Predicting Bed Mobility in a Simple River Channel

Science.gov (United States)

Wydzga, M. A.; Legleiter, C.; Dunne, T.

2007-12-01

Prediction of the frequency and spatial pattern of bed mobility in gravel bed rivers is central to a wide range of theoretical and applied interests ranging from sediment transport to the impacts of natural or managed floods on aquatic organisms. Although bed mobility has been investigated in numerous flume and field studies, accurate predictions of grain entrainment and transport in gravel bed rivers remain elusive. Alluvial rivers typically encompass a much wider range of hydraulic and sedimentological conditions than those that have been recreated in laboratory flume studies upon which many grain entrainment and transport models are based. These flume studies are limited to the examination of processes occurring over the short term, commonly with the absence of slower processes such as fine-grain infilling. On the other hand, in field studies key variables can not be controlled and the spatial complexity of processes and conditions complicate data collection and analysis. A unique opportunity currently exists to help bridge this gap between laboratory and field studies: a 3.2 km long, recently constructed, single thread, alternate bar, gravel bed river channel of the Merced River. This channel, constructed for ecosystem restoration purposes, is slowly developing greater complexity, but is still currently defined by a simple plan form and cross-sectional channel geometry compared to most natural gravel bed river channels. This channel can thus be considered a full-scale flume. In the six years since the channel was constructed, a wider range of sedimentological bed conditions have evolved than have been created in a laboratory flume. We are characterizing the bed grain sizes, flow field, grain entrainment, and the sedimentological or bed state conditions in this simple channel. The flow field is modeled using a calibrated, 2D hydrodynamic flow model, MD_SWMS. Grain entrainment is measured with both metal tags inserted into the bed, and painted rock tracers

Impact of optical phonon scattering on inversion channel mobility in 4H-SiC trenched MOSFETs

Science.gov (United States)

Kutsuki, Katsuhiro; Kawaji, Sachiko; Watanabe, Yukihiko; Onishi, Toru; Fujiwara, Hirokazu; Yamamoto, Kensaku; Yamamoto, Toshimasa

2017-04-01

Temperature characteristics of the channel mobility were investigated for 4H-SiC trenched MOSFETs in the range from 30 to 200 °C. The conventional model of channel mobility limited by carrier scattering is based on Si-MOSFETs and shows a greatly different channel mobility from the experimental value, especially at high temperatures. On the other hand, our improved mobility model taking into account optical phonon scattering yielded results in excellent agreement with experimental results. Moreover, the major factors limiting the channel mobility were found to be Coulomb scattering in a low effective field (<0.7 MV/cm) and optical phonon scattering in a high effective field.

Increase in electron mobility of InGaAs/InP composite channel high electron mobility transistor structure due to SiN passivation

International Nuclear Information System (INIS)

Liu Yuwei; Wang Hong; Radhakrishnan, K.

2007-01-01

The influence of silicon nitride passivation on electron mobility of InGaAs/InP composite channel high electron mobility transistor structure has been studied. Different from the structures with single InGaAs channel, an increase in effective mobility μ e with a negligible change of sheet carrier density n s after SiN deposition is clearly observed in the composite channel structures. The enhancement of μ e could be explained under the framework of electrons transferring from the InP sub-channel into InGaAs channel region due to the energy band bending at the surface region caused by SiN passivation, which is further confirmed by low temperature photoluminescence measurements

A Novel Criterion for Optimum MultilevelCoding Systems in Mobile Fading Channels

Institute of Scientific and Technical Information of China (English)

YUAN Dongfeng; WANG Chengxiang; YAO Qi; CAO Zhigang

2001-01-01

A novel criterion that is "capac-ity rule" and "mapping rule" for the design of op-timum MLC scheme over mobile fading channels isproposed.According to this theory,the performanceof multilevel coding with multistage decoding schemes(MLC/MSD) in mobile fading channels is investi-gated,in which BCH codes are chosen as componentcodes,and three mapping strategies with 8ASK mod-ulation are used.Numerical results indicate that whencode rates of component codes in MLC scheme are de-signed based on "capacity rule",the performance ofthe system with block partitioning (BP) is optimumfor Rayleigh fading channels,while the performance ofthe system with Ungerboeck partioning (UP) is bestfor AWGN channels.

AN EVOLUTIONARY ALGORITHM FOR CHANNEL ASSIGNMENT PROBLEM IN WIRELESS MOBILE NETWORKS

Directory of Open Access Journals (Sweden)

Yee Shin Chia

2012-12-01

Full Text Available The channel assignment problem in wireless mobile network is the assignment of appropriate frequency spectrum to incoming calls while maintaining a satisfactory level of electromagnetic compatibility (EMC constraints. An effective channel assignment strategy is important due to the limited capacity of frequency spectrum in wireless mobile network. Most of the existing channel assignment strategies are based on deterministic methods. In this paper, an adaptive genetic algorithm (GA based channel assignment strategy is introduced for resource management and to reduce the effect of EMC interferences. The most significant advantage of the proposed optimization method is its capability to handle both the reassignment of channels for existing calls as well as the allocation of channel to a new incoming call in an adaptive process to maximize the utility of the limited resources. It is capable to adapt the population size to the number of eligible channels for a particular cell upon new call arrivals to achieve reasonable convergence speed. The MATLAB simulation on a 49-cells network model for both uniform and nonuniform call traffic distributions showed that the proposed channel optimization method can always achieve a lower average new incoming call blocking probability compared to the deterministic based channel assignment strategy.

Measuring the lateral charge-carrier mobility in metal-insulator-semiconductor capacitors via Kelvin-probe.

Science.gov (United States)

Milotti, Valeria; Pietsch, Manuel; Strunk, Karl-Philipp; Melzer, Christian

2018-01-01

We report a Kelvin-probe method to investigate the lateral charge-transport properties of semiconductors, most notably the charge-carrier mobility. The method is based on successive charging and discharging of a pre-biased metal-insulator-semiconductor stack by an alternating voltage applied to one edge of a laterally confined semiconductor layer. The charge carriers spreading along the insulator-semiconductor interface are directly measured by a Kelvin-probe, following the time evolution of the surface potential. A model is presented, describing the device response for arbitrary applied biases allowing the extraction of the lateral charge-carrier mobility from experimentally measured surface potentials. The method is tested using the organic semiconductor poly(3-hexylthiophene), and the extracted mobilities are validated through current voltage measurements on respective field-effect transistors. Our widely applicable approach enables robust measurements of the lateral charge-carrier mobility in semiconductors with weak impact from the utilized contact materials.

Measuring the lateral charge-carrier mobility in metal-insulator-semiconductor capacitors via Kelvin-probe

Science.gov (United States)

Milotti, Valeria; Pietsch, Manuel; Strunk, Karl-Philipp; Melzer, Christian

2018-01-01

We report a Kelvin-probe method to investigate the lateral charge-transport properties of semiconductors, most notably the charge-carrier mobility. The method is based on successive charging and discharging of a pre-biased metal-insulator-semiconductor stack by an alternating voltage applied to one edge of a laterally confined semiconductor layer. The charge carriers spreading along the insulator-semiconductor interface are directly measured by a Kelvin-probe, following the time evolution of the surface potential. A model is presented, describing the device response for arbitrary applied biases allowing the extraction of the lateral charge-carrier mobility from experimentally measured surface potentials. The method is tested using the organic semiconductor poly(3-hexylthiophene), and the extracted mobilities are validated through current voltage measurements on respective field-effect transistors. Our widely applicable approach enables robust measurements of the lateral charge-carrier mobility in semiconductors with weak impact from the utilized contact materials.

Hole mobility enhancement of p-MOSFETs using global and local Ge-channel technologies

International Nuclear Information System (INIS)

Takagi, Shinichi; Tezuka, T.; Irisawa, T.; Nakaharai, S.; Maeda, T.; Numata, T.; Ikeda, K.; Sugiyama, N.

2006-01-01

Mobility enhancement technologies have currently been recognized as mandatory for future scaled MOSFETs. In this paper, we review our recent results on high hole mobility p-MOSFETs using global/local SiGe or Ge channels. There are two directions for introducing SiGe or Ge channels into Si CMOS platform. One is to use SiGe or Ge global substrates and the other is to form SiGe or Ge-channel regions locally on Si wafers. In both cases, the Ge condensation technique, where Ge-channel layers are formed by oxidizing SiGe films on SOI substrates, are effectively utilized. As for the global technologies, ultrathin GOI substrates are prepared and used to fabricate high mobility GOI p-MOSFETs. As for the local technologies, SGOI or GOI channels are formed locally in the active area of p-MOSFETs on SOI wafers. It is shown that the hole mobility enhancement factor of as high as 10 is obtained in locally fabricated p-MOSFETs through the effects of high-Ge content and the compressive strain. Furthermore, the local Ge-channel technologies are combined with global SiGe or Ge substrates for pursuing the optimal and individual design of n-MOSFETs and p-MOSFETs on a single Si wafer. The CMOS device composed of strained-Si n-MOSFETs and SGOI p-MOSFETs is successfully integrated on a same wafer, which is a promising CMOS structure under deep sub 100 nm technology nodes

Lateral mobility of plasma membrane lipids in dividing Xenopus eggs.

Science.gov (United States)

Tetteroo, P A; Bluemink, J G; Dictus, W J; van Zoelen, E J; de Laat, S W

1984-07-01

The lateral mobility of plasma membrane lipids was analyzed during first cleavage of Xenopus laevis eggs by fluorescence photobleaching recovery (FPR) measurements, using the lipid analogs 5-(N-hexadecanoyl)aminofluorescein ("HEDAF") and 5-(N-tetradecanoyl)aminofluorescein ("TEDAF") as probes. The preexisting plasma membrane of the animal side showed an inhomogeneous, dotted fluorescence pattern after labeling and the lateral mobility of both probes used was below the detection limits of the FPR method (D much less than 10(-10) cm2/sec). In contrast, the preexisting plasma membrane of the vegetal side exhibited homogeneous fluorescence and the lateral diffusion coefficient of both probes used was relatively high (HEDAF, D = 2.8 X 10(-8) cm2/sec; TEDAF, D = 2.4 X 10(-8) cm2/sec). In the cleaving egg visible transfer of HEDAF or TEDAF from prelabeled plasma membrane to the new membrane in the furrow did not occur, even on the vegetal side. Upon labeling during cleavage, however, the new membrane was uniformly labeled and both probes were mobile, as in the vegetal preexisting plasma membrane. These data show that the membrane of the dividing Xenopus egg comprises three macrodomains: (i) the animal preexisting plasma membrane; (ii) the vegetal preexisting plasma membrane; (iii) the new furrow membrane.

Modulation of Membrane Protein Lateral Mobility by Polyphosphates and Polyamines

Science.gov (United States)

Schindler, Melvin; Koppel, Dennis E.; Sheetz, Michael P.

1980-03-01

The lateral mobility of fluorescein-labeled membrane glycoproteins was measured in whole unlysed erythrocytes and erythrocyte ghosts by the technique of ``fluorescence redistribution after fusion.'' Measurements were made on polyethylene glycol-fused cell pairs in which only one member of the couplet was initially fluorescently labeled. Diffusion coefficients were estimated from the rate of fluorescence redistribution determined from successive scans with a focused laser beam across individual fused pairs. This technique allows for the analysis of diffusion within cell membranes without the possible damaging photochemical events caused by photobleaching. It was found that lateral mobility of erythrocyte proteins can be increased by the addition of polyphosphates (i.e., ATP and 2,3-diphosphoglycerate) and decreased by the addition of organic polyamines (i.e., neomycin and spermine). This control is exerted by these molecules only when they contact the cytoplasmic side of the membrane and is not dependent upon high-energy phosphates. Microviscosity experiments employing diphenylhexatriene demonstrated no changes in membrane lipid state as a function of these reagents. Our results, in conjunction with data on the physical interactions of cytoskeletal proteins, suggest that the diffusion effector molecules alter the lateral mobility of erythrocyte membrane proteins through modifications of interactions in the shell, which is composed of spectrin, actin, and component 4.1.

An aberrant vascular channel in the petrous bone: persistent lateral capital vein?

International Nuclear Information System (INIS)

Hermans, Robert; Rensburg, Leon J. van

2009-01-01

An aberrant channel was identified on CT in the petrous bone in four patients presenting with unrelated otological symptoms. These channels occurred unilaterally in each case. In two patients, the channel was seen to run between the sigmoid sinus sulcus and the superior petrosal sinus sulcus; in one of these patients, a vascular structure was identified within this channel on MRI, connecting the sigmoid sinus and the superior petrosal sinus. In the two other patients, an aberrant channel was seen between the superior petrosal sinus sulcus and the posterior genu of the facial nerve canal. There were no symptoms that could be attributed to the presence of these channels. We postulate that these aberrant vascular channels correspond to a persistent embryological vein, the lateral capital vein. (orig.)

An aberrant vascular channel in the petrous bone: persistent lateral capital vein?

Energy Technology Data Exchange (ETDEWEB)

Hermans, Robert [University Hospitals Leuven, Department of Radiology, Leuven (Belgium); Rensburg, Leon J. van [University of the Western Cape, Department of Radiology and Diagnostics, Tygerberg (South Africa)

2009-12-15

An aberrant channel was identified on CT in the petrous bone in four patients presenting with unrelated otological symptoms. These channels occurred unilaterally in each case. In two patients, the channel was seen to run between the sigmoid sinus sulcus and the superior petrosal sinus sulcus; in one of these patients, a vascular structure was identified within this channel on MRI, connecting the sigmoid sinus and the superior petrosal sinus. In the two other patients, an aberrant channel was seen between the superior petrosal sinus sulcus and the posterior genu of the facial nerve canal. There were no symptoms that could be attributed to the presence of these channels. We postulate that these aberrant vascular channels correspond to a persistent embryological vein, the lateral capital vein. (orig.)

Analysis of Multipath Mitigation Techniques with Land Mobile Satellite Channel Model

Directory of Open Access Journals (Sweden)

M. Z. H. Bhuiyan J. Zhang

2012-12-01

is of utmost importance to analyze the performance of different multipath mitigation techniques in some realistic measurement-based channel models, for example, the Land Mobile Satellite (LMS channel model [1]-[4], developed at the German Aerospace Center (DLR. The DLR LMS channel model is widely used for simulating the positioning accuracy of mobile satellite navigation receivers in urban outdoor scenarios. The main objective of this paper is to present a comprehensive analysis of some of the most promising techniques with the DLR LMS channel model in varying multipath scenarios. Four multipath mitigation techniques are chosen herein for performance comparison, namely, the narrow Early-Minus-Late (nEML, the High Resolution Correlator, the C/N0-based two stage delay tracking technique, and the Reduced Search Space Maximum Likelihood (RSSML delay estimator. The first two techniques are the most popular and traditional ones used in nowadays GNSS receivers, whereas the later two techniques are comparatively new and are advanced techniques, recently proposed by the authors. In addition, the implementation of the RSSML is optimized here for a narrow-bandwidth receiver configuration in the sense that it now requires a significantly less number of correlators and memory than its original implementation. The simulation results show that the reduced-complexity RSSML achieves the best multipath mitigation performance in moderate-to-good carrier-to-noise density ratio with the DLR LMS channel model in varying multipath scenarios.

Effective Scheme of Channel Tracking and Estimation for Mobile WiMAX DL-PUSC System

Directory of Open Access Journals (Sweden)

Phuong Thi Thu Pham

2010-01-01

Full Text Available This paper introduces an effective joint scheme of channel estimation and tracking for downlink partial usage of subchannel (DL-PUSC mode of mobile WiMAX system. Based on the pilot pattern of this particular system, some channel estimation methods including conventional interpolations and a more favorable least-squares line fitting (LSLF technique are comparatively studied. Besides, channel estimation performance can be remarkably improved by taking advantage of channel tracking derived from the preamble symbol. System performances in terms of packet error rate (PER and user link throughput are investigated in various channels adopted from the well-known ITU models for mobile environments. Simulation results show a significant performance enhancement when the proposed joint scheme is utilized, at least 5 dB, compared to only commonly used channel estimation approaches.

Method for Evaluation of Outage Probability on Random Access Channel in Mobile Communication Systems

Science.gov (United States)

Kollár, Martin

2012-05-01

In order to access the cell in all mobile communication technologies a so called random-access procedure is used. For example in GSM this is represented by sending the CHANNEL REQUEST message from Mobile Station (MS) to Base Transceiver Station (BTS) which is consequently forwarded as an CHANNEL REQUIRED message to the Base Station Controller (BSC). If the BTS decodes some noise on the Random Access Channel (RACH) as random access by mistake (so- called ‘phantom RACH') then it is a question of pure coincidence which èstablishment cause’ the BTS thinks to have recognized. A typical invalid channel access request or phantom RACH is characterized by an IMMEDIATE ASSIGNMENT procedure (assignment of an SDCCH or TCH) which is not followed by sending an ESTABLISH INDICATION from MS to BTS. In this paper a mathematical model for evaluation of the Power RACH Busy Threshold (RACHBT) in order to guaranty in advance determined outage probability on RACH is described and discussed as well. It focuses on Global System for Mobile Communications (GSM) however the obtained results can be generalized on remaining mobile technologies (ie WCDMA and LTE).

Evidence from lateral mobility studies for dynamic interactions of a mutant influenza hemagglutinin with coated pits.

Science.gov (United States)

Fire, E; Zwart, D E; Roth, M G; Henis, Y I

1991-12-01

Replacement of cysteine at position 543 by tyrosine in the influenza virus hemagglutinin (HA) protein enables the endocytosis of the mutant protein (Tyr 543) through coated pits (Lazarovits, J., and M. G. Roth. 1988. Cell. 53:743-752). To investigate the interactions between Tyr 543 and the clathrin coats in the plasma membrane of live cells, we performed fluorescence photobleaching recovery measurements comparing the lateral mobilities of Tyr 543 (which enters coated pits) and wild-type HA (HA wt, which is excluded from coated pits), following their expression in CV-1 cells by SV-40 vectors. While both proteins exhibited the same high mobile fractions, the lateral diffusion rate of Tyr 543 was significantly slower than that of HA wt. Incubation of the cells in a sucrose-containing hypertonic medium, a treatment that disperses the membrane-associated coated pits, resulted in similar lateral mobilities for Tyr 543 and HA wt. These findings indicate that the lateral motion of Tyr 543 (but not of HA wt) is inhibited by transient interactions with coated pits (which are essentially immobile on the time scale of the lateral mobility measurements). Acidification of the cytoplasm by prepulsing the cells with NH4Cl (a treatment that arrests the pinching-off of coated vesicles from the plasma membrane and alters the clathrin lattice morphology) led to immobilization of a significant part of the Tyr 543 molecules, presumably due to their entrapment in coated pits for the entire duration of the lateral mobility measurement. Furthermore, in both untreated and cytosol-acidified cells, the restrictions on Tyr 543 mobility were less pronounced in the cold, suggesting that the mobility-restricting interactions are temperature dependent and become weaker at low temperatures. From these studies we conclude the following. (a) Lateral mobility measurements are capable of detecting interactions of transmembrane proteins with coated pits in intact cells. (b) The interactions of Tyr 543

Hard Fusion Based Spectrum Sensing over Mobile Fading Channels in Cognitive Vehicular Networks.

Science.gov (United States)

Qian, Xiaomin; Hao, Li; Ni, Dadong; Tran, Quang Thanh

2018-02-06

An explosive growth in vehicular wireless applications gives rise to spectrum resource starvation. Cognitive radio has been used in vehicular networks to mitigate the impending spectrum starvation problem by allowing vehicles to fully exploit spectrum opportunities unoccupied by licensed users. Efficient and effective detection of licensed user is a critical issue to realize cognitive radio applications. However, spectrum sensing in vehicular environments is a very challenging task due to vehicle mobility. For instance, vehicle mobility has a large effect on the wireless channel, thereby impacting the detection performance of spectrum sensing. Thus, gargantuan efforts have been made in order to analyze the fading properties of mobile radio channel in vehicular environments. Indeed, numerous studies have demonstrated that the wireless channel in vehicular environments can be characterized by a temporally correlated Rayleigh fading. In this paper, we focus on energy detection for spectrum sensing and a counting rule for cooperative sensing based on Neyman-Pearson criteria. Further, we go into the effect of the sensing and reporting channel conditions on the sensing performance under the temporally correlated Rayleigh channel. For local and cooperative sensing, we derive some alternative expressions for the average probability of misdetection. The pertinent numerical and simulating results are provided to further validate our theoretical analyses under a variety of scenarios.

Channels of Social Mobility of Russian Society: World War I influence

Directory of Open Access Journals (Sweden)

Vadim M. Rynkov

2016-09-01

Full Text Available The article deals with World War I influence on dynamics of social processes in Russia. The subject of the research is limited by the channels of social mobility, which mean horizontal or mainly horizontal movement in social space. The conclusions are based on studying statistic sources and modern historiography. In 1914–1917 due to war influence severe deformation of previously stable working channels of social mobility took place. Large groups of people who had not had any prerequisites of social status change started to migrate. Some channels almost stopped working, such as agrarian migration, seasonal work, but some new ones emerged, such as refugees, captivity, desertion. The war effaced estates boundaries and deformed class groups. Produced by war, the processes of society restructuring are characterized by high level of social entropy – the most important prerequisite of revolutionary explosion of 1917.

Hall effect mobility for SiC MOSFETs with increasing dose of nitrogen implantation into channel region

Science.gov (United States)

Noguchi, Munetaka; Iwamatsu, Toshiaki; Amishiro, Hiroyuki; Watanabe, Hiroshi; Kita, Koji; Yamakawa, Satoshi

2018-04-01

The Hall effect mobility (μHall) of the Si-face 4H-SiC metal–oxide–semiconductor field effect transistor (MOSFET) with a nitrogen (N)-implanted channel region was investigated by increasing the N dose. The μHall in the channel region was systematically examined regarding channel structures, that is, the surface and buried channels. It was experimentally demonstrated that increasing the N dose results in an improvement in μHall in the channel region due to the formation of the buried channel. However, further increase in N dose was found to decrease the μHall in the channel region, owing to the decrease in the electron mobility in the N-implanted bulk region.

Polymer ferroelectric field-effect memory device with SnO channel layer exhibits record hole mobility

KAUST Repository

Caraveo-Frescas, Jesus Alfonso; Khan, M. A.; Alshareef, Husam N.

2014-01-01

Here we report for the first time a hybrid p-channel polymer ferroelectric field-effect transistor memory device with record mobility. The memory device, fabricated at 200C on both plastic polyimide and glass substrates, uses ferroelectric polymer P(VDF-TrFE) as the gate dielectric and transparent p-type oxide (SnO) as the active channel layer. A record mobility of 3.3 cm 2V-1s-1, large memory window (~16 V), low read voltages (~-1 V), and excellent retention characteristics up to 5000 sec have been achieved. The mobility achieved in our devices is over 10 times higher than previously reported polymer ferroelectric field-effect transistor memory with p-type channel. This demonstration opens the door for the development of non-volatile memory devices based on dual channel for emerging transparent and flexible electronic devices.

Polymer ferroelectric field-effect memory device with SnO channel layer exhibits record hole mobility

KAUST Repository

Caraveo-Frescas, Jesus Alfonso

2014-06-10

Here we report for the first time a hybrid p-channel polymer ferroelectric field-effect transistor memory device with record mobility. The memory device, fabricated at 200C on both plastic polyimide and glass substrates, uses ferroelectric polymer P(VDF-TrFE) as the gate dielectric and transparent p-type oxide (SnO) as the active channel layer. A record mobility of 3.3 cm 2V-1s-1, large memory window (~16 V), low read voltages (~-1 V), and excellent retention characteristics up to 5000 sec have been achieved. The mobility achieved in our devices is over 10 times higher than previously reported polymer ferroelectric field-effect transistor memory with p-type channel. This demonstration opens the door for the development of non-volatile memory devices based on dual channel for emerging transparent and flexible electronic devices.

The Mobility and Dispersal of Augmented Gravel in Upland Channels: a Knowledge-limited Practise in Supply-limited Channels

Science.gov (United States)

Downs, P. W.; Gilvear, D. J.

2017-12-01

Most river restoration research has been directed at rivers in the highly populated alluvial lowlands: significantly less is known about effectively rehabilitating upland channels, in part because the dynamics of sediment transfer are less well understood. Upland gravel augmentation is thus both a somewhat unproven method for rehabilitating degraded aquatic habitats in sediment-poor reaches, but also a natural experiment in better understanding sediment dynamics in steep, hydraulically-complex river channels. Monitoring on the River Avon in SW England since Water Year (WY) 2015 uses seismic impact plates, RFID-tagged particles and detailed channel bed mapping to establish the mobility rates of augmented particles, their dispersal distances and settling locations relative to flows received. Particles are highly, and equally, mobile: in WY2015, 17 sub-bankfull flows moved at least 60% of augmented particles with volumetric movement non-linearly correlated to flow energy but not to particle size. Waning rates of transport over the year suggest supply limitations. This relationship breaks down early in WY2017 where a two-year flow event moved 40% of the particles in just two months - confounding factors may include particle mass differences and particle supplies from upstream. Median particle travel distances correlate well to energy applied and suggest a long-tailed fan of dispersal with supplemental controls including channel curvature, boulder presence and stream power. Locally, particles are deposited preferentially around boulders and in sheltered river margins but also perched in clusters above the low-flow channel. High tracer mobility makes median transport distances highly dependent on the survey length - in WY2017 some particles travelled 300 m in a 3-month period that included the two-year flood event. Further, in WY2017 median transport distance as a function of volumetric transport suggested significant transport beyond the target reach. The observed

Instability of shallow open channel flow with lateral velocity gradients

Energy Technology Data Exchange (ETDEWEB)

Lima, A C; Izumi, N, E-mail: adriano@eng.hokudai.ac.jp, E-mail: nizumi@eng.hokudai.ac.jp [River and Watershed Engineering Laboratory, Hokkaido University, Sapporo, 060-8628 (Japan)

2011-12-22

The turbulent flow in a wide rectangular open channel partially covered with vegetation is studied using linear stability analysis. In the base state normal flow condition, the water depth is constant and the transverse velocity vanishes, while there is a lateral gradient in the streamwise velocity with an inflexion point at the boundary between the vegetated zone and the main channel. The Reynolds stress is expressed by introducing the eddy viscosity, which is obtained from assuming a logarithmic distribution of the velocity near the bed. Perturbation expansions are introduced to the streamwise and transverse velocities, as well as to the water depth. The system of governing equations was solved in order to determine the maximum growth rate of the perturbations as a function of parameters which describe physical characteristics of the channel and the flow.

Lateral mobility of plasma membrane lipids in dividing Xenopus eggs

NARCIS (Netherlands)

Laat, S.W. de; Tetteroo, P.A.T.; Bluemink, J.G.; Dictus, W.J.A.G.; Zoelen, E.J.J. van

1984-01-01

The lateral mobility of plasma membrane lipids was analyzed during first cleavage of Xaopus Levis eggs by fluorescence photobleaching recovery (FPR) measurements, using the lipid analogs 5-(N-hexadecanoyl)aminofluorescein (“HEDAF”) and 5-(N-tetradecanoyl)aminofluorescein (“TEDAF”) as probes. The

Developing and exploring a theory for the lateral erosion of bedrock channels for use in landscape evolution models

Directory of Open Access Journals (Sweden)

A. L. Langston

2018-01-01

Full Text Available Understanding how a bedrock river erodes its banks laterally is a frontier in geomorphology. Theories for the vertical incision of bedrock channels are widely implemented in the current generation of landscape evolution models. However, in general existing models do not seek to implement the lateral migration of bedrock channel walls. This is problematic, as modeling geomorphic processes such as terrace formation and hillslope–channel coupling depends on the accurate simulation of valley widening. We have developed and implemented a theory for the lateral migration of bedrock channel walls in a catchment-scale landscape evolution model. Two model formulations are presented, one representing the slow process of widening a bedrock canyon and the other representing undercutting, slumping, and rapid downstream sediment transport that occurs in softer bedrock. Model experiments were run with a range of values for bedrock erodibility and tendency towards transport- or detachment-limited behavior and varying magnitudes of sediment flux and water discharge in order to determine the role that each plays in the development of wide bedrock valleys. The results show that this simple, physics-based theory for the lateral erosion of bedrock channels produces bedrock valleys that are many times wider than the grid discretization scale. This theory for the lateral erosion of bedrock channel walls and the numerical implementation of the theory in a catchment-scale landscape evolution model is a significant first step towards understanding the factors that control the rates and spatial extent of wide bedrock valleys.

Developing and exploring a theory for the lateral erosion of bedrock channels for use in landscape evolution models

Science.gov (United States)

Langston, Abigail L.; Tucker, Gregory E.

2018-01-01

Understanding how a bedrock river erodes its banks laterally is a frontier in geomorphology. Theories for the vertical incision of bedrock channels are widely implemented in the current generation of landscape evolution models. However, in general existing models do not seek to implement the lateral migration of bedrock channel walls. This is problematic, as modeling geomorphic processes such as terrace formation and hillslope-channel coupling depends on the accurate simulation of valley widening. We have developed and implemented a theory for the lateral migration of bedrock channel walls in a catchment-scale landscape evolution model. Two model formulations are presented, one representing the slow process of widening a bedrock canyon and the other representing undercutting, slumping, and rapid downstream sediment transport that occurs in softer bedrock. Model experiments were run with a range of values for bedrock erodibility and tendency towards transport- or detachment-limited behavior and varying magnitudes of sediment flux and water discharge in order to determine the role that each plays in the development of wide bedrock valleys. The results show that this simple, physics-based theory for the lateral erosion of bedrock channels produces bedrock valleys that are many times wider than the grid discretization scale. This theory for the lateral erosion of bedrock channel walls and the numerical implementation of the theory in a catchment-scale landscape evolution model is a significant first step towards understanding the factors that control the rates and spatial extent of wide bedrock valleys.

Extended Kalman Filter Channel Estimation for Line-of-Sight Detection in WCDMA Mobile Positioning

Directory of Open Access Journals (Sweden)

Abdelmonaem Lakhzouri

2003-12-01

Full Text Available In mobile positioning, it is very important to estimate correctly the delay between the transmitter and the receiver. When the receiver is in line-of-sight (LOS condition with the transmitter, the computation of the mobile position in two dimensions becomes straightforward. In this paper, the problem of LOS detection in WCDMA for mobile positioning is considered, together with joint estimation of the delays and channel coefficients. These are very challenging topics in multipath fading channels because LOS component is not always present, and when it is present, it might be severely affected by interfering paths spaced at less than one chip distance (closely spaced paths. The extended Kalman filter (EKF is used to estimate jointly the delays and complex channel coefficients. The decision whether the LOS component is present or not is based on statistical tests to determine the distribution of the channel coefficient corresponding to the first path. The statistical test-based techniques are practical, simple, and of low computation complexity, which is suitable for WCDMA receivers. These techniques can provide an accurate decision whether LOS component is present or not.

Lateral current generation in n-AlGaAs/GaAs heterojunction channels by Schottky-barrier gate illumination

Energy Technology Data Exchange (ETDEWEB)

Kawazu, Takuya; Noda, Takeshi; Sakuma, Yoshiki [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Sakaki, Hiroyuki [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Toyota Technological Institute, 2-12-1 Hisakata, Tempaku-ku, Nagoya 468-8511 (Japan)

2015-01-12

We observe lateral currents induced in an n-AlGaAs/GaAs heterojunction channel of Hall bar geometry, when an asymmetric position of the Schottky metal gate is locally irradiated by a near-infrared laser beam. When the left side of the Schottky gate is illuminated with the laser, the lateral current flows from left to right in the two dimensional electron gas (2DEG) channel. In contrast, the right side illumination leads to the current from right to left. The magnitude of the lateral current is almost linearly dependent on the beam position, the current reaching its maximum for the beam at the edge of the Schottky gate. The experimental findings are well explained by a theory based on the current-continuity equation, where the lateral current in the 2DEG channel is driven by the photocurrent which vertically flows from the 2DEG to the Schottky gate.

News Media Channels : Complements or Substitutes? Evidence from Mobile Phone Usage

NARCIS (Netherlands)

Xu, Jiao; Forman, Chris; Kim, Jun B.; Van Ittersum, Koert

The media industry has undergone a fundamental shift over the past decade as new online distribution channels have proliferated in an unprecedented manner. Although mobile devices have experienced rapid adoption among consumers, their effect on consumer behavior and their subsequent implications for

Indium–gallium–zinc oxide thin film transistors with a hybrid-channel structure for defect suppression and mobility improvement

International Nuclear Information System (INIS)

Lin, Huang-Kai; Su, Liang-Yu; Hung, Chia-Chin; Huang, JianJang

2013-01-01

In this work, we explore an indium gallium zinc oxide (IGZO) thin film transistor structure with a vacuum annealed IGZO thin film inserted between the dielectric and typical channel layers. The device demonstrates a better subthreshold swing and field-effect mobility due to the suppression of defects in the channel and the channel/dielectric interface. The hybrid channel structure also exhibits the flexibility of adjusting the threshold voltage. The superior carrier mobility was then verified from the transient response of the inverter circuit constructed by the devices. - Highlights: • Additional in-situ annealed In–Ga–ZnO film was inserted in thin film transistor (TFT). • Traps are suppressed and field effect mobility is improved in the TFT. • An inverter with the device structure has a better transient response

Indium–gallium–zinc oxide thin film transistors with a hybrid-channel structure for defect suppression and mobility improvement

Energy Technology Data Exchange (ETDEWEB)

Lin, Huang-Kai; Su, Liang-Yu; Hung, Chia-Chin [Graduate Institute of Photonics and Optoelectronics, National Taiwan University, 1, Roosevelt Road, Sec. 4, Taipei 106, Taiwan (China); Huang, JianJang, E-mail: jjhuang@cc.ee.ntu.edu.tw [Graduate Institute of Photonics and Optoelectronics, National Taiwan University, 1, Roosevelt Road, Sec. 4, Taipei 106, Taiwan (China); Department of Electrical Engineering, National Taiwan University, 1, Roosevelt Road, Sec. 4, Taipei 106, Taiwan (China)

2013-07-01

In this work, we explore an indium gallium zinc oxide (IGZO) thin film transistor structure with a vacuum annealed IGZO thin film inserted between the dielectric and typical channel layers. The device demonstrates a better subthreshold swing and field-effect mobility due to the suppression of defects in the channel and the channel/dielectric interface. The hybrid channel structure also exhibits the flexibility of adjusting the threshold voltage. The superior carrier mobility was then verified from the transient response of the inverter circuit constructed by the devices. - Highlights: • Additional in-situ annealed In–Ga–ZnO film was inserted in thin film transistor (TFT). • Traps are suppressed and field effect mobility is improved in the TFT. • An inverter with the device structure has a better transient response.

A new channel allocation scheme and performance optimizing for mobile multimedia wireless networks

Institute of Scientific and Technical Information of China (English)

ZHAO Fang-ming; JIANG Ling-ge; MA Ming-da

2008-01-01

A multimedia channel allocation scheme is proposed and studied in terms of the connection-level QoS. A new traffic model based on multidimensional Markov chain is developed considering the traffic charac-teristic of two special periods of time. And the pre-emptive priority strategies are used to classify real-time serv-ices and non-real-time services. Real-time service is given higher priority for its allowance to pre-empt channels used by non-real-time service. Considering the mobility of persons in a day, which affects the mobile user's den-sity, the simulation was conducted involving the two pre-emptive priority strategies. The result of some compari-sons shows the feasibility of the proposed scheme.

Tracking- and Scintillation-Aware Channel Model for GEO Satellite to Land Mobile Terminals at Ku-Band

Directory of Open Access Journals (Sweden)

Ali M. Al-Saegh

2015-01-01

Full Text Available Recent advances in satellite to land mobile terminal services and technologies, which utilize high frequencies with directional antennas, have made the design of an appropriate model for land mobile satellite (LMS channels a necessity. This paper presents LMS channel model at Ku-band with features that enhance accuracy, comprehensiveness, and reliability. The effect of satellite tracking loss at different mobile terminal speeds is considered for directional mobile antenna systems, a reliable tropospheric scintillation model for an LMS scenario at tropical and temperate regions is presented, and finally a new quality indicator module for different modulation and coding schemes is included. The proposed extended LMS channel (ELMSC model is designed based on actual experimental measurements and can be applied to narrow- and wide-band signals at different regions and at different speeds and multichannel states. The proposed model exhibits lower root mean square error (RMSE and significant performance observation compared with the conventional model in terms of the signal fluctuations, fade depth, signal-to-noise ratio (SNR, and quality indicators accompanied for several transmission schemes.

Sedimentation rate and lateral migration of tidal channels in the Lagoon of Venice (Northern Italy)

Science.gov (United States)

Donnici, Sandra; Madricardo, Fantina; Serandrei-Barbero, Rossana

2017-11-01

Tidal channels are crucial for the functioning of highly valuable coastal environments, such as estuaries and lagoons. Their properties, however, are currently less understood than those of river systems. To elucidate their past behaviour, an extensive geophysical investigation was performed to reconstruct the evolution of channels and tidal surfaces in the central part of the Lagoon of Venice (Italy) over the past 5000 years. Comparing high-spatial-resolution acoustic data and sedimentary facies analyses of 41 cores, 29 of which were radiocarbon dated, revealed the sedimentation rates in different lagoonal environments and allowed the migration of two large meanders to be reconstructed. The average sedimentation rate of the study succession in the different sedimentary environments was 1.27 mm yr-1. The lateral migration rates were 13-23 m/century. This estimate is consistent with the lateral migration rates determined by comparing aerial photographs of recent channels. Comparing the buried channels with historical and current maps showed that, in general, the number of active channels is now reduced. Their morphology was sometimes simplified by artificial interventions. An understanding of the impact of the artificial interventions over time is useful for the management and conservation of tidal environments, particularly for the Lagoon of Venice, where management authorities are currently debating the possible deepening and rectification of large navigation channels.

Investigating the Lateral Mixing Coefficient in a Compound Channel with Emergent Vegetation over the Floodplain

Directory of Open Access Journals (Sweden)

Hossein hamidifar

2017-02-01

Full Text Available Introduction: Water quality control is very important for people, animals and plants. Predicting the spread of contaminants is important for managing and protecting rivers and streams to the balance of the ecosystem. Pollutants are introduced into waterways, though a variety of sources such as point and non-point sources. Under steady state conditions, where longitudinal mixing is not significant, studying the lateral mixing is essential in evaluating the influence of pollutants on water quality. Lateral or transverse mixing is the hydraulic process by which a plume of contaminant spreads laterally and dilutes. In water quality management, the transverse mixing is more significant than either vertical or longitudinal dispersion, especially, when dealing with the release of wastes from point sources. Hence, a wide range of field, laboratory and numerical modelling approaches, including laboratory and field measurements, and analytical and numerical investigations have been developed, to quantify the lateral mixing coefficient. However, most of the researchers have ignored the effects of vegetation on the lateral mixing process in their studies. Many studies have shown that the flow characteristics through vegetation are different from those in non-vegetated waterways. For example, laboratory studies have revealed that flow velocity and large-scale turbulence tend to be greatly decreased within a plant canopy, because the resistance to flow by the vegetation. Also, vegetation affects the transport of dissolved and particulate material, such as sediment, nutrients and pollutants. In this study, the effect of the floodplain vegetation on lateral mixing coefficient in compound channels is investigated experimentally. Also, a comparison is made between the results of the present study with those obtained by previous researchers. Materials and Methods: Experiments were carried out in a laboratory flume 18m long, 0.9m wide and 0.6m high with an

Channel mobility degradation and charge trapping in high-k/metal gate NMOSFETs

International Nuclear Information System (INIS)

Mathew, Shajan; Bera, L.K.; Balasubramanian, N.; Joo, M.S.; Cho, B.J.

2004-01-01

NMOSFETs with Metalo-Organic Chemical Vapor Deposited (MOCVD) HfAlO gate dielectric and TiN metal gate have been fabricated. Channel electron mobility was measured using the split-CV method and compared with SiO 2 devices. All high-k devices showed lower mobility compared with SiO 2 reference devices. High-k MOSFETs exhibited significant charge trapping and threshold instability. Threshold voltage recovery with time was studied on devices with oxide/nitride interfacial layer between high-k film and silicon substrate

Lateral mobility of minibasins during shortening: Insights from the SE Precaspian Basin, Kazakhstan

Science.gov (United States)

Duffy, Oliver B.; Fernandez, Naiara; Hudec, Michael R.; Jackson, Martin P. A.; Burg, George; Dooley, Tim P.; Jackson, Christopher A.-L.

2017-04-01

Minibasin provinces are widespread and can be found in all types of salt tectonic settings, many of which are prone to shortening. Previous studies of how minibasin provinces shorten assume that the salt between the minibasins is homogeneous and that the base of salt is flat or of low relief, such that minibasins are free to move laterally. Here we investigate how minibasin provinces respond to shortening when the lateral mobility of the minibasins is restricted by intra-salt sediment bodies, in order to gain a greater understanding of the controls on the structural styles and modes of tectono-stratigraphic evolution exhibited in minibasin provinces. We examine a borehole-constrained, 3D seismic reflection dataset from the SE Precaspian Basin (onshore western Kazakhstan). The study area is characterised by large, supra-salt minibasins and an array of smaller intra-salt sediment packages distributed between these larger minibasins. We first outline the evidence of episodic shortening between the Late Triassic and present, after the onset of supra-salt minibasin subsidence. Next, we document spatial variations in shortening style, showing how these relate to the concentration of intra-salt sediment packages. Finally, we develop synoptic models showing how intra-salt sediment packages influence both the lateral mobility of minibasins during shortening and the resultant structural style, and we compare and contrast our findings with existing models and other natural examples of shortened minibasin provinces. We conclude that minibasin provinces may have different degrees of lateral mobility depending on the presence, or absence, of intrasalt barriers, and that these variations provide a first-order control on basin-shortening style and tectono-stratigraphic evolution.

Scattering and mobility in indium gallium arsenide channel, pseudomorphic high electron mobility transistors (InGaAs pHEMTs)

International Nuclear Information System (INIS)

Pearson, J.L.

1999-03-01

Extensive transport measurements have been completed on deep and shallow-channelled InGaAs p-HEMTs of varying growth temperature, indium content, spacer thickness and doping density, with a view to a thorough characterisation, both in the metallic and the localised regimes. Particular emphasis was given to MBE grown layers, with characteristics applicable for device use, but low measurement temperatures were necessary to resolve the elastic scattering mechanisms. Measurements made in the metallic regime included transport and quantum mobility - the former over a range of temperatures between 1.5K to 300K. Conductivity measurements were also acquired in the strong localisation regime between about 1.5K and 100K. Experimentally determined parameters were tested for comparison with those predicted by an electrostatic model. Excellent agreement was obtained for carrier density. Other parameters were less well predicted, but the relevant experimental measurements, including linear depletion of the 2DEG, were sensitive to any excess doping above a 'critical' value determined by the model. At low temperature (1.5K), it was found that in all samples tested, transport mobility was strongly limited at all carrier densities by a large q mechanism, possibly intrinsic to the channel. This was ascribed either to scattering by the long-range potentials arising from the indium concentration fluctuations or fluctuations in the thickness of the channel layer. This mechanism dominates the transport at low carrier densities for all samples, but at high carrier density, an additional mechanism is significant for samples with the thinnest spacers tested (2.5nm). This is ascribed to direct electron interaction with the states of the donor layer, and produces a characteristic transport mobility peak. At higher carrier densities, past the peak, quantum mobility was found only to increase monotonically in value. Remote ionised impurity scattering while significant, particularly for samples

Exploiting the pliability and lateral mobility of Pickering emulsion for enhanced vaccination

Science.gov (United States)

Xia, Yufei; Wu, Jie; Wei, Wei; Du, Yiqun; Wan, Tao; Ma, Xiaowei; An, Wenqi; Guo, Aiying; Miao, Chunyu; Yue, Hua; Li, Shuoguo; Cao, Xuetao; Su, Zhiguo; Ma, Guanghui

2018-02-01

A major challenge in vaccine formulations is the stimulation of both the humoral and cellular immune response for well-defined antigens with high efficacy and safety. Adjuvant research has focused on developing particulate carriers to model the sizes, shapes and compositions of microbes or diseased cells, but not antigen fluidity and pliability. Here, we develop Pickering emulsions--that is, particle-stabilized emulsions that retain the force-dependent deformability and lateral mobility of presented antigens while displaying high biosafety and antigen-loading capabilities. Compared with solid particles and conventional surfactant-stabilized emulsions, the optimized Pickering emulsions enhance the recruitment, antigen uptake and activation of antigen-presenting cells, potently stimulating both humoral and cellular adaptive responses, and thus increasing the survival of mice upon lethal challenge. The pliability and lateral mobility of antigen-loaded Pickering emulsions may provide a facile, effective, safe and broadly applicable strategy to enhance adaptive immunity against infections and diseases.

Mid-term results of lateral unicondylar mobile bearing knee arthroplasty: a multicentre study of 363 cases.

Science.gov (United States)

Walker, T; Zahn, N; Bruckner, T; Streit, M R; Mohr, G; Aldinger, P R; Clarius, M; Gotterbarm, T

2018-01-01

The aim of this independent multicentre study was to assess the mid-term results of mobile bearing unicondylar knee arthroplasty (UKA) for isolated lateral osteoarthritis of the knee joint. We retrospectively evaluated 363 consecutive, lateral UKAs (346 patients) performed using the Oxford domed lateral prosthesis undertaken in three high-volume knee arthroplasty centres between 2006 and 2014. Mean age of the patients at surgery was 65 years (36 to 88) with a mean final follow-up of 37 months (12 to 93) RESULTS: A total of 36 (10.5%) patients underwent revision surgery, giving a survival rate of 90.1% at three years (95% confidence intervals (CI) 86.1 to 93.1; number at risk: 155) and 85.0% at five years (95% CI 77.9 to 89.9; number at risk: 43). Dislocation of the mobile bearing occurred in 18 patients (5.6%) at three years (95% CI 1.0 to 16.4; number at risk: 154) and in 20 patients (8.5%) at five years (95% CI 1.0 to 27.0; number at risk: 42). There were no significant differences in the dislocation rate between the participating centres or the surgeons. We were not able to identify an effect of each surgeon's learning curve on the dislocation rate of the mobile bearing. The clinical outcome in patients without revision surgery at final follow-up was good to excellent, with a mean Oxford knee score of 40.3 (95% CI 39.4 to 41.2), a mean Tegner activity score of 3.2 (95% CI 3.1 to 3.3) and a mean University of California, Los Angeles score of 5.7 (95% CI 5.5 to 5.9). Our data, which consists of a high number of patients treated with mobile bearing UKA in the lateral compartment, indicates a high revision rate of 15% at five years with dislocation of the mobile bearing being the main reason for implant failure. Despite the good functional and clinical results and the high patient satisfaction in our study group, we therefore discontinued using mobile-bearing lateral UKA in favour of a fixed-bearing component. Cite this article: Bone Joint J 2018;100-B:42-9. ©2018

Monte Carlo simulation of ballistic transport in high-mobility channels

Energy Technology Data Exchange (ETDEWEB)

Sabatini, G; Marinchio, H; Palermo, C; Varani, L; Daoud, T; Teissier, R [Institut d' Electronique du Sud (CNRS UMR 5214) - Universite Montpellier II (France); Rodilla, H; Gonzalez, T; Mateos, J, E-mail: sabatini@ies.univ-montp2.f [Departamento de Fisica Aplicada - Universidad de Salamanca (Spain)

2009-11-15

By means of Monte Carlo simulations coupled with a two-dimensional Poisson solver, we evaluate directly the possibility to use high mobility materials in ultra fast devices exploiting ballistic transport. To this purpose, we have calculated specific physical quantities such as the transit time, the transit velocity, the free flight time and the mean free path as functions of applied voltage in InAs channels with different lengths, from 2000 nm down to 50 nm. In this way the transition from diffusive to ballistic transport is carefully described. We remark a high value of the mean transit velocity with a maximum of 14x10{sup 5} m/s for a 50 nm-long channel and a transit time shorter than 0.1 ps, corresponding to a cutoff frequency in the terahertz domain. The percentage of ballistic electrons and the number of scatterings as functions of distance are also reported, showing the strong influence of quasi-ballistic transport in the shorter channels.

Monte Carlo simulation of ballistic transport in high-mobility channels

International Nuclear Information System (INIS)

Sabatini, G; Marinchio, H; Palermo, C; Varani, L; Daoud, T; Teissier, R; Rodilla, H; Gonzalez, T; Mateos, J

2009-01-01

By means of Monte Carlo simulations coupled with a two-dimensional Poisson solver, we evaluate directly the possibility to use high mobility materials in ultra fast devices exploiting ballistic transport. To this purpose, we have calculated specific physical quantities such as the transit time, the transit velocity, the free flight time and the mean free path as functions of applied voltage in InAs channels with different lengths, from 2000 nm down to 50 nm. In this way the transition from diffusive to ballistic transport is carefully described. We remark a high value of the mean transit velocity with a maximum of 14x10 5 m/s for a 50 nm-long channel and a transit time shorter than 0.1 ps, corresponding to a cutoff frequency in the terahertz domain. The percentage of ballistic electrons and the number of scatterings as functions of distance are also reported, showing the strong influence of quasi-ballistic transport in the shorter channels.

Understanding determinants of consumer mobile health usage intentions, assimilation, and channel preferences.

Science.gov (United States)

Rai, Arun; Chen, Liwei; Pye, Jessica; Baird, Aaron

2013-08-02

Consumer use of mobile devices as health service delivery aids (mHealth) is growing, especially as smartphones become ubiquitous. However, questions remain as to how consumer traits, health perceptions, situational characteristics, and demographics may affect consumer mHealth usage intentions, assimilation, and channel preferences. We examine how consumers' personal innovativeness toward mobile services (PIMS), perceived health conditions, health care availability, health care utilization, demographics, and socioeconomic status affect their (1) mHealth usage intentions and extent of mHealth assimilation, and (2) preference for mHealth as a complement or substitute for in-person doctor visits. Leveraging constructs from research in technology acceptance, technology assimilation, consumer behavior, and health informatics, we developed a cross-sectional online survey to study determinants of consumers' mHealth usage intentions, assimilation, and channel preferences. Data were collected from 1132 nationally representative US consumers and analyzed by using moderated multivariate regressions and ANOVA. The results indicate that (1) 430 of 1132 consumers in our sample (37.99%) have started using mHealth, (2) a larger quantity of consumers are favorable to using mHealth as a complement to in-person doctor visits (758/1132, 66.96%) than as a substitute (532/1132, 47.00%), and (3) consumers' PIMS and perceived health conditions have significant positive direct influences on mHealth usage intentions, assimilation, and channel preferences, and significant positive interactive influences on assimilation and channel preferences. The independent variables within the moderated regressions collectively explained 59.70% variance in mHealth usage intentions, 60.41% in mHealth assimilation, 34.29% in preference for complementary use of mHealth, and 45.30% in preference for substitutive use of mHealth. In a follow-up ANOVA examination, we found that those who were more favorable

Statistical Modeling, Simulation, and Experimental Verification of Wideband Indoor Mobile Radio Channels

Directory of Open Access Journals (Sweden)

Yuanyuan Ma

2018-01-01

Full Text Available This paper focuses on the modeling, simulation, and experimental verification of wideband single-input single-output (SISO mobile fading channels for indoor propagation environments. The indoor reference channel model is derived from a geometrical rectangle scattering model, which consists of an infinite number of scatterers. It is assumed that the scatterers are exponentially distributed over the two-dimensional (2D horizontal plane of a rectangular room. Analytical expressions are derived for the probability density function (PDF of the angle of arrival (AOA, the PDF of the propagation path length, the power delay profile (PDP, and the frequency correlation function (FCF. An efficient sum-of-cisoids (SOC channel simulator is derived from the nonrealizable reference model by employing the SOC principle. It is shown that the SOC channel simulator approximates closely the reference model with respect to the FCF. The SOC channel simulator enables the performance evaluation of wideband indoor wireless communication systems with reduced realization expenditure. Moreover, the rationality and usefulness of the derived indoor channel model is confirmed by various measurements at 2.4, 5, and 60 GHz.

Studies on diversion cross-flow between two parallel channels communicating by a lateral slot. II

International Nuclear Information System (INIS)

Tapucu, A.; Merilo, M.

1977-01-01

The axial pressure variations of two parallel channels with single phase flows communicating by a long lateral slot have been studied experimentally. Using mass and momentum conservation principles, the axial pressure variations have been derived in terms of two parameters ksub(d) and ksub(r), for donor and recipient channels, respectively. These parameters include the combined effect of fluid transferred from donor to recipient channel, and drag force brought on by the connection gap, and are functions of the velocities and slot geometry parameters. A pressure difference oscillation between channels along the slot has been detected which is sinusoidal with wave lengths which seem to be a function of the gap clearance. (Auth.)

Improved Mobility Performance in LTE Co-Channel HetNets Through Speed Differentiated Enhancements

DEFF Research Database (Denmark)

Barbera, Simone; Michaelsen, Per Henrik; Säily, Mikko

2012-01-01

, requiring minimum assistance and signaling from the network. Extensive system level simulations are used to quantify the benefits. Results confirm that the proposed solutions offer improvements in several mobility key performance indicators such as radio link failure, number of handovers, offload to pico......This paper analyzes the mobility performance of LTE (Long Term Evolution) co-channel heterogeneous networks (HetNet) with macro and pico cells. Improved methods for differentiating offload and mobility robustness as a function of the UE (User Equipment) mobility are proposed. The suggested solution...... comprises two key elements, namely enhanced UE MSE (Mobility State Estimation), as well as optimized methods such that high speed users are primarily kept at the macro layer, while the offload to pico cells for low speed users is maximized. The proposed methods are designed as UE autonomous solutions...

Activation of protein kinase C alters the intracellular distribution and mobility of cardiac Na+ channels.

Science.gov (United States)

Hallaq, Haifa; Wang, Dao W; Kunic, Jennifer D; George, Alfred L; Wells, K Sam; Murray, Katherine T

2012-02-01

Na(+) current derived from expression of the cardiac isoform SCN5A is reduced by receptor-mediated or direct activation of protein kinase C (PKC). Previous work has suggested a possible role for loss of Na(+) channels at the plasma membrane in this effect, but the results are controversial. In this study, we tested the hypothesis that PKC activation acutely modulates the intracellular distribution of SCN5A channels and that this effect can be visualized in living cells. In human embryonic kidney cells that stably expressed SCN5A with green fluorescent protein (GFP) fused to the channel COOH-terminus (SCN5A-GFP), Na(+) currents were suppressed by an exposure to PKC activation. Using confocal microscopy, colocalization of SCN5A-GFP channels with the plasma membrane under control and stimulated conditions was quantified. A separate population of SCN5A channels containing an extracellular epitope was immunolabeled to permit temporally stable labeling of the plasma membrane. Our results demonstrated that Na(+) channels were preferentially trafficked away from the plasma membrane by PKC activation, with a major contribution by Ca(2+)-sensitive or conventional PKC isoforms, whereas stimulation of protein kinase A (PKA) had the opposite effect. Removal of the conserved PKC site Ser(1503) or exposure to the NADPH oxidase inhibitor apocynin eliminated the PKC-mediated effect to alter channel trafficking, indicating that both channel phosphorylation and ROS were required. Experiments using fluorescence recovery after photobleaching demonstrated that both PKC and PKA also modified channel mobility in a manner consistent with the dynamics of channel distribution. These results demonstrate that the activation of protein kinases can acutely regulate the intracellular distribution and molecular mobility of cardiac Na(+) channels in living cells.

Performance Characterization of a Real-Time Massive MIMO System with LOS Mobile Channels

OpenAIRE

Harris, Paul; Malkowsky, Steffen; Vieira, Joao; Hassan, Fredrik Tufvesson Wael Boukley; Liu, Liang; Beach, Mark; Armour, Simon; Edfors, Ove

2017-01-01

The first measured results for massive multiple input, multiple-output (MIMO) performance in a line-of-sight (LOS) scenario with moderate mobility are presented, with 8 users served in real-time using a 100 antenna base Station (BS) at 3.7 GHz. When such a large number of channels dynamically change, the inherent propagation and processing delay has a critical relationship with the rate of change, as the use of outdated channel information can result in severe detection and precoding inaccura...

Single molecule microscopy on Store-Operated Calcium channels

International Nuclear Information System (INIS)

Madl, J.

2011-01-01

Store-Operated Calcium Entry is essential for many signaling processes in non-excitable cells. The best studied Store-Operated Calcium current is the Calcium-Release-Activated-Calcium (CRAC) current in T-cells and mast cells, with Orai1 representing the essential pore forming subunit. Functional CRAC channels in store-depleted cells are composed of four Orai1 subunits. However, the stoichiometric composition in resting cells is still discussed controversially: both a tetrameric and a dimeric stoichiometry of resting-state Orai1 have been reported for immobilized or immobile Orai1 proteins. The aim of this thesis was to design a more versatile approach that allows reliable determination of the subunit stoichiometry of mobile Orai1 channels. The motive for this approach is that mobile sub-fractions of the entire Orai1 population provide the cleanest pool of data, devoid of contributions e.g. from immobile Orai1 clusters or Orai1-loaded vesicles attached to the plasma membrane. Moreover, resting-state Orai1 is predominantly mobile, and mobility appears critical for the lateral redistribution which occurs upon store depletion. The method per se is based on single molecule fluorescence microscopy and brightness analysis. Orai1 proteins were fused to a monomeric variant of Green Fluorescent Protein (mGFP) and over-expressed in a human cell line (T24). The 1:1 labeling stoichiometry allows using the brightness of individual Orai1-mGFP channels as a direct measure of the pore stoichiometry. Due to over-expression a potential mixing with endogenous Orai1 can be neglected. However, over-expression of Orai1-mGFP results in channel densities that are too high to allow for resolving single channels using diffraction limited optical microscopy. In order to overcome this challenge, I developed an experimental strategy that allows reduction of the density of actively fluorescent Orai1-mGFP channels without altering the labeling stoichiometry. In order to reduce the surface density

MIMO Channel Model with Propagation Mechanism and the Properties of Correlation and Eigenvalue in Mobile Environments

Directory of Open Access Journals (Sweden)

Yuuki Kanemiyo

2012-01-01

Full Text Available This paper described a spatial correlation and eigenvalue in a multiple-input multiple-output (MIMO channel. A MIMO channel model with a multipath propagation mechanism was proposed and showed the channel matrix. The spatial correlation coefficient formula −,′−′( between MIMO channel matrix elements was derived for the model and was expressed as a directive wave term added to the product of mobile site correlation −′( and base site correlation −′( without LOS path, which are calculated independently of each other. By using −,′−′(, it is possible to create the channel matrix element with a fixed correlation value estimated by −,′−′( for a given multipath condition and a given antenna configuration. Furthermore, the correlation and the channel matrix eigenvalue were simulated, and the simulated and theoretical correlation values agreed well. The simulated eigenvalue showed that the average of the first eigenvalue λ1 hardly depends on the correlation −,′−′(, but the others do depend on −,′−′( and approach 1 as −,′−′( decreases. Moreover, as the path moves into LOS, the 1 state with mobile movement becomes more stable than the 1 of NLOS path.

Electrical characterization of Ω-gated uniaxial tensile strained Si nanowire-array metal-oxide-semiconductor field effect transistors with - and channel orientations

International Nuclear Information System (INIS)

Habicht, Stefan; Feste, Sebastian; Zhao, Qing-Tai; Buca, Dan; Mantl, Siegfried

2012-01-01

Nanowire-array metal-oxide-semiconductor field effect transistors (MOSFETs) were fabricated along and crystal directions on (001) un-/strained silicon-on-insulator substrates. Lateral strain relaxation through patterning was employed to transform biaxial tensile strain into uniaxial tensile strain along the nanowire. Devices feature ideal subthreshold swings and maximum on-current/off-current ratios of 10 11 for n and p-type transistors on both substrates. Electron and hole mobilities were extracted by split C–V method. For p-MOSFETs an increased mobility is observed for channel direction devices compared to devices. The n-MOSFETs showed a 45% increased electron mobility compared to devices. The comparison of strained and unstrained n-MOSFETs along and clearly demonstrates improved electron mobilities for strained channels of both channel orientations.

Revisiting of Channel Access Mechanisms in Mobile Wireless Networks through Exploiting Physical Layer Technologies

Directory of Open Access Journals (Sweden)

Junmei Yao

2018-01-01

Full Text Available The wireless local area networks (WLANs have been widely deployed with the rapid development of mobile devices and have further been brought into new applications with infrastructure mobility due to the growth of unmanned aerial vehicles (UAVs. However, the WLANs still face persistent challenge on increasing the network throughput to meet the customer’s requirement and fight against the node mobility. Interference is a well-known issue that would degrade the network performance due to the broadcast characteristics of the wireless signals. Moreover, with infrastructure mobility, the interference becomes the key obstacle in pursuing the channel capacity. Legacy interference management mechanism through the channel access control in the MAC layer design of the 802.11 standard has some well-known drawbacks, such as exposed and hidden terminal problems, inefficient rate adaptation, and retransmission schemes, making the efficient interference management an everlasting research topic over the years. Recently, interference management through exploiting physical layer mechanisms has attracted much research interest and has been proven to be a promising way to improve the network throughput, especially under the infrastructure mobility scenarios which provides more indicators for node dynamics. In this paper, we introduce a series of representative physical layer techniques and analyze how they are exploited for interference management to improve the network performance. We also provide some discussions about the research challenges and give potential future research topics in this area.

Lateral transport of solutes in microfluidic channels using electrochemically generated gradients in redox-active surfactants.

Science.gov (United States)

Liu, Xiaoyang; Abbott, Nicholas L

2011-04-15

We report principles for a continuous flow process that can separate solutes based on a driving force for selective transport that is generated by a lateral concentration gradient of a redox-active surfactant across a microfluidic channel. Microfluidic channels fabricated with gold electrodes lining each vertical wall were used to electrochemically generate concentration gradients of the redox-active surfactant 11-ferrocenylundecyl-trimethylammonium bromide (FTMA) in a direction perpendicular to the flow. The interactions of three solutes (a hydrophobic dye, 1-phenylazo-2-naphthylamine (yellow AB), an amphiphilic molecule, 2-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-pentanoyl)-1-hexadecanoyl-sn-glycero-3-phosphocholine (BODIPY C(5)-HPC), and an organic salt, 1-methylpyridinium-3-sulfonate (MPS)) with the lateral gradients in surfactant/micelle concentration were shown to drive the formation of solute-specific concentration gradients. Two distinct physical mechanisms were identified to lead to the solute concentration gradients: solubilization of solutes by micelles and differential adsorption of the solutes onto the walls of the microchannels in the presence of the surfactant concentration gradient. These two mechanisms were used to demonstrate delipidation of a mixture of BODIPY C(5)-HPC (lipid) and MPS and purification of BODIPY C(5)-HPC from a mixture of BODIPY C(5)-HPC and yellow AB. Overall, the results of this study demonstrate that lateral concentration gradients of redox-active surfactants formed within microfluidic channels can be used to transport solutes across the microfluidic channels in a solute-dependent manner. The approach employs electrical potentials (solutions having high ionic strength (>0.1M), and offers the basis of continuous processes for the purification or separation of solutes in microscale systems. © 2011 American Chemical Society

Surface dynamics of voltage-gated ion channels

Science.gov (United States)

Heine, Martin; Ciuraszkiewicz, Anna; Voigt, Andreas; Heck, Jennifer; Bikbaev, Arthur

2016-01-01

ABSTRACT Neurons encode information in fast changes of the membrane potential, and thus electrical membrane properties are critically important for the integration and processing of synaptic inputs by a neuron. These electrical properties are largely determined by ion channels embedded in the membrane. The distribution of most ion channels in the membrane is not spatially uniform: they undergo activity-driven changes in the range of minutes to days. Even in the range of milliseconds, the composition and topology of ion channels are not static but engage in highly dynamic processes including stochastic or activity-dependent transient association of the pore-forming and auxiliary subunits, lateral diffusion, as well as clustering of different channels. In this review we briefly discuss the potential impact of mobile sodium, calcium and potassium ion channels and the functional significance of this for individual neurons and neuronal networks. PMID:26891382

Investigation of different classifiers and channel configurations of a mobile P300-based brain-computer interface.

Science.gov (United States)

Ludwig, Simone A; Kong, Jun

2017-12-01

Innovative methods and new technologies have significantly improved the quality of our daily life. However, disabled people, for example those that cannot use their arms and legs anymore, often cannot benefit from these developments, since they cannot use their hands to interact with traditional interaction methods (such as mouse or keyboard) to communicate with a computer system. A brain-computer interface (BCI) system allows such a disabled person to control an external device via brain waves. Past research mostly dealt with static interfaces, which limit users to a stationary location. However, since we are living in a world that is highly mobile, this paper evaluates a speller interface on a mobile phone used in a moving condition. The spelling experiments were conducted with 14 able-bodied subjects using visual flashes as the stimulus to spell 47 alphanumeric characters (38 letters and 9 numbers). This data was then used for the classification experiments. In par- ticular, two research directions are pursued. The first investigates the impact of different classification algorithms, and the second direction looks at the channel configuration, i.e., which channels are most beneficial in terms of achieving the highest classification accuracy. The evaluation results indicate that the Bayesian Linear Discriminant Analysis algorithm achieves the best accuracy. Also, the findings of the investigation on the channel configuration, which can potentially reduce the amount of data processing on a mobile device with limited computing capacity, is especially useful in mobile BCIs.

The Planform Mobility of Large River Channel Confluences

Science.gov (United States)

Sambrook Smith, Greg; Dixon, Simon; Nicholas, Andrew; Bull, Jon; Vardy, Mark; Best, James; Goodbred, Steven; Sarker, Maminul

2017-04-01

Large river confluences are widely acknowledged as exerting a controlling influence upon both upstream and downstream morphology and thus channel planform evolution. Despite their importance, little is known concerning their longer-term evolution and planform morphodynamics, with much of the literature focusing on confluences as representing fixed, nodal points in the fluvial network. In contrast, some studies of large sand bed rivers in India and Bangladesh have shown large river confluences can be highly mobile, although the extent to which this is representative of large confluences around the world is unknown. Confluences have also been shown to generate substantial bed scours, and if the confluence location is mobile these scours could 'comb' across wide areas. This paper presents field data of large confluences morphologies in the Ganges-Brahmaputra-Meghna river basin, illustrating the spatial extent of large river bed scours and showing scour depth can extend below base level, enhancing long term preservation potential. Based on a global review of the planform of large river confluences using Landsat imagery from 1972 to 2014 this study demonstrates such scour features can be highly mobile and there is an array of confluence morphodynamic types: from freely migrating confluences, through confluences migrating on decadal timescales to fixed confluences. Based on this analysis, a conceptual model of large river confluence types is proposed, which shows large river confluences can be sites of extensive bank erosion and avulsion, creating substantial management challenges. We quantify the abundance of mobile confluence types by classifying all large confluences in both the Amazon and Ganges-Brahmaputra-Meghna basins, showing these two large rivers have contrasting confluence morphodynamics. We show large river confluences have multiple scales of planform adjustment with important implications for river management, infrastructure and interpretation of the rock

Turbulence characteristics of flow in an open channel with temporally varying mobile bedforms

Directory of Open Access Journals (Sweden)

Hanmaiahgari Prashanth Reddy

2017-03-01

Full Text Available Turbulence of flow over mobile bedforms in natural open channels is not yet clearly understood. An attempt is made in this paper to determine the effect of naturally formed mobile bedforms on velocities, turbulent intensities and turbulent stresses. Instantaneous velocities are measured using a two-dimensional particle image velocimetry (PIV to evaluate the turbulence structure of free surface flow over a fixed (immobile bed, a weakly mobile bed and a temporally varying mobile bed with different stages of bedform development. This paper documents the vertical distribution of velocity, turbulence intensities, Reynolds shear stress and higher-order moments including skewness and turbulent diffusion factors. Analysis of the velocity distributions shows a substantial decrease of velocity near the bed with increasing bedform mobility due to increased friction. A modified logarithmic law with a reduced von Kármán constant and increased velocity shift is proposed for the case of the mobile bedforms. A significant increase in the Reynolds shear stress is observed in the mobile bedforms experiments accompanied by changes over the entire flow depth compared to an immobile bed. The skewness factor distribution was found to be different in the case of the flow over the mobile bedforms. All higher-order turbulence descriptors are found to be significantly affected by the formation of temporally varying and non-equilibrium mobile bedforms. Quadrant analysis indicates that sweep and outward events are found to be dominant in strongly mobile bedforms and govern the bedform mobility.

Variability of bed mobility in natural, gravel-bed channels and adjustments to sediment load at local and reach scales

Science.gov (United States)

Thomas E. Lisle; Jonathan M. Nelson; John Pitlick; Mary Ann Madej; Brent L. Barkett

2000-01-01

Abstract - Local variations in boundary shear stress acting on bed-surface particles control patterns of bed load transport and channel evolution during varying stream discharges. At the reach scale a channel adjusts to imposed water and sediment supply through mutual interactions among channel form, local grain size, and local flow dynamics that govern bed mobility...

Lateral Dispersal and Foraging Behavior of Entomopathogenic Nematodes in the Absence and Presence of Mobile and Non-Mobile Hosts.

Directory of Open Access Journals (Sweden)

Harit K Bal

Full Text Available Entomopathogenic nematodes have been classified into cruisers (active searchers and ambushers (sit and wait foragers. However, little is known about their dispersal and foraging behavior at population level in soil. We studied lateral dispersal of the ambush foraging Steinernema carpocapsae (ALL strain and cruise foraging Heterorhabditis bacteriophora (GPS11 strain from infected host cadavers in microcosms (0.05 m2 containing Wooster silt-loam soil (Oxyaquic fragiudalf and vegetation in the presence or absence of non-mobile and mobile hosts. Results showed that the presence of a non-mobile host (Galleria mellonella larva in a wire mesh cage enhanced H. bacteriophora dispersal for up to 24 hr compared with no-host treatment, but had no impact on S. carpocapsae dispersal. In contrast, presence of a mobile host (G. mellonella larvae increased dispersal of S. carpocapsae compared with no host treatment, but had no effect on H. bacteriophora dispersal. Also H. bacteriophora was better at infecting non-mobile than mobile hosts released into the microcosms and S. carpocapsae was better at infecting mobile than non-mobile hosts, thus affirming the established cruiser-ambusher theory. However, results also revealed that a large proportion of infective juveniles (IJs of both species stayed near (≤ 3.8 cm the source cadaver (88-96% S. carpocapsae; 67-79% H. bacteriophora, and the proportion of IJs reaching the farthest distance (11.4 cm was significantly higher for S. carpocapsae (1.4% than H. bacteriophora (0.4% in the presence of mobile hosts. S. carpocapsae also had higher average population displacement than H. bacteriophora in the presence of both the non-mobile (5.07 vs. 3.6 cm/day and mobile (8.06 vs. 5.3 cm/day hosts. We conclude that the two species differ in their dispersal and foraging behavior at the population level and this behavior is affected by both the presence and absence of hosts and by their mobility.

Mobile Phone Ratiometric Imaging Enables Highly Sensitive Fluorescence Lateral Flow Immunoassays without External Optical Filters.

Science.gov (United States)

Shah, Kamal G; Singh, Vidhi; Kauffman, Peter C; Abe, Koji; Yager, Paul

2018-05-14

Paper-based diagnostic tests based on the lateral flow immunoassay concept promise low-cost, point-of-care detection of infectious diseases, but such assays suffer from poor limits of detection. One factor that contributes to poor analytical performance is a reliance on low-contrast chromophoric optical labels such as gold nanoparticles. Previous attempts to improve the sensitivity of paper-based diagnostics include replacing chromophoric labels with enzymes, fluorophores, or phosphors at the expense of increased fluidic complexity or the need for device readers with costly optoelectronics. Several groups, including our own, have proposed mobile phones as suitable point-of-care readers due to their low cost, ease of use, and ubiquity. However, extant mobile phone fluorescence readers require costly optical filters and were typically validated with only one camera sensor module, which is inappropriate for potential point-of-care use. In response, we propose to couple low-cost ultraviolet light-emitting diodes with long Stokes-shift quantum dots to enable ratiometric mobile phone fluorescence measurements without optical filters. Ratiometric imaging with unmodified smartphone cameras improves the contrast and attenuates the impact of excitation intensity variability by 15×. Practical application was shown with a lateral flow immunoassay for influenza A with nucleoproteins spiked into simulated nasal matrix. Limits of detection of 1.5 and 2.6 fmol were attained on two mobile phones, which are comparable to a gel imager (1.9 fmol), 10× better than imaging gold nanoparticles on a scanner (18 fmol), and >2 orders of magnitude better than gold nanoparticle-labeled assays imaged with mobile phones. Use of the proposed filter-free mobile phone imaging scheme is a first step toward enabling a new generation of highly sensitive, point-of-care fluorescence assays.

Channel Access and Power Control for Mobile Crowdsourcing in Device-to-Device Underlaid Cellular Networks

Directory of Open Access Journals (Sweden)

Yue Ma

2018-01-01

Full Text Available With the access of a myriad of smart handheld devices in cellular networks, mobile crowdsourcing becomes increasingly popular, which can leverage omnipresent mobile devices to promote the complicated crowdsourcing tasks. Device-to-device (D2D communication is highly desired in mobile crowdsourcing when cellular communications are costly. The D2D cellular network is more preferable for mobile crowdsourcing than conventional cellular network. Therefore, this paper addresses the channel access and power control problem in the D2D underlaid cellular networks. We propose a novel semidistributed network-assisted power and a channel access control scheme for D2D user equipment (DUE pieces. It can control the interference from DUE pieces to the cellular user accurately and has low information feedback overhead. For the proposed scheme, the stochastic geometry tool is employed and analytic expressions are derived for the coverage probabilities of both the cellular link and D2D links. We analyze the impact of key system parameters on the proposed scheme. The Pareto optimal access threshold maximizing the total area spectral efficiency is obtained. Unlike the existing works, the performances of the cellular link and D2D links are both considered. Simulation results show that the proposed method can improve the total area spectral efficiency significantly compared to existing schemes.

Influence of the elastic deformation of a foam on its mobility in channels of linearly varying width.

Science.gov (United States)

Dollet, Benjamin; Jones, Siân A; Méheust, Yves; Cantat, Isabelle

2014-08-01

We study foam flow in an elementary model porous medium consisting of a convergent and a divergent channel positioned side by side and possessing a fixed joint porosity. Configurations of converging or diverging channels are ubiquitous at the pore scale in porous media, as all channels linking pores possess a converging and diverging part. The resulting flow kinematics imposes asymmetric bubble deformations in the two channels, which modulate foam-wall friction and strongly impact the flux distribution. We measure, as well as quantitatively predict, the ratio of the fluxes in the two channels as a function of the channel widths by modeling pressure drops of both viscous and capillary origins. This study reveals the crucial importance of boundary-induced bubble deformation on the mobility of a flowing foam, resulting in particular in flow irreversibility.

Lateral mobility of plasma membrane lipids in Xenopus eggs: Regional differences related to animal/vegetal polarity

NARCIS (Netherlands)

Laat, S.W. de; Bluemink, J.G.; Dictus, W.J.A.G.; Zoelen, E.J.J. van; Tetteroo, P.A.T.; Tertoolen, L.G.J.

1984-01-01

Regional differences in the lateral mobility properties of plasma membrane lipids were studied in unfertilized and fertilized Xenopus eggs by fluorescence photobleaching recovery (FPR) measurements. Out of a variety of commonly used lipid probes only the aminofluorescein- -1abelled fatty

Decrease in effective electron mobility in the channel of a metal-oxide-semiconductor transistor as the gate length is decreased

International Nuclear Information System (INIS)

Frantsuzov, A. A.; Boyarkina, N. I.; Popov, V. P.

2008-01-01

Effective electron mobility μ eff in channels of metal-oxide-semiconductor transistors with a gate length L in the range of 3.8 to 0.34 μm was measured; the transistors were formed on wafers of the silicon-oninsulator type. It was found that μ eff decreases as L is decreased. It is shown that this decrease can be accounted for by the effect of series resistances of the source and drain only if it is assumed that there is a rapid increase in these resistances as the gate voltage is decreased. This assumption is difficult to substantiate. A more realistic model is suggested; this model accounts for the observed decrease in μ eff as L is decreased. The model implies that zones with a mobility lower than that in the middle part of the channel originate at the edges of the gate. An analysis shows that, in this case, the plot of the dependence of 1/μ eff on 1/L should be linear, which is exactly what is observed experimentally. The use of this plot makes it possible to determine both the electron mobility μ 0 in the middle part of the channel and the quantity A that characterizes the zones with lowered mobility at the gate’s edges.

Relay Selections for Security and Reliability in Mobile Communication Networks over Nakagami-m Fading Channels

Directory of Open Access Journals (Sweden)

Hongji Huang

2017-01-01

Full Text Available This paper studies the relay selection schemes in mobile communication system over Nakagami-m channel. To make efficient use of licensed spectrum, both single relay selection (SRS scheme and multirelays selection (MRS scheme over the Nakagami-m channel are proposed. Also, the intercept probability (IP and outage probability (OP of the proposed SRS and MRS for the communication links depending on realistic spectrum sensing are derived. Furthermore, this paper assesses the manifestation of conventional direct transmission scheme to compare with the proposed SRS and MRS ones based on the Nakagami-m channel, and the security-reliability trade-off (SRT performance of the proposed schemes and the conventional schemes is well investigated. Additionally, the SRT of the proposed SRS and MRS schemes is demonstrated better than that of direct transmission scheme over the Nakagami-m channel, which can protect the communication transmissions against eavesdropping attacks. Additionally, simulation results show that our proposed relay selection schemes achieve better SRT performance than that of conventional direct transmission over the Nakagami-m channel.

Enhancement mode GaN-based multiple-submicron channel array gate-recessed fin metal-oxide-semiconductor high-electron mobility transistors

Science.gov (United States)

Lee, Ching-Ting; Wang, Chun-Chi

2018-04-01

To study the function of channel width in multiple-submicron channel array, we fabricated the enhancement mode GaN-based gate-recessed fin metal-oxide-semiconductor high-electron mobility transistors (MOS-HEMTs) with a channel width of 450 nm and 195 nm, respectively. In view of the enhanced gate controllability in a narrower fin-channel structure, the transconductance was improved from 115 mS/mm to 151 mS/mm, the unit gain cutoff frequency was improved from 6.2 GHz to 6.8 GHz, and the maximum oscillation frequency was improved from 12.1 GHz to 13.1 GHz of the devices with a channel width of 195 nm, compared with the devices with a channel width of 450 nm.

The effect of metallization contact resistance on the measurement of the field effect mobility of long-channel unannealed amorphous In–Zn–O thin film transistors

International Nuclear Information System (INIS)

Lee, Sunghwan; Park, Hongsik; Paine, David C.

2012-01-01

The effect of contact resistance on the measurement of the field effect mobility of compositionally homogeneous channel indium zinc oxide (IZO)/IZO metallization thin film transistors (TFTs) is reported. The TFTs studied in this work operate in depletion mode as n-channel field effect devices with a field effect mobility calculated in the linear regime (μ FE ) of 20 ± 1.9 cm 2 /Vs and similar of 18 ± 1.3 cm 2 /Vs when calculated in the saturation regime (μ FE sat ). These values, however, significantly underestimate the channel mobility since a large part of the applied drain voltage is dropped across the source/drain contact interface. The transmission line method was employed to characterize the contact resistance and it was found that the conducting-IZO/semiconducting-IZO channel contact is highly resistive (specific contact resistance, ρ C > 100 Ωcm 2 ) and, further, this contact resistance is modulated with applied gate voltage. Accounting for the contact resistance (which is large and modulated by gate voltage), the corrected μ FE is shown to be 39 ± 2.6 cm 2 /Vs which is consistent with Hall mobility measurements of high carrier density IZO.

On the high charge-carrier mobility in polyaniline molecular channels in nanogaps between carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Emelianov, A. V., E-mail: emmsowton@gmail.com; Romashkin, A. V.; Tsarik, K. A. [National Research University of Electronic Technology (MIET) (Russian Federation); Nasibulin, A. G. [Skolkovo Institute of Science and Technology (Russian Federation); Nevolin, V. K.; Bobrinetskiy, I. I. [National Research University of Electronic Technology (MIET) (Russian Federation)

2017-04-15

This study is devoted to the fabrication of molecular semiconductor channels based on polymer molecules with nanoscale electrodes made of single-walled carbon nanotubes. A reproducible technology for forming nanoscale gaps in carbon nanotubes using a focused Ga{sup +} ion beam is proposed. Polyaniline molecules are deposited into nanogaps up to 30 nm wide between nanotubes by electrophoresis from N-methyl-2-pyrrolidone solution. As a result, molecular organic transistors are fabricated, in which the field effect is studied and the molecular-channel mobility is determined as 0.1 cm{sup 2}/(V s) at an on/off current ratio of 5 × 10{sup 2}.

Signal processing for mobile communications handbook

CERN Document Server

Ibnkahla, Mohamed

2004-01-01

INTRODUCTIONSignal Processing for Future Mobile Communications Systems: Challenges and Perspectives; Quazi Mehbubar Rahman and Mohamed IbnkahlaCHANNEL MODELING AND ESTIMATIONMultipath Propagation Models for Broadband Wireless Systems; Andreas F. Molisch and Fredrik TufvessonModeling and Estimation of Mobile Channels; Jitendra K. TugnaitMobile Satellite Channels: Statistical Models and Performance Analysis; Giovanni E. Corazza, Alessandro Vanelli-Coralli, Raffaella Pedone, and Massimo NeriMobile Velocity Estimation for Wireless Communications; Bouchra Senadji, Ghazem Azemi, and Boualem Boashash

Reliability of high mobility SiGe channel MOSFETs for future CMOS applications

CERN Document Server

Franco, Jacopo; Groeseneken, Guido

2014-01-01

Due to the ever increasing electric fields in scaled CMOS devices, reliability is becoming a showstopper for further scaled technology nodes. Although several groups have already demonstrated functional Si channel devices with aggressively scaled Equivalent Oxide Thickness (EOT) down to 5Å, a 10 year reliable device operation cannot be guaranteed anymore due to severe Negative Bias Temperature Instability. This book focuses on the reliability of the novel (Si)Ge channel quantum well pMOSFET technology. This technology is being considered for possible implementation in next CMOS technology nodes, thanks to its benefit in terms of carrier mobility and device threshold voltage tuning. We observe that it also opens a degree of freedom for device reliability optimization. By properly tuning the device gate stack, sufficiently reliable ultra-thin EOT devices with a 10 years lifetime at operating conditions are demonstrated. The extensive experimental datasets collected on a variety of processed 300mm wafers and pr...

Improved Mobility and Bias Stability of Thin Film Transistors Using the Double-Layer a-InGaZnO/a-InGaZnO:N Channel.

Science.gov (United States)

Yu, H; Zhang, L; Li, X H; Xu, H Y; Liu, Y C

2016-04-01

The amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistors (TFTs) were demonstrated based on a double-layer channel structure, where the channel is composed of an ultrathin nitro-genated a-IGZO (a-IGZO:N) layer and an undoped a-IGZO layer. The double-layer channel device showed higher saturation mobility and lower threshold-voltage shift (5.74 cm2/Vs, 2.6 V) compared to its single-layer counterpart (0.17 cm2/Vs, 7.23 V). The improvement can be attributed to three aspects: (1) improved carrier transport properties of the channel by the a-IGZO:N layer with high carrier mobility and the a-IGZO layer with high carrier concentration, (2) reduced interfacial trap density between the active channel and the gate insulator, and (3) higher surface flatness of the double-layer channel. Our study reveals key insights into double-layer channel, involving selecting more suitable electrical property for back-channel layer and more suitable interface modification for active layer. Meanwhile, room temperature fabrication amorphous TFTs offer certain advantages on better flexibility and higher uniformity over a large area.

Hybrid complementary circuits based on p-channel organic and n-channel metal oxide transistors with balanced carrier mobilities of up to 10 cm2/Vs

KAUST Repository

Isakov, Ivan

2016-12-29

We report the development of hybrid complementary inverters based on p-channel organic and n-channel metal oxide thin-film transistors (TFTs) both processed from solution at <200 °C. For the organic TFTs, a ternary blend consisting of the small-molecule 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene, the polymer indacenodithiophene-benzothiadiazole (CIDT-BT) and the p-type dopant CF was employed, whereas the isotype InO/ZnO heterojunction was used for the n-channel TFTs. When integrated on the same substrate, p- and n-channel devices exhibited balanced carrier mobilities up to 10 cm/Vs. Hybrid complementary inverters based on these devices show high signal gain (>30 V/V) and wide noise margins (70%). The moderate processing temperatures employed and the achieved level of device performance highlight the tremendous potential of the technology for application in the emerging sector of large-area microelectronics.

Hybrid complementary circuits based on p-channel organic and n-channel metal oxide transistors with balanced carrier mobilities of up to 10 cm2/Vs

KAUST Repository

Isakov, Ivan; Paterson, Alexandra F.; Solomeshch, Olga; Tessler, Nir; Zhang, Qiang; Li, Jun; Zhang, Xixiang; Fei, Zhuping; Heeney, Martin; Anthopoulos, Thomas D.

2016-01-01

We report the development of hybrid complementary inverters based on p-channel organic and n-channel metal oxide thin-film transistors (TFTs) both processed from solution at <200 °C. For the organic TFTs, a ternary blend consisting of the small-molecule 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene, the polymer indacenodithiophene-benzothiadiazole (CIDT-BT) and the p-type dopant CF was employed, whereas the isotype InO/ZnO heterojunction was used for the n-channel TFTs. When integrated on the same substrate, p- and n-channel devices exhibited balanced carrier mobilities up to 10 cm/Vs. Hybrid complementary inverters based on these devices show high signal gain (>30 V/V) and wide noise margins (70%). The moderate processing temperatures employed and the achieved level of device performance highlight the tremendous potential of the technology for application in the emerging sector of large-area microelectronics.

Regional differences in the lateral mobility of plasma membrane lipids in a molluscan embryo

OpenAIRE

Speksnijder, J.E.; Dohmen, M.R.; Tertoolen, L.G.J.; Laat, S.W. de

1985-01-01

Regional and temporal differences in plasma membrane lipid mobility have been analyzed during the first three cleavage cycles of the embryo of the polar-lobe-forming mollusc Nassarius reticulatus by the fluorescence photobleaching recovery (FPR) method, using 1,1′-ditetradecyl 3,3,3′,3′-tetramethylindocarbocyanine iodide (C14diI) as a fluorescent lipid probe. During this period of development the lateral diffusion coefficient of membrane lipids is consistently greater in the vegetal polar lob...

Development of 2-channel (532 nm and 355 nm) mobile LIDAR for mapping particulate matter in the atmosphere

CSIR Research Space (South Africa)

Sivakumar, V

2010-09-01

Full Text Available In this paper, the authors describe the developmentof 2-Channel (532 nm and 355 nm) mobile LIDAR system for studying atmospheric particulate matter. The system is currently tested in house at the Council for Scientific and Industrial Research...

Recall of mobile phone usage and laterality in young people: The multinational Mobi-Expo study.

Science.gov (United States)

Goedhart, Geertje; van Wel, Luuk; Langer, Chelsea E; de Llobet Viladoms, Patricia; Wiart, Joe; Hours, Martine; Kromhout, Hans; Benke, Geza; Bouka, Evdoxia; Bruchim, Revital; Choi, Kyung-Hwa; Eng, Amanda; Ha, Mina; Huss, Anke; Kiyohara, Kosuke; Kojimahara, Noriko; Krewski, Daniel; Lacour, Brigitte; 't Mannetje, Andrea; Maule, Milena; Migliore, Enrica; Mohipp, Charmaine; Momoli, Franco; Petridou, Eleni Th; Radon, Katja; Remen, Thomas; Sadetzki, Siegal; Sim, Malcolm; Weinmann, Tobias; Cardis, Elisabeth; Vrijheid, Martine; Vermeulen, Roel

2018-08-01

To study recall of mobile phone usage, including laterality and hands-free use, in young people. Actual mobile phone use was recorded among volunteers aged between 10 and 24 years from 12 countries by the software application XMobiSense and was compared with self-reported mobile phone use at 6 and 18 months after using the application. The application recorded number and duration of voice calls, number of text messages, amount of data transfer, laterality (% of call time the phone was near the right or left side of the head, or neither), and hands-free usage. After data cleaning, 466 participants were available for the main analyses (recorded vs. self-reported phone use after 6 months). Participants were on average 18.6 years old (IQR 15.2-21.8 years). The Spearman correlation coefficients between recorded and self-reported (after 6 months) number and duration of voice calls were 0.68 and 0.65, respectively. Number of calls was on average underestimated by the participants (adjusted geometric mean ratio (GMR) self-report/recorded = 0.52, 95% CI = 0.47-0.58), while duration of calls was overestimated (GMR=1.32, 95%, CI = 1.15-1.52). The ratios significantly differed by country, age, maternal educational level, and level of reported phone use, but not by time of the interview (6 vs. 18 months). Individuals who reported low mobile phone use underestimated their use, while individuals who reported the highest level of phone use were more likely to overestimate their use. Individuals who reported using the phone mainly on the right side of the head used it more on the right (71.1%) than the left (28.9%) side. Self-reported left side users, however, used the phone only slightly more on the left (53.3%) than the right (46.7%) side. Recorded percentage hands-free use (headset, speaker mode, Bluetooth) increased with increasing self-reported frequency of hands-free device usage. Frequent (≥50% of call time) reported headset or speaker mode use corresponded with 17

Muddy lateral accretion and low stream power in a sub-recent confined channel belt, Rhine-Meuse delta, central Netherlands

NARCIS (Netherlands)

Makaske, B.; Weerts, H.J.T.

2005-01-01

The Hennisdijk fluvial system in the central Rhine-Meuse delta is an abandoned Rhine distributary that was active on a wide floodplain from 3800 to 3000 years BP. Cross-sectional geometry, lithological characteristics and planform patterns of the channel-belt deposits indicate lateral migration of

A Finite Element Solution of Lateral Periodic Poisson–Boltzmann Model for Membrane Channel Proteins

Science.gov (United States)

Xu, Jingjie; Lu, Benzhuo

2018-01-01

Membrane channel proteins control the diffusion of ions across biological membranes. They are closely related to the processes of various organizational mechanisms, such as: cardiac impulse, muscle contraction and hormone secretion. Introducing a membrane region into implicit solvation models extends the ability of the Poisson–Boltzmann (PB) equation to handle membrane proteins. The use of lateral periodic boundary conditions can properly simulate the discrete distribution of membrane proteins on the membrane plane and avoid boundary effects, which are caused by the finite box size in the traditional PB calculations. In this work, we: (1) develop a first finite element solver (FEPB) to solve the PB equation with a two-dimensional periodicity for membrane channel proteins, with different numerical treatments of the singular charges distributions in the channel protein; (2) add the membrane as a dielectric slab in the PB model, and use an improved mesh construction method to automatically identify the membrane channel/pore region even with a tilt angle relative to the z-axis; and (3) add a non-polar solvation energy term to complete the estimation of the total solvation energy of a membrane protein. A mesh resolution of about 0.25 Å (cubic grid space)/0.36 Å (tetrahedron edge length) is found to be most accurate in linear finite element calculation of the PB solvation energy. Computational studies are performed on a few exemplary molecules. The results indicate that all factors, the membrane thickness, the length of periodic box, membrane dielectric constant, pore region dielectric constant, and ionic strength, have individually considerable influence on the solvation energy of a channel protein. This demonstrates the necessity to treat all of those effects in the PB model for membrane protein simulations. PMID:29495644

Transformational Electronics: Towards Flexible Low-Cost High Mobility Channel Materials

KAUST Repository

Nassar, Joanna M.

2014-05-01

For the last four decades, Si CMOS technology has been advancing with Moore’s law prediction, working itself down to the sub-20 nm regime. However, fundamental problems and limitations arise with the down-scaling of transistors and thus new innovations needed to be discovered in order to further improve device performance without compromising power consumption and size. Thus, a lot of studies have focused on the development of new CMOS compatible architectures as well as the discovery of new high mobility channel materials that will allow further miniaturization of CMOS transistors and improvement of device performance. Pushing the limits even further, flexible and foldable electronics seem to be the new attractive topic. By being able to make our devices flexible through a CMOS compatible process, one will be able to integrate hundreds of billions of more transistors in a small volumetric space, allowing to increase the performance and speed of our electronics all together with making things thinner, lighter, smaller and even interactive with the human skin. Thus, in this thesis, we introduce for the first time a cost-effective CMOS compatible approach to make high-k/metal gate devices on flexible Germanium (Ge) and Silicon-Germanium (SiGe) platforms. In the first part, we will look at the various approaches in the literature that has been developed to get flexible platforms, as well as we will give a brief overview about epitaxial growth of Si1-xGex films. We will also examine the electrical properties of the Si1-xGex alloys up to Ge (x=1) and discuss how strain affects the band structure diagram, and thus the mobility of the material. We will also review the material growth properties as well as the state-of-the-art results on high mobility metal-oxide semiconductor capacitors (MOSCAPs) using strained SiGe films. Then, we will introduce the flexible process that we have developed, based on a cost-effective “trench-protect-release-reuse” approach, utilizing

Hole mobility and remote scattering in strained InGaSb quantum well MOSFET channels with Al{sub 2}O{sub 3} oxide

Energy Technology Data Exchange (ETDEWEB)

Kumar Madisetti, Shailesh; Chidambaram, Thenappan; Nagaiah, Padmaja; Tokranov, Vadim; Yakimov, Michael; Oktyabrsky, Serge [College of Nanoscale Science and Engineering, University at Albany - SUNY, 257 Fuller Road, Albany, NY 12203 (United States)

2013-08-15

Hall mobility and major scattering mechanisms in surface and buried MBE grown strained InGaSb quantum well (QW) MOSFET channels with in-situ grown Al{sub 2}O{sub 3} gate oxide are analyzed as a function of sheet hole density, top-barrier thickness and temperature. Mobility dependence on Al{sub 0.8}Ga{sub 0.2}Sb top-barrier thickness shows that the relative contribution of interface-related scattering is as low as {proportional_to}30% in the surface QW channel. An InAs top capping layer reduces the interface scattering even further; the sample with 3 nm total top-barrier thickness demonstrates mobility of 980 cm{sup 2}/Vs giving sheet resistance of 4.3 k{Omega}/sq, very close to the minimum QW resistance in the bulk. The mobility-temperature dependences indicate that the interface-related scattering is dominated by remote Coulomb scattering at hole densities <1 x 10{sup 12} cm{sup -2}. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Lateral mobility of plasma membrane proteins in dividing eggs of the loach (Misgurnus fossilis): Regional differences and changes during the cell cycle.

Science.gov (United States)

Bozhkova, V P; Budayova, M; Kvasnicka, P; Cigankova, N; Chorvat, D

1994-12-01

Regional differences in lateral diffusion rates of fluorescence-labeled proteins have been studied in the plasma membrane of dividing eggs of the loach (Misgurnus fossilis) by fluorescence recovery after photobleaching (FRAP). Apparent animal-vegetal differences in fluorescence intensity, lateral diffusion coefficients, and fractions of mobile proteins have been found, with all these quantities being higher in the animal pole region than in the yolk region. Cyclic changes in protein diffusion coefficients and mobile fractions during the first few cell cycles have also been recorded. Soon after the end of a cleavage, the diffusion coefficient reaches its minimal value and increases rapidly before the next cleavage.

Strained Si channel NMOSFETs using a stress field with Si1-yC y source and drain stressors

International Nuclear Information System (INIS)

Chang, S.T.; Tasi, H.-S.; Kung, C.Y.

2006-01-01

The strain field in the silicon channel of a metal-oxide-semiconductor transistor with silicon-carbon alloy source and drain stressors was evaluated using the commercial process simulator FLOOPS-ISE TM . The physical origin of the strain components in the transistor channel region was explained. The magnitude and distribution of the strain components, and their dependence on device design parameters such as the spacing L G between the silicon-carbon alloy stressors, the carbon mole fraction in the stressors and stressor depth were investigated. Reducing the stressor spacing L G or increasing the carbon mole fraction in the stressors and stressor depth increases the magnitude of the vertical compressive stress and the lateral tensile stress in the portion of the N channel region where the inversion charge resides. This is beneficial for improving the electron mobility in n-channel metal-oxide-semiconductor transistors. A simple guiding principle for an optimum combination of the above-mentioned device design parameters in terms of mobility enhancement, drain current enhancement and the tradeoff consideration for junction leakage current degradation

Investigation of high mobility pseudomorphic SiGe p-channels in Si MOSFETS at low and high electric fields

International Nuclear Information System (INIS)

Palmer, Martin John

2001-01-01

Silicon Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) for high speed, high current applications are rapidly approaching the physical and financial limits of the technology. This opens opportunities for the incorporation of materials with intrinsically better transport characteristics. An alloy of silicon and germanium is one such material that is gaining much recognition as the active component of MOSFETs and as the secondary structures (such as the gate electrode). This work examines a batch of buried channel Si 0.64 Ge 0.36 p-MOSFETs, with a minimum effective length of 0.35 μm, under different bias conditions and at different temperatures. High current and transconductance enhancements are apparent at long gate lengths. The carrier mobility is up to a factor of 2.5 times that of silicon at room temperature and 7.5 times at 4 K. A clear trend of decreasing peak mobility with decreasing silicon cap thickness is evident. Simulations show that scattering caused by the roughness of the SiO 2 /Si interface dominates, rather than alloy scattering or Si/SiGe roughness, even for a buried channel. This scattering increases with the proximity of the carriers to the interface. An increase of interface trap density with decreasing cap thickness, demonstrates that segregated germanium exists some distance into the cap and interferes with the oxidation process. This will increase scattering through increased SiO 2 /Si roughness and increased trapped charge. The short channel, high field results are comparable or slightly worse than those of silicon due to lower saturation drift velocity. However, fitting to a drift-diffusion model shows an apparent increase in saturation velocity for short channels, especially at low temperatures. This effect correlates with the low field mobility and is greater for devices containing SiGe. This is an indication of velocity overshoot, which may enhance the performance of SiGe MOSFETs at deep submicron gate lengths. (author)

Lateral mobility of plasma membrane lipids in Xenopus eggs: Regional differences related to animal/vegetal polarity

OpenAIRE

Laat, S.W. de; Bluemink, J.G.; Dictus, W.J.A.G.; Zoelen, E.J.J. van; Tetteroo, P.A.T.; Tertoolen, L.G.J.

1984-01-01

Regional differences in the lateral mobility properties of plasma membrane lipids were studied in unfertilized and fertilized Xenopus eggs by fluorescence photobleaching recovery (FPR) measurements. Out of a variety of commonly used lipid probes only the aminofluorescein- -1abelled fatty acids HEDAF (5-(N-hexadecanoyl)- aminofluorescein) and TEDAF (5-(N-tetradecanoyl)-aminofluorescein) appear to distribute itself in the plasma membrane. Under all experimental conditions used these molecules s...

Morphological resilience to flow fluctuations of fine sediment deposits in bank lateral cavities

Science.gov (United States)

Juez, C.; Thalmann, M.; Schleiss, A. J.; Franca, M. J.

2018-05-01

Lateral cavities are built in the banks of rivers for several purposes: to create harbors, to capture sediment, to keep a central navigable channel (i.e., Casiers de Girardon in the Rhone river) or to promote the formation of aquatic habitats if a limited amount of sediment is captured, providing hydraulic and morphologic diversity (i.e., the case of Japanese Wandos). This work is focused on this latter purpose: promotion of hydraulic and morphologic diversity. In these scenarios, an increase in the flow discharge in the main channel may, however, re-mobilize the deposit of sediment inside these lateral embayments and cause a sudden increase of the sediment concentration and turbidity in the main channel. It is thus of interest to characterize the resistance and resilience of these sedimentary deposits when the main channel is subjected to high flow or flushing events. Laboratory tests were carried out for five different normalized geometries of the cavities installed in the banks of an open channel and for five hydrographs with different levels of unsteadiness. Water depth, sediment deposit mass, sediment concentration and area covered by the settled sediments were recorded throughout each experiment. Although sediment deposits established at equilibrium before the flushing events are different depending on the geometry of the cavities, generally, they are recovered after being flushed by the high flow events. It is shown that the resistance and resilience of the sediment deposits are strongly dependent on the flow field and the mass exchange between the main channel and the cavities. This mass exchange is governed by the geometry of the cavities and the magnitude of the hydrographs applied.

The subcellular distribution of T-type Ca2+ channels in interneurons of the lateral geniculate nucleus.

Science.gov (United States)

Allken, Vaneeda; Chepkoech, Joy-Loi; Einevoll, Gaute T; Halnes, Geir

2014-01-01

Inhibitory interneurons (INs) in the lateral geniculate nucleus (LGN) provide both axonal and dendritic GABA output to thalamocortical relay cells (TCs). Distal parts of the IN dendrites often enter into complex arrangements known as triadic synapses, where the IN dendrite plays a dual role as postsynaptic to retinal input and presynaptic to TC dendrites. Dendritic GABA release can be triggered by retinal input, in a highly localized process that is functionally isolated from the soma, but can also be triggered by somatically elicited Ca(2+)-spikes and possibly by backpropagating action potentials. Ca(2+)-spikes in INs are predominantly mediated by T-type Ca(2+)-channels (T-channels). Due to the complex nature of the dendritic signalling, the function of the IN is likely to depend critically on how T-channels are distributed over the somatodendritic membrane (T-distribution). To study the relationship between the T-distribution and several IN response properties, we here run a series of simulations where we vary the T-distribution in a multicompartmental IN model with a realistic morphology. We find that the somatic response to somatic current injection is facilitated by a high T-channel density in the soma-region. Conversely, a high T-channel density in the distal dendritic region is found to facilitate dendritic signalling in both the outward direction (increases the response in distal dendrites to somatic input) and the inward direction (the soma responds stronger to distal synaptic input). The real T-distribution is likely to reflect a compromise between several neural functions, involving somatic response patterns and dendritic signalling.

Suppression of surface-originated gate lag by a dual-channel AlN/GaN high electron mobility transistor architecture

Science.gov (United States)

Deen, David A.; Storm, David F.; Scott Katzer, D.; Bass, R.; Meyer, David J.

2016-08-01

A dual-channel AlN/GaN high electron mobility transistor (HEMT) architecture is demonstrated that leverages ultra-thin epitaxial layers to suppress surface-related gate lag. Two high-density two-dimensional electron gas (2DEG) channels are utilized in an AlN/GaN/AlN/GaN heterostructure wherein the top 2DEG serves as a quasi-equipotential that screens potential fluctuations resulting from distributed surface and interface states. The bottom channel serves as the transistor's modulated channel. Dual-channel AlN/GaN heterostructures were grown by molecular beam epitaxy on free-standing hydride vapor phase epitaxy GaN substrates. HEMTs fabricated with 300 nm long recessed gates demonstrated a gate lag ratio (GLR) of 0.88 with no degradation in drain current after bias stressed in subthreshold. These structures additionally achieved small signal metrics ft/fmax of 27/46 GHz. These performance results are contrasted with the non-recessed gate dual-channel HEMT with a GLR of 0.74 and 82 mA/mm current collapse with ft/fmax of 48/60 GHz.

Lateral mobility of plasma membrane lipids in Xenopus eggs: Regional differences related to animal/vegetal polarity become extreme upon fertilization

NARCIS (Netherlands)

Bluemink, J.G.; Dictus, W.J.A.G.; Zoelen, E.J.J. van; Tetteroo, P.A.T.; Tertoolen, L.G.J.; Laat, S.W. de

1984-01-01

Regional differences in the lateral mobility properties of plasma membrane lipids have been studied in unfertilized and fertilizedxaqpus eggs by fluorescence photobleaching recovery (FPR) measurements. Out of a variety of commonly used lipid probes only the aminofluorescein-labeled fatty acids

Smart Mobility – Encouraging sustainable mobility behaviour by designing and implementing policies with citizen involvement

Directory of Open Access Journals (Sweden)

Edith Maier

2012-10-01

Full Text Available The paper discusses the theoretical concepts, design considerations and preliminary findings from Smart Mobility, a research project currently being undertaken with the City of St. Gallen. The project aims at designing measures to encourage the increased use of public and non-motorised transport by integrating behavioural economic principles into public policy. The extensive involvement of citizens and their participation in the design of the measures are to support their democratic legitimization and later acceptance. The paper describes the energy policies behind the project and outlines the theoretical framework for integrating behavioural insights into public policy. The strategies envisaged include participatory instruments and methods, especially the use of existing social media channels, capitalizing on social processes and norms to increase the motivation of individuals to use public transport, creating an open innovation space by means of crowdsourcing as well as the proper framing of political communication to achieve changes in mobility patterns.

Direct Growth of High Mobility and Low-Noise Lateral MoS2 -Graphene Heterostructure Electronics.

Science.gov (United States)

Behranginia, Amirhossein; Yasaei, Poya; Majee, Arnab K; Sangwan, Vinod K; Long, Fei; Foss, Cameron J; Foroozan, Tara; Fuladi, Shadi; Hantehzadeh, Mohammad Reza; Shahbazian-Yassar, Reza; Hersam, Mark C; Aksamija, Zlatan; Salehi-Khojin, Amin

2017-08-01

Reliable fabrication of lateral interfaces between conducting and semiconducting 2D materials is considered a major technological advancement for the next generation of highly packed all-2D electronic circuitry. This study employs seed-free consecutive chemical vapor deposition processes to synthesize high-quality lateral MoS 2 -graphene heterostructures and comprehensively investigated their electronic properties through a combination of various experimental techniques and theoretical modeling. These results show that the MoS 2 -graphene devices exhibit an order of magnitude higher mobility and lower noise metrics compared to conventional MoS 2 -metal devices as a result of energy band rearrangement and smaller Schottky barrier height at the contacts. These findings suggest that MoS 2 -graphene in-plane heterostructures are promising materials for the scale-up of all-2D circuitry with superlative electrical performance. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Suppression of surface-originated gate lag by a dual-channel AlN/GaN high electron mobility transistor architecture

International Nuclear Information System (INIS)

Deen, David A.; Storm, David F.; Scott Katzer, D.; Bass, R.; Meyer, David J.

2016-01-01

A dual-channel AlN/GaN high electron mobility transistor (HEMT) architecture is demonstrated that leverages ultra-thin epitaxial layers to suppress surface-related gate lag. Two high-density two-dimensional electron gas (2DEG) channels are utilized in an AlN/GaN/AlN/GaN heterostructure wherein the top 2DEG serves as a quasi-equipotential that screens potential fluctuations resulting from distributed surface and interface states. The bottom channel serves as the transistor's modulated channel. Dual-channel AlN/GaN heterostructures were grown by molecular beam epitaxy on free-standing hydride vapor phase epitaxy GaN substrates. HEMTs fabricated with 300 nm long recessed gates demonstrated a gate lag ratio (GLR) of 0.88 with no degradation in drain current after bias stressed in subthreshold. These structures additionally achieved small signal metrics f_t/f_m_a_x of 27/46 GHz. These performance results are contrasted with the non-recessed gate dual-channel HEMT with a GLR of 0.74 and 82 mA/mm current collapse with f_t/f_m_a_x of 48/60 GHz.

Suppression of surface-originated gate lag by a dual-channel AlN/GaN high electron mobility transistor architecture

Energy Technology Data Exchange (ETDEWEB)

Deen, David A., E-mail: david.deen@alumni.nd.edu; Storm, David F.; Scott Katzer, D.; Bass, R.; Meyer, David J. [Naval Research Laboratory, Electronics Science and Technology Division, Washington, DC 20375 (United States)

2016-08-08

A dual-channel AlN/GaN high electron mobility transistor (HEMT) architecture is demonstrated that leverages ultra-thin epitaxial layers to suppress surface-related gate lag. Two high-density two-dimensional electron gas (2DEG) channels are utilized in an AlN/GaN/AlN/GaN heterostructure wherein the top 2DEG serves as a quasi-equipotential that screens potential fluctuations resulting from distributed surface and interface states. The bottom channel serves as the transistor's modulated channel. Dual-channel AlN/GaN heterostructures were grown by molecular beam epitaxy on free-standing hydride vapor phase epitaxy GaN substrates. HEMTs fabricated with 300 nm long recessed gates demonstrated a gate lag ratio (GLR) of 0.88 with no degradation in drain current after bias stressed in subthreshold. These structures additionally achieved small signal metrics f{sub t}/f{sub max} of 27/46 GHz. These performance results are contrasted with the non-recessed gate dual-channel HEMT with a GLR of 0.74 and 82 mA/mm current collapse with f{sub t}/f{sub max} of 48/60 GHz.

Lateral mobility of plasma membrane lipids in a molluscan egg: Evidence for an animal/vegetal polarity

OpenAIRE

Laat, S.W. de; Speksnijder, J.E.; Dohmen, M.R.; Zoelen, E. van; Tertoolen, L.G.J.; Bluemink, J.G.

1984-01-01

The lateral diffusion of the lipid analog C₁₄-diI (3', 3'-dihexadecylindocarbocyanine iodide) was measured in the plasma membrane of early embryos of the mollusc Nassarius reticulatus using the FPR-(Fluorescence Photobleaching Recovery) method. At almost all stages measured (from fertilized egg up to 8-cell stage) the diffusion coefficient (D) of the mobile fraction (MF) of C₁₄-diI is significantly higher in the plasma membrane of the polar lobe as compared to the plasma membrane of the anima...

Consumers’ Attitudes Towards Mobile Marketing and Mobile Commerce in Consumer Markets

OpenAIRE

Suleyman Barutcu

2008-01-01

Advances in information and communication technologies are not only offering new marketing channels to companies but also significantly influencing the ways in which companies conduct their businesses and marketing activities. This paper analyses the possible significant impacts of mobile phone technology developments on marketing, and offers insights into mobile commerce and mobile marketing, which have not previously been investigated in Turkey. In the survey, mobile phone users' attitudes ...

RAC-Multi: Reader Anti-Collision Algorithm for Multichannel Mobile RFID Networks

Directory of Open Access Journals (Sweden)

Kwangcheol Shin

2009-12-01

Full Text Available At present, RFID is installed on mobile devices such as mobile phones or PDAs and provides a means to obtain information about objects equipped with an RFID tag over a multi-channeled telecommunication networks. To use mobile RFIDs, reader collision problems should be addressed given that readers are continuously moving. Moreover, in a multichannel environment for mobile RFIDs, interference between adjacent channels should be considered. This work first defines a new concept of a reader collision problem between adjacent channels and then suggests a novel reader anti-collision algorithm for RFID readers that use multiple channels. To avoid interference with adjacent channels, the suggested algorithm separates data channels into odd and even numbered channels and allocates odd-numbered channels first to readers. It also sets an unused channel between the control channel and data channels to ensure that control messages and the signal of the adjacent channel experience no interference. Experimental results show that suggested algorithm shows throughput improvements ranging from 29% to 46% for tag identifications compared to the GENTLE reader anti-collision algorithm for multichannel RFID networks.

Adoption and Business Value of Mobile Retail Channel: A Dependency Perspective on Mobile Commerce

Science.gov (United States)

Chou, Yen-Chun

2013-01-01

Forrest Research estimated that revenues derived from mobile devices will grow at an annual rate of 39% to reach $31 billion by 2016. With the tremendous market growth, mobile banking, mobile marketing, and mobile retailing have been recently introduced to satisfy customer needs. Academic and practical articles have widely discussed unique…

Problems of noise modeling in the presence of total current branching in high electron mobility transistor and field-effect transistor channels

International Nuclear Information System (INIS)

Shiktorov, P; Starikov, E; Gružinskis, V; Varani, L; Sabatini, G; Marinchio, H; Reggiani, L

2009-01-01

In the framework of analytical and hydrodynamic models for the description of carrier transport and noise in high electron mobility transistor/field-effect transistor channels the main features of the intrinsic noise of transistors are investigated under continuous branching of the current between channel and gate. It is shown that the current-noise and voltage-noise spectra at the transistor terminals contain an excess noise related to thermal excitation of plasma wave modes in the dielectric layer between the channel and gate. It is found that the set of modes of excited plasma waves can be governed by the external embedding circuits, thus violating a universal description of noise in terms of Norton and Thevenin noise generators

The absence of chlorophyll b affects lateral mobility of photosynthetic complexes and lipids in grana membranes of Arabidopsis and barley chlorina mutants.

Science.gov (United States)

Tyutereva, Elena V; Evkaikina, Anastasiia I; Ivanova, Alexandra N; Voitsekhovskaja, Olga V

2017-09-01

The lateral mobility of integral components of thylakoid membranes, such as plastoquinone, xanthophylls, and pigment-protein complexes, is critical for the maintenance of efficient light harvesting, high rates of linear electron transport, and successful repair of damaged photosystem II (PSII). The packaging of the photosynthetic pigment-protein complexes in the membrane depends on their size and stereometric parameters which in turn depend on the composition of the complexes. Chlorophyll b (Chlb) is an important regulator of antenna size and composition. In this study, the lateral mobility (the mobile fraction size) of pigment-protein complexes and lipids in grana membranes was analyzed in chlorina mutants of Arabidopsis and barley lacking Chlb. In the Arabidopsis ch1-3 mutant, diffusion of membrane lipids decreased as compared to wild-type plants, but the diffusion of photosynthetic complexes was not affected. In the barley chlorina f2 3613 mutant, the diffusion of pigment-protein complexes significantly decreased, while the diffusion of lipids increased, as compared to wild-type plants. We propose that the size of the mobile fractions of pigment-protein complexes in grana membranes in vivo is higher than reported previously. The data are discussed in the context of the protein composition of antennae, characteristics of the plastoquinone pool, and production of reactive oxygen species in leaves of chlorina mutants.

Spin relaxation through lateral spin transport in heavily doped n -type silicon

Science.gov (United States)

Ishikawa, M.; Oka, T.; Fujita, Y.; Sugiyama, H.; Saito, Y.; Hamaya, K.

2017-03-01

We experimentally study temperature-dependent spin relaxation including lateral spin diffusion in heavily doped n -type silicon (n+-Si ) layers by measuring nonlocal magnetoresistance in small-sized CoFe/MgO/Si lateral spin-valve (LSV) devices. Even at room temperature, we observe large spin signals, 50-fold the magnitude of those in previous works on n+-Si . By measuring spin signals in LSVs with various center-to-center distances between contacts, we reliably evaluate the temperature-dependent spin diffusion length (λSi) and spin lifetime (τSi). We find that the temperature dependence of τSi is affected by that of the diffusion constant in the n+-Si layers, meaning that it is important to understand the temperature dependence of the channel mobility. A possible origin of the temperature dependence of τSi is discussed in terms of the recent theories by Dery and co-workers.

Mobile Advertising : A Case study of Mobile advertising Solutions

OpenAIRE

Salim, Ali; Alikhani, Nima

2009-01-01

This report has been produced as a result of a Thesis assignment conducted at Ericsson. Itspurpose is to give an overview of the Mobile Advertising industry. In this report an overviewof mobile advertising is presented and thru which channels advertising could be used. Thenthree mobile advertising campaigns are shown and described with background, strategy andresults. The different global markets, the different actors in the value chain and how the onlinebehavior has changed are analyzed. The...

Computer models for fading channels with applications to digital transmission

Science.gov (United States)

Loo, Chun; Secord, Norman

1991-11-01

The authors describe computer models for Rayleigh, Rician, log-normal, and land-mobile-satellite fading channels. All computer models for the fading channels are based on the manipulation of a white Gaussian random process. This process is approximated by a sum of sinusoids with random phase angle. These models compare very well with analytical models in terms of their probability distribution of envelope and phase of the fading signal. For the land mobile satellite fading channel, results of level crossing rate and average fade duration are given. These results show that the computer models can provide a good coarse estimate of the time statistic of the faded signal. Also, for the land-mobile-satellite fading channel, the results show that a 3-pole Butterworth shaping filter should be used with the model. An example of the application of the land-mobile-satellite fading-channel model to predict the performance of a differential phase-shift keying signal is described.

Lateral Erosion Encourages Vertical Incision in a Bimodal Alluvial River

Science.gov (United States)

Gran, K. B.

2015-12-01

Sand can have a strong impact on gravel transport, increasing gravel transport rates by orders of magnitude as sand content increases. Recent experimental work by others indicates that adding sand to an armored bed can even cause armor to break-up and mobilize. These two elements together help explain observations from a bimodal sand and gravel-bedded river, where lateral migration into sand-rich alluvium breaks up the armor layer, encouraging further incision into the bed. Detailed bedload measurements were coupled with surface and subsurface grain size analyses and cross-sectional surveys in a seasonally-incised channel carved into the upper alluvial fan of the Pasig-Potrero River at Mount Pinatubo, Philippines. Pinatubo erupted in 1991, filling valleys draining the flanks of the volcano with primarily sand-sized pyroclastic flow debris. Twenty years after the eruption, sand-rich sediment inputs are strongly seasonal, with most sediment input to the channel during the rainy season. During the dry season, flow condenses from a wide braided planform to a single-thread channel in most of the upper basin, extending several km onto the alluvial fan. This change in planform creates similar unit discharge ranges in summer and winter. Lower sediment loads in the dry season drive vertical incision until the bed is sufficiently armored. Incision proceeds downstream in a wave, with increasing sediment transport rates and decreasing grain size with distance downstream, eventually reaching a gravel-sand transition and return to a braided planform. Incision depths in the gravel-bedded section exceeded 3 meters in parts of a 4 km-long study reach, a depth too great to be explained by predictions from simple winnowing during incision. Instead, lateral migration into sand-rich alluvium provides sufficient fine sediment to break up the armor surface, allowing incision to start anew and increasing the total depth of the seasonally-incised valley. Lateral migration is recorded in a

Lateral and vertical channel movement and potential for bed-material movement on the Madison River downstream from Earthquake Lake, Montana

Science.gov (United States)

Chase, Katherine J.; McCarthy, Peter M.

2012-01-01

and to investigate the potential for bed material movement along the same reach. The purpose of this report is to present information about the lateral and vertical movement of the Madison River from 1970 to 2006 for a 1-mile reach downstream from Earthquake Lake and for Raynolds Pass Bridge, and to provide an analysis of the potential for bed-material movement so that MADTAC can evaluate the applicability of the previously determined threshold streamflow for initiation of damaging erosion. As part of this study channel cross sections originally surveyed by the USGS in 1971 were resurveyed in 2006. Incremental channel-movement distances were determined by comparing the stream centerlines from 14 aerial photographs taken between 1970 and 2006. Depths of channel incision and aggregation were determined by comparing the 2006 and 1971 cross-section and water-surface data. Particle sizes of bed and bank materials were measured in 2006 and 2008 using the pebble-count method and sieve analyses. A one-dimensional hydraulic-flow model (HEC-RAS) was used to calculate mean boundary-shear stresses for various streamflows; these calculated boundary-shear stresses were compared to calculated critical-shear stresses for the bed materials to determine the potential for bed-material movement. A comparison of lateral channel movement distances with annual peak streamflows shows that streamflows higher than the 3,500-ft3/s threshold were followed by lateral channel movement except from 1991 to 1992 and possibly from 1996 to 1997. However, it was not possible to discern whether the channel moved gradually or suddenly, or in response to one peak flow, to several peak flows, or to sustained flows. The channel moved between 2002 and 2005 even when streamflows were less than the threshold streamflow of 3,500 ft3/s. Comparisons of cross sections and aerial photographs show that the channel has moved laterally and incised and aggraded to varying degrees. The channel has developed meander bends

Historical perspectives on channel pattern in the Clark Fork River, Montana and implications for post-dam removal restoration

Science.gov (United States)

Woelfle-Erskine, C. A.; Wilcox, A. C.

2009-12-01

Active restoration approaches such as channel reconstruction have moved beyond the realm of small streams and are being applied to larger rivers. Uncertainties arising from limited knowledge, fluvial and ecosystem variability, and contaminants are especially significant in restoration of large rivers, where project costs and the social, infrastructural, and ecological costs of failure are high. We use the case of Milltown Dam removal on the Clark Fork River, Montana and subsequent channel reconstruction in the former reservoir to examine the use of historical research and uncertainty analysis in river restoration. At a cost of approximately $120 million, the Milltown Dam removal involves the mechanical removal of approximately 2 million cubic meters of sediments contaminated by upstream mining, followed by restoration of the former reservoir reach in which a single-thread meandering channel is being constructed. Historical maps, surveys, photographs, and accounts suggest a conceptual model of a multi-thread, anastomosing river in the reach targeted for channel reconstruction, upstream of the confluence of the Clark Fork and Blackfoot Rivers. We supplemented historical research with analysis of aerial photographs, topographic data, and USGS stage-discharge measurements in a lotic but reservoir-influenced reach of the Clark Fork River within our study area to estimate avulsion frequency (0.8 avulsions/year over a 70-year period) and average rates of lateral migration and aggradation. These were used to calculate the mobility number, a dimensionless relationship between channel filling and lateral migration timescales that can be used to predict whether a river’s planform is single or multi-threaded. The mobility number within our study reach ranged from 0.6 (multi-thread channel) to 1.7 (transitional channel). We predict that, in the absence of active channel reconstruction, the post-dam channel pattern would evolve to one that alternates between single and multi

Lateral Scapular Slide Test and Scapular Mobility in Volleyball Players

Science.gov (United States)

Ozunlu, Nihan; Tekeli, Hatice; Baltaci, Gul

2011-01-01

Context: The stability of the scapula in relation to the entire moving upper extremity is the key in the throwing sequence. The importance of scapular positioning in volleyball players has been well documented in the literature, but no one has compared scapular positioning between volleyball players and sedentary people. Objective: To compare measurements of scapular mobility obtained using the lateral scapular slide test between volleyball players and sedentary participants without shoulder impairments and to compare changes in scapular mobility in players according to the number of years of sport participation. Design: Cross-sectional study. Setting: University research laboratory. Patients or Other Participants: A total of 121 people at a single university volunteered. Of these, 67 were sedentary (age = 24.3 ± 2.34 years, height = 1.69 ± 0.09 m, mass = 65.1 ± 11.91 kg); 54 were volleyball players from 4 professional teams and were separated into 2 groups according to their years of sport participation. The first group was named young players (n = 31; age = 17.7 ± 2.58 years, height = 1.83 ± 0.10 m, mass = 68.3 ± 12.21 kg, sport participation ≤ 9 years), and the second group was named old players (n = 23; age = 26.9 ± 3.39 years, height = 1.95 ± 4.38 m, mass = 90.7 ± 5.75 kg, sport participation ≥ 10 years). Main Outcome Measure(s): Study participants completed a rating scale for pain and a questionnaire about demographic and shoulder problems. One assessor performed the lateral scapular slide test and additional flexibility measurements around the shoulder girdle. Flexibility (external rotation, internal rotation) and scapular position (1, 2, 3) were compared among groups (young players, old players, sedentary people) and between sides (dominant, nondominant). Results: In sedentary participants, we found differences for position 1 (t66 = 3.327, P = .002), position 2 (t66 = 2.491, P = .004), position 3 (t66 = 2.512, P = .006), and internal rotation

Lateral control strategy for a hypersonic cruise missile

Directory of Open Access Journals (Sweden)

Yonghua Fan

2017-04-01

Full Text Available Hypersonic cruise missile always adopts the configuration of waverider body with the restraint of scramjet. As a result, the lateral motion exhibits serious coupling, and the controller design of the lateral lateral system cannot be conducted separately for yaw channel and roll channel. A multiple input and multiple output optimal control method with integrators is presented to design the lateral combined control system for hypersonic cruise missile. A hypersonic cruise missile lateral model is linearized as a multiple input and multiple output plant, which is coupled by kinematics and fin deflection between yaw and roll. In lateral combined controller, the integrators are augmented, respectively, into the loop of roll angle and lateral overload to ensure that the commands are tracked with zero steady-state error. Through simulation, the proposed controller demonstrates good performance in tracking the command of roll angle and lateral overload.

Temperature dependence of ballistic mobility in a metamorphic InGaAs/InAlAs high electron mobility transistor

International Nuclear Information System (INIS)

Lee, Jongkyong; Gang, Suhyun; Jo, Yongcheol; Kim, Jongmin; Woo, Hyeonseok; Han, Jaeseok; Kim, Hyungsang; Im, Hyunsik

2014-01-01

We have investigated the temperature dependence of ballistic mobility in a 100 nm-long InGaAs/InAlAs metamorphic high-electron-mobility transistor designed for millimeter-wavelength RF applications. To extract the temperature dependence of quasi-ballistic mobility, our experiment involves measurements of the effective mobility in the low-bias linear region of the transistor and of the collision-dominated Hall mobility using a gated Hall bar of the same epitaxial structure. The data measured from the experiment are consistent with that of modeled ballistic mobility based on ballistic transport theory. These results advance the understanding of ballistic transport in various transistors with a nano-scale channel length that is comparable to the carrier's mean free path in the channel.

The Meaning of Social Participation for Daily Mobility in Later Life: an Ethnographic Case Study of a Senior Project in a Swedish Urban Neighbourhood.

Science.gov (United States)

Stjernborg, Vanessa

2017-01-01

This paper presents an ethnographic case study that aims to understand the meaning of social participation in a neighbourhood for daily mobility in later life. In the study, the mobility of the participants of a senior-citizen project was monitored over 18 months. The project was founded as a result of a municipal district's targeting of social sustainability. The results show that social participation had positive effects on the daily mobility of the participants. The implementation of broad-minded thinking from the municipality and the cooperation of various municipal actors were shown to be essential for the positive outcome of this project.

Long-term exposure to mobile communication radiation: An analysis of time-variability of electric field level in GSM900 down-link channels

International Nuclear Information System (INIS)

Miclaus, S.; Bechet, P.; Gheorghevici, M.

2013-01-01

Interest for knowing long-term human exposure levels due to mobile communications has increased in the last years. It has been shown that short-term exposure assessment made under standard procedural restrictions is not reliable when it comes to conclusions on long-term exposure levels. The present work is the result of a several week analysis of time variability of electric field level inside traffic and control channels of the GSM900 mobile communication down-link band and it indicates that a temporal model to allow future predictions of exposure on the long run is obtainable. Collecting, processing and statistically analysing the data provide expression of the maximum and weighted field strengths and their evolution in time. Specific electromagnetic footprints of the channels have been extracted, differentiations between their characteristics have been emphasised and practical advice is provided, with the scope of contributing to the development of reliable procedures for long-term exposure assessment. (authors)

A propagation-measurement-based evaluation of channel characteristics and models pertinent to the expansion of mobile radio systems to frequencies beyond 2 GHz

NARCIS (Netherlands)

Bultitude, R.J.C.; Schenk, T.C.W.; Op de Kamp, N.A.A.; Adnani, N.

2007-01-01

64This paper concerns the measurement-based comparison of urban microcellular mobile radio channel characteristics at 1.9 GHz and a higher frequency, i.e., 5.8 GHz, where future wireless systems could operate. Characteristics that are reported include transmission loss, root-mean-square delay

Lateral mobility of plasma membrane lipids in Xenopus eggs: Regional differences related to animal/vegetal polarity become extreme upon fertilization

OpenAIRE

Bluemink, J.G.; Dictus, W.J.A.G.; Zoelen, E.J.J. van; Tetteroo, P.A.T.; Tertoolen, L.G.J.; Laat, S.W. de

1984-01-01

Regional differences in the lateral mobility properties of plasma membrane lipids have been studied in unfertilized and fertilizedxaqpus eggs by fluorescence photobleaching recovery (FPR) measurements. Out of a variety of commonly used lipid probes only the aminofluorescein-labeled fatty acids HEDAF (5-(N-hexadecanoyl)-aminofluorescein) and TEDAF (5-(N-tetradecanoyl)-aminofluorescein) appear to partition into the plasma membrane. Under all experimental conditions used these molecules show par...

Wireless-Uplinks-Based Energy-Efficient Scheduling in Mobile Cloud Computing

Directory of Open Access Journals (Sweden)

Xing Liu

2015-01-01

Full Text Available Mobile cloud computing (MCC combines cloud computing and mobile internet to improve the computational capabilities of resource-constrained mobile devices (MDs. In MCC, mobile users could not only improve the computational capability of MDs but also save operation consumption by offloading the mobile applications to the cloud. However, MCC faces the problem of energy efficiency because of time-varying channels when the offloading is being executed. In this paper, we address the issue of energy-efficient scheduling for wireless uplink in MCC. By introducing Lyapunov optimization, we first propose a scheduling algorithm that can dynamically choose channel to transmit data based on queue backlog and channel statistics. Then, we show that the proposed scheduling algorithm can make a tradeoff between queue backlog and energy consumption in a channel-aware MCC system. Simulation results show that the proposed scheduling algorithm can reduce the time average energy consumption for offloading compared to the existing algorithm.

Characterization of Series Resistance and Mobility Degradation Parameter and Optimizing Choice of Oxide Thickness in Thin Oxide N-Channel MOSFET

Directory of Open Access Journals (Sweden)

Noureddine Maouhoub

2011-01-01

Full Text Available We present two methods to extract the series resistance and the mobility degradation parameter in short-channel MOSFETs. The principle of the first method is based on the comparison between the exponential model and the classical model of effective mobility and for the second method is based on directly calculating the two parameters by solving a system of two equations obtained by using two different points in strong inversion at small drain bias from the characteristic (. The results obtained by these techniques have shown a better agreement with data measurements and allowed in the same time to determine the surface roughness amplitude and its influence on the maximum drain current and give the optimal oxide thickness.

Atomic-Monolayer Two-Dimensional Lateral Quasi-Heterojunction Bipolar Transistors with Resonant Tunneling Phenomenon

KAUST Repository

Lin, Che-Yu

2017-10-04

High-frequency operation with ultra-thin, lightweight and extremely flexible semiconducting electronics are highly desirable for the development of mobile devices, wearable electronic systems and defense technologies. In this work, the first experimental observation of quasi-heterojunction bipolar transistors utilizing a monolayer of the lateral WSe2-MoS2 junctions as the conducting p-n channel is demonstrated. Both lateral n-p-n and p-n-p heterojunction bipolar transistors are fabricated to exhibit the output characteristics and current gain. A maximum common-emitter current gain of around 3 is obtained in our prototype two-dimensional quasi-heterojunction bipolar transistors. Interestingly, we also observe the negative differential resistance in the electrical characteristics. A potential mechanism is that the negative differential resistance is induced by resonant tunneling phenomenon due to the formation of quantum well under applying high bias voltages. Our results open the door to two-dimensional materials for high-frequency, high-speed, high-density and flexible electronics.

Atomic-Monolayer Two-Dimensional Lateral Quasi-Heterojunction Bipolar Transistors with Resonant Tunneling Phenomenon

KAUST Repository

Lin, Che-Yu; Zhu, Xiaodan; Tsai, Shin-Hung; Tsai, Shiao-Po; Lei, Sidong; Li, Ming-Yang; Shi, Yumeng; Li, Lain-Jong; Huang, Shyh-Jer; Wu, Wen-Fa; Yeh, Wen-Kuan; Su, Yan-Kuin; Wang, Kang L.; Lan, Yann-Wen

2017-01-01

High-frequency operation with ultra-thin, lightweight and extremely flexible semiconducting electronics are highly desirable for the development of mobile devices, wearable electronic systems and defense technologies. In this work, the first experimental observation of quasi-heterojunction bipolar transistors utilizing a monolayer of the lateral WSe2-MoS2 junctions as the conducting p-n channel is demonstrated. Both lateral n-p-n and p-n-p heterojunction bipolar transistors are fabricated to exhibit the output characteristics and current gain. A maximum common-emitter current gain of around 3 is obtained in our prototype two-dimensional quasi-heterojunction bipolar transistors. Interestingly, we also observe the negative differential resistance in the electrical characteristics. A potential mechanism is that the negative differential resistance is induced by resonant tunneling phenomenon due to the formation of quantum well under applying high bias voltages. Our results open the door to two-dimensional materials for high-frequency, high-speed, high-density and flexible electronics.

Atomic-Monolayer Two-Dimensional Lateral Quasi-Heterojunction Bipolar Transistors with Resonant Tunneling Phenomenon.

Science.gov (United States)

Lin, Che-Yu; Zhu, Xiaodan; Tsai, Shin-Hung; Tsai, Shiao-Po; Lei, Sidong; Shi, Yumeng; Li, Lain-Jong; Huang, Shyh-Jer; Wu, Wen-Fa; Yeh, Wen-Kuan; Su, Yan-Kuin; Wang, Kang L; Lan, Yann-Wen

2017-11-28

High-frequency operation with ultrathin, lightweight, and extremely flexible semiconducting electronics is highly desirable for the development of mobile devices, wearable electronic systems, and defense technologies. In this work, the experimental observation of quasi-heterojunction bipolar transistors utilizing a monolayer of the lateral WSe 2 -MoS 2 junctions as the conducting p-n channel is demonstrated. Both lateral n-p-n and p-n-p heterojunction bipolar transistors are fabricated to exhibit the output characteristics and current gain. A maximum common-emitter current gain of around 3 is obtained in our prototype two-dimensional quasi-heterojunction bipolar transistors. Interestingly, we also observe the negative differential resistance in the electrical characteristics. A potential mechanism is that the negative differential resistance is induced by resonant tunneling phenomenon due to the formation of quantum well under applying high bias voltages. Our results open the door to two-dimensional materials for high-frequency, high-speed, high-density, and flexible electronics.

THE RISE OF MOBILE BANKING

Directory of Open Access Journals (Sweden)

IMOLA DRIGĂ

2015-12-01

Full Text Available To meet customer’s expectations and needs, electronic banking services have allowed financial transactions to simplify and have increased their attractiveness. Over the past few year, in order to increase customer comfort and maintain profitability, banks around the world have adopted innovative banking technologies and modern e-banking services, such as internet and mobile banking. As a matter of fact, banking over mobile phones is the newest e-banking service with several benefits for both customers and banks. The paper aims to provide an overview of the latest electronic financial channel, underlining various aspects of mobile banking as it represents a key distribution channel for a growing number of customers.

Trends in Mobile Marketing

OpenAIRE

Chocholová, Petra

2010-01-01

The principal aim of this thesis is to assess the state of the mobile marketing as of the first quarter of 2011 and to discuss various scenarios of the future development. This thesis defines the terms "mobile marketing" and "mobile advertising" and identifies the main players in the industry. It explores the main categories of mobile advertising such as mobile messaging, in-content and mobile internet advertising. Later, it analyzes the latest trends in the industry and describes in detail t...

QUEUING ANALYSIS OF CAR SERVICING CUSTOMERS USED SINGLE CHANNEL MODEL AND KENDALL'S NOTATION IN PT. ARMADA MOBIL PURWOKERTO

Directory of Open Access Journals (Sweden)

Tugiyono

2013-04-01

Full Text Available This study aims to identify the customer’s problem queue, specify the model queue, the arrival and customer service frequency distributions at PT. Armada Mobil Purwokerto. Methods of the research conducted by observing and measuring directly the research object, the data from the study was calculated according to the theory of queues. The result appropriate to single channel queuing model Poisson distribution of the arrivals, exponential distribution of the time service. The characteristized of Kendall’s notation is M/M/3/3/571.

Potassium channels as drugs targets in therapy of cardiovascular diseases: 25 years later

Directory of Open Access Journals (Sweden)

Protić Dragana

2013-03-01

Full Text Available Potassium channels are the most variable ion channel group. They participate in numerous cardiovascular functions, for example regulation of vascular tone, maintenance of resting cardiac membrane potential and excitability of cardiac conduction tissue. Both drugs and endogenous ligands could modulate potassium channel function, belonging to the potassium channel blockers or openers. Modulation of potassium channels could be a therapeutic or adverse drug action. Class III antiarrhythmic agents block the potassium channels, thereby prolonging repolarization phase of action potential with resulting prolongation of effective refractory period. Their effectiveness against supraventricular and ventricular arrhythmias should be weighted against their proarrhythmogenic potential. In addition, numerous other antiarrhythmic agents could modulate potassium channels as well. Diazoxide, minoxidil and nicorandil (well known arterial vasodilators, as well as numerous newly synthesized substances with still unknown therapeutic potential, belong to the potassium channel activators/openers. Therapeutic use of such vasodilators may involve treatment of hypertension (diazoxide, minoxidil and stable angina (nicorandil. Their use might be accompanied with side effects, such as vasodilation, edema, hypotension and reflex tachycardia. Potassium channel openers have also an important role in the treatment of peripheral vascular disease and pulmonary hypertension. In the future, drugs with selective effects on the vascular or cardiac potassium channels could be useful therapeutic agents.

POTASSIUM CHANNELS AS DRUGS TARGETS IN THERAPY OF CARDIOVASCULAR DESEASES: 25 YEARS LATER

Directory of Open Access Journals (Sweden)

Protić Dragana

2013-01-01

Full Text Available Potassium channels are the most variable ion channel group. They participate in numerous cardiovascular functions, for example regulation of vascular tone, maintenance of resting cardiac membrane potential and excitability of cardiac conduction tissue. Both drugs and endogenous ligands could modulate potassium channel function, belonging to the potassium channel blockers or openers. Modulation of potassium channels could be a therapeutic or adverse drug action. Class III antiarrhythmic agents block the potassium channels, thereby prolonging repolarization phase of action potential with resulting prolongation of effective refractory period. Their effectiveness against supraventricular and ventricular arrhythmias should be weighted against their proarrhythmogenic potential. In addition, numerous other antiarrhythmic agents could modulate potassium channels as well. Diazoxide, minoxidil and nicorandil (well known arterial vasodilators, as well as numerous newly synthesized substances with still unknown therapeutic potential, belong to the potassium channel activators/ openers. Therapeutic use of such vasodilators may involve treatment of hypertension (diazoxide, minoxidil and stable angina (nicorandil. Their use might be accompanied with side effects, such as vasodilation, edema, hypotension and reflex tachycardia. Potassium channel openers have also an important role in the treatment of peripheral vascular disease and pulmonary hypertension. In the future, drugs with selective effects on the vascular or cardiac potassium channels could be useful therapeutic agents.

Channel box

International Nuclear Information System (INIS)

Tanabe, Akira.

1993-01-01

In a channel box of a BWR type reactor, protruding pads are disposed in axial position on the lateral side of a channel box opposing to a control rod and facing the outer side portion of the control rod in a reactor core loaded state. In the initial loading stage of fuel assemblies, channel fasteners and spacer pads are abutted against each other in the upper portion between the channel boxes sandwiching the control rod therebetween. Further, in the lower portion, a gap as a channel for the movement of the control rod is ensured by the support of fuel support metals. If the channel box is bent toward the control rod along with reactor operation, the pads are abutted against each other to always ensure the gap through which the control rod can move easily. Further, when the pads are brought into contact with each other, the bending deformation of the channel box is corrected by urging to each other. Thus, the control rod can always be moved smoothly to attain reactor safety operation. (N.H.)

Understanding channel and contact effects on transport in 1-dimensional nanotransistors.

Energy Technology Data Exchange (ETDEWEB)

Swartzentruber, Brian S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Delker, Collin James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Yoo, Jinkyoung [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Janes, David B. [Purdue Univ., West Lafayette, IN (United States)

2015-02-01

Nanowire transistors are generally formed by metal contacts to a uniformly doped nanowire. The transistor can be modeled as a series combination of resistances from both the channel and the contacts. In this study, a simple model is proposed consisting of a resistive channel in series with two Schottky metal-semiconductor contacts modeled using the WKB approximation. This model captures several phenomena commonly observed in nanowire transistor measurements, including the mobility as a function of gate potential, mobility reduction with respect to bulk mobility, and non-linearities in output characteristics. For example, the maximum measured mobility as a function of gate voltage in a nanowire transistor can be predicted based on the semiconductor bulk mobility in addition to barrier height and other properties of the contact. The model is then extended to nanowires with axial p-n junctions having an inde- pendent gate over each wire segment by splitting the channel resistance into a series component for each doping segment. Finally, the contact-channel model is applied to low-frequency noise analysis in nanowire devices, where the noise can be generated in both the channel and the contacts. Because contacts play a major, yet often neglected, role in nanowire transistor operation, they must be accounted for in order to extract meaningful parameters from I-V and noise measurements.

Negative differential resistance of InGaAs dual channel transistors

International Nuclear Information System (INIS)

Sugaya, T; Yamane, T; Hori, S; Komori, K; Yonei, K

2006-01-01

We demonstrate a new type of velocity modulation transistor (VMT) with an InGaAs dual channel structure fabricated on an InP (001) substrate. The dual channel structure consists of a high mobility 10 nm In 0.53 Ga 0.47 As quantum well, a 2 nm In 0.52 Al 0.48 As barrier layer, and a low mobility 1 nm In 0.26 Ga 0.74 As quantum well. The VMTs have a negative differential resistance (NDR) effect with a low source-drain voltage of 0.38 V. The NDR characteristics can be clearly seen in the temperature range of 50 to 220 K with a gate voltage of 5 V. The NDR mechanism is thought to be the carrier transfer from the high mobility to the low mobility channels. Three-terminal VMTs are favorable for applications to highfrequency, high-speed, and low-power consumption devices

Interface Engineering for Precise Threshold Voltage Control in Multilayer-Channel Thin Film Transistors

KAUST Repository

Park, Jihoon

2016-11-29

Multilayer channel structure is used to effectively manipulate the threshold voltage of zinc oxide transistors without degrading its field-effect mobility. Transistors operating in enhancement mode with good mobility are fabricated by optimizing the structure of the multilayer channel. The optimization is attributed to the formation of additional channel and suppression of the diffusion of absorbed water molecules and oxygen vacancies.

Interface Engineering for Precise Threshold Voltage Control in Multilayer-Channel Thin Film Transistors

KAUST Repository

Park, Jihoon; Alshammari, Fwzah Hamud; Wang, Zhenwei; Alshareef, Husam N.

2016-01-01

Multilayer channel structure is used to effectively manipulate the threshold voltage of zinc oxide transistors without degrading its field-effect mobility. Transistors operating in enhancement mode with good mobility are fabricated by optimizing the structure of the multilayer channel. The optimization is attributed to the formation of additional channel and suppression of the diffusion of absorbed water molecules and oxygen vacancies.

Low-temperature mobility measurements on CMOS devices

International Nuclear Information System (INIS)

Hairpetian, A.; Gitlin, D.; Viswanathan, C.R.

1989-01-01

The surface channel mobility of carriers in eta- and rho-MOS transistors fabricated in a CMOS process was accurately determined at low temperatures down to 5 Κ. The mobility was obtained by an accurate measurement of the inversion charge density using a split C-V technique and the conductance at low drain voltages. The split C-V technique was validated at all temperatures using a one-dimensional Poisson solver (MOSCAP), which was modified for low-temperature application. The mobility dependence on the perpendicular electric field for different substrate bias values appears to have different temperature dependence for eta- and rho-channel devices. The electron mobility increases with a decrease in temperature at all gate voltages. On the other hand, the hole mobility exhibits a different temperature behavior depending upon whether the gate voltage corresponds to strong inversion or is near threshold

[Mobility of a polyethylene tibial insert in a mobile total knee prosthesis].

Science.gov (United States)

Castel, E; Roger, B; Camproux, A; Saillant, G

1999-03-01

We have studied the mobility of a mobile tibial implant in total knee arthroplasty (TKA) by a radiographical evaluation. We analyzed mobility of the polyethylene tibial insert of 15 "G2S" TKA implanted for one year or more. We established a dynamic radiographical evaluation. We used 3 weight-bearing radiographs: AP in extension and two lateral (one in extension and one at 90 degrees of flexion), two AP with femoral internal and external rotation, 2 strict lateral X-rays in neutral rotation in antero-posterior replacement with a 25 kilograms strength Telos, and 2 AP in varus and valgus with Telos. Wilcoxon's test and Fisher's exact test were used for statistical evaluation. Our study demonstrated preservation of the polyethylene mobility in tibial TKA implant in all movements: in rotation, in antero-posterior translation with Telos, and even in antero-posterior translation during physiological condition with flexion-extension weight-bearing radiographs. Statistical tests were very significant. We noticed that flexion induced anterior translation of tibial polyethylene when PCL was preserved. This study answered to our question whether mobility of TKA tibial implant persists after implantation. This mobility should reduce loosening forces to the tibia and stress in the polyethylene component. Now we have to determine the amplitude of mobility required to reach this objective.

Regional differences in the lateral mobility of plasma membrane lipids in a molluscan embryo.

Science.gov (United States)

Speksnijder, J E; Dohmen, M R; Tertoolen, L G; de Laat, S W

1985-07-01

Regional and temporal differences in plasma membrane lipid mobility have been analyzed during the first three cleavage cycles of the embryo of the polar-lobe-forming mollusc Nassarius reticulatus by the fluorescence photobleaching recovery (FPR) method, using 1,1'-ditetradecyl 3,3,3',3'-tetramethylindocarbocyanine iodide (C14diI) as a fluorescent lipid probe. During this period of development the lateral diffusion coefficient of membrane lipids is consistently greater in the vegetal polar lobe area as compared to the animal plasma membrane area (on average 30%), demonstrating the existence of an animal-vegetal polarity in plasma membrane properties. At third cleavage, the differences between animal and vegetal plasma membrane region become even more pronounced; in the four animal micromeres the diffusion coefficient (D) and mobile fraction (MF) are 2.9 +/- 0.2 X 10(-9) cm2/sec and 51 +/- 2%, respectively, while in the four vegetal macromeres D = 5.0 +/- 0.3 X 10(-9) cm2/sec and MF = 78 +/- 2%. Superimposed upon the observed animal-vegetal polarity, the lateral diffusion in the polar lobe membrane area shows a cell-cycle-dependent modulation. The highest mean values for D are reached during the S phase (ranging from 7.0 to 7.8 X 10(-9) cm2/sec in the three cycles measured), while at the end of G2 phase and during early mitosis mean values for D have decreased significantly (ranging from 5.0 to 5.9 X 10(-9) cm2/sec). Diffusion rates in the animal membranes of the embryo are constant during the three successive cell cycles (D = 4.3-5.0 X 10(-9) cm2/sec), except for a peak at the S phase of the first cell cycle (D = 6.0 X 10(-9) cm2/sec). These results are discussed in relation with previously observed ultrastructural heterogeneities in the Nassarius egg plasma membrane. It is speculated that the observed animal-vegetal polarity in the organization of the egg membrane might play an important role in the process of cell diversification during early development.

78 FR 77359 - Eighth Coast Guard District Annual Safety Zones; New Year's Eve Celebration/City of Mobile...

Science.gov (United States)

2013-12-23

...-AA00 Eighth Coast Guard District Annual Safety Zones; New Year's Eve Celebration/City of Mobile; Mobile Channel; Mobile, AL AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard will enforce the City of Mobile New Year's Eve Celebration safety zone in the Mobile Channel, Mobile, AL from...

Analysis of China Mobile Sales Channel Strategy in 4rd Generation Era%4G时代中国移动渠道策略探析

Institute of Scientific and Technical Information of China (English)

张玲玲

2015-01-01

In December, 2013, 4rd Generation communications business mobile network licences were issued means China's telecom industry entered the era of 4rd Generation. Compared with 3rd Generation, 4rd Generation has certain advantages no matter in speed, bearing, content or commercial, technical. China Mobile is the ifrst to launch 4rd Generation services test the water, then in the era of 4rd Generation, China mobile should be how to clear their advantages and disadvantages in the 4rd Generation environment, and how to formulate the corresponding channel strategy based on the advantages and disadvantages of 4rd Generation, so as to get more market share. This article analyzes the macro environment of the big background of China Mobile in the era of 4rd Generation, and made a SWOT analysis on the development of Chinese mobile channel, and based on this, puts forward the corresponding channel strategy.%2013年12月，4G通讯业务牌照的正式发放意味着我国电信行业进入了4G时代。4G相比于3G，无论在速度上、承载上、内容上或者商用上、技术上都有一定的优势。中国移动是启动4G业务的最先试水者，那么在4G时代，中国移动应如何清晰自己在4G环境中的优劣势，并基于4G的优劣势来制定相应的渠道策略，从而得到更大的市场份额获得胜利。文章分析了中国移动在4G时代这个大背景下的宏观环境，并对中国移动渠道发展做了SWOT分析，在此基础上提出相应的渠道策略。

Lateral convection and diffusion of sediment in straight rivers

DEFF Research Database (Denmark)

Christensen, Henrik Bo; Fredsøe, Jørgen

1998-01-01

and a higher level of turbulence at the channel centre, than in the near bank zones, which means that the ability to support suspended sediment will decrease from the channel centre. The two turbulence models give different estimates for the lateral transport, which mainly are caused by turbulence generated......The lateral transport of suspended sediment in a straight river cross section with a parabolic shaped bed is studied be use of a k-e and a full Reynolds stress turbulence model. Due to depth variations a lateral transport of suspended sediment is generated. This is mainly caused by the slopping bed...... secondary flow cells in the Reynolds stress model. The flow cells make zones with alternately high and low sediment concentration, and thereby much higher local gradients in the lateral direction. Both models found a net inward lateral transport. The transport by convection was found more dominant than...

On the Design and Realization of Adaptive Equalization for Mobile Communication

NARCIS (Netherlands)

Tijdhof, J.J.H.; Tijdhof, J.J.H.; van Bussel, J.; van Heerde, C.J.E.; Slump, Cornelis H.; Bentum, Marinus Jan

1997-01-01

In this paper the reduction of intersymbol interference (ISI) in mobile communication channels is addressed. A well known technique for ISI reduction is adaptive equalization in which the time-varying characteristics of the mobile channel are tracked by an adaptive algorithm. We compare different

Environmental monitoring systems: a new type of mobile laboratory

International Nuclear Information System (INIS)

Bruecher, L.; Langmueller, G.; Tuerschmann, G.

1999-01-01

Nuclear facilities are obligated to monitor the environmental radiation in their vicinity, which is often fulfilled by monitoring cars, combined with fixed monitoring stations. The MOLAR Mobile Laboratory for Environmental Radiation Monitoring as described here is being used under normal and accident conditions as a spot check monitoring system or to perform continuous measurements along a driving track. The mobile laboratories are continuously connected with the control centre's CRCS Central Radiological Computer System, where the RIS Radiological Information System provides corresponding evaluation functions. The mobile labs contain measuring and controlling units like γ-dose rate monitors, γ-spectrometer with a HpGe High Purity Germanium detector, a lead shielded measuring cell and MCA Multi-Channel Analyser, portable β-contamination monitor, α/β/γ multipurpose quick measuring unit, aerosol and iodine sampling units. The collected samples are safely stored for the transport to the environmental laboratory for being analysed later. The geographical location of the moving car is continuously determined by the satellite based GPS Global Positioning System and transferred in the on-board rack mounted computer system for being stored and locally displayed. Real-time data transmission via radio and mobile phone is continuously performed to supply the RIS Radiological Information System in the control centre via radio and mobile phone. The latter also serves for voice communication. Currently three MOLAR systems can be operated parallel and independent from the control centre. The system is ready to be extended to more mobile labs. This combination of mobile monitoring, sample analysis and radiological assessment of environmental data in combination with process occurrences has turned out to be a powerful instrument for emergency preparedness and environmental supervising. (orig.) [de

CACNA1H missense mutations associated with amyotrophic lateral sclerosis alter Ca(v)3.2 T-type calcium channel activity and reticular thalamic neuron firing

Czech Academy of Sciences Publication Activity Database

Rzhepetskyy, Yuriy; Lazniewska, Joanna; Blesneac, I.; Pamphlett, R.; Weiss, Norbert

2016-01-01

Roč. 10, č. 6 (2016), s. 466-477 ISSN 1933-6950 R&D Projects: GA ČR GA15-13556S; GA MŠk 7AMB15FR015 Institutional support: RVO:61388963 Keywords : ALS * amyotrophic lateral sclerosis * biophysics * CACNA1H * Ca(v)3 * 2 channel Subject RIV: CE - Biochemistry Impact factor: 2.042, year: 2016

Service Level Agreement for the QoS Guaranteed Mobile IPTV Services over Mobile WiMAX Networks

OpenAIRE

Chowdhury, Mostafa Zaman; Trung, Bui Minh; Jang, Yeong Min; Kim, Young-Il; Ryu, Won

2011-01-01

While mobile IPTV services are supported through the mobile WiMAX networks, there must need some guaranteed bandwidth for the IPTV services especially if IPTV and non-IPTV services are simultaneously supported by the mobile WiMAX networks. The quality of an IPTV service definitely depends on the allocated bandwidth for that channel. However, due to the high quality IPTV services and to support of huge non-IPTV traffic over mobile WiMAX networks, it is not possible to guarantee the sufficient ...

Video quality measure for mobile IPTV service

Science.gov (United States)

Kim, Wonjun; Kim, Changick

2008-08-01

Mobile IPTV is a multimedia service based on wireless networks with interactivity and mobility. Under mobile IPTV scenarios, people can watch various contents whenever they want and even deliver their request to service providers through the network. However, the frequent change of the wireless channel bandwidth may hinder the quality of service. In this paper, we propose an objective video quality measure (VQM) for mobile IPTV services, which is focused on the jitter measurement. Jitter is the result of frame repetition during the delay and one of the most severe impairments in the video transmission via mobile channels. We first employ YUV color space to compute the duration and occurrences of jitter and the motion activity. Then the VQM is modeled by the combination of these three factors and the result of subjective assessment. Since the proposed VQM is based on no-reference (NR) model, it can be applied for real-time applications. Experimental results show that the proposed VQM highly correlates to subjective evaluation.

Sediment and Vegetation Controls on Delta Channel Networks

Science.gov (United States)

Lauzon, R.; Murray, A. B.; Piliouras, A.; Kim, W.

2016-12-01

Numerous factors control the patterns of distributary channels formed on a delta, including water and sediment discharge, grain size, sea level rise rates, and vegetation type. In turn, these channel networks influence the shape and evolution of a delta, including what types of plant and animal life - such as humans - it can support. Previous fluvial modeling and flume experiments, outside of the delta context, have addressed how interactions between sediment and vegetation, through their influence on lateral transport of sediment, determine what type of channel networks develops. Similar interactions likely also shape delta flow patterns. Vegetation introduces cohesion, tending to reduce channel migration rates and strengthen existing channel banks, reinforcing existing channels and resulting in localized, relatively stable flow patterns. On the other hand, sediment transport processes can result in lateral migration and frequent switching of active channels, resulting in flow resembling that of a braided stream. While previous studies of deltas have indirectly explored the effects of vegetation through the introduction of cohesive sediment, we directly incorporate key effects of vegetation on flow and sediment transport into the delta-building model DeltaRCM to explore how these effects influence delta channel network formation. Model development is informed by laboratory flume experiments at UT Austin. Here we present initial results of experiments exploring the effects of sea level rise rate, sediment grain size, vegetation type, and vegetation growth rate on delta channel network morphology. These results support the hypothesis that the ability for lateral transport of sediment to occur plays a key role in determining the evolution of delta channel networks and delta morphology.

Mobile-ip Aeronautical Network Simulation Study

Science.gov (United States)

Ivancic, William D.; Tran, Diepchi T.

2001-01-01

NASA is interested in applying mobile Internet protocol (mobile-ip) technologies to its space and aeronautics programs. In particular, mobile-ip will play a major role in the Advanced Aeronautic Transportation Technology (AATT), the Weather Information Communication (WINCOMM), and the Small Aircraft Transportation System (SATS) aeronautics programs. This report presents the results of a simulation study of mobile-ip for an aeronautical network. The study was performed to determine the performance of the transmission control protocol (TCP) in a mobile-ip environment and to gain an understanding of how long delays, handoffs, and noisy channels affect mobile-ip performance.

Study of performance scaling of 22-nm epitaxial delta-doped channel MOS transistor

Science.gov (United States)

Sengupta, Sarmista; Pandit, Soumya

2015-06-01

Epitaxial delta-doped channel (EδDC) profile is a promising approach for extending the scalability of bulk metal oxide semiconductor (MOS) technology for low-power system-on-chip applications. A comparative study between EδDC bulk MOS transistor with gate length Lg = 22 nm and a conventional uniformly doped channel (UDC) bulk MOS transistor, with respect to various digital and analogue performances, is presented. The study has been performed using Silvaco technology computer-aided design device simulator, calibrated with experimental results. This study reveals that at smaller gate length, EδDC transistor outperforms the UDC transistor with respect to various studied performances. The reduced contribution of the lateral electric field in the channel plays the key role in this regard. Further, the carrier mobility in EδDC transistor is higher compared to UDC transistor. For moderate gate and drain bias, the impact ionisation rate of the carriers for EδDC MOS transistor is lower than that of the UDC transistor. In addition, at 22 nm, the performances of a EδDC transistor are competitive to that of an ultra-thin body silicon-on-insulator transistor.

Promotion and monetization in publishing mobile applications

Directory of Open Access Journals (Sweden)

Fernando Peinado Miguel

2016-07-01

Full Text Available The road to new technologies and digital systems of transmission of the message produce unpublished business channels to support the media management current. And the printed media can benefit since they can find greater advantages in this new channel of increasing consumption: mobile greater advantages in this new channel of increasing consumption: mobile applications. The modern editor coexists with these new technologies, scheduled or native applications on web languages that offer multiple possibilities of loyalty, monetization, distribution and synergies with the channels already considered classics. The study of apps to generate revenue in the media can be the new contextual paradigm of the Periodismo and establish the key factors for a better profitability of the participants this industry, increasingly weakened financially and business by the accelerated arrival of technology in publishing groups accustomed to changes of slow evolution.

Growth parameter optimization and interface treatment for enhanced electron mobility in heavily strained GaInAs/AlInAs high electron mobility transistor structures

International Nuclear Information System (INIS)

Fedoryshyn, Yuriy; Ostinelli, Olivier; Alt, Andreas; Pallin, Angel; Bolognesi, Colombo R.

2014-01-01

The optimization of heavily strained Ga 0.25 In 0.75 As/Al 0.48 In 0.52 As high electron mobility transistor structures is discussed in detail. The growth parameters and the channel layer interfaces were optimized in order to maximize the mobility of the two-dimensional electron gas. Structures composed of an 11 nm thick channel layer and a 4 nm thick spacer layer exhibited electron mobilities as high as 15 100 cm 2 /Vs and 70 000 cm 2 /Vs at 300 and 77 K, respectively, for channels including InAs strained layers. The sheet carrier density was kept above 2.5 × 10 12  cm −2 throughout the entire study

Driving advertising into mobile mediums : Study of consumer attitudes towards mobile advertising and of factors affecting on them

OpenAIRE

Pietz, Michal; Storbacka, Lauri

2007-01-01

The high penetration rate of mobile phones along with the recent technological development has created a whole new marketing medium named mobile advertising filled with possibilities for the advertisers. Earlier studies have although indicated the success of this new advertising channel to depend on user acceptance of receiving mobile ads. Wherefore a study of consumer attitudes towards mobile advertising can be considered necessary in order to create a lucrative business. Even though this to...

Mobile communication and intermediality

DEFF Research Database (Denmark)

Helles, Rasmus

2013-01-01

communicative affordances of mobile devices in order to understand how people choose between them for different purposes. It is argued that mobile communication makes intermediality especially central, as the choice of medium is detached from the location of stationary media and begins to follow the user across......The article argues the importance of intermediality as a concept for research in mobile communication and media. The constant availability of several, partially overlapping channels for communication (texting, calls, email, Facebook, etc.) requires that we adopt an integrated view of the various...

47 CFR 22.905 - Channels for cellular service.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Channels for cellular service. 22.905 Section... MOBILE SERVICES Cellular Radiotelephone Service § 22.905 Channels for cellular service. The following frequency bands are allocated for assignment to service providers in the Cellular Radiotelephone Service. (a...

A Hot Knife Through Ice-Cream: Earthflow Response to Channel Incision (Or Channel Response to Earthflows?), Eel River Canyon, California

Science.gov (United States)

Mackey, B. H.; Roering, J. J.; McKean, J. A.

2007-12-01

Abundant glacier-like earthflow features are recognized as a primary erosional process in the highly erodable Franciscan Melange of the Eel River Basin, CA. Despite their prominence in this "melting ice-cream" topography, many questions regarding their effects on the long term sediment flux from this rapidly eroding basin remain unresolved. For example, does an earthflow's basal shear zone propagate vertically downwards with vertical river incision? What controls the upslope and lateral extent of individual earthflows? How does the erosive power of a river influence the rate of earthflow movement, or conversely do earthflow toe deposits regulate the rate of river incision? Here we present preliminary findings derived from study of 200km2 of lidar data (1m resolution) covering hillslopes adjacent to 30km of the Eel River. Lidar allows detailed analysis of the interaction between earthflows and the drainage network, and we document how inferred changes in local base level are propagated throughout adjacent hillslopes via earthflow movement. The most active earthflows (determined by field surveying and analysis of aerial photos rectified using lidar- generated digital topography) coincide with locally steep sections of channel, while downstream of the most active flows we frequently observe less-active or dormant earthflows. This observation supports the idea that the locations of the most active earthflows coincide with headward propagating knickpoints in the channel. The rate of earthflow movement appears to slow when an earthflow exhausts the upslope area of easily mobilized sediment. Earthflow toes can protrude directly into the channel, causing the channel to narrow and steepen, and even undercut the opposite bank. Large resistant boulders (>2m diameter) transported by the earthflow accumulate in the streambed and appear to both act as a check on further channel incision and earthflow movement. In contrast, areas adjacent to active earthflows exhibit smooth

An FPGA-Based Adaptable 200 MHz Bandwidth Channel Sounder for Wireless Communication Channel Characterisation

Directory of Open Access Journals (Sweden)

David L. Ndzi

2011-01-01

Full Text Available This paper describes the development of a fast adaptable FPGA-based wideband channel sounder with signal bandwidths of up to 200 MHz and channel sampling rates up to 5.4 kHz. The application of FPGA allows the user to vary the number of real-time channel response averages, channel sampling interval, and duration of measurement. The waveform, bandwidth, and frequency resolution of the sounder can be adapted for any channel under investigation. The design approach and technology used has led to a reduction in size and weight by more than 60%. This makes the sounder ideal for mobile time-variant wireless communication channels studies. Averaging allows processing gains of up to 30 dB to be achieved for measurement in weak signal conditions. The technique applied also improves reliability, reduces power consumption, and has shifted sounder design complexity from hardware to software. Test results show that the sounder can detect very small-scale variations in channels.

Accurate Extraction of Charge Carrier Mobility in 4-Probe Field-Effect Transistors

KAUST Repository

Choi, Hyun Ho; Rodionov, Yaroslav I.; Paterson, Alexandra F.; Panidi, Julianna; Saranin, Danila; Kharlamov, Nikolai; Didenko, Sergei I.; Anthopoulos, Thomas D.; Cho, Kilwon; Podzorov, Vitaly

2018-01-01

Charge carrier mobility is an important characteristic of organic field-effect transistors (OFETs) and other semiconductor devices. However, accurate mobility determination in FETs is frequently compromised by issues related to Schottky-barrier contact resistance, that can be efficiently addressed by measurements in 4-probe/Hall-bar contact geometry. Here, it is shown that this technique, widely used in materials science, can still lead to significant mobility overestimation due to longitudinal channel shunting caused by voltage probes in 4-probe structures. This effect is investigated numerically and experimentally in specially designed multiterminal OFETs based on optimized novel organic-semiconductor blends and bulk single crystals. Numerical simulations reveal that 4-probe FETs with long but narrow channels and wide voltage probes are especially prone to channel shunting, that can lead to mobilities overestimated by as much as 350%. In addition, the first Hall effect measurements in blended OFETs are reported and how Hall mobility can be affected by channel shunting is shown. As a solution to this problem, a numerical correction factor is introduced that can be used to obtain much more accurate experimental mobilities. This methodology is relevant to characterization of a variety of materials, including organic semiconductors, inorganic oxides, monolayer materials, as well as carbon nanotube and semiconductor nanocrystal arrays.

Accurate Extraction of Charge Carrier Mobility in 4-Probe Field-Effect Transistors

KAUST Repository

Choi, Hyun Ho

2018-04-30

Charge carrier mobility is an important characteristic of organic field-effect transistors (OFETs) and other semiconductor devices. However, accurate mobility determination in FETs is frequently compromised by issues related to Schottky-barrier contact resistance, that can be efficiently addressed by measurements in 4-probe/Hall-bar contact geometry. Here, it is shown that this technique, widely used in materials science, can still lead to significant mobility overestimation due to longitudinal channel shunting caused by voltage probes in 4-probe structures. This effect is investigated numerically and experimentally in specially designed multiterminal OFETs based on optimized novel organic-semiconductor blends and bulk single crystals. Numerical simulations reveal that 4-probe FETs with long but narrow channels and wide voltage probes are especially prone to channel shunting, that can lead to mobilities overestimated by as much as 350%. In addition, the first Hall effect measurements in blended OFETs are reported and how Hall mobility can be affected by channel shunting is shown. As a solution to this problem, a numerical correction factor is introduced that can be used to obtain much more accurate experimental mobilities. This methodology is relevant to characterization of a variety of materials, including organic semiconductors, inorganic oxides, monolayer materials, as well as carbon nanotube and semiconductor nanocrystal arrays.

Next Step Mobile: Strategy, Services, & PRM

Science.gov (United States)

Thomas, Lisa Carlucci

2012-01-01

As emerging information technologies have driven demand for new library communication channels, there has been increased interest in the use of mobile tools to promote interaction, expand outreach, market programs, and enhance the library experience. Libraries today are at widely different levels of mobile engagement, a gap poised to grow as…

Downlink Channel Estimation in Cellular Systems with Antenna Arrays at Base Stations Using Channel Probing with Feedback

Directory of Open Access Journals (Sweden)

Biguesh Mehrzad

2004-01-01

Full Text Available In mobile communication systems with multisensor antennas at base stations, downlink channel estimation plays a key role because accurate channel estimates are needed for transmit beamforming. One efficient approach to this problem is channel probing with feedback. In this method, the base station array transmits probing (training signals. The channel is then estimated from feedback reports provided by the users. This paper studies the performance of the channel probing method with feedback using a multisensor base station antenna array and single-sensor users. The least squares (LS, linear minimum mean square error (LMMSE, and a new scaled LS (SLS approaches to the channel estimation are studied. Optimal choice of probing signals is investigated for each of these techniques and their channel estimation performances are analyzed. In the case of multiple LS channel estimates, the best linear unbiased estimation (BLUE scheme for their linear combining is developed and studied.

Laboratory Experiments on Meandering Meltwater Channels

Science.gov (United States)

Fernandez, R.; Berens, J.; Parker, G.; Stark, C. P.

2017-12-01

Meandering channels of all scales and flowing over a wide variety of media have common planform patterns. Although the analogy in planform suggests there is a common underlying framework, the constitutive relations driving planform evolution through vertical incision/deposition and lateral migration differ from medium to medium. The driving processes in alluvial and mixed bedrock-alluvial meandering channels have been studied substantially over the last decades. However, this is not the case for meandering channels in other media such as ice or soluble rock. Here we present results from experiments conducted at the Ven Te Chow Hydrosystems Laboratory of the University of Illinois at Urbana-Champaign on meltwater meandering channels. A rivulet is carved into an ice block and water is allowed to flow at a constant discharge. Planform evolution is analyzed with time lapse imaging and complemented with rubber molds of the channel once the experiment is over. These molds give us the full 3D structure of the meandering, including incisional overhang. Vertical incision rates are measured throughout the run by taking elevations along the channel, and these measurements are complemented with analysis from the molds. We show examples of meandering of intense amplitude with deep overhangs. Features resembling scroll bars document cyclically punctuated melting. We report on lateral migration rates, incision rates, sinuosity, channel depths, channel widths, reach averaged velocities, bend wavelengths and amplitudes and compare them to values reported in the literature for alluvial rivers.

Reduced thermal resistance in AlGaN/GaN multi-mesa-channel high electron mobility transistors

Energy Technology Data Exchange (ETDEWEB)

Asubar, Joel T., E-mail: joel@rciqe.hokudai.ac.jp; Yatabe, Zenji; Hashizume, Tamotsu [Research Center for Integrated Quantum Electronics (RCIQE) and Graduate School of Information Science and Technology, Hokkaido University, Sapporo (Japan); Japan Science and Technology Agency (JST), CREST, 102-0075 Tokyo (Japan)

2014-08-04

Dramatic reduction of thermal resistance was achieved in AlGaN/GaN Multi-Mesa-Channel (MMC) high electron mobility transistors (HEMTs) on sapphire substrates. Compared with the conventional planar device, the MMC HEMT exhibits much less negative slope of the I{sub D}-V{sub DS} curves at high V{sub DS} regime, indicating less self-heating. Using a method proposed by Menozzi and co-workers, we obtained a thermal resistance of 4.8 K-mm/W at ambient temperature of ∼350 K and power dissipation of ∼9 W/mm. This value compares well to 4.1 K-mm/W, which is the thermal resistance of AlGaN/GaN HEMTs on expensive single crystal diamond substrates and the lowest reported value in literature.

Airport mobile marketing as a channel to promote cross-selling

Directory of Open Access Journals (Sweden)

Lázaro Florido-Benítez

2016-12-01

Full Text Available Purpose: The purpose of this study is to analyze the airport mobile marketing and what elements have had a positive or negative influence in cross-selling via an airport app.  Design/methodology: For this analysis, a survey was conducted to users that use the Schiphol Amsterdam Airport app. A total of 103 questionnaires were analyzed using structural equation modeling.  Findings: This study found that security/control factor supplied by the mobile marketing tool to passengers at the airport, it has been demonstrated that it favours an increase in cross-selling. in addition, if an airport is perceived to have a good brand image, it will have a positive effect in cross-selling.  Originality/value: This paper is the first research that examines the impact of mobile marketing in airports. Smelling multiple products and services to the same client before, during, and post consumption  is a marketing technique that intends to (1 satisfy a client’s need and (2 increase a company’s profit by using cross-selling and other complementary services. Airline companies are experts in carrying out this activity, and airports have found that mobile applications are the perfect tool to increase their commercial profits. Offering complementary products and services is a very lucrative business, and a mobile device or smartphone are -- and will become -- the ideal medium to meet users’ demands as well as to improve the passenger experience.  Keywords: mobile marketing, cross-selling, information, security-control, image-perception, satisfaction, WOM

AlGaN/GaN double-channel HEMT

International Nuclear Information System (INIS)

Quan Si; Hao Yue; Ma Xiaohua; Zheng Pengtian; Xie Yuanbin

2010-01-01

The fabrication of AlGaN/GaN double-channel high electron mobility transistors on sapphire substrates is reported. Two carrier channels are formed in an AlGaN/GaN/AlGaN/GaN multilayer structure. The DC performance of the resulting double-channel HEMT shows a wider high transconductance region compared with single-channel HEMT. Simulations provide an explanation for the influence of the double-channel on the high transconductance region. The buffer trap is suggested to be related to the wide region of high transconductance. The RF characteristics are also studied. (semiconductor devices)

Sediment Mobilization and Storage Dynamics of a Debris Flow Impacted Stream Channel using Multi-Temporal Structure from Motion Photogrammetry

Science.gov (United States)

Bailey, T. L.; Sutherland-Montoya, D.

2015-12-01

High resolution topographic analysis methods have become important tools in geomorphology. Structure from Motion photogrammetry offers a compelling vehicle for geomorphic change detection in fluvial environments. This process can produce arbitrarily high resolution, geographically registered spectral and topographic coverages from a collection of overlapping digital imagery from consumer cameras. Cuneo Creek has had three historically observed episodes of rapid aggradation (1955, 1964, and 1997). The debris flow deposits continue to be major sources of sediment sixty years after the initial slope failure. Previous studies have monitored the sediment storage volume and particle size since 1976 (in 1976, 1982, 1983, 1985, 1986, 1987, 1998, 2003). We reoccupied 3 previously surveyed stream cross sections on Sept 30, 2014 and March 30, 2015, and produced photogrammetric point clouds using a pole mounted camera with a remote view finder to take nadir view images from 4.3 meters above the channel bed. Ground control points were registered using survey grade GPS and typical cross sections used over 100 images to build the structure model. This process simultaneously collects channel geometry and we used it to also generate surface texture metrics, and produced DEMs with point cloud densities above 5000 points / m2. In the period between the surveys, a five year recurrence interval discharge of 20 m3/s scoured the channel. Surface particle size distribution has been determined for each observation period using image segmentation algorithms based on spectral distance and compactness. Topographic differencing between the point clouds shows substantial channel bed mobilization and reorganization. The net decline in sediment storage is in excess of 4 x 10^5 cubic meters since the 1964 aggradation peak, with associated coarsening of surface particle sizes. These new methods provide a promising rapid assessment tool for measurement of channel responses to sediment inputs.

USE OF MOBILE TECHNOLOGY IN BANKING SERVICES

Directory of Open Access Journals (Sweden)

ALIN ISAC

2013-12-01

Full Text Available Technology and applications of mobile phones offer many opportunities for businesses, they also presenting a continuous development and new challenges. Although this service is currently viewed with reluctance by customers, banks need to overcome this drawback and understand how this service can be combined with other alternative channels such as social media, to create value for customers. In this paper I presented information about present and perspectives in mobile applications industry, what can a mobile application do in banking, banking mobile applications in Romania, mobile banking applications worldwide.

Wavy Channel architecture thin film transistor (TFT) using amorphous zinc oxide for high-performance and low-power semiconductor circuits

KAUST Repository

Hanna, Amir; Hussain, Aftab M.; Hussain, Muhammad Mustafa

2015-01-01

We report a Wavy Channel (WC) architecture thin film transistor (TFT) for extended device width by integrating continuous vertical fin like features with lateral continuous plane in the substrate. For a WC TFT which has 50% larger device width, the enhancement in the output drive current is 100%, when compared to a conventional planar TFT consuming the same chip area. This current increase is attributed to both the extra width and enhanced field effect mobility due to corner effects. This shows the potential of WC architecture to boast circuit performance without the need for aggressive gate length scaling. © 2015 IEEE.

Wavy Channel architecture thin film transistor (TFT) using amorphous zinc oxide for high-performance and low-power semiconductor circuits

KAUST Repository

Hanna, Amir

2015-08-12

We report a Wavy Channel (WC) architecture thin film transistor (TFT) for extended device width by integrating continuous vertical fin like features with lateral continuous plane in the substrate. For a WC TFT which has 50% larger device width, the enhancement in the output drive current is 100%, when compared to a conventional planar TFT consuming the same chip area. This current increase is attributed to both the extra width and enhanced field effect mobility due to corner effects. This shows the potential of WC architecture to boast circuit performance without the need for aggressive gate length scaling. © 2015 IEEE.

New distribution channels for advertising through computer games and mobile devices.

OpenAIRE

Sivagnanasuntharam, Sivasathees

2008-01-01

The development in advertising industry has lately gone from open advertising through few, major distribution channels to a hidden and targeting advertising integrated into everyday life. Advertisers grow increasingly unhappy with the value delivered by the traditional mediums. They turn to alternative distribution channels in order to increase the success rate of advertising campaigns. Channels seen as unattractively with little purchasing power previously are attracting advertisers attenti...

Opening communication channels with people living with HIV using mobile phone text messaging: insights from the CAMPS trial.

Science.gov (United States)

Mbuagbaw, Lawrence; Thabane, Lehana; Ongolo-Zogo, Pierre

2013-04-04

Using two-way mobile phone text messages to improve adherence to antiretroviral medication enhances communication between patients and health workers. We describe the implications of participants' responses to text messages in the Cameroon Mobile Phone SMS (CAMPS) trial. This is a cross-sectional analysis of data from the intervention arm of the CAMPS trial. CAMPS was a randomized controlled trial of motivational text messaging versus usual care to improve adherence to antiretroviral medication among people living with HIV in Yaounde, Cameroon (n = 200) over a 6 month period. Participants in the intervention arm (n = 101) were given a contact phone number, but were not required to respond to their reminder messages. If they did, their responses were noted and reported as counts and percentages. We received 99 phone calls and 55 text messages (154 responses) from 48 participants during the study period. The median number of responses was 1 (first quartile [Q1]: 1; third quartile [Q3]: 3). Half (n = 79, 51.1%) of them were expressions of gratitude. The rest included requests for logistical (n = 21, 13.6%), medical (n = 20, 12.9%) and financial (n = 11, 7.1%) support. Initiating two-way mobile communication opens more channels for people living with HIV to express unmet needs. Researchers, policy makers and clinicians should be ready to respond to the needs expressed by patients who respond to text messages. Pan-African Clinical Trials Registry: PACTR201011000261458;

Electron mobility of two-dimensional electron gas in InGaN heterostructures: Effects of alloy disorder and random dipole scatterings

Science.gov (United States)

Hoshino, Tomoki; Mori, Nobuya

2018-04-01

InGaN has a smaller electron effective mass and is expected to be used as a channel material for high-electron-mobility transistors. However, it is an alloy semiconductor with a random distribution of atoms, which introduces additional scattering mechanisms: alloy disorder and random dipole scatterings. In this work, we calculate the electron mobility in InGaN- and GaN-channel high-electron-mobility transistors (HEMTs) while taking into account acoustic deformation potential, polar optical phonon, alloy disorder, and random dipole scatterings. For InGaN-channel HEMTs, we find that not only alloy disorder but also random dipole scattering has a strong impact on the electron mobility and it significantly decreases as the In mole fraction of the channel increases. Our calculation also shows that the channel thickness w dependence of the mobility is rather weak when w > 1 nm for In0.1Ga0.9N-channel HEMTs.

Stochastic Channel Modeling for Railway Tunnel Scenarios at 25 GHz

Directory of Open Access Journals (Sweden)

Danping He

2018-02-01

Full Text Available More people prefer using rail traffic for travel or for commuting owing to its convenience and flexibility. The railway scenario has become an important communication scenario in the fifth generation era. The communication system should be designed to support high‐data‐rate demands with seamless connectivity at a high mobility. In this paper, the channel characteristics are studied and modeled for the railway tunnel scenario with straight and curved route shapes. On the basis of measurements using the “Mobile Hotspot Network” system, a three‐dimensional ray tracer (RT is calibrated and validated for the target scenarios. More channel characteristics are explored via RT simulations at 25.25 GHz with a 500‐MHz bandwidth. The key channel parameters are extracted, provided, and incorporated into a 3rd‐Generation‐Partnership‐Project‐like stochastic channel generator. The necessary channel information can be practically realized, which can support the link‐level and system‐level design of the communication system in similar scenarios.

The Sustainable Interventions for Mobile Phone′s Hazards

OpenAIRE

Senthil MV; Sakthi MV

2015-01-01

Mobile phones are universally popular due to its convenience. Mobile phones solve problems and offer new channels of communication and just by using a device small enough to fit into one hand. On the other hand, mobile phones are harmful to the environment and the society which makes health problems, pollution problems via discharge of its radiations. Mobile phones have recently fallen into the examine on their sustainability and their potential effects on the environment. This study discusse...

Medical reliable network using concatenated channel codes through GSM network.

Science.gov (United States)

Ahmed, Emtithal; Kohno, Ryuji

2013-01-01

Although the 4(th) generation (4G) of global mobile communication network, i.e. Long Term Evolution (LTE) coexisting with the 3(rd) generation (3G) has successfully started; the 2(nd) generation (2G), i.e. Global System for Mobile communication (GSM) still playing an important role in many developing countries. Without any other reliable network infrastructure, GSM can be applied for tele-monitoring applications, where high mobility and low cost are necessary. A core objective of this paper is to introduce the design of a more reliable and dependable Medical Network Channel Code system (MNCC) through GSM Network. MNCC design based on simple concatenated channel code, which is cascade of an inner code (GSM) and an extra outer code (Convolution Code) in order to protect medical data more robust against channel errors than other data using the existing GSM network. In this paper, the MNCC system will provide Bit Error Rate (BER) equivalent to the BER for medical tele monitoring of physiological signals, which is 10(-5) or less. The performance of the MNCC has been proven and investigated using computer simulations under different channels condition such as, Additive White Gaussian Noise (AWGN), Rayleigh noise and burst noise. Generally the MNCC system has been providing better performance as compared to GSM.

Introduction of performance boosters like Ge as channel material for the future of CMOS

Energy Technology Data Exchange (ETDEWEB)

Samia, Slimani, E-mail: slimani.samia@gmail.com [Faculty of Electrical and Computer Engineering Mouloud Mammeri University (UMMTO), BP 17 RP 15000, Tizi-Ouzou (Algeria); Laboratoire de Modélisation et Méthodes de calcul LMMC,20002 Saida (Algeria); Bouaza, Djellouli, E-mail: djelbou@hotmail.fr [University of Saida, Department of Electronic (Algeria); Laboratoire de Modélisation et Méthodes de calcul LMMC,20002 Saida (Algeria)

2016-06-10

High mobility materials are being considered to replace Si in the channel to achieve higher drive currents and switching speeds. Ge is one of new attractive channel materials that require CMOS scaling For future technology nodes and future high performance P-MOSFETS, we have studied a nanoscale SOI DG MOSFETs using quantum simulation approach on DG MOSFETs within the variation of Ge channel concentration and in the presence of source and drain doping by replacing Silicon in the channel by Ge using various dielectric constant. The use of high mobility channel (like Ge) to maximize the MOSFET IDsat and simultaneously circumvent the poor electrostatic control to suppress short-channel effects and enhance source injection velocity. The leakage current (I{sub off}) can be controlled by different gates oxide thickness more ever the required threshold voltage (V{sub TH}) can be achieved by keeping gate work function and altering the doping channel.

Lateral mobility of plasma membrane lipids in Xenopus eggs: regional differences related to animal/vegetal polarity become extreme upon fertilization.

Science.gov (United States)

Dictus, W J; van Zoelen, E J; Tetteroo, P A; Tertoolen, L G; de Laat, S W; Bluemink, J G

1984-01-01

Regional differences in the lateral mobility properties of plasma membrane lipids have been studied in unfertilized and fertilized Xenopus eggs by fluorescence photobleaching recovery (FPR) measurements. Out of a variety of commonly used lipid probes only the aminofluorescein-labeled fatty acids HEDAF (5-(N-hexadecanoyl)-aminofluorescein) and TEDAF (5-(N-tetradecanoyl)-aminofluorescein) appear to partition into the plasma membrane. Under all experimental conditions used these molecules show partial recovery upon photobleaching indicating the existence of lipidic microdomains. In the unfertilized egg the mobile fraction of plasma membrane lipids (approximately 50%) has a fivefold smaller lateral diffusion coefficient (D = 1.5 X 10(-8) cm2/sec) in the animal than in the vegetal plasma membrane (D = 7.6 X 10(-8) cm2/sec). This demonstrates the presence of an animal/vegetal polarity within the Xenopus egg plasma membrane. Upon fertilization this polarity is strongly (greater than 100X) enhanced leading to the formation of two distinct macrodomains within the plasma membrane. At the animal side of the egg lipids are completely immobilized on the time scale of FPR measurements (D less than 10(-10) cm2/sec), whereas at the vegetal side D is only slightly reduced (D = 4.4 X 10(-8) cm2/sec). The immobilization of animal plasma membrane lipids, which could play a role in the polyspermy block, probably arises by the fusion of cortical granules which are more numerous here. The transition between the animal and the vegetal domain is sharp and coincides with the boundary between the presumptive ecto- and endoderm. The role of regional differences in the plasma membrane is discussed in relation to cell diversification in early development.

Mobile marketing and its implementations

OpenAIRE

Latto, Joel

2014-01-01

Latto, Joel Mobile marketing and its implementations Jyväskylä: University of Jyväskylä, 2014, 33 p. Information Systems Science, Bachelor’s Thesis Supervisor: Salo, Markus Mobile devices have become increasingly important marketing channel in recent years for all kinds of organizations. They allow marketers to bring forward relevant marketing information for the consumers based on location, purchase history, time and technology available. Although not brand new way of mar...

Experimental effect of flow depth on ratio discharge in lateral intakes in river bend

International Nuclear Information System (INIS)

Masjedi, A; Foroushani, E P

2012-01-01

Open-channel dividing flow is characterized by the inflow and outflow discharges, the upstream and downstream water depths, and the recirculation flow in the branch channel. In general, diversion flow can be categorized as natural and artificial flow. Natural flow diversion usually occurs as braiding or cut-off in bend rivers, while artificial flow is man-made to divert flow by lateral intake channels for water supply. This study presents the results of a laboratory research into effect intake flow depth on ratio discharge in lateral intakes in 180 degree bend. Investigation on lateral intake and determination of intake flow depth is among the most important issues in lateral intake on ratio discharge with model intake flow depth were measured in a laboratory flume under clear-water. Experiments were conducted for various intake flow depths and with different discharges. It was found that by increasing the flow depth at 180 degree flume bend, ratio discharge increases.

Wireless-Uplinks-Based Energy-Efficient Scheduling in Mobile Cloud Computing

OpenAIRE

Xing Liu; Chaowei Yuan; Zhen Yang; Enda Peng

2015-01-01

Mobile cloud computing (MCC) combines cloud computing and mobile internet to improve the computational capabilities of resource-constrained mobile devices (MDs). In MCC, mobile users could not only improve the computational capability of MDs but also save operation consumption by offloading the mobile applications to the cloud. However, MCC faces the problem of energy efficiency because of time-varying channels when the offloading is being executed. In this paper, we address the issue of ener...

Improved timing recovery in wireless mobile receivers | Olwal ...

African Journals Online (AJOL)

The problem of timing recovery in wireless mobile receiver systems is critical. This is partly because timing recovery functions must follow rapid parameter changes inherent in mobile systems and partly because both bandwidth and power must be conserved in low signal to noise ratio communication channels. The ultimate ...

Holistic hybrid (Omni-channel) approach to retailing and customer experience: A review, conceptual framework and future research directions

OpenAIRE

Hickman, Ellie

2015-01-01

The manner in which customers shop is evolving and there has been an increase in customers shopping online and in physical shops using a multi-channel approach (Hsiao, Yen & Li, 2012). Customers now shop using mobile phones, tablets and have access to shopping sources 24 hours a day. Multi-channel shopping is where customers use multiple channels such as online, in-store, catalogues or mobile devices to purchase products or services (Zhang et al., 2010). Research has shown that multi-channel ...

Acceptable Channel Switching Delays for Mobile TV

DEFF Research Database (Denmark)

Fleury, Alexandre; Pedersen, Jakob Schou; Larsen, Lars Bo

2011-01-01

as well as three potential effect factors: the transition type, the test environment and the audiovisual content. The results show that delays longer than 5.7 seconds annoyed test participants, and that the transition type had a significant impact on the rating of channel switching delays. However......, neither the test environment nor the audiovisual content influenced the ratings significantly. Finally, a discussion of these results and directions for future research are proposed....

Incentive Mechanisms for Mobile Music Distribution

Science.gov (United States)

Furini, Marco; Montangero, Manuela

The mobile digital world is seen as an important business opportunity for two main reasons: the widespread usage of cellphones (more than two billions [30], most of them with sound features) and the pervasiveness of mobile technologies. As a result, music industry and telecoms are bringing the successful Internet-based music market strategy into the mobile scenario: record labels are setting up agreements with cellphone network providers (Sprint, Verizon, Vodafone, Orange just to name a few) to offer a download music service also in the mobile scenario. The strategy is to use wireless channels to distribute music contents in the attempt of replicating the success of the Internet-based download scenario.

House Prices, Geographical Mobility, and Unemployment

DEFF Research Database (Denmark)

Ingholt, Marcus Mølbak

2017-01-01

Geographical mobility correlates positively with house prices and negatively with unemployment over the U.S. business cycle. I present a DSGE model in which declining house prices and tight credit conditions impede the mobility of indebted workers. This reduces the workers’ cross-area competition...... for jobs, causing wages and unemployment to rise. A Bayesian estimation shows that this channel more than quadruples the response of unemployment to adverse housing market shocks. The estimation also shows that adverse housing market shocks caused the decline in mobility during the Great Recession. Absent...

Rode's iterative calculation of surface optical phonon scattering limited electron mobility in N-polar GaN devices

International Nuclear Information System (INIS)

Ghosh, Krishnendu; Singisetti, Uttam

2015-01-01

N-polar GaN channel mobility is important for high frequency device applications. Here, we report theoretical calculations on the surface optical (SO) phonon scattering rate of two-dimensional electron gas (2DEG) in N-polar GaN quantum well channels with high-k dielectrics. Rode's iterative calculation is used to predict the scattering rate and mobility. Coupling of the GaN plasmon modes with the SO modes is taken into account and dynamic screening is employed under linear polarization response. The effect of SO phonons on 2DEG mobility was found to be small at >5 nm channel thickness. However, the SO mobility in 3 nm N-polar GaN channels with HfO 2 and ZrO 2 high-k dielectrics is low and limits the total mobility. The SO scattering for SiN dielectric on GaN was found to be negligible due to its high SO phonon energy. Using Al 2 O 3 , the SO phonon scattering does not affect mobility significantly only except the case when the channel is too thin with a low 2DEG density

Tourism distribution channels

OpenAIRE

Camilleri, Mark Anthony

2017-01-01

The distribution channels link the customers with the businesses. For many years, the tourism businesses may have distributed their products and services through intermediaries. However, the latest advances in technology have brought significant changes in this regard. More individuals and corporate customers are increasingly benefiting of ubiquitous technologies, including digital media. The development of mobile devices and their applications, are offering a wide range of possibilities to t...

A Gradually Varied Approach to Model Turbidity Currents in Submarine Channels

Science.gov (United States)

Bolla Pittaluga, M.; Frascati, A.; Falivene, O.

2018-01-01

We develop a one-dimensional model to describe the dynamics of turbidity current flowing in submarine channels. We consider the flow as a steady state polydisperse suspension accounting for water detrainment from the clear water-turbid interface, for spatial variations of the channel width and for water and sediment lateral overspill from the channel levees. Moreover, we account for sediment exchange with the bed extending the model to deal with situations where the current meets a nonerodible bed. Results show that when water detrainment is accounted for, the flow thickness becomes approximately constant proceeding downstream. Similarly, in the presence of channel levees, the flow tends to adjust to channel relief through the lateral loss of water and sediment. As more mud is spilled above the levees relative to sand, the flow becomes more sand rich proceeding downstream when lateral overspill is present. Velocity and flow thickness predicted by the model are then validated by showing good agreement with laboratory observations. Finally, the model is applied to the Monterey Canyon bathymetric data matching satisfactorily the December 2002 event field measurements and predicting a runout length consistent with observations.

Analysis of mobile pre-payment (pay in advance) and post-payment (pay later) services

NARCIS (Netherlands)

Molina-Castillo, Francisco Jose; Rodriguez-Guirao, Alicia; Lopez-Nicolas, Carolina; Bouwman, W.A.G.A.

2016-01-01

The diffusion of mobile payments (M-payments) is still in its early stages and further research is needed to understand what motivates or restricts people's behaviour when using mobile services. Based on a sample of Dutch mobile service users, this study analyses the antecedents of two types of

Spatial adjustments of mountain channels to changes in the sediment supply regime

Science.gov (United States)

Elgueta, M. A.; Hassan, M. A.; von Flotow, C. M.

2012-12-01

Sediment supply is a key controlling factor in bed morphology and sediment mobility. Under a low supply regime, bed structuring develops and reduces sediment mobility. Under high supply, structuring is suppressed and the bed exhibits patchiness. This study examines the spatial response of a mountain stream channel to changes in the sediment supply regime. To achieve this goal, a flume experiment was conducted in the Mountain Channel Hydraulic Experimental Laboratory at the University of British Columbia. An 18 meter long, one meter wide flume, with a slope of three percent was used. Seven continuous runs were conducted. Each of them lasted 40 hours, under constant flow and different sediment supply regimes, which included no feed, constant feed and episodic supply. In each run, bed elevation, bed grain size distribution, flow resistance, sediment mobility and degree of armoring were determined. Flume results were compared to field data from a 600 meter channel reach that exhibits rapid, riffle-pool and step-pool morphology in UBC Malcolm Knapp Research Forest. The study gave the possibility to analyze in detail the spatial adjustment of a mountain channel to changes in the sediment supply regime, including episodic inputs.

Changes in spinal mobility with increasing age in women.

Science.gov (United States)

Einkauf, D K; Gohdes, M L; Jensen, G M; Jewell, M J

1987-03-01

The purpose of our study was to determine changes in spinal mobility for women aged 20 to 84 years. Anterior flexion, right and left lateral flexion, and extension were measured on 109 healthy women. The modified Schober method was used to measure anterior flexion. Standard goniometry was used to measure lateral flexion and extension. The results of the study indicated that spinal mobility decreases with advancing age. The most significant (p less than .05) differences occurred between the two youngest and the two oldest age categories. Data gathered in this study indicate that physical therapists should consider the effects of age on spinal mobility when assessing spinal range of motion. A simple, objective method for measuring spinal mobility is presented. Suggestions for future research are given.

Reviewing the Role of Media Attributes in Mobilizing Protest Participation

NARCIS (Netherlands)

van den Broek, Tijs Adriaan; Ehrenhard, Michel Léon

2014-01-01

Activist groups increasingly use computer-mediated communication (CMC) channels to mobilize large groups of consumers to persuade incumbent firms to change their contested strategies or practices. The attributes of CMC channels change the effectiveness of persuasion processes in organizations.

Rapid multiplex detection of 10 foodborne pathogens with an up-converting phosphor technology-based 10-channel lateral flow assay

Science.gov (United States)

Zhao, Yong; Wang, Haoran; Zhang, Pingping; Sun, Chongyun; Wang, Xiaochen; Wang, Xinrui; Yang, Ruifu; Wang, Chengbin; Zhou, Lei

2016-01-01

The rapid high-throughput detection of foodborne pathogens is essential in controlling food safety. In this study, a 10-channel up-converting phosphor technology-based lateral flow (TC-UPT-LF) assay was established for the rapid and simultaneous detection of 10 epidemic foodborne pathogens. Ten different single-target UPT-LF strips were developed and integrated into one TC-UPT-LF disc with optimization. Without enrichment the TC-UPT-LF assay had a detection sensitivity of 104 CFU mL−1 or 105 CFU mL−1 for each pathogen, and after sample enrichment it was 10 CFU/0.6 mg. The assay also showed good linearity, allowing quantitative detection, with a linear fitting coefficient of determination (R2) of 0.916–0.998. The 10 detection channels did not cross-react, so multiple targets could be specifically detected. When 279 real food samples were tested, the assay was highly consistent (100%) with culture-based methods. The results for 110 food samples artificially contaminated with single or multiple targets showed a high detection rate (≥80%) for most target bacteria. Overall, the TC-UPT-LF assay allows the rapid, quantitative, and simultaneous detection of 10 kinds of foodborne pathogens within 20 min, and is especially suitable for the rapid detection and surveillance of foodborne pathogens in food and water. PMID:26884128

Predictive techniques for river channel evolution and maintenance

Science.gov (United States)

Nelson, J.M.

1996-01-01

Predicting changes in alluvial channel morphology associated with anthropogenic and natural changes in flow and/or sediment supply is a critical part of the management of riverine systems. Over the past few years, advances in the understanding of the physics of sediment transport in conjunction with rapidly increasing capabilities in computational fluid dynamics have yielded now approaches to problems in river mechanics. Techniques appropriate for length scales ranging from reaches to bars and bedforms are described here. Examples of the use of these computational approaches are discussed for three cases: (1) the design of diversion scenarios that maintain channel morphology in steep cobble-bedded channels in Colorado, (2) determination of channel maintenance flows for the preservation of channel islands in the Snake River in Idaho, and (3) prediction of the temporal evolution of deposits in lateral separation zones for future assessment of the impacts of various dam release scenarios on lateral separation deposits in the Colorado River in Grand Canyon. With continued development of their scientific and technical components, the methodologies described here can provide powerful tools for the management of river environments in the future.

Mobile banking: New trend in the contemporary banking sector

Directory of Open Access Journals (Sweden)

Sanader Dušica

2014-01-01

Full Text Available In the late 1990s and early 2000s, banking has undergone and is still undergoing some considerable changes, adjusting itself to the new circumstances and challenges in its environment. Modern information technologies have granted an opportunity to banks to expand their operations and adjust their offer of products and services, placing them through the new communication channels. The increasing reliance on mobile devices, especially the so-called smart phones, has facilitated the development of a new form of banking, known as mobile banking. Mobile banking is a specific channel of electronic banking, enabling clients to communicate with the bank via mobile devices. The bank's products and services are, thus, available to the clients at any time and at any place, and the banking sector is expected to perfectly understand the needs of today's clients, before implementing mobile banking. The research in this paper focuses on mobile banking, as a segment of electronic banking, which has developed under the influence of modern information technologies. The paper elaborates on the main characteristics of mobile banking, its advantages, but also its drawbacks that the banks and their clients are facing in the process of its utilization (or its implementation in practice. Moreover, the paper presents the trends of using mobile banking in the world and in Serbia, along with the tendencies for developing new services.

Subthreshold Current and Swing Modeling of Gate Underlap DG MOSFETs with a Source/Drain Lateral Gaussian Doping Profile

Science.gov (United States)

Singh, Kunal; Kumar, Sanjay; Goel, Ekta; Singh, Balraj; Kumar, Mirgender; Dubey, Sarvesh; Jit, Satyabrata

2017-01-01

This paper proposes a new model for the subthreshold current and swing of the short-channel symmetric underlap ultrathin double gate metal oxide field effect transistors with a source/drain lateral Gaussian doping profile. The channel potential model already reported earlier has been utilized to formulate the closed form expression for the subthreshold current and swing of the device. The effects of the lateral straggle and geometrical parameters such as the channel length, channel thickness, and oxide thickness on the off current and subthreshold slope have been demonstrated. The devices with source/drain lateral Gaussian doping profiles in the underlap structure are observed to be highly resistant to short channel effects while improving the current drive. The proposed model is validated by comparing the results with the numerical simulation data obtained by using the commercially available ATLAS™, a two-dimensional (2-D) device simulator from SILVACO.

Evaluating Ubiquitous Media Usability Challenges: Content Transfer and Channel Switching Delays

DEFF Research Database (Denmark)

Fleury, Alexandre; Pedersen, Jakob Schou; Larsen, Lars Bo

2011-01-01

As ubiquitous media is developing rapidly, new HCI challenges emerge. In this paper, we address usability issues related to the transfer of content between fixed and mobile devices, as well as channel switching delays on mobile devices. We first provide an extensive review of the field. We...

Adaptive Mobile Positioning in WCDMA Networks

Directory of Open Access Journals (Sweden)

Dong B.

2005-01-01

Full Text Available We propose a new technique for mobile tracking in wideband code-division multiple-access (WCDMA systems employing multiple receive antennas. To achieve a high estimation accuracy, the algorithm utilizes the time difference of arrival (TDOA measurements in the forward link pilot channel, the angle of arrival (AOA measurements in the reverse-link pilot channel, as well as the received signal strength. The mobility dynamic is modelled by a first-order autoregressive (AR vector process with an additional discrete state variable as the motion offset, which evolves according to a discrete-time Markov chain. It is assumed that the parameters in this model are unknown and must be jointly estimated by the tracking algorithm. By viewing a nonlinear dynamic system such as a jump-Markov model, we develop an efficient auxiliary particle filtering algorithm to track both the discrete and continuous state variables of this system as well as the associated system parameters. Simulation results are provided to demonstrate the excellent performance of the proposed adaptive mobile positioning algorithm in WCDMA networks.

The elusive character of discontinuous deep-water channels: New insights from Lucia Chica channel system, offshore California

Science.gov (United States)

Maier, K.L.; Fildani, A.; Paull, C.K.; Graham, S.A.; McHargue, T.R.; Caress, D.W.; McGann, M.

2011-01-01

New high-resolution autonomous underwater vehicle (AUV) seafloor images, with 1 m lateral resolution and 0.3 m vertical resolution, reveal unexpected seafloor rugosity and low-relief (thalwegs were interpreted originally from lower-resolution images, but newly acquired AUV data indicate that a single sinuous channel fed a series of discontinuous lower-relief channels. These discontinuous channels were created by at least four avulsion events. Channel relief, defined as the height from the thalweg to the levee crest, controls avulsions and overall stratigraphic architecture of the depositional area. Flowstripped turbidity currents separated into and reactivated multiple channels to create a distributary pattern and developed discontinuous trains of cyclic scours and megaflutes, which may be erosional precursors to continuous channels. The diverse features now imaged in the Lucia Chica channel system (offshore California) are likely common in modern and ancient systems with similar overall morphologies, but have not been previously mapped with lower-resolution detection methods in any of these systems. ?? 2011 Geological Society of America.

Study of the influence of the laterality of mobile phone use on the SAR induced in two head models

Science.gov (United States)

Ghanmi, Amal; Varsier, Nadège; Hadjem, Abdelhamid; Conil, Emmanuelle; Picon, Odile; Wiart, Joe

2013-05-01

The objective of this paper is to investigate and to analyse the influence of the laterality of mobile phone use on the exposure of the brain to radio-frequencies (RF) and electromagnetic fields (EMF) from different mobile phone models using the finite-difference time-domain (FDTD) method. The study focuses on the comparison of the specific absorption rate (SAR) induced on the right and left sides of two numerical adult and child head models. The heads are exposed by both phone models operating in GSM frequency bands for both ipsilateral and contralateral configurations. A slight SAR difference between the two sides of the heads is noted. The results show that the variation between the left and the right sides is more important at 1800 MHz for an ipsilateral use. Indeed, at this frequency, the variation can even reach 20% for the SAR10g and the SAR1g induced in the head and in the brain, respectively. Moreover, the average SAR induced by the mobile phone in the half hemisphere of the brain in ipsilateral exposure is higher than in contralateral exposure. Owing to the superficial character of energy deposition at 1800 MHz, this difference in the SAR induced for the ipsilateral and contralateral usages is more significant at 1800 MHz than at 900 MHz. The results have shown that depending on the phantom head models, the SAR distribution in the brain can vary because of differences in anatomical proportions and in the geometry of the head models. The induced SAR in child head and in sub-regions of the brain is significantly higher (up to 30%) compared to the adult head. This paper confirms also that the shape/design of the mobile and the location of the antenna can have a large influence at high frequency on the exposure of the brain, particularly on the SAR distribution and on the distinguished brain regions.

Introduction to digital mobile communication

CERN Document Server

Akaiwa, Yoshihiko

2015-01-01

Introduces digital mobile communications with an emphasis on digital transmission methods This book presents mathematical analyses of signals, mobile radio channels, and digital modulation methods. The new edition covers the evolution of wireless communications technologies and systems. The major new topics are OFDM (orthogonal frequency domain multiplexing), MIMO (multi-input multi-output) systems, frequency-domain equalization, the turbo codes, LDPC (low density parity check code), ACELP (algebraic code excited linear predictive) voice coding, dynamic scheduling for wireless packet data t

Asymmetric fluxes of water and sediments in a mesotidal mudflat channel

Science.gov (United States)

Mariotti, G.; Fagherazzi, S.

2011-01-01

The hydrodynamics of a small tributary channel and its adjacent mudflat is studied in Willapa Bay, Washington State, USA. Velocity profiles and water levels are simultaneously measured at different locations in the channel and on the mudflat for two weeks. The above tidal flat and channel hydrodynamics differ remarkably during the tidal cycle. When the water surface level is above the tidal flat elevation, the channel is inactive. At this stage, the above tidal flat flow is predominantly aligned along the Bay axis, oscillating with the tide as a standing wave with peak velocities up to 0.3 m/s. When the mudflat becomes emergent, the flow concentrates in the channel. During this stage, current velocities up to 1 m/s are measured during ebb; and up to 0.6 m/s during flood. Standard equations for open-channel flow are utilized to study the channel hydrodynamics. From the continuity equation, a lateral inflow is predicted during ebb, which likely originates from the drainage of the mudflat through the lateral runnels. Both advective acceleration and lateral discharge terms, estimated directly from the velocity profiles, play a significant role in the momentum equation. The computed drag coefficient for bottom friction is small, due to an absence of vegetation and bottom bedforms in the channel. Sediment fluxes are calculated by combining flow and suspended sediment concentration estimated using the acoustic backscatter signal of the instruments. A net export of the sediment from the channel is found during ebb, which is not balanced by the sediment import during flood. When the mudflat is submerged, ebb-flood asymmetries in suspended sediment concentration are present, leading to a net sediment flux toward the inner part of the Willapa Bay. Finally, a residual flow is detected inside the channel at high slack water, probably associated with the thermohaline circulation.

Mobility Enhancement in Amorphous In-Ga-Zn-O Thin-Film Transistor by Induced Metallic in Nanoparticles and Cu Electrodes.

Science.gov (United States)

Hu, Shiben; Ning, Honglong; Lu, Kuankuan; Fang, Zhiqiang; Li, Yuzhi; Yao, Rihui; Xu, Miao; Wang, Lei; Peng, Junbiao; Lu, Xubing

2018-03-27

In this work, we fabricated a high-mobility amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) based on alumina oxide (Al 2 O 3 ) passivation layer (PVL) and copper (Cu) source/drain electrodes (S/D). The mechanism of the high mobility for a-IGZO TFT was proposed and experimentally demonstrated. The conductivity of the channel layer was significantly improved due to the formation of metallic In nanoparticles on the back channel during Al 2 O 3 PVL sputtering. In addition, Ar atmosphere annealing induced the Schottky contact formation between the Cu S/D and the channel layer caused by Cu diffusion. In conjunction with high conductivity channel and Schottky contact, the a-IGZO TFT based on Cu S/D and Al 2 O 3 PVL exhibited remarkable mobility of 33.5-220.1 cm 2 /Vs when channel length varies from 60 to 560 μ m. This work presents a feasible way to implement high mobility and Cu electrodes in a-IGZO TFT, simultaneously.

Morphology of channels and channel-sand bodies in the Glauconitic sandstone member (Upper Mannville), Little Bow area, Alberta

Energy Technology Data Exchange (ETDEWEB)

Hopkins, J.C.; Hermanson, S.W.; Lawton, D.C.

1982-12-01

Large channels in the Glauconitic sandstone member of southern Alberta have proved to be difficult exploration targets because of an irregular distribution of reservoir sands within the channels. In the Little Bow area, two channels are present in the lower part of the Glauconitic member and have cut into the underlying Calcareous member. The channels can be recognized where they truncate regional markers of the Calcareous member -- the Bantry shale and Ostracod limestone, and where channel-fill deposits exhibit uniform geophysical log characters, indicating sandstone- or mudstone-filled reaches. Sediments of the Glauconitic member adjacent to the channels comprise a series of splay sandstones and mudstones that prograded into interdistributary bays of the lower delta plain. The two channels associated with these deposits are interpreted as distributary channels. Sand bodies within the channels formed as lateral bars and are isolated by mudstones which mark the abandoned stream course. Geological exploration for these discontinuous channel sandstones is difficult, and high-resolutio seismic data integrated with sound geologic modelling are critical for successful prospect delineation.

Shaping Air Mobility Forces for Future Relevance

Science.gov (United States)

2017-01-01

King Air University Press 600 Chennault Circle, Building 1405 Maxwell AFB, AL 36112-6010 afri.aupress@us.af.mil http://aupress.au.af.mil...the congressional study’s Persian Gulf scenario.37 Later Defense Department air mobility plans continued the CMMS pat- tern of paring down air mobility

Business Models for Mobile Media Services : A case study in China mainland market

OpenAIRE

Huang, Jin

2012-01-01

Mobile media OTT service such as mobile music and mobile video is believed to be the next big revenue driver for mobile operator’s mobile broadband business. The media industry is willing to take mobile distribution channel to increase the content value. In Europe, there are already several successful cooperation cases between online media service provider and mobile operator, such as Spotify and Telia. However, with more complicated market and business environment in China, the mobile media ...

Acid sensing ion channel 1 in lateral hypothalamus contributes to breathing control.

Directory of Open Access Journals (Sweden)

Nana Song

Full Text Available Acid-sensing ion channels (ASICs are present in neurons and may contribute to chemoreception. Among six subunits of ASICs, ASIC1 is mainly expressed in the central nervous system. Recently, multiple sites in the brain including the lateral hypothalamus (LH have been found to be sensitive to extracellular acidification. Since LH contains orexin neurons and innervates the medulla respiratory center, we hypothesize that ASIC1 is expressed on the orexin neuron and contributes to acid-induced increase in respiratory drive. To test this hypothesis, we used double immunofluorescence to determine whether ASIC1 is expressed on orexin neurons in the LH, and assessed integrated phrenic nerve discharge (iPND in intact rats in response to acidification of the LH. We found that ASIC1 was co-localized with orexinA in the LH. Microinjection of acidified artificial cerebrospinal fluid increased the amplitude of iPND by 70% (pH 7.4 v.s. pH 6.5:1.05±0.12 v.s. 1.70±0.10, n = 6, P<0.001 and increased the respiratory drive (peak amplitude of iPND/inspiratory time, PA/Ti by 40% (1.10±0.23 v.s. 1.50±0.38, P<0.05. This stimulatory effect was abolished by blocking ASIC1 with a nonselective inhibitor (amiloride 10 mM, a selective inhibitor (PcTX1, 10 nM or by damaging orexin neurons in the LH. Current results support our hypothesis that the orexin neuron in the LH can exert an excitation on respiration via ASIC1 during local acidosis. Since central acidification is involved in breathing dysfunction in a variety of pulmonary diseases, understanding its underlying mechanism may improve patient management.

Possibilities of B2C buying and selling using mobile devices in comparison with Inter.

OpenAIRE

Sonia San Martín Gutiérrez; Blanca López Catalán

2010-01-01

New technologies have involved a great opportunity to improve business management. On the one hand, Internet is beginning to be a selling channel that is valid and complementary of the traditional channel, apart from being a channel to search information and socialize. On the other hand and recently, mobile marketing is useful in a commercial sense: the mobile phone incorporates television, camera, radio, chat and now firms are introducing in the issue of advertising and in other regions in s...

Possibilities of B2C buying and selling using mobile devices in comparison with Internet

OpenAIRE

Sonia San Martín Gutiérrez; Blanca López Catalán

2010-01-01

New technologies have involved a great opportunity to improve business management. On the one hand, Internet is beginning to be a selling channel that is valid and complementary of the traditional channel, apart from being a channel to search information and socialize. On the other hand and recently, mobile marketing is useful in a commercial sense: the mobile phone incorporates television, camera, radio, chat and now firms are introducing in the issue of advertising and in other regions in s...

Minimum Probability of Error-Based Equalization Algorithms for Fading Channels

Directory of Open Access Journals (Sweden)

Janos Levendovszky

2007-06-01

Full Text Available Novel channel equalizer algorithms are introduced for wireless communication systems to combat channel distortions resulting from multipath propagation. The novel algorithms are based on newly derived bounds on the probability of error (PE and guarantee better performance than the traditional zero forcing (ZF or minimum mean square error (MMSE algorithms. The new equalization methods require channel state information which is obtained by a fast adaptive channel identification algorithm. As a result, the combined convergence time needed for channel identification and PE minimization still remains smaller than the convergence time of traditional adaptive algorithms, yielding real-time equalization. The performance of the new algorithms is tested by extensive simulations on standard mobile channels.

Mobile App versus Website: A Comparative Eye-Tracking Case Study of Topshop

OpenAIRE

Zofija Tupikovskaja-Omovie; David Tyler; Sam Dhanapala; Steve Hayes

2015-01-01

The UK is leading in online retail and mobile adoption. However, there is a dearth of information relating to mobile apparel retail, and developing an understanding about consumer browsing and purchase behaviour in m-retail channel would provide apparel marketers, mobile website and app developers with the necessary understanding of consumers' needs. Despite the rapid growth of mobile retail businesses, no published study has examined shopping behaviour on fashion mobile ...

Top-gate organic depletion and inversion transistors with doped channel and injection contact

Energy Technology Data Exchange (ETDEWEB)

Liu, Xuhai; Kasemann, Daniel, E-mail: daniel.kasemann@iapp.de; Leo, Karl [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Strasse 1, 01069 Dresden (Germany)

2015-03-09

Organic field-effect transistors constitute a vibrant research field and open application perspectives in flexible electronics. For a commercial breakthrough, however, significant performance improvements are still needed, e.g., stable and high charge carrier mobility and on-off ratio, tunable threshold voltage, as well as integrability criteria such as n- and p-channel operation and top-gate architecture. Here, we show pentacene-based top-gate organic transistors operated in depletion and inversion regimes, realized by doping source and drain contacts as well as a thin layer of the transistor channel. By varying the doping concentration and the thickness of the doped channel, we control the position of the threshold voltage without degrading on-off ratio or mobility. Capacitance-voltage measurements show that an inversion channel can indeed be formed, e.g., an n-doped channel can be inverted to a p-type inversion channel with highly p-doped contacts. The Cytop polymer dielectric minimizes hysteresis, and the transistors can be biased for prolonged cycles without a shift of threshold voltage, indicating excellent operation stability.

Design and characterization of a laterally mounted phased-array transducer breast-specific MRgHIFU device with integrated 11-channel receiver array.

Science.gov (United States)

Payne, A; Merrill, R; Minalga, E; Vyas, U; de Bever, J; Todd, N; Hadley, R; Dumont, E; Neumayer, L; Christensen, D; Roemer, R; Parker, D

2012-03-01

This work presents the design and preliminary evaluation of a new laterally mounted phased-array MRI-guided high-intensity focused ultrasound (MRgHIFU) system with an integrated 11-channel phased-array radio frequency (RF) coil intended for breast cancer treatment. The design goals for the system included the ability to treat the majority of tumor locations, to increase the MR image's signal-to-noise ratio (SNR) throughout the treatment volume and to provide adequate comfort for the patient. In order to treat the majority of the breast volume, the device was designed such that the treated breast is suspended in a 17-cm diameter treatment cylinder. A laterally shooting 1-MHz, 256-element phased-array ultrasound transducer with flexible positioning is mounted outside the treatment cylinder. This configuration achieves a reduced water volume to minimize RF coil loading effects, to position the coils closer to the breast for increased signal sensitivity, and to reduce the MR image noise associated with using water as the coupling fluid. This design uses an 11-channel phased-array RF coil that is placed on the outer surface of the cylinder surrounding the breast. Mechanical positioning of the transducer and electronic steering of the focal spot enable placement of the ultrasound focus at arbitrary locations throughout the suspended breast. The treatment platform allows the patient to lie prone in a face-down position. The system was tested for comfort with 18 normal volunteers and SNR capabilities in one normal volunteer and for heating accuracy and stability in homogeneous phantom and inhomogeneous ex vivo porcine tissue. There was a 61% increase in mean relative SNR achieved in a homogeneous phantom using the 11-channel RF coil when compared to using only a single-loop coil around the chest wall. The repeatability of the system's energy delivery in a single location was excellent, with less than 3% variability between repeated temperature measurements at the same

Characterization of SiO2/SiC interface states and channel mobility from MOSFET characteristics including variable-range hopping at cryogenic temperature

Directory of Open Access Journals (Sweden)

Hironori Yoshioka

2018-04-01

Full Text Available The characteristics of SiC MOSFETs (drain current vs. gate voltage were measured at 0.14−350 K and analyzed considering variable-range hopping conduction through interface states. The total interface state density was determined to be 5.4×1012 cm−2 from the additional shift in the threshold gate voltage with a temperature change. The wave-function size of interface states was determined from the temperature dependence of the measured hopping current and was comparable to the theoretical value. The channel mobility was approximately 100 cm2V−1s−1 and was almost independent of temperature.

Characterization of SiO2/SiC interface states and channel mobility from MOSFET characteristics including variable-range hopping at cryogenic temperature

Science.gov (United States)

Yoshioka, Hironori; Hirata, Kazuto

2018-04-01

The characteristics of SiC MOSFETs (drain current vs. gate voltage) were measured at 0.14-350 K and analyzed considering variable-range hopping conduction through interface states. The total interface state density was determined to be 5.4×1012 cm-2 from the additional shift in the threshold gate voltage with a temperature change. The wave-function size of interface states was determined from the temperature dependence of the measured hopping current and was comparable to the theoretical value. The channel mobility was approximately 100 cm2V-1s-1 and was almost independent of temperature.

Mobile Banking: a Customer Relationship Management (Crm) Channel

OpenAIRE

Budiardjo, Eko K; Aprillovi, Dewi

2009-01-01

Meningkatnya pengguna handphone mendorong bank meluncurkan produk-produk layanan perbankan melalui handphone yang dikenal dengan sebutan Mobile Banking (M-Banking). Dalam konteks Customer Relationship Management (CRM), kehadiran M-Banking juga memberikan kontribusi dalam meningkatkan dan mempertahankan kesetiaan pelanggan. Strategi sukses membangun CRM sangat dipengaruhi oleh kepandaian tim pemasaran dalam memahami perilaku dan kebutuhan pelanggan, yang dapat diterjemahkan kedalam kelompok tr...

Branding and Channel Issues in E-commerce from an Information System’s Perspective

DEFF Research Database (Denmark)

Hansen, Rina; Tambo, Torben

2011-01-01

E-commerce has matured and become mainstream. The fashion industry is now competing strongly in the digital markets. Beside traditional web-shops, new sales and branding channels are emerging e.g. M-commerce (mobile); social commerce; marketplaces; gaming etc. E-commerce and multi-channel retailing...... fashion companies’ existing and future sales and branding channels from an IS perspective. Future research suggestions include long-term challenges and benefits of distinct electronic channels....

The Effect of Current Trends in Mobile Marketing on Traditional Marketing Communications and Customer Relationship Management

OpenAIRE

Hoffmann, Kristina

2011-01-01

As consumers increasingly prefer mobile devices as their main communication and entertainment channel, it becomes more and more important for marketers as well. Mobile marketing today does not only include sending SMS and E-mail but rather is becoming a whole new interactive, rich-media marketing channel with possibilities for direct engagement with ads and brands like never before. This research attempts to provide a greater understanding about the effects of current trends in mobile mark...

Mobility-Enhanced Reliable Geographical Forwarding in Cognitive Radio Sensor Networks

Directory of Open Access Journals (Sweden)

Suleiman Zubair

2016-01-01

Full Text Available The emergence of the Internet of Things and the proliferation of mobile wireless devices has brought the area of mobile cognitive radio sensor networks (MCRSN to the research spot light. Notwithstanding the potentials of CRSNs in terms of opportunistic channel usage for bursty traffic, the effect of the mobility of resource-constrained nodes to route stability, mobility-induced spatio-temporal spectral opportunities and primary user (PU protection still remain open issues that need to be jointly addressed. To this effect, this paper proposes a mobile reliable geographical forwarding routing (MROR protocol. MROR provides a robust mobile framework for geographical forwarding that is based on a mobility-induced channel availability model. It presents a comprehensive routing strategy that considers PU activity (to take care of routes that have to be built through PU coverage, PU signal protection (by the introduction of a mobility-induced guard (mguard distance and the random mobility-induced spatio-temporal spectrum opportunities (for enhancement of throughput. It also addresses the issue of frequent route maintenance that arises when speeds of the mobile nodes are considered as a routing metric. As a result, simulation has shown the ability of MROR to reduce the route failure rate by about 65% as against other schemes. In addition, further results show that MROR can improve both the throughput and goodput at the sink in an energy-efficient manner that is required in CRSNs as against compared works.

Mobility-Enhanced Reliable Geographical Forwarding in Cognitive Radio Sensor Networks.

Science.gov (United States)

Zubair, Suleiman; Syed Yusoff, Sharifah Kamilah; Fisal, Norsheila

2016-01-29

The emergence of the Internet of Things and the proliferation of mobile wireless devices has brought the area of mobile cognitive radio sensor networks (MCRSN) to the research spot light. Notwithstanding the potentials of CRSNs in terms of opportunistic channel usage for bursty traffic, the effect of the mobility of resource-constrained nodes to route stability, mobility-induced spatio-temporal spectral opportunities and primary user (PU) protection still remain open issues that need to be jointly addressed. To this effect, this paper proposes a mobile reliable geographical forwarding routing (MROR) protocol. MROR provides a robust mobile framework for geographical forwarding that is based on a mobility-induced channel availability model. It presents a comprehensive routing strategy that considers PU activity (to take care of routes that have to be built through PU coverage), PU signal protection (by the introduction of a mobility-induced guard (mguard) distance) and the random mobility-induced spatio-temporal spectrum opportunities (for enhancement of throughput). It also addresses the issue of frequent route maintenance that arises when speeds of the mobile nodes are considered as a routing metric. As a result, simulation has shown the ability of MROR to reduce the route failure rate by about 65% as against other schemes. In addition, further results show that MROR can improve both the throughput and goodput at the sink in an energy-efficient manner that is required in CRSNs as against compared works.

Mobility-Enhanced Reliable Geographical Forwarding in Cognitive Radio Sensor Networks

Science.gov (United States)

Zubair, Suleiman; Syed Yusoff, Sharifah Kamilah; Fisal, Norsheila

2016-01-01

The emergence of the Internet of Things and the proliferation of mobile wireless devices has brought the area of mobile cognitive radio sensor networks (MCRSN) to the research spot light. Notwithstanding the potentials of CRSNs in terms of opportunistic channel usage for bursty traffic, the effect of the mobility of resource-constrained nodes to route stability, mobility-induced spatio-temporal spectral opportunities and primary user (PU) protection still remain open issues that need to be jointly addressed. To this effect, this paper proposes a mobile reliable geographical forwarding routing (MROR) protocol. MROR provides a robust mobile framework for geographical forwarding that is based on a mobility-induced channel availability model. It presents a comprehensive routing strategy that considers PU activity (to take care of routes that have to be built through PU coverage), PU signal protection (by the introduction of a mobility-induced guard (mguard) distance) and the random mobility-induced spatio-temporal spectrum opportunities (for enhancement of throughput). It also addresses the issue of frequent route maintenance that arises when speeds of the mobile nodes are considered as a routing metric. As a result, simulation has shown the ability of MROR to reduce the route failure rate by about 65% as against other schemes. In addition, further results show that MROR can improve both the throughput and goodput at the sink in an energy-efficient manner that is required in CRSNs as against compared works. PMID:26840312

Mobile phone usage does not affect sudden sensorineural hearing loss.

Science.gov (United States)

Sagiv, D; Migirov, L; Madgar, O; Nakache, G; Wolf, M; Shapira, Y

2018-01-01

Recent studies found that mobile phone users had a significantly greater risk of having elevated thresholds in speech frequencies. This study investigated the correlation between the laterality of sudden sensorineural hearing loss, handedness and the preferred ear for mobile phone use. The study included all patients who presented with sudden sensorineural hearing loss to the Department of Otolaryngology - Head and Neck Surgery in our tertiary referral medical centre between 2014 and 2016. Patients were asked to indicate their dominant hand and preferred ear for mobile phone use. The study comprised 160 patients. No correlation was found between the dominant hand or preferred ear for mobile phone use and the side of sudden sensorineural hearing loss. There was no correlation between the side of the sudden sensorineural hearing loss (preferable or non-preferable for mobile phone use) and audiometric characteristics. No correlation was found between the laterality of ears used for mobile phone and sudden sensorineural hearing loss.

MIMO channel measurements using optical links on small mobile terminals

DEFF Research Database (Denmark)

Yanakiev, Boyan; Nielsen, Jesper Ødum; Pedersen, Gert Frølund

2010-01-01

This paper looks at a novel measurement device for propagation channel measurements using a fiber optic link. Although the idea of using optical links is not new, most of the developments in the area are either too big [5], short range [6] or suitable for anechoic chamber only [7]. The device...... presented here is specifically designed to fit in a very small volume and is optimized for low power consumption (runs on small battery), thus imitating the phone electronics. It can be used for anechoic chamber measurements, however it is designed for long range channel sounding measurements....

An analysis of density-wave oscillations in ventilated channels

International Nuclear Information System (INIS)

Taleyarkhan, R.P.

1982-01-01

A mathematical model has been developed for the linear stability analyses of a system of ventilated parallel boiling channels. The model can accommodate phasic slip, arbitrary non-uniform axial power distributions, distributed local losses, heater wall dynamics, channel-to-channel radial power skews, discrete or continuous ventilation between the channels, turbulent mixing between the channels, various donor-cell options for the lateral transport of energy and momentum, and a transverse momentum equation, including storage and cross-flow inertia. A special matrix reduction scheme was developed to efficiently solve the system of linearized, Laplace transformed, nodal equations. The digital computer programs, MAZDA-1F, MAZDA-4S and MAZDA-4F, were written for the numerical evaluation of the mathematical model developed. MAZDA-1F is a frequency domain code which can be used for the study of linear stability of a single boiling channel. MAZDA-4S evaluates the steady-state flow and pressure fields in a system of ventilated parallel channels. The frequency domain code, MAZDA-4F, can then be used to assess the linear stability of the flow field obtained with MAZDA-4S. A parametric study using MAZDA-1F and MAZDA-4F revealed that phasic slip, axial power distribution, heater wall dynamics, local losses, lateral ventilation and radial power skew can have a significant effect on the stability characteristics of the system

Seismic stochastic inversion identify river channel sand body

Science.gov (United States)

He, Z.

2015-12-01

The technology of seismic inversion is regarded as one of the most important part of geophysics. By using the technology of seismic inversion and the theory of stochastic simulation, the concept of seismic stochastic inversion is proposed.Seismic stochastic inversion can play an significant role in the identifying river channel sand body. Accurate sand body description is a crucial parameter to measure oilfield development and oilfield stimulation during the middle and later periods. Besides, rational well spacing density is an essential condition for efficient production. Based on the geological knowledge of a certain oilfield, in line with the use of seismic stochastic inversion, the river channel sand body in the work area is identified. In this paper, firstly, the single river channel body from the composite river channel body is subdivided. Secondly, the distribution of river channel body is ascertained in order to ascertain the direction of rivers. Morever, the superimposed relationship among the sand body is analyzed, especially among the inter-well sand body. The last but not at the least, via the analysis of inversion results of first vacuating the wells and continuous infilling later, it is meeted the most needs well spacing density that can obtain the optimal inversion result. It would serve effective guidance for oilfield stimulation.

[An autopsy case of amyotrophic lateral sclerosis with prominent muscle cramps, fasciculation, and high titer of anti-voltage gated potassium channel (VGKC) complex antibody].

Science.gov (United States)

Sato, Aki; Sakai, Naoko; Shinbo, Junsuke; Hashidate, Hideki; Igarashi, Shuichi; Kakita, Akiyoshi; Yamazaki, Motoyoshi

2014-01-01

The patient was a 55-year-old male who had prominent fasciculation and muscle cramps. Muscle weakness and atrophy of the trunk, respiratory system, and extremities gradually progressed. On the basis of these features, we diagnosed this patient as having amyotrophic lateral sclerosis (ALS), however, the upper motor neuron signs were not significant. Following the detection of the anti-voltage gated potassium channel (VGKC) complex antibody at 907.5 pM (normal VGKC complex antibody in the development of cramp-fasciculation syndrome has been speculated. In this ALS patient, the antibodies might be associated with pathomechanisms underlying the characteristic symptoms.

A Novel OFDM Channel Estimation Algorithm with ICI Mitigation over Fast Fading Channels

Directory of Open Access Journals (Sweden)

C. Tao

2010-06-01

Full Text Available Orthogonal frequency-division multiplexing (OFDM is well-known as a high-bit-rate transmission technique, but the Doppler frequency offset due to the high speed movement destroys the orthogonality of the subcarriers resulting in the intercarrier interference (ICI, and degrades the performance of the system at the same time. In this paper a novel OFDM channel estimation algorithm with ICI mitigation based on the ICI self-cancellation scheme is proposed. With this method, a more accurate channel estimation is obtained by comb-type double pilots and then ICI coefficients can be obtained to mitigate the ICI on each subcarrier under the assumption that the channel impulse response (CIR varies in a linear fashion. The theoretical analysis and simulation results show that the bit error rate (BER and spectral efficiency performances are improved significantly under high-speed mobility conditions (350 km/h – 500 km/h in comparison to ZHAO’s ICI self-cancellation scheme.

Financial Technologies: A Note on Mobile Payment

Directory of Open Access Journals (Sweden)

Song Yee Leng

2018-02-01

Full Text Available The financial market is currently disrupted by the rise of new technologies "FinTech” a short form for financial technology, which profoundly reshapes the financial intermediary structure and makes financial services more efficient. Mobile technology with Internet-enabled devices are the next logical phase of the World Wide Web campaign such as mobile phone taking over the mass market and will fundamentally change the way products are buy and sell as well as financial services especially the mobile payment system. This research examines changes payment method in financial services, particularly those involving mobile payments that can create new channels for consumers to purchase goods and services using mobile phone. Mobile payment application is ready to replace traditional cash, checks, credit and debit card throughout the country. In this stage of development, the current situation of mobile payment market, review the previous literature on mobile payment services, analysis use of mobile payment worldwide and various initiatives use mobile phones to offer financial services for those ‘unbanked’.

Financial Technologies: A Note on Mobile Payment

Directory of Open Access Journals (Sweden)

Song Yee Leng

2018-02-01

Full Text Available The financial market is currently disrupted by the rise of new technologies “FinTech” a short form of financial technology, which profoundly reshapes the financial intermediary structure and makes financial services more efficient. Mobile technology with Internet-enabled devices are the next logical phase of the World Wide Web a campaign such as mobile phone taking over the mass market and will fundamentally change the way products are bought and sold as well as financial services especially the mobile payment system. This research examines changes payment method in financial services, particularly those involving mobile payments that can create new channels for consumers to purchase goods and services using a mobile phone. Mobile payment application is ready to replace traditional cash, checks, credit and debit card throughout the country. In this stage of development, the current situation of mobile payment market, review the previous literature on mobile payment services, analysis use of mobile payment worldwide and various initiatives use mobile phones to offer financial services for those ‘unbanked’.

GSM-PKI solution enabling secure mobile communications.

Science.gov (United States)

Jelekäinen, Pekka

2004-03-31

Because of its wide distribution and ease of use, the mobile phone, as a reliable personal communications channel, offers an excellent basis for the provision of reliable electronic communications services. In Finland, ca. 75% of the citizens have a mobile phone and, at present and most likely also in the future, it is the most widely spread service channel allowing reliable electronic communications. Despite the restricted functions of the mobile phone, the citizens can use the phone also as a communications medium. In 2001, the Finns sent over 1 billion SMS messages. In Finland, TeliaSonera Finland Oyi and the Population Register Centre (PRC) have closed a co-operation agreement with the aim of creating a mobile phone service for the electronic identification of a person. The co-operation launched is a significant development project from the perspective of the citizens. As a result, the consumers will have a new alternative for reliable electronic communications and commerce in data networks in addition to the electronic identification card. In the future, it will be possible to use the services of both public administration and the private sector by means of a mobile phone more reliably than before, without a physical visit, e.g. to a health centre or to another provider of healthcare services. The possibility of identification and signature by a mobile phone allows an easier provision of versatile services irrespective of time and place, because, in addition to voice, text message, and WAP functions, the service can be utilised also in communications services through the Internet, in which case, the mobile phone acts like a card reader. From the perspective of reliable personal mobile communications, the healthcare sector is one of the most significant and challenging application areas.

n-Channel semiconductor materials design for organic complementary circuits.

Science.gov (United States)

Usta, Hakan; Facchetti, Antonio; Marks, Tobin J

2011-07-19

emphasis on structure-property relationships. We then examine the synthesis and properties of carbonyl-functionalized oligomers, which constitute second-generation n-channel oligothiophenes, in both vacuum- and solution-processed FETs. These materials have high carrier mobilities and good air stability. In parallel, exceptionally electron-deficient cyano-functionalized arylenediimide derivatives are discussed as early examples of thermodynamically air-stable, high-performance n-channel semiconductors; they exhibit record electron mobilities of up to 0.64 cm(2)/V·s. Furthermore, we provide an overview of highly soluble ladder-type macromolecular semiconductors as OFET components, which combine ambient stability with solution processibility. A high electron mobility of 0.16 cm(2)/V·s is obtained under ambient conditions for solution-processed films. Finally, examples of polymeric n-channel semiconductors with electron mobilities as high as 0.85 cm(2)/V·s are discussed; these constitute an important advance toward fully printed polymeric electronic circuitry. Density functional theory (DFT) computations reveal important trends in molecular physicochemical and semiconducting properties, which, when combined with experimental data, shed new light on molecular charge transport characteristics. Our data provide the basis for a fundamental understanding of charge transport in high-performance n-channel organic semiconductors. Moreover, our results provide a road map for developing functional, complementary organic circuitry, which requires combining p- and n-channel transistors.

Comparison of mobility extraction methods based on field-effect measurements for graphene

Directory of Open Access Journals (Sweden)

Hua Zhong

2015-05-01

Full Text Available Carrier mobility extraction methods for graphene based on field-effect measurements are explored and compared according to theoretical analysis and experimental results. A group of graphene devices with different channel lengths were fabricated and measured, and carrier mobility is extracted from those electrical transfer curves using three different methods. Accuracy and applicability of those methods were compared. Transfer length method (TLM can obtain accurate density dependent mobility and contact resistance at relative high carrier density based on data from a group of devices, and then can act as a standard method to verify other methods. As two of the most popular methods, direct transconductance method (DTM and fitting method (FTM can extract mobility easily based on transfer curve of a sole graphene device. DTM offers an underestimated mobility at any carrier density owing to the neglect of contact resistances, and the accuracy can be improved through fabricating field-effect transistors with long channel and good contacts. FTM assumes a constant mobility independent on carrier density, and then can obtain mobility, contact resistance and residual density stimulations through fitting a transfer curve. However, FTM tends to obtain a mobility value near Dirac point and then overestimates carrier mobility of graphene. Comparing with the DTM and FTM, TLM could offer a much more accurate and carrier density dependent mobility, that reflects the complete properties of graphene carrier mobility.

Mobility Enhancement in Amorphous In-Ga-Zn-O Thin-Film Transistor by Induced Metallic in Nanoparticles and Cu Electrodes

Directory of Open Access Journals (Sweden)

Shiben Hu

2018-03-01

Full Text Available In this work, we fabricated a high-mobility amorphous indium-gallium-zinc-oxide (a-IGZO thin-film transistor (TFT based on alumina oxide (Al 2 O 3 passivation layer (PVL and copper (Cu source/drain electrodes (S/D. The mechanism of the high mobility for a-IGZO TFT was proposed and experimentally demonstrated. The conductivity of the channel layer was significantly improved due to the formation of metallic In nanoparticles on the back channel during Al 2 O 3 PVL sputtering. In addition, Ar atmosphere annealing induced the Schottky contact formation between the Cu S/D and the channel layer caused by Cu diffusion. In conjunction with high conductivity channel and Schottky contact, the a-IGZO TFT based on Cu S/D and Al 2 O 3 PVL exhibited remarkable mobility of 33.5–220.1 cm 2 /Vs when channel length varies from 60 to 560 μ m. This work presents a feasible way to implement high mobility and Cu electrodes in a-IGZO TFT, simultaneously.

X-ray image segmentation for vertebral mobility analysis

International Nuclear Information System (INIS)

Benjelloun, Mohammed; Mahmoudi, Said

2008-01-01

The goal of this work is to extract the parameters determining vertebral motion and its variation during flexion-extension movements using a computer vision tool for estimating and analyzing vertebral mobility. To compute vertebral body motion parameters we propose a comparative study between two segmentation methods proposed and applied to lateral X-ray images of the cervical spine. The two vertebra contour detection methods include (1) a discrete dynamic contour model (DDCM) and (2) a template matching process associated with a polar signature system. These two methods not only enable vertebra segmentation but also extract parameters that can be used to evaluate vertebral mobility. Lateral cervical spine views including 100 views in flexion, extension and neutral orientations were available for evaluation. Vertebral body motion was evaluated by human observers and using automatic methods. The results provided by the automated approaches were consistent with manual measures obtained by 15 human observers. The automated techniques provide acceptable results for the assessment of vertebral body mobility in flexion and extension on lateral views of the cervical spine. (orig.)

Phase-Type Models of Channel-Holding Times in Cellular Communication Systems

DEFF Research Database (Denmark)

Christensen, Thomas Kaare; Nielsen, Bo Friis; Iversen, Villy Bæk

2004-01-01

In this paper, we derive the distribution of the channel-holding time when both cell-residence and call-holding times are phase-type distributed. Furthermore, the distribution of the number of handovers, the conditional channel-holding time distributions, and the channel-holding time when cell re...... residence times are correlated are derived. All distributions are of phase type, making them very general and flexible. The channel-holding times are of importance in performance evaluation and simulation of cellular mobile communication systems.......In this paper, we derive the distribution of the channel-holding time when both cell-residence and call-holding times are phase-type distributed. Furthermore, the distribution of the number of handovers, the conditional channel-holding time distributions, and the channel-holding time when cell...

Channel-Mediated Lactate Release by K+-Stimulated Astrocytes

KAUST Repository

Sotelo-Hitschfeld, T.; Niemeyer, M. I.; Machler, P.; Ruminot, I.; Lerchundi, R.; Wyss, M. T.; Stobart, J.; Fernandez-Moncada, I.; Valdebenito, R.; Garrido-Gerter, P.; Contreras-Baeza, Y.; Schneider, B. L.; Aebischer, P.; Lengacher, S.; San Martin, A.; Le Douce, J.; Bonvento, G.; Magistretti, Pierre J.; Sepulveda, F. V.; Weber, B.; Barros, L. F.

2015-01-01

in response to local field stimulation. The existence of an astrocytic lactate reservoir and its quick mobilization via an ion channel in response to a neuronal cue provides fresh support to lactate roles in neuronal fueling and in gliotransmission.

Can combining web and mobile communication channels reveal concealed customer value?

OpenAIRE

Bothorel, Grégoire; Vanheems, Régine; Guérin, Anne

2015-01-01

International audience; Many firms have implemented a customer-value based segmentation to improve the efficiency of MARCOM campaigns as part of their long term customer relationship strategies (Kumar 2010, Thomas et al. 2005).If distribution channel addition may increase the intrinsic customer value (Kumar 2005, Rangaswamy 2005) in a US context as well as in a French context (Vanheems 2009), few studies have been conducted about the impact of adding a new communication channel during the sam...

Disruption of ATP-sensitive potassium channel function in skeletal muscles promotes production and secretion of musclin

Energy Technology Data Exchange (ETDEWEB)

Sierra, Ana, E-mail: ana-sierra@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Subbotina, Ekaterina, E-mail: ekaterina-subbotina@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Zhu, Zhiyong, E-mail: zhiyong-zhu@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Gao, Zhan, E-mail: zhan-gao@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Koganti, Siva Rama Krishna, E-mail: sivaramakrishna.koganti@ttuhc.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Coetzee, William A., E-mail: william.coetzee@nyumc.org [Department of Pediatrics, NYU School of Medicine, New York, NY 10016 (United States); Goldhamer, David J., E-mail: david.goldhamer@uconn.edu [Center for Regenerative Biology, Department of Molecular and Cell Biology, Advanced Technology Laboratory, University of Connecticut, 1392 Storrs Road Unit 4243, Storrs, Connecticut 06269 (United States); Hodgson-Zingman, Denice M., E-mail: denice-zingman@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, Iowa City, IA 52242 (United States); Zingman, Leonid V., E-mail: leonid-zingman@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, Iowa City, IA 52242 (United States); Department of Veterans Affairs, Medical Center, Iowa City, IA 52242 (United States)

2016-02-26

Sarcolemmal ATP-sensitive potassium (K{sub ATP}) channels control skeletal muscle energy use through their ability to adjust membrane excitability and related cell functions in accordance with cellular metabolic status. Mice with disrupted skeletal muscle K{sub ATP} channels exhibit reduced adipocyte size and increased fatty acid release into the circulation. As yet, the molecular mechanisms underlying this link between skeletal muscle K{sub ATP} channel function and adipose mobilization have not been established. Here, we demonstrate that skeletal muscle-specific disruption of K{sub ATP} channel function in transgenic (TG) mice promotes production and secretion of musclin. Musclin is a myokine with high homology to atrial natriuretic peptide (ANP) that enhances ANP signaling by competing for elimination. Augmented musclin production in TG mice is driven by a molecular cascade resulting in enhanced acetylation and nuclear exclusion of the transcription factor forkhead box O1 (FOXO1) – an inhibitor of transcription of the musclin encoding gene. Musclin production/secretion in TG is paired with increased mobilization of fatty acids and a clear trend toward increased circulating ANP, an activator of lipolysis. These data establish K{sub ATP} channel-dependent musclin production as a potential mechanistic link coupling “local” skeletal muscle energy consumption with mobilization of bodily resources from fat. Understanding such mechanisms is an important step toward designing interventions to manage metabolic disorders including those related to excess body fat and associated co-morbidities. - Highlights: • ATP-sensitive K{sup +} channels regulate musclin production by skeletal muscles. • Lipolytic ANP signaling is promoted by augmented skeletal muscle musclin production. • Skeletal muscle musclin transcription is promoted by a CaMKII/HDAC/FOXO1 pathway. • Musclin links adipose mobilization to energy use in K{sub ATP} channel deficient skeletal muscle.

Disruption of ATP-sensitive potassium channel function in skeletal muscles promotes production and secretion of musclin

International Nuclear Information System (INIS)

Sierra, Ana; Subbotina, Ekaterina; Zhu, Zhiyong; Gao, Zhan; Koganti, Siva Rama Krishna; Coetzee, William A.; Goldhamer, David J.; Hodgson-Zingman, Denice M.; Zingman, Leonid V.

2016-01-01

Sarcolemmal ATP-sensitive potassium (K_A_T_P) channels control skeletal muscle energy use through their ability to adjust membrane excitability and related cell functions in accordance with cellular metabolic status. Mice with disrupted skeletal muscle K_A_T_P channels exhibit reduced adipocyte size and increased fatty acid release into the circulation. As yet, the molecular mechanisms underlying this link between skeletal muscle K_A_T_P channel function and adipose mobilization have not been established. Here, we demonstrate that skeletal muscle-specific disruption of K_A_T_P channel function in transgenic (TG) mice promotes production and secretion of musclin. Musclin is a myokine with high homology to atrial natriuretic peptide (ANP) that enhances ANP signaling by competing for elimination. Augmented musclin production in TG mice is driven by a molecular cascade resulting in enhanced acetylation and nuclear exclusion of the transcription factor forkhead box O1 (FOXO1) – an inhibitor of transcription of the musclin encoding gene. Musclin production/secretion in TG is paired with increased mobilization of fatty acids and a clear trend toward increased circulating ANP, an activator of lipolysis. These data establish K_A_T_P channel-dependent musclin production as a potential mechanistic link coupling “local” skeletal muscle energy consumption with mobilization of bodily resources from fat. Understanding such mechanisms is an important step toward designing interventions to manage metabolic disorders including those related to excess body fat and associated co-morbidities. - Highlights: • ATP-sensitive K"+ channels regulate musclin production by skeletal muscles. • Lipolytic ANP signaling is promoted by augmented skeletal muscle musclin production. • Skeletal muscle musclin transcription is promoted by a CaMKII/HDAC/FOXO1 pathway. • Musclin links adipose mobilization to energy use in K_A_T_P channel deficient skeletal muscle.

Low-field mobility and carrier transport mechanism transition in nanoscale MOSFETs

International Nuclear Information System (INIS)

Liu Hongwei; Wang Runsheng; Huang Ru; Zhang Xing

2010-01-01

This paper extends the flux scattering method to study the carrier transport property in nanoscale MOSFETs with special emphasis on the low-field mobility and the transport mechanism transition. A unified analytical expression for the low-field mobility is proposed, which covers the entire regime from drift-diffusion transport to quasi-ballistic transport in 1-D, 2-D and 3-D MOSFETs. Two key parameters, namely the long-channel low-field mobility (μ 0 ) and the low-field mean free path (λ 0 ), are obtained from the experimental data, and the transport mechanism transition in MOSFETs is further discussed both experimentally and theoretically. Our work shows that λ 0 is available to characterize the inherent transition of the carrier transport mechanism rather than the low-field mobility. The mobility reduces in the MOSFET with the shrinking of the channel length; however, λ 0 is nearly a constant, and λ 0 can be used as the 'entry criterion' to determine whether the device begins to operate under quasi-ballistic transport to some extent. (semiconductor devices)

Boost Up Carrier Mobility for Ferroelectric Organic Transistor Memory via Buffering Interfacial Polarization Fluctuation

Science.gov (United States)

Sun, Huabin; Wang, Qijing; Li, Yun; Lin, Yen-Fu; Wang, Yu; Yin, Yao; Xu, Yong; Liu, Chuan; Tsukagoshi, Kazuhito; Pan, Lijia; Wang, Xizhang; Hu, Zheng; Shi, Yi

2014-11-01

Ferroelectric organic field-effect transistors (Fe-OFETs) have been attractive for a variety of non-volatile memory device applications. One of the critical issues of Fe-OFETs is the improvement of carrier mobility in semiconducting channels. In this article, we propose a novel interfacial buffering method that inserts an ultrathin poly(methyl methacrylate) (PMMA) between ferroelectric polymer and organic semiconductor layers. A high field-effect mobility (μFET) up to 4.6 cm2 V-1 s-1 is obtained. Subsequently, the programming process in our Fe-OFETs is mainly dominated by the switching between two ferroelectric polarizations rather than by the mobility-determined charge accumulation at the channel. Thus, the ``reading'' and ``programming'' speeds are significantly improved. Investigations show that the polarization fluctuation at semiconductor/insulator interfaces, which affect the charge transport in conducting channels, can be suppressed effectively using our method.

A decentralized scheduling algorithm for time synchronized channel hopping

Directory of Open Access Journals (Sweden)

Andrew Tinka

2011-09-01

Full Text Available Time Synchronized Channel Hopping (TSCH is an existing Medium Access Control scheme which enables robust communication through channel hopping and high data rates through synchronization. It is based on a time-slotted architecture, and its correct functioning depends on a schedule which is typically computed by a central node. This paper presents, to our knowledge, the first scheduling algorithm for TSCH networks which both is distributed and which copes with mobile nodes. Two variations on scheduling algorithms are presented. Aloha-based scheduling allocates one channel for broadcasting advertisements for new neighbors. Reservation- based scheduling augments Aloha-based scheduling with a dedicated timeslot for targeted advertisements based on gossip information. A mobile ad hoc motorized sensor network with frequent connectivity changes is studied, and the performance of the two proposed algorithms is assessed. This performance analysis uses both simulation results and the results of a field deployment of floating wireless sensors in an estuarial canal environment. Reservation-based scheduling performs significantly better than Aloha-based scheduling, suggesting that the improved network reactivity is worth the increased algorithmic complexity and resource consumption.

Adaptive Detection and ISI Mitigation for Mobile Molecular Communication.

Science.gov (United States)

Chang, Ge; Lin, Lin; Yan, Hao

2018-03-01

Current studies on modulation and detection schemes in molecular communication mainly focus on the scenarios with static transmitters and receivers. However, mobile molecular communication is needed in many envisioned applications, such as target tracking and drug delivery. Until now, investigations about mobile molecular communication have been limited. In this paper, a static transmitter and a mobile bacterium-based receiver performing random walk are considered. In this mobile scenario, the channel impulse response changes due to the dynamic change of the distance between the transmitter and the receiver. Detection schemes based on fixed distance fail in signal detection in such a scenario. Furthermore, the intersymbol interference (ISI) effect becomes more complex due to the dynamic character of the signal which makes the estimation and mitigation of the ISI even more difficult. In this paper, an adaptive ISI mitigation method and two adaptive detection schemes are proposed for this mobile scenario. In the proposed scheme, adaptive ISI mitigation, estimation of dynamic distance, and the corresponding impulse response reconstruction are performed in each symbol interval. Based on the dynamic channel impulse response in each interval, two adaptive detection schemes, concentration-based adaptive threshold detection and peak-time-based adaptive detection, are proposed for signal detection. Simulations demonstrate that the ISI effect is significantly reduced and the adaptive detection schemes are reliable and robust for mobile molecular communication.

In-service communication channel sensing based on reflectometry for TWDM-PON systems

Science.gov (United States)

Iida, Daisuke; Kuwano, Shigeru; Terada, Jun

2014-05-01

Many base stations are accommodated in TWDM-PON based mobile backhaul and fronthaul networks for future radio access, and failed connections in an optical network unit (ONU) wavelength channel severely degrade system performance. A cost effective in-service ONU wavelength channel monitor is essential to ensure proper system operation without failed connections. To address this issue we propose a reflectometry-based remote sensing method that provides wavelength channel information with the optical line terminal (OLT)-ONU distance. The method realizes real-time monitoring of ONU wavelength channels without signal quality degradation. Experimental results show it achieves wavelength channel distinction with high distance resolution.

Analysis of density-wave oscillations in ventilated channels

International Nuclear Information System (INIS)

Taleyarkhan, R.; Podowski, M.; Lahey, R.T. Jr.

1983-03-01

A mathematical model has been developed for the linear stability analyses of a system of ventilated parallel boiling channels. The model can accomodate phasic slip, arbitrary non-uniform axial power distributions, distributed local losses, heater wall dynamics, channel-to-channel radial power skews, discrete or continuous ventilation between the channels, turbulent mixing between the channels, various donor-cell options for the lateral transport of energy and momentum, and a transverse momentum equation, including storage and crossflow inertia. A special matrix reduction scheme was developed to efficiently solve the system of linearized, Laplace transformed , nodal equations. The digital computer programs, MAZDA-1F, MAZDA-4S and MAZDA-4F, were written for the numerical evaluation of the mathematical model developed

Multichannel MAC Layer In Mobile Ad—Hoc Network

Science.gov (United States)

Logesh, K.; Rao, Samba Siva

2010-11-01

This paper we presented the design objectives and technical challenges in Multichannel MAC protocols in Mobile Ad-hoc Network. In IEEE 802.11 a/b/g standards allow use of multiple channels, only a single channel is popularly used, due to the lack of efficient protocols that enable use of Multiple Channels. Even though complex environments in ad hoc networks require a combined control of physical (PHY) and medium access control (MAC) layers resources in order to optimize performance. And also we discuss the characteristics of cross-layer frame and give a multichannel MAC approach.

THE USE OF NEW DISTRIBUTION CHANNELS TO INCREASE THE EFFICIENCY OF INSURANCE COMPANIES

Directory of Open Access Journals (Sweden)

Olga N. Kozlova

2017-09-01

Full Text Available The article deals with the issues of increasing the efficiency of insurance companies on the basis of using new non-traditional distribution channels. The relevance of the topic is justified by the automation of management processes, a new generation of consumers focused on new technologies, the use of the Internet, growing and selling functional mobile gadgets. The insurance companies use new distribution channels via the Internet network along with the traditional means for the expansion of the insurance portfolio and attracting active and passive consumers. The calculations carried out on the basis of the data of the Bank of Russia show that the share of such sales is growing, but not leading. The use of the Internet depends on many factors, but primarily on the types of insurance. The authors carry out calculations on the use of distribution channels in various types of insurance. The complexity and variety of products on life insurance requires qualified intermediaries, therefore, the use of new distribution channels here is not widespread in contrast to classical accident insurance or compulsory insurance, where sales are more efficient when organizing through the Internet. Selling through Internet has a number of advantages that reduce the cost of doing business, reduce the agency network, the cost of print advertising to attract passive and strengthen the relationship with active consumers. The authors also conduct analysis of the advantages and disadvantages of using mobile gadgets to work with potential customers, quantitative and qualitative benefits of implementing mobile apps in the work of insurance companies. The conclusions are made about the complexity of calculation of economic efficiency of implementing mobile applications. The possible directions of increasing the efficiency of using new distribution channels by insurance companies are defined.

Statistical Analysis of Radio Propagation Channel in Ruins Environment

Directory of Open Access Journals (Sweden)

Jiao He

2015-01-01

Full Text Available The cellphone based localization system for search and rescue in complex high density ruins has attracted a great interest in recent years, where the radio channel characteristics are critical for design and development of such a system. This paper presents a spatial smoothing estimation via rotational invariance technique (SS-ESPRIT for radio channel characterization of high density ruins. The radio propagations at three typical mobile communication bands (0.9, 1.8, and 2 GHz are investigated in two different scenarios. Channel parameters, such as arrival time, delays, and complex amplitudes, are statistically analyzed. Furthermore, a channel simulator is built based on these statistics. By comparison analysis of average excess delay and delay spread, the validation results show a good agreement between the measurements and channel modeling results.

Analysis of Handoff Mechanisms in Mobile IP

Science.gov (United States)

Jayaraj, Maria Nadine Simonel; Issac, Biju; Haldar, Manas Kumar

2011-06-01

One of the most important challenges in mobile Internet Protocol (IP) is to provide service for a mobile node to maintain its connectivity to network when it moves from one domain to another. IP is responsible for routing packets across network. The first major version of IP is the Internet Protocol version 4 (IPv4). It is one of the dominant protocols relevant to wireless network. Later a newer version of IP called the IPv6 was proposed. Mobile IPv6 is mainly introduced for the purpose of mobility. Mobility management enables network to locate roaming nodes in order to deliver packets and maintain connections with them when moving into new domains. Handoff occurs when a mobile node moves from one network to another. It is a key factor of mobility because a mobile node can trigger several handoffs during a session. This paper briefly explains on mobile IP and its handoff issues, along with the drawbacks of mobile IP.

Involvement of plasma membrane Ca2+ channels, IP3 receptors, and ryanodine receptors in the generation of spontaneous rhythmic contractions of the cricket lateral oviduct.

Science.gov (United States)

Tamashiro, Hirotake; Yoshino, Masami

2014-12-01

In the present study, the isolated cricket (Gryllus bimaculatus) lateral oviduct exhibited spontaneous rhythmic contractions (SRCs) with a frequency of 0.29±0.009 Hz (n=43) and an amplitude of 14.6±1.25 mg (n=29). SRCs completely disappeared following removal of extracellular Ca2+ using a solution containing 5mM EGTA. Application of the non-specific Ca2+ channel blockers Co2+, Ni2+, and Cd2+ also decreased both the frequency and amplitude of SRCs in dose-dependent manners, suggesting that Ca2+ entry through plasma membrane Ca2+ channels is essential for the generation of SRCs. Application of ryanodine (30 μM), which depletes intracellular Ca2+ by locking ryanodine receptor (RyR)-Ca2+ channels in an open state, gradually reduced the frequency and amplitude of SRCs. A RyR antagonist, tetracaine, reduced both the frequency and amplitude of SRCs, whereas a RyR activator, caffeine, increased the frequency of SRCs with a subsequent increase in basal tonus, indicating that RyRs are essential for generating SRCs. To further investigate the involvement of phospholipase C (PLC) and inositol 1,4,5-trisphosphate receptors (IP3Rs) in SRCs, we examined the effect of a PLC inhibitor, U73122, and an IP3R antagonist, 2-aminoethoxydiphenyl borate (2-APB), on SRCs. Separately, U73122 (10 μM) and 2-APB (30-50 μM) both significantly reduced the amplitude of SRCs with little effect on their frequency, further indicating that the PLC/IP3R signaling pathway is fundamental to the modulation of the amplitude of SRCs. A hypotonic-induced increase in the frequency and amplitude of SRCs and a hypertonic-induced decrease in the frequency and amplitude of SRCs indicated that mechanical stretch of the lateral oviduct is involved in the generation of SRCs. The sarcoplasmic reticulum Ca2+-pump ATPase inhibitors thapsigargin and cyclopiazonic acid impaired or suppressed the relaxation phase of SRCs. Taken together, the present results indicate that Ca2+ influx through plasma membrane Ca2

The transverse dynamics of flow in a tidal channel within a greater strait

Science.gov (United States)

Khosravi, Maziar; Siadatmousavi, Seyed Mostafa; Vennell, Ross; Chegini, Vahid

2018-02-01

Vessel-mounted ADCP measurements were conducted to describe the transverse structure of flow between the two headland tips in Khuran Channel, south of Iran (26° 45' N), where the highest tidal velocities in spring tides were 1.8 m/s. Current profiles were obtained using a 614.4 kHz TRDI WorkHorse Broadband ADCP over nine repetitions of three cross-channel transects during one semidiurnal tidal cycle. The 2.2-km-long transects ran north/south across the channel. A least-square fit to semidiurnal, quarter-diurnal, and sixth diurnal harmonics was used to separate the tidal signals from the observed flow. Spatial gradients showed that the greatest lateral shears and convergences were found over the northern channel and near the northern headland tip due to very sharp bathymetric changes in this area. Contrary to the historical assumption, the across-channel momentum balance in the Khuran Channel was ageostrophic. The current study represents one of the few examples reported where the lateral friction influences the across-channel momentum balance.

Structural Evolution and Mobile Shale Deformation in the Eastern Niger Delta

International Nuclear Information System (INIS)

Wiener, R. W.; Aikhionbare, D. O. L.

2002-01-01

Regional cross-sections and restorations of the eastern delta constructed from 2D and 3D seismic data show the structural evolution of paired extensional contractional belts and the kinematic and geometric evolution of mobile shale. The delta consists of an updip extensional belt and downdip zones of transitional and contractional deformation linked by a regional detachment. The extensional belt is characterized by zones of N-dipping (counterregional) and S-dipping (regional) normal faults.In the regional fault trend, sediment accommodation space is created largely by lateral movement of mobile substrate due to sediment loading and gravity. The transitional belt is characterized by low relief, shale-cored detachment folds and normal faults. The contractional belt consists of 2 parts, the high relief shale-cored detachment fold belt (mobile shale) and the fold/thrust belt: In the mobile shale belt, anticlines are generally symmetric and characterized by parallel-folded cover and highly variable thickness in the underlying ductile shale zone.Palinspastic restoration of the mobile shale by area balance shows a high degree of lateral and vertical mobility. Isostatic restoration of the depositional wedge that is the precursor to the mobile shale suggests lateral movement of 10s of kms from the extensional to the contractional domain. The fold and thrust belt is characterized by a train of asymmetric fault-related folds. The zone of ductile substrate is thin in this area, which may account for the change in structural style from high relief detachment folds in the mobile shale belt to a more classic fold/thrust belt style to the south

Channel planform evolution: Spatial and temporal aspect

Science.gov (United States)

Rusnák, M.; Frandofer, M.; Lehotský, M.

2012-04-01

The recent period is characterized by impacts of climate change. Increasing magnitude and frequency of flood events results in morphological and morphodynamical changes of river channels. It is a challenge for the fluvial geomorphology to highlight the morphological response to these events, because the knowledge of the morphological-sedimentological attributes of the river channel is the first step in pursue of a comprehensive knowledge of the riverine landscape and impact on its sustainable management. Research of the spatial variability of landforms and the regime of processes creates an appropriate knowledge base for other sciences interested in the riverine as well as terrestrial systems. The contribution deals with the morphological changes of the channel pattern of the River Topľa (115 km in total length, 1506 km2 of catchment area, average annual discharge 8.08 m3.s-1 in mouth). The 72.5 km long segment has been studied (Strahler ord. 4-7). It represents a transient from the mountain cobble-bed to the basin fine gravel-bed river. The Topľa is a less regulated and laterally partly confined river in northeastern Slovakia, with flysch geology. Three time horizons of the remote sensing imagery (1987, 2002 and 2009) have been analyzed using the GIS, with the reference time horizon of 1987. The analysis consists of identification and delimitation of an active channel bank line and the delimitation of the channel bars in the mentioned series of imageries. The active channel width, area of channel bars, lateral channel shift and area stricken by bank erosion were studied via overlaying layers. The last attribute showed a significant increase: during the 1987-2002 period the area of 32.6 ha was eroded, whereas during the following period (2002-2009) of frequent and intensive floods up to 70.0 ha was eroded. Likewise, the maximum channel shift was 260 m and 443 m in 1987-2002 and in 2002-2009 respectively. The key results are not only the values of these parameters

Adaptive guard channel allocation scheme with buffer for mobile ...

African Journals Online (AJOL)

The devastating effect congestion has on the quality of service delivery and overall network performance demands an utmost attention. This certainly calls for taking some expedient measures to deal with congestion so as to salvage the network from total collapse. In this paper, an adaptive guard channel allocation scheme ...

CB3PMF - Thermohidraulic analysis using the open lateral boundary method

International Nuclear Information System (INIS)

Borges, R.C.; Andrade, G.G. de

1985-01-01

A calculation method for the thermohydraulic analysis of a nuclear reator having a large number of sub-channels is presented. The method uses the open lateral boundary which mantains the influence of the external boundaries of the channel under study and adds to the external face of the channel physical model important characteristcs that other computational models identify only at the sub-channel level. This permits to keep the mixture characteristics that exist between the channel under analysis and the neighboring ones from the previous step. This method is shown be valid, reliable and applicable to the steady state thermohydraulic analysis and permits greater flexibility in the application of coefficients and correlations. The additional computing time is negligible compared to the information obtained. (F.E.) [pt

Long distance synchronization of mobile robots

NARCIS (Netherlands)

Alvarez Aguirre, A.; Nijmeijer, H.; Oguchi, T.

2010-01-01

This paper considers the long distance master-slave and mutual synchronization of unicycle-type mobile robots. The issues that arise when the elements of a robotic network are placed in different locations are addressed, specifically the time-delay induced by the communication channel linking the

Multibeam smart antenna field trial experiments in mobile radio environments

Science.gov (United States)

Perini, Patrick

1996-01-01

Several types of high gain multibeam antennas were tested and compared to traditional sector and omni antennas in various mobile radio environments. A vehicle equipped with a mobile transmitter drove in several mobile radio environments while the received signal strength (RSS) was recorded on multiple antenna channels attached to multibeam, sector and omni directional antennas. The RSS data recorded included the fast (rayleigh) fading and was averaged into local means based on the mobile's position/speed. Description of the experiment and analysis of the gain improvement, average RSS, diversity gain are presented.

EXPERIMENTAL STUDY ON SEDIMENT DISTRIBUTION AT CHANNEL BIFURCATION

Institute of Scientific and Technical Information of China (English)

G.M. Tarekul ISLAM; M.R. KABIR; Ainun NISHAT

2002-01-01

This paper presents the experimental results on the distribution of sediments at channel bifurcation.The experiments have been conducted in a physical model of channel bifurcation. It consists of a straight main channel which bifurcates into two branch channels of different widths. The test rig is a mobile bed with fixed bank. Four different noses have been used to study the phenomenon. For each nose, three upstream discharges viz. 20 l/s, 30 l/s and 40 l/s have been employed. From the measured data, discharges and sediment transport ratios per unit width are calculated in the downstream branches.These data have been set to the general nodal point relation and a set of equations has been developed to describe the distribution of sediments to the downstream branches for different nose angles.

Adaptive security protocol selection for mobile computing

NARCIS (Netherlands)

Pontes Soares Rocha, B.; Costa, D.N.O.; Moreira, R.A.; Rezende, C.G.; Loureiro, A.A.F.; Boukerche, A.

2010-01-01

The mobile computing paradigm has introduced new problems for application developers. Challenges include heterogeneity of hardware, software, and communication protocols, variability of resource limitations and varying wireless channel quality. In this scenario, security becomes a major concern for

Deaf mobile application accessibility requirements

Science.gov (United States)

Nathan, Shelena Soosay; Hussain, Azham; Hashim, Nor Laily

2016-08-01

Requirement for deaf mobile applications need to be analysed to ensure the disabilities need are instilled into the mobile applications developed for them. Universal design is understandable to comply every user needs, however specific disability is argued by the authors to have different need and requirements. These differences are among the reasons for these applications being developed to target for a specific group of people, however they are less usable and later abandoned. This study focuses on deriving requirements that are needed by the deaf in their mobile applications that are meant specifically for them. Studies on previous literature was conducted it can be concluded that graphic, text, multimedia and sign language interpreter are among mostly required features to be included in their mobile application to ensure the applications are usable for this community.

SO-limited mobility in a germanium inversion channel with non-ideal metal gate

International Nuclear Information System (INIS)

Shah, Raheel; De Souza, M.M.

2008-01-01

Germanium is an attractive candidate for ultra fast CMOS technology due to its potential for doubling electron mobility and quadrupling hole mobility in comparison to silicon. To maintain the requirements of the International Technology Roadmap for Semiconductors (ITRS), high-κ insulators and metal gates will be required in conjunction with Ge technology. Key issues which will have to be addressed in achieving Ge technology are: trap free insulators, assessment of appropriate crystallographic orientations and the selection of gate metals for the best mobility. In this work mobilities are evaluated for Ge-nMOSFET with two metal gates (Al and TiN) and high-κ (HfO 2 ) insulator. Scattering with bulk phonons, surface roughness and high-κ phonons are taken into account. It is predicted that Al as the gate material on Ge {100} substrate performs 50% better than Ge {111} orientation at a sheet concentration of 1 x 10 13 cm -2 . Surface roughness is likely to be the most damaging mobility degradation mechanism at high fields for Ge {111}

Efficient Mobile Client Caching Supporting Transaction Semantics

Directory of Open Access Journals (Sweden)

IlYoung Chung

2000-05-01

Full Text Available In mobile client-server database systems, caching of frequently accessed data is an important technique that will reduce the contention on the narrow bandwidth wireless channel. As the server in mobile environments may not have any information about the state of its clients' cache(stateless server, using broadcasting approach to transmit the updated data lists to numerous concurrent mobile clients is an attractive approach. In this paper, a caching policy is proposed to maintain cache consistency for mobile computers. The proposed protocol adopts asynchronous(non-periodic broadcasting as the cache invalidation scheme, and supports transaction semantics in mobile environments. With the asynchronous broadcasting approach, the proposed protocol can improve the throughput by reducing the abortion of transactions with low communication costs. We study the performance of the protocol by means of simulation experiments.

Effects of Mobile Text Advertising on Consumer Purchase Intention: A Moderated Mediation Analysis

OpenAIRE

Hongyan, Lin; Zhankui, Chen

2017-01-01

Mobile shopping is increasing in prevalence and has become a necessary part of many people's daily lives. However, one main channel for mobile shopping, mobile shopping applications (apps), has not been thoroughly investigated. This study focused on mobile text advertising delivered from mobile shopping apps using the intention to purchase as the dependent variable for testing its marketing effect. In the context of a promotion focus vs. a prevention focus, we used Higgins' regulatory focus t...

Maintenance of an obstruction-forced pool in a gravel-bed channel: streamflow, channel morphology, and sediment transport.

Science.gov (United States)

Richard D. Woodsmith; Marwan A. Hassan

2005-01-01

Maintenance of pool morphology in a stream channel with a mobile bed requires hydraulic conditions at moderate to high flows that route bed load through the pool as it is delivered from upstream. Through field measurements of discharge, vertical velocity profiles, bed load transport, and streambed scour, fill, and grain-size distribution, we found that maintenance of a...

Mobile operators as banks or vice-versa? and: the challenges of Mobile channels for banks

NARCIS (Netherlands)

L-F. Pau (Louis-François)

2004-01-01

textabstractThis short paper addresses the strategic challenges of deposit banks, and payment clearinghouses, posed by the growing role of mobile operators as collectors and payment agents of flow of cash for themselves and third parties. Through analysis and data analysis from selected operators ,

Consistent bone marrow-derived cell mobilization following repeated short courses of granulocyte-colony-stimulating factor in patients with amyotrophic lateral sclerosis: results from a multicenter prospective trial.

Science.gov (United States)

Tarella, Corrado; Rutella, Sergio; Gualandi, Francesca; Melazzini, Mario; Scimè, Rosanna; Petrini, Mario; Moglia, Cristina; Ulla, Marco; Omedé, Paola; Bella, Vincenzo La; Corbo, Massimo; Silani, Vincenzo; Siciliano, Gabriele; Mora, Gabriele; Caponnetto, Claudia; Sabatelli, Mario; Chiò, Adriano

2010-01-01

The aim of this study was to evaluate and characterize the feasibility and safety of bone marrow-derived cell (BMC) mobilization following repeated courses of granulocyte-colony stimulating factor (G-CSF) in patients with amyotrophic lateral sclerosis (ALS). Between January 2006 and March 2007, 26 ALS patients entered a multicenter trial that included four courses of BMC mobilization at 3-month intervals. In each course, G-CSF (5 microg/kg b.i.d.) was administered for four consecutive days; 18% mannitol was also given. Mobilization was monitored by flow cytometry analysis of circulating CD34(+) cells and by in vitro colony assay for clonogenic progenitors. Co-expression by CD34(+) cells of CD133, CD90, CD184, CD117 and CD31 was also assessed. Twenty patients completed the four-course schedule. One patient died and one refused to continue the program before starting the mobilization courses; four discontinued the study protocol because of disease progression. Overall, 89 G-CSF courses were delivered. There were two severe adverse events: one prolactinoma and one deep vein thrombosis. There were no discontinuations as a result of toxic complications. Circulating CD34(+) cells were monitored during 85 G-CSF courses and were always markedly increased; the range of median peak values was 41-57/microL, with no significant differences among the four G-CSF courses. Circulating clonogenic progenitor levels paralleled CD34(+) cell levels. Most mobilized CD34(+) cells co-expressed stem cell markers, with a significant increase in CD133 co-expression. It is feasible to deliver repeated courses of G-CSF to mobilize a substantial number of CD34(+) cells in patients with ALS; mobilized BMC include immature cells with potential clinical usefulness.

Determinants of Consumer Perceptions toward Mobile Advertising - A Comparison between Japan and Austria

OpenAIRE

Sinkovics, Noemi; Liu, Chia Ling Eunice; Sinkovics, Rudolf R.; Pezderka, Noemi; Haghirian, Parissa

2012-01-01

Mobile marketing provides an innovative channel for transmitting advertising messages to customers via mobile devices. The growth of mobile advertising in recent years requires that researchers and practitioners understand consumer perceptions of this form of advertising. The purpose of this paper is to investigate factors influencing the perception of mobile advertising in different cultures. Based on samples from Austria and Japan, we empirically examine relevant m-advertising effects. The ...

Correcting lateral response artifacts from flatbed scanners for radiochromic film dosimetry

International Nuclear Information System (INIS)

Lewis, David; Chan, Maria F.

2015-01-01

Purpose: A known factor affecting the accuracy of radiochromic film dosimetry is the lateral response artifact (LRA) induced by nonuniform response of a flatbed scanner in the direction perpendicular to the scan direction. This work reports a practical solution to eliminate such artifacts for all forms of dose QA. Methods: EBT3 films from a single production lot (02181401) cut into rectangular 4 × 5 cm 2 pieces, with the long dimension parallel to the long dimension of the original 20.3 × 25.4 cm 2 sheets, were exposed at a depth of 5 cm on a Varian Trilogy at the center of a 20 × 20 cm 2 open field at seven doses between 50 and 1600 cGy using 6 MV photons. These films together with an unexposed film from the same production lot were lined one next to the other on an Epson 10000XL or 11000XL scanner in portrait orientation with their long dimension parallel to the scan direction. Scanned images were then obtained with the line of films positioned at seven discrete lateral locations perpendicular to the scan direction. The process was repeated in landscape orientation and on three other Epson scanners. Data were also collected for three additional production lots of EBT3 film (11051302, 03031401, and 03171403). From measurements at the various lateral positions, the scanner response was determined as a function of the lateral position of the scanned film. For a given color channel X, the response at any lateral position L is related to the response at the center, C, of the scanner by Response(C, D, X) = A L,X + B L,X ⋅Response(L, D, X), where D is dose and the coefficients A L,X and B L,X are determined from the film measurements at the center of the scanner and six other discrete lateral positions. The values at intermediate lateral positions were obtained by linear interpolation. The coefficients were determined for the red, green, and blue color channels, preserving the ability to apply triple-channel dosimetry once corrections were applied to compensate for

Correcting lateral response artifacts from flatbed scanners for radiochromic film dosimetry.

Science.gov (United States)

Lewis, David; Chan, Maria F

2015-01-01

A known factor affecting the accuracy of radiochromic film dosimetry is the lateral response artifact (LRA) induced by nonuniform response of a flatbed scanner in the direction perpendicular to the scan direction. This work reports a practical solution to eliminate such artifacts for all forms of dose QA. EBT3 films from a single production lot (02181401) cut into rectangular 4 × 5 cm(2) pieces, with the long dimension parallel to the long dimension of the original 20.3 × 25.4 cm(2) sheets, were exposed at a depth of 5 cm on a Varian Trilogy at the center of a 20 × 20 cm(2) open field at seven doses between 50 and 1600 cGy using 6 MV photons. These films together with an unexposed film from the same production lot were lined one next to the other on an Epson 10000 XL or 11000 XL scanner in portrait orientation with their long dimension parallel to the scan direction. Scanned images were then obtained with the line of films positioned at seven discrete lateral locations perpendicular to the scan direction. The process was repeated in landscape orientation and on three other Epson scanners. Data were also collected for three additional production lots of EBT3 film (11051302, 03031401, and 03171403). From measurements at the various lateral positions, the scanner response was determined as a function of the lateral position of the scanned film. For a given color channel X, the response at any lateral position L is related to the response at the center, C, of the scanner by Response(C, D, X) = A(L,X) + B(L,X) ⋅ Response(L, D, X), where D is dose and the coefficients A(L,X) and B(L,X) are determined from the film measurements at the center of the scanner and six other discrete lateral positions. The values at intermediate lateral positions were obtained by linear interpolation. The coefficients were determined for the red, green, and blue color channels, preserving the ability to apply triple-channel dosimetry once corrections were applied to compensate for the

Correcting lateral response artifacts from flatbed scanners for radiochromic film dosimetry

Energy Technology Data Exchange (ETDEWEB)

Lewis, David [RCF Consulting, LLC, 54 Benedict Road, Monroe, Connecticut 06468 (United States); Chan, Maria F., E-mail: chanm@mskcc.org [Memorial Sloan-Kettering Cancer Center, 136 Mountain View Boulevard, Basking Ridge, New Jersey 07920 (United States)

2015-01-15

Purpose: A known factor affecting the accuracy of radiochromic film dosimetry is the lateral response artifact (LRA) induced by nonuniform response of a flatbed scanner in the direction perpendicular to the scan direction. This work reports a practical solution to eliminate such artifacts for all forms of dose QA. Methods: EBT3 films from a single production lot (02181401) cut into rectangular 4 × 5 cm{sup 2} pieces, with the long dimension parallel to the long dimension of the original 20.3 × 25.4 cm{sup 2} sheets, were exposed at a depth of 5 cm on a Varian Trilogy at the center of a 20 × 20 cm{sup 2} open field at seven doses between 50 and 1600 cGy using 6 MV photons. These films together with an unexposed film from the same production lot were lined one next to the other on an Epson 10000XL or 11000XL scanner in portrait orientation with their long dimension parallel to the scan direction. Scanned images were then obtained with the line of films positioned at seven discrete lateral locations perpendicular to the scan direction. The process was repeated in landscape orientation and on three other Epson scanners. Data were also collected for three additional production lots of EBT3 film (11051302, 03031401, and 03171403). From measurements at the various lateral positions, the scanner response was determined as a function of the lateral position of the scanned film. For a given color channel X, the response at any lateral position L is related to the response at the center, C, of the scanner by Response(C, D, X) = A{sub L,X} + B{sub L,X}⋅Response(L, D, X), where D is dose and the coefficients A{sub L,X} and B{sub L,X} are determined from the film measurements at the center of the scanner and six other discrete lateral positions. The values at intermediate lateral positions were obtained by linear interpolation. The coefficients were determined for the red, green, and blue color channels, preserving the ability to apply triple-channel dosimetry once

School Mobility and Developmental Outcomes in Young Adulthood

Science.gov (United States)

Herbers, Janette E.; Reynolds, Arthur J.; Chen, Chin-Chih

2014-01-01

School mobility has been shown to increase the risk of poor achievement, behavior problems, grade retention, and high school drop-out. Using data over 25 years from the Chicago Longitudinal Study, we investigated the unique risk of school moves on a variety of young adult outcomes including educational attainment, occupational prestige, depression symptoms, and criminal arrests. We also investigated how the timing of school mobility, whether earlier or later in the academic career, may differentially predict these outcomes over and above associated risks. Results indicate that students who experience more school changes between kindergarten and twelfth grade are less likely to complete high school on time, complete fewer years of school, attain lower levels of occupational prestige, are more likely to experience symptoms of depression, and are more likely to be arrested as adults. Furthermore, the number of school moves predicted above and beyond associated risks such as residential mobility and family poverty. When timing of school mobility was examined, results indicated more negative outcomes associated with moves later in the grade school career, particularly between fourth and eighth grade. PMID:23627959

Predictors of older adults' personal and community mobility: using a comprehensive theoretical mobility framework.

Science.gov (United States)

Umstattd Meyer, M Renée; Janke, Megan C; Beaujean, A Alexander

2014-06-01

Forty-six percent of older adults report limitations in their mobility, and maintaining mobility is considered an important factor in keeping adults independent and active in later life. This study tests a comprehensive theoretical framework of mobility (Webber, S. C., Porter, M. M., & Menec, V. H. [2010]. Mobility in older adults: A comprehensive framework. The Gerontologist, 50[4], 443-450. doi:10.1093/geront/gnq013) identifying multiple determinants that additively influence mobility (financial, psychosocial, environmental, physical, and cognitive), as well as cross-cutting influences of gender, culture, and biography. Structural equation modeling was used to examine several models of mobility using data from 6,112 respondents in the Health and Retirement Study (mean age: 74.74, 85% white, 41% male, 57% married). The original measurement model fit the data well. When both personal and community mobility were simultaneously predicted, only the physical, cognitive, psychosocial, and environmental determinants were retained in the independent models. Age and marital status also predicted personal and community mobility. Although most of these relationships were in the expected direction, interestingly when both forms of mobility were included in the model, poorer cognitive ability was associated with greater personal mobility in the final model. Results indicate the importance of accounting for and examining comprehensive models of mobility. The factors affecting older adults' mobility are complex, and these relationships need to be explored in more depth to ensure the maintenance of individuals' independence and quality of life.

Investigation of enhancement-mode AlGaN/GaN nanowire channel high-electron-mobility transistor with oxygen-containing plasma treatment

Science.gov (United States)

He, Yunlong; Wang, Chong; Mi, Minhan; Zhang, Meng; Zhu, Qing; Zhang, Peng; Wu, Ji; Zhang, Hengshuang; Zheng, Xuefeng; Yang, Ling; Duan, Xiaoling; Ma, Xiaohua; Hao, Yue

2017-05-01

A novel enhancement-mode (E-mode) AlGaN/GaN high-electron-mobility transistor (HEMT) has been fabricated, by combining nanowire channel (NC) structure fabrication and N2O (or O2) plasma treatment. A comparison of two NC-HEMTs with different plasma treatments has been made. The NC-HEMT with N2O plasma treatment shows an output current of 610 mA/mm and a peak transconductance of 450 mS/mm. The DIBL of the NC-HEMT with N2O plasma treatment is as low as 2 mV/V, and an SS of 70 mV/decade is achieved. The device exhibits an intrinsic current gain cutoff frequency f T of 19 GHz and a maximum oscillation frequency f max of 58 GHz.

The Influence of Mobile Marketing on Consumer Attitude Study at Student of Sam Ratulangi University

OpenAIRE

Nicolaas, Gisyela P.Z.

2016-01-01

Advances in Information and Communication Technology not only offers new marketing channels of communication and interactivity to the company but also significantly affect the way companies conduct their business and marketing activities.Marketing on Mobile devices has become one of the most popular channels of communicating with intending and potential customers, particularly in the form of text advertising through Instant Messaging Service. The study aims to determine the effect of mobile m...

Excitation of fluorescent nanoparticles by channel plasmon polaritons propagating in V-grooves

DEFF Research Database (Denmark)

Cuesta, Irene Fernandez; Nielsen, Rasmus Bundgaard; Boltasseva, Alexandra

2009-01-01

Recently, it has been proven that light can be squeezed into metallic channels with subwavelength lateral dimensions. Here, we present the study of the propagation of channel plasmon polaritons confined in gold V-grooves, filled with fluorescent particles. In this way, channel plasmon polaritons......-diameter beads, we show the possibility of individual excitation, what may have applications to develop very sensitive biosensors....

Accurate Sybil Attack Detection Based on Fine-Grained Physical Channel Information

Directory of Open Access Journals (Sweden)

Chundong Wang

2018-03-01

Full Text Available With the development of the Internet-of-Things (IoT, wireless network security has more and more attention paid to it. The Sybil attack is one of the famous wireless attacks that can forge wireless devices to steal information from clients. These forged devices may constantly attack target access points to crush the wireless network. In this paper, we propose a novel Sybil attack detection based on Channel State Information (CSI. This detection algorithm can tell whether the static devices are Sybil attackers by combining a self-adaptive multiple signal classification algorithm with the Received Signal Strength Indicator (RSSI. Moreover, we develop a novel tracing scheme to cluster the channel characteristics of mobile devices and detect dynamic attackers that change their channel characteristics in an error area. Finally, we experiment on mobile and commercial WiFi devices. Our algorithm can effectively distinguish the Sybil devices. The experimental results show that our Sybil attack detection system achieves high accuracy for both static and dynamic scenarios. Therefore, combining the phase and similarity of channel features, the multi-dimensional analysis of CSI can effectively detect Sybil nodes and improve the security of wireless networks.

Accurate Sybil Attack Detection Based on Fine-Grained Physical Channel Information.

Science.gov (United States)

Wang, Chundong; Zhu, Likun; Gong, Liangyi; Zhao, Zhentang; Yang, Lei; Liu, Zheli; Cheng, Xiaochun

2018-03-15

With the development of the Internet-of-Things (IoT), wireless network security has more and more attention paid to it. The Sybil attack is one of the famous wireless attacks that can forge wireless devices to steal information from clients. These forged devices may constantly attack target access points to crush the wireless network. In this paper, we propose a novel Sybil attack detection based on Channel State Information (CSI). This detection algorithm can tell whether the static devices are Sybil attackers by combining a self-adaptive multiple signal classification algorithm with the Received Signal Strength Indicator (RSSI). Moreover, we develop a novel tracing scheme to cluster the channel characteristics of mobile devices and detect dynamic attackers that change their channel characteristics in an error area. Finally, we experiment on mobile and commercial WiFi devices. Our algorithm can effectively distinguish the Sybil devices. The experimental results show that our Sybil attack detection system achieves high accuracy for both static and dynamic scenarios. Therefore, combining the phase and similarity of channel features, the multi-dimensional analysis of CSI can effectively detect Sybil nodes and improve the security of wireless networks.

An Optimal Design of Multiple Antenna Positions on Mobile Devices Based on Mutual Coupling Analysis

Directory of Open Access Journals (Sweden)

Peerapong Uthansakul

2011-01-01

Full Text Available The topic of practical implementation of multiple antenna systems for mobile communications has recently gained a lot of attention. Due to the area constraint on a mobile device, the problem of how to design such a system in order to achieve the best benefit is still a huge challenge. In this paper, genetic algorithm (GA is used to find the optimal antenna positions on a mobile device. Two cases of 3×3 and 4×4 MIMO systems are undertaken. The effect of mutual coupling based on Z-parameter is the main factor to determine the MIMO capacity concerning the objective function of GA search. The results confirm the success of the proposed method to design MIMO antenna positions on a mobile device. Moreover, this paper introduces the method to design the antenna positions for the condition of nondeterministic channel. The concern of channel variation has been included in the process of finding optimal MIMO antenna positions. The results suggest that the averaging position from all GA solutions according to all channel conditions provides the most acceptable benefit.

Performance Analysis of a Two-Hop MIMO Mobile-to-Mobile via Stratospheric-Relay Link Employing Hierarchical Modulation

Directory of Open Access Journals (Sweden)

Nikolaos Nomikos

2013-01-01

Full Text Available Next generation wireless communication networks intend to take advantage of the integration of terrestrial and aerospace infrastructures. Besides, multiple-input multiple-output (MIMO architecture is the key technology, which has brought the wireless gigabit vision closer to reality. In this direction, high-altitude platforms (HAPs could act as relay stations in the stratosphere transferring information from an uplink to a downlink MIMO channel. This paper investigates the performance of a novel transmission scheme for the delivery of mobile-to-mobile (M-to-M services via a stratospheric relay. It is assumed that the source, relay, and destination nodes are equipped with multiple antennas and that amplify-and-forward (AF relaying is adopted. The performance is analyzed through rigorous simulations in terms of the bit-error rate (BER by using a recently proposed 3D geometry-based reference model in spatially correlated flat-fading MIMO channels, employing a hierarchical broadcast technique and minimum mean square error (MMSE receivers.

Vehicular Networking Enhancement And Multi-Channel Routing Optimization, Based on Multi-Objective Metric and Minimum Spanning Tree

Directory of Open Access Journals (Sweden)

Peppino Fazio

2013-01-01

Full Text Available Vehicular Ad hoc NETworks (VANETs represent a particular mobile technology that permits the communication among vehicles, offering security and comfort. Nowadays, distributed mobile wireless computing is becoming a very important communications paradigm, due to its flexibility to adapt to different mobile applications. VANETs are a practical example of data exchanging among real mobile nodes. To enable communications within an ad-hoc network, characterized by continuous node movements, routing protocols are needed to react to frequent changes in network topology. In this paper, the attention is focused mainly on the network layer of VANETs, proposing a novel approach to reduce the interference level during mobile transmission, based on the multi-channel nature of IEEE 802.11p (1609.4 standard. In this work a new routing protocol based on Distance Vector algorithm is presented to reduce the delay end to end and to increase packet delivery ratio (PDR and throughput in VANETs. A new metric is also proposed, based on the maximization of the average Signal-to-Interference Ratio (SIR level and the link duration probability between two VANET nodes. In order to relieve the effects of the co-channel interference perceived by mobile nodes, transmission channels are switched on a basis of a periodical SIR evaluation. A Network Simulator has been used for implementing and testing the proposed idea.

Metal-interconnection-free integration of InGaN/GaN light emitting diodes with AlGaN/GaN high electron mobility transistors

Energy Technology Data Exchange (ETDEWEB)

Liu, Chao; Cai, Yuefei; Liu, Zhaojun; Ma, Jun; Lau, Kei May, E-mail: eekmlau@ust.hk [Photonics Technology Center, Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

2015-05-04

We report a metal-interconnection-free integration scheme for InGaN/GaN light emitting diodes (LEDs) and AlGaN/GaN high electron mobility transistors (HEMTs) by combining selective epi removal (SER) and selective epitaxial growth (SEG) techniques. SER of HEMT epi was carried out first to expose the bottom unintentionally doped GaN buffer and the sidewall GaN channel. A LED structure was regrown in the SER region with the bottom n-type GaN layer (n-electrode of the LED) connected to the HEMTs laterally, enabling monolithic integration of the HEMTs and LEDs (HEMT-LED) without metal-interconnection. In addition to saving substrate real estate, minimal interface resistance between the regrown n-type GaN and the HEMT channel is a significant improvement over metal-interconnection. Furthermore, excellent off-state leakage characteristics of the driving transistor can also be guaranteed in such an integration scheme.

Metal-interconnection-free integration of InGaN/GaN light emitting diodes with AlGaN/GaN high electron mobility transistors

International Nuclear Information System (INIS)

Liu, Chao; Cai, Yuefei; Liu, Zhaojun; Ma, Jun; Lau, Kei May

2015-01-01

We report a metal-interconnection-free integration scheme for InGaN/GaN light emitting diodes (LEDs) and AlGaN/GaN high electron mobility transistors (HEMTs) by combining selective epi removal (SER) and selective epitaxial growth (SEG) techniques. SER of HEMT epi was carried out first to expose the bottom unintentionally doped GaN buffer and the sidewall GaN channel. A LED structure was regrown in the SER region with the bottom n-type GaN layer (n-electrode of the LED) connected to the HEMTs laterally, enabling monolithic integration of the HEMTs and LEDs (HEMT-LED) without metal-interconnection. In addition to saving substrate real estate, minimal interface resistance between the regrown n-type GaN and the HEMT channel is a significant improvement over metal-interconnection. Furthermore, excellent off-state leakage characteristics of the driving transistor can also be guaranteed in such an integration scheme

MOBILE MARKETING - TRENDS ON THE ROMANIAN ADVERTISING MARKET

OpenAIRE

Dinu Cristina; Iatagan Mariana; Natalia Manea

2010-01-01

In these times of economic crisis, the advertising market goes through a difficult period, as companies reduce marketing budgets drastically trying to reduce their costs. For some companies, mobile phone can be a very effective communication channel because mobile adds are much cheaper than classic advertising, offers many advantages as a means to promote and may become an "ally" of those companies that support sustainable development and social responsibility. The article present a SWOT anal...

Performance of TCP over UMTS common and dedicated channels

NARCIS (Netherlands)

Lo, Anthony; Heijenk, Geert; Bruma, Cezar; Gameiro, A.

2003-01-01

Universal Mobile Telecommunications System (UMTS) is a third-generation cellular network that enables high-speed wireless Internet access. This paper investigates the performance of Transmission Control Protocol (TCP) over UMTS utilizing a common and four dedicated transport channels with bit rates

Radiation-Induced Short Channel (RISCE) and Narrow Channel (RINCE) Effects in 65 and 130 nm MOSFETs

CERN Document Server

Faccio, F; Cornale, D; Paccagnella, A; Gerardin, S

2015-01-01

The behavior of transistors in commercial-grade complementary metal-oxide semiconductor technologies in the 65 and 130 nm nodes has been explored up to a total ionizing dose of 1 Grad. The large dose tolerance of the thin gate oxide is confirmed, but defects in the spacer and STI oxides have a strong effect on the performance of the transistors. A radiation-induced short channel effect is traced to charge trapping in the spacers used for drain engineering, while a radiation-induced narrow channel effect is due to defect generation in the lateral isolation oxide (STI). These strongly degrade the electrical characteristics of short and narrow channel transistors at high doses, and their magnitude depends on the applied bias and temperature during irradiation in a complex way.

Enhanced electrical properties of dual-layer channel ZnO thin film transistors prepared by atomic layer deposition

Science.gov (United States)

Li, Huijin; Han, Dedong; Dong, Junchen; Yu, Wen; Liang, Yi; Luo, Zhen; Zhang, Shengdong; Zhang, Xing; Wang, Yi

2018-05-01

The thin film transistors (TFTs) with a dual-layer channel structure combing ZnO thin layer grown at 200 °C and ZnO film grown at 120 °C by atomic layer deposition are fabricated. The dual-layer channel TFT exhibits a low leakage current of 2.8 × 10-13 A, Ion/Ioff ratio of 3.4 × 109, saturation mobility μsat of 12 cm2 V-1 s-1, subthreshold swing (SS) of 0.25 V/decade. The SS value decreases to 0.18 V/decade after the annealing treatment in O2 due to the reduction of the trap states at the channel/dielectric interface and in the bulk channel layer. The enhanced performance obtained from the dual-layer channel TFTs is due to the ability of maintaining high mobility and suppressing the increase in the off-current at the same time.

Beamforming transmission in IEEE 802.11ac under time-varying channels.

Science.gov (United States)

Yu, Heejung; Kim, Taejoon

2014-01-01

The IEEE 802.11ac wireless local area network (WLAN) standard has adopted beamforming (BF) schemes to improve spectral efficiency and throughput with multiple antennas. To design the transmit beam, a channel sounding process to feedback channel state information (CSI) is required. Due to sounding overhead, throughput increases with the amount of transmit data under static channels. Under practical channel conditions with mobility, however, the mismatch between the transmit beam and the channel at transmission time causes performance loss when transmission duration after channel sounding is too long. When the fading rate, payload size, and operating signal-to-noise ratio are given, the optimal transmission duration (i.e., packet length) can be determined to maximize throughput. The relationship between packet length and throughput is also investigated for single-user and multiuser BF modes.

Mobile caecum and ascending colon syndrome in a Nigerian adult

African Journals Online (AJOL)

posterior peritoneum. Appendectomy and caecopexy, using a lateral peritoneal flap were performed. The diagnosis of mobile caecal syndrome should be considered in patients with chronic right lower quadrant pain, and appendectomy and caecopexy offers a great relief. Keywords: Adult, ascending colon, mobile caecum, ...

Regimes of Two-Phase Flow in Short Rectangular Channel

Science.gov (United States)

Chinnov, Evgeny A.; Guzanov, Vladimir V.; Cheverda, Vyacheslav; Markovich, Dmitry M.; Kabov, Oleg A.

2009-08-01

Experimental study of two-phase flow in the short rectangular horizontal channel with height 440 μm has been performed. Characteristics of liquid motion inside the channel have been registered and measured by the Laser Induced Fluorescence technique. New information has allowed determining more precisely the characteristics of churn regime and boundaries between different regimes of two-phase flow. It was shown that formation of some two-phase flow regimes and transitions between them are determined by instability of the flow in the lateral parts of the channel.

The development of a laterally confined laboratory fan delta under sediment supply reduction

Science.gov (United States)

Zhang, Xiaofeng; Wang, Siqiang; Wu, Xi; Xu, Shun; Li, Zhangyong

2016-03-01

In previous fan delta experiments, the effect of lateral confinement was generally ignored as these fans were usually unconfined with semiconical geometries. However, in gorge areas, fan development is usually laterally confined by valley walls. This study investigates autogenic processes of fan deltas in a laterally confined experimental tank. The experiment is divided into three phases. The sediment supply is held constant within each phase, so the autogenic processes of the fan are separated from the allogenic forcings. Results indicate that laterally confined fan deltas have higher progradation and aggradation potential, more regular channel braiding, and more even transverse sedimentation than unconfined fans. Besides, responses of fan deltas to sediment supply reduction are investigated in this research. At the initiation of the second and third phases, sediment feed rates are instantaneously reduced so that the allogenic forcings are predominant. Observations show that under sediment supply reduction, channelization on fan deltas are more pronounced and durations of the fluvial cycles are longer. The adjustment of fan morphology becomes slower as the self-regulation capacity of the fan decreases with reduced sediment supply.

Do Affective Variables Make a Difference in Consumers Behavior Toward Mobile Advertising?

OpenAIRE

Mart?nez-Ruiz, Mar?a Pilar; Izquierdo-Yusta, Alicia; Olarte-Pascual, Cristina; Reinares-Lara, Eva

2017-01-01

Research into permission-based mobile marketing is increasingly common due to the widespread adoption of mobile technology and its use as a communication channel. Yet few studies have attempted to analyze the factors that determine attitudes toward mobile advertising while simultaneously considering: the links among them and consumers' intentions, behavior, and/or cognitive and affective variables simultaneously. The present research therefore sought to deepen understanding of the antecedents...

Early-life Medicaid Coverage and Intergenerational Economic Mobility.

Science.gov (United States)

O'Brien, Rourke L; Robertson, Cassandra L

2018-04-01

New data reveal significant variation in economic mobility outcomes across U.S. localities. This suggests that social structures, institutions, and public policies-particularly those that influence critical early-life environments-play an important role in shaping mobility processes. Using new county-level estimates of intergenerational economic mobility for children born between 1980 and 1986, we exploit the uneven expansions of Medicaid eligibility across states to isolate the causal effect of this specific policy change on mobility outcomes. Instrumental-variable regression models reveal that increasing the proportion of low-income pregnant women eligible for Medicaid improved the mobility outcomes of their children in adulthood. We find no evidence that Medicaid coverage in later childhood years influences mobility outcomes. This study has implications for the normative evaluation of this policy intervention as well as our understanding of mobility processes in an era of rising inequality.

Effective mobility enhancement of amorphous In-Ga-Zn-O thin-film transistors by holographically generated periodic conductor

Energy Technology Data Exchange (ETDEWEB)

Jeong, Jaewook [School of Information and Communication Engineering, Chungbuk National University, Cheongju (Korea, Republic of); Kim, Joonwoo; Jeong, Soon Moon [Division of Nano and Energy Convergence Research, Daegu Gyeongbuk Institute of Science and Technology, Daegu (Korea, Republic of); Kim, Donghyun; Hong, Yongtaek, E-mail: yongtaek@snu.ac.kr [Department of Electrical and Communication Engineering, Seoul National University, Seoul (Korea, Republic of); Jeon, Heonsu [Department of Physics & Astronomy, Seoul National University, Seoul (Korea, Republic of)

2016-08-15

In this study, we demonstrate a mobility enhancement structure for fully transparent amorphous indium-gallium-zinc-oxide thin-film transistors (a-IGZO TFTs) by embedding a holographically generated periodic nano-conductor in the back-channel regions. The intrinsic field-effect mobility was enhanced up to 2 times compared to that of a reference sample. The enhancement originated from a decrease in the effective channel length due to the highly conductive nano-conductor region. By combining conventional and holographic lithography, the performance of the a-IGZO TFT can be effectively improved without varying the composition of the channel layer.

Effective mobility enhancement of amorphous In-Ga-Zn-O thin-film transistors by holographically generated periodic conductor

International Nuclear Information System (INIS)

Jeong, Jaewook; Kim, Joonwoo; Jeong, Soon Moon; Kim, Donghyun; Hong, Yongtaek; Jeon, Heonsu

2016-01-01

In this study, we demonstrate a mobility enhancement structure for fully transparent amorphous indium-gallium-zinc-oxide thin-film transistors (a-IGZO TFTs) by embedding a holographically generated periodic nano-conductor in the back-channel regions. The intrinsic field-effect mobility was enhanced up to 2 times compared to that of a reference sample. The enhancement originated from a decrease in the effective channel length due to the highly conductive nano-conductor region. By combining conventional and holographic lithography, the performance of the a-IGZO TFT can be effectively improved without varying the composition of the channel layer.

Bedtime mobile phone use and sleep in adults.

Science.gov (United States)

Exelmans, Liese; Van den Bulck, Jan

2016-01-01

The few studies that have investigated the relationship between mobile phone use and sleep have mainly been conducted among children and adolescents. In adults, very little is known about mobile phone usage in bed our after lights out. This cross-sectional study set out to examine the association between bedtime mobile phone use and sleep among adults. A sample of 844 Flemish adults (18-94 years old) participated in a survey about electronic media use and sleep habits. Self-reported sleep quality, daytime fatigue and insomnia were measured using the Pittsburgh Sleep Quality Index (PSQI), the Fatigue Assessment Scale (FAS) and the Bergen Insomnia Scale (BIS), respectively. Data were analyzed using hierarchical and multinomial regression analyses. Half of the respondents owned a smartphone, and six out of ten took their mobile phone with them to the bedroom. Sending/receiving text messages and/or phone calls after lights out significantly predicted respondents' scores on the PSQI, particularly longer sleep latency, worse sleep efficiency, more sleep disturbance and more daytime dysfunction. Bedtime mobile phone use predicted respondents' later self-reported rise time, higher insomnia score and increased fatigue. Age significantly moderated the relationship between bedtime mobile phone use and fatigue, rise time, and sleep duration. An increase in bedtime mobile phone use was associated with more fatigue and later rise times among younger respondents (≤ 41.5 years old and ≤ 40.8 years old respectively); but it was related to an earlier rise time and shorter sleep duration among older respondents (≥ 60.15 years old and ≥ 66.4 years old respectively). Findings suggest that bedtime mobile phone use is negatively related to sleep outcomes in adults, too. It warrants continued scholarly attention as the functionalities of mobile phones evolve rapidly and exponentially. Copyright © 2015 Elsevier Ltd. All rights reserved.

Functional diversity of potassium channel voltage-sensing domains.

Science.gov (United States)

Islas, León D

2016-01-01

Voltage-gated potassium channels or Kv's are membrane proteins with fundamental physiological roles. They are composed of 2 main functional protein domains, the pore domain, which regulates ion permeation, and the voltage-sensing domain, which is in charge of sensing voltage and undergoing a conformational change that is later transduced into pore opening. The voltage-sensing domain or VSD is a highly conserved structural motif found in all voltage-gated ion channels and can also exist as an independent feature, giving rise to voltage sensitive enzymes and also sustaining proton fluxes in proton-permeable channels. In spite of the structural conservation of VSDs in potassium channels, there are several differences in the details of VSD function found across variants of Kvs. These differences are mainly reflected in variations in the electrostatic energy needed to open different potassium channels. In turn, the differences in detailed VSD functioning among voltage-gated potassium channels might have physiological consequences that have not been explored and which might reflect evolutionary adaptations to the different roles played by Kv channels in cell physiology.

A FD/DAMA network architecture for the first generation land mobile satellite services

Science.gov (United States)

Yan, T.-Y.; Wang, C.; Cheng, U.; Dessouky, K.; Rafferty, W.

1989-01-01

A frequency division/demand assigned multiple access (FD/DAMA) network architecture for the first-generation land mobile satellite services is presented. Rationales and technical approaches are described. In this architecture, each mobile subscriber must follow a channel access protocol to make a service request to the network management center before transmission for either open-end or closed-end services. Open-end service requests will be processed on a blocked call cleared basis, while closed-end requests will be processed on a first-come-first-served basis. Two channel access protocols are investigated, namely, a recently proposed multiple channel collision resolution scheme which provides a significantly higher useful throughput, and the traditional slotted Aloha scheme. The number of channels allocated for either open-end or closed-end services can be adaptively changed according to aggregated traffic requests. Both theoretical and simulation results are presented. Theoretical results have been verified by simulation on the JPL network testbed.

Get Mobile – The Smartphone Brain Scanner

DEFF Research Database (Denmark)

Stahlhut, Carsten; Stopczynski, Arkadiusz; Petersen, Michael Kai

This demonstration will provide live-interaction with a smartphone brain scanner consisting of a low-cost wireless 14-channel EEG headset (Emotiv Epoc) and a mobile device. With our system it is possible to perform real-time functional brain imaging on a smartphone device, including stimulus...

A III-V nanowire channel on silicon for high-performance vertical transistors.

Science.gov (United States)

Tomioka, Katsuhiro; Yoshimura, Masatoshi; Fukui, Takashi

2012-08-09

Silicon transistors are expected to have new gate architectures, channel materials and switching mechanisms in ten years' time. The trend in transistor scaling has already led to a change in gate structure from two dimensions to three, used in fin field-effect transistors, to avoid problems inherent in miniaturization such as high off-state leakage current and the short-channel effect. At present, planar and fin architectures using III-V materials, specifically InGaAs, are being explored as alternative fast channels on silicon because of their high electron mobility and high-quality interface with gate dielectrics. The idea of surrounding-gate transistors, in which the gate is wrapped around a nanowire channel to provide the best possible electrostatic gate control, using InGaAs channels on silicon, however, has been less well investigated because of difficulties in integrating free-standing InGaAs nanostructures on silicon. Here we report the position-controlled growth of vertical InGaAs nanowires on silicon without any buffering technique and demonstrate surrounding-gate transistors using InGaAs nanowires and InGaAs/InP/InAlAs/InGaAs core-multishell nanowires as channels. Surrounding-gate transistors using core-multishell nanowire channels with a six-sided, high-electron-mobility transistor structure greatly enhance the on-state current and transconductance while keeping good gate controllability. These devices provide a route to making vertically oriented transistors for the next generation of field-effect transistors and may be useful as building blocks for wireless networks on silicon platforms.

Key scattering mechanisms limiting the lateral transport in a modulation-doped polar heterojunction

Energy Technology Data Exchange (ETDEWEB)

Tien, Nguyen Thanh, E-mail: nttien@ctu.edu.vn; Thao, Pham Thi Bich [College of Natural Sciences, Can Tho University, 3-2 Road, Can Tho City (Viet Nam); Thao, Dinh Nhu [Center for Theoretical and Computational Physics, College of Education, Hue University, 34 Le Loi Street, Hue City (Viet Nam); Quang, Doan Nhat [Institute of Physics, Vietnamese Academy of Science and Technology, 10 Dao Tan Street, Hanoi (Viet Nam)

2016-06-07

We present a study of the lateral transport of a two-dimensional electron gas (2DEG) in a modulation-doped polar heterojunction (HJ). In contrast to previous studies, we assume that the Coulomb correlation among ionized impurities and among charged dislocations in the HJ is so strong that the 2DEG low-temperature mobility is not limited by impurity and dislocation scattering. The mobility, however, is specified by alloy disorder scattering and combined roughness scattering, which is the total effect induced by both the potential barrier and polarization roughness. The obtained results show that the alloy disorder and combined roughness scattering strongly depend on the alloy content and on the near-interface electron distribution. Our theory is capable of explaining the bell-shaped dependence of the lateral mobility on alloy content observed in AlGaN/GaN and on 2DEG density observed in AlN/GaN, which have not previously been explained.

Understanding the conductive channel evolution in Na:WO3-x-based planar devices

Science.gov (United States)

Shang, Dashan; Li, Peining; Wang, Tao; Carria, Egidio; Sun, Jirong; Shen, Baogen; Taubner, Thomas; Valov, Ilia; Waser, Rainer; Wuttig, Matthias

2015-03-01

An ion migration process in a solid electrolyte is important for ion-based functional devices, such as fuel cells, batteries, electrochromics, gas sensors, and resistive switching systems. In this study, a planar sandwich structure is prepared by depositing tungsten oxide (WO3-x) films on a soda-lime glass substrate, from which Na+ diffuses into the WO3-x films during the deposition. The entire process of Na+ migration driven by an alternating electric field is visualized in the Na-doped WO3-x films in the form of conductive channel by in situ optical imaging combined with infrared spectroscopy and near-field imaging techniques. A reversible change of geometry between a parabolic and a bar channel is observed with the resistance change of the devices. The peculiar channel evolution is interpreted by a thermal-stress-induced mechanical deformation of the films and an asymmetric Na+ mobility between the parabolic and the bar channels. These results exemplify a typical ion migration process driven by an alternating electric field in a solid electrolyte with a low ion mobility and are expected to be beneficial to improve the controllability of the ion migration in ion-based functional devices, such as resistive switching devices.An ion migration process in a solid electrolyte is important for ion-based functional devices, such as fuel cells, batteries, electrochromics, gas sensors, and resistive switching systems. In this study, a planar sandwich structure is prepared by depositing tungsten oxide (WO3-x) films on a soda-lime glass substrate, from which Na+ diffuses into the WO3-x films during the deposition. The entire process of Na+ migration driven by an alternating electric field is visualized in the Na-doped WO3-x films in the form of conductive channel by in situ optical imaging combined with infrared spectroscopy and near-field imaging techniques. A reversible change of geometry between a parabolic and a bar channel is observed with the resistance change of the

The impact of uniaxial stress on subband structure and mobility of strain Si NMOSFETs

International Nuclear Information System (INIS)

Chang, S.T.; Liao, S.H.; Lin, C.-Y.

2008-01-01

An effect of stress distortion on the conduction band structure was derived by k.p method considering a second order perturbation. From k.p conduction band calculations, stress-induced band edge split and the change of effective mass are quantitatively evaluated. The physical reasons of warped subband structure and abnormal mobility enhancement by uniaxial stress are investigated. Variation rates of experimental electron mobility in the silicon n-channel metal-oxide-semiconductor field-effect-transistors under a [110] uniaxial stress as a function of channel direction is theoretically studied

Cross-Layer optimization of the packet loss rate in mobile videoconferencing applications

OpenAIRE

Rivera-Rodríguez, R.; Olivares-Domínguez, O. E.; Serrano-Santoyo, A.

2010-01-01

Videoconferencing transmission over wireless channels presents relevant challenges in mobile scenarios at vehicular speeds. Previous contributions are focused on the optimization of the transmission of multimedia and delay-sensitive applications over the forward link. In this paper, a new Quality of Service (QoS) parameter adaptation scheme is proposed. This scheme applies the Cross-Layer Design technique on the reverse link of an 1xEV-DO Revision 0 channel. As the wireless channel parameters...

Marketing communication strategy of Finnish and Japanese mobile game developers and publishers

OpenAIRE

Cheng, Yi-Tung

2017-01-01

Both the marketing communication strategy of mobile game industry and the industry itself have been drastically evolving in the past years since the development of computation, data transfer and communication technology on mobile devices. Marketing communication has been considered a significant part in marketing strategy, but the marketing communication strategy, activity and channels were not well investigated so far. In this study, 9 SMEs Finnish and Japanese mobile game developers and pub...

Discharge estimation in compound channels with fixed and mobile ...

Indian Academy of Sciences (India)

flowdata.bham.ac.uk (university website). 2-D formulae generally account for bed shear, lateral shear, and secondary flow effects via 3 coefficients f, and . In this paper, the secondary flow term() used within the 2-D methods analysed here ...

Mobility-Aware User Association in Uplink Cellular Networks

KAUST Repository

Arshad, Rabe; Elsawy, Hesham; Sorour, Sameh; Alouini, Mohamed-Slim; Al-Naffouri, Tareq Y.

2017-01-01

This letter studies the mobility aware user-to-BS association policies, within a stochastic geometry framework, in two tier uplink cellular networks with fractional channel inversion power control. Particularly, we model the base stations’ locations using the widely accepted poisson point process and obtain the coverage probability and handover cost expressions for the coupled and decoupled uplink and downlink associations. To this end, we compute the average throughput for the mobile users and study the merits and demerits of each association strategy.

Mobility-Aware User Association in Uplink Cellular Networks

KAUST Repository

Arshad, Rabe

2017-07-20

This letter studies the mobility aware user-to-BS association policies, within a stochastic geometry framework, in two tier uplink cellular networks with fractional channel inversion power control. Particularly, we model the base stations’ locations using the widely accepted poisson point process and obtain the coverage probability and handover cost expressions for the coupled and decoupled uplink and downlink associations. To this end, we compute the average throughput for the mobile users and study the merits and demerits of each association strategy.

Reservoir architecture patterns of sandy gravel braided distributary channel

Directory of Open Access Journals (Sweden)

Senlin Yin

2016-06-01

Full Text Available The purpose of this study was to discuss shape, scale and superimposed types of sandy gravel bodies in sandy-gravel braided distributary channel. Lithofacies analysis, hierarchy bounding surface analysis and subsurface dense well pattern combining with outcrops method were used to examine reservoir architecture patterns of sandy gravel braided distributary channel based on cores, well logging, and outcrops data, and the reservoir architecture patterns of sandy gravel braided distributary channels in different grades have been established. The study shows: (1 The main reservoir architecture elements for sandy gravel braided channel delta are distributary channel and overbank sand, while reservoir flow barrier elements are interchannel and lacustrine mudstone. (2 The compound sand bodies in the sandy gravel braided delta distributary channel take on three shapes: sheet-like distributary channel sand body, interweave strip distributary channel sand body, single strip distributary channel sand body. (3 Identification marks of single distributary channel include: elevation of sand body top, lateral overlaying, “thick-thin-thick” feature of sand bodies, interchannel mudstone and overbank sand between distributary channels and the differences in well log curve shape of sand bodies. (4 Nine lithofacies types were distinguished in distributary channel unit interior, different channel units have different lithofacies association sequence.

DATA MANAGEMENT SYSTEM FOR MOBILE SATELLITE PROPAGATION DATA

Science.gov (United States)

Kantak, A. V.

1994-01-01

The "Data Management System for Mobile Satellite Propogation" package is a collection of FORTRAN programs and UNIX shell scripts designed to handle the huge amounts of data resulting from Mobile Satellite propogation experiments. These experiments are designed to assist in defining channels for mobile satellite systems. By understanding multipath fading characteristics of the channel, doppler effects, and blockage due to manmade objects as well as natural surroundings, characterization of the channel can be realized. Propogation experiments, then, are performed using a prototype of the system simulating the ultimate product environment. After the data from these experiments is generated, the researcher must access this data with a minimum of effort and to derive some standard results. The programs included in this package manipulate the data files generated by the NASA/JPL Mobile Satellite propogation experiment on an interactive basis. In the experiment, a transmitter operating at 869 MHz was carried to an altitude of 32Km by a stratospheric balloon. A vehicle within the line-of-sight of the transmitter was then driven around, splitting the incoming signal into I and Q channels, and sampling the resulting signal strength at 1000 samples per second. The data was collected at various antenna elavation angles and different times of day generating the ancillary data for the experiment. This package contains a program to convert the binary format of the data generated into standard ASCII format suitable for use with a wide variety of machine architectures. Also included is a UNIX shell-script designed to parse this ASCII file into those records of data that match the researcher's desired values for the ancillary data parameters. In addition, four FORTRAN programs are included to obtain standard quantities from the data. Quantities such as probability of signal level greater than or equal to a specified signal level, probability density of the signal levels, frequency

Double-gate junctionless transistor model including short-channel effects

International Nuclear Information System (INIS)

Paz, B C; Pavanello, M A; Ávila-Herrera, F; Cerdeira, A

2015-01-01

This work presents a physically based model for double-gate junctionless transistors (JLTs), continuous in all operation regimes. To describe short-channel transistors, short-channel effects (SCEs), such as increase of the channel potential due to drain bias, carrier velocity saturation and mobility degradation due to vertical and longitudinal electric fields, are included in a previous model developed for long-channel double-gate JLTs. To validate the model, an analysis is made by using three-dimensional numerical simulations performed in a Sentaurus Device Simulator from Synopsys. Different doping concentrations, channel widths and channel lengths are considered in this work. Besides that, the series resistance influence is numerically included and validated for a wide range of source and drain extensions. In order to check if the SCEs are appropriately described, besides drain current, transconductance and output conductance characteristics, the following parameters are analyzed to demonstrate the good agreement between model and simulation and the SCEs occurrence in this technology: threshold voltage (V TH ), subthreshold slope (S) and drain induced barrier lowering. (paper)

Mobile Phone Banking Usage Behaviour: An Australian Perspective

Directory of Open Access Journals (Sweden)

Majharul Talukder

2014-12-01

Full Text Available While the use of mobile phones in financial transactions is witnessing phenomenal growth at the international level, its growth has been relatively slow in Australia. Drawing on the theory of reasoned action and technology adoption framework, this paper reports the results concerning a survey of mobile phone users for banking transactions in Australia. The paper specifically identified the factors affecting usage behaviour when mobile phone banking services were engaged. The findings broaden and deepen our understanding of the usage of mobile-based banking in the information age. This paper contributes to the knowledge of this subject by including identification and testing of constructs of predictors regarding mobile phone banking, which are additional to those employed in the extant theories indicated above. The findings of this paper have important policy implications for banks in terms of understanding the underlying factors that drive customers’ mobile banking for financial transactions. Accordingly, design strategies have been developed to promote mobile phone banking – a cost effective channel for delivering financial services.

Spatial Dynamic Wideband Modeling of the MIMO Satellite-to-Earth Channel

OpenAIRE

Lehner, Andreas; Steingass, Alexander

2014-01-01

A novel MIMO (multiple input multiple output) satellite channel model that allows the generation of associated channel impulse response (CIR) time series depending on the movement profile of a land mobile terminal is presented in this paper. Based on high precise wideband measurements in L-band the model reproduces the correlated shadowing and multipath conditions in rich detail. The model includes time and space variant echo signals appearing and disappearing in dependence on the receive ...

Modems for emerging digital cellular-mobile radio system

Science.gov (United States)

Feher, Kamilo

1991-01-01

Digital modem techniques for emerging digital cellular telecommunications-mobile radio system applications are described and analyzed. In particular, theoretical performance, experimental results, principles of operation, and various architectures of pi/4-QPSK (pi/4-shifted coherent or differential QPSK) modems for second-generation US digital cellular radio system applications are presented. The spectral/power efficiency and performance of the pi/4-QPSK modems (American and Japanese digital cellular emerging standards) are studied and briefly compared to GMSK (Gaussian minimum-shift keying) modems (proposed for European DECT and GSM cellular standards). Improved filtering strategies and digital pilot-aided (digital channel sounding) techniques are also considered for pi/4-QPSK and other digital modems. These techniques could significantly improve the performance of digital cellular and other digital land mobile and satellite mobile radio systems. More spectrally efficient modem trends for future cellular/mobile (land mobile) and satellite communication systems applications are also highlighted.

Further development of a facility for channeling studies: application to lattice location

International Nuclear Information System (INIS)

Lopes, D.R.

1984-08-01

Equipment modifications at the Lawrence Berkeley Laboratory (LBL) Rutherford backscattering facility, including the addition of a high precision goniometer, have been made to enhance the performance of channeling experiments. The angular divergence of the alpha particle beam was also reduced to 0 by improving the collimation. To demonstrate improved channeling capability angular scans were performed about the [100], [110], and [111] axial channels of a 3400 A (100) silicon membrane. Both the minimum yield, chi/sub min/, and the critical angle, psi/sub 1/2/, were consistent with accepted values. A preliminary investigation of the lattice location of cobalt on the (100) silicon surface was undertaken. Approximately 4.5 x 10 15 Co atoms/cm 2 were electron beam deposited on a 3900 A, HF etched silicon membrane in a system using oilless pumps. Preliminary channeling data taken approximately one month later indicated a preferred site for approximately 16% of the cobalt atoms. Channeling data obtained six months later with the new goniometer showed no evidence for a preferred site. Room temperature oxidation between experiments was observed and is thought to have affected the location of the cobalt atoms. 33 references, 15 figures

Detection of falls using accelerometers and mobile phone technology.

Science.gov (United States)

Lee, Raymond Y W; Carlisle, Alison J

2011-11-01

to study the sensitivity and specificity of fall detection using mobile phone technology. an experimental investigation using motion signals detected by the mobile phone. the research was conducted in a laboratory setting, and 18 healthy adults (12 males and 6 females; age = 29 ± 8.7 years) were recruited. each participant was requested to perform three trials of four different types of simulated falls (forwards, backwards, lateral left and lateral right) and eight other everyday activities (sit-to-stand, stand-to-sit, level walking, walking up- and downstairs, answering the phone, picking up an object and getting up from supine). Acceleration was measured using two devices, a mobile phone and an independent accelerometer attached to the waist of the participants. Bland-Altman analysis shows a higher degree of agreement between the data recorded by the two devices. Using individual upper and lower detection thresholds, the specificity and sensitivity for mobile phone were 0.81 and 0.77, respectively, and for external accelerometer they were 0.82 and 0.96, respectively. fall detection using a mobile phone is a feasible and highly attractive technology for older adults, especially those living alone. It may be best achieved with an accelerometer attached to the waist, which transmits signals wirelessly to a phone.

Paraffin molecule mobility in channel clathrates of urea on spectroscopic NMR relaxation data

CERN Document Server

Kriger, Y G; Chekhova, G N

2001-01-01

The temperature dependences of the protons spin-lattice relaxation time (T sub I) in the channel clathrates of urea with paraffins are measured. The data on the T sub I are interpreted within the frames of the model of the paraffins molecules and their fragments orientation in the clathrate channels. The dynamics peculiarities are connected with the disproportion effects of these compounds

Categorisation of Mobile EEG: A Researcher’s Perspective

Directory of Open Access Journals (Sweden)

Anthony D. Bateson

2017-01-01

Full Text Available Researchers are increasingly attempting to undertake electroencephalography (EEG recordings in novel environments and contexts outside of the traditional static laboratory setting. The term “mobile EEG,” although commonly used to describe many of these undertakings, is ambiguous, since it attempts to encompass a wide range of EEG device mobility, participant mobility, and system specifications used across investigations. To provide quantitative parameters for “mobile EEG,” we developed a Categorisation of Mobile EEG (CoME scheme based upon scoring of device mobility (D, from 0, off-body, to 5, head-mounted with no additional equipment, participant mobility (P, from 0, static, to 5, unconstrained running, system specification (S, from 4, lowest, to 20, highest, and number of channels (C used. The CoME scheme was applied to twenty-nine published mobile EEG studies. Device mobility scores ranged from 0D to 4D, participant mobility scores from 0P to 4P, and system specification scores from 6S to 17S. The format of the scores for the four parameters is given, for example, as (2D, 4P, 17S, 32C and readily enables comparisons across studies. Our CoME scheme enables researchers to quantify the degree of device mobility, participant mobility, and system specification used in their “mobile EEG” investigations in a standardised way.

A new method for mobile phone image denoising

Science.gov (United States)

Jin, Lianghai; Jin, Min; Li, Xiang; Xu, Xiangyang

2015-12-01

Images captured by mobile phone cameras via pipeline processing usually contain various kinds of noises, especially granular noise with different shapes and sizes in both luminance and chrominance channels. In chrominance channels, noise is closely related to image brightness. To improve image quality, this paper presents a new method to denoise such mobile phone images. The proposed scheme converts the noisy RGB image to luminance and chrominance images, which are then denoised by a common filtering framework. The common filtering framework processes a noisy pixel by first excluding the neighborhood pixels that significantly deviate from the (vector) median and then utilizing the other neighborhood pixels to restore the current pixel. In the framework, the strength of chrominance image denoising is controlled by image brightness. The experimental results show that the proposed method obviously outperforms some other representative denoising methods in terms of both objective measure and visual evaluation.

Differentiating submarine channel-related thin-bedded turbidite facies: Outcrop examples from the Rosario Formation, Mexico

Science.gov (United States)

Hansen, Larissa; Callow, Richard; Kane, Ian; Kneller, Ben

2017-08-01

Thin-bedded turbidites deposited by sediment gravity flows that spill from submarine channels often contain significant volumes of sand in laterally continuous beds. These can make up over 50% of the channel-belt fill volume, and can thus form commercially important hydrocarbon reservoirs. Thin-bedded turbidites can be deposited in environments that include levees and depositional terraces, which are distinguished on the basis of their external morphology and internal architecture. Levees have a distinctive wedge shaped morphology, thinning away from the channel, and confine both channels (internal levees) and channel-belts (external levees). Terraces are flat-lying features that are elevated above the active channel within a broad channel-belt. Despite the ubiquity of terraces and levees in modern submarine channel systems, the recognition of these environments in outcrop and in the subsurface is challenging. In this outcrop study of the Upper Cretaceous Rosario Formation (Baja California, Mexico), lateral transects based on multiple logged sections of thin-bedded turbidites reveal systematic differences in sandstone layer thicknesses, sandstone proportion, palaeocurrents, sedimentary structures and ichnology between channel-belt and external levee thin-bedded turbidites. Depositional terrace deposits have a larger standard deviation in sandstone layer thicknesses than external levees because they are topographically lower, and experience a wider range of turbidity current sizes overspilling from different parts of the channel-belt. The thickness of sandstone layers within external levees decreases away from the channel-belt while those in depositional terraces are less laterally variable. Depositional terrace environments of the channel-belt are characterized by high bioturbation intensities, and contain distinctive trace fossil assemblages, often dominated by ichnofabrics of the echinoid trace fossil Scolicia. These assemblages contrast with the lower

Mobile phone interventions for tuberculosis should ensure access to mobile phones to enhance equity - A prospective, observational cohort study in Peruvian shantytowns.

Science.gov (United States)

Saunders, Matthew J; Wingfield, Tom; Tovar, Marco A; Herlihy, Niamh; Rocha, Claudio; Zevallos, Karine; Montoya, Rosario; Ramos, Eric; Datta, Sumona; Evans, Carlton A

2018-06-04

Mobile phone interventions have been advocated for tuberculosis care, but little is known about access of target populations to mobile phones. We studied mobile phone access amongst patients with tuberculosis, focusing on vulnerable patients and patients who later had adverse treatment outcomes. In a prospective cohort study in Callao, Peru, we recruited and interviewed 2,584 patients with tuberculosis between 2007-2013 and followed them until 2016 for adverse treatment outcomes using national treatment registers. Subsequently, we recruited a further 622 patients between 2016-2017. Data were analysed using logistic regression and by calculating relative risks (RR). Between 2007-2013, the proportion of the general population of Peru without mobile phone access averaged 7.8% but for patients with tuberculosis was 18% (pmobile phone access, patients without access at recruitment were more likely to subsequently have incomplete treatment (20% versus 13%, RR=1.5; p=0.001) or an adverse treatment outcome (29% versus 23% RR=1.3; p=0.006). Between 2016 and 2017, the proportion of patients without access dropped to 8.9% overall, but remained the same (18%) as in 2012 among the poorest third. Access to mobile phones among patients with tuberculosis is insufficient, and rarest in patients who are poorer and later have adverse treatment outcomes. Thus, mobile phone interventions to improve tuberculosis care may be least accessed by the priority populations for whom they are intended. Such interventions should ensure access to mobile phones to enhance equity. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Undergraduates’ attitudes toward mobile advertising

OpenAIRE

Usta, Resul

2009-01-01

The rapid proliferation of mobile devices such as cellular phones has created a new communication channel for marketing. Currently, cellular phones are mostly used for Short Messaging Service (SMS) advertising. The aim of this study is to explore the factors that underline undergraduates’ attitudes toward SMS advertising. The results obtained indicated factors such as entertainment, informativeness, irritation, reliability, general attitude and permission and incentive-based advertising. The ...

Direct Numerical Simulation Sediment Transport in Horizontal Channel

International Nuclear Information System (INIS)

Uhlmann, M.

2006-01-01

We numerically simulate turbulent flow in a horizontal plane channel over a bed of mobile particles. All scales of fluid motion are resolved without modeling and the phase interface is accurately represented. Our results indicate a possible scenario for the onset of erosion through collective motion induced by buffer-layer streaks. (Author) 27 refs

Channel Estimation on the (EW RLS Algorithm Model of MIMO OFDM in Wireless Communication

Directory of Open Access Journals (Sweden)

Sarnin Suzi Seroja

2016-01-01

(correspond to different mobility speeds and Monte Carlo simulations are performed and the MSE and BER performance versus SNR are obtained by averaging over 10000 channel realization. For comparisons, the BER performance is also presented for perfectly known channel at the receiver. In all the simulations, perfect synchronization between the transmitter and the receiver is assumed.

Characterizing New Channels of Communication: A Case Study of Municipal 311 Requests in Edmonton, Canada

Directory of Open Access Journals (Sweden)

Qing Lu

2016-06-01

Full Text Available City governments around the world are developing and expanding how they connect to citizens. Technologies play an important role in making this connection, and one frequent way that cities connect with citizens is through 311-style request systems. 311 is a non-emergency municipal notification system that uses telephone, email, web forms, and increasingly, mobile applications to allow citizens to notify government of infrastructure issues and make requests for municipal services. In many ways, this process of citizen contribution mirrors the provision of volunteered geographic information, that is spatially-referenced user generated content. This research presents a case study of the city of Edmonton, Canada, an early adopter of multi-channel 311 service request systems, including telephone, email, web form, and mobile app 311 request channels. Three methods of analysis are used to characterize and compare these different channels over three years of request data; a comparison of relative request share for each channel, a spatial hot spot analysis, and regression models to compare channel usage with sociodemographic variables. The results of this study indicate a shift in channel usage from traditional to Internet-enabled, that this shift is mirrored in the hotspots of request activity, and that specific digital inequalities exist that reinforce this distinction between traditional and Internet-enabled reporting channels.

Joint Transmit Antenna Selection and Power Allocation for ISDF Relaying Mobile-to-Mobile Sensor Networks.

Science.gov (United States)

Xu, Lingwei; Zhang, Hao; Gulliver, T Aaron

2016-02-19

The outage probability (OP) performance of multiple-relay incremental-selective decode-and-forward (ISDF) relaying mobile-to-mobile (M2M) sensor networks with transmit antenna selection (TAS) over N-Nakagami fading channels is investigated. Exact closed-form OP expressions for both optimal and suboptimal TAS schemes are derived. The power allocation problem is formulated to determine the optimal division of transmit power between the broadcast and relay phases. The OP performance under different conditions is evaluated via numerical simulation to verify the analysis. These results show that the optimal TAS scheme has better OP performance than the suboptimal scheme. Further, the power allocation parameter has a significant influence on the OP performance.

Push Attack: Binding Virtual and Real Identities Using Mobile Push Notifications

Directory of Open Access Journals (Sweden)

Pierpaolo Loreti

2018-01-01

Full Text Available Popular mobile apps use push notifications extensively to offer an “always connected” experience to their users. Social networking apps use them as a real-time channel to notify users about new private messages or new social interactions (e.g., friendship request, tagging, etc.. Despite the cryptography used to protect these communication channels, the strict temporal binding between the actions that trigger the notifications and the reception of the notification messages in the mobile device may represent a privacy issue. In this work, we present the push notification attack designed to bind the physical owners of mobile devices with their virtual identities, even if pseudonyms are used. In an online attack, an active attacker triggers a push notification and captures the notification packets that transit in the network. In an offline attack, a passive attacker correlates the social network activity of a user with the received push notification. The push notification attack bypasses the standard ways of protecting user privacy based on the network layer by operating at the application level. It requires no additional software on the victim’s mobile device.

Channel estimation for physical layer network coding systems

CERN Document Server

Gao, Feifei; Wang, Gongpu

2014-01-01

This SpringerBrief presents channel estimation strategies for the physical later network coding (PLNC) systems. Along with a review of PLNC architectures, this brief examines new challenges brought by the special structure of bi-directional two-hop transmissions that are different from the traditional point-to-point systems and unidirectional relay systems. The authors discuss the channel estimation strategies over typical fading scenarios, including frequency flat fading, frequency selective fading and time selective fading, as well as future research directions. Chapters explore the performa

Indoor positioning using differential Wi-Fi lateration

Science.gov (United States)

Retscher, Guenther; Tatschl, Thomas

2017-12-01

For Wi-Fi positioning usually location fingerprinting or (tri)lateration are employed whereby the received signal strengths (RSSs) of the surrounding Wi-Fi Access Points (APs) are scanned on the mobile devices and used to perform localization. Within the scope of this study, the position of a mobile user is determined on the basis of lateration. Two new differential approaches are developed and compared to two common models, i.e., the one-slope and multi-wall model, for the conversion of the measured RSS of the Wi-Fi signals into ranges. The two novel methods are termed DWi-Fi as they are derived either from the well-known DGPS or VLBI positioning principles. They make use of a network of reference stations deployed in the area of interest. From continuous RSS observations on these reference stations correction parameters are derived and applied by the user in real-time. This approach leads to a reduced influence of temporal and spatial variations and various propagation effects on the positioning result. In practical use cases conducted in a multi-storey office building with three different smartphones, it is proven that the two DWi-Fi approaches outperform the common models as static positioning yielded to position errors of about 5 m in average under good spatial conditions.

Design of a hybrid command and control mobile botnet

CSIR Research Space (South Africa)

Pieterse, H

2013-05-01

Full Text Available and control mobile botnet. The hybrid design explores the efficiency of multiple command and control channels against the following objectives: no single point of failure within the topology, low cost for command dissemination, limited network activities...

Laser--Doppler anemometry technique applied to two-phase dispersed flows in a rectangular channel

International Nuclear Information System (INIS)

Lee, S.L.; Srinivasan, J.

1979-01-01

A new optical technique using Laser--Doppler anemometry has been applied to the local measurement of turbulent upward flow of a dilute water droplet--air two-phase dispersion in a vertical rectangular channel. Individually examined were over 20,000 droplet signals coming from each of a total of ten transversely placed measuring points, the closest of which to the channel wall was 250 μ away from the wall. Two flows of different patterns due to different imposed flow conditions were investigated, one with and the other without a liquid film formed on the channel wall. Reported are the size and number density distribution and the axial and lateral velocity distributions for the droplets as well as the axial and lateral velocity distributions for the air

Personalized System of Instruction and Mobile-Learning Models 2014 and Beyond

Directory of Open Access Journals (Sweden)

Laura Thompson

2014-04-01

Full Text Available The purpose of this study is to analyze the delivery method used in Personalize System of Instruction (PSI. Asynchronous in nature, the PSI model may provide viable alternatives m-learning platforms, while at the same time fulfilling some of the theories of social science research. Learning style types are also presented in this study. A strategic alignment model is measured against the learning style types in efforts to map the feasibility of m-learning in social sciences versus other educational research. In the case of m-learning, stakeholders include but are not limited to curriculum creators, ISPs and those who host mobile sites, streaming content providers, mobile phone users, instructors, educational institutions and mobile phone carriers. Verifying the mobile authenticity of students receiving instruction, and the burden of proof is also presented in this study as it relates to models used in the banking industry. Adobe, ComF5 and AXMEDIS [2] are a few companies that provide full multi-platform support for multiple mobile based distribution channels. Mobile protocol and the development of mobile applications must minimize frustrations experienced by users. Issues and concerns in this area range from screen size and resolution of content, and the balance of reading text versus seeing live streaming video, all the way to screen scrolling and mobile keyboard functionality. The conceptual framework for Platform as a Service and Infrastructure as a Service are presented to access, capture and share pedagogies toward distribution. [2] AXMEDIS (2006, December. Automating production of cross media content for multi-channel distribution. Axmedis 2nd Annual Conference on Content Distribution.

Spectral Subtraction Approach for Interference Reduction of MIMO Channel Wireless Systems

Directory of Open Access Journals (Sweden)

Tomohiro Ono

2005-08-01

Full Text Available In this paper, a generalized spectral subtraction approach for reducing additive impulsive noise, narrowband signals, white Gaussian noise and DS-CDMA interferences in MIMO channel DS-CDMA wireless communication systems is investigated. The interference noise reduction or suppression is essential problem in wireless mobile communication systems to improve the quality of communication. The spectrum subtraction scheme is applied to the interference noise reduction problems for noisy MIMO channel systems. The interferences in space and time domain signals can effectively be suppressed by selecting threshold values, and the computational load with the FFT is not large. Further, the fading effects of channel are compensated by spectral modification with the spectral subtraction process. In the simulations, the effectiveness of the proposed methods for the MIMO channel DS-CDMA is shown to compare with the conventional MIMO channel DS-CDMA.

Reduced Sodium Current in the Lateral Ventricular Wall Induces Inferolateral J-Waves.

Science.gov (United States)

Meijborg, Veronique M F; Potse, Mark; Conrath, Chantal E; Belterman, Charly N W; De Bakker, Jacques M T; Coronel, Ruben

2016-01-01

J-waves in inferolateral leads are associated with a higher risk for idiopathic ventricular fibrillation. We aimed to test potential mechanisms (depolarization or repolarization dependent) responsible for inferolateral J-waves. We hypothesized that inferolateral J-waves can be caused by regional delayed activation of myocardium that is activated late during normal conditions. Computer simulations were performed to evaluate how J-point elevation is influenced by reducing sodium current conductivity (GNa), increasing transient outward current conductivity (Gto), or cellular uncoupling in three predefined ventricular regions (lateral, anterior, or septal). Two pig hearts were Langendorff-perfused with selective perfusion with a sodium channel blocker of lateral or anterior/septal regions. Volume-conducted pseudo-electrocardiograms (ECG) were recorded to detect the presence of J-waves. Epicardial unipolar electrograms were simultaneously recorded to obtain activation times (AT). Simulation data showed that conduction slowing, caused by reduced sodium current, in lateral, but not in other regions induced inferolateral J-waves. An increase in transient outward potassium current or cellular uncoupling in the lateral zone elicited slight J-point elevations which did not meet J-wave criteria. Additional conduction slowing in the entire heart attenuated J-waves and J-point elevations on the ECG, because of masking by the QRS. Experimental data confirmed that conduction slowing attributed to sodium channel blockade in the left lateral but not in the anterior/septal ventricular region induced inferolateral J-waves. J-waves coincided with the delayed activation. Reduced sodium current in the left lateral ventricular myocardium can cause inferolateral J-waves on the ECG.

A two-dimensional fully analytical model with polarization effect for off-state channel potential and electric field distributions of GaN-based field-plated high electron mobility transistor

International Nuclear Information System (INIS)

Mao Wei; She Wei-Bo; Zhang Chao; Zhang Jin-Cheng; Zhang Jin-Feng; Liu Hong-Xia; Yang Lin-An; Zhang Kai; Zhao Sheng-Lei; Chen Yong-He; Zheng Xue-Feng; Hao Yue; Yang Cui; Ma Xiao-Hua

2014-01-01

In this paper, we present a two-dimensional (2D) fully analytical model with consideration of polarization effect for the channel potential and electric field distributions of the gate field-plated high electron mobility transistor (FP-HEMT) on the basis of 2D Poisson's solution. The dependences of the channel potential and electric field distributions on drain bias, polarization charge density, FP structure parameters, AlGaN/GaN material parameters, etc. are investigated. A simple and convenient approach to designing high breakdown voltage FP-HEMTs is also proposed. The validity of this model is demonstrated by comparison with the numerical simulations with Silvaco—Atlas. The method in this paper can be extended to the development of other analytical models for different device structures, such as MIS-HEMTs, multiple-FP HETMs, slant-FP HEMTs, etc. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Channel Bottom Morphology in the Deltaic Reach of the Song Hau (mekong) River Channel in Vietnam

Science.gov (United States)

Allison, M. A.; Weathers, H. D., III; Meselhe, E. A.

2016-02-01

Boat-based, channel bathymetry and bankline elevation studies were conducted in the tidal and estuarine Mekong River channel using multibeam bathymetry and LIDAR corrected for elevation by RTK satellite positioning. Two mapping campaigns, one at high discharge in October 2014 and one at low discharge in March 2015, were conducted in the lower 100 km reach of the Song Hau distributary channel to (1) examine bottom morphology and its relationship to sediment transport, and (2) to provide information to setup the grid for a multi-dimensional and reduced complexity models of channel hydrodynamics and sediment dynamics. Sand fields were identified in multibeam data by the presence of dunes that were as large as 2-4 m high and 40-80 m wavelength and by clean sands in bottom grabs. Extensive areas of sand at the head and toe of mid-channel islands displayed 10-25 m diameter circular pits that could be correlated with bucket dredge, sand mining activities observed at some of the sites. Large areas of the channel floor were relict (containing little or no modern sediment) in the high discharge campaign, identifiable by the presence of along channel erosional furrows and terraced outcrops along the channel floor and margins. Laterally extensive flat areas were also observed in the channel thalweg. Both these and the relict areas were sampled by bottom grab as stiff silty clays. Complex cross-channel combinations of these morphologies were observed in some transects, suggesting strong bottom steering of tidal and riverine currents. Relative to high discharge, transects above and below the salt penetration limit showed evidence of shallowing in the thalweg and adjacent sloping areas at low discharge in March 2015. This shallowing, combined with the reduced extent of sand fields and furrowed areas, and soft muds in grabs, suggests seasonal trapping of fine grained sediment is occurring by estuarine and tidal circulation.

Performance Limits of Energy Harvesting Communications under Imperfect Channel State Information

KAUST Repository

Zenaidi, Mohamed Ridah; Rezki, Zouheir; Tembine, Hamidou; Alouini, Mohamed-Slim

2015-01-01

to mobility and environmental changes. In this work, we consider the problem of power allocation taking into account the energy arrivals over time and the degree of channel state information (CSI) available at the transmitter, in order to maximize

Performance limits of energy harvesting communications under imperfect channel state information

KAUST Repository

Zenaidi, Mohamed Ridha; Rezki, Zouheir; Tembine, Hamidou; Alouini, Mohamed-Slim

2016-01-01

to mobility and environmental changes. In this paper, we consider the problem of power allocation taking into account the energy arrivals over time and the degree of channel state information (CSI) available at the transmitter, in order to maximize

Channels of social influence for decision making in restaurants: A case study

Directory of Open Access Journals (Sweden)

M. Romero-Charneco

2018-05-01

Full Text Available Consumers use the Internet to obtain information on tourism products and services. When evaluating the alternatives, they are faced with a large volume of information that makes their purchasing decision difficult. In this context, the generalized use of mobile instant messaging (MIM has led to the implementation of chatbots in these channels, to help to plan the purchase. This research explores restaurant selection through a WhatsApp mobile instant messaging (MIM chatbot. A study is made of the channels consulted by travellers on Web 2.0 as well as the search models and restaurant selection processes, and a case study is presented. The results allow the diagnosis of the main criteria of user behaviour in this type of conversational interface in the decision-making process related to gastronomic consumption.

Asymmetric, compressive, SiGe epilayers on Si grown by lateral liquid-phase epitaxy utilizing a distinction between dislocation nucleation and glide critical thicknesses

Science.gov (United States)

O'Reilly, Andrew J.; Quitoriano, Nathaniel

2018-01-01

Uniaxially strained Si1-xGex channels have been proposed as a solution for high mobility channels in next-generation MOSFETS to ensure continued device improvement as the benefits from further miniaturisation are diminishing. Previously proposed techniques to deposit uniaxially strained Si1-xGex epilayers on Si (0 0 1) substrates require multiple deposition steps and only yielded thin strips of uniaxially strained films. A lateral liquid-phase epitaxy (LLPE) technique was developed to deposit a blanket epilayer of asymmetrically strained Si97.4Ge2.6 on Si in a single step, where the epilayer was fully strained in the growth direction and 31% strain-relaxed in the orthogonal direction. The LLPE technique promoted the glide of misfit dislocations, which nucleated in a region with an orthogonal misfit dislocation network, into a region where the dislocation nucleation was inhibited. This created an array of parallel misfit dislocations which were the source of the asymmetric strain. By observing the thicknesses at which the dislocation network transitions from orthogonal to parallel and at which point dislocation glide is exhausted, the separate critical thicknesses for dislocation nucleation and dislocation glide can be determined.

Organic-inorganic hybrid materials as semiconducting channels in thin-film field-effect transistors

Science.gov (United States)

Kagan; Mitzi; Dimitrakopoulos

1999-10-29

Organic-inorganic hybrid materials promise both the superior carrier mobility of inorganic semiconductors and the processability of organic materials. A thin-film field-effect transistor having an organic-inorganic hybrid material as the semiconducting channel was demonstrated. Hybrids based on the perovskite structure crystallize from solution to form oriented molecular-scale composites of alternating organic and inorganic sheets. Spin-coated thin films of the semiconducting perovskite (C(6)H(5)C(2)H(4)NH(3))(2)SnI(4) form the conducting channel, with field-effect mobilities of 0.6 square centimeters per volt-second and current modulation greater than 10(4). Molecular engineering of the organic and inorganic components of the hybrids is expected to further improve device performance for low-cost thin-film transistors.

Characteristics of GaAs/AlGaAs-doped channel MISFET's at cryogenic temperatures

International Nuclear Information System (INIS)

Laskar, J.; Kolodzey, J.; Ketterson, A.A.; Adesida, I.; Cho, A.Y.

1990-01-01

The authors present high-frequency measurements at cryogenic temperatures to 125 K of 0.3-μm gate length GaAs/Al 0.3 Ga 0.7 As metal insulator semiconductor field-effect transistors (MISFET's) with a doped channel. Experimental results demonstrate significant improvement in performance including an increase in the maximum frequency of oscillation f max from 70 to 81 GHz and an increase in the unity current gain cutoff frequency f T from 46 to 57 GHz. Independently determined decreases in electron mobility and increases in electron velocity under similar conditions lead to the conclusion that carrier velocity and not mobility controls transport in these devices. These results show the high-speed potential of doped channel MISFET's at both room temperature and cryogenic temperatures

Understanding mobility degeneration mechanism in organic thin-film transistors (OTFT)

Science.gov (United States)

Wang, Wei; Wang, Long; Xu, Guangwei; Gao, Nan; Wang, Lingfei; Ji, Zhuoyu; Lu, Congyan; Lu, Nianduan; Li, Ling; Liu, Miwng

2017-08-01

Mobility degradation at high gate bias is often observed in organic thin film transistors. We propose a mechanism for this confusing phenomenon, based on the percolation theory with the presence of disordered energy landscape with an exponential density of states. Within a simple model we show how the surface states at insulator/organic interface trap a portion of channel carriers, and result in decrease of mobility as well as source/drain current with gate voltage. Depending on the competition between the carrier accumulation and surface trapping effect, two different carrier density dependences of mobility are obtained, in excellent agreement with experiment data.

Cooperative ad hoc networks for energy and delay efficient content distribution with fast channel variations

KAUST Repository

Atat, Rachad

2012-11-20

Cooperative ad hoc networks for the efficient distribution of content of common interest are studied in the case of fast channel variations. Mobiles are grouped into cooperative clusters for the purpose of receiving the content with optimized energy efficiency. Data are sent to mobile terminals on a long range (LR) link, and then, the terminals exchange the content by using an appropriate short range wireless technology. When channel state information is available for the LR links, unicasting is used on the LR. When accurate channel state information is not available, threshold-based multicasting is implemented on the LR. Energy minimization is formulated as an optimization problem for each scenario, and the optimal solutions are determined in closed form in scenarios with fast channel variations. Results show significant energy savings in the proposed schemes compared with the noncooperative case and other previous related work. Furthermore, the energy minimizing solutions are shown to lead to reduced delay in the content distribution process. Practical implementation aspects of the proposed methods are also discussed. © 2012 John Wiley & Sons, Ltd.

Cooperative ad hoc networks for energy and delay efficient content distribution with fast channel variations

KAUST Repository

Atat, Rachad; Yaacoub, Elias E.; Alouini, Mohamed-Slim; Abu-Dayya, Adnan A.

2012-01-01

Cooperative ad hoc networks for the efficient distribution of content of common interest are studied in the case of fast channel variations. Mobiles are grouped into cooperative clusters for the purpose of receiving the content with optimized energy efficiency. Data are sent to mobile terminals on a long range (LR) link, and then, the terminals exchange the content by using an appropriate short range wireless technology. When channel state information is available for the LR links, unicasting is used on the LR. When accurate channel state information is not available, threshold-based multicasting is implemented on the LR. Energy minimization is formulated as an optimization problem for each scenario, and the optimal solutions are determined in closed form in scenarios with fast channel variations. Results show significant energy savings in the proposed schemes compared with the noncooperative case and other previous related work. Furthermore, the energy minimizing solutions are shown to lead to reduced delay in the content distribution process. Practical implementation aspects of the proposed methods are also discussed. © 2012 John Wiley & Sons, Ltd.

Exploring technology acceptance for mobile services

Directory of Open Access Journals (Sweden)

Kenny Phan

2011-07-01

Full Text Available Purpose: Mobile phone industries are no longer relying on voice services. It is predicted that data services are expected to be a remediation for the declining of average revenue per user (ARPU in telecommunication market. The purpose of this paper is to find the factors that influence the acceptance/adoption of mobile services.Design/methodology/approach: This paper utilizes quantitative method. Questionnaire were distributed to collect the data. The questionnaires are designed specifically to address the factors related to mobile services. Later on, this paper uses Analytical Hierarchical Process (AHP and Cluster analysis to identify the factors that influence the adoption of mobile services.Findings: The results show that ease of use and usefulness are top two factors that influence the adoption of mobile services.Research limitations/implications: The sample for the study is relatively small. For future research, the sample should be increased. The data collection should also look into different devices and operating system of mobile phones to find if there is any significant difference in adopting mobile services.Practical implications: This framework is expected to be able to help the mobile services provider to design better mobile services that can attract users to adopt them. Originality/value: This is the follow on research on the previous study that employed different method. This study is to confirm and support the findings from previous study.

The role of knowledge management in mobile marketing

Directory of Open Access Journals (Sweden)

Łukowski, Wojciech

2017-09-01

Full Text Available Mobile marketing is one of the fastest growing channels of marketing information. Mobile terminal devices and mobile networks allow for mass personalisation of content transmitted to individual recipients thereby facilitating recipient segmentation within one-to-one marketing. Mobile marketing means using interactive wireless media to provide clients with personal information with precise profiling using geo-location, time, and often associated with their interests, sex or other attributes, promoting goods, services and ideas, thus, also generating added value for all the process participants. Mobile media has completely transformed the present concept of marketing campaigns and has opened up a wide array of new opportunities for advertisers. They have also brought new challenges for companies using CRM and KM. In a study involving a group of students, efforts were made to determine the factors which are likely to contribute to finding the answer to the question of how to effectively run mobile marketing campaigns and what should be taken into account when using the tools and knowledge offered by knowledge management and customer relationship management.

2D IR spectroscopy reveals the role of water in the binding of channel-blocking drugs to the influenza M2 channel

International Nuclear Information System (INIS)

Ghosh, Ayanjeet; Gai, Feng; Hochstrasser, Robin M.; Wang, Jun; DeGrado, William F.; Moroz, Yurii S.; Korendovych, Ivan V.; Zanni, Martin

2014-01-01

Water is an integral part of the homotetrameric M2 proton channel of the influenza A virus, which not only assists proton conduction but could also play an important role in stabilizing channel-blocking drugs. Herein, we employ two dimensional infrared (2D IR) spectroscopy and site-specific IR probes, i.e., the amide I bands arising from isotopically labeled Ala30 and Gly34 residues, to probe how binding of either rimantadine or 7,7-spiran amine affects the water dynamics inside the M2 channel. Our results show, at neutral pH where the channel is non-conducting, that drug binding leads to a significant increase in the mobility of the channel water. A similar trend is also observed at pH 5.0 although the difference becomes smaller. Taken together, these results indicate that the channel water facilitates drug binding by increasing its entropy. Furthermore, the 2D IR spectral signatures obtained for both probes under different conditions collectively support a binding mechanism whereby amantadine-like drugs dock in the channel with their ammonium moiety pointing toward the histidine residues and interacting with a nearby water cluster, as predicted by molecular dynamics simulations. We believe these findings have important implications for designing new anti-influenza drugs

2D IR spectroscopy reveals the role of water in the binding of channel-blocking drugs to the influenza M2 channel

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Ayanjeet, E-mail: ayanjeet@sas.upenn.edu, E-mail: gai@sas.upenn.edu; Gai, Feng, E-mail: ayanjeet@sas.upenn.edu, E-mail: gai@sas.upenn.edu; Hochstrasser, Robin M. [Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Wang, Jun; DeGrado, William F. [Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California 94143 (United States); Moroz, Yurii S.; Korendovych, Ivan V. [Department of Chemistry, Syracuse University, Syracuse, New York 13244 (United States); Zanni, Martin [Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706 (United States)

2014-06-21

Water is an integral part of the homotetrameric M2 proton channel of the influenza A virus, which not only assists proton conduction but could also play an important role in stabilizing channel-blocking drugs. Herein, we employ two dimensional infrared (2D IR) spectroscopy and site-specific IR probes, i.e., the amide I bands arising from isotopically labeled Ala30 and Gly34 residues, to probe how binding of either rimantadine or 7,7-spiran amine affects the water dynamics inside the M2 channel. Our results show, at neutral pH where the channel is non-conducting, that drug binding leads to a significant increase in the mobility of the channel water. A similar trend is also observed at pH 5.0 although the difference becomes smaller. Taken together, these results indicate that the channel water facilitates drug binding by increasing its entropy. Furthermore, the 2D IR spectral signatures obtained for both probes under different conditions collectively support a binding mechanism whereby amantadine-like drugs dock in the channel with their ammonium moiety pointing toward the histidine residues and interacting with a nearby water cluster, as predicted by molecular dynamics simulations. We believe these findings have important implications for designing new anti-influenza drugs.

A morphometric investigation on breed-specific features affecting sagittal rotational and lateral bending mobility in the canine cervical spine (c3-c7).

Science.gov (United States)

Breit, S; Künzel, W

2004-08-01

Vertebral and inter-vertebral parameters obtained in large breeds (n = 74), small breeds (n = 35), and Dachshunds (n = 30) were compared to reveal potential differences in the range of motion of the cervical spine between these three groups of breeds. Body size normalized dimensions of vertebral and inter-vertebral parameters and correlations between these indicate large canine breeds to have a tendency towards higher range of motion in sagittal rotation and lateral bending compared with Dachshunds and small breeds. Higher mobility in large breeds is based on significantly (P inter-vertebral discs, wider but shorter cranial and caudal articular surfaces, larger differences in width between caudal and cranial joining facets (compared with Dachshunds from C3/4 to C6/7, compared with small breeds from C4/5 to C5/6), and larger differences in length between caudal and cranial joining facets. Large differences in width between caudal and cranial joining facets were associated with small distances between the most medial (C3/4 to C6/7) and lateral (C3/4 to C5/6) aspects of the articular surfaces as well as with small differences in length between caudal and cranial joining facets (C3/4 to C5/6). This suggests that from C3/4 to C5/6 a higher range of motion in lateral bending is coupled to a lower range of motion in sagittal rotation. The present findings contribute also to explain the higher incidence of degenerative lesions of the cervical spine in large dogs.

A Mobile Satellite Experiment (MSAT-X) network definition

Science.gov (United States)

Wang, Charles C.; Yan, Tsun-Yee

1990-01-01

The network architecture development of the Mobile Satellite Experiment (MSAT-X) project for the past few years is described. The results and findings of the network research activities carried out under the MSAT-X project are summarized. A framework is presented upon which the Mobile Satellite Systems (MSSs) operator can design a commercial network. A sample network configuration and its capability are also included under the projected scenario. The Communication Interconnection aspect of the MSAT-X network is discussed. In the MSAT-X network structure two basic protocols are presented: the channel access protocol, and the link connection protocol. The error-control techniques used in the MSAT-X project and the packet structure are also discussed. A description of two testbeds developed for experimentally simulating the channel access protocol and link control protocol, respectively, is presented. A sample network configuration and some future network activities of the MSAT-X project are also presented.

Long-term mobile phone use and acoustic neuroma risk.

Science.gov (United States)

Pettersson, David; Mathiesen, Tiit; Prochazka, Michaela; Bergenheim, Tommy; Florentzson, Rut; Harder, Henrik; Nyberg, Gunnar; Siesjö, Peter; Feychting, Maria

2014-03-01

There is concern about potential effects of radiofrequency fields generated by mobile phones on cancer risk. Most previous studies have found no association between mobile phone use and acoustic neuroma, although information about long-term use is limited. We conducted a population-based, nation-wide, case-control study of acoustic neuroma in Sweden. Eligible cases were persons aged 20 to 69 years, who were diagnosed between 2002 and 2007. Controls were randomly selected from the population registry, matched on age, sex, and residential area. Postal questionnaires were completed by 451 cases (83%) and 710 controls (65%). Ever having used mobile phones regularly (defined as weekly use for at least 6 months) was associated with an odds ratio (OR) of 1.18 (95% confidence interval = 0.88 to 1.59). The association was weaker for the longest induction time (≥10 years) (1.11 [0.76 to 1.61]) and for regular use on the tumor side (0.98 [0.68 to 1.43]). The OR for the highest quartile of cumulative calling time (≥680 hours) was 1.46 (0.98 to 2.17). Restricting analyses to histologically confirmed cases reduced all ORs; the OR for ≥680 hours was 1.14 (0.63 to 2.07). A similar pattern was seen for cordless land-line phones, although with slightly higher ORs. Analyses of the complete history of laterality of mobile phone revealed considerable bias in laterality analyses. The findings do not support the hypothesis that long-term mobile phone use increases the risk of acoustic neuroma. The study suggests that phone use might increase the likelihood that an acoustic neuroma case is detected and that there could be bias in the laterality analyses performed in previous studies.

Effects of Micromachining Processes on Electro-Osmotic Flow Mobility of Glass Surfaces

Directory of Open Access Journals (Sweden)

Norihisa Miki

2013-03-01

Full Text Available Silica glass is frequently used as a device material for micro/nano fluidic devices due to its excellent properties, such as transparency and chemical resistance. Wet etching by hydrofluoric acid and dry etching by neutral loop discharge (NLD plasma etching are currently used to micromachine glass to form micro/nano fluidic channels. Electro-osmotic flow (EOF is one of the most effective methods to drive liquids into the channels. EOF mobility is affected by a property of the micromachined glass surfaces, which includes surface roughness that is determined by the manufacturing processes. In this paper, we investigate the effect of micromaching processes on the glass surface topography and the EOF mobility. We prepared glass surfaces by either wet etching or by NLD plasma etching, investigated the surface topography using atomic force microscopy, and attempted to correlate it with EOF generated in the micro-channels of the machined glass. Experiments revealed that the EOF mobility strongly depends on the surface roughness, and therefore upon the fabrication process used. A particularly strong dependency was observed when the surface roughness was on the order of the electric double layer thickness or below. We believe that the correlation described in this paper can be of great help in the design of micro/nano fluidic devices.

Understanding Use Situated in Real-world Mobile Contexts

DEFF Research Database (Denmark)

Korn, Matthias

where the activity is happening) by leveraging three keyenablers: (1) the high penetration of smart phones, (2) their easy programmability and (3) the large-scale distribution channels for mobile applications that come with the platforms. My approach suggests a triggered response solicitation, which......  Our understanding of users' everyday practices in their natural contexts is still very limited. Insights are often only available from studies conducted outside of the context itself. I propose a new approach to study use situated in real-world everyday mobile contexts (at the time and place...

Prospects for the Use of Mobile Marketing Tools

Directory of Open Access Journals (Sweden)

Robert Stalmach

2011-07-01

Full Text Available Mobile marketing has some undeniable advantages over other communication channels, such as interactivity, location based services and impulsiveness (spontaneity. However, a cell phone and other mobile devices are treated by users as personal devices in relation to which they are reluctant to see the interference from outside. The challenge for the industry is therefore a good understanding of the restrictions associated with this form of communication. Factors specific to m-marketing include profile of the recipient, the context and motivations of the user in motion.

Tracking Human Mobility Using WiFi Signals

DEFF Research Database (Denmark)

Sapiezynski, Piotr; Stopczynski, Arkadiusz; Gatej, Radu

2015-01-01

We study six months of human mobility data, including WiFi and GPS traces recorded with high temporal resolution, and find that time series of WiFi scans contain a strong latent location signal. In fact, due to inherent stability and low entropy of human mobility, it is possible to assign location...... to WiFi access points based on a very small number of GPS samples and then use these access points as location beacons. Using just one GPS observation per day per person allows us to estimate the location of, and subsequently use, WiFi access points to account for 80% of mobility across a population....... These results reveal a great opportunity for using ubiquitous WiFi routers for high-resolution outdoor positioning, but also significant privacy implications of such side-channel location tracking....

Delivering Live Multimedia Streams to Mobile Hosts in a Wireless Internet with Multiple Content Aggregators

NARCIS (Netherlands)

Bianchi, G.; Hesselman, C.E.W.; Eertink, E.H.; Eertink, Henk; Kermani, P.; Lee, S.J.; Widya, I.A.; Huizer, E.

We consider the distribution of channels of live multimedia content (e.g., radio or TV broadcasts) via multiple content aggregators. In our work, an aggregator receives channels from content sources and redistributes them to a potentially large number of mobile hosts. Each aggregator can offer a

Genome-wide analysis of mechanosensitive channel of small ...

African Journals Online (AJOL)

Mechanosensitive (MS) ion channels are transmembrane proteins that open and close in response to mechanical forces produced by osmotic pressure, sound, touch and gravity. In plants, MS have an important role in different biological processes like gravity detection, maintenance of plastid shape and size, lateral root ...

Effect of Channel Thickness, Annealing Temperature and Channel Length on Nanoscale Ga2O3-In2O3-ZnO Thin Film Transistor Performance.

Science.gov (United States)

Kumaresan, Yogeenth; Pak, Yusin; Lim, Namsoo; Lee, Ryeri; Song, Hui; Kim, Tae Heon; Choi, Boran; Jung, Gun Young

2016-06-01

We demonstrated the effect of active layer (channel) thickness and annealing temperature on the electrical performances of Ga2O3-In2O3-ZnO (GIZO) thin film transistor (TFT) having nanoscale channel width (W/L: 500 nm/100 μm). We found that the electron carrier concentration of the channel was decreased significantly with increasing the annealing temperature (100 degrees C to 300 degrees C). Accordingly, the threshold voltage (V(T)) was shifted towards positive voltage (-12.2 V to 10.8 V). In case of channel thickness, the V(T) was shifted towards negative voltage with increasing the channel thickness. The device with channel thickness of 90 nm annealed at 200 degrees C revealed the best device performances in terms of mobility (10.86 cm2/Vs) and V(T) (0.8 V). The effect of channel length was also studied, in which the channel width, thickness and annealing temperature were kept constant such as 500 nm, 90 nm and 200 degrees C, respectively. The channel length influenced the on-current level significantly with small variation of V(T), resulting in lower value of on/off current ratio with increasing the channel length. The device with channel length of 0.5 μm showed enhanced on/off current ratio of 10(6) with minimum V(T) of 0.26 V.

Protecting Touch: Authenticated App-To-Server Channels for Mobile Devices Using NFC Tags

Directory of Open Access Journals (Sweden)

Fernando Kaway Carvalho Ota

2017-07-01

Full Text Available Traditional authentication methods (e.g., password, PIN often do not scale well to the context of mobile devices in terms of security and usability. However, the adoption of Near Field Communication (NFC on a broad range of smartphones enables the use of NFC-enabled tokens as an additional authentication factor. This additional factor can help to improve the security, as well as usability of mobile apps. In this paper, we evaluate the use of different types of existing NFC tags as tokens for establishing authenticated secure sessions between smartphone apps and web services. Based on this evaluation, we present two concepts for a user-friendly secure authentication mechanism for mobile apps, the Protecting Touch (PT architectures. These two architectures are designed to be implemented with either end of the spectrum of inexpensive and widely-available NFC tags while maintaining a reasonable trade-off between security, availability and cost.

Evaluation efficiency for mobile as discharge measurement device for partially filled circular channel

Directory of Open Access Journals (Sweden)

I.M.H. Rashwan

2013-06-01

Full Text Available Discharge measurement is an important step in engineering applications such as sewerage system, irrigation and drainage system. Mobile flume is a simple and low-cost discharge measuring device constructed of two pieces of pipes, one installed vertically inside the other. The circular mobile flume depends on the concept of developing a contracted zone to have a control section. To evaluate the efficiency of this type of device mathematical and experimental studies are presented. Specific energy, discharge and Froude number equations are used to develop mathematical model. Experimental work is carried out to measure the discharge values corresponding to the specific energy values. The experimental data is used to evaluate the mobile flume as a device to measure discharge. A new equation for the discharge coefficient is presented. This equation can be used to determined accurate discharge with knowing the contraction ratio and measured specific energy.

Optimal channel utilization and service protection in cellular communication systems

DEFF Research Database (Denmark)

Iversen, Villy Bæk

1997-01-01

In mobile communications an efficient utilization of the channels is of great importance.In this paper we consider the basic principles for obtaining the maximum utilization, and we study strategies for obtaining these limits.In general a high degree of sharing is efficient, but requires service...... protection mechanisms for protecting services and subscriber groups.We study cellular systems with overlaid cells, and the effect of overlapping cells, and we show that by dynamic channel allocation we obtain a high utilization.The models are generalizations of the Erlang-B formula, and can be evaluated...

RoCoMAR: Robots' Controllable Mobility Aided Routing and Relay Architecture for Mobile Sensor Networks

Science.gov (United States)

Van Le, Duc; Oh, Hoon; Yoon, Seokhoon

2013-01-01

In a practical deployment, mobile sensor network (MSN) suffers from a low performance due to high node mobility, time-varying wireless channel properties, and obstacles between communicating nodes. In order to tackle the problem of low network performance and provide a desired end-to-end data transfer quality, in this paper we propose a novel ad hoc routing and relaying architecture, namely RoCoMAR (Robots' Controllable Mobility Aided Routing) that uses robotic nodes' controllable mobility. RoCoMAR repeatedly performs link reinforcement process with the objective of maximizing the network throughput, in which the link with the lowest quality on the path is identified and replaced with high quality links by placing a robotic node as a relay at an optimal position. The robotic node resigns as a relay if the objective is achieved or no more gain can be obtained with a new relay. Once placed as a relay, the robotic node performs adaptive link maintenance by adjusting its position according to the movements of regular nodes. The simulation results show that RoCoMAR outperforms existing ad hoc routing protocols for MSN in terms of network throughput and end-to-end delay. PMID:23881134

RoCoMAR: Robots’ Controllable Mobility Aided Routing and Relay Architecture for Mobile Sensor Networks

Directory of Open Access Journals (Sweden)

Seokhoon Yoon

2013-07-01

Full Text Available In a practical deployment, mobile sensor network (MSN suffers from a low performance due to high node mobility, time-varying wireless channel properties, and obstacles between communicating nodes. In order to tackle the problem of low network performance and provide a desired end-to-end data transfer quality, in this paper we propose a novel ad hoc routing and relaying architecture, namely RoCoMAR (Robots’ Controllable Mobility Aided Routing that uses robotic nodes’ controllable mobility. RoCoMAR repeatedly performs link reinforcement process with the objective of maximizing the network throughput, in which the link with the lowest quality on the path is identified and replaced with high quality links by placing a robotic node as a relay at an optimal position. The robotic node resigns as a relay if the objective is achieved or no more gain can be obtained with a new relay. Once placed as a relay, the robotic node performs adaptive link maintenance by adjusting its position according to the movements of regular nodes. The simulation results show that RoCoMAR outperforms existing ad hoc routing protocols for MSN in terms of network throughput and end-to-end delay.

Reconfigurable mobile manipulation for accident response

International Nuclear Information System (INIS)

Anderson, Robert J.; Morse, William D.; Shirey, David L.; Cdebaca, DanielL M.; Hoffman, John P. Jr.; Lucy, William E.

2000-01-01

The need for a telerobotic vehicle with hazard sensing and integral manipulation capabilities has been identified for use in transportation accidents where nuclear weapons are involved. The Accident Response Mobile Manipulation System (ARMMS) platform has been developed to provide remote dexterous manipulation and hazard sensing for the Accident Response Group (ARG) at Sandia National Laboratories. The ARMMS' mobility platform is a military HMMWV [High Mobility Multipurpose Wheeled Vehicle] that is teleoperated over RF or Fiber Optic communication channels. ARMMS is equipped with two high strength Schilling Titan II manipulators and a suite of hazardous gas and radiation sensors. Recently, a modular telerobotic control architecture call SMART (Sandia Modular Architecture for Robotic and Teleoperation) has been applied to ARMMS. SMART enables input devices and many system behaviors to be rapidly configured in the field for specific mission needs. This paper summarizes current SMART developments applied to ARMMS

The key drivers and barriers to the use of Mobile Payments from consumer's perspective

OpenAIRE

Sunna, Shadi

2013-01-01

The nearly ubiquitous presence and the continually expanding capabilities of the mobile devices as well as the evolution of the smartphones provide an additional channel for payments, improve the shopping experience and present cutting-edge opportunities for merchants to involve consumers, and drive sales. Despite the positive prediction in past years in relation to the growth, mobile payment services have failed to seduce consumers. The problem of the mass adoption of mobile payments in gene...

Blind cooperative diversity using distributed space-time coding in block fading channels

KAUST Repository

Tourki, Kamel; Alouini, Mohamed-Slim; Deneire, Luc

2010-01-01

Mobile users with single antennas can still take advantage of spatial diversity through cooperative space-time encoded transmission. In this paper, we consider a scheme in which a relay chooses to cooperate only if its source-relay channel

Ultra-short channel GaN high electron mobility transistor-like Gunn diode with composite contact

Energy Technology Data Exchange (ETDEWEB)

Wang, Ying; Yang, Lin' an, E-mail: layang@xidian.edu.cn; Wang, Zhizhe; Chen, Qing; Huang, Yonghong; Dai, Yang; Chen, Haoran; Zhao, Hongliang; Hao, Yue [The State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi' an 710071 (China)

2014-09-07

We present a numerical analysis on an ultra-short channel AlGaN/GaN HEMT-like planar Gunn diode based on the velocity-field dependence of two-dimensional electron gas (2-DEG) channel accounting for the ballistic electron acceleration and the inter-valley transfer. In particular, we propose a Schottky-ohmic composite contact instead of traditional ohmic contact for the Gunn diode in order to significantly suppress the impact ionization at the anode side and shorten the “dead zone” at the cathode side, which is beneficial to the formation and propagation of dipole domain in the ultra-short 2-DEG channel and the promotion of conversion efficiency. The influence of the surface donor-like traps on the electron domain in the 2-DEG channel is also included in the simulation.

Can coarse surface layers in gravel-bedded rivers be mobilized by finer gravel bedload?

Science.gov (United States)

Venditti, J. G.; Dietrich, W. E.; Nelson, P. A.; Wydzga, M. A.; Fadde, J.; Sklar, L.

2005-12-01

In response to reductions in sediment supply, gravel-bed rivers undergo a coarsening of the sediments that comprise the river's bed and, over some longer time scale, a river's grade may also be reduced as sediments are depleted from upstream reaches. Coarse, degraded river reaches are commonly observed downstream of dams across the Western United States. Following dam closure, these riverbeds become immobile under the altered flow and sediment supply regimes, leading to a reduction in the available salmon spawning and rearing habitat. Gravel augmentation to these streams is now common practice. This augmentation is typically seen as resurfacing the static coarse bed. As an alternative, we propose that the addition of appropriately finer gravels to these channels may be capable of mobilizing an otherwise immobile coarse surface layer, creating the potential to release fine material trapped beneath the surface. A series of laboratory experiments are being undertaken to test this hypothesis in a 30 m long and 0.86 m wide gravel-bedded flume channel using a constant discharge and a unimodal bed sediment with a median grain size of 8 mm and no sand present. The channel width-to-depth ratio of ~4 suppresses the development of lateral topography and allows us to focus on grain-to-grain interactions. Experiments proceed by maintaining a constant sediment feed until an equilibrium grade and transport rate are established, starving the flume of sediment for at least 24 hours, and then adding narrowly graded gravel over a period of one to two hours at a rate that is ~4x the bedload rate observed prior to terminating the sediment supply. The bed prior to sediment addition has an armor median grain size that is typically twice that of the subsurface and feed size distribution. The volume and median grain size of the resulting pulses are varied. Pulses move downstream rapidly with well-defined fronts in the form of bedload sheets and cause peaks in the sediment flux

Limited mobility of dioxins near San Jacinto super fund site (waste pit) in the Houston Ship Channel, Texas due to strong sediment sorption.

Science.gov (United States)

Louchouarn, Patrick; Seward, Shaya M; Cornelissen, Gerard; Arp, Hans Peter H; Yeager, Kevin M; Brinkmeyer, Robin; Santschi, Peter H

2018-02-20

Sediments from a waste pit in Houston Ship Channel (HSC) were characterized using a number of molecular markers of natural organic matter fractions (e.g., pyrogenic carbon residues, PAHs, lignins), in addition to dioxins, in order to test the hypothesis that the dispersal and mobility of dioxins from the waste pit in the San Jacinto River is minimal. Station SG-6, sampled at the site of the submerged waste pit, had the highest dioxin/furan concentrations reported for the Houston Ship Channel/Galveston Bay (HSC/GB) system (10,000-46,000 pg/g), which translated into some of the highest reported World Health Organization Toxic Equivalents (TEQs: 2000-11,000 pg/g) in HSC sediments. Using a multi-tracer approach, this study confirmed our hypothesis that sludges from chlorinated pulps are a very likely source of dioxins/furans to this pit. However, this material also contained large quantities of additional hydrophobic organic contaminants (PAHs) and pyrogenic markers (soot-BC, levoglucosan), pointing to the co-occurrence of petroleum hydrocarbons and combustion byproducts. Comparison of dioxin/furan signatures in the waste pit with those from sediments of the HSC and a control site suggests that the remobilization of contaminated particles did not occur beyond the close vicinity of the pit itself. The dioxins/furans in sediments outside the waste pit within the HSC are rather from other diffuse inputs, entering the sedimentary environment through the air and water, and which are comprised of a mixture of industrial and municipal sources. Fingerprinting of waste pit dioxins indicates that their composition is typical of pulp and paper sources. Measured pore water concentrations were 1 order of magnitude lower than estimated values, calculated from a multiphase sorption model, indicating low mobility of dioxins within the waste pit. This is likely accomplished by co-occurring and strong sorbing pyrogenic and petrogenic residues in the waste pit, which tend to keep

Transfer Error and Correction Approach in Mobile Network

Science.gov (United States)

Xiao-kai, Wu; Yong-jin, Shi; Da-jin, Chen; Bing-he, Ma; Qi-li, Zhou

With the development of information technology and social progress, human demand for information has become increasingly diverse, wherever and whenever people want to be able to easily, quickly and flexibly via voice, data, images and video and other means to communicate. Visual information to the people direct and vivid image, image / video transmission also been widespread attention. Although the third generation mobile communication systems and the emergence and rapid development of IP networks, making video communications is becoming the main business of the wireless communications, however, the actual wireless and IP channel will lead to error generation, such as: wireless channel multi- fading channels generated error and blocking IP packet loss and so on. Due to channel bandwidth limitations, the video communication compression coding of data is often beyond the data, and compress data after the error is very sensitive to error conditions caused a serious decline in image quality.

Channel and island change in the lower Platte River, Eastern Nebraska, USA: 1855 2005

Science.gov (United States)

Joeckel, R. M.; Henebry, G. M.

2008-12-01

The lower Platte River has undergone considerable change in channel and bar characteristics since the mid-1850s in four 20-25 km-long study stretches. The same net effect of historical channel shrinkage that was detected upstream from Grand Island, Nebraska, can also be detected in the lower river but differences in the behaviors of study stretches upstream and downstream from major tributaries are striking. The least relative decrease occurred downstream from the Loup River confluence, and the stretch downstream from the Elkhorn River confluence actually showed an increase in channel area during the 1940s. Bank erosion was also greater downstream of the tributaries between ca. 1860 and 1938/1941, particularly in stretch RG, which showed more lateral migration. The cumulative island area and the ratio of island area to channel area relative to the 1938/1941 baseline data showed comparatively great fluctuations in median island size in both downstream stretches. The erratic behavior of island size distributions over time indicates that large islands were accreted to the banks at different times, and that some small, newly-stabilized islands were episodically "flushed" out of the system. In the upstream stretches the stabilization of mobile bars to create new, small islands had a more consistent impact over time. Channel decrease by the abandonment of large, long-lived anabranches and by the in-place narrowing resulting from island accretion were more prominent in these upstream stretches. Across all of the study area, channel area appears to be stabilizing gradually as the rate of decrease lessens. This trend began earliest in stretch RG in the late 1950s and was accompanied by shifts in the size distributions of stabilized islands in that stretch into the 1960s. Elsewhere, even in the easternmost study stretch, stabilizing was occurring by the late 1960s, the same time frame documented by investigations of the Platte system upstream of the study area. Comprehensive

Seismic patterns and migration history of submarine fan channels in deep-water area, Niger Delta, West Africa

Science.gov (United States)

Zhang, Guotao; Zhang, Shangfeng; Li, Yuan

2015-04-01

The channels of deep-water submarine fan under Niger delta slope are characterized by large dimensions special deposition positions and complex formation processes, its geographical location and sedimentary environment also hinder the research and exploration development. According to the strata slicing, RMS amplitude attribute and other techniques, we exhibit the platforms patterns of channels at different period, and based on the analysis of internal architecture and deformation history of channel-leveed systems, migration and evolution process of channel systems could be understood accurately. A great quantity of isolated channels develop in middle Miocene and aggrading streams in late Miocene, which generating because of large scale of turbidity caused by the drop of second order sea-level, which characterized by vertical accretion at smooth channel, while vertical accretion and lateral migration at bend. Evolution of channel systems can be divided into three stages: the initial erosion, erosion and filling alternately, and abandoned stage. With these three stages, the sinuosity of channel change from moderate to high, then decrease. Incision and filling of channels, being during the three development phases, is the driving force of meander-loops migration, which promote three kinds of migration patterns: lateral, down-system and combination migration. The research provides theoretical basis for high-precision prediction and evaluation of deep-water reservoir.

Understanding the conductive channel evolution in Na:WO(3-x)-based planar devices.

Science.gov (United States)

Shang, Dashan; Li, Peining; Wang, Tao; Carria, Egidio; Sun, Jirong; Shen, Baogen; Taubner, Thomas; Valov, Ilia; Waser, Rainer; Wuttig, Matthias

2015-04-14

An ion migration process in a solid electrolyte is important for ion-based functional devices, such as fuel cells, batteries, electrochromics, gas sensors, and resistive switching systems. In this study, a planar sandwich structure is prepared by depositing tungsten oxide (WO(3-x)) films on a soda-lime glass substrate, from which Na(+) diffuses into the WO(3-x) films during the deposition. The entire process of Na(+) migration driven by an alternating electric field is visualized in the Na-doped WO(3-x) films in the form of conductive channel by in situ optical imaging combined with infrared spectroscopy and near-field imaging techniques. A reversible change of geometry between a parabolic and a bar channel is observed with the resistance change of the devices. The peculiar channel evolution is interpreted by a thermal-stress-induced mechanical deformation of the films and an asymmetric Na(+) mobility between the parabolic and the bar channels. These results exemplify a typical ion migration process driven by an alternating electric field in a solid electrolyte with a low ion mobility and are expected to be beneficial to improve the controllability of the ion migration in ion-based functional devices, such as resistive switching devices.

Tonoplast aquaporins facilitate lateral root emergence

DEFF Research Database (Denmark)

Reinhardt, Hagen; Hachez, Charles; Bienert, Manuela Désirée

2016-01-01

Aquaporins (AQPs) are water channels allowing fast and passive diffusion of water across cell membranes. It was hypothesized that AQPs contribute to cell elongation processes by allowing water influx across the plasma membrane and the tonoplast to maintain adequate turgor pressure. Here, we report...... mutants showed no or minor reduction in growth of the main root. This phenotype was due to the retardation of LRP emergence. Live cell imaging revealed that tight spatiotemporal control of TIP abundance in the tonoplast of the different LRP cells is pivotal to mediating this developmental process. While...... lateral root emergence is correlated to a reduction of AtTIP1;1 and AtTIP1;2 protein levels in LRPs, expression of AtTIP2;1 is specifically needed in a restricted cell population at the base, then later at the flanks, of developing LRPs. Interestingly, the LRP emergence phenotype of the triple tip mutants...

Imaging an optogenetic pH sensor reveals that protons mediate lateral inhibition in the retina.

Science.gov (United States)

Wang, Tzu-Ming; Holzhausen, Lars C; Kramer, Richard H

2014-02-01

The reciprocal synapse between photoreceptors and horizontal cells underlies lateral inhibition and establishes the antagonistic center-surround receptive fields of retinal neurons to enhance visual contrast. Despite decades of study, the signal mediating the negative feedback from horizontal cells to cones has remained under debate because the small, invaginated synaptic cleft has precluded measurement. Using zebrafish retinas, we show that light elicits a change in synaptic proton concentration with the correct magnitude, kinetics and spatial dependence to account for lateral inhibition. Light, which hyperpolarizes horizontal cells, causes synaptic alkalinization, whereas activating an exogenously expressed ligand-gated Na(+) channel, which depolarizes horizontal cells, causes synaptic acidification. Whereas acidification was prevented by blocking a proton pump, re-alkalinization was prevented by blocking proton-permeant ion channels, suggesting that distinct mechanisms underlie proton efflux and influx. These findings reveal that protons mediate lateral inhibition in the retina, raising the possibility that protons are unrecognized retrograde messengers elsewhere in the nervous system.

Design of a hybrid command and control mobile botnet: Presentation

CSIR Research Space (South Africa)

Pieterse, H

2013-03-01

Full Text Available smartphones controlled by a botmaster through a command and control network to serve a malicious purpose. This study presents the design of a hybrid command and control mobile botnet. It describes the propagation vectors, command and control channels...

PROXY-BASED PATCHING STREAM TRANSMISSION STRATEGY IN MOBILE STREAMING MEDIA SYSTEM

Institute of Scientific and Technical Information of China (English)

Liao Jianxin; Lei Zhengxiong; Ma Xutao; Zhu Xiaomin

2006-01-01

A mobile transmission strategy, PMPatching (Proxy-based Mobile Patching) transmission strategy is proposed, it applies to the proxy-based mobile streaming media system in Wideband Code Division Multiple Access (WCDMA) network. Performance of the whole system can be improved by using patching stream to transmit anterior part of the suffix that had been played back, and by batching all the demands for the suffix arrived in prefix period and patching stream transmission threshold period. Experimental results show that this strategy can efficiently reduce average network transmission cost and number of channels consumed in central streaming media server.

Uranium in tertiary stream channels, Lake Frome area, South Australia

International Nuclear Information System (INIS)

Brunt, D.A.

1978-01-01

Uranium exploration over a wide area of the Southern Frome Embayment, South Australia, has defined a number of Lower Tertiary fluvial palacochannels incised in older rocks. The buried channels contain similar stratigraphic sequences of interbedded sand, silt, and clay, probably derived from the adjacent uranium-rich Olary Province. Uranium mineralization is pervasive within two major palacochannels, and four small uranium deposits have been found in the basal sands of these channel sequences, at the margins of extensive tongues of limonitic sand. A genetic model is proposed suggesting formation by a uraniferous geochemical cell which migrated down the stream gradient and concentrated uranium on its lateral margins adjacent to the channel bank

Mobility Modification Alleviates Environmental Influence on Incident Mobility Difficulty among Community-Dwelling Older People: A Two-Year Follow-Up Study

Science.gov (United States)

Portegijs, Erja; Viljanen, Anne; Iwarsson, Susanne; Rantanen, Taina

2016-01-01

Background Environmental barriers increase risk for mobility difficulties in old age. Mobility difficulty is preceded by a phase where people try to postpone a difficulty through mobility modification. We studied whether perceived environmental mobility barriers outdoors correlate with mobility modification and mobility difficulty, predict development of mobility difficulty over a two-year follow-up, and whether mobility modification alleviates the risk for difficulty. Methods At baseline, 848 people aged 75–90 were interviewed face-to-face. Telephone follow-up interviews were conducted one (n = 816) and two years (n = 761) later. Environmental barriers to mobility were self-reported using a15-item structured questionnaire at baseline, summed and divided into tertiles (0, 1 and 2 or more barriers). Mobility difficulty was assessed as self-reported ability to walk 2 km at all assessment points and categorized into ‘no difficulty’, ‘no difficulty but mobility modifications’ (reducing frequency, stopping walking, using an aid, slowing down or resting during the performance) and ‘difficulty’. Results At baseline, 212 participants reported mobility modifications and 356 mobility difficulties. Those reporting one or multiple environmental barriers had twice the odds for mobility modifications and up to five times the odds for mobility difficulty compared to those reporting no environmental barriers. After multiple adjustments for health and functioning, reporting multiple environmental barriers outdoors continued to predict the development of incident mobility difficulty over the two-year follow-up. Mobility modifications attenuated the association. Conclusion For older people who successfully modify their performance, environmental influence on incident mobility difficulty can be diminished. Older people use mobility modification to alleviate environmental press on mobility. PMID:27104750

Emulation Based Performance Investigation of FTP File Downloads over UMTS Dedicated Channels

DEFF Research Database (Denmark)

Teyeb, Oumer; Boussif, Malek; Sørensen, Troels Bundgaard

2005-01-01

The Radio Link Control (RLC) protocol of Universal Mobile Telecommunication System (UMTS) provides a link layer reliability that could mitigate the effects of the hostile radio propagation channel on packet data transmission. The RLC standard provides several mechanisms and associated parameters ...

Branding and Channel Issues in E-commerce from an Information System’s Perspective

OpenAIRE

Hansen, Rina; Tambo, Torben

2011-01-01

E-commerce has matured and become mainstream. The fashion industry is now competing strongly in the digital markets. Beside traditional web-shops, new sales and branding channels are emerging e.g. M-commerce (mobile); social commerce; marketplaces; gaming etc. E-commerce and multi-channel retailing (MCR) now have a less technology-centric perspective while focusing more on sales and branding, although technology is the carrier and imposes limits. Corporate information systems are extended to ...

Development of eStudent iOS mobile application

Directory of Open Access Journals (Sweden)

Mladjan Antic

2013-01-01

Full Text Available Abstract— iOS is the Apple mobile operating system, for Apple mobile devices. Initially developed for iPhone, and later for iPod Touch, iPad, AppleTV. The Metropolitan University has a Web application titled eStudent, which enables students by Web to get information about their marks for all subjects, their financies, exam scheduling, professors and assistents, and send exam registration and feedback about teaching, etc. This paper explains the development of the mobile application eStudent on the iOS platform. This application enables students whenever they want, by using their iPhone mobile phone, to get access to the information from the eStudent Web application, and to present it on their iPhone User Interface (UI. This paper explains in details software requirements analysis, system architecture, system modelling, and UI of the eStudent iOS mobile application.

LDPC Decoding on GPU for Mobile Device

Directory of Open Access Journals (Sweden)

Yiqin Lu

2016-01-01

Full Text Available A flexible software LDPC decoder that exploits data parallelism for simultaneous multicode words decoding on the mobile device is proposed in this paper, supported by multithreading on OpenCL based graphics processing units. By dividing the check matrix into several parts to make full use of both the local memory and private memory on GPU and properly modify the code capacity each time, our implementation on a mobile phone shows throughputs above 100 Mbps and delay is less than 1.6 millisecond in decoding, which make high-speed communication like video calling possible. To realize efficient software LDPC decoding on the mobile device, the LDPC decoding feature on communication baseband chip should be replaced to save the cost and make it easier to upgrade decoder to be compatible with a variety of channel access schemes.

A communication theoretical analysis of FRET-based mobile ad hoc molecular nanonetworks.

Science.gov (United States)

Kuscu, Murat; Akan, Ozgur B

2014-09-01

Nanonetworks refer to a group of nanosized machines with very basic operational capabilities communicating to each other in order to accomplish more complex tasks such as in-body drug delivery, or chemical defense. Realizing reliable and high-rate communication between these nanomachines is a fundamental problem for the practicality of these nanonetworks. Recently, we have proposed a molecular communication method based on Förster Resonance Energy Transfer (FRET) which is a nonradiative excited state energy transfer phenomenon observed among fluorescent molecules, i.e., fluorophores. We have modeled the FRET-based communication channel considering the fluorophores as single-molecular immobile nanomachines, and shown its reliability at high rates, and practicality at the current stage of nanotechnology. In this study, for the first time in the literature, we investigate the network of mobile nanomachines communicating through FRET. We introduce two novel mobile molecular nanonetworks: FRET-based mobile molecular sensor/actor nanonetwork (FRET-MSAN) which is a distributed system of mobile fluorophores acting as sensor or actor node; and FRET-based mobile ad hoc molecular nanonetwork (FRET-MAMNET) which consists of fluorophore-based nanotransmitter, nanoreceivers and nanorelays. We model the single message propagation based on birth-death processes with continuous time Markov chains. We evaluate the performance of FRET-MSAN and FRET-MAMNET in terms of successful transmission probability and mean extinction time of the messages, system throughput, channel capacity and achievable communication rates.

Low-voltage back-gated atmospheric pressure chemical vapor deposition based graphene-striped channel transistor with high-κ dielectric showing room-temperature mobility > 11 000 cm2/V·s

KAUST Repository

Smith, Casey; Qaisi, Ramy M.; Liu, Zhihong; Yu, Qingkai; Hussain, Muhammad Mustafa

2013-01-01

Utilization of graphene may help realize innovative low-power replacements for III-V materials based high electron mobility transistors while extending operational frequencies closer to the THz regime for superior wireless communications, imaging, and other novel applications. Device architectures explored to date suffer a fundamental performance roadblock due to lack of compatible deposition techniques for nanometer-scale dielectrics required to efficiently modulate graphene transconductance (gm) while maintaining low gate capacitance-voltage product (CgsVgs). Here we show integration of a scaled (10 nm) high-κ gate dielectric aluminum oxide (Al2O3) with an atmospheric pressure chemical vapor deposition (APCVD)-derived graphene channel composed of multiple 0.25 μm stripes to repeatedly realize room-temperature mobility of 11 000 cm 2/V·s or higher. This high performance is attributed to the APCVD graphene growth quality, excellent interfacial properties of the gate dielectric, conductivity enhancement in the graphene stripes due to low t ox/Wgraphene ratio, and scaled high-κ dielectric gate modulation of carrier density allowing full actuation of the device with only ±1 V applied bias. The superior drive current and conductance at Vdd = 1 V compared to other top-gated devices requiring undesirable seed (such as aluminum and poly vinyl alcohol)-assisted dielectric deposition, bottom gate devices requiring excessive gate voltage for actuation, or monolithic (nonstriped) channels suggest that this facile transistor structure provides critical insight toward future device design and process integration to maximize CVD-based graphene transistor performance. © 2013 American Chemical Society.

Low-voltage back-gated atmospheric pressure chemical vapor deposition based graphene-striped channel transistor with high-κ dielectric showing room-temperature mobility > 11 000 cm2/V·s

KAUST Repository

Smith, Casey

2013-07-23

Utilization of graphene may help realize innovative low-power replacements for III-V materials based high electron mobility transistors while extending operational frequencies closer to the THz regime for superior wireless communications, imaging, and other novel applications. Device architectures explored to date suffer a fundamental performance roadblock due to lack of compatible deposition techniques for nanometer-scale dielectrics required to efficiently modulate graphene transconductance (gm) while maintaining low gate capacitance-voltage product (CgsVgs). Here we show integration of a scaled (10 nm) high-κ gate dielectric aluminum oxide (Al2O3) with an atmospheric pressure chemical vapor deposition (APCVD)-derived graphene channel composed of multiple 0.25 μm stripes to repeatedly realize room-temperature mobility of 11 000 cm 2/V·s or higher. This high performance is attributed to the APCVD graphene growth quality, excellent interfacial properties of the gate dielectric, conductivity enhancement in the graphene stripes due to low t ox/Wgraphene ratio, and scaled high-κ dielectric gate modulation of carrier density allowing full actuation of the device with only ±1 V applied bias. The superior drive current and conductance at Vdd = 1 V compared to other top-gated devices requiring undesirable seed (such as aluminum and poly vinyl alcohol)-assisted dielectric deposition, bottom gate devices requiring excessive gate voltage for actuation, or monolithic (nonstriped) channels suggest that this facile transistor structure provides critical insight toward future device design and process integration to maximize CVD-based graphene transistor performance. © 2013 American Chemical Society.

Differential distribution of the sodium‐activated potassium channels slick and slack in mouse brain

Science.gov (United States)

Knaus, Hans‐Günther; Schwarzer, Christoph

2015-01-01

ABSTRACT The sodium‐activated potassium channels Slick (Slo2.1, KCNT2) and Slack (Slo2.2, KCNT1) are high‐conductance potassium channels of the Slo family. In neurons, Slick and Slack channels are involved in the generation of slow afterhyperpolarization, in the regulation of firing patterns, and in setting and stabilizing the resting membrane potential. The distribution and subcellular localization of Slick and Slack channels in the mouse brain have not yet been established in detail. The present study addresses this issue through in situ hybridization and immunohistochemistry. Both channels were widely distributed and exhibited distinct distribution patterns. However, in some brain regions, their expression overlapped. Intense Slick channel immunoreactivity was observed in processes, varicosities, and neuronal cell bodies of the olfactory bulb, granular zones of cortical regions, hippocampus, amygdala, lateral septal nuclei, certain hypothalamic and midbrain nuclei, and several regions of the brainstem. The Slack channel showed primarily a diffuse immunostaining pattern, and labeling of cell somata and processes was observed only occasionally. The highest Slack channel expression was detected in the olfactory bulb, lateral septal nuclei, basal ganglia, and distinct areas of the midbrain, brainstem, and cerebellar cortex. In addition, comparing our data obtained from mouse brain with a previously published study on rat brain revealed some differences in the expression and distribution of Slick and Slack channels in these species. J. Comp. Neurol. 524:2093–2116, 2016. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc. PMID:26587966

Differential distribution of the sodium-activated potassium channels slick and slack in mouse brain.

Science.gov (United States)

Rizzi, Sandra; Knaus, Hans-Günther; Schwarzer, Christoph

2016-07-01

The sodium-activated potassium channels Slick (Slo2.1, KCNT2) and Slack (Slo2.2, KCNT1) are high-conductance potassium channels of the Slo family. In neurons, Slick and Slack channels are involved in the generation of slow afterhyperpolarization, in the regulation of firing patterns, and in setting and stabilizing the resting membrane potential. The distribution and subcellular localization of Slick and Slack channels in the mouse brain have not yet been established in detail. The present study addresses this issue through in situ hybridization and immunohistochemistry. Both channels were widely distributed and exhibited distinct distribution patterns. However, in some brain regions, their expression overlapped. Intense Slick channel immunoreactivity was observed in processes, varicosities, and neuronal cell bodies of the olfactory bulb, granular zones of cortical regions, hippocampus, amygdala, lateral septal nuclei, certain hypothalamic and midbrain nuclei, and several regions of the brainstem. The Slack channel showed primarily a diffuse immunostaining pattern, and labeling of cell somata and processes was observed only occasionally. The highest Slack channel expression was detected in the olfactory bulb, lateral septal nuclei, basal ganglia, and distinct areas of the midbrain, brainstem, and cerebellar cortex. In addition, comparing our data obtained from mouse brain with a previously published study on rat brain revealed some differences in the expression and distribution of Slick and Slack channels in these species. J. Comp. Neurol. 524:2093-2116, 2016. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.

Sequential grouping constraints on across-channel auditory processing

DEFF Research Database (Denmark)

Oxenham, Andrew J.; Dau, Torsten

2005-01-01

Søren Buus was one of the pioneers in the study of across-channel auditory processing. His influential 1985 paper showed that introducing slow fluctuations to a low-frequency masker could reduce the detection thresholds of a high-frequency signal by as much as 25 dB [S. Buus, J. Acoust. Soc. Am. 78......, 1958–1965 (1985)]. Søren explained this surprising result in terms of the spread of masker excitation and across-channel processing of envelope fluctuations. A later study [S. Buus and C. Pan, J. Acoust. Soc. Am. 96, 1445–1457 (1994)] pioneered the use of the same stimuli in tasks where across......-channel processing could either help or hinder performance. In the present set of studies we also use paradigms in which across-channel processing can lead to either improvement or deterioration in performance. We show that sequential grouping constraints can affect both types of paradigm. In particular...

Probing channel temperature profiles in Al{sub x}Ga{sub 1−x}N/GaN high electron mobility transistors on 200 mm diameter Si(111) by optical spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Kyaw, L. M., E-mail: a0048661@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology, and Research), Singapore 117602 (Singapore); Bera, L. K.; Dolmanan, S. B.; Tan, H. R.; Bhat, T. N.; Tripathy, S., E-mail: tripathy-sudhiranjan@imre.a-star.edu.sg [Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology, and Research), Singapore 117602 (Singapore); Liu, Y.; Bera, M. K.; Singh, S. P.; Chor, E. F. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore)

2014-08-18

Using micro-Raman and photoluminescence (PL) techniques, the channel temperature profile is probed in Al{sub x}Ga{sub 1-x}N/GaN high electron mobility transistors (HEMTs) fabricated on a 200 mm diameter Si(111) substrate. In particular, RuO{sub x}-based gate is used due to the semitransparent nature to the optical excitation wavelengths, thus allowing much accurate thermal investigations underneath the gate. To determine the channel temperature profile in devices subjected to different electrical bias voltages, the GaN band-edge PL peak shift calibration with respect to temperature is used. PL analyses show a maximum channel temperature up to 435 K underneath the gate edge between gate and drain, where the estimated thermal resistance in such a HEMT structure is about 13.7 KmmW{sup −1} at a power dissipation of ∼10 W/mm. The temperature profiles from micro-Raman measurements are also addressed from the E{sub 2}-high optical phonon peak shift of GaN, and this method also probes the temperature-induced peak shifts of optical phonon from Si thus showing the nature of thermal characteristics at the AlN/Si substrate interface.

Dynamic Location and Forwarding Pointers for Mobility Management

Directory of Open Access Journals (Sweden)

Charles Abondo

2005-01-01

Full Text Available GSM and IS-41 are two mobility management standards widely used in second generation networks. These two standards lean on a centralized architecture made up of home location registers (HLRs and visitor location registers (VLRs. From these standards, the location update and search procedures always imply interrogation of the HLR, even if the two mobile terminals that want to communicate are in the same location area. Given the limited bandwidth of the radio operator channel and the new time sensitive applications of third-generation systems, such an approach of mobility management is not convenient for the next generation mobile networks. This paper proposes a method for reducing the processing load and the signalization traffic generated by update and search location procedures compared to IS-41 standard. Taking into account the specific characteristics of the traffic in the mobile networks, it introduces a semi-dynamic approach based on a hybrid architecture using forwarding pointers without the load related to the dynamic models. Numerical results show that such a method significantly improves the efficiency of location procedures.

Why is CDMA the solution for mobile satellite communication

Science.gov (United States)

Gilhousen, Klein S.; Jacobs, Irwin M.; Padovani, Roberto; Weaver, Lindsay A.

1989-01-01

It is demonstrated that spread spectrum Code Division Multiple Access (CDMA) systems provide an economically superior solution to satellite mobile communications by increasing the system maximum capacity with respect to single channel per carrier Frequency Division Multiple Access (FDMA) systems. Following the comparative analysis of CDMA and FDMA systems, the design of a model that was developed to test the feasibility of the approach and the performance of a spread spectrum system in a mobile environment. Results of extensive computer simulations as well as laboratory and field tests results are presented.

A Study on the Measuring of Consumers’ Perception towards the Mobile Marketing Campaigns in Air Transportation

OpenAIRE

Ozlem Atalik; Fatma Selin Sak; Eren Sezgen

2015-01-01

A widespread usage of mobile devices in our age creates a new marketing channel for the corporations to reach the consumers in an effective way. Being effective, personalized marketing tool, mobile marketing attracts the aviation sector, whose aim is to create an environment for the users so that they can require any product and service or pay and learn about them with their mobile devices from anywhere they want. Accordingly, the purpose of this study is to measure the mobile technology usag...

The effect of perceived mobility necessity in the choice of departure time

DEFF Research Database (Denmark)

Thorhauge, Mikkel; Cherchi, Elisabetta; Rich, Jeppe

2014-01-01

is likely to affect the choice of departure time. However departure time choice is also related to the full daily activity pattern, such as a restriction or a preference in one activity may form restrictions in the flexibility of other activities and thereby affect the preference for the related departure...... time. In this paper we investigate how the latent effect of the perceived mobility necessities affects the choice of departure time. A stated choice experiment collected among workers who commute to Copenhagen center is used to estimate 9 hybrid choice models where the discrete choice of departing...... before or later than the current trip depends on the latent construct of the perceived mobility necessities. Results show that individuals who perceive they have high mobility necessity tend to prefer the current departure time, and in particular dislike departing later. However the latent variables...

Small Terminal MIMO Channels with User Interaction

DEFF Research Database (Denmark)

Pedersen, Gert Frølund; Andersen, Jørgen Bach; Eggers, Patrick Claus F.

2007-01-01

This paper gives an overview of results obtained from measurements of different types of multiple-input multiple-output (MIMO) channels. For the indoor case measurements were made at 5.8 GHz from access points (APs) to mobile stations (MSs) at different places in a large open office type room. Th...... an investigation of the potentials for communication between cars approaching as well as in convoy and from inside and outside the car....

Principles of mobile computing and communications

CERN Document Server

Othman, Mazliza

2007-01-01

Introduction Mobile Computing Applications Evolution of Wireless Networks and Services Summary Cellular Network Architecture UMTS Architecture Public Land Mobile Network Interfaces User Authentication Frequency Reuse Channel Assignment Location Registration and Update Handover Procedures CDMA The Move toward 3G Networks Wireless Local Area Networks IEEE 802.11 Standard IEEE 802.11b Standard (Wi-Fi) IEEE 802.11a Standard IEEE 802.11g Standard HIPERLAN/2 IEEE 802.1x Standard IEEE 802.11i Standard IEEE 802.11e Standard Security Issues IP over 802.11 WLAN Integrating 802.11 WLAN and UMTS Summary Wireless Personal Area Networks HomeRF Bluetooth Technology IEEE 802.15.3 Standard Home Area Networks Summary Wireless Sensor Networks Applications of WSNs Requirements for WSNs WSN Architecture The 802.15.4 Standard The ZigBee Protocol Power Conservation Techniques Network and Communications Configuration of Sensor Networks WSN and Emergency Response Applications Summary Mobile Ad Hoc Networks AODV DSR OLSR TBRPF Summary...

Effect of Potassium Channel Modulators on Morphine Withdrawal in Mice

Directory of Open Access Journals (Sweden)

Vikas Seth

2010-01-01

Full Text Available The present study was conducted to investigate the effect of potassium channel openers and blockers on morphine withdrawal syndrome. Mice were rendered dependent on morphine by subcutaneous injection of morphine; four hours later, withdrawal was induced by using an opioid antagonist, naloxone. Mice were observed for 30 minutes for the withdrawal signs ie, the characteristic jumping, hyperactivity, urination and diarrhea. ATP-dependent potassium (K + ATP channel modulators were injected intraperitoneally (i.p. 30 minutes before the naloxone. It was found that a K + ATP channel opener, minoxidil (12.5–50 mg/kg i.p., suppressed the morphine withdrawal significantly. On the other hand, the K + ATP channel blocker glibenclamide (12.5–50 mg/kg i.p. caused a significant facilitation of the withdrawal. Glibenclamide was also found to abolish the minoxidil's inhibitory effect on morphine withdrawal. The study concludes that K + ATP channels play an important role in the genesis of morphine withdrawal and K + ATP channel openers could be useful in the management of opioid withdrawal. As morphine opens K + ATP channels in neurons, the channel openers possibly act by mimicking the effects of morphine on neuronal K + currents.

Ultimate response time of high electron mobility transistors

International Nuclear Information System (INIS)

Rudin, Sergey; Rupper, Greg; Shur, Michael

2015-01-01

We present theoretical studies of the response time of the two-dimensional gated electron gas to femtosecond pulses. Our hydrodynamic simulations show that the device response to a short pulse or a step-function signal is either smooth or oscillating time-decay at low and high mobility, μ, values, respectively. At small gate voltage swings, U 0  = U g  − U th , where U g is the gate voltage and U th is the threshold voltage, such that μU 0 /L < v s , where L is the channel length and v s is the effective electron saturation velocity, the decay time in the low mobility samples is on the order of L 2 /(μU 0 ), in agreement with the analytical drift model. However, the decay is preceded by a delay time on the order of L/s, where s is the plasma wave velocity. This delay is the ballistic transport signature in collision-dominated devices, which becomes important during very short time periods. In the high mobility devices, the period of the decaying oscillations is on the order of the plasma wave velocity transit time. Our analysis shows that short channel field effect transistors operating in the plasmonic regime can meet the requirements for applications as terahertz detectors, mixers, delay lines, and phase shifters in ultra high-speed wireless communication circuits

Relationship between patellar mobility and patellofemoral joint cartilage degeneration after anterior cruciate ligament reconstruction.

Science.gov (United States)

Ota, Susumu; Kurokouchi, Kazutoshi; Takahashi, Shigeo; Yoda, Masaki; Yamamoto, Ryuichiro; Sakai, Tadahiro

2017-11-01

Patellofemoral cartilage degeneration is a potential complication of anterior cruciate ligament reconstruction (ACLR) surgery. Hypomobility of the patella in the coronal plane is often observed after ACLR. Few studies, however, have examined the relationship between cartilage degeneration in the patellofemoral joint and mobility after ACLR. The present study investigated 1) the coronal mobility of the patella after ACLR, 2) the relationship between patellar mobility and cartilage degeneration of the patellofemoral joint, and 3) the relationship between patellar mobility and knee joint function after ACLR. Forty patients who underwent medial hamstring-based ACLR participated in the study. Lateral and medial patellar displacements were assessed with a modified patellofemoral arthrometer, and the absolute values of the displacements were normalized to patient height. The International Cartilage Repair Society (ICRS) cartilage injury classification of the patellar and femoral (trochlear) surfaces, and the Lysholm Knee Scoring Scale were used to evaluate knee function. Lateral and medial patellar displacements were reduced compared with the non-operated knee at the second-look arthroscopy and bone staple extraction operation (second operation; 24.4 ± 7.9 months after ACLR, Ppatellofemoral joint (patella and trochlea) were significantly worse than those pre-ACLR. Neither lateral nor medial patellar mobility, however, were significantly correlated with the ICRS grade or the Lysholm score. Although patellar mobility at approximately 2 years after ACLR was decreased compared to the non-operated knee, small displacement of the patella was not related to cartilage degeneration or knee joint function at the time of the second operation.

Reliable Ant Colony Routing Algorithm for Dual-Channel Mobile Ad Hoc Networks

Directory of Open Access Journals (Sweden)

YongQiang Li

2018-01-01

Full Text Available For the problem of poor link reliability caused by high-speed dynamic changes and congestion owing to low network bandwidth in ad hoc networks, an ant colony routing algorithm, based on reliable path under dual-channel condition (DSAR, is proposed. First, dual-channel communication mode is used to improve network bandwidth, and a hierarchical network model is proposed to optimize the dual-layer network. Thus, we reduce network congestion and communication delay. Second, a comprehensive reliable path selection strategy is designed, and the reliable path is selected ahead of time to reduce the probability of routing restart. Finally, the ant colony algorithm is used to improve the adaptability of the routing algorithm to changes of network topology. Simulation results show that DSAR improves the reliability of routing, packet delivery, and throughput.

Enhancing interaural-delay-based extents of laterality at high frequencies by using ``transposed stimuli''

Science.gov (United States)

Bernstein, Leslie R.; Trahiotis, Constantine

2003-06-01

An acoustic pointing task was used to determine whether interaural temporal disparities (ITDs) conveyed by high-frequency ``transposed'' stimuli would produce larger extents of laterality than ITDs conveyed by bands of high-frequency Gaussian noise. The envelopes of transposed stimuli are designed to provide high-frequency channels with information similar to that conveyed by the waveforms of low-frequency stimuli. Lateralization was measured for low-frequency Gaussian noises, the same noises transposed to 4 kHz, and high-frequency Gaussian bands of noise centered at 4 kHz. Extents of laterality obtained with the transposed stimuli were greater than those obtained with bands of Gaussian noise centered at 4 kHz and, in some cases, were equivalent to those obtained with low-frequency stimuli. In a second experiment, the general effects on lateral position produced by imposed combinations of bandwidth, ITD, and interaural phase disparities (IPDs) on low-frequency stimuli remained when those stimuli were transposed to 4 kHz. Overall, the data were fairly well accounted for by a model that computes the cross-correlation subsequent to known stages of peripheral auditory processing augmented by low-pass filtering of the envelopes within the high-frequency channels of each ear.

THE USE OF NEW DISTRIBUTION CHANNELS TO INCREASE THE EFFICIENCY OF INSURANCE COMPANIES

OpenAIRE

Olga N. Kozlova; Olga N. Kotova; Elizaveta V. Pavlovskaya

2017-01-01

The article deals with the issues of increasing the efficiency of insurance companies on the basis of using new non-traditional distribution channels. The relevance of the topic is justified by the automation of management processes, a new generation of consumers focused on new technologies, the use of the Internet, growing and selling functional mobile gadgets. The insurance companies use new distribution channels via the Internet network along with the traditional means for the expansion of...

Mobile MSN Messenger: Still a Complement?

Directory of Open Access Journals (Sweden)

Marcus Nyberg

2008-10-01

Full Text Available In order to understand how mobile instant messaging services can fit into the users’ current communication behavior, Ericsson Research performed a qualitative user study in Sweden in May 2007. The results showed that the respondents were positive towards (free of charge mobile MSN Messenger and perceived it as an ex¬tension of the computer-based version that could be used anywhere. However, although MSN Messenger on the com¬puter definitely was considered as a ‘must-have’ application, the mobile version was only perceived as a ‘nice-to-have’ application and a complement to text mes¬saging (SMS. Almost one year later, in April 2008, Ericsson Research performed a short qualita¬tive follow-up study with the same set of respondents to un¬derstand if and how the mobile MSN Messenger usage had changed. The results actually revealed that none of the re¬spondents used mobile MSN Messenger anymore as the application no longer was free of charge. On a general level, the study highlights important considera¬tions when intro¬ducing computer-based concepts and Internet services in a mo¬bile environment.

A Case of Morvan Syndrome Mimicking Amyotrophic Lateral Sclerosis With Frontotemporal Dementia.

Science.gov (United States)

Freund, Brin; Maddali, Manoj; Lloyd, Thomas E

2016-06-01

Morvan syndrome is a rare autoimmune/paraneoplastic disorder involving antibodies to the voltage-gated potassium channel complex. It is defined by subacute encephalopathy, neuromuscular hyperexcitability, dysautonomia, and sleep disturbance. It may present a diagnostic dilemma when trying to differentiate from amyotrophic lateral sclerosis with frontotemporal dementia. A 76-year-old man with a history of untreated prostate adenocarcinoma was evaluated for subacute cognitive decline, diffuse muscle cramps, and hyponatremia. MRI demonstrated atrophy most prominent in the frontal and temporal regions. Electromyography (EMG) demonstrated diffuse myokymia/neuromyotonia. Polysomnography lacked REM and N3 sleep. Paraneoplastic panel detected antibodies to voltage-gated potassium channel complex (CASPR2 subtype). It is difficult to differentiate between Morvan syndrome and amyotrophic lateral sclerosis with frontotemporal dementia with examination and neuroimaging alone. There may be a link between Morvan syndrome and prostate adenocarcinoma which could help with screening/diagnosis. The authors found that laboratory and neurophysiological tests are indispensable in diagnosing and treating Morvan syndrome.

Effect of ion irradiation-produced defects on the mobility of dislocations in 304 stainless steel

International Nuclear Information System (INIS)

Briceno, M.; Fenske, J.; Dadfarnia, M.; Sofronis, P.; Robertson, I.M.

2011-01-01

The impact of heavy-ion produced defects on the mobility of dislocations, dislocation sources and newly generated dislocations in 304 stainless steel are discovered by performing irradiation and deformation experiments in real time in the transmission electron microscope. Dislocations mobile prior to the irradiation are effectively locked in position by the irradiation, but the irradiation has no discernible impact on the ability of a source to generate dislocations. The motion and mobility of a dislocation is altered by the irradiation. It becomes irregular and jerky and the mobility increases slowly with time as the radiation-produced defects are annihilated locally. Channels created by dislocations ejected from grain boundary dislocation sources were found to have a natural width, as the emission sites within the boundary were spaced close together. Finally, the distribution of dislocations, basically, an inverse dislocation pile-up, within a cleared channel suggests a new mechanism for generating high local levels of stress at grain boundaries. The impact of these observations on the mechanical properties of irradiated materials is discussed briefly.

Effect of ion irradiation-produced defects on the mobility of dislocations in 304 stainless steel

Energy Technology Data Exchange (ETDEWEB)

Briceno, M.; Fenske, J. [Department of Materials Science and Engineering, University of Illinois, Urbana, IL 61801 (United States); Dadfarnia, M.; Sofronis, P. [Department of Mechanical Science and Engineering, University of Illinois, Urbana, IL 61801 (United States); Robertson, I.M., E-mail: ian.robertson@tcd.ie [Department of Materials Science and Engineering, University of Illinois, Urbana, IL 61801 (United States)

2011-02-01

The impact of heavy-ion produced defects on the mobility of dislocations, dislocation sources and newly generated dislocations in 304 stainless steel are discovered by performing irradiation and deformation experiments in real time in the transmission electron microscope. Dislocations mobile prior to the irradiation are effectively locked in position by the irradiation, but the irradiation has no discernible impact on the ability of a source to generate dislocations. The motion and mobility of a dislocation is altered by the irradiation. It becomes irregular and jerky and the mobility increases slowly with time as the radiation-produced defects are annihilated locally. Channels created by dislocations ejected from grain boundary dislocation sources were found to have a natural width, as the emission sites within the boundary were spaced close together. Finally, the distribution of dislocations, basically, an inverse dislocation pile-up, within a cleared channel suggests a new mechanism for generating high local levels of stress at grain boundaries. The impact of these observations on the mechanical properties of irradiated materials is discussed briefly.

Spread spectrum mobile communication experiment using ETS-V satellite

Science.gov (United States)

Ikegami, Tetsushi; Suzuki, Ryutaro; Kadowaki, Naoto; Taira, Shinichi; Sato, Nobuyasu

1990-01-01

The spread spectrum technique is attractive for application to mobile satellite communications, because of its random access capability, immunity to inter-system interference, and robustness to overloading. A novel direct sequence spread spectrum communication equipment is developed for land mobile satellite applications. The equipment is developed based on a matched filter technique to improve the initial acquisition performance. The data rate is 2.4 kilobits per sec. and the PN clock rate is 2.4552 mega-Hz. This equipment also has a function of measuring the multipath delay profile of land mobile satellite channel, making use of a correlation property of a PN code. This paper gives an outline of the equipment and the field test results with ETS-V satellite.

Footwear width and balance-recovery reactions: A new approach to improving lateral stability in older adults.

Science.gov (United States)

Yamaguchi, Takeshi; Cheng, Kenneth C; McKay, Sandra M; Maki, Brian E

Age-related difficulty in controlling lateral stability is of crucial importance because lateral falls increase risk of debilitating hip-fracture injury. This study examined whether a small increase in footwear sole width can improve ability of older adults to regain lateral stability subsequent to balance perturbation. The study involved sixteen healthy, ambulatory, community-dwelling older adults (aged 65-78). Widened base-of-support (WBOS) footwear was simulated by affixing polystyrene-foam blocks (20mm wide) on the medial and lateral sides of rubber overshoes; unaltered overshoes were worn in normal (NBOS) trials. Balance perturbations were applied using a motion platform. Gait, mobility and agility tests revealed no adverse effects of wearing the WBOS footwear. Lateral-perturbation tests showed that the WBOS footwear improved ability to stabilize the body without stepping (p=0.002). Depending on the perturbation magnitude, the frequency of stepping was reduced by up to 25% (64% of NBOS trials vs 39% of WBOS trials). In addition, the WBOS footwear appeared to improve ability to maintain lateral stability during forward-step reactions, as evidenced by reduced incidence of additional lateral steps (p=0.04) after stepping over an obstacle in response to a forward-fall perturbation. A small increase in sole width can improve certain aspects of lateral stability in older adults, without compromising mobility and agility. This finding supports the viability of WBOS footwear as an intervention to improve balance. Further research is needed to test populations with more severe balance impairments, examine user compliance, and determine if WBOS footwear actually reduces falling risk in daily life.

Graphene/Pentacene Barristor with Ion-Gel Gate Dielectric: Flexible Ambipolar Transistor with High Mobility and On/Off Ratio.

Science.gov (United States)

Oh, Gwangtaek; Kim, Jin-Soo; Jeon, Ji Hoon; Won, EunA; Son, Jong Wan; Lee, Duk Hyun; Kim, Cheol Kyeom; Jang, Jingon; Lee, Takhee; Park, Bae Ho

2015-07-28

High-quality channel layer is required for next-generation flexible electronic devices. Graphene is a good candidate due to its high carrier mobility and unique ambipolar transport characteristics but typically shows a low on/off ratio caused by gapless band structure. Popularly investigated organic semiconductors, such as pentacene, suffer from poor carrier mobility. Here, we propose a graphene/pentacene channel layer with high-k ion-gel gate dielectric. The graphene/pentacene device shows both high on/off ratio and carrier mobility as well as excellent mechanical flexibility. Most importantly, it reveals ambipolar behaviors and related negative differential resistance, which are controlled by external bias. Therefore, our graphene/pentacene barristor with ion-gel gate dielectric can offer various flexible device applications with high performances.

Isometric muscle strength and mobility capacity in children with cerebral palsy.

Science.gov (United States)

Dallmeijer, Annet J; Rameckers, Eugene A; Houdijk, Han; de Groot, Sonja; Scholtes, Vanessa A; Becher, Jules G

2017-01-01

To determine the relationship between isometric leg muscle strength and mobility capacity in children with cerebral palsy (CP) compared to typically developing (TD) peers. Participants were 62 children with CP (6-13 years), able to walk with (n = 10) or without (n = 52) walking aids, and 47 TD children. Isometric muscle strength of five muscle groups of the leg was measured using hand-held dynamometry. Mobility capacity was assessed with the 1-min walk, the 10-m walk, sit-to-stand, lateral-step-up and timed-stair tests. Isometric strength of children with CP was reduced to 36-82% of TD. When adjusted for age and height, the percentage of variance in mobility capacity that was explained by isometric strength of the leg muscles was 21-24% (walking speed), 25% (sit-to-stand), 28% (lateral-step-up) and 35% (timed-stair) in children with CP. Hip abductors and knee flexors had the largest contribution to the explained variance, while knee extensors showed the weakest correlation. Weak or no associations were found between strength and mobility capacity in TD children. Isometric strength, especially hip abductor and knee flexor strength, is moderately related to mobility capacity in children with CP, but not in TD children. To what extent training of these muscle groups will lead to better mobility capacity needs further study. Implications for Rehabilitation Strength training in children with cerebral palsy (CP) may be targeted more specifically at hip abductors and knee flexors. The moderate associations imply that large improvements in mobility capacity may not be expected when strength increases.

Co-evolution of Riparian Vegetation and Channel Dynamics in an Aggrading Braided River System, Mount Pinatubo, Philippines

Science.gov (United States)

Gran, K. B.; Michal, T.

2014-12-01

Increased bank stability by riparian vegetation in braided rivers can decrease bed reworking rates and focus the flow. The magnitude of influence and resulting channel morphology are functions of vegetation strength vs. channel dynamics, a concept encapsulated in a dimensionless ratio between timescales for vegetation growth and channel reworking known as T*. We investigate this relationship in an aggrading braided river at Mount Pinatubo, Philippines, and compare results to numerical and physical models. Gradual reductions in post-eruption sediment loads have reduced bed reworking rates, allowing vegetation to persist year-round and impact channel dynamics on the Pasig-Potrero and Sacobia Rivers. From 2009-2011, we collected data detailing vegetation extent, type, density, and root strength. Incorporating these data into RipRoot and BSTEM models shows cohesion due to roots increased from zero in unvegetated conditions to >10.2 kPa in densely-growing grasses. Field-based parameters were incorporated into a cellular model comparing vegetation growth and sediment mobility effects on braided channel dynamics. The model shows that both low sediment mobility and high vegetation strength lead to less active systems, reflecting trends observed in the field. An estimated T* between 0.8 - 2.3 for the Pasig-Potrero River suggests channels were mobile enough to maintain the braidplain width clear of vegetation and even experience slight gains in area through annual removal of existing vegetation. However, persistent vegetation focused flow and thus aggradation over the unvegetated fraction of braidplain, leading to an aggradational imbalance and transition to a more avulsive state. While physical models predict continued narrowing of the active braidplain as T* declines, the future trajectory of channel-vegetation interactions at Pinatubo as sedimentation rates decline appears more complicated due to strong seasonal variability in precipitation and sediment loads. By 2011

Turning the tide: estuarine bars and mutually evasive ebb- and flood-dominated channels

Science.gov (United States)

Kleinhans, M. G.; Leuven, J.; van der Vegt, M.; Baar, A. W.; Braat, L.; Bergsma, L.; Weisscher, S.

2015-12-01

Estuaries have perpetually changing and interacting channels and shoals formed by ebb and flood currents, but we lack a descriptive taxonomy and forecasting model. We explore the hypotheses that the great variation of bar and shoal morphologies are explained by similar factors as river bars, namely channel aspect ratio, sediment mobility and limits on bar erosion and chute cutoff caused by cohesive sediment. Here we use remote sensing data and a novel tidal flume setup, the Metronome, to create estuaries or short estuarine reaches from idealized initial conditions, with and without mud supply at the fluvial boundary. Bar width-depth ratios in estuaries are similar to those in braided rivers. In unconfined (cohesionless) experimental estuaries, bar- and channel dynamics increase with increasing river discharge. Ebb- and flood-dominated channels are ubiquitous even in entirely straight sections. The apparent stability of ebb- and flood channels is partly explained by the inherent instability of symmetrical channel bifurcations as in rivers.

Improving the security of the Hwang-Su protocol for mobile networks

African Journals Online (AJOL)

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Improving the security of the Hwang-Su protocol for mobile networks. Miloud Ait Hemad, My ... Furthermore, the wireless data channel is low data rate. These restrictions have an ..... Research in Security and Privacy. Wu T. Y. and Tsen Y. M., ...

Multiserver Queue with Guard Channel for Priority and Retrial Customers

Directory of Open Access Journals (Sweden)

Kazuki Kajiwara

2016-01-01

Full Text Available This paper considers a retrial queueing model where a group of guard channels is reserved for priority and retrial customers. Priority and normal customers arrive at the system according to two distinct Poisson processes. Priority customers are accepted if there is an idle channel upon arrival while normal customers are accepted if and only if the number of idle channels is larger than the number of guard channels. Blocked customers (priority or normal join a virtual orbit and repeat their attempts in a later time. Customers from the orbit (retrial customers are accepted if there is an idle channel available upon arrival. We formulate the queueing system using a level dependent quasi-birth-and-death (QBD process. We obtain a Taylor series expansion for the nonzero elements of the rate matrices of the level dependent QBD process. Using the expansion results, we obtain an asymptotic upper bound for the joint stationary distribution of the number of busy channels and that of customers in the orbit. Furthermore, we develop an efficient numerical algorithm to calculate the joint stationary distribution.

Genesis and sedimentary record of blind channel and islands of the anabranching river: An evolution model

Science.gov (United States)

Leli, Isabel T.; Stevaux, José C.; Assine, Mário L.

2018-02-01

Blind channel (BC) is a fluvial feature formed by attachment of a lateral sand bar to an island or riverbank. It consists of a 10- to 20-m wide and hundreds to thousands meters long channel, parallel to the island or bank, closed at its upstream end by accretion to the island. It is an important feature in anabranching rivers that plays an important role in both the island formation and river ecology. This paper discusses the formation processes, functioning, evolution, and the sedimentary record of a blind channel, related landforms, and its context on island development in the Upper Paraná River. The evolution of this morphologic feature involves (1) formation of a lateral or attachment bar beside an island with the development of a channel in between; (2) vertical accretion of mud deposits during the flood and vegetal development on the bar; (3) the upstream channel closure that generates the blind channel; and (4) annexation of the blind channel to the island. A blind channel is semilotic to lentic, that is not totally integrated to the dynamics of the main active channel and that acts as a nursery for fingerlings and macrophytes. The sedimentary facies succession of BCs are relatively simple and characterized by cross-stratified sand covered by organic muddy sediments. Based on facies analysis of 12 cores, we identified a succession of environments that contribute to the formation of islands: channel bar, blind channel, pond, and swamp. Blind channel formation and its related bar-island attachment are relevant processes associated with the growing of large island evolution in some anabranching rivers.

Martian channels and valleys - Their characteristics, distribution, and age

Science.gov (United States)

Carr, M. H.; Clow, G. D.

1981-01-01

The distribution and ages of Martian channels and valleys, which are generally believed to have been cut by running water, are examined with particular emphasis on the small branching networks referred to as runoff channels or valley networks. Valleys at latitudes from 65 deg S to 65 deg N were surveyed on Viking images at resolutions between 125 and 300 m. Almost all of the valleys are found in the old cratered terrain, in areas characterized by high elevations, low albedos and low violet/red ratios. The networks are deduced to have formed early in the history of the planet, with a formation rate declining rapidly shortly after the decline of the cratering rate 3.9 billion years ago. Two types of outflow channels are distinguished: unconfined, in which broad swaths of terrain are scoured, and confined, in which flow is restricted to discrete channels. Both types start at local sources, and have formed episodically throughout Martian history. Fretted channels, found mainly in two latitude belts characterized by relatively rapid erosion along escarpments, are explained by the lateral enlargement of other channels by mass wasting.

Association between vestibular schwannomas and mobile phone use.

Science.gov (United States)

Moon, In Seok; Kim, Bo Gyung; Kim, Jinna; Lee, Jong Dae; Lee, Won-Sang

2014-01-01

Vestibular schwannomas (VSs) grow in the region where the energy from mobile phone use is absorbed. We examined the associations of VSs with mobile phone use. This study included 119 patients who had undergone surgical tumor removal. We used two approaches in this investigation. First, a case-control study for the association of mobile phone use and incidence of VSs was conducted. Both cases and controls were investigated with questions based on INTERPHONE guidelines. Amount of mobile phone use according to duration, daily amount, and cumulative hours were compared between two groups. We also conducted a case-case study. The location and volume of the tumors were investigated by MRI. Associations between the estimated amount of mobile phone use and tumor volume and between the laterality of phone use and tumor location were analyzed. In a case-control study, the odds ratio (OR) of tumor incidence according to mobile phone use was 0.956. In the case-case study, tumor volume and estimated cumulative hours showed a strong correlation (r(2) = 0.144, p = 0.002), and regular mobile phone users showed tumors of a markedly larger volume than those of non-regular users (p mobile phones and tumor volume that showed strong correlation with amount of mobile phone use, thus there is a possibility that mobile phone use may affect tumor growth.

Scheduling and Control of Multi-Node Mobile Communications Systems With Randomly-Varying Channels by Stability Methods

National Research Council Canada - National Science Library

Kushner, Harold J

2005-01-01

We consider a communications network consisting of many mobiles. There are random external data processes arriving at some of the mobiles, each destined for a unique destination or set of destinations...

Information Flow along Catfish Marketing Channels in Nigeria: Whither the Role of Mobile Telephony?

OpenAIRE

Animashaun, Jubril Olayinka; Fakayode, S.B.; Ayinde, Opeyemi Eyitayo

2013-01-01

The objectives of this study were two-folds. First, examined the use of mobile phone technology to facilitate catfish marketing and second, identified the determinants of variations in the frequency of mobile phone use for catfish marketing among agents involved in the marketing chain. The study was carried out in Kwara-state, Nigeria. One hundred and forty respondents were stratified and randomly sampled and data was collected through the use of well-designed questionnaires. Descriptive and ...