Blandino, Rémi; Barbieri, Marco; Etesse, Jean; Grangier, Philippe; Tualle-Brouri, Rosa
2012-01-01
We show that the maximum transmission distance of continuous-variable quantum key distribution in presence of a Gaussian noisy lossy channel can be arbitrarily increased using a linear noiseless amplifier. We explicitly consider a protocol using amplitude and phase modulated coherent states with reverse reconciliation. We find that a noiseless amplifier with amplitude gain g can increase the maximum admissible losses by a factor 1/g^2.
Blandino, Rémi; Etesse, Jean; Grangier, Philippe [Laboratoire Charles Fabry, Institut d' Optique, CNRS, Université Paris-Sud, 2 avenue Augustin Fresnel, 91127 Palaiseau Cedex (France); Leverrier, Anthony [Institute for Theoretical Physics, ETH Zurich, 8093 Zurich, Switzerland and INRIA Paris-Rocquencourt, 78153 Le Chesnay Cedex (France); Barbieri, Marco [Laboratoire Charles Fabry, Institut d' Optique, CNRS, Université Paris-Sud, 2 avenue Augustin Fresnel, 91127 Palaiseau Cedex, France and Clarendon Laboratory, Department of Physics, University of Oxford, OX1 3PU (United Kingdom); Tualle-Brouri, Rosa [Laboratoire Charles Fabry, Institut d' Optique, CNRS, Université Paris-Sud, 2 avenue Augustin Fresnel, 91127 Palaiseau Cedex, France and Institut Universitaire de France, 103 boulevard St. Michel, 75005, Paris (France)
2014-12-04
We show that the maximum transmission distance of continuous-variable quantum key distribution in presence of a Gaussian noisy lossy channel can be arbitrarily increased using a heralded noiseless linear amplifier. We explicitly consider a protocol using amplitude and phase modulated coherent states with reverse reconciliation. Assuming that the secret key rate drops to zero for a line transmittance T{sub lim}, we find that a noiseless amplifier with amplitude gain g can improve this value to T{sub lim}/g{sup 2}, corresponding to an increase in distance proportional to log g. We also show that the tolerance against noise is increased.
Alderson, Tim L.; Svenja Huntemann
2013-01-01
Singleton-type upper bounds on the minimum Lee distance of general (not necessarily linear) Lee codes over ℤq are discussed. Two bounds known for linear codes are shown to also hold in the general case, and several new bounds are established. Codes meeting these bounds are investigated and in some cases characterised.
Maximum likelihood estimates of pairwise rearrangement distances.
Serdoz, Stuart; Egri-Nagy, Attila; Sumner, Jeremy; Holland, Barbara R; Jarvis, Peter D; Tanaka, Mark M; Francis, Andrew R
2017-06-21
Accurate estimation of evolutionary distances between taxa is important for many phylogenetic reconstruction methods. Distances can be estimated using a range of different evolutionary models, from single nucleotide polymorphisms to large-scale genome rearrangements. Corresponding corrections for genome rearrangement distances fall into 3 categories: Empirical computational studies, Bayesian/MCMC approaches, and combinatorial approaches. Here, we introduce a maximum likelihood estimator for the inversion distance between a pair of genomes, using a group-theoretic approach to modelling inversions introduced recently. This MLE functions as a corrected distance: in particular, we show that because of the way sequences of inversions interact with each other, it is quite possible for minimal distance and MLE distance to differently order the distances of two genomes from a third. The second aspect tackles the problem of accounting for the symmetries of circular arrangements. While, generally, a frame of reference is locked, and all computation made accordingly, this work incorporates the action of the dihedral group so that distance estimates are free from any a priori frame of reference. The philosophy of accounting for symmetries can be applied to any existing correction method, for which examples are offered. Copyright © 2017 Elsevier Ltd. All rights reserved.
李凤娥
2012-01-01
对磁共振无线电能传输系统的最大传输距离问题进行了电路模型研究,先描述了与最大传输距离密切相关的频率分裂现象,进而定义了频率分裂方程、脊方程、谷方程,随后利用脊方程确定了系统的频率分裂临界点,频率分裂临界点对应的传输距离就是系统的最大传输距离.探讨了系统最大传输距离与系统关键参数的关系.最后,利用文献中已有的实验数据,对上述理论进行了实验验证.%Circuit analysis is employed to investigate the maximum transfer distance problem in magnetic resonance wireless power transmission systems. It is described firstly the frequency splitting phenomena that are closely related to the maximum transfer distance problem. Next, the splitting equation, the ridge equation and the trough equation are defined, and the critical splitting point is found through the ridge equation. The maximum transfer distance is uniquely determined by the critical splitting point, and the relationship between the maximum transfer distance and the key system parameters is elucidated. Finally, above theory is validated by the experimental data from the literature.
Predicting species' maximum dispersal distances from simple plant traits.
Tamme, Riin; Götzenberger, Lars; Zobel, Martin; Bullock, James M; Hooftman, Danny A P; Kaasik, Ants; Pärtel, Meelis
2014-02-01
Many studies have shown plant species' dispersal distances to be strongly related to life-history traits, but how well different traits can predict dispersal distances is not yet known. We used cross-validation techniques and a global data set (576 plant species) to measure the predictive power of simple plant traits to estimate species' maximum dispersal distances. Including dispersal syndrome (wind, animal, ant, ballistic, and no special syndrome), growth form (tree, shrub, herb), seed mass, seed release height, and terminal velocity in different combinations as explanatory variables we constructed models to explain variation in measured maximum dispersal distances and evaluated their power to predict maximum dispersal distances. Predictions are more accurate, but also limited to a particular set of species, if data on more specific traits, such as terminal velocity, are available. The best model (R2 = 0.60) included dispersal syndrome, growth form, and terminal velocity as fixed effects. Reasonable predictions of maximum dispersal distance (R2 = 0.53) are also possible when using only the simplest and most commonly measured traits; dispersal syndrome and growth form together with species taxonomy data. We provide a function (dispeRsal) to be run in the software package R. This enables researchers to estimate maximum dispersal distances with confidence intervals for plant species using measured traits as predictors. Easily obtainable trait data, such as dispersal syndrome (inferred from seed morphology) and growth form, enable predictions to be made for a large number of species.
Covariance of maximum likelihood evolutionary distances between sequences aligned pairwise.
Dessimoz, Christophe; Gil, Manuel
2008-06-23
The estimation of a distance between two biological sequences is a fundamental process in molecular evolution. It is usually performed by maximum likelihood (ML) on characters aligned either pairwise or jointly in a multiple sequence alignment (MSA). Estimators for the covariance of pairs from an MSA are known, but we are not aware of any solution for cases of pairs aligned independently. In large-scale analyses, it may be too costly to compute MSAs every time distances must be compared, and therefore a covariance estimator for distances estimated from pairs aligned independently is desirable. Knowledge of covariances improves any process that compares or combines distances, such as in generalized least-squares phylogenetic tree building, orthology inference, or lateral gene transfer detection. In this paper, we introduce an estimator for the covariance of distances from sequences aligned pairwise. Its performance is analyzed through extensive Monte Carlo simulations, and compared to the well-known variance estimator of ML distances. Our covariance estimator can be used together with the ML variance estimator to form covariance matrices. The estimator performs similarly to the ML variance estimator. In particular, it shows no sign of bias when sequence divergence is below 150 PAM units (i.e. above ~29% expected sequence identity). Above that distance, the covariances tend to be underestimated, but then ML variances are also underestimated.
Long distance electron transmission in marine sediment
Risgaard-Petersen, Nils; Nielsen, Lars Peter
processes leads to formation of electrical fields, which modifies ion transport. The local proton producing and proton consuming half reactions induces pH extremes that accelerate dissolution of iron sul-phides and calcium carbonates in anoxic layers and promotes the formation of Mg-calcite and iron oxides...... in the oxic zone. Oxygen seems to be the major electron acceptor in the coupled system, and more than 40% of the oxygen consumption can be driven by long distance electron transmission. The major e-donor is sulfide, which is oxidized to sulfate, and iron sulphides are the major sources for sulfide...
On the Threshold of Maximum-Distance Separable Codes
Kindarji, Bruno; Chabanne, Hervé
2010-01-01
Starting from a practical use of Reed-Solomon codes in a cryptographic scheme published in Indocrypt'09, this paper deals with the threshold of linear $q$-ary error-correcting codes. The security of this scheme is based on the intractability of polynomial reconstruction when there is too much noise in the vector. Our approach switches from this paradigm to an Information Theoretical point of view: is there a class of elements that are so far away from the code that the list size is always superpolynomial? Or, dually speaking, is Maximum-Likelihood decoding almost surely impossible? We relate this issue to the decoding threshold of a code, and show that when the minimal distance of the code is high enough, the threshold effect is very sharp. In a second part, we explicit lower-bounds on the threshold of Maximum-Distance Separable codes such as Reed-Solomon codes, and compute the threshold for the toy example that motivates this study.
Distance Protection of Cross-Bonded Transmission Cable-Systems
Bak, Claus Leth; F. Jensen, Christian
2014-01-01
In this paper the problems of protecting a cross-bonded cable system using distance protection are analysed. The combination of the desire to expand the high voltage transmission grid and the public's opinion towards new installations of overhead lines (OHL), more and more transmission cable syst...
Technology for extending transmission distance of EPON system
Li ZHANG; Deming LIU; Cbuanbao ZHANG; Guangsbeng WU
2009-01-01
At present, the maximal transmission distance between the optical line terminal (OLT) and opticalnetwork unit (ONU) of an Ethemet passive optical network (EPON) system is 20 km.However, this distance should be extended to 50 km or even longer in some applications such as fiber to the village (FTTV).A method for extending the transmission distance of an EPON system is proposed in this paper, in which the optical power amplifier and the adjustment of dynamic bandwidth allocation (DBA) are the key technologies.
Separation distance and static transmission error of involute spur gears
Tse, David K.; Lin, Hsiang H.
1992-01-01
The effects of separation distance and deflection of gear teeth on the static transmission error of involute spur gears are investigated. In this paper, only low-contact-ratio gears with true involute profile are studied. Gear ratio and tooth addendum are varied to examine their effects on the separation distance and static transmission error. Results obtained from the investigation shows that the contact ratio and static transmission error are affected significantly if considering the separation distance. In general, the magnitude of contact ratio has been increased and the variation of static transmission error has been smoothed. The most significant change occurs for a gear pair with a theoretical contact ratio close to 1.95.
Separation distance and static transmission error of involute spur gears
Tse, David K.; Lin, Hsiang H.
1992-07-01
The effects of separation distance and deflection of gear teeth on the static transmission error of involute spur gears are investigated. In this paper, only low-contact-ratio gears with true involute profile are studied. Gear ratio and tooth addendum are varied to examine their effects on the separation distance and static transmission error. Results obtained from the investigation shows that the contact ratio and static transmission error are affected significantly if considering the separation distance. In general, the magnitude of contact ratio has been increased and the variation of static transmission error has been smoothed. The most significant change occurs for a gear pair with a theoretical contact ratio close to 1.95.
Long distance transmission of diagnostic cardiovascular information.
Caldwell, M A; Miles, R; Barrington, W
1996-01-01
Availability of advanced cardiac diagnostic procedures has proven to decrease the morbidity and mortality associated with common cardiovascular diseases. It was requested that the University of Nebraska Medical Center (UNMC) provide a rural hospital with advanced cardiology services. The services included monitoring of inpatients and rapid interpretation of cardiac diagnostic tests. UNMC proposed to solve this problem by building a computer-based system to transmit diagnostic cardiac information from a rural hospital to UNMC for interpretation by a cardiologist. The information transmitted to UNMC was grouped into two categories: 1) cardiovascular ultrasound, 2) ambulatory and 12-lead electrocardiograms. The information consisted of digital and analog waveform information, static images, and 30 fps video. The system provided rapid data transmission to UNMC over a T-1 line. The system utilized a compression technology which did not degrade the interpretation quality of the data. This system has increased the availability of advanced cardiac diagnostic services to general medical practitioners in a rural hospital. In addition, the system has significantly reduced the time and cost to transmit vital cardiac diagnostic information, thus improving the quality of care received by rural patients.
Long distance transmission through distributed erbium-doped fibers
Rottwitt, Karsten; Povlsen, Jørn Hedegaard; Bjarklev, Anders Overgaard
1993-01-01
High bit rate, all-optical long-distance transmission could be created through the combined use of loss-compensating gain in erbium-doped fibers and solitons. A detailed analysis of the distributed erbium-doped fiber, including the spectral-gain dependency, is combined with an optimum design...... of the transmission fiber and general bit-error-rate calculations. Changes in wavenumber, group velocity, and fiber dispersion due to erbium doping in a single-mode fiber are evaluated, and a reduction in bit-error rates due to the erbium spectral-gain profile is shown. Transmission through distributed erbium...
Effect of Distance on Light Transmission Through Polymerized Resin Composite.
Aromaa, M K; Lassila, L V J; Vallittu, P K
2017-09-01
Light transmittance of dental composites varies between products and shades, but also light curing units differ to each other in their irradiance and fiber optic structure of curing tip. The aim of this study was to investigate whether there is linear relationship between the distance of the curing tip to the resin composite and irradiance at lower surface of the resin composite. Disks of 1 mm thickness (6mm diameter) were fabricated. Light transmittance (intensity) through the disk was measured at distance of 0, 2, 4, 6, 8, 10 mm from the light tip with two light curing units Elipar S10 (3M-ESPE) and Silverlight (GC). Irradiance ratio (irradiance on the sensor surface without the composite disk / with the composite disk) was calculated and plotted against the distance of the light curing tip. Statistical analysis was carried out using analysis of covariance (ANCOVA, Tukey's, α =0.05). Irradiance ratio varied between 18% to 24% with Silverlight and 21% to 26% with Elipar S10 light curing units. There were statistically significant differences between the ratios with different distances of the light curing tip (p⟨0.05). Interestingly, the highest irradiance ratio for Elipar S10 unit was found with 4 mm distance of the tip, whereas Silverlight unit had the highest ratio with 6 mm distance. Out of two tested resin composites, the flowable composite showed higher irradiance ratio than regular packable resin composite. Increase of distance of the light curing tip from the composite surface decreased the absolute irradiance underneath of composite, as expected. However, there seemed to be device dependent optimal distance of 4-6 mm to reach the most efficient irradiance ratio through the composite resin keeping in mind that most efficient transmission of light through the material is reached by having light curing tip in contact to the material. Copyright© 2017 Dennis Barber Ltd.
Relationship Between Maximum Aerobic Speed Performance and Distance Covered in Rugby Union Games.
Swaby, Rick; Jones, Paul A; Comfort, Paul
2016-10-01
Swaby, R, Jones, PA, and Comfort, P. Relationship between maximum aerobic speed performance and distance covered in rugby union games. J Strength Cond Res 30(10): 2788-2793, 2016-Researchers have shown a clear relationship between aerobic fitness and the distance covered in professional soccer, although no research has identified such a relationship in rugby union. Therefore, the aim of the study was to identify whether there was a relationship between maximal aerobic speed (MAS) and the distance covered in rugby union games. Fourteen professional rugby union players (age = 26 ± 6 years, height = 1.90 ± 0.12 m, mass = 107.1 ± 24.1 kg) participated in this investigation. Each player performed a MAS test on 3 separate occasions during the preseason, to determine reliability and provide baseline data, and participated in 6 competitive games during the early stages of the season. Game data were collected using global positioning system technology. No significant difference (p > 0.05) in total distance covered was observed between games. Relationships between players' MAS and the average distance covered from 6 competitive games were explored using Pearson's correlation coefficients, with MAS performance showing a strong relationship with distance covered during match play (r = 0.746, p aerobic fitness to increase the distance that the athlete covers in the game.
Self-reported maximum walking distance in persons with MS may affect the EDSS.
Berger, Warren; Payne, Michael W C; Morrow, Sarah A
2017-08-15
In persons with MS (PwMS), the Expanded Disability Status Scale (EDSS) is used to monitor disability progression. Scores between 4.0 and 7.0 are determined by maximum walking distance. Self-estimation of this value is often employed in clinic settings. To examine the accuracy with which PwMS estimate their walking distance, and observe subsequent changes to the EDSS. This prospective cohort study recruited PwMS with previously recorded EDSS of 3.5-7.0. Participants estimated their maximum walking distance and then walked as far as they could along a pre-specified course. Each distance was converted to an EDSS score, the "estimated EDSS" and the "actual EDSS". Chi-Square analysis was used to compare EDSS scores. Logistic regression was used to determine predictors of inaccurate estimations. Of the 66 PwMS in this study, 43.9% had a difference in the actual EDSS compared to the estimated EDSS. Median estimated EDSS was 4.75 (range 3.0-7.0); after walking assessment, median actual EDSS was 5.0 (range 3.0-7.0), which represented a significant difference [X(2) (df 64, N=66)=206.9; pEDSS decreased in 9 PwMS (13.6%) and increased in 20 PwMS (30.3%). Logistic regression did not find any demographic/disease characteristic to be predictive of this discrepancy. Some PwMS do not accurately estimate maximum walking distance; only 56.1% of PwMS accurately estimated their actual EDSS. Copyright © 2017 Elsevier B.V. All rights reserved.
Two-dimensional maximum local variation based on image euclidean distance for face recognition.
Gao, Quanxue; Gao, Feifei; Zhang, Hailin; Hao, Xiu-Juan; Wang, Xiaogang
2013-10-01
Manifold learning concerns the local manifold structure of high dimensional data, and many related algorithms are developed to improve image classification performance. None of them, however, consider both the relationships among pixels in images and the geometrical properties of various images during learning the reduced space. In this paper, we propose a linear approach, called two-dimensional maximum local variation (2DMLV), for face recognition. In 2DMLV, we encode the relationships among pixels in images using the image Euclidean distance instead of conventional Euclidean distance in estimating the variation of values of images, and then incorporate the local variation, which characterizes the diversity of images and discriminating information, into the objective function of dimensionality reduction. Extensive experiments demonstrate the effectiveness of our approach.
Long distance transmission of bulk power: the EHV-UHV DC challenge
Clerici, A.; Valtorta, G.
1994-12-31
This paper deals with technical and economical analysis of transmission of powers in the range from 1000 to 5000 MW and distances included between 1000 to 4000 km. The advantages of adoption of UHV DC transmission are evident especially for the longest distances and the largest power levels considered. (author) 4 refs., 9 figs.
Applying the maximum information principle to cell transmission model of tra-ffic flow
刘喜敏; 卢守峰
2013-01-01
This paper integrates the maximum information principle with the Cell Transmission Model (CTM) to formulate the velo-city distribution evolution of vehicle traffic flow. The proposed discrete traffic kinetic model uses the cell transmission model to cal-culate the macroscopic variables of the vehicle transmission, and the maximum information principle to examine the velocity distri-bution in each cell. The velocity distribution based on maximum information principle is solved by the Lagrange multiplier method. The advantage of the proposed model is that it can simultaneously calculate the hydrodynamic variables and velocity distribution at the cell level. An example shows how the proposed model works. The proposed model is a hybrid traffic simulation model, which can be used to understand the self-organization phenomena in traffic flows and predict the traffic evolution.
Mansoureh Haj Mohammad Hosseini
2011-04-01
Full Text Available In this paper, a bi-objective mathematical model for emergency services location-allocation problem on a tree network considering maximum distance constraint is presented. The first objective function called centdian is a weighted mean of a minisum and a minimax criterion and the second one is a maximal covering criterion. For the solution of the bi-objective optimization problem, the problem is split in two sub problems: the selection of the best set of locations, and a demand assignment problem to evaluate each selection of locations. We propose a heuristic algorithm to characterize the efficient location point set on the network. Finally, some numerical examples are presented to illustrate the effectiveness of the proposed algorithms.
NONE
1997-06-01
The bibliography contains citations concerning the design, development, and evaluation of superconducting cables and power transmission lines for long distance energy transmission. Topics include methods of cryogenic refrigeration and electrical insulation, fabrication and development of niobium alloy conductors, energy loss analysis, and dielectric design of superconducting power transmission systems. Government research reports on superconducting technology for electric power transmission and distribution are also reviewed.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)
Innovative air vessel design for long distance transmission pipelines
Leruth, P.; Pothof, I.W.M.
2012-01-01
The Shuweihat Water Transmission Scheme (SWTS, UAE) consists of a twin DN1600 DI PN25 pipeline transmitting 150 MIGD over 250 km from Shuweihat Desalination plant to Mussafah (Abu Dhabi city). The Scheme is divided in two subsequent systems, each with a tank farm and a pump station delivering water
Singh, Surinder
2010-05-01
In this article, the pulse restoration of different fibers is compared to obtain the optimum fiber. The dispersion-compensated fiber, having a high ability for pulse restoration, is optimized to reduce the self-phase modulation effect by taking the effective core area of the fiber. Then the optimized dispersion-compensated fibers are used in wavelength division multiplex transmission to increase the maximum distance of transmission. Here, 16 channels with a channel spacing of 200 GHz are modulated by an optical LiNbO3 phase modulator with non-return-to-zero format and transmitted over 1,050 km by using dispersion-compensated fibers with an effective core area of 30 pm2 and erbium-doped fiber amplifiers. The adequate quality factor and output power of different channels are observed at 70 km, 350 km, and 1,050 km. As the distance is increased, the quality factor falls.
Innovative air vessel design for long distance transmission pipelines
Leruth, P.; Pothof, I. W. M.
2012-01-01
The Shuweihat Water Transmission Scheme (SWTS, UAE) consists of a twin DN1600 DI PN25 pipeline transmitting 150 MIGD over 250 km from Shuweihat Desalination plant to Mussafah (Abu Dhabi city). The Scheme is divided in two subsequent systems, each with a tank farm and a pump station delivering water to downstream terminal reservoirs and direct consumers. The first system (Lot A) transmits water from Shuweihat to Mirfa (100 km). The second (Lot C) is from Mirfa to Mussafah (150 km). The pipelin...
Jat, Prahlad; Serre, Marc L
2016-12-01
Widespread contamination of surface water chloride is an emerging environmental concern. Consequently accurate and cost-effective methods are needed to estimate chloride along all river miles of potentially contaminated watersheds. Here we introduce a Bayesian Maximum Entropy (BME) space/time geostatistical estimation framework that uses river distances, and we compare it with Euclidean BME to estimate surface water chloride from 2005 to 2014 in the Gunpowder-Patapsco, Severn, and Patuxent subbasins in Maryland. River BME improves the cross-validation R(2) by 23.67% over Euclidean BME, and river BME maps are significantly different than Euclidean BME maps, indicating that it is important to use river BME maps to assess water quality impairment. The river BME maps of chloride concentration show wide contamination throughout Baltimore and Columbia-Ellicott cities, the disappearance of a clean buffer separating these two large urban areas, and the emergence of multiple localized pockets of contamination in surrounding areas. The number of impaired river miles increased by 0.55% per year in 2005-2009 and by 1.23% per year in 2011-2014, corresponding to a marked acceleration of the rate of impairment. Our results support the need for control measures and increased monitoring of unassessed river miles.
Optimum Projection Angle for Attaining Maximum Distance in a Rugby Place Kick
Nicholas P. Linthorne
2014-03-01
Full Text Available This study investigated the effect of projection angle on the distance attained in a rugby place kick. A male rugby player performed 49 maximum-effort kicks using projection angles of between 20 and 50°. The kicks were recorded by a video camera at 50 Hz and a 2 D biomechanical analysis was conducted to obtain measures of the projection velocity and projection angle of the ball. The player’s optimum projection angle was calculated by substituting a mathematical expression for the relationship between projection velocity and projection angle into the equations for the aerodynamic flight of a rugby ball. We found that the player’s calculated optimum projection angle (30.6°, 95% confidence limits ± 1.9° was in close agreement with his preferred projection angle (mean value 30.8°, 95% confidence limits ± 2.1°. The player’s calculated optimum projection angle was also similar to projection angles previously reported for skilled rugby players. The optimum projection angle in a rugby place kick is considerably less than 45° because the projection velocity that a player can produce decreases substantially as projection angle is increased. Aerodynamic forces and the requirement to clear the crossbar have little effect on the optimum projection angle.
Finite Element Analysis of the Maximum Stress at the Joints of the Transmission Tower
Itam, Zarina; Beddu, Salmia; Liyana Mohd Kamal, Nur; Bamashmos, Khaled H.
2016-03-01
Transmission towers are tall structures, usually a steel lattice tower, used to support an overhead power line. Usually, transmission towers are analyzed as frame-truss systems and the members are assumed to be pin-connected without explicitly considering the effects of joints on the tower behavior. In this research, an engineering example of joint will be analyzed with the consideration of the joint detailing to investigate how it will affect the tower analysis. A static analysis using STAAD Pro was conducted to indicate the joint with the maximum stress. This joint will then be explicitly analyzed in ANSYS using the Finite Element Method. Three approaches were used in the software which are the simple plate model, bonded contact with no bolts, and beam element bolts. Results from the joint analysis show that stress values increased with joint details consideration. This proves that joints and connections play an important role in the distribution of stress within the transmission tower.
The distribution of pairwise genetic distances: a tool for investigating disease transmission.
Worby, Colin J; Chang, Hsiao-Han; Hanage, William P; Lipsitch, Marc
2014-12-01
Whole-genome sequencing of pathogens has recently been used to investigate disease outbreaks and is likely to play a growing role in real-time epidemiological studies. Methods to analyze high-resolution genomic data in this context are still lacking, and inferring transmission dynamics from such data typically requires many assumptions. While recent studies have proposed methods to infer who infected whom based on genetic distance between isolates from different individuals, the link between epidemiological relationship and genetic distance is still not well understood. In this study, we investigated the distribution of pairwise genetic distances between samples taken from infected hosts during an outbreak. We proposed an analytically tractable approximation to this distribution, which provides a framework to evaluate the likelihood of particular transmission routes. Our method accounts for the transmission of a genetically diverse inoculum, a possibility overlooked in most analyses. We demonstrated that our approximation can provide a robust estimation of the posterior probability of transmission routes in an outbreak and may be used to rule out transmission events at a particular probability threshold. We applied our method to data collected during an outbreak of methicillin-resistant Staphylococcus aureus, ruling out several potential transmission links. Our study sheds light on the accumulation of mutations in a pathogen during an epidemic and provides tools to investigate transmission dynamics, avoiding the intensive computation necessary in many existing methods.
Maximum Likelihood Timing and Carrier Synchronization in Burst-Mode Satellite Transmissions
Morelli Michele
2007-01-01
Full Text Available This paper investigates the joint maximum likelihood (ML estimation of the carrier frequency offset, timing error, and carrier phase in burst-mode satellite transmissions over an AWGN channel. The synchronization process is assisted by a training sequence appended in front of each burst and composed of alternating binary symbols. The use of this particular pilot pattern results into an estimation algorithm of affordable complexity that operates in a decoupled fashion. In particular, the frequency offset is measured first and independently of the other parameters. Timing and phase estimates are subsequently computed through simple closed-form expressions. The performance of the proposed scheme is investigated by computer simulation and compared with Cramer-Rao bounds. It turns out that the estimation accuracy is very close to the theoretical limits up to relatively low signal-to-noise ratios. This makes the algorithm well suited for turbo-coded transmissions operating near the Shannon limit.
Maximum Likelihood Timing and Carrier Synchronization in Burst-Mode Satellite Transmissions
Michele Morelli
2007-06-01
Full Text Available This paper investigates the joint maximum likelihood (ML estimation of the carrier frequency offset, timing error, and carrier phase in burst-mode satellite transmissions over an AWGN channel. The synchronization process is assisted by a training sequence appended in front of each burst and composed of alternating binary symbols. The use of this particular pilot pattern results into an estimation algorithm of affordable complexity that operates in a decoupled fashion. In particular, the frequency offset is measured first and independently of the other parameters. Timing and phase estimates are subsequently computed through simple closed-form expressions. The performance of the proposed scheme is investigated by computer simulation and compared with Cramer-Rao bounds. It turns out that the estimation accuracy is very close to the theoretical limits up to relatively low signal-to-noise ratios. This makes the algorithm well suited for turbo-coded transmissions operating near the Shannon limit.
Estimating infectious disease transmission distances using the overall distribution of cases.
Salje, Henrik; Cummings, Derek A T; Lessler, Justin
2016-12-01
The average spatial distance between transmission-linked cases is a fundamental property of infectious disease dispersal. However, the distance between a case and their infector is rarely measurable. Contact-tracing investigations are resource intensive or even impossible, particularly when only a subset of cases are detected. Here, we developed an approach that uses onset dates, the generation time distribution and location information to estimate the mean transmission distance. We tested our method using outbreak simulations. We then applied it to the 2001 foot-and-mouth outbreak in Cumbria, UK, and compared our results to contact-tracing activities. In simulations with a true mean distance of 106m, the average mean distance estimated was 109m when cases were fully observed (95% range of 71-142). Estimates remained consistent with the true mean distance when only five percent of cases were observed, (average estimate of 128m, 95% range 87-165). Estimates were robust to spatial heterogeneity in the underlying population. We estimated that both the mean and the standard deviation of the transmission distance during the 2001 foot-and-mouth outbreak was 8.9km (95% CI: 8.4km-9.7km). Contact-tracing activities found similar values of 6.3km (5.2km-7.4km) and 11.2km (9.5km-12.8km), respectively. We were also able to capture the drop in mean transmission distance over the course of the outbreak. Our approach is applicable across diseases, robust to under-reporting and can inform interventions and surveillance.
Optical fiber cable for transmission of high power laser energy over great distances
Zediker, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Moxley, Joel F.; Koblick, Yeshaya
2016-05-24
There is provided a system and apparatus for the transmission of high power laser energy over great distances without substantial power loss and without the presence of stimulated Raman scattering. There is further provided systems and optical fiber cable configurations and optical fiber structures for the delivering high power laser energy over great distances to a tool or surface to perform an operation or work with the tool or upon the surface.
Optical fiber cable for transmission of high power laser energy over great distances
Zediker, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Moxley, Joel F.; Koblick, Yeshaya
2016-05-24
There is provided a system and apparatus for the transmission of high power laser energy over great distances without substantial power loss and without the presence of stimulated Raman scattering. There is further provided systems and optical fiber cable configurations and optical fiber structures for the delivering high power laser energy over great distances to a tool or surface to perform an operation or work with the tool or upon the surface.
Fundamental design of a distributed erbium-doped fiber amplifier for long-distance transmission
Rottwitt, Karsten; Bjarklev, Anders Overgaard; Povlsen, Jørn Hedegaard;
1992-01-01
Comprehensive theoretical analysis on the design of a distributed erbium-doped fiber amplifier for long-distance transmission has been carried out, using a highly accurate model. The dispersion of the optical fiber as a function of the numerical aperture and the cutoff wavelength is included...
Andrey A. Toropov
2001-06-01
Full Text Available The enthalpy of formation of a set of 60 hydroarbons is calculated on the basis of topological descriptors defined from the distance and detour matrices within the realm of the QSAR/QSPR theory. Linear and non-linear polynomials fittings are made and results show the need to resort to higher-order regression equations in order to get better concordances between theoretical results and experimental available data. Besides, topological indices computed from maximum order distances seems to yield rather satisfactory predictions of heats of formation for hydrocarbons.
Alvah C. Stahlnecker IV
2008-12-01
Full Text Available A percentage of either measured or predicted maximum heart rate is commonly used to prescribe and measure exercise intensity. However, maximum heart rate in athletes may be greater during competition or training than during laboratory exercise testing. Thus, the aim of the present investigation was to determine if endurance-trained runners train and compete at or above laboratory measures of 'maximum' heart rate. Maximum heart rates were measured utilising a treadmill graded exercise test (GXT in a laboratory setting using 10 female and 10 male National Collegiate Athletic Association (NCAA division 2 cross-country and distance event track athletes. Maximum training and competition heart rates were measured during a high-intensity interval training day (TR HR and during competition (COMP HR at an NCAA meet. TR HR (207 ± 5.0 b·min-1; means ± SEM and COMP HR (206 ± 4 b·min-1 were significantly (p < 0.05 higher than maximum heart rates obtained during the GXT (194 ± 2 b·min-1. The heart rate at the ventilatory threshold measured in the laboratory occurred at 83.3 ± 2.5% of the heart rate at VO2 max with no differences between the men and women. However, the heart rate at the ventilatory threshold measured in the laboratory was only 77% of the maximal COMP HR or TR HR. In order to optimize training-induced adaptation, training intensity for NCAA division 2 distance event runners should not be based on laboratory assessment of maximum heart rate, but instead on maximum heart rate obtained either during training or during competition
Analysis of the 5 iron golf swing when hitting for maximum distance.
Healy, Aoife; Moran, Kieran A; Dickson, Jane; Hurley, Cillian; Smeaton, Alan F; O'Connor, Noel E; Kelly, Philip; Haahr, Mads; Chockalingam, Nachiappan
2011-07-01
Most previous research on golf swing mechanics has focused on the driver club. The aim of this study was to identify the kinematic factors that contribute to greater hitting distance when using the 5 iron club. Three-dimensional marker coordinate data were collected (250 Hz) to calculate joint kinematics at eight key swing events, while a swing analyser measured club swing and ball launch characteristics. Thirty male participants were assigned to one of two groups, based on their ball launch speed (high: 52.9 ± 2.1 m · s(-1); low: 39.9 ± 5.2 m · s(-1)). Statistical analyses were used to identify variables that differed significantly between the two groups. Results showed significant differences were evident between the two groups for club face impact point and a number of joint angles and angular velocities, with greater shoulder flexion and less left shoulder internal rotation in the backswing, greater extension angular velocity in both shoulders at early downswing, greater left shoulder adduction angular velocity at ball contact, greater hip joint movement and X Factor angle during the downswing, and greater left elbow extension early in the downswing appearing to contribute to greater hitting distance with the 5 iron club.
The SN 1006 Remnant Optical Proper Motions, Deep Imaging, Distance, and Brightness at Maximum
Winkler, P F; Long, K S; Gupta, Gaurav; Long, Knox S.
2002-01-01
We report the first measurement of proper motions in the SN1006 remnant (G327.6+14.6) based entirely on digital images. CCD images from three epochs spanning a period of 11 years are used: 1987 from Las Campanas, and 1991 and 1998 from CTIO. Measuring the shift of delicate Balmer filaments along the northwest rim of the remnant, we obtain proper motions of 280 +/- 8 mas/yr along the entire length where the filaments are well defined, with little systematic variation along the filaments. We also report very deep Halpha imaging observations of the entire remnant that clearly show very faint emission surrounding almost the entire shell, as well as some diffuse emission regions in the (projected) interior. Combining the proper motion measurement with a recent measurement of the shock velocity based on spectra of the same filaments by Ghavamian et al. leads to a distance of 2.17 +/- 0.08 kpc to SN1006. Several lines of argument suggest that SN1006 was a Type Ia event, so the improved distance measurement can be co...
Optical fiber configurations for transmission of laser energy over great distances
Rinzler, Charles C; Zediker, Mark S
2013-10-29
There are provided optical fiber configurations that provide for the delivery of laser energy, and in particular, the transmission and delivery of high power laser energy over great distances. These configurations further are hardened to protect the optical fibers from the stresses and conditions of an intended application. The configurations provide means for determining the additional fiber length (AFL) need to obtain the benefits of such additional fiber, while avoiding bending losses.
Optical fiber configurations for transmission of laser energy over great distances
Rinzler, Charles C; Zediker, Mark S
2014-11-04
There are provided optical fiber configurations that provide for the delivery of laser energy, and in particular, the transmission and delivery of high power laser energy over great distances. These configurations further are hardened to protect the optical fibers from the stresses and conditions of an intended application. The configurations provide means for determining the additional fiber length (AFL) need to obtain the benefits of such additional fiber, while avoiding bending losses.
Efficient utilization of wind power: Long-distance transmission or local consumption?
Sun, Yuanzhang; Ma, Xiyuan; Xu, Jian; Bao, Yi; Liao, Siyang
2017-09-01
Excess wind power produced in wind-intensive areas is normally delivered to remote load centers via long-distance transmission lines. This paper presents a comparison between long-distance transmission, which has gained popularity, and local energy consumption, in which a fraction of the generated wind power can be locally consumed by energy-intensive industries. First, the challenges and solutions to the long-distance transmission and local consumption of wind power are presented. Then, the two approaches to the utilization of wind power are compared in terms of system security, reliability, cost, and capability to utilize wind energy. Finally, the economic feasibility and technical feasibility of the local consumption of wind power are demonstrated by a large and isolated industrial power system, or supermicrogrid, in China. The coal-fired generators together with the short-term interruptible electrolytic aluminum load in the supermicrogrid are able to compensate for the intermittency of wind power. In the long term, the transfer of high-energy-consumption industries to wind-rich areas and their local consumption of the available wind power are beneficial.
Radtke, U. [PreussenElektra AG, Hannover (Germany)
1998-12-31
High-voltage DC transmission is a world-wide established technology for low-cost transmission of large amounts of electricity over long distances. Thanks to HVDC transmission, large amounts of electricity can now for the first time also be transmitted over long distances via ocean cable, something that cannot be done with AC power cables. HVDC transmission is independent of grid frequencies and can link grids of different frequency and different quality of frequency. Interconnected grids coupled via DC circuits can exploit additional technical and economic advantages such as mutual supply of power reserves, balancing of peak load, and modulation of active and reactive power. (orig.) [Deutsch] Die Hochspannungs-Gleichstromuebertragung (HGUe) ist eine weltweit etablierte Technik zur kostenguenstigen Uebertragung grosser elektrischer Leistungen ueber grosse Entfernungen. Sie schafft erstmals die Moeglichkeit, auch mittels Seekabel grosse Leistungen ueber Entfernungen zu uebertragen, die mit der Drehstromtechnik nicht moeglich sind. HGUeist unabhaengig von den Netzfrequenzen und kann Netze unterschiedlicher Frequenz und Frequenzguete miteinander verbinden. Ueber Gleichstromkreise gekuppelte Verbundnetze koennen zusaetzliche technische und wirtschaftliche Vorteile wie gegenseitige Bereitstellung von Kraftwerksreserven, Spitzenlastausgleich sowie Wirk- und Blindleistungsmodulation nutzt. (orig.)
Åse Helen Garseth
Full Text Available The extent and effect of disease interaction and pathogen exchange between wild and farmed fish populations is an ongoing debate and an area of research that is difficult to explore. The objective of this study was to investigate pathogen transmission between farmed and wild Atlantic salmon (Salmo salar L. populations in Norway by means of molecular epidemiology. Piscine reovirus (PRV was selected as the model organism as it is widely distributed in both farmed and wild Atlantic salmon in Norway, and because infection not necessarily will lead to mortality through development of disease. A matrix comprised of PRV protein coding sequences S1, S2 and S4 from wild, hatchery-reared and farmed Atlantic salmon in addition to one sea-trout (Salmo trutta L. was examined. Phylogenetic analyses based on maximum likelihood and Bayesian inference indicate long distance transport of PRV and exchange of virus between populations. The results are discussed in the context of Atlantic salmon ecology and the structure of the Norwegian salmon industry. We conclude that the lack of a geographical pattern in the phylogenetic trees is caused by extensive exchange of PRV. In addition, the detailed topography of the trees indicates long distance transportation of PRV. Through its size, structure and infection status, the Atlantic salmon farming industry has the capacity to play a central role in both long distance transportation and transmission of pathogens. Despite extensive migration, wild salmon probably play a minor role as they are fewer in numbers, appear at lower densities and are less likely to be infected. An open question is the relationship between the PRV sequences found in marine fish and those originating from salmon.
Molburg, J. C.; Kavicky, J. A.; Picel, K. C.
2008-03-03
This report focuses on transmission lines, which operate at voltages of 115 kV and higher. Currently, the highest voltage lines comprising the North American power grid are at 765 kV. The grid is the network of transmission lines that interconnect most large power plants on the North American continent. One transmission line at this high voltage was built near Chicago as part of the interconnection for three large nuclear power plants southwest of the city. Lines at this voltage also serve markets in New York and New England, also very high demand regions. The large power transfers along the West Coast are generally at 230 or 500 kV. Just as there are practical limits to centralization of power production, there are practical limits to increasing line voltage. As voltage increases, the height of the supporting towers, the size of the insulators, the distance between conductors on a tower, and even the width of the right-of-way (ROW) required increase. These design features safely isolate the electric power, which has an increasing tendency to arc to ground as the voltage (or electrical potential) increases. In addition, very high voltages (345 kV and above) are subject to corona losses. These losses are a result of ionization of the atmosphere, and can amount to several megawatts of wasted power. Furthermore, they are a local nuisance to radio transmission and can produce a noticeable hum. Centralized power production has advantages of economies of scale and special resource availability (for instance, hydro resources), but centralized power requires long-distance transfers of power both to reach customers and to provide interconnections for reliability. Long distances are most economically served at high voltages, which require large-scale equipment and impose a substantial footprint on the corridors through which power passes. The most visible components of the transmission system are the conductors that provide paths for the power and the towers that keep these
Study on long distance transmission technique of weak photocurrent signal in laser gas sensor
Liming Wang; Yujun Zhang; Hongbin Li; Yi Zhou; Kun You; Ying He; Wenqing Liu
2012-01-01
The continuous monitoring of H2S gas concentration is a common problem in natural gas desulfurization process technology.Tunable diode laser absorption spectroscopy (TDLAS) is a preferred technology for continuous monitoring of gas in industrial sites,because of its high selectivity,high sensitivity,and fast response.We discuss the technical solutions of on-line monitoring of H2S in natural gas desulfurization process technology based on TDLAS,and study the security design of monitoring system in inflammable and explosive areas.We also design a weak photocurrent signal converting circuit and perform experiments on transmission characteristics of different distances.The signal-to-noise ratio (SNR) of laser absorption spectrum does not decrease after the 1 500-m transmission.The detection limit is 300 ppb.The system can be operated stably and reliably,and satisfies the need for continuous monitoring of the H2S in natural gas desulfurization process.
Sakata, Tadashi; Yamamoto, Kazuo; Sekioka, Shozo; Yokoyama, Shigeru
We examined the lightning frequency reported by Eriksson and the lightning current distribution shown in IEC 62305-1. The lightning striking coefficient is assumed to be related to height of structures. The lightning current distribution to ground which was applicable to the electro-geometric model is estimated. Using the assumption of lightning striking distance coefficient and the estimated lightning current distribution, we calculated the lightning frequency and the lightning current distribution, concerning lightning shielding effect in transmission lines. The calculation results of the lightning frequency and the lightning current distributions were compared with the observation results, and agree satisfactorily with them.
Risgaard-Petersen, Nils; Nielsen, Lars Peter
sulfide oxidation leads to electric field formation, sulfide depletion and acidification of the upper centimeters of the sediment. This promoted ion migration and dissolution of carbonates and iron sulfides. Sulfide released from iron sulfides was the major e-donor in the system. Ferrous iron released...... from iron sulfides was to a large extend deposited in the oxic zone as iron oxides and Ca2+ eventually precipitates at the surface as due to high pH caused by cathodic oxygen reduction. The result show how long distance electron transmission allows oxygen to drive the allocation of important minerals...
Artificial Neural Network-Based Fault Distance Locator for Double-Circuit Transmission Lines
Anamika Jain
2013-01-01
Full Text Available This paper analyses two different approaches of fault distance location in a double circuit transmission lines, using artificial neural networks. The single and modular artificial neural networks were developed for determining the fault distance location under varying types of faults in both the circuits. The proposed method uses the voltages and currents signals available at only the local end of the line. The model of the example power system is developed using Matlab/Simulink software. Effects of variations in power system parameters, for example, fault inception angle, CT saturation, source strength, its X/R ratios, fault resistance, fault type and distance to fault have been investigated extensively on the performance of the neural network based protection scheme (for all ten faults in both the circuits. Additionally, the effects of network changes: namely, double circuit operation and single circuit operation, have also been considered. Thus, the present work considers the entire range of possible operating conditions, which has not been reported earlier. The comparative results of single and modular neural network indicate that the modular approach gives correct fault location with better accuracy. It is adaptive to variation in power system parameters, network changes and works successfully under a variety of operating conditions.
Benhabib, S; Duan, J; Wu, X; Cardan, R; Shen, S; Huang, M; Popple, R; Brezovich, I [UniversityAlabama Birmingham, Birmingham, AL (United Kingdom)
2014-06-01
Purpose: The dosimetric effect of the treatment couch is non-negligible in today's radiotherapy treatment. To accurately include couch in dose calculation, we investigated the dependence of couch transmission factors on field size and couch-isocenter distance. Methods: Couch transmission factors for Varian Exact Couch were determined by taking the ratios of ionization of a posterior-anterior beam with and without the couch in the beam path. Measurements were performed at the isocenter using a PTW cylindrical ionization chamber (Model 31030) with an Aluminum buildup cap of 1.1 cm thick for the 6 MV photon beam. Ionization readings for beam sizes ranging from 2 × 2 cm2 to 40 × 40 cm2 were taken. Transmission factors for couch-isocenter distances ranging from 3 cm to 20 cm were also investigated. Results: The couch transmission factors increased with the field size approximately in an exponential manner. For the field sizes that we tested, the transmission factor ranged from 0.976 to 0.992 for couch-isocenter distance of 3 cm. The transmission factor was also monotonically dependent on couch-isocenter separation distance, but in a lighter magnitude. For the tested couch heights, the transmission factor ranged from 0.974 – 0.972 for 2 × 2 cm2 field size and 0.992 – 0.986 for 40 × 40 cm2 field size. The dependence on couch-isocenter distance is stronger for larger field size. Conclusions: The transmission factor of a radiotherapy treatment couch increases with field size of the radiation beam and its distance from the isocenter. Such characterization of the couch transmission factor helps improve the accuracy of couch modeling for radiotherapy treatment planning.
DFT based spatial multiplexing and maximum ratio transmission for mm-wawe large MIMO
Phan-Huy, D.-T.; Tölli, A.; Rajatheva, N.;
2014-01-01
By using large point-to-point multiple input multiple output (MIMO), spatial multiplexing of a large number of data streams in wireless communications using millimeter-waves (mm-waves) can be achieved. However, according to the antenna spacing and transmitter-receiver distance, the MIMO channel...
Notaguchi, Michitaka; Abe, Mitsutomo; Kimura, Takahiro; Daimon, Yasufumi; Kobayashi, Toshinori; Yamaguchi, Ayako; Tomita, Yuki; Dohi, Koji; Mori, Masashi; Araki, Takashi
2008-11-01
Day length perceived by a leaf is a major environmental factor that controls the timing of flowering. It has been believed that a mobile, long-distance signal called florigen is produced in the leaf under inductive day length conditions, and is transported to the shoot apex where it triggers floral morphogenesis. Grafting experiments have shown that florigen is transmissible from a donor plant that has been subjected to inductive day length to an uninduced recipient plant. However, the nature of florigen has long remained elusive. Arabidopsis FLOWERING LOCUS T (FT) is expressed in cotyledons and leaves in response to inductive long days (LDs). FT protein, with a basic region/leucine zipper (bZIP) transcription factor FD, acts in the shoot apex to induce target meristem identity genes such as APETALA1 (AP1) and initiates floral morphogenesis. Recent studies have provided evidence that the FT protein in Arabidopsis and corresponding proteins in other species are an important part of florigen. Our work shows that the FT activity, either from overexpressing or inducible transgenes or from the endogenous gene, to promote flowering is transmissible through a graft junction, and that an FT protein with a T7 tag is transported from a donor scion to the apical region of recipient stock plants and becomes detectable within a day or two. The sequence and structure of mRNA are not of critical importance for the long-distance action of the FT gene. These observations led to the conclusion that the FT protein, but not mRNA, is the essential component of florigen.
Air quality and climate benefits of long-distance electricity transmission in China
Peng, Wei; Yuan, Jiahai; Zhao, Yu; Lin, Meiyun; Zhang, Qiang; Victor, David G.; Mauzerall, Denise L.
2017-06-01
China is the world’s top carbon emitter and suffers from severe air pollution. It has recently made commitments to improve air quality and to peak its CO2 emissions by 2030. We examine one strategy that can potentially address both issues—utilizing long-distance electricity transmission to bring renewable power to the polluted eastern provinces. Based on an integrated assessment using state-of-the-science atmospheric modeling and recent epidemiological evidence, we find that transmitting a hybrid of renewable (60%) and coal power (40%) (Hybrid-by-wire) reduces 16% more national air-pollution-associated deaths and decreases three times more carbon emissions than transmitting only coal-based electricity. Moreover, although we find that transmitting coal power (Coal-by-Wire, CbW) is slightly more effective at reducing air pollution impacts than replacing old coal power plants with newer cleaner ones in the east (Coal-by-Rail, CbR) (CbW achieves a 6% greater reduction in national total air-pollution-related mortalities than CbR), both coal scenarios have approximately the same carbon emissions. We thus demonstrate that coordinating transmission planning with renewable energy deployment is critical to maximize both local air quality benefits and global climate benefits.
Lawrence, K E; Summers, S R; Heath, A C G; McFadden, A M J; Pulford, D J; Pomroy, W E
2016-07-15
The tick-borne haemoparasite Theileria orientalis is the most important infectious cause of anaemia in New Zealand cattle. Since 2012 a previously unrecorded type, T. orientalis type 2 (Ikeda), has been associated with disease outbreaks of anaemia, lethargy, jaundice and deaths on over 1000 New Zealand cattle farms, with most of the affected farms found in the upper North Island. The aim of this study was to model the relative environmental suitability for T. orientalis transmission throughout New Zealand, to predict the proportion of cattle farms potentially suitable for active T. orientalis infection by region, island and the whole of New Zealand and to estimate the average relative environmental suitability per farm by region, island and the whole of New Zealand. The relative environmental suitability for T. orientalis transmission was estimated using the Maxent (maximum entropy) modelling program. The Maxent model predicted that 99% of North Island cattle farms (n=36,257), 64% South Island cattle farms (n=15,542) and 89% of New Zealand cattle farms overall (n=51,799) could potentially be suitable for T. orientalis transmission. The average relative environmental suitability of T. orientalis transmission at the farm level was 0.34 in the North Island, 0.02 in the South Island and 0.24 overall. The study showed that the potential spatial distribution of T. orientalis environmental suitability was much greater than presumed in the early part of the Theileria associated bovine anaemia (TABA) epidemic. Maximum entropy offers a computer efficient method of modelling the probability of habitat suitability for an arthropod vectored disease. This model could help estimate the boundaries of the endemically stable and endemically unstable areas for T. orientalis transmission within New Zealand and be of considerable value in informing practitioner and farmer biosecurity decisions in these respective areas.
Potential benefits of long-distance electricity transmission in China for air quality and climate
Peng, W.; Mauzerall, D. L.; Yuan, J.; Zhao, Y.; Lin, M.; Zhang, Q.
2015-12-01
China is expanding west-to-east long-distance electricity transmission capacity with the aim of reducing eastern coal power production and resulting air pollution. In addition to coal power, this new grid capacity can be used to transport renewable-generated electricity with resulting climate co-benefits. Here we use an integrated assessment to evaluate the air quality and climate benefits of twelve proposed transmission lines in China, and compare two energy-by-wire strategies that transmit 1) only coal power (Coal-by-wire, CbW) or 2) combined renewable plus coal power (Renewable and coal-by-wire, (RE+C)bW), with 3) the current practice of transporting coal by rail for conversion to electricity near eastern demand centers (Coal-by-rail, CbR). Based on a regional atmospheric chemistry model, WRF-Chem, electricity transmission through the proposed lines leads to 2-3 μg/m3 (2-7%) reduction in the annual mean concentrations of fine particulate matter (PM2.5) in the eastern provinces relative to 2010 levels, roughly ~1 μg/m3 greater than the reduction achieved in CbR where dirty coal units are locally replaced with efficient ones. Although the eastern air quality improvement is similar irrespective of the fuel source to power the lines, adding coal generation results in up to 3% increase in annual mean PM2.5 levels in some exporting provinces, whereas such increase is not observed when most added capacity is renewable-based. Counting both the economic value of reduced carbon emissions and the health-related air quality benefits can significantly improve the cost-effectiveness of transmitting both renewable and coal power. Comparing (RE+C)bW with the two coal-based options, we find not only 20% larger reduction in air-pollution-related deaths, but also three times greater reduction in CO2 emissions. Our study hence demonstrates the significance of coordinating renewable energy planning with transmission planning to simultaneously tackle air pollution and climate
Khairuzzaman, Md; Zhang, Chao; Igarashi, Koji; Katoh, Kazuhiro; Kikuchi, Kazuro
2010-03-01
We describe a successful introduction of maximum-likelihood-sequence estimation (MLSE) into digital coherent receivers together with finite-impulse response (FIR) filters in order to equalize both linear and nonlinear fiber impairments. The MLSE equalizer based on the Viterbi algorithm is implemented in the offline digital signal processing (DSP) core. We transmit 20-Gbit/s quadrature phase-shift keying (QPSK) signals through a 200-km-long standard single-mode fiber. The bit-error rate performance shows that the MLSE equalizer outperforms the conventional adaptive FIR filter, especially when nonlinear impairments are predominant.
Cherevatskiy, Stanislav; Troester, Eckehard [Energynautics GmbH, Langen (Germany)
2012-07-01
In the past few years a significant growth of the number of photovoltaic (PV) systems has been observed worldwide and particularly in Europe. Increasing maturity of this technology and growing manufacturing capacities have led to a considerable decline in prices. Looking at a future possible development of installed PV capacities in Europe, the paper at hand investigates how well the available PV energy is made use of when the installed capacity of PV reaches nearly 2000 gigawatt-peak (GWp). A methodology is presented that aims at optimal placement of PV plants taking into consideration region-specific irradiation conditions in Europe and restrictions imposed by the transmission network. Additionally, a mehtod for optimized placement and dimensioning of storage systems along with their best possible operation strategy is applied for assessment of the effect on PV utilization. (orig.)
Takemura, Shunsuke; Kobayashi, Manabu; Yoshimoto, Kazuo
2016-10-01
Frequency-dependent model of the apparent radiation pattern has been extensively incorporated into engineering and scientific applications for high-frequency seismic waves, but distance-dependent properties have not yet been fully taken into account. We investigated the unified characteristics of frequency and distance dependences in both apparent P- and S-wave radiation patterns during local crustal earthquakes. Observed distortions of the apparent P- and S-wave radiation patterns could be simply modeled by using a function of the normalized hypocentral distance, which is a product of the wave number and hypocentral distance. This behavior suggests that major cause of distortion of the apparent radiation pattern is seismic wave scattering and diffraction within the heterogeneous crust. On the basis of observed normalized hypocentral distance dependency, we proposed a method for prediction of spatial distributions of maximum P- and S-wave amplitudes. Our method incorporating normalized hypocentral distance dependence of the apparent radiation pattern reproduced the observed spatial distributions of maximum P- and S-wave amplitudes over a wide frequency and distance ranges successfully.[Figure not available: see fulltext.
Kato, Mitsuro [Department of Macromolecular Science and Engineering, Graduate School of Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Kyoto 606-8585 (Japan); Research and Development Department, Nitto Analytical Techno-Center Co., Ltd., 1-1-2, Shimohozumi, Ibaraki-city, Osaka 567-8680 (Japan); Kawase, Noboru [Research and Development Department, Nitto Analytical Techno-Center Co., Ltd., 1-1-2, Shimohozumi, Ibaraki-city, Osaka 567-8680 (Japan); Kaneko, Takeshi [Department of Macromolecular Science and Engineering, Graduate School of Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Kyoto 606-8585 (Japan); Toh, Shoichi; Matsumura, Syo [Research Laboratory of High-Voltage Electron Microscope, Kyushu University, 6-10-1, Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Jinnai, Hiroshi [Department of Macromolecular Science and Engineering, Graduate School of Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Kyoto 606-8585 (Japan)], E-mail: hjinnai@kit.ac.jp
2008-02-15
In our recent study, the complete rotation of a rod-shaped specimen during transmission electron microscopy (TEM) has been successfully carried out, yielding a truly quantitative three-dimensional (3D) structure of a ZrO{sub 2}/polymer nano-composite. This result allows the further development of transmission electron microtomography (TEMT) for materials science. The diameter of the rod-shaped specimen was about 150 nm, which may not be statistically large enough to evaluate structural parameters, e.g., volume fraction of Zr nano-particles. Thus, it is preferable to image rods with larger diameters in 3D. In this study, several rod-shaped specimens whose diameters ranged from 150 to 530 nm were subjected to the 'distortion-free TEMT'. The maximum diameters, l, observable under 200 and 300 kV-TEMTs were, respectively, 460-470 and 600-670 nm (corresponding the maximum relative diameters, l/{lambda} ({lambda}: mean free path), were ca. 2.2 and 2.7-3.0)
UHF Passive RFID标签最大阅读距离的研究%Study on maximum reading distance of UHF Passive RFID tag
谢晶晶; 赵东东
2012-01-01
特定的RFID阅读器与标签之间的最大阅读距离是衡量标签性能的一个重要因素.首先介绍了RFID工作原理,同时介绍本文所要研究的无源UHF RFID系统.在前向链路方向,根据福利斯空间公式推出标签最大阅读距离的理论公式,并且用MATLAB软件仿真了功率传输系数、标签工作频率与阅读距离之间的关系,然后分析得到了后向链路方向阅读器所能接收到的反向散射能量的公式,通过代入实际数据证实了最大阅读距离公式的理论上的可靠性.在此基础上,搭建一个实际的测量最大距离的实验平台,从而通过实际试验验证推出的理论计算公式的准确性程度的确是比较高的,最后又根据推导出来的的最大阅读距离公式,从标签和阅读器2个方面分析了影响最大阅读距离的因素和提高最大阅读距离的方法.研究对象是超高频(UHF) (902～928 MHz)的无源RFID系统,阅读器与标签的天线都是线极化单天线.%The maximum read distance is an important factor to mfaiurp the performance of the tag. The principle of the RFID system is introduced, then the principle of the passive UHF RFID system is given. In the direction of the forward link,the theoretical maximum reading distance formula is derived according to the Friis formula. Then the relation between the power transmitting coefficient and the maximum reading distance and the relation between the working frequency and the maximum reading distance are simulated using MATLAB. Then the reverse scattering power formula which the reader can get is derived,and the theoretical reliability of the maximum reading range is verified according to the substitution of the practical data. On the basis of it,a experiment platform is built to measure the practical maximum reading distance, then the distinction between the theoretical maximum reading distance and the practical maximum reading distance is small, so the practical reliability of
Klofai, Yerima [Department of Physics, Higher Teacher Training College, University of Maroua, PO Box 46 Maroua (Cameroon); Essimbi, B Z [Department of Physics, Faculty of Science, University of Yaounde 1, PO Box 812 Yaounde (Cameroon); Jaeger, D, E-mail: bessimb@yahoo.fr [ZHO, Optoelectronik, Universitaet Duisburg-Essen, D-47048 Duisburg (Germany)
2011-10-15
Pulse propagation on high-frequency dissipative nonlinear transmission lines (NLTLs)/resonant tunneling diode line cascaded maps is investigated for long-distance propagation of short pulses. Applying perturbative analysis, we show that the dynamics of each line is reduced to an expanded Korteweg-de Vries-Burgers equation. Moreover, it is found by computer experiments that the soliton developed in NLTLs experiences an exponential amplitude decay on the one hand and an exponential amplitude growth on the other. As a result, the behavior of a pulse in special electrical networks made of concatenated pieces of lines is closely similar to the transmission of information in optical/electrical communication systems.
Befus, M; Mukherjee, D V; Herzig, C T A; Lowy, F D; Larson, E
2017-07-01
Prisons/jails are thought to amplify the transmission of Staphylococcus aureus (SA) particularly methicillin-resistant SA infection and colonisation. Two independently pooled cross-sectional samples of detainees being admitted or discharged from two New York State maximum-security prisons were used to explore this concept. Private interviews of participants were conducted, during which the anterior nares and oropharynx were sampled and assessed for SA colonisation. Log-binomial regression and correspondence analysis (CA) were used to evaluate the prevalence of colonisation at entry as compared with discharge. Approximately 51% of admitted (N = 404) and 41% of discharged (N = 439) female detainees were colonised with SA. Among males, 59% of those admitted (N = 427) and 49% of those discharged (N = 393) were colonised. Females had a statistically significant higher prevalence (1·26: P = 0·003) whereas males showed no significant difference (1·06; P = 0·003) in SA prevalence between entry and discharge. CA demonstrated that some strains, such as spa types t571 and t002, might have an affinity for certain mucosal sites. Contrary to our hypothesis, the prison setting did not amplify SA transmission, and CA proved to be a useful tool in describing the population structure of strains according to time and/or mucosal site.
Furbish, David J.; Schmeeckle, Mark; Schumer, Rina; Fathel, Siobhan L.
2016-01-01
We describe the most likely forms of the probability distributions of bed load particle velocities, accelerations, hop distances, and travel times, in a manner that formally appeals to inferential statistics while honoring mechanical and kinematic constraints imposed by equilibrium transport conditions. The analysis is based on E. Jaynes's elaboration of the implications of the similarity between the Gibbs entropy in statistical mechanics and the Shannon entropy in information theory. By maximizing the information entropy of a distribution subject to known constraints on its moments, our choice of the form of the distribution is unbiased. The analysis suggests that particle velocities and travel times are exponentially distributed and that particle accelerations follow a Laplace distribution with zero mean. Particle hop distances, viewed alone, ought to be distributed exponentially. However, the covariance between hop distances and travel times precludes this result. Instead, the covariance structure suggests that hop distances follow a Weibull distribution. These distributions are consistent with high-resolution measurements obtained from high-speed imaging of bed load particle motions. The analysis brings us closer to choosing distributions based on our mechanical insight.
Igarashi, Koji; Tsuritani, Takehiro; Morita, Itsuro; Tsuchida, Yukihiro; Maeda, Koichi; Tadakuma, Masateru; Saito, Tsunetoshi; Watanabe, Kengo; Imamura, Katsunori; Sugizaki, Ryuichi; Suzuki, Masatoshi
2014-01-27
We show super-Nyquist-WDM transmission technique, where optical signals with duobinary-pulse shaping can be wavelength-multiplexed with frequency spacing of below baudrate. Duobinary-pulse shaping can reduce the signal bandwidth to be a half of baudrate while controlling inter-symbol interference can be compensated by the maximum likelihood sequence estimation in a receiver. First, we experimentally evaluate crosstalk characteristics as a function of channel spacing between the dual-channel DP-QPSK signals with duobinary-pulse shaping. As a result, the crosstalk penalty can be almost negligible as far as the ratio of baudrate to frequency spacing is maintained to be less than 1.20. Next, we demonstrate 140.7-Tbit/s, 7,326-km transmission of 7 × 201-channel 25-GHz-spaced super-Nyquist-WDM 100-Gbit/s optical signals using seven-core fiber and full C-band seven-core EDFAs. To the best of our knowledge, this is one of the first reports of high-capacity transmission experiments with capacity-distance product in excess of 1 Exabit/s · km.
Débora Martins Cattoni
2009-12-01
Full Text Available INTRODUÇÃO: a distância interincisiva máxima é um importante aspecto na avaliação miofuncional orofacial, pois distúrbios miofuncionais orofaciais podem limitar a abertura da boca. OBJETIVO: mensurar a distância interincisiva máxima de crianças respiradoras bucais, relacionando-a com a idade, e comparar as médias dessas medidas com as médias dessa distância em crianças sem queixas fonoaudiológicas. MÉTODOS: participaram 99 crianças respiradoras bucais, de ambos os gêneros, com idades entre 7 anos e 11 anos e 11 meses, leucodermas, em dentadura mista. O grupo controle foi composto por 253 crianças, com idades entre 7 anos e 11 anos e 11 meses, leucodermas, em dentadura mista, sem queixas fonoaudiológicas. RESULTADOS: os achados evidenciam que a média das distâncias interincisivas máximas das crianças respiradoras bucais foi, no total da amostra, de 43,55mm, não apresentando diferença estatisticamente significativa entre as médias, segundo a idade. Não houve diferença estatisticamente significativa entre as médias da distância interincisiva máxima dos respiradores bucais e as médias dessa medida das crianças do grupo controle. CONCLUSÕES: a distância interincisiva máxima é uma medida que não variou nos respiradores bucais, durante a dentadura mista, segundo a idade, e parece não estar alterada em portadores desse tipo de disfunção. Aponta-se, também, a importância do uso do paquímetro na avaliação objetiva da distância interincisiva máxima.INTRODUCTION: The maximum interincisal distance is an important aspect in the orofacial myofunctional evaluation, because orofacial myofunctional disorders can limit the mouth opening. AIM: To describe the maximum interincisal distance of the mouth breathing children, according to age, and to compare the averages of the maximum interincisal distance of mouth breathing children to those of children with no history of speech-language pathology disorders. METHODS
Cuenca, José; Aleza, Pablo; Juárez, José; García-Lor, Andrés; Froelicher, Yann; Navarro, Luis; Ollitrault, Patrick
2015-01-01
Polyploidisation is a key source of diversification and speciation in plants. Most researchers consider sexual polyploidisation leading to unreduced gamete as its main origin. Unreduced gametes are useful in several crop breeding schemes. Their formation mechanism, i.e., First-Division Restitution (FDR) or Second-Division Restitution (SDR), greatly impacts the gametic and population structures and, therefore, the breeding efficiency. Previous methods to identify the underlying mechanism required the analysis of a large set of markers over large progeny. This work develops a new maximum-likelihood method to identify the unreduced gamete formation mechanism both at the population and individual levels using independent centromeric markers. Knowledge of marker-centromere distances greatly improves the statistical power of the comparison between the SDR and FDR hypotheses. Simulating data demonstrated the importance of selecting markers very close to the centromere to obtain significant conclusions at individual level. This new method was used to identify the meiotic restitution mechanism in nineteen mandarin genotypes used as female parents in triploid citrus breeding. SDR was identified for 85.3% of 543 triploid hybrids and FDR for 0.6%. No significant conclusions were obtained for 14.1% of the hybrids. At population level SDR was the predominant mechanisms for the 19 parental mandarins. PMID:25894579
Cuenca, José; Aleza, Pablo; Juárez, José; García-Lor, Andrés; Froelicher, Yann; Navarro, Luis; Ollitrault, Patrick
2015-04-20
Polyploidisation is a key source of diversification and speciation in plants. Most researchers consider sexual polyploidisation leading to unreduced gamete as its main origin. Unreduced gametes are useful in several crop breeding schemes. Their formation mechanism, i.e., First-Division Restitution (FDR) or Second-Division Restitution (SDR), greatly impacts the gametic and population structures and, therefore, the breeding efficiency. Previous methods to identify the underlying mechanism required the analysis of a large set of markers over large progeny. This work develops a new maximum-likelihood method to identify the unreduced gamete formation mechanism both at the population and individual levels using independent centromeric markers. Knowledge of marker-centromere distances greatly improves the statistical power of the comparison between the SDR and FDR hypotheses. Simulating data demonstrated the importance of selecting markers very close to the centromere to obtain significant conclusions at individual level. This new method was used to identify the meiotic restitution mechanism in nineteen mandarin genotypes used as female parents in triploid citrus breeding. SDR was identified for 85.3% of 543 triploid hybrids and FDR for 0.6%. No significant conclusions were obtained for 14.1% of the hybrids. At population level SDR was the predominant mechanisms for the 19 parental mandarins.
Broadband IP Stream Transmission Experiments over Global and Long Distance Networks
Kimio; Oguchi; Tetsuro; Fujii; Atsushi; Takahara; Toshiaki; Miyazaki; Kazuo; Hagimoto; Sadayasu; Ono
2003-01-01
Super High Definition (SHD) movies were successfully transmitted as streaming contents at about 300 Mbps for the first time over a long distance IP network (more than 3,000 km), in conjunction with the experimental verification of traffic control and scalable multicast technologies.
B. W. Butler; T. Wallace; J. Hogge
2015-01-01
Towers and poles supporting power transmission and telecommunication lines have collapsed due to heating from wildland fires. Such occurrences have led to interruptions in power or communication in large municipal areas with associated social and political implications as well as increased immediate danger to humans. Vegetation clearance standards for overhead...
B. W. Butler; J. Webb; J. Hogge; T. Wallace
2015-01-01
Towers and poles supporting power transmission and telecommunication lines have collapsed due to heating from wildland fires. Such occurrences have led to interruptions in power or communication in large municipal areas with associated social and political implications as well as increased immediate danger to humans. Unfortunately, no studies address the question of...
Silva, Filipe Miguel Faria da; Bak, Claus Leth
2017-01-01
Multiple-circuit transmission lines combining different voltage levels in one tower present extra challenges when setting a protection philosophy, as faults between voltage levels are possible. This paper presents a detailed theoretical analysis of such combined faults, including the development...... of a formula for estimating the magnitude of the short-circuit current. It is demonstrated that if the faulted phase from the higher voltage level leads the faulted phase from the lower voltage level, a distance relay at the higher voltage level sees the fault in the forward direction, whereas a distance relay...... at the lower voltage level sees the fault in the reverse direction. The opposite happens if the lower voltage level leads the higher voltage level. It is also demonstrated that the magnitude of fault currents of combined faults is normally slightly larger than of equivalent single-phase-to-ground fault...
Islam, Md. Saiful; Sultana, Jakeya; Rana, Sohel; Islam, Mohammad Rakibul; Faisal, Mohammad; Kaijage, Shubi F.; Abbott, Derek
2017-03-01
In this paper, we present a porous-core circular photonic crystal fiber (PC-CPCF) with ultra-low material loss for efficient terahertz wave transmission. The full vector finite element method with an ideally matched layer boundary condition is used to characterize the wave guiding properties of the proposed fiber. At an operating frequency of 1 THz, simulated results exhibit an extremely low effective material loss of 0.043 cm-1, higher core power fraction of 47% and ultra-flattened dispersion variation of 0.09 ps/THz/cm. The effects of important design properties such as single mode operation, confinement loss and effective area of the fiber are investigated in the terahertz regime. Moreover, the proposed fiber can be fabricated using the capillary stacking or sol-gel technique and be useful for long distance transmission of terahertz waves.
West, Anthony C. F.; Novakowski, Kent S.; Gazor, Saeed
2006-06-01
We propose a new method to estimate the transmissivities of bedrock fractures from transmissivities measured in intervals of fixed length along a borehole. We define the scale of a fracture set by the inverse of the density of the Poisson point process assumed to represent their locations along the borehole wall, and we assume a lognormal distribution for their transmissivities. The parameters of the latter distribution are estimated by maximizing the likelihood of a left-censored subset of the data where the degree of censorship depends on the scale of the considered fracture set. We applied the method to sets of interval transmissivities simulated by summing random fracture transmissivities drawn from a specified population. We found the estimated distributions compared well to the transmissivity distributions of similarly scaled subsets of the most transmissive fractures from among the specified population. Estimation accuracy was most sensitive to the variance in the transmissivities of the fracture population. Using the proposed method, we estimated the transmissivities of fractures at increasing scale from hydraulic test data collected at a fixed scale in Smithville, Ontario, Canada. This is an important advancement since the resultant curves of transmissivity parameters versus fracture set scale would only previously have been obtainable from hydraulic tests conducted with increasing test interval length and with degrading equipment precision. Finally, on the basis of the properties of the proposed method, we propose guidelines for the design of fixed interval length hydraulic testing programs that require minimal prior knowledge of the rock.
Long-distance transmission of light in a scintillator-based radiation detector
Dowell, Jonathan L.; Talbott, Dale V.; Hehlen, Markus P.
2017-07-11
Scintillator-based radiation detectors capable of transmitting light indicating the presence of radiation for long distances are disclosed herein. A radiation detector can include a scintillator layer and a light-guide layer. The scintillator layer is configured to produce light upon receiving incident radiation. The light-guide layer is configured to receive light produced by the scintillator layer and either propagate the received light through the radiation detector or absorb the received light and emit light, through fluorescence, that is propagated through the radiation detector. A radiation detector can also include an outer layer partially surrounding the scintillator layer and light-guide layer. The index of refraction of the light-guide layer can be greater than the index of refraction of adjacent layers.
A Reliable Adaptive High-Definition Transmission System for Distance Learning
无
2007-01-01
There is an increasing demand for supporting high-quality real-time audiovisual services for the next generation wired and wireless networks. However, due to variety of bandwidths of different networks, it is a great challenge for deployment. In this paper, a novel high-definition (HD) video transmission system was proposed which depends upon reliable compound multicast protocols and QoS control over the various kinds of networks.This system detects client's network condition and assigns it to a proper proxy. Each proxy is capable of detecting network parameters and adaptively tuning such transport parameters as bit rate, video resolution, frame rate and QoS mechanisms to this condition. It also provides FEC error recovery under consideration of characteristics of MPEG4 video codec. Our simulation demonstrates that different network clients such as ADSL, CERNET, and CERNET2 can receive more video reliability with less delay.
Haubrich, H.J.; Fritz, W.; Stobrawe, M. [RWTH Aachen (Germany). Inst. fuer Elektrische Anlagen und Energiewirtschaft
1998-09-01
The expert opinion for `Determination of practicable transmission paths segments for billing of power transfer operations under TPA`, commissioned by the Vereinigung Deutscher Elektrizitaetswerke (VDEW), was presented in February 1998. The study was to define on the basis of a map of existing distribution systems and system ownerships, practicable transmission distances or path segments for the billing of transfer operations. Information acquisition for the study encompassed selective documentation of geographic data and electrical characteristics of high voltage as well as medium and low voltage grids owned by companies members of VDEW. (orig./CB) [Deutsch] Im Februar 1998 wurde das im Auftrag der Vereinigung Deutscher Elektrizitaetswerke (VDEW) erstellte Gutachten `Bestimmung von praxisorientierten Grenzentfernungen fuer Durchleitungen` in Frankfurt/Main vorgestellt. Dessen Aufgabe war es, Grenzentfernungen fuer Durchleitungen im Rahmen der Verbaendevereinbarung aus der tatsaechlichen Ausdehnung realer Netze abzuleiten. Dazu wurden bei einer repraesentativen Auswahl von VDEW-Mitgliedsunternehmen charakteristische geografische und elektrische Kenngroessen von Hoch-, Mittel- und Niederspannungsnetzen erfasst. (orig.)
Vilmos Simon
2013-01-01
The aim of this study is to define optimal tooth modifications,introduced by appropriately chosen head-cutter geometry and machine tool setting,to simultaneously minimize tooth contact pressure and angular displacement error of the driven gear (transmission error) of face-hobbed spiral bevel gears.As a result of these modifications,the gear pair becomes mismatched,and a point contact replaces the theoretical line contact.In the applied loaded tooth contact analysis it is assumed that the point contact under load is spreading over a surface along the whole or part of the “potential” contact line.A computer program was developed to implement the formulation provided above.By using this program the influence of tooth modifications introduced by the variation in machine tool settings and in head cutter data on load and pressure distributions,transmission errors,and fillet stresses is investigated and discussed.The correlation between the ease-off obtained by pinion tooth modifications and the corresponding tooth contact pressure distribution is investigated and the obtained results are presented.
Kobayashi, N., E-mail: kobayashi@nscl.msu.edu [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Whitmore, K.; Iwasaki, H. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824-1321 (United States)
2016-09-11
The possible appearance of nuclear halos in ground and excited states close to the particle-decay threshold is of great importance in the investigation of nuclear structure and few-body correlations at the limit of stability. In order to obtain direct evidence of the halo structure manifested in nuclear excited states, we have considered a new method to measure the interaction cross sections of excited states. The combination of the transmission method and the recoil distance Doppler-shift method with a plunger device enables us to measure the number of interactions of the excited states in a target. Formulae to determine the interaction cross section are derived, and key issues to realize measurements are discussed. Dominant sources of errors are uncertainties in the excited-state lifetimes and γ-ray yields. We examine prototype experiments and perform simulations to study the impact of each uncertainty on the final result. This method provides a novel opportunity to perform cross section measurements on the excited states of rare isotopes.
Wilson, D; Mills, M; Wang, B [University of Louisville, Louisville, KY (United States)
2014-06-15
Purpose: Carbon fiber materials have been increasingly used clinically, mainly in orthopedics, as an alternative to metallic implants because of their minimal artifacts on CT and MRI images. This study characterizes the transmission and backscatter property of carbon fiber plates (CarboFix Orthopedics, Herzeliya, Israel) with measurements for radiation therapy applications, and compares them to traditional Stainless Steel (SS) and Titanium (Ti) metal materials. Methods: For the transmission measurements, 1-mm-thick test plate was placed upstream from a plane parallel Markus chamber, separated by various thicknesses of polystyrene plates in 0.5 cm increments between 0 and 5 cm. With this setup, we quantified the radiation transmission as a function of distance to the inhomogeneity interface. The LINAC source to detector distance was maintained at 100 cm and 200 MU was delivered for each measurement. Two 3-cm solid water phantoms were placed at the top and bottom to provide build up. All the measurements were performed for 6 MV and 18 MV photons. The backscatter measurements had the identical setup, except that the test plate was downstream of the chamber from radiation. Results: The carbon fiber plates did not introduce any measureable inhomogeneity effect on the transmission and backscatter factor because of its low atomic number. In contrast, traditional metal implant materials caused up to 15% dose difference at upstream and 25% backscatter at downstream from radiation. Such differences decrease as the distance to the inhomogeneity interface increases and become unmeasurable at distance of 3 cm and 1 cm for upstream and downstream, respectively. Conclusion: A new type of carbon fiber implant plate was evaluated and found to have minimal inhomogeneity effect in MV radiation beams. Patients would benefit from a carbon based implant over metal for radiation therapy due to their minimal backscatter and imaging artifacts.
Bak, Claus Leth; Sigurbjörnsson, Ragnar; Bukh, Bjarne;
2016-01-01
Combined transmission lines where different voltage levels shares same towers are used in transmission systems in order to save way of right. Faults between different voltage levels results in complex fault current distributions due to mutual couplings and the fact that the faulted phases no longer...
Zhang, Xiaoping; Xu, Xuejun; Liu, Bing; Zhang, Zhendong
2017-03-01
The running condition of long distance water pipeline are complicated and changeable, and the lag of water flow is obvious, which is the key technical problem to be solved in the process of regulation and control. According to the present situation of the long-distance water conveyance project, the visualization simulation technology is used to study the operation and management of the long-distance water conveyance pipeline based on OpenGL technology. The system developed in this paper can combine pipeline information, working condition data and relevant data to provide a visualization platform for analysis and decision-making of project management and operation.
Bak, Claus Leth; Sigurbjörnsson, Ragnar; Bukh, Bjarne
2016-01-01
Combined transmission lines where different voltage levels shares same towers are used in transmission systems in order to save way of right. Faults between different voltage levels results in complex fault current distributions due to mutual couplings and the fact that the faulted phases no longer...... impedance for combined faults and thereby shed light on relay trips. This study uses actual fault records, analytical method and PSCAD simulation studies to analyse combined faults in an existing 400 and 150 kV transmission line owned by Danish TSO Energinet.dk. The results clearly show that an accurate...
Jun Yu
2015-01-01
Full Text Available Optimization of energy consumption in Wireless Sensor Network (WSN nodes has become a critical link that constrains the engineering application of the smart grid due to the fact that the smart grid is characterized by long-distance transmission in a special environment. The paper proposes a linear hierarchical network topological structure specific to WSN energy conservation in environmental monitoring of the long-distance electric transmission lines in the smart grid. Based on the topological structural characteristics and optimization of network layers, the paper also proposes a Topological Structure be Layered Configurations (TSLC routing algorithm to improve the quality of WSN data transmission performance. Coprocessing of the network layer and the media access control (MAC layer is achieved by using the cross-layer design method, accessing the status for the nodes in the network layer and obtaining the status of the network nodes of the MAC layer. It efficiently saves the energy of the whole network, improves the quality of the network service performance, and prolongs the life cycle of the network.
40 Gb/s optical transmission systems
Buxens Azcoaga, Alvaro Juan; Nielsen, Steen Krogh
2003-01-01
application (maximum distance of 40 km) the maximum PMD coeficient allowed in the transmission fiber, 0.4 ps=pkm, is below the values defined by actual standards, 0.5 ps=pkm. The most promising PMD compensation methods are presented and their advantages and disadvantages are discussed. A PMD compensator based...
Sitaras, Ioannis; Rousou, Xanthoula; Kalthoff, Donata; Beer, Martin; Peeters, Ben; de Jong, Mart C M
2016-01-01
Highly pathogenic avian influenza (HPAI) H5N1 epidemics in poultry cause huge economic losses as well as sporadic human morbidity and mortality. Vaccination in poultry has often been reported as being ineffective in preventing transmission and as a potential driving force in the selection of immune escape mutants. We conducted transmission experiments to evaluate the transmission dynamics of HPAI H5N1 strains in chickens vaccinated with high and low doses of immune escape mutants we have previously selected, and analysed the data using mathematical models. Remarkably, we demonstrate that the effect of antigenic distances between the vaccine and challenge strains used in this study is too small to influence the transmission dynamics of the strains used. This is because the effect of a sufficient vaccine dose on antibody levels against the challenge viruses is large enough to compensate for any decrease in antibody titres due to antigenic differences between vaccine and challenge strains. Our results show that at least under experimental conditions, vaccination will remain effective even after antigenic changes as may be caused by the initial selection in vaccinated birds.
El-Diasty, Fouad; El-Hennawi, H. A.; El-Ghandoor, H.; Soliman, Mona A.
2013-12-01
Intermodal and intramodal dispersions signify one of the problems in graded-index multi-mode optical fibers (GRIN) used for LAN communication systems and for sensing applications. A central index dip (depression) in the profile of core refractive-index may occur due to the CVD fabrication processes. The index dip may also be intentionally designed to broaden the fundamental mode field profile toward a plateau-like distribution, which have advantages for fiber-source connections, fiber amplifiers and self-imaging applications. Effect of core central index dip on the propagation parameters of GRIN fiber, such as intermodal dispersion, intramodal dispersion and root-mean-square broadening, is investigated. The conventional methods usually study optical signal propagation in optical fiber in terms of mode characteristics and the number of modes, but in this work multiple-beam Fizeau interferometry is proposed as an inductive but alternative methodology to afford a radial approach to determine dispersion, pulse broadening and maximum transmission rate in GRIN optical fiber having a central index dip.
Maximilien Brice
2012-01-01
Signature of the Collaboration agreement contract between CERN and IASS on High Current, Long Distance Superconducting Power Transmission Lines signed Dr.Steve Myers Director of Acc Tech and Prof. Carlo Rubbia.
Study on maximum distance testing with low power dissipation%降低最大距离测试码输入功耗研究
张鼎; 徐拾义
2014-01-01
Random testing has been long employed for testing of faults in digital systems. However, there are some fatal defects of it due to its low efficiency in testing. Aiming at this problem, a new concept of distance between test patterns is proposed. It is known that the larger distance between two test patterns the more different faults can be detected by these two patterns. Therefore, a new pseudo-random testing is proposed earlier called distance based random testing which can be more efficient in testing than that of traditional one. On the other hand, since the distance between two patterns in this method is large enough so that the power dissipation of applying test sequence is greatly increased when testing. This paper is just to present a novel way of changing the order of test patterns in the sequence when applying the tests so as to reduce the power dissipation as much as possible to reach the objective of lowering the power dissipation in testing.%伪随机测试在数字系统的故障测试中已经得到了多年的应用，但传统的伪随机测试存在着效率比较低的缺陷。针对该缺陷提出了在伪随机测试方法中引入测试码之间距离的概念。根据测试码之间距离越大，能检测到不同故障的数目概率也越大的假设，基于测试码之间距离的随机测试法（简称基于距离测试法）可以生成一组测试码序列。但是由于基于距离测试法所生成的测试码相邻间距离的变大，将造成相邻输入码之间的跳变次数增多，使得输入测试码时所需要的功耗急剧增大。针对该情况，提出对伪随机测试法生成的测试码输入顺序进行重新排序和调整的概念，从而达到降低测试功耗的最终目标。
基于RS-485长距离数据传输系统设计%A Long Distance Data Transmission System Designed Based on RS-485
江洋; 杨俊峰; 宋克柱
2013-01-01
为了满足现在大型核物理实验中数据传输的需要,设计了一种基于RS-485、异步串口通信协议的长距离数据传输系统；系统采用现场可编程门阵列(Field programmable gate array,FPGA)作为主控芯片,在FPGA的内部实现异步串口通信协议编解码、时钟数据恢复,同时使用RS485收发芯片Max3467来增强差分信号的驱动能力,提高了该系统在长距离数据传输中的可靠性；目前该系统可以20.48 Mbps的单线波特率在100 m双绞线电缆上实现无误码数据传输.%A long distance data transmission system based on RS-485 and Universal Asynchronous Receiver/Transmitter (UART) is designed for long distance data transmission in large physics experiments.This system used Field Programmable Gate Array (FPGA) as main control chip.UART and Clock Data Recovery (CDR) were implemented in FPGA.And the chips,Max3467,were used to drive electric signal on cables.All these improved reliability of the system in data transmission part.This system worked on 100 meters long cable and at data rate of 20.48 Mbps with no errors.
Chiba Shigeru
2007-09-01
Full Text Available Abstract Background Computer graphics and virtual reality techniques are useful to develop automatic and effective rehabilitation systems. However, a kind of virtual environment including unstable visual images presented to wide field screen or a head mounted display tends to induce motion sickness. The motion sickness induced in using a rehabilitation system not only inhibits effective training but also may harm patients' health. There are few studies that have objectively evaluated the effects of the repetitive exposures to these stimuli on humans. The purpose of this study is to investigate the adaptation to visually induced motion sickness by physiological data. Methods An experiment was carried out in which the same video image was presented to human subjects three times. We evaluated changes of the intensity of motion sickness they suffered from by a subjective score and the physiological index ρmax, which is defined as the maximum cross-correlation coefficient between heart rate and pulse wave transmission time and is considered to reflect the autonomic nervous activity. Results The results showed adaptation to visually-induced motion sickness by the repetitive presentation of the same image both in the subjective and the objective indices. However, there were some subjects whose intensity of sickness increased. Thus, it was possible to know the part in the video image which related to motion sickness by analyzing changes in ρmax with time. Conclusion The physiological index, ρmax, will be a good index for assessing the adaptation process to visually induced motion sickness and may be useful in checking the safety of rehabilitation systems with new image technologies.
Silva, Filipe Miguel Faria da; Bak, Claus Leth
2017-01-01
Multiple-circuit transmission lines combining different voltage levels in one tower present extra challenges when setting a protection philosophy, as faults between voltage levels are possible. In this paper, the fault loop impedance of combined faults is compared with the fault loop impedance...... of single-phase-to-ground faults at the higher voltage level of the multiple-circuit line and it is demonstrated that they are similar for high short-circuit powers; however, the fault loop impedance of a combined fault may increase substantially as the short-circuit power of the system decreases......-phase-to-ground faults are also capable of protecting the line against combined faults, being only advisable to increase the resistive limit of the protection zone if the network has lower short-circuit power. If the length of the line at lower voltage level is less than of the lien at higher voltage level...
Cortesi, Nicola; Peña-Angulo, Dhais; Simolo, Claudia; Stepanek, Peter; Brunetti, Michele; Gonzalez-Hidalgo, José Carlos
2014-05-01
One of the key point in the develop of the MOTEDAS dataset (see Poster 1 MOTEDAS) in the framework of the HIDROCAES Project (Impactos Hidrológicos del Calentamiento Global en España, Spanish Ministery of Research CGL2011-27574-C02-01) is the reference series for which no generalized metadata exist. In this poster we present an analysis of spatial variability of monthly minimum and maximum temperatures in the conterminous land of Spain (Iberian Peninsula, IP), by using the Correlation Decay Distance function (CDD), with the aim of evaluating, at sub-regional level, the optimal threshold distance between neighbouring stations for producing the set of reference series used in the quality control (see MOTEDAS Poster 1) and the reconstruction (see MOREDAS Poster 3). The CDD analysis for Tmax and Tmin was performed calculating a correlation matrix at monthly scale between 1981-2010 among monthly mean values of maximum (Tmax) and minimum (Tmin) temperature series (with at least 90% of data), free of anomalous data and homogenized (see MOTEDAS Poster 1), obtained from AEMEt archives (National Spanish Meteorological Agency). Monthly anomalies (difference between data and mean 1981-2010) were used to prevent the dominant effect of annual cycle in the CDD annual estimation. For each station, and time scale, the common variance r2 (using the square of Pearson's correlation coefficient) was calculated between all neighbouring temperature series and the relation between r2 and distance was modelled according to the following equation (1): Log (r2ij) = b*°dij (1) being Log(rij2) the common variance between target (i) and neighbouring series (j), dij the distance between them and b the slope of the ordinary least-squares linear regression model applied taking into account only the surrounding stations within a starting radius of 50 km and with a minimum of 5 stations required. Finally, monthly, seasonal and annual CDD values were interpolated using the Ordinary Kriging with a
裘愉涛; 潘武略; 倪传坤; 何荷; 明浩
2015-01-01
分析了具备低电压穿越(LVRT)能力的双馈式风电场送出线路故障暂态特性。风电送出线路风场侧保护测得的电压与电流主要频率分量不一致，致使传统的依据工频电压、电流相量的距离保护元件动作性能受到严重影响，无法正常工作。基于输电线路时域模型的解微分方程算法不涉及信号的频域信息，可以克服送出线电压、电流主频不同带来的影响，但受高频分量的影响较大。等传变距离保护相较传统的解微分方程算法，增加了低通滤波及故障点电压重构两个环节，显著改善了算法的测距性能。PSCAD/EMTDC仿真结果表明，线路不同位置处发生不同类型故障时，等传变距离保护算法均可以实现快速、准确测距。%The fault features of outgoing transmission line in DFIG-based wind plant with the capacity of low-voltage ride-through (LVRT) are analyzed. The main frequency inconsistency between voltage and current of wind farm outgoing transmission line leads a serious impact on the action performance of traditional distance protection element based on power frequency voltage and current phasor. The differential equation algorithm based on the time-domain differential equation model of transmission line does not involve the frequency-domain information of the signal, thus it is unaffected by the main frequency inconsistency between voltage and current of wind farm outgoing transmission line. But the high-frequency characteristic of the differential equation algorithm is poor. Compared with the traditional differential equation algorithm, two processes are gained in the equal transfer process-based distance protection, low-pass filtering and re-structuring of the voltage at the fault point, which significantly improves the performance of the algorithm. The PSCAD/EMTDC simulation results show that the distance element which employs the equal transfer process-based distance protection
Finney, Ben; Bentley, Jerry
The transmission of ancient Greek learning and science to medieval western Europe via the translation of Greek and Arab texts is often cited as a terrestrial example of "learning at a distance" that could occur by means of the decipherment of radio messages from advanced extraterrestrial civilizations. However, the translation between such closely related languages as Greek, Latin and Arabic and the decipherment of radio messages from an extraterrestrial civilization to the point where humans could understand them are only nominally analogous tasks. A terrestrial example of such "learning at a distance" from an ancient civilization that perhaps better prepares us for thinking about the immense task inherent in any interstellar knowledge transmission is provided by the lengthy and troubled efforts of western scholars to decipher the inscriptions left by the ancient Maya and to learn from them about this ancient civilization. Only recently, with the rejection of the ideographic fallacy that Maya glyphs symbolized ideas directly without the mediation of language and with the application of linguistic knowledge of Maya languages has it been possible to decipher the Maya inscriptions and learn from them about their science and culture. This experience suggests that without any knowledge of languages in which extraterrestrial messages might be composed, their decipherment could be most problematic. The Maya case is also relevant to the common suggestion that advanced extraterrestrials would deliberately compose messages not in their own natural languages but in artificial ones using logic, numbers, and scientific constants presumably shared among all intelligent civilizations, or at least those in their radio-communicative phases. Numbers and calendrical dating system were the first parts of the Mayan inscriptions to be translated, albeit with the aid of partial "Rosetta stones" left by the Spanish conquerors. This success served, however, to reinforce the ideographic
Representing distance, consuming distance
Larsen, Gunvor Riber
to mobility and its social context. Such an understanding can be approached through representations, as distance is being represented in various ways, most noticeably in maps and through the notions of space and Otherness. The question this talk subsequently asks is whether these representations of distance...... are being consumed in the contemporary society, in the same way as places, media, cultures and status are being consumed (Urry 1995, Featherstone 2007). An exploration of distance and its representations through contemporary consumption theory could expose what role distance plays in forming...... are present in theoretical and empirical elaborations on mobility, but these remain largely implicit and unchallenged (Bauman 1998). This talk will endeavour to unmask distance as a theoretical entity by exploring ways in which distance can be understood and by discussing distance through its representations...
陈文仙; 陈乾宏; 张惠娟
2015-01-01
主要研究了电磁共振式无线电能传输(WPT)系统的距离传输特性以及提高传输距离的途径。利用互感模型解释了电磁共振式 WPT 系统的工作原理，同时，通过理论求解得到了系统关于距离的传输特性表达式。在此基础上，进一步研究了提高系统传输距离的途径。研究表明，电磁共振式 WPT 系统存在电压增益与输出功率特性的最优距离点，同时系统高频化是提高传输距离与传输效率的有效途径。最后，搭建了一个电磁共振式 WPT 实验装置进行实验验证，实验结果与理论分析结果一致。%This paper mainly studies the distance transmission characteristics of the magnetic resonance wireless power transmission system and methods to improve the transmission distance.The mutual model is used to explain the operation principle of magnetic resonance wireless power transmission system,while the expression between the transfer characteristic and the distance is obtained by theoretical analysis on the system.On this basis,further research aimed to improve the system transmission distance is done.It has been found that there is an optimal distance point in the magnetic resonance wireless power transmission system,and improving the resonance frequency of the system is an effective way to increase transmission distance.Finally,a magnetic resonance wireless power transmission system is set up for experimental verification.The experimental results are in agreement with theoretical analysis.
Adams, James L.
1961-01-01
A series of pursuit tracking tasks were performed incorporating a transport lag in the control loop. The target was a mixture of four sine waves, the fastest having a frequency of 16 cycles per minute at full speed. An attempt was made to design the experiments so that they would provide data applicable to remote control of a ground vehicle over long transmission distances. Three programs were run. In each the time lag was placed between the control and the display. In the first program a velocity control was used and the operator was told that his knob controlled a vehicle, the problem represented a road 9 and he was to drive his vehicle along the road 9 using the delayed vehicle position as feedback for whatever means he desired. The objective was not to match the display traces. In the second program a velocity control was used, and the operator was told that the problem trace represented a road and the delayed trace represented a vehicle and he was to keep them together. The objective was to match display traces. The third program was identical with the first, except that an acceleration control was used rather than a velocity control. Target speeds used were full speed, 1/2 speed, 1/4 speed, 1/8 speed, and 1/16 speed. Time lags were 1/4 second, l/2 second, 1 second, 1-1/2 second, 2 second, 3 second, and 6 seconds. The experimental results are presented in the last section of this report.
Ziegler, Gerhard
2011-01-01
Distance protection provides the basis for network protection in transmission systems and meshed distribution systems. This book covers the fundamentals of distance protection and the special features of numerical technology. The emphasis is placed on the application of numerical distance relays in distribution and transmission systems.This book is aimed at students and engineers who wish to familiarise themselves with the subject of power system protection, as well as the experienced user, entering the area of numerical distance protection. Furthermore it serves as a reference guide for s
Kinkhabwala, Ali
2013-01-01
The most fundamental problem in statistics is the inference of an unknown probability distribution from a finite number of samples. For a specific observed data set, answers to the following questions would be desirable: (1) Estimation: Which candidate distribution provides the best fit to the observed data?, (2) Goodness-of-fit: How concordant is this distribution with the observed data?, and (3) Uncertainty: How concordant are other candidate distributions with the observed data? A simple unified approach for univariate data that addresses these traditionally distinct statistical notions is presented called "maximum fidelity". Maximum fidelity is a strict frequentist approach that is fundamentally based on model concordance with the observed data. The fidelity statistic is a general information measure based on the coordinate-independent cumulative distribution and critical yet previously neglected symmetry considerations. An approximation for the null distribution of the fidelity allows its direct conversi...
Twisted Light Transmission over 143 kilometers
Krenn, Mario; Fink, Matthias; Fickler, Robert; Ursin, Rupert; Malik, Mehul; Zeilinger, Anton
2016-01-01
Spatial modes of light can potentially carry a vast amount of information, making them promising candidates for both classical and quantum communication. However, the distribution of such modes over large distances remains difficult. Intermodal coupling complicates their use with common fibers, while free-space transmission is thought to be strongly influenced by atmospheric turbulence. Here we show the transmission of orbital angular momentum modes of light over a distance of 143 kilometers between two Canary Islands, which is 50 times greater than the maximum distance achieved previously. As a demonstration of the transmission quality, we use superpositions of these modes to encode a short message. At the receiver, an artificial neural network is used for distinguishing between the different twisted light superpositions. The algorithm is able to identify different mode superpositions with an accuracy of more than 80% up to the third mode order, and decode the transmitted message with an error rate of 8.33%....
徐君; 徐富红; 蔡体健; 王彩玲; 黄德昌; 李伟平
2015-01-01
In hyperspectral unmixing, PPI algorithm is a relatively mature algorithm, but each projection vector in PPI algorithm is generated randomly, and the endmembers extracted by PPI algorithm are not stable. That is, different endmembers can be obtained from the same image by repeatedly running PPI algorithm. This paper, based on the convex geometry description of linear spectral mixing model, utilized the feature that the endmem-bers are the endpoints of the single convex body enclosed in the hyperspectral image feature space, and proposed a novel pure pixel index algorithm for endmember extraction based on the maximum distance. The average of the spectral vectors of all the sample points is calculated and used as the center of a hypersphere. Next, we calcu-late the Euclidean distances of all the sample points to the center of the hypersphere, and design a radius of equal to or greater than the maximum distance for the hypersphere in the feature space to include all of the sample points. We evenly select the reference points on the surface of the hypersphere. The farthest sample point with re-spect to each reference point can be found by calculating the Euclidean distance. Subsequently, every sample point’s frequency of being the most distant to the reference points is recorded as an index to evaluate whether the sample point is an endmember or not. Finally, we use the AVIRIS data of Nevada Cuprite to testify this algo-rithm. The experimental results illustrate that the precision of the endmember extraction using the algorithm pro-posed in this paper is better than N-FINDR algorithm and VCA algorithm in general. Moreover, it has a good ro-bustness and could overcome the instability of PPI algorithm caused by random projection.%在高光谱混合像元分解中，PPI算法是一种比较成熟的算法，但PPI算法中每次投影向量的生成都是随机的，多次执行PPI算法后端元提取的结果并不稳定。本文以线性
NONE
1997-03-01
A workshop was held at Tokyo in March, 1997 on the research and development and feasibility study for international collaboration on photovoltaic (PV) power generation and long-distance energy transmission technologies utilizing desert areas environment. Two speakers from the USA, one from Italy, and two from China were invited, and four speakers in Japan presented papers. A total of 48 persons participated. In the technical sessions, `World energy demand and PV system potential` by Prof. Kurokawa, `Long distance transmission of PV power` by Mr. A. Invenizzi, `Case studies of large scale PV systems distributed throughout desert areas of the world` by Mr. Hirasawa, `Linking renewable energy resources around the world` by Mr. P. Meisen, `Properties of large scale PV plant in the USA` by Mr. J. Benner, `Future prospect of PV electrification in China` by Mr. Kong Li, `Application of large-scale PV systems in deserts in China` by Mr. Isomura, and `Effects of large-scale PV power plant in a climatic desert areas` by Prof. Ihara were presented. 38 refs., 62 figs., 29 tabs.
Jeong, M K; Hwang, C; Nam, H; Cho, Y S; Kang, B Y; Cho, E C
2017-02-01
The purpose of this study was to determine how the energies supplied from a cosmetic vibrator are deeply or far transferred into organs and tissues, and how these depths or distances are influenced by tissue elasticity. External vibration energy was applied to model skin surfaces through a facial cleansing vibrator, and we measured a distance- and depth-dependent energy that was transferred to model skin matrices. As model skin matrices, we synthesized hard and soft poly(dimethylsiloxane) (PDMS) gels, as well as hydrogels with a modulus of 2.63 MPa, 0.33 MPa and 21 kPa, respectively, mostly representing those of skin and other organs. The transfer of vibration energy was measured either by increasing the separation distances or by increasing the depth from the vibrator. The energies were transmitted deeper into the hard PDMS than into the soft PDMS and hydrogel matrices. This finding implies that the vibration forces influence a larger area of the gel matrices when the gels are more elastic (or rigid). There were no appreciable differences between the soft PDMS and hydrogel matrices. However, the absorbed energies were more concentrated in the area closest to the vibrator with decreasing elasticity of the matrix. Softer materials absorbed most of the supplied energy around the point of the vibrator. In contrast, harder materials scattered the external energy over a broad area. The current results are the first report in estimating how the external energy is deeply or distantly transferred into a model skins depending on the elastic moduli of the models skins. In doing so, the results would be potentially useful in predicting the health of cells, tissues and organs exposed to various stimuli. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.
郑成志; 高金良; 王焕君; 金溪
2012-01-01
In order to economically and effectively achieve water hammer prevention in long-distance water transmission pipeline, the performance of water hammer arrester was analyzed, and after many simulations, the water hammer prevention problem in one flat long-distance water transmission project in northwest China was solved using water hammer arrester and some other protection devices. For the flat long-distance water transmission pipeline, the negative pressure is a prominent reason for pump stoppage due to accident, and the water hammer arrester can effectively achieve this water hammer prevention. To increase elevation in some nodes of the flat water transmission pipeline can reduce the risk of water hammer. When there are two parallel pipelines, it is necessary to check water hammer prevention measures in special conditions. In addition, "the installation of air valves on submerged pipeline is discussed.%为了经济高效地实现长距离输水管线的水锤防护,分析了抗水锤气压罐的性能,并经过模拟计算,综合运用抗水锤气压罐及其他水锤防护设备,解决了我国西北某长距离平坦输水管线工程的水锤防护问题.模拟表明,长距离平坦输水管线事故停泵的突出问题是管线负压,抗水锤气压罐能有效实现该类水锤的防护；在平坦的输水管线局部增加管线高程,能降低水锤危害；当双线输水时,有必要对特殊运行工况下的水锤防护措施进行校核.此外,还讨论了淹没管道上空气阀的设置问题.
文安; 王聪; 李建设; 于芮技; 莫天文; 魏承志; 寻斌斌; 李银红
2014-01-01
双分叉线路是输电线路增容改建工程中产生的一种特殊结构线路。可以增大线路输送容量，提高走廊利用率，并且节约建设投资，缩短工期，停电时间较短。从双分叉线路结构特点和保护原理入手，分析了双分叉结构对继电保护整定计算的影响。分析表明，对于双分叉线路，采用改建后线路的实际测量参数，或根据原线路参数计算得到的修正参数，及时调整零序补偿系数中的相应一次值，然后按简单线路整定方法进行整定即可，不会造成保护玉段超越误动。为继电保护整定计算工作提供了依据。%Double-branched transmission line is a special structure in the extension and reconstruction of transmission lines.It can be used to increase the capacity of transmission lines, improve transmission corridors' use efficiency, save cost, shorten construction pe-riod and outage time.A model for double-branched lines has been established based on its structure, and on this basis, effect of the double branched structure to selectivity of ground distance protection has been discussed.The analysis shows that, for transmission lines with double-branched structure, it only needs to calculate zero-sequence compensating coefficient with the correct actual meas-ured value of the newly structured lines or the adjusted parameters, that can get reasonable setting values in the light of the original setting calculation method for usual lines.It provides more reasonable principles when determining the grounding distance protection settings.
Iliceto, S; D'Ambrosio, G; Scrutinio, D; Marangelli, V; Boni, L; Rizzon, P
1993-01-01
A special computer network has been specifically designed and realized to connect 36 Italian cardiological institutions to a central core laboratory. This network, which has been created to run the CEDIM Multicenter Trial (effects of L-carnitine on left ventricular function in patients with myocardial infarction assessed by digital echocardiography), enables automatic verification, via computer, 24 hours a day, of patient eligibility criteria, randomization, transmission, and filing of real-time left ventricular echocardiographic examinations. All the investigators participating in the CEDIM trial underwent several training courses as well as dummy run procedures to achieve optimal performance of all the operational procedures required for the network to function smoothly and correctly. This paper describes the aims of this special network, its technical characteristics, and the investigator training and dummy run procedures.
1997-12-01
A study reviewing the existing Army Distance Learning Plan (ADLP) and current Distance Learning practices, with a focus on the Army’s training and...educational challenges and the benefits of applying Distance Learning techniques. The ASB study panel makes six specific recommendations, the most
焦在滨; 齐倩; 杨黎明; 王优胤; 宁荣
2014-01-01
受电容式电压互感器(capacitive voltage transformer， CVT)暂态特性的影响，高压输电线路距离保护易发生暂态超越而误动，影响电力系统的安全稳定运行。提出了一种不受 CVT 暂态特性影响的距离保护新原理。该原理以 CVT能够正确传变工频量为基础，通过基于矩阵束的准确工频量提取方法计算保护安装处电压电流的工频量，利用贝瑞龙模型计算长距离输电线路整定点处的电压和电流，最终以整定点为观测点，通过传统的距离保护算法与方向元件配合确定故障点的位置，该原理不受CVT暂态特性的影响，同时考虑了长距离输电线路分布参数效应对距离保护的影响，具有较好的性能，仿真结果验证了所提算法的有效性。%Affected by transient characteristic of capacitor voltage transformer (CVT), the distance protection for HV transmission line is easily to mal-operate due to transient overreach, thus the secure and stable operation of power grid is affected. A new distance protection scheme that is not affected by the transient characteristics of CVT is proposed and its principle is as following:firstly, on the basis that the CVT can transmit and transform power frequency phasor, by means of the matrix pencil based accurate power frequency phasor extraction method the power frequency phasors of voltage and current at the position where the protection is installed are calculated;secondly, the voltage and current at the position of the long distance transmission line, where the protection is set, are calculated by Bergeron model; finally, coordinating with directional element and taking the setting point as the observation point, the fault point is located by traditional distance protection algorithm. The proposed principle is not affected by transient characteristic of CVT and the impacts of distributed parameters of the long distance transmission line are taken into account, thus the
徐兴元; 章玥; 季民河※; 宋洋
2013-01-01
calculated theoretical maximum transmission distance for the deployment of the given sensor nodes wa
韩业辉; 庞杨; 赵超趣; 梅雪松
2015-01-01
通过介绍一种盖革计数管信号检测电路，在此基础上组成了完整的长距离信号传输电路，此电路在实际应用中具有抗干扰能力强、线路简单、脉冲信号传输好、信号幅度大、运行稳定等特点，配合相应接口电路，具有安全栅、光电隔离等功能，可满足一般化工装置安全防爆的要求。%Through the introduction of Geiger counter tube, this paper gives a suitable long-distance transmission Geiger counter signal detection circuit. In actual application, this circuit has the characteristics of strong anti-interference ability, simple circuit, good pulse signal transmission, and can meet the requirements of the general chemical plant safety explosion-proof.
Takahashi, O; Sato, K.; Goto, K.; Sirosaki, T. [Tohoku Electric Power Co. Inc, Miyagi (Japan); Sanekata, J.; Amano, M.; Endo, M. [Hitachi Ltd., Tokyo (Japan)
1997-06-20
An adjustable speed flywheel generator (FWG) is composed of a dynamotor and a flywheel which can accumulate energy as rotational energy. Its adjustable device operates owing to exciting the rotors by three-phase current. When the rotational speed does not coincide with the synchronous one, difference between the two, namely the slipped frequency, excites the rotors. According to this principle, the flywheel can run synchronizing with the transmission system. Selection of the location for FWGs being important from the standpoint of large-capacity and long-distance transmission, a PQ-sensitivity method has been proposed as a new technique, which can estimate the effect of both FWG`s active and reactive power with ease. Besides, regarding an input signal for stabilizing control, new method has been developed which apply the frequency of the bus instead of the power flow. Owing to this method, conventional stepwise changes of the power flow at every opening three-phase single-circuit have disappeared. As for the capacity of the FWG, the fact that the capacity of the exciter depends on the slip investigated, a designing method has been proposed. 8 refs., 17 figs., 3 tabs.
Design of High-Speed Data and Long-Distance Transmission System Based on FPGA%基于FPGA的高速数据长线传输系统的设计
郭宝锋; 韩壮志; 何强; 尚朝轩; 曾慧燕; 马少闯
2012-01-01
Design scheme of high-speed and long-distance transmission system is proposed, whose core is Cyclone II series FPGA chip EP2C5T144, based on low voltage differential signals (LVDS) interface technology. The scheme implements serial-to-parallel conversion, parallel-to-serial conversion, LVDS' driving and receiving through FPGA, it solves some problems such as the voltage conversion of different interface standards, impedance matching, the signals' attenuation and resumption in the process of long-distance transmission. The scheme has advantages of simple design, strong anti-jamming ability, small size, low cost and high integration. Experimental results show that the system works steadily, the serial data transmitting at the speed of 50 Mb/s on the 100 m unshielded twisted pair with the perfect transmission effect, which fully meet the need of design.%提出了以CycloneⅡ系列FPGA芯片EP2C5T144为核心,基于低压差分信号(LVDS)接口技术的高速数据长线传输系统的设计方案,该方案利用FPGA实现数据的串/并、并/串转换以及LVDS信号的驱动和接收,解决了不同接口标准的电平转换、阻抗匹配以及信号长线传输过程中的衰减与恢复等问题,具有设计简单、抗干扰能力强、体积小、成本低、集成度高等优点.通过实验表明,该系统工作稳定,实现了串行数据在100m非屏蔽双绞线上以50 Mb/s的速率传输,并且具有良好的传输效果,完全满足系统设计要求.
Bennett, Charles H; Li, Ming; Vitanyi, Paul M B; Zurek, Wojciech H
2010-01-01
While Kolmogorov complexity is the accepted absolute measure of information content in an individual finite object, a similarly absolute notion is needed for the information distance between two individual objects, for example, two pictures. We give several natural definitions of a universal information metric, based on length of shortest programs for either ordinary computations or reversible (dissipationless) computations. It turns out that these definitions are equivalent up to an additive logarithmic term. We show that the information distance is a universal cognitive similarity distance. We investigate the maximal correlation of the shortest programs involved, the maximal uncorrelation of programs (a generalization of the Slepian-Wolf theorem of classical information theory), and the density properties of the discrete metric spaces induced by the information distances. A related distance measures the amount of nonreversibility of a computation. Using the physical theory of reversible computation, we give...
Cacti with maximum Kirchhoff index
Wang, Wen-Rui; Pan, Xiang-Feng
2015-01-01
The concept of resistance distance was first proposed by Klein and Randi\\'c. The Kirchhoff index $Kf(G)$ of a graph $G$ is the sum of resistance distance between all pairs of vertices in $G$. A connected graph $G$ is called a cactus if each block of $G$ is either an edge or a cycle. Let $Cat(n;t)$ be the set of connected cacti possessing $n$ vertices and $t$ cycles, where $0\\leq t \\leq \\lfloor\\frac{n-1}{2}\\rfloor$. In this paper, the maximum kirchhoff index of cacti are characterized, as well...
30 Gbps 4-PAM transmission over 200 m of MMF using an 850 nm VCSEL.
Szczerba, Krzysztof; Westbergh, Petter; Karout, Johnny; Gustavsson, Johan; Haglund, Åsa; Karlsson, Magnus; Andrekson, Peter; Agrell, Erik; Larsson, Anders
2011-12-12
We present high speed real time, error free 4-PAM transmission for short range optical links based on a VCSEL operating at 850 nm, a multimode fibre and a simple intensity detector. Transmission speeds of 25 Gbps and 30 Gbps are demonstrated, and the maximum fibre reaches were 300 m and 200 m, respectively. The 4-PAM is also compared with OOK transmission at 25 Gbps, and we find that at this bit rate 4-PAM increases the error free transmission distance in the multimode fibre by 100 m, compared to OOK.
McQuinn, Kristen B W; Dolphin, Andrew E; Berg, Danielle; Kennicutt, Robert
2016-01-01
Great investments of observing time have been dedicated to the study of nearby spiral galaxies with diverse goals ranging from understanding the star formation process to characterizing their dark matter distributions. Accurate distances are fundamental to interpreting observations of these galaxies, yet many of the best studied nearby galaxies have distances based on methods with relatively large uncertainties. We have started a program to derive accurate distances to these galaxies. Here we measure the distance to M51 - the Whirlpool galaxy - from newly obtained Hubble Space Telescope optical imaging using the tip of the red giant branch method. We measure the distance modulus to be 8.58+/-0.10 Mpc (statistical), corresponding to a distance modulus of 29.67+/-0.02 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian Maximum Likelihood technique that reduces measurement unce...
Twisted light transmission over 143 km
Krenn, Mario; Handsteiner, Johannes; Fink, Matthias; Fickler, Robert; Ursin, Rupert; Malik, Mehul; Zeilinger, Anton
2016-11-01
Spatial modes of light can potentially carry a vast amount of information, making them promising candidates for both classical and quantum communication. However, the distribution of such modes over large distances remains difficult. Intermodal coupling complicates their use with common fibers, whereas free-space transmission is thought to be strongly influenced by atmospheric turbulence. Here, we show the transmission of orbital angular momentum modes of light over a distance of 143 km between two Canary Islands, which is 50× greater than the maximum distance achieved previously. As a demonstration of the transmission quality, we use superpositions of these modes to encode a short message. At the receiver, an artificial neural network is used for distinguishing between the different twisted light superpositions. The algorithm is able to identify different mode superpositions with an accuracy of more than 80% up to the third mode order and decode the transmitted message with an error rate of 8.33%. Using our data, we estimate that the distribution of orbital angular momentum entanglement over more than 100 km of free space is feasible. Moreover, the quality of our free-space link can be further improved by the use of state-of-the-art adaptive optics systems.
VIDEO TRANSMISSION SYSTEM IN ITV APPLICATION
WangYancai; WangQunwei; WangZhaohui
1996-01-01
The transmission characteristics of video transmission mediums,coaxial cable and optical fiber ,are discussed in the paper. The formulas for frequency bandwidthare given to evaluate the video transmission distance. For typical video transmissionsystems with BB/IM and PFM/IM using optical fiber as the channel, expressions andcalculating results for both SIN and sensitivity are given. Finally. the principle for selecting different type of transmission systems according to transmission distances of the industrial TV is presented.
Maximum Autocorrelation Factorial Kriging
Nielsen, Allan Aasbjerg; Conradsen, Knut; Pedersen, John L.
2000-01-01
This paper describes maximum autocorrelation factor (MAF) analysis, maximum autocorrelation factorial kriging, and its application to irregularly sampled stream sediment geochemical data from South Greenland. Kriged MAF images are compared with kriged images of varimax rotated factors from...
Saito, Atsushi; Cavalli, Valeria
2016-02-01
Neurons are extremely polarized cells. Axon lengths often exceed the dimension of the neuronal cell body by several orders of magnitude. These extreme axonal lengths imply that neurons have mastered efficient mechanisms for long distance signaling between soma and synaptic terminal. These elaborate mechanisms are required for neuronal development and maintenance of the nervous system. Neurons can fine-tune long distance signaling through calcium wave propagation and bidirectional transport of proteins, vesicles, and mRNAs along microtubules. The signal transmission over extreme lengths also ensures that information about axon injury is communicated to the soma and allows for repair mechanisms to be engaged. This review focuses on the different mechanisms employed by neurons to signal over long axonal distances and how signals are interpreted in the soma, with an emphasis on proteomic studies. We also discuss how proteomic approaches could help further deciphering the signaling mechanisms operating over long distance in axons. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.
Distance learning for similarity estimation.
Yu, Jie; Amores, Jaume; Sebe, Nicu; Radeva, Petia; Tian, Qi
2008-03-01
In this paper, we present a general guideline to find a better distance measure for similarity estimation based on statistical analysis of distribution models and distance functions. A new set of distance measures are derived from the harmonic distance, the geometric distance, and their generalized variants according to the Maximum Likelihood theory. These measures can provide a more accurate feature model than the classical Euclidean and Manhattan distances. We also find that the feature elements are often from heterogeneous sources that may have different influence on similarity estimation. Therefore, the assumption of single isotropic distribution model is often inappropriate. To alleviate this problem, we use a boosted distance measure framework that finds multiple distance measures which fit the distribution of selected feature elements best for accurate similarity estimation. The new distance measures for similarity estimation are tested on two applications: stereo matching and motion tracking in video sequences. The performance of boosted distance measure is further evaluated on several benchmark data sets from the UCI repository and two image retrieval applications. In all the experiments, robust results are obtained based on the proposed methods.
Dobrzynski, Leonard; Akjouj, Abdellatif; Li, Changsheng, E-mail: Abdellatif.Akjouj@univ-lille1.fr [Centre National de la Recherche Scientifique, Universite Lille Nord de France, Lille1, Institut d' Electronique, de Microelectronique et de Nanotechnologie, Unite de Physique, Batiment P5, 59655 Villeneuve d' Ascq Cedex (France)
2011-09-14
Plasmon cross transmission avoids the frontal collision between two plasmons traveling in opposite directions along a guide. The guide is made out of equidistant identical metal dots. Thanks to two resonator dots, the plasmon frontal impact is avoided by transmission of the two plasmons from the input guide to an output one. The resonator and guide dots are identical in size and metal composition. The dipole-dipole interactions are restricted to first nearest neighbors. A convenient metal doping is assumed to compensate exactly all attenuations. The parameters are the nearest neighbor distances between the dots. These distances are rescaled to the chain nearest neighbor distance d. The system has two symmetry mirror planes. This simple model enables us to obtain two analytic tuning relations for the plasmon cross transmission. The intensities of the transmitted signals versus kd, where k is the plasmon propagation vector, are also given. (paper)
Unit distances and diameters in Euclidean spaces
Swanepoel, Konrad J
2007-01-01
We show that the maximum number of unit distances or of diameters in a set of n points in d-dimensional Euclidean space is attained only by specific types of Lenz constructions, for all d >= 4 and n sufficiently large, depending on d. As a corollary we determine the exact maximum number of unit distances for all even d >= 6, and the exact maximum number of diameters for all d >= 4, for all $n$ sufficiently large, depending on d.
林躜; 李磊; 陈俊华; 郑堤; 唐辰; 李浩
2014-01-01
In order to solve the problem of low energy capturing efficiency of the horizontal axis turbine in tidal current power generation system at low current speed, a variable pump counter torque reference value model was established. In this study, based on the maximum power tracking theory and the torque equilibrium equation of turbine versus variable pump, a control system with indirect speed control, pressure feedback, and torque control was designed to achieve the maximum power capture of the turbine by regulating the output of the variable pump in a small range. The performance of the designed control system was simulated by means of the Automation Studio software, and corresponding sea test was conducted. Test results showed that the control system ran steadily, the captured power coefficient of the turbine fluctuated near 0.35 and 0.33, respectively, in the simulation and sea trials; compared with the uncontrolled, these numbers increased by 0.03 and 0.05, respectively. The capture efficiency of the turbine was enhanced, and the effectiveness of the control system was verified.%文章为解决水平轴潮流能发电系统在低于设计流速下叶轮能量捕获效率低的问题,运用最大功率跟踪控制理论及叶轮与变量泵传动轴力矩平衡方程,建立了变量泵反力矩参考值模型,设计了间接速度控制的压力反馈加转矩控制系统,通过小范围内调节变量泵排量,实现叶轮最大功率捕获。整个系统的性能在自动化工作室(automation studio)中进行了仿真测试,实验样机也进行了海上试验。仿真测试和海试结果显示,该控制系统工作稳定性好,仿真和海试时叶轮的捕获功率系数分别在0.35和0.33附近波动,相比不加控制,分别增加了约0.03和0.05,提高了叶轮的捕获效率,验证了控制系统的有效性。
McQuinn, Kristen. B. W.; Skillman, Evan D.; Dolphin, Andrew E.; Berg, Danielle; Kennicutt, Robert
2016-11-01
M104 (NGC 4594; the Sombrero galaxy) is a nearby, well-studied elliptical galaxy included in scores of surveys focused on understanding the details of galaxy evolution. Despite the importance of observations of M104, a consensus distance has not yet been established. Here, we use newly obtained Hubble Space Telescope optical imaging to measure the distance to M104 based on the tip of the red giant branch (TRGB) method. Our measurement yields the distance to M104 to be 9.55 ± 0.13 ± 0.31 Mpc equivalent to a distance modulus of 29.90 ± 0.03 ± 0.07 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian maximum likelihood technique that reduces measurement uncertainties. The most discrepant previous results are due to Tully-Fisher method distances, which are likely inappropriate for M104 given its peculiar morphology and structure. Our results are part of a larger program to measure accurate distances to a sample of well-known spiral galaxies (including M51, M74, and M63) using the TRGB method. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.
McQuinn, Kristen. B. W.; Skillman, Evan D.; Dolphin, Andrew E.; Berg, Danielle; Kennicutt, Robert
2016-07-01
Great investments of observing time have been dedicated to the study of nearby spiral galaxies with diverse goals ranging from understanding the star formation process to characterizing their dark matter distributions. Accurate distances are fundamental to interpreting observations of these galaxies, yet many of the best studied nearby galaxies have distances based on methods with relatively large uncertainties. We have started a program to derive accurate distances to these galaxies. Here we measure the distance to M51—the Whirlpool galaxy—from newly obtained Hubble Space Telescope optical imaging using the tip of the red giant branch method. We measure the distance modulus to be 8.58 ± 0.10 Mpc (statistical), corresponding to a distance modulus of 29.67 ± 0.02 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian Maximum Likelihood technique that reduces measurement uncertainties. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.
Maximum Autocorrelation Factorial Kriging
Nielsen, Allan Aasbjerg; Conradsen, Knut; Pedersen, John L.; Steenfelt, Agnete
2000-01-01
This paper describes maximum autocorrelation factor (MAF) analysis, maximum autocorrelation factorial kriging, and its application to irregularly sampled stream sediment geochemical data from South Greenland. Kriged MAF images are compared with kriged images of varimax rotated factors from an ordinary non-spatial factor analysis, and they are interpreted in a geological context. It is demonstrated that MAF analysis contrary to ordinary non-spatial factor analysis gives an objective discrimina...
The Distance Field Model and Distance Constrained MAP Adaptation Algorithm
YUPeng; WANGZuoying
2003-01-01
Spatial structure information, i.e., the rel-ative position information of phonetic states in the feature space, is long to be carefully researched yet. In this pa-per, a new model named “Distance Field” is proposed to describe the spatial structure information. Based on this model, a modified MAP adaptation algorithm named dis-tance constrained maximum a poateriori (DCMAP) is in-troduced. The distance field model gives large penalty when the spatial structure is destroyed. As a result the DCMAP reserves the spatial structure information in adaptation process. Experiments show the Distance Field Model improves the performance of MAP adapta-tion. Further results show DCMAP has strong cross-state estimation ability, which is used to train a well-performed speaker-dependent model by data from only part of pho-
McQuinn, Kristen B W; Dolphin, Andrew E; Berg, Danielle; Kennicutt, Robert
2016-01-01
M104 (NGC 4594; the Sombrero galaxy) is a nearby, well-studied elliptical galaxy included in scores of surveys focused on understanding the details of galaxy evolution. Despite the importance of observations of M104, a consensus distance has not yet been established. Here, we use newly obtained Hubble Space Telescope optical imaging to measure the distance to M104 based on the tip of the red giant branch method. Our measurement yields the distance to M104 to be 9.55 +/- 0.13 +/- 0.31 Mpc equivalent to a distance modulus of 29.90 +/- 0.03 +/- 0.07 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian Maximum Likelihood technique that reduces measurement uncertainties. The most discrepant previous results are due to Tully-Fisher method distances, which are likely inappropriate for M104 given its peculiar morphology and structure. Our results are part of a larger program to measu...
Maximum likely scale estimation
Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo
2005-01-01
A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...
Maximum Throughput in Multiple-Antenna Systems
Zamani, Mahdi
2012-01-01
The point-to-point multiple-antenna channel is investigated in uncorrelated block fading environment with Rayleigh distribution. The maximum throughput and maximum expected-rate of this channel are derived under the assumption that the transmitter is oblivious to the channel state information (CSI), however, the receiver has perfect CSI. First, we prove that in multiple-input single-output (MISO) channels, the optimum transmission strategy maximizing the throughput is to use all available antennas and perform equal power allocation with uncorrelated signals. Furthermore, to increase the expected-rate, multi-layer coding is applied. Analogously, we establish that sending uncorrelated signals and performing equal power allocation across all available antennas at each layer is optimum. A closed form expression for the maximum continuous-layer expected-rate of MISO channels is also obtained. Moreover, we investigate multiple-input multiple-output (MIMO) channels, and formulate the maximum throughput in the asympt...
MAXIMUM PRODUCTION OF TRANSMISSION MESSAGES RATE FOR SERVICE DISCOVERY PROTOCOLS
Intisar Al-Mejibli
2011-12-01
Full Text Available Minimizing the number of dropped User Datagram Protocol (UDP messages in a network is regarded asa challenge by researchers. This issue represents serious problems for many protocols particularly thosethat depend on sending messages as part of their strategy, such us service discovery protocols.This paper proposes and evaluates an algorithm to predict the minimum period of time required betweentwo or more consecutive messages and suggests the minimum queue sizes for the routers, to manage thetraffic and minimise the number of dropped messages that has been caused by either congestion or queueoverflow or both together. The algorithm has been applied to the Universal Plug and Play (UPnPprotocol using ns2 simulator. It was tested when the routers were connected in two configurations; as acentralized and de centralized. The message length and bandwidth of the links among the routers weretaken in the consideration. The result shows Better improvement in number of dropped messages `amongthe routers.
Maximum information photoelectron metrology
Hockett, P; Wollenhaupt, M; Baumert, T
2015-01-01
Photoelectron interferograms, manifested in photoelectron angular distributions (PADs), are a high-information, coherent observable. In order to obtain the maximum information from angle-resolved photoionization experiments it is desirable to record the full, 3D, photoelectron momentum distribution. Here we apply tomographic reconstruction techniques to obtain such 3D distributions from multiphoton ionization of potassium atoms, and fully analyse the energy and angular content of the 3D data. The PADs obtained as a function of energy indicate good agreement with previous 2D data and detailed analysis [Hockett et. al., Phys. Rev. Lett. 112, 223001 (2014)] over the main spectral features, but also indicate unexpected symmetry-breaking in certain regions of momentum space, thus revealing additional continuum interferences which cannot otherwise be observed. These observations reflect the presence of additional ionization pathways and, most generally, illustrate the power of maximum information measurements of th...
The Wiener maximum quadratic assignment problem
Cela, Eranda; Woeginger, Gerhard J
2011-01-01
We investigate a special case of the maximum quadratic assignment problem where one matrix is a product matrix and the other matrix is the distance matrix of a one-dimensional point set. We show that this special case, which we call the Wiener maximum quadratic assignment problem, is NP-hard in the ordinary sense and solvable in pseudo-polynomial time. Our approach also yields a polynomial time solution for the following problem from chemical graph theory: Find a tree that maximizes the Wiener index among all trees with a prescribed degree sequence. This settles an open problem from the literature.
On the maximum sufficient range of interstellar vessels
Cartin, Daniel
2011-01-01
This paper considers the likely maximum range of space vessels providing the basis of a mature interstellar transportation network. Using the principle of sufficiency, it is argued that this range will be less than three parsecs for the average interstellar vessel. This maximum range provides access from the Solar System to a large majority of nearby stellar systems, with total travel distances within the network not excessively greater than actual physical distance.
Transmission of single and multiple viral variants in primary HIV-1 subtype C infection.
Vladimir Novitsky
Full Text Available To address whether sequences of viral gag and env quasispecies collected during the early post-acute period can be utilized to determine multiplicity of transmitted HIV's, recently developed approaches for analysis of viral evolution in acute HIV-1 infection [1,2] were applied. Specifically, phylogenetic reconstruction, inter- and intra-patient distribution of maximum and mean genetic distances, analysis of Poisson fitness, shape of highlighter plots, recombination analysis, and estimation of time to the most recent common ancestor (tMRCA were utilized for resolving multiplicity of HIV-1 transmission in a set of viral quasispecies collected within 50 days post-seroconversion (p/s in 25 HIV-infected individuals with estimated time of seroconversion. The decision on multiplicity of HIV infection was made based on the model's fit with, or failure to explain, the observed extent of viral sequence heterogeneity. The initial analysis was based on phylogeny, inter-patient distribution of maximum and mean distances, and Poisson fitness, and was able to resolve multiplicity of HIV transmission in 20 of 25 (80% cases. Additional analysis involved distribution of individual viral distances, highlighter plots, recombination analysis, and estimation of tMRCA, and resolved 4 of the 5 remaining cases. Overall, transmission of a single viral variant was identified in 16 of 25 (64% cases, and transmission of multiple variants was evident in 8 of 25 (32% cases. In one case multiplicity of HIV-1 transmission could not be determined. In primary HIV-1 subtype C infection, samples collected within 50 days p/s and analyzed by a single-genome amplification/sequencing technique can provide reliable identification of transmission multiplicity in 24 of 25 (96% cases. Observed transmission frequency of a single viral variant and multiple viral variants were within the ranges of 64% to 68%, and 32% to 36%, respectively.
Maximum Likelihood Associative Memories
Gripon, Vincent; Rabbat, Michael
2013-01-01
Associative memories are structures that store data in such a way that it can later be retrieved given only a part of its content -- a sort-of error/erasure-resilience property. They are used in applications ranging from caches and memory management in CPUs to database engines. In this work we study associative memories built on the maximum likelihood principle. We derive minimum residual error rates when the data stored comes from a uniform binary source. Second, we determine the minimum amo...
Maximum likely scale estimation
Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo
2005-01-01
A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and....../or having different derivative orders. Although the principle is applicable to a wide variety of image models, the main focus here is on the Brownian model and its use for scale selection in natural images. Furthermore, in the examples provided, the simplifying assumption is made that the behavior...... of the measurements is completely characterized by all moments up to second order....
Favourite distances in high dimensions
Swanepoel, Konrad J
2011-01-01
Let $S$ be a set of $n$ points in $d$-dimensional Euclidean space. Assign to each $x\\in S$ an arbitrary distance $r(x)>0$. Let $e_r(x,S)$ denote the number of points in $S$ at distance $r(x)$ from $x$. Avis, Erd\\"os and Pach (1988) introduced the extremal quantity $f_d(n)=\\max\\sum_{x\\in S}e_r(x,S)$, where the maximum is taken over all $n$-point sets $S$ in $d$-dimensional space and all assignments $r\\colon S\\to(0,\\infty)$ of distances. We give a quick derivation of the asymptotics of the error term of $f_d(n)$ using only the analogous asymptotics of the maximum number of unit distance pairs in a set of $n$ points, which improves on previous results of Avis, Erd\\"os and Pach (1988) and Erd\\"os and Pach (1990). Then we prove a stability result for $d\\geq 4$, asserting that if $(S,r)$ with $|S|=n$ satisfies $e_r(S)=f_d(n)-o(n^2)$, then, up to $o(n)$ points, $S$ is a Lenz construction with $r$ constant. Finally we use stability to show that for $n$ sufficiently large (depending on $d$) the pairs $(S,r)$ that atta...
Deza, Michel Marie
2016-01-01
This 4th edition of the leading reference volume on distance metrics is characterized by updated and rewritten sections on some items suggested by experts and readers, as well a general streamlining of content and the addition of essential new topics. Though the structure remains unchanged, the new edition also explores recent advances in the use of distances and metrics for e.g. generalized distances, probability theory, graph theory, coding theory, data analysis. New topics in the purely mathematical sections include e.g. the Vitanyi multiset-metric, algebraic point-conic distance, triangular ratio metric, Rossi-Hamming metric, Taneja distance, spectral semimetric between graphs, channel metrization, and Maryland bridge distance. The multidisciplinary sections have also been supplemented with new topics, including: dynamic time wrapping distance, memory distance, allometry, atmospheric depth, elliptic orbit distance, VLBI distance measurements, the astronomical system of units, and walkability distance. Lea...
F. TopsÃƒÂ¸e
2001-09-01
Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over
Bourdine, Anton V.; Zhukov, Alexander E.
2017-04-01
High bit rate laser-based data transmission over silica optical fibers with enlarged core diameter in comparison with standard singlemode fibers is found variety infocommunication applications. Since IEEE 802.3z standard was ratified on 1998 this technique started to be widely used for short-range in-premises distributed multi-Gigabit networks based on new generation laser optimized multimode fibers 50/125 of Cat. OM2…OM4. Nowadays it becomes to be in demand for on-board cable systems and industrial network applications requiring 1Gps and more bit rates over fibers with extremely enlarged core diameter up to 100 μm. This work presents an alternative method for design the special refractive index profiles of silica few-mode fibers with extremely enlarged core diameter, that provides modal bandwidth enhancing under a few-mode regime of laser-based data optical transmission. Here some results are presented concerning with refractive index profile synthesis for few-mode fibers with reduced differential mode delay for "O"-band central region, as well as computed differential mode delay spectral curves corresponding to profiles for fibers 50/125 and 100/125 for in-premises and on-board/industrial cable systems.
刘建华; 刁美玲; 王春艳; 陈晨; 高金良
2012-01-01
为研究长距离、超高扬程、一次加压提升的长距离输水系统水锤防护问题,结合我国西北地区某工程实例,针对超高扬程达370 m、一次加压提升的长距离输水系统建立了水锤防护设备模型.以特征线法对其进行求解,分别以两阶段控制阀、单向调压塔、气压罐为水锤防护设备方案,建立水锤防护设备模型,分别模拟分析事故停泵管线水锤防护效果,最终通过综合对比技术性能和经济性能来确定最优的水锤防护方案.结果表明,对于超高扬程、一次加压提升的长距离输水系统,在水泵出口处设置气压罐进行水锤防护,能够有效缓解过高和过低的水锤压力,水锤防护效果好.针对不同长距离输水工程特点,建立各种水锤防护设备模型,以特征线法进行求解,其求解结果有效指导水锤防护方案的优选.%For the study of long distance, high lift, a pressurization hoisting for long distance water system water hammer protection problems in Northwest China, combined with an engineering example, the high lift up to 370 m, a pressurization hoisting for long distance water system was established for the water hammer protection device model. The characteristic line method to solve the model, respectively to two stage control valve, one-way pressure regulating tower, pressure tank for water hammer protection equipment plan, establishment of water hammer protection equipment model, respectively, simulation analysis of accidental pump stop pipeline water hammer protection effect, ultimately through the comprehensive comparison of technical and economic performance to determine the optimal water hammer protection scheme. The results showed that, for high lift, a pressurization hoisting long distance water transfer system, the pump outlet pressure tank for water hammer protection settings, could effectively alleviate the high and low water pressure, water hammer protection effect was good
Regularized maximum correntropy machine
Wang, Jim Jing-Yan
2015-02-12
In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.
SEXUAL DIMORPHISM OF MAXIMUM FEMORAL LENGTH
Pandya A M
2011-04-01
Full Text Available Sexual identification from the skeletal parts has medico legal and anthropological importance. Present study aims to obtain values of maximum femoral length and to evaluate its possible usefulness in determining correct sexual identification. Study sample consisted of 184 dry, normal, adult, human femora (136 male & 48 female from skeletal collections of Anatomy department, M. P. Shah Medical College, Jamnagar, Gujarat. Maximum length of femur was considered as maximum vertical distance between upper end of head of femur and the lowest point on femoral condyle, measured with the osteometric board. Mean Values obtained were, 451.81 and 417.48 for right male and female, and 453.35 and 420.44 for left male and female respectively. Higher value in male was statistically highly significant (P< 0.001 on both sides. Demarking point (D.P. analysis of the data showed that right femora with maximum length more than 476.70 were definitely male and less than 379.99 were definitely female; while for left bones, femora with maximum length more than 484.49 were definitely male and less than 385.73 were definitely female. Maximum length identified 13.43% of right male femora, 4.35% of right female femora, 7.25% of left male femora and 8% of left female femora. [National J of Med Res 2011; 1(2.000: 67-70
Indira Gandhi National Open University, New Delhi (India). Distance Education Council.
Since its inception in India in 1962, distance education has grown in popularity. The Distance Education Council (DEC) directs distance learning within India's higher education system. The DEC's promotion, coordination, and maintenance of standards for distance education are its three major roles. Its initiatives include grants, support for…
Training for Distance Teaching through Distance Learning.
Cadorath, Jill; Harris, Simon; Encinas, Fatima
2002-01-01
Describes a mixed-mode bachelor degree course in English language teaching at the Universidad Autonoma de Puebla (Mexico) that was designed to help practicing teachers write appropriate distance education materials by giving them the experience of being distance students. Includes a course outline and results of a course evaluation. (Author/LRW)
Equalized near maximum likelihood detector
2012-01-01
This paper presents new detector that is used to mitigate intersymbol interference introduced by bandlimited channels. This detector is named equalized near maximum likelihood detector which combines nonlinear equalizer and near maximum likelihood detector. Simulation results show that the performance of equalized near maximum likelihood detector is better than the performance of nonlinear equalizer but worse than near maximum likelihood detector.
Cheeseman, Peter; Stutz, John
2005-01-01
A long standing mystery in using Maximum Entropy (MaxEnt) is how to deal with constraints whose values are uncertain. This situation arises when constraint values are estimated from data, because of finite sample sizes. One approach to this problem, advocated by E.T. Jaynes [1], is to ignore this uncertainty, and treat the empirically observed values as exact. We refer to this as the classic MaxEnt approach. Classic MaxEnt gives point probabilities (subject to the given constraints), rather than probability densities. We develop an alternative approach that assumes that the uncertain constraint values are represented by a probability density {e.g: a Gaussian), and this uncertainty yields a MaxEnt posterior probability density. That is, the classic MaxEnt point probabilities are regarded as a multidimensional function of the given constraint values, and uncertainty on these values is transmitted through the MaxEnt function to give uncertainty over the MaXEnt probabilities. We illustrate this approach by explicitly calculating the generalized MaxEnt density for a simple but common case, then show how this can be extended numerically to the general case. This paper expands the generalized MaxEnt concept introduced in a previous paper [3].
HVDC power transmission technology assessment
Hauth, R.L.; Tatro, P.J.; Railing, B.D. [New England Power Service Co., Westborough, MA (United States); Johnson, B.K.; Stewart, J.R. [Power Technologies, Inc., Schenectady, NY (United States); Fink, J.L.
1997-04-01
The purpose of this study was to develop an assessment of the national utility system`s needs for electric transmission during the period 1995-2020 that could be met by future reduced-cost HVDC systems. The assessment was to include an economic evaluation of HVDC as a means for meeting those needs as well as a comparison with competing technologies such as ac transmission with and without Flexible AC Transmission System (FACTS) controllers. The role of force commutated dc converters was to be assumed where appropriate. The assessment begins by identifying the general needs for transmission in the U.S. in the context of a future deregulated power industry. The possible roles for direct current transmission are then postulated in terms of representative scenarios. A few of the scenarios are illustrated with the help of actual U.S. system examples. non-traditional applications as well as traditional applications such as long lines and asynchronous interconnections are discussed. The classical ``break-even distance`` concept for comparing HVDC and ac lines is used to assess the selected scenarios. The impact of reduced-cost converters is reflected in terms of the break-even distance. This report presents a comprehensive review of the functional benefits of HVDC transmission and updated cost data for both ac and dc system components. It also provides some provocative thoughts on how direct current transmission might be applied to better utilize and expand our nation`s increasingly stressed transmission assets.
Deza, Michel Marie
2014-01-01
This updated and revised third edition of the leading reference volume on distance metrics includes new items from very active research areas in the use of distances and metrics such as geometry, graph theory, probability theory and analysis. Among the new topics included are, for example, polyhedral metric space, nearness matrix problems, distances between belief assignments, distance-related animal settings, diamond-cutting distances, natural units of length, Heidegger’s de-severance distance, and brain distances. The publication of this volume coincides with intensifying research efforts into metric spaces and especially distance design for applications. Accurate metrics have become a crucial goal in computational biology, image analysis, speech recognition and information retrieval. Leaving aside the practical questions that arise during the selection of a ‘good’ distance function, this work focuses on providing the research community with an invaluable comprehensive listing of the main available di...
Cakoni, Fioralba; Haddar, Houssem
2013-10-01
In inverse scattering theory, transmission eigenvalues can be seen as the extension of the notion of resonant frequencies for impenetrable objects to the case of penetrable dielectrics. The transmission eigenvalue problem is a relatively late arrival to the spectral theory of partial differential equations. Its first appearance was in 1986 in a paper by Kirsch who was investigating the denseness of far-field patterns for scattering solutions of the Helmholtz equation or, in more modern terminology, the injectivity of the far-field operator [1]. The paper of Kirsch was soon followed by a more systematic study by Colton and Monk in the context of developing the dual space method for solving the inverse scattering problem for acoustic waves in an inhomogeneous medium [2]. In this paper they showed that for a spherically stratified media transmission eigenvalues existed and formed a discrete set. Numerical examples were also given showing that in principle transmission eigenvalues could be determined from the far-field data. This first period of interest in transmission eigenvalues was concluded with papers by Colton et al in 1989 [3] and Rynne and Sleeman in 1991 [4] showing that for an inhomogeneous medium (not necessarily spherically stratified) transmission eigenvalues, if they existed, formed a discrete set. For the next seventeen years transmission eigenvalues were ignored. This was mainly due to the fact that, with the introduction of various sampling methods to determine the shape of an inhomogeneous medium from far-field data, transmission eigenvalues were something to be avoided and hence the fact that transmission eigenvalues formed at most a discrete set was deemed to be sufficient. In addition, questions related to the existence of transmission eigenvalues or the structure of associated eigenvectors were recognized as being particularly difficult due to the nonlinearity of the eigenvalue problem and the special structure of the associated transmission
Distances from Planetary Nebulae
Ciardullo, R
2003-01-01
The [O III] 5007 planetary nebula luminosity function (PNLF) occupies an important place on the extragalactic distance ladder. Since it is the only method that is applicable to all the large galaxies of the Local Supercluster, it is uniquely useful for cross-checking results and linking the Population I and Population II distance scales. We review the physics underlying the method, demonstrate its precision, and illustrate its value by comparing its distances to distances obtained from Cepheids and the Surface Brightness Fluctuation (SBF) method. We use the Cepheid and PNLF distances to 13 galaxies to show that the metallicity dependence of the PNLF cutoff is in excellent agreement with that predicted from theory, and that no additional systematic corrections are needed for either method. However, when we compare the Cepheid-calibrated PNLF distance scale with the Cepheid-calibrated SBF distance scale, we find a significant offset: although the relative distances of both methods are in excellent agreement, th...
A generalized evidence distance
Hongming Mo; Xi Lu; Yong Deng
2016-01-01
How to efficiently measure the distance between two basic probability assignments (BPAs) is an open issue. In this paper, a new method to measure the distance between two BPAs is proposed, based on two existing measures of evidence distance. The new proposed method is comprehen-sive and generalized. Numerical examples are used to ilus-trate the effectiveness of the proposed method.
Maximum a posteriori decoder for digital communications
Altes, Richard A. (Inventor)
1997-01-01
A system and method for decoding by identification of the most likely phase coded signal corresponding to received data. The present invention has particular application to communication with signals that experience spurious random phase perturbations. The generalized estimator-correlator uses a maximum a posteriori (MAP) estimator to generate phase estimates for correlation with incoming data samples and for correlation with mean phases indicative of unique hypothesized signals. The result is a MAP likelihood statistic for each hypothesized transmission, wherein the highest value statistic identifies the transmitted signal.
CORA: Emission Line Fitting with Maximum Likelihood
Ness, Jan-Uwe; Wichmann, Rainer
2011-12-01
CORA analyzes emission line spectra with low count numbers and fits them to a line using the maximum likelihood technique. CORA uses a rigorous application of Poisson statistics. From the assumption of Poissonian noise, the software derives the probability for a model of the emission line spectrum to represent the measured spectrum. The likelihood function is used as a criterion for optimizing the parameters of the theoretical spectrum and a fixed point equation is derived allowing an efficient way to obtain line fluxes. CORA has been applied to an X-ray spectrum with the Low Energy Transmission Grating Spectrometer (LETGS) on board the Chandra observatory.
Larsen, Gunvor Riber
The environmental impact of tourism mobility is linked to the distances travelled in order to reach a holiday destination, and with tourists travelling more and further than previously, an understanding of how the tourists view the distance they travel across becomes relevant. Based on interviews...... contribute to an understanding of how it is possible to change tourism travel behaviour towards becoming more sustainable. How tourists 'consume distance' is discussed, from the practical level of actually driving the car or sitting in the air plane, to the symbolic consumption of distance that occurs when...... travelling on holiday becomes part of a lifestyle and a social positioning game. Further, different types of tourist distance consumers are identified, ranging from the reluctant to the deliberate and nonchalant distance consumers, who display very differing attitudes towards the distance they all travel...
Ristad, E S; Ristad, Eric Sven; Yianilos, Peter N.
1996-01-01
In many applications, it is necessary to determine the similarity of two strings. A widely-used notion of string similarity is the edit distance: the minimum number of insertions, deletions, and substitutions required to transform one string into the other. In this report, we provide a stochastic model for string edit distance. Our stochastic model allows us to learn a string edit distance function from a corpus of examples. We illustrate the utility of our approach by applying it to the difficult problem of learning the pronunciation of words in conversational speech. In this application, we learn a string edit distance with one fourth the error rate of the untrained Levenshtein distance. Our approach is applicable to any string classification problem that may be solved using a similarity function against a database of labeled prototypes. Keywords: string edit distance, Levenshtein distance, stochastic transduction, syntactic pattern recognition, prototype dictionary, spelling correction, string correction, ...
Interface Simulation Distances
Pavol Černý
2012-10-01
Full Text Available The classical (boolean notion of refinement for behavioral interfaces of system components is the alternating refinement preorder. In this paper, we define a distance for interfaces, called interface simulation distance. It makes the alternating refinement preorder quantitative by, intuitively, tolerating errors (while counting them in the alternating simulation game. We show that the interface simulation distance satisfies the triangle inequality, that the distance between two interfaces does not increase under parallel composition with a third interface, and that the distance between two interfaces can be bounded from above and below by distances between abstractions of the two interfaces. We illustrate the framework, and the properties of the distances under composition of interfaces, with two case studies.
邱建; 曾耿晖; 李一泉; 陈志光; 屠卿瑞; 张葆红
2015-01-01
A complete detecting impedance analysis model of transmission lines with mutual inductance is developed from the angle of setting.In the model,the influence mechanism of various factors on the measured impendence of grounding distance protection is qualitatively analyzed and quantitatively validated.With these results,the conditions for the simplified model which can calculate the extreme values of the measured impendence are proposed.On this basis and by referring to typical extreme value cases in the power system,the sideline current addition influence of the detecting impendence of transmission lines with mutual inductance is further analyzed.Finally,the optimal relay setting strategy for the grounding distance protection based on the analysis results is proposed.The strategy is implemented in Guangdong power grid.Actual application results show that the optimal strategy is able to improve the adaptability and performance of grounding distance protection.%从整定的角度建立互感线路感受阻抗分析完整模型，并对模型中各因素影响互感线路接地距离保护测量阻抗的机理进行定性分析和定量验证，提出了求取测量阻抗极值的简化模型条件。在此基础上结合电网中典型极值工况进一步对互感线路感受阻抗的助增影响进行分析。最后，根据分析结论提出了接地距离保护定值的整定优化策略，该整定策略已在广东电网全面应用，实际应用结果表明该整定策略能够提高接地距离保护定值的适应性，改善了接地距离保护定值的性能。
Mohamed, Abd El Naser A; Rashed, Ahmed Nabih Zaki; Nabawy, Amina E M El
2009-01-01
In the present paper, the transmission performance analysis of digital wire and wireless optical links in local and wide areas optical networks have been modeled and parametrically investigated over wide range of the affecting parameters. Moreover, we have analyzed the basic equations of the comparative study of the performance of digital fiber optic links with wire and wireless optical links. The development of optical wireless communication systems is accelerating as a high cost effective to wire fiber optic links. The optical wireless technology is used mostly in wide bandwidth data transmission applications. Finally, we have investigated the maximum transmission distance and data transmission bit rates that can be achieved within digital wire and wireless optical links for local and wide areas optical network applications.
A study on geometry effect of transmission coil for micro size magnetic induction coil
Lee, Kyung Hwa; Jun, Byoung Ok; Kim, Seunguk; Lee, Gwang Jun; Ryu, Mingyu; Choi, Ji-Woong; Jang, Jae Eun
2016-05-01
The effects of transmission (Tx) coil structure have been studied for micro-size magnetic induction coil. The size of the receiving (Rx) coil should be shrunk to the micrometer level for the various new applications such as micro-robot and wireless body implanted devices. In case of the macro-scale magnetic induction coil, the power transmission efficiency is generally considered to be higher as the inductance of the transmission coil became larger; however, the large size difference between macro-size Tx coil and micro-size Rx coil can decrease the power transmission efficiency due to the difference of resonance frequency. Here, we study a correlation of the power transmission with the size and distance between the macro-size Tx and micro-size Rx coils using magnetic induction technique. The maximum power efficiency was 0.28/0.23/0.13/0.12% at the distance of 0.3/1/3/5 cm between Rx and Tx coil. In addition, more efficient wireless power transferring method is suggested with a floating coil for the body implantable devices. The voltage output increased up to 5.4 mV than the original one Tx coil system. The results demonstrated the foundational wireless power transferring system with enhanced power efficiency.
崔迪
2015-01-01
Abstract:Quantum transmission is based on quantum entanglement, which is a kind of the phenomenon of quantum mechanics. Quantum object refers to two or more between the localized, the classic strong correlation. When two object quantum entanglement in the quantum state is not independent, but related, and the correlation distance, a pair of electronic of entanglement state, no matter how far apart, they spin direction will remain an up and a down. If one of the electronic spin direction is changed, another of the electron spin direction wil follow to change immediately.
Transmissions in vehicles 2010
NONE
2010-07-01
Within the international VDI congress 'Gears in vehicles 2010' of the VDI Wissensforum GmbH (Duesseldorf, Federal Republic of Germany) between 22nd and 23rd June, 2010, in Friedrichshafen (Federal Republic of Germany), the following lectures were held: (1) 8HP70H - The moldhybrid transmission from ZF - Cjallenges and achievements (P. Gutmann); (2) GETRAG boosted range extender - A highly flexible electric powertrain for maximum CO{sub 2} reduction (S. Huepkes); (3) E-Transmission between full-hybrid and E-drive (P. Tenberge); (4) Reducing NO{sub x} and particulate emissions in electrified drivelines (R. Kuberczyk); (5) Simulation aided HEV and EV development: from the component to the whole powertrain (A. Gacometti); (6) Investigations on operating behaviour of the optimized CVT hybrid driveline (B.-R. Hoehn); (7) Customer-oriented dimensioning of electrified drivetrains (M. Eghtessad); (8) Decentralized optimal control strategy for parallel hybrid electric vehicles (A. Frenkel); (9) The new generation 6-speed automatic transmission AF40 (G. Bednarek); (10) Customized mechatronic solutions for integrated transmission control units (M. Wieczorek); (11) The optimal automatic transmission for front-transverse applications - Planetary transmissions or dual clutch transmissions? (G. Gumpoltsberger); (12) The new shift-by-wire gearshift lever for the Audi A8 - Requirements and concept (T. Guttenbergere); (13) The new shift-by-wire gearshift lever for the Audi A8 - Realization (A. Giefer); (14) Fuel-efficient transmissions of the future: Calculation of the efficiency factor for vehicle transmissions (B. Volpert); (15) HT-ACM: A new polymer generation for static and dynamic gearbox sealing solutions (E. Osen); (16) 'Energy efficiency equipped solutions by SKF' for power train applications - A contribution to CO{sub 2} - emission reduction and sustainability (T. Bobke); (17) 6-Ratio planetary shift transmission controlled by 4 external brakes, and design
Glen Gatin
2013-06-01
Full Text Available This analysis began with inquiries into the substantive area of distance education using the classic grounded theory method. Analysis revealed a pattern of problemsolving behavior, from which the theory Keeping Your Distance emerged. The theory is an integrated set of concepts referring to the conscious and unconscious strategiesthat people use to regulate distance, physical and representative, in their everyday lives. Strategies are used to control physical, emotional, and psychological realities and to conserve personal energy in interactions with individuals and/or institutions.For all social interactions, people use a personalized algorithm of engagement that mitigates conditions and consequences and preserves optimal distance. Keeping Your Distance provides a theoretical starting point for considerations of the changing notions of distance. In part, these changes have been brought about bydevelopments in the fields of Information and Communication Technology (ICT and online social networking.
... Abroad Treatment Basic Statistics Get Tested Find an HIV testing site near you. Enter ZIP code or city Follow HIV/AIDS CDC HIV CDC HIV/AIDS See RSS | ... on HIV Syndicated Content Website Feedback HIV/AIDS HIV Transmission Language: English (US) EspaÃ±ol (Spanish) Recommend ...
Fotini Karinou
2017-02-01
Full Text Available We experimentally investigate the transmission performance of 56 Gb/s four-level pulse amplitude modulation (PAM-4 over 30-km standard single mode fiber (SMF using a C-band EML for low-cost metro and short-reach wavelength division multiplexing (WDM applications. Bit error rate (BER performance below the HD-FEC threshold is achieved for up to 30-km maximum reported distance without employing dispersion compensation fiber (DCF in the link.
Normalized information distance
Vitányi, P.M.B.; Balbach, F.J.; Cilibrasi, R.L.; Li, M.; Emmert-Streib, F.; Dehmer, M.
2009-01-01
The normalized information distance is a universal distance measure for objects of all kinds. It is based on Kolmogorov complexity and thus uncomputable, but there are ways to utilize it. First, compression algorithms can be used to approximate the Kolmogorov complexity if the objects have a string
Normalized information distance
Vitányi, P.M.B.; Balbach, F.J.; Cilibrasi, R.L.; Li, M.
2008-01-01
The normalized information distance is a universal distance measure for objects of all kinds. It is based on Kolmogorov complexity and thus uncomputable, but there are ways to utilize it. First, compression algorithms can be used to approximate the Kolmogorov complexity if the objects have a string
Incremental Distance Transforms (IDT)
Schouten, Theo E.; van den Broek, Egon; Erçil, A.; Çetin, M.; Boyer, K.; Lee, S.-W.
2010-01-01
A new generic scheme for incremental implementations of distance transforms (DT) is presented: Incremental Distance Transforms (IDT). This scheme is applied on the cityblock, Chamfer, and three recent exact Euclidean DT (E2DT). A benchmark shows that for all five DT, the incremental implementation r
ORDERED WEIGHTED DISTANCE MEASURE
Zeshui XU; Jian CHEN
2008-01-01
The aim of this paper is to develop an ordered weighted distance (OWD) measure, which is thegeneralization of some widely used distance measures, including the normalized Hamming distance, the normalized Euclidean distance, the normalized geometric distance, the max distance, the median distance and the min distance, etc. Moreover, the ordered weighted averaging operator, the generalized ordered weighted aggregation operator, the ordered weighted geometric operator, the averaging operator, the geometric mean operator, the ordered weighted square root operator, the square root operator, the max operator, the median operator and the min operator axe also the special cases of the OWD measure. Some methods depending on the input arguments are given to determine the weights associated with the OWD measure. The prominent characteristic of the OWD measure is that it can relieve (or intensify) the influence of unduly large or unduly small deviations on the aggregation results by assigning them low (or high) weights. This desirable characteristic makes the OWD measure very suitable to be used in many actual fields, including group decision making, medical diagnosis, data mining, and pattern recognition, etc. Finally, based on the OWD measure, we develop a group decision making approach, and illustrate it with a numerical example.
C. Binder (C.); C. Heilmann (Conrad)
2017-01-01
markdownabstractEver since the publication of Peter Singer’s article ‘‘Famine, Affluence, and Morality’’ has the question of whether the (geographical) distance to people in need affects our moral duties towards them been a hotly debated issue. Does geographical distance affect our moral duties?
Biomechanics of Distance Running.
Cavanagh, Peter R., Ed.
Contributions from researchers in the field of running mechanics are included in the 13 chapters of this book. The following topics are covered: (1) "The Mechanics of Distance Running: A Historical Perspective" (Peter Cavanagh); (2) "Stride Length in Distance Running: Velocity, Body Dimensions, and Added Mass Effects" (Peter Cavanagh, Rodger…
Distance Learning Environment Demonstration.
1996-11-01
The Distance Learning Environment Demonstration (DLED) was a comparative study of distributed multimedia computer-based training using low cost high...measurement. The DLED project provides baseline research in the effective use of distance learning and multimedia communications over a wide area ATM/SONET
C. Binder (C.); C. Heilmann (Conrad)
2017-01-01
markdownabstractEver since the publication of Peter Singer’s article ‘‘Famine, Affluence, and Morality’’ has the question of whether the (geographical) distance to people in need affects our moral duties towards them been a hotly debated issue. Does geographical distance affect our moral
Estimating distances from parallaxes
Astraatmadja, Tri L.; Bailer-Jones, Coryn
2017-01-01
In astrometric surveys such as Gaia and LSST, parallaxes will be measured for about a billion stars, but zero distances will be measured. Distances must be inferred from the parallaxes, and the common inference practice is by inverting the parallax. This, however, is only appropriate when there is no noise present. As noise will always be present and most stars in future surveys will have non-negligible fractional parallax uncertainties, we must treat distance estimation as an inference problem. The usage of prior assumptions become unavoidable. In this talk I will present a method on how to infer distances using Bayesian inference. Three minimalists, isotropic priors are used, as well an anisotropic prior derived from the observability of stars in a Milky Way model. The performance of these priors are investigated using a simulated Gaia-like catalogue. Recent results of distance estimation using the parallaxes of 2 million Gaia DR1 stars will also be discussed.
Normalized Information Distance
Vitanyi, Paul M B; Cilibrasi, Rudi L; Li, Ming
2008-01-01
The normalized information distance is a universal distance measure for objects of all kinds. It is based on Kolmogorov complexity and thus uncomputable, but there are ways to utilize it. First, compression algorithms can be used to approximate the Kolmogorov complexity if the objects have a string representation. Second, for names and abstract concepts, page count statistics from the World Wide Web can be used. These practical realizations of the normalized information distance can then be applied to machine learning tasks, expecially clustering, to perform feature-free and parameter-free data mining. This chapter discusses the theoretical foundations of the normalized information distance and both practical realizations. It presents numerous examples of successful real-world applications based on these distance measures, ranging from bioinformatics to music clustering to machine translation.
76 FR 5796 - Gas Transmission Northwest Corporation; Notice of Application
2011-02-02
..., 2011. Take notice that on January 14, 2011, Gas Transmission Northwest Corporation (GTN), 717 Texas... capacity and GTN's related obligation to provide transportation service related to maximum...
On the maximum backscattering cross section of passive linear arrays
Solymar, L.; Appel-Hansen, Jørgen
1974-01-01
The maximum backscattering cross section of an equispaced linear array connected to a reactive network and consisting of isotropic radiators is calculated forn = 2, 3, and 4 elements as a function of the incident angle and of the distance between the elements. On the basis of the results obtained...
Estimating distances from parallaxes
Bailer-Jones, C A L
2015-01-01
Astrometric surveys such as Gaia and LSST will measure parallaxes for hundreds of millions of stars. Yet they will not measure a single distance. Rather, a distance must be estimated from a parallax. In this didactic article, I show that doing this is not trivial once the fractional parallax error is larger than about 20%, which will be the case for about 80% of stars in the Gaia catalogue. Estimating distances is an inference problem in which the use of prior assumptions is unavoidable. I investigate the properties and performance of various priors and examine their implications. A supposed uninformative uniform prior in distance is shown to give very poor distance estimates (large bias and variance). Any prior with a sharp cut-off at some distance has similar problems. The choice of prior depends on the information one has available - and is willing to use - concerning, for example, the survey and the Galaxy. I demonstrate that a simple prior which decreases asymptotically to zero at infinite distance has g...
MOTIVATION FOR DISTANCE EDUCATION
R zvan TEF NESCU
2009-10-01
Full Text Available Beginning with the 1980’s the new information, communication and computer based technologies stimulated the development of the distance education. In Romania the universities adapted rapidly to this type of learning that became an important financing source for most of them. In this article we approach the causes of attraction for the distance education. For this purpose we use an investigation we did on a group of students at Distance Education including interviews regarding their reasons for choosing this type of learning.
OECD Maximum Residue Limit Calculator
With the goal of harmonizing the calculation of maximum residue limits (MRLs) across the Organisation for Economic Cooperation and Development, the OECD has developed an MRL Calculator. View the calculator.
Dual-Rate Transmission Reduces Weather Effects
Posner, E. C.
1984-01-01
Scheme ensures maximum data received on average. Dual-rate scheme for maximizing data returned during spacecraft mission, adaptable, as is or with modifications, to high-frequency terrestrial data transmission. Data rate fixed in advance at minimum value guarantees reasonable prospect of success during bad weather. Dualrate strategy yields net data rate 2.5 times best achievable with single transmission rate.
Wei, Chia-Chien
2012-11-05
This work theoretically studies the transmission performance of a DML-based OFDM system by small-signal approximation, and the model considers both the transient and adiabatic chirps. The dispersion-induced distortion is modeled as subcarrier-to-subcarrier intermixing interference (SSII), and the theoretical SSII agrees with the distortion obtained from large-signal simulation statistically and deterministically. The analysis shows that the presence of the adiabatic chirp will ease power fading or even provide gain, but will increase the SSII to deteriorate OFDM signals after dispersive transmission. Furthermore, this work also proposes a novel iterative equalization to eliminate the SSII. From the simulation, the distortion could be effectively mitigated by the proposed equalization such that the maximum transmission distance of the DML-based OFDM signal is significantly improved. For instance, the transmission distance of a 30-Gbps DML-based OFDM signal can be extended from 10 km to more than 100 km. Besides, since the dispersion-induced distortion could be effectively mitigated by the equalization, negative power penalties are observed at some distances due to chirp-induced power gain.
Distance learning perspectives.
Pandza, Haris; Masic, Izet
2013-01-01
The development of modern technology and the Internet has enabled the explosive growth of distance learning. distance learning is a process that is increasingly present in the world. This is the field of education focused on educating students who are not physically present in the traditional classrooms or student's campus. described as a process where the source of information is separated from the students in space and time. If there are situations that require the physical presence of students, such as when a student is required to physically attend the exam, this is called a hybrid form of distance learning. This technology is increasingly used worldwide. The Internet has become the main communication channel for the development of distance learning.
Learning Pullback HMM Distances.
Cuzzolin, Fabio; Sapienza, Michael
2014-07-01
Recent work in action recognition has exposed the limitations of methods which directly classify local features extracted from spatio-temporal video volumes. In opposition, encoding the actions' dynamics via generative dynamical models has a number of attractive features: however, using all-purpose distances for their classification does not necessarily deliver good results. We propose a general framework for learning distance functions for generative dynamical models, given a training set of labelled videos. The optimal distance function is selected among a family of pullback ones, induced by a parametrised automorphism of the space of models. We focus here on hidden Markov models and their model space, and design an appropriate automorphism there. Experimental results are presented which show how pullback learning greatly improves action recognition performances with respect to base distances.
A Distance Measure for Genome Phylogenetic Analysis
Cao, Minh Duc; Allison, Lloyd; Dix, Trevor
Phylogenetic analyses of species based on single genes or parts of the genomes are often inconsistent because of factors such as variable rates of evolution and horizontal gene transfer. The availability of more and more sequenced genomes allows phylogeny construction from complete genomes that is less sensitive to such inconsistency. For such long sequences, construction methods like maximum parsimony and maximum likelihood are often not possible due to their intensive computational requirement. Another class of tree construction methods, namely distance-based methods, require a measure of distances between any two genomes. Some measures such as evolutionary edit distance of gene order and gene content are computational expensive or do not perform well when the gene content of the organisms are similar. This study presents an information theoretic measure of genetic distances between genomes based on the biological compression algorithm expert model. We demonstrate that our distance measure can be applied to reconstruct the consensus phylogenetic tree of a number of Plasmodium parasites from their genomes, the statistical bias of which would mislead conventional analysis methods. Our approach is also used to successfully construct a plausible evolutionary tree for the γ-Proteobacteria group whose genomes are known to contain many horizontally transferred genes.
Timing and order of transmission events is not directly reflected in a pathogen phylogeny.
Romero-Severson, Ethan; Skar, Helena; Bulla, Ingo; Albert, Jan; Leitner, Thomas
2014-09-01
Pathogen phylogenies are often used to infer spread among hosts. There is, however, not an exact match between the pathogen phylogeny and the host transmission history. Here, we examine in detail the limitations of this relationship. First, all splits in a pathogen phylogeny of more than 1 host occur within hosts, not at the moment of transmission, predating the transmission events as described by the pretransmission interval. Second, the order in which nodes in a phylogeny occur may be reflective of the within-host dynamics rather than epidemiologic relationships. To investigate these phenomena, motivated by within-host diversity patterns, we developed a two-phase coalescent model that includes a transmission bottleneck followed by linear outgrowth to a maximum population size followed by either stabilization or decline of the population. The model predicts that the pretransmission interval shrinks compared with predictions based on constant population size or a simple transmission bottleneck. Because lineages coalesce faster in a small population, the probability of a pathogen phylogeny to resemble the transmission history depends on when after infection a donor transmits to a new host. We also show that the probability of inferring the incorrect order of multiple transmissions from the same host is high. Finally, we compare time of HIV-1 infection informed by genetic distances in phylogenies to independent biomarker data, and show that, indeed, the pretransmission interval biases phylogeny-based estimates of when transmissions occurred. We describe situations where caution is needed not to misinterpret which parts of a phylogeny that may indicate outbreaks and tight transmission clusters. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution 2014. This work is written by US Government employees and is in the public domain in the US.
Yamanaka, Kota; Hirata, Shinnosuke; Hachiya, Hiroyuki
2016-07-01
Ultrasonic distance measurement for obstacles has been recently applied in automobiles. The pulse-echo method based on the transmission of an ultrasonic pulse and time-of-flight (TOF) determination of the reflected echo is one of the typical methods of ultrasonic distance measurement. Improvement of the signal-to-noise ratio (SNR) of the echo and the avoidance of crosstalk between ultrasonic sensors in the pulse-echo method are required in automotive measurement. The SNR of the reflected echo and the resolution of the TOF are improved by the employment of pulse compression using a maximum-length sequence (M-sequence), which is one of the binary pseudorandom sequences generated from a linear feedback shift register (LFSR). Crosstalk is avoided by using transmitted signals coded by different M-sequences generated from different LFSRs. In the case of lower-order M-sequences, however, the number of measurement channels corresponding to the pattern of the LFSR is not enough. In this paper, pulse compression using linear-frequency-modulated (LFM) signals coded by M-sequences has been proposed. The coding of LFM signals by the same M-sequence can produce different transmitted signals and increase the number of measurement channels. In the proposed method, however, the truncation noise in autocorrelation functions and the interference noise in cross-correlation functions degrade the SNRs of received echoes. Therefore, autocorrelation properties and cross-correlation properties in all patterns of combinations of coded LFM signals are evaluated.
Maximum life spiral bevel reduction design
Savage, M.; Prasanna, M. G.; Coe, H. H.
1992-07-01
Optimization is applied to the design of a spiral bevel gear reduction for maximum life at a given size. A modified feasible directions search algorithm permits a wide variety of inequality constraints and exact design requirements to be met with low sensitivity to initial values. Gear tooth bending strength and minimum contact ratio under load are included in the active constraints. The optimal design of the spiral bevel gear reduction includes the selection of bearing and shaft proportions in addition to gear mesh parameters. System life is maximized subject to a fixed back-cone distance of the spiral bevel gear set for a specified speed ratio, shaft angle, input torque, and power. Significant parameters in the design are: the spiral angle, the pressure angle, the numbers of teeth on the pinion and gear, and the location and size of the four support bearings. Interpolated polynomials expand the discrete bearing properties and proportions into continuous variables for gradient optimization. After finding the continuous optimum, a designer can analyze near optimal designs for comparison and selection. Design examples show the influence of the bearing lives on the gear parameters in the optimal configurations. For a fixed back-cone distance, optimal designs with larger shaft angles have larger service lives.
孙良; 赵匀; 姚佳明; 郑建; 俞高红; 祝宇
2012-01-01
In order to solve the problems such as grasping seedling obliquely and shaping wider plant hole, a wide - narrow distance transplanting mechanism with spatial planetary gear train composed of elliptical bevel gears and crossed cylindrical gears was put forward. Kinematical model was established based on the transmission characteristics. Furthermore, the proposed mechanism was proved capable of taking the advantages, which known as grasping seedling more vertically and shaping narrower plant hole, by the analysis on relation among the lateral offsets,, lateral plant hole of spatial planting trajectory and shaft angle. A optimization program about wide - narrow distance transplanting mechanism was written to research on the kinematics, and a set of optimal parameters meeting the working requirements of wide -narrow distance rice transplanter was obtained by the method of human - computer conversation afterward. Then configuration of elliptical bevel gear was achieved and virtual prototype test was performed by the software named ADAMS. Finally, a model machining of the transplanting mechanism as well as its testing was made, and concluding that the structural design and its parameters was suited to the requirements of wide - narrow distance rice transplanter.%针对现有宽窄行分插机构存在斜取秧和大穴口问题,提出一种由椭圆锥齿轮-交错圆柱齿轮混合传动的空间行星轮系宽窄行分插机构.分析了椭圆锥齿轮的传动特性,建立了机构的运动学模型.通过分析插秧轨迹的横向线位移、横向插秧穴口边长与传动齿轮交错角的关系,得出椭圆锥齿轮-交错圆柱齿轮混合传动方式可以兼顾斜置式和齿轮交错传动式的小穴口、直取秧的优点.开发了宽窄行分插机构参数优化软件,进行了机构的运动特征分析,并通过人机交互方式优化了一组满足宽窄行插秧机的机构参数.利用仿真软件ADAMS实现了椭圆锥齿轮齿廓的设计,并
Haddouk, Lise
2015-01-01
Nowadays in the context of the cyberculture, computer-mediated inter-subjective relationships are part of our everyday lives, in both the professional and personal spheres, and for all age groups. In the clinical field, many applications have been developed to facilitate the exchange of informations and mediate the relationship between patient and therapist. In psychology, more or less immersive technologies are used, to encourage the feeling of presence among the users, and to trigger certain psychological processes. In our research, we have explored the remote clinical interview through videoconferencing, with the development and utilisation of the iPSY platform, totally focused on this objective. In this context, we have considered the notion of intersubjectivity, despite the physical absence. This research is leading us today to envision the notions of distance and presence, and possibly to redefine them. Thus, can we still oppose physical distance to psychological distance? Can we still affirm that the physical absence does not permit a psychological co-presence in certain interactions, like this observed in video interviews? The results show that the psychological processes, activated in this context, are similar to those observed in "traditional" clinical consults between the patient and the therapist. However, certain specifics have led us to consider the concept of distance, here influenced by the framework, and to observe its effects. This distance could possibly constitute a therapeutic lever for some patients, notably for those who have difficulties establishing the right psychological distance in their relationships with others. According to these results, can "distance" still be opposed to "presence", or could it be re-defined? This also opens up questions on the more general concept of digital relationships, and the definition of their specificities.
Maximum margin Bayesian network classifiers.
Pernkopf, Franz; Wohlmayr, Michael; Tschiatschek, Sebastian
2012-03-01
We present a maximum margin parameter learning algorithm for Bayesian network classifiers using a conjugate gradient (CG) method for optimization. In contrast to previous approaches, we maintain the normalization constraints on the parameters of the Bayesian network during optimization, i.e., the probabilistic interpretation of the model is not lost. This enables us to handle missing features in discriminatively optimized Bayesian networks. In experiments, we compare the classification performance of maximum margin parameter learning to conditional likelihood and maximum likelihood learning approaches. Discriminative parameter learning significantly outperforms generative maximum likelihood estimation for naive Bayes and tree augmented naive Bayes structures on all considered data sets. Furthermore, maximizing the margin dominates the conditional likelihood approach in terms of classification performance in most cases. We provide results for a recently proposed maximum margin optimization approach based on convex relaxation. While the classification results are highly similar, our CG-based optimization is computationally up to orders of magnitude faster. Margin-optimized Bayesian network classifiers achieve classification performance comparable to support vector machines (SVMs) using fewer parameters. Moreover, we show that unanticipated missing feature values during classification can be easily processed by discriminatively optimized Bayesian network classifiers, a case where discriminative classifiers usually require mechanisms to complete unknown feature values in the data first.
Maximum Entropy in Drug Discovery
Chih-Yuan Tseng
2014-07-01
Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.
Miniaturized module for the wireless transmission of measurements with Bluetooth.
Roth, H; Schwaibold, M; Moor, C; Schöchlin, J; Bolz, A
2002-01-01
The wiring of patients for obtaining medical measurements has many disadvantages. In order to limit these, a miniaturized module was developed which digitalizes analog signals and sends the signal wirelessly to the receiver using Bluetooth. Bluetooth is especially suitable for this application because distances of up to 10 m are possible with low power consumption and robust transmission with encryption. The module consists of a Bluetooth chip, which is initialized in such a way by a microcontroller that connections from other bluetooth receivers can be accepted. The signals are then transmitted to the distant end. The maximum bit rate of the 23 mm x 30 mm module is 73.5 kBit/s. At 4.7 kBit/s, the current consumption is 12 mA.
Distance learning for similarity estimation
Yu, J.; Amores, J.; Sebe, N.; Radeva, P.; Tian, Q.
2008-01-01
In this paper, we present a general guideline to find a better distance measure for similarity estimation based on statistical analysis of distribution models and distance functions. A new set of distance measures are derived from the harmonic distance, the geometric distance, and their generalized
Antirandom Testing: A Distance-Based Approach
Shen Hui Wu
2008-01-01
Full Text Available Random testing requires each test to be selected randomly regardless of the tests previously applied. This paper introduces the concept of antirandom testing where each test applied is chosen such that its total distance from all previous tests is maximum. This spans the test vector space to the maximum extent possible for a given number of vectors. An algorithm for generating antirandom tests is presented. Compared with traditional pseudorandom testing, antirandom testing is found to be very effective when a high-fault coverage needs to be achieved with a limited number of test vectors. The superiority of the new approach is even more significant for testing bridging faults.
Stereoscopic distance perception
Foley, John M.
1989-01-01
Limited cue, open-loop tasks in which a human observer indicates distances or relations among distances are discussed. By open-loop tasks, it is meant tasks in which the observer gets no feedback as to the accuracy of the responses. What happens when cues are added and when the loop is closed are considered. The implications of this research for the effectiveness of visual displays is discussed. Errors in visual distance tasks do not necessarily mean that the percept is in error. The error could arise in transformations that intervene between the percept and the response. It is argued that the percept is in error. It is also argued that there exist post-perceptual transformations that may contribute to the error or be modified by feedback to correct for the error.
Distances to Dark Clouds: Comparing Extinction Distances to Maser Parallax Distances
Foster, Jonathan B; Benjamin, Robert A; Hoare, Melvin G; Jackson, James M
2012-01-01
We test two different methods of using near-infrared extinction to estimate distances to dark clouds in the first quadrant of the Galaxy using large near infrared (2MASS and UKIDSS) surveys. VLBI parallax measurements of masers around massive young stars provide the most direct and bias-free measurement of the distance to these dark clouds. We compare the extinction distance estimates to these maser parallax distances. We also compare these distances to kinematic distances, including recent re-calibrations of the Galactic rotation curve. The extinction distance methods agree with the maser parallax distances (within the errors) between 66% and 100% of the time (depending on method and input survey) and between 85% and 100% of the time outside of the crowded Galactic center. Although the sample size is small, extinction distance methods reproduce maser parallax distances better than kinematic distances; furthermore, extinction distance methods do not suffer from the kinematic distance ambiguity. This validatio...
Sets avoiding integral distances
Kurz, Sascha
2012-01-01
We study open point sets in Euclidean spaces $\\mathbb{R}^d$ without a pair of points an integral distance apart. By a result of Furstenberg, Katznelson, and Weiss such sets must be of Lebesgue upper density zero. We are interested in how large such sets can be in $d$-dimensional volume. We determine the lower and upper bounds for the volumes of the sets in terms of the number of their connected components and dimension, and also give some exact values. Our problem can be viewed as a kind of inverse to known problems on sets with pairwise rational or integral distances.
Hansen, Finn J. S.; Clausen, Christian
2001-01-01
The case study represents an example of a top-down introduction of distance teaching as part of Danish trials with the introduction of multimedia in education. The study is concerned with the background, aim and context of the trial as well as the role and working of the technology and the organi......The case study represents an example of a top-down introduction of distance teaching as part of Danish trials with the introduction of multimedia in education. The study is concerned with the background, aim and context of the trial as well as the role and working of the technology...
Greenslade, Thomas B., Jr.
1985-01-01
Discusses a series of experiments performed by Thomas Hope in 1805 which show the temperature at which water has its maximum density. Early data cast into a modern form as well as guidelines and recent data collected from the author provide background for duplicating Hope's experiments in the classroom. (JN)
Abolishing the maximum tension principle
Dabrowski, Mariusz P
2015-01-01
We find the series of example theories for which the relativistic limit of maximum tension $F_{max} = c^2/4G$ represented by the entropic force can be abolished. Among them the varying constants theories, some generalized entropy models applied both for cosmological and black hole horizons as well as some generalized uncertainty principle models.
Abolishing the maximum tension principle
Mariusz P. Da̧browski
2015-09-01
Full Text Available We find the series of example theories for which the relativistic limit of maximum tension Fmax=c4/4G represented by the entropic force can be abolished. Among them the varying constants theories, some generalized entropy models applied both for cosmological and black hole horizons as well as some generalized uncertainty principle models.
Predicting dispersal distance in mammals: a trait-based approach.
Whitmee, Sarah; Orme, C David L
2013-01-01
Dispersal is one of the principal mechanisms influencing ecological and evolutionary processes but quantitative empirical data are unfortunately scarce. As dispersal is likely to influence population responses to climate change, whether by adaptation or by migration, there is an urgent need to obtain estimates of dispersal distance. Cross-species correlative approaches identifying predictors of dispersal distance can provide much-needed insights into this data-scarce area. Here, we describe the compilation of a new data set of natal dispersal distances and use it to test life-history predictors of dispersal distance in mammals and examine the strength of the phylogenetic signal in dispersal distance. We find that both maximum and median dispersal distances have strong phylogenetic signals. No single model performs best in describing either maximum or median dispersal distances when phylogeny is taken into account but many models show high explanatory power, suggesting that dispersal distance per generation can be estimated for mammals with comparatively little data availability. Home range area, geographic range size and body mass are identified as the most important terms across models. Cross-validation of models supports the ability of these variables to predict dispersal distances, suggesting that models may be extended to species where dispersal distance is unknown.
Distances to star forming regions
Loinard, Laurent
2014-01-01
The determination of accurate distances to star-forming regions are discussed in the broader historical context of astronomical distance measurements. We summarize recent results for regions within 1 kpc and present perspectives for the near and more distance future.
Point of Connection Transmission Pricing in India
Soonee, S. K.; Barpanda, S. S.; Joshi, Mohit; Mishra, Nripen; Bhardwaj, Vaishally
2013-05-01
The National Electricity Policy (NEP) [1], issued by the Government of India, mandates transmission prices to be distance and direction sensitive and capture utilization of the network by each network user. In line with the mandate, the Central Electricity Regulatory Commission (CERC) [2] has issued Sharing of Interstate Transmission Charges and Losses Regulations, 2010 [3], to introduce point of connection (PoC)-based transmission pricing methodology in India. The methodology under the above regulations introduces one of the major reforms of its kind in the Indian power sector and seeks to share the total transmission charges in proportion to respective utilization of the transmission system by different entities. In this paper, the authors have enumerated their experience gained from the implementation of PoC-based transmission pricing regime in India. Authors have also discussed various issues encountered in the process of implementation and the methodology adopted.
Ortiz-Arroyo, Daniel; Yazdani, Hossein
2017-01-01
The accuracy of machine learning methods for clustering depends on the optimal selection of similarity functions. Conventional distance functions for the vector space might cause an algorithm to being affected by some dominant features that may skew its ﬁnal results. This paper introduces a ﬂexib...
Encyclopedia of Distance Learning
Howard, Caroline, Ed.; Boettecher, Judith, Ed.; Justice, Lorraine, Ed.; Schenk, Karen, Ed.; Rogers, Patricia, Ed.; Berg, Gary, Ed.
2005-01-01
The innovations in computer and communications technologies combined with on-going needs to deliver educational programs to students regardless of their physical locations, have lead to the innovation of distance education programs and technologies. To keep up with recent developments in both areas of technologies and techniques related to…
Accreditation of Distance Learning
Demirel, Ergün
2016-01-01
The higher education institutes aspire to gain reputation of quality having accreditation from internationally recognized awarding bodies. The accreditation leads and provides quality assurance for education. Although distance learning becomes a significant part of the education system in the 21st century, there is still a common opinion that the…
Rahman, Monsurur; Karim, Reza; Byramjee, Framarz
2015-01-01
Many educational institutions in the United States are currently offering programs through distance learning, and that trend is rising. In almost all spheres of education a developing country like Bangladesh needs to make available the expertise of the most qualified faculty to her distant people. But the fundamental question remains as to whether…
Murphy, Elizabeth; Rodriguez-Manzanares, Maria A.
2012-01-01
Rapport has been recognized as important in learning in general but little is known about its importance in distance education (DE). The study we report on in this paper provides insights into the importance of rapport in DE as well as challenges to and indicators of rapport-building in DE. The study relied on interviews with 42 Canadian…
Misconceptions of Astronomical Distances
Miller, Brian W.; Brewer, William F.
2010-01-01
Previous empirical studies using multiple-choice procedures have suggested that there are misconceptions about the scale of astronomical distances. The present study provides a quantitative estimate of the nature of this misconception among US university students by asking them, in an open-ended response format, to make estimates of the distances…
Maximum Genus of Strong Embeddings
Er-ling Wei; Yan-pei Liu; Han Ren
2003-01-01
The strong embedding conjecture states that any 2-connected graph has a strong embedding on some surface. It implies the circuit double cover conjecture: Any 2-connected graph has a circuit double cover.Conversely, it is not true. But for a 3-regular graph, the two conjectures are equivalent. In this paper, a characterization of graphs having a strong embedding with exactly 3 faces, which is the strong embedding of maximum genus, is given. In addition, some graphs with the property are provided. More generally, an upper bound of the maximum genus of strong embeddings of a graph is presented too. Lastly, it is shown that the interpolation theorem is true to planar Halin graph.
Remizov, Ivan D
2009-01-01
In this note, we represent a subdifferential of a maximum functional defined on the space of all real-valued continuous functions on a given metric compact set. For a given argument, $f$ it coincides with the set of all probability measures on the set of points maximizing $f$ on the initial compact set. This complete characterization lies in the heart of several important identities in microeconomics, such as Roy's identity, Sheppard's lemma, as well as duality theory in production and linear programming.
The Testability of Maximum Magnitude
Clements, R.; Schorlemmer, D.; Gonzalez, A.; Zoeller, G.; Schneider, M.
2012-12-01
Recent disasters caused by earthquakes of unexpectedly large magnitude (such as Tohoku) illustrate the need for reliable assessments of the seismic hazard. Estimates of the maximum possible magnitude M at a given fault or in a particular zone are essential parameters in probabilistic seismic hazard assessment (PSHA), but their accuracy remains untested. In this study, we discuss the testability of long-term and short-term M estimates and the limitations that arise from testing such rare events. Of considerable importance is whether or not those limitations imply a lack of testability of a useful maximum magnitude estimate, and whether this should have any influence on current PSHA methodology. We use a simple extreme value theory approach to derive a probability distribution for the expected maximum magnitude in a future time interval, and we perform a sensitivity analysis on this distribution to determine if there is a reasonable avenue available for testing M estimates as they are commonly reported today: devoid of an appropriate probability distribution of their own and estimated only for infinite time (or relatively large untestable periods). Our results imply that any attempt at testing such estimates is futile, and that the distribution is highly sensitive to M estimates only under certain optimal conditions that are rarely observed in practice. In the future we suggest that PSHA modelers be brutally honest about the uncertainty of M estimates, or must find a way to decrease its influence on the estimated hazard.
Alternative Multiview Maximum Entropy Discrimination.
Chao, Guoqing; Sun, Shiliang
2016-07-01
Maximum entropy discrimination (MED) is a general framework for discriminative estimation based on maximum entropy and maximum margin principles, and can produce hard-margin support vector machines under some assumptions. Recently, the multiview version of MED multiview MED (MVMED) was proposed. In this paper, we try to explore a more natural MVMED framework by assuming two separate distributions p1( Θ1) over the first-view classifier parameter Θ1 and p2( Θ2) over the second-view classifier parameter Θ2 . We name the new MVMED framework as alternative MVMED (AMVMED), which enforces the posteriors of two view margins to be equal. The proposed AMVMED is more flexible than the existing MVMED, because compared with MVMED, which optimizes one relative entropy, AMVMED assigns one relative entropy term to each of the two views, thus incorporating a tradeoff between the two views. We give the detailed solving procedure, which can be divided into two steps. The first step is solving our optimization problem without considering the equal margin posteriors from two views, and then, in the second step, we consider the equal posteriors. Experimental results on multiple real-world data sets verify the effectiveness of the AMVMED, and comparisons with MVMED are also reported.
New Comparison of HVDC and HVAC Transmission system
Vahid Behravesh
2012-06-01
Full Text Available Alternating current (AC is the main driving force in the industries and residential areas, but for the long transmission line (more than 400 miles AC transmission is more expensive than that of direct current (DC. Technically, AC transmission line control is more complicated because of the frequency. DC transmission does not have these limitations, which has led to build long HVDC transmission lines over the last 40 years. HVDC technology made possible to transfer bulk power over long distances. This paper presents a comparative evaluation of HVDC and HVAC transmission systems .
Incorporating Linguistic Structure into Maximum Entropy Language Models
FANG GaoLin(方高林); GAO Wen(高文); WANG ZhaoQi(王兆其)
2003-01-01
In statistical language models, how to integrate diverse linguistic knowledge in a general framework for long-distance dependencies is a challenging issue. In this paper, an improved language model incorporating linguistic structure into maximum entropy framework is presented.The proposed model combines trigram with the structure knowledge of base phrase in which trigram is used to capture the local relation between words, while the structure knowledge of base phrase is considered to represent the long-distance relations between syntactical structures. The knowledge of syntax, semantics and vocabulary is integrated into the maximum entropy framework.Experimental results show that the proposed model improves by 24% for language model perplexity and increases about 3% for sign language recognition rate compared with the trigram model.
Fuzzy clustering with Minkowski distance
P.J.F. Groenen (Patrick); U. Kaymak (Uzay); J.M. van Rosmalen (Joost)
2006-01-01
textabstractDistances in the well known fuzzy c-means algorithm of Bezdek (1973) are measured by the squared Euclidean distance. Other distances have been used as well in fuzzy clustering. For example, Jajuga (1991) proposed to use the L_1-distance and Bobrowski and Bezdek (1991) also used the L_inf
Rabaglia, Cristina D; Maglio, Sam J; Krehm, Madelaine; Seok, Jin H; Trope, Yaacov
2016-07-01
Human languages may be more than completely arbitrary symbolic systems. A growing literature supports sound symbolism, or the existence of consistent, intuitive relationships between speech sounds and specific concepts. Prior work establishes that these sound-to-meaning mappings can shape language-related judgments and decisions, but do their effects generalize beyond merely the linguistic and truly color how we navigate our environment? We examine this possibility, relating a predominant sound symbolic distinction (vowel frontness) to a novel associate (spatial proximity) in five studies. We show that changing one vowel in a label can influence estimations of distance, impacting judgment, perception, and action. The results (1) provide the first experimental support for a relationship between vowels and spatial distance and (2) demonstrate that sound-to-meaning mappings have outcomes that extend beyond just language and can - through a single sound - influence how we perceive and behave toward objects in the world. Copyright © 2016 Elsevier B.V. All rights reserved.
Tolman's Luminosity-Distance, Poincare's Light-Distance and Cayley-Klein's Hyperbolic Distance
Pierseaux, Yves
2009-01-01
We deduce Tolman's formula of luminosity-distance in Cosmology from Poincare's definition of light-distance with Lorentz Transformation (LT).In Minkowskian metric, if distance is proper time (as it is often argued) then light-distance must be also the shortest distance, like proper duration (unlike Einstein's longest length within rest system). By introducing Poincare's proper light-distance in Einstein's basic synchronization we deduce a dilated distance between observer and receding mirror (with relativistic Doppler factor). Such a distance corresponds not to an Euclidean distance (Einstein's rigid rod) but to an Hyperbolic distance (Cayley-Klein) with a Lobatchevskian Horizon. From a basic proportionality hyperbolic distance-velocity, we deduce the law of Hubble. By following Penrose's Lobatchevskian representation of LT, we transform Special Relativity (SR) into an Hyperbolic Cosmological Relativity (HCR). by using only the LT but the whole LT. In Hyperbolic Rotation motion (basic active LT or Einstein's ...
Skillicorn, David; Walther, Olivier; Zheng, Quan
is a combination of the physical geography of the target environment, and the mental and physical cost of following a seemingly random pattern of attacks. Focusing on the distance and time between attacks and taking into consideration the transaction costs that state boundaries impose, we wish to understand what......” of North and West Africa that depicts the permeability to violence. A better understanding of how location, time, and borders condition attacks enables planning, prepositioning, and response....
ZHANG Wenliang; JIANG Jun; GUO Jian; LU Jiayu
2012-01-01
There will be more and more AC transmission lines near oil/gas pipelines in the future.So in order to determine the safe distance between them,simple and effective methods are required for engineers to efficiently evaluate the electromagnetic effect on oil/gas pipelines due to faults of AC transmission lines.In this paper,an easily handled fitting formula is obtained based on multiple calculation results,which is the maximum voltage on the pipeline anticorrosive coating produced by 1 000 kV AC transmission line under single phase ground fault.Although the calculation results obtained from the fitting formula differ from those gained by precise calculation with softwares,the verification of the formula shows that it is applicable for engineering calculation.This research could be applied to evaluate the electromagnetic effect of 1 000 kV AC transmission line under single-phase ground fault on nearby pipelines,as well as to determine the safe distance or the maximum parallel length.
Maximum Likelihood Sequence Detection Receivers for Nonlinear Optical Channels
2015-01-01
The space-time whitened matched filter (ST-WMF) maximum likelihood sequence detection (MLSD) architecture has been recently proposed (Maggio et al., 2014). Its objective is reducing implementation complexity in transmissions over nonlinear dispersive channels. The ST-WMF-MLSD receiver (i) drastically reduces the number of states of the Viterbi decoder (VD) and (ii) offers a smooth trade-off between performance and complexity. In this work the ST-WMF-MLSD receiver is investigated in detail. We...
Monge Distance between Quantum States
Zyczkowski, K; Zyczkowski, Karol; Slomczynski, Wojciech
1998-01-01
We define a metric in the space of quantum states taking the Monge distance between corresponding Husimi distributions (Q--functions). This quantity fulfills the axioms of a metric and satisfies the following semiclassical property: the distance between two coherent states is equal to the Euclidean distance between corresponding points in the classical phase space. We compute analytically distances between certain states (coherent, squeezed, Fock and thermal) and discuss a scheme for numerical computation of Monge distance for two arbitrary quantum states.
Generic maximum likely scale selection
Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo
2007-01-01
The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...... on second order moments of multiple measurements outputs at a fixed location. These measurements, which reflect local image structure, consist in the cases considered here of Gaussian derivatives taken at several scales and/or having different derivative orders....
Parameters optimization for magnetic resonance coupling wireless power transmission.
Li, Changsheng; Zhang, He; Jiang, Xiaohua
2014-01-01
Taking maximum power transmission and power stable transmission as research objectives, optimal design for the wireless power transmission system based on magnetic resonance coupling is carried out in this paper. Firstly, based on the mutual coupling model, mathematical expressions of optimal coupling coefficients for the maximum power transmission target are deduced. Whereafter, methods of enhancing power transmission stability based on parameters optimal design are investigated. It is found that the sensitivity of the load power to the transmission parameters can be reduced and the power transmission stability can be enhanced by improving the system resonance frequency or coupling coefficient between the driving/pick-up coil and the transmission/receiving coil. Experiment results are well conformed to the theoretical analysis conclusions.
Parameters Optimization for Magnetic Resonance Coupling Wireless Power Transmission
Changsheng Li
2014-01-01
Full Text Available Taking maximum power transmission and power stable transmission as research objectives, optimal design for the wireless power transmission system based on magnetic resonance coupling is carried out in this paper. Firstly, based on the mutual coupling model, mathematical expressions of optimal coupling coefficients for the maximum power transmission target are deduced. Whereafter, methods of enhancing power transmission stability based on parameters optimal design are investigated. It is found that the sensitivity of the load power to the transmission parameters can be reduced and the power transmission stability can be enhanced by improving the system resonance frequency or coupling coefficient between the driving/pick-up coil and the transmission/receiving coil. Experiment results are well conformed to the theoretical analysis conclusions.
Game theory of social distancing in response to an epidemic.
Timothy C Reluga
2010-05-01
Full Text Available Social distancing practices are changes in behavior that prevent disease transmission by reducing contact rates between susceptible individuals and infected individuals who may transmit the disease. Social distancing practices can reduce the severity of an epidemic, but the benefits of social distancing depend on the extent to which it is used by individuals. Individuals are sometimes reluctant to pay the costs inherent in social distancing, and this can limit its effectiveness as a control measure. This paper formulates a differential-game to identify how individuals would best use social distancing and related self-protective behaviors during an epidemic. The epidemic is described by a simple, well-mixed ordinary differential equation model. We use the differential game to study potential value of social distancing as a mitigation measure by calculating the equilibrium behaviors under a variety of cost-functions. Numerical methods are used to calculate the total costs of an epidemic under equilibrium behaviors as a function of the time to mass vaccination, following epidemic identification. The key parameters in the analysis are the basic reproduction number and the baseline efficiency of social distancing. The results show that social distancing is most beneficial to individuals for basic reproduction numbers around 2. In the absence of vaccination or other intervention measures, optimal social distancing never recovers more than 30% of the cost of infection. We also show how the window of opportunity for vaccine development lengthens as the efficiency of social distancing and detection improve.
Game theory of social distancing in response to an epidemic.
Reluga, Timothy C
2010-05-27
Social distancing practices are changes in behavior that prevent disease transmission by reducing contact rates between susceptible individuals and infected individuals who may transmit the disease. Social distancing practices can reduce the severity of an epidemic, but the benefits of social distancing depend on the extent to which it is used by individuals. Individuals are sometimes reluctant to pay the costs inherent in social distancing, and this can limit its effectiveness as a control measure. This paper formulates a differential-game to identify how individuals would best use social distancing and related self-protective behaviors during an epidemic. The epidemic is described by a simple, well-mixed ordinary differential equation model. We use the differential game to study potential value of social distancing as a mitigation measure by calculating the equilibrium behaviors under a variety of cost-functions. Numerical methods are used to calculate the total costs of an epidemic under equilibrium behaviors as a function of the time to mass vaccination, following epidemic identification. The key parameters in the analysis are the basic reproduction number and the baseline efficiency of social distancing. The results show that social distancing is most beneficial to individuals for basic reproduction numbers around 2. In the absence of vaccination or other intervention measures, optimal social distancing never recovers more than 30% of the cost of infection. We also show how the window of opportunity for vaccine development lengthens as the efficiency of social distancing and detection improve.
Economics and Maximum Entropy Production
Lorenz, R. D.
2003-04-01
Price differentials, sales volume and profit can be seen as analogues of temperature difference, heat flow and work or entropy production in the climate system. One aspect in which economic systems exhibit more clarity than the climate is that the empirical and/or statistical mechanical tendency for systems to seek a maximum in production is very evident in economics, in that the profit motive is very clear. Noting the common link between 1/f noise, power laws and Self-Organized Criticality with Maximum Entropy Production, the power law fluctuations in security and commodity prices is not inconsistent with the analogy. There is an additional thermodynamic analogy, in that scarcity is valued. A commodity concentrated among a few traders is valued highly by the many who do not have it. The market therefore encourages via prices the spreading of those goods among a wider group, just as heat tends to diffuse, increasing entropy. I explore some empirical price-volume relationships of metals and meteorites in this context.
Gladders, M D; Burns, C R; Attard, A; Casey, M P; Hamilton, D; Mallén-Ornelas, G; Karr, J L; Poirier, S M; Sawicki, M; Barrientos, F; Barkhouse, W A; Brodwin, M; Clark, J; McNaughton, R; Ruetalo-Pacheco, M; Mochnacki, S W; Gladders, Michael D.; Clarke, Tracy E.; Burns, Christopher R.; Attard, Allen; Casey, Michael P.; Hamilton, Devon; Mallen-Ornelas, Gabriela; Karr, Jennifer L.; Poirier, Sara M.; Sawicki, Marcin; Barrientos, Felipe; Barkhouse, Wayne; Brodwin, Mark; Clark, Jason; Naughton, Rosemary Mc; Ruetalo-Pacheco, Marcelo; Mochnacki, Stefan W.
1998-01-01
We present the first set of distance limits from the David Dunlap Observatory Intermediate Velocity Cloud (DDO IVC) distance project. Such distance measures are crucial to understanding the origins and dynamics of IVCs, as the distances set most of the basic physical parameters for the clouds. Currently there are very few IVCs with reliably known distances. This paper describes in some detail the basic techniques used to measure distances, with particular emphasis on the the analysis of interstellar absorption line data, which forms the basis of our distance determinations. As an example, we provide a detailed description of our distance determination for the Draco Cloud. Preliminary distance limits for a total of eleven clouds are provided.
Advanced hierarchical distance sampling
Royle, Andy
2016-01-01
In this chapter, we cover a number of important extensions of the basic hierarchical distance-sampling (HDS) framework from Chapter 8. First, we discuss the inclusion of “individual covariates,” such as group size, in the HDS model. This is important in many surveys where animals form natural groups that are the primary observation unit, with the size of the group expected to have some influence on detectability. We also discuss HDS integrated with time-removal and double-observer or capture-recapture sampling. These “combined protocols” can be formulated as HDS models with individual covariates, and thus they have a commonality with HDS models involving group structure (group size being just another individual covariate). We cover several varieties of open-population HDS models that accommodate population dynamics. On one end of the spectrum, we cover models that allow replicate distance sampling surveys within a year, which estimate abundance relative to availability and temporary emigration through time. We consider a robust design version of that model. We then consider models with explicit dynamics based on the Dail and Madsen (2011) model and the work of Sollmann et al. (2015). The final major theme of this chapter is relatively newly developed spatial distance sampling models that accommodate explicit models describing the spatial distribution of individuals known as Point Process models. We provide novel formulations of spatial DS and HDS models in this chapter, including implementations of those models in the unmarked package using a hack of the pcount function for N-mixture models.
CORA - emission line fitting with Maximum Likelihood
Ness, J.-U.; Wichmann, R.
2002-07-01
The advent of pipeline-processed data both from space- and ground-based observatories often disposes of the need of full-fledged data reduction software with its associated steep learning curve. In many cases, a simple tool doing just one task, and doing it right, is all one wishes. In this spirit we introduce CORA, a line fitting tool based on the maximum likelihood technique, which has been developed for the analysis of emission line spectra with low count numbers and has successfully been used in several publications. CORA uses a rigorous application of Poisson statistics. From the assumption of Poissonian noise we derive the probability for a model of the emission line spectrum to represent the measured spectrum. The likelihood function is used as a criterion for optimizing the parameters of the theoretical spectrum and a fixed point equation is derived allowing an efficient way to obtain line fluxes. As an example we demonstrate the functionality of the program with an X-ray spectrum of Capella obtained with the Low Energy Transmission Grating Spectrometer (LETGS) on board the Chandra observatory and choose the analysis of the Ne IX triplet around 13.5 Å.
2016-03-02
520, 2004. 16 [12] E.C. Hall and R.M. Willett. Online convex optimization in dynamic environ- ments. Selected Topics in Signal Processing, IEEE Journal...Conference on Machine Learning, pages 1160–1167. ACM, 2008. [25] Eric P Xing, Michael I Jordan, Stuart Russell, and Andrew Y Ng. Distance metric...whereBψ is any Bregman divergence and ηt is the learning rate parameter. From ( Hall & Willett, 2015) we have: Theorem 1. G` = max θ∈Θ,`∈L ‖∇f(θ)‖ φmax = 1
Ivlev, B I
2005-01-01
Quantum tunneling between two potential wells in a magnetic field can be strongly increased when the potential barrier varies in the direction perpendicular to the line connecting the two wells and remains constant along this line. A periodic structure of the wave function is formed in the direction joining the wells. The resulting motion can be coherent like motion in a conventional narrow band periodic structure. A particle penetrates the barrier over a long distance which strongly contrasts to WKB-like tunneling. The whole problem is stationary. The coherent process can be influenced by dissipation.
Bodini, Olivier; Fernique, Thomas
2009-01-01
In this paper, a structural property of the set of lozenge tilings of a 2n-gon is highlighted. We introduce a simple combinatorial value called Hamming-distance, which is a lower bound for the flipdistance (i.e. the number of necessary local transformations involving three lozenges) between two given tilings. It is here proven that, for n5, We show that there is some deficient pairs of tilings for which the flip connection needs more flips than the combinatorial lower bound indicates.
Hansen, Finn J. S.; Clausen, Christian
2001-01-01
and the organisational set-up. It is debated which kind of social learning that has taken place. The innovation process was based on the implementation of an inflexible video-conference system without any proactive considerations of organisational change or pedagocical development. User appropriation of the technology......The case study represents an example of a top-down introduction of distance teaching as part of Danish trials with the introduction of multimedia in education. The study is concerned with the background, aim and context of the trial as well as the role and working of the technology...
Blasco, Francisco Lazaro
2011-01-01
A novel fountain coding scheme has been introduced. The scheme consists of a parallel concatenation of a MDS block code with a LRFC code, both constructed over the same field, $F_q$. The performance of the concatenated fountain coding scheme has been analyzed through derivation of tight bounds on the probability of decoding failure as a function of the overhead. It has been shown how the concatenated scheme performs as well as LRFC codes in channels characterized by high erasure probabilities, whereas they provide failure probabilities lower by several orders of magnitude at moderate/low erasure probabilities.
Distance Learning. Volume I: Distance Learning Analysis Study.
1998-09-01
The primary focus of this project is the determination of the feasibility and cost effectiveness of applying Distance Learning strategies to 22...selected PPSCP courses and development of a Distance Learning Analysis Procedures Manual.
PERBANDINGAN EUCLIDEAN DISTANCE DENGAN CANBERRA DISTANCE PADA FACE RECOGNITION
Sendhy Rachmat Wurdianarto
2014-08-01
Full Text Available Perkembangan ilmu pada dunia komputer sangatlah pesat. Salah satu yang menandai hal ini adalah ilmu komputer telah merambah pada dunia biometrik. Arti biometrik sendiri adalah karakter-karakter manusia yang dapat digunakan untuk membedakan antara orang yang satu dengan yang lainnya. Salah satu pemanfaatan karakter / organ tubuh pada setiap manusia yang digunakan untuk identifikasi (pengenalan adalah dengan memanfaatkan wajah. Dari permasalahan diatas dalam pengenalan lebih tentang aplikasi Matlab pada Face Recognation menggunakan metode Euclidean Distance dan Canberra Distance. Model pengembangan aplikasi yang digunakan adalah model waterfall. Model waterfall beriisi rangkaian aktivitas proses yang disajikan dalam proses analisa kebutuhan, desain menggunakan UML (Unified Modeling Language, inputan objek gambar diproses menggunakan Euclidean Distance dan Canberra Distance. Kesimpulan yang dapat ditarik adalah aplikasi face Recognation menggunakan metode euclidean Distance dan Canverra Distance terdapat kelebihan dan kekurangan masing-masing. Untuk kedepannya aplikasi tersebut dapat dikembangkan dengan menggunakan objek berupa video ataupun objek lainnya. Kata kunci : Euclidean Distance, Face Recognition, Biometrik, Canberra Distance
Objects of maximum electromagnetic chirality
Fernandez-Corbaton, Ivan
2015-01-01
We introduce a definition of the electromagnetic chirality of an object and show that it has an upper bound. The upper bound is attained if and only if the object is transparent for fields of one handedness (helicity). Additionally, electromagnetic duality symmetry, i.e. helicity preservation upon scattering, turns out to be a necessary condition for reciprocal scatterers to attain the upper bound. We use these results to provide requirements for the design of such extremal scatterers. The requirements can be formulated as constraints on the polarizability tensors for dipolar scatterers or as material constitutive relations. We also outline two applications for objects of maximum electromagnetic chirality: A twofold resonantly enhanced and background free circular dichroism measurement setup, and angle independent helicity filtering glasses.
Maximum mutual information regularized classification
Wang, Jim Jing-Yan
2014-09-07
In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.
The strong maximum principle revisited
Pucci, Patrizia; Serrin, James
In this paper we first present the classical maximum principle due to E. Hopf, together with an extended commentary and discussion of Hopf's paper. We emphasize the comparison technique invented by Hopf to prove this principle, which has since become a main mathematical tool for the study of second order elliptic partial differential equations and has generated an enormous number of important applications. While Hopf's principle is generally understood to apply to linear equations, it is in fact also crucial in nonlinear theories, such as those under consideration here. In particular, we shall treat and discuss recent generalizations of the strong maximum principle, and also the compact support principle, for the case of singular quasilinear elliptic differential inequalities, under generally weak assumptions on the quasilinear operators and the nonlinearities involved. Our principal interest is in necessary and sufficient conditions for the validity of both principles; in exposing and simplifying earlier proofs of corresponding results; and in extending the conclusions to wider classes of singular operators than previously considered. The results have unexpected ramifications for other problems, as will develop from the exposition, e.g. two point boundary value problems for singular quasilinear ordinary differential equations (Sections 3 and 4); the exterior Dirichlet boundary value problem (Section 5); the existence of dead cores and compact support solutions, i.e. dead cores at infinity (Section 7); Euler-Lagrange inequalities on a Riemannian manifold (Section 9); comparison and uniqueness theorems for solutions of singular quasilinear differential inequalities (Section 10). The case of p-regular elliptic inequalities is briefly considered in Section 11.
Resource-constrained maximum network throughput on space networks
Yanling Xing; Ning Ge; Youzheng Wang
2015-01-01
This paper investigates the maximum network through-put for resource-constrained space networks based on the delay and disruption-tolerant networking (DTN) architecture. Specifical y, this paper proposes a methodology for calculating the maximum network throughput of multiple transmission tasks under storage and delay constraints over a space network. A mixed-integer linear programming (MILP) is formulated to solve this problem. Simula-tions results show that the proposed methodology can successful y calculate the optimal throughput of a space network under storage and delay constraints, as wel as a clear, monotonic relationship between end-to-end delay and the maximum network throughput under storage constraints. At the same time, the optimization re-sults shine light on the routing and transport protocol design in space communication, which can be used to obtain the optimal network throughput.
Minimal distances between SCFTs
Buican, Matthew [Department of Physics and Astronomy, Rutgers University,Piscataway, NJ 08854 (United States)
2014-01-28
We study lower bounds on the minimal distance in theory space between four-dimensional superconformal field theories (SCFTs) connected via broad classes of renormalization group (RG) flows preserving various amounts of supersymmetry (SUSY). For N=1 RG flows, the ultraviolet (UV) and infrared (IR) endpoints of the flow can be parametrically close. On the other hand, for RG flows emanating from a maximally supersymmetric SCFT, the distance to the IR theory cannot be arbitrarily small regardless of the amount of (non-trivial) SUSY preserved along the flow. The case of RG flows from N=2 UV SCFTs is more subtle. We argue that for RG flows preserving the full N=2 SUSY, there are various obstructions to finding examples with parametrically close UV and IR endpoints. Under reasonable assumptions, these obstructions include: unitarity, known bounds on the c central charge derived from associativity of the operator product expansion, and the central charge bounds of Hofman and Maldacena. On the other hand, for RG flows that break N=2→N=1, it is possible to find IR fixed points that are parametrically close to the UV ones. In this case, we argue that if the UV SCFT possesses a single stress tensor, then such RG flows excite of order all the degrees of freedom of the UV theory. Furthermore, if the UV theory has some flavor symmetry, we argue that the UV central charges should not be too large relative to certain parameters in the theory.
Survey of Transmission Cost Allocation Methodologies for Regional Transmission Organizations
Fink, S.; Porter, K.; Mudd, C.; Rogers, J.
2011-02-01
The report presents transmission cost allocation methodologies for reliability transmission projects, generation interconnection, and economic transmission projects for all Regional Transmission Organizations.
Transmission capacity of wireless networks
Weber, Steven
2012-01-01
Transmission capacity (TC) is a performance metric for wireless networks that measures the spatial intensity of successful transmissions per unit area, subject to a constraint on the permissible outage probability (where outage occurs when the SINR at a receiver is below a threshold). This volume gives a unified treatment of the TC framework that has been developed by the authors and their collaborators over the past decade. The mathematical framework underlying the analysis (reviewed in Ch. 2) is stochastic geometry: Poisson point processes model the locations of interferers, and (stable) shot noise processes represent the aggregate interference seen at a receiver. Ch. 3 presents TC results (exact, asymptotic, and bounds) on a simple model in order to illustrate a key strength of the framework: analytical tractability yields explicit performance dependence upon key model parameters. Ch. 4 presents enhancements to this basic model --- channel fading, variable link distances, and multi-hop. Ch. 5 presents four...
Visualizing Mixed Variable-Type Multidimensional Data Using Tree Distances
2015-09-01
VARIABLE-TYPE MULTIDIMENSIONAL DATA USING TREE DISTANCES by Yoav Shaham September 2015 Thesis Advisor: Lyn R. Whitaker Second Reader...TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE VISUALIZING MIXED VARIABLE-TYPE MULTIDIMENSIONAL DATA USING TREE DISTANCES 5...public release; distribution is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) This research explores the use of the tree
Klimov, A. N.; Kulik, S. P.; Molotkov, S. N.; Potapova, T. A.
2017-03-01
In the paper by Gleim et al (2016 Opt. Express 24 2619), it was declared that the system of quantum cryptography, exploiting quantum key distribution (QKD) protocol BB84 with the additional reference state and encoding in a sub-carrier, is able to distribute secret keys at a distance of 210 km. The following shows that a simple attack realized with a beam splitter results in a loss of privacy of the keys over substantially smaller distances. It turns out that the actual length of the secret key transmission for the QKD system encoding in the sub-carrier frequency is ten times less than that declared in Gleim et al (2016 Opt. Express 24 2619). Therefore it is impossible to safely use the keys when distributed at a larger length of the communication channel than shown below. The maximum communication distance does not exceed 22 km, even in the most optimistic scenario.
Inferring Pedigree Graphs from Genetic Distances
Tamura, Takeyuki; Ito, Hiro
In this paper, we study a problem of inferring blood relationships which satisfy a given matrix of genetic distances between all pairs of n nodes. Blood relationships are represented by our proposed graph class, which is called a pedigree graph. A pedigree graph is a directed acyclic graph in which the maximum indegree is at most two. We show that the number of pedigree graphs which satisfy the condition of given genetic distances may be exponential, but they can be represented by one directed acyclic graph with n nodes. Moreover, an O(n3) time algorithm which solves the problem is also given. Although phylogenetic trees and phylogenetic networks are similar data structures to pedigree graphs, it seems that inferring methods for phylogenetic trees and networks cannot be applied to infer pedigree graphs since nodes of phylogenetic trees and networks represent species whereas nodes of pedigree graphs represent individuals. We also show an O(n2) time algorithm which detects a contradiction between a given pedigreee graph and distance matrix of genetic distances.
Corrosive effects of hvdc transmission
Cornwell, F.E.; Backstrom, T.E.
1966-02-01
Field tests using ac transmission lines for introduction of direct current into the earth at widely separated points are described. One test circuit was between a Tracy pumping plant and a Shasta power plant in California, and two others were in the Hoover power plant area. Evaluation of the effects of such ground currents on corrosion of buried metalwork was a primary aim of the tests. Potential gradients, pipe-to-soil potentials, and soil resistivities are discussed in detail. Estimates are made of the distances from ehv dc terminal installations within which corrosion prevention procedures may become necessary.
Wang, Guangye; Gao, Yingming; Wang, Jinpeng; Chen, Ailin; Li, Ping; Zou, Nianyu
2016-10-01
Visible light communication (VLC) systems have an advantage for simultaneously achieving communication and illumination. To strengthen the performance of VLC by using RGB light-emitting diodes (LEDs) while meeting the lighting requirements, the channel capacity and the transmission capability of the system are improved by utilizing the wavelength division multiplexing (WDM) technology. We make the chromaticity of the merged white light suitable for human eyes by the experiment. The parameters of merged white light based on RGB LEDs and the merging ratio data measured by the experiment are given. Hence, we study and analyze the eye diagrams and bit error rate (BER) of different optical channels. The simulation results show that maximum transmission rate of the output signal is up to 3.3 Gbit/s, and the BER is less than 10-5 with a transmission distance of 2.5 m while meeting standard illumination requirements.
Distance stereotest using a 3-dimensional monitor for adult subjects.
Kim, Jongshin; Yang, Hee Kyung; Kim, Youngmin; Lee, Byoungho; Hwang, Jeong-Min
2011-06-01
To evaluate the validity and test-retest reliability of a contour-based 3-dimensional (3-D) monitor distance stereotest (distance 3-D stereotest) and to measure the maximum horizontal disparity that can be fused with disparity vergence for determining the largest measurable disparity of true stereopsis. Observational case series. Sixty-four normal adult subjects (age range, 23 to 39 years) were recruited. Contour-based circles (crossed disparity, 5000 to 20 seconds of arc; Microsoft Visual Studio C(++) 6.0; Microsoft, Inc, Seattle, Washington, USA) were generated on a 3-D monitor (46-inch stereoscopic display) using polarization glasses and were presented to subjects with normal binocularity at 3 m. While the position of the stimulus changed among 4 possible locations, the subjects were instructed to press the corresponding position of the stimulus on a keypad. The results with the new distance 3-D stereotest were compared with those from the distance Randot stereotest. The results of the distance 3-D stereotest and the distance Randot stereotests were identical in 64% and within 1 disparity level in 97% of normal adults. Scores obtained with the 2 tests showed a statistically significant correlation (r = 0.324, P = .009). The half-width of the 95% limit of agreement was 0.47 log seconds of arc (1.55 octaves) using the distance 3-D stereotest--similar to or better than that obtained with conventional distance stereotests. The maximum binocular disparity that can be fused with vergence was 1828 ± 794 seconds of arc (range, 4000 to 500). The distance 3-D stereotest showed good concordance with the distance Randot stereotest and relatively good test-retest reliability, supporting the validity of the distance 3-D stereotest. The normative data set obtained from the present study can serve as a useful reference for quantitative assessment of a wide range of binocular sensory abnormalities. Copyright © 2011 Elsevier Inc. All rights reserved.
Improved directional-distance filter
2008-01-01
This paper proposes a new spatial-distance weighting function.By combining the weighting function and the traditional directional-distance filter (DDF) in a novel way,a new vector filter-the adaptive distance-weighted directional-distance filter (ADWDDF)-is presented.The experimental results show that the proposed solution provides better filtering performance and preserves better image chromaticity and edge or detail information compared with the traditional DDF and some other typical vector filters.
Isolation by distance, web service
Bohonak Andrew J; Jensen Jeffrey L; Kelley Scott T
2005-01-01
Abstract Background The population genetic pattern known as "isolation by distance" results from spatially limited gene flow and is a commonly observed phenomenon in natural populations. However, few software programs exist for estimating the degree of isolation by distance among populations, and they tend not to be user-friendly. Results We have created Isolation by Distance Web Service (IBDWS) a user-friendly web interface for determining patterns of isolation by distance. Using this site, ...
Exploring Relay Cooperation for Secure and Reliable Transmission in Two-HopWireless Networks
Yulong Shen
2014-03-01
Full Text Available This work considers the problem of secure and reliable information transmission via relay cooperation in two-hop relay wireless networks without the information of both eavesdropper channels and locations. While previous work on this problem mainly studied infinite networks and their asymptotic behavior and scaling law results, this papers focuses on a more practical network with finite number of system nodes and explores the corresponding exact result on the number of eavesdroppers one network can tolerate to ensure desired secrecy and reliability. We first study the scenario where path-loss is equal between all pairs of nodes and consider two transmission protocols there, one adopts an optimal but complex relay selection process with less load balance capacity while the other adopts a random but simple relay selection process with good load balance capacity. Theoretical analysis and numerical results are then provided to determine the maximum number of eavesdroppers one network can tolerate to ensure a desired performance in terms of the secrecy outage probability and transmission outage probability. We further extend our study to the more general scenario where path-loss between each pair of nodes also depends on the distance between them, for which a new transmission protocol with both preferable relay selection and good load balance as well as the corresponding theoretical analysis and numerical results are presented.
Maximum Range of a Projectile Thrown from Constant-Speed Circular Motion
Poljak, Nikola
2016-11-01
The problem of determining the angle θ at which a point mass launched from ground level with a given speed v0 will reach a maximum distance is a standard exercise in mechanics. There are many possible ways of solving this problem, leading to the well-known answer of θ = π/4, producing a maximum range of D max = v0 2 / g , with g being the free-fall acceleration. Conceptually and calculationally more difficult problems have been suggested to improve student proficiency in projectile motion, with the most famous example being the Tarzan swing problem. The problem of determining the maximum distance of a point mass thrown from constant-speed circular motion is presented and analyzed in detail in this text. The calculational results confirm several conceptually derived conclusions regarding the initial throw position and provide some details on the angles and the way of throwing (underhand or overhand) that produce the maximum throw distance.
The problem of the maximum volumes and particle horizon in the Friedmann universe model
Gong, S. M.
1989-08-01
The maximum volume of the closed Friedmann universe is further investigated and is shown to be 2 x pi squared x R cubed (t), instead of pi squared x R cubed (t) as found previously. This discrepancy comes from the incomplete use of the volume formula of 3-dimensional spherical space in the astronomical literature. Mathematically, the maximum volume exists at any cosmic time t in a 3-dimensional spherical case. However, the Friedmann closed universe in expansion reaches its maximum volume only at the time of the maximum scale factor. The particle horizon has no limitation for the farthest objects in the closed Friedmann universe if the proper distance of objects is compared with the particle horizon as is should be. This leads to absurdity if the luminosity distance of objects is compared with the proper distance of the particle horizon.
Maximum entropy production in daisyworld
Maunu, Haley A.; Knuth, Kevin H.
2012-05-01
Daisyworld was first introduced in 1983 by Watson and Lovelock as a model that illustrates how life can influence a planet's climate. These models typically involve modeling a planetary surface on which black and white daisies can grow thus influencing the local surface albedo and therefore also the temperature distribution. Since then, variations of daisyworld have been applied to study problems ranging from ecological systems to global climate. Much of the interest in daisyworld models is due to the fact that they enable one to study self-regulating systems. These models are nonlinear, and as such they exhibit sensitive dependence on initial conditions, and depending on the specifics of the model they can also exhibit feedback loops, oscillations, and chaotic behavior. Many daisyworld models are thermodynamic in nature in that they rely on heat flux and temperature gradients. However, what is not well-known is whether, or even why, a daisyworld model might settle into a maximum entropy production (MEP) state. With the aim to better understand these systems, this paper will discuss what is known about the role of MEP in daisyworld models.
Maximum stellar iron core mass
F W Giacobbe
2003-03-01
An analytical method of estimating the mass of a stellar iron core, just prior to core collapse, is described in this paper. The method employed depends, in part, upon an estimate of the true relativistic mass increase experienced by electrons within a highly compressed iron core, just prior to core collapse, and is signiﬁcantly different from a more typical Chandrasekhar mass limit approach. This technique produced a maximum stellar iron core mass value of 2.69 × 1030 kg (1.35 solar masses). This mass value is very near to the typical mass values found for neutron stars in a recent survey of actual neutron star masses. Although slightly lower and higher neutron star masses may also be found, lower mass neutron stars are believed to be formed as a result of enhanced iron core compression due to the weight of non-ferrous matter overlying the iron cores within large stars. And, higher mass neutron stars are likely to be formed as a result of fallback or accretion of additional matter after an initial collapse event involving an iron core having a mass no greater than 2.69 × 1030 kg.
Maximum Matchings via Glauber Dynamics
Jindal, Anant; Pal, Manjish
2011-01-01
In this paper we study the classic problem of computing a maximum cardinality matching in general graphs $G = (V, E)$. The best known algorithm for this problem till date runs in $O(m \\sqrt{n})$ time due to Micali and Vazirani \\cite{MV80}. Even for general bipartite graphs this is the best known running time (the algorithm of Karp and Hopcroft \\cite{HK73} also achieves this bound). For regular bipartite graphs one can achieve an $O(m)$ time algorithm which, following a series of papers, has been recently improved to $O(n \\log n)$ by Goel, Kapralov and Khanna (STOC 2010) \\cite{GKK10}. In this paper we present a randomized algorithm based on the Markov Chain Monte Carlo paradigm which runs in $O(m \\log^2 n)$ time, thereby obtaining a significant improvement over \\cite{MV80}. We use a Markov chain similar to the \\emph{hard-core model} for Glauber Dynamics with \\emph{fugacity} parameter $\\lambda$, which is used to sample independent sets in a graph from the Gibbs Distribution \\cite{V99}, to design a faster algori...
Reconsidering Moore's Transactional Distance Theory
Giossos, Yiannis; Koutsouba, Maria; Lionarakis, Antonis; Skavantzos, Kosmas
2009-01-01
One of the core theories of distance education is Michael Graham Moore's "Theory of Transactional Distance" that provides the broad framework of the pedagogy of distance education and allows the generation of almost infinite number of hypotheses for research. However, the review of the existing studies relating to the theory showed the use of a…
2011-01-10
...: Establishing Maximum Allowable Operating Pressure or Maximum Operating Pressure Using Record Evidence, and... facilities of their responsibilities, under Federal integrity management (IM) regulations, to perform... system, especially when calculating Maximum Allowable Operating Pressure (MAOP) or Maximum Operating...
The Sherpa Maximum Likelihood Estimator
Nguyen, D.; Doe, S.; Evans, I.; Hain, R.; Primini, F.
2011-07-01
A primary goal for the second release of the Chandra Source Catalog (CSC) is to include X-ray sources with as few as 5 photon counts detected in stacked observations of the same field, while maintaining acceptable detection efficiency and false source rates. Aggressive source detection methods will result in detection of many false positive source candidates. Candidate detections will then be sent to a new tool, the Maximum Likelihood Estimator (MLE), to evaluate the likelihood that a detection is a real source. MLE uses the Sherpa modeling and fitting engine to fit a model of a background and source to multiple overlapping candidate source regions. A background model is calculated by simultaneously fitting the observed photon flux in multiple background regions. This model is used to determine the quality of the fit statistic for a background-only hypothesis in the potential source region. The statistic for a background-plus-source hypothesis is calculated by adding a Gaussian source model convolved with the appropriate Chandra point spread function (PSF) and simultaneously fitting the observed photon flux in each observation in the stack. Since a candidate source may be located anywhere in the field of view of each stacked observation, a different PSF must be used for each observation because of the strong spatial dependence of the Chandra PSF. The likelihood of a valid source being detected is a function of the two statistics (for background alone, and for background-plus-source). The MLE tool is an extensible Python module with potential for use by the general Chandra user.
Vestige: Maximum likelihood phylogenetic footprinting
Maxwell Peter
2005-05-01
Full Text Available Abstract Background Phylogenetic footprinting is the identification of functional regions of DNA by their evolutionary conservation. This is achieved by comparing orthologous regions from multiple species and identifying the DNA regions that have diverged less than neutral DNA. Vestige is a phylogenetic footprinting package built on the PyEvolve toolkit that uses probabilistic molecular evolutionary modelling to represent aspects of sequence evolution, including the conventional divergence measure employed by other footprinting approaches. In addition to measuring the divergence, Vestige allows the expansion of the definition of a phylogenetic footprint to include variation in the distribution of any molecular evolutionary processes. This is achieved by displaying the distribution of model parameters that represent partitions of molecular evolutionary substitutions. Examination of the spatial incidence of these effects across regions of the genome can identify DNA segments that differ in the nature of the evolutionary process. Results Vestige was applied to a reference dataset of the SCL locus from four species and provided clear identification of the known conserved regions in this dataset. To demonstrate the flexibility to use diverse models of molecular evolution and dissect the nature of the evolutionary process Vestige was used to footprint the Ka/Ks ratio in primate BRCA1 with a codon model of evolution. Two regions of putative adaptive evolution were identified illustrating the ability of Vestige to represent the spatial distribution of distinct molecular evolutionary processes. Conclusion Vestige provides a flexible, open platform for phylogenetic footprinting. Underpinned by the PyEvolve toolkit, Vestige provides a framework for visualising the signatures of evolutionary processes across the genome of numerous organisms simultaneously. By exploiting the maximum-likelihood statistical framework, the complex interplay between mutational
Burke, Kyle; Heubach, Silvia; Huggan, Melissa; Huntemann, Svenja
2016-01-01
We study the computational complexity of distance games, a class of combinatorial games played on graphs. A move consists of colouring an uncoloured vertex subject to it not being at certain distances determined by two sets, D and S. D is the set of forbidden distances for colouring vertices in different colors, while S is the set of forbidden distances for the same colour. The last player to move wins. Well-known examples of distance games are Node-Kayles, Snort, and Col, whose complexities ...
Distance learning and perioperative nursing.
Gruendemann, Barbara J
2007-03-01
Distance learning in nursing education is arriving with unprecedented speed, which has led to much uncertainty among educators. This article provides an overview of distance learning and its application to perioperative nursing. Lack of face-to-face interaction is of foremost concern in distance learning, and educators must develop new teaching strategies to address this problem. Models for assessing outcomes and effectiveness are important tools to use when implementing a distance learning program. Basic perioperative nursing concepts, skills, procedures, and recommended practices can be introduced effectively with online distance learning modalities and then reinforced through a clinical component.
Paintball velocity as a function of distance traveled
Pat Chiarawongse
2008-06-01
Full Text Available The relationship between the distance a paintball travels through air and its velocity is investigated by firing a paintball into a ballistic pendulum from a range of distances. The motion of the pendulum was filmed and analyzed by using video analysis software. The velocity of the paintball on impact was calculated from the maximum horizontal displacement of the pendulum. It is shown that the velocity of a paintball decreases exponentially with distance traveled, as expected. The average muzzle velocity of the paint balls is found with an estimate of the drag coefficient
Paintball velocity as a function of distance traveled
Pat Chiarawongse
2008-06-01
Full Text Available The relationship between the distance a paintball travels through air and its velocity is investigated by firing a paintball into a ballistic pendulum from a range of distances. The motion of the pendulum was filmed and analyzed by using video analysis software. The velocity of the paintball on impact was calculated from the maximum horizontal displacement of the pendulum. It is shown that the velocity of a paintball decreases exponentially with distance traveled, as expected. The average muzzle velocity of the paint balls is found with an estimate of the drag coefficient.
Binney, James; Kordopatis, Georges; McMillan, Paul J; Sharma, Sanjib; Zwitter, Tomaz; Bienayme, Olivier; Bland-Hawthorn, Joss; Steinmetz, Matthias; Gilmore, Gerry; Williams, Mary E K; Navarro, Julio; Grebel, Eva K; Helmi, Amina; Parker, Quentin; Reid, Warren A; Seabroke, George; Watson, Fred; Wyse, Rosie F G
2013-01-01
Probability density functions are determined from new stellar parameters for the distance moduli of stars for which the RAdial Velocity Experiment (RAVE) has obtained spectra with S/N>=10. The expectation value of distance is larger than the distance implied by the expectation of distance modulus; the latter is itself larger than the distance implied by the expectation value of the parallax. Our parallaxes of Hipparcos stars agree well with the values measured by Hipparcos, so the expectation of parallax is the most reliable distance indicator. The latter are improved by taking extinction into account. We provide one- two- or three-Gaussian fits to the distance pdfs. The effective temperature absolute-magnitude diagram of our stars is significantly improved when these pdfs are used to make the diagram. We use the method of kinematic corrections devised by Schoenrich, Binney & Asplund to check for systematic errors in our estimators for ordinary stars and confirm the conclusion reached from the Hipparcos s...
Ni, Kai; Wang, Lanlan; Zhou, Qian; Li, Xinghui; Dong, Hao; Wang, Xiaohao
2016-11-01
The real-time distance measurement system with dual femtosecond comb lasers combines time-of-flight and interferometric measurement. It has advantages of wide-range, high-accuracy and fast speed at the rate about 10000 pts/s. Such a distance measurement system needs dedicated higher performance of the data acquisition and processing hardware platform to support. This paper introduces the dedicated platform of the developed absolute distance measurement system. This platform is divided into three parts according to their respective functions. First part is the data acquisition module, which function is mainly to realize the A/D conversion. In this part we designed a sampling clock adjustment module to assist the A/D conversion module to sample accurately. The sampling clock adjustment module accept a 250MHz maximum reference clock input, which from the same femtosecond laser source as the optical measurement system, then generate an output clock for the A/D converter that can be delayed up to 20ns with a resolution of 714ps. This data acquisition module can convert the analog laser pulse signal to digital signal with a 14 bits resolution and a 250 MSPS maximum sample rate. Second is the data processing and storage module consists of FPGA and DDR3 modules. The FPGA module calculates the test distance by the 16 bits digital sampling signal from the front data acquisition module. The DDR3 module implements sampling data caching. Finally part is the data transmission and peripheral interfaces module based on three DB9 and USB2.0. We can easily debug the platform in the PC and implement communication with upper machine. We tested our system used dedicate test bench in real-time. The scope of the measurement system range is 0 to 3 meters and the measurement deviation is less than 10um.
Fast computation of distance estimators
Lagergren Jens
2007-03-01
Full Text Available Abstract Background Some distance methods are among the most commonly used methods for reconstructing phylogenetic trees from sequence data. The input to a distance method is a distance matrix, containing estimated pairwise distances between all pairs of taxa. Distance methods themselves are often fast, e.g., the famous and popular Neighbor Joining (NJ algorithm reconstructs a phylogeny of n taxa in time O(n3. Unfortunately, the fastest practical algorithms known for Computing the distance matrix, from n sequences of length l, takes time proportional to l·n2. Since the sequence length typically is much larger than the number of taxa, the distance estimation is the bottleneck in phylogeny reconstruction. This bottleneck is especially apparent in reconstruction of large phylogenies or in applications where many trees have to be reconstructed, e.g., bootstrapping and genome wide applications. Results We give an advanced algorithm for Computing the number of mutational events between DNA sequences which is significantly faster than both Phylip and Paup. Moreover, we give a new method for estimating pairwise distances between sequences which contain ambiguity Symbols. This new method is shown to be more accurate as well as faster than earlier methods. Conclusion Our novel algorithm for Computing distance estimators provides a valuable tool in phylogeny reconstruction. Since the running time of our distance estimation algorithm is comparable to that of most distance methods, the previous bottleneck is removed. All distance methods, such as NJ, require a distance matrix as input and, hence, our novel algorithm significantly improves the overall running time of all distance methods. In particular, we show for real world biological applications how the running time of phylogeny reconstruction using NJ is improved from a matter of hours to a matter of seconds.
van Weerdenburg, John; Velàzquez-Benitez, Amado; van Uden, Roy; Sillard, Pierre; Molin, Denis; Amezcua-Correa, Adrian; Antonio-Lopez, Enrique; Kuschnerov, Maxim; Huijskens, Frans; de Waardt, Hugo; Koonen, Ton; Amezcua-Correa, Rodrigo; Okonkwo, Chigo
2015-09-21
To unlock the cost benefits of space division multiplexing transmission systems, higher spatial multiplicity is required. Here, we investigate a potential route to increasing the number of spatial mode channels within a single core few-mode fiber. Key for longer transmission distances and low computational complexity is the fabrication of fibers with low differential mode group delays. As such in this work, we combine wavelength and mode-division multiplexed transmission over a 4.45 km low-DMGD 6-LP-mode fiber by employing low-loss all-fiber 10-port photonic lanterns to couple light in and out of the fiber. Hence, a minimum DMGD of 0.2 ns (maximum 0.357 ns) is measured after 4.45 km. Instrumental to the multi-mode transmission system is the employed time-domain-SDM receiver, allowing 10 spatial mode channels (over both polarizations) to be captured using only 3 coherent receivers and real-time oscilloscopes in comparison with 10 for conventional methods. The spatial channels were unraveled using 20 × 20 multiple-input multiple-output digital signal processing. By employing a novel round-robin encoding technique, stable performance over a long measurement period demonstrates the feasibility of 10x increase in single-core multi-mode transmission.
Spectrally Shaped DP-16QAM Super-Channel Transmission with Multi-Channel Digital Back-Propagation
Maher, Robert; Xu, Tianhua; Galdino, Lidia; Sato, Masaki; Alvarado, Alex; Shi, Kai; Savory, Seb J.; Thomsen, Benn C.; Killey, Robert I.; Bayvel, Polina
2015-02-01
The achievable transmission capacity of conventional optical fibre communication systems is limited by nonlinear distortions due to the Kerr effect and the difficulty in modulating the optical field to effectively use the available fibre bandwidth. In order to achieve a high information spectral density (ISD), while simultaneously maintaining transmission reach, multi-channel fibre nonlinearity compensation and spectrally efficient data encoding must be utilised. In this work, we use a single coherent super-receiver to simultaneously receive a DP-16QAM super-channel, consisting of seven spectrally shaped 10GBd sub-carriers spaced at the Nyquist frequency. Effective nonlinearity mitigation is achieved using multi-channel digital back-propagation (MC-DBP) and this technique is combined with an optimised forward error correction implementation to demonstrate a record gain in transmission reach of 85%; increasing the maximum transmission distance from 3190 km to 5890 km, with an ISD of 6.60 b/s/Hz. In addition, this report outlines for the first time, the sensitivity of MC-DBP gain to linear transmission line impairments and defines a trade-off between performance and complexity.
Planning with Reachable Distances
Tang, Xinyu
2009-01-01
Motion planning for spatially constrained robots is difficult due to additional constraints placed on the robot, such as closure constraints for closed chains or requirements on end effector placement for articulated linkages. It is usually computationally too expensive to apply sampling-based planners to these problems since it is difficult to generate valid configurations. We overcome this challenge by redefining the robot\\'s degrees of freedom and constraints into a new set of parameters, called reachable distance space (RD-space), in which all configurations lie in the set of constraint-satisfying subspaces. This enables us to directly sample the constrained subspaces with complexity linear in the robot\\'s number of degrees of freedom. In addition to supporting efficient sampling, we show that the RD-space formulation naturally supports planning, and in particular, we design a local planner suitable for use by sampling-based planners. We demonstrate the effectiveness and efficiency of our approach for several systems including closed chain planning with multiple loops, restricted end effector sampling, and on-line planning for drawing/sculpting. We can sample single-loop closed chain systems with 1000 links in time comparable to open chain sampling, and we can generate samples for 1000-link multi-loop systems of varying topology in less than a second. © 2009 Springer-Verlag.
Scaling of Natal Dispersal Distances in Terrestrial Birds and Mammals
Glenn D. Sutherland
2000-07-01
Full Text Available Natal dispersal is a process that is critical in the spatial dynamics of populations, including population spread, recolonization, and gene flow. It is a central focus of conservation issues for many vertebrate species. Using data for 77 bird and 68 mammal species, we tested whether median and maximum natal dispersal distances were correlated with body mass, diet type, social system, taxonomic family, and migratory status. Body mass and diet type were found to predict both median and maximum natal dispersal distances in mammals: large species dispersed farther than small ones, and carnivorous species dispersed farther than herbivores and omnivores. Similar relationships occurred for carnivorous bird species, but not for herbivorous or omnivorous ones. Natal dispersal distances in birds or mammals were not significantly related to broad categories of social systems. Only in birds were factors such as taxonomic relatedness and migratory status correlated with natal dispersal, and then only for maximum distances. Summary properties of dispersal processes appeared to be derived from interactions among behavioral and morphological characteristics of species and from their linkages to the dynamics of resource availability in landscapes. In all the species we examined, most dispersers moved relatively short distances, and long-distance dispersal was uncommon. On the basis of these findings, we fit an empirical model based on the negative exponential distribution for calculating minimum probabilities that animals disperse particular distances from their natal areas. This model, coupled with knowledge of a species' body mass and diet type, can be used to conservatively predict dispersal distances for different species and examine possible consequences of large-scale habitat alterations on connectedness between populations. Taken together, our results can provide managers with the means to identify species vulnerable to landscape-level habitat changes
Tendon Force Transmission at the Nanoscale
Svensson, René
2013-01-01
of connective tissue function that are poorly understood. One such aspect is the microscopic mechanisms of force transmission through tendons over macroscopic distances. Force transmission is at the heart of tendon function, but the large range of scales in the hierarchical structure of tendons has made...... it difficult to tackle. The tendon hierarchy ranges from molecules (2 nm) over fibrils (200 nm), fibers (2 μm) and fascicles (200 μm) to tendons (10 mm), and to derive the mechanisms of force transmission it is necessary to know the mechanical behavior at each hierarchical level. The aim of the present work...... was to elucidate the mechanisms of force transmission in tendons primarily by investigating the mechanical behavior at the hierarchical level of collagen fibrils. To do so we have developed an atomic force microscopy (AFM) method for tensile testing of native collagen fibrils. The thesis contains five papers...
Lamandé, Mathieu; Schjønning, Per
the soil-tyre interface were measured in separate tests by 17 stress transducers across the width of the tyres. The results showed that the inflation pressure controlled the level of maximum stresses at 0.3 m depth, while the wheel load was correlated to the measured stresses at 0.9 m depth. This supports......We urgently need increased quantitative knowledge on stress transmission in real soils loaded with agricultural machinery. 3D measurements of vertical stresses under tracked wheels were performed in situ in a Stagnic Luvisol (clay content 20 %) continuously cropped with small grain cereals....... The tests took place in the spring at field capacity when the topsoil had not been tilled for 1½ year. Two Nokian ELS Radial-ply tyres (800/50R34 and 560/45R22.5) were loaded with two specific loads (30 kN and 60 kN). We used rated tyre inflation pressures for traffic in the field (≤10 km h-1 driving speed...
Maximum tunneling velocities in symmetric double well potentials
Manz, Jörn; Schmidt, Burkhard; Yang, Yonggang
2014-01-01
We consider coherent tunneling of one-dimensional model systems in non-cyclic or cyclic symmetric double well potentials. Generic potentials are constructed which allow for analytical estimates of the quantum dynamics in the non-relativistic deep tunneling regime, in terms of the tunneling distance, barrier height and mass (or moment of inertia). For cyclic systems, the results may be scaled to agree well with periodic potentials for which semi-analytical results in terms of Mathieu functions exist. Starting from a wavepacket which is initially localized in one of the potential wells, the subsequent periodic tunneling is associated with tunneling velocities. These velocities (or angular velocities) are evaluated as the ratio of the flux densities versus the probability densities. The maximum velocities are found under the top of the barrier where they scale as the square root of the ratio of barrier height and mass (or moment of inertia), independent of the tunneling distance. They are applied exemplarily to ...
Spatial outline of malaria transmission in Iran
Mohammad Barati; Hossein Keshavarz-valian; Majid Habibi-nokhandan; Ahmad Raeisi; Leyla Faraji; Abdoreza Salahi-moghaddam
2012-01-01
Objective: To conduct for modeling spatial distribution of malaria transmission in Iran. Methods: Records of all malaria cases from the period 2008-2010 in Iran were retrieved for malaria control department, MOH&ME. Metrological data including annual rainfall, maximum and minimum temperature, relative humidity, altitude, demographic, districts border shapefiles, and NDVI images received from Iranian Climatologic Research Center. Data arranged in ArcGIS. Results:Results: 99.65%of malaria transmission cases were focused in southeast part of Iran. These transmissions had statistically correlation with altitude (650 m), maximum (30℃), minimum (20℃) and average temperature (25.3℃). Statistical correlation and overall relationship between NDVI (118.81), relative humidity (≥45%) and rainfall in southeast area was defined and explained in this study. Conclusions: According to ecological condition and mentioned cut-off points, predictive map was generated using cokriging method.
On distances between phylogenetic trees
DasGupta, B. [Rutgers Univ., Camden, NJ (United States); He, X. [SUNY, Buffalo, NY (United States); Jiang, T. [McMaster Univ., Hamilton, Ontario (Canada)] [and others
1997-06-01
Different phylogenetic trees for the same group of species are often produced either by procedures that use diverse optimality criteria or from different genes in the study of molecular evolution. Comparing these trees to find their similarities and dissimilarities, i.e. distance, is thus an important issue in computational molecular biology. The nearest neighbor interchange distance and the subtree-transfer distance are two major distance metrics that have been proposed and extensively studied for different reasons. Despite their many appealing aspects such as simplicity and sensitivity to tree topologies, computing these distances has remained very challenging. This article studies the complexity and efficient approximation algorithms for computing the nni distance and a natural extension of the subtree-transfer distance, called the linear-cost subtree-transfer distance. The linear-cost subtree-transfer model is more logical than the subtree-transfer model and in fact coincides with the nni model under certain conditions. The following results have been obtained as part of our project of building a comprehensive software package for computing distances between phylogenies. (1) Computing the nni distance is NP-complete. This solves a 25 year old open question appearing again and again in, for example, under the complexity-theoretic assumption of P {ne} NP. We also answer an open question regarding the nni distance between unlabeled trees for which an erroneous proof appeared in. We give an algorithm to compute the optimal nni sequence in time O(n{sup 2} logn + n {circ} 2{sup O(d)}), where the nni distance is at most d. (2) Biological applications require us to extend the nni and linear-cost subtree-transfer models to weighted phylogenies, where edge weights indicate the length of evolution along each edge. We present a logarithmic ratio approximation algorithm for nni and a ratio 2 approximation algorithm for linear-cost subtree-transfer, on weighted trees.
DISTANCE EDUCATOR: A Multiskill Personality
Sangeeta MALIK
2013-01-01
Full Text Available When we talk about a distance educator and a conventional educator the difference we found nd about both of them is that, a distance educator needs to play multiple roles as compared to a conventional educator. They require more skills and knowledge cater to the needs of the learner. In this article we will cover all the responsible areas of a distance educator & why we should consider them as a multiskill personality?
378 Average Distance Travelled To School by Primary and ...
User
2010-10-17
Oct 17, 2010 ... students walk over one kilometer to school, the outcomes would not be in the .... respondents were the heads of the primary and secondary schools .... maximum distance as low as 28.57% for primary school pupils and 18.75 ...
Real-time Loudspeaker Distance Estimation with Stereo Audio
Nielsen, Jesper Kjær; Gaubitch, Nikolay; Heusdens, Richard
2015-01-01
. In this paper, we propose to use the desired audio signal instead. Specifically, we treat the case of estimating the distance between two loudspeakers playing back a stereo music or speech signal. In this connection, we develop a real-time maximum likelihood estimator and demonstrate that it has a variance...
Bayesian and maximum likelihood estimation of genetic maps
York, Thomas L.; Durrett, Richard T.; Tanksley, Steven;
2005-01-01
There has recently been increased interest in the use of Markov Chain Monte Carlo (MCMC)-based Bayesian methods for estimating genetic maps. The advantage of these methods is that they can deal accurately with missing data and genotyping errors. Here we present an extension of the previous methods...... that makes the Bayesian method applicable to large data sets. We present an extensive simulation study examining the statistical properties of the method and comparing it with the likelihood method implemented in Mapmaker. We show that the Maximum A Posteriori (MAP) estimator of the genetic distances...
Doctoral education from a distance.
Effken, Judith A
2008-12-01
This article describes the environmental factors that have contributed to the recent rapid growth of nursing doctoral education at a distance. Early and recent efforts to deliver distance doctoral education are discussed, using The University of Arizona College of Nursing experience as the key exemplar. The Community of Inquiry model is introduced as an appropriate model for doctoral education and then used as a framework to evaluate the current state of the art in distance doctoral nursing education. Successes and challenges in delivering doctoral education from a distance are described.
The Extended Edit Distance Metric
Fuad, Muhammad Marwan Muhammad
2007-01-01
Similarity search is an important problem in information retrieval. This similarity is based on a distance. Symbolic representation of time series has attracted many researchers recently, since it reduces the dimensionality of these high dimensional data objects. We propose a new distance metric that is applied to symbolic data objects and we test it on time series data bases in a classification task. We compare it to other distances that are well known in the literature for symbolic data objects. We also prove, mathematically, that our distance is metric.
Transactional Distance and Autonomy in a Distance Learning Environment
Vasiloudis, G.; Koutsouba, M.; Giossos, Y.; Mavroidis, I.
2015-01-01
This paper studies the transactional distance between the students and the tutor as well as the autonomy of students in a postgraduate course of the Hellenic Open University (HOU). The aim of the paper is to examine how the relation between autonomy and transactional distance evolves during an academic year and how this relation is affected by…
Distance spectra and Distance energy of Integral Circulant Graphs
c, Aleksandar Ili\\'
2011-01-01
The distance energy of a graph $G$ is a recently developed energy-type invariant, defined as the sum of absolute values of the eigenvalues of the distance matrix of $G$. There was a vast research for the pairs and families of non-cospectral graphs having equal distance energy, and most of these constructions were based on the join of graphs. A graph is called circulant if it is Cayley graph on the circulant group, i.e. its adjacency matrix is circulant. A graph is called integral if all eigenvalues of its adjacency matrix are integers. Integral circulant graphs play an important role in modeling quantum spin networks supporting the perfect state transfer. In this paper, we characterize the distance spectra of integral circulant graphs and prove that these graphs have integral eigenvalues of distance matrix $D$. Furthermore, we calculate the distance spectra and distance energy of unitary Cayley graphs. In conclusion, we present two families of pairs $(G_1, G_2)$ of integral circulant graphs with equal distanc...
Enhanced bit rate-distance product impulse radio ultra-wideband over fiber link
Rodes Lopez, Roberto; Jensen, Jesper Bevensee; Caballero Jambrina, Antonio
2010-01-01
We report on a record distance and bit rate-wireless impulse radio (IR) ultra-wideband (UWB) link with combined transmission over a 20 km long fiber link. We are able to improve the compliance with the regulated frequency emission mask and achieve bit rate-distance products as high as 16 Gbit/s·m....
Receiver function estimated by maximum entropy deconvolution
吴庆举; 田小波; 张乃铃; 李卫平; 曾融生
2003-01-01
Maximum entropy deconvolution is presented to estimate receiver function, with the maximum entropy as the rule to determine auto-correlation and cross-correlation functions. The Toeplitz equation and Levinson algorithm are used to calculate the iterative formula of error-predicting filter, and receiver function is then estimated. During extrapolation, reflective coefficient is always less than 1, which keeps maximum entropy deconvolution stable. The maximum entropy of the data outside window increases the resolution of receiver function. Both synthetic and real seismograms show that maximum entropy deconvolution is an effective method to measure receiver function in time-domain.
Maximum Power from a Solar Panel
Michael Miller
2010-01-01
Full Text Available Solar energy has become a promising alternative to conventional fossil fuel sources. Solar panels are used to collect solar radiation and convert it into electricity. One of the techniques used to maximize the effectiveness of this energy alternative is to maximize the power output of the solar collector. In this project the maximum power is calculated by determining the voltage and the current of maximum power. These quantities are determined by finding the maximum value for the equation for power using differentiation. After the maximum values are found for each time of day, each individual quantity, voltage of maximum power, current of maximum power, and maximum power is plotted as a function of the time of day.
Cultural Transmission of Civicness
Ljunge, Jan Martin
2012-01-01
This paper estimates the intergeneration transmission of civicness by studying second generation immigrants in 29 European countries with ancestry in 83 nations. There is significant transmission of civicness both on the mother’s and the father’s side. The estimates are quantitatively significant...... and provide evidence on the transmission of trustworthiness....
Cultural Transmission of Civicness
Ljunge, Jan Martin
This paper estimates the intergeneration transmission of civicness by studying second generation immigrants in 29 European countries with ancestry in 83 nations. There is significant transmission of civicness both on the mother’s and the father’s side. The estimates are quantitatively significant...... and provide evidence on the transmission of trustworthiness....
Virtual Bioinformatics Distance Learning Suite
Tolvanen, Martti; Vihinen, Mauno
2004-01-01
Distance learning as a computer-aided concept allows students to take courses from anywhere at any time. In bioinformatics, computers are needed to collect, store, process, and analyze massive amounts of biological and biomedical data. We have applied the concept of distance learning in virtual bioinformatics to provide university course material…
The Psychology of Psychic Distance
Håkanson, Lars; Ambos, Björn; Schuster, Anja
2016-01-01
and their theoretical underpinnings assume psychic distances to be symmetric. Building on insights from psychology and sociology, this paper demonstrates how national factors and cognitive processes interact in the formation of asymmetric distance perceptions. The results suggest that exposure to other countries...
Quality Content in Distance Education
Yildiz, Ezgi Pelin; Isman, Aytekin
2016-01-01
In parallel with technological advances in today's world of education activities can be conducted without the constraints of time and space. One of the most important of these activities is distance education. The success of the distance education is possible with content quality. The proliferation of e-learning environment has brought a need for…
Virtual Bioinformatics Distance Learning Suite
Tolvanen, Martti; Vihinen, Mauno
2004-01-01
Distance learning as a computer-aided concept allows students to take courses from anywhere at any time. In bioinformatics, computers are needed to collect, store, process, and analyze massive amounts of biological and biomedical data. We have applied the concept of distance learning in virtual bioinformatics to provide university course material…
Distance labeling schemes for trees
Alstrup, Stephen; Gørtz, Inge Li; Bistrup Halvorsen, Esben;
2016-01-01
We consider distance labeling schemes for trees: given a tree with n nodes, label the nodes with binary strings such that, given the labels of any two nodes, one can determine, by looking only at the labels, the distance in the tree between the two nodes. A lower bound by Gavoille et al. [Gavoill...
Binney, J.; Burnett, B.; Kordopatis, G.; McMillan, P. J.; Sharma, S.; Zwitter, T.; Bienayme, O.; Bland-Hawthorn, J.; Steinmetz, M.; Gilmore, G.; Williams, M. E. K.; Navarro, J.; Grebel, E. K.; Helmi, A.; Parker, Q.; Reid, W. A.; Seabroke, G.; Watson, F.; Wyse, R. F. G.
Probability density functions (pdfs) are determined from new stellar parameters for the distance moduli of stars for which the RAdial Velocity Experiment (RAVE) has obtained spectra with S/N >= 10. Single-Gaussian fits to the pdf in distance modulus suffice for roughly half the stars, with most of
Distance labeling schemes for trees
Alstrup, Stephen; Gørtz, Inge Li; Bistrup Halvorsen, Esben
2016-01-01
variants such as, for example, small distances in trees [Alstrup et al., SODA, 2003]. We improve the known upper and lower bounds of exact distance labeling by showing that 1/4 log2(n) bits are needed and that 1/2 log2(n) bits are sufficient. We also give (1 + ε)-stretch labeling schemes using Theta...
Faculty Attitudes about Distance Education
Smidt, Esther; McDyre, Brian; Bunk, Jennifer; Li, Rui; Gatenby, Tanya
2014-01-01
In recent years, there has been a dramatic increase in distance learning in higher education. Given this, it is extremely important to understand faculty attitudes about distance education, not only because they can vary widely, but also because it is the faculty, through their design and implementation of online courses, that will shape the…
Distance-constrained grid colouring
Aszalós László
2016-06-01
Full Text Available Distance-constrained colouring is a mathematical model of the frequency assignment problem. This colouring can be treated as an optimization problem so we can use the toolbar of the optimization to solve concrete problems. In this paper, we show performance of distance-constrained grid colouring for two methods which are good in map colouring.
Hierarchical traits distances explain grassland Fabaceae species’ ecological niches distances
Florian eFort
2015-02-01
Full Text Available Fabaceae species play a key role in ecosystem functioning through their capacity to fix atmospheric nitrogen via their symbiosis with Rhizobium bacteria. To increase benefits of using Fabaceae in agricultural systems, it is necessary to find ways to evaluate species or genotypes having potential adaptations to sub-optimal growth conditions. We evaluated the relevance of phylogenetic distance, absolute trait distance and hierarchical trait distance for comparing the adaptation of 13 grassland Fabaceae species to different habitats, i.e. ecological niches. We measured a wide range of functional traits (root traits, leaf traits and whole plant traits in these species. Species phylogenetic and ecological distances were assessed from a species-level phylogenetic tree and species’ ecological indicator values, respectively. We demonstrated that differences in ecological niches between grassland Fabaceae species were related more to their hierarchical trait distances than to their phylogenetic distances. We showed that grassland Fabaceae functional traits tend to converge among species with the same ecological requirements. Species with acquisitive root strategies (thin roots, shallow root systems are competitive species adapted to non-stressful meadows, while conservative ones (coarse roots, deep root systems are able to tolerate stressful continental climates. In contrast, acquisitive species appeared to be able to tolerate low soil-P availability, while conservative ones need high P availability. Finally we highlight that traits converge along the ecological gradient, providing the assumption that species with similar root-trait values are better able to coexist, regardless of their phylogenetic distance.
Interleaved Core Assignment for Bidirectional Transmission in Multi-Core Fibers
Ye, Feihong; Morioka, Toshio
2013-01-01
We study interleaved core assignment for bidirectional transmission in multi-core fibers. By combining it with heterogeneous core structure in an 18-core fiber, the transmission distance is extended by 10 times compared to homogeneous core structure with unidirectional transmission, achieving...
Interleaved Core Assignment for Bidirectional Transmission in Multi-Core Fibers
2013-01-01
We study interleaved core assignment for bidirectional transmission in multi-core fibers. By combining it with heterogeneous core structure in an 18-core fiber, the transmission distance is extended by 10 times compared to homogeneous core structure with unidirectional transmission, achieving a total capacity of 1 Pb/s per direction.
Interleaved Core Assignment for Bidirectional Transmission in Multi-Core Fibers
Ye, Feihong; Morioka, Toshio
2013-01-01
We study interleaved core assignment for bidirectional transmission in multi-core fibers. By combining it with heterogeneous core structure in an 18-core fiber, the transmission distance is extended by 10 times compared to homogeneous core structure with unidirectional transmission, achieving a t...
On the rate of convergence of the maximum likelihood estimator of a k-monotone density
WELLNER; Jon; A
2009-01-01
Bounds for the bracketing entropy of the classes of bounded k-monotone functions on [0,A] are obtained under both the Hellinger distance and the Lp(Q) distance,where 1 p < ∞ and Q is a probability measure on [0,A].The result is then applied to obtain the rate of convergence of the maximum likelihood estimator of a k-monotone density.
On the rate of convergence of the maximum likelihood estimator of a K-monotone density
GAO FuChang; WELLNER Jon A
2009-01-01
Bounds for the bracketing entropy of the classes of bounded K-monotone functions on [0, A] are obtained under both the Hellinger distance and the LP(Q) distance, where 1 ≤ p < ∞ and Q is a probability measure on [0, A]. The result is then applied to obtain the rate of convergence of the maximum likelihood estimator of a K-monotone density.
Distance labeling schemes for trees
Alstrup, Stephen; Gørtz, Inge Li; Bistrup Halvorsen, Esben
2016-01-01
We consider distance labeling schemes for trees: given a tree with n nodes, label the nodes with binary strings such that, given the labels of any two nodes, one can determine, by looking only at the labels, the distance in the tree between the two nodes. A lower bound by Gavoille et al. [Gavoille...... variants such as, for example, small distances in trees [Alstrup et al., SODA, 2003]. We improve the known upper and lower bounds of exact distance labeling by showing that 1/4 log2(n) bits are needed and that 1/2 log2(n) bits are sufficient. We also give (1 + ε)-stretch labeling schemes using Theta......(log(n)) bits for constant ε> 0. (1 + ε)-stretch labeling schemes with polylogarithmic label size have previously been established for doubling dimension graphs by Talwar [Talwar, STOC, 2004]. In addition, we present matching upper and lower bounds for distance labeling for caterpillars, showing that labels...
Maximum range of a projectile thrown from constant-speed circular motion
Poljak, Nikola
2016-01-01
The problem of determining the angle at which a point mass launched from ground level with a given speed is a standard exercise in mechanics. Similar, yet conceptually and calculationally more difficult problems have been suggested to improve student proficiency in projectile motion. The problem of determining the maximum distance of a rock thrown from a rotating arm motion is presented and analyzed in detail in this text. The calculational results confirm several conceptually derived conclusions regarding the initial throw position and provide some details on the angles and the way of throwing (underhand or overhand) which produce the maximum throw distance.
The automotive transmission book
Fischer, Robert; Jürgens, Gunter; Najork, Rolf; Pollak, Burkhard
2015-01-01
This book presents essential information on systems and interactions in automotive transmission technology and outlines the methodologies used to analyze and develop transmission concepts and designs. Functions of and interactions between components and subassemblies of transmissions are introduced, providing a basis for designing transmission systems and for determining their potentials and properties in vehicle-specific applications: passenger cars, trucks, buses, tractors, and motorcycles. With these fundamentals the presentation provides universal resources for both state-of-the-art and future transmission technologies, including systems for electric and hybrid electric vehicles.
Distance Computation Between Non-Holonomic Motions with Constant Accelerations
Enrique J. Bernabeu
2013-09-01
Full Text Available A method for computing the distance between two moving robots or between a mobile robot and a dynamic obstacle with linear or arc‐like motions and with constant accelerations is presented in this paper. This distance is obtained without stepping or discretizing the motions of the robots or obstacles. The robots and obstacles are modelled by convex hulls. This technique obtains the future instant in time when two moving objects will be at their minimum translational distance ‐ i.e., at their minimum separation or maximum penetration (if they will collide. This distance and the future instant in time are computed in parallel. This method is intended to be run each time new information from the world is received and, consequently, it can be used for generating collision‐free trajectories for non‐holonomic mobile robots.
[Evolutionary process unveiled by the maximum genetic diversity hypothesis].
Huang, Yi-Min; Xia, Meng-Ying; Huang, Shi
2013-05-01
As two major popular theories to explain evolutionary facts, the neutral theory and Neo-Darwinism, despite their proven virtues in certain areas, still fail to offer comprehensive explanations to such fundamental evolutionary phenomena as the genetic equidistance result, abundant overlap sites, increase in complexity over time, incomplete understanding of genetic diversity, and inconsistencies with fossil and archaeological records. Maximum genetic diversity hypothesis (MGD), however, constructs a more complete evolutionary genetics theory that incorporates all of the proven virtues of existing theories and adds to them the novel concept of a maximum or optimum limit on genetic distance or diversity. It has yet to meet a contradiction and explained for the first time the half-century old Genetic Equidistance phenomenon as well as most other major evolutionary facts. It provides practical and quantitative ways of studying complexity. Molecular interpretation using MGD-based methods reveal novel insights on the origins of humans and other primates that are consistent with fossil evidence and common sense, and reestablished the important role of China in the evolution of humans. MGD theory has also uncovered an important genetic mechanism in the construction of complex traits and the pathogenesis of complex diseases. We here made a series of sequence comparisons among yeasts, fishes and primates to illustrate the concept of limit on genetic distance. The idea of limit or optimum is in line with the yin-yang paradigm in the traditional Chinese view of the universal creative law in nature.
Bordetella pertussis transmission.
Trainor, Elizabeth A; Nicholson, Tracy L; Merkel, Tod J
2015-11-01
Bordetella pertussis and B. bronchiseptica are Gram-negative bacterial respiratory pathogens. Bordetella pertussis is the causative agent of whooping cough and is considered a human-adapted variant of B. bronchiseptica. Bordetella pertussis and B. bronchiseptica share mechanisms of pathogenesis and are genetically closely related. However, despite the close genetic relatedness, these Bordetella species differ in several classic fundamental aspects of bacterial pathogens such as host range, pathologies and persistence. The development of the baboon model for the study of B. pertussis transmission, along with the development of the swine and mouse model for the study of B. bronchiseptica, has enabled the investigation of different aspects of transmission including the route, attack rate, role of bacterial and host factors, and the impact of vaccination on transmission. This review will focus on B. pertussis transmission and how animal models of B. pertussis transmission and transmission models using the closely related B. bronchiseptica have increased our understanding of B. pertussis transmission.
Transmission of Information by Longitudinal Electromagnetic Waves
Barashenkov, V S; Yuriev, M Z
2001-01-01
In Maxwell electrodynamics longitudinal wave irradiation is strongly forbidden by the so-called gauge invariance. However, these waves are present in virtual quantum processes and they can be used to transfer information at macroscopic distances by the displacement of the interference picture due to the change of the phase of electron wave function. The transmission can be carried out so that it will be hidden for usual observation.
The inverse maximum dynamic flow problem
BAGHERIAN; Mehri
2010-01-01
We consider the inverse maximum dynamic flow (IMDF) problem.IMDF problem can be described as: how to change the capacity vector of a dynamic network as little as possible so that a given feasible dynamic flow becomes a maximum dynamic flow.After discussing some characteristics of this problem,it is converted to a constrained minimum dynamic cut problem.Then an efficient algorithm which uses two maximum dynamic flow algorithms is proposed to solve the problem.
Reducing the distance in distance-caregiving by technology innovation
Lazelle E Benefield
2007-07-01
Full Text Available Lazelle E Benefield1, Cornelia Beck21College of Nursing, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA; 2Pat & Willard Walker Family Memory Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USAAbstract: Family caregivers are responsible for the home care of over 34 million older adults in the United States. For many, the elder family member lives more than an hour’s distance away. Distance caregiving is a growing alternative to more familiar models where: 1 the elder and the family caregiver(s may reside in the same household; or 2 the family caregiver may live nearby but not in the same household as the elder. The distance caregiving model involves elders and their family caregivers who live at some distance, defined as more than a 60-minute commute, from one another. Evidence suggests that distance caregiving is a distinct phenomenon, differs substantially from on-site family caregiving, and requires additional assistance to support the physical, social, and contextual dimensions of the caregiving process. Technology-based assists could virtually connect the caregiver and elder and provide strong support that addresses the elder’s physical, social, cognitive, and/or sensory impairments. Therefore, in today’s era of high technology, it is surprising that so few affordable innovations are being marketed for distance caregiving. This article addresses distance caregiving, proposes the use of technology innovation to support caregiving, and suggests a research agenda to better inform policy decisions related to the unique needs of this situation.Keywords: caregiving, family, distance, technology, elders
Maximum permissible voltage of YBCO coated conductors
Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z. [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Hong, Z., E-mail: zhiyong.hong@sjtu.edu.cn [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Wang, D.; Zhou, H.; Shen, X.; Shen, C. [Qingpu Power Supply Company, State Grid Shanghai Municipal Electric Power Company, Shanghai (China)
2014-06-15
Highlights: • We examine three kinds of tapes’ maximum permissible voltage. • We examine the relationship between quenching duration and maximum permissible voltage. • Continuous I{sub c} degradations under repetitive quenching where tapes reaching maximum permissible voltage. • The relationship between maximum permissible voltage and resistance, temperature. - Abstract: Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (I{sub c}) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the I{sub c} degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.
A Fast Parametric Maximum Flow Algorithm. Revision,
1987-07-01
26]. ". N. Perfect sharing arises in a network transmission problem studied by Itai and Rodeh [21] and 1 Gusfield [17] and in a network...the network transmission scheduling problem described below. Another application will arise in Section 4.2. Scheduling transmissions. Itai and Rodeh...constructed from the flow in 0(m) time as described in [21]. Itai and Rodeh proposed two 22 "-N., -- %’%’ % %""’ . ,’ ""€"" ",. . -",/a
Radio and distance learning in Pakistan.
Abbas, R
1987-01-01
Radio is a powerful communication vehicle in Pakistan able to reach 3/4 of urban and 2/3 of rural households. Until 1974, most radio broadcasts of the Pakistan Broadcasting Corporation, a state monopoly, were in the categories of music, drama, and features; news and current affairs; and religious broadcasts. The Allama Iqbal Open University (AIOU), a distance learning educational institution, was established through an act of the Pakistan Parliament in 1974 and is the only institution in the country to use radio broadcasts for its curriculum. Also established in 1974 within the AIOU was the Institute of Educational Technology (IET). The IET channels the transmission and flow of well-designed educational messages and lessons from the teachers to the students by employing distance teaching methodology that seeks to reinforce students' weekly lessons. IET closely integrates its activities within the University's academic departments. IET staff members not only participate in the development of course curriculum and syllabi, but also help to identify course content needing reinforcement through radio. While the teachers at AIOU convert the course curricula into distance-learning self-study activity-oriented correspondence texts, IET producers transcribe these scripts into actual production scripts. Feedback from students and findings of the University's Research and Statistical Cell are used to make revisions in the scripts. The AIOU enrolls an average of 100,000 students each year. Expansion is being limited only by the costs of purchasing time from the Pakistan Broadcasting Corporation (Rs 2000 for a 15-minute lesson) and the availability of appropriate time slots.
Distance education ethics : How technique impacts morality and deontology
Marty, Olivier
2014-01-01
Using a hybrid episteme of descriptive education science and prescriptive philosophy of education, I will question the problem of distance education ethics, focusing on how new techniques are impacting morality and deontology. I will focus on every aspect of these ethics: accessibility and neutrality of media as to what concerns morality; then transmission of values and engineering of organizational culture concerning deontology. I will finally study the relationship between morality and deon...
Harmonics in transmission power systems
Wiechowski, Wojciech Tomasz
to perform more detailed harmonic studies emerged. Since the transmission network has a complex structure and its impedance varies with frequency in a nonlinear fashion, such harmonic study would require a detailed computer model of the network. Consequently, a PhD project proposal titled "Harmonics....... It is concluded that since some background harmonic distortion is practically always present in the network, a method based on variation of harmonic values must be used. The incremental values of harmonic distortion will allow to verify the harmonic model, despite the existence of background harmonic distortion...... GPS-synchronized OMICRON CMC256 units. Two such units are installed at 400 kV substations at both ends of the disconnected line and a third unit is located at a substation in a distance of 80 km. Time domain "snap-shot" measurements of three-phase voltages and currents are synchronously taken for some...
Distance Learning for Special Populations
Bates, Rodger A.
2012-01-01
Distance education strategies for remotely deployed, highly mobile, or institutionalized populations are reviewed and critiqued. Specifically, asynchronous, offline responses for special military units, Native Americans on remote reservations, prison populations and other geographically, temporally or technologically isolated niche populations are…
ECONOMICS OF DISTANCE EDUCATION RECONSIDERED
Wolfram LAASER
2008-07-01
Full Text Available ABSTRACT According to Gartner a certain hype of e-Learning was followed by a downturn but eLearning will continue to be an important factor in learning scenarios. However the economic viability of e-learning projects will be questioned with more scrutiny than in earlier periods. Therefore it seems to be a good opportunity to see what can be learned from past experience in costing distance learning projects and what aspects are added by current attempts to measure economic efficiency. After reviewing early research about costing distance learning some more recent approaches will be discussed, such as eLearning ROI-calculators and the concept of total cost of ownership. Furthermore some microeconomic effects referring to localization of distance learning courses are outlined. Finally several unsolved issues in costing distance education are summarized.
Distance Education in Technological Age
R .C. SHARMA
2005-04-01
Full Text Available Distance Education in Technological AgeRomesh Verma (Editor, New Delhi: Anmol Publications, 2005, ISBN 81-261-2210-2, pp. 419 Reviewed by R C SHARMARegional DirectorIndira Gandhi National Open University-INDIA The advancements in information and communication technologies have brought significant changes in the way the open and distance learning are provided to the learners. The impact of such changes is quite visible in both developed and developing countries. Switching over to online mode, joining hands with private initiatives and making a presence in foreign waters, are some of the hallmarks of the open and distance education (ODE institutions in developing countries. The compilation of twenty six essays on themes as applicable to ODE has resulted in the book, Distance Education in Technological Age. These essays follow a progressive style of narration, starting from describing conceptual framework of distance education, how the distance education was emerged on the global scene and in India, and then goes on to discuss emergence of online distance education and research aspects in ODE. The initial four chapters provide a detailed account of historical development and growth of distance education in India and State Open University and National Open University Model in India . Student support services are pivot to any distance education and much of its success depends on how well the support services are provided. These are discussed from national and international perspective. The issues of collaborative learning, learning on demand, life long learning, learning-unlearning and re-learning model and strategic alliances have also given due space by the authors. An assortment of technologies like communication technology, domestic technology, information technology, mass media and entertainment technology, media technology and educational technology give an idea of how these technologies are being adopted in the open universities. The study
KNOWLEDGE DISTANCE IN INFORMATION SYSTEMS
Yuhua QIAN; Jiye LIANG; Chuangyin DANG; Feng WANG; Wei XU
2007-01-01
In this paper, we first introduce the concepts of knowledge closeness and knowledge distance for measuring the sameness and the difference among knowledge in an information system, respectively.The relationship between these two concepts is a strictly mutual complement relation. We then investigate some important properties of knowledge distance and perform experimental analyses on two public data sets, which show the presented measure appears to be well suited to characterize the nature of knowledge in an information system. Finally, we establish the relationship between the knowledge distance and knowledge granulation, which shows that two variants of the knowledge distance can also be used to construct the knowledge granulation. These results will be helpful for studying uncertainty in information systems.
Graph distance for complex networks
Shimada, Yutaka; Hirata, Yoshito; Ikeguchi, Tohru; Aihara, Kazuyuki
2016-10-01
Networks are widely used as a tool for describing diverse real complex systems and have been successfully applied to many fields. The distance between networks is one of the most fundamental concepts for properly classifying real networks, detecting temporal changes in network structures, and effectively predicting their temporal evolution. However, this distance has rarely been discussed in the theory of complex networks. Here, we propose a graph distance between networks based on a Laplacian matrix that reflects the structural and dynamical properties of networked dynamical systems. Our results indicate that the Laplacian-based graph distance effectively quantifies the structural difference between complex networks. We further show that our approach successfully elucidates the temporal properties underlying temporal networks observed in the context of face-to-face human interactions.
Are contemporary tourists consuming distance?
Larsen, Gunvor Riber
2012. Background The background for this research, which explores how tourists represent distance and whether or not distance can be said to be consumed by contemporary tourists, is the increasing leisure mobility of people. Travelling for the purpose of visiting friends and relatives is increasing...... of understanding mobility at a conceptual level, and distance matters to people's manifest mobility: how they travel and how far they travel are central elements of their movements. Therefore leisure mobility (indeed all mobility) is the activity of relating across distance, either through actual corporeal...... that is an inherent part of manifest mobility. Numerous definitions and conceptualisations of tourism have been discussed over the years, with MacCannell (1976) pioneering studies of tourism and leisure travel through to Lash and Urry's (1994) post tourist and Jansson's (2002) hyper-tourist. These definitions...
Academy Distance Learning Tools (IRIS)
Department of Transportation — IRIS is a suite of front-end web applications utilizing a centralized back-end Oracle database. The system fully supports the FAA Academy's Distance Learning Program...
Distance education: turf and technology.
Pickard, M R
1992-07-01
Distance learning fits with the mission and strategic plan of the University of Texas at Arlington. We believe these educational opportunities in nursing are highly desirable. The Board of Nurse Examiners for the State of Texas has approved this project and the Texas Higher Education Coordinating Board has approved it as a pilot project. The school will continue evaluation and creative problem-solving in the use of distance education.
Categorical perception of tactile distance
Knight, F. L. C.; Longo, M. R.; Bremner, A.J.
2014-01-01
The tactile surface forms a continuous sheet covering the body. And yet, the perceived distance between two touches varies across stimulation sites. Perceived tactile distance is larger when stimuli cross over the wrist, compared to when both fall on either the hand or the forearm. This effect could reflect a categorical distortion of tactile space across body-part boundaries (in which stimuli crossing the wrist boundary are perceptually elongated) or may simply reflect a localised increased ...
Generalised maximum entropy and heterogeneous technologies
Oude Lansink, A.G.J.M.
1999-01-01
Generalised maximum entropy methods are used to estimate a dual model of production on panel data of Dutch cash crop farms over the period 1970-1992. The generalised maximum entropy approach allows a coherent system of input demand and output supply equations to be estimated for each farm in the sam
20 CFR 229.48 - Family maximum.
2010-04-01
... month on one person's earnings record is limited. This limited amount is called the family maximum. The family maximum used to adjust the social security overall minimum rate is based on the employee's Overall..., when any of the persons entitled to benefits on the insured individual's compensation would, except...
The maximum rotation of a galactic disc
Bottema, R
1997-01-01
The observed stellar velocity dispersions of galactic discs show that the maximum rotation of a disc is on average 63% of the observed maximum rotation. This criterion can, however, not be applied to small or low surface brightness (LSB) galaxies because such systems show, in general, a continuously
Farooq, Muhammad U.; Al Asmari, AbdulRahman; Javid, Choudhary Z.
2012-01-01
Technology-based initiatives have transformed the process of teaching and learning activities at formal institutions generally and distance education institutions particularly. Distance education is at the heart of the digital age making maximum use of the emerging technologies. Researchers have favoured computer mediated communications (CMC) for…
Single Wave Overtopping Volumes and their Travel Distance for Rubble Mound Breakwaters
Andersen, Thomas Lykke; Burcharth, Hans F.; Gironella, F. X.
2009-01-01
In the present paper small and large scale overtopping data for rubble mound structures have been analysed with respect to single wave overtopping volumes and their travel distance. The analysis has led to formulae for estimation of maximum single wave overtopping volumes and their travel distance...
Categorical perception of tactile distance.
Knight, Frances Le Cornu; Longo, Matthew R; Bremner, Andrew J
2014-05-01
The tactile surface forms a continuous sheet covering the body. And yet, the perceived distance between two touches varies across stimulation sites. Perceived tactile distance is larger when stimuli cross over the wrist, compared to when both fall on either the hand or the forearm. This effect could reflect a categorical distortion of tactile space across body-part boundaries (in which stimuli crossing the wrist boundary are perceptually elongated) or may simply reflect a localised increased in acuity surrounding anatomical landmarks (in which stimuli near the wrist are perceptually elongated). We tested these two interpretations across two experiments, by comparing a well-documented bias to perceive mediolateral tactile distances across the forearm/hand as larger than proximodistal ones along the forearm/hand at three different sites (hand, wrist, and forearm). According to the 'categorical' interpretation, tactile distances should be elongated selectively in the proximodistal axis thus reducing the anisotropy. According to the 'localised acuity' interpretation, distances will be perceptually elongated in the vicinity of the wrist regardless of orientation, leading to increased overall size without affecting anisotropy. Consistent with the categorical account, we found a reduction in the magnitude of anisotropy at the wrist, with no evidence of a corresponding localised increase in precision. These findings demonstrate that we reference touch to a representation of the body that is categorically segmented into discrete parts, which consequently influences the perception of tactile distance.
Distance learning at biomedical faculties in bosnia & herzegovina.
Masic, Zlatan; Novo, Ahmed; Masic, Izet; Kudumovic, Mensura; Toromanovic, Selim; Rama, Admir; Dzananovic, Almir; Bander, Ilda; Basic, Mirza; Guso, Emir; Balta, Eldar
2005-01-01
Increase and development of distance learning technologies over the past decade has exposed the potential and the efficiency of new technologies. Benefit and use of contemporary information technologies is the area where medical informatics got the most on understanding and importance. Definition of distance learning as "use of technologies based on health care delivered on distance" covers areas such as electronic health, tele-health (e-health), telematics, telemedicine, tele-education, etc. For the need of e-health, telemedicine, tele-education and distance learning there are various technologies and communication systems from standard telephone lines to the system of transmission digitalized signals with modem, optical fiber, satellite links, wireless technologies, etc. Tele-education represents health education on distance, using Information Communication Technologies(ICT), as well as continuous education of a health system beneficiaries and use of electronic libraries, data bases or electronic data with data bases of knowledge. In this paper authors described activities on introduction of distance learning in teaching process at Medical faculty, University of Sarajevo, Bosnia and Herzegovina. Internet was not really meant to be a means of human communication at first; but the clearly the Net become a main piece of human communication.
Duality of Maximum Entropy and Minimum Divergence
Shinto Eguchi
2014-06-01
Full Text Available We discuss a special class of generalized divergence measures by the use of generator functions. Any divergence measure in the class is separated into the difference between cross and diagonal entropy. The diagonal entropy measure in the class associates with a model of maximum entropy distributions; the divergence measure leads to statistical estimation via minimization, for arbitrarily giving a statistical model. The dualistic relationship between the maximum entropy model and the minimum divergence estimation is explored in the framework of information geometry. The model of maximum entropy distributions is characterized to be totally geodesic with respect to the linear connection associated with the divergence. A natural extension for the classical theory for the maximum likelihood method under the maximum entropy model in terms of the Boltzmann-Gibbs-Shannon entropy is given. We discuss the duality in detail for Tsallis entropy as a typical example.
G. Iannaccone
2007-06-01
Full Text Available ?In this paper we studied the physical properties of the Gulf of Naples (Southern Italy for its use as a commu- nication channel for the acoustic transmission of digital data acquired by seismic instruments on the seafloor to a moored buoy. The acoustic link will be assured by high frequency acoustic modems operating with a central frequency of 100 kHz and a band pass of 10 kHz. The main operational requirements of data transmission con- cern the near horizontal acoustic link, the maximum depth of the sea being about 300 m and the planned hori- zontal distance between seismic instruments and buoy 2 km. This study constructs the signal-to-noise ratio maps to understand the limits beyond which the clarity of the transmission is no longer considered reliable. Using ray- theory, we compute the amplitudes of a transmitted signal at a grid of 21×12 receivers to calculate the transmis- sion loss at each receiver. The signal-to-noise ratio is finally computed for each receiver knowing also the trans- mitter source level and the acoustic noise level in the Gulf of Naples. The results show that the multipath effects predominate over the effects produced by the sound velocity gradient in the sea in the summer period. In the case of omnidirectional transmitters with a Source Level (SL of 165 dB and a baud rate of 2.4 kbit/s, the results al- so show that distances of 1400-1600 m can be reached throughout the year for transmitter-receiver connections below 50 m depth in the underwater acoustic channel.
Impedance matching wireless power transmission system for biomedical devices.
Lum, Kin Yun; Lindén, Maria; Tan, Tian Swee
2015-01-01
For medical application, the efficiency and transmission distance of the wireless power transfer (WPT) are always the main concern. Research has been showing that the impedance matching is one of the critical factors for dealing with the problem. However, there is not much work performed taking both the source and load sides into consideration. Both sides matching is crucial in achieving an optimum overall performance, and the present work proposes a circuit model analysis for design and implementation. The proposed technique was validated against experiment and software simulation. Result was showing an improvement in transmission distance up to 6 times, and efficiency at this transmission distance had been improved up to 7 times as compared to the impedance mismatch system. The system had demonstrated a near-constant transfer efficiency for an operating range of 2cm-12cm.
Boundary condition effects on maximum groundwater withdrawal in coastal aquifers.
Lu, Chunhui; Chen, Yiming; Luo, Jian
2012-01-01
Prevention of sea water intrusion in coastal aquifers subject to groundwater withdrawal requires optimization of well pumping rates to maximize the water supply while avoiding sea water intrusion. Boundary conditions and the aquifer domain size have significant influences on simulating flow and concentration fields and estimating maximum pumping rates. In this study, an analytical solution is derived based on the potential-flow theory for evaluating maximum groundwater pumping rates in a domain with a constant hydraulic head landward boundary. An empirical correction factor, which was introduced by Pool and Carrera (2011) to account for mixing in the case with a constant recharge rate boundary condition, is found also applicable for the case with a constant hydraulic head boundary condition, and therefore greatly improves the usefulness of the sharp-interface analytical solution. Comparing with the solution for a constant recharge rate boundary, we find that a constant hydraulic head boundary often yields larger estimations of the maximum pumping rate and when the domain size is five times greater than the distance between the well and the coastline, the effect of setting different landward boundary conditions becomes insignificant with a relative difference between two solutions less than 2.5%. These findings can serve as a preliminary guidance for conducting numerical simulations and designing tank-scale laboratory experiments for studying groundwater withdrawal problems in coastal aquifers with minimized boundary condition effects.
Understanding ebola virus transmission.
Judson, Seth; Prescott, Joseph; Munster, Vincent
2015-02-03
An unprecedented number of Ebola virus infections among healthcare workers and patients have raised questions about our understanding of Ebola virus transmission. Here, we explore different routes of Ebola virus transmission between people, summarizing the known epidemiological and experimental data. From this data, we expose important gaps in Ebola virus research pertinent to outbreak situations. We further propose experiments and methods of data collection that will enable scientists to fill these voids in our knowledge about the transmission of Ebola virus.
Series Transmission Line Transformer
Buckles, Robert A.; Booth, Rex; Yen, Boris T.
2004-06-29
A series transmission line transformer is set forth which includes two or more of impedance matched sets of at least two transmissions lines such as shielded cables, connected in parallel at one end ans series at the other in a cascading fashion. The cables are wound about a magnetic core. The series transmission line transformer (STLT) which can provide for higher impedance ratios and bandwidths, which is scalable, and which is of simpler design and construction.
A Q-Modulation Technique for Efficient Inductive Power Transmission.
Kiani, Mehdi; Lee, Byunghun; Yeon, Pyungwoo; Ghovanloo, Maysam
2015-12-01
A fully-integrated power management ASIC for efficient inductive power transmission has been presented capable of automatic load transformation using a method, called Q-modulation. Q-modulation is an adaptive scheme that offers load matching against a wide range of loading (RL ) and coupling distance (d23 ) variations in inductive links to maintain high power transfer efficiency (PTE). It is suitable for inductive powering implantable microelectronic devices (IMDs), recharging mobile electronics, and electric vehicles. In Q-modulation, the zero-crossings of the induced current in the receiver (Rx) LC-tank are detected and a low-loss switch chops the Rx LC-tank for part of the power carrier cycle to form a high-Q LC-tank and store the maximum energy, which is then transferred to RL by opening the switch. By adjusting the duty cycle (D), the loaded-Q of the Rx LC-tank can be dynamically modulated to compensate for variations in RL . A Q-modulation power management (QMPM) prototype chip was fabricated in a 0.35-μm standard CMOS process, occupying 4.8 mm(2). In a 1.45 W wireless power transfer setup, using a class-E power amplifier (PA) operating at 2 MHz, the QMPM successfully increased the inductive link PTE and the overall power efficiency by 98.5% and 120.7% at d23 = 8 cm, respectively, by compensating for 150 Ω variation in RL at D = 45%.
EVALUATION OF DISTANCE EDUCATION IN DENTISTRY GRADUATION COURSE
Helbert Eustáquio Cardoso da Silva
2014-05-01
Full Text Available The curricula of Dentistry are in the process of modernization , to suit the labor market geared to the needs of the population . The changes seek a teaching method that is conducive to student elfmanagement of their knowledge through a transdisciplinary vision. Objective: To examine about the training of teachers responsible for the disciplines of dentistry , as well as new possibilities of knowledge transmission . In this context, the distance is shown as an alternative to the continuing education of future dentists , covering new technologies and new methods of teaching adults. Methods: Through a literature review , we discuss about the goals of the national curriculum guidelines and the training of teachers of courses in dentistry and also surveys are presented in distance education in healthcare. Results: The study shows successful application of distance learning for adult learners courses in Dentistry .
Max–min distance nonnegative matrix factorization
Wang, Jim Jing-Yan
2014-10-26
Nonnegative Matrix Factorization (NMF) has been a popular representation method for pattern classification problems. It tries to decompose a nonnegative matrix of data samples as the product of a nonnegative basis matrix and a nonnegative coefficient matrix. The columns of the coefficient matrix can be used as new representations of these data samples. However, traditional NMF methods ignore class labels of the data samples. In this paper, we propose a novel supervised NMF algorithm to improve the discriminative ability of the new representation by using the class labels. Using the class labels, we separate all the data sample pairs into within-class pairs and between-class pairs. To improve the discriminative ability of the new NMF representations, we propose to minimize the maximum distance of the within-class pairs in the new NMF space, and meanwhile to maximize the minimum distance of the between-class pairs. With this criterion, we construct an objective function and optimize it with regard to basis and coefficient matrices, and slack variables alternatively, resulting in an iterative algorithm. The proposed algorithm is evaluated on three pattern classification problems and experiment results show that it outperforms the state-of-the-art supervised NMF methods.
Shashi Prakash Dwivedi
2014-01-01
Full Text Available The objective of the present work is to study the effects of laser power, joining speed, and stand-off distance on the joint strength of PET and 316 L stainless steel joint. The process parameters were optimized using response methodology for achieving good joint strength. The central composite design (CCD has been utilized to plan the experiments and response surface methodology (RSM is employed to develop mathematical model between laser transmission joining parameters and desired response (joint strength. From the ANOVA (analysis of variance, it was concluded that laser power is contributing more and it is followed by joining speed and stand-off distance. In the range of process parameters, the result shows that laser power increases and joint strength increases. Whereas joining speed increases, joint strength increases. The joint strength increases with the increase of the stand-off distance until it reaches the center value; the joint strength then starts to decrease with the increase of stand-off distance beyond the center limit. Optimum values of laser power, joining speed, and stand-off distance were found to be 18 watt, 100 mm/min, and 2 mm to get the maximum joint strength (predicted: 88.48 MPa. There was approximately 3.37% error in the experimental and modeled results of joint strength.
Center—Distance Continuous Probability Models and the Distance Measure
郑方; 吴文虎; 等
1998-01-01
In this paper,a new statistic model named Center-Distance Continuous Probability Model(CDCPM)for speech recognition is described,which is based on Center-Distance Normal(CDN)distribution.In a CDCPM,the probability transition matrix is omitted,and the observation probability density function(PDF)in each state is in the form of embedded multiple-model(EMM)based on the Nearest Neighbour rule.The experimental results on two giant real-world Chinese speech databases and a real-world continuous-manner 2000 phrase system show that this model is a powerful one.Also,a distance measure for CDPMs is proposed which is based on the Bayesian minimum classification error(MCE) discrimination.
The inverse maximum flow problem with lower and upper bounds for the flow
Deaconu Adrian
2008-01-01
Full Text Available The general inverse maximum flow problem (denoted GIMF is considered, where lower and upper bounds for the flow are changed so that a given feasible flow becomes a maximum flow and the distance (considering l1 norm between the initial vector of bounds and the modified vector is minimum. Strongly and weakly polynomial algorithms for solving this problem are proposed. In the paper it is also proved that the inverse maximum flow problem where only the upper bound for the flow is changed (IMF is a particular case of the GIMF problem.
Cetin, Bilge Kartal; Prasad, Neeli R.; Prasad, Ramjee
2011-01-01
of the maximum lifetime routing problem that considers the operation modes of the node. Solution of the linear programming gives the upper analytical bound for the network lifetime. In order to illustrate teh application of the optimization model, we solved teh problem for different parameter settings...... protocols, and the energy model for transmission. In this paper, we tackle the routing challenge for maximum lifetime of the sensor network. We introduce a novel linear programming approach to the maximum lifetime routing problem. To the best of our knowledge, this is the first mathematical programming...
Automatic Classification of Protein Structure Using the Maximum Contact Map Overlap Metric
Andonov, R.; Djidjev, H.; Klau, G.W.; Le Boudic-Jamin, M.; Wohlers, I.
2015-01-01
In this work, we propose a new distance measure for comparing two protein structures based on their contact map representations. We show that our novel measure, which we refer to as the maximum contact map overlap (max-CMO) metric, satisfies all properties of a metric on the space of protein represe
Conceptualizing Educational Research in Distance Education.
Watkins, Ryan; Schlosser, Charles
2003-01-01
Suggests a starting place for formal inquiry into distance education. Topics covered include: background on educational research and research on distance education; research paradigms that are applicable to distance education; subsystems of a distance education program; and a matrix for conceptualizing distance education research. (MES)
Computing Distances between Probabilistic Automata
Mathieu Tracol
2011-07-01
Full Text Available We present relaxed notions of simulation and bisimulation on Probabilistic Automata (PA, that allow some error epsilon. When epsilon is zero we retrieve the usual notions of bisimulation and simulation on PAs. We give logical characterisations of these notions by choosing suitable logics which differ from the elementary ones, L with negation and L without negation, by the modal operator. Using flow networks, we show how to compute the relations in PTIME. This allows the definition of an efficiently computable non-discounted distance between the states of a PA. A natural modification of this distance is introduced, to obtain a discounted distance, which weakens the influence of long term transitions. We compare our notions of distance to others previously defined and illustrate our approach on various examples. We also show that our distance is not expansive with respect to process algebra operators. Although L without negation is a suitable logic to characterise epsilon-(bisimulation on deterministic PAs, it is not for general PAs; interestingly, we prove that it does characterise weaker notions, called a priori epsilon-(bisimulation, which we prove to be NP-difficult to decide.
Distance sampling methods and applications
Buckland, S T; Marques, T A; Oedekoven, C S
2015-01-01
In this book, the authors cover the basic methods and advances within distance sampling that are most valuable to practitioners and in ecology more broadly. This is the fourth book dedicated to distance sampling. In the decade since the last book published, there have been a number of new developments. The intervening years have also shown which advances are of most use. This self-contained book covers topics from the previous publications, while also including recent developments in method, software and application. Distance sampling refers to a suite of methods, including line and point transect sampling, in which animal density or abundance is estimated from a sample of distances to detected individuals. The book illustrates these methods through case studies; data sets and computer code are supplied to readers through the book’s accompanying website. Some of the case studies use the software Distance, while others use R code. The book is in three parts. The first part addresses basic methods, the ...
Individual differences in distance perception.
Jackson, Russell E
2009-05-07
Distance perception is among the most pervasive mental phenomena and the oldest research topics in behavioural science. However, we do not understand well the most pervasive finding of distance perception research, that of large individual differences. There are large individual differences in acrophobia (fear of heights), which we commonly assume consists of an abnormal fear of stimuli perceived normally. Evolved navigation theory (ENT) instead suggests that acrophobia consists of a more normal fear of stimuli perceived abnormally. ENT suggests that distance perception individual differences produce major components of acrophobia. Acrophobia tested over a broad range in the present study predicted large individual differences in distance estimation of surfaces that could produce falls. This fear of heights correlated positively with distance estimates of a vertical surface-even among non-acrophobic individuals at no risk of falling and without knowledge of being tested for acrophobia. Acrophobia score predicted magnitude of the descent illusion, which is thought to reflect the risk of falling. These data hold important implications in environmental navigation, clinical aetiology and the evolution of visual systems.
ICT USAGE BY DISTANCE LEARNERS IN INDIA
Ashish Kumar AWADHIYA
2014-07-01
Full Text Available Open Universities across the world are embracing ICT based teaching and learning process to disseminate quality education to their learners spread across the globe. In India availability and access of ICT and learner characteristics are uneven and vary from state to state. Hence it is important to establish the facts about ICT access among learners, their ICT usage patterns and their readiness to use ICT for educational purpose. In view of this, a study was conducted with the objective to find out the access level of ICT among distance learners. The analysis indicates that maximum learners have desktop/laptops and most of them are accessing internet very frequently from their home. The analysis also indicates that maximum respondents are browsing social networking sites followed by educational and e-mail service providing websites. Findings suggest that there is a need to generate ICT based tutorials complemented with social networking tools and mobile applications. Study also shows that learners are equipped with mobile phones and they are browsing internet through it and also availing support services offered by the university. Hence possibility of integrating mobile phone services may be used for providing learner support services and content delivery.
Poverty and price transmission
Elleby, Christian
A key parameter determining the welfare impact from a world market shock is the transmission elasticity which measures the average domestic response to an international price change. Many studies have estimated price transmission elasticities for a large number of countries but the variation in t...
Cultural Transmission of Civicness
Ljunge, Jan Martin
This paper estimates the intergeneration transmission of civicness by studying second generation immigrants in 29 European countries with ancestry in 83 nations. There is significant transmission of civicness both on the mother’s and the father’s side. The estimates are quantitatively significant...
An Analytical Approach to Opportunistic Transmission under Rayleigh Fading Channels
Yousaf Bin Zikria; Sung Won Kim; Heejung Yu; Seung Yeob Nam
2015-01-01
In cognitive radio sensor networks, the routing methods including multiple relays have been extensively studied to achieve higher throughput and lower end-to-end delay. As one of innovative approaches, the opportunistic routing scheme was proposed. In this paper, the effectiveness of the opportunistic transmission in terms of reliability and delay of transmission is verified with an analytical way. For the analysis, we establish the probabilistic model with respect to distance and the number ...
Offshore windfarm connection with low frequency AC transmission technology
Qin, Nan; Xu, Zhao; You, Shi
2009-01-01
This paper investigates the feasibility of using the low frequency AC transmission (LFAC) system, e.g. fraction of 50 Hz or 60 Hz, for connecting the large offshore wind farm to the grid by modelling and simulation. The LFAC system improves the transmission capacity and distance compared to the c...... to the reduced inductive reactance of the grid. Moreover, the harmonics introduced by the frequency converter may require extra filters to be installed in such system....
The maximum intelligible range of the human voice
Boren, Braxton
This dissertation examines the acoustics of the spoken voice at high levels and the maximum number of people that could hear such a voice unamplified in the open air. In particular, it examines an early auditory experiment by Benjamin Franklin which sought to determine the maximum intelligible crowd for the Anglican preacher George Whitefield in the eighteenth century. Using Franklin's description of the experiment and a noise source on Front Street, the geometry and diffraction effects of such a noise source are examined to more precisely pinpoint Franklin's position when Whitefield's voice ceased to be intelligible. Based on historical maps, drawings, and prints, the geometry and material of Market Street is constructed as a computer model which is then used to construct an acoustic cone tracing model. Based on minimal values of the Speech Transmission Index (STI) at Franklin's position, Whitefield's on-axis Sound Pressure Level (SPL) at 1 m is determined, leading to estimates centering around 90 dBA. Recordings are carried out on trained actors and singers to determine their maximum time-averaged SPL at 1 m. This suggests that the greatest average SPL achievable by the human voice is 90-91 dBA, similar to the median estimates for Whitefield's voice. The sites of Whitefield's largest crowds are acoustically modeled based on historical evidence and maps. Based on Whitefield's SPL, the minimal STI value, and the crowd's background noise, this allows a prediction of the minimally intelligible area for each site. These yield maximum crowd estimates of 50,000 under ideal conditions, while crowds of 20,000 to 30,000 seem more reasonable when the crowd was reasonably quiet and Whitefield's voice was near 90 dBA.
Interspecies transmission of prions.
Afanasieva, E G; Kushnirov, V V; Ter-Avanesyan, M D
2011-12-01
Mammalian prions are infectious agents of proteinaceous nature that cause several incurable neurodegenerative diseases. Interspecies transmission of prions is usually impeded or impossible. Barriers in prion transmission are caused by small interspecies differences in the primary structure of prion proteins. The barriers can also depend on the strain (variant) of a transmitted prion. Interspecies barriers were also shown for yeast prions, which define some heritable phenotypes. Yeast prions reproduce all the main traits of prion transmission barriers observed for mammals. This allowed to show that the barrier in prion transmission can be observed even upon copolymerization of two prionogenic proteins. Available data allow elucidation of the mechanisms that impede prion transmission or make it impossible.
Nonlinear magnetoinductive transmission lines
Lazarides, Nikos; Tsironis, G P
2011-01-01
Power transmission in one-dimensional nonlinear magnetic metamaterials driven at one end is investigated numerically and analytically in a wide frequency range. The nonlinear magnetic metamaterials are composed of varactor-loaded split-ring resonators which are coupled magnetically through their mutual inductances, forming thus a magnetoiductive transmission line. In the linear limit, significant power transmission along the array only appears for frequencies inside the linear magnetoinductive wave band. We present analytical, closed form solutions for the magnetoinductive waves transmitting the power in this regime, and their discrete frequency dispersion. When nonlinearity is important, more frequency bands with significant power transmission along the array may appear. In the equivalent circuit picture, the nonlinear magnetoiductive transmission line driven at one end by a relatively weak electromotive force, can be modeled by coupled resistive-inductive-capacitive (RLC) circuits with voltage-dependent cap...
A dual method for maximum entropy restoration
Smith, C. B.
1979-01-01
A simple iterative dual algorithm for maximum entropy image restoration is presented. The dual algorithm involves fewer parameters than conventional minimization in the image space. Minicomputer test results for Fourier synthesis with inadequate phantom data are given.
Photoemission spectromicroscopy with MAXIMUM at Wisconsin
Ng, W.; Ray-Chaudhuri, A.K.; Cole, R.K.; Wallace, J.; Crossley, S.; Crossley, D.; Chen, G.; Green, M.; Guo, J.; Hansen, R.W.C.; Cerrina, F.; Margaritondo, G. (Dept. of Electrical Engineering, Dept. of Physics and Synchrotron Radiation Center, Univ. of Wisconsin, Madison (USA)); Underwood, J.H.; Korthright, J.; Perera, R.C.C. (Center for X-ray Optics, Accelerator and Fusion Research Div., Lawrence Berkeley Lab., CA (USA))
1990-06-01
We describe the development of the scanning photoemission spectromicroscope MAXIMUM at the Wisoncsin Synchrotron Radiation Center, which uses radiation from a 30-period undulator. The article includes a discussion of the first tests after the initial commissioning. (orig.).
Maximum-likelihood method in quantum estimation
Paris, M G A; Sacchi, M F
2001-01-01
The maximum-likelihood method for quantum estimation is reviewed and applied to the reconstruction of density matrix of spin and radiation as well as to the determination of several parameters of interest in quantum optics.
Asymmetric distances for binary embeddings.
Gordo, Albert; Perronnin, Florent; Gong, Yunchao; Lazebnik, Svetlana
2014-01-01
In large-scale query-by-example retrieval, embedding image signatures in a binary space offers two benefits: data compression and search efficiency. While most embedding algorithms binarize both query and database signatures, it has been noted that this is not strictly a requirement. Indeed, asymmetric schemes that binarize the database signatures but not the query still enjoy the same two benefits but may provide superior accuracy. In this work, we propose two general asymmetric distances that are applicable to a wide variety of embedding techniques including locality sensitive hashing (LSH), locality sensitive binary codes (LSBC), spectral hashing (SH), PCA embedding (PCAE), PCAE with random rotations (PCAE-RR), and PCAE with iterative quantization (PCAE-ITQ). We experiment on four public benchmarks containing up to 1M images and show that the proposed asymmetric distances consistently lead to large improvements over the symmetric Hamming distance for all binary embedding techniques.
Ghost imaging with broad distance
段德洋; 张路; 杜少将; 夏云杰
2015-01-01
We present a scheme that is able to achieve the ghost imaging with broad distance. The physical nature of our scheme is that the different wavelength beams are separated in free space by an optical media according to the slow light or dispersion principle. Meanwhile, the equality of the optical distance of the two light arms is not violated. The photon correlation is achieved by the rotating ground glass plate (RGGP) and spatial light modulator (SLM), respectively. Our work shows that a monochromic ghost image can be obtained in the case of RGGP. More importantly, the position (or distance) of the object can be ascertained by the color of the image. Thus, the imaging and ranging processes are combined as one process for the first time to the best of our knowledge. In the case of SLM, we can obtain a colored image regardless of where the object is.
Euclidean distance geometry an introduction
Liberti, Leo
2017-01-01
This textbook, the first of its kind, presents the fundamentals of distance geometry: theory, useful methodologies for obtaining solutions, and real world applications. Concise proofs are given and step-by-step algorithms for solving fundamental problems efficiently and precisely are presented in Mathematica®, enabling the reader to experiment with concepts and methods as they are introduced. Descriptive graphics, examples, and problems, accompany the real gems of the text, namely the applications in visualization of graphs, localization of sensor networks, protein conformation from distance data, clock synchronization protocols, robotics, and control of unmanned underwater vehicles, to name several. Aimed at intermediate undergraduates, beginning graduate students, researchers, and practitioners, the reader with a basic knowledge of linear algebra will gain an understanding of the basic theories of distance geometry and why they work in real life.
Virtual bioinformatics distance learning suite*.
Tolvanen, Martti; Vihinen, Mauno
2004-05-01
Distance learning as a computer-aided concept allows students to take courses from anywhere at any time. In bioinformatics, computers are needed to collect, store, process, and analyze massive amounts of biological and biomedical data. We have applied the concept of distance learning in virtual bioinformatics to provide university course material over the Internet. Currently, we provide two fully computer-based courses, "Introduction to Bioinformatics" and "Bioinformatics in Functional Genomics." Here we will discuss the application of distance learning in bioinformatics training and our experiences gained during the 3 years that we have run the courses, with about 400 students from a number of universities. The courses are available at bioinf.uta.fi.
The Distance Geometry of Music
Demaine, Erik D; Meijer, Henk; Rappaport, David; Taslakian, Perouz; Toussaint, Godfried T; Winograd, Terry; Wood, David R
2007-01-01
We demonstrate relationships between the classic Euclidean algorithm and many other fields of study, particularly in the context of music and distance geometry. Specifically, we show how the structure of the Euclidean algorithm defines a family of rhythms which encompass over forty timelines (\\emph{ostinatos}) from traditional world music. We prove that these \\emph{Euclidean rhythms} have the mathematical property that their onset patterns are distributed as evenly as possible: they maximize the sum of the Euclidean distances between all pairs of onsets, viewing onsets as points on a circle. Indeed, Euclidean rhythms are the unique rhythms that maximize this notion of \\emph{evenness}. We also show that essentially all Euclidean rhythms are \\emph{deep}: each distinct distance between onsets occurs with a unique multiplicity, and these multiplicies form an interval $1,2,...,k-1$. Finally, we characterize all deep rhythms, showing that they form a subclass of generated rhythms, which in turn proves a useful prop...
An Improved Maximum C/I Scheduling Algorithm Combined with HARQ
无
2003-01-01
It is well known that traffic in downlink will be much greater than that in uplink in 3 G and that beyond. High Speed Downlink Packet Access(HSDPA) is the solution to transmission for high-speed downlink packet service in UMTS, of which Maximum C/I scheduling is one of the important algorithms related to performance enhancement. An improved scheme, Thorough Maximum C/I scheduling algorithm, is presented in this article, in which every transmitted frame has the maximum C/I. The simulation results show that the new Maximum C/I scheme outperforms the conventional scheme in throughput performance and delay performance, and that the FER decreases faster as the maximum number of the retransmission increases.
The maximum entropy technique. System's statistical description
Belashev, B Z
2002-01-01
The maximum entropy technique (MENT) is applied for searching the distribution functions of physical values. MENT takes into consideration the demand of maximum entropy, the characteristics of the system and the connection conditions, naturally. It is allowed to apply MENT for statistical description of closed and open systems. The examples in which MENT had been used for the description of the equilibrium and nonequilibrium states and the states far from the thermodynamical equilibrium are considered
19 CFR 114.23 - Maximum period.
2010-04-01
... 19 Customs Duties 1 2010-04-01 2010-04-01 false Maximum period. 114.23 Section 114.23 Customs... CARNETS Processing of Carnets § 114.23 Maximum period. (a) A.T.A. carnet. No A.T.A. carnet with a period of validity exceeding 1 year from date of issue shall be accepted. This period of validity cannot be...
Maximum-Likelihood Detection Of Noncoherent CPM
Divsalar, Dariush; Simon, Marvin K.
1993-01-01
Simplified detectors proposed for use in maximum-likelihood-sequence detection of symbols in alphabet of size M transmitted by uncoded, full-response continuous phase modulation over radio channel with additive white Gaussian noise. Structures of receivers derived from particular interpretation of maximum-likelihood metrics. Receivers include front ends, structures of which depends only on M, analogous to those in receivers of coherent CPM. Parts of receivers following front ends have structures, complexity of which would depend on N.
Maximum tunneling velocities in symmetric double well potentials
Manz, Jörn [State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, 92, Wucheng Road, Taiyuan 030006 (China); Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin (Germany); Schild, Axel [Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin (Germany); Schmidt, Burkhard, E-mail: burkhard.schmidt@fu-berlin.de [Institut für Mathematik, Freie Universität Berlin, Arnimallee 6, 14195 Berlin (Germany); Yang, Yonggang, E-mail: ygyang@sxu.edu.cn [State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, 92, Wucheng Road, Taiyuan 030006 (China)
2014-10-17
Highlights: • Coherent tunneling in one-dimensional symmetric double well potentials. • Potentials for analytical estimates in the deep tunneling regime. • Maximum velocities scale as the square root of the ratio of barrier height and mass. • In chemical physics maximum tunneling velocities are in the order of a few km/s. - Abstract: We consider coherent tunneling of one-dimensional model systems in non-cyclic or cyclic symmetric double well potentials. Generic potentials are constructed which allow for analytical estimates of the quantum dynamics in the non-relativistic deep tunneling regime, in terms of the tunneling distance, barrier height and mass (or moment of inertia). For cyclic systems, the results may be scaled to agree well with periodic potentials for which semi-analytical results in terms of Mathieu functions exist. Starting from a wavepacket which is initially localized in one of the potential wells, the subsequent periodic tunneling is associated with tunneling velocities. These velocities (or angular velocities) are evaluated as the ratio of the flux densities versus the probability densities. The maximum velocities are found under the top of the barrier where they scale as the square root of the ratio of barrier height and mass (or moment of inertia), independent of the tunneling distance. They are applied exemplarily to several prototypical molecular models of non-cyclic and cyclic tunneling, including ammonia inversion, Cope rearrangement of semibullvalene, torsions of molecular fragments, and rotational tunneling in strong laser fields. Typical maximum velocities and angular velocities are in the order of a few km/s and from 10 to 100 THz for our non-cyclic and cyclic systems, respectively, much faster than time-averaged velocities. Even for the more extreme case of an electron tunneling through a barrier of height of one Hartree, the velocity is only about one percent of the speed of light. Estimates of the corresponding time scales for
Adaptive Distance Protection for Microgrids
Lin, Hengwei; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez
2015-01-01
Due to the increasing penetration of distributed generation resources, more and more microgrids can be found in distribution systems. This paper proposes a phasor measurement unit based distance protection strategy for microgrids in distribution system. At the same time, transfer tripping scheme...... is adopted to accelerate the tripping speed of the relays on the weak lines. The protection methodology is tested on a mid-voltage microgrid network in Aalborg, Denmark. The results show that the adaptive distance protection methodology has good selectivity and sensitivity. What is more, this system also has...
Fast Exact Euclidean Distance (FEED) Transformation
Schouten, Theo; Broek, van den Egon; Kittler, J.; Petrou, M.; Nixon, M.
2004-01-01
Fast Exact Euclidean Distance (FEED) transformation is introduced, starting from the inverse of the distance transformation. The prohibitive computational cost of a naive implementation of traditional Euclidean Distance Transformation, is tackled by three operations: restriction of both the number o
Distance Based Method for Outlier Detection of Body Sensor Networks
Haibin Zhang
2016-01-01
Full Text Available We propose a distance based method for the outlier detection of body sensor networks. Firstly, we use a Kernel Density Estimation (KDE to calculate the probability of the distance to k nearest neighbors for diagnosed data. If the probability is less than a threshold, and the distance of this data to its left and right neighbors is greater than a pre-defined value, the diagnosed data is decided as an outlier. Further, we formalize a sliding window based method to improve the outlier detection performance. Finally, to estimate the KDE by training sensor readings with errors, we introduce a Hidden Markov Model (HMM based method to estimate the most probable ground truth values which have the maximum probability to produce the training data. Simulation results show that the proposed method possesses a good detection accuracy with a low false alarm rate.
Transmission of asymmetric coupling double-ring resonator
Zhao, C. Y.; Tan, W. H.
2015-02-01
Based on the asymmetry between waveguide and double ring, the transmission and phase characteristics of coupled double-ring resonators are analyzed systemically. It is shown that the initial detuning determines the shape of transmission spectrum. The transmission spectrum of all-optical analog to electromagnetic inducted transparency (EIT) is controlled by tuning the asymmetric coupled parameter and loss. With the increasing of asymmetric coupled parameter, the transmission spectrum changes from EIT-like profile to Lorenz profile. The EIT-like transmission spectrum results from the interference between two Lorenz profiles. With the increasing of the loss, the transmission spectrum full frequency width at half-maximum broadens and its peak declines. The detuning and loss also make significant influences on the phase profile.
Munster, P.; Horvath, T.; Havlis, O.; Vojtech, J.; Radil, J.; Velc, R.; Skaljo, E.
2017-05-01
Since optical fibre is a standard medium for all current and new networks, these optical networks offer possibility for connecting new applications over long distances almost to anywhere. However with increasing number of applications, the large number of dedicated fibres will be necessary. This constitution is quite unpractical in terms of costs, however since wavelength division multiplexing enables transmission of multiple different signals over one fibre it is more than suitable to use this technology for cost reduction and network efficiency increase. Wavelength division multiplexing technology is common in data networks where parameters of all signals may be optimized (especially maximum optical power launched into the fibre) for simultaneous transmission. In case of non-data applications the situation is more difficult because each application is connected by different type of signal and with its own requirements for transmission parameters. Hence it is necessary to evaluate possible interactions before field deployment. In this paper we deal with possible interaction of a coherent 100 Gb/s dual polarisation QPSK data signal with new applications like accurate time and stable frequency transmission and high-power pulse signal used for distributed sensing. In laboratory setup we performed a measurement with a standard G.652D single mode optical fibre and also with G.655 fibre which can also be found in some networks and may be source of more nonlinear interactions. All signals were transmitted in a grid with 100GHz spacing according to ITU standard. Results confirmed our assumptions that 100GHz spacing is not large enough and also that G.655 optical fibre is prone to more non-linear interactions.
Sainudiin, Raazesh; Welch, David
2016-12-07
We derive a combinatorial stochastic process for the evolution of the transmission tree over the infected vertices of a host contact network in a susceptible-infected (SI) model of an epidemic. Models of transmission trees are crucial to understanding the evolution of pathogen populations. We provide an explicit description of the transmission process on the product state space of (rooted planar ranked labelled) binary transmission trees and labelled host contact networks with SI-tags as a discrete-state continuous-time Markov chain. We give the exact probability of any transmission tree when the host contact network is a complete, star or path network - three illustrative examples. We then develop a biparametric Beta-splitting model that directly generates transmission trees with exact probabilities as a function of the model parameters, but without explicitly modelling the underlying contact network, and show that for specific values of the parameters we can recover the exact probabilities for our three example networks through the Markov chain construction that explicitly models the underlying contact network. We use the maximum likelihood estimator (MLE) to consistently infer the two parameters driving the transmission process based on observations of the transmission trees and use the exact MLE to characterize equivalence classes over the space of contact networks with a single initial infection. An exploratory simulation study of the MLEs from transmission trees sampled from three other deterministic and four random families of classical contact networks is conducted to shed light on the relation between the MLEs of these families with some implications for statistical inference along with pointers to further extensions of our models. The insights developed here are also applicable to the simplest models of "meme" evolution in online social media networks through transmission events that can be distilled from observable actions such as "likes", "mentions
Quantum-limited heat conduction over macroscopic distances
Partanen, Matti; Tan, Kuan Yen; Govenius, Joonas; Lake, Russell E.; Mäkelä, Miika K.; Tanttu, Tuomo; Möttönen, Mikko
2016-05-01
The emerging quantum technological apparatuses, such as the quantum computer, call for extreme performance in thermal engineering. Cold distant heat sinks are needed for the quantized electric degrees of freedom owing to the increasing packaging density and heat dissipation. Importantly, quantum mechanics sets a fundamental upper limit for the flow of information and heat, which is quantified by the quantum of thermal conductance. However, the short distance between the heat-exchanging bodies in the previous experiments hinders their applicability in quantum technology. Here, we present experimental observations of quantum-limited heat conduction over macroscopic distances extending to a metre. We achieved this improvement of four orders of magnitude in the distance by utilizing microwave photons travelling in superconducting transmission lines. Thus, it seems that quantum-limited heat conduction has no fundamental distance cutoff. This work establishes the integration of normal-metal components into the framework of circuit quantum electrodynamics, which provides a basis for the superconducting quantum computer. Especially, our results facilitate remote cooling of nanoelectronic devices using faraway in situ-tunable heat sinks. Furthermore, quantum-limited heat conduction is important in contemporary thermodynamics. Here, the long distance may lead to ultimately efficient mesoscopic heat engines with promising practical applications.
The Future of Distance Education.
Saba, Farhad
2000-01-01
Examines factors that will influence how distance education is practiced in the first few decades of this new century. Discusses developments in digital technology; the exponential growth of knowledge about the brain, as well as physiology, chemistry, and psychology of learning; the system relationship between individual learners and instructors;…
Using Podcasts in Distance Education
Koppelman, Herman
2013-01-01
This paper discusses three possible ways of applying podcasts in distance education: podcasts of recordings of virtual classes, podcasts produced for specific pedagogical aims, and podcasts produced by external organizations. Through a survey we gained insight in the (until now limited) experiences of our distant students with podcasts, and also…
Distance Education Instructional Model Applications.
Jackman, Diane H.; Swan, Michael K.
1995-01-01
A survey of graduate students involved in distance education on North Dakota State University's Interactive Video Network included 80 on campus and 13 off. The instructional models rated most effective were role playing, simulation, jurisprudential (Socratic method), memorization, synectics, and inquiry. Direct instruction was rated least…
Distance, Lending Relationships, and Competition
Degryse, H.A.; Ongena, S.
2003-01-01
A recent string of theoretical papers has highlighted the importance of geographical distance in explaining loan rates for small firms.Lenders located in the vicinity of small firms face significantly lower transportation and monitoring costs, and hence wield considerable market power, if competing
Lessons in Developing Distance Learning.
Gant, Lenora Peters
1996-01-01
Describes the use of video teletraining (VTT) for distance learning in the Department of Defense. Topics include planning and organizing the VTT facility, staff development, site facilitators, the necessity of protocol, instructional design and development strategies, student involvement and interactivity, and evaluation and assessment. (LRW)
Communication Barriers in Distance Education
Isman, Aytekin; Dabaj, Fahme; Altinay, Fahriye; Altinay, Zehra
2003-01-01
Communication is a key concept as being the major tool for people in order to satisfy their needs. It is an activity which refers as process and effective communication requires qualified communication with the elimination of communication barriers. As it is known, distance education is a new trend by following contemporary facilities and tools…
Distance Learning: Untried and Untrue
Halfond, Jay A.
2010-01-01
G. K. Chesterton famously once said: "Christianity has not been tried and found wanting; it has been found difficult and not tried." This, the author believes, applies to distance learning as well. There is far too much self-congratulatory hyperbole about the growth and pervasiveness of online learning--which exaggerates reality and overlooks the…
Curriculum Control in Distance Education.
Chesterton, Paul
1985-01-01
The nature of distance education is to shift the locus of curriculum control toward the institution and its staff and away from the students. This imposes a responsibility on the institution to examine and evaluate the values and assumptions underlying the decision-making and the implications of the patterns of control that emerge. (Author/MSE)
Distance, Lending Relationships and Competition
Degryse, H.A.; Ongena, S.
2002-01-01
A recent string of theoretical papers highlights the importance of geographical distance in explaining pricing and availability of loans to small firms.Lenders located in the vicinity of small firms have significantly lower monitoring and transaction costs, and hence considerable market power if com
Video Surveillance using Distance Maps
Schouten, Theo E.; Kuppens, Harco C.; Broek, van den Egon L.; Kehtarnavaz, Nasser; Laplante, Phillip A.
2006-01-01
Human vigilance is limited; hence, automatic motion and distance detection is one of the central issues in video surveillance. Hereby, many aspects are of importance, this paper specially addresses: efficiency, achieving real-time performance, accuracy, and robustness against various noise factors.
Gesture Interaction at a Distance
Fikkert, F.W.
2010-01-01
The aim of this work is to explore, from a perspective of human behavior, which gestures are suited to control large display surfaces from a short distance away; why that is so; and, equally important, how such an interface can be made a reality. A well-known example of the type of interface that is
The Perception of Ideological Distance
Granberg, Donald; Brown, Thad A.
1992-01-01
Data from national election studies in Britain, the Netherlands, Sweden, and the U.S. were analyzed to test hypotheses concerning the perception of ideological distance between parties and candidates. The first hypothesis, derived from Sherif's social judgment theory and Heider's balance theory, was
Isolation by distance, web service
Bohonak Andrew J
2005-03-01
Full Text Available Abstract Background The population genetic pattern known as "isolation by distance" results from spatially limited gene flow and is a commonly observed phenomenon in natural populations. However, few software programs exist for estimating the degree of isolation by distance among populations, and they tend not to be user-friendly. Results We have created Isolation by Distance Web Service (IBDWS a user-friendly web interface for determining patterns of isolation by distance. Using this site, population geneticists can perform a variety of powerful statistical tests including Mantel tests, Reduced Major Axis (RMA regression analysis, as well as calculate FST between all pairs of populations and perform basic summary statistics (e.g., heterozygosity. All statistical results, including publication-quality scatter plots in Postscript format, are returned rapidly to the user and can be easily downloaded. Conclusion IBDWS population genetics analysis software is hosted at http://phage.sdsu.edu/~jensen/ and documentation is available at http://www.bio.sdsu.edu/pub/andy/IBD.html. The source code has been made available on Source Forge at http://sourceforge.net/projects/ibdws/.
Video surveillance using distance maps
Schouten, Theo E.; Kuppens, Harco C.; van den Broek, Egon; Kehtarnavaz, Nasser; Laplante, Phillip A,
2006-01-01
Human vigilance is limited; hence, automatic motion and distance detection is one of the central issues in video surveillance. Hereby, many aspects are of importance, this paper specially addresses: efficiency, achieving real-time performance, accuracy, and robustness against various noise factors.
A SECOND LIFE FOR DISTANCE LEARNING
Jace HARGIS
2008-04-01
Full Text Available “Throughout time, humans have utilized different technological tools to enhance both basic communication and learning. For instance, humans have gone from cave drawings to web sites; from petroglyphics to blogging; from conversations to instant messaging; and from story telling to podcasting.” (Hargis & Rakita, 2005. This phrase provides an insight to the evolution from oral to literacy to electracy modes of transmission. “Electracy describes the kind of “literacy” or skill and facility necessary to exploit the full communicative potential of new electronic media such as multimedia, hypermedia, social software, and virtual worlds” (Wikipedia, 2007. I would like to share thoughts on the potential to expand attributes and connections of electracy through a new learning environment. Although most of us struggle with living one life, creating a second life may be an answer to some of the challenges relating to learning outside of the formal classroom. The literature has provided many labels out of classroom learning – distance learning, distributed learning, correspondence classes, asynchronous, hybrid, online, electronic, e-learning, etc., but for the purposes of this paper, I will use an umbrella term, simply called informal learning. Informal learning settings are typically museums, zoological parks, aquaria, science and technology centers, etc... They are also characterized as places where motivation is internal, the content is variable and possibly un-sequenced, attendance is voluntary, displays and objects are provided, learners are of all ages, and there is more diversity in the learners’ backgrounds (Koran & Koran, 1988. Koran and Koran (1986 suggested that besides learning, curiosity, interest, appreciation, motivation, and generalization all could be considered among the desired outcomes of a visit to an informal setting. I would like to briefly share a modern informal setting and how I believe pedagogically it can address
Understanding Ebola Virus Transmission
Seth Judson
2015-02-01
Full Text Available An unprecedented number of Ebola virus infections among healthcare workers and patients have raised questions about our understanding of Ebola virus transmission. Here, we explore different routes of Ebola virus transmission between people, summarizing the known epidemiological and experimental data. From this data, we expose important gaps in Ebola virus research pertinent to outbreak situations. We further propose experiments and methods of data collection that will enable scientists to fill these voids in our knowledge about the transmission of Ebola virus.
Tractor Transmissions. A Teaching Reference.
American Association for Agricultural Engineering and Vocational Agriculture, Athens, GA.
The manual was developed as a reference for teaching students about transmissions in farm tractors. The manual is divided into five sections: (1) transmission history, (2) gears and bearings in transmission, (3) sliding-gear transmissions, (4) planetary gearing, and (5) glossary. The working principles of the sliding-gear transmission, the most…
Transmission Cost Allocation Methodologies for Regional Transmission Organizations
Fink, S.; Rogers, J.; Porter, K.
2010-07-01
This report describes transmission cost allocation methodologies for transmission projects developed to maintain or enhance reliability, to interconnect new generators, or to access new resources and enhance competitive bulk power markets, otherwise known as economic transmission projects.
Microwave beam power transmission at an arbitrary range
Pinero, L. R.; Christian, J. L., Jr.; Acosta, R. J.
1992-01-01
The power transfer efficiency between two circular apertures at an arbitrary range is obtained numerically. The apertures can have generally different sizes and arbitrary taper illuminations. The effects of distance and taper illumination on the transmission efficiency are investigated for equal size apertures. The result shows that microwave beam power is more effective at close ranges, namely distances less than 2D(exp 2)/lambda. Also shown was the power transfer efficiency increase with taper illumination for close range distances. A computer program was developed for calculating the power transfer efficiency at an arbitrary range.
Measuring Cosmic Distances with Stellar Heart Beats
2004-10-01
possible with long-baseline interferometry. Also on this front, the VLT Interferometer is now opening a new field of observational astrophysics. Three VLTI baselines ESO PR Photo 30b/04 ESO PR Photo 30b/04 Title [Preview - JPEG: 400 x 345 pix - 112k] [Normal - JPEG: 800 x 690 pix - 276k] Caption: ESO PR Photo 30b/04 is a view of the Paranal platform with the three baselines used for the VLTI observations of Cepheids (in red). ESO PR Photo 30c/04 ESO PR Photo 30c/04 Title [Preview - JPEG: 400 x 367 pix - 88k] [Normal - JPEG: 800 x 734 pix - 180k] Caption: ESO PR Photo 30c/04 shows the VINCI observations of the pulsation of the Cepheid variable L Car (P = 35.5 days, red dots) and the adjusted radius curve (green line), as deduced from the integration of the radial velocity measured on this star over its pulsation period. Some time ago, an undaunted team of French and Swiss astronomers [1] started a major research programme aimed at measuring the distance to several Cepheids by means of the above outlined Baade-Wesselink interferometric method. For these observations they combined sets of two beams - one set from the two VLTI Test Siderostats with 0.35m aperture and the other set from two Unit Telescopes (Antu and Melipal; 8.2m mirrors) - with the VINCI (VLT Interferometer Commissioning Instrument) facility. Three VLTI baselines were used for this programme with, respectively, 66, 140 and 102.5m ground length. ESO PR Photo 30b/04 shows the respective positions on the VLTI platform. The observations were made in the near-infrared K-band. A total of 69 individual angular diameter measurements were obtained with the VLTI, over more than 100 hours of total telescope time, distributed over 68 nights; the largest angular diameter measured was 0.0032 arcsec (L Car at maximum). Seven Cepheids observable from Paranal Observatory were selected for this programme: X and W Sagittarii, Eta Aquilae, Beta Doradus, Zeta Gemini, Y Ophiocus and L Carinae. Their periods range from 7 to 35
Wu, Bo; Zhou, Xian; Ma, Yanan; Luo, Jun; Zhong, Kangping; Qiu, Shaofeng; Feng, Zhiyong; Luo, Yazhi; Agustin, Mikel; Ledentsov, Nikolay; Kropp, Joerg; Shchukin, Vitaly; Ledentsov, Nikolay N.; Eddie, Iain; Chao, Lu
2016-03-01
Discrete Multitone Transmission (DMT) transmission over standard multimode fiber (MMF) using high-speed single (SM) and multimode (MM) Vertical-Cavity Surface-Emitting Lasers (VCSELs) is studied. Transmission speed in the range of 72Gbps to 82Gbps over 300m -100m distances of OM4 fiber is realized, respectively, at Bit-Error-Ratio (BER) 100Gbps data transmission over >300m MMF distances at the BER levels matching the industry standards will become possible.
The maximum rotation of a galactic disc
Bottema, R
1997-01-01
The observed stellar velocity dispersions of galactic discs show that the maximum rotation of a disc is on average 63% of the observed maximum rotation. This criterion can, however, not be applied to small or low surface brightness (LSB) galaxies because such systems show, in general, a continuously rising rotation curve until the outermost measured radial position. That is why a general relation has been derived, giving the maximum rotation for a disc depending on the luminosity, surface brightness, and colour of the disc. As a physical basis of this relation serves an adopted fixed mass-to-light ratio as a function of colour. That functionality is consistent with results from population synthesis models and its absolute value is determined from the observed stellar velocity dispersions. The derived maximum disc rotation is compared with a number of observed maximum rotations, clearly demonstrating the need for appreciable amounts of dark matter in the disc region and even more so for LSB galaxies. Matters h...
Maximum permissible voltage of YBCO coated conductors
Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z.; Hong, Z.; Wang, D.; Zhou, H.; Shen, X.; Shen, C.
2014-06-01
Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (Ic) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the Ic degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.
Computing Rooted and Unrooted Maximum Consistent Supertrees
van Iersel, Leo
2009-01-01
A chief problem in phylogenetics and database theory is the computation of a maximum consistent tree from a set of rooted or unrooted trees. A standard input are triplets, rooted binary trees on three leaves, or quartets, unrooted binary trees on four leaves. We give exact algorithms constructing rooted and unrooted maximum consistent supertrees in time O(2^n n^5 m^2 log(m)) for a set of m triplets (quartets), each one distinctly leaf-labeled by some subset of n labels. The algorithms extend to weighted triplets (quartets). We further present fast exact algorithms for constructing rooted and unrooted maximum consistent trees in polynomial space. Finally, for a set T of m rooted or unrooted trees with maximum degree D and distinctly leaf-labeled by some subset of a set L of n labels, we compute, in O(2^{mD} n^m m^5 n^6 log(m)) time, a tree distinctly leaf-labeled by a maximum-size subset X of L that all trees in T, when restricted to X, are consistent with.
Maximum magnitude earthquakes induced by fluid injection
McGarr, Arthur F.
2014-01-01
Analysis of numerous case histories of earthquake sequences induced by fluid injection at depth reveals that the maximum magnitude appears to be limited according to the total volume of fluid injected. Similarly, the maximum seismic moment seems to have an upper bound proportional to the total volume of injected fluid. Activities involving fluid injection include (1) hydraulic fracturing of shale formations or coal seams to extract gas and oil, (2) disposal of wastewater from these gas and oil activities by injection into deep aquifers, and (3) the development of enhanced geothermal systems by injecting water into hot, low-permeability rock. Of these three operations, wastewater disposal is observed to be associated with the largest earthquakes, with maximum magnitudes sometimes exceeding 5. To estimate the maximum earthquake that could be induced by a given fluid injection project, the rock mass is assumed to be fully saturated, brittle, to respond to injection with a sequence of earthquakes localized to the region weakened by the pore pressure increase of the injection operation and to have a Gutenberg-Richter magnitude distribution with a b value of 1. If these assumptions correctly describe the circumstances of the largest earthquake, then the maximum seismic moment is limited to the volume of injected liquid times the modulus of rigidity. Observations from the available case histories of earthquakes induced by fluid injection are consistent with this bound on seismic moment. In view of the uncertainties in this analysis, however, this should not be regarded as an absolute physical limit.
Maximum magnitude earthquakes induced by fluid injection
McGarr, A.
2014-02-01
Analysis of numerous case histories of earthquake sequences induced by fluid injection at depth reveals that the maximum magnitude appears to be limited according to the total volume of fluid injected. Similarly, the maximum seismic moment seems to have an upper bound proportional to the total volume of injected fluid. Activities involving fluid injection include (1) hydraulic fracturing of shale formations or coal seams to extract gas and oil, (2) disposal of wastewater from these gas and oil activities by injection into deep aquifers, and (3) the development of enhanced geothermal systems by injecting water into hot, low-permeability rock. Of these three operations, wastewater disposal is observed to be associated with the largest earthquakes, with maximum magnitudes sometimes exceeding 5. To estimate the maximum earthquake that could be induced by a given fluid injection project, the rock mass is assumed to be fully saturated, brittle, to respond to injection with a sequence of earthquakes localized to the region weakened by the pore pressure increase of the injection operation and to have a Gutenberg-Richter magnitude distribution with a b value of 1. If these assumptions correctly describe the circumstances of the largest earthquake, then the maximum seismic moment is limited to the volume of injected liquid times the modulus of rigidity. Observations from the available case histories of earthquakes induced by fluid injection are consistent with this bound on seismic moment. In view of the uncertainties in this analysis, however, this should not be regarded as an absolute physical limit.
A Streaming Distance Transform Algorithm for Neighborhood-Sequence Distances
Nicolas Normand
2014-09-01
Full Text Available We describe an algorithm that computes a “translated” 2D Neighborhood-Sequence Distance Transform (DT using a look up table approach. It requires a single raster scan of the input image and produces one line of output for every line of input. The neighborhood sequence is specified either by providing one period of some integer periodic sequence or by providing the rate of appearance of neighborhoods. The full algorithm optionally derives the regular (centered DT from the “translated” DT, providing the result image on-the-ﬂy, with a minimal delay, before the input image is fully processed. Its efficiency can benefit all applications that use neighborhood- sequence distances, particularly when pipelined processing architectures are involved, or when the size of objects in the source image is limited.
Cheung, J; Morin, O [University of California San Francisco, San Francisco, CA (United States)
2015-06-15
Purpose: To evaluate the influence of a new commercial transmission detector on radiotherapy beams of various energies. Methods: A transmission detector designed for online treatment monitoring was characterized on a TrueBeam STx linear accelerator with 6MV, 6FFF, 10MV, and 10FFF beams. Measurements of beam characteristics including percentage depth doses (PDDs), inplane and crossplane off-axis profiles at different depths, transmission factors, and skin dose were acquired at field sizes of 3×3cm, 5×5m, 10×10cm, and 20×20cm at 100cm and 80cm source-to-surface distance (SSD). All measurements were taken with and without the transmission detector in the path of the beam. A CC04 chamber was used for all profile and transmission factor measurements. Skin dose was assessed at 100cm, 90cm, and 80cm SSD and using a variety of detectors (Roos and Markus parallel-plate chambers, and OSLD). Results: The PDDs showed small differences between the unperturbed and perturbed beams for both 100cm and 80cm SSD (≤4mm dmax difference and <1.2% average profile difference). The differences were larger for the flattened beams and at larger field sizes. The off-axis profiles showed similar trends. The penumbras looked similar with and without the transmission detector. Comparisons in the central 80% of the profile showed a maximum average (maximum) profile difference between all field sizes of 0.756% (1.535%) and 0.739% (3.682%) for 100cm and 80cm SSD, respectively. The average measured skin dose at 100cm (80cm) SSD for 10×10cm field size was <4% (<35%) dose increase for all energies. For 20×20cm field size, this value increased to <10% (≤45%). Conclusion: The transmission detector has minimal effect on the clinically relevant radiotherapy beams for IMRT and VMAT (field sizes 10×10cm and less). For larger field sizes, some perturbations are observable which would need to be assessed for clinical impact. The authors of this publication has research support from IBA Dosimetry.
Lucani, Daniel E; Médard, Muriel
2008-01-01
The underwater acoustic channel is characterized by a path loss that depends not only on the transmission distance, but also on the signal frequency. As a consequence, transmission bandwidth depends on the transmission distance, a feature that distinguishes an underwater acoustic system from a terrestrial radio system. The exact relationship between power, transmission band, distance and capacity for the Gaussian noise scenario is a complicated one. This work provides a closed-form approximate model for 1) power consumption, 2) band-edge frequency and 3) bandwidth as functions of distance and capacity required for a data link. This approximate model is obtained by numerical evaluation of analytical results which takes into account physical models of acoustic propagation loss and ambient noise. The closed-form approximations may become useful tools in the design and analysis of underwater acoustic networks.
Watching Handball Transmissions
Frandsen, Kirsten
2010-01-01
, due to the dramaturgic structure of handball transmissions, viewers consider such transmissions particularly reliable and effective sources of entertainment. The transmissions’ entertainment value derives from their specific ability to give the viewers a complex experience of feeling autonomous...... and competent when mastering the game and in relation to others. The study shows that entertainment concerns both affective involvement and identity formation, as social and cultural meaning seem to be at the root of involvement. Even though both men and women find great joy in the transmissions, their viewing...... is embedded in quite diverse patterns regarding additional media use. This points to gendered differences regarding how the entertaining experience is basically received and the qualities sought and pursued in the transmissions....
Electric Power Transmission Lines
Department of Homeland Security — Transmission Lines are the system of structures, wires, insulators and associated hardware that carry electric energy from one point to another in an electric power...
Webbe, G.
1965-01-01
Accurate quantitative assessment is essential to any study of disease transmission; in relation to the transmission of bilharziasis the most important characteristics that have to be determined include density, reproduction and mortality rates, the age and sex structure of the population, dispersion and the intrinsic rate of natural increase (the biotic potential). The author discusses techniques that have been developed to yield this and other information and stresses the need to evaluate such techniques objectively. Some basic principles of population ecology are defined and discussed in relation to the control of transmission. It is considered that laboratory studies can be usefully carried on in conjunction with field work but that they cannot be substituted for field investigations in determining the parameters of bilharziasis transmission for a given area. PMID:5294586
Kansas Electric Transmission Lines
Kansas Data Access and Support Center — This data set is a digital representation of the EletcircTransmission lines for the State of Kansas as maintained by the Kansas Corporation Commission. Data is...
... Serology Publications and Resources Multimedia MMWR Articles Outbreak Articles Related Links World Health Organization Medline Plus Transmission of Mumps Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir ...
Hall, David R.; Hall, Jr., H. Tracy
2007-07-24
A transmission system in a downhole component comprises a data transmission element in both ends of the downhole component. Each data transmission element houses an electrically conducting coil in a MCEI circular trough. The electrically conducting coil comprises at least two generally fractional loops. In the preferred embodiment, the transmission elements are connected by an electrical conductor. Preferably, the electrical conductor is a coaxial cable. Preferably, the MCEI trough comprises ferrite. In the preferred embodiment, the fractional loops are connected by a connecting cable. In one aspect of the present invention, the connecting cable is a pair of twisted wires. In one embodiment the connecting cable is a shielded pair of twisted wires. In another aspect of the present invention, the connecting cable is a coaxial cable. The connecting cable may be disposed outside of the MCEI circular trough.
Maximum Multiflow in Wireless Network Coding
Zhou, Jin-Yi; Jiang, Yong; Zheng, Hai-Tao
2012-01-01
In a multihop wireless network, wireless interference is crucial to the maximum multiflow (MMF) problem, which studies the maximum throughput between multiple pairs of sources and sinks. In this paper, we observe that network coding could help to decrease the impacts of wireless interference, and propose a framework to study the MMF problem for multihop wireless networks with network coding. Firstly, a network model is set up to describe the new conflict relations modified by network coding. Then, we formulate a linear programming problem to compute the maximum throughput and show its superiority over one in networks without coding. Finally, the MMF problem in wireless network coding is shown to be NP-hard and a polynomial approximation algorithm is proposed.
Dependence of maximum concentration from chemical accidents on release duration
Hanna, Steven; Chang, Joseph
2017-01-01
Chemical accidents often involve releases of a total mass, Q, of stored material in a tank over a time duration, td, of less than a few minutes. The value of td is usually uncertain because of lack of knowledge of key information, such as the size and location of the hole and the pressure and temperature of the chemical. In addition, it is rare that eyewitnesses or video cameras are present at the time of the accident. For inhalation hazards, serious health effects (such as damage to the respiratory system) are determined by short term averages (pressurized liquefied chlorine releases from tanks are given, focusing on scenarios from the Jack Rabbit I (JR I) field experiment. The analytical calculations and the predictions of the SLAB dense gas dispersion model agree that the ratio of maximum C for two different td's is greatest (as much as a factor of ten) near the source. At large distances (beyond a few km for the JR I scenarios), where tt exceeds both td's, the ratio of maximum C approaches unity.
Eliminating Perinatal HIV Transmission
2012-11-26
In this podcast, CDCâs Dr. Steve Nesheim discusses perinatal HIV transmission, including the importance of preventing HIV among women, preconception care, and timely HIV testing of the mother. Dr. Nesheim also introduces the revised curriculum Eliminating Perinatal HIV Transmission intended for faculty of OB/GYN and pediatric residents and nurse midwifery students. Created: 11/26/2012 by Division of HIV/AIDS Prevention. Date Released: 11/26/2012.
Stimulus-dependent maximum entropy models of neural population codes.
Granot-Atedgi, Einat; Tkačik, Gašper; Segev, Ronen; Schneidman, Elad
2013-01-01
Neural populations encode information about their stimulus in a collective fashion, by joint activity patterns of spiking and silence. A full account of this mapping from stimulus to neural activity is given by the conditional probability distribution over neural codewords given the sensory input. For large populations, direct sampling of these distributions is impossible, and so we must rely on constructing appropriate models. We show here that in a population of 100 retinal ganglion cells in the salamander retina responding to temporal white-noise stimuli, dependencies between cells play an important encoding role. We introduce the stimulus-dependent maximum entropy (SDME) model-a minimal extension of the canonical linear-nonlinear model of a single neuron, to a pairwise-coupled neural population. We find that the SDME model gives a more accurate account of single cell responses and in particular significantly outperforms uncoupled models in reproducing the distributions of population codewords emitted in response to a stimulus. We show how the SDME model, in conjunction with static maximum entropy models of population vocabulary, can be used to estimate information-theoretic quantities like average surprise and information transmission in a neural population.
Stimulus-dependent maximum entropy models of neural population codes.
Einat Granot-Atedgi
Full Text Available Neural populations encode information about their stimulus in a collective fashion, by joint activity patterns of spiking and silence. A full account of this mapping from stimulus to neural activity is given by the conditional probability distribution over neural codewords given the sensory input. For large populations, direct sampling of these distributions is impossible, and so we must rely on constructing appropriate models. We show here that in a population of 100 retinal ganglion cells in the salamander retina responding to temporal white-noise stimuli, dependencies between cells play an important encoding role. We introduce the stimulus-dependent maximum entropy (SDME model-a minimal extension of the canonical linear-nonlinear model of a single neuron, to a pairwise-coupled neural population. We find that the SDME model gives a more accurate account of single cell responses and in particular significantly outperforms uncoupled models in reproducing the distributions of population codewords emitted in response to a stimulus. We show how the SDME model, in conjunction with static maximum entropy models of population vocabulary, can be used to estimate information-theoretic quantities like average surprise and information transmission in a neural population.
Tunable Transmission-Line Metamaterials Mimicking Electromagnetically Induced Transparency
Feng, T. H.; Han, H. P.
2016-11-01
Tunable transmission-line (TL) metamaterials mimicking electromagnetically induced transparency (EIT) have been studied. Firstly, two types of tunable TL EIT-like metamaterial, based on the double split-ring resonator (DSRR) and single split-ring resonator (SSRR), were fabricated and their transmission properties carefully compared. The results showed that the transmittance maximum was almost invariable with shift of the transparency window for the tunable DSRR-based TL EIT-like metamaterial, but for the tunable SSRR-based TL EIT-like metamaterial, the transmittance maximum gradually diminished with shift of the transparency window toward the center of the absorption band. Moreover, the reason for these different transmission properties was explored, revealing that the reduction of the transmittance maximum of the transparency window for the tunable SSRR-based TL EIT-like metamaterial is mainly due to energy loss caused by the resistance of the loaded varactor diodes.
The NFL Combine 40-Yard Dash: How Important is Maximum Velocity?
Clark, Kenneth P; Rieger, Randall H; Bruno, Richard F; Stearne, David J
2017-06-22
This investigation analyzed the sprint velocity profiles for athletes who completed the 40-yard (36.6m) dash at the 2016 NFL Combine. The purpose was to evaluate the relationship between maximum velocity and sprint performance, and to compare acceleration patterns for fast and slow athletes. Using freely available online sources, data were collected for body mass and sprint performance (36.6m time with split intervals at 9.1 and 18.3m). For each athlete, split times were utilized to generate modeled curves of distance vs. time, velocity vs. time, and velocity vs. distance using a mono-exponential equation. Model parameters were used to quantify acceleration patterns as the ratio of maximum velocity to maximum acceleration (vmax / amax, or τ). Linear regression was used to evaluate the relationship between maximum velocity and sprint performance for the entire sample. Additionally, athletes were categorized into fast and slow groups based on maximum velocity, with independent t-tests and effect size statistics used to evaluate between-group differences in sprint performance and acceleration patterns. Results indicated that maximum velocity was strongly correlated with sprint performance across 9.1m, 18.3m, and 36.6m (r of 0.72, 0.83, and 0.94, respectively). However, both fast and slow groups accelerated in a similar pattern relative to maximum velocity (τ = 0.768 ± 0.068s for the fast group and τ = 0.773 ± 0.070s for the slow group). We conclude that maximum velocity is of critical importance to 36.6m time, and inclusion of more maximum velocity training may be warranted for athletes preparing for the NFL Combine.
Maximum confidence measurements via probabilistic quantum cloning
Zhang Wen-Hai; Yu Long-Bao; Cao Zhuo-Liang; Ye Liu
2013-01-01
Probabilistic quantum cloning (PQC) cannot copy a set of linearly dependent quantum states.In this paper,we show that if incorrect copies are allowed to be produced,linearly dependent quantum states may also be cloned by the PQC.By exploiting this kind of PQC to clone a special set of three linearly dependent quantum states,we derive the upper bound of the maximum confidence measure of a set.An explicit transformation of the maximum confidence measure is presented.
Maximum floodflows in the conterminous United States
Crippen, John R.; Bue, Conrad D.
1977-01-01
Peak floodflows from thousands of observation sites within the conterminous United States were studied to provide a guide for estimating potential maximum floodflows. Data were selected from 883 sites with drainage areas of less than 10,000 square miles (25,900 square kilometers) and were grouped into regional sets. Outstanding floods for each region were plotted on graphs, and envelope curves were computed that offer reasonable limits for estimates of maximum floods. The curves indicate that floods may occur that are two to three times greater than those known for most streams.
Revealing the Maximum Strength in Nanotwinned Copper
Lu, L.; Chen, X.; Huang, Xiaoxu
2009-01-01
The strength of polycrystalline materials increases with decreasing grain size. Below a critical size, smaller grains might lead to softening, as suggested by atomistic simulations. The strongest size should arise at a transition in deformation mechanism from lattice dislocation activities to grain...... boundary–related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced...
The Maximum Resource Bin Packing Problem
Boyar, J.; Epstein, L.; Favrholdt, L.M.
2006-01-01
Usually, for bin packing problems, we try to minimize the number of bins used or in the case of the dual bin packing problem, maximize the number or total size of accepted items. This paper presents results for the opposite problems, where we would like to maximize the number of bins used...... algorithms, First-Fit-Increasing and First-Fit-Decreasing for the maximum resource variant of classical bin packing. For the on-line variant, we define maximum resource variants of classical and dual bin packing. For dual bin packing, no on-line algorithm is competitive. For classical bin packing, we find...
Maximum entropy analysis of EGRET data
Pohl, M.; Strong, A.W.
1997-01-01
EGRET data are usually analysed on the basis of the Maximum-Likelihood method \\cite{ma96} in a search for point sources in excess to a model for the background radiation (e.g. \\cite{hu97}). This method depends strongly on the quality of the background model, and thus may have high systematic unce...... uncertainties in region of strong and uncertain background like the Galactic Center region. Here we show images of such regions obtained by the quantified Maximum-Entropy method. We also discuss a possible further use of MEM in the analysis of problematic regions of the sky....
Revealing the Maximum Strength in Nanotwinned Copper
Lu, L.; Chen, X.; Huang, Xiaoxu
2009-01-01
The strength of polycrystalline materials increases with decreasing grain size. Below a critical size, smaller grains might lead to softening, as suggested by atomistic simulations. The strongest size should arise at a transition in deformation mechanism from lattice dislocation activities to grain...... boundary–related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced...
Maximum phytoplankton concentrations in the sea
Jackson, G.A.; Kiørboe, Thomas
2008-01-01
A simplification of plankton dynamics using coagulation theory provides predictions of the maximum algal concentration sustainable in aquatic systems. These predictions have previously been tested successfully against results from iron fertilization experiments. We extend the test to data collected...... in the North Atlantic as part of the Bermuda Atlantic Time Series program as well as data collected off Southern California as part of the Southern California Bight Study program. The observed maximum particulate organic carbon and volumetric particle concentrations are consistent with the predictions...
Inverse design of periodic metallic slits for extraordinary optical transmission
Deng, Yongbo; Liu, Zhenyu; Wu, Yihui
2016-01-01
The inverse design methodology of periodic metallic slits for extraordinary optical transmission is presented based on the topology optimization method. Several topological configurations of periodic metallic slits with typical subwavelength size are derived with transmission peaks at the prescribed incident wavelengths in the visible light region, where the transmissivity is enhanced by effective excitation of surface-plasmon-polariton at the inlet side of the slit, Fabry-P\\'erot resonance of surface-plasmon-polariton inside the slit and radiation of the electromagnetic energy at the outlet side of the slit. The transmission peaks of the derived metallic configurations are raised along with the red shift of the incident wavelength, because of the reduction of the energy absorption and increase of the propagation distance of surface-plasmon-polariton. And the shift of transmission peak is controlled by prescribing a different incident wavelength in the corresponding topology optimization problem. To reduce th...
Image compression and transmission based on LAN
Huang, Sujuan; Li, Yufeng; Zhang, Zhijiang
2004-11-01
In this work an embedded system is designed which implements MPEG-2 LAN transmission of CVBS or S-video signal. The hardware consists of three parts. The first is digitization of analog inputs CVBS or S-video (Y/C) from TV or VTR sources. The second is MPEG-2 compression coding primarily performed by a MPEG-2 1chip audio/video encoder. Its output is MPEG-2 system PS/TS. The third part includes data stream packing, accessing LAN and system control based on an ARM microcontroller. It packs the encoded stream into Ethernet data frames and accesses LAN, and accepts Ethernet data packets bearing control information from the network and decodes corresponding commands to control digitization, coding, and other operations. In order to increase the network transmission rate to conform to the MEPG-2 data stream, an efficient TCP/IP network protocol stack is constructed directly from network hardware provided by the embedded system, instead of using an ordinary operating system for embedded systems. In the design of the network protocol stack to obtain a high LAN transmission rate on a low-end ARM, a special transmission channel is opened for the MPEG-2 stream. The designed system has been tested on an experimental LAN. The experiment shows a maximum LAN transmission rate up to 12.7 Mbps with good sound and image quality, and satisfactory system reliability.
2012-02-08
... Energy Regulatory Commission Zephyr Power Transmission, LLC; Pathfinder Power Transmission, LLC; Duke... (Commission), 18 CFR 381.302, Zephyr Power Transmission, LLC (Zephyr), Pathfinder Power Transmission, LLC (PPT... to exercise its negotiated rate authority for Zephyr Power Transmission Project; (2) that...
National transmission grid study
Abraham, Spencer [USDOE Office of the Secretary of Energy, Washington, DC (United States)
2003-05-31
The National Energy Policy Plan directed the U.S. Department of Energy (DOE) to conduct a study to examine the benefits of establishing a national electricity transmission grid and to identify transmission bottlenecks and measures to address them. DOE began by conducting an independent analysis of U.S. electricity markets and identifying transmission system bottlenecks using DOE’s Policy Office Electricity Modeling System (POEMS). DOE’s analysis, presented in Section 2, confirms the central role of the nation’s transmission system in lowering costs to consumers through increased trade. More importantly, DOE’s analysis also confirms the results of previous studies, which show that transmission bottlenecks and related transmission system market practices are adding hundreds of millions of dollars to consumers’ electricity bills each year. A more detailed technical overview of the use of POEMS is provided in Appendix A. DOE led an extensive, open, public input process and heard a wide range of comments and recommendations that have all been considered.1 More than 150 participants registered for three public workshops held in Detroit, MI (September 24, 2001); Atlanta, GA (September 26, 2001); and Phoenix, AZ (September 28, 2001).
Lucani, Daniel E; Stojanovic, Milica
2008-01-01
The goal of this paper is two-fold. First, to establish a tractable model for the underwater acoustic channel useful for network optimization in terms of convexity. Second, to propose a network coding based lower bound for transmission power in underwater acoustic networks, and compare this bound to the performance of several network layer schemes. The underwater acoustic channel is characterized by a path loss that depends strongly on transmission distance and signal frequency. The exact relationship among power, transmission band, distance and capacity for the Gaussian noise scenario is a complicated one. We provide a closed-form approximate model for 1) transmission power and 2) optimal frequency band to use, as functions of distance and capacity. The model is obtained through numerical evaluation of analytical results that take into account physical models of acoustic propagation loss and ambient noise. Network coding is applied to determine a lower bound to transmission power for a multicast scenario, fo...
COMPARISON OF SELECTED PHYSIOLOGICAL VARIABLES OF PLAYERS BELONGING TO VARIOUS DISTANCE RUNNERS
Satpal Yadav
2009-12-01
Full Text Available The purpose of the study was to compare the selected physiological variables namely; maximum oxygen consumption, vital capacity, resting heart rate and hemoglobin content among various distance runners. Thesubjects were selected from the male athlete’s of Gwalior district of various distance runners i.e. short, middle and long distance runners for this study. Ten (10 male athletes from each groups namely short, middle and long distance groups were selected as the subject for the study. Selected physiological variables such as maximum oxygen consumption, vital capacity, resting heart rate and hemoglobin content were presented to compare the players belonging to various distance runners namely short, middle and long distance. To see the significant difference of selected physiological variables among the players belonging to various distance runners the analysis of variance “F-ratio” was applied at.05 level of significance. For further analysis “Post-Hoc Test” (LSD Test was applied. The short distance runners had shown significantly different level of VO2 max (72.727 in comparison to middle distance (75.854 and long distance (77.094 runners. However, the middle and long distance runners had shown more or less same level of VO2. Further long distance runners had shown better efficiency of heart as its mean value (56.3 was lowest among all the three groups in relation to resting heartrate. On the other hand long, middle and short distance runners had shown more or less same vital capacity and hemoglobin content with a small range of variation.
Effective Teaching in Distance Education. ERIC Digest.
Mielke, Dan
Distance education is an alternative method for delivering academic course work to students unable to attend traditional campus-based classes. This Digest presents information on the many forms of distance education and keys to successful teaching with distance education. Distance education is a method of education in which the learner is…
The intractability of computing the Hamming distance
Manthey, Bodo; Reischuk, Rüdiger
2005-01-01
Given a string x and a language L, the Hamming distance of x to L is the minimum Hamming distance of x to any string in L. The edit distance of a string to a language is analogously defined. First, we prove that there is a language in $AC^0$ such that both Hamming and edit distance to this language
Distance Education Use in Rural Schools
Hannum, Wallace H.; Irvin, Matthew J.; Banks, Jonathan B.; Farmer, Thomas W.
2009-01-01
A national survey of rural school systems in the United States was conducted to determine the extent to which distance education is being utilized by rural schools, the technologies used, the curriculum areas impacted, the perceived needs for distance education, their satisfaction with distance education, and the barriers to distance education…
History and Heritage in Distance Education
Anderson, Bill; Simpson, Mary
2012-01-01
Distance education's history is a tremendous resource for all involved in distance education. Some aspects of that history provide enduring touchstones for present distance educators, creating a heritage that should not be overlooked as distance education continues to develop and expand. In this article we draw on the concept of generational…
Determining distances using asteroseismic methods
Aguirre, V Silva; Basu, S; Campante, T L; Chaplin, W J; Huber, D; Miglio, A; Serenelli, A M; WG#1, KASC
2012-01-01
Asteroseismology has been extremely successful in determining the properties of stars in different evolutionary stages with a remarkable level of precision. However, to fully exploit its potential, robust methods for estimating stellar parameters are required and independent verification of the results is needed. In this talk, I present a new technique developed to obtain stellar properties by coupling asteroseismic analysis with the InfraRed Flux Method. Using two global seismic observables and multi-band photometry, the technique determines masses, radii, effective temperatures, bolometric fluxes, and thus distances for field stars in a self-consistent manner. Applying our method to a sample of solar-like oscillators in the {\\it Kepler} field that have accurate {\\it Hipparcos} parallaxes, we find agreement in our distance determinations to better than 5%. Comparison with measurements of spectroscopic effective temperatures and interferometric radii also validate our results, and show that our technique can ...
Managerial Distance and Virtual Ownership
Hansmann, Henry; Thomsen, Steen
Industrial foundations are autonomous nonprofit entities that own and control one or more conventional business firms. These foundations are common in Northern Europe, where they own a number of internationally prominent companies. Previous studies have indicated, surprisingly, that companies con......, but corporate governance and fiduciary behavior more generally....... on differences among the industrial foundations themselves. We work with a rich data set comprising 113 foundation-owned Danish companies over the period 2003-2008. We focus in particular on a composite structural factor that we term “managerial distance.” We propose this as a measure of the extent to which......-seeking outside owners of the company. Consistent with this hypothesis, our empirical analysis shows a positive, significant, and robust association between managerial distance and the economic performance of foundation owned companies. The findings appear to illuminate not just foundation governance...
Theological Librarianship from a Distance
Melody Diehl Detar
2015-08-01
Full Text Available This essay examines distance theological librarianship and the field’s suitability for remote librarians. A brief introduction to the landscape of online programs in theological education is followed by an overview of virtual librarianship and how theological librarians may serve students while working from a distance themselves. The essay then describes a method for initiating a remote librarian position in a theological library context, and then reviews the steps of determining whether remote work is feasible and desirable at an institution, approaching leadership with a plan, setting up a trial remote work period, and assessing its success. Particular emphasis is given to communication expectations, modes of virtual reference and instruction, campus committee service and meaningful ways of remaining part of the campus community.
Moral distance in dictator games
Fernando Aguiar
2008-04-01
Full Text Available We perform an experimental investigation using a dictator game in which individuals must make a moral decision --- to give or not to give an amount of money to poor people in the Third World. A questionnaire in which the subjects are asked about the reasons for their decision shows that, at least in this case, moral motivations carry a heavy weight in the decision: the majority of dictators give the money for reasons of a consequentialist nature. Based on the results presented here and of other analogous experiments, we conclude that dicator behavior can be understood in terms of moral distance rather than social distance and that it systematically deviates from the egoism assumption in economic models and game theory. %extit{JEL}: A13, C72, C91
Social distancing strategies against disease spreading
Valdez, L. D.; Buono, C.; Macri, P. A.; Braunstein, L. A.
2014-03-01
The recurrent infectious diseases and their increasing impact on the society has promoted the study of strategies to slow down the epidemic spreading. In this review we outline the applications of percolation theory to describe strategies against epidemic spreading on complex networks. We give a general outlook of the relation between link percolation and the susceptible-infected-recovered model, and introduce the node void percolation process to describe the dilution of the network composed by healthy individual, i.e, the network that sustain the functionality of a society. Then, we survey two strategies: the quenched disorder strategy where an heterogeneous distribution of contact intensities is induced in society, and the intermittent social distancing strategy where health individuals are persuaded to avoid contact with their neighbors for intermittent periods of time. Using percolation tools, we show that both strategies may halt the epidemic spreading. Finally, we discuss the role of the transmissibility, i.e, the effective probability to transmit a disease, on the performance of the strategies to slow down the epidemic spreading.
100G WDM Transmission over 100 meter Multimode Fiber
Cimoli, Bruno; Estaran Tolosa, Jose Manuel; Rodes Lopez, Guillermo Arturo
We present a comparative performance analysis for wavelength-grid selection in WDM shortrange multimode-fibers. We study 100Gbps links over OM2, OM3 and OM4 fibers and show it is feasible to reach over 100 m transmission distances....
SHIELD: Distance Estimates from Hubble Space Telescope Imaging
Cave, Ian; Cannon, J. M.; Larson, E.; Marshall, M.; Moody, S.; Adams, E. A.; Dolphin, A. E.; Elson, E. C.; Giovanelli, R.; Haynes, M. P.; McQuinn, K. B.; Ott, J.; Saintonge, A.; Salzer, J. J.; Skillman, E. D.
2013-01-01
The Survey of HI in Extremely Low-mass Dwarfs (SHIELD) is an ongoing study of twelve galaxies with HI masses between 106 and 107 Solar masses, detected by the Arecibo Legacy Fast ALFA (ALFALFA) survey. Here we present new Hubble Space Telescope (HST) imaging of the SHIELD galaxies. The primary goal is to determine the distance of each galaxy. We apply two techniques to measure the apparent magnitude of the tip of the red giant branch (TRGB) feature in the HST color magnitude diagrams. First, a custom designed edge detection filter was written to determine the TRGB magnitude based on a user-selected region of the color magnitude diagram. Second, we apply the maximum likelihood technique implemented in the "TRGBtool" software package (Makarov et al. 2006). In addition to the distances based on the TRGB feature, we also use the MATCH software (Dolphin 2002) to determine the best-fit distance based on the overall CMD morphology. We compare these distance estimates for all members of the SHIELD galaxies, and present a final table of distances that is used in each of the companion SHIELD presentations.
Students’ Role in Distance Learning
Beers Fägersten, Kristy
2008-01-01
1. IntroductionMuch of the support that students have in a traditional classroom is absent in a distance learning course. In the traditional classroom, the learner is together with his or her classmates and the teacher; learning is socially embedded. Students can talk to each other and may learn from each other as they go through the learning process together. They also witness the teacher’s expression of the knowledge firsthand. The class participants communicate to each other not ...
Distance probes of dark energy
Kim, A. G.; Padmanabhan, N.; Aldering, G.; Allen, S. W.; Baltay, C.; Cahn, R. N.; D’Andrea, C. B.; Dalal, N.; Dawson, K. S.; Denney, K. D.; Eisenstein, D. J.; Finley, D. A.; Freedman, W. L.; Ho, S.; Holz, D. E.; Kasen, D.; Kent, S. M.; Kessler, R.; Kuhlmann, S.; Linder, E. V.; Martini, P.; Nugent, P. E.; Perlmutter, S.; Peterson, B. M.; Riess, A. G.; Rubin, D.; Sako, M.; Suntzeff, N. V.; Suzuki, N.; Thomas, R. C.; Wood-Vasey, W. M.; Woosley, S. E.
2015-03-01
This document presents the results from the Distances subgroup of the Cosmic Frontier Community Planning Study (Snowmass 2013). We summarize the current state of the field as well as future prospects and challenges. In addition to the established probes using Type Ia supernovae and baryon acoustic oscillations, we also consider prospective methods based on clusters, active galactic nuclei, gravitational wave sirens and strong lensing time delays.
Hardware Euclidean Distance Transform Implementation
XIE Ying-hua; ZENG Pei-feng; TANG Li-ping
2004-01-01
Based on an efficient algorithm of Euclidean distance transform for binary images, a circuit of O(N2) size is proposed. With in-place calculation, both the intermediate data storing and the result output use the same memory with the input data. This reduces the amount of memory largely. By replacing multipliers with counters, comparators, and adders, the circuit size is further reduced and its calculation speed is improved also.
Distance Probes of Dark Energy
Kim, A; Aldering, G; Allen, S; Baltay, C; Cahn, R; D'Andrea, C; Dalal, N; Dawson, K; Denney, K; Eisenstein, D; Finley, D; Freedman, W; Ho, S; Holz, D; Kent, A; Kasen, D; Kessler, R; Kuhlmann, S; Linder, E; Martini, P; Nugent, P; Perlmutter, S; Peterson, B; Riess, A; Rubin, D; Sako, M; Suntzeff, N; Suzuki, N; Thomas, R; Wood-Vasey, W M; Woosley, S
2013-01-01
This document presents the results from the Distances subgroup of the Cosmic Frontier Community Planning Study (Snowmass 2013). We summarize the current state of the field as well as future prospects and challenges. In addition to the established probes using Type IA supernovae and baryon acoustic oscillations, we also consider prospective methods based on clusters, active galactic nuclei, gravitational wave sirens and strong lensing time delays.
Distance effects in electrochemical micromachining
2016-01-01
Considering exponential dependence of currents on double-layer voltage and the feedback effect of the electrolyte resistance, a distance effect in electrochemical micromachining is found, namely that both time constant and double-layer voltage depend on the separation of electrodes. The double-layer voltage is the real voltage used in processing. Under DC voltage, the apparent voltages between two electrodes are constant for different separations, but the real voltages change with the separat...
Analysis of Photovoltaic Maximum Power Point Trackers
Veerachary, Mummadi
The photovoltaic generator exhibits a non-linear i-v characteristic and its maximum power point (MPP) varies with solar insolation. An intermediate switch-mode dc-dc converter is required to extract maximum power from the photovoltaic array. In this paper buck, boost and buck-boost topologies are considered and a detailed mathematical analysis, both for continuous and discontinuous inductor current operation, is given for MPP operation. The conditions on the connected load values and duty ratio are derived for achieving the satisfactory maximum power point operation. Further, it is shown that certain load values, falling out of the optimal range, will drive the operating point away from the true maximum power point. Detailed comparison of various topologies for MPPT is given. Selection of the converter topology for a given loading is discussed. Detailed discussion on circuit-oriented model development is given and then MPPT effectiveness of various converter systems is verified through simulations. Proposed theory and analysis is validated through experimental investigations.
On maximum cycle packings in polyhedral graphs
Peter Recht
2014-04-01
Full Text Available This paper addresses upper and lower bounds for the cardinality of a maximum vertex-/edge-disjoint cycle packing in a polyhedral graph G. Bounds on the cardinality of such packings are provided, that depend on the size, the order or the number of faces of G, respectively. Polyhedral graphs are constructed, that attain these bounds.
Hard graphs for the maximum clique problem
Hoede, Cornelis
1988-01-01
The maximum clique problem is one of the NP-complete problems. There are graphs for which a reduction technique exists that transforms the problem for these graphs into one for graphs with specific properties in polynomial time. The resulting graphs do not grow exponentially in order and number. Gra
Maximum Likelihood Estimation of Search Costs
J.L. Moraga-Gonzalez (José Luis); M.R. Wildenbeest (Matthijs)
2006-01-01
textabstractIn a recent paper Hong and Shum (forthcoming) present a structural methodology to estimate search cost distributions. We extend their approach to the case of oligopoly and present a maximum likelihood estimate of the search cost distribution. We apply our method to a data set of online p
Weak Scale From the Maximum Entropy Principle
Hamada, Yuta; Kawana, Kiyoharu
2015-01-01
The theory of multiverse and wormholes suggests that the parameters of the Standard Model are fixed in such a way that the radiation of the $S^{3}$ universe at the final stage $S_{rad}$ becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the Standard Model, we can check whether $S_{rad}$ actually becomes maximum at the observed values. In this paper, we regard $S_{rad}$ at the final stage as a function of the weak scale ( the Higgs expectation value ) $v_{h}$, and show that it becomes maximum around $v_{h}={\\cal{O}}(300\\text{GeV})$ when the dimensionless couplings in the Standard Model, that is, the Higgs self coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by \\begin{equation} v_{h}\\sim\\frac{T_{BBN}^{2}}{M_{pl}y_{e}^{5}},\
Weak scale from the maximum entropy principle
Hamada, Yuta; Kawai, Hikaru; Kawana, Kiyoharu
2015-03-01
The theory of the multiverse and wormholes suggests that the parameters of the Standard Model (SM) are fixed in such a way that the radiation of the S3 universe at the final stage S_rad becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the SM, we can check whether S_rad actually becomes maximum at the observed values. In this paper, we regard S_rad at the final stage as a function of the weak scale (the Higgs expectation value) vh, and show that it becomes maximum around vh = {{O}} (300 GeV) when the dimensionless couplings in the SM, i.e., the Higgs self-coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by vh ˜ T_{BBN}2 / (M_{pl}ye5), where ye is the Yukawa coupling of electron, T_BBN is the temperature at which the Big Bang nucleosynthesis starts, and M_pl is the Planck mass.
Global characterization of the Holocene Thermal Maximum
Renssen, H.; Seppä, H.; Crosta, X.; Goosse, H.; Roche, D.M.V.A.P.
2012-01-01
We analyze the global variations in the timing and magnitude of the Holocene Thermal Maximum (HTM) and their dependence on various forcings in transient simulations covering the last 9000 years (9 ka), performed with a global atmosphere-ocean-vegetation model. In these experiments, we consider the i
Instance Optimality of the Adaptive Maximum Strategy
L. Diening; C. Kreuzer; R. Stevenson
2016-01-01
In this paper, we prove that the standard adaptive finite element method with a (modified) maximum marking strategy is instance optimal for the total error, being the square root of the squared energy error plus the squared oscillation. This result will be derived in the model setting of Poisson’s e
Maximum phonation time: variability and reliability.
Speyer, Renée; Bogaardt, Hans C A; Passos, Valéria Lima; Roodenburg, Nel P H D; Zumach, Anne; Heijnen, Mariëlle A M; Baijens, Laura W J; Fleskens, Stijn J H M; Brunings, Jan W
2010-05-01
The objective of the study was to determine maximum phonation time reliability as a function of the number of trials, days, and raters in dysphonic and control subjects. Two groups of adult subjects participated in this reliability study: a group of outpatients with functional or organic dysphonia versus a group of healthy control subjects matched by age and gender. Over a period of maximally 6 weeks, three video recordings were made of five subjects' maximum phonation time trials. A panel of five experts were responsible for all measurements, including a repeated measurement of the subjects' first recordings. Patients showed significantly shorter maximum phonation times compared with healthy controls (on average, 6.6 seconds shorter). The averaged interclass correlation coefficient (ICC) over all raters per trial for the first day was 0.998. The averaged reliability coefficient per rater and per trial for repeated measurements of the first day's data was 0.997, indicating high intrarater reliability. The mean reliability coefficient per day for one trial was 0.939. When using five trials, the reliability increased to 0.987. The reliability over five trials for a single day was 0.836; for 2 days, 0.911; and for 3 days, 0.935. To conclude, the maximum phonation time has proven to be a highly reliable measure in voice assessment. A single rater is sufficient to provide highly reliable measurements.
Maximum Phonation Time: Variability and Reliability
R. Speyer; H.C.A. Bogaardt; V.L. Passos; N.P.H.D. Roodenburg; A. Zumach; M.A.M. Heijnen; L.W.J. Baijens; S.J.H.M. Fleskens; J.W. Brunings
2010-01-01
The objective of the study was to determine maximum phonation time reliability as a function of the number of trials, days, and raters in dysphonic and control subjects. Two groups of adult subjects participated in this reliability study: a group of outpatients with functional or organic dysphonia v
Maximum likelihood estimation of fractionally cointegrated systems
Lasak, Katarzyna
In this paper we consider a fractionally cointegrated error correction model and investigate asymptotic properties of the maximum likelihood (ML) estimators of the matrix of the cointe- gration relations, the degree of fractional cointegration, the matrix of the speed of adjustment...
Maximum likelihood estimation for integrated diffusion processes
Baltazar-Larios, Fernando; Sørensen, Michael
EM-algorithm to obtain maximum likelihood estimates of the parameters in the diffusion model. As part of the algorithm, we use a recent simple method for approximate simulation of diffusion bridges. In simulation studies for the Ornstein-Uhlenbeck process and the CIR process the proposed method works...
Maximum gain of Yagi-Uda arrays
Bojsen, J.H.; Schjær-Jacobsen, Hans; Nilsson, E.
1971-01-01
Numerical optimisation techniques have been used to find the maximum gain of some specific parasitic arrays. The gain of an array of infinitely thin, equispaced dipoles loaded with arbitrary reactances has been optimised. The results show that standard travelling-wave design methods are not optimum....... Yagi–Uda arrays with equal and unequal spacing have also been optimised with experimental verification....
The Magnetotail at Lunar Distance
Sibeck, D. G.
2015-12-01
This presentation reviews some of the single-point observations of the magnetotail at lunar distances made by ALSEP, Explorer 33, 35, ISEE-3, and Geotail that form the framework for interpreting more recent dual-spacecraft ARTEMIS observations. Earth's distant magnetotail flaps, twists, and flattens in response to variations in the solar wind flow direction and interplanetary magnetic field (IMF) orientation. It may even disappear leaving nothing more than a wake during strongly northward IMF orientations. Standing slow mode expansion fans provide for a gradual transition between magnetotail lobe and magnetosheath plasma and magnetic field parameters. The distant neutral line may at times reside at lunar distances, creating jets of sunward-streaming plasma within the cislunar plasma sheet and layers of streaming energetic particles on its boundaries. Reconnection at near-Earth neutral lines releases antisunward-moving plasmoids that transit lunar distances, briefly expanding the diameter of the plasma sheet and magnetotail. Taken as a whole, the distant magnetotail is a fascinating plasma laboratory and a region of great important to the magnetosphere.
Support Services for Distance Education
Sandra Frieden
1999-01-01
Full Text Available The creation and operation of a distance education support infrastructure requires the collaboration of virtually all administrative departments whose activities deal with students and faculty, and all participating academic departments. Implementation can build on where the institution is and design service-oriented strategies that strengthen institutional support and commitment. Issues to address include planning, faculty issues and concerns, policies and guidelines, approval processes, scheduling, training, publicity, information-line operations, informational materials, orientation and registration processes, class coordination and support, testing, evaluations, receive site management, partnerships, budgets, staffing, library and e-mail support, and different delivery modes (microwave, compressed video, radio, satellite, public television/cable, video tape and online. The process is ongoing and increasingly participative as various groups on campus begin to get involved with distance education activities. The distance education unit must continuously examine and revise its processes and procedures to maintain the academic integrity and service excellence of its programs. Its a daunting prospect to revise the way things have been done for many years, but each department has an opportunity to respond to new ways of serving and reaching students.
Fingerprinting with Minimum Distance Decoding
Lin, Shih-Chun; Gamal, Hesham El
2007-01-01
This work adopts an information theoretic framework for the design of collusion-resistant coding/decoding schemes for digital fingerprinting. More specifically, the minimum distance decision rule is used to identify 1 out of t pirates. Achievable rates, under this detection rule, are characterized in two distinct scenarios. First, we consider the averaging attack where a random coding argument is used to show that the rate 1/2 is achievable with t=2 pirates. Our study is then extended to the general case of arbitrary $t$ highlighting the underlying complexity-performance tradeoff. Overall, these results establish the significant performance gains offered by minimum distance decoding as compared to other approaches based on orthogonal codes and correlation detectors. In the second scenario, we characterize the achievable rates, with minimum distance decoding, under any collusion attack that satisfies the marking assumption. For t=2 pirates, we show that the rate $1-H(0.25)\\approx 0.188$ is achievable using an ...
Editorial ~ Global Diversity of Distance Education
2001-01-01
In a panel presentation at the recent International Council for Open and Distance Education (ICDE) world conference in Dusseldorf, Germany, I had the opportunity to explain the unique role and mission of International Review of Research in Open and Distance Learning (IRRODL) vis – vis our more established sister journals: Open Praxis, Open Learning, Journal of Distance Education, Distance Education, and American Journal of Distance Education. Although all of these journals share a common comm...
The Monge distance between quantum states
Zyczkowski, Karol [Institute for Plasma Research, University of Maryland, College Park, MD (United States); Slomczynski, Wojciech [Instytut Matematyki, Uniwersytet Jagiellonski, Cracow (Poland)
1998-11-13
We define a metric in the space of quantum states taking the Monge distance between corresponding Husimi distributions (Q-functions). This quantity fulfils the axioms of a metric and satisfies the following semiclassical property: the distance between two coherent states is equal to the Euclidean distance between corresponding points in the classical phase space. We compute analytically distances between certain states (coherent, squeezed, Fock and thermal) and discuss a scheme for numerical computation of Monge distance for two arbitrary quantum states. (author)
[Travel time and distances to Norwegian out-of-hours casualty clinics].
Raknes, Guttorm; Morken, Tone; Hunskår, Steinar
2014-11-01
Geographical factors have an impact on the utilisation of out-of-hours services. In this study we have investigated the travel distance to out-of-hours casualty clinics in Norwegian municipalities in 2011 and the number of municipalities covered by the proposed recommendations for secondary on-call arrangements due to long distances. We estimated the average maximum travel times and distances in Norwegian municipalities using a postcode-based method. Separate analyses were performed for municipalities with a single, permanently located casualty clinic. Altogether 417 out of 430 municipalities were included. We present the median value of the maximum travel times and distances for the included municipalities. The median maximum average travel distance for the municipalities was 19 km. The median maximum average travel time was 22 minutes. In 40 of the municipalities (10 %) the median maximum average travel time exceeded 60 minutes, and in 97 municipalities (23 %) the median maximum average travel time exceeded 40 minutes. The population of these groups comprised 2 % and 5 % of the country's total population respectively. For municipalities with permanent emergency facilities(N = 316), the median average flight time 16 minutes and median average distance 13 km.. In many municipalities, the inhabitants have a long average journey to out-of-hours emergency health services, but seen as a whole, the inhabitants of these municipalities account for a very small proportion of the Norwegian population. The results indicate that the proposed recommendations for secondary on-call duty based on long distances apply to only a small number of inhabitants. The recommendations should therefore be adjusted and reformulated to become more relevant.
Lisianthus cultivation using differentiated light transmission nets
Paulo Hercilio Viegas Rodrigues
2016-08-01
Full Text Available The Lisianthus stands out as one of the ten most cut flowers sold in the world. The use of meshes in a different light transmission is gaining more space in horticulture with promising results in greenhouse. The aim of this study was to evaluate the development of lisianthus grown in different light transmission meshes in blue, black, red and control treatments, which were transplanted 20 seedlings to cultivate Snow white with three replications, and therefore, 60 plants 240 plants per treatment in total. Agronomic characteristics such as plant height and length of the top pair of leaves were evaluated at 15, 38, 59, 82 and 105 days after transplanting. Other features such as early flowering, thick stem, distance between us and weight of the harvested stems were obtained at harvest stage. At the end of the evaluations, the treatment of red net was the most consistent with a significant difference in stem height and earliness in flowering.
Wild edible plant knowledge, distribution and transmission
Turreira Garcia, Nerea; Theilade, Ida; Meilby, Henrik;
2015-01-01
–1985 with WEPs as the main source of food. Major variables possibly determining knowledge and therefore investigated were socio-demographic characteristics, distance to and abundance of natural resources and main source of knowledge transmission. A reference list of species was prepared with the help of three......% of the cases, which led to increased knowledge of plants and ability to recognise them. Conclusions: The WEP survey may serve as a reference point and as a useful compilation of knowledge for the community for their current and future generations. This study shows that the elder and the refugees living...
Dynamics of a multi-mode maximum entangled coherent state over an amplitude damping channel
A. E1 Allati; Y. Hassouni; N. Metwally
2011-01-01
The dynamics of the maximum entangled coherent state traveling through an amplitude damping channel is investigated.For small values of the transmissivity rate,the traveling state is very fragile to this noise channel,which suffers from the phase flip error with high probability. The entanglement decays smoothly for larger values of the transmissivity rate and speedily for smaller values of this rate.As the number of modes increases,the traveling state over this noise channel quickly loses its entanglement.The odd and even states vanish at the same value of field intensity.
Dynamics of multi-modes maximum entangled coherent state over amplitude damping channel
Allati, A El; Metwally, N
2012-01-01
The dynamics of maximum entangled coherent state travels through an amplitude damping channel is investigated. For small values of the transmissivity rate the travelling state is very fragile to this noise channel, where it suffers from the phase flip error with high probability. The entanglement decays smoothly for larger values of the transmissivity rate and speedily for smaller values of this rate. As the number of modes increases, the travelling state over this noise channel loses its entanglement hastily. The odd and even states vanish at the same value of the field intensity.
Economics Of Optical Fibre Transmission Systems
Murray, W. J.
1983-08-01
Optical fibre as a telecommunication transmission medium has become one of the most significant developments so far of the digital era. A major contributory factor to the availability of optical fibre transmission systems has been the outstanding progress in the technology of manufacturing high quality glass fibre having relatively low attenuation and broad bandwidths. This and other achievements has enabled manufacturers in the United Kingdom to develop a range of optical fibre cables and transmission equipment for operation over short and long distances at the CCITT recommended digital hierarchical rates of 2, 8, 34 and 140Mbit/s which have been adopted by British Telecom (BT) for modernisation to an all digital transmission network. These optical fibre systems are now becoming increasingly price and performance competitive with conventional technology in many parts of telecommunications networks. In the British Telecom (BT) network the 140Mbit/s optical fibre systems are now economically competitive with equivalent systems on coaxial cable and microwave radio. The economics of 8 and 34Mbit/s systems are not yet sufficiently attractive, compared with 2Mbit/s digital line systems on pair type copper cables, for large scale use in rural and local distribution networks and are presently only justified on cost in and around large cities. As system costs decrease large applications are predicted particularly in support of future high speed data, cable television and visual information services.
Eastern wind integration and transmission study overview
Corbus, D. [United States Dept. of Energy, Golden, CO (United States). National Renewable Energy Laboratory
2009-07-01
This presentation discussed the electricity system operational impacts and benefits of long distance transmission accessing multiple wind resources in New England. The aim of the eastern wind integration and transmission study (EWITS) was to determine the impact of geographical diversity on system variability, and to understand the role of wind forecasting in ensuring reliability. Mesoscale modelling was evaluated, as well as transmission and integration studies. Mesoscale modelling is conducted to identify wind sites and develop high quality wind resource data sets, as well as to develop wind power plant outputs. Scenarios for 20 and 30 per cent wind integration includes the development of local resources with lower capacity factors; and high capacity factor wind development with larger transmission components. All the scenarios required the use of offshore wind resources. The study also examined export capacity for each of the studied areas. Wind integration, reliability analyses, and hourly modelling approaches were reviewed. Future research will include sensitivity studies related to carbon pricing and stochastic modelling. tabs., figs.
Opportunistic Cooperative Reliable Transmission Protocol for Wireless Sensor Networks
Hua Guo
2014-04-01
Full Text Available The high reliability requirement of data transmission in wireless sensor networks has been a large challenge due to the random mobility and network topoloy instability, as well as restriction of energy consumption and system life time. In this work, the relationship matirx of distance and speed was created at first. Then the binay tree of mobility and reliabiliy was proposed based on the distance relationship matrix. The optimal relay nodes with high reliabiliy were selected by seeking the binay tree. The high reliable opportunistic cooperative data transmission scheme was presnted finally. The outcome of both mathematical analysis and NS simulation indicate that the proposed mechanism is superior to the traditional data transmission mechnism such as the reliability, system throughput and energy efficiency and so on.
A novel transmission line protection using DOST and SVM
M. Jaya Bharata Reddy
2016-06-01
Full Text Available This paper proposes a smart fault detection, classification and location (SFDCL methodology for transmission systems with multi-generators using discrete orthogonal Stockwell transform (DOST. The methodology is based on synchronized current measurements from remote telemetry units (RTUs installed at both ends of the transmission line. The energy coefficients extracted from the transient current signals due to occurrence of different types of faults using DOST are being utilized for real-time fault detection and classification. Support vector machine (SVM has been deployed for locating the fault distance using the extracted coefficients. A comparative study is performed for establishing the superiority of SVM over other popular computational intelligence methods, such as adaptive neuro-fuzzy inference system (ANFIS and artificial neural network (ANN, for more precise and reliable estimation of fault distance. The results corroborate the effectiveness of the suggested SFDCL algorithm for real-time transmission line fault detection, classification and localization.
Ultrahigh Transmission Optical Nanofibers
Hoffman, J E; Grover, J A; Solano, P; Kordell, P R; Wong-Campos, J D; Orozco, L A; Rolston, S L
2014-01-01
We present a procedure for reproducibly fabricating ultrahigh transmission optical nanofibers (530 nm diameter and 84 mm stretch) with single-mode transmissions of 99.95 $ \\pm$ 0.02%, which represents a loss from tapering of 2.6 $\\,\\times \\,$ 10$^{-5}$ dB/mm when normalized to the entire stretch. When controllably launching the next family of higher-order modes on a fiber with 195 mm stretch, we achieve a transmission of 97.8 $\\pm$ 2.8%, which has a loss from tapering of 5.0 $\\,\\times \\,$ 10$^{-4}$ dB/mm when normalized to the entire stretch. Our pulling and transfer procedures allow us to fabricate optical nanofibers that transmit more than 400 mW in high vacuum conditions. These results, published as parameters in our previous work, present an improvement of two orders of magnitude less loss for the fundamental mode and an increase in transmission of more than 300% for higher-order modes, when following the protocols detailed in this paper. We extract from the transmission during the pull, the only reported...
Guo, Jin; Guo, Shuxiang; Tamiya, Takashi; Hirata, Hideyuki; Ishihara, Hidenori
2016-03-01
An Internet-based tele-operative robotic catheter operating system was designed for vascular interventional surgery, to afford unskilled surgeons the opportunity to learn basic catheter/guidewire skills, while allowing experienced physicians to perform surgeries cooperatively. Remote surgical procedures, limited by variable transmission times for visual feedback, have been associated with deterioration in operability and vascular wall damage during surgery. At the patient's location, the catheter shape/position was detected in real time and converted into three-dimensional coordinates in a world coordinate system. At the operation location, the catheter shape was reconstructed in a virtual-reality environment, based on the coordinates received. The data volume reduction significantly reduced visual feedback transmission times. Remote transmission experiments, conducted over inter-country distances, demonstrated the improved performance of the proposed prototype. The maximum error for the catheter shape reconstruction was 0.93 mm and the transmission time was reduced considerably. The results were positive and demonstrate the feasibility of remote surgery using conventional network infrastructures. Copyright © 2015 John Wiley & Sons, Ltd.
RELIABILITY ASSESSMENT OF TRANSMISSION TOWER OF 220 KV M/C “MA” VERTICAL MEMBERS
M.V.R.SATYANARAYANA
2014-04-01
Full Text Available Transmission line towers are used to support conductors carrying extra high voltage (EHV electric transmission lines and one or two ground wires at suitable distance. These also carry vary heavy currents, to the tune of several hundred amperes. This has necessitated the use of tall towers to support the transmission line conductors carrying EHV. The cost of transmission line tower is 30% to 40% of total cost of transmission line. The problem of efficiently designing structural system involves reliability constraints imposed at both serviceability and ultimate limit state. Methods are developed using structural reliability principle to evaluate time dependent reliability of structure. These methods enable the impact on safety and serviceability of uncertainties in loading conditions, structural degradation due to aggressive environment to be assessed qualitatively. The prediction of service life of damaged or deteriorated steel structures remains at the stage of parametric studies, inspite of intensive research on corrosion in steel structures for the past three decades. Service live of steel structures is limited by the susceptibility of the member to corrosion. Oxidation of iron leads to the formulation of various products (such as ferrous and ferric oxides, some of which occupy much greater volume than the original iron that gets consumed by the corrosion process. At this stage the member loses its ability to resist the forces. This project is a study on reliability assessment of 220 kV transmission towers. In this the 220 kV tower consists of 33.935 m height arranged in 12 height Panels and it contain 225 members. The wind load on tower for zone –II condition is calculated according to IS Code IS: 802 (part – 1/Section – 1: 1995. The tower is analyzed as space truss for full load condition using STAAD Pro 2007. In this work the variation of reliability index of members with decrease in area of cross section are studied. The compression
Long-distance practical quantum key distribution by entanglement swapping
Scherer, Artur; Tittel, Wolfgang
2010-01-01
We develop a model for practical, entanglement-based long-distance quantum key distribution employing entanglement swapping as a key building block. Relying only on existing off-the-shelf technology, we show how to optimize resources so as to maximize secret key distribution rates. The tools comprise lossy transmission links, such as telecom optical fibers or free space, parametric down-conversion sources of entangled photon pairs, and threshold detectors that are inefficient and have dark counts. Our analysis provides the optimal trade-off between detector efficiency and dark counts, which are usually competing, as well as the optimal source brightness that maximizes the secret key rate for specified distances (i.e. loss) between sender and receiver.
Next Generation Large Capacity Long Distance Fiber To The Home
N. M. A. Ayad and M. Elazazy
2011-07-01
Full Text Available Optical device technologies for photonic networks, are focusing on integrated optical device technologies for digital coherent optical transmission technologies. With the rapid spread of fiber to the home (FTTH, broadband video services and mobile Internet devices now require a highly functional optical network infrastructure with a large capacity 100-Gbit/s/channel system based on digital coherent technology is considered to be a promising candidate for next-generation large-capacity long-distance optical communication systems. The optical components required for such systems, such as Polarization Division Multiplexed Quadrate Phase Shift Keying (PDM-QPSK optical modulator, integrated receiver, and local light source, are under development. Opto-electrical integration technologies, which enable us to construct small, low-cost, and highly functional optical components, will play an important role in providing cost-effective transmission equipment for future 100-Gbit/s/ch and post-100-Gbit/s/ch optical communications
FT and florigen long-distance flowering control in plants.
Putterill, Joanna; Varkonyi-Gasic, Erika
2016-10-01
The great hunt for florigen, the universal, long distance flowering regulator proposed by Chailakhan in the 1930s, resulted in the discovery a decade ago that FT-like proteins fulfilled the predictions for florigen. They are small (∼175 amino acids), globular, phosphatidylethanolamine-binding (PEBP) proteins, phloem-expressed, graft-transmissible and able to move to the shoot apex to act as potent stimulators of flowering in many plants. Genes that regulate Arabidopsis FT protein movement and some features of Arabidopsis FT protein that make it an effective florigen have recently been identified. Although floral promotion via graft transmission of FT has not been demonstrated in trees, FT-like genes have been successfully applied to reducing the long juvenile (pre-flowering) phase of many trees enabling fast track breeding.
Probabilistic transmission system planning
Li, Wenyuan
2011-01-01
"The book is composed of 12 chapters and three appendices, and can be divided into four parts. The first part includes Chapters 2 to 7, which discuss the concepts, models, methods and data in probabilistic transmission planning. The second part, Chapters 8 to 11, addresses four essential issues in probabilistic transmission planning applications using actual utility systems as examples. Chapter 12, as the third part, focuses on a special issue, i.e. how to deal with uncertainty of data in probabilistic transmission planning. The fourth part consists of three appendices, which provide the basic knowledge in mathematics for probabilistic planning. Please refer to the attached table of contents which is given in a very detailed manner"--
Aerosol Transmission of Filoviruses
Berhanu Mekibib
2016-05-01
Full Text Available Filoviruses have become a worldwide public health concern because of their potential for introductions into non-endemic countries through international travel and the international transport of infected animals or animal products. Since it was first identified in 1976, in the Democratic Republic of Congo (formerly Zaire and Sudan, the 2013–2015 western African Ebola virus disease (EVD outbreak is the largest, both by number of cases and geographical extension, and deadliest, recorded so far in medical history. The source of ebolaviruses for human index case(s in most outbreaks is presumptively associated with handling of bush meat or contact with fruit bats. Transmission among humans occurs easily when a person comes in contact with contaminated body fluids of patients, but our understanding of other transmission routes is still fragmentary. This review deals with the controversial issue of aerosol transmission of filoviruses.
Aerosol Transmission of Filoviruses.
Mekibib, Berhanu; Ariën, Kevin K
2016-05-23
Filoviruses have become a worldwide public health concern because of their potential for introductions into non-endemic countries through international travel and the international transport of infected animals or animal products. Since it was first identified in 1976, in the Democratic Republic of Congo (formerly Zaire) and Sudan, the 2013-2015 western African Ebola virus disease (EVD) outbreak is the largest, both by number of cases and geographical extension, and deadliest, recorded so far in medical history. The source of ebolaviruses for human index case(s) in most outbreaks is presumptively associated with handling of bush meat or contact with fruit bats. Transmission among humans occurs easily when a person comes in contact with contaminated body fluids of patients, but our understanding of other transmission routes is still fragmentary. This review deals with the controversial issue of aerosol transmission of filoviruses.
Modeling a data transmission network by means of the Teledacya information subsystems
Palmowska, K.
1982-11-01
Rapid assessment of the reasonableness of results from various kinds of prognostication fundamentals and assumptions concerning the development of data transmission networks, important with respect to the extent of loading on a long distance telecommunications transmission network was examined. Initial evaluations demonstrated that loading determined according to existing prediction methods has essential importance for the planning of an entire telecommunication network.
Grakhova, Elizaveta P.; Rommel, Simon; Jurado-Navas, Antonio
2016-01-01
Ultra-wideband impulse-radio wireless transmission under the stringent conditions and complex shape of the Russian spectral emission mask is experimentally demonstrated for the first time. Transmission of 1Gbit/s and 1.25Gbit/s signals over distances of 6m and 3m is achieved with a BER below 3.8×...
15Gbit/s Duobinary Transmission Over a W-Band Radio-over-Fiber Link
Rommel, Simon; Vegas Olmos, Juan José; Tafur Monroy, Idelfonso
2016-01-01
In this paper the transmission of a 15Gbit/s duobinary signal over a W-band hybrid photonic wireless link is demonstrated experimentally. The radio-over-fiber link consists of 10km SMF and a wireless distance of 50m, utilizing RF carriers at 83–87GHz. Transmission of a 15Gbit/s duobinary signal...
Model Selection Through Sparse Maximum Likelihood Estimation
Banerjee, Onureena; D'Aspremont, Alexandre
2007-01-01
We consider the problem of estimating the parameters of a Gaussian or binary distribution in such a way that the resulting undirected graphical model is sparse. Our approach is to solve a maximum likelihood problem with an added l_1-norm penalty term. The problem as formulated is convex but the memory requirements and complexity of existing interior point methods are prohibitive for problems with more than tens of nodes. We present two new algorithms for solving problems with at least a thousand nodes in the Gaussian case. Our first algorithm uses block coordinate descent, and can be interpreted as recursive l_1-norm penalized regression. Our second algorithm, based on Nesterov's first order method, yields a complexity estimate with a better dependence on problem size than existing interior point methods. Using a log determinant relaxation of the log partition function (Wainwright & Jordan (2006)), we show that these same algorithms can be used to solve an approximate sparse maximum likelihood problem for...
Maximum-entropy description of animal movement.
Fleming, Chris H; Subaşı, Yiğit; Calabrese, Justin M
2015-03-01
We introduce a class of maximum-entropy states that naturally includes within it all of the major continuous-time stochastic processes that have been applied to animal movement, including Brownian motion, Ornstein-Uhlenbeck motion, integrated Ornstein-Uhlenbeck motion, a recently discovered hybrid of the previous models, and a new model that describes central-place foraging. We are also able to predict a further hierarchy of new models that will emerge as data quality improves to better resolve the underlying continuity of animal movement. Finally, we also show that Langevin equations must obey a fluctuation-dissipation theorem to generate processes that fall from this class of maximum-entropy distributions when the constraints are purely kinematic.