Diamond Heat-Spreader for Submillimeter-Wave Frequency Multipliers
Lin, Robert H.; Schlecht, Erich T.; Chattopadhyay, Goutam; Gill, John J.; Mehdi, Imran; Siegel, Peter H.; Ward, John S.; Lee, Choonsup; Thomas, Bertrand C.; Maestrini, Alain
2010-01-01
The planar GaAs Shottky diode frequency multiplier is a critical technology for the local oscillator (LO) for submillimeter- wave heterodyne receivers due to low mass, tenability, long lifetime, and room-temperature operation. The use of a W-band (75-100 GHz) power amplifier followed by a frequency multiplier is the most common for submillimeter-wave sources. Its greatest challenge is to provide enough input power to the LO for instruments onboard future planetary missions. Recently, JPL produced 800 mW at 92.5 GHz by combining four MMICs in parallel in a balanced configuration. As more power at W-band is available to the multipliers, their power-handling capability be comes more important. High operating temperatures can lead to degradation of conversion efficiency or catastrophic failure. The goal of this innovation is to reduce the thermal resistance by attaching diamond film as a heat-spreader on the backside of multipliers to improve their power-handling capability. Polycrystalline diamond is deposited by hot-filament chemical vapor deposition (CVD). This diamond film acts as a heat-spreader to both the existing 250- and 300-GHz triplers, and has a high thermal conductivity (1,000-1,200 W/mK). It is approximately 2.5 times greater than copper (401 W/mK) and 20 times greater than GaAs (46 W/mK). It is an electrical insulator (resistivity approx. equals 10(exp 15) Ohms-cm), and has a low relative dielectric constant of 5.7. Diamond heat-spreaders reduce by at least 200 C at 250 mW of input power, compared to the tripler without diamond, according to thermal simulation. This superior thermal management provides a 100-percent increase in power-handling capability. For example, with this innovation, 40-mW output power has been achieved from a 250-GHz tripler at 350-mW input power, while the previous triplers, without diamond, suffered catastrophic failures. This breakthrough provides a stepping-stone for frequency multipliers-based LO up to 3 THz. The future work
On-Chip Power-Combining for High-Power Schottky Diode Based Frequency Multipliers
Siles Perez, Jose Vicente (Inventor); Chattopadhyay, Goutam (Inventor); Lee, Choonsup (Inventor); Schlecht, Erich T. (Inventor); Jung-Kubiak, Cecile D. (Inventor); Mehdi, Imran (Inventor)
2015-01-01
A novel MMIC on-chip power-combined frequency multiplier device and a method of fabricating the same, comprising two or more multiplying structures integrated on a single chip, wherein each of the integrated multiplying structures are electrically identical and each of the multiplying structures include one input antenna (E-probe) for receiving an input signal in the millimeter-wave, submillimeter-wave or terahertz frequency range inputted on the chip, a stripline based input matching network electrically connecting the input antennas to two or more Schottky diodes in a balanced configuration, two or more Schottky diodes that are used as nonlinear semiconductor devices to generate harmonics out of the input signal and produce the multiplied output signal, stripline based output matching networks for transmitting the output signal from the Schottky diodes to an output antenna, and an output antenna (E-probe) for transmitting the output signal off the chip into the output waveguide transmission line.
Microwave Frequency Multiplier
Velazco, J. E.
2017-02-01
High-power microwave radiation is used in the Deep Space Network (DSN) and Goldstone Solar System Radar (GSSR) for uplink communications with spacecraft and for monitoring asteroids and space debris, respectively. Intense X-band (7.1 to 8.6 GHz) microwave signals are produced for these applications via klystron and traveling-wave microwave vacuum tubes. In order to achieve higher data rate communications with spacecraft, the DSN is planning to gradually furnish several of its deep space stations with uplink systems that employ Ka-band (34-GHz) radiation. Also, the next generation of planetary radar, such as Ka-Band Objects Observation and Monitoring (KaBOOM), is considering frequencies in the Ka-band range (34 to 36 GHz) in order to achieve higher target resolution. Current commercial Ka-band sources are limited to power levels that range from hundreds of watts up to a kilowatt and, at the high-power end, tend to suffer from poor reliability. In either case, there is a clear need for stable Ka-band sources that can produce kilowatts of power with high reliability. In this article, we present a new concept for high-power, high-frequency generation (including Ka-band) that we refer to as the microwave frequency multiplier (MFM). The MFM is a two-cavity vacuum tube concept where low-frequency (2 to 8 GHz) power is fed into the input cavity to modulate and accelerate an electron beam. In the second cavity, the modulated electron beam excites and amplifies high-power microwaves at a frequency that is a multiple integer of the input cavity's frequency. Frequency multiplication factors in the 4 to 10 range are being considered for the current application, although higher multiplication factors are feasible. This novel beam-wave interaction allows the MFM to produce high-power, high-frequency radiation with high efficiency. A key feature of the MFM is that it uses significantly larger cavities than its klystron counterparts, thus greatly reducing power density and arcing
InP HEMT Integrated Circuits for Submillimeter Wave Radiometers in Earth Remote Sensing
Deal, William R.; Chattopadhyay, Goutam
2012-01-01
The operating frequency of InP integrated circuits has pushed well into the Submillimeter Wave frequency band, with amplification reported as high as 670 GHz. This paper provides an overview of current performance and potential application of InP HEMT to Submillimeter Wave radiometers for earth remote sensing.
Submillimeter Wave Antenna With Slow Wave Feed Line
DEFF Research Database (Denmark)
Zhurbenko, Vitaliy; Krozer, Viktor; Kotiranta, Mikko
2009-01-01
Submillimeter wave radiation, which is also referred to as terahertz radiation, has not been extensively explored until recently due to a lack of reliable components and devices in this frequency range. Current advances in technology have made it possible to explore this portion of the electromag...
Linewidth of submillimeter wave flux-flow oscillators
DEFF Research Database (Denmark)
Koshelets, V.P.; Shitov, S.V.; Shchukin, A.V.
1996-01-01
A reliable technique for wide band measurements of the spectral linewidth of superconducting oscillators integrated on-chip with superconductor-insulator-superconductor (SIS) detectors has been, developed, The spectral linewidth of flux-flow oscillators (FFO) based on the unidirectional and visco...... reference source has been demonstrated. The proposed technique may improve the sensitivity, frequency resolution, and stability of the fully superconducting integrated submillimeter wave receiver. (C) 1996 American Institute of Physics....
Compact Receiver Front Ends for Submillimeter-Wave Applications
Mehdi, Imran; Chattopadhyay, Goutam; Schlecht, Erich T.; Lin, Robert H.; Sin, Seth; Peralta, Alejandro; Lee, Choonsup; Gill, John J.; Gulkis, Samuel; Thomas, Bertrand C.
2012-01-01
The current generation of submillimeter-wave instruments is relatively mass and power-hungry. The receiver front ends (RFEs) of a submillimeter instrument form the heart of the instrument, and any mass reduction achieved in this subsystem is propagated through the instrument. In the current implementation, the RFE consists of different blocks for the mixer and LO circuits. The motivation for this work is to reduce the mass of the RFE by integrating the mixer and LO circuits in one waveguide block. The mixer and its associated LO chips will all be packaged in a single waveguide package. This will reduce the mass of the RFE and also provide a number of other advantages. By bringing the mixer and LO circuits close together, losses in the waveguide will be reduced. Moreover, the compact nature of the block will allow for better thermal control of the block, which is important in order to reduce gain fluctuations. A single waveguide block with a 600- GHz RFE functionality (based on a subharmonically pumped Schottky diode pair) has been demonstrated. The block is about 3x3x3 cubic centimeters. The block combines the mixer and multiplier chip in a single package. 3D electromagnetic simulations were carried out to design the waveguide circuit around the mixer and multiplier chip. The circuit is optimized to provide maximum output power and maximum bandwidth. An integrated submillimeter front end featuring a 520-600-GHz sub-harmonic mixer and a 260-300-GHz frequency tripler in a single cavity was tested. Both devices used GaAs MMIC membrane planar Schottky diode technology. The sub-harmonic mixer/tripler circuit has been tested using conventional metal-machined blocks. Measurement results on the metal block give best DSB (double sideband) mixer noise temperature of 2,360 K and conversion losses of 7.7 dB at 520 GHz. The LO input power required to pump the integrated tripler/sub-harmonic mixer is between 30 and 50 mW.
T-shaped emitter metal heterojunction bipolar transistors for submillimeter wave applications
Fung, Andy; Samoska, Lorene; Velebir, Jim; Siege, Peter; Rodwell, Mark; Paidi, Vamsi; Griffth, Zach; Urteaga, Miguel; Malik, Roger
2004-01-01
We report on the development of submillimeter wave transistors at JPL. The goal of the effort is to produce advance-reliable high frequency and high power amplifiers, voltage controlled oscillators, active multipliers, and high-speed mixed-signal circuits for space borne applications. The technology in development to achieve this is based on the Indium Phosphide (InP) Heterojunction Bipolar Transistor (HBT). The HBT is well suited for high speed, high power and uniform (across wafer) performance, due to the ability to tailor the material structure that electrons traverse through by well-controlled epitaxial growth methods. InP with its compatible lattice matched alloys such as indium gallium arsenide (InGaAs) and indium aluminium arsenide (InAlAs) provides for high electron velocities and high voltage breakdown capabilities. The epitaxial methods for this material system are fairly mature, however the implementation of high performance and reliable transistors are still under development by many laboratories. Our most recently fabricated, second generation mesa HBTs at JPL have extrapolated current gain cutoff frequency (FJ of 142GHz and power gain cutoff frequency (Fm,) of approximately 160GHz. This represents a 13% and 33% improvement of Ft and F, respectively, compared to the first generation mesa HBTs [l]. Analysis based on the University of California, Santa Barbara (UCSB) device model, RF device characteristics can be significantly improved by reducing base contact resistance and base metal contact width. We will describe our effort towards increasing transistor performance and yield.
Submillimeter wave GaAs Schottky diode application based study and optimization for 0.1-1.5 THz
Jenabi, Sarvenaz; Malekabadi, Ali; Deslandes, Dominic; Boone, Francois; Charlebois, Serge A.
2017-08-01
In this paper, a design and optimization method for submillimeter-wave Schottky diode is proposed. Parasitic capacitance is significantly reduced to under 20% of the total capacitance of the diode. The parasitic capacitance value is measured to be 0.6 fF for 1 μm anode radius which increased the cut-off frequency to 1.5 THz. A corresponding microfabrication process that provides higher degrees of freedom for the anode diameter, air-bridge dimensions and distance to the substrate is introduced and implemented. The DC and RF measurements are provided and compared with the simulations. In order to provide a better understanding of the diode behavior, the limiting factors of the cut-off frequency for different applications are studied and compared. For the mixer/multiplier mode, an improved and expanded formulation for calculation of the cut-off frequency is introduced. It is shown that the usable voltage bias range (with acceptable cut-off frequency) is limited by the exponential reduction of junction resistance, Rj , in mixer/multiplier mode.
A LOW-PHASE NOISE FREQUENCY MULTIPLIER CHAIN ...
African Journals Online (AJOL)
ABSTRACT. In this paper a low phase-noise frequency multiplier chain from lOMHz to 480MHz, built in two stages and intended for use as a base for the synthesis of frequencies upto the far infrared. (FIR) region, is presented. Different methods of frequency multiplication were used and the associated circuit diagrams given.
Quantum noise frequency correlations of multiply scattered light
DEFF Research Database (Denmark)
Lodahl, Peter
2006-01-01
Frequency correlations in multiply scattered light that are present in quantum fluctuations are investigated. The speckle correlations for quantum and classical noise are compared and are found to depend markedly differently on optical frequency, which was confirmed in a recent experiment....... Furthermore, novel mesoscopic correlations are predicted that depend on the photon statistics of the incoming light....
Observational Approach to Molecular Cloud Evolutation with the Submillimeter-Wave CI Lines
Oka, T.; Yamamoto, S.
Neutral carbon atoms (CI) play important roles both in chemistry and cooling processes of interstellar molecular clouds. It is thus crucial to explore its large area distribution to obtain information on formation processes and thermal balance of molecular clouds. However, observations of the submillimeter-wave CI lines have been limited to small areas around some representative objects. We have constructed a 1.2 m submillimeter-wave telescope at the summit of Mt.Fuji. The telescope was designed for the exclusive use of surveying molecular clouds in two submillimeter-wave CI lines, 3 P1 -3 P0 (492GHz) and 3 P2 -3 P1 (809 GHz), of atomic carbon. A superconductor-insulator-superconductor (SIS) mixer receiver was equipped on the Nasmyth focus of the telescope. The receiver noise temperatures [Trx(DSB)] are 300 K and 1000 K for the 492 GHz and the 809 GHz mixers, respectively. The intermediate frequency is centered at 2 GHz, having a 700 MHz bandwidth. An acousto-optical spectrometer (AOS) with 1024 channel outputs is used as a receiver backend. The telescope was installed at Nishi-yasugawara (alt. 3725 m), which is 200 m north of the highest peak, Kengamine (3776 m), in July 1998. It has b en operatede successfully during 4 observing seasons in a remote way from the Hongo campus of the University of Tokyo. We have already observed more than 40 square degrees of the sky with the CI 492 GHz line. The distribution of CI emission is found to be different from those of the 13 CO or C1 8 O emission in some clouds. These differences are discussed in relation to formation processes of molecular clouds.
A Frequency Multiplier Based on Time Recursive Processing
Directory of Open Access Journals (Sweden)
D. M. Perisic
2017-12-01
Full Text Available This paper describes a digital frequency multiplier for a pulse rate. The multiplier is based on the recursive processing of the input and output periods and their time differences. Special emphasis is devoted to the techniques which provide the development of multipliers based on this principle. The circuit is defined by two system parameters. One is the ratio of two clock frequencies and the other is a division factor of a binary counter. The realization of the circuit is described. The region of the system parameters for the stable circuit is presented. The different aspects of applications and limitations in realization of the circuit are considered. All mathematical analyses are made using a Z transform approach. It is shown that the circuit can be also used in tracking and prediction applications. Computer simulations are performed to prove the correctness of the math and the whole approach.
A low-cost fabrication method for sub-millimeter wave GaAs Schottky diode
Jenabi, Sarvenaz; Deslandes, Dominic; Boone, Francois; Charlebois, Serge A.
2017-10-01
In this paper, a submillimeter-wave Schottky diode is designed and simulated. Effect of Schottky layer thickness on cut-off frequency is studied. A novel microfabrication process is proposed and implemented. The presented microfabrication process avoids electron-beam (e-beam) lithography which reduces the cost. Also, this process provides more flexibility in selection of design parameters and allows significant reduction in the device parasitic capacitance. A key feature of the process is that the Schottky contact, the air-bridges, and the transmission lines, are fabricated in a single lift-off step. This process relies on a planarization method that is suitable for trenches of 1-10 μm deep and is tolerant to end-point variations. The fabricated diode is measured and results are compared with simulations. A very good agreement between simulation and measurement results are observed.
The role of THz and submillimeter wave technology in DHS
Coty, Thomas; Fuller-Tedeschi, Anna
2011-06-01
THz and submillimeter wave technology is of great interest to DHS S&T due to the non-ionizing and clothing penetrating properties of the spectral region. Imaging in the region allows for standoff imaging of concealed threats such as Improvised Explosive Devices (IED) at operationally relevant distances. DHS S&T is investing in this area with the development of components such as detectors and sources for active imaging as well as full sensor systems in the future. The fundamental characterization of the region is also being explored with DHS funding by imaging well-characterized rough surface scattering targets. Analysis of these images will yield data to be used in evaluating assumptions currently made in current performance models. This along with the relevant field applications will be addressed.
A 260-340 GHz Dual Chip Frequency Tripler for THz Frequency Multiplier Chains
Maestrini, Alain; Tripon-Canseliet, Charlotte; Ward, John S.; Gill, John J.; Mehdi, Imran
2006-01-01
We designed and fabricated a fix-tuned balanced frequency tripler working in the 260-340 GHz band to be the first stage of a x3x3x3 multiplier chain to 2.7 THz. The design of a dual-chip version of this multiplier featuring an input splitter / output combiner as part of the input / output matching networks of both chips - with no degradation of the expected bandwidth and efficiency- will be presented.
Demonstration of a phase-lockable microwave to submillimeter wave sweeper
Waltman, Steve B.; Hollberg, Leo W.; McIntosh, Alexander K.; Brown, Elliott R.
1996-12-01
The development of low-temperature-grown GaAs photomixers enables the construction of a microwave to submillimeter- wave source capable of large frequency sweeps. By utilizing semiconductor diode lasers to drive the photomixer, this source is all solid-state and compact, and has small power consumption. Frequency stabilization of the semiconductor diode lasers allows this source to be phase-locked to an external microwave reference. Two 805 nm extended-cavity- diode lasers are mixed in a low-temperature-grown GaAs photoconductive photomixer. The difference-frequency mixing product is radiated by a planar spiral antenna and collimated by a Si lens. This output is phase-locked to a microwave reference by downconverting it in a whisker- contacted Schottky-barrier diode harmonic mixer and using the output to offset-phase-lock one laser to the other. The photomixer output power is 300 nW at 200 GHz and 10 nW at 1.6 THz, as measured by a 4 K InSb bolometer calibrated with a methanol laser and a power meter at 526 and 812 GHz.
Monolithic watt-level millimeter-wave diode-grid frequency tripler array
Hwu, R. J.; Luhmann, N. C., Jr.; Rutledge, D. B.; Hancock, B.; Lieneweg, U.
1988-01-01
In order to provide watt-level CW output power throughout the millimeter and submillimeter wave region, thousands of solid-state diodes have been monolithically integrated using a metal grid to produce a highly efficient frequency multiplier. Devices considered include GaAs Schottky diodes, thin MOS diodes, and GaAs Barrier-Intrinsic-N(+)diodes. The performance of the present compact low-cost device has been theoretically and experimentally validated.
A low-phase noise frequency multiplier chain | Abdo | Zede Journal
African Journals Online (AJOL)
'In this paper a low phase-noise frequency multiplier chain from lOMHz to 480MHz, built in two stages and intended for use as a base for the synthesis of frequencies upto the far infrared (FIR) region, is presented. Different methods of frequency multiplication were used and the associated circuit diagrams given.
Limitations in THz Power Generation with Schottky Diode Varactor Frequency Multipliers
DEFF Research Database (Denmark)
Krozer, Viktor; Loata, G.; Grajal, J.
2002-01-01
, at increasing frequencies the power drops with f-3 instead of the f-2 predicted by theory. In this contribution we provide an overview of state-of-the-art results. A comparison with theoretically achievable multiplier performance reveals that the devices employed at higher frequencies are operating...
Aripin, Haji; Mitsudo, Seitaro; Sudiana, I. Nyoman; Tani, Shinji; Sako, Katsuhide; Fujii, Yutaka; Saito, Teruo; Idehara, Toshitaka; Sabchevski, Sliven
2011-06-01
In this paper, we present and discuss experimental results from a microwave sintering of a silica-glass ceramic, produced from a silica xerogel extracted from a sago waste ash. As a radiation source for the microwave heating a sub-millimeter wave gyrotron (Gyrotron FU CW I) with an output frequency of 300 GHz has been used. The powders of silica xerogel have been dry pressed and then sintered at temperatures ranging from 300°C to 1500°C. The influence of the sintering temperature on the technological properties such as porosity and bulk density was studied in detail. Furthermore, X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy have been used in order to study the structure of the produced silica glass-ceramics. It has been found that the silica xerogel crystallizes at a temperature of 800°C, which is about 200°C lower than the one observed in the conventional process. The silica xerogel samples sintered by their irradiation with a sub-millimeter wave at 900°C for 18 minutes are fully crystallized into a silica glass-ceramic with a density of about 2.2 g/cm3 and cristobalite as a major crystalline phase. The results obtained in this study allow one to conclude that the microwave sintering with sub-millimeter waves is an appropriate technological process for production of silica glass-ceramics from a silica xerogel and is characterized with such advantages as shorter times of the thermal cycle, lower sintering temperatures and higher quality of the final product.
Novel transmission lines for the submillimeter-wave region
Katehi, Linda P. B.
1992-01-01
Accounts are given of the two approaches to the design of low-loss sub-mm-wave transmission lines for intelligent computer control guidance, command systems for space applications, and sensors operating in an optically opaque environment. These are: (1) the extension of the mm-wave monolithic technology to higher frequencies, although this approach is restricted to the lower end of the sub-mm spectrum, up to 500 GHz, due to ohmic losses; and (2) the extension of optical techniques to lower frequencies. This second approach is also limited, to the higher end of the sub-mm spectrum. Available characterizations of these technologies' electrical properties are presented.
Bulk submillimeter-wave mixers: Strain and superlattices
Litvak, M. M.; Pickett, H. M.
1980-01-01
Strained germanium crystals, doped with gallium, were used as heterodyne mixers at THz frequencies, with infrared bandwidths approaching a GHz. The mixer performance (conversion loss and mixer noise) was analyzed in terms of nonlinearities associated with acceptor levels and with relaxation rates of free holes. Comparison was made with similar mixers employing low lying donor levels in high purity GaAs and with hot electron InSb mixers.
New technologies for the detection of millimeter and submillimeter waves
Energy Technology Data Exchange (ETDEWEB)
Richards, P.L.; Clarke, J.; Gildemeister, J.M.; Lanting, T.; Lee, A.T.; Myers, M.J.; Schwan, D.; Skidmore, J.T.; Spieler, H.G.; Yoon, Jongsoo
2001-09-20
Voltage-biased superconducting bolometers have many operational advantages over conventional bolometer technology including sensitivity, linearity, speed, and immunity from environmental disturbance. A review is given of the Berkeley program for developing this new technology. Developments include fully lithographed individual bolometers in the spiderweb configuration, arrays of 1024 close-packed absorber-coupled bolometers, antenna-coupled bolometers, and a frequency-domain SQUID readout multiplexer.
On-Chip Power-Combining for High-Power Schottky Diode-Based Frequency Multipliers
Chattopadhyay, Goutam; Mehdi, Imran; Schlecht, Erich T.; Lee, Choonsup; Siles, Jose V.; Maestrini, Alain E.; Thomas, Bertrand; Jung, Cecile D.
2013-01-01
A 1.6-THz power-combined Schottky frequency tripler was designed to handle approximately 30 mW input power. The design of Schottky-based triplers at this frequency range is mainly constrained by the shrinkage of the waveguide dimensions with frequency and the minimum diode mesa sizes, which limits the maximum number of diodes that can be placed on the chip to no more than two. Hence, multiple-chip power-combined schemes become necessary to increase the power-handling capabilities of high-frequency multipliers. The design presented here overcomes difficulties by performing the power-combining directly on-chip. Four E-probes are located at a single input waveguide in order to equally pump four multiplying structures (featuring two diodes each). The produced output power is then recombined at the output using the same concept.
Directory of Open Access Journals (Sweden)
M. Kasal
2006-06-01
Full Text Available A novel method for the optimization of the active frequency multiplier utilizing the harmonic terminating impedances with the defected ground structures (DGS has been developed. Furthermore, a new type of the low-pass filter with DGS for the higher harmonic suppression will be reported. Experimental conversion gains (14.52 dB for the doubler, 5.56 dB for the tripler and 0.43 dB for the quadrupler and real power-added efficiency (32.76 % for the doubler, 10.15 % for the tripler and 1.42 % for the quadrupler have been attained. To our knowledge, in the considered frequency range, these results represent the best performance reported up to date for the active frequency multipliers utilizing the low-cost BJTs.
Effect of cooling on the efficiency of Schottky varactor frequency multipliers at millimeter waves
Louhi, Jyrki; Raiesanen, Antti; Erickson, Neal
1992-01-01
The efficiency of the Schottky diode multiplier can be increased by cooling the diode to 77 K. The main reason for better efficiency is the increased mobility of the free carriers. Because of that the series resistance decreases and a few dB higher efficiency can be expected at low input power levels. At high output frequencies and at high power levels, the current saturation decreases the efficiency of the multiplication. When the diode is cooled the maximum current of the diode increases and much more output power can be expected. There are also slight changes in the I-V characteristic and in the diode junction capacitance, but they have a negligible effect on the efficiency of the multiplier.
Energy Technology Data Exchange (ETDEWEB)
Okubo, S. [Kobe Univ., Graduate School of Science and Technology, Kobe, Hyogo (Japan); Goto, T.; Tanaka, T.; Ohta, H. [Kobe Univ. (Japan). Dept. of Physics; Mogi, I.; Watanabe, K.; Motokawa, M. [Tohoku Univ., Sendai (Japan). Inst. for Materials Research
1999-07-01
To gain information of anisotropy of Ho{sub 2}Cu{sub 2}O{sub 5} the aligned powder sample was prepared under the static high magnetic field of 5T. Millimeter and submillimeter wave ESR measurements of aligned Ho{sub 2}Cu{sub 2}O{sub 5} samples have been performed for the first time in the frequency region from 50 to 430 GHz using the pulsed magnetic field up to 16T at 1.8K. Antiferromagnetic resonances were observed clearly at 1.8K. AFMR modes of easy axis change at two critical fields. The temperature dependence measurements were also performed and the Neel temperature of the system is discussed. (author)
EPR and AFMR of Bi2CuO4 in Submillimeter Wave Region
Ohta, Hitoshi; Yoshida, Kazuhiro; Matsuya, Takashi; Nanba, Takao; Motokawa, Mitsuhiro; Yamada, Kazuyoshi; Endoh, Yasuo; Hosoya, Shoichi
1992-08-01
Paramagnetic and antiferromagnetic resonance have been observed in single crystals of Bi2CuO4 in submillimeter wave region using pulsed magnetic fields at temperatures from 4.2 K to 265 K. At the paramagnetic state, g-values have been determined to be g//{=}2.26± 0.01 and g\\bot{=}2.04± 0.01. The angular independent line-widths are 0.37± 0.03 T which is quantitatively explained by the dipole interaction and anisotropic exchange interaction. An antiferromagnetic resonance mode of planer type antiferromagnet has been observed below the Néel temperature and explained by the conventional antiferromagnetic theory.
DEFF Research Database (Denmark)
Zhao, Ying; Deng, Lei; Pang, Xiaodan
2011-01-01
We present a W-band fiber-wireless transmission system based on a nonlinear frequency multiplier for high-speed wireless short range access applications. By implementing a baseband digital signal predistortion scheme, intensive nonlinear distortions induced in a sextuple frequency multiplier can...... be effectively pre-compensated. Without using costly W-band components, a transmission system with 26km fiber and 4m wireless transmission operating at 99.6GHz is experimentally validated. Adjacent-channel power ratio (ACPR) improvements for IQ-modulated vector signals are guaranteed and transmission...
Directory of Open Access Journals (Sweden)
V. V. Konashchuk
2013-07-01
Full Text Available The article studies functioning of the scheme of transformation power through the converter wind-power installations during emergency operation. The main types of emergencies for this converter are considered. An approach to the calculation of short-circuit current of a synchronous generator and short-circuit current of an LC-circuit is presented. Protection elements (voltage limiters, fuses, fast current sensors are given for circuit protection and the reliability in emergency conditions is offered. Unlike classic circuit diagrams for wind-power installations, the circuit diagrams without multiplying gear for turbo-generator wind-рower installations have a self-stabilization effect of electromechanical system under optimal conditions in a wide range of a wind flow. In order to improve its effectiveness and implement an offline mode, you need to use converters to match the frequency of the generator voltage and that the frequency of network. Circuit diagrams of such converters have a complex structure, they contain a number of power supplies and rectifiers, capacitive storages, pulse converters and multi-level inverters.
A retrieval algorithm of hydrometer profile for submillimeter-wave radiometer
Liu, Yuli; Buehler, Stefan; Liu, Heguang
2017-04-01
Vertical profiles of particle microphysics perform vital functions for the estimation of climatic feedback. This paper proposes a new algorithm to retrieve the profile of the parameters of the hydrometeor(i.e., ice, snow, rain, liquid cloud, graupel) based on passive submillimeter-wave measurements. These parameters include water content and particle size. The first part of the algorithm builds the database and retrieves the integrated quantities. Database is built up by Atmospheric Radiative Transfer Simulator(ARTS), which uses atmosphere data to simulate the corresponding brightness temperature. Neural network, trained by the precalculated database, is developed to retrieve the water path for each type of particles. The second part of the algorithm analyses the statistical relationship between water path and vertical parameters profiles. Based on the strong dependence existing between vertical layers in the profiles, Principal Component Analysis(PCA) technique is applied. The third part of the algorithm uses the forward model explicitly to retrieve the hydrometeor profiles. Cost function is calculated in each iteration, and Differential Evolution(DE) algorithm is used to adjust the parameter values during the evolutionary process. The performance of this algorithm is planning to be verified for both simulation database and measurement data, by retrieving profiles in comparison with the initial one. Results show that this algorithm has the ability to retrieve the hydrometeor profiles efficiently. The combination of ARTS and optimization algorithm can get much better results than the commonly used database approach. Meanwhile, the concept that ARTS can be used explicitly in the retrieval process shows great potential in providing solution to other retrieval problems.
Zhang, Hao; Dong, Shuai; Zhang, Yuan; He, Bo
In this paper, we investigate the intermediate-frequency oscillation in a SEPIC power-factor-correction (PFC) converter under one-cycle control. The converter operates in continuous conduction mode (CCM). A systematic method is proposed to analyze the bifurcation behavior and explain the inherent physical mechanism of the intermediate-frequency oscillation. Based on the nonlinear averaged model, the approximate analytical expressions of the nominal periodic equilibrium state are calculated with the help of Galerkin approach. Then, the stability of the system is judged by the Floquet theory and the Floquet multiplier movement of the monodromy matrix is analyzed to reveal the underlying mechanism of the intermediate-frequency oscillation behavior. In addition, Floquet multiplier sensitivity is proposed to facilitate the selection of key parameters with respect to system stability so as to guide the optimal design of the system. Finally, PSpice circuit experiments are performed to verify the above theoretical and numerical ones.
Sul, Onejae; Kim, Kyumin; Jung, Yungwoo; Choi, Eunsuk; Lee, Seung-Beck
2017-09-01
The ambipolar band structure of graphene presents unique opportunities for novel electronic device applications. A cycle of gate voltage sweep in a conventional graphene transistor produces a frequency-doubled output current. To increase the frequency further, we used various graphene doping control techniques to produce Dirac voltage engineered graphene channels. The various surface treatments and substrate conditions produced differently doped graphene channels that were integrated on a single substrate and multiple Dirac voltages were observed by applying a single gate voltage sweep. We applied the Dirac voltage engineering techniques to graphene field-effect transistors on a single chip for the fabrication of a frequency multiplier and a logic inverter demonstrating analog and digital circuit application possibilities.
A Compact 600 GHz Electronically Tunable Vector Measurement System for Submillimeter Wave Imaging
Dengler, Robert; Maiwald, Frank; Siegel, Peter H.
2006-01-01
The design of a complete vector measurement system being tested over 560-635 GHz is presented. The topics include: 1) Current State-of-the-Art in Vector Measurements; 2) Submillimeter Active Imaging Requirements; 3) 600 GHz Vector Measurement System; 4) 450 MHz IF Signal; 5) 450 MHz IF signal @ 1 kHz Res. BW; 6) 450 MHz IF Signal Mixed with Shifted 450 MHz Reference Signal; 7) Reference Signal Offset Generator; 8) Cavity Bandpass Filter; 9) Miniature Multistage Helical Filter; 10) X36 450 MHz Multiplier; 11) 600 GHz Test Setup; 12) 600 GHz Transmit Module; 13) 600 GHz Receive Module; 14) Performance Tests: Amplitude Stability & Dynamic Range; 15) Performance Tests: Phase Stability; 16) Stability at Imaging Bandwidths; 17) Phase Measurement Verification; and 18) The Next Step: Imaging.
Design of an All-Digital Synchronized Frequency Multiplier Based on a Dual-Loop (D/FLL Architecture
Directory of Open Access Journals (Sweden)
Maher Assaad
2012-01-01
Full Text Available This paper presents a new architecture for a synchronized frequency multiplier circuit. The proposed architecture is an all-digital dual-loop delay- and frequency-locked loops circuit, which has several advantages, namely, it does not have the jitter accumulation issue that is normally encountered in PLL and can be adapted easily for different FPGA families as well as implemented as an integrated circuit. Moreover, it can be used in supplying a clock reference for distributed digital processing systems as well as intra/interchip communication in system-on-chip (SoC. The proposed architecture is designed using the Verilog language and synthesized for the Altera DE2-70 development board. The experimental results validate the expected phase tracking as well as the synthesizing properties. For the measurement and validation purpose, an input reference signal in the range of 1.94–2.62 MHz was injected; the generated clock signal has a higher frequency, and it is in the range of 124.2–167.9 MHz with a frequency step (i.e., resolution of 0.168 MHz. The synthesized design requires 330 logic elements using the above Altera board.
A 60 GHz Frequency Generator Based on a 20 GHz Oscillator and an Implicit Multiplier
Zong, Z.; Babaie, M.; Staszewski, R.B.
2016-01-01
This paper proposes a mm-wave frequency generation technique that improves its phase noise (PN) performance and power efficiency. The main idea is that a fundamental 20 GHz signal and its sufficiently strong third harmonic at 60 GHz are generated simultaneously in a single oscillator. The desired 60
DEFF Research Database (Denmark)
Michaelsen, Rasmus Schandorph; Johansen, Tom Keinicke; Krozer, Viktor
2013-01-01
Instead of using frequency multipliers before a fundamental mixer, subharmonic mixers can be used. In order to develop novel subharmonic mixer architectures it is necessary to know the exact signal phase at the nonlinear element. The purpose of this paper is to generalize the description of the s......Instead of using frequency multipliers before a fundamental mixer, subharmonic mixers can be used. In order to develop novel subharmonic mixer architectures it is necessary to know the exact signal phase at the nonlinear element. The purpose of this paper is to generalize the description...
Solar Flash Sub-Millimeter Wave Range Spectrum Part Radiation Modeling
Directory of Open Access Journals (Sweden)
V. Yu. Shustikov
2015-01-01
Full Text Available Currently, solar flares are under observation on the RT-7.5 radio telescope of BMSTU. This telescope operates in a little-studied range of the spectrum, at wavelengths of 3.2 and 2.2 mm (93 and 140 GHz, thereby providing unique information about parameters of the chromosphere plasma and zone of the temperature minimum. Observations on various instruments provided relatively small amount of data on the radio emission flare at frequencies close to 93 GHz, and at frequency of 140 GHz such observations were not carried out. For these reasons, data collected from the RT-7.5 radio telescope are of high value (Shustikov et al., 2012.This work describes modeling and gives interpretation of the reason for raising flux density spectrum of sub-millimeter radio frequency emission using as an example the GOES flare of class M 5.3 occurred on 04.07.2012 in the active region 11515. This flare was observed on the RT-7.5 radio telescope of BMSTU and was described by Shustikov et al. (2012 and by Smirnova et al. (2013, where it has been suggested that the reason for raising radio frequency emission is a bremsstrahlung of the thermal electrons in the hot plasma of the solar chromosphere. Rough estimates of the plasma temperature at the flare source were obtained.This paper proposes model calculations of the flux density spectrum of the sub-millimeter radio emission based on the gyrosynchrotron Fleischman-Kuznetsov code (Fleishman & Kuznetsov, 2010. Section 1 briefly describes observational data, tools and processing methods used in the work. Section 2 shows results of modeling the flare radio emission. Section 3 discusses results and conclusions.Numerical modeling the sub-millimeter part of the spectrum of the radio flux density for the GOES flare of class M5.3 has been carried out. This flare occurred in the active region 11515 on 04.07.2012. Modeling was based on the observations on the BMSTU’s RT-7.5 radio telescope.The paper draws conclusion based on the
Directory of Open Access Journals (Sweden)
P. Baron
2011-10-01
Full Text Available This paper describes the algorithms of the level-2 research (L2r processing chain developed for the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES. The chain has been developed in parallel to the operational chain for conducting researches on calibration and retrieval algorithms. L2r chain products are available to the scientific community. The objective of version 2 is the retrieval of the vertical distribution of trace gases in the altitude range of 18–90 km. A theoretical error analysis is conducted to estimate the retrieval feasibility of key parameters of the processing: line-of-sight elevation tangent altitudes (or angles, temperature and ozone profiles. While pointing information is often retrieved from molecular oxygen lines, there is no oxygen line in the SMILES spectra, so the strong ozone line at 625.371 GHz has been chosen. The pointing parameters and the ozone profiles are retrieved from the line wings which are measured with high signal to noise ratio, whereas the temperature profile is retrieved from the optically thick line center. The main systematic component of the retrieval error was found to be the neglect of the non-linearity of the radiometric gain in the calibration procedure. This causes a temperature retrieval error of 5–10 K. Because of these large temperature errors, it is not possible to construct a reliable hydrostatic pressure profile. However, as a consequence of the retrieval of pointing parameters, pressure induced errors are significantly reduced if the retrieved trace gas profiles are represented on pressure levels instead of geometric altitude levels. Further, various setups of trace gas retrievals have been tested. The error analysis for the retrieved HOCl profile demonstrates that best results for inverting weak lines can be obtained by using narrow spectral windows.
Millimeter/submillimeter-wave spectrum of the VCl(+) radical in its X (4)Sigma(-) ground state.
Halfen, D T; Ziurys, L M
2009-11-26
The pure rotational spectrum of the molecular ion VCl(+) (X (4)Sigma(-)) has been recorded from 274 to 419 GHz using a combination of millimeter direct absorption and velocity modulation spectroscopy. This study is the first spectroscopic measurement of this species in the laboratory, which has also enabled the determination of the ground state term, (4)Sigma(-). VCl(+) was produced in an AC discharge of VCl(4) and argon. Fifteen and eleven rotational transitions were recorded for the V(35)Cl(+) and V(37)Cl(+) isotopologues, respectively. The fine structure splittings of the (4)Sigma(-) state were found to deviate significantly from a case (b) pattern. Specifically, spin components from adjacent rotational transitions were found to overlap in frequency. Unusual vanadium hyperfine splittings were also observed in the VCl(+) spectra; the expected vanadium octet was clearly present for the F(2) and F(3) spin components but was partially collapsed and reversed in frequency ordering in the F(1) and F(4) cases. The data were analyzed in a global fit, and rotational, fine structure, and hyperfine constants were determined. For VCl(+), the values of both the spin-spin and spin-rotation parameters are extremely large, as were the third-order hyperfine and spin-rotation terms, b(s) and gamma(s). For example, the spin-spin constant is lambda = 417 900(22 700) MHz, while gamma = 6567(51) MHz. The values of these constants indicate a high density of excited electronic states close to the ground state, which contribute to second and third-order spin-orbit coupling. The hyperfine constants suggest a sigma(1)pi(2) electron configuration, as opposed to sigma(1)delta(2), as found in VS and VO. The bond length of VCl(+), r(0) = 2.119(2) A, is shorter than that of VCl by 0.1 A, which has r(0) = 2.219 A. The decrease in bond length is attributed to an increase in the electrostatic attraction between V(2+) and Cl(-), as opposed to V(+) and Cl(-) for VCl.
Comprehensive Submillimeter Wave Studies of the Isotopic Species of a Major Weed: Methyl Formate
Margulès, L.; Motiyenko, R.; Huet, T. R.; Coudert, L. H.; Kleiner, I.; Carvajal, M.; Mollendal, H.; Guillemin, J.-C.
2010-06-01
Complex organic molecules are relatively heavy, their maximum absorption is in the millimetric domain at about 300 GHz. But the most abondant, like methyl formate, could be detected in the ISM up to 900 GHz. We will present here the last results obtained about the two 18O and the doubly-deuterated species of methyl formate. This concludes the systematic investigation up to 660 GHz for the mono-substituted isotopic species with either 13C, 18O, or D, which began in 2006. The lines from these isotopic species will certainly be present in the spectra which will be recorded in the next years with the very sensitive telescope ALMA, HERSHEL and SOFIA. The detection of isotopic species is very important for the astrophysical community to improve the interstellar chemical modeling and to understand the formation mechanism of these complex organic molecules. Our interest was also on the theoretical aspects. Like other complex organic molecules, methyl formate displays a large amplitude motion. Here it is the rotation of the methyl group with respect to the rest of the molecule. Theoretical models were developed to reproduce accurately the observed frequencies for large quantum numbers values as J-values as high as 70 could be reached. Similarly the investigation of the doubly-deuterated HCOOCHD_2 was undertaken to test the model developed for mono-deuterated HCOOCH_2D. This work is supported by ANR-08-BLAN-0054 and ANR-08-BLAN-0225. C. Comito, P. Schilke, T. G. Phillips, et al., Astrophys. J. Supp. 156 (2005) 127. L. Margulès, L. H. Coudert, H. Mollendal, et al., J. Mol. Spec. 254 (2009) 55.
DEFF Research Database (Denmark)
Zhao, Ying; Pang, Xiaodan; Deng, Lei
2011-01-01
We present a digital predistortion technique to effectively compensate high nonlinearity of a sextuple multiplier operating at 99.6GHz. An 18.9dB adjacent-channel power ratio (ACPR) improvement is guaranteed and a W-band fiber-wireless system is experimentally investigated.......We present a digital predistortion technique to effectively compensate high nonlinearity of a sextuple multiplier operating at 99.6GHz. An 18.9dB adjacent-channel power ratio (ACPR) improvement is guaranteed and a W-band fiber-wireless system is experimentally investigated....
2013-01-01
A few weeks ago, I had a vague notion of what TED was, and how it worked, but now I’m a confirmed fan. It was my privilege to host CERN’s first TEDx event last Friday, and I can honestly say that I can’t remember a time when I was exposed to so much brilliance in such a short time. TEDxCERN was designed to give a platform to science. That’s why we called it Multiplying Dimensions – a nod towards the work we do here, while pointing to the broader importance of science in society. We had talks ranging from the most subtle pondering on the nature of consciousness to an eighteen year old researcher urging us to be patient, and to learn from our mistakes. We had musical interludes that included encounters between the choirs of local schools and will.i.am, between an Israeli pianist and an Iranian percussionist, and between Grand Opera and high humour. And although I opened the event by announcing it as a day off from physics, we had a quite brill...
Golant, E I
2002-01-01
A mathematical model has been developed for electronic coherent tunneling through the triple-barrier quantum-dimensional semiconductor heterostructures in the terahertz electric field. Using this model the frequency dependences of the negative dynamic conductivity for triple-barrier structures with coherent electron tunneling through the split energy levels are investigated. It has been shown that these structures can be employed in far-infrared coherent quantum lasers, the wave length being 600 mu m (5 THz)
Baron, Philippe; Manago, Naohiro; Ozeki, Hiroyuki; Irimajiri, Yoshihisa; Murtagh, Donal; Uzawa, Yoshinori; Ochiai, Satoshi; Shiotani, Masato; Suzuki, Makoto
2015-10-01
Satellite missions for measuring winds in the troposphere and thermosphere will be launched in a near future. There is no plan to observe winds in the altitude range between 30-90 km, though middle atmospheric winds are recognized as an essential parameter in various atmospheric research areas. Sub-millimetre limb sounders have the capability to fill this altitude gap. In this paper, we summarize the wind retrievals obtained from the Japanese Superconducting Submillimeter Wave Limb Emission Sounder (SMILES) which operated from the International Space Station between September 2009 and April 2010. The results illustrate the potential of such instruments to measure winds. They also show the need of improving the wind representation in the models in the Tropics, and globally in the mesosphere. A wind measurement sensitivity study has been conducted for its successor, SMILES-2, which is being studied in Japan. If it is realized, sub-millimeter and terahertz molecular lines suitable to determine line-of-sight winds will be measured. It is shown that with the current instrument definition, line-of-sight winds can be observed from 20 km up to more than 160 km. Winds can be retrieved with a precision better than 5 ms-1 and a vertical resolution of 2-3 km between 35-90 km. Above 90 km, the precision is better than 10 ms-1 with a vertical resolution of 3-5 km. Measurements can be performed day and night with a similar sensitivity. Requirements on observation parameters such as the antenna size, the satellite altitude are discussed. An alternative setting for the spectral bands is examined. The new setting is compatible with the general scientific objectives of the mission and the instrument design. It allows to improve the wind measurement sensitivity between 35 to 90 km by a factor 2. It is also shown that retrievals can be performed with a vertical resolution of 1 km and a precision of 5-10 ms-1 between 50 and 90 km.
Pressure multiplying dispenser
DeFord, Henry S.; Moss, Owen R.
1986-01-01
A pressure multiplying dispenser for delivering fluid, preferably as a spray to the atmosphere, from a source of fluid, preferably a spray bottle, is described. The dispenser includes in combination a hollow cylindrical member, a nozzle delivery tube within the cylindrical member and a hollow actuator piston slideable within the cylindrical member which acts to multiply the pressure of a squeeze applied to the spray bottle.
Sidharth, B. G.
2006-01-01
It is now generally believed that our observable universe is one amongst a very large number - may be $10^{500}$ - of parallel universes. Following the author's own model in this context, we argue that this conglomeration of universes defines a multiply connected super space.
Flowers, William L., Jr.; Harris, John B.
1981-01-01
The multiplier effect is discussed as it applies to the field of continuing education. The authors' main point is that one grant or contract can, and should, be used as the basis for building organizational competencies and capabilities that will secure other funds. (Author/CT)
Pritha Mitra; Tigran Poghosyan
2015-01-01
Amid renewed crisis, falling tax revenues, and rising debt, Ukraine faces serious fiscal consolidation needs. Durable fiscal adjustment can support economic confidence and rebuild buffers but what is its overall impact on growth? How effective are revenue versus spending instruments? Does current or capital spending have a larger impact? Applying a structural vector autoregressive model, this paper finds that Ukraineâ€™s near-term revenue and spending multipliers are well below one. In the me...
Gabbiani, F.; Krapp, H.; Koch, C.; Laurent, G.
1998-03-01
LGMD and DCMD are a pair of identified neurons in the locust brain thought to be involved in visually triggered escape behavior. LGMD integrates visual inputs in its dendritic arbor, converts them into spikes transmitted in a 1:1 manner to DCMD which relays this information to motor centers. We measured the spike activity of DCMD during simulated object approach and observed that its peak occured prior to the expected collision. The time difference between peak activity and collision depended linearly on the ratio of object size to approach velocity, as expected if LGMD/DCMD were detecting the moment in time when the approaching object reaches a fixed angular threshold θ_thresh on the locust's retina. The response of LGMD/DCMD could be fitted by multiplying the angular velocity at which an approaching object is increasing in size over the retina, dot θ, with an exponential function of the object's angular size, θ: f(t) = g(dot θ(t-δ) e^-α θ(t-δ)) where g is a static non-linearity, α a constant related to the angular threshold detected by LGMD/DCMD (θ_thresh = arctan (2/α)) and δ denotes the lag of the neuronal response with respect to the stimulus. This suggests that LGMD/DCMD derives its angular threshold sensitivity by multiplying dot θ with an exponential of θ. A biophysical implementation would be through linear summation of excitatory and inhibitory inputs proportional to log(dot θ) and -α θ, followed by a conversion to spike rate according to the static non-linearity (g circ exp). We have performed several experiments to test this hypothesis.
Temperature Effects in Varactors and Multipliers
East, J.; Mehdi, Imran
2001-01-01
Varactor diode multipliers are a critical part of many THz measurement systems. The power and efficiencies of these devices limit the available power for THz sources. Varactor operation is determined by the physics of the varactor device and a careful doping profile design is needed to optimize the performance. Higher doped devices are limited by junction breakdown and lower doped structures are limited by current saturation. Higher doped structures typically have higher efficiencies and lower doped structures typically have higher powers at the same operating frequency and impedance level. However, the device material properties are also a function of the operating temperature. Recent experimental evidence has shown that the power output of a multiplier can be improved by cooling the device. We have used a particle Monte Carlo simulation to investigate the temperature dependent velocity vs. electric field in GaAs. This information was then included in a nonlinear device circuit simulator to predict multiplier performance for various temperatures and device designs. This paper will describe the results of this analysis of temperature dependent multiplier operation.
Last multipliers on Lie algebroids
Indian Academy of Sciences (India)
∗Stefan cel Mare University, Suceava, România. E-mail: mcrasm@uaic.ro; cristinah@usv.ro. MS received 27 March 2008; revised 4 September .... For example, in dimension 2, the notions of last multiplier and integrating factor are identical and Sophus Lie suggested a method to associate a last multiplier to every sym-.
VizieR Online Data Catalog: NH2CH2CN transition frequencies (Degli
Degli Esposti, C.; Dore, L.; Melosso, M.; Kobayashi, K.; Fujita, C.; Ozeki, H.
2017-08-01
The present experiments were carried out in two laboratories, at Bologna and Toho Universities, respectively. The experiment at Bologna was conducted in the frequency ranges 80-115 and 240-290GHz using a source-modulation millimeter/submillimeter-wave spectrometer. The experiment at Toho University was conducted in frequency regions complementary to those investigated in Bologna, reaching a frequency as high as 450GHz, with essentially the same apparatus and experimental conditions of the previous work (Motoki+ 2013, J/ApJS/209/23). (1 data file).
Multiplied Environmental Literacy. Final Report.
Buethe, Chris
This booklet presents a pupil-oriented program designed to increase the environmental literacy of teachers and students in Indiana schools through a programmed multiplier effect. Junior and senior high school science teachers were prepared to teach students the meanings of 44 selected environmental terms and related concepts. Those teachers then…
When is the government spending multiplier large?
Lawrence Christiano; Martin Eichenbaum; Sergio Rebelo
2010-01-01
We argue that the government-spending multiplier can be much larger than one when the zero lower bound on the nominal interest rate binds. The larger is the fraction of government spending that occurs while the nominal interest rate is zero, the larger is the value of the multiplier. After providing intuition for these results, we investigate the size of the multiplier in a dynamic, stochastic, general equilibrium model. In this model the multiplier effect is substantially larger than one whe...
Array Multipliers for High Throughput in Xilinx FPGAs with 6-Input LUTs
Directory of Open Access Journals (Sweden)
E. George Walters
2016-09-01
Full Text Available Multiplication is the dominant operation for many applications implemented on field-programmable gate arrays (FPGAs. Although most current FPGA families have embedded hard multipliers, soft multipliers using lookup tables (LUTs in the logic fabric remain important. This paper presents a novel two-operand addition circuit (patent pending that combines radix-4 partial-product generation with addition and shows how it can be used to implement two’s-complement array multipliers. The circuit is specific to modern Xilinx FPGAs that are based on a 6-input LUT architecture. Proposed pipelined multipliers use 42%–52% fewer LUTs, and some versions can be clocked up to 23% faster than delay-optimized LogiCORE IP multipliers. This allows 1.72–2.10-times as many multipliers to be implemented in the same logic fabric and potentially offers 1.86–2.58-times the throughput by increasing the clock frequency.
groups by their Schur multiplier
Indian Academy of Sciences (India)
22
A CHARACTERIZATION OF FINITE p-GROUPS BY THEIR SCHUR MULTIPLIER. 7. Now consider groups of order p7 of exponent p. By [14] it follows that there is only one capable group. G = 〈x1, ··· ,x5,c1,c2 | [x2,x1]=[x5,x3] = c1, [x3,x1]=[x5,x4] = c2〉 upto isomorphism. By Theorem 2.3 we have |M(G)| = p9 as |X| = |X1| = p9 ...
Operator valued integral multiplier functions | Fourie | Quaestiones ...
African Journals Online (AJOL)
In recent years, several papers were devoted to the study of (p, q)-summing sequences of operators and their applications in the theory of Banach spaces. In the present paper we initiate a similar study of “integral multiplier functions”, thereby introducing these spaces of operator valued multiplier functions as normed spaces ...
ON LU FACTORIZATION ALGORITHM WITH MULTIPLIERS
African Journals Online (AJOL)
In this paper, we propose a straightforward method based on multipliers derived from modification of. Gaussion elimination algorithm. KEY WORDS: Lower and Upper Triangular Matrices, Multipliers. INTRODUCTION. Let A be a square matrix of order n. An LU factorization or decomposition is a decomposition of the form:.
The gas electron multiplier (GEM)
Bouclier, Roger; Dominik, Wojciech; Hoch, M; Labbé, J C; Million, Gilbert; Ropelewski, Leszek; Sauli, Fabio; Sharma, A
1996-01-01
We describe operating priciples and results obtained with a new detector component: the Gas Electrons Multiplier (GEM). Consisting of a thin composite sheet with two metal layers separated by a thin insulator, and pierced by a regular matrix of open channels, the GEM electrode, inserted on the path of electrons in a gas detector, allows to transfer the charge with an amplification factor approaching ten. Uniform response and high rate capability are demonstrated. Coupled to another device, multiwire or micro-strip chamber, the GEM electrode permit to obtain higher gains or less critical operation; separation of the sensitive (conversion) volume and the detection volume has other advantages, as a built-in delay (useful for triggering purposes) and the possibility of applying high fields on the photo-cathode of ring imaging detectors to improve efficiency. Multiple GEM grids in the same gas volume allow to obtain large amplification factors in a succession of steps, leading to the realization of an effective ga...
Gaseous Electron Multiplier (GEM) Detectors
Gnanvo, Kondo
2017-09-01
Gaseous detectors have played a pivotal role as tracking devices in the field of particle physics experiments for the last fifty years. Recent advances in photolithography and micro processing techniques have enabled the transition from Multi Wire Proportional Chambers (MWPCs) and Drift Chambers to a new family of gaseous detectors refer to as Micro Pattern Gaseous Detectors (MPGDs). MPGDs combine the basic gas amplification principle with micro-structure printed circuits to provide detectors with excellent spatial and time resolution, high rate capability, low material budget and high radiation tolerance. Gas Electron Multiplier (GEMs) is a well-established MPGD technology invented by F. Sauli at CERN in 1997 and deployed various high energy physics (HEP) and nuclear NP experiment for tracking systems of current and future NP experiments. GEM detector combines an exceptional high rate capability (1 MHz / mm2) and robustness against harsh radiation environment with excellent position and timing resolution performances. Recent breakthroughs over the past decade have allowed the possibility for large area GEMs, making them cost effective and high-performance detector candidates to play pivotal role in current and future particle physics experiments. After a brief introduction of the basic principle of GEM technology, I will give a brief overview of the GEM detectors used in particle physics experiments over the past decades and especially in the NP community at Thomas Jefferson National Laboratory (JLab) and Brookhaven National Laboratory (BNL). I will follow by a review of state of the art of the new GEM development for the next generation of colliders such as Electron Ion Collider (EIC) or High Luminosity LHC and future Nuclear Physics experiments. I will conclude with a presentation of the CERN-based RD51 collaboration established in 2008 and its major achievements regarding technological developments and applications of MPGDs.
Imaging with the gas electron multiplier
Sauli, Fabio
2007-01-01
The Gas Electron Multiplier (GEM), introduced several years ago, is finding numerous applications thanks to its excellent performances in detecting and localizing ionizing radiation. This note summarizes recent developments of the technology, and presents some examples of applications.
Economic Multipliers and Mega-Event Analysis
Victor Matheson
2004-01-01
Critics of economic impact studies that purport to show that mega-events such as the Olympics bring large benefits to the communities “lucky” enough to host them frequently cite the use of inappropriate multipliers as a primary reason why these impact studies overstate the true economic gains to the hosts of these events. This brief paper shows in a numerical example how mega-events may lead to inflated multipliers and exaggerated claims of economic benefits.
Characterization of Material Properties at Terahertz Frequencies
National Research Council Canada - National Science Library
Giles, Robert H
1995-01-01
... a decade. Research in modeling radar requires design of a wide range of measurements systems using current submillimeter-wave source/detector technology, establishment of precise calibration standards...
Multiplier-free filters for wideband SAR
DEFF Research Database (Denmark)
Dall, Jørgen; Christensen, Erik Lintz
2001-01-01
This paper derives a set of parameters to be optimized when designing filters for digital demodulation and range prefiltering in SAR systems. Aiming at an implementation in field programmable gate arrays (FPGAs), an approach for the design of multiplier-free filters is outlined. Design results...
Fourier Multiplier Theorems Involving Type and Cotype
Rozendaal, J.; Veraar, M.C.
2017-01-01
In this paper we develop the theory of Fourier multiplier operators (Formula presented.), for Banach spaces X and Y, (Formula presented.) and (Formula presented.) an operator-valued symbol. The case (Formula presented.) has been studied extensively since the 1980s, but far less is known for
A 200 GHz tripler using a single barrier varactor
Choudhury, Debabani; Frerking, Margaret A.; Batelaan, Paul D.
1993-01-01
The GaAs Schottky varactor diode is the nonlinear device most commonly used for submillimeter wave harmonic generation. Output power adequate to serve as a local oscillator source for SIS tunnel junctions has been demonstrated with whisker-contacted GaAs Schottky varactor multipliers in waveguide mounts up to about 800 GHz. In this paper, we present results for a tripler to 200 GHz using a new multiplier device, the single barrier varactor (SBV). This new varactor has potential advantages such as stronger nonlinearities or special symmetry, which make it attractive for submillimeter wave frequency multiplication. The performance of a tripler using a SBV over a output frequency range from 186 to 207 GHz has been measured in a crossed waveguide mount. The theoretical performance of the device has been calculated using large signal analysis. A comparison of theoretical and measured results and a discussion of various losses in the mount and the varactor have also been presented.
A 200 GHz tripler using single barrier varactor
Choudhury, Debabani; Frerking, Margaret A.; Batelaan, Paul D.
1992-01-01
The GaAs Schottky varactor diode is the nonlinear device most commonly used for submillimeter wave harmonic generation. Output power adequate to serve as a local oscillator source for SIS tunnel junctions has been demonstrated with whisker-contacted GaAs Schottky varactor multipliers in waveguide mounts up to about 800 GHz. In this paper, we present results for a tripler to 200 GHz using a new multiplier device, the single barrier varactor (SBV). This new varactor has a potential advantages such as stronger nonlinearities or special symmetry, which make it attractive for submillimeter wave frequency multiplication. The performance of a tripler using a SBV over a output frequency range from 186 to 207 GHz has been measured in a crossed waveguide mount. The theoretical performance of the device has been calculated using large signal analysis. A comparison of theoretical and measured results and a discussion of various losses in the mount and the varactor have also been presented.
Measurement of plasma conductivity using faraday rotation of submillimeter waves
Energy Technology Data Exchange (ETDEWEB)
Kuzmenko, P.J.; Self, S.A.
1983-03-01
This paper examines the application of Faraday rotation to the measurement of electron combustion MHD plasmas. Details on the design of a working system are given, including the selection of operating wavelength. A theoretical comparison between the Faraday rotation technique and two-path interferometry shows Faraday rotation in its simplest form to be somewhat less sensitive to changes in electron concentration. This deficit can be balanced against greater immunity to vibration and thermal drift. Improved techniques of measuring the rotation angle promise greater sensitivity. A preliminary experiment has verified the technique.
Time-area efficient multiplier-free recursive filter architectures for FPGA implementation
DEFF Research Database (Denmark)
Shajaan, Mohammad; Sørensen, John Aasted
1996-01-01
Simultaneous design of multiplier-free recursive filters (IIR filters) and their hardware implementation in Xilinx field programmable gate array (XC4000) is presented. The hardware design methodology leads to high performance recursive filters with sampling frequencies in the interval 15-21 MHz (...
The power of fiscal multipliers in Croatia
Directory of Open Access Journals (Sweden)
Ana Grdović Gnip
2014-06-01
Full Text Available This paper investigates fiscal multipliers in Croatia in the period 1996Q1-2011Q4. For this purpose, a Blanchard Perotti three variable baseline SVAR is employed as a no regime-switch model, along with a four variable baseline STVAR as a regime-switch model. Results show that during recessions fiscal multipliers in Croatia tend to be much larger and move in line with Keynesian assumptions, i.e. a positive government spending shock increases output, private consumption and private investment, while oppositely a positive tax shock worsens the same macroeconomic variables. Moreover, during recession times government spending for purchases of goods and services seems to be the most effective fiscal instrument for boosting economic activity.
Peer Effects: Social Multiplier or Social Norms?
Liu, Xiaodong; Patacchini, Eleonora; Zenou, Yves
2013-01-01
We develop an unified model embedding different behavioral mechanisms of social interactions and design a statistical model selection test to discriminate between them in empirical applications. This framework is applied to study peer effects in education and delinquent behavior for adolescents in the United States. We find that there are strong social multiplier effects in crime while, for education, social norms matter the most. This suggests that, for crime, individual-based policies are m...
Automobile Industry Retail Price Equivalent and Indirect Cost Multipliers
This report develops a modified multiplier, referred to as an indirect cost (IC) multiplier, which specifically evaluates the components of indirect costs that are likely to be affected by vehicle modifications associated with environmental regulation. A range of IC multipliers a...
Searching for Biotic Multipliers of Climate Change.
Urban, Mark C; Zarnetske, Phoebe L; Skelly, David K
2017-07-01
As climates change, biologists need to prioritize which species to understand, predict, and protect. One way is to identify key species that are both sensitive to climate change and that disproportionately affect communities and ecosystems. These "biotic multipliers" provide efficient targets for research and conservation. Here, we propose eight mechanistic hypotheses related to impact and sensitivity that suggest that top consumers might often act as biotic multipliers of climate change. For impact, top consumers often affect communities and ecosystems through strong top-down effects. For sensitivity, metabolic theory and data suggest that photosynthesis and respiration differ in temperature responses, potentially increasing the sensitivity of consumers relative to plants. Larger-bodied organisms are typically more thermally sensitive than smaller ones, suggesting how large top consumers might be more sensitive than their smaller prey. In addition, traits related to predation are more sensitive than defensive traits to temperature. Top consumers might also be more sensitive because they often lag behind prey in phenological responses. The combination of low population sizes and demographic traits of top consumers could make them more sensitive to disturbances like climate change, which could slow their recovery. As top consumers are positioned at the top of the food chain, many small effects can accumulate from other trophic levels to affect top consumers. Finally, top consumers also often disperse more frequently and farther than prey, potentially leading to greater sensitivity to climate-induced changes in ranges and subsequent impacts on invaded communities. Overall, we expect that large, ectothermic top consumers and mobile predators might frequently be biotic multipliers of climate change. However, this prediction depends on the particular features of species, habitats, and ecosystems. In specific cases, herbivores, plants, or pathogens might be more
Multipliers on Generalized Mixed Norm Sequence Spaces
Directory of Open Access Journals (Sweden)
Oscar Blasco
2014-01-01
Full Text Available Given 1≤p,q≤∞ and sequences of integers (nkk and (nk′k such that nk≤nk′≤nk+1, the generalized mixed norm space ℓℐ(p,q is defined as those sequences (ajj such that ((∑j∈Ik|aj|p1/pk∈ℓq where Ik={j∈ℕ0 s.t. nk≤j
Multiplier policies for digital signal processing
Taylor, Fred J.; Ma, Gin-Kou
1990-01-01
The successful design of digital signal processing (DSP) systems and subsystems is often predicted on realizing fast multiplication in digital hardware. This tutorial provides the reader with a broad perspective of this important field and the pedagogy needed to understand the basic principles of digital multiplication. Both conventional and nonconventional methods of implementing multiplication, representing a mix of speed/complexity tradeoffs, are presented. Some are based on traditional shift/add structures, whereas others strive for greater mathematical sophistication. Topics include stand-alone fixed-point multipliers, cellular arrays, memory intensive policies, homomorphic systems, and modular arithmetic.
Energy Technology Data Exchange (ETDEWEB)
Cazzoli, Gabriele; Lattanzi, Valerio; Puzzarini, Cristina [Dipartimento di Chimica “Giacomo Ciamician”, Università di Bologna, Via Selmi 2, I-40126 Bologna (Italy); Alonso, José Luis [Grupo de Espectroscopía Molecular (GEM), Unidad Asociada CSIC, Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Universidad de Valladolid, E-47005 Valladolid (Spain); Gauss, Jürgen, E-mail: cristina.puzzarini@unibo.it [Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz (Germany)
2015-06-10
The rotational spectrum of the mono-deuterated isotopologue of water, HD{sup 16}O, has been investigated in the millimeter- and submillimeter-wave frequency regions, up to 1.6 THz. The Lamb-dip technique has been exploited to obtain sub-Doppler resolution and to resolve the hyperfine (hf) structure due to the deuterium and hydrogen nuclei, thus enabling the accurate determination of the corresponding hf parameters. Their experimental determination has been supported by high-level quantum-chemical calculations. The Lamb-dip measurements have been supplemented by Doppler-limited measurements (weak high-J and high-frequency transitions) in order to extend the predictive capability of the available spectroscopic constants. The possibility of resolving hf splittings in astronomical spectra has been discussed.
Stimulus versus Austerity: The Asymmetric Government Spending Multiplier
Barnichon, Régis; MATTHES, Christian
2015-01-01
Despite intense scrutiny estimates of the government spending multiplier remain highly uncertain with values ranging from 0.5 to 2. While a fiscal consolidation is generally assumed to have the same (mirror-image) effect as a fiscal expansion, we show that relaxing this assumption is crucial to understanding the effects of fiscal policy. The government spending multiplier is substantially below 1 for fiscal expansions, but the multiplier is substantially above 1 for fiscal consolidations.
Hadamard Multipliers and Abel Dual of Hardy Spaces
Directory of Open Access Journals (Sweden)
Paweł Mleczko
2016-01-01
Full Text Available The paper is devoted to the study of Hadamard multipliers of functions from the abstract Hardy classes generated by rearrangement invariant spaces. In particular the relation between the existence of such multiplier and the boundedness of the appropriate convolution operator on spaces of measurable functions is presented. As an application, the description of Hadamard multipliers into H∞ is given and the Abel type theorem for mentioned Hardy spaces is proved.
Multipliers on weighted Hardy spaces over certain totally disconnected groups
Directory of Open Access Journals (Sweden)
Toshiyuki Kitada
1988-01-01
Full Text Available In this note, we consider the multipliers on weighted H1 spaces over totally disconnected locally compact abelian groups with a suitable sequence of open compact subgroups (Vilenkin groups. We first show an (H1,L1 multiplier result from which Onneweer's theorem follows. We also give an (H1,H1 multiplier result under a condition of Baernstein-Sawyer type.
Four-gate transistor analog multiplier circuit
Mojarradi, Mohammad M. (Inventor); Blalock, Benjamin (Inventor); Cristoloveanu, Sorin (Inventor); Chen, Suheng (Inventor); Akarvardar, Kerem (Inventor)
2011-01-01
A differential output analog multiplier circuit utilizing four G.sup.4-FETs, each source connected to a current source. The four G.sup.4-FETs may be grouped into two pairs of two G.sup.4-FETs each, where one pair has its drains connected to a load, and the other par has its drains connected to another load. The differential output voltage is taken at the two loads. In one embodiment, for each G.sup.4-FET, the first and second junction gates are each connected together, where a first input voltage is applied to the front gates of each pair, and a second input voltage is applied to the first junction gates of each pair. Other embodiments are described and claimed.
Gas Electron multipliers for low energy beams
Arnold, F; Ropelewski, L; Spanggaard, J; Tranquille, G
2010-01-01
Gas Electron Multipliers (GEM) find their way to more and more applications in beam instrumentation. Gas Electron Multiplication uses a very similar physical phenomenon to that of Multi Wire Proportional Chambers (MWPC) but for small profile monitors they are much more cost efficient both to produce and to maintain. This paper presents the new GEM profile monitors intended to replace the MWPCs currently used at CERN’s low energy Antiproton Decelerator (AD). It will be shown how GEMs overcome the documented problems of profile measurements with MWPCs for low energy beams, where the interaction of the beam with the detector has a large influence on the measured profile. Results will be shown of profile measurements performed at 5 MeV using four different GEM prototypes, with discussion on the possible use of GEMs at even lower energies needed at the AD in 2013.
Efek Multiplier Zakat terhadap Pendapatan di Provinsi DKI Jakarta
Al Arif, M Nur Rianto
2012-01-01
The aim of this research is to analyse the multiplier effect of zakâh revenue in DKI Jakarta. A study case at Badan Amil Zakat, Infak, and Sadaqah (BAZIS) DKI Jakarta. Least square method is used to analyze the data. The coefficients will be used to calculate the multiplier effect of zakâh-revenue and it will be compared with the economy without zakah revenue. The results showed 2,522 multiplier effects of zakâh-revenue and 3.561 multiplier effect ofeconomic income without zakâh-revenue. Thi...
Reconfigurable Low Energy Multiplier for Multimedia System Design
National Research Council Canada - National Science Library
Kim, Suhwan
2000-01-01
This paper proposes a reconfigurable pipelined multiplier architecture that achieves high performance and very low energy dissipation by adapting its structure to computational requirements over time...
Brendle, Katrina; Kordel, Max; Schneider, Erik; Wagner, Danny; Bräse, Stefan; Weis, Patrick; Kappes, Manfred M.
2017-10-01
We have determined breakdown curves for a range of multiply charged benzylpyridinium-substituted porphyrin cations by collision induced dissociation measurements (CID) as mediated by resonant pulsed radio-frequency (rf) excitation in a helium-filled linear ion trap. Measurements were compared with the predictions of DFT calculations. We find a linear correlation between experimental fragmentation thresholds (in instrumental units of "normalized collision energy") and theoretical dissociation energies, suggesting that these species can be used as calibrants to gauge the fragmentation energetics of closely related systems. We have confirmed this by also studying the fragmentation thresholds of metalloporphyrin-based ions - including multiply negatively charged metalloporphyrin oligomers. Unfortunately, the slope of the linear correlation obtained for benzylpyridinium-substituted porphyrin multications differs significantly from that obtained by us for a set of smaller, singly charged substituted benzylpyridines put forward as "thermometer" ions in previous work. Multiplying the threshold energies in an ad hoc fashion by the ion charge basically reconciles both calibration curves. We conclude that one should use caution when applying small, singly charged benzylpyridines as calibrants to gauge the CID of large, multiply charged ions in ion-trap mass spectrometers.
Multiplier convergent series and uniform convergence of mapping ...
Indian Academy of Sciences (India)
j=1 Aj (xj ) converges uniformly with respect to (xj ) in any M ∈ M. Moreover, in the last section we give some applications for mapping series. 2. The space of multiplier convergent series. First, we define the frame property of complex sequence set λ, which is important in studying multiplier convergent series. DEFINITION 2.1.
Multipliers for the absolute Euler summability of Fourier series
Indian Academy of Sciences (India)
In this paper, the author has investigated necessary and sufficient conditions for the absolute Euler summability of the Fourier series with multipliers. These conditions are weaker than those obtained earlier by some workers. It is further shown that the multipliers are best possible in certain sense.
Circuit multiplies pulse width modulation, exhibits linear transfer function
Carlson, A. W.; Furciniti, A.
1967-01-01
Modulation multiplier provides a simple means of multiplying the width modulation of a pulse train by a constant factor. It operates directly on a pulse width modulated input signal to generate an output pulse train having a greater degree of width modulation than the input signal.
An algebra of absolutely continuous functions and its multipliers
Indian Academy of Sciences (India)
Introduction. Let I = [0, 1] be the compact topological semigroup with max multiplication and usual topology. C(I),Lp(I), 1 ≤ p ≤ ∞ are the associated Banach algebras. Larsen [5] obtained multipliers for the Banach algebra L1(I). Baker, Pym and Vasudeva [1] obtain characterizations of multipliers from Lp(I) to Lr(I), 1 ≤ r, ...
Beyond Linear Delay Multipliers in Air Transport
Directory of Open Access Journals (Sweden)
Seddik Belkoura
2017-01-01
Full Text Available Delays are considered one of the most important burdens of air transport, both for their social and environmental consequences and for the cost they cause for airlines and passengers. It is therefore not surprising that a large effort has been devoted to study how they propagate through the system. One of the most important indicators to assess such propagation is the delay multiplier, a ratio between outbound and inbound average delays; in spite of its widespread utilisation, its simplicity precludes capturing all details about the dynamics behind the diffusion process. Here we present a methodology that extracts a more complete relationship between the in- and outbound delays, distinguishing a linear and a nonlinear phase and thus yielding a richer description of the system’s response as a function of the delay magnitude. We validate the methodology through the study of a historical data set of flights crossing the European airspace and show how its most important airports have heterogeneous ways of reacting to extreme delays and that this reaction strongly depends on some of their global properties.
Negative probability of random multiplier in turbulence
Bai, Xuan; Su, Weidong
2017-11-01
The random multiplicative process (RMP), which has been proposed for over 50 years, is a convenient phenomenological ansatz of turbulence cascade. In the RMP, the fluctuation in a large scale is statistically mapped to the one in a small scale by the linear action of an independent random multiplier (RM). Simple as it is, the RMP is powerful enough since all of the known scaling laws can be included in this model. So far as we know, however, a direct extraction for the probability density function (PDF) of RM has been absent yet. The reason is the deconvolution during the process is ill-posed. Nevertheless, with the progress in the studies of inverse problems, the situation can be changed. By using some new regularization techniques, for the first time we recover the PDFs of the RMs in some turbulent flows. All the consistent results from various methods point to an amazing observation-the PDFs can attain negative values in some intervals; and this can also be justified by some properties of infinitely divisible distributions. Despite the conceptual unconventionality, the present study illustrates the implications of negative probability in turbulence in several aspects, with emphasis on its role in describing the interaction between fluctuations at different scales. This work is supported by the NSFC (No. 11221062 and No. 11521091).
Optimizing strassen matrix multiply on GPUs
ul Hasan Khan, Ayaz
2015-06-01
© 2015 IEEE. Many core systems are basically designed for applications having large data parallelism. Strassen Matrix Multiply (MM) can be formulated as a depth first (DFS) traversal of a recursion tree where all cores work in parallel on computing each of the NxN sub-matrices that reduces storage at the detriment of large data motion to gather and aggregate the results. We propose Strassen and Winograd algorithms (S-MM and W-MM) based on three optimizations: a set of basic algebra functions to reduce overhead, invoking efficient library (CUBLAS 5.5), and parameter-tuning of parametric kernel to improve resource occupancy. On GPUs, W-MM and S-MM with one recursion level outperform CUBLAS 5.5 Library with up to twice as faster for large arrays satisfying N>=2048 and N>=3072, respectively. Compared to NVIDIA SDK library, S-MM and W-MM achieved a speedup between 20x to 80x for the above arrays. The proposed approach can be used to enhance the performance of CUBLAS and MKL libraries.
On an Integrated Transfer Matrix method for multiply connected mufflers
Vijayasree, N. K.; Munjal, M. L.
2012-04-01
The commercial automotive mufflers are generally of a complicated shape with multiply connected parts and complex acoustic elements. The analysis of such complex mufflers has always been a great challenge. In this paper, an Integrated Transfer Matrix method has been developed to analyze complex mufflers. Integrated transfer matrix relates the state variables across the entire cross-section of the muffler shell, as one moves along the axis of the muffler, and can be partitioned appropriately in order to relate the state variables of different tubes constituting the cross-section. The paper presents a generalized one-dimensional (1-D) approach, using the transfer matrices of simple acoustic elements, which are available from the literature. The present approach is robust and flexible owing to its capability to construct an overall matrix of the muffler with the transfer matrices of individual acoustic elements and boundary conditions, which can then be used to evaluate the transmission loss, insertion loss, etc. Results from the present approach have been validated through comparisons with the available experimental and three-dimensional finite element method (FEM) based results. The results show good agreement with both measurements and FEM analysis up to the cut-off frequency.
Sociophysics of sexism: normal and anomalous petrie multipliers
Eliazar, Iddo
2015-07-01
A recent mathematical model by Karen Petrie explains how sexism towards women can arise in organizations where male and female are equally sexist. Indeed, the Petrie model predicts that such sexism will emerge whenever there is a male majority, and quantifies this majority bias by the ‘Petrie multiplier’: the square of the male/female ratio. In this paper—emulating the shift from ‘normal’ to ‘anomalous’ diffusion—we generalize the Petrie model to a stochastic Poisson model that accommodates heterogeneously sexist men and woman, and that extends the ‘normal’ quadratic Petrie multiplier to ‘anomalous’ non-quadratic multipliers. The Petrie multipliers span a full spectrum of behaviors which we classify into four universal types. A variation of the stochastic Poisson model and its Petrie multipliers is further applied to the context of cyber warfare.
Gauss-Bonnet dark energy by Lagrange multipliers
Capozziello, Salvatore; Makarenko, Andrey N.; Odintsov, Sergei D.
2013-04-01
A string-inspired effective theory of gravity, containing Gauss-Bonnet invariant interacting with a scalar field, is considered in view of obtaining cosmological dark energy solutions. A Lagrange multiplier is inserted into the action in order to achieve the cosmological reconstruction by selecting suitable forms of couplings and potentials. Several cosmological exact solutions (including dark energy of quintessence, phantom, or Little Rip type) are derived in the presence and in the absence of the Lagrange multiplier showing the difference in the two dynamical approaches. In the models that we consider, the Lagrange multiplier behaves as a sort of dust fluid that realizes the transitions between matter-dominated and dark energy epochs. The relation between Lagrange multipliers and Noether symmetries is discussed.
Hidden Abilities Discovered Among Multiply Handicapped Blind Children
Klineman, Janet
1975-01-01
The effectiveness of an objective, systematic assessment and individualized programing approach for discovering new channels of learning is illustrated with case study evaluations of multiply handicapped visually impaired children with complex learning and behavioral problems. (SB)
EFEK MULTIPLIER ZAKAT TERHADAP PENDAPATAN DI PROVINSI DKI JAKARTA
Directory of Open Access Journals (Sweden)
M. Nur Rianto Al Arif
2016-02-01
Full Text Available The aim of this research is to analyse the multiplier effect of zakâh revenue in DKI Jakarta. A study case at Badan Amil Zakat, Infak, and Sadaqah (BAZIS DKI Jakarta. Least square method is used to analyze the data. The coefficients will be used to calculate the multiplier effect of zakâh-revenue and it will be compared with the economy without zakah revenue. The results showed 2,522 multiplier effects of zakâh-revenue and 3.561 multiplier effect ofeconomic income without zakâh-revenue. This suggests that the management of zakat in BAZIS Jakarta still can have a significant influence on the economy.DOI: 10.15408/aiq.v4i1.2533
Instructional Computing Project Uses "Multiplier Effect" to Train Florida Teachers.
Roblyer, M. D.; Castine, W. H.
1987-01-01
Reviews the efforts undertaken in the Florida Model Microcomputer Trainer Project (FMMTP) and its statewide impact. Outlines its procedural strategies, trainer curriculum, networking system, and the results of its multiplier effect. (ML)
Efek Multiplier Zakat Terhadap Pendapatan di Propinsi DKI Jakarta
Directory of Open Access Journals (Sweden)
M. Nur Rianto Al Arif
2015-10-01
Full Text Available The aim of this research is to analyze the multiplier effect of zakah revenue in DKI Jakarta, a study case at Badan Amil Zakat, Infak, and Shadaqah (BAZIS DKI Jakarta. Least square methods is used to analyze the data. The coefficient will be used to calculate the multiplier effect of zakah revenue and it will be compared with the economy without zakah revenue. The result showed 2,522 multiplier effects of zakah revenue and 3,561 multiplier effect of economic income without zakah revenue. This suggest that the management of zakah in BAZIS DKI Jakarta still can have a significant influence on the economyDOI: 10.15408/aiq.v4i1.2079
Operational Safety Requirements Neutron Multiplier Facility in 329 Building
Energy Technology Data Exchange (ETDEWEB)
EA. Lepel
1992-10-01
The operational safety requirements (OSRs) presented in this report define the conditions, safe boundaries and management control needed for safely operating the Neutron Multiplier Facility in the 329 Building Annex.
Isometric multipliers of a vector valued Beurling algebra on a ...
Indian Academy of Sciences (India)
Abstract. Let (S, ω) be a weighted abelian semigroup, let Mω(S) be the semigroup of ω-bounded multipliers of S, and let A be a strictly convex commutative Banach algebra with identity. It is shown that T is an onto isometric multiplier of l1(S,ω, A) if and only if there exists an invertible σ ∈ Mω(S), a unitary point a ∈ A, and a k ...
Fiscal Multipliers and Public Debt Dynamics in Consolidations
Salto, Matteo; Boussard, Jocelyn; de Castro Fernández, Francisco
2013-01-01
The success of a consolidation in reducing the debt ratio depends crucially on the value of the multiplier, which measures the impact of consolidation on growth, and on the reaction of sovereign yields to such a consolidation. We present a theoretical framework that formalizes the re spo nse of the public debt ratio to fiscal consolidations in relation to the value of fiscal multipliers, the starting debt level and the cyclical elasticity of the budget balance. We also assess the role of ...
Dong, Biao; Sun, Qing; Liu, Wu-Ming; Ji, An-Chun; Zhang, Xiao-Fei; Zhang, Shou-Gang
2017-07-01
We consider a binary dipolar Bose-Einstein condensate with repulsive contact and dipolar interactions under rotation. Our results show that the interplay among short-range interaction, long-range interaction, and rotation can give rise to a rich variety of topological configurations, including giant skyrmions with multiply topological charges and skyrmion-vortex lattices. In particular, we find that for fixed rotation frequencies, tuning the short- and long-range interactions can derive novel ground-state phases, such as a meron pair composed of two fractional skyrmions and a skyrmion with topological charge Q =2 centered in giant skyrmions.
Truncated multipliers through power-gating for degrading precision arithmetic
DEFF Research Database (Denmark)
Albicocco, Pietro; Cardarilli, Gian Carlo; Nannarelli, Alberto
2013-01-01
When reducing the power dissipation of resource constrained electronic systems is a priority, some precision can be traded-off for lower power consumption. In signal processing, it is possible to have an acceptable quality of the signal even introducing some errors. In this work, we apply power-g...... to multipliers to obtain a programmable truncated multiplier. The method consists in disabling the least-significant columns of the multiplier by power-gating logic in the partial products generation and accumulation array.......When reducing the power dissipation of resource constrained electronic systems is a priority, some precision can be traded-off for lower power consumption. In signal processing, it is possible to have an acceptable quality of the signal even introducing some errors. In this work, we apply power-gating...
Multiplier Accounting of Indian Mining Industry: The Application
Hussain, Azhar; Karmakar, Netai Chandra
2017-10-01
In the previous paper (Hussain and Karmakar in Inst Eng India Ser, 2014. doi: 10.1007/s40033-014-0058-0), the concepts of input-output transaction matrix and multiplier were explained in detail. Input-output multipliers are indicators used for predicting the total impact on an economy due to changes in its industrial demand and output which is calculated using transaction matrix. The aim of this paper is to present an application of the concepts with respect to the mining industry, showing progress in different sectors of mining with time and explaining different outcomes from the results obtained. The analysis shows that a few mineral industries saw a significant growth in their multiplier values over the years.
Radial multipliers on amalgamated free products of II-factors
DEFF Research Database (Denmark)
Möller, Sören
2014-01-01
Let ℳi be a family of II1-factors, containing a common II1-subfactor 풩, such that [ℳi : 풩] ∈ ℕ0 for all i. Furthermore, let ϕ: ℕ0 → ℂ. We show that if a Hankel matrix related to ϕ is trace-class, then there exists a unique completely bounded map Mϕ on the amalgamated free product of the ℳi...... with amalgamation over 풩, which acts as a radial multiplier. Hereby, we extend a result of Haagerup and the author for radial multipliers on reduced free products of unital C*- and von Neumann algebras....
Directory of Open Access Journals (Sweden)
I. V. Bandurkin
2005-01-01
Full Text Available A method of organizing electron-wave interaction at the multiplied frequency of the signal wave is proposed. This type of electron-wave interaction provides multiplied-frequency electron bunching, which leads to formation of an intense harmonic of the electron current at a selected multiplied frequency of the signal wave. This effect is attractive for the use in klystron-type cyclotron masers with frequency multiplication as a way to increase the output frequency and improve the selectivity.
Familiar Sports and Activities Adapted for Multiply Impaired Persons.
Schilling, Mary Lou, Ed.
1984-01-01
Means of adapting some familiar and popular physical activities for multiply impaired persons are described. Games reviewed are dice baseball, one base baseball, in-house bowling, wheelchair bowling, ramp bowling, swing-ball bowling, table tennis, shuffleboard, beanbag bingo and tic-tac-toe, balloon basketball, circle football, and wheelchair…
Problems with Accurate Atomic Lfetime Measurements of Multiply Charged Ions
Energy Technology Data Exchange (ETDEWEB)
Trabert, E
2009-02-19
A number of recent atomic lifetime measurements on multiply charged ions have reported uncertainties lower than 1%. Such a level of accuracy challenges theory, which is a good thing. However, a few lessons learned from earlier precision lifetime measurements on atoms and singly charged ions suggest to remain cautious about the systematic errors of experimental techniques.
The Gas Electron Multiplier Chamber Exhibition LEPFest 2000
2000-01-01
The Gas Electron Multiplier (GEM) is a novel device introduced in 1996.Large area detectors based on this technology are in construction for high energy physics detectors.This technology can also be used for high-rate X-ray imaging in medical diagnostics and for monitoring irradiation during cancer treatment
Potential energy curves for neutral and multiply charged carbon ...
Indian Academy of Sciences (India)
physics pp. 49–55. Potential energy curves for neutral and multiply charged carbon monoxide. PRADEEP KUMAR1 and N SATHYAMURTHY1,2,3,∗. 1Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India. 2Indian Institute of Science Education and Research Mohali, MGSIPAP Complex,.
Detection of differential item functioning using Lagrange multiplier tests
Glas, Cornelis A.W.
1998-01-01
Abstract: In the present paper it is shown that differential item functioning can be evaluated using the Lagrange multiplier test or Rao’s efficient score test. The test is presented in the framework of a number of IRT models such as the Rasch model, the OPLM, the 2-parameter logistic model, the
Detection of differential item functioning using Lagrange multiplier tests
Glas, Cornelis A.W.
1996-01-01
In this paper it is shown that differential item functioning can be evaluated using the Lagrange multiplier test or C. R. Rao's efficient score test. The test is presented in the framework of a number of item response theory (IRT) models such as the Rasch model, the one-parameter logistic model, the
Orientation and Mobility for Multiply Handicapped Blind Children.
Wood, Thomas A.
A research project was conducted to investigate sensory, concept, and locomotion skills in severely multiply handicapped children. The project involved the development of evaluation and teaching materials to be utilized by classroom teachers and paraprofessionals with multi-handicapped children with severe visual deficits. The programed…
Multipliers for the absolute Euler summability of Fourier series
Indian Academy of Sciences (India)
Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45
Multipliers; absolute summability; summability of factored Fourier series; absolute Euler summability. 1. ... In 1968, Mohanty and Mohapatra [12] began the study of absolute Euler summability of. Fourier series by proving the ..... (q > 0) summable. In the case when δ is non-zero real number, we define f (t ) =.. log δ k.
The evolution of unconditional strategies via the 'multiplier effect'.
McNamara, John M; Dall, Sasha R X
2011-03-01
Ostensibly, it makes sense in a changeable world to condition behaviour and development on information when it is available. Nevertheless, unconditional behavioural and life history strategies are widespread. Here, we show how intergenerational effects can limit the evolutionary value of responding to reliable environmental cues, and thus favour the evolutionary persistence of otherwise paradoxical unconditional strategies. While cue-ignoring genotypes do poorly in the wrong environments, in the right environment they will leave many copies of themselves, which will themselves leave many copies, and so on, leading genotypes to accumulate in habitats in which they do well. We call this 'The Multiplier Effect'. We explore the consequences of the multiplier effect by focussing on the ecologically important phenomenon of natal philopatry. We model the environment as a large number of temporally varying breeding sites connected by natal dispersal between sites. Our aim is to identify which aspects of an environment promote the multiplier effect. We show, if sites remain connected through some background level of 'accidental' dispersal, unconditional natal philopatry can evolve even when there is density dependence (with its accompanying kin competition effects), and cues that are only mildly erroneous. Thus, the multiplier effect may underpin the evolution and maintenance of unconditional strategies such as natal philopatry in many biological systems. © 2011 Blackwell Publishing Ltd/CNRS.
A CMOS four-quadrant analog current multiplier
Wiegerink, Remco J.
1991-01-01
A CMOS four-quadrant analog current multiplier is described. The circuit is based on the square-law characteristic of an MOS transistor and is insensitive to temperature and process variations. The circuit is insensitive to the body effect so it is not necessary to place transistors in individual
Robust formation control of marine surface craft using Lagrange multipliers
DEFF Research Database (Denmark)
Ihle, Ivar-Andre F.; Jouffroy, Jerome; Fossen, Thor I.
2006-01-01
This paper presents a formation modelling scheme based on a set of inter-body constraint functions and Lagrangian multipliers. Formation control for a °eet of marine craft is achieved by stabilizing the auxiliary constraints such that the desired formation con¯guration appears. In the proposed...
The role of the Jacobi last multiplier and isochronous systems
Indian Academy of Sciences (India)
Abstract. We employ Jacobi's last multiplier (JLM) to study planar differential systems. In particu- lar, we examine its role in the transformation of the temporal variable for a system of ODEs originally analysed by Calogero–Leyvraz in course of their identification of isochronous systems. We also show that JLM simplifies to a ...
Multipliers of Ap((0 ,((0 ,((0,∞)) with order convolution
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
Introduction. The algebra Ap(G) of elements in L1(G) whose Fourier transforms belong to Lp( ˆG) and the multipliers for these algebras have been studied by various authors [1,7–9]. Let. I = (0, ∞) be the locally compact idempotent commutative topological semigroup with the usual topology and max multiplication and ˆI be ...
Multiplying Is More than Math--It's Also Good Management
Foster, Elise; Wiseman, Liz
2015-01-01
Studying more than 400 educational leaders, the authors propose a new model for leadership and management rooted in the belief that there is latent intelligence inside schools and educational organizations. Their findings suggest two dramatically different types of leaders, Multipliers and Diminishers. The five disciplines that distinguish…
Development and applications of gas electron multiplier detectors
Sauli, Fabio
2003-01-01
An overview of the recent developments in the field of gas electron multiplier (GEM) detectors was presented. Cascading of several GEM foils permits the sustaining of large gains and thereby allows the detection of minimum ionizing particles. The application of GEM included, fast and position sensitive detection in particle physics, medicine, neutron spectrometry, and astrophysics. (Edited abstract) 19 Refs.
Spot Pricing When Lagrange Multipliers Are Not Unique
DEFF Research Database (Denmark)
Feng, Donghan; Xu, Zhao; Zhong, Jin
2012-01-01
on multipliers cannot generate a unique clearing price. Although such situations are rare, they can cause significant uncertainties and complexities in market dispatch. In practice, this situation is solved through simple empirical methods, which may cause additional operations or biased allocation. Based...... on a strict extension of the principles of spot pricing and surplus allocation, we propose a new pricing methodology that can yield unique, impartial, and robust solution. The new method has been analyzed and compared with other pricing approaches in accordance with spot pricing theory. Case studies support......Classical spot pricing theory is based on multipliers of the primal problem of an optimal market dispatch, i.e., the solution of the dual problem. However, the dual problem of market dispatch may yield multiple solutions. In these circumstances, spot pricing or any standard pricing practice based...
Dynamic effects of fiscal policy and fiscal multipliers in Croatia
Directory of Open Access Journals (Sweden)
Milan Deskar-Škrbić
2013-06-01
Full Text Available The aim of this paper is to analyze the effects of discretionary measures of fiscal policy on the economic activity and to estimate the size of fiscal multipliers in Croatia. Econometric framework is based on the structural VAR model (SVAR, with Blanchard-Perotti identification method that uses information on institutional characteristics of fiscal system. The analysis is conducted on quarterly data for total expenditures and indirect taxes of central, central consolidated and general consolidated government and aggregate demand for the period from 2004-2012. The results show that our initial assumptions about the difference in the size of the multiplier of government expenditures and indirect tax revenues between three levels of government consolidation have been confirmed.
Using of the Algorithm of Lagrange Multipliers in Image Restoration
Stojanovic, Igor; Kraljevski, Ivan; Chungurski, Slavco
2010-01-01
This paper presents a method based on algorithm of Lagrange multipliers. The method is use for the removal of blur in an X-ray caused by uniform linear motion. This method assumes that linear motion corresponds to an integral number of pixels. The resolution of the restored image remains at very high level. The main contribution of the method was found on the Improvement in Signal to Noise Ration (ISNR) that has been increase significantly compared to the classic techniques.
Multiply-negatively charged aluminium clusters and fullerenes
Energy Technology Data Exchange (ETDEWEB)
Walsh, Noelle
2008-07-15
Multiply negatively charged aluminium clusters and fullerenes were generated in a Penning trap using the 'electron-bath' technique. Aluminium monoanions were generated using a laser vaporisation source. After this, two-, three- and four-times negatively charged aluminium clusters were generated for the first time. This research marks the first observation of tetra-anionic metal clusters in the gas phase. Additionally, doubly-negatively charged fullerenes were generated. The smallest fullerene dianion observed contained 70 atoms. (orig.)
Study of multi anode photo multiplier tubes at low gains
Eisenhardt, S; Bibby, J; Libby, J
2001-01-01
We describe a preliminary study of the signal shape of the Multianode Photo Multiplier Tubes (MaPMT) at low gain. We investigate the feasibility of running the MaPMT at gains of around 30000 e which would allow to use front-end chips that have been developed for silicon detectors or micro strip gas chambers. In addition we have investigated the focusing properties of an improved design of the MaPMT.
Radial multipliers on reduced free products of operator algebras
DEFF Research Database (Denmark)
Haagerup, Uffe; Møller, Søren
2012-01-01
Let AiAi be a family of unital C¿C¿-algebras, respectively, of von Neumann algebras and ¿:N0¿C¿:N0¿C. We show that if a Hankel matrix related to ¿ is trace-class, then there exists a unique completely bounded map M¿M¿ on the reduced free product of the AiAi, which acts as a radial multiplier. Her...
Electron capture dissociation of singly and multiply phosphorylated peptides
DEFF Research Database (Denmark)
Stensballe, A; Jensen, Ole Nørregaard; Olsen, J V
2000-01-01
Analysis of phosphotyrosine and phosphoserine containing peptides by nano-electrospray Fourier transform ion cyclotron resonance (FTICR) mass spectrometry established electron capture dissociation (ECD) as a viable method for phosphopeptide sequencing. In general, ECD spectra of synthetic...... and native phosphopeptides appeared less complex than conventional collision activated dissociation (CAD) mass spectra of these species. ECD of multiply protonated phosphopeptide ions generated mainly c- and z(.)-type peptide fragment ion series. No loss of water, phosphate groups or phosphoric acid from...
2-D imaging with cascaded GEM/MHSP multipliers
Maia, J M; Breskin, Amos; Chechik, R; Veloso, J F C A; Dos Santos, J M F
2007-01-01
The imaging properties of cascaded-GEM (Gas Electron Multiplier) and cascaded-GEM/MHSP (Micro-Hole and Strip Plate) gaseous electron multipliers, equipped with 2-D Wedge & Strip (W&S) readout electrodes, are presented. The W&S electrode was capacitively coupled to the electron multiplier through a resistive electrode, to adapt the charge-cloud size to the 1.6 mm readout pitch. The studies were carried out with soft X-rays and single UV-photons in Ar/5%CH4 gas mixture at atmospheric pressure. Spatial resolutions of ~225μm and ~250μm (FWHM) were reached, with 5.9 keV X-rays, in 3-GEM and 2-GEM/MHSP based detectors, respectively. Single photoelectrons, emitted from a CsI photocathode deposited on the top electrode of the first GEM in the cascade, were localized with resolution of ~ 170μm (FWHM) in a 4-GEM gaseous photomultiplier.
Energy Technology Data Exchange (ETDEWEB)
Feng, Shechao Charles
1995-02-01
This is the final report on the grant, entitled `applications of mesoscopic physics to novel correlations and fluctuations of speckle patterns: imaging and tomography with multiply scattered classical waves`, which expired on September 14, 1994. The author summarizes the highlights of this research program, and lists the publications supported by this grant. The report is divided into sections, titled: application of mesoscopic fluctuations theory to correlations and fluctuations of multiply scattered light; quantum transport in localized electronic systems; electron-phonon inelastic scattering rate and the temperature scaling exponent in integer quantum Hall effect; high frequency quantum transport in quantum well devices.
Ionization and bound-state relativistic quantum dynamics in laser-driven multiply charged ions
Energy Technology Data Exchange (ETDEWEB)
Hetzheim, Henrik
2009-01-14
The interaction of ultra-strong laser fields with multiply charged hydrogen-like ions can be distinguished in an ionization and a bound dynamics regime. Both are investigated by means of numerically solving the Dirac equation in two dimensions and by a classical relativistic Monte-Carlo simulation. For a better understanding of highly nonlinear physical processes the development of a well characterized ultra-intense relativistic laser field strength has been driven forward, capable of studying e.g. the magnetic field effects of the laser resulting in an additional electron motion in the laser propagation direction. A novel method to sensitively measure these ultra-strong laser intensities is developed and employed from the optical via the UV towards the XUV frequency regime. In the bound dynamics field, the determination of multiphoton transition matrixelements has been investigated between different bound states via Rabi oscillations. (orig.)
Abbiati, Giuseppe; La Salandra, Vincenzo; Bursi, Oreste S.; Caracoglia, Luca
2018-02-01
Successful online hybrid (numerical/physical) dynamic substructuring simulations have shown their potential in enabling realistic dynamic analysis of almost any type of non-linear structural system (e.g., an as-built/isolated viaduct, a petrochemical piping system subjected to non-stationary seismic loading, etc.). Moreover, owing to faster and more accurate testing equipment, a number of different offline experimental substructuring methods, operating both in time (e.g. the impulse-based substructuring) and frequency domains (i.e. the Lagrange multiplier frequency-based substructuring), have been employed in mechanical engineering to examine dynamic substructure coupling. Numerous studies have dealt with the above-mentioned methods and with consequent uncertainty propagation issues, either associated with experimental errors or modelling assumptions. Nonetheless, a limited number of publications have systematically cross-examined the performance of the various Experimental Dynamic Substructuring (EDS) methods and the possibility of their exploitation in a complementary way to expedite a hybrid experiment/numerical simulation. From this perspective, this paper performs a comparative uncertainty propagation analysis of three EDS algorithms for coupling physical and numerical subdomains with a dual assembly approach based on localized Lagrange multipliers. The main results and comparisons are based on a series of Monte Carlo simulations carried out on a five-DoF linear/non-linear chain-like systems that include typical aleatoric uncertainties emerging from measurement errors and excitation loads. In addition, we propose a new Composite-EDS (C-EDS) method to fuse both online and offline algorithms into a unique simulator. Capitalizing from the results of a more complex case study composed of a coupled isolated tank-piping system, we provide a feasible way to employ the C-EDS method when nonlinearities and multi-point constraints are present in the emulated system.
Auditing the multiply-related concepts within the UMLS.
Mougin, Fleur; Grabar, Natalia
2014-10-01
This work focuses on multiply-related Unified Medical Language System (UMLS) concepts, that is, concepts associated through multiple relations. The relations involved in such situations are audited to determine whether they are provided by source vocabularies or result from the integration of these vocabularies within the UMLS. We study the compatibility of the multiple relations which associate the concepts under investigation and try to explain the reason why they co-occur. Towards this end, we analyze the relations both at the concept and term levels. In addition, we randomly select 288 concepts associated through contradictory relations and manually analyze them. At the UMLS scale, only 0.7% of combinations of relations are contradictory, while homogeneous combinations are observed in one-third of situations. At the scale of source vocabularies, one-third do not contain more than one relation between the concepts under investigation. Among the remaining source vocabularies, seven of them mainly present multiple non-homogeneous relations between terms. Analysis at the term level also shows that only in a quarter of cases are the source vocabularies responsible for the presence of multiply-related concepts in the UMLS. These results are available at: http://www.isped.u-bordeaux2.fr/ArticleJAMIA/results_multiply_related_concepts.aspx. Manual analysis was useful to explain the conceptualization difference in relations between terms across source vocabularies. The exploitation of source relations was helpful for understanding why some source vocabularies describe multiple relations between a given pair of terms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Determination of Ultimate Torque for Multiply Connected Cross Section Rod
Directory of Open Access Journals (Sweden)
V. L. Danilov
2015-01-01
Full Text Available The aim of this work is to determine load-carrying capability of the multiply cross-section rod. This calculation is based on the model of the ideal plasticity of the material, so that the desired ultimate torque is a torque at which the entire cross section goes into a plastic state.The article discusses the cylindrical multiply cross-section rod. To satisfy the equilibrium equation and the condition of plasticity simultaneously, two stress function Ф and φ are introduced. By mathematical transformations it has been proved that Ф is constant along the path, and a formula to find its values on the contours has been obtained. The paper also presents the rationale of the line of stress discontinuity and obtained relationships, which allow us to derive the equations break lines for simple interaction of neighboring circuits, such as two lines, straight lines and circles, circles and a different sign of the curvature.After substitution into the boundary condition at the end of the stress function Ф and mathematical transformations a formula is obtained to determine the ultimate torque for the multiply cross-section rod.Using the doubly connected cross-section and three-connected cross-section rods as an example the application of the formula of ultimate torque is studied.For doubly connected cross-section rod, the paper offers a formula of the torque versus the radius of the rod, the aperture radius and the distance between their centers. It also clearly demonstrates the torque dependence both on the ratio of the radii and on the displacement of hole. It is shown that the value of the torque is more influenced by the displacement of hole, rather than by the ratio of the radii.For the three-connected cross-section rod the paper shows the integration feature that consists in selection of a coordinate system. As an example, the ultimate torque is found by two methods: analytical one and 3D modeling. The method of 3D modeling is based on the Nadai
On Lagrange Multipliers in Work with Quality and Reliability Assurance
DEFF Research Database (Denmark)
Vidal, Rene Victor Valqui; Becker, P.
1986-01-01
In optimizing some property of a system, reliability say, a designer usually has to accept certain constraints regarding cost, completion time, volume, weight, etc. The solution of optimization problems with boundary constraints can be helped substantially by the use of Lagrange multipliers...... techniques (LMT). With representative examples of increasing complexity, the wide applicability of LMT is illustrated. Two particular features are put in focus. First, an easy to follow yet powerful new graphical approach is presented, Second, the concept of Fuller-Polya maps is shown to be helpful...
Interatomic Coulombic decay cascades in multiply excited neon clusters
Nagaya, K.; Iablonskyi, D.; Golubev, N. V.; Matsunami, K.; Fukuzawa, H.; Motomura, K.; Nishiyama, T.; Sakai, T.; Tachibana, T.; Mondal, S.; Wada, S.; Prince, K. C.; Callegari, C.; Miron, C.; Saito, N.; Yabashi, M.; Demekhin, Ph. V.; Cederbaum, L. S.; Kuleff, A. I.; Yao, M.; Ueda, K.
2016-01-01
In high-intensity laser light, matter can be ionized by direct multiphoton absorption even at photon energies below the ionization threshold. However on tuning the laser to the lowest resonant transition, the system becomes multiply excited, and more efficient, indirect ionization pathways become operative. These mechanisms are known as interatomic Coulombic decay (ICD), where one of the species de-excites to its ground state, transferring its energy to ionize another excited species. Here we show that on tuning to a higher resonant transition, a previously unknown type of interatomic Coulombic decay, intra-Rydberg ICD occurs. In it, de-excitation of an atom to a close-lying Rydberg state leads to electron emission from another neighbouring Rydberg atom. Moreover, systems multiply excited to higher Rydberg states will decay by a cascade of such processes, producing even more ions. The intra-Rydberg ICD and cascades are expected to be ubiquitous in weakly-bound systems exposed to high-intensity resonant radiation. PMID:27917867
Compliant displacement-multiplying apparatus for microelectromechanical systems
Energy Technology Data Exchange (ETDEWEB)
Kota, Sridhar (9391 Quail Ridge Run, Brighton, MI 48114); Rodgers, M. Steven (12216 Papaya Ct., NE., Albuquerque, NM 87111); Hetrick, Joel A. (818 S. Gammon, Apartment 4, Madison, WI 53719)
2001-01-01
A pivotless compliant structure is disclosed that can be used to increase the geometric advantage or mechanical advantage of a microelectromechanical (MEM) actuator such as an electrostatic comb actuator, a capacitive-plate electrostatic actuator, or a thermal actuator. The compliant structure, based on a combination of interconnected flexible beams and cross-beams formed of one or more layers of polysilicon or silicon nitride, can provide a geometric advantage of from about 5:1 to about 60:1 to multiply a 0.25-3 .mu.m displacement provided by a short-stroke actuator so that such an actuator can be used to generate a displacement stroke of about 10-34 .mu.m to operate a ratchet-driven MEM device or a microengine. The compliant structure has less play than conventional displacement-multiplying devices based on lever arms and pivoting joints, and is expected to be more reliable than such devices. The compliant structure and an associated electrostatic or thermal actuator can be formed on a common substrate (e.g. silicon) using surface micromachining.
Deflation Expectation Financial System and Decline in Money Multiplier(in Japanese)
IIDA Yasuyuki
2005-01-01
The money multiplier is in a continuous downward trend now since the bubble burst, and, in addition, the trend has accelerated after 2000. It is said that the monetary policy is difficult because the money multiplier has declined. To think about the monetary policy for the future, we should think about the cause of the decline of the money multiplier. I want to verify two typical hypotheses "Deflation Expectation Hypothesis" and "Financial System Hypothesis" for the decision of the money mult...
Scientific requirements and frequency selection for SMILES-2 proposal
Manago, Naohiro; Suzuki, Makoto; Ozeki, Hiroyuki
Superconducting Submillimeter-Wave Limb-emission Sounder (SMILES) was the first instrument to use 4K cooled SIS (Superconductor-Insulator-Superconductor) detection system for the observation of the atmosphere in the frequency regions 625 GHz (Bands A and B) and 650 GHz (Band C). It has demonstrated its high sensitivity (System Temperature, Tsys, 250 K) for measuring stratospheric and mesospheric species, O _{3}, HCl, ClO, HO _{2}, HOCl, BrO, and O _{3} isotopes from Oct. 12, 2009 to Apr. 21, 2010. Since SMILES operation has terminated after only 6 months operation due to failure of sub-mm local oscillator (and later 4K cooler system), there exist strong scientific demand to develop successor of SMILES, the SMILES-2, which has optimized and enhanced frequency coverage to observe: (a) BrO and HOCl without interferences of stronger emission lines, (b) N _{2}O, H _{2}O, NO _{2}, and CH _{3}Cl not covered by the SMILES frequency regions, and (c) O _{2} line to measure temperature. This paper discusses possible SMILES-2 band selection considering limited instrument resources (number of SIS mixers and sub-mm local oscillator) and scientific requirements. Temperature can be observed by using O _{2} emission lines. We selected 487.249 GHz, which is highest frequency below SMILES 600 GHz observation, O _{2} line to obtain highest vertical IFOV. There is H _{2}O line at 488.1 GHz. Two spectrometers (FFT spectrometer), one with 4 GHz bandwidth and 1 MHz resolution for retrieval of temperature and other species, and the other with high frequency resolution (60 km) and line of sight wind velocity (2 m/s precision). In the case of 4K cooling, temperature can be retrieved within 2% up to 100 km. In summary, current SMILES-2 scientific requirements can be achieved by having sub-mm frequency bands listed in Table 1, (1) 487±2 GHz (O _{2}, H _{2}O), (2) 527±2 GHz (BrO, NO _{2}, H _{2}CO, N _{2}O, HO _{2}, etc), (3) 614±2 GHz (HOCl), (4) 626±2 GHz (SMILES Bands A+B), (5) 637±2
Directory of Open Access Journals (Sweden)
Domingues M. O.
2013-12-01
Full Text Available We present a new adaptive multiresoltion method for the numerical simulation of ideal magnetohydrodynamics. The governing equations, i.e., the compressible Euler equations coupled with the Maxwell equations are discretized using a finite volume scheme on a two-dimensional Cartesian mesh. Adaptivity in space is obtained via Harten’s cell average multiresolution analysis, which allows the reliable introduction of a locally refined mesh while controlling the error. The explicit time discretization uses a compact Runge–Kutta method for local time stepping and an embedded Runge-Kutta scheme for automatic time step control. An extended generalized Lagrangian multiplier approach with the mixed hyperbolic-parabolic correction type is used to control the incompressibility of the magnetic field. Applications to a two-dimensional problem illustrate the properties of the method. Memory savings and numerical divergences of magnetic field are reported and the accuracy of the adaptive computations is assessed by comparing with the available exact solution.
Proximity effects in cold gases of multiply charged atoms (Review)
Chikina, I.; Shikin, V.
2016-07-01
Possible proximity effects in gases of cold, multiply charged atoms are discussed. Here we deal with rarefied gases with densities nd of multiply charged (Z ≫ 1) atoms at low temperatures in the well-known Thomas-Fermi (TF) approximation, which can be used to evaluate the statistical properties of single atoms. In order to retain the advantages of the TF formalism, which is successful for symmetric problems, the external boundary conditions accounting for the finiteness of the density of atoms (donors), nd ≠ 0, are also symmetrized (using a spherical Wigner-Seitz cell) and formulated in a standard way that conserves the total charge within the cell. The model shows that at zero temperature in a rarefied gas of multiply charged atoms there is an effective long-range interaction Eproxi(nd), the sign of which depends on the properties of the outer shells of individual atoms. The long-range character of the interaction Eproxi is evaluated by comparing it with the properties of the well-known London dispersive attraction ELond(nd) 0 and for the alkali and alkaline-earth elements Eproxi theory through the temperature dependence of the different versions of Eproxi. The anomaly in the thermal proximity effect shows up in the following way: for T ≠ 0 there is no equilibrium solution of TS statistics for single multiply charged atoms in a vacuum when the effect is present. Instability is suppressed in a Wigner-Seitz model under the assumption that there are no electron fluxes through the outer boundary R3 ∝ n-1d of a Wigner-Seitz cell. Eproxi corresponds to the definition of the correlation energy in a gas of interacting particles. This review is written so as to enable comparison of the results of the TF formalism with the standard assumptions of the correlation theory for classical plasmas. The classic example from work on weak solutions (including charged solutions)—the use of semi-impermeable membranes for studies of osmotic pressure—is highly appropriate for
Antiproton beam profile measurements using Gas Electron Multipliers
Duarte Pinto, Serge; Spanggaard, Jens; Tranquille, Gerard
2011-01-01
The new beam profile measurement for the Antiproton Decelerator (AD) at CERN is based on a single Gas Electron Multiplier (GEM) with a 2D readout structure. This detector is very light, ~0.4% X_0, as required by the low energy of the antiprotons, 5.3 MeV. This overcomes the problems previously encountered with multi-wire proportional chambers (MWPC) for the same purpose, where beam interactions with the detector severely affect the obtained profiles. A prototype was installed and successfully tested in late 2010, with another five detectors now installed in the ASACUSA and AEgIS beam lines. We will provide a detailed description of the detector and discuss the results obtained. The success of these detectors in the AD makes GEM-based detectors likely candidates for upgrade of the beam profile monitors in all experimental areas at CERN. The various types of MWPC currently in use are aging and becoming increasingly difficult to maintain.
Electromagnetic Radiation in Multiply Connected Robertson-Walker Cosmologies
Tomaschitz, R
1993-01-01
Maxwell's equations on a topologically nontrivial cosmological background are studied. The cosmology is locally determined by a Robertson-Walker line element, but the spacelike slices are open hyperbolic manifolds, whose topology and geometry may vary in time. In this context the spectral resolution of Maxwell's equations in terms of horospherical elementary waves generated at infinity of hyperbolic space is given. The wave fronts are orthogonal to bundles of unstable geodesic rays, and the eikonal of geometric optics appears just as the phase of the horospherical waves. This fact is used to attach to the unstable geodesic rays a quantum mechanical momentum. In doing so the quantized energy-momentum tensor of the radiation field is constructed in a geometrically and dynamically transparent way, without appealing to the intricacies of the second quantization. In particular Planck's radiation formula, and the bearing of the multiply connected topology on the fluctuations in the temperature of the background rad...
Development of a micro-array-type electron multiplier
Fukuda, D; Takahashi, H; Nakazawa, M; Kawarabayashi, J; Hirata, Y; Numazawa, T; Haga, T
1999-01-01
This paper describes the development of a micro-array-type electron multiplier (MAEM) and its application to preamplification of a hybrid photo diode (HPD) system. The MAEM consists of several dynode plates fabricated by micromachining techniques. In our simulation of the electron multiplication process in the HPD system, 4500 gain is easily obtained with the total voltage of 6 kV. No spread of electron charges into the neighboring channels is observed in the MAEM device. Consequently, very high position resolution can be achieved if the pixel-type PD is used with the MAEM. The simulation also showed small fluctuation of the electron transit time of 23 ps in the MAEM, thus very high timing resolution can be achieved.
Development of a micro-array-type electron multiplier
Energy Technology Data Exchange (ETDEWEB)
Fukuda, D. E-mail: fukuda@sophie.q.t.u-tokyo.ac.jp; Inoue, M.; Takahashi, H.; Nakazawa, M.; Kawarabayashi, J.; Hirata, Y.; Numazawa, T.; Haga, T
1999-10-21
This paper describes the development of a micro-array-type electron multiplier (MAEM) and its application to preamplification of a hybrid photo diode (HPD) system. The MAEM consists of several dynode plates fabricated by micromachining techniques. In our simulation of the electron multiplication process in the HPD system, 4500 gain is easily obtained with the total voltage of 6 kV. No spread of electron charges into the neighboring channels is observed in the MAEM device. Consequently, very high position resolution can be achieved if the pixel-type PD is used with the MAEM. The simulation also showed small fluctuation of the electron transit time of 23 ps in the MAEM, thus very high timing resolution can be achieved.
Evaluation of interventions to reduce multiply controlled vocal stereotypy.
Scalzo, Rachel; Henry, Kelsey; Davis, Tonya N; Amos, Kally; Zoch, Tamara; Turchan, Sarah; Wagner, Tara
2015-07-01
This study examined four interventions targeted at decreasing multiply controlled vocal stereotypy for a 12-year-old boy diagnosed with autism spectrum disorder and a severe intellectual disability. These interventions included Noncontingent Music, Differential Reinforcement of Other Behaviors, Self-Recording, and Functional Communication Training (FCT). In addition to measuring vocal stereotypy during each condition, task engagement and challenging behavior were also monitored. Across conditions, vocal stereotypy did not vary significantly from baseline except in FCT, when it decreased significantly. Task engagement was higher in this condition as well. It is hypothesized that FCT provided an enriched environment by increasing social interaction and access to desired items as well as removal of less preferred activities. For these reasons, there was a decrease in the need for the participant to engage in vocal stereotypy and challenging behavior and increase in his ability to engage in a task. © The Author(s) 2015.
Lagrange multiplier for perishable inventory model considering warehouse capacity planning
Amran, Tiena Gustina; Fatima, Zenny
2017-06-01
This paper presented Lagrange Muktiplier approach for solving perishable raw material inventory planning considering warehouse capacity. A food company faced an issue of managing perishable raw materials and marinades which have limited shelf life. Another constraint to be considered was the capacity of the warehouse. Therefore, an inventory model considering shelf life and raw material warehouse capacity are needed in order to minimize the company's inventory cost. The inventory model implemented in this study was the adapted economic order quantity (EOQ) model which is optimized using Lagrange multiplier. The model and solution approach were applied to solve a case industry in a food manufacturer. The result showed that the total inventory cost decreased 2.42% after applying the proposed approach.
Strength of the reversible, garbage-free 2 ^{k} ±1 multiplier
DEFF Research Database (Denmark)
Rotenberg, Eva; Cranch, James; Thomsen, Michael Kirkedal
2013-01-01
Recently, a reversible garbage-free 2 k ±1 constant-multiplier circuit was presented by Axelsen and Thomsen. This was the first construction of a garbage-free, reversible circuit for multiplication with non-trivial constants. At the time, the strength, that is, the range of constants obtainable...... by cascading these circuits, was unknown. In this paper, we show that there exist infinitely many constants we cannot multiply by using cascades of 2 k ±1-multipliers; in fact, there exist infinitely many primes we cannot multiply by. Using these results, we further provide an algorithm for determining whether...
Submillimeter-Wave Polarimetric Compact Ranges for Scale-Model Radar Measurements
National Research Council Canada - National Science Library
Coulombe, Michael J; Waldman, Jerry; Giles, R. H; Gatesman, Andrew J; Goyette, Thomas M; Nixon, William
2002-01-01
.... A dielectric material fabrication and characterization capability has also been developed to fabricate custom anechoic materials for the ranges as well as scaled dielectric parts for the models and clutter scenes...
Superconducting Coplanar Waveguide Filters for Submillimeter Wave On-Chip Filterbank Spectrometers
Endo, A.; Yates, S. J. C.; Bueno, J.; Thoen, D. J.; Murugesan, V.; Baryshev, A. M.; Klapwijk, T. M.; van der Werf, P. P.; Baselmans, J. J. A.
2016-01-01
We show the first experimental results which prove that superconducting NbTiN coplanar-waveguide resonators can achieve a loaded Q factor in excess of 800 in the 350 GHz band. These resonators can be used as narrow band pass filters for on-chip filter bank spectrometers for astronomy. Moreover, the
Superconducting Coplanar Waveguide Filters for Submillimeter Wave On-Chip Filterbank Spectrometers
Endo, A.; Yates, S.J.C.; Bueno, J.; Thoen, D.J.; Murugesan, V.; Baryshev, A.M.; Klapwijk, T.M.; Van der Werf, P.P.; Baselmans, J.J.A.
2016-01-01
We show the first experimental results which prove that superconducting NbTiN coplanar–waveguide resonators can achieve a loaded Q factor in excess of 800 in the 350 GHz band. These resonators can be used as narrow band pass filters for on-chip filter bank spectrometers for astronomy. Moreover, the
Advanced Amplifier Based Receiver Front Ends for Submillimeter-Wave-Sounders Project
National Aeronautics and Space Administration — Develop high electron mobility transistor (HEMT) amplifier based heterodyne radiometers to provide high sensitivity at millimeter and submillimeter wavelengths with...
Atmospheric Attenuation of Millimeter and Submillimeter Waves: Models and Computer Code
1979-10-15
oli i (f o.tl olwn ,.,...ssŕ: TZ - a.Th ai prnite enurdbn MI0l0- a -- tSU VtsR bu h aaee o rprac i satrn rp-c i- bji’l Tlw M 11--P disi, ribiut iont...Contract NAS-5-21624. iaan, Mei-Yuan (19 ) Microstructure of c-ujulus clouds, Isv. Geophys. 8er. No. 2:362-376, tUogg, D.C. and Chu , T S. (1975) The role
Superconducting Resonator Spectrometer for Millimeter- and Submillimeter-Wave Astrophysics Project
National Aeronautics and Space Administration — "We propose to develop a novel ultra-compact spectrograph-on-a-chip for the submillimeter and millimeter waveband. SuperSpec uses planar lithographed superconducting...
Recent results on measurement of plasma conductivity using Faraday rotation of submillimeter waves
Energy Technology Data Exchange (ETDEWEB)
Kuzmenko, P.J.; Self, S.A.
1982-01-01
This paper examines the application of Faraday rotation to the measurement of electron concentration in combustion MHD plasmas. Details on the design of a working system are given including the selection of operating wavelength. A theoretical comparison between the Faraday rotation technique and two path interferometry shows Faraday rotation in its simplest form to be somewhat less sensitive to changes in electron concentration. This deficit can be balanced against greater immunity to vibration and thermal drift. Improved techniques of measuring the rotation angle promise greater sensitivity. A preliminary experiment has verified the technique.
Modelling and Simulation of Magnetron Infection Guns for Submillimeter Wave Gyrotrons
S.P.SABCHEVSKI; G.M.Mladenov; IDEHARA, T
1999-01-01
The software package GUN-MIG has been developed for computer simulation of beam formation in magnetron injection guns (MIG). It is based on a fully relativistic self-consistent physical model which takes into account the specific problems and requirements that are being encountered in the analysis and design of MIG for gyrotrons. Besides providing a general outline of the physical models and the program implementation of the code, several illustrative examples of the numerical experiments wit...
Systems and Science Studies for Millimeter- and Submillimeter-wave Earth Venture Missions Project
National Aeronautics and Space Administration — The plan to develop a cost-compliant EV-i instrument concept entails developing a science and instrument-performance trade space that considers channel selection,...
Relations between bilinear multipliers on Rn,Tn Rn,Tn Rn,Tn and Zn ...
Indian Academy of Sciences (India)
Carro and Gillespie [5] and Grafakos [11]. Also, for some other transference results in the bilinear setting, see [2, 3] and [6]. In the same paper de Leeuw observed that periodic multipliers on R are precisely the ones which are multipliers on Z and vice versa. In §3 we investigate the bilinear analogue of these results.
Improved 64-bit Radix-16 Booth Multiplier Based on Partial Product Array Height Reduction
DEFF Research Database (Denmark)
Antelo, Elisardo; Montuschi, Paolo; Nannarelli, Alberto
2016-01-01
In this paper, we describe an optimization for binary radix-16 (modified) Booth recoded multipliers to reduce the maximum height of the partial product columns to ï£®n/4ï£¹ for [Formula: see text] unsigned operands. This is in contrast to the conventional maximum height of ï£®(n+1)/4ï£¹. Therefore......, a reduction of one unit in the maximum height is achieved. This reduction may add flexibility during the design of the pipelined multiplier to meet the design goals, it may allow further optimizations of the partial product array reduction stage in terms of area/delay/power and/or may allow additional addends...... to be included in the partial product array without increasing the delay. The method can be extended to Booth recoded radix-8 multipliers, signed multipliers, combined signed/unsigned multipliers, and other values of n....
Upgrading PhotoMultiplier Tube bases for FNAL E1039
Salinas, Roy; SeaQuest Collaboration
2017-09-01
Experiment 1039 at Fermilab National Laboratory is designed to study the spin structure within the nucleon. To effectively work towards a better understanding of the ``spin crisis'' concerning the quarks and gluons within the nucleon, E1039 will employ a polarized target and a 120 GeV proton beam. The E906/SeaQuest spectrometer will be reused for E1039 since it was designed to measure Drell-Yan events from interactions with quarks in the nucleon sea. The spectrometer consists of several detectors with multiple planes of scintillating hodoscopes, tracking chambers, and two large dipole magnets. An issue arose in the later stages of Experiment 906 regarding the scintillating PhotoMultiplier Tubes(PMTs) high current bases for the first two hodoscope stations. Heat produced in the PMT bases created damage to components on the primary circuit board resulting in failures after years of running. Multiple solutions focused on thermally connecting the daughter cards to the metal shielding pipe while also providing electrical isolation of the high voltages present. Comparisons of thermally conductive adhesive and epoxy were studied with several heat spreaders. This poster will cover the options considered and the chosen solution to the upgrade to the hodoscope PMT bases. Supported by U.S. D.O.E. Medium Energy Nuclear Physics under Grant DE-FG02-03ER41243.
Time-division-multiplex control scheme for voltage multiplier rectifiers
Directory of Open Access Journals (Sweden)
Bin-Han Liu
2017-03-01
Full Text Available A voltage multiplier rectifier with a novel time-division-multiplexing (TDM control scheme for high step-up converters is proposed in this study. In the proposed TDM control scheme, two full-wave voltage doubler rectifiers can be combined to realise a voltage quadrupler rectifier. The proposed voltage quadrupler rectifier can reduce transformer turn ratio and transformer size for high step-up converters and also reduce voltage stress for the output capacitors and rectifier diodes. An N-times voltage rectifier can be straightforwardly produced by extending the concepts from the proposed TDM control scheme. A phase-shift full-bridge (PSFB converter is adopted in the primary side of the proposed voltage quadrupler rectifier to construct a PSFB quadrupler converter. Experimental results for the PSFB quadrupler converter demonstrate the performance of the proposed TDM control scheme for voltage quadrupler rectifiers. An 8-times voltage rectifier is simulated to determine the validity of extending the proposed TDM control scheme to realise an N-times voltage rectifier. Experimental and simulation results show that the proposed TDM control scheme has great potential to be used in high step-up converters.
Gas Electron Multiplier Detectors for TREK at J-PARC
Dongwi, Bishoy
2013-10-01
Lepton flavor universality is a basic assumption of the Standard Model (SM). The proposed experiment E36 at J-PARC in Japan measures decay widths of stopped K+ using the TREK (Time Reversal Experiment with Kaons) detector system to conduct precision measurements of RK = Γ (K+ -->e+ ν) / Γ (K+ -->μ+ ν) in search of lepton flavor universality violation. The SM prediction for the ratio of leptonic K+ decays is highly precise with an uncertainty of △RK /RK = 4 .10-4 . Any observed deviation from the SM prediction would yield clear indication of New Physics beyond the Standard Model. To test lepton flavor universality violation a total uncertainty for the decay ratio of Ke 2 /Kμ 2 is aimed to be 0 . 25 % (0 . 20 % stat + 0 . 15 % sys). The second portion of the experiment searches for heavy sterile neutrinos (N) in the K+ -->μ+ N decay and allows for further stringent searches for light new particles as a byproduct. Gas Electron Multiplier (GEM) detectors will be constructed for this experiment in order to measure charged tracks of μ+ and e+ from charged K+ decay. I will present Geant4 simulations of the TREK setup augmented with the GEM detectors. This work has been supported by DOE Early Career Award DE-SC0003884.
Multiply-Imputed Synthetic Data: Advice to the Imputer
Directory of Open Access Journals (Sweden)
Loong Bronwyn
2017-12-01
Full Text Available Several statistical agencies have started to use multiply-imputed synthetic microdata to create public-use data in major surveys. The purpose of doing this is to protect the confidentiality of respondents’ identities and sensitive attributes, while allowing standard complete-data analyses of microdata. A key challenge, faced by advocates of synthetic data, is demonstrating that valid statistical inferences can be obtained from such synthetic data for non-confidential questions. Large discrepancies between observed-data and synthetic-data analytic results for such questions may arise because of uncongeniality; that is, differences in the types of inputs available to the imputer, who has access to the actual data, and to the analyst, who has access only to the synthetic data. Here, we discuss a simple, but possibly canonical, example of uncongeniality when using multiple imputation to create synthetic data, which specifically addresses the choices made by the imputer. An initial, unanticipated but not surprising, conclusion is that non-confidential design information used to impute synthetic data should be released with the confidential synthetic data to allow users of synthetic data to avoid possible grossly conservative inferences.
Permeability criteria for effective function of passive countercurrent multiplier.
Layton, H E; Knepper, M A; Chou, C L
1996-01-01
The urine concentrating effect of the mammalian renal inner medulla has been attributed to countercurrent multiplication of a transepithelial osmotic difference arising from passive absorption of NaCl from thin ascending limbs of long loops of Henle. This study assesses, both mathematically and experimentally, whether the permeability criteria for effective function of this passive hypothesis are consistent with transport properties measured in long loops of Henle of chinchilla. Mathematical simulations incorporating loop of Henle transepithelial permeabilities idealized for the passive hypothesis generated a steep inner medullary osmotic gradient, confirming the fundamental feasibility of the passive hypothesis. However, when permeabilities measured in chinchilla were used, no inner medullary gradient was generated. A key parameter in the apparent failure of the passive hypothesis is the long-loop descending limb (LDL) urea permeability, which must be small to prevent significant transepithelial urea flux into inner medullary LDL. Consequently, experiments in isolated perfused thin LDL were conducted to determine whether the urea permeability may be lower under conditions more nearly resembling those in the inner medulla. LDL segments were dissected from 30-70% of the distance along the inner medullary axis of the chinchilla kidney. The factors tested were NaCl concentration (125-400 mM in perfusate and bath), urea concentration (5-500 mM in perfusate and bath), calcium concentration (2-8 mM in perfusate and bath), and protamine concentration (300 micrograms/ml in perfusate). None of these factors significantly altered the measured urea permeability, which exceeded 20 x 10(-5) cm/s for all conditions. Simulation results show that this moderately high urea permeability in LDL is an order of magnitude too high for effective operation of the passive countercurrent multiplier.
Configurable multiplier modules for an adaptive computing system
Directory of Open Access Journals (Sweden)
O. A. Pfänder
2006-01-01
Full Text Available The importance of reconfigurable hardware is increasing steadily. For example, the primary approach of using adaptive systems based on programmable gate arrays and configurable routing resources has gone mainstream and high-performance programmable logic devices are rivaling traditional application-specific hardwired integrated circuits. Also, the idea of moving from the 2-D domain into a 3-D design which stacks several active layers above each other is gaining momentum in research and industry, to cope with the demand for smaller devices with a higher scale of integration. However, optimized arithmetic blocks in course-grain reconfigurable arrays as well as field-programmable architectures still play an important role. In countless digital systems and signal processing applications, the multiplication is one of the critical challenges, where in many cases a trade-off between area usage and data throughput has to be made. But the a priori choice of word-length and number representation can also be replaced by a dynamic choice at run-time, in order to improve flexibility, area efficiency and the level of parallelism in computation. In this contribution, we look at an adaptive computing system called 3-D-SoftChip to point out what parameters are crucial to implement flexible multiplier blocks into optimized elements for accelerated processing. The 3-D-SoftChip architecture uses a novel approach to 3-dimensional integration based on flip-chip bonding with indium bumps. The modular construction, the introduction of interfaces to realize the exchange of intermediate data, and the reconfigurable sign handling approach will be explained, as well as a beneficial way to handle and distribute the numerous required control signals.
The Origins of the SPAR-H Method's Performance Shaping Factor Multipliers
Energy Technology Data Exchange (ETDEWEB)
Ronald L. Boring; Harold S. Blackman
2007-08-01
The Standardized Plant Analysis Risk-Human Reliability Analysis (SPAR-H) method has proved to be a reliable, easy-to-use method for human reliability analysis. Calculation of human error probability (HEP) rates is especially straightforward, starting with pre-defined nominal error rates for cognitive vs. action oriented tasks, and incorporating performance shaping factor (PSF) multipliers upon those nominal error rates. SPAR-H uses eight PSFs with multipliers typically corresponding to nominal, degraded, and severely degraded human performance for individual PSFs. Additionally, some PSFs feature multipliers to reflect enhanced performance. Although SPAR-H enjoys widespread use among industry and regulators, current source documents on SPAR-H such as NUREG/CR-6883 do not provide a clear account of the origin of these multipliers. The present paper redresses this shortcoming and documents the historic development of the SPAR-H PSF multipliers, from the initial use of nominal error rates, to the selection of the eight PSFs, to the mapping of multipliers to available data sources such as a Technique for Human Error Rate Prediction (THERP). Where error rates were not readily derived from THERP and other sources, expert judgment was used to extrapolate appropriate values. In documenting key background information on the multipliers, this paper provides a much needed cross-reference for human reliability practitioners and researchers of SPAR-H to validate analyses and research findings.
Effect of the equity multiplier indicator in companies according the sectors
Directory of Open Access Journals (Sweden)
Lenka Lízalová
2013-01-01
Full Text Available Managers carry out the demand of the owners to maximise the rentability of invested capital with regards to the taken risk. The tool that evaluates the suitability to indebt in order to reach a higher rentability is the equity multiplier indicator. An analysis of the multiplier was carried out on 10 years of data from 456 Czech companies. Based on the data from these companies the influence of two components of the multiplier, which characterise the influence of indebtedness on the return on equity, was analysed. These components are “financial leverage” and “interest burden”, these having an antagonistic effect. The low variability of the equity multiplier is apparent in the companies of the administrative and support service sector and it is also relatively low in the companies of the agriculture, forestry and fishing sector; on the contrary, in for example the professional, scientific and technical activities and the sector of water, sewage and waste there are companies with higher variability of the equity multiplier. The paper identifies companies (in view of their sector specialization inclining to a larger utility of debts to increase the return on equity. The largest equity is reached in companies of the construction sector; the lowest effect of the multiplier is to be found in companies of the agriculture sector. The resulting value of the multiplier is to a large extent determined by the financial leverage indicator, to a lower extent and at the same time negatively by the interest burden indicator.
Analysis of multiplier effects of ICT sectors – a Croatian case
Directory of Open Access Journals (Sweden)
Damira Keček
2016-04-01
Full Text Available The impact of Information and Communication Technology (ICT on economic growth and development has nowadays proven to be significant for almost all national economies. In this paper, a quantitative analysis of the impact of ICT on Croatian economic growth is performed using the input-output (IO method. The direct and indirect effects of ICT sectors are analysed. Subsequently, simple output multipliers and simple value added multipliers are then calculated. The results indicate that there are no significant differences between the ICT multipliers for the Croatian economy in 2010 and multipliers of other sectors. The largest values of multipliers of all ICT sectors are attributed to the one of ICT service sector. Moreover, significant changes were also not observed when comparing ICT multipliers for the Croatian economy in 2004 and 2010. In addition to Croatia, multiplier analysis of ICT sectors was conducted for the group of new and long-standing European Union member states. The conclusion is that, in new member states, the implementation and usage of ICT has a lower contribution to economic growth and development.
A terahertz grid frequency doubler
Moussessian, Alina; Wanke, Michael C.; Li, Yongjun; Chiao, Jung-Chih; Allen, S. James; Crowe, Thomas W.; Rutledge, David B.
1998-01-01
We present a 144-element terahertz quasi-optical grid frequency doubler. The grid is a planar structure with bow-tie antennas as a unit cell, each loaded with a planar Schottky diode. The maximum output power measured for this grid is 24 mW at 1 THz for 3.1-μs 500-GHz input pulses with a peak input power of 47 W. An efficiency of 0.17% for an input power of 6.3 W and output power of 10.8 mW is measured. To date, this is the largest recorded output power for a multiplier at terahertz frequenci...
CORDIC TECHNIQUES FOR FIXED ANGLE OF ROTATION IN MULTIPLYING OPERATION OF QUATERNIONS
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N. A. Petrovsky
2015-01-01
Full Text Available The article contains a number of solutions for the key element of paraunitary filter banks based on quaternionic algebra (Q-PUBF – the multiplier of quaternions with usage of CORDIC (Coordinate Rotation Digital Computer techniques for the fixed angle of rotation where, unlike known solutions, 4D rotation control parameters are represented by nonlinear function of shifts number of input operands of the microrotation operation. Suggested approach of the multiplier designing on a quaternion-constant allows reaching the maximum performance of the multiplier scheme with low use of resources, for example, of FPGA.
Implementation gap between the theory and practice of biodiversity offset multipliers
DEFF Research Database (Denmark)
Bull, Joseph William; Lloyd, Samuel P.; Strange, Niels
2017-01-01
Emerging policies worldwide require biodiversity gains as compensation for losses associated with economic development, seeking to achieve “no net loss” (NNL). Multipliers – factors by which gains are larger than associated losses – can be crucial for true NNL. Here, we review the theoretical...... when considering, for example, ecological uncertainties. We propose even larger multipliers required to satisfy previously ignored considerations – including prospect theory, taboo trades, and power relationships. Conversely, our data analyses show that multipliers are smaller in practice, regularly...
Design of Integrated Circuits Approaching Terahertz Frequencies
DEFF Research Database (Denmark)
Yan, Lei
In this thesis, monolithic microwave integrated circuits(MMICs) are presented for millimeter-wave and submillimeter-wave or terahertz(THz) applications. Millimeter-wave power generation from solid state devices is not only crucial for the emerging high data rate wireless communications but also...... are designed based on the monolithic membrane supported Schottky diodes, which is under development at Chalmers University of Technology, Sweden. To simplify the baseband circuitry, the received IF signal from the subharmonic mixer is further amplified and downconverted to the DC range with a low noise...
High-Speed Low-Jitter Frequency Multiplication in CMOS
van de Beek, R.C.H.
2004-01-01
This thesis deals with high-speed Clock and Frequency Multiplication. The term `high-speedù applies to both the output and the reference frequency of the multiplier. Much emphasis is placed on analysis and optimization of the total timing inaccuracies, and on implementing a high-speed feedback
Multiply Surface-Functionalized Nanoporous Carbon for Vehicular Hydrogen Storage
Energy Technology Data Exchange (ETDEWEB)
Pfeifer, Peter [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics; Gillespie, Andrew [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics; Stalla, David [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics; Dohnke, Elmar [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics
2017-02-20
The purpose of the project “Multiply Surface-Functionalized Nanoporous Carbon for Vehicular Hydrogen Storage” is the development of materials that store hydrogen (H_{2}) by adsorption in quantities and at conditions that outperform current compressed-gas H_{2} storage systems for electric power generation from hydrogen fuel cells (HFCs). Prominent areas of interest for HFCs are light-duty vehicles (“hydrogen cars”) and replacement of batteries with HFC systems in a wide spectrum of applications, ranging from forklifts to unmanned areal vehicles to portable power sources. State-of-the-art compressed H_{2} tanks operate at pressures between 350 and 700 bar at ambient temperature and store 3-4 percent of H_{2} by weight (wt%) and less than 25 grams of H_{2} per liter (g/L) of tank volume. Thus, the purpose of the project is to engineer adsorbents that achieve storage capacities better than compressed H_{2} at pressures less than 350 bar. Adsorption holds H_{2} molecules as a high-density film on the surface of a solid at low pressure, by virtue of attractive surface-gas interactions. At a given pressure, the density of the adsorbed film is the higher the stronger the binding of the molecules to the surface is (high binding energies). Thus, critical for high storage capacities are high surface areas, high binding energies, and low void fractions (high void fractions, such as in interstitial space between adsorbent particles, “waste” storage volume by holding hydrogen as non-adsorbed gas). Coexistence of high surface area and low void fraction makes the ideal adsorbent a nanoporous monolith, with pores wide enough to hold high-density hydrogen films, narrow enough to minimize storage as non-adsorbed gas, and thin walls between pores to minimize the volume occupied by solid instead of hydrogen. A monolith can be machined to fit into a rectangular tank (low pressure, conformable tank), cylindrical tank
Paley's multiplier method does not accurately predict adult height in children with bone sarcoma
National Research Council Canada - National Science Library
Gilg, Magdalena Maria; Wibmer, Christine; Andreou, Dimosthenis; Avian, Alexander; Sovinz, Petra; Maurer-Ertl, Werner; Tunn, Per-Ulf; Leithner, Andreas
2014-01-01
.... Paley's multiplier is used for height prediction in healthy children, and has been suggested as a method to make growth predictions for children with osteosarcoma and Ewing's sarcoma when considering...
Chen, Shaobo; Chen, Pingxiuqi; Shao, Qiliang; Basha Shaik, Nazeem; Xie, Jiafeng
2017-05-01
The elliptic curve cryptography (ECC) provides much stronger security per bits compared to the traditional cryptosystem, and hence it is an ideal role in secure communication in smart grid. On the other side, secure implementation of finite field multiplication over GF(2 m ) is considered as the bottle neck of ECC. In this paper, we present a novel obfuscation strategy for secure implementation of systolic field multiplier for ECC in smart grid. First, for the first time, we propose a novel obfuscation technique to derive a novel obfuscated systolic finite field multiplier for ECC implementation. Then, we employ the DNA cryptography coding strategy to obfuscate the field multiplier further. Finally, we obtain the area-time-power complexity of the proposed field multiplier to confirm the efficiency of the proposed design. The proposed design is highly obfuscated with low overhead, suitable for secure cryptosystem in smart grid.
Investigation of the Decelerating Field of an Electron Multiplier under Negative Ion Impact
DEFF Research Database (Denmark)
Larsen, Elfinn; Kjeldgaard, K.
1973-01-01
The effect of the decelerating field of an electron multiplier towards negative ions was investigated under standard mass spectrometric conditions. Diminishing of this decelerating field by changing of the potential of the electron multiplier increased the overall sensitivity to negative ions by ...... by a factor of 100. The secondary electron emission coefficient for the negative halogen ions relative to I− were measured on CuBe at the kinetic energies 1.0 and 1.5 keV.......The effect of the decelerating field of an electron multiplier towards negative ions was investigated under standard mass spectrometric conditions. Diminishing of this decelerating field by changing of the potential of the electron multiplier increased the overall sensitivity to negative ions...
Karatsuba-Ofman Multiplier with Integrated Modular Reduction for GF(2m
Directory of Open Access Journals (Sweden)
CUEVAS-FARFAN, E.
2013-05-01
Full Text Available In this paper a novel GF(2m multiplier based on Karatsuba-Ofman Algorithm is presented. A binary field multiplication in polynomial basis is typically viewed as a two steps process, a polynomial multiplication followed by a modular reduction step. This research proposes a modification to the original Karatsuba-Ofman Algorithm in order to integrate the modular reduction inside the polynomial multiplication step. Modular reduction is achieved by using parallel linear feedback registers. The new algorithm is described in detail and results from a hardware implementation on FPGA technology are discussed. The hardware architecture is described in VHDL and synthesized for a Virtex-6 device. Although the proposed field multiplier can be implemented for arbitrary finite fields, the targeted finite fields are recommended for Elliptic Curve Cryptography. Comparing other KOA multipliers, our proposed multiplier uses 36% less area resources and improves the maximum delay in 10%.
On the existence of conservation law multiplier for partial differential equations
Zhang, Zhi-Yong
2015-02-01
In this paper, we use the property of nonlinear self-adjointness with differential substitution to study the existence of conservation law multiplier for partial differential equations (PDEs). Firstly, we give a sufficient and necessary condition for the existence of the multipliers involving only independent and dependent variables, which is the nonlinear self-adjointness of the studying PDEs. Secondly, a necessary condition for the existence of the multipliers involving derivatives is given for the general evolution PDEs, which is the nonlinear self-adjointness with differential substitution. Finally, applications of multiplier and nonlinear self-adjointness with differential substitution methods to nonlinear telegraph equations and a class of Korteweg-de Vries (KdV) type equations are performed and different types of conservation laws are constructed.
Cost-efficient design of a quantum multiplier-accumulator unit
Babu, Hafiz Md. Hasan
2017-01-01
This paper proposes a cost-efficient quantum multiplier-accumulator unit. The paper also presents a fast multiplication algorithm and designs a novel quantum multiplier device based on the proposed algorithm with the optimum time complexity as multiplier is the major device of a multiplier-accumulator unit. We show that the proposed multiplication technique has time complexity O((3 log2n)+1), whereas the best known existing technique has O(n log2 n), where n is the number of qubits. In addition, our design proposes three new quantum circuits: a circuit representing a quantum full-adder, a circuit known as quantum ANDing circuit, which performs the ANDing operation and a circuit presenting quantum accumulator. Moreover, the proposed quantum multiplier-accumulator unit is the first ever quantum multiplier-accumulator circuit in the literature till now, which has reduced garbage outputs and ancillary inputs to a great extent. The comparative study shows that the proposed quantum multiplier performs better than the existing multipliers in terms of depth, quantum gates, delays, area and power with the increasing number of qubits. Moreover, we design the proposed quantum multiplier-accumulator unit, which performs better than the existing ones in terms of hardware and delay complexities, e.g., the proposed (n× n)—qubit quantum multiplier-accumulator unit requires O(n2) hardware and O(log2n) delay complexities, whereas the best known existing quantum multiplier-accumulator unit requires O(n3) hardware and O((n-1)2 +1+n) delay complexities. In addition, the proposed design achieves an improvement of 13.04, 60.08 and 27.2% for 4× 4, 7.87, 51.8 and 27.1% for 8× 8, 4.24, 52.14 and 27% for 16× 16, 2.19, 52.15 and 27.26% for 32 × 32 and 0.78, 52.18 and 27.28% for 128 × 128-qubit multiplications over the best known existing approach in terms of number of quantum gates, ancillary inputs and garbage outputs, respectively. Moreover, on average, the proposed design gains an
Solution of second order linear fuzzy difference equation by Lagrange's multiplier method
Directory of Open Access Journals (Sweden)
Sankar Prasad Mondal
2016-06-01
Full Text Available In this paper we execute the solution procedure for second order linear fuzzy difference equation by Lagrange's multiplier method. In crisp sense the difference equation are easy to solve, but when we take in fuzzy sense it forms a system of difference equation which is not so easy to solve. By the help of Lagrange's multiplier we can solved it easily. The results are illustrated by two different numerical examples and followed by two applications.
$L^p$-results for fractional integration and multipliers for the Jacobi transform
Johansen, Troels Roussau
2011-01-01
We use precise asymptotic expansions for Jacobi functions $\\phi^{(\\alpha,\\beta)}_\\lambda$ parameters $\\alpha$, $\\beta$ satisfying $\\alpha>1/2$, $\\alpha>\\beta>-1/2$, to generalizing classical H\\"ormander-type multiplier theorem for the spherical transform on a rank one Riemannian symmetric space (by Clerc/Stein and Stanton/Tomas) to the framework of Jacobi analysis. In particular, multiplier results for the spherical transform on Damek--Ricci spaces are subsumed by this approach, and it yields...
Analysis of multiplier effects of ICT sectors – a Croatian case
Keček, Damira; Žajdela Hrustek, Nikolina; Dušak, Vesna
2016-01-01
The impact of Information and Communication Technology (ICT) on economic growth and development has nowadays proven to be significant for almost all national economies. In this paper, a quantitative analysis of the impact of ICT on Croatian economic growth is performed using the input-output (IO) method. The direct and indirect effects of ICT sectors are analysed. Subsequently, simple output multipliers and simple value added multipliers are then calculated. The results indicate that there ar...
DEFF Research Database (Denmark)
Thingholm, Tine E; Jensen, Ole N; Robinson, Phillip J
2008-01-01
spectrometric analysis, such as immobilized metal affinity chromatography or titanium dioxide the coverage of the phosphoproteome of a given sample is limited. Here we report a simple and rapid strategy - SIMAC - for sequential separation of mono-phosphorylated peptides and multiply phosphorylated peptides from...... and an optimized titanium dioxide chromatographic method. More than double the total number of identified phosphorylation sites was obtained with SIMAC, primarily from a three-fold increase in recovery of multiply phosphorylated peptides....
Isometric multipliers of Lp (G, X) Lp (G, X) Lp (G, X)
Indian Academy of Sciences (India)
We use the characterization of isometries of L p ( G , X ) onto itself to characterize the isometric, invertible, left multipliers of L p ( G , X ) for 1 ≤ < ∞, ≠ 2, under the assumption that is not the l p -direct sum of two non-zero subspaces. In fact we prove that if is an isometric left multiplier of L p ( G , X ) onto itself then ...
The Photon-Assisted Cascaded Electron Multiplier Operation in CF4 for Ion Backflow Suppression
Amaro, F. D.; Veloso, J. F. C. A.; dos Santos, J. M. F.; Breskin, A.; Chechik, R.; Lyashenko, A.
2008-06-01
The operation of the recently introduced photon assisted cascaded electron multiplier (PACEM) in CF4 is investigated. The PACEM uses the VUV scintillation produced in the electron avalanches of the first multiplier of the cascade to transfer the signal to the subsequent ones. The VUV scintillation induces the emission of a large number of photoelectrons from a Csl photocathode placed on the top-surface of the second multiplier. The photoelectrons are further multiplied in the subsequent stages of the cascade, resulting in efficient signal amplification. A mesh, set at a fixed voltage, is placed between the first and the second multipliers to block the charge transfer between them, thus suppressing all the ion backflow (IBF) heading to the first cascade element. The PACEM electrically isolates the first multiplier of the cascade and only the ions produced in the electron avalanches of the first element may flow back into the drift region. Operating in CF4, absolute IBFs as low as 1 ion per primary electron are achieved for drift fields of 0.1 kV/cm, while for fields of 0.5 kV/cm the absolute IBF is 10 ions/primary electron. This corresponds to an IBF of 10-4 at gains of 104, for time projection chambers (TPC) operating conditions, and IBFs of 10-5 at gains of 106 for gaseous photomultipliers (GPM) operating conditions.
Improved Quantization Error Compensation Method for Fixed-Width Booth Multipliers
Directory of Open Access Journals (Sweden)
Xiaolong Ma
2014-01-01
Full Text Available A novel quantization error (QE compensation method is proposed in design of high accuracy fixed-width radix-4 Booth multipliers, which will effectively reduce the QE and save the area of multipliers when they are employed in cognitive radio (CR detector and digital signal processor (DSP. The truncated partial-products of the proposed multipliers are finely divided into three sections: reserved section, adaptive compensation section, and constant compensation section. The QE compensation carries of the multipliers are generated by applying probability estimation based on a shrunken minor truncated section which is a combination of the constant compensation and adaptive compensation. The proposed compensation method not only reduces the QE of the fixed-width Booth multipliers, but also avoids the exhaustive computing resources (time and memory during getting the compensation carries by statistical simulation. The proposed method can achieve higher accuracy than the existing works under the same area and power budgets. Simulation and experiment results show that the improved compensation method has the minimum power-delay products compared with the existing methods under the same area and can save up to 30% area for realization of full-width radix-4 Booth multipliers.
VLSI Implementation of Fault Tolerance Multiplier based on Reversible Logic Gate
Ahmad, Nabihah; Hakimi Mokhtar, Ahmad; Othman, Nurmiza binti; Fhong Soon, Chin; Rahman, Ab Al Hadi Ab
2017-08-01
Multiplier is one of the essential component in the digital world such as in digital signal processing, microprocessor, quantum computing and widely used in arithmetic unit. Due to the complexity of the multiplier, tendency of errors are very high. This paper aimed to design a 2×2 bit Fault Tolerance Multiplier based on Reversible logic gate with low power consumption and high performance. This design have been implemented using 90nm Complemetary Metal Oxide Semiconductor (CMOS) technology in Synopsys Electronic Design Automation (EDA) Tools. Implementation of the multiplier architecture is by using the reversible logic gates. The fault tolerance multiplier used the combination of three reversible logic gate which are Double Feynman gate (F2G), New Fault Tolerance (NFT) gate and Islam Gate (IG) with the area of 160μm x 420.3μm (67.25 mm2). This design achieved a low power consumption of 122.85μW and propagation delay of 16.99ns. The fault tolerance multiplier proposed achieved a low power consumption and high performance which suitable for application of modern computing as it has a fault tolerance capabilities.
Modeling of parasitic elements in high voltage multiplier modules
Wang, J.
2014-01-01
It is an inevitable trend that the power conversion module will have higher switching frequency and smaller volume in the future. Bandgap devices, such as SiC and GaN devices, accelerate the process. With this process, the parasitic elements in the module will probably have stronger influence on
Varghese, Babu; Rajan, Vinayakrishnan; Van Leeuwen, Ton G.; Steenbergen, Wiendelt
2008-02-01
We describe an improved method for coherence domain path length resolved measurements of multiply scattered photons in turbid media. An electro-optic phase modulator sinusoidally modulates the phase in the reference arm of a low coherence fiber optic Mach-Zehnder interferometer, at a high phase modulation angle. For dynamic turbid media this results in Doppler broadened phase modulation interference peaks at the modulation frequency and its multiples. The signal to noise ratio is increased by almost one order or magnitude for large modulation angles and the shape of the spectral peaks resulting from the interference of Doppler shifted sample waves and reference light is not changed. The path length dependent Doppler broadening is compared with the theoretical predictions in the single scattered and diffusive regimes. The experimentally measured optical path lengths are validated with the Monte Carlo technique.
Power-Combined GaN Amplifier with 2.28-W Output Power at 87 GHz
Fung, King Man; Ward, John; Chattopadhyay, Goutam; Lin, Robert H.; Samoska, Lorene A.; Kangaslahti, Pekka P.; Mehdi, Imran; Lambrigtsen, Bjorn H.; Goldsmith, Paul F.; Soria, Mary M.;
2011-01-01
Future remote sensing instruments will require focal plane spectrometer arrays with higher resolution at high frequencies. One of the major components of spectrometers are the local oscillator (LO) signal sources that are used to drive mixers to down-convert received radio-frequency (RF) signals to intermediate frequencies (IFs) for analysis. By advancing LO technology through increasing output power and efficiency, and reducing component size, these advances will improve performance and simplify architecture of spectrometer array systems. W-band power amplifiers (PAs) are an essential element of current frequency-multiplied submillimeter-wave LO signal sources. This work utilizes GaN monolithic millimeter-wave integrated circuit (MMIC) PAs developed from a new HRL Laboratories LLC 0.15- m gate length GaN semiconductor transistor. By additionally waveguide power combining PA MMIC modules, the researchers here target the highest output power performance and efficiency in the smallest volume achievable for W-band.
Wave reflection and transmission in multiply stented blood vessels
Papathanasiou, T. K.; Movchan, A. B.; Bigoni, D.
2017-06-01
Closed circulatory systems display an exquisite balance between vascular elasticity and viscous fluid effects, to induce pulse-smoothing and avoid resonance during the cardiac cycle. Stents in the arterial tree alter this balance through stiffening and because a periodic structure is introduced, capable of interacting with the fluid in a complex way. While the former feature has been investigated, the latter received no attention so far. But periodic structures are the building blocks of metamaterials, known for their `non-natural' behaviour. Thus, the investigation of a stent's periodic microstructure dynamical interactions is crucial to assess possible pathological responses. A one-dimensional fluid-structure interaction model, simple enough to allow an analytical solution for situations of interest involving one or two interacting stents, is introduced. It is determined: (i) whether or not frequency bands exist in which reflected blood pulses are highly increased and (ii) if these bands are close to the characteristic frequencies of arteries and finally, (iii) if the internal structure of the stent can sensibly affect arterial blood dynamics. It is shown that, while the periodic structure of an isolated stent can induce anomalous reflection only in pathological conditions, the presence of two interacting stents is more critical, and high reflection can occur at frequencies not far from the physiological values.
Schlack, Robert; Ravens-Sieberer, Ulrike; Petermann, Franz
2013-06-01
This study investigates self-rated mental health in terms of psychological problems, protective factors and health-related quality of life (HRQOL) in a nationally representative sample of adolescents (n=6813) aged 11-17 involved in violence with varying frequency. Using MANCOVA and ANCOVA, youth with single and multiple histories of violent victimisation and violence perpetration were contrasted with non-involved comparisons. The results show that even low levels of violence involvement were associated with more problems, fewer protective factors and impaired HRQOL. Multiply victimised youth - not perpetrating victims - stood out with internalising, peer and hyperactivity/inattention problems. Discriminant function analysis separated non-involved from violence-affected youth, and multiply victimised from not multiply victimised youth. Externalising behaviours, family issues, male sex and school functioning predicted group separation on the first function (proportion variance explained 80.0%), while internalising and peer issues were predictive for the second function (PVE 14.2%). Implications for prevention, intervention and research are discussed. Copyright © 2013 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.
Mokhtar, Md Asjad; Kamalakar Darpe, Ashish; Gupta, Kshitij
2017-08-01
The ever-increasing need of highly efficient rotating machinery causes reduction in the clearance between rotating and non-rotating parts and increase in the chances of interaction between these parts. The rotor-stator contact, known as rub, has always been recognized as one of the potential causes of rotor system malfunctions and a source of secondary failures. It is one of few causes that influence both lateral and torsional vibrations. In this paper, the rotor stator interaction phenomenon is investigated in the finite element framework using Lagrange multiplier based contact mechanics approach. The stator is modelled as a beam that can respond to axial penetration and lateral friction force during the contact with the rotor. It ensures dynamic stator contact boundary and more realistic contact conditions in contrast to most of the earlier approaches. The rotor bending-torsional mode coupling during contact is considered and the vibration response in bending and torsion are analysed. The effect of parameters such as clearance, friction coefficient and stator stiffness are studied at various operating speeds and it has been found that certain parameter values generate peculiar rub related features. Presence of sub-harmonics in the lateral vibration frequency spectra are prominently observed when the rotor operates near the integer multiple of its lateral critical speed. The spectrum cascade of torsional vibration shows the presence of bending critical speed along with the larger amplitudes of frequencies close to torsional natural frequency of the rotor. When m × 1/n X frequency component of rotational frequency comes closer to the torsional natural frequency, stronger torsional vibration amplitude is noticed in the spectrum cascade. The combined information from the stator vibration and rotor lateral-torsional vibration spectral features is proposed for robust rub identification.
Multi-MW 22.8 GHz Harmonic Multiplier - RF Power Source for High-Gradient Accelerator R&D
Energy Technology Data Exchange (ETDEWEB)
Jay L. Hirshfield
2012-07-26
Electrodynamic and particle simulation studies have been carried out to optimize design of a two-cavity harmonic frequency multiplier, in which a linear electron beam is energized by rotating fields near cyclotron resonance in a TE111 cavity in a uniform magnetic field, and in which the beam then radiates coherently at the nth harmonic into a TEn11 output cavity. Examples are worked out in detail for 7th and 2nd harmonic converters, showing RF-to-RF conversion efficiencies of 45% and 88%, respectively at 19.992 GHz (K-band) and 5.712 GHz (C-band), for a drive frequency of 2.856 GHz. Details are shown of RF infrastructure (S-band klystron, modulator) and harmonic converter components (drive cavity, output cavities, electron beam source and modulator, beam collector) for the two harmonic converters to be tested. Details are also given for the two-frequency (S- and C-band) coherent multi-MW test stand for RF breakdown and RF gun studies.
On Adjusting the H-P Filter for the Frequency of Observations
Uhlig, H.F.H.V.S.; Ravn, M.
1997-01-01
This paper studies how the HP-Filter should be adjusted, when changing the frequency of observations. The usual choices in the literature are to adjust the smoothing parameter by multiplying it with either the square of the observation frequency ratios or simply with the observation frequency. In
A graphene based frequency quadrupler
Cheng, Chuantong; Huang, Beiju; Mao, Xurui; Zhang, Zanyun; Zhang, Zan; Geng, Zhaoxin; Xue, Ping; Chen, Hongda
2017-04-01
Benefit from exceptional electrical transport properties, graphene receives worldwide attentions, especially in the domain of high frequency electronics. Due to absence of effective bandgap causing off-state the device, graphene material is extraordinarily suitable for analog circuits rather than digital applications. With this unique ambipolar behavior, graphene can be exploited and utilized to achieve high performance for frequency multipliers. Here, dual-gated graphene field-effect transistors have been firstly used to achieve frequency quadrupling. Two Dirac points in the transfer curves of the designed GFETs can be observed by tuning top-gate voltages, which is essential to generate the fourth harmonic. By applying 200 kHz sinusoid input, arround 50% of the output signal radio frequency power is concentrated at the desired frequency of 800 kHz. Additionally, in suitable operation areas, our devices can work as high performance frequency doublers and frequency triplers. Considered both simple device structure and potential superhigh carrier mobility of graphene material, graphene-based frequency quadruplers may have lots of superiorities in regards to ultrahigh frequency electronic applications in near future. Moreover, versatility of carbon material system is far-reaching for realization of complementary metal-oxide-semiconductor compatible electrically active devices.
Rais, Muhammad H.
2010-06-01
This paper presents Field Programmable Gate Array (FPGA) implementation of standard and truncated multipliers using Very High Speed Integrated Circuit Hardware Description Language (VHDL). Truncated multiplier is a good candidate for digital signal processing (DSP) applications such as finite impulse response (FIR) and discrete cosine transform (DCT). Remarkable reduction in FPGA resources, delay, and power can be achieved using truncated multipliers instead of standard parallel multipliers when the full precision of the standard multiplier is not required. The truncated multipliers show significant improvement as compared to standard multipliers. Results show that the anomaly in Spartan-3 AN average connection and maximum pin delay have been efficiently reduced in Virtex-4 device.
Economic Multipliers and Sectoral Linkages: Ghana and the New Oil Sector
Directory of Open Access Journals (Sweden)
Dennis Nchor
2016-01-01
Full Text Available The study seeks to assess the structure of the economy of Ghana in terms of changes in the economic structure before and after the production of oil in commercial quantities. This is viewed with regards to economic multipliers, sectoral interdependence and trade concentration. The results show that changes occurred with regards to multipliers and sectoral interdependence. The output multipliers of most sectors have declined. The results also show that the agricultural sector experienced an initial decline in its growth while industry experienced an increase. The performance of the services sector was relatively stable for the period covered by the study. There is a decline in the level of trade concentration though on a whole the concentration index is still high. The study employed input-output modeling techniques and the data was obtained from the Ghana statistical service and the World Development Indicators.
Calculation of simultaneous chemical and phase equilibrium by the methodof Lagrange multipliers
DEFF Research Database (Denmark)
Tsanas, Christos; Stenby, Erling Halfdan; Yan, Wei
2017-01-01
The purpose of this work is to develop a general, reliable and efficient algorithm, which is able to deal with multiple reactions in multiphase systems. We selected the method of Lagrange multipliers to minimize the Gibbs energy of the system, under material balance constraints. Lagrange multipli......The purpose of this work is to develop a general, reliable and efficient algorithm, which is able to deal with multiple reactions in multiphase systems. We selected the method of Lagrange multipliers to minimize the Gibbs energy of the system, under material balance constraints. Lagrange...... iteration in the inner loop and non-ideality updated in the outer loop, thus giving an overall linear convergence rate. Stability analysis is used to introduce additional phases sequentially so as to obtain the final multiphase solution. The procedure was successfully tested on vapor-liquid equilibrium (VLE......) and vapor-liquid-liquid equilibrium (VLLE) of reaction systems....
Directory of Open Access Journals (Sweden)
Siti Komsiyah
2012-06-01
Full Text Available On electric power system operation, economic planning problem is one variable to take into account due to operational cost efficiency. Economic Dispatch problem of electric power generation is discussed in this study to manage the output division on several units based on the the required load demand, with minimum operating cost yet is able to satisfy equality and inequality constraint of all units and system. In this study the Economic Dispatch problem which has non linear cost function is solved using swarm intelligent method is Gaussian Particle Swarm Optimization (GPSO and Lagrange Multiplier. GPSO is a population-based stochastic algorithms which their moving is inspired by swarm intelligent and probabilities theories. To analize its accuracy, the Economic Dispatch solution by GPSO method is compared with Lagrange Multiplier method. From the test result it is proved that GPSO method gives economic planning calculation better than Lagrange Multiplier does.
The Photon-Assisted Cascaded Electron Multiplier: a concept for potential avalanche-ion blocking
Veloso, J. F. C. A.; Amaro, F. D.; dos Santos, J. M. F.; Breskin, A.; Lyashenko, A.; Chechik, R.
2006-08-01
We present a Photon-Assisted Cascaded Electron Multipliers (PACEM) which has a potential for ion back-flow blocking in gaseous radiation detectors: the avalanche from a first multiplication stage propagates to the successive one via its photons, which in turn induce photoelectron emission from a photocathode deposited on the second multiplier stage; the multiplication process may further continue via electron-avalanche propagation. The photonmediated stage allows, by a proper choice of geometry and fields, complete blocking of the ion back-flow into the first element; thus, only ions from the latter will flow back to the drift region. The PACEM concept was validated in a double-MHSP (Micro-Hole & Strip Plate) cascaded multiplier operated in xenon, where the intermediate scintillation stage provided optical gain of ~60. The double-MHSP detector had a total gain above 104 and energy resolution of 18% FWHM for 5.9 keV x-rays.
The Photon-Assisted Cascaded Electron Multiplier: a concept for potential avalanche-ion blocking
Energy Technology Data Exchange (ETDEWEB)
Veloso, J F C A [Physics Dept., University of Aveiro, 3810-193 Aveiro (Portugal); Amaro, F D [Physics Dept., University of Coimbra, 3004-516 Coimbra (Portugal); Santos, J M F dos [Physics Dept., University of Coimbra, 3004-516 Coimbra (Portugal); Breskin, A [Dept. of Particle Physics, Weizmann Institute of Science, 76100 Rehovot (Israel); Lyashenko, A [Dept. of Particle Physics, Weizmann Institute of Science, 76100 Rehovot (Israel); Chechik, R [Dept. of Particle Physics, The Weizmann Institute of Science, 76100 Rehovot (Israel)
2006-08-15
We present a Photon-Assisted Cascaded Electron Multipliers (PACEM) which has a potential for ion back-flow blocking in gaseous radiation detectors: the avalanche from a first multiplication stage propagates to the successive one via its photons, which in turn induce photoelectron emission from a photocathode deposited on the second multiplier stage; the multiplication process may further continue via electron-avalanche propagation. The photonmediated stage allows, by a proper choice of geometry and fields, complete blocking of the ion back-flow into the first element; thus, only ions from the latter will flow back to the drift region. The PACEM concept was validated in a double-MHSP (Micro-Hole and Strip Plate) cascaded multiplier operated in xenon, where the intermediate scintillation stage provided optical gain of {approx}60. The double-MHSP detector had a total gain above 10{sup 4} and energy resolution of 18% FWHM for 5.9 keV x-rays.
Design of Low Power Multiplier with Energy Efficient Full Adder Using DPTAAL
Directory of Open Access Journals (Sweden)
A. Kishore Kumar
2013-01-01
Full Text Available Asynchronous adiabatic logic (AAL is a novel lowpower design technique which combines the energy saving benefits of asynchronous systems with adiabatic benefits. In this paper, energy efficient full adder using double pass transistor with asynchronous adiabatic logic (DPTAAL is used to design a low power multiplier. Asynchronous adiabatic circuits are very low power circuits to preserve energy for reuse, which reduces the amount of energy drawn directly from the power supply. In this work, an 8×8 multiplier using DPTAAL is designed and simulated, which exhibits low power and reliable logical operations. To improve the circuit performance at reduced voltage level, double pass transistor logic (DPL is introduced. The power results of the proposed multiplier design are compared with the conventional CMOS implementation. Simulation results show significant improvement in power for clock rates ranging from 100 MHz to 300 MHz.
Proposal for electro-optic multiplier based on dual transverse electro-optic Kerr effect.
Li, Changsheng
2008-10-20
A novel electro-optic multiplier is proposed, which can perform voltage multiplication operation by use of the Kerr medium exhibiting dual transverse electro-optic Kerr effect. In this kind of Kerr medium, electro-optic phase retardation is proportional to the square of its applied electric field, and orientations of the field-induced birefringent axes are only related to the direction of the field. Based on this effect, we can design an electro-optic multiplier by selecting the crystals of 6/mmm, 432, and m3m classes and isotropic Kerr media such as glass. Simple calculation demonstrates that a kind of glass-ceramic material with a large Kerr constant can be used for the design of the proposed electro-optic multiplier.
Sigafoos, J; Meikle, B
1996-01-01
Functional communication training was used to replace multiply determined problem behavior in two boys with autism. Experiment 1 involved a functional analysis of several topographies of problem behavior using a variation of the procedures described by Iwata, Dorsey, Slifer, Bauman, and Richman. Results suggested that aggression, self-injury, and disruption were multiply determined (i.e., maintained by both attention and access to preferred objects). Experiment 2 involved a multiple-baseline design across subjects. The focus of intervention was to replace aggression, self-injury, and disruption with functionally equivalent communicative alternatives. Both boys were taught alternative "mands" to recruit attention and request preferred objects. Acquisition of these alternative communication skills was associated with concurrent decreases in aggression, self-injury, and disruption. Results suggest that multiply determined challenging behavior can be decreased by teaching an alternative communication skill to replace each assessed function of the problem behavior.
Schedulling Economical Thermal Power Plant 500 KV Java-Bali System Using Lagrange Multiplier
Sartika, N.; Abdullah, A. G.; Hakim, D. L.
2017-03-01
The highest cost of electricity generation operation is fuel cost. Therefore, it is necessary to optimize the thermal generator scheduling. The present study aimed at obtaining the schedule and load sharing of the electric power generation, in order to gain the minimum fuel cost, with regard to inequality and equality constraints. The data tested was the thermal generation system of 500 kV Java-Bali using daily loads. This study employed a lagrange multiplier method to perform the economic scheduling. This method is one of mathematical techniques commonly used to solve economic dispatch problems. The results of the optimation of lagrange multiplier were compared with the real condition in the field. Based on the optimation results, it was found that the lagrange multiplier method is more economical than the real condition of system.
Low Voltage Floating Gate MOS Transistor Based Four-Quadrant Multiplier
Directory of Open Access Journals (Sweden)
R. Srivastava
2014-12-01
Full Text Available This paper presents a four-quadrant multiplier based on square-law characteristic of floating gate MOSFET (FGMOS in saturation region. The proposed circuit uses square-difference identity and the differential voltage squarer proposed by Gupta et al. to implement the multiplication function. The proposed multiplier employs eight FGMOS transistors and two resistors only. The FGMOS implementation of the multiplier allows low voltage operation, reduced power consumption and minimum transistor count. The second order effects caused due to mobility degradation, component mismatch and temperature variations are discussed. Performance of the proposed circuit is verified at ±0.75 V in TSMC 0.18 µm CMOS, BSIM3 and Level 49 technology by using Cadence Spectre simulator.
Multiply charged ion dissociation in Fourier transform ion cyclotron resonance mass spectrometer
Energy Technology Data Exchange (ETDEWEB)
Wu, Qinyuan; Bakhtair, R.; Sherman, M.G.; Hofstadler, S.A.; Smith, R.D. [Pacific Northwest Laboratory, Richland, WA (United States)
1994-12-31
Bimolecular ions of up to MDa size with thousands of charges have recently been trapped and studied in this laboratory using electrospray ionization (ESI) and Fourier transform ion cyclotron resonance mass spectrometer (FTICRMS). For structural analysis, multiply charged ions generated by ESI can be dissociated at the interface, by collision induced dissociation (CID) or Surface induced dissociation (SID). However, charge exchange with the surface and charge partition among the fragments significantly complicate the SID and CID spectra of multiply charged large ions. High resolution FTICR is an ideal solution to this problem.
Yunus, Arif A. M.; Murid, Ali H. M.
2017-04-01
This paper presents a boundary integral equation method with the adjoint generalized Neumann kernel for conformal mapping of unbounded multiply connected regions. The canonical region is the entire complex plane bounded by an infinite straight slit on the line Im ω = 0 and finite logarithmic spiral slits. Some linear boundary integral equations are constructed from a boundary relationship satisfied by an analytic function on a multiply connected region. These integral equations are uniquely solvable. The kernel involved in these integral equations is the adjoint generalized Neumann kernel.
Energy Technology Data Exchange (ETDEWEB)
WELLNER,A.; NELLIST,P.D.; PALMER,R.E.; AINDOW,M.; WILCOXON,JESS P.
2000-07-18
The influence of the substrate on the translational and orientational ordering in sub-monolayer films of passivated multiply-twinned gold clusters has been investigated using high resolution and dark field transmission electron microscopy. Although clear differences were observed in the degree of translational ordering on amorphous carbon and etched silicon substrates, there was no corresponding variation in the crystallographic orientation of the nanocrystal cores. The results demonstrate that the orientation of passivated clusters with multiply-twinned cores is effectively random with respect to both the superlattice and the substrate.
Energy Technology Data Exchange (ETDEWEB)
Lai, N.D.
2003-07-15
crystal. Applications to the generation of microwaves and submillimeter waves using these two-frequency sources in the visible spectrum are discussed. (author)
Traveling-Wave Tube Amplifier for THz Frequencies
DEFF Research Database (Denmark)
Kotiranta, Mikko; Krozer, Viktor; Zhurbenko, Vitaliy
The lack of a compact and powerful terahertz source has been hindering the application of terahertz radiation in many fields. Frequency multipliers can be used in conjunction with an electronic solid-state source to obtain power levels up to around 1 mW. A higher power may be generated with vacuu...
Discovery of a faint, star-forming, multiply lensed, Lyman-α blob
Caminha, G. B.; Karman, W.; Rosati, P.; Caputi, K. I.; Arrigoni Battaia, F.; Balestra, I.; Grillo, C.; Mercurio, A.; Nonino, M.; Vanzella, E.
2016-01-01
We report the discovery of a multiply lensed Lyman-α blob (LAB) behind the galaxy cluster AS1063 using the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT). The background source is at z = 3.117 and is intrinsically faint compared to almost all previously reported LABs. We
Ionization and fragmentation modes of nucleobases after collisions with multiply charged ions
Hoekstra, R.; Morgenstern, R.; Schlathoelter, T.
2004-01-01
We studied multiply charged ion (MCI) induced ionization, excitation and fragmentation of the nucleobases uracil and thymine. Ions of different charge state at velocities between 0.2 and 0.4 atomic units were used as projectiles. By means of time-of-flight spectrometry of the collision products in a
Modeling of Schottky Barrier Diode Millimeter-Wave Multipliers at Cryogenic Temperatures
DEFF Research Database (Denmark)
Johansen, Tom K.; Rybalko, Oleksandr; Zhurbenko, Vitaliy
2015-01-01
We report on the evaluation of Schottky barrier diode GaAs multipliers at cryogenic temperatures. A GaAs Schottky barrier diode model is developed for theoretical estimation of doubler performance. The model is used to predict efficiency of doublers from room to cryogenic temperatures...
Faster multiplier and squaring units for evaluation of powers and monomials: a hardware approach
Srinivasan, Aparna
2013-03-01
In processors, especially DSPs, the most recurring operations are those that involve exponents and monomials. In this paper, the use of a multiplier and squaring technique based on Vedic mathematics is suggested. Algorithms for calculation of monomials and exponents that make use of the described hardware are also stated.
Effects of the Implicit or Explicit Use of 1 on Students' Responses When Multiplying Monomials.
Anderson, Ann
1995-01-01
Tests of (n=105) ninth-grade algebra students involving the addition and multiplication of monomials found that common, systematic errors made when multiplying monomials were related logically to the symbolism used and the algebraic convention of using an implicit 1 as an exponent. (16 references) (MKR)
Ultra-low-power, class-AB, CMOS four-quadrant current multiplier
Sawigun, C.; Serdijn, W.A.
2009-01-01
A class-AB four-quadrant current multiplier constituted by a class-AB current amplifier and a current splitter which can handle input signals in excess of ten times the bias current is presented. The proposed circuit operation is based on the exponential characteristic of BJTs or subthreshold
Composite Field Multiplier based on Look-Up Table for Elliptic Curve Cryptography Implementation
Directory of Open Access Journals (Sweden)
Marisa W. Paryasto
2013-09-01
Full Text Available Implementing a secure cryptosystem requires operations involving hundreds of bits. One of the most recommended algorithm is Elliptic Curve Cryptography (ECC. The complexity of elliptic curve algorithms and parameters with hundreds of bits requires specific design and implementation strategy. The design architecture must be customized according to security requirement, available resources and parameter choices. In this work we propose the use of composite field to implement finite field multiplication for ECC implementation. We use 299-bit keylength represented in GF((21323 instead of in GF(2299. Composite field multiplier can be implemented using different multiplier for ground-field and for extension field. In this paper, LUT is used for multiplication in the ground-field and classic multiplieris used for the extension field multiplication. A generic architecture for the multiplier is presented. Implementation is done with VHDL with the target device Altera DE2. The work in this paper uses the simplest algorithm to confirm the idea that by dividing field into composite, use different multiplier for base and extension field would give better trade-off for time and area. This work will be the beginning of our more advanced further research that implements composite-field using Mastrovito Hybrid, KOA and LUT.
Directory of Open Access Journals (Sweden)
Chunhong Tian
2017-01-01
Full Text Available We are concerned with the regularity criterion for weak solutions to the 3D incompressible MHD equations in this paper. We show that if some partial derivatives of the velocity components and magnetic components belong to the multiplier spaces, then the solution actually is smooth on (0,T.
High dynamic range isotope ratio measurements using an analog electron multiplier
Czech Academy of Sciences Publication Activity Database
Williams, P.; Lorinčík, Jan; Franzreb, K.; Herwig, R.
2013-01-01
Roč. 45, č. 1 (2013), s. 549-552 ISSN 0142-2421 R&D Projects: GA MŠk ME 894 Institutional support: RVO:67985882 Keywords : Isotope ratios * electron multiplier * dynamic range Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.393, year: 2013
Directory of Open Access Journals (Sweden)
Sankar Prasad Mondal
2013-11-01
Full Text Available In this paper the First Order Linear Fuzzy Ordinary Differential Equations are described. Here coefficients and /or initial condition of said differential equation are taken as the Generalized Triangular Fuzzy Numbers (GTFNs.The solution procedure of this Fuzzy Differential Equation is developed by Lagrange Multiplier Method. An imprecise barometric pressure problem is described.
Implementation gap between the theory and practice of biodiversity offset multipliers
DEFF Research Database (Denmark)
Bull, Joseph William; Lloyd, Samuel P.; Strange, Niels
2017-01-01
Emerging policies worldwide require biodiversity gains as compensation for losses associated with economic development, seeking to achieve “no net loss” (NNL). Multipliers – factors by which gains are larger than associated losses – can be crucial for true NNL. Here, we review the theoretical...
An Innovative Approach of Binary Double Stage Multiplier for Real Time Applications
Kalyani Lakshmi, T.; Nayeemuddin, D.; Samba Siva Nayak, R.; Singh, Yadu, Dr.; Lokaiah, P.; Subbarao, A. V.
2017-08-01
In today’s world of portable and super fast electronic gadgets, speed is major concern point. Multiplication is used in many applications such as Fourier transform, discrete cosine transform, and digital filtering. If the multipliers too slow, the performance of entire circuits will be reduced. On VLSI implementation level, the area also becomes quite important as more area means more system cost. So, speed and area are two important parameters in VLSI Design. This paper presents the design a Double Stage multiplier for 32*32 binary bit number multiplication. The proposed system consists of 2 stages of operation. The two stages of operation is used to complete the operation of multiplier. By extending the bits of generator an additional product of Double Stage multiplier is obtained. By lowering the complexity of the product of partial reduction we can reduce the area and delay. So, multiplication operation is performed by the Double Stage is efficient with the less area and it reduces delay i.e., speed is increased.
Harley, Randall K.; And Others
In the final report on the project to develop programed instruction in orientation and mobility for use by teachers of multiply impaired blind children, the development of the evaluation scales and programed instruction in four basic areas of precane training, the results of field testing, and the dissemination activities are described. An…
Harley, Randall K.
Described is the development of a programed instruction manual in mobility and orientation skills for multiply handicapped blind children. Detailed are procedures involved in creating a developmental scale to assess five basic areas: use of a seated guide, seating, trailing, protective skills, and route travel. Results are reported for a pilot…
A Classical Conditioning Procedure for the Hearing Assessment of Multiply Handicapped Persons.
Lancioni, Giulio E.; And Others
1989-01-01
Hearing assessments of multiply handicapped children/adolescents were conducted using classical conditioning (with an air puff as unconditioned stimulus) and operant conditioning (with a modified visual reinforcement audiometry procedure or edible reinforcement). Findings indicate that classical conditioning was successful with 21 of the 23…
Evaluation of multiplier effect of housing investments in the city economy
Ovsiannikova, T.; Rabtsevich, O.; Yugova, I.
2017-01-01
The given study presents evaluation of the role and significance of housing investments providing stable social and economic development of a city. It also justifies multiplier impact of investments in housing construction on all the sectors of urban economy. Growth of housing investments generates multiplier effect triggering the development of other different interrelated sectors. The paper suggests approach developed by the authors to evaluate the level of city development. It involves defining gross city product on the basis of integral criterion of gross value added of types of economic activities in the city economy. The algorithm of gross value added generation in urban economy is presented as a result of multiplier effect of housing investments. The evaluation of the mentioned effect was shown on the case of the city of Tomsk (Russia). The study has revealed that multiplier effect allows obtaining four rubles of added value out of one ruble of housing investments in the city economy. Methods used in the present study include the ones of the System of National Accounts, as well as methods of statistical and structural analysis. It has been proved that priority investment in housing construction is considered to be the key factor for stable social and economic development of the city. Developed approach is intended for justification of priority directions in municipal and regional investment policy. City and regional governing bodies and potential investors are the ones to apply the given approach.
Energy and intensity distributions of 279 keV multiply scattered ...
Indian Academy of Sciences (India)
An inverse response matrix converts the observed pulse-height distribution of a NaI(Tl) scintillation detector to a true photon spectrum. This also results in extraction of intensity and energy distributions of multiply scattered events originating from interactions of 279 keV photons with thick targets of bronze. The observed ...
An Exploration of Social Media Use among Multiply Minoritized LGBTQ Youth
Lucero, Alfie Leanna
2013-01-01
This study responds to a need for research in a fast-growing and significant area of study, that of exploring, understanding, and documenting the numerous ways that multiply marginalized LGBTQ youth between the ages of 14 and 17 use social media. The primary research question examined whether social media provide safe spaces for multiply…
The Multiplier Effect: A Strategy for the Continuing Education of School Psychologists
Lesiak, Walter; And Others
1975-01-01
Twenty-two school psychologists participated in a year long institute designed to test the use of a multiplier effect in the continuing professional development of school psychologists in Michigan. Results indicated that 550 school psychologists attended two in-service meetings with generally favorable reactions. (Author)
The net multiplier is a new key sector indicator : Reply to De Mesnard's comment
Oosterhaven, Jan
Most of the comment of de Mesnard applies to a causal interpretation of the net multiplier that is applied to economically impossible exogenous (changes in) total output. This reply shows that this interpretation is incorrect and that his further argumentation is based on a time inconsistent
Multiply periodic states and isolated skyrmions in an anisotropic frustrated magnet
Mostovoy, Maxim; Leonov, Andrey
2015-01-01
Multiply periodic states appear in a wide variety of physical contexts, such as the Rayleigh–Bénard convection, Faraday waves, liquid crystals and skyrmion crystals recently observed in chiral magnets. Here we study the phase diagram of an anisotropic frustrated magnet which contains five different
The impact of founder events on chromosomal variability in multiply mating species
DEFF Research Database (Denmark)
Pool, John E; Nielsen, Rasmus
2008-01-01
size reductions and recent bottlenecks leading to decreased X/A diversity ratios. Here we use theory and simulation to investigate a separate demographic effect-that of founder events involving multiply mated females-and find that it leads to much stronger reductions in X/A diversity ratios than...
Testing of money multiplier model for Pakistan: does monetary base carry any information?
Directory of Open Access Journals (Sweden)
Muhammad Arshad Khan
2010-02-01
Full Text Available This paper tests the constancy and stationarity of mechanic version of the money multiplier model for Pakistan using monthly data over the period 1972M1-2009M2. We split the data into pre-liberalization (1972M1-1990M12 and post-liberalization (1991M1-2009M2 periods to examine the impact of financial sector reforms. We first examine the constancy and stationarity of the money multiplier and the results suggest the money multiplier remains non-stationary for the entire sample period and sub-periods. We then tested cointegration between money supply and monetary base and find the evidence of cointegration between two variables for the entire period and two sub-periods. The coefficient restrictions are satisfied only for the post-liberalization period. Two-way long-run causality between money supply and monetary base is found for the entire period and post-liberalization. For the post-liberalization period the evidence of short-run causality running from monetary base to money supply is also identified. On the whole, the results suggest that money multiplier model can serve as framework for conducting short-run monetary policy in Pakistan. However, the monetary authority may consider the co-movements between money supply and reserve money at the time of conducting monetary policy.
Time-area efficient multiplier-free filter architectures for FPGA implementation
DEFF Research Database (Denmark)
Shajaan, Mohammad; Nielsen, Karsten; Sørensen, John Aasted
1995-01-01
Simultaneous design of multiplier-free filters and their hardware implementation in Xilinx field programmable gate array (XC4000) is presented. The filter synthesis method is a new approach based on cascade coupling of low order sections. The complexity of the design algorithm is 𝒪 (filter o...
Pointwise Multipliers on Spaces of Homogeneous Type in the Sense of Coifman and Weiss
Directory of Open Access Journals (Sweden)
Yanchang Han
2014-01-01
homogeneous type in the sense of Coifman and Weiss, pointwise multipliers of inhomogeneous Besov and Triebel-Lizorkin spaces are obtained. We make no additional assumptions on the quasi-metric or the doubling measure. Hence, the results of this paper extend earlier related results to a more general setting.
A Low-jitter 2.5-to-10 GHz Clock Multiplier Unit in CMOS
van de Beek, R.C.H.; Vaucher, C.S.; Leenaerts, D.M.W.; Klumperink, Eric A.M.; Nauta, Bram
Abstract— This paper demonstrates a low-jitter clock multiplier unit [1] that generates a 10 GHz output clock from a 2.5 GHz reference clock. An integrated 10 GHz LCoscillator is locked to the input clock, using a simple and fast phase detector circuit. This phase detector overcomes the speed
KAJIAN EFEK MULTIPLIER PRODUK UNGGULAN BERBASIS KLUSTER UKM PENGOLAHAN IKAN ASAP
Directory of Open Access Journals (Sweden)
Yusmar Ardhi Hidayat
2015-05-01
Full Text Available The purpose of this research are to analyze scale of production of leading commodities and multiplier effect of cultivation and smoked fish in Wonosari, Bonang Demak. This research applies census method in collecting data from all business unit which identified as leading commodities in Wirosari Village, Bonang, Demak Regency. Regarding survey conducted, there are 18 catfish breeders and 49 smoked fish small business used as respondent. Primary data used in this research are rate of production in basis goods, land area, capital, raw materials, manpower, and income multiplier. To support empirical discussion, tools of analysis used in this research are descriptive statistics and income multiplier. Results of this research are primary commodities in Wonosari Village are smoked fish and fresh cat fish. Total production of smoked fish reaches 6.4 Ton each day for with type of smoked fish such as river cat fish, tongkol, sting-ray, cat fish, and other river fish. Meanwhile total production of catfish breeding reaches 105 Ton in first harvest after 2-3 months. Based on that number, smoked fish business promise higher profit than profits catfish breeding. Tujuan penelitian ini adalah menganalisis tingkat produksi dan efek multiplier produk unggulan budidaya dan pengasapan ikan di Desa Wonosari, Bonang Kabupaten Demak. Penelitian mengunakan metode sensus dengan mencari data dari semua unit usaha yang merupakan produk unggulan di Desa Wirosari, Bonang Kecamatan Demak. Responden yang diperoleh sejumlah 18 pembudidaya ikan dan 49 usaha pengasapan ikan. Data primer yang akan digunakan yaitu data jumlah produksi komoditas unggulan, luas lahan, jumlah modal, bahan baku, tenaga kerja, dan multiplier pendapatan. Alat analisis yang digunakan dalam penelitian ini adalah statistik deskriptif, dan indeks multiplier pendapatan. Hasil penelitian menunjukkan bahwa komoditas unggulan Desa Wonosari Kecamatan Bonang Kabupaten Demak adalah Ikan Asap dan Budidaya Ikan Lele
DO PUBLIC AND PRIVATE DEBT LEVELS AFFECT THE SIZE OF FISCAL MULTIPLIERS?
Directory of Open Access Journals (Sweden)
Chairul Adi
2017-09-01
Full Text Available This paper investigates the effectiveness of fiscal policies – as measured by the impact and cumulative multipliers – and how they interact with public and private debt. Harnessing the moderated panel regression approach, based on the yearly data set of several economies during the period from 1996 to 2012, the analysis is focused on the impact of spending-and-revenue-based fiscal policies on economic growth and how these fiscal instruments interact with public and private indebtedness. The result of spending stimuli advocates the basic Keynesian theory. An increase in public expenditures contemporaneously generates a positive multiplier, of around 0.29 – 0.44 and around 0.45 – 0.58 during two years. Decomposing the expenditures into their elements, this paper documents a stronger impact from public investment than that from government purchases. On the other hand, the revenue stimuli seem to follow the Ricardian Equivalence Hypothesis (REH, arguing that current tax cuts are inconsequential. The impact and cumulative multipliers for this fiscal instrument have mixed results, ranging from -0.21 to 0.05 and -0.26 to 0.06, respectively. Moreover, no robust evidence is found to support the argument that government debt moderates the effectiveness of fiscal policies. The size of the multipliers for both spending and revenue policies remain constant with the level of public debt. On the other hand, private debt appears to show a statistically significant moderating effect on spending stimuli. Its impact on spending multipliers, however, is economically insignificant. The moderation effect of private debt on the revenue stimuli does not seem to exist. Finally, this paper documents that both public and private debt exhibit a negative and statistically significant estimation for economic output.
Elaboration and research of planetary precessional multiplier type K-H-V
Bostan, I.; Dulgheru, V.; Ciobanu, R.
2016-08-01
The multiplier is an indispensable part of the micro hydropower plant and high power wind turbine. It helps to increase rotor low speeds limited by the water flow small velocity and by the relative big placement diameter of the blades that participate in the energy conversion. For example, the microhydrostation rotor's speed is (2 - 3) min'1 for water flow velocity V= (1...1,6) m/s and for blade placement diameter D = 4 m. Diversity of requirements forwarded by the beneficiaries of mechanical transmissions consists, in particular, in increasing reliability, efficiency and lifting capacity, and in reducing the mass and dimensions. It becomes more and more difficult to satisfy the mentioned demands by partial updating of traditional transmissions. The target problem can be solved with special effects by developing new types of multipliers based on precessional planetary transmissions with multiple gear, that were developed by the authors. Absolute multiplicity of precessional gear (up to 100% pairs of teeth simultaneously involved in gearing, compared to 5%-7% - in classical gearings) provides increased lifting capacity and small mass and dimensions. To mention that until now precessional planetary transmissions have been researched and applied mainly in reducers. Therefore it was necessary to carry out theoretical research to determine the geometrical parameters of the precessional gear that operates in multiplier mode. Also, it was necessary to develop new conceptual diagrams of precessional transmissions that function under multiplier regime. The majority of precessional planetary transmissions diagrams developed previously operate efficiently in reducer's regime. Depending on the structural diagram, precessional transmissions fall into two main types - K-H-V and 2K-H, from which a wide range of constructive solutions with wide kinematical and functional options that operate in multiplier regime.
Enhancing shelf life of minimally processed multiplier onion using silicone membrane.
Naik, Ravindra; Ambrose, Dawn C P; Raghavan, G S Vijaya; Annamalai, S J K
2014-12-01
The aim of storage of minimal processed product is to increase the shelf life and thereby extend the period of availability of minimally processed produce. The silicone membrane makes use of the ability of polymer to permit selective passage of gases at different rates according to their physical and chemical properties. Here, the product stored maintains its own atmosphere by the combined effects of respiration process of the commodity and the diffusion rate through the membrane. A study was undertaken to enhance the shelf life of minimally processed multiplier onion with silicone membrane. The respiration activity was recorded at a temperature of 30 ± 2 °C (RH = 60 %) and 5 ± 1 °C (RH = 90 %). The respiration was found to be 23.4, 15.6, 10 mg CO2kg(-1)h(-1) at 5 ± 1 °C and 140, 110, 60 mg CO2kg(-1) h(-1) at 30 ± 2° for the peeled, sliced and diced multiplier onion, respectively. The respiration rate for the fresh multiplier onion was recorded to be 5, 10 mg CO2kg(-1) h(-1) at 5 ± 1 °C and 30 ± 1 ° C, respectively. Based on the shelf life studies and on the sensory evaluation, it was found that only the peeled multiplier onion could be stored. The sliced and diced multiplier onion did not have the required shelf life. The shelf life of the multiplier onion in the peel form could be increased from 4-5 days to 14 days by using the combined effect of silicone membrane (6 cm(2)/kg) and low temperature (5 ± 1 °C).
Energy Technology Data Exchange (ETDEWEB)
Golubev, V.N.; Dulin, V.A.; Kazanskij, Yu.A.
1986-10-01
To refine neutron capture cross sections for structural elements used in fast power reactors the neutron balance in multiplying media with neutron multiplication factor K/sub infinity/=1 has been studied at KBR and ERMINE critical assemblies. Reactivity of multiplying cells consisting of uranium and structural elements is measured as well as reactivity coefficients of individual structural materials. Corresponding calculations are performed using the versions of group constants applied in designing the fast reactors in the USSR and France. The CARNAVAL 4 constant version predicts well a fraction of neutron absorptions in steel and nickel for the spectra typical for a power reactor (ERMINE assembly). For softer spectra (KBR assembly) the agreement with experiment is better when the BNAB-78 constant version is used.
Directory of Open Access Journals (Sweden)
Lina Hamouche
2017-02-01
Full Text Available Bacteria adopt social behavior to expand into new territory, led by specialized swarmers, before forming a biofilm. Such mass migration of Bacillus subtilis on a synthetic medium produces hyperbranching dendrites that transiently (equivalent to 4 to 5 generations of growth maintain a cellular monolayer over long distances, greatly facilitating single-cell gene expression analysis. Paradoxically, while cells in the dendrites (nonswarmers might be expected to grow exponentially, the rate of swarm expansion is constant, suggesting that some cells are not multiplying. Little attention has been paid to which cells in a swarm are actually multiplying and contributing to the overall biomass. Here, we show in situ that DNA replication, protein translation and peptidoglycan synthesis are primarily restricted to the swarmer cells at dendrite tips. Thus, these specialized cells not only lead the population forward but are apparently the source of all cells in the stems of early dendrites. We developed a simple mathematical model that supports this conclusion.
Post-2008 Brazilian fiscal policy: an interpretation through the analysis of fiscal multipliers
Directory of Open Access Journals (Sweden)
Celso José Costa Junior
Full Text Available Abstract The global crisis that erupted in 2007 led many countries to embark on countercyclical fiscal policies as a way to cushion the blow of a depressed aggregate demand. Advocates of discretionary measures emphasize that fiscal policy can indeed stimulate the economy. The main goal of this work is to assess whether the fiscal policies pursued by the Brazilian government in the aftermath of the 2008 crisis, succeeded in bringing the economy back on track in a sustainable fashion. To this end, the fiscal multipliers of five different shocks are studied in a small open-economy New Keynesian framework. Our results point to the government spending and public investment as the most effective fiscal tools for combating the crisis. However, the highest fiscal multiplier turned out to be the one associated with excise tax reductions.
DEFF Research Database (Denmark)
Goswami, Kavita; Pandey, Bishwajeet; Kumar, Tanesh
2017-01-01
with high speed as compared with traditional array and booth multipliers. Vedic Multiplier contains a total of sixteen algorithms/sutras for predominantly logical operations. This research focuses on thermal aspects and energy efficiency of wireless communications systems with the thermal aware low power......This paper deals with low power multiplier design that plays a significant role in green wireless communications systems. Over the period of time, researchers have proposed various multiplier designs in order to get high speed. Vedic multiplier is considered as one of the low power multiplier along...... design of Vedic Multiplier. Temperature plays an important role on the performance of any device. The primary purpose of this research is to enhance the thermal stability of the wireless communications. Energy efficient IO standards are used to decrease the power dissipation of Vedic Multiplier...
A convolution type characterization for Lp - multipliers for the Heisenberg group
Directory of Open Access Journals (Sweden)
R. Radha
2007-01-01
Full Text Available It is well known that if m is an Lp - multiplier for the Fourier transform on ℝn(1
Isometric multipliers of Lp(G, X) Lp(G, X) Lp(G, X)
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
Abstract. Let G be a locally compact group with a fixed right Haar measure and X a separable Banach space. Let Lp(G, X) be the space of X-valued measurable functions whose norm-functions are in the usual Lp . A left multiplier of Lp(G, X) is a bounded linear operator on Lp(G, X) which commutes with all left translations.
Ad Hoc Microphone Array Beamforming Using the Primal-Dual Method of Multipliers
DEFF Research Database (Denmark)
Tavakoli, Vincent Mohammad; Jensen, Jesper Rindom; Heusdens, Richard
2016-01-01
In the recent years, there have been increasing amount of researches aiming at optimal beamforming with ad hoc microphone arrays, mostly with fusion-based schemes. However, huge amount of computational complexity and communication overhead impede many of these algorithms from being useful...... the distributed linearly-constrained minimum variance beamformer using the the state of the art primal-dual method of multipliers. We study the proposed algorithm with an experiment....
The unitary cover of a finite group and the exponent of the Schur multiplier
Sambonet, Nicola
2013-01-01
For a finite group we introduce a particular central extension, the unitary cover, having minimal exponent among those satisfying the projective lifting property. We obtain new bounds for the exponent of the Schur multiplier relating to subnormal series, and we discover new families for which the bound is the exponent of the group. Finally, we show that unitary covers are controlled by the Zel'manov solution of the restricted Burnside problem for 2-generator groups.
Design of a new tissue-equivalent proportional counter based on a gas electron multiplier
Energy Technology Data Exchange (ETDEWEB)
Farahmand, M. E-mail: m.farahmand@iri.tudelft.nl; Bos, A.J.J.; Huizenga, J.; De Nardo, L.; Eijk, C.W.E. van
2003-08-21
By employing a Gas Electron Multiplier a new type of mini multi-element Tissue-Equivalent Proportional Counter (TEPC) has been designed and constructed. In this paper, we describe the design of this novel counter. The first pulse height measurements with this counter for both methane- and propane-based Tissue Equivalent gases are presented. These results show promising properties for application of this novel type TEPC in microdosimetric measurements.
Integrated MOS four-quadrant analogue multiplier using switched-capacitor technique
Yasumoto, M.; Enomoto, T.
1982-09-01
A fully integrated four-quadrant analog multiplier based on switched-capacitor technique for realisation of high-speed and high-density analog LSIs was developed using a MOS VLSI process. Excellent characteristics such as low total harmonic distortion of -50 dB for two input signals of 1 Vp-p, large dynamic range of 80 dB and fast operation speed of 2 MHz clock rate were obtained. Application to convolvers and correlators is also demonstrated.
Energy Technology Data Exchange (ETDEWEB)
Wehrenberg, P.J.; Clark, K.C.
1976-10-01
The absolute detection efficiency for protons and for hydrogen atoms in the energy range 5--60 keV is determined for a resistance strip magnetic electron multiplier particle-counting system. Significant history-dependent gain variations are discussed. The detector system is suitable for use in coincidence experiments requiring particle-counting rates to 1.0 MHz and timing accuracies of 3.0 nsec. (AIP)
Occurrence of the Cys311 DRD2 variant in a pedigree multiply affected with panic disorder
Energy Technology Data Exchange (ETDEWEB)
Crawford, F.; Hoyne, J.; Diaz, P. [Univ. of South Florida, Tampa, FL (United States)] [and others
1995-08-14
Following the detection of the rare DRD2 codon 311 variant (Ser{yields}Cys) in an affected member from a large, multiply affected panic disorder family, we investigated the occurrence of this variant in other family members. The variant occurred in both affected and unaffected individuals. Further screening in panic disorder sib pairs unrelated to this family failed to detect the Cys311 variant. Our data suggests that this variant has no pathogenic role in panic disorder. 18 refs., 1 fig.
A Lagrange multiplier and Hopfield-type barrier function method for the traveling salesman problem.
Dang, Chuangyin; Xu, Lei
2002-02-01
A Lagrange multiplier and Hopfield-type barrier function method is proposed for approximating a solution of the traveling salesman problem. The method is derived from applications of Lagrange multipliers and a Hopfield-type barrier function and attempts to produce a solution of high quality by generating a minimum point of a barrier problem for a sequence of descending values of the barrier parameter. For any given value of the barrier parameter, the method searches for a minimum point of the barrier problem in a feasible descent direction, which has a desired property that lower and upper bounds on variables are always satisfied automatically if the step length is a number between zero and one. At each iteration, the feasible descent direction is found by updating Lagrange multipliers with a globally convergent iterative procedure. For any given value of the barrier parameter, the method converges to a stationary point of the barrier problem without any condition on the objective function. Theoretical and numerical results show that the method seems more effective and efficient than the softassign algorithm.
Directory of Open Access Journals (Sweden)
Laia Pié
2017-12-01
Full Text Available The aim of this paper is to study the effect that implementing the agreement signed by the European Union at the end of 2008 will have on reducing greenhouse gas emissions in Catalonia. Emission multipliers and the impact of reducing emissions by 10%, in sectors not covered by the EU ETS (EU Emissions Trading System and reducing those that are covered by 21%, are analysed. More specifically, the effects on the endogenous income of the multiplier model (production, factorial and private income is studied, while reducing and increasing endogenous income and the decomposition of emission multipliers into open, own and circular effects is analysed to include the different channels of the process of generating CO2 equivalent emissions. The empirical application is for the Catalan economy and uses economic and environmental data for the year 2001. The results show that increases in greenhouse gas emissions will essentially depend on the account that receives the exogenous inflow in demand. Greenhouse gas emissions in Catalonia are affected very differently at the sectoral level and the effects of production activities, factors of production and consumption on air pollution are very heterogeneous. The analytical approach used in this paper provides interesting results that can help to design and implement policies to reduce emissions.
Directory of Open Access Journals (Sweden)
Sonja C. Jähnig
2017-04-01
Full Text Available Given the scientific consensus that climate change is impacting biodiversity, estimates of future climate change effects on stream communities and assessments of potential biases are necessary. Here, we propose a simple technique to approximate changes in invertebrate and fish biomonitoring results. Taxa lists for 60 (invertebrate and 52 (fish sites were each modified by 10 multipliers as stepwise 5% or 10% changes in abundances to simulate potential climate-change severity, reflecting increasing climate change effects. These 10 multipliers were based on the stream zonation preference for invertebrates and the Fish Region Index (FRI values for fish, both reflecting the longitudinal gradient present in river ecosystems. The original and modified taxa lists were analyzed using the standard assessment software for the particular group, followed by analysis of key biomonitoring metrics. For invertebrates, our simulations affected small good quality streams more often negatively while large poor mountain streams showed a tendency to improve. Forty percent of the invertebrate data sites showed a change in the final ecological assessment class when using the multipliers, with the poor quality sites changing more often. For fish, metric changes were variable, but the FRI ratio showed mostly positive responses, i.e., a shift in FRI towards downstream communities. The results are discussed as an example that facilitates the interpretation of potential climate-change effects with varying severity. Further, we discuss the simplified approach and implications for assessment from climate change induced range shifts.
Detection of Submillimeter-wave [C i] Emission in Gaseous Debris Disks of 49 Ceti and β Pictoris
Energy Technology Data Exchange (ETDEWEB)
Higuchi, Aya E.; Sakai, Nami [The Institute of Physical and Chemical Research (RIKEN), 2-1, Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Sato, Aki; Tsukagoshi, Takashi; Momose, Munetake [College of Science, Ibaraki University, Bunkyo 2-1-1, Mito 310-8512 (Japan); Iwasaki, Kazunari [Department of Environmental Systems Science, Doshisha University, Tatara Miyakodani 1-3, Kyotanabe City, Kyoto 610-0394 (Japan); Kobayashi, Hiroshi; Ishihara, Daisuke; Watanabe, Sakae; Kaneda, Hidehiro [Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602 (Japan); Yamamoto, Satoshi, E-mail: aya.higuchi@riken.jp [Department of Physics, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)
2017-04-10
We have detected [C i] {sup 3} P {sub 1}–{sup 3} P {sub 0} emissions in the gaseous debris disks of 49 Ceti and β Pictoris with the 10 m telescope of the Atacama Submillimeter Telescope Experiment, which is the first detection of such emissions. The line profiles of [C i] are found to resemble those of CO( J = 3–2) observed with the same telescope and the Atacama Large Millimeter/submillimeter Array. This result suggests that atomic carbon (C) coexists with CO in the debris disks and is likely formed by the photodissociation of CO. Assuming an optically thin [C i] emission with the excitation temperature ranging from 30 to 100 K, the column density of C is evaluated to be (2.2 ± 0.2) × 10{sup 17} and (2.5 ± 0.7) × 10{sup 16} cm{sup −2} for 49 Ceti and β Pictoris, respectively. The C/CO column density ratio is thus derived to be 54 ± 19 and 69 ± 42 for 49 Ceti and β Pictoris, respectively. These ratios are higher than those of molecular clouds and diffuse clouds by an order of magnitude. The unusually high ratios of C to CO are likely attributed to a lack of H{sub 2} molecules needed to reproduce CO molecules efficiently from C. This result implies a small number of H{sub 2} molecules in the gas disk, i.e., there is an appreciable contribution of secondary gas from dust grains.
1998-09-01
conditioned by the asymmetric distribution of the small-scale roughness slopes. Its distribution function described by Gram- Charlie series in case sea...Kravchenko and A.F. Chaplin , "On the Excitation of Superconducting Impedance Plane", DAN SSSR, Vol. 326, No.2, pp.272-275, 1992. 16. V.F...Kravchenko and A.F. Chaplin , "Excitation of Superconducting Circular and Elliptic Cylinder", DAN SSSR, Vol. 326, No.4, pp.633-636, 1992. 17. V.F. Kravchenko
Energy Technology Data Exchange (ETDEWEB)
Esposti, Claudio Degli; Dore, Luca; Melosso, Mattia [Dipartimento di Chimica “Giacomo Ciamician”, Università di Bologna, via Selmi 2, I-40126 Bologna (Italy); Kobayashi, Kaori [Department of Physics, Faculty of Science, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan); Fujita, Chiho; Ozeki, Hiroyuki, E-mail: ozeki@env.sci.toho-u.ac.jp [Department of Environmental Science, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, 274-8510 (Japan)
2017-06-01
It is important to study possible precursors of amino acids such as glycine to enable future searches in interstellar space. Aminoacetonitrile (NH{sub 2}CH{sub 2}CN) is one of the most feasible molecules for this purpose. This molecule was already detected toward Sgr B2(N). Aminoacetonitrile has a few low-lying vibrational excited states, and transitions within these states may be found in space. In this study, the pure-rotational transitions in the three lowest vibrational states in the 80–450 GHz range have been assigned and analyzed. It was found to be very important to include Coriolis coupling between the two lowest vibrational fundamentals, while the third one was unperturbed. The partition function was evaluated considering these new results.
Lucke, Robert L.; Fischer, Jacqueline; Polegre, Arturo M.; Beintema, Douwe A.
2005-10-01
Placement of a scatter cone at the center of the secondary of a Cassegrain telescope greatly reduces Narcissus reflection. To calculate the remaining Narcissus reflection, a time-consuming physical optics code such as GRASP8 is often used to model the effects of reflection and diffraction. Fortunately, the Cassegrain geometry is sufficiently simple that a combination of theoretical analysis and Fourier propagation can yield rapid, accurate results at submillimeter wavelengths. We compare these results with those from GRASP8 for the heterodyne instrument for the far-infrared on the Herschel Space Observatory and confirm the effectiveness of the chosen scatter cone design.
MULTIPLIER EVENT AND TRANSNATIONAL MEETING #6 AS A PART OF THE ESIPP PROJECT
Directory of Open Access Journals (Sweden)
Ana Shikaleska
2017-10-01
Full Text Available Multiplier Event and Transnational Meeting #6 was held as a part of the ESIPP project in the period from 28- 30 of June in Northampton, England. The Multiplier event was held at King’s Park Conference Centre, on the 28th June. After the registration of the 80 guests, Professor David Preece from the UON introduced the ESIPPproject. Presentations and parent voices from Macedonia, Cyprus and Croatia were presented through videos. In the second part of the event, presentations were introduced by Debby Elley ( mother of two children with autism and from Meike Illing-Whitby ( OT from Germany on the subject “Motor Coordination differences in children with Autism Spectrum Disorder (ASD”. The event finished with evaluations and a plenary. On Thursday 29 June at the UON, the meeting started with introductions and update from the Project Management workstream (David Preece and Paul Bramble, reporting about activity since the last meeting and interim report – feedback and actions to maximise project success. Paul Bramble gave a finances update. Jasmina Troshanska gave an update of Internal QA. After that, Cristina Fernandez gave a dissemination update. The second part of the meeting was feedback & discussion about the Multiplier Event in Croatia, planning for Skopje, Cyprus and Croatia regarding the next Multiplier Events and Transnational Meetings, ME content including publicity/links to policy makers , autism parent training roadmap launch (Cyprus March 18, TM 7-8 dates and locations. Paul Bramble talked about impact indicators. The meeting ended with a session led and facilitated by Gareth Long, external auditor, about maximising impact and sustainability and achieving ESIPP’s goals, and a plenary session. On Friday 30 June, in the Senate Building of UON the second meeting took place. There were two parallel sessions in two separate rooms . In room 1 partners were analysing content and delivery of Parent Training Programme, and in room 2 David
DEFF Research Database (Denmark)
Goswami, Kavita; Pandey, Bishwajeet; Hussain, Dil muhammed Akbar
2016-01-01
Multiplier is used for multiplication of a signal and a constant in digital signal processing (DSP). 28nm technology based Vedic multiplier is implemented with use of VHDL HDL, Xilinx ISE, Kintex-7 FPGA and XPower Analyzer. Vedic multiplier gain speed improvements by parallelizing the generation...... of partial products with their concurrent summations. In this work, we are exploring the feasibility of Vedic multiplier in Data Encryption Algorithm, DSP, reliable system, multimedia and fault tolerant systems. In our work, we are using 11 different IO standards from HSTL (High Speed Transistor Logic...... Programmable Gate Array (FPGA) in order to reduce the development cost. The development cost for Application Specific Integrated Circuits (ASICs) are high in compare to FPGA. Selection of the most energy efficient IO standards in place of signal gating is the main design methodology for design of energy...
Pilot Study of Cartilage Repair in the Knee Joint with Multiply Incised Chondral Allograft
Vancsodi, Jozsef; Farkas, Boglarka; Fazekas, Adam; Nagy, Szilvia Anett; Bogner, Peter; Vermes, Csaba; Than, Peter
2015-01-01
Background Focal cartilage lesions in the knee joint have limited capacity to heal. Current animal experiments show that incisions of the deep zone of a cartilage allograft allow acceptable integration for the graft. Questions/Purposes We performed this clinical study to determine (1) if the multiply incised cartilage graft is surgically applicable for focal cartilage lesions, (2) whether this allograft has a potential to integrate to the repair site, and (3) if patients show clinical improvement. Patients and Methods Seven patients with 8 chondral lesions were enrolled into the study. Symptomatic lesions between 2 and 8 cm2 were accepted. Additional injuries were allowed but were addressed simultaneously. Grafts were tailored to match and the deep zone of the cartilage was multiply incised to augment the basal integration before securing in place. Rigorous postoperative physiotherapy followed. At 12 and 24 months the patients’ satisfaction were measured and serial magnetic resonance imaging (MRI) was performed in 6 patients. Results Following the implantations no adverse reaction occurred. MRI evaluation postoperatively showed the graft in place in 5 out of 6 patients. In 1 patient, MRI suggested partial delamination at 1 year and graft degeneration at 2 years. Short Form–36 health survey and the Lysholm knee score demonstrated a significant improvement in the first year; however, by 2 years there was a noticeable drop in the scores. Conclusions. Multiply incised pure chondral allograft used for cartilage repair appears to be a relatively safe method. Further studies are necessary to assess its potential in cartilage repair before its clinical use. PMID:26069710
Mixed Analog/Digital Matrix-Vector Multiplier for Neural Network Synapses
DEFF Research Database (Denmark)
Lehmann, Torsten; Bruun, Erik; Dietrich, Casper
1996-01-01
In this work we present a hardware efficient matrix-vector multiplier architecture for artificial neural networks with digitally stored synapse strengths. We present a novel technique for manipulating bipolar inputs based on an analog two's complements method and an accurate current rectifier....../sign detector. Measurements on a CMOS test chip are presented and validates the techniques. Further, we propose to use an analog extension, based on a simple capacitive storage, for enhancing weight resolution during learning. It is shown that the implementation of Hebbian learning and back-propagation learning...
Applying of the Algorithm of Lagrange Multipliers in the Removal of Blur in Images
Stojanovic, Igor; Kraljevski, Ivan; Chungurski, Slavco
2010-01-01
This paper presents a non-iterative method that finds application in a broad scientific field such as digital image restoration. The method, based on algorithm of Lagrange multipliers, is use for the removal of blur in an X-ray caused by uniform linear motion. This method assumes that linear motion corresponds to an integral number of pixels. The resolution of the restored image remains at very high level. The main contribution of the method was found on the Improvement in Signal to Noise Rat...
Evaluation of countable multipliers within the framework of a matrix of regional social accounting
Directory of Open Access Journals (Sweden)
Manuel Alejandro Cardenete
2003-01-01
Full Text Available The main goal of this paper is to present a recent Social AccountingMatrix for the region of Andalusia (SAMAND95. Using a variety of available data,such as the Regional Income and Product Accounts, the 1995 Input-Output Table forAndalusia, as well as some national level data, we have constructed a square SAMthat reflects all flows and interactions for the base year. With the database we haveperformed a modeling exercise that allows us to obtain accounting multipliers, and their decomposition into direct, indirect, and induced effects, that show some of thestructural relationship among productive sectors.
An aging study of a gas electron multiplier with micro-strip gas chamber readout
Miyamoto, J
1999-01-01
We have performed an aging study of a Gas Electron Multiplier (GEM) readout with a Micro-Strip Gas Chamber (MSGC). The GEM is constructed from Kapton and copper, and the MSGC is constructed from semiconductive glass and gold. When the detector (GEM+MSGC) is operated in an argon-dimethyl ether (DME) gas mixture and irradiated with a 5.4 keV photon beam, about 220 mC/cm of charge can be accumulated without degradation of the detector performance. This corresponds to about 20 years of operation at the LHC.
The Early Exercise Premium Representation for American Options on Multiply Assets
Energy Technology Data Exchange (ETDEWEB)
Klimsiak, Tomasz, E-mail: tomas@mat.umk.pl; Rozkosz, Andrzej, E-mail: rozkosz@mat.umk.pl [Nicolaus Copernicus University, Faculty of Mathematics and Computer Science (Poland)
2016-02-15
In the paper we consider the problem of valuation of American options written on dividend-paying assets whose price dynamics follow the classical multidimensional Black and Scholes model. We provide a general early exercise premium representation formula for options with payoff functions which are convex or satisfy mild regularity assumptions. Examples include index options, spread options, call on max options, put on min options, multiply strike options and power-product options. In the proof of the formula we exploit close connections between the optimal stopping problems associated with valuation of American options, obstacle problems and reflected backward stochastic differential equations.
Riehle, Fritz
2006-01-01
Of all measurement units, frequency is the one that may be determined with the highest degree of accuracy. It equally allows precise measurements of other physical and technical quantities, whenever they can be measured in terms of frequency.This volume covers the central methods and techniques relevant for frequency standards developed in physics, electronics, quantum electronics, and statistics. After a review of the basic principles, the book looks at the realisation of commonly used components. It then continues with the description and characterisation of important frequency standards
Directory of Open Access Journals (Sweden)
Jesse D Deere
Full Text Available Highly active antiretroviral therapy (HAART can reduce levels of human immunodeficiency virus type 1 (HIV-1 to undetectable levels in infected individuals, but the virus is not eradicated. The mechanisms of viral persistence during HAART are poorly defined, but some reservoirs have been identified, such as latently infected resting memory CD4⁺ T cells. During latency, in addition to blocks at the initiation and elongation steps of viral transcription, there is a block in the export of viral RNA (vRNA, leading to the accumulation of multiply-spliced transcripts in the nucleus. Two of the genes encoded by the multiply-spliced transcripts are Tat and Rev, which are essential early in the viral replication cycle and might indicate the state of infection in a given population of cells. Here, the levels of multiply-spliced transcripts were compared to the levels of gag-containing RNA in tissue samples from RT-SHIV-infected rhesus macaques treated with HAART. Splice site sequence variation was identified during development of a TaqMan PCR assay. Multiply-spliced transcripts were detected in gastrointestinal and lymphatic tissues, but not the thymus. Levels of multiply-spliced transcripts were lower than levels of gag RNA, and both correlated with plasma virus loads. The ratio of multiply-spliced to gag RNA was greatest in the gastrointestinal samples from macaques with plasma virus loads <50 vRNA copies per mL at necropsy. Levels of gag RNA and multiply-spliced mRNA in tissues from RT-SHIV-infected macaques correlate with plasma virus load.
Coupled-Multiplier Accelerator Produces High-Power Electron Beams for Industrial Applications
Hatridge, M.; McIntyre, P.; Roberson, S.; Sattarov, A.; Thomas, E.; Meitzler, Charles
2003-08-01
The coupled multiplier is a new approach to efficient generation of MeV d.c. power for accelerator applications. High voltage is produced by a series of modules, each of which consists of a high-power alternator, step-up transformer, and 3-phase multiplier circuit. The alternators are connected mechanically along a rotating shaft, and connected by insulating flexible couplers. This approach differs from all previous d.c. technologies in that power is delivered to the various stages of the system mechanically, rather than through capacitive or inductive electrical coupling. For this reason the capital cost depends linearly on required voltage and power, rather than quadratically as with conventional technologies. The CM technology enables multiple electron beams to be driven within a common supply and insulating housing. MeV electron beam is extremely effective in decomposing organic contaminants in water. A 1 MeV, 100 kW industrial accelerator using the CM technology has been built and is being installed for treatment of wastewater at a petrochemical plant.
A Fluid Structure Algorithm with Lagrange Multipliers to Model Free Swimming
Sahin, Mehmet; Dilek, Ezgi
2017-11-01
A new monolithic approach is prosed to solve the fluid-structure interaction (FSI) problem with Lagrange multipliers in order to model free swimming/flying. In the present approach, the fluid domain is modeled by the incompressible Navier-Stokes equations and discretized using an Arbitrary Lagrangian-Eulerian (ALE) formulation based on the stable side-centered unstructured finite volume method. The solid domain is modeled by the constitutive laws for the nonlinear Saint Venant-Kirchhoff material and the classical Galerkin finite element method is used to discretize the governing equations in a Lagrangian frame. In order to impose the body motion/deformation, the distance between the constraint pair nodes is imposed using the Lagrange multipliers, which is independent from the frame of reference. The resulting algebraic linear equations are solved in a fully coupled manner using a dual approach (null space method). The present numerical algorithm is initially validated for the classical FSI benchmark problems and then applied to the free swimming of three linked ellipses. The authors are grateful for the use of the computing resources provided by the National Center for High Performance Computing (UYBHM) under Grant Number 10752009 and the computing facilities at TUBITAK-ULAKBIM, High Performance and Grid Computing Center.
Tomaschitz, R
1994-01-01
We investigate scattering effects in open Robertson-Walker cosmologies whose spacelike slices are multiply connected hyperbolic manifolds. We work out an example in which the 3-space is infinite and has the topology of a solid torus. The world-lines in these cosmologies are unstable, and classical probability densities evolving under the horospherical geodesic flow show dispersion, as do the densities of scalar wave packets. The rate of dispersion depends crucially on the expansion factor, and we calculate the time evolution of their widths. We find that the cosmic expansion can confine dispersion: The diameter of the domain of chaoticity in the 3-manifold provides the natural, time-dependent length unit in an infinite, multiply connected universe. In a toroidal 3-space manifold this diameter is just the length of the limit cycle. On this scale we find that the densities take a finite limit width in the late stage of the expansion. In the early stage classical densities and conformally coupled fields approach...
Verbist, L; Jacobs, J; Hens, K
1991-01-01
To study the activity of ceftibuten, we obtained multiply-resistant isolates from approximately 20 hospitals in Belgium. Against Enterobacteriaceae, all of the tested comparative compounds were more active than cefaclor, and ceftibuten and tigemonam were the most active of the agents tested. Ceftibuten MIC50s were less than or equal to 1 microgram/ml for most enteric bacilli species and 85% of strains were susceptible (less than or equal to 8 micrograms/ml). This level of activity compared favorably to that recorded for cefaclor (less than or equal to 8 micrograms/ml), cefetamet (less than or equal to 4 micrograms/ml), and cefteram (less than or equal to 1 microgram/ml), that is, 37%, 69%, and 59%, respectively. Ceftibuten, cefetamet, cefteram, and tigemonam were highly active against isolates of Haemophilus influenzae and Neisseria gonorrhoeae. None of the comparative agents were as active as cefaclor against staphylococcal isolates. Against streptococci, cefteram was the most active, and tigemonam the least active of the agents. The MIC90s of ceftibuten for strains of Streptococcus pneumoniae and Streptococcus pyogenes were 2 micrograms/ml and 0.5 microgram/ml, respectively. Strains of Streptococcus agalactiae were resistant to both ceftibuten and tigemonam; cefaclor and cefteram inhibited 100% of isolates of this species. Strains of Enterococcus faecalis and Pseudomonas aeruginosa were consistently resistant to all of the compounds. Overall, ceftibuten exhibited potent activity against many multiply-resistant clinical isolates.
Mutations in NRXN1 in a family multiply affected with brain disorders
DEFF Research Database (Denmark)
Duong, Linh; Klitten, Laura L; Møller, Rikke S
2012-01-01
Mutation of the neurexin1-gene, NRXN1, interrupting the expression of neurexin1 has been associated with schizophrenia, autism, and intellectual disability. We have identified a family multiply affected with psychiatric, neurological, and somatic disorders along with an intricate co-segregation o......Mutation of the neurexin1-gene, NRXN1, interrupting the expression of neurexin1 has been associated with schizophrenia, autism, and intellectual disability. We have identified a family multiply affected with psychiatric, neurological, and somatic disorders along with an intricate co...... to be deleterious to NRXN1. The deletion was passed on from the patient's mother who was clinically characterized by sub-diagnostic autistic traits in addition to type 1 diabetes mellitus. The point mutation was subsequently found in the patient's brother, suffering from a psychotic disorder, which implies...... that the point mutation was inherited from the deceased father, who was diagnosed with schizophrenia. The observations suggest a possible gene-dose effect of NRXN1 mutations on type and severity of mental illness and support the notion that the penetrance and pleiotropy of pathogenic CNVs in general...
Computational Design Scheme for Wind Turbine Drive-Train Based on Lagrange Multipliers
Directory of Open Access Journals (Sweden)
Mohammed Saleh
2017-01-01
Full Text Available The design optimization of wind turbines and their subsystems will make them competitive as an ideal alternative for energy. This paper proposed a design procedure for one of these subsystems, which is the Wind Turbine Drive-Train (WTDT. The design of the WTDT is based on the load assumptions and considered as the most significant parameter for increasing the efficiency of energy generation. In industry, these loads are supplemented by expert assumptions and manipulated to design the transmission elements. In contrary, in this work, the multibody system approach is used to estimate the static as well as dynamic loads based on the Lagrange multipliers. Lagrange multipliers are numerical parameters associated with the holonomic and nonholonomic constraints assigned in the drive-train model. The proposed scheme includes computational manipulations of kinematic constraints, mapping the generalized forces into Cartesian respective, and enactment of velocity-based constrains. Based on the dynamic model and the obtained forces, the design process of a planetary stage of WTDT is implemented with trade-off’s optimization in terms of gearing parameters. A wind turbine of 1.4 megawatts is introduced as an evaluation study of the proposed procedure, in which the main advantage is the systematic nature of designing complex systems in motion.
Qing, Guangyan; Lu, Qi; Li, Xiuling; Liu, Jing; Ye, Mingliang; Liang, Xinmiao; Sun, Taolei
2017-09-06
Multisite phosphorylation is an important and common mechanism for finely regulating protein functions and subsequent cellular responses. However, this study is largely restricted by the difficulty to capture low-abundance multiply phosphorylated peptides (MPPs) from complex biosamples owing to the limitation of enrichment materials and their interactions with phosphates. Here we show that smart polymer can serve as an ideal platform to resolve this challenge. Driven by specific but tunable hydrogen bonding interactions, the smart polymer displays differential complexation with MPPs, singly phosphorylated and non-modified peptides. Importantly, MPP binding can be modulated conveniently and precisely by solution conditions, resulting in highly controllable MPP adsorption on material surface. This facilitates excellent performance in MPP enrichment and separation from model proteins and real biosamples. High enrichment selectivity and coverage, extraordinary adsorption capacities and recovery towards MPPs, as well as high discovery rates of unique phosphorylation sites, suggest its great potential in phosphoproteomics studies.Capture of low-abundance multiply phosphorylated peptides (MPPs) is difficult due to limitation of enrichment materials and their interactions with phosphates. Here the authors show, a smart polymer driven by specific but tunable hydrogen bonding interactions can differentially complex with MPPs, singly phosphorylated and non-modified peptides.
Directory of Open Access Journals (Sweden)
Wolfgang Arthofer
Full Text Available Wolbachia are wide-spread, endogenous α-Proteobacteria of arthropods and filarial nematodes. 15-75% of all insect species are infected with these endosymbionts that alter their host's reproduction to facilitate their spread. In recent years, many insect species infected with multiple Wolbachia strains have been identified. As the endosymbionts are not cultivable outside living cells, strain typing relies on molecular methods. A Multi Locus Sequence Typing (MLST system was established for standardizing Wolbachia strain identification. However, MLST requires hosts to harbour individual and not multiple strains of supergroups without recombination. This study revisits the applicability of the current MLST protocols and introduces Allele Intersection Analysis (AIA as a novel approach. AIA utilizes natural variations in infection patterns and allows correct strain assignment of MLST alleles in multiply infected host species without the need of artificial strain segregation. AIA identifies pairs of multiply infected individuals that share Wolbachia and differ in only one strain. In such pairs, the shared MLST sequences can be used to assign alleles to distinct strains. Furthermore, AIA is a powerful tool to detect recombination events. The underlying principle of AIA may easily be adopted for MLST approaches in other uncultivable bacterial genera that occur as multiple strain infections and the concept may find application in metagenomic high-throughput parallel sequencing projects.
Drago, S.; Sebastiano, Fabio; Leenaerts, Dominicus Martinus Wilhelmus; Breems, Lucien Johannes; Nauta, Bram
2010-01-01
A low power frequency synthesiser circuit (30) for a radio transceiver, the synthesiser circuit comprising: a digital controlled oscillator configured to generate an output signal having a frequency controlled by an input digital control word (DCW); a feedback loop connected between an output and an
Frequency dependence of the effective elastic moduli of cavernous bodies
Sibiryakov, E. B.
2014-09-01
The dependence of the effective parameters of microheterogeneous media on the frequency and structure of the pore space is obtained using the boundary integral equation method. The potential method is first used to solve dynamic three-dimensional elastic problems in multiply connected domains in the case of stationary oscillations. It is shown that if the wavelength corresponds to a finite number of blocks, the effective elastic moduli decrease.
[Diagnostic value of multiply biopsies and endocervical curettage on cervical lesions].
Zhang, Ling; Du, Hui; Zhang, Wei; Yang, Bin; Wang, Chun; Belinson, Jerome L; Wu, Ruifang
2015-04-01
To investigate the value of multiply biopsies and endocervical curettage (ECC) on diagnosing cervical lesions. For the detection of cervical lesions, Shenzhen cervical cancer screening trial II (SHENCCAST II) program combined methods of HPV screening with liquid-based cytology (LBC), any positive indicators was then performed multiply biopsies and ECC under colopscopy. A total of 2,558 clear colposcopic images and pathological diagnoses were reviewed. To analyse the pathological results and primary screening results of the negative colopscopic images for discussing the value of multiply biopsies and ECC. Overall 2,558 women's colposcopic images and sampling results were completed and validated. 69.98% (1,790/2,558) women had normal colposcopy appearances. Among them, 2.23% (40/1,790) were diagnosed as cervical intraepithelial neoplasia II or worse (CIN II+). The odds ratio of high-grade squamous intraepithelial lesion (HSIL) was 28.37 (P=0.000) and atypical squamous cell cannot exclude HSIL (ASC-H) was 15.07 (P=0.001). HPV types 16, 52, 58, 31, 33 and 18 were related to high-grade cervical lesion with the odds ratio of 3.11 (P=0.017). Hybrid capture II (HC-II) DNA test results shown that women with HPV positive were 3.58 times more risky than those of HPV negative, which was related to high-grade cervical lesion (P=0.025). Among the 2,558 women, CIN II+ detective rate from ECC were 40.7% (44/108) in older group (≥40 years) were higher than that of 19.2% (24/125) in younger group (biopsies were 90.7% (98/108) in older group (≥40 years) were higher than that of 88.8% (111/125) in younger group (0.05). The highest risky items of detecting CIN II+ were as follows: (1) HSIL or ASC-H; (2) HPV types 16, 18, 52 and 58 positive (either one); (3) HC-II HPV positive, at least 2 of the 3 items were included among 32 cases of the 40 CIN II+ with normal colposcopy appearances. The results shown that only performed multi-site biopsies with abnormal colposcopy appearances may
Peng, Song; Liu, Zhiguo; Sun, Tianxi; Wang, Guangfu; Ma, Yongzhong; Ding, Xunliang
2014-08-01
Confocal micro X-ray fluorescence (CM-XRF) with quasi-monochromatic excitation based on polycapillary X-ray optics was used to measure the thickness of multi-ply films. The relative errors of measuring an Fe film with a thickness of 16.3 μm and a Cu film with a thickness of 24.5 μm were 7.3% and 0.4%, respectively. The non-destructive and in-situ measurement of the thickness and uniformity of multi-ply films of Cu, Fe and Ni on a silicon surface was performed. CM-XRF was convenient in in-situ and elementally resolved analysis of the thickness of multi-ply films without a cumbersome theoretical correction model. Copyright © 2014 Elsevier Ltd. All rights reserved.
Analytical, steady-state model of gain saturation in channel electron multipliers
Giudicotti, L
2002-01-01
By using the transmission line modeling (TLM) technique we derive a simple model describing the saturation of the gain in channel electron multipliers and show that it generalizes and extends a previous steady-state model due to Shikhaliev. Then by introducing a physically consistent rational approximation of the non-linear gain equation we derive an exact, steady-state, analytical solution in which, contrary to other empirical assumptions about the functional dependence of the internal voltage are not required. The model is then used to simulate a multianode microchannel plate (MCP) photomultiplier, showing that the computed gain in saturated conditions is qualitatively in agreement with published experimental data. Finally, we discuss the general validity of our model, we suggest possible measurements and comment existing data relevant for its validation.
DEFF Research Database (Denmark)
Catani, Paul; Teräsvirta, Timo; Yin, Meiqun
A Lagrange multiplier test for testing the parametric structure of a constant conditional correlation generalized autoregressive conditional heteroskedasticity (CCC-GARCH) model is proposed. The test is based on decomposing the CCC-GARCH model multiplicatively into two components, one of which...... represents the null model, whereas the other one describes the misspeci…cation. A simulation study shows that the test has good …nite sample properties. We compare the test with other tests for misspeci…cation of multivariate GARCH models. The test has high power against alternatives where the misspeci......…cation is in the GARCH parameters and is superior to other tests. The test is not greatly affected by misspeci…cation in the conditional correlations and is therefore well suited for considering misspeci…cation of GARCH equations....
Directory of Open Access Journals (Sweden)
Akihide Hemmi
2013-01-01
Full Text Available A novel two dimensional surface plasmon resonance (SPR sensor system with a multi-point sensing region is described. The use of multiplied beam splitting optics, as a core technology, permitted multi-point sensing to be achieved. This system was capable of simultaneously measuring nine sensing points. Calibration curves for sucrose obtained on nine sensing points were linear in the range of 0–10% with a correlation factor of 0.996–0.998 with a relative standard deviation of 0.090–4.0%. The detection limits defined as S/N = 3 were 1.98 × 10−6–3.91 × 10−5 RIU. This sensitivity is comparable to that of conventional SPR sensors.
Hemmi, Akihide; Mizumura, Ryosuke; Kawanishi, Ryuta; Nakajima, Hizuru; Zeng, Hulie; Uchiyama, Katsumi; Kaneki, Noriaki; Imato, Toshihiko
2013-01-08
A novel two dimensional surface plasmon resonance (SPR) sensor system with a multi-point sensing region is described. The use of multiplied beam splitting optics, as a core technology, permitted multi-point sensing to be achieved. This system was capable of simultaneously measuring nine sensing points. Calibration curves for sucrose obtained on nine sensing points were linear in the range of 0-10% with a correlation factor of 0.996-0.998 with a relative standard deviation of 0.090-4.0%. The detection limits defined as S/N = 3 were 1.98 × 10(-6) - 3.91 × 10(-5) RIU. This sensitivity is comparable to that of conventional SPR sensors.
Input-constrained model predictive control via the alternating direction method of multipliers
DEFF Research Database (Denmark)
Sokoler, Leo Emil; Frison, Gianluca; Andersen, Martin S.
2014-01-01
This paper presents an algorithm, based on the alternating direction method of multipliers, for the convex optimal control problem arising in input-constrained model predictive control. We develop an efficient implementation of the algorithm for the extended linear quadratic control problem (LQCP......) with input and input-rate limits. The algorithm alternates between solving an extended LQCP and a highly structured quadratic program. These quadratic programs are solved using a Riccati iteration procedure, and a structure-exploiting interior-point method, respectively. The computational cost per iteration...... is quadratic in the dimensions of the controlled system, and linear in the length of the prediction horizon. Simulations show that the approach proposed in this paper is more than an order of magnitude faster than several state-of-the-art quadratic programming algorithms, and that the difference in computation...
Development of a New Multiplying Assembly for Research, Validation, Evaluation, and Learning
Energy Technology Data Exchange (ETDEWEB)
David L. Chichester
2012-10-01
A new multiplying test assembly is under development at Idaho National Laboratory (INL) to support research, validation, evaluation, and learning. The item is comprised of two stacked highly-enriched uranium (HEU) cylinders each 11.4 cm in diameter and having a combined height of 8.4 cm. The combined mass is 14.4 kg of HEU. Calculations for the bare configuration of the assembly indicate a multiplication level of >2.5 (keff = 0.62). Reflected configurations of the assembly, using either polyethylene or tungsten, are possible and have the capability of raising its multiplication level to approximately 8. This paper will describe the MCNP calculations performed to assess the assembly's multiplication level under different conditions and describe the resource available at INL to support visiting researchers in their use of the material. We will also describe some preliminary calculations and test activities using the assembly to study neutron multiplicity.
Electron transfer in multiply bridged donor-acceptor molecules: Dephasing and quantum coherence.
Goldsmith, Randall H; Wasielewski, Michael R; Ratner, Mark A
2006-10-19
We present a simple theoretical treatment of nonadiabatic electron transfer in multiply bridged donor-bridge-acceptor molecules using the density matrix formalism. Destructive interference can result from different signed couplings between bridge sites, with the simplest system being a four-site Joachim-type molecular interferometer. Previous work has shown that deposition of energy on the bridge sites erases the interference and recovers transport. We show that pure local dephasing, a completely elastic process, is also capable of eliminating destructive interference and regaining transport. Destructive interference as a result of system connectivity can explain the familiar ortho-meta-para reactivity of benzene bridges. We also show that pure dephasing can yield a coalescence of ortho, meta, and para effective coupling strengths and suggest a system to observe this effect experimentally.
Truss Structure Optimization with Subset Simulation and Augmented Lagrangian Multiplier Method
Directory of Open Access Journals (Sweden)
Feng Du
2017-11-01
Full Text Available This paper presents a global optimization method for structural design optimization, which integrates subset simulation optimization (SSO and the dynamic augmented Lagrangian multiplier method (DALMM. The proposed method formulates the structural design optimization as a series of unconstrained optimization sub-problems using DALMM and makes use of SSO to find the global optimum. The combined strategy guarantees that the proposed method can automatically detect active constraints and provide global optimal solutions with finite penalty parameters. The accuracy and robustness of the proposed method are demonstrated by four classical truss sizing problems. The results are compared with those reported in the literature, and show a remarkable statistical performance based on 30 independent runs.
iPTF16geu: A multiply imaged, gravitationally lensed type Ia supernova
Goobar, A.; Amanullah, R.; Kulkarni, S. R.; Nugent, P. E.; Johansson, J.; Steidel, C.; Law, D.; Mörtsell, E.; Quimby, R.; Blagorodnova, N.; Brandeker, A.; Cao, Y.; Cooray, A.; Ferretti, R.; Fremling, C.; Hangard, L.; Kasliwal, M.; Kupfer, T.; Lunnan, R.; Masci, F.; Miller, A. A.; Nayyeri, H.; Neill, J. D.; Ofek, E. O.; Papadogiannakis, S.; Petrushevska, T.; Ravi, V.; Sollerman, J.; Sullivan, M.; Taddia, F.; Walters, R.; Wilson, D.; Yan, L.; Yaron, O.
2017-04-01
We report the discovery of a multiply imaged, gravitationally lensed type Ia supernova, iPTF16geu (SN 2016geu), at redshift z = 0.409. This phenomenon was identified because the light from the stellar explosion was magnified more than 50 times by the curvature of space around matter in an intervening galaxy. We used high-spatial-resolution observations to resolve four images of the lensed supernova, approximately 0.3 arc seconds from the center of the foreground galaxy. The observations probe a physical scale of ~1 kiloparsec, smaller than is typical in other studies of extragalactic gravitational lensing. The large magnification and symmetric image configuration imply close alignment between the lines of sight to the supernova and to the lens. The relative magnifications of the four images provide evidence for substructures in the lensing galaxy.
Gas electron multiplier (GEM) operation with tissue-equivalent gases at various pressures
Energy Technology Data Exchange (ETDEWEB)
Farahmand, M. E-mail: m.farahmand@iri.tudelft.nl; Bos, A.J.J.; Eijk, C.W.E. van
2003-06-21
We have studied the operation of two different Gas Electron Multiplier (GEM) structures in both methane and propane based Tissue-Equivalent (TE) gases at different pressures varying from 0.1 to 1 atm. This work was motivated to explore the possibility of using a GEM for a new type of Tissue Equivalent Proportional Counter. In methane based TE gas, a maximum safe GEM gain of 1.5x10{sup 3} has been reached while in propane based TE gas this is 6x10{sup 3}. These maxima have been reached at different gas pressures depending on GEM structure and TE gas. Furthermore, we observed a decrease of the GEM gain in time before it becomes stable. Charge up/polarisation effects can explain this.
Two-dimensional modeling of multiply scattered laser radiation in optically dense aerosols
Energy Technology Data Exchange (ETDEWEB)
Zardecki, A.; Gerstl, S.A.W.; Embury, J.F.
1982-01-01
The discrete ordinates finite element radiation transport code TWOTRAN is applied to describe the multiple scattering of a laser beam from a reflecting target. For a model scenario involving a 99% relative humidity rural aerosol, we compute the average intensity of the scattered radiation and correction factors to the Lambert-Beer law arising from multiple scattering. As our results indicate, two-dimensional x-y and r-z geometry modeling can reliably describe a realistic three-dimensional scenario. Specific results are presented for the two visual ranges of 1.52 and 0.76 km which show that for sufficiently high aerosol concentrations (e.g., equivalent to V = 0.76 km) the target signature in a distant detector becomes dominated by multiply scattered radiation from interactions of the laser light with the aerosol environment.
Lee, Cheng-Ling; Lee, Ray-Kuang; Kao, Yee-Mou
2006-11-13
We present the synthesis of multi-channel fiber Bragg grating (MCFBG) filters for dense wavelength-division-multiplexing (DWDM) application by using a simple optimization approach based on a Lagrange multiplier optimization (LMO) method. We demonstrate for the first time that the LMO method can be used to constrain various parameters of the designed MCFBG filters for practical application demands and fabrication requirements. The designed filters have a number of merits, i.e., flat-top and low dispersion spectral response as well as single stage. Above all, the maximum amplitude of the index modulation profiles of the designed MCFBGs can be substantially reduced under the applied constrained condition. The simulation results demonstrate that the LMO algorithm can provide a potential alternative for complex fiber grating filter design problems.
Generation of symmetry coordinates for crystals using multiplier representations of the space groups
DEFF Research Database (Denmark)
Hansen, Flemming Yssing
1978-01-01
Symmetry coordinates play an important role in the normal-mode calculations of crystals. It is therefore of great importance to have a general method, which may be applied for any crystal at any wave vector, to generate these. The multiplier representations of the space groups as given by Kovalev...... and the projection-operator technique provide a basis for such a method. The method is illustrated for the nonsymmorphic D36 space group, and the theoretical background for the representations of space groups in general is reviewed and illustrated on the example above. It is desirable to perform the projection...... of symmetry coordinates in such a way that they may be used for as many wave vectors as possible. We discuss how to achieve this goal. The detailed illustrations should make it simple to apply the theory in any other case....
Elemental analysis with multiply charged 7. 5-MeV nitrogen ions
Energy Technology Data Exchange (ETDEWEB)
Gavrilov, F.F.; Puzanov, A.A.; Smirnov, V.Ya.; Ushakov, Yu.A.
1975-08-01
A determination of the capabilities of elemental analysis using a beam of multiply charged ions was made. The maximum sensitivity which was achieved in the analysis for bismuth when working with a beam of 7.5-MeV nitrogen ions 0.5 mm in diameter incident on films with a thickness less than 0.3 ..mu..g/cm/sup 2/ was 10/sup -10/ g for an irradiation time of 10 min. In this case, the number of counts at the peak of the L/sub ..cap alpha../ line was 500. The specified energy resolution of the spectrometer makes it possible to separate all neighboring chemical elements heavier than copper. With an improvement in the energy resolution of the spectrometer and the use of ions with greater energy per nucleon, multicomponent specimens containing all elements heavier than carbon can be analyzed and the sensitivity can be increased by several orders of magnitude. (JRD)
Construction and performance of a micro-pattern stereo detector with two gas electron multipliers
Energy Technology Data Exchange (ETDEWEB)
Barvich, T.; Bluem, P.; Erdmann, M. E-mail: Martin.Erdmann@cern.ch; Fahrer, M.; Kaercher, K.; Kuehn, F.; Moermann, D.; Mueller, Th.; Neuberger, D.; Roederer, F.; Simonis, H.J.; Skiba, A.; Thuemmel, W.H.; Weiler, Th.; Weseler, S
2002-06-11
The construction of a micro-pattern gas detector of dimensions 40x10 cm{sup 2} is described. Two gas electron multiplier foils (GEM) provide the internal amplification stages. A two-layer readout structure was used, manufactured using the same technology as the GEM foils. The strips of each layer cross at an effective crossing angle of 6.7 deg. and have a 406 {mu}m pitch. The performance of the detector has been evaluated in a muon beam at CERN using a silicon telescope as reference system. The position resolutions of two orthogonal coordinates are measured to be 50 {mu}m and 1 mm, respectively. The muon detection efficiency for two-dimensional space points reaches 96%.
Performance test of a micro-pattern stereo detector with two gas electron multipliers
Energy Technology Data Exchange (ETDEWEB)
Barvich, T.; Bluem, P.; Erdmann, M. E-mail: martin.erdmann@cern.ch; Fahrer, M.; Kaercher, K.; Kuehn, F.; Moermann, D.; Mueller, Th.; Neuberger, D.; Roederer, F.; Simonis, H.J.; Skiba, A.; Thuemmel, W.H.; Weiler, Th.; Weseler, S
2002-02-01
We report on the performance of a large micro-pattern detector with two gas electron multiplier foils and a two-layer readout structure at ground potential. The two readout layers each have a 406 {mu}m pitch and cross at an effective angle of 6.7 deg. . This structure allows for two orthogonal coordinates to be determined. Using a muon beam at CERN together with a silicon tracking system, the position resolutions of the two coordinates are measured to be 50 {mu}m and 1 mm respectively (1 standard deviation). The muon detection efficiency for the two-dimensional space points reaches 96%. The detector was found to be well operational over a wide range in the settings of the different electrical fields.
Characterization of photo-multiplier tube as ex-vessel radiation detector in tokamak
Jo, Jungmin; Cheon, MunSeong; Kim, Junghee; An, YoungHwa; Park, Seungil; Chung, Kyoung-Jae; Hwang, Y. S.
2017-09-01
Feasibility of using conventional photo-multiplier tubes (PMTs) without a scintillator as an ex-vessel radiation detector in a tokamak environment is studied. Basic irradiation tests using standard gamma ray sources and a d-d neutron generator showed that the PMT is responding both to gamma photons and neutrons, possibly due to the direct generation of secondary electrons inside the PMT by the impingement of high energy photons. Because of the selective sensitivity of the PMT to hard x-ray and neutrons in ohmic and neutral beam injected plasmas, respectively, it is shown that the PMT with certain configuration can be utilized either to monitor the fluctuation in the fusion neutron generation rate or to study the behavior of runaway electrons in tokamaks.
Multi-Functional Current Multiplier by High Temperature Superconducting Magnet Energy Storage
Yamada, S.; Hishinuma, Y.; Aso, Y.
We had been developing a current multiplier by inductive storage (CMIS). The prototype of CMIS consists of 12 storage copper coil with switching units. Coils and feeders are cooled by the liquid nitrogen to reduce the resistivity. Output current pulse with 480 A could be generated, by charging the coils to 40 A. The continuous current pulses of 666 pulses per minute were obtained owing to the fast switching of coil currents by using IGBTs. Two types of the multi-functional CMIS were designed conceptually; one is for mega ampere and the other is for long pulse. The system consists of the superconducting (SC) magnet section with a temperature of 20 K and the IGBT control switch section with a temperature of 77 K. The SC coil is cooled down from 77 to 20 K by a G-M refrigerator. The IGBT control switches are soaked in liquid nitrogen to reduce the total resistance from CMIS coils to the load.
The gain in Thick GEM multipliers and its time-evolution
Alexeev, M; Bradamante, F; Bressan, A; Buechele, M; Chiosso, M; Ciliberti, P; Dalla Torre, S; Dasgupta, S; Denisov, O; Duic, V; Finger, M; Finger Jr, M; Fischer, H; Gobbo, B; Gregori, M; Herrmann, F; Koenigsmann, K; Levorato, S; Maggiora, A; Makke, N; Martin, A; Menon, G; Novakova, K; Novy, J; Panzieri, D; Pereira, F A; Santos, C A; Sbrizzai, G; Schiavon, P; Schopferer, S; Slunecka, M; Sozzi, F; Steiger, L; Sulc, M; Takekawa, S; Tessarotto, F; Veloso, J F C A
2016-01-01
In the context of a project to upgrade the gas photon detectors of COMPASS RICH-1, we have performed an R&D programme aimed to develop photon detectors based on multi-layer arrangements of thick GEM electron multipliers coupled to a CsI photoconverter. For this purpose, thick GEMs have been characterised in detail including the gain performance, its dependance on the geometrical parameters and its time-evolution, a feature exhibited by the gas detectors with open insulator surfaces. The variation due to this evolution drammatically depends on the parameters themselves. In the present article we summarise the outcomes of the studies dedicated to the thick GEM gain and its evolution versus time. We also include a qualitative model which accounts for the peculiar details of the observed thick GEM gain time-evolution.
The South African wildlife ranching sector: A Social Accounting Matrix Leontief multiplier analysis
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Philippus C. Cloete
2014-10-01
Research purpose: The purpose of this article is to put into context the relative economic contribution of the wildlife ranching sector, as opposed to other land-use options in South Africa. Motivation for the study: Growth in the wildlife ranching sector at the cost of other traditional farming practices resulted in disagreements amongst various role players about the impact thereof on the national economy. The controversy can most probably be explained by different beliefs, coupled with the lack of a proper understanding and quantification of the wildlife ranching sector’s contribution toward the economy. Research methodology: The study employed a Social Accounting Matrix-based Leontief multiplier analysis for South Africa. Main findings: Results from the multiplier analysis revealed that developments within the wildlife ranching sector are likely to make a relatively more superior contribution towards the economy, especially when compared to similar land-use options such as extensive livestock production. Practical/managerial implications: It has been acknowledged by both academia and private sector that a major need exists for more research on the South African wildlife ranching industry, specifically looking at issues such as the industries, economic and social contributions, potentials and constraints. The research, therefore, contributes toward the depth of economic information and research regarding the South African wildlife sector. Contribution/value added: The research provides valuable information in dealing with the ‘popular belief’, especially amongst some of South Africa’s decision makers, namely, that growth in the wildlife ranching sector is not or does not have the ability to contribute significantly toward economic and socioeconomic factors.
The South African wildlife ranching sector: A Social Accounting Matrix Leontief multiplier analysis
Directory of Open Access Journals (Sweden)
Philippus C. Cloete
2014-02-01
Full Text Available Orientation: There is startlingly little economic research on the South African wildlife sector which contributes toward disputes regarding the economic contribution of the sector.Research purpose: The purpose of this article is to put into context the relative economic contribution of the wildlife ranching sector, as opposed to other land-use options in South Africa.Motivation for the study: Growth in the wildlife ranching sector at the cost of other traditional farming practices resulted in disagreements amongst various role players about the impact thereof on the national economy. The controversy can most probably be explained by different beliefs, coupled with the lack of a proper understanding and quantification of the wildlife ranching sector’s contribution toward the economy.Research methodology: The study employed a Social Accounting Matrix-based Leontief multiplier analysis for South Africa.Main findings: Results from the multiplier analysis revealed that developments within the wildlife ranching sector are likely to make a relatively more superior contribution towards the economy, especially when compared to similar land-use options such as extensive livestock production.Practical/managerial implications: It has been acknowledged by both academia and private sector that a major need exists for more research on the South African wildlife ranching industry, specifically looking at issues such as the industries, economic and social contributions, potentials and constraints. The research, therefore, contributes toward the depth of economic information and research regarding the South African wildlife sector.Contribution/value added: The research provides valuable information in dealing with the ‘popular belief’, especially amongst some of South Africa’s decision makers, namely, that growth in the wildlife ranching sector is not or does not have the ability to contribute significantly toward economic and socioeconomic factors.
Group-Based Alternating Direction Method of Multipliers for Distributed Linear Classification.
Wang, Huihui; Gao, Yang; Shi, Yinghuan; Wang, Ruili
2017-11-01
The alternating direction method of multipliers (ADMM) algorithm has been widely employed for distributed machine learning tasks. However, it suffers from several limitations, e.g., a relative low convergence speed, and an expensive time cost. To this end, in this paper, a novel method, namely the group-based ADMM (GADMM), is proposed for distributed linear classification. In particular, to accelerate the convergence speed and improve global consensus, a group layer is first utilized in GADMM to divide all the slave nodes into several groups. Then, all the local variables (from the slave nodes) are gathered in the group layer to generate different group variables. Finally, by using a weighted average method, the group variables are coordinated to update the global variable (from the master node) until the solution of the global problem is reached. According to the theoretical analysis, we found that: 1) GADMM can mathematically converge at the rate , where is the number of outer iterations and 2) by using the grouping methods, GADMM can improve the convergence speed compared with the distributed ADMM framework without grouping methods. Moreover, we systematically evaluate GADMM on four publicly available LIBSVM datasets. Compared with disADMM and stochastic dual coordinate ascent with alternating direction method of multipliers-ADMM, for distributed classification, GADMM is able to reduce the number of outer iterations, which leads to faster convergence speed and better global consensus. In particular, the statistical significance test has been experimentally conducted and the results validate that GADMM can significantly save up to 30% of the total time cost (with less than 0.6% accuracy loss) compared with disADMM on large-scale datasets, e.g., webspam and epsilon.
Orengo, D J; Puerma, E; Papaceit, M; Segarra, C; Aguadé, M
2015-06-01
Genome sequence comparison across the Drosophila genus revealed that some fixed inversion breakpoints had been multiply reused at this long timescale. Cytological studies of Drosophila inversion polymorphism had previously shown that, also at this shorter timescale, some breakpoints had been multiply reused. The paucity of molecularly characterized polymorphic inversion breakpoints has so far precluded contrasting whether cytologically shared breakpoints of these relatively young inversions are actually reused at the molecular level. The E chromosome of Drosophila subobscura stands out because it presents several inversion complexes. This is the case of the E1+2+9+3 arrangement that originated from the ancestral Est arrangement through the sequential accumulation of four inversions (E1, E2, E9 and E3) sharing some breakpoints. We recently identified the breakpoints of inversions E1 and E2, which allowed establishing reuse at the molecular level of the cytologically shared breakpoint of these inversions. Here, we identified and sequenced the breakpoints of inversions E9 and E3, because they share breakpoints at sections 58D and 64C with those of inversions E1 and E2. This has allowed establishing that E9 and E3 originated through the staggered-break mechanism. Most importantly, sequence comparison has revealed the multiple reuse at the molecular level of the proximal breakpoint (section 58D), which would have been used at least by inversions E2, E9 and E3. In contrast, the distal breakpoint (section 64C) might have been only reused once by inversions E1 and E2, because the distal E3 breakpoint is displaced >70 kb from the other breakpoint limits.
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Bander Al-Zahrani
2014-05-01
Full Text Available In this paper, we derive the recurrence relations for the moments of function of single and two order statistics from Lindley distribution. We also consider the maximum likelihood estimation (MLE of the parameter of the distribution based on multiply type-II censoring. However maximum likelihood estimator does not have an explicit form for the involved parameter. In order to compute the MLE of the parameter, Monte Carlo simulation is used. A comparative study is presented between classical MLE and MLE from multiply type-II censored sample.
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Andrés Blancas
2003-11-01
Full Text Available This paper addresses the financial unlinkage in Mexico through an accounting multiplier analysis derived from a SAM for a one-sector economy. Such an analysis provides a useful tool to quantify processes of structural financial change in terms of "stylized parameters". We identify and measure the financial unlinkage with financial backward and forward linkage indices derived from the accounting multipliers. The results can also help to the quality of policy decisions by identifying key and weak financial institutions and by giving a better understanding of how an impact of an initial financial injection travels within a structure.
Varghese, Babu; Rajan, Vinayakrishnan; van Leeuwen, Ton; Steenbergen, Wiendelt
2008-01-01
We describe an improved method for coherence domain path length resolved measurements of multiply scattered photons in turbid media. An electro-optic phase modulator sinusoidally modulates the phase in the reference arm of a low coherence fiber optic Mach–Zehnder interferometer, at a high phase
Energy Technology Data Exchange (ETDEWEB)
Buscaglia, G.C.; Lopez, A. [Centro Atomico Bariloche and Inst. Balseiro, Bariloche (Argentina); Bolech, C. [Rutgers - the State Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy
2000-07-01
A numerical method for the solution of the time-dependent Ginzburg-Landau equations is detailed. The method is based on the popular technique of gauge invariant variables. Extension of the method to multiply connected domains is addressed. An implementation of the method is made available through the Web. (orig.)
Kim, Holak; Lim, Youbong; Seon, Jongho; Choe, Wonho; Korea Advanced Institute of Science and Technology (KAIST) Collaboration; Kyung Hee University Collaboration
2014-10-01
Operation performance and ion beam characteristics in the presence of multiply charged ions in cylindrical Hall thruster (CHT) and annular Hall thruster (AHT) plasmas are compared under identical conditions such as channel diameter, channel depth, and propellant flow rate. According to our previous results, the propellant utilization of the 200 W class CHT well exceeds unity [1,2] and the papers suggest that this may be related to the presence of multiply charged ions. In this work, we report the large fractions of Xe2+ and Xe3+ ions measured in the CHT plasma, which are about 16--26% and 6--7%, respectively. The measured values of specific impulse and thrust are higher by 1.4 times in CHT than in AHT at 300 V of the anode voltage, and it is found that the high fraction of multiply charged ions is responsible for the higher values of specific impulse and thrust. The details of the comparison of the overall performance and beam characteristics associated with multiply charged ions in AHT and CHT will be presented. This work was partly supported by the Space Core Technology Program (Grant No. 2014M1A3A3A02034510) and the Korea Institute of Materials Science (KIMS) (Grant No. 10043470).
Hartlep, Thomas; Cuzzi, Jeffrey N.; Weston, Brian
2017-03-01
Turbulent flows preferentially concentrate inertial particles depending on their stopping time or Stokes number, which can lead to significant spatial variations in the particle concentration. Cascade models are one way to describe this process in statistical terms. Here, we use a direct numerical simulation (DNS) dataset of homogeneous, isotropic turbulence to determine probability distribution functions (PDFs) for cascade multipliers, which determine the ratio by which a property is partitioned into subvolumes as an eddy is envisioned to decay into smaller eddies. We present a technique for correcting effects of small particle numbers in the statistics. We determine multiplier PDFs for particle number, flow dissipation, and enstrophy, all of which are shown to be scale dependent. However, the particle multiplier PDFs collapse when scaled with an appropriately defined local Stokes number. As anticipated from earlier works, dissipation and enstrophy multiplier PDFs reach an asymptote for sufficiently small spatial scales. From the DNS measurements, we derive a cascade model that is used it to make predictions for the radial distribution function (RDF) for arbitrarily high Reynolds numbers, Re, finding good agreement with the asymptotic, infinite Re inertial range theory of Zaichik and Alipchenkov [New J. Phys. 11, 103018 (2009), 10.1088/1367-2630/11/10/103018]. We discuss implications of these results for the statistical modeling of the turbulent clustering process in the inertial range for high Reynolds numbers inaccessible to numerical simulations.
Claus, Richard N.; And Others
The evaluation report describes special education services provided to trainable mentally impaired (TMI), autistic impaired (AI), severely multiply impaired (SXI), and severely mentally impaired (SMI) students at and through the Melvin G. Millet Learning Center (Bridgeport, Michigan). The eight program components are described individually and…
Martin, S.; Ortega, C.; Chen, L.; Bredy, R.; Vernier, A.; Dugourd, P.; Antoine, R.; Bernard, J.; Reitsma, G.; Gonzalez Magana, Olmo; Hoekstra, Ronnie; Schlathölter, Thomas
2014-01-01
Electron-transfer processes in interaction between highly charged ions and multiply protonated proteins have been studied. Collisions between Xe8+ at 96 keV and protonated cytochrome-C at selected charge state (q from 15+ to 19+) result inmass spectra composed mainly of intact molecular ions. From
Lomov, S.V.; Barburski, M.; Stoilova, Tz.; Verpoest, I.; Akkerman, Remko; Loendersloot, Richard; ten Thije, R.H.W.
2005-01-01
Deformability of bi- and quadri-axial multi-axial multiply stitched preforms is studied in biaxial tension, shear (picture frame test) and compression. The results complement KES-F measurements in the low load range, reported in the Part 2 of the series (Compos A, 34, 2003, 359–70). The biaxial
A High Efficiency Multiple-Anode 260-340 GHz Frequency Tripler
Maestrini, Alain; Tripon-Canseliet, Charlotte; Ward, John S.; Gill, John J.; Mehdi, Imran
2006-01-01
We report on the fabrication at the Jet Propulsion Laboratory of a fixed-tuned split-block waveguide balanced frequency tripler working in the 260-340 GHz band. This tripler will be the first stage of a x3x3x3 multiplier chain to 2.7 THz (the last stages of which are being fabricated at JPL) and is therefore optimized for high power operation. The multiplier features six GaAs Schottky planar diodes in a balanced configuration integrated on a GaAs membrane. Special attention was put on splitting the input power as evenly as possible among the diodes in order to ensure that no diode is overdriven. Preliminary RF tests indicate that the multiplier covers the expected bandwidth and that the efficiency is in the range 1.5-7.5 % with 100 mW of input power.
Increased burst size in multiply infected cells can alter basic virus dynamics
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Cummings Kara W
2012-05-01
Full Text Available Abstract Background The dynamics of viral infections have been studied extensively in a variety of settings, both experimentally and with mathematical models. The majority of mathematical models assumes that only one virus can infect a given cell at a time. It is, however, clear that especially in the context of high viral load, cells can become infected with multiple copies of a virus, a process called coinfection. This has been best demonstrated experimentally for human immunodeficiency virus (HIV, although it is thought to be equally relevant for a number of other viral infections. In a previously explored mathematical model, the viral output from an infected cell does not depend on the number of viruses that reside in the cell, i.e. viral replication is limited by cellular rather than viral factors. In this case, basic virus dynamics properties are not altered by coinfection. Results Here, we explore the alternative assumption that multiply infected cells are characterized by an increased burst size and find that this can fundamentally alter model predictions. Under this scenario, establishment of infection may not be solely determined by the basic reproductive ratio of the virus, but can depend on the initial virus load. Upon infection, the virus population need not follow straight exponential growth. Instead, the exponential rate of growth can increase over time as virus load becomes larger. Moreover, the model suggests that the ability of anti-viral drugs to suppress the virus population can depend on the virus load upon initiation of therapy. This is because more coinfected cells, which produce more virus, are present at higher virus loads. Hence, the degree of drug resistance is not only determined by the viral genotype, but also by the prevalence of coinfected cells. Conclusions Our work shows how an increased burst size in multiply infected cells can alter basic infection dynamics. This forms the basis for future experimental testing
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Sebastião Renato Valverde
2003-06-01
Full Text Available Este trabalho trata da importância do setor florestal para o desenvolvimento socioeconômico brasileiro por meio dos modelos econômicos de equilíbrio geral multissetoriais, através das análises das matrizes de insumo-produto (MIP e de contabilidade social (MCS. As principais fontes dos dados foram as Tabelas de Insumo-Produto (TIP do Instituto Brasileiro de Geografia e Estatística (IBGE, além de informações obtidas no Banco Nacional de Desenvolvimento Econômico e Social (BNDES, no Banco Central (BACEN e na Secretaria da Receita Federal (SRF, referentes ao ano de 1995. Observou-se que tão importante quanto contribuir para a geração e formação do PIB, de emprego, impostos, salários e balança comercial é o poder que um setor produtivo tem a mais que o outro de multiplicar estes indicadores quando uma unidade monetária é gasta a mais pelos consumidores finais na demanda por produtos deste determinado setor. Os resultados indicaram que o setor florestal é um dos setores da economia brasileira que apresentou os maiores efeitos multiplicadores para os indicadores socioeconômicos, sendo superiores aos de outros como o da indústria automobilística, de equipamentos elétricos e eletrônicos, de máquinas e equipamentos e de produtos químicos e petróleo.This study evaluated the important role the forestry sector plays in the Brazilian economic development by means of the multisector general economic equilibrium models, through the analyses of the Input-Output Matrix (IOM and the Social Accounting Matrix (SAM. The main sources were the Input-Output Tables (IOT from the Brazilian Institute of Geography and Statistics (IBGE, the National Bank of Economic and Social Development (BNDES, from the Brazilian Central Bank (BACEN and the Brazilian Federal Revenue Office (SRF, for 1995. It was observed that the extra power a productive sector has over another to multiply GDP, jobs, taxes, salaries and trade balance, is as important as
Linkage analysis of alternative anxiety phenotypes in multiply affected panic disorder families
Fyer, Abby J.; Costa, Ramiro; Haghighi, Fatemeh; Logue, Mark W.; Knowles, James A.; Weissman, Myrna M.; Hodge, Susan E.; Hamilton, Steven P.
2013-01-01
Background The choice of phenotype definitions for genetic studies of panic and phobic disorders is complicated by family, twin and neurobiological data indicating both distinct and shared risk factors as well as heterogeneity within categories. We previously reported a genome scan in 120 multiplex panic disorder (PD) families using a phenotype that closely adhered to the DSM IV PD definition. Here we extend this work by conducting exploratory linkage analyses in this same pedigree set using ten additional literature- based panic and phobia-related phenotypes that take into account aspects of these hypothesized complexities. Methods Multiply affected families (> 2 individuals with PD) were recruited from clinical and non-clinical sources, evaluated by clinician administered semi-structured interview and subsequent blind consensus best estimate procedure. Each phenotype was analyzed under dominant and recessive models using parametric 2-point (homogeneity and heterogeneity), multipoint, and non-parametric methods. Empirically based permutations were used to estimate model specific and global (across all phenotypes) p-values. Results The highest score was a 2-point lod (4.27, global p specific or social phobia” under a recessive model and conditions of homogeneity. There was minimal support for linkage to any of the remaining nine phenotypes. Conclusions Though interpretation of findings is limited by sample size and the large number of phenotypes and models analyzed these data suggest a region on chromosome 13 as a potential site for further exploration in relation to risk for specific and social phobias. PMID:22525237
Gao, Hao
2016-04-07
For the treatment planning during intensity modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT), beam fluence maps can be first optimized via fluence map optimization (FMO) under the given dose prescriptions and constraints to conformally deliver the radiation dose to the targets while sparing the organs-at-risk, and then segmented into deliverable MLC apertures via leaf or arc sequencing algorithms. This work is to develop an efficient algorithm for FMO based on alternating direction method of multipliers (ADMM). Here we consider FMO with the least-square cost function and non-negative fluence constraints, and its solution algorithm is based on ADMM, which is efficient and simple-to-implement. In addition, an empirical method for optimizing the ADMM parameter is developed to improve the robustness of the ADMM algorithm. The ADMM based FMO solver was benchmarked with the quadratic programming method based on the interior-point (IP) method using the CORT dataset. The comparison results suggested the ADMM solver had a similar plan quality with slightly smaller total objective function value than IP. A simple-to-implement ADMM based FMO solver with empirical parameter optimization is proposed for IMRT or VMAT.
Chen, Shanshan; Du, Hongwei; Wu, Linna; Jin, Jiaquan; Qiu, Bensheng
2017-04-27
The challenge of reconstructing a sparse medical magnetic resonance image based on compressed sensing from undersampled k-space data has been investigated within recent years. As total variation (TV) performs well in preserving edge, one type of approach considers TV-regularization as a sparse structure to solve a convex optimization problem. Nevertheless, this convex optimization problem is both nonlinear and nonsmooth, and thus difficult to handle, especially for a large-scale problem. Therefore, it is essential to develop efficient algorithms to solve a very broad class of TV-regularized problems. In this paper, we propose an efficient algorithm referred to as the fast linearized preconditioned alternating direction method of multipliers (FLPADMM), to solve an augmented TV-regularized model that adds a quadratic term to enforce image smoothness. Because of the separable structure of this model, FLPADMM decomposes the convex problem into two subproblems. Each subproblem can be alternatively minimized by augmented Lagrangian function. Furthermore, a linearized strategy and multistep weighted scheme can be easily combined for more effective image recovery. The method of the present study showed improved accuracy and efficiency, in comparison to other methods. Furthermore, the experiments conducted on in vivo data showed that our algorithm achieved a higher signal-to-noise ratio (SNR), lower relative error (Rel.Err), and better structural similarity (SSIM) index in comparison to other state-of-the-art algorithms. Extensive experiments demonstrate that the proposed algorithm exhibits superior performance in accuracy and efficiency than conventional compressed sensing MRI algorithms.
AIDS pacient's long-term battle with multiply recurrent tuberculosis: reinfection or reactivation?
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A. Reniero
Full Text Available The advent of Mycobacterium tuberculosis strain genotyping has allowed differentiation between disease relapse and exogenous re-infection. We report here a remarkable case of multiply recurrent tuberculosis in a patient living with HIV. Between 1995 and 2009, a young HIV-infected intravenous drug user, who was reluctant to comply with anti-retroviral treatment, underwent at least five tuberculosis episodes caused by three distinct M. tuberculosis strains sharply differentiated by drug susceptibility profile, genotype and infectious source. Eventually, the patient died during a relapse of tuberculosis due to a notorious multidrug-resistant outbreak-strain, which infected him during a prolonged hospitalization in the epicentre of such outbreak. Whether recurrent tuberculosis is due to a new infection or to reactivation of a previous one is a century-long controversial question. In our patient, both conditions alternated throughout his 15 years of living with HIV. Cases such as this might not be exceptional in certain underprivileged suburban areas of Argentina and should raise concern over three pending issues in tuberculosis control policies, namely secondary preventing therapy, institutional infection control and patient follow-up throughout the health network system.
Linear and Quadratic Interpolators Using Truncated-Matrix Multipliers and Squarers
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E. George Walters III
2015-11-01
Full Text Available This paper presents a technique for designing linear and quadratic interpolators for function approximation using truncated multipliers and squarers. Initial coefficient values are found using a Chebyshev-series approximation and then adjusted through exhaustive simulation to minimize the maximum absolute error of the interpolator output. This technique is suitable for any function and any precision up to 24 bits (IEEE single precision. Designs for linear and quadratic interpolators that implement the 1/x, 1/ √ x, log2(1+2x, log2(x and 2x functions are presented and analyzed as examples. Results show that a proposed 24-bit interpolator computing 1/x with a design specification of ±1 unit in the last place of the product (ulp error uses 16.4% less area and 15.3% less power than a comparable standard interpolator with the same error specification. Sixteen-bit linear interpolators for other functions are shown to use up to 17.3% less area and 12.1% less power, and 16-bit quadratic interpolators are shown to use up to 25.8% less area and 24.7% less power.
THick Gas Electron Multiplier (THGEM) detector readout based on TDC-FPGAs
Energy Technology Data Exchange (ETDEWEB)
Buechele, Maximilian; Fischer, Horst; Gorzellik, Matthias; Grussenmeyer, Tobias; Herrmann, Florian; Joerg, Philipp; Kremser, Paul; Schopferer, Sebastian [Physikalisches Institut, Albert-Ludwigs-Universitaet Freiburg (Germany); Collaboration: THGEM Group of the COMPASS Collaboration
2014-07-01
The RD51 program has been investigating a novel photon detector technology called THGEM, aimed to be operated in future Ring Imaging Cherenkov (RICH) Counters. The THGEM design is adopted from the Gas Electron Multiplier (GEM) using Printed Circuit Board (PCB) material. The manufacturing process uses standard PCB drilling and etching techniques which allows to cover large detector areas at gains up to 10{sup 6} in a mechanically robust and very cost-efficient manner. Promising results have also been obtained with a hybrid approach, which combines the THGEM with a Micromega layer to further suppress the ion back flow to the photocathode. In the course of the RICH-1 detector upgrade of the COMPASS experiment at CERN, the existing Multi Wire Proportional Chambers will partly be replaced by a set of THGEMs. For the digital readout, we are designing a front-end board processing 384 detector channels by TDC-FPGAs. The boards reading a single THGEM chamber are connected in a star topology in order to exploit the data rate capability of the optical transceivers interfacing with the downstream data acquisition system.
Multi-anode photon-multiplier readout electronics for the LHCb ring imaging Cherenkov detectors
Smale, N J
2004-01-01
A readout system for the Ring Imaging CHerenkov (RICH) detectors of the LHCb experiment has been developed. Two detector technologies for the measurement of Cherenkov photons are considered, the Multi-Anode Photo-Multiplier Tube (MAPMT) and the Hybrid Photon Detector (HPD), both of which meet the RICH requirements. The properties of the MAPMT are evaluated using a controlled single-photon source; a pixel-to-pixel gain variation of ~3 and a typical signal to noise of ~20 is measured. The relative tube efficiency is found to be reduced by ~26 % due to the detailed focusing structure of the MAPMT device. A radiation hard application-specific integrated circuit (ASIC) chip, the Beetle1.2MA0, has been developed to capture and store signals from a pair of MAPMTs. The Beetle1.2MA0 is built on the architecture of the Beetle family that was designed for silicon strip detectors, the difference being a modified front-end amplifier. The 128 input-channels of the Beetle1.2MA0 have a charge-sensitive pre-amplifier followed...
Operation of a load current multiplier on a nanosecond mega-ampere pulse forming line generator
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A. S. Chuvatin
2010-01-01
Full Text Available We investigate the operation of a load current multiplier (LCM on a pulse-forming-line nanosecond pulse-power generator. Potential benefits of using the LCM technique on such generators are studied analytically for a simplified case. A concrete LCM design on the Zebra accelerator (1.9 Ohm, ∼1 MA, 100 ns is described. This design is demonstrated experimentally with high-voltage power pulses having a rise time of dozens of nanoseconds. Higher currents and magnetic energies were observed in constant-inductance solid-state loads when a better generator-to-load energy coupling was achieved. The load current on Zebra was increased from the nominal 0.8–0.9 MA up to about 1.6 MA. This result was obtained without modifying the generator energetics or architecture and it is in good agreement with the presented numerical simulations. Validation of the LCM technique at a nanosecond time scale is of importance for the high-energy-density physics research.
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Lang Thierry
2009-03-01
Full Text Available Abstract Background Mammal macrophages (MΦ display a wide range of functions which contribute to surveying and maintaining tissue integrity. One such function is phagocytosis, a process known to be subverted by parasites like Leishmania (L. Indeed, the intracellular development of L. amazonensis amastigote relies on the biogenesis and dynamic remodelling of a phagolysosome, termed the parasitophorous vacuole, primarily within dermal MΦ. Results Using BALB/c mouse bone marrow-derived MΦ loaded or not with amastigotes, we analyzed the transcriptional signatures of MΦ 24 h later, when the amastigote population was growing. Total RNA from MΦ cultures were processed and hybridized onto Affymetrix Mouse430_2 GeneChips®, and some transcripts were also analyzed by Real-Time quantitative PCR (RTQPCR. A total of 1,248 probe-sets showed significant differential expression. Comparable fold-change values were obtained between the Affymetrix technology and the RTQPCR method. Ingenuity Pathway Analysis software® pinpointed the up-regulation of the sterol biosynthesis pathway (p-value = 1.31e-02 involving several genes (1.95 to 4.30 fold change values, and the modulation of various genes involved in polyamine synthesis and in pro/counter-inflammatory signalling. Conclusion Our findings suggest that the amastigote growth relies on early coordinated gene expression of the MΦ lipid and polyamine pathways. Moreover, these MΦ hosting multiplying L. amazonensis amastigotes display a transcriptional profile biased towards parasite-and host tissue-protective processes.
Laplace's equation and the Dirichlet-Neumann map in multiply connected domains
Greenbaum, A.; Greengard, L.; Mcfadden, G. B.
1993-01-01
A variety of problems in material science and fluid dynamics require the solution of Laplace's equation in multiply connected domains. Integral equation methods are natural candidates for such problems, since they discretize the boundary alone, require no special effort for free boundaries, and achieve superalgebraic convergence rates on sufficiently smooth domains in two space dimensions, regardless of shape. Current integral equation methods for the Dirichlet problem, however, require the solution of M independent problems of dimension N, where M is the number of boundary components and N is the total number of points in the discretization. In this paper, we present a new boundary integral equation approach, valid for both interior and exterior problems, which requires the solution of a single linear system of dimension N + M. We solve this system by making use of an iterative method (GMRES) combined with the last multipole method for the rapid calculation of the necessary matrix vector products. For a two-dimensional system with 200 components and 100 points on each boundary, we gain a speedup of a factor of 100 from the new analytic formulation and a factor of 50 from the fast multipole method. The resulting scheme brings large scale calculations in extremely complex domains within practical reach.
Gao, Hao
2016-04-01
For the treatment planning during intensity modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT), beam fluence maps can be first optimized via fluence map optimization (FMO) under the given dose prescriptions and constraints to conformally deliver the radiation dose to the targets while sparing the organs-at-risk, and then segmented into deliverable MLC apertures via leaf or arc sequencing algorithms. This work is to develop an efficient algorithm for FMO based on alternating direction method of multipliers (ADMM). Here we consider FMO with the least-square cost function and non-negative fluence constraints, and its solution algorithm is based on ADMM, which is efficient and simple-to-implement. In addition, an empirical method for optimizing the ADMM parameter is developed to improve the robustness of the ADMM algorithm. The ADMM based FMO solver was benchmarked with the quadratic programming method based on the interior-point (IP) method using the CORT dataset. The comparison results suggested the ADMM solver had a similar plan quality with slightly smaller total objective function value than IP. A simple-to-implement ADMM based FMO solver with empirical parameter optimization is proposed for IMRT or VMAT.
Bryden, Francesca; Maruani, Antoine; Rodrigues, João M M; Cheng, Miffy H Y; Savoie, Huguette; Beeby, Andrew; Chudasama, Vijay; Boyle, Ross W
2017-12-20
Exploitation of photosensitizers as payloads for antibody-based anticancer therapeutics offers a novel alternative to the small pool of commonly utilized cytotoxins. However, existing bioconjugation methodologies are incompatible with the requirement of increased antibody loading without compromising antibody function, stability, or homogeneity. Herein, we describe the first application of dendritic multiplier groups to allow the loading of more than 4 porphyrins to a full IgG antibody in a site-specific and highly homogeneous manner. Photophysical evaluation of UV-visible absorbance and singlet oxygen quantum yields highlighted porphyrin-dendron 14 as the best candidate for bioconjugation; with subsequent bioconjugation producing a HER2-targeted therapeutic with average loading ratios of 15.4:1. In vitro evaluation of conjugate 18 demonstrated a nanomolar photocytotoxic effect in a target cell line, which overexpresses HER2, with no observed photocytotoxicity at the same concentration in a control cell line which expresses native HER2 levels, or in the absence of irradiation with visible light.
The economic impact and multiplier effect of a family practice clinic on an academic medical center.
Schneeweiss, R; Ellsbury, K; Hart, L G; Geyman, J P
1989-07-21
Academic medical centers are facing the need to expand their primary care referral base in an increasingly competitive medical environment. This study describes the medical care provided during a 1-year period to 6304 patients registered with a family practice clinic located in an academic medical center. The relative distribution of primary care, secondary referrals, inpatient admissions, and their associated costs are presented. The multiplier effect of the primary care clinic on the academic medical center was substantial. For every $1 billed for ambulatory primary care, there was $6.40 billed elsewhere in the system. Each full-time equivalent family physician generated a calculated sum of $784,752 in direct, billed charges for the hospital and $241,276 in professional fees for the other specialty consultants. The cost of supporting a primary care clinic is likely to be more than offset by the revenues generated from the use of hospital and referral services by patients who received care in the primary care setting.
Accounting of Multiplier Effect as a Required Element in Assessing the Effects of Social Programs
Directory of Open Access Journals (Sweden)
Yuliya Georgievna Lavrikova
2015-12-01
Full Text Available The article substantiates the importance of taking into account indirect effects of the programs, projects, activities (mainly social when deciding on the need to implement them. The problem of providing society with decent living conditions is studied. The article proves that in spite of some positive trends in the Russian construction market the issues of housing availability do not lose their significance. It notes that a variety of approaches to solving this problem have been developed, that is why it is critical to assess the effectiveness of each solution in order to choose the most suitable one. One of the tools for alleviating this problem – a program of housing construction savings – is discussed in detail; by means of the specially designed universal computational model we determine fiscal effectiveness of this program application in the Sverdlovsk Oblast. The analysis shows that the accounting of multiplier effect reveals the full range of possible effects of the program that can significantly affect the adoption of the decision to initiate actions necessary for their implementation
Hui, Rui-Hua; Hou, Dong-Yan; Li, Tie-Chun; Liu, Xiao-Yuan
2006-09-01
Important chemical constituents analysis for the total flavone and total saponin in Gynostemma pentaphyllum is described. The colour reactions of flavones and saponines with vanillin-perchloric acid in acetic acid produced the good absorptions at 451 and 547 nm, but the absorption peaks too overlapped to be determined simultaneously. A new method for the total flavone and the total saponin in Gynostemma pentaphyllum to be determined by signal multiplier spectrophotometry simultaneously without any preliminary separation was proposed. For quantitative analysis, the rutinum as a standard of the total flavone and the ginsenoside Rb1 as standard of the total saponin were applied. The experiment results showed that the regression equations of concentration and deltaA were obtained: deltaAflavone = 0.0133+4.417 0Cflavone, relation coefficient rflavone = 0.9994, and the total flavone concentrations were in 0-0. 16 microg x mI(-1) with deltaA obeying linear relation; deltaAsaporin = 2.775 5Csaponin -0.8881 x 10(-2), relation coefficient rsaponin = 0.9991, and the total saponin concentrations were in 0-0.30 microg x mL(-1) with deltaA obeying linear relation respectively. The recovery ratio was 104.0%-113.0% and 86.8%-94.6% respectively. The RSDflavone was less than 0.58% (n = 9) and RSDsaponin was less than 0. 35% (n=9) respectively. The proposed method is simple, rapid accurate and feasible.
Ke, Ge-Yang; Pan, Yan; Yin, Jian; Huang, Chang-Qin
2017-03-01
Multitask learning (MTL) aims to improve the generalization performance of multiple tasks by exploiting the shared factors among them. Various metrics (e.g., $F$-score, area under the ROC curve) are used to evaluate the performances of MTL methods. Most existing MTL methods try to minimize either the misclassified errors for classification or the mean squared errors for regression. In this paper, we propose a method to directly optimize the evaluation metrics for a large family of MTL problems. The formulation of MTL that directly optimizes evaluation metrics is the combination of two parts: 1) a regularizer defined on the weight matrix over all tasks, in order to capture the relatedness of these tasks and 2) a sum of multiple structured hinge losses, each corresponding to a surrogate of some evaluation metric on one task. This formulation is challenging in optimization because both of its parts are nonsmooth. To tackle this issue, we propose a novel optimization procedure based on the alternating direction scheme of multipliers, where we decompose the whole optimization problem into a subproblem corresponding to the regularizer and another subproblem corresponding to the structured hinge losses. For a large family of MTL problems, the first subproblem has closed-form solutions. To solve the second subproblem, we propose an efficient primal-dual algorithm via coordinate ascent. Extensive evaluation results demonstrate that, in a large family of MTL problems, the proposed MTL method of directly optimization evaluation metrics has superior performance gains against the corresponding baseline methods.
Properties of the Flight Model Gas Electron Multiplier for the GEMS Mission
Takeuchi, Yoko; Kitaguchi, Takao; Hayato, Asami; Tamagawa, Toru; Iwakiri, Wataru; Asami, Fumi; Yoshikawa, Akifumi; Kaneko, Kenta; Enoto, Teruaki; Black, Kevin;
2014-01-01
We present the gain properties of the gas electron multiplier (GEM) foil in pure dimethyl ether (DME) at 190 Torr. The GEM is one of the micro pattern gas detectors and it is adopted as a key part of the X-ray polarimeter for the GEMS mission. The X-ray polarimeter is a time projection chamber operating in pure DME gas at 190 Torr. We describe experimental results of (1) the maximum gain the GEM can achieve without any discharges, (2) the linearity of the energy scale for the GEM operation, and (3) the two-dimensional gain variation of the active area. First, our experiment with 6.4 keV X-ray irradiation of the whole GEM area demonstrates that the maximum effective gain is 2 x 10(exp 4) with the applied voltage of 580 V. Second, the measured energy scale is linear among three energies of 4.5, 6.4, and 8.0 keV. Third, the two-dimensional gain mapping test derives the standard deviation of the gain variability of 7% across the active area.
Homotopy symmetry in the multiply connected twin paradox of special relativity
Roukema, Boudewijn F.; Bajtlik, Stanislaw
2008-10-01
In a multiply connected space, the two twins of the special relativity twin paradox move with constant relative speed and meet second time without acceleration. The twins' situations appear to be symmetrical despite the need for one to be younger due to time dilation. Here, the suggestion that the apparent symmetry is broken by homotopy classes of the twins' worldlines is re-examined using space-time diagrams. It is found that each twin finds her own spatial path to have zero winding index and that of the other twin to have unity-winding index, i.e. the twins' worldlines' relative homotopy classes are symmetrical. Although the twins' apparent symmetry is in fact broken by the need for the non-favoured twin to non-simultaneously identify spatial domain boundaries, the non-favoured twin cannot detect her disfavoured state if she only measures the homotopy classes of the two twins' projected worldlines, contrary to what was previously suggested. We also note that for the non-favoured twin, the fundamental domain can be chosen by identifying time boundaries (with a spatial offset) instead of space boundaries (with a temporal offset).
The current status of the Gas Electron Multiplier (GEM) research at Kasetsart University, Thailand
Kumpiranon, P.; Kulasri, K.; Rittirong, A.; Saenboonruang, K.
2017-06-01
During the past decade, Gas Electron Multiplier (GEM) detectors have been greatly developed and utilized in numbers of applications including advanced nuclear and particle researches, medical imaging, astrophysics, and neutron detection for national security. Our GEM research group at the Department of Applied Radiation and Isotopes, Faculty of Science, Kasetsart University, Thailand, realized in its excellent properties/potentials and started extensive researches on GEM detectors. To build a strong foundation on our research group, two 10 cm × 10 cm triple GEM detectors were characterized on their important properties including absolute gains and detection uniformity. Moreover, to widen applications of the GEM detector, our group had modified the GEM detector by introducing either solid or gaseous neutron converters to the detector so that the detector could effectively detect neutrons. These modifications included coating a thin film of 10B and natB to the GEM drift cathode for thermal neutron detection and flowing a gas mixture of He/CO2 (80:20 and 70:30) and C4H10/He/CO2 (7:70:23) for fast neutron detection. Results showed that the modified GEM-based neutron detector could detect both types of neutrons with different relative efficiencies and gains depending on thicknesses and types of neutron converters. This article discusses basic knowledge of the GEM detector, construction and testing procedures, results, and discussion.
Trickett, Penelope K; Kim, Kihyun; Prindle, John
2011-10-01
Based on the data obtained through Child Protective Services (CPS) case records abstraction, this study aimed to explore patterns of overlapping types of child maltreatment in a sample of urban, ethnically diverse male and female youth (n= 303) identified as maltreated by a large public child welfare agency. A cluster analysis was conducted on data for 303 maltreated youth. The overall categorization of four types of abuse (i.e., physical, sexual, emotional abuse and neglect) was used to provide a starting point for clustering of the 303 cases and then the subtypes of emotional abuse were broken down in the clusters. The different clusters of child maltreatment were compared on the multiple outcomes such as mental health, behavior problems, self-perception, and cognitive development. In this study, we identified four clusters of child maltreatment experiences. Three patterns involved emotional abuse. One cluster of children experienced all four types. Different clusters were differentially associated with multiple outcome measures. In general, multiply-maltreated youth fared worst, especially when the cluster involved sexual abuse. Also, sex differences were found in these associations. Boys who experienced multiple types of maltreatment showed more difficulties than girls. These results reiterate the importance of creating more complex models of child maltreatment. Children who have experienced various types of maltreatment are especially in need of more attention from professionals and resources should be allocated accordingly. Copyright Â© 2011 Elsevier Ltd. All rights reserved.
Taylor coefficients and coefficient multipliers of Hardy and Bergman-type spaces
Jevtić, Miroljub; Arsenović, Miloš
2016-01-01
This book provides a systematic overview of the theory of Taylor coefficients of functions in some classical spaces of analytic functions and especially of the coefficient multipliers between spaces of Hardy type. Offering a comprehensive reference guide to the subject, it is the first of its kind in this area. After several introductory chapters covering the basic material, a large variety of results obtained over the past 80 years, including the most recent ones, are treated in detail. Several chapters end with discussions of practical applications and related topics that graduate students and experts in other subjects may find useful for their own purposes. Thus, a further aim of the book is to communicate to non-specialists some concrete facts that may be of value in their own work. The book can also be used as a textbook or a supplementary reference for an advanced graduate course. It is primarily intended for specialists in complex and functional analysis, graduate students, and experts in other related...
Gas electron multipliers. Development of large area GEMS and spherical GEMS
Energy Technology Data Exchange (ETDEWEB)
Pinto, Serge Duarte
2011-08-15
Gaseous radiation detectors have been a crucial part of high-energy physics instrumentation since the 1960s, when the first multiwire proportional counters were built. In the 1990s the first micropattern gas detectors (MPGDS) saw the light; with sub-millimeter feature sizes these novel detectors were faster and more accurate than their predecessors. The gas electron multiplier (GEM) is one of the most successful of these technologies. It is a charge multiplication structure made from a copper clad polymer foil, pierced with a regular and dense pattern of holes. I describe the properties and the application of GEMs and GEM. detectors, and the research and development I have done on this technology. Two of the main objectives were the development of large area GEMs ({proportional_to}m{sup 2}) for particle physics experiments and GEMs with a spherical shape for X-ray or neutron diffraction detectors. Both have been realized, and the new techniques involved are finding their way to applications in research and industry. (orig.)
Interaction of singly and multiply charged ions with a lithium-fluoride surface
Wirtz, L
2001-01-01
Charge transfer between slow ions and an ionic crystal surface still poses a considerable challenge to theory due to the intrinsic many-body character of the system. For the neutralization of multiply charged ions in front of metal surfaces, the Classical Over the Barrier (COB) model is a widely used tool. We present an extension of this model to ionic crystal surfaces where the localization of valence electrons at the anion sites and the lack of cylindrical symmetry of the ion-surface system impede a simple analytical estimate of electron transfer rates. We use a classical trajectory Monte Carlo approach to calculate electron transfer rates for different charge states of the projectile ion. With these rates we perform a Monte Carlo simulation of the neutralization of slow Ne10+ ions in vertical incidence on an LiF surface. Capture of one or several electrons may lead to a local positive charge up of the surface. The projectile dynamics depends on the balance between the repulsion due to this charge and the a...
Deconvolving images with unknown boundaries using the alternating direction method of multipliers.
Almeida, Mariana S C; Figueiredo, Mario
2013-08-01
The alternating direction method of multipliers (ADMM) has recently sparked interest as a flexible and efficient optimization tool for inverse problems, namely, image deconvolution and reconstruction under non-smooth convex regularization. ADMM achieves state-of-the-art speed by adopting a divide and conquer strategy, wherein a hard problem is split into simpler, efficiently solvable sub-problems (e.g., using fast Fourier or wavelet transforms, or simple proximity operators). In deconvolution, one of these sub-problems involves a matrix inversion (i.e., solving a linear system), which can be done efficiently (in the discrete Fourier domain) if the observation operator is circulant, i.e., under periodic boundary conditions. This paper extends ADMM-based image deconvolution to the more realistic scenario of unknown boundary, where the observation operator is modeled as the composition of a convolution (with arbitrary boundary conditions) with a spatial mask that keeps only pixels that do not depend on the unknown boundary. The proposed approach also handles, at no extra cost, problems that combine the recovery of missing pixels (i.e., inpainting) with deconvolution. We show that the resulting algorithms inherit the convergence guarantees of ADMM and illustrate its performance on non-periodic deblurring (with and without inpainting of interior pixels) under total-variation and frame-based regularization.
Large Gas Electron Multiplier Trackers for Super Bigbite Spectrometer at Jefferson lab Hall A
Saenboonruang, K.; Gnanvo, K.; Liyanage, N.; Nelyubin, V.; Sacher, S.; Cisbani, E.; Musico, P.; Wojtsekhowski, B.
2013-04-01
The 12 GeV upgrade at Jefferson Lab (JLAB) makes many exciting nuclear experiments possible. These experiments also require new high performance instrumentation. The Super Bigbite Spectrometer (SBS) was proposed to perform a series of high precision nucleon form factor experiments at large momentum transfer. The SBS will be capable of operating at a very high luminosity and provide a large solid angle acceptance of 76 msr. SBS will be equipped with a double focal plane polarimeter. Thus, SBS will have three large trackers made of Gas Electron Multiplier (GEM) chambers. The first, second, and third trackers will consist of six, four, and four tracking layers respectively. When completed in 2017, the SBS GEM trackers will form one of the largest sets of GEM chambers in the world. The GEM trackers allow the SBS to operate under high background rates over 500 kHz/cm^2, while providing an excellent spatial resolution of 70 μm. The first tracker will be constructed at the Istituto Nazionale di Fisica Nucleare in Italy, while the second and third trackers will be built at the University of Virginia. In 2012, the first UVa SBS GEM chamber prototype was successfully constructed and tested. The GEM chamber construction details and test results will be presented in this talk.
A 1.2 THz Planar Tripler Using GaAs Membrane Based Chips
Bruston, J.; Maestrini, A.; Pukala, D.; Martin, S.; Nakamura, B.; Mehdi, I.
2001-01-01
Fabrication technology for submillimeter-wave monolithic circuits has made tremendous progress in recent years and it is now possible to fabricate sub-micron GaAs Schottky devices on a number of substrate types, such as membranes, frame-less membranes or substrateless circuits. These new technologies allow designers to implement very high frequency circuits, either Schottky mixers or multipliers, in a radically new manner. This paper will address the design, fabrication, and preliminary results of a 1.2 THz planar tripler fabricated on a GaAs frame-less membrane, the concept of which was described previously. The tripler uses a diode pair in an antiparallel configuration similar to designs used at lower frequency. To date, this tripler has produced a peak output power of 80 microW with 0.9% efficiency at room temperature (at 1126 GHz). The measured fix-tuned 3 dB bandwidth is about 3.5%. When cooled, the output power reached a peak of 195 microW at 120 K and 250 microW at 50 K. The ease with which this circuit was implemented along with the superb achieved performance indicates that properly designed planar devices such as this tripler can now usher in a new era of practical very high frequency multipliers.
Power Amplifier Module with 734-mW Continuous Wave Output Power
Fung, King Man; Samoska, Lorene A.; Kangaslahti, Pekka P.; Lamgrigtsen, Bjorn H.; Goldsmith, Paul F.; Lin, Robert H.; Soria, Mary M.; Cooperrider, Joelle T.; Micovic, Moroslav; Kurdoghlian, Ara
2010-01-01
Research findings were reported from an investigation of new gallium nitride (GaN) monolithic millimeter-wave integrated circuit (MMIC) power amplifiers (PAs) targeting the highest output power and the highest efficiency for class-A operation in W-band (75-110 GHz). W-band PAs are a major component of many frequency multiplied submillimeter-wave LO signal sources. For spectrometer arrays, substantial W-band power is required due to the passive lossy frequency multipliers-to generate higher frequency signals in nonlinear Schottky diode-based LO sources. By advancing PA technology, the LO system performance can be increased with possible cost reductions compared to current GaAs PAs. High-power, high-efficiency GaN PAs are cross-cutting and can enable more efficient local oscillator distribution systems for new astrophysics and planetary receivers and heterodyne array instruments. It can also allow for a new, electronically scannable solid-state array technology for future Earth science radar instruments and communications platforms.
Formal Verification of an Iterative Low-Power x86 Floating-Point Multiplier with Redundant Feedback
Directory of Open Access Journals (Sweden)
Peter-Michael Seidel
2011-10-01
Full Text Available We present the formal verification of a low-power x86 floating-point multiplier. The multiplier operates iteratively and feeds back intermediate results in redundant representation. It supports x87 and SSE instructions in various precisions and can block the issuing of new instructions. The design has been optimized for low-power operation and has not been constrained by the formal verification effort. Additional improvements for the implementation were identified through formal verification. The formal verification of the design also incorporates the implementation of clock-gating and control logic. The core of the verification effort was based on ACL2 theorem proving. Additionally, model checking has been used to verify some properties of the floating-point scheduler that are relevant for the correct operation of the unit.
Directory of Open Access Journals (Sweden)
Siti Komsiyah
2014-06-01
Full Text Available In the operating process of electrical energy, economic planning is the main goal to be achieved. The goal of economic dispatch problem is determining the combination of optimal power distribution to a number of operating generator units so that the electricity demand in a certain area is fulfilled without ignoring the constraints that exist, so it is obtained a minimum total generation cost. Optimization method that is used is the Gaussian Particle Swarm Optimization (GPSO, while for the validation of the results, the obtained solution with the GPSO will be compared with the solution obtained by mathematical methods Extended Lagrange Multiplier (ELM or the Lagrange multiplier method which its functions are expanded. The solution that is calculated is generation output in Megawatt of 23 thermal generating units system in Mahakam, East Kalimantan, which had a total cost of optimal generating (minimum.
Directory of Open Access Journals (Sweden)
Jun Taek Lee
2017-01-01
Full Text Available Multifractal (or singularity spectra widths w allow diagnosing cascade structure through comparing original series’ widths wOrig to surrogate series’ widths wSurr. However, interpretations of 0
Mozaffarzadeh, Moein; Mahloojifar, Ali; Orooji, Mahdi; Adabi, Saba; Nasiriavanaki, Mohammadreza
2017-04-05
Photoacoustic imaging (PAI) is an emerging medical imaging modality capable of providing high spatial resolution of Ultrasound (US) imaging and high contrast of optical imaging. Delay-and-Sum (DAS) is the most common beamforming algorithm in PAI. However, using DAS beamformer leads to low resolution images and considerable contribution of offaxis signals. A new paradigm namely Delay-Multiply-and-Sum (DMAS), which was originally used as a reconstruction algorithm in confocal microwave imaging, was introduced to overcome the challenges in DAS. DMAS was used in PAI systems and it was shown that this algorithm results in resolution improvement and sidelobe degrading. However, DMAS is still sensitive to high levels of noise, and resolution improvement is not satisfying. Here, we propose a novel algorithm based on DAS algebra inside DMAS formula expansion, Double Stage DMAS (DSDMAS), which improves the image resolution and levels of sidelobe, and is much less sensitive to high level of noise compared to DMAS. The performance of DS-DMAS algorithm is evaluated numerically and experimentally. The resulted images are evaluated qualitatively and quantitatively using established quality metrics including signal-to-noise ratio (SNR), full-widthhalf- maximum (FWHM) and contrast ratio (CR). It is shown that DS-DMAS outperforms DAS and DMAS at the expense of higher computational load. DS-DMAS reduces the lateral valley for about 15 dB and improves the SNR and FWHM better than 13% and 30%, respectively. Moreover, the levels of sidelobe are reduced for about 10 dB in comparison with those in DMAS.
Nuclear retention of multiply spliced HIV-1 RNA in resting CD4+ T cells.
Directory of Open Access Journals (Sweden)
Kara G Lassen
2006-07-01
Full Text Available HIV-1 latency in resting CD4+ T cells represents a major barrier to virus eradication in patients on highly active antiretroviral therapy (HAART. We describe here a novel post-transcriptional block in HIV-1 gene expression in resting CD4+ T cells from patients on HAART. This block involves the aberrant localization of multiply spliced (MS HIV-1 RNAs encoding the critical positive regulators Tat and Rev. Although these RNAs had no previously described export defect, we show that they exhibit strict nuclear localization in resting CD4+ T cells from patients on HAART. Overexpression of the transcriptional activator Tat from non-HIV vectors allowed virus production in these cells. Thus, the nuclear retention of MS HIV-1 RNA interrupts a positive feedback loop and contributes to the non-productive nature of infection of resting CD4+ T cells. To define the mechanism of nuclear retention, proteomic analysis was used to identify proteins that bind MS HIV-1 RNA. Polypyrimidine tract binding protein (PTB was identified as an HIV-1 RNA-binding protein differentially expressed in resting and activated CD4+ T cells. Overexpression of PTB in resting CD4+ T cells from patients on HAART allowed cytoplasmic accumulation of HIV-1 RNAs. PTB overexpression also induced virus production by resting CD4+ T cells. Virus culture experiments showed that overexpression of PTB in resting CD4+ T cells from patients on HAART allowed release of replication-competent virus, while preserving a resting cellular phenotype. Whether through effects on RNA export or another mechanism, the ability of PTB to reverse latency without inducing cellular activation is a result with therapeutic implications.
Sharma, A
1999-01-01
In this paper a detailed description of how to simulate charge transfer processes in a gaseous device is presented, taking the gas electron multiplier (GEM) as an example. A 3-dimensional simulation of the electric field and avalanche is performed. Results on charge transport are compared to experiment and agree within experimental errors; the avalanche mechanism and positive ion feedback are studied. The procedures used in the simulation are described in detail, and program scripts are appended. (15 refs).
Addanki Purna Ramesh; Tilak, A. V. N.; Prasad, A.M.
2012-01-01
In this paper, we propose a new multiplier-and-accumulator (MAC) architecture for low power and high speed arithmetic. High speed and low power MAC units are required for applications of digital signal processing like Fast Fourier Transform, Finite Impulse Response filters, convolution etc. For improving the speed and reducing the dynamic power, there is a need to reduce the glitches (1 to 0 transition) and spikes (0 to 1 transition). Adder designed using spurious power suppression technique ...
Sun, Xiuhui; Jiang, Kezhu; Zhang, Nan; Guo, Shaojun; Huang, Xiaoqing
2015-07-28
Despite that different facets have distinct catalytic behavior, the important role of twin defects on enhancing the catalytic performance of metallic nanocrystals is largely unrevealed. The key challenge in demonstrating the importance of twin defects for catalysis is the extreme difficulties in creating nanostructures with the same exposed facets but tunable twin defects that are suitable for catalytic investigations. Herein, we show an efficient synthetic strategy to selectively synthesize {111}-terminated Pt3Cu nanocrystals with controllable crystalline features. Two distinct {111}-bounded shapes, namely, multiply-twinned Pt3Cu icosahedra and single-crystalline Pt3Cu octahedra, are successfully prepared by simply changing the types of Cu precursors with the other growth parameters unchanged. Electrocatalytic studies show that the {111}-terminated Pt3Cu nanocrystals exhibit the very interesting crystalline nature-dependent electrocatalytic activities toward both the oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) with multiply-twinned Pt3Cu icosahedra demonstrating enhanced electrocatalytic activities compared to the single-crystalline Pt3Cu octahedra due to their additional yet important effect of twin defect. As a result, under the multiple tuning conditions (alloy, shape, and twin effects), the multiply-twinned Pt3Cu icosahedra exhibit much enhanced electrocatalytic activities in both ORR and MOR with respect to the Pt black. The present work highlights the importance of twin defects in enhancing electrocatalytic activities of metallic nanocrystals.
DEFF Research Database (Denmark)
Madhok, Shivani; Pandey, Bishwajeet; Kaur, Amanpreet
2015-01-01
standards. Frequency scaling is one of the best energy efficient techniques for FPGA based VLSI design and is used in this paper. At the end we can conclude that we can conclude that there is 23-40% saving of total power dissipation by using SSTL IO standard at 25 degree Celsius. The main reason for power...... consumption is leakage power at different IO Standards and at different frequencies. In this research work only FPGA work has been performed not ultra scale FPGA....
ALL-Digital Baseband 65nm PLL/FPLL Clock Multiplier Using 10-Cell Library
Schuler, Robert L., Jr.; Wu, Qiong; Liu, Rui; Chen, Li; Madala, Shridhar
2014-01-01
PLLs for clock generation are essential for modern circuits, to generate specialized frequencies for many interfaces and high frequencies for chip internal operation. These circuits depend on analog circuits and careful tailoring for each new process, and making them fault tolerant is an incompletely solved problem. Until now, all digital PLLs have been restricted to sampled data DSP techniques and not available for the highest frequency baseband applications. This paper presents the design and preliminary evaluation of an all-digital baseband technique built entirely with an easily portable 10-cell digital library. The library is also described, as it aids in research and low volume design porting to new processes. The advantages of the digital approach are the wide variety of techniques available to give varying degrees of fault tolerance, and the simplicity of porting the design to new processes, even to exotic processes that may not have analog capability. The only tuning parameter is digital gate delay. An all-digital approach presents unique problems and standard analog loop stability design criteria cannot be directly used. Because of the quantization of frequency, there is effectively infinite gain for very small loop error feedback. The numerically controlled oscillator (NCO) based on a tapped delay line cannot be reliably updated while a pulse is active in the delay line, and ordinarily does not have enough frequency resolution for a low-jitter output.
Photonic-assisted microwave frequency multiplication with a tunable multiplication factor.
Gao, Liang; Liu, Weilin; Chen, Xiangfei; Yao, Jianping
2013-11-01
Photonic-assisted microwave frequency multiplication with a tunable multiplication factor (MF) based on an optical comb generator and an embedded single-passband microwave photonic filter (MPF) is proposed and demonstrated. The optical comb is generated using two cascaded modulators which are driven by a microwave reference signal. By applying the optical comb to a photodetector, a fundamental frequency corresponding to the comb spacing and its harmonics is generated. Thanks to the embedded single-passband MPF, only one harmonic is selected by the single-passband MPF. Thus, a single-frequency frequency-multiplied microwave signal is generated. In the proposed system, the embedded single-passband MPF is formed by using a sliced broadband optical source and a section of dispersion-compensating fiber (DCF). By tuning the central frequency of the passband at a frequency corresponding to that of a specific harmonic, a microwave signal at that specific frequency is generated. The proposed system is experimentally demonstrated. A frequency-multiplied microwave signal with an MF from 1 to 5 is generated. The phase noise and frequency tunability of the generated microwave signal are also investigated.
MMIC Replacement for Gunn Diode Oscillators
Crowe, Thomas W.; Porterfield, David
2011-01-01
An all-solid-state replacement for high-frequency Gunn diode oscillators (GDOs) has been proposed for use in NASA s millimeter- and submillimeter-wave sensing instruments. Highly developed microwave oscillators are used to achieve a low-noise and highly stable reference signal in the 10-40-GHz band. Compact amplifiers and high-power frequency multipliers extend the signal to the 100-500-GHz band with minimal added phase noise and output power sufficient for NASA missions. This technology can achieve improved output power and frequency agility, while maintaining phase noise and stability comparable to other GDOs. Additional developments of the technology include: a frequency quadrupler to 145 GHz with 18 percent efficiency and 15 percent fixed tuned bandwidth; frequency doublers featuring 124, 240, and 480 GHz; an integrated 874-GHz subharmonic mixer with a mixer noise temperature of 3,000 K DSB (double sideband) and mixer conversion loss of 11.8 dB DSB; a high-efficiency frequency tripler design with peak output power of 23 mW and 14 mW, and efficiency of 16 and 13 percent, respectively; millimeter-wave integrated circuit (MMIC) power amplifiers to the 30-40 GHz band with high DC power efficiency; and an 874-GHz radiometer suitable for airborne observation with state-of-the-art sensitivity at room temperature and less than 5 W of total power consumption.
National Research Council Canada - National Science Library
Park, Choonkil; lee, Jung Rye; Shin, Dong Yun; Gordji, Madjid Eshaghi
2011-01-01
...: a fixed point approach. J. Inequal. Appl. 2011, Article ID 957541, 9pp. (2011)] proved the Hyers-Ulam stability of quadratic double centralizers and quadratic multipliers on Banach algebras by fixed point method...
Directory of Open Access Journals (Sweden)
Dr. Nariye SEYDAMETOVA
2007-05-01
Full Text Available The problem of learning Crimean Tatar Turkish in a systematic way is one of the important problems of Tatar linguists. In Crimean Tatar language, the main nuances of creating word, the system, meaning and properties of multiplying morphemes are not given briefly. Nonetheless, the evolution of semantic relations between multiplied words is an important issue. This paper will mention about these relations.
Directory of Open Access Journals (Sweden)
Yanmin Hu
2010-07-01
Full Text Available In a clinical infection, multiplying and non-multiplying bacteria co-exist. Antibiotics kill multiplying bacteria, but they are very inefficient at killing non-multipliers which leads to slow or partial death of the total target population of microbes in an infected tissue. This prolongs the duration of therapy, increases the emergence of resistance and so contributes to the short life span of antibiotics after they reach the market. Targeting non-multiplying bacteria from the onset of an antibiotic development program is a new concept. This paper describes the proof of principle for this concept, which has resulted in the development of the first antibiotic using this approach. The antibiotic, called HT61, is a small quinolone-derived compound with a molecular mass of about 400 Daltons, and is active against non-multiplying bacteria, including methicillin sensitive and resistant, as well as Panton-Valentine leukocidin-carrying Staphylococcus aureus. It also kills mupirocin resistant MRSA. The mechanism of action of the drug is depolarisation of the cell membrane and destruction of the cell wall. The speed of kill is within two hours. In comparison to the conventional antibiotics, HT61 kills non-multiplying cells more effectively, 6 logs versus less than one log for major marketed antibiotics. HT61 kills methicillin sensitive and resistant S. aureus in the murine skin bacterial colonization and infection models. No resistant phenotype was produced during 50 serial cultures over a one year period. The antibiotic caused no adverse affects after application to the skin of minipigs. Targeting non-multiplying bacteria using this method should be able to yield many new classes of antibiotic. These antibiotics may be able to reduce the rate of emergence of resistance, shorten the duration of therapy, and reduce relapse rates.
Digital intermediate frequency QAM modulator using parallel processing
Pao, Hsueh-Yuan [Livermore, CA; Tran, Binh-Nien [San Ramon, CA
2008-05-27
The digital Intermediate Frequency (IF) modulator applies to various modulation types and offers a simple and low cost method to implement a high-speed digital IF modulator using field programmable gate arrays (FPGAs). The architecture eliminates multipliers and sequential processing by storing the pre-computed modulated cosine and sine carriers in ROM look-up-tables (LUTs). The high-speed input data stream is parallel processed using the corresponding LUTs, which reduces the main processing speed, allowing the use of low cost FPGAs.
Design of a Wideband 900 GHz Balanced Frequency Tripler for Radioastronomy
Tripon-Canseliet, Charlotte; Maestrini, Alain; Mehdi, Imran
2004-01-01
We report on the design of a fix-tuned split-block waveguide balanced frequency tripler working nominally at 900GHz. It uses a GaAs Schottky planar diode pair in a balanced configuration. The circuit will be fabricated with JPL membrane technology in order to minimize dielectric loading. The multiplier is bias-less to dramatically ease the mounting and the operating procedure. At room temperature, the expected output power is 50- 130 (micro)W in the band 800-970 GHz when the tripler is pumped with 4mW. By modifying the waveguide input and output matching circuit, the multiplier can be tuned to operate at lower frequencies.
Maurin, Olga; Bignand, Michel; Jost, Daniel; Travers, Stéphane; Raclot, Stéphane; Trichereau, Julie; Bon, Olivier; Frattini, Benoit; Loeb, Thomas; Lecarpentier, Eric; Noto, René; Poncelin de Raucourt, Gaëtan; Tourtier, Jean-Pierre
2017-10-01
Whenever a mass casualty incident (MCI) occurs, it is essential to anticipate the final number of victims to dispatch the adequate number of ambulances. In France, the custom is to multiply the initial number of prehospital victims by 2-4 to predict the final number. However, no one has yet validated this multiplying factor (MF) as a predictive tool. We aimed to build a statistical model to predict the final number of victims from their initial count. We observed retrospectively over 30 years of MCIs triggered in a large urban area. We considered three types of events: explosions, fires, and road traffic accidents. We collected the initial and final numbers of victims, with distinction between deaths, critical victims (T1), and delayed or minimal victims (T2-T3). The MF was calculated for each category of victims according to each type of event. Using a Poisson multivariate regression, we calculated the incidence risk ratio (IRR) of the final number of T1 as a function of the initial deaths and the initial T2-T3 counts, while controlling for potential confounding variables. Sixty-eight MCIs were included. The final number of T1 increased with the initial incidence of deaths [IRR: 1.8 (1.4-2.2)], the initial number of T2-T3 being greater than 12 [IRR: 1.6 (1.3-2.1)], and the presence of one or more explosion [IRR: 1.4 (1.1-1.8)]. The MF seems to be an appealing decision-making tool to anticipate the need for ambulance resources. In explosive MCIs, we recommend multiplying T1 by 1.4 to estimate final count and the need for supplementary advanced life support teams.
Directory of Open Access Journals (Sweden)
E. George Walters
2017-11-01
Full Text Available Multiplication by a constant is a common operation for many signal, image, and video processing applications that are implemented in field-programmable gate arrays (FPGAs. Constant-coefficient multipliers (KCMs are often implemented in the logic fabric using lookup tables (LUTs, reserving embedded hard multipliers for general-purpose multiplication. This paper describes a two-operand addition circuit from previous work and shows how it can be used to generate and add pre-computed partial products to implement KCMs. A novel method for pre-computing partial products for KCMs with a negative constant is also presented. These KCMs are then extended to have two to eight coefficients that may be selected by a control signal at runtime to implement time-multiplexed multiple-constant multiplication. Synthesis results show that proposed pipelined KCMs use 27.4% fewer LUTs on average and have a median LUT-delay product that is 12% lower than comparable LogiCORE IP KCMs. Proposed pipelined KCMs with two to eight selectable coefficients use 46% to 70% fewer LUTs than the best LogiCORE IP based alternative and most are faster than using a LogiCORE IP multiplier with a coefficient lookup function. They also outperform the state-of-the-art in the literature, using 22% to 57% fewer slices than the smallest pipelined adder graph (PAG fusion designs and operate 7% to 30% faster than the fastest PAG fusion designs for the same operand size and number of selectable coefficients. For KCMs and KCMs with selectable coefficients of a given operand size, the placement and routing of LUTs remains the same for all positive and negative constant values, which is advantageous for runtime partial reconfiguration.
Fearon, Elizabeth; Chabata, Sungai T; Thompson, Jennifer A; Cowan, Frances M; Hargreaves, James R
2017-09-14
While guidance exists for obtaining population size estimates using multiplier methods with respondent-driven sampling surveys, we lack specific guidance for making sample size decisions. To guide the design of multiplier method population size estimation studies using respondent-driven sampling surveys to reduce the random error around the estimate obtained. The population size estimate is obtained by dividing the number of individuals receiving a service or the number of unique objects distributed (M) by the proportion of individuals in a representative survey who report receipt of the service or object (P). We have developed an approach to sample size calculation, interpreting methods to estimate the variance around estimates obtained using multiplier methods in conjunction with research into design effects and respondent-driven sampling. We describe an application to estimate the number of female sex workers in Harare, Zimbabwe. There is high variance in estimates. Random error around the size estimate reflects uncertainty from M and P, particularly when the estimate of P in the respondent-driven sampling survey is low. As expected, sample size requirements are higher when the design effect of the survey is assumed to be greater. We suggest a method for investigating the effects of sample size on the precision of a population size estimate obtained using multipler methods and respondent-driven sampling. Uncertainty in the size estimate is high, particularly when P is small, so balancing against other potential sources of bias, we advise researchers to consider longer service attendance reference periods and to distribute more unique objects, which is likely to result in a higher estimate of P in the respondent-driven sampling survey.
In vivo optical path lengths and path length resolved doppler shifts of multiply scattered light.
Varghese, Babu; Rajan, Vinayakrishnan; Van Leeuwen, Ton G; Steenbergen, Wiendelt
2010-11-01
% and that measured on the dorsal and palmar sides of the forearm are 32% and 17%, respectively. The path length distributions depend on the skin site that is being probed and the intra-individual inter-site variability is higher than the inter-individual within-site variability measured on comparable sites between different individuals. In this study, we demonstrated, for the first time to our knowledge, that in vivo path length resolved perfusion measurements are feasible. Optical path length distributions of multiply scattered light, spanning a range of 0-6 mm, and their response to external stimuli such as occlusion and capsicum cream provocation have been measured. This method will enable better interpretation of inter- and intra-individual inter-site variations in the LDF readings that are introduced by the variance in tissue optical properties. The inter- and intra-individual inter-site variations measured with our setup results indicate that that these variations should be taken into account while comparing the perfusion readings from comparable sites between individuals and from different sites of the same individual. Furthermore, the observed inter- and intra-individual inter-site variations in path length resolved Doppler measurements indicate the inherent limitation of conventional LDPM that restrict its clinical usefulness, due to its dependence on the unknown photon path length. Consequently, this method will enable to correctly interpret or counter-act the inter- and intra-individual inter-site variations in the LDF readings introduced by the variance in tissue optical properties. This approach also enables to discriminate between the Doppler-shifted photons resulting from interaction with the moving red blood cells and the non-shifted light scattered only by the surrounding static tissue matrices. © 2010 Wiley-Liss, Inc.
Photoionisation detection of single {sup 87}Rb-atoms using channel electron multipliers
Energy Technology Data Exchange (ETDEWEB)
Henkel, Florian Alexander
2011-09-02
Fast and efficient detection of single atoms is a universal requirement concerning modern experiments in atom physics, quantum optics, and precision spectroscopy. In particular for future quantum information and quantum communication technologies, the efficient readout of qubit states encoded in single atoms or ions is an elementary prerequisite. The rapid development in the field of quantum optics and atom optics in the recent years has enabled to prepare individual atoms as quantum memories or arrays of single atoms as qubit registers. With such systems, the implementation of quantum computation or quantum communication protocols seems feasible. This thesis describes a novel detection scheme which enables fast and efficient state analysis of single neutral atoms. The detection scheme is based on photoionisation and consists of two parts: the hyperfine-state selective photoionisation of single atoms and the registration of the generated photoion-electron pairs via two channel electron multipliers (CEMs). In this work, both parts were investigated in two separate experiments. For the first step, a photoionisation probability of p{sub ion}=0.991 within an ionisation time of t{sub ion}=386 ns is achieved for a single {sup 87}Rb-atom in an optical dipole trap. For the second part, a compact detection system for the ionisation fragments was developed consisting of two opposing CEM detectors. Measurements show that single neutral atoms can be detected via their ionisation fragments with a detection efficiency of {eta}{sub atom}=0.991 within a detection time of t{sub det}=415.5 ns. In a future combined setup, this will allow the state-selective readout of optically trapped, single neutral {sup 87}Rb-atoms via photoionisation detection with an estimated detection efficiency {eta}=0.982 and a detection time of t{sub tot} = 802 ns. Although initially developed for single {sup 87}Rb-atoms, the concept of photoionisation detection is in principle generally applicable to any
The impact of locally multiply damaged sites (LMDS) induced by ionizing radiation in mammalian cells
Energy Technology Data Exchange (ETDEWEB)
Averbeck, D.; Boucher, D. [Institut Curie-Section de Recherche, UMR2027 CNRS, LCR-V28 du CEA, Centre Universitaire, 91405 Orsay Cedex (France)
2006-07-01
Monte Carlo calculations have shown that ionising radiations produce a specific type of clustered cell damage called locally multiply damaged sites or LMDS. These lesions consist of closely positioned single-strand breaks, (oxidative) base damage and DNA double-strand breaks (DSB) in between one helical turn of DNA. As specific markers of radiation-induced damage these lesions are likely to condition biological responses and are thus of great interest for radiation protection. Calculations indicate that there should be more LMDS induced by high than by low LET radiation, and they should be absent in un-irradiated cells. Processes like K-shell activation and local Auger electron emission can be expected to add complex DSB or LMDS, producing significant chromosomal damage. In the discussion of the specificity of ionising radiation in comparison to other genotoxic agents, many arguments have been put forward that these lesions should be particularly deleterious for living cells. Complex lesions of that type should represent big obstacles for DNA repair and give rise to high lethality. Moreover, cellular attempts to repair them could accentuate harm, leading to mutations, genetic instability and cancer. In vitro experiments with oligonucleotides containing an artificially introduced set of base damage and SSB in different combinations have shown that depending on the close positioning of the damage on DNA, repair enzymes, and even whole cell extracts, are unable to repair properly and may stimulate mis-repair. Pulsed field gel electrophoresis (PFGE) in conjunction with enzymatic treatments has been used to detect LMDS in mammalian cells after high and low LET radiation. In order to further define the importance of LMDS for radiation induced cellular responses, we studied the induction of LMDS as a function of radiation dose and dose rate in mammalian cells (CHO and MRC5) using {sup 137}Cs gamma-radiation. Using PFGE and specific glycosylases to convert oxidative damage
High Frequency Amplitude Detector for GMI Magnetic Sensors
Directory of Open Access Journals (Sweden)
Aktham Asfour
2014-12-01
Full Text Available A new concept of a high-frequency amplitude detector and demodulator for Giant-Magneto-Impedance (GMI sensors is presented. This concept combines a half wave rectifier, with outstanding capabilities and high speed, and a feedback approach that ensures the amplitude detection with easily adjustable gain. The developed detector is capable of measuring high-frequency and very low amplitude signals without the use of diode-based active rectifiers or analog multipliers. The performances of this detector are addressed throughout the paper. The full circuitry of the design is given, together with a comprehensive theoretical study of the concept and experimental validation. The detector has been used for the amplitude measurement of both single frequency and pulsed signals and for the demodulation of amplitude-modulated signals. It has also been successfully integrated in a GMI sensor prototype. Magnetic field and electrical current measurements in open- and closed-loop of this sensor have also been conducted.
Chaurasia, Ashok; Harel, Ofer
2015-02-10
Tests for regression coefficients such as global, local, and partial F-tests are common in applied research. In the framework of multiple imputation, there are several papers addressing tests for regression coefficients. However, for simultaneous hypothesis testing, the existing methods are computationally intensive because they involve calculation with vectors and (inversion of) matrices. In this paper, we propose a simple method based on the scalar entity, coefficient of determination, to perform (global, local, and partial) F-tests with multiply imputed data. The proposed method is evaluated using simulated data and applied to suicide prevention data. Copyright © 2014 John Wiley & Sons, Ltd.
Directory of Open Access Journals (Sweden)
Tom La
Full Text Available Swine dysentery (SD is a mucohaemorrhagic colitis of grower/finisher pigs classically resulting from infection by the anaerobic intestinal spirochaete Brachyspira hyodysenteriae. This study aimed to determine whether B. hyodysenteriae isolates from pigs in three healthy German multiplier herds supplying gilts to other farms differed from isolates from nine German production herds with SD. Isolates were subjected to whole genomic sequencing, and in silico multilocus sequence typing showed that those from the three multiplier herds were of previously undescribed sequence types (ST132, ST133 and ST134, with all isolates from the same herd having the same ST. All isolates were examined for the presence of 332 genes encoding predicted virulence or virulence lifestyle associated factors, and these were well conserved. Isolates from one multiplier herd were atypical in being weakly haemolytic: they had 10 amino acid substitutions in the haemolysin III protein and five in the haemolysin activation protein compared to reference strain WA1, and had a disruption in the promoter site of the hlyA gene. These changes likely contribute to the weakly haemolytic phenotype and putative lack of virulence. These same isolates also had nine base pair insertions in the iron metabolism genes bitB and bitC and lacked five of six plasmid genes that previously have been associated with colonisation. Other overall differences between isolates from the different herds were in genes from three of five outer membrane proteins, which were not found in all the isolates, and in members of a block of six plasmid genes. Isolates from three herds with SD had all six plasmid genes, while isolates lacking some of these genes were found in the three healthy herds-but also in isolates from six herds with SD. Other differences in genes of unknown function or in gene expression may contribute to variation in virulence; alternatively, superior husbandry and better general health may have
The time-dependent P{sub 1} model for the neutronics of multiplying systems. A review
Energy Technology Data Exchange (ETDEWEB)
Coppa, G.G.M.; Dulla, S.; Ravetto, P. [Politecnico di Torino (Italy). Dipt. di Energetica
2010-08-15
The derivation of the time-dependent P{sub 1} model by the spherical harmonics expansion approach to solve the neutron transport equation is reviewed and its main features and physical characteristics are illustrated. The telegrapher's equation is presented and its formulation for multiplying systems is discussed. In particular, it is evidenced that the presence of a time derivative of the source terms in the telegrapher's equation implies the appearance of time derivatives of the flux and of the precursor concentrations. The role of these terms is evaluated and discussed. (orig.)
Yamada, S.; Nakayama, H.; Aso, Y.
2014-05-01
We had been developing a current multiplier by inductive storage (CMIS). The CMIS consists of 24 storage copper coils, which soaked into the liquid nitrogen, demonstrates a 24 kA of output current and the continuous current pulses of 3 pulses per second. Switching performance of the IGBTs and diode were tested in the liquid nitrogen bath. These experimental data were used to design the mega-ampere class CMIS. The system consists of the superconductive magnet section with a temperature of 20 K and the IGBT control switch section with a temperature of 77 K.
Aird, J J; Cheesman, C L; Schade, A T; Monsell, F P
2017-01-01
The Avon Longitudinal Study of Parents and Children (ALSPAC) prospective cohort was used to determine the accuracy of the Paley multiplier method for predicting leg length. Using menarche as a proxy, physiological age was then used to increase the accuracy of the multiplier. Chronological age was corrected in female patients over the age of eight years with documented date of first menses. Final sub-ischial leg length and predicted final leg length were predicted for all data points. Good correlation was demonstrated between the Paley and ALSPAC data. The average error in prediction depended on the time of assessment, tending to improve as the child got older. It varied from 2.2 cm at the age of seven years to 1.8 cm at the age of 14 years. When chronological age was corrected, the accuracy of multiplier increased. Age correction of 50% improved multiplier predictions by up to 28%. There appears to have been no significant change in growth trajectories of the two populations who were chronologically separated by 40 years. While the Paley data were based on extracting trends from averaged data, the ALSPAC dataset provides descriptive statistics from which it is possible to compare populations and assess the accuracy of the multiplier method. The data suggest that the accuracy improves as the patient gets close to the average skeletal maturity but that results need to be interpreted in conjunction with a radiological assessment of the growth plates. The magnitude of the errors in prediction suggest that when using the multiplier, the clinician must remain vigilant and prepared to perform a contralateral epiphyseodisis if the prediction proves to be wrong. The data suggest a relationship between the multiplier and menarche. There appears to be a factorisation and when accounting for physiological age, one needs to correct by 50% of the difference between chronological and physiological age.
Directory of Open Access Journals (Sweden)
Xiao-Hui Luo
2011-05-01
Full Text Available The feasibility and the clinical value of the enzyme-multiplied immunoassay technique (EMIT monitoring of blood concentrations of cyclosporine A (CsA in patients treated with CsA were investigated after kidney transplantation. The validation method was performed to the EMIT determination of CsA blood concentration, the CsA whole blood âtrough concentrations (C0 of patients in different time periods after renal transplantation were monitored, and combined with the clinical complications, the statistical results were analyzed and compared. EMIT was precise, accurate and stable, also with a high quality control. The mean postoperative blood concentration of CsA was as follows: 12 months, (185.6Â Â±Â 28.1ng/mL. The toxic reaction rate of CsA blood concentration within the recommended therapeutic concentration was 14. 1%, significantly lower than that of the none-recommended dose group (37.2% (PÂ <Â 0.05; the transplantation rejection rate was 4.4%, significantly lower than that of the none-recommended dose group (22.5% (PÂ <Â 0.05. Using EMIT to monitor the blood concentration of CsA as the routine laboratory method is feasible, and is able to reduce the CsA toxicity and rejection significantly, leading to achieving the desired therapeutic effect. Keywords: enzyme-multiplied immunoassay technique, renal transplantation, cyclosporin A, blood concentration monitoring
Foundotos, M.; Nolet, G.
2009-12-01
In order to constrain the shallow structure of the Earth in global tomography, Love and Rayleigh waves are often used. However these waves are mostly sensitive to the S wave velocity structure. P-wave energy is either evanescent, or leaking away at every surface reflection that generates an S wave which travels much deeper into the mantle. For that reason, to study the shallow P velocity structure of the Earth, we need to study P-waves at regional distances if a good seismic station coverage is available. Otherwise we can use multiple P reflections at teleseismic distance when regional data are not available (as in the oceans for instance). The major aim of this work was first of all to ensure that these multiply reflected P waves can adequately be observed in real data and also to investigate how many reflections at the surface these reflected waves can still be seen and to investigate how strongly the amplitude of multiply reflected P diminishes because of energy loss into S waves. For this study we are comparing the synthetic predictions computed with a Spectral Element Method for a spherically symmetric earth (Nissen-Meyer et al, 2007) with observed data. We used 150 events recorded (26575 seismograms) from the dense network of US ARRAY, which allows us to make a very large number of observations. Our study shows that three times reflected PPP waves are very well observed for epicentral distances > 60 degrees and for events with Mw 90 degrees.
Vortex algebra by multiply cascaded four-wave mixing of femtosecond optical beams.
Hansinger, Peter; Maleshkov, Georgi; Garanovich, Ivan L; Skryabin, Dmitry V; Neshev, Dragomir N; Dreischuh, Alexander; Paulus, Gerhard G
2014-05-05
Experiments performed with different vortex pump beams show for the first time the algebra of the vortex topological charge cascade, that evolves in the process of nonlinear wave mixing of optical vortex beams in Kerr media due to competition of four-wave mixing with self-and cross-phase modulation. This leads to the coherent generation of complex singular beams within a spectral bandwidth larger than 200nm. Our experimental results are in good agreement with frequency-domain numerical calculations that describe the newly generated spectral satellites.
Maximilien Brice
2002-01-01
Photo 0210005_11: The CTF3 linac accelerates an electron beam up to 350 MeV. Photo 0210005_1: At the front, the yellow dipole is used for the spectrometer line. At the back, a doublet of blue quadrupole for the matching. Photo 0210005_03: The CTF3 transfer line between the electron linac and the isochronous ring. Photo 0210005_04: One arc of the EPA isochronous ring. Photo 0210005_06: The CTF3 bunching system. The first RF wave guide feeds the Pre-Buncher while the second RF wave guide feeds the Buncher. They provide a bunched electron beam at 4 MeV. The blue magnet is a solenoid around the Buncher. Photo 0210005_07: A LIL accelerating structure used for CTF3. It is 4.5 meters long and provides an energy gain of 45 MeV. One can see 3 quadrupoles around the RF structure.
Frequency noise in frequency swept fiber laser
DEFF Research Database (Denmark)
Pedersen, Anders Tegtmeier; Rottwitt, Karsten
2013-01-01
This Letter presents a measurement of the spectral content of frequency shifted pulses generated by a lightwave synthesized frequency sweeper. We found that each pulse is shifted in frequency with very high accuracy. We also discovered that noise originating from light leaking through the acousto...
VizieR Online Data Catalog: Sub-millimeter spectra of 2-hydroxyacetonitrile (Margules+, 2017)
Margules, L.; McGuire, B. A.; Senent, M. L.; Motiyenko, R. A.; Remijan, A.; Guillemin, J. C.
2017-02-01
Measured frequencies and residuals from the global fit of the submillimeter-wave data for 2-hydroxyacetonitrile and files used for SPFIT. Detailled explanations on SPFIT could be found at https://www.astro.uni-koeln.de/cdms/pickett (4 data files).
1987-10-01
Technology Metil -Oxide-Metal (MOM) diodes are the fastest detector known. They are used in the frequency range from microwave to submillimeter wave and...moderate rain, smoke and dust; endoscopic laser treatment and laser surgery delivery systems, to name a few. These major areas of appli- cation
Directory of Open Access Journals (Sweden)
Yan-Xia Lin
2015-12-01
Full Text Available Lin (2014 developed a framework of the method of the sample-moment-based density approximant, for estimating the probability density function of microdata based on noise multiplied data. Theoretically, it provides a promising method for data users in generating the synthetic data of the original data without accessing the original data; however, technical issues can cause problems implementing the method. In this paper, we describe a software package called MaskDensity14, written in the R language, that uses a computational approach to solve the technical issues and makes the method of the sample-moment-based density approximant feasible. MaskDensity14 has applications in many areas, such as sharing clinical trial data and survey data without releasing the original data.
Green, Francis
2011-03-01
Employability strongly moderates the effects of unemployment and of job insecurity on life satisfaction and mental health. Using nationally representative panel data from Australia, I find that an increase in employability from zero to 100% cancels around three quarters, in some cases more, of the detrimental effect of unemployment. Employability also matters for employees: an increase in men's employability from zero to 100% reduces the detrimental effect of job insecurity by more than half. The effects of extreme job insecurity and of unemployment are large and of comparable magnitudes. The findings are used to compute estimates of the well-being trade-off between increases in job insecurity and increases in employability, relevant to the support of "flexicurity" policies, and of the "misery multiplier", the extent to which the effect of a rise in aggregate unemployment on those becoming unemployed is supplemented by the effects on others' insecurity and employability. Copyright © 2010 Elsevier B.V. All rights reserved.
The multiplier effect of the health education-risk reduction program in 28 states and 1 territory.
Kreuter, M W; Christensen, G M; Divincenzo, A
1982-01-01
The multiplier effect of the Health Education-Risk Reduction (HE-RR) Grants Program funded by the Public Health Service is examined to identify outcomes for the period 1978-81. Responses to a questionnaire from the directors of health education of 28 States and 1 Territory supplied the information concerning new health promotion activities generated by the program. The directors were asked to identify and give cost estimates of new activities that resulted from State-level and local intervention projects. A method for calculating the extent to which the HE-RR program influenced new health promotion activities that were funded by alternate sources was devised. The calculation, termed the new activity rate, was applied to the survey data. Rates calculated for the HE-RR program revealed that it generated nearly $4 million in new health promotion activities, most of them funded by the private and voluntary segments of society.
DEFF Research Database (Denmark)
Bhaskar, Mahajan Sagar; Padamanaban, Sanjeevi Kumar; Blaabjerg, Frede
2016-01-01
In this paper hybrid non isolated and non-invertingCockcroft-Walton multiplier based 2Nx InterleavedBoost converter (2Nx IBC) for renewable energy applications is presented. The presented hybrid boost converter topology is derived from non-inverting Nx Multilevel Boost Converter (Nx MBC......) and inverting Nx Multilevel Boost Converter (Nx MBC). In renewable energy applications, generated voltage needs to be stepped up with high conversion ratio using a DC-DC converter at voltage levels as per the application requirement. The advantages of the presentedtopology of interleaved converter are high...... voltage conversion ratio, reduce ripple, low voltage stress, non-inverting output voltage without utilizing the high duty cycle, coupled inductors and transformer. The main advantage of presented topology consists in increasing voltage gain by adding capacitor and diode into circuitry without disturbing...
Energy Technology Data Exchange (ETDEWEB)
Chernyshova, M., E-mail: maryna.chernyshova@ipplm.pl; Malinowski, K.; Czarski, T.; Kowalska-Strzęciwilk, E. [Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw (Poland); Wojeński, A.; Poźniak, K. T.; Kasprowicz, G.; Krawczyk, R.; Kolasiński, P.; Zabołotny, W.; Zienkiewicz, P. [Institute of Electronic Systems, Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw (Poland); Vezinet, D.; Herrmann, A. [Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany); Mazon, D.; Jardin, A. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)
2016-11-15
A Gaseous Electron Multiplier (GEM)-based detector is being developed for soft X-ray diagnostics on tokamaks. Its main goal is to facilitate transport studies of impurities like tungsten. Such studies are very relevant to ITER, where the excessive accumulation of impurities in the plasma core should be avoided. This contribution provides details of the preliminary tests at ASDEX Upgrade (AUG) with a focus on the most important aspects for detector operation in harsh radiation environment. It was shown that both spatially and spectrally resolved data could be collected, in a reasonable agreement with other AUG diagnostics. Contributions to the GEM signal include also hard X-rays, gammas, and neutrons. First simulations of the effect of high-energy photons have helped understanding these contributions.
Development of the first prototypes of Silicon PhotoMultiplier (SiPM) at ITC-irst
Energy Technology Data Exchange (ETDEWEB)
Dinu, N. [INFN Sezione di Padova (Gruppo Collegato di Trento), Trento 38050 (Italy)]. E-mail: dinu@itc.it; Battiston, R. [Universita di Perugia and INFN Sezione di Perugia, Perugia 06123 (Italy); Boscardin, M. [ITC-irst, Divisione Microsistemi, Trento 38050 (Italy); Collazuol, G. [Scuola Normale Superiore and INFN Sezione di Pisa, Pisa 56127 (Italy); Corsi, F. [DEE-Politecnico di Bari and INFN Sezione di Bari, Bari I-70125 (Italy); Dalla Betta, G.F. [INFN Sezione di Padova (Gruppo Collegato di Trento), Trento 38050 (Italy); Dipartimento di Informatica e Telecomunicazioni, Universita di Trento, Trento 38050 (Italy); Del Guerra, A. [Dipartimento di Fisica ' E. Fermi' and INFN Sezione di Pisa, Pisa 56127 (Italy); Llosa, G. [Dipartimento di Fisica ' E. Fermi' and INFN Sezione di Pisa, Pisa 56127 (Italy); Ionica, M. [Universita di Perugia and INFN Sezione di Perugia, Perugia 06123 (Italy); Levi, G. [Dipartimento di Fisica and INFN Sezione di Bologna, Bologna 40127 (Italy); Marcatili, S. [Dipartimento di Fisica ' E. Fermi' and INFN Sezione di Pisa, Pisa 56127 (Italy); Marzocca, C. [DEE-Politecnico di Bari and INFN Sezione di Bari, Bari I-70125 (Italy); Piemonte, C. [ITC-irst, Divisione Microsistemi, Trento 38050 (Italy); Pignatel, G. [Universita di Perugia and INFN Sezione di Perugia, Perugia 06123 (Italy); Pozza, A. [ITC-irst, Divisione Microsistemi, Trento 38050 (Italy); Quadrani, L. [Dipartimento di Fisica and INFN Sezione di Bologna, Bologna 40127 (Italy); Sbarra, C. [Centro Studi e Ricerche ' E. Fermi' , Compendio Viminale, 00184 Rome (Italy); Zorzi, N. [ITC-irst, Divisione Microsistemi, Trento 38050 (Italy)
2007-03-01
In the frame of INFN-ITC-irst collaboration new Silicon PhotoMultiplier (SiPM) prototypes have been produced at ITC-irst (Trento, Italy). Each SiPM covers an area of 1 mm{sup 2} and brings together 625 micro-cells of 40x40 {mu}m{sup 2} size connected in parallel as to form a single read-out element. Each micro-cell consists of a Geiger Mode Avalanche Photodiode (GM-APD) in series with its quenching resistance. This article reports the main characteristics of these prototypes as well as the ongoing activity of our collaboration on the development of SiPM devices for medical and space physics applications.
Energy Technology Data Exchange (ETDEWEB)
Connor, S.E.J. [Department of Neuroradiology, Kings Healthcare NHS Trust, King' s College Hospital, Denmark Hill, SE5 9RS, London (United Kingdom); Ng, V. [Department of Neuroimaging, Maudsley Hospital, London (United Kingdom); McDonald, C.; Schulze, K.; Morgan, K.; Dazzan, P.; Murray, R.M. [Division of Psychological Medicine, Institute of Psychiatry, London (United Kingdom)
2004-07-01
Hippocampal shape anomaly (HSA), characterised by a rounded hippocampus, has been documented in congenital malformations and epileptic patients. Subtle structural hippocampal abnormalities have been demonstrated in patients with schizophrenia. We tested the hypothesis that HSA is more frequent in schizophrenia, particularly in patients from families multiply affected by schizophrenia, and that HSA is transmitted within these families. We also aimed to define the anatomical features of the hippocampus and other cerebral structures in the HSA spectrum and to determine the prevalence of HSA in a control group. We reviewed the magnetic resonance imaging of a large number of subjects with schizophrenia and bipolar disorder, many of who came from multiply affected families, relatives of the affected probands, and controls. Quantitative measures of hippocampal shape and position and other qualitative anatomical measures were performed (including depth of dominant sulcus cortical cap, angle of dominant sulcus and hippocampal fissure, bulk of collateral white matter, prominence of temporal horn lateral recess and blurring of internal hippocampal architecture) on subjects with HSA. A spectrum of mild, moderate and severe HSA was defined. The prevalence of HSA was, 7.8% for the controls (n=218), 9.3% for all schizophrenic subjects (n=151) and 12.3% for familial schizophrenic subjects (n=57). There was a greater prevalence of moderate or severe forms of HSA in familial schizophrenics than controls. However, there was no increase in the prevalence of HSA in the unaffected first-degree relatives of schizophrenic patients or in patients with familial bipolar disorder. HSA was rarely transmitted in families. HSA was frequently associated with a deep, vertical collateral/occipito-temporal sulcus and a steep hippocampal fissure. Our data raise the possibility that HSA is linked to disturbances of certain neurodevelopmental genes associated with schizophrenia. However, the lack of
Fantini, Sergio; Franceschini, Maria-Angela; Fishkin, Joshua B.; Gratton, Enrico
1994-07-01
On the basis of the diffusion theory model, frequency-domain spectroscopy allows for a quantitative determination of the absorption ((mu) a) and scattering ((mu) s') coefficient spectra of a homogeneous multiple scattering medium. We performed measurements using an intensity modulated light emitting diode (LED) as the light source. The LED's spectral distribution permits the study of a spectral region extending for about 80 nm. Data sets (phase shift and average intensity) at two different source-detector distances are acquired: the absorption and scattering coefficient spectra of the medium are then calculated from analytical expressions for (mu) a and (mu) s'. Methylene blue (peak absorption wavelength 656 nm) is used as a test absorbing material. The methylene blue is dissolved in an aqueous Liposyn solution which serves as the multiple scattering medium. The relative amounts of absorber and scatterer are chosen such that the values of (mu) a and (mu) s' match typical values in tissues. The results obtained for (mu) a((lambda) ) with this LED based technique are in quantitative agreement with those obtained with a standard spectrophotometer in a nonscattering regime.
Multiple Frequency Parametric Sonar
2015-09-28
300003 1 MULTIPLE FREQUENCY PARAMETRIC SONAR STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and...a method for increasing the bandwidth of a parametric sonar system by using multiple primary frequencies rather than only two primary frequencies...2) Description of Prior Art [0004] Parametric sonar generates narrow beams at low frequencies by projecting sound at two distinct primary
Younis, Mohammad I.
2016-03-10
Embodiments of multi-frequency excitation are described. In various embodiments, a natural frequency of a device may be determined. In turn, a first voltage amplitude and first fixed frequency of a first source of excitation can be selected for the device based on the natural frequency. Additionally, a second voltage amplitude of a second source of excitation can be selected for the device, and the first and second sources of excitation can be applied to the device. After applying the first and second sources of excitation, a frequency of the second source of excitation can be swept. Using the methods of multi- frequency excitation described herein, new operating frequencies, operating frequency ranges, resonance frequencies, resonance frequency ranges, and/or resonance responses can be achieved for devices and systems.
1977-05-01
factor, while X is defined as X = (T/2)(f/f(1 )), (3) with f the frequency variable ( w/27), and f(l) the antiresonance frequency at the fundamental...the frequency spectruml, cioLi-negtigibly. For coatings of mass in- per unit area lumped on each surface, the reduced mass-loading variable is j= Fi/ph...2. The quantity multiplying Tk in (40) is called the Onoe funcion : 46 G (M) = +2k2/D. is plotted versus 0 for various k values and for M = 1, 3, and
Energy Technology Data Exchange (ETDEWEB)
Odagiri, Takeshi; Nakano, Motoyoshi; Tanabe, Takehiko; Kumagai, Yoshiaki [Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan); Suzuki, Isao H; Kouchi, Noriyuki, E-mail: joe@chem.titech.ac.j [Photon Factory, IMSS, KEK, Tsukuba, Ibaraki 305-0801 (Japan)
2009-11-01
The cross sections for the generation of a photon-pair from excited fragments in photoexcitation of H{sub 2}O have been measured as a function of incident photon energy. The multiply excited states of H{sub 2}O have been observed even above the adiabatic double ionization potential.
Strickland, Tricia K.; Maccini, Paula
2013-01-01
We examined the effects of the Concrete-Representational-Abstract Integration strategy on the ability of secondary students with learning disabilities to multiply linear algebraic expressions embedded within contextualized area problems. A multiple-probe design across three participants was used. Results indicated that the integration of the…
Energy Technology Data Exchange (ETDEWEB)
Grau Malonda, A.; Garcia-Torano, E.
1984-07-01
In this paper counting efficiency as a function of a free parameter (the figure of merit) has been computed. The results are applicable to liquid scintillator systems with a single multiplier phototube. Tables of counting efficiency for 62 pure beta emitters are given for figures of merit in the range 0.25 to 50. (Author) 16 refs.
Directory of Open Access Journals (Sweden)
Dereje Berihun Sitotaw
2016-01-01
Full Text Available The study focuses on effect of twist multiplier on single jersey and 1 × 1 rib knitted fabrics loop length, loop shape, and tightness factors properties. For the study 100% cotton fiber which is processed into 40Ne (English count carded ring spun yarn is used. Three twist levels of 900 turns/m, 1050 turns/m, and 1200 turns/m with respective twist multipliers of 3.6, 4.2, and 4.8 are used. The single jersey produced from the three twist multipliers is named as Sj1 which is produced from 3.6, Sj2 from 4.2, and Sj3 from 4.8. Similarly, 1 × 1 rib is denoted as R1 which is produced from 3.6, R2 from 4.2, and R3 from 4.8. The test was performed as per ASTM D1776-Practice for Conditioning Textiles for Testing. The tests done for ten specimens and the results showed that loop length, loop shape, and tightness factors properties of single jersey and 1 × 1 rib knitted fabrics are significantly influenced by twist multipliers variation.
Crul, Maurice; Schneider, Jens; Keskiner, Elif; Lelie, Frans
2017-01-01
We introduce what we have coined the multiplier effect. We explain the steep upward mobility of children of low-educated immigrants by studying how they overcome obstacles on their regular pathway, via alternative routes or through loopholes in the education and labour market system. The idea of the
DEFF Research Database (Denmark)
Bhaskar, Mahajan Sagar; Padmanaban, Sanjeevikumar; Fedák, Viliam
2017-01-01
; such as a photovoltaic (PV) system with a Multilevel Inverter (MLI), electrical drives, automotive, hybrid electric cars etc. The proposed topology is derived by attaching the Cockcroft Walton (CW) multiplier to an upper L-converter of the LL topology of XY family. The mode of operation of L-LMBC with mathematical...
Dudu, Washington Takawira
2017-01-01
This paper explores the experiences of 37 physical science high school teachers who participated in a professional development (PD) programme coordinated by three Experimento multipliers. The Experimento programme is a Siemens Stiftung international educational programme aimed at providing didactic and methodological approaches to classroom…
A 2.5-10-GHz clock multiplier unit with 0.22-ps RMS jitter in standard 0.18-μm CMOS
van de Beek, R.C.H.; Vaucher, Cicero S.; Leenaerts, Domine M.W.; Klumperink, Eric A.M.; Nauta, Bram
This paper demonstrates a low-jitter clock multiplier unit that generates a 10-GHz output clock from a 2.5-GHz reference clock. An integrated 10-GHz LC oscillator is locked to the input clock, using a simple and fast phase detector circuit that overcomes the speed limitation of a conventional
Yarnell, Lisa M; Pasch, Keryn E; Brown, H Shelton; Perry, Cheryl L; Komro, Kelli A
2014-09-01
A social multiplier effect is a social interaction in which the behavior of a person in a social network varies with the normative behavior of others in the network, also known as an endogenous interaction. Policies and intervention efforts can harness social multiplier effects because, in theory, interventions on a subset of individuals will have "spillover effects" on other individuals in the network. This study investigates potential social multiplier effects for violence in middle schools, and whether there is evidence for a social multiplier effect transmitted from girls to boys. Three years of longitudinal data (2003-2005) from Project Northland Chicago were used to investigate this question, with a sample consisting of youth in Grades 6 through 8 in 61 Chicago Public Schools (N = 4,233 at Grade 6, N = 3,771 at Grade 7, and N = 3,793 at Grade 8). The sample was 49.3% female, and primarily African American (41.9%) and Latino/a (28.7%), with smaller proportions of whites (12.9%), Asians (5.2%) and other ethnicities. Results from two sets of regression models estimating the effects of 20th (low), 50th (average), and 80th (high) percentile scores for girls and boys on levels of violence in each gender group revealed evidence for social multiplier effects. Specifically, boys and girls were both influenced by social multiplier effects within their own gender group, and boys were also affected by normative violence scores among girls, typically those of the best-behaved (20th percentile) girls. The finding that girls may have positive social influence on boys' levels of violent behavior extends prior findings of beneficial social effects of girls on boys in the domains of education and risky driving. Further, this social normative effect presents a potential opportunity to improve school-based intervention efforts for reducing violence among youth by leveraging girls as carriers of a social multiplier effect for reduced violence in the middle school environmental
Pasch, Keryn E.; Brown, H. Shelton; Perry, Cheryl L.; Komro, Kelli A.
2014-01-01
A social multiplier effect is a social interaction in which the behavior of a person in a social network varies with the normative behavior of others in the network, also known as an endogenous interaction. Policies and intervention efforts can harness social multiplier effects because, in theory, interventions on a subset of individuals will have “spillover effects” on other individuals in the network. This study investigates potential social multiplier effects for violence in middle schools, and whether there is evidence for a social multiplier effect transmitted from girls to boys. Three years of longitudinal data (2003–2005) from Project Northland Chicago (PNC) were used to investigate this question, with a sample consisting of youth in Grades 6 through 8 in 61 Chicago Public Schools (N = 4233 at Grade 6, N = 3771 at Grade 7, and N = 3793 at Grade 8). The sample was 49.3% female, and primarily African American (41.9%) and Latino/a (28.7%), with smaller proportions of whites (12.9%), Asians (5.2%) and other ethnicities. Results from two sets of regression models estimating the effects of 20th (low), 50th (average), and 80th (high) percentile scores for girls and boys on levels of violence in each gender group revealed evidence for social multiplier effects. Specifically, boys and girls were both influenced by social multiplier effects within their own gender group, and boys were also affected by normative violence scores among girls, typically those of the best-behaved (20th percentile) girls. The finding that girls may have positive social influence on boys’ levels of violent behavior extends prior findings of beneficial social effects of girls on boys in the domains of education and risky driving. Further, this social normative effect presents a potential opportunity to improve school-based intervention efforts for reducing violence among youth by leveraging girls as carriers of a social multiplier effect for reduced violence in the middle school
Indium Single-Ion Frequency Standard
Nagourney, Warren
2001-01-01
A single laser-cooled indium ion is a promising candidate for an ultimate resolution optical time or frequency standard. It can be shown that single ions from group IIIA of the periodic table (indium, thallium, etc.) can have extremely small systematic errors. In addition to being free from Doppler, transit-time and collisional shifts, these ions are also quite insensitive to perturbations from ambient magnetic and electric fields (mainly due to the use of a J=0-0 transition for spectroscopy). Of all group IIIA ions, indium seems to be the most practical, since it is heavy enough to have a tolerable intercombination cooling transition rate and (unlike thallium) has transitions which are easily accessible with frequency multiplied continuous-wave lasers. A single indium ion standard has a potential inaccuracy of one part in 10(exp 18) for integration times of 10(exp 6) seconds. We have made substantial progress during the grant period in constructing a frequency standard based upon a single indium ion. At the beginning of the grant period, single indium ions were being successfully trapped, but the lasers and optical systems were inadequate to achieve the desired goal. We have considerably improved the stability of the dye laser used to cool the ions and locked it to a molecular resonance line, making it possible to observe stable cooling-line fluorescence from a single indium ion for reasonable periods of time, as required by the demands of precision spectroscopy. We have substantially improved the single-ion fluorescence signal with significant benefits for the detection efficiency of forbidden transitions using the 'shelving' technique. Finally, we have constructed a compact, efficient UV 'clock' laser and observed 'clock' transitions in single indium ions using this laser system. We will elaborate on these accomplishments.
Frequency selectivity at very low centre frequencies
DEFF Research Database (Denmark)
Orellana, Carlos Andrés Jurado; Pedersen, Christian Sejer; Marquardt, Torsten
2010-01-01
measurements based on OAE suppression techniques and notched-noise masking data psychophysically measured for centre frequencies in the range 50-125 Hz, this study examines how individual differences in frequency selectivity, as well as in masking, may occur at very low CFs due to individual differences...... in the shape of the METFs, thought to be affected by the helicotrema impedance. Preliminary analysis indicates that individual differences in the METFs might underlay the observed individual differences in frequency selectivity. Main effects predicted by the calculations are a pronounced flattening off...
... medlineplus.gov/ency/article/002125.htm Physical exam frequency To use the sharing features on this page, ... screening; Checkup Images Blood pressure check Physical exam frequency References Atkins D, Barton M. The periodic health ...
Static electromagnetic frequency changers
Rozhanskii, L L
1963-01-01
Static Electromagnetic Frequency Changers is about the theory, design, construction, and applications of static electromagnetic frequency changers, devices that used for multiplication or division of alternating current frequency. It is originally published in the Russian language. This book is organized into five chapters. The first three chapters introduce the readers to the principles of operation, the construction, and the potential applications of static electromagnetic frequency changers and to the principles of their design. The two concluding chapters use some hitherto unpublished work
Cheah, Jonathon Y. C.
1994-02-01
A low cost technique of frequency reference distribution within a VSAT network is discussed. This technique allows the use of a modestly frequency stable oscillator as the master frequency reference in the hub of a star-connected VSAT network. The need for extremely frequency stable OCXOs in VSATs is completely avoided. This technique was successfully incorporated in the early commercial VSAT networks. It contributes partially to the low cost nature of some of the VSAT networks available today.
Modeling Frequency Comb Sources
Directory of Open Access Journals (Sweden)
Li Feng
2016-06-01
Full Text Available Frequency comb sources have revolutionized metrology and spectroscopy and found applications in many fields. Stable, low-cost, high-quality frequency comb sources are important to these applications. Modeling of the frequency comb sources will help the understanding of the operation mechanism and optimization of the design of such sources. In this paper,we review the theoretical models used and recent progress of the modeling of frequency comb sources.
Matrone, Giulia; Savoia, Alessandro Stuart; Caliano, Giosuè; Magenes, Giovanni
2017-03-01
The Synthetic Aperture Focusing (SAF) technique makes it possible to achieve a higher and more uniform quality of ultrasound images throughout depth, as if both transmit and receive dynamic focusing were applied. In this work we combine a particular implementation of SAF, called Synthetic Transmit Aperture (STA) technique, in which a single element in turn transmits and all the array elements receive the ultrasound wave, with the Filtered-Delay Multiply and Sum (F-DMAS) non-linear beamforming algorithm that we presented in a previous paper. We show that using F-DMAS, which is based on a measure of backscattered signal spatial correlation, B-mode images have a higher contrast resolution but suffer from a loss of brightness away from the transmit focus, when a classical scan with receive-only dynamic focusing is performed. On the other hand, when synthetic transmit focusing is achieved by implementing STA, such a loss is compensated for and a higher depth of field is obtained, as signal coherence improves. A drawback of SAF/STA however is the reduced signal-to-noise ratio, due to single-element transmission; in the paper we also analyze how this influences F-DMAS images. Finally, a preliminary investigation on the use of the classical monostatic SAF technique with F-DMAS beamforming is also carried out to evaluate its potential performances. Copyright © 2016 Elsevier B.V. All rights reserved.
Little, Jeffrey W.; Tyrrell, Brian M.; D'Onofrio, Richard; Berger, Paul J.; Fernandez-Cull, Christy
2014-06-01
A digital pixel CMOS focal plane array has been developed to enable low latency implementations of image processing systems such as centroid trackers, Shack-Hartman wavefront sensors, and Fitts correlation trackers through the use of in-pixel digital signal processing (DSP) and generic parallel pipelined multiply accumulate (MAC) units. Light intensity digitization occurs at the pixel level, enabling in-pixel DSP and noiseless data transfer from the pixel array to the peripheral processing units. The pipelined processing of row and column image data prior to off chip readout reduces the required output bandwidth of the image sensor, thus reducing the latency of computations necessary to implement various image processing systems. Data volume reductions of over 80% lead to sub 10μs latency for completing various tracking and sensor algorithms. This paper details the architecture of the pixel-processing imager (PPI) and presents some initial results from a prototype device fabricated in a standard 65nm CMOS process hybridized to a commercial off-the-shelf short-wave infrared (SWIR) detector array.
Preliminary results of the Gas Electron Multiplier (GEM) as real-time beam monitor in hadron therapy
Energy Technology Data Exchange (ETDEWEB)
Aza, E., E-mail: eleni.aza@cern.ch [CERN, Geneva 23, 1211 Geneva (Switzerland); AUTH, Department of Physics, 54124 Thessaloniki (Greece); Ciocca, M. [Fondazione CNAO, Strada Campeggi 53, 27100 Pavia (Italy); Murtas, F. [CERN, Geneva 23, 1211 Geneva (Switzerland); LNF-INFN, Via Fermi 40, 00044 Frascati (Italy); Puddu, S. [CERN, Geneva 23, 1211 Geneva (Switzerland); AEC-LHEP, University of Bern, Sidlerstrasse 5, 3012 Bern (Switzerland); Pullia, M. [Fondazione CNAO, Strada Campeggi 53, 27100 Pavia (Italy); Silari, M. [CERN, Geneva 23, 1211 Geneva (Switzerland)
2017-01-01
The use of proton and carbon ion beams in cancer therapy (also known as hadron therapy) is progressively growing worldwide due to their improved dose distributions, sparing of healthy tissues and (for carbon ions) increased radiobiological effectiveness especially for radio-resistant tumours. Strict Quality Assurance (QA) protocols need to be followed for guaranteeing the clinical beam specifications. The aim of this study was to assess the performance of a gaseous detector based on the Gas Electron Multiplier (GEM) technology for measuring the beam spot dimensions and the homogeneity of the scanned irradiation field, which are daily QA tasks commonly performed using radiochromic films. Measurements performed at the National Centre for Oncological Hadron Therapy (CNAO) in Pavia (Italy) showed that the detector is able to monitor the 2D beam image on-line with a pad granularity of 2 mm and a response proportional to the number of delivered particles. The dose homogeneity was measured with low deviation from the results obtained with radiochromic films.
Energy Technology Data Exchange (ETDEWEB)
DeMange, P; Marian, J; de Caro, M S; Caro, A
2009-03-16
Concept designs for the laser-initiated fusion/fission engine (LIFE) include a neutron multiplication blanket containing Be pebbles flowing in a molten salt coolant. These pebbles must be designed to withstand the extreme irradiation and temperature conditions in the blanket to enable a safe and cost-effective operation of LIFE. In this work, we develop design criteria for spherical Be pebbles on the basis of their thermomechanical behavior under continued neutron exposure. We consider the effects of high fluence/fast flux on the elastic, thermal and mechanical properties of nuclear-grade Be. Our results suggest a maximum pebble diameter of 30 mm to avoid tensile failure, coated with an anti-corrosive, high-strength metallic shell to avoid failure by pebble contact. Moreover, we find that the operation temperature must always be kept above 450 C to enable creep to relax the stresses induced by swelling, which we estimate to be at least 16 months if uncoated and up to six years when coated. We identify the sources of uncertainty on the properties used and discuss the advantages of new intermetallic beryllides and their use in LIFE's neutron multiplier. To establish Be-pebble lifetimes with improved confidence, reliable experiments to measure irradiation creep must be performed.
Gola, Mohit
2017-01-01
As the CERN LHC is heading towards a high luminosity phase a very high flux is expected in the endcaps of the CMS Detector. The presence of muons in collision events can be due to rare or new physics so it is important to maintain the high trigger efficiency of the CMS muon system. The CMS Collaboration has proposed to instrument the high-eta region (1.6 lt IetaI lt 2.2) of the muon endcaps with Gas Electron Multiplier (GEM) detectors, referred to as GE1/1 chambers, during the LS2. This technology will help in maintaining optimum trigger performance with maximum selection efficiency of muons even in a high flux environment. We describe plans for a Slice Test to installa few GE1/1 chambers covering 50 degrees in azimuthal angle within the CMS detector in 2017, with subsequent operation during the current Run 2 of the LHC. We show the performance of the GE1/1 chambers to be installed during the slice test, specifically GEM foil leakage currents, chamber gas volume integrity, high voltage circuit performanc...
Dickson, S.; Gausa, M. A.; Robertson, S. H.; Sternovsky, Z.
2012-12-01
We demonstrate that a channel electron multiplier (CEM) can be operated on a sounding rocket in the pulse-counting mode from 120 km to 75 km altitude without the cryogenic evacuation used in the past. Evacuation of the CEM is provided only by aerodynamic flow around the rocket. This demonstration is motivated by the need for additional flights of mass spectrometers to clarify the fate of metallic compounds and ions ablated from micrometeorites and their possible role in the nucleation of noctilucent clouds. The CEMs were flown as guest instruments on the two sounding rockets of the CHAMPS (CHarge And mass of Meteoritic smoke ParticleS) rocket campaign which were launched into the mesosphere in October 2011 from Andøya Rocket Range, Norway. Modeling of the aerodynamic flow around the payload with Direct Simulation Monte-Carlo (DSMC) code showed that the pressure is reduced below ambient in the void beneath an aft-facing surface. An enclosure containing the CEM was placed above an aft-facing deck and a valve was opened on the downleg to expose the CEM to the aerodynamically evacuated region below. The CEM operated successfully from apogee down to ~75 km. A Pirani gauge confirmed pressures reduced to as low as 20% of ambient with the extent of reduction dependent upon altitude and velocity. Additional DSMC simulations indicate that there are alternate payload designs with improved aerodynamic pumping for forward mounted instruments such as mass spectrometers.
Dickson, Shannon; Gausa, Michael; Robertson, Scott; Sternovsky, Zoltan
2013-04-01
We demonstrate that a channel electron multiplier (CEM) can be operated on a sounding rocket in the pulse-counting mode from 120 km to 80 km altitude without the cryogenic evacuation used in the past. Evacuation of the CEM is provided only by aerodynamic flow around the rocket. This demonstration is motivated by the need for additional flights of mass spectrometers to clarify the fate of metallic compounds and ions ablated from micrometeorites and their possible role in the nucleation of noctilucent clouds. The CEMs were flown as guest instruments on two sounding rockets to the mesosphere. Modeling of the aerodynamic flow around the payload with Direct Simulation Monte-Carlo (DSMC) code showed that the pressure is reduced below ambient in the void behind (relative to the direction of motion) an aft-facing surface. An enclosure containing the CEM was placed forward of an aft-facing deck and a valve was opened during flight to expose the CEM to the aerodynamically evacuated region behind it. The CEM operated successfully from apogee down to ∼80 km. A Pirani gauge confirmed pressures reduced to as low as 20% of ambient with the extent of reduction dependent upon altitude and velocity. Additional DSMC simulations indicate that there are alternate payload designs with improved aerodynamic pumping for forward mounted instruments such as mass spectrometers.
Cavalli, F; Naimzada, A; Pecora, N
2017-10-01
In the present paper, we investigate the dynamics of a model in which the real part of the economy, described within a multiplier-accelerator framework, interacts with a financial market with heterogeneous speculators, in order to study the channels through which the two sectors influence each other. Employing analytical and numerical tools, we investigate stability conditions as well as bifurcations and possible periodic, quasi-periodic, and chaotic dynamics, enlightening how the degree of market interaction, together with the accelerator parameter and the intervention of the fiscal authority, may affect the business cycle and the course of the financial market. In particular, we show that even if the steady state is locally stable, multistability phenomena can occur, with several and complex dynamic structures coexisting with the steady state. Finally, simulations reveal that the proposed model is able to explain several statistical properties and stylized facts observed in real financial markets, including persistent high volatility, fat-tailed return distributions, volatility clustering, and positive autocorrelation of absolute returns.
Directory of Open Access Journals (Sweden)
George Philippidis
2014-11-01
Full Text Available The concept of 'bioeconomy' is gathering momentum in European Union (EU policy circles as a sustainable model of growth to reconcile continued wealth generation and employment with bio-based sustainable resource usage. Unfortunately, in the literature an economy-wide quantitative assessment covering the full diversity of this sector is lacking due to relatively poor data availability for disaggregated bio-based activities. This research represents a first step by employing social accounting matrices (SAMs for each EU27 member encompassing a highly disaggregated treatment of traditional 'bio-based' agricultural and food activities, as well as additional identifiable bioeconomic activities from the national accounts data. Employing backward-linkage (BL, forward-linkage (FL and employment multipliers, the aim is to profile and assess comparative structural patterns both across bioeconomic sectors and EU Member States. The results indicate six clusters of EU member countries with homogeneous bioeconomy structures. Within cluster statistical tests reveal a high tendency toward 'backward orientation' or demand driven wealth generation, whilst inter-cluster statistical comparisons by bio-based sector show only a moderate degree of heterogeneous BL wealth generation and, with the exception of only two sectors, a uniformly homogeneous degree of FL wealth generation. With the exception of forestry, fishing and wood activities, bio-based employment generation prospects are below non bioeconomy activities. Finally, milk and dairy are established as 'key sectors'.
Energy Technology Data Exchange (ETDEWEB)
Falcone, A., E-mail: andrea.falcone@pv.infn.it [University of Pavia – Via Bassi 6, 27100 Pavia (Italy); INFN Sezione di Pavia – Via Bassi 6, 27100 Pavia (Italy); Bertoni, R. [INFN Sezione di Milano Bicocca – Piazza della Scienza 3, 20126 Milano (Italy); Boffelli, F. [University of Pavia – Via Bassi 6, 27100 Pavia (Italy); INFN Sezione di Pavia – Via Bassi 6, 27100 Pavia (Italy); Bonesini, M. [INFN Sezione di Milano Bicocca – Piazza della Scienza 3, 20126 Milano (Italy); Cervi, T. [University of Pavia – Via Bassi 6, 27100 Pavia (Italy); Menegolli, A. [University of Pavia – Via Bassi 6, 27100 Pavia (Italy); INFN Sezione di Pavia – Via Bassi 6, 27100 Pavia (Italy); Montanari, C.; Prata, M.C.; Rappoldi, A.; Raselli, G.L.; Rossella, M. [INFN Sezione di Pavia – Via Bassi 6, 27100 Pavia (Italy); Spanu, M. [University of Pavia – Via Bassi 6, 27100 Pavia (Italy); Torti, M. [University of Pavia – Via Bassi 6, 27100 Pavia (Italy); INFN Sezione di Pavia – Via Bassi 6, 27100 Pavia (Italy); Zani, A. [INFN Sezione di Pavia – Via Bassi 6, 27100 Pavia (Italy)
2015-07-01
An evaluation of the behavior of three large cathode area photo-multiplier tubes, Hamamatsu R5912 Mod and R5912-02 Mod, and ETL 9357 KFLB, was carried out both at room and cryogenic temperature, using a 405 nm light source. The main electrical and optical features of the devices were studied; the obtained results were compared with the characteristics of the ETL 9357 FLA tubes, used in the ICARUS experiment. Tubes were also studied as a function of the Earth's magnetic field and an evaluation of the quantum efficiency was made in the vacuum ultraviolet light region. - Highlights: • We tested three 8-in. PMTs both at room and at cryogenic temperature. • The response as a function of the terrestrial magnetic field was tested. • The quantum efficiency for VUV light was measured. • Gain, linearity and dark count rate at 77 K and at 300 K were compared. • The PMTs were found able to work at cryogenic temperature.
Warner, Paul
2017-09-01
For any appreciable radiation source, such as a nuclear reactor core or radiation physics accelerator, there will be the safety requirement to shield operators from the effects of the radiation from the source. Both the size and weight of the shield need to be minimised to reduce costs (and to increase the space available for the maintenance envelope on a plant). This needs to be balanced against legal radiation dose safety limits and the requirement to reduce the dose to operators As Low As Reasonably Practicable (ALARP). This paper describes a method that can be used, early in a shield design, to scope the design and provide a practical estimation of the size of the shield by optimising the shield internals. In particular, a theoretical model representative of a small reactor is used to demonstrate that the primary shielding radius, thickness of the primary shielding inner wall and the thicknesses of two steel inner walls, can be set using the Lagrange multiplier method with a constraint on the total flux on the outside of the shielding. The results from the optimisation are presented and an RZ finite element transport theory calculation is used to demonstrate that, using the optimised geometry, the constraint is achieved.
Kanbar, Ghazwan; Engels, Wolf
2005-09-30
The ectoparasitic bee mite, Varroa destructor, is highly adapted to its natural and adopted honey bee hosts, Apis cerana and Apis mellifera. Adult females perforate the integument of bee pupae in such a way that they and their progeny can feed. We examined the wounds that founder females made, and usually found one, and rarely up to three, integumental wounds on pupae of A. mellifera multiply infested by V. destructor. The punctures were mainly on the 2nd abdominal sternite of the host. These perforations are used repeatedly as feeding sites by these hemolymph-sucking mites and by their progeny. The diameter of the wounds increased during pupal development. In brood cells containing 4-5 invading female mites and their progeny, healing of the wound is delayed, normally occurring just before the imaginal moult of the bee pupa. These wounds are subject to microbial infections, and they are relevant to the evolution of behavioral traits in these parasitic mites and their relations to host bees.
Directory of Open Access Journals (Sweden)
Warner Paul
2017-01-01
Full Text Available For any appreciable radiation source, such as a nuclear reactor core or radiation physics accelerator, there will be the safety requirement to shield operators from the effects of the radiation from the source. Both the size and weight of the shield need to be minimised to reduce costs (and to increase the space available for the maintenance envelope on a plant. This needs to be balanced against legal radiation dose safety limits and the requirement to reduce the dose to operators As Low As Reasonably Practicable (ALARP. This paper describes a method that can be used, early in a shield design, to scope the design and provide a practical estimation of the size of the shield by optimising the shield internals. In particular, a theoretical model representative of a small reactor is used to demonstrate that the primary shielding radius, thickness of the primary shielding inner wall and the thicknesses of two steel inner walls, can be set using the Lagrange multiplier method with a constraint on the total flux on the outside of the shielding. The results from the optimisation are presented and an RZ finite element transport theory calculation is used to demonstrate that, using the optimised geometry, the constraint is achieved.
Zander, Anette
2001-01-01
Micro strip gas chambers (MSGCs) are promising candidates for large scale applications. They combine a good spatial resolution with high granularity and low cost. As a possible extension of the plain MSGC, a Gas Electron Multiplier (GEM) foil may be implemented into the detector in order to increase the safety of operation. It was planned to equip the outer part of the tracking system of the Compact Muon Solenoid (CMS) experiment at the future Large Hadron Collider (LHC) at the Centre de Recherche Nucleaire (CERN) with MSGCs. In the barrel part of the tracker, plain MSGCs were to be used. For the forward part, the MSGC+GEM technology was envisaged. This thesis describes the assembly and test of a pre-series of 18 fully functional MSGC+GEM forward detector modules to determine their radiation hardness and their readiness for mass production. Five of the modules were built at Aachen, thirteen more at the 'Institut für Experimentelle Kernphysik' in Karlsruhe. For the pre-series, two different types of GEM foils...
Directory of Open Access Journals (Sweden)
Mahdi M. M. El-Arini
2013-01-01
Full Text Available In recent years, the solar energy has become one of the most important alternative sources of electric energy, so it is important to operate photovoltaic (PV panel at the optimal point to obtain the possible maximum efficiency. This paper presents a new optimization approach to maximize the electrical power of a PV panel. The technique which is based on objective function represents the output power of the PV panel and constraints, equality and inequality. First the dummy variables that have effect on the output power are classified into two categories: dependent and independent. The proposed approach is a multistage one as the genetic algorithm, GA, is used to obtain the best initial population at optimal solution and this initial population is fed to Lagrange multiplier algorithm (LM, then a comparison between the two algorithms, GA and LM, is performed. The proposed technique is applied to solar radiation measured at Helwan city at latitude 29.87°, Egypt. The results showed that the proposed technique is applicable.
Qiu, Jinhuan; Huang, Qirong
1992-01-01
The study of the inversion algorithm for the single scatter lidar equation, for quantitative determination of cloud (or aerosol) optical properties, has received much attention over the last thirty years. Some of the difficulties associated with the solution of this equation are not yet solved. One problem is that a single scatter lidar equation has two unknowns. Because of this, the determination of the far-end boundary value, in the case of Klett's algorithm, is a problem if the atmosphere is optically inhomogeneous. Another difficulty concerns multiple scattering. There is a large error in the extinction distribution solution, in many cases, if only the single scattering component is considered, while neglecting the multiple scattering component. However, the use of multiple scattering in the remote sensing of aerosol or cloud optical properties is promising. In our early study, an inversion method for simultaneous determination of the cloud (or aerosol) Extinction Coefficient Distribution (ECD) and its Forward Scattering Phase Function (FSPF) was proposed according to multiply scattered lidar returns with two fields of view for the receiver. The method is based on a parameterized multiple scatter lidar equation. This paper is devoted to further numerical tests and an experimental study of lidar measurements of cloud ECD and FSPF using this method.
Cavalli, F.; Naimzada, A.; Pecora, N.
2017-10-01
In the present paper, we investigate the dynamics of a model in which the real part of the economy, described within a multiplier-accelerator framework, interacts with a financial market with heterogeneous speculators, in order to study the channels through which the two sectors influence each other. Employing analytical and numerical tools, we investigate stability conditions as well as bifurcations and possible periodic, quasi-periodic, and chaotic dynamics, enlightening how the degree of market interaction, together with the accelerator parameter and the intervention of the fiscal authority, may affect the business cycle and the course of the financial market. In particular, we show that even if the steady state is locally stable, multistability phenomena can occur, with several and complex dynamic structures coexisting with the steady state. Finally, simulations reveal that the proposed model is able to explain several statistical properties and stylized facts observed in real financial markets, including persistent high volatility, fat-tailed return distributions, volatility clustering, and positive autocorrelation of absolute returns.
Studying multiply shocked states in HMX and TATB based explosives with a gas gun ring up geometry
Ferguson, James; Finnegan, Simon; Millett, Jeremy; Goff, Michael
2017-06-01
A series of ring up shots investigating partially reacted and multiply shocked states in both HMX and TATB based explosives are reported on. Results of experiments using PCTFE and LiF in place of the explosives are also described. The experiments were performed using 50 mm diameter bore and 70 mm diameter bore single stage gas guns. By locating the target between a high impedance copper flyer and sapphire window, shocks of increasing magnitude are reflected into the target at each interface. The particle velocity at the target-window interface was measured using multiple points of HetV reflected from an 800 nm layer of gold sputtered onto the sapphire. The stress state at the target-flyer interface were observed using manganin gauges. A range of different input pressures were investigated, these were picked to either allow a comparison to double shock and particle velocity work, or to provide the maximum number of rings within the one dimensional time. For the inert shots input pressures matched the explosive shots.
McMullen, Timothy; Liyanage, Nilanga; Xiong, Weizhi; Zhao, Zhiwen
2017-01-01
Our research has focused on simulating the response of a Gas Electron Multiplier (GEM) detector using computational methods. GEM detectors provide a cost effective solution for radiation detection in high rate environments. A detailed simulation of GEM detector response to radiation is essential for the successful adaption of these detectors to different applications. Using Geant4 Monte Carlo (GEMC), a wrapper around Geant4 which has been successfully used to simulate the Solenoidal Large Intensity Device (SoLID) at Jefferson Lab, we are developing a simulation of a GEM chamber similar to the detectors currently used in our lab. We are also refining an object-oriented digitization program, which translates energy deposition information from GEMC into electronic readout which resembles the readout from our physical detectors. We have run the simulation with beta particles produced by the simulated decay of a 90Sr source, as well as with a simulated bremsstrahlung spectrum. Comparing the simulation data with real GEM data taken under similar conditions is used to refine the simulation parameters. Comparisons between results from the simulations and results from detector tests will be presented.
Sharma, Ram Krishna
2017-01-01
The High Luminosity LHC (HL-LHC) will provide exceptional high instantaneous and integrated luminosity. The forward region $\\mid \\eta \\mid \\geq 1.5$ of the CMS detector will face extremely high particle rates in tens of $KHz/cm^{2}$ and hence it will affect the momentum resolution and longevity of the muon detectors. To overcome these issues the CMS collaboration has decided to install new large size rate capable Triple Gas Electron Multiplier (GEM) detectors in the forward region of CMS muon system. The first set of Triple GEM detectors will be installed in the GE1/1 region $(1.5 \\leq \\eta \\leq 2.2)$ of muon endcap during the LS2 of the LHC and the next one will be installed in the GE2/1 region $(1.6 \\leq \\eta \\leq 2.5)$, during the LS3. Towards this goal, full-size CMS Triple GEM prototype chambers have been fabricated and put under the test beam at the CERN SPS test beam facility. The GEM detectors were operated with two gas mixtures $Ar/CO_{2}$ (70/30) and $Ar/CO_{2}/CF_{4}$ (40/15/45). In 2014 and 2016, ...
Directory of Open Access Journals (Sweden)
Burhan Khurshid
2015-05-01
Full Text Available Modern Field Programmable Gate Arrays (FPGA are fast moving into the consumer market and their domain has expanded from prototype designing to low and medium volume productions. FPGAs are proving to be an attractive replacement for Application Specific Integrated Circuits (ASIC primarily because of the low Non-recurring Engineering (NRE costs associated with FPGA platforms. This has prompted FPGA vendors to improve the capacity and flexibility of the underlying primitive fabric and include specialized macro support and intellectual property (IP cores in their offerings. However, most of the work related to FPGA implementations does not take full advantage of these offerings. This is primarily because designers rely mainly on the technology-independent optimization to enhance the performance of the system and completely neglect the speed-up that is achievable using these embedded primitives and macro support. In this paper, we consider the technology-dependent optimization of fixed-point bit-parallel multipliers by carrying out their implementations using embedded primitives and macro support that are inherent in modern day FPGAs. Our implementation targets three different FPGA families viz. Spartan-6, Virtex-4 and Virtex-5. The implementation results indicate that a considerable speed up in performance is achievable using these embedded FPGA resources.
Larsen-Freeman, Diane
2002-01-01
Responds to Ellis (2002), which focuses on frequency in language processing, language use, and language acquisition. Contextualizes the frequency factor in terms of the evolution of second language acquisition (SLA) research. Suggests that although relevant and important, the frequency factor requires greater definition and qualification.…
John F. Caratti
2006-01-01
The FIREMON Cover/Frequency (CF) method is used to assess changes in plant species cover and frequency for a macroplot. This method uses multiple quadrats to sample within-plot variation and quantify statistically valid changes in plant species cover, height, and frequency over time. Because it is difficult to estimate cover in quadrats for larger plants, this method...
Eastern Frequency Response Study
Energy Technology Data Exchange (ETDEWEB)
Miller, N.W.; Shao, M.; Pajic, S.; D' Aquila, R.
2013-05-01
This study was specifically designed to investigate the frequency response of the Eastern Interconnection that results from large loss-of-generation events of the type targeted by the North American Electric Reliability Corp. Standard BAL-003 Frequency Response and Frequency Bias Setting (NERC 2012a), under possible future system conditions with high levels of wind generation.
The frequency polygon reconsidered.
van Casteren, P.H.F.M.
1997-01-01
The frequency polygon is not compatible with the given frequency distribution in the sense that the areas within the classes are not proportional to the frequencies. As a consequence, the polygon is too flat. Therefore, an alternative polygon is constructed as a continuous version of the histogram
Broadband frequency conversion
DEFF Research Database (Denmark)
Sanders, Nicolai Højer; Jensen, Ole Bjarlin; Dam, Jeppe Seidelin
We demonstrate a method for frequency conversion of broadly tunable or broad bandwidth light in a static, passive setup. Using simple optical components like lenses, mirrors and gratings and a BiBO crystal as the nonlinear material, we are able to frequency double a single-frequency, tunable...
Low frequency piezoresonance defined dynamic control of terahertz wave propagation.
Dutta, Moumita; Betal, Soutik; Peralta, Xomalin G; Bhalla, Amar S; Guo, Ruyan
2016-11-30
Phase modulators are one of the key components of many applications in electromagnetic and opto-electric wave propagations. Phase-shifters play an integral role in communications, imaging and in coherent material excitations. In order to realize the terahertz (THz) electromagnetic spectrum as a fully-functional bandwidth, the development of a family of efficient THz phase modulators is needed. Although there have been quite a few attempts to implement THz phase modulators based on quantum-well structures, liquid crystals, or meta-materials, significantly improved sensitivity and dynamic control for phase modulation, as we believe can be enabled by piezoelectric-resonance devices, is yet to be investigated. In this article we provide an experimental demonstration of phase modulation of THz beam by operating a ferroelectric single crystal LiNbO3 film device at the piezo-resonance. The piezo-resonance, excited by an external a.c. electric field, develops a coupling between electromagnetic and lattice-wave and this coupling governs the wave propagation of the incident THz beam by modulating its phase transfer function. We report the understanding developed in this work can facilitate the design and fabrication of a family of resonance-defined highly sensitive and extremely low energy sub-millimeter wave sensors and modulators.
High-frequency, three-phase current controller implementation in an FPGA
Energy Technology Data Exchange (ETDEWEB)
Hartmann, M.; Round, S. D.; Kolar, J. W.
2008-07-01
Three phase rectifiers with switching frequencies of 500 kHz or more require high speed current controllers. At such high switching frequencies analog controllers as well as high speed digital signal processing (DSP) systems have limited performance. In this paper, two high speed current controller implementations using two different field-programmable gate arrays (FPGA) - one for switching frequencies up to 1 MHz and one for switching frequencies beyond 1 MHz - are presented to overcome this performance limitation. Starting with the digital system design all the blocks of the signal chain, containing analog-to-digital (A/D) interface, digital controller implementation using HW-multipliers and implementation of a novel high speed, high resolution pulse width modulation (PWM) are discussed and compared. Final measurements verify the performance of the controllers. (author)
Frequency selective infrared sensors
Davids, Paul; Peters, David W
2013-05-28
A frequency selective infrared (IR) photodetector having a predetermined frequency band. The exemplary frequency selective photodetector includes: a dielectric IR absorber having a first surface and a second surface substantially parallel to the first surface; an electrode electrically coupled to the first surface of the dielectric IR absorber; and a frequency selective surface plasmonic (FSSP) structure formed on the second surface of the dielectric IR absorber. The FSSP structure is designed to selectively transmit radiation in the predetermined frequency band that is incident on the FSSP structure substantially independent of the angle of incidence of the incident radiation on the FSSP structure.
Radio frequency spectrum management
Sujdak, E. J., Jr.
1980-03-01
This thesis is a study of radio frequency spectrum management as practiced by agencies and departments of the Federal Government. After a brief introduction to the international agency involved in radio frequency spectrum management, the author concentrates on Federal agencies engaged in frequency management. These agencies include the National Telecommunications and Information Administration (NTIA), the Interdepartment Radio Advisory Committee (IRAC), and the Department of Defense (DoD). Based on an analysis of Department of Defense frequency assignment procedures, recommendations are given concerning decentralizing military frequency assignment by delegating broader authority to unified commanders. This proposal includes a recommendation to colocate the individual Service frequency management offices at the Washington level. This would result in reduced travel costs, lower manpower requirements, and a common tri-Service frequency management data base.
Chambers, L. H.
2011-12-01
An individual scientist might look at the huge numbers of students and the public who constitute a potential audience for education and public outreach (EPO) and conclude that he/she has no hope to make a difference. This talk will share some strategies that have the potential to multiply a scientist's for maximum effect, and some evidence that indeed one person CAN make a difference. The first strategy is to leverage: that is, find a person or group who already has an ongoing EPO activity that relates to your subject area, and use it as a way to get your information out to an existing, interested audience. This benefits you because you don't have to begin from scratch to build an audience for your information, and it benefits them because they get great new content to keep their audience interested. The second strategy is to synergize: that is, cooperate or coordinate with an existing EPO group, or with colleagues with similar interests. Use your expertise to develop new resources that fit into an existing program. Cooperate with an existing EPO group so they can help you navigate details like review processes, aligning your resource to education standards, and helping tailor your information to the needs of the education audience. The third strategy is to use technology to approximate cloning: that is, to propagate yourself and your information via multiple channels. However, this strategy should not be used until after you have tested and honed your information through a number of in-person interactions with the audience(s) you seek to reach, and have developed some communications skills that help you connect with students and teachers. One lesson that you may learn from such interactions is that scientists aren't like other people. We have a distinct vocabulary, culture, and habits of mind that distinguish us from others. This is a key strength for science, but sometimes a barrier for EPO. By personal contact with non-scientists, we can learn again how to
Directory of Open Access Journals (Sweden)
N. Mindu
2014-01-01
Full Text Available The derivation of conservation laws for the magma equation using the multiplier method for both the power law and exponential law relating the permeability and matrix viscosity to the voidage is considered. It is found that all known conserved vectors for the magma equation and the new conserved vectors for the exponential laws can be derived using multipliers which depend on the voidage and spatial derivatives of the voidage. It is also found that the conserved vectors are associated with the Lie point symmetry of the magma equation which generates travelling wave solutions which may explain by the double reduction theorem for associated Lie point symmetries why many of the known analytical solutions are travelling waves.
Hong, Youngjoon; Nicholls, David P.
2017-09-01
The capability to rapidly and robustly simulate the scattering of linear waves by periodic, multiply layered media in two and three dimensions is crucial in many engineering applications. In this regard, we present a High-Order Perturbation of Surfaces method for linear wave scattering in a multiply layered periodic medium to find an accurate numerical solution of the governing Helmholtz equations. For this we truncate the bi-infinite computational domain to a finite one with artificial boundaries, above and below the structure, and enforce transparent boundary conditions there via Dirichlet-Neumann Operators. This is followed by a Transformed Field Expansion resulting in a Fourier collocation, Legendre-Galerkin, Taylor series method for solving the problem in a transformed set of coordinates. Assorted numerical simulations display the spectral convergence of the proposed algorithm.
Timmer, P; Peek, H
2010-01-01
The described system is developed in the framework of a deep-sea submerged Very Large Volume neutrino Telescope where photons are detected by a large number of Photo Multiplier Tubes. These PMTs are placed in optical modules (OM). A basic Cockcroft-Walton (CW) voltage multiplier circuit design is used to generate multiple voltages to drive the dynodes of the photomultiplier tube. To achieve a long lifetime and a high reliability the dissipation in the OM must be kept to the minimum. The design is also constrained by size restrictions, load current, voltage range, and the maximum allowable ripple in the output voltage. A surface mount PMT-base PCB prototype is designed and successfully tested. The system draws less than 1.5 mA of supply current at a voltage of 3.3 V with outputs up to -1400 Vdc cathode voltage, a factor 10 less than the commercially available state of the art
Kang, Suk-Bok; Han, Jun-Tae
2015-01-01
Many studies have considered a truncated and censored samples which are type-I, type-II and hybrid censoring scheme. The inverse Weibull distribution has been utilized for the analysis of life testing and reliability data. Also, this distribution is a very flexible distribution. The inverse Rayleigh distribution and inverse exponential distribution are a special case of the inverse Weibull distribution. In this paper, we derive the approximate maximum likelihood estimators (AMLEs) of the scale parameter and the shape parameter in the inverse Weibull distribution under multiply type-II censoring. We also propose a simple graphical method for goodness-on-fit test based on multiply type-II censored samples using AMLEs.
Chaikovskaya, Ludmila I; Zege, Eleonora P; Katsev, Iosif L; Hirschberger, Markus; Oppel, Ulrich G
2009-01-20
Quite recently, a semi-analytical approach to the sounding of multiply scattering media (clouds, seawaters) using multiple-field-of-view and CCD lidars with polarization devices was developed. The angular distributions of polarized components of the lidar returns from multiply scattering media computed on the basis of this theory using the small-angle approximation are presented and discussed. The semi-analytical nature of the solution makes the computation procedure faster. The obtained data are compared with results provided by the most advanced Monte Carlo algorithms for simulation of modern lidar performance. The good agreement between data provided by the semi-analytical approach and Monte Carlo computations assures one that these approaches can serve as a reliable theoretical base for interpretation and inversion of cloud lidar sounding data obtained with polarized lidars, including polarized multiple-field-of-view and CCD lidars.
Directory of Open Access Journals (Sweden)
Fan Meng
Full Text Available This paper studies the problem of the restoration of images corrupted by mixed Gaussian-impulse noise. In recent years, low-rank matrix reconstruction has become a research hotspot in many scientific and engineering domains such as machine learning, image processing, computer vision and bioinformatics, which mainly involves the problem of matrix completion and robust principal component analysis, namely recovering a low-rank matrix from an incomplete but accurate sampling subset of its entries and from an observed data matrix with an unknown fraction of its entries being arbitrarily corrupted, respectively. Inspired by these ideas, we consider the problem of recovering a low-rank matrix from an incomplete sampling subset of its entries with an unknown fraction of the samplings contaminated by arbitrary errors, which is defined as the problem of matrix completion from corrupted samplings and modeled as a convex optimization problem that minimizes a combination of the nuclear norm and the l(1-norm in this paper. Meanwhile, we put forward a novel and effective algorithm called augmented Lagrange multipliers to exactly solve the problem. For mixed Gaussian-impulse noise removal, we regard it as the problem of matrix completion from corrupted samplings, and restore the noisy image following an impulse-detecting procedure. Compared with some existing methods for mixed noise removal, the recovery quality performance of our method is dominant if images possess low-rank features such as geometrically regular textures and similar structured contents; especially when the density of impulse noise is relatively high and the variance of Gaussian noise is small, our method can outperform the traditional methods significantly not only in the simultaneous removal of Gaussian noise and impulse noise, and the restoration ability for a low-rank image matrix, but also in the preservation of textures and details in the image.
Meng, Fan; Yang, Xiaomei; Zhou, Chenghu
2014-01-01
This paper studies the problem of the restoration of images corrupted by mixed Gaussian-impulse noise. In recent years, low-rank matrix reconstruction has become a research hotspot in many scientific and engineering domains such as machine learning, image processing, computer vision and bioinformatics, which mainly involves the problem of matrix completion and robust principal component analysis, namely recovering a low-rank matrix from an incomplete but accurate sampling subset of its entries and from an observed data matrix with an unknown fraction of its entries being arbitrarily corrupted, respectively. Inspired by these ideas, we consider the problem of recovering a low-rank matrix from an incomplete sampling subset of its entries with an unknown fraction of the samplings contaminated by arbitrary errors, which is defined as the problem of matrix completion from corrupted samplings and modeled as a convex optimization problem that minimizes a combination of the nuclear norm and the l(1)-norm in this paper. Meanwhile, we put forward a novel and effective algorithm called augmented Lagrange multipliers to exactly solve the problem. For mixed Gaussian-impulse noise removal, we regard it as the problem of matrix completion from corrupted samplings, and restore the noisy image following an impulse-detecting procedure. Compared with some existing methods for mixed noise removal, the recovery quality performance of our method is dominant if images possess low-rank features such as geometrically regular textures and similar structured contents; especially when the density of impulse noise is relatively high and the variance of Gaussian noise is small, our method can outperform the traditional methods significantly not only in the simultaneous removal of Gaussian noise and impulse noise, and the restoration ability for a low-rank image matrix, but also in the preservation of textures and details in the image.
Directory of Open Access Journals (Sweden)
Lucienne Heideman
2011-12-01
Full Text Available Local Economic Development (LED is a contested concept in southern Africa, and has become synonymous with delivery of generic job-creation projects, often grant-dependent and unsustainable. Municipal LED has followed this pattern in South Africa since 1994, with little lasting success. Each local economy is unique, and has its own problems and opportunities. The ’Plugging the Leaks’ method recognizes that communities themselves know best how money enters and exits their area. By asking people to analyse their local economy as a 'leaky bucket', the method puts control back in the hands of local people, rather than external experts, and allows them to analyse their own local economy to identify gaps and opportunities for enterprise. By better networking and working collectively to improve their local economy, local communities are able to re-circulate cash internally. This circulation of cash is explained as the local multiplier effect in the workshops. A pilot process of running ‘Plugging the Leaks’ workshops in low income communities in South Africa and Namibia revealed that spending choices in these communities are severely limited in a context where there is no effective welfare state. Therefore, empowerment with this method came from the discovery of collective action and networking, rather than from individual spending choices. Local start-up business tends to be limited to survivalist and copy-cat one-person ventures, and are a last resort when formal employment is absent. In this context collective enterprise offers the necessary empowerment for people to attempt financially sustainable ventures that respond to a gap in the local economy. The pilot project is attempting to show that municipal LED staff can play the role of facilitator for initiating the enterprise-identification process and further mobilise state enterprise support agencies around the locus of LED, without crossing the line between facilitation and implementation
Backer, Jantien; Spierenburg, Marcel; van der Spek, Arco; Elbers, Armin
2010-10-15
In the Spring of 2009, a veterinarian reported suspected classical swine fever (CSF) on a multiplier pig farm in the southern part of The Netherlands (close to the Belgian border). Over a 5-week period there had been a number of sick sows and an excessively high percentage of stillborn and preterm piglets. Sick animals were treated with anti-inflammatory drugs and antibiotics, but did not respond as well as anticipated. A visiting specialist team from the Food Safety Authority could not exclude CSF as the cause of the clinical problems and sent blood samples to the reference laboratory in Lelystad for a PCR test on CSF antigen. Fortunately, test results obtained 6 hours later were negative for CSF, and the disease control measures were lifted. It later appeared that porcine reproductive and respiratory syndrome (PRRSV) might have been responsible for the problems. But what if CSF had caused the clinical problems? A CSF-transmission model was used to simulate CSF outbreaks dependent on the duration of the high-risk period (HRP). As the duration of the HRP increased, there was an exponential growth in the number of pig farms infected during this period. Simulations also showed that with a longer HRP, the virus spread over greater distances from the source herd. It was also investigated whether a possible CSF outbreak could be detected on the basis of an increased mortality and hence increased number of cadavers sent to a rendering plant. However, the calculated mortality incidence was not sensitive enough to serve as an alarm signal. It is recommended that CSF-exclusion diagnostics be used much earlier in similar clinical situations on pig farms.
Radio frequency detection assembly and method for detecting radio frequencies
Cown, Steven H.; Derr, Kurt Warren
2010-03-16
A radio frequency detection assembly is described and which includes a radio frequency detector which detects a radio frequency emission produced by a radio frequency emitter from a given location which is remote relative to the radio frequency detector; a location assembly electrically coupled with the radio frequency detector and which is operable to estimate the location of the radio frequency emitter from the radio frequency emission which has been received; and a radio frequency transmitter electrically coupled with the radio frequency detector and the location assembly, and which transmits a radio frequency signal which reports the presence of the radio frequency emitter.
Energy Technology Data Exchange (ETDEWEB)
Doerry, Armin W.; Andrews, John
2017-05-09
The various technologies presented herein relate to incorporating one or more notches into a radar spectrum, whereby the notches relate to one or more frequencies for which no radar transmission is to occur. An instantaneous frequency is monitored and if the frequency is determined to be of a restricted frequency, then a radar signal can be modified. Modification can include replacing the signal with a signal having a different instantaneous amplitude, a different instantaneous phase, etc. The modification can occur in a WFS prior to a DAC, as well as prior to a sin ROM component and/or a cos ROM component. Further, the notch can be dithered to enable formation of a deep notch. The notch can also undergo signal transitioning to enable formation of a deep notch. The restricted frequencies can be stored in a LUT against which an instantaneous frequency can be compared.
Directory of Open Access Journals (Sweden)
Radu BOGATEANU
2009-09-01
Full Text Available The low frequency damper is an autonomous equipment for damping vibrations with the 1-20Hz range.Its autonomy enables the equipment to be located in various mechanical systems, without requiring special hydraulic installations.The low frequency damper was designed for damping the low frequency oscillations occurring in the circuit controls of the upgraded IAR-99 Aircraft.The low frequency damper is a novelty in the aerospace field ,with applicability in several areas as it can be built up in an appropriate range of dimensions meeting the requirements of different beneficiaries. On this line an equipment able to damp an extended frequency range was performed for damping oscillations in the pipes of the nuclear power plants.This damper, tested in INCAS laboratories matched the requirements of the beneficiary.The low frequency damper is patented – the patent no. 114583C1/2000 is held by INCAS.
Pion, Sébastien D S; Nana-Djeunga, Hugues C; Kamgno, Joseph; Tendongfor, Nicholas; Wanji, Samuel; Njiokou, Flobert; Prichard, Roger K; Boussinesq, Michel
2013-01-01
Ivermectin has been the keystone of onchocerciasis control for the last 25 years. Sub-optimal responses to the drug have been reported in Ghanaian communities under long-term treatment. We assessed, in two Cameroonian foci, whether the microfilaricidal and/or embryostatic effects of ivermectin on Onchocerca volvulus have been altered after several years of drug pressure. We compared the dynamics of O. volvulus skin microfilarial densities after ivermectin treatment in two cohorts with contrasting exposure to this drug: one received repeated treatment for 13 years whereas the other had no history of large-scale treatments (referred to as controls). Microfilarial densities were assessed 15, 80 and 180 days after ivermectin in 122 multiply treated and 127 ivermectin-naïve individuals. Comparisons were adjusted for individual factors related to microfilarial density: age and number of nodules. Two weeks post ivermectin, microfilarial density dropped equally (98% reduction) in the ivermectin-naïve and multiply treated groups. Between 15 and 180 days post ivermectin, the proportion of individuals with skin microfilariae doubled (from 30.8% to 67.8%) in controls and quadrupled (from 19.8% to 76.9%) in multiply treated individuals but the mean densities remained low in both sites. In fact, between 15 and 80 days, the repopulation rate was significantly higher in the multiply treated individuals than in the controls but no such difference was demonstrated when extending the follow-up to 180 days. The repopulation rate by microfilariae was associated with host factors: negatively with age and positively with the number of nodules. These observations may indicate that the worms from the multi-treated area recover mf productivity earlier but would be less productive than the worms from the ivermectin-naïve area between 80 and 180 days after ivermectin. Moreover, they do not support the operation of a strong cumulative effect of repeated treatments on the fecundity of female
Directory of Open Access Journals (Sweden)
Hakan Kum
2012-01-01
Full Text Available This study examines the validity of the purchasing power parity (PPP in Turkey for annual data from 1953 to 2009. While results from both the ADF unit root and the DF-GLS unit root test indicate mixed results, PPP holds for Turkey with the presence of structural breaks which are obtained by Zivot and Andrews and Lagrange Multiplier unit root tests.
Rector, Annabel; Bossart, Gregory D.; Ghim, Shin-je; Sundberg, John P.; Jenson, A. Bennett; Van Ranst, Marc
2004-01-01
By using an isothermal multiply primed rolling-circle amplification protocol, the complete genomic DNA of a novel papillomavirus was amplified from a skin lesion biopsy of a Florida manatee (Trichechus manatus latirostris), one of the most endangered marine mammals in United States coastal waters. The nucleotide sequence, genome organization, and phylogenetic position of the Trichechus manatus latirostris papillomavirus type 1 (TmPV-1) were determined. TmPV-1 is the first virus isolated from ...
Berekaa, Mahmoud M.; Steinbüchel, Alexander
2000-01-01
Among several bacterial species belonging to the general Gordonia, Mycobacterium, Micromonospora, Pseudomonas, and Rhodococcus, only two mycobacterial isolates, Mycobacterium fortuitum strain NF4 and the new isolate Mycobacterium ratisbonense strain SD4, which was isolated from a sewage treatment plant, were capable of utilizing the multiply branched hydrocarbon squalane (2,6,10,15,19,23-hexamethyltetracosane) and its analogous unsaturated hydrocarbon squalene as the sole carbon source for gr...
Directory of Open Access Journals (Sweden)
Komsiyah S.
2014-03-01
Full Text Available The objective in this paper is about economic dispatch problem of electric power generation where scheduling the committed generating units outputs so as to meet the required load demand at minimum operating cost, while satisfying all units and system equality and inequality constraint. In the operating of electric power system, an economic planning problem is one of variables that its must be considered since economically planning will give more efficiency in operational cost. In this paper the economic dispatch problem which has non linear cost function solved by using swarm intelligent method is Gaussian Particle Swarm Optimization (GPSO and Lagrange Multiplier. GPSO is a population-based stochastic algorithms which their moving inspired by swarm intelligent and probabilities theories. To analize its accuracy, the economic dispatch solution by GPSO method will be compared with Lagrange multiplier method. From the running test result the GPSO method give economically planning calculation which it better than Lagrange multiplier method and the GPSO method faster to getting error convergence. Therefore the GPSO method have better performance to getting global best solution than the Lagrange method.
Komsiyah, S.
2014-03-01
The objective in this paper is about economic dispatch problem of electric power generation where scheduling the committed generating units outputs so as to meet the required load demand at minimum operating cost, while satisfying all units and system equality and inequality constraint. In the operating of electric power system, an economic planning problem is one of variables that its must be considered since economically planning will give more efficiency in operational cost. In this paper the economic dispatch problem which has non linear cost function solved by using swarm intelligent method is Gaussian Particle Swarm Optimization (GPSO) and Lagrange Multiplier. GPSO is a population-based stochastic algorithms which their moving inspired by swarm intelligent and probabilities theories. To analize its accuracy, the economic dispatch solution by GPSO method will be compared with Lagrange multiplier method. From the running test result the GPSO method give economically planning calculation which it better than Lagrange multiplier method and the GPSO method faster to getting error convergence. Therefore the GPSO method have better performance to getting global best solution than the Lagrange method.
Husain, Muhammad Jami; Khondker, Bazlul Haque
2016-01-01
In Bangladesh, where tobacco use is pervasive, reducing tobacco use is economically beneficial. This paper uses the latest Bangladesh social accounting matrix (SAM) multiplier model to quantify the economy-wide impact of demand-driven changes in tobacco cultivation, bidi industries, and cigarette industries. First, we compute various income multiplier values (i.e. backward linkages) for all production activities in the economy to quantify the impact of changes in demand for the corresponding products on gross output for 86 activities, demand for 86 commodities, returns to four factors of production, and income for eight household groups. Next, we rank tobacco production activities by income multiplier values relative to other sectors. Finally, we present three hypothetical 'tobacco-free economy' scenarios by diverting demand from tobacco products into other sectors of the economy and quantifying the economy-wide impact. The simulation exercises with three different tobacco-free scenarios show that, compared to the baseline values, total sectoral output increases by 0.92%, 1.3%, and 0.75%. The corresponding increases in the total factor returns (i.e. GDP) are 1.57%, 1.75%, and 1.75%. Similarly, total household income increases by 1.40%, 1.58%, and 1.55%.
Nonlinear Frequency Compression
Scollie, Susan; Glista, Danielle; Seelisch, Andreas
2013-01-01
Frequency lowering technologies offer an alternative amplification solution for severe to profound high frequency hearing losses. While frequency lowering technologies may improve audibility of high frequency sounds, the very nature of this processing can affect the perceived sound quality. This article reports the results from two studies that investigated the impact of a nonlinear frequency compression (NFC) algorithm on perceived sound quality. In the first study, the cutoff frequency and compression ratio parameters of the NFC algorithm were varied, and their effect on the speech quality was measured subjectively with 12 normal hearing adults, 12 normal hearing children, 13 hearing impaired adults, and 9 hearing impaired children. In the second study, 12 normal hearing and 8 hearing impaired adult listeners rated the quality of speech in quiet, speech in noise, and music after processing with a different set of NFC parameters. Results showed that the cutoff frequency parameter had more impact on sound quality ratings than the compression ratio, and that the hearing impaired adults were more tolerant to increased frequency compression than normal hearing adults. No statistically significant differences were found in the sound quality ratings of speech-in-noise and music stimuli processed through various NFC settings by hearing impaired listeners. These findings suggest that there may be an acceptable range of NFC settings for hearing impaired individuals where sound quality is not adversely affected. These results may assist an Audiologist in clinical NFC hearing aid fittings for achieving a balance between high frequency audibility and sound quality. PMID:23539261
Frequency selective terahertz retroreflectors
Williams, Richard James
The use of novel optical structures operating at terahertz frequencies in industrial and military applications continues to grow. Some of these novel structures include gratings, frequency selective surfaces, metamaterials and metasurfaces, and retroreflectors. A retroreflector is a device that exhibits enhanced backscatter by concentrating the reflected wave in the direction of the source. Retroreflectors have applications in a variety of diverse fields such as aviation, radar systems, antenna technology, communications, navigation, passive identification, and metrology due to their large acceptance angles and frequency bandwidth. This thesis describes the design, fabrication, and characterization of a retroreflector designed for terahertz frequencies and the incorporation of a frequency selective surface in order to endow the retroreflector with narrow-band frequency performance. The radar cross section of several spherical lens reflectors operating at terahertz frequencies was investigated. Spherical lens reflectors with diameters ranging from 2 mm to 8 mm were fabricated from fused silica ball lenses and their radar cross section was measured at 100 GHz, 160 GHz, and 350 GHz. Crossed-dipole frequency selective surfaces exhibiting band-pass characteristics at 350 GHz fabricated from 12 um-thick Nickel screens were applied to the apertures of the spherical lens reflectors. The radar cross section of the frequency selective retroreflectors was measured at 160 GHz and 350 GHz to demonstrate proof-of-concept of narrow-band terahertz performance.
Frequency Response Analysis Tool
Energy Technology Data Exchange (ETDEWEB)
Etingov, Pavel V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kosterev, Dmitry [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dai, T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2014-12-01
Frequency response has received a lot of attention in recent years at the national level, which culminated in the development and approval of North American Electricity Reliability Corporation (NERC) BAL-003-1 Frequency Response and Frequency Bias Setting Reliability Standard. This report is prepared to describe the details of the work conducted by Pacific Northwest National Laboratory (PNNL) in collaboration with the Bonneville Power Administration and Western Electricity Coordinating Council (WECC) Joint Synchronized Information Subcommittee (JSIS) to develop a frequency response analysis tool (FRAT). The document provides the details on the methodology and main features of the FRAT. The tool manages the database of under-frequency events and calculates the frequency response baseline. Frequency response calculations are consistent with frequency response measure (FRM) in NERC BAL-003-1 for an interconnection and balancing authority. The FRAT can use both phasor measurement unit (PMU) data, where available, and supervisory control and data acquisition (SCADA) data. The tool is also capable of automatically generating NERC Frequency Response Survey (FRS) forms required by BAL-003-1 Standard.
Some properties of frequency dependent linear transformations in digital filter design
Constantinides, A. G.; Tzanettis, E.
The aim of the present study is to provide a theoretical framework from which the properties of known frequency-dependent linear transformation methods for digital filter design can be derived and further methods can be developed. The results obtained apply to all the subcases of linear transformations described in the literature, e.g., wave digital filters, and IVR and MTR transformations. It is found that the bilinear transformation used for the transition from the analog to digital domain imposes a constraint that limits the degree of freedom in the design. The constraint affects both the values of the multipliers within the filter and the simplicity of the derived structures.
Electrothermal frequency reference
Makinwa, K.A.A.; Kashmiri, S.M.
2011-01-01
An electrothermal frequency-locked loop (EFLL) circuit is described. This EFLL circuit includes an oscillator in a feedback loop. A drive circuit in the EFLL circuit generates a first signal having a fundamental frequency, and an electrothermal filter (ETF) in the EFLL circuit provides a second
Single frequency intracavity SRO
DEFF Research Database (Denmark)
Abitan, Haim; Buchhave, Preben
2000-01-01
Summary form only given. A single resonance optical parametric oscillator (SRO) is inserted intracavity to a CW high power, single frequency, and ring Nd:YVO4 laser. We obtain a stable single frequency CW SRO with output at 1.7-1.9 μm (idler) and a resonating signal at 2.3-2.6 μm. The behavior...
Magnetostatic wave oscillator frequencies
Sethares, J. C.; Stiglitz, M. R.; Weinberg, I. J.
1981-03-01
The frequencies of magnetostatic wave (MSW) oscillators employing three principal modes of propagation, surface (MSSW), forward (MSFVW), and backward (MSBVW) volume waves, have been investigated. Previous (MSW) oscillator papers dealt with MSSW. Oscillators were fabricated using LPE-YIG MSW delay lines in a feedback loop of a 2-4 GHz amplifier. Wide and narrow band transducers were employed. Oscillator frequency as a function of biasing field is in agreement with a theoretical analysis. The analysis predicts frequency in terms of material parameters, biasing field, and transducer geometry. With wide band transducers a comb of frequencies is generated. Narrow band transducers for MSSW and MSFVW select a single mode; and MSBVW selects two modes. Spurious modes, attributed to instrumentation, are more than 20 dB below the main response, and bandwidths are less than 0.005 percent. No other spurious modes are observed. MSW oscillators produce clean electronically tunable signals and appear attractive in frequency agile systems.
Microfabricated ion frequency standard
Schwindt, Peter; Biedermann, Grant; Blain, Matthew G.; Stick, Daniel L.; Serkland, Darwin K.; Olsson, III, Roy H.
2010-12-28
A microfabricated ion frequency standard (i.e. an ion clock) is disclosed with a permanently-sealed vacuum package containing a source of ytterbium (Yb) ions and an octupole ion trap. The source of Yb ions is a micro-hotplate which generates Yb atoms which are then ionized by a ultraviolet light-emitting diode or a field-emission electron source. The octupole ion trap, which confines the Yb ions, is formed from suspended electrodes on a number of stacked-up substrates. A microwave source excites a ground-state transition frequency of the Yb ions, with a frequency-doubled vertical-external-cavity laser (VECSEL) then exciting the Yb ions up to an excited state to produce fluorescent light which is used to tune the microwave source to the ground-state transition frequency, with the microwave source providing a precise frequency output for the ion clock.
Wave-number-frequency spectrum for turbulence from a random sweeping hypothesis with mean flow.
Wilczek, M; Narita, Y
2012-12-01
We derive the energy spectrum in wave-number-frequency space for turbulent flows based on Kraichnan's idealized random sweeping hypothesis with additional mean flow, which yields the instantaneous energy spectrum multiplied by a Gaussian frequency distribution. The model spectrum has two adjustable parameters, the mean flow velocity and the sweeping velocity, and has the property that the power-law index of the wave-number spectrum translates to the frequency spectrum, invariant for arbitrary choices of the mean velocity and sweeping velocity. The model spectrum incorporates both Taylor's frozen-in flow approximation and the random sweeping approximation in a natural way and can be used to distinguish between these two effects when applied to real time-resolved multipoint turbulence data. Evaluated in real space, its properties with respect to space-time velocity correlations are discussed, and a comparison to the recently introduced elliptic model is drawn.
Design and characterization of a multi-frequency bioimpedance measurement prototype
Mattia Neto, O. E.; Porto, R. W.; Aya, J. C. C.
2012-12-01
A multi-frequency bioimpedance measurement prototype is proposed, validated and characterized. It consists of an Improved Howland Current Source controlled by voltage, a load voltage sensing scheme through a discrete 3-opamp instrumentation amplifier, a phase and quadrature demodulation setup through analog multipliers, and digitization and processing of the signals using a digital benchtop multimeter. The electrical characterization of the measurement channel was done for resistive loads only, on four different circuits. Measurements were made on 10 frequencies, from 100 kHz to 1 MHz, with 10 load resistances, from 100 Ω to 1 kΩ, to obtain linearity, absolute error and frequency response. The best performance among the four circuits was a maximum absolute error of 5.55 %, and -1.93 % of load current variation at the worst case scenario.
Tsai, Tsung-Han; Zhou, Chao; Adler, Desmond C; Fujimoto, James G
2009-11-09
We demonstrate a frequency comb (FC) swept laser and a frequency comb Fourier domain mode locked (FC-FDML) laser for applications in optical coherence tomography (OCT). The fiber-based FC swept lasers operate at a sweep rate of 1kHz and 120kHz, respectively over a 135nm tuning range centered at 1310nm with average output powers of 50mW. A 25GHz free spectral range frequency comb filter in the swept lasers causes the lasers to generate a series of well defined frequency steps. The narrow bandwidth (0.015nm) of the frequency comb filter enables a approximately -1.2dB sensitivity roll off over approximately 3mm range, compared to conventional swept source and FDML lasers which have -10dB and -5dB roll offs, respectively. Measurements at very long ranges are possible with minimal sensitivity loss, however reflections from outside the principal measurement range of 0-3mm appear aliased back into the principal range. In addition, the frequency comb output from the lasers are equally spaced in frequency (linear in k-space). The filtered laser output can be used to self-clock the OCT interference signal sampling, enabling direct fast Fourier transformation of the fringe signals, without the need for fringe recalibration procedures. The design and operation principles of FC swept lasers are discussed and designs for short cavity lasers for OCT and interferometric measurement applications are proposed.
Full-degrees-of-freedom frequency based substructuring
Drozg, Armin; Čepon, Gregor; Boltežar, Miha
2018-01-01
Dividing the whole system into multiple subsystems and a separate dynamic analysis is common practice in the field of structural dynamics. The substructuring process improves the computational efficiency and enables an effective realization of the local optimization, modal updating and sensitivity analyses. This paper focuses on frequency-based substructuring methods using experimentally obtained data. An efficient substructuring process has already been demonstrated using numerically obtained frequency-response functions (FRFs). However, the experimental process suffers from several difficulties, among which, many of them are related to the rotational degrees of freedom. Thus, several attempts have been made to measure, expand or combine numerical correction methods in order to obtain a complete response model. The proposed methods have numerous limitations and are not yet generally applicable. Therefore, in this paper an alternative approach based on experimentally obtained data only, is proposed. The force-excited part of the FRF matrix is measured with piezoelectric translational and rotational direct accelerometers. The incomplete moment-excited part of the FRF matrix is expanded, based on the modal model. The proposed procedure is integrated in a Lagrange Multiplier Frequency Based Substructuring method and demonstrated on a simple beam structure, where the connection coordinates are mainly associated with the rotational degrees of freedom.
Digital Radio Frequency Memories
Hey-Shipton, Gregory L.
The Digital RF Memory (DRFM) is gradually replacing the recirculating Frequency Memory Loop (FML). The shortcomings of the FML in the area of limited storage time, single signal processing, and limited ECM capabilities are overcome by the use of the DRFM. There are several architectures for the DRFM but all of them accomplish the same basic function: to convert an incoming RF signal to a low enough frequency to allow storage in a digital memory and subsequent upconversion to the original signal frequency. Multiple signal handling capabilities on a pulse by pulse basis and software controlled ECM generation make the DRFM a powerful addition to any ECM suite.
Broadband frequency conversion
DEFF Research Database (Denmark)
Sanders, Nicolai; Jensen, Ole Bjarlin; Tidemand-Lichtenberg, Peter
We present a simple, passive and static setup for broadband frequency conversion. By using simple optical components like lenses, mirrors and gratings, we obtain the spectral angular dispersion to match the second harmonic generation phasematching angles in a nonlinear BiBO crystal. We are able...... to frequency double a single-frequency diode laser, tunable in the 1020-1090 nm range, with almost equal efficiency for all wavelengths. In the experimental setup, the width of the phasematch was increased with a factor of 50. The method can easily be extended to other wavelength ranges and nonlinear crystals...
Single frequency semiconductor lasers
Fang, Zujie; Chen, Gaoting; Qu, Ronghui
2017-01-01
This book systematically introduces the single frequency semiconductor laser, which is widely used in many vital advanced technologies, such as the laser cooling of atoms and atomic clock, high-precision measurements and spectroscopy, coherent optical communications, and advanced optical sensors. It presents both the fundamentals and characteristics of semiconductor lasers, including basic F-P structure and monolithic integrated structures; interprets laser noises and their measurements; and explains mechanisms and technologies relating to the main aspects of single frequency lasers, including external cavity lasers, frequency stabilization technologies, frequency sweeping, optical phase locked loops, and so on. It paints a clear, physical picture of related technologies and reviews new developments in the field as well. It will be a useful reference to graduate students, researchers, and engineers in the field.
Lunch frequency among adolescents
DEFF Research Database (Denmark)
Pedersen, Trine Pagh; Holstein, Bjørn E; Krølner, Rikke
2016-01-01
frequency was most common among students who were boys, 13- and 15-year-olds, from medium and low family social class, descendants of immigrants, living in a single-parent family and in a reconstructed family. School-level analyses suggested that having access to a canteen at school was associated with low......OBJECTIVE: To investigate: (i) how lunch frequency of adolescents varies between schools and between classes within schools; (ii) the associations between frequency of lunch and individual sociodemographic factors and school characteristics; and (iii) if any observed associations between lunch...... frequency and school characteristics vary by gender and age groups. DESIGN: Cross-sectional study in which students and school headmasters completed self-administered questionnaires. Associations were estimated by multilevel multivariate logistic regression. SETTING: The Danish arm of the Health Behaviour...
Zhao, Q.; Schelen, B.; Schouten, R.
2012-01-01
We have built an all-solid-state camera that is directly modulated at the pixel level for frequency-domain fluorescence lifetime imaging microscopy (FLIM) measurements. This novel camera eliminates the need for an image intensifier through the use of an application-specific charge coupled device
Quad-Chip Double-Balanced Frequency Tripler
Lin, Robert H.; Ward, John S.; Bruneau, Peter J.; Mehdi, Imran; Thomas, Bertrand C.; Maestrini, Alain
2010-01-01
Solid-state frequency multipliers are used to produce tunable broadband sources at millimeter and submillimeter wavelengths. The maximum power produced by a single chip is limited by the electrical breakdown of the semiconductor and by the thermal management properties of the chip. The solution is to split the drive power to a frequency tripler using waveguides to divide the power among four chips, then recombine the output power from the four chips back into a single waveguide. To achieve this, a waveguide branchline quadrature hybrid coupler splits a 100-GHz input signal into two paths with a 90 relative phase shift. These two paths are split again by a pair of waveguide Y-junctions. The signals from the four outputs of the Y-junctions are tripled in frequency using balanced Schottky diode frequency triplers before being recombined with another pair of Y-junctions. A final waveguide branchline quadrature hybrid coupler completes the combination. Using four chips instead of one enables using four-times higher power input, and produces a nearly four-fold power output as compared to using a single chip. The phase shifts introduced by the quadrature hybrid couplers provide isolation for the input and output waveguides, effectively eliminating standing waves between it and surrounding components. This is accomplished without introducing the high losses and expense of ferrite isolators. A practical use of this technology is to drive local oscillators as was demonstrated around 300 GHz for a heterodyne spectrometer operating in the 2-3-THz band. Heterodyne spectroscopy in this frequency band is especially valuable for astrophysics due to the presence of a very large number of molecular spectral lines. Besides high-resolution radar and spectrographic screening applications, this technology could also be useful for laboratory spectroscopy.
Hiraga, F
2015-12-01
The beam-shaping assembly for boron neutron capture therapies with a compact accelerator-driven subcritical neutron multiplier was designed so that an epithermal neutron flux of 1.9×10(9) cm(-2) s(-1) at the treatment position was generated by 5 MeV protons in a beam current of 2 mA. Changes in the atomic density of (135)Xe in the nuclear fuel due to the operation of the beam-shaping assembly were estimated. The criticality safety of the beam-shaping assembly in terms of Xe poisoning is discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
Sébastien D S Pion
Full Text Available BACKGROUND/OBJECTIVE: Ivermectin has been the keystone of onchocerciasis control for the last 25 years. Sub-optimal responses to the drug have been reported in Ghanaian communities under long-term treatment. We assessed, in two Cameroonian foci, whether the microfilaricidal and/or embryostatic effects of ivermectin on Onchocerca volvulus have been altered after several years of drug pressure. METHODS: We compared the dynamics of O. volvulus skin microfilarial densities after ivermectin treatment in two cohorts with contrasting exposure to this drug: one received repeated treatment for 13 years whereas the other had no history of large-scale treatments (referred to as controls. Microfilarial densities were assessed 15, 80 and 180 days after ivermectin in 122 multiply treated and 127 ivermectin-naïve individuals. Comparisons were adjusted for individual factors related to microfilarial density: age and number of nodules. FINDINGS: Two weeks post ivermectin, microfilarial density dropped equally (98% reduction in the ivermectin-naïve and multiply treated groups. Between 15 and 180 days post ivermectin, the proportion of individuals with skin microfilariae doubled (from 30.8% to 67.8% in controls and quadrupled (from 19.8% to 76.9% in multiply treated individuals but the mean densities remained low in both sites. In fact, between 15 and 80 days, the repopulation rate was significantly higher in the multiply treated individuals than in the controls but no such difference was demonstrated when extending the follow-up to 180 days. The repopulation rate by microfilariae was associated with host factors: negatively with age and positively with the number of nodules. CONCLUSION: These observations may indicate that the worms from the multi-treated area recover mf productivity earlier but would be less productive than the worms from the ivermectin-naïve area between 80 and 180 days after ivermectin. Moreover, they do not support the operation of a
Energy Technology Data Exchange (ETDEWEB)
Ortiz, J. F.; Grau, A.
1985-07-01
In the present paper an iterative method is applied to study the variation of dynode response in the multiplier phototube. Three different situation are considered that correspond to the following ways of electronic incidence on the first dynode: incidence of exactly one electron, incidence of exactly r electrons and incidence of an average r electrons. The responses are given for a number of steps between 1 and 5, and for values of the multiplication factor of 2.1, 2.5, 3 and 5. We study also the variance, the skewness and the excess of jurtosis for different multiplication factors. (Author) 11 refs.
DEFF Research Database (Denmark)
Bhaskar, Mahajan Sagar; Padmanaban, Sanjeevikumar; Blaabjerg, Frede
2016-01-01
In this treatise, 4Nx hybrid Non Inverting & Non Isolated (NI-NI) DC-DC interleaved multi-level boost converter (4Nx IMBC) for renewable energy applications is proposed. The proposed 4Nx IMBC is derived by coalescing the feature of 2Nx DC-DC Interleaved Multi-level Boost Converter (2Nx IMBC......), voltage-lift-switched-inductor-modified (VLSlm Cell) and Cockcroft Walton (CW) voltage multipliers. The 4Nx converter provides 4N times more conversion voltage ratio compared to conventional boost converter where N denotes the number of output stages of the 4Nx IMBC. To make renewable energy sources...
Fast fundamental frequency estimation
DEFF Research Database (Denmark)
Nielsen, Jesper Kjær; Jensen, Tobias Lindstrøm; Jensen, Jesper Rindom
2017-01-01
Modelling signals as being periodic is common in many applications. Such periodic signals can be represented by a weighted sum of sinusoids with frequencies being an integer multiple of the fundamental frequency. Due to its widespread use, numerous methods have been proposed to estimate the funda......Modelling signals as being periodic is common in many applications. Such periodic signals can be represented by a weighted sum of sinusoids with frequencies being an integer multiple of the fundamental frequency. Due to its widespread use, numerous methods have been proposed to estimate...... the fundamental frequency, and the maximum likelihood (ML) estimator is the most accurate estimator in statistical terms. When the noise is assumed to be white and Gaussian, the ML estimator is identical to the non-linear least squares (NLS) estimator. Despite being optimal in a statistical sense, the NLS...... estimator has a high computational complexity. In this paper, we propose an algorithm for lowering this complexity significantly by showing that the NLS estimator can be computed efficiently by solving two Toeplitz-plus-Hankel systems of equations and by exploiting the recursive-in-order matrix structures...
Frequency Standards and Metrology
Maleki, Lute
2009-04-01
Preface / Lute Maleki -- Symposium history / Jacques Vanier -- Symposium photos -- pt. I. Fundamental physics. Variation of fundamental constants from the big bang to atomic clocks: theory and observations (Invited) / V. V. Flambaum and J. C. Berengut. Alpha-dot or not: comparison of two single atom optical clocks (Invited) / T. Rosenband ... [et al.]. Variation of the fine-structure constant and laser cooling of atomic dysprosium (Invited) / N. A. Leefer ... [et al.]. Measurement of short range forces using cold atoms (Invited) / F. Pereira Dos Santos ... [et al.]. Atom interferometry experiments in fundamental physics (Invited) / S. W. Chiow ... [et al.]. Space science applications of frequency standards and metrology (Invited) / M. Tinto -- pt. II. Frequency & metrology. Quantum metrology with lattice-confined ultracold Sr atoms (Invited) / A. D. Ludlow ... [et al.]. LNE-SYRTE clock ensemble: new [symbol]Rb hyperfine frequency measurement - spectroscopy of [symbol]Hg optical clock transition (Invited) / M. Petersen ... [et al.]. Precise measurements of S-wave scattering phase shifts with a juggling atomic clock (Invited) / S. Gensemer ... [et al.]. Absolute frequency measurement of the [symbol] clock transition (Invited) / M. Chwalla ... [et al.]. The semiclassical stochastic-field/atom interaction problem (Invited) / J. Camparo. Phase and frequency noise metrology (Invited) / E. Rubiola ... [et al.]. Optical spectroscopy of atomic hydrogen for an improved determination of the Rydberg constant / J. L. Flowers ... [et al.] -- pt. III. Clock applications in space. Recent progress on the ACES mission (Invited) / L. Cacciapuoti and C. Salomon. The SAGAS mission (Invited) / P. Wolf. Small mercury microwave ion clock for navigation and radioScience (Invited) / J. D. Prestage ... [et al.]. Astro-comb: revolutionizing precision spectroscopy in astrophysics (Invited) / C. E. Kramer ... [et al.]. High frequency very long baseline interferometry: frequency standards and
Sanchez, Aniel; Perez-Riverol, Yasset; González, Luis Javier; Noda, Jesus; Betancourt, Lazaro; Ramos, Yassel; Gil, Jeovanis; Vera, Roberto; Padrón, Gabriel; Besada, Vladimir
2010-10-15
Edman degradation in the gas phase has been observed by collision activated dissociation of N-terminal phenylthiocarbamoyl (PTC) protonated peptide to yield abundant complementary b₁ and y(n-1) ion pairs. Here, we demonstrated the relation between the observed losses of aniline and/or the entire PTC derivatizing group with the availability of mobile protons using electrospray ionization mass spectrometry. In order to select the peptides with more efficient fragmentation, while simplifying the mixture of peptides, we extend the phenylisotiocyanate (PITC) derivatization of amino groups to the selective isolation of multiply charged peptides (those having the number of arginines and histidines residues higher than one) using a procedure previously developed in our group. Thus, it was possible to identify in the filtered protein database the sequence of the isolated multiply charged peptides derived from a single protein and a complex mixture of proteins extracted from Escherichia coli using only the molecular mass and the N-terminal amino acid information. For this purpose, we developed a novel bioinformatic tool for automatic identification of peptides from liquid chromatography-tandem mass spectrometry (LC-MS/MS) experiments, which potentially can be used in high-throughput proteomics.
High frequency electromagnetic dosimetry
Sánchez-Hernández, David A
2009-01-01
Along with the growth of RF and microwave technology applications, there is a mounting concern about the possible adverse effects over human health from electromagnetic radiation. Addressing this issue and putting it into perspective, this groundbreaking resource provides critical details on the latest advances in high frequency electromagnetic dosimetry.
Frequency scanning microstrip antennas
DEFF Research Database (Denmark)
Danielsen, Magnus; Jørgensen, Rolf
1979-01-01
The principles of using radiating microstrip resonators as elements in a frequency scanning antenna array are described. The resonators are cascade-coupled. This gives a scan of the main lobe due to the phase-shift in the resonator in addition to that created by the transmission line phase...
Metamaterial for Radar Frequencies
2012-09-01
capacitive coupling with adjacent patches, as shown in Figure 3. The via provides inductance to ground. Figure 3. (a) Planar LH distributed periodic...After [20]). The capacitance in the structure balances out the inductance present when the cylinder is placed in a square array. The metallic... RADAR FREQUENCIES by Szu Hau Tan September 2012 Thesis Advisor: David C. Jenn Second Reader: James Calusdian
Frequency of orthodontic extraction
Dardengo, Camila de S.; Fernandes, Luciana Q. P.; Capelli, Jonas
2016-01-01
Introduction: The option of dental extraction for orthodontic purposes has been debated for more than 100 years, including periods when it was widely used in treatment, including the present, during which other methods are used to avoid dental extractions. The objective was to analyze the frequency of tooth extraction treatment performed between 1980 and 2011 at the Orthodontic Clinic of Universidade Estadual do Rio de Janeiro (UERJ). Material and Methods: The clinical records of 1484 patients undergoing orthodontic treatment were evaluated. The frequency of extractions was evaluated with regard to sex, Angle's classification, the different combinations of extractions and the period when orthodontic treatment began. Chi-square test was used to determine correlations between variables, while the chi-square test for trends was used to assess the frequency of extractions over the years. Results: There was a reduction of approximately 20% in the frequency of cases treated with tooth extraction over the last 32 years. The most frequently extracted teeth were first premolars. Patients with Class I malocclusion showed fewer extractions, while Class II patients underwent a higher number of extraction treatment. There were no statistically significant differences with regard to sex. Conclusion: New features introduced into the orthodontic clinic and new esthetic concepts contributed to reducing the number of cases treated with dental extractions. However, dental extractions for orthodontic purposes are still well indicated in certain cases. PMID:27007762
Microminiature radio frequency transmitter for communication and tracking applications
Crutcher, Richard I.; Emery, Mike S.; Falter, Kelly G.; Nowlin, C. H.; Rochelle, Jim M.; Clonts, Lloyd G.
1997-02-01
A micro-miniature radio frequency (rf) transmitter has been developed and demonstrated by the Oak Ridge National Laboratory. The objective of the rf transmitter development was to maximize the transmission distance while drastically shrinking the overall transmitter size, including antenna. Based on analysis and testing, an application-specific integrated circuit (ASIC) with a 16-GHz gallium arsenide (GaAs) oscillator and integrated on-chip antenna was designed and fabricated using microwave monolithic integrated circuit (MMIC) technology. Details of the development and the results of various field tests are discussed. The rf transmitter is applicable to covert surveillance and tracking scenarios due to its small size of 2.2 multiplied by 2.2 mm, including the antenna. Additionally, the 16-GHz frequency is well above the operational range of consumer-grade radio scanners, providing a degree of protection from unauthorized interception. Variations of the transmitter design have been demonstrated for tracking and tagging beacons, transmission of digital data, and transmission of real-time analog video from a surveillance camera. Preliminary laboratory measurements indicate adaptability to direct-sequence spread-spectrum transmission, providing a low probability of intercept and/or detection. Concepts related to law enforcement applications are presented.
Silveira, Vladímir de Aquino; Souza, Givago da Silva; Gomes, Bruno Duarte; Rodrigues, Anderson Raiol; Silveira, Luiz Carlos de Lima
2014-01-01
We used psychometric functions to estimate the joint entropy for space discrimination and spatial frequency discrimination. Space discrimination was taken as discrimination of spatial extent. Seven subjects were tested. Gábor functions comprising unidimensionalsinusoidal gratings (0.4, 2, and 10 cpd) and bidimensionalGaussian envelopes (1°) were used as reference stimuli. The experiment comprised the comparison between reference and test stimulithat differed in grating's spatial frequency or envelope's standard deviation. We tested 21 different envelope's standard deviations around the reference standard deviation to study spatial extent discrimination and 19 different grating's spatial frequencies around the reference spatial frequency to study spatial frequency discrimination. Two series of psychometric functions were obtained for 2%, 5%, 10%, and 100% stimulus contrast. The psychometric function data points for spatial extent discrimination or spatial frequency discrimination were fitted with Gaussian functions using the least square method, and the spatial extent and spatial frequency entropies were estimated from the standard deviation of these Gaussian functions. Then, joint entropy was obtained by multiplying the square root of space extent entropy times the spatial frequency entropy. We compared our results to the theoretical minimum for unidimensional Gábor functions, 1/4π or 0.0796. At low and intermediate spatial frequencies and high contrasts, joint entropy reached levels below the theoretical minimum, suggesting non-linear interactions between two or more visual mechanisms. We concluded that non-linear interactions of visual pathways, such as the M and P pathways, could explain joint entropy values below the theoretical minimum at low and intermediate spatial frequencies and high contrasts. These non-linear interactions might be at work at intermediate and high contrasts at all spatial frequencies once there was a substantial decrease in joint
Multi-frequency local wavenumber analysis and ply correlation of delamination damage.
Juarez, Peter D; Leckey, Cara A C
2015-09-01
Wavenumber domain analysis through use of scanning laser Doppler vibrometry has been shown to be effective for non-contact inspection of damage in composites. Qualitative and semi-quantitative local wavenumber analysis of realistic delamination damage and quantitative analysis of idealized damage scenarios (Teflon inserts) have been performed previously in the literature. This paper presents a new methodology based on multi-frequency local wavenumber analysis for quantitative assessment of multi-ply delamination damage in carbon fiber reinforced polymer (CFRP) composite specimens. The methodology is presented and applied to a real world damage scenario (impact damage in an aerospace CFRP composite). The methodology yields delamination size and also correlates local wavenumber results from multiple excitation frequencies to theoretical dispersion curves in order to robustly determine the delamination ply depth. Results from the wavenumber based technique are validated against a traditional nondestructive evaluation method. Published by Elsevier B.V.
Chen, Xilun; Wang, Xiangchuan; Pan, Shilong
2017-03-01
An implementation of a distance measurement system using double-sideband with suppressed carrier modulation (DSB-SC) frequency scanning interferometry is proposed to reduce the variations in the optical path and improve the measurement accuracy. In this proposed system, the electro-optic DSB-SC is used to create dual-swept signals with opposite scanning directions. For each swept signal, the relative distance between the reference arm and the measuring arm is determined by the beat frequency of signals from two arms. By multiplying both beat signals, measurement errors caused by variations in the optical path can be greatly reduced. As an experimental demonstration, a vibration was introduced in the optical path length. The experimental results show that the variations can be suppressed for over 19.9 dB.
Low frequency phase signal measurement with high frequency squeezing
Zhai, Zehui; Gao, Jiangrui
2011-01-01
We calculate the utility of high-frequency squeezed-state enhanced two-frequency interferometry for low-frequency phase measurement. To use the high-frequency sidebands of the squeezed light, a two-frequency intense laser is used in the interferometry instead of a single-frequency laser as usual. We find that the readout signal can be contaminated by the high-frequency phase vibration, but this is easy to check and avoid. A proof-of-principle experiment is in the reach of modern quantum optic...
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.
Vortices at Microwave Frequencies
Silva, Enrico; Pompeo, Nicola; Dobrovolskiy, Oleksandr V.
2017-11-01
The behavior of vortices at microwave frequencies is an extremely useful source of information on the microscopic parameters that enter the description of the vortex dynamics. This feature has acquired particular relevance since the discovery of unusual superconductors, such as cuprates. Microwave investigation then extended its field of application to many families of superconductors, including the artificially nanostructured materials. It is then important to understand the basics of the physics of vortices moving at high frequency, as well as to understand what information the experiments can yield (and what they can not). The aim of this brief review is to introduce the readers to some basic aspects of the physics of vortices under a microwave electromagnetic field, and to guide them to an understanding of the experiment, also by means of the illustration of some relevant results.
Breakfast frequency among adolescents
DEFF Research Database (Denmark)
Pedersen, Trine Pagh; Holstein, Bjørn E; Damsgaard, Mogens Trab
2016-01-01
, quality of family communication and family support. Further, analyses suggested that the associations were more pronounced among girls, immigrants and adolescents from other family structure than traditional. The study highlights the importance of the family setting in promoting regular breakfast......OBJECTIVE: To investigate (i) associations between adolescents' frequency of breakfast and family functioning (close relations to parents, quality of family communication and family support) and (ii) if any observed associations between breakfast frequency and family functioning vary...... by sociodemographic factors. DESIGN: School-based cross-sectional study. Students completed a web-based questionnaire. Associations were estimated by multilevel multivariate logistic regression. SETTING: Danish arm of the Health Behaviour in School-aged Children study, 2014. SUBJECTS: Adolescents aged 13 and 15 years...
Frequency steerable acoustic transducers
Senesi, Matteo
Structural health monitoring (SHM) is an active research area devoted to the assessment of the structural integrity of critical components of aerospace, civil and mechanical systems. Guided wave methods have been proposed for SHM of plate-like structures using permanently attached piezoelectric transducers, which generate and sense waves to evaluate the presence of damage. Effective interrogation of structural health is often facilitated by sensors and actuators with the ability to perform electronic, i.e. phased array, scanning. The objective of this research is to design an innovative directional piezoelectric transducer to be employed for the localization of broadband acoustic events, or for the generation of Lamb waves for active interrogation of structural health. The proposed Frequency Steerable Acoustic Transducers (FSATs) are characterized by a spatial arrangement of active material which leads to directional characteristics varying with frequency. Thus FSATs can be employed both for directional sensing and generation of guided waves without relying on phasing and control of a large number of channels. The analytical expression of the shape of the FSATs is obtained through a theoretical formulation for continuously distributed active material as part of a shaped piezoelectric device. The FSAT configurations analyzed in this work are a quadrilateral array and a geometry which corresponds to a spiral in the wavenumber domain. The quadrilateral array is experimentally validated, confirming the concept of frequency-dependent directionality. Its limited directivity is improved by the Wavenumber Spiral FSAT (WS-FSAT), which, instead, is characterized by a continuous frequency dependent directionality. Preliminary validations of the WS-FSAT, using a laser doppler vibrometer, are followed by the implementation of the WS-FSAT as a properly shaped piezo transducer. The prototype is first used for localization of acoustic broadband sources. Signal processing
Radio Frequency Spectrum Management
1980-03-01
limits, emmission standards, etc., cover many pages. Other available non-technical policy statements are of the motherhood-and-apple-pie ilk. Further...and 2) by allowing the onscene commander who is acutely aware of the radio frequency emmission environment in his area to make assignments. The author...need for investment in specific human capi- tal vice on the job experience, it will never eliminate it. Rather vice education and training in