry and university researchers and is published at national and international conferences.

  6. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Projects » Learn the Link - Drugs and HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 – ... and to help us Send the Message . Get the Facts What are HIV and AIDS? HIV (human ...

  7. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... the link between drug abuse and HIV infection. It contains information for young people, parents and teachers, ... present time. The virus (HIV) and the disease it causes (AIDS) are often linked and referred to ...

  8. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... the Link - Drugs and HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 –Ongoing Behaviors ... GA: CDC, DHHS. Retrieved June 2012 How are Drug Abuse and HIV Related? Drug abuse and addiction ...

  9. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... the Link - Drugs and HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 –Ongoing Behaviors ... GA: CDC, DHHS. Retrieved June 2012 How are Drug Abuse and HIV Related? Drug abuse and addiction ...

  10. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... the link between drug abuse and HIV infection. It contains information for young people, parents and teachers, ... present time. The virus (HIV) and the disease it causes (AIDS) are often linked and referred to ...

  11. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Projects » Learn the Link - Drugs and HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 – ... and to help us Send the Message . Get the Facts What are HIV and AIDS? HIV (human ...

  12. Linking quality goals and product development competences

    DEFF Research Database (Denmark)

    Olsen, Johanne Rønnow; Harmsen, Hanne; Friis, Alan

    2008-01-01

    Quality is a main determinant of consumer food choice. Product development is accordingly a key activity for companies, because it generates the products on the quality of which consumer choices are based. In this respect, product development managers have a focal role, as their personal quality......, including reversed laddering sessions with 18 product development managers. Discrepancies between managerial and consumer quality goals are uncovered. Furthermore, the results point to two general dilemmas faced by product development managers in relation to quality; an external stakeholder dilemma...... orientation influence the way product development is performed. The aim of this paper is to investigate managerial quality goals and how these may be linked to product development competences, which has not previously been studied. The study draws on an empirical, qualitative study in the Danish food industry...

  13. ITK optical links backup document

    CERN Document Server

    Huffman, B T; The ATLAS collaboration; Flick, T; Ye, J

    2013-01-01

    This document describes the proposed optical links to be used for the ITK in the phase II upgrade. The current R&D for optical links pursued in the Versatile Link group is reviewed. In particular the results demonstrating the radiation tolerance of all the on-detector components are documented. The bandwidth requirements and the resulting numerology are given.

  14. Hyperbolic semi-adequate links

    OpenAIRE

    Futer, David; Kalfagianni, Efstratia; Purcell, Jessica S.

    2013-01-01

    We provide a diagrammatic criterion for semi-adequate links to be hyperbolic. We also give a conjectural description of the satellite structures of semi-adequate links. One application of our result is that the closures of sufficiently complicated positive braids are hyperbolic links.

  15. Diversity Management

    DEFF Research Database (Denmark)

    Ravazzani, Silvia

    2016-01-01

    This entry provides an overview of diversity management which, in the context of organizations, consists in the strategic process of harnessing the potential of all employees to create an inclusive environment and, at the same time, contribute to meeting organizational goals. The entry first...... describes the complex construct of diversity that has been variously conceptualized in the literature, embracing multiple social and informational diversity dimensions such as gender, age, culture, values, and workstyle. This is followed by illustration of the historical development of diversity-management...... discourse and practice, and possible overarching approaches guiding organizations. It goes on to elucidate elements linked to the implementation of diversity management: positive and negative outcomes, most spread practices including communication, and contingency factors shaping the understanding...

  16. Martel's links with USA

    Directory of Open Access Journals (Sweden)

    Trevor Shaw

    1997-01-01

    Full Text Available Of the 29% foreign members in the Société de Spéléologie, five lived in USA. They were Luella Owen (the only woman member of the Société, R. Ellsworth Cali, H.C. Hovey, E Van Epps and C. R. Blackall. E.S. Balch, though not a member, also knew Martel. These members, between them, published ten papers in Spelunca, which also reviewed their other work. The activities of these six, and their links with France, are discussed. Martel actively encouraged cave work in America, as elsewhere, and Hovey, who had been with him during the survey of Aven Armand, he knew quite well. In 1912 Martel at last visited USA himself and the barometer readings he took in Mamoth Cave to measure altitude enabled him to draw the first longitudinal section of the cave since 1835.

  17. Linking place and mind

    DEFF Research Database (Denmark)

    Jensen, Marie Møller

    2016-01-01

    This paper investigates the salience of vernacular Tyneside forms on the basis of theories of enregisterment and exemplar processing. On one level, exemplar theory provides a psycholinguistic account of how the link between social value and linguistic features is possible. Conversely, integrating...... the notion of social value into exemplar theory extends the value of this originally cognitive theory to social domains. It is suggested that the association of social value and particular local, linguistic forms may contribute to the salience of these forms among local speakers. The empirical work reported...... here takes the form of a questionnaire study, which aims to uncover Tyneside inhabitants' awareness of forms as well as their affiliation with the local community. Results showed differences in frequency perceptions between participants themselves and others which indicate that speakers can identify...

  18. Ecosystem Management. A Management View

    DEFF Research Database (Denmark)

    Ravn-Jonsen, Lars

    The need for management of the marine ecosystem using a broad perspective has been recommended under a variety of names. This paper uses the term Ecosystem Management, which is seen as a convergence between the ecological idea of an organisational hierarchy and the idea of strategic planning...... with a planning hierarchy---with the ecosystem being the strategic planning level. Management planning requires, in order to establish a quantifiable means and ends chain, that the goals at the ecosystem level can be linked to operational levels; ecosystem properties must therefore be reducible to lower...... genetic relation. The population structure is below the ecosystem in terms of the planning level, and goals for the community's genetic structure cannot be meaningful defined without setting strategic goals at the ecosystem level for functional groups....

  19. Auditing dynamic links to online information resources.

    Science.gov (United States)

    Li, Jianhua; Cimino, James J

    2007-10-11

    The Columbia University Infobutton Manager (IM) is a system that provides dynamically generated, context-specific links between clinical information systems and online information resources. The resources range from local documents, to commercially available document sets and search engines. The links provided by the IM can be reliably created, but there is no guarantee that they will function reliably, since the resources to which they point are subject to unannounced changes and failures. We have developed a set of tools to audit the links periodically to determine if the resources are available and if the IM has sufficient information to generate all the links needed by its users. These tools have been in use since February, 2006 and have provided timely warnings on many occasions. These warnings have allowed us to correct problems with resource access before they became apparent to our users and often before the resource maintainers were aware of the problems. The tools have thus helped us provide clinicians with a dependable level of service.

  20. 高管团队社会网络与企业决策绩效的联系机制:理论整合的视角%The Link Mechanism of the Top Management Team Social Networks and Firm Decision-making Performance: Theoretical Integration Perspective

    Institute of Scientific and Technical Information of China (English)

    杨生斌; 段春龙; 张倩

    2013-01-01

    The relationship between the Top Management Team (TMT)social networks and the firm performance is one of the hot issues of domestic and international Strategic Human Resource Management researches in recent years. The decision-making performance of the TMT is the essential factor affecting the firm performance. Therefore, in this paper, with TMT social networks as the access point and with integrations of management roles theory and information theory, cognitive conflict theory and trust theory, the mechanism of the intrinsic link between the TMT social networks and business decision—making performance is discussed.%高层管理团队社会网络与企业绩效之间的关系,是近年来国内外战略人力资源管理研究的热点问题之一.高管团队决策绩效是影响企业绩效的一个非常重要的因素.文章以TMT社会网络为切入点,整合管理者角色理论、信息理论、认知冲突理论以及信任理论,探讨了TMT社会网络和企业决策绩效之间的内在联系机制.