Propagation Delay Variations under Process Deviation in Driver Interconnect Load System

2010 ◽  
Author(s):  
K.G. Verma ◽  
B.K. Kaushik ◽  
R. Singh
Keyword(s):  
Propagation Delay ◽  
Delay Variations

scholarly journals Technical Note: Remote sensing of sea surface salinity using the propagation of low-frequency navigation signals

2014 ◽  
Vol 11 (6) ◽  
pp. 2971-2978
Author(s):  
I. Astin ◽  
Y. Feng
Keyword(s):  
Remote Sensing ◽  
Low Frequency ◽  
Potential Method ◽  
Propagation Delay ◽  
Technical Note ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Surface Salinity ◽  
Delay Variations ◽  
Navigation Signals

Abstract. This paper introduces a potential method for the remote sensing of sea surface salinity (SSS) using measured propagation delay of low-frequency Loran-C signals transmitted over an all-seawater path between the Sylt station in Germany and an integrated Loran-C/GPS receiver located in Harwich, UK. The overall delay variations in Loran-C surface waves along the path may be explained by changes in sea surface properties (especially the temperature and salinity), as well as atmospheric dynamics that determine the refractive index of the atmosphere. After removing the atmospheric and sea surface temperature (SST) effects, the residual delay revealed a temporal variation similar to that of SSS data obtained by the European Space Agency's Soil Moisture and Ocean Salinity (SMOS) satellite.

scholarly journals Dispersion measure variability for 36 millisecond pulsars at 150 MHz with LOFAR

2020 ◽  
Vol 644 ◽  
pp. A153
Author(s):  
J. Y. Donner ◽  
J. P. W. Verbiest ◽  
C. Tiburzi ◽  
S. Osłowski ◽  
J. Künsemöller ◽  
...  
Keyword(s):  
Time Series ◽  
Low Frequency ◽  
Propagation Delay ◽  
Dispersion Measure ◽  
Millisecond Pulsars ◽  
Low Frequencies ◽  
Pulsar Timing ◽  
Variable Dispersion ◽  
Delay Variations ◽  
Plasma Dispersion

Context. Radio pulses from pulsars are affected by plasma dispersion, which results in a frequency-dependent propagation delay. Variations in the magnitude of this effect lead to an additional source of red noise in pulsar timing experiments, including pulsar timing arrays (PTAs) that aim to detect nanohertz gravitational waves. Aims. We aim to quantify the time-variable dispersion with much improved precision and characterise the spectrum of these variations. Methods. We use the pulsar timing technique to obtain highly precise dispersion measure (DM) time series. Our dataset consists of observations of 36 millisecond pulsars, which were observed for up to 7.1 yr with the LOw Frequency ARray (LOFAR) telescope at a centre frequency of ~150 MHz. Seventeen of these sources were observed with a weekly cadence, while the rest were observed at monthly cadence. Results. We achieve a median DM precision of the order of 10−5 cm−3 pc for a significant fraction of our sources. We detect significant variations of the DM in all pulsars with a median DM uncertainty of less than 2 × 10−4 cm−3 pc. The noise contribution to pulsar timing experiments at higher frequencies is calculated to be at a level of 0.1–10 μs at 1.4 GHz over a timespan of a few years, which is in many cases larger than the typical timing precision of 1 μs or better that PTAs aim for. We found no evidence for a dependence of DM on radio frequency for any of the sources in our sample. Conclusions. The DM time series we obtained using LOFAR could in principle be used to correct higher-frequency data for the variations of the dispersive delay. However, there is currently the practical restriction that pulsars tend to provide either highly precise times of arrival (ToAs) at 1.4 GHz or a high DM precision at low frequencies, but not both, due to spectral properties. Combining the higher-frequency ToAs with those from LOFAR to measure the infinite-frequency ToA and DM would improve the result.

scholarly journals Design and Analysis of Handshake-Based MAC with Delay Variations in Underwater Acoustic Networks

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4159
Author(s):  
Chao Dong ◽  
Yankun Chen ◽  
Quansheng Guan ◽  
Fei Ji ◽  
Hua Yu ◽  
...  
Keyword(s):  
Propagation Speed ◽  
Propagation Delay ◽  
Medium Access ◽  
Underwater Acoustic ◽  
Slot Length ◽  
Wide Range ◽  
Acoustic Networks ◽  
Underwater Acoustic Networks ◽  
Delay Variations ◽  
The Impact

The long propagation delay in underwater acoustic channels has attracted tremendous attentions in designing Medium Access Control (MAC). The low acoustic propagation speed and wide area of the acoustic communication range led to a wide range of variations in the propagation delay. This paper identifies an important characteristic of two-scale delay variations by field test results. We carry out simulations to study the impact of delay variations on MAC, and the results suggest a slot length adaptation scheme for the handshake and slotting based MAC. We further model an absorbing Markov chain to derive the closed-form equation for the throughput of MAC with adaptive slot length. Both the analytical and simulation results show that our proposed slot length adaptation improves significantly the throughput of MAC in underwater acoustic networks. Particularly, the Slotted-FAMA with an adaptive slot length achieves more than double the throughput than the Slotted-FAMA with a fixed slot length in a network with six nodes.

scholarly journals Technical Note: Remote sensing of sea surface salinity using the propagation of low-frequency navigation signals

Ocean Science ◽  
2015 ◽  
Vol 11 (5) ◽  
pp. 695-698
Author(s):  
I. Astin ◽  
Y. Feng
Keyword(s):  
Remote Sensing ◽  
Low Frequency ◽  
Potential Method ◽  
Propagation Delay ◽  
Technical Note ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Surface Salinity ◽  
Delay Variations ◽  
Navigation Signals

Abstract. This paper introduces a potential method for the remote sensing of sea surface salinity (SSS) using the measured propagation delay of low-frequency Loran-C signals transmitted over an all-seawater path between the Sylt station in Germany and an integrated Loran-C/GPS receiver located in Harwich, UK. The overall delay variations in Loran-C surface waves along the path may be explained by changes in sea surface properties (especially the temperature and salinity), as well as atmospheric properties that determine the refractive index of the atmosphere. After removing the atmospheric and sea surface temperature (SST) effects from the measured delay, the residual delay revealed a temporal variation similar to that of SSS data obtained by the European Space Agency's Soil Moisture and Ocean Salinity (SMOS) satellite.

Materials Issues and Characterization of Low-k Dielectric Materials

MRS Bulletin ◽  
1997 ◽  
Vol 22 (10) ◽  
pp. 49-54 ◽  
Author(s):  
E. Todd Ryan ◽  
Andrew J. McKerrow ◽  
Jihperng Leu ◽  
Paul S. Ho
Keyword(s):  
Process Integration ◽  
Dielectric Materials ◽  
Propagation Delay ◽  
Thermomechanical Properties ◽  
General Criterion ◽  
Crosstalk Noise ◽  
Total Delay ◽  
Interlayer Dielectrics ◽  
Performance Improvements ◽  
And Performance

Continuing improvement in device density and performance has significantly affected the dimensions and complexity of the wiring structure for on-chip interconnects. These enhancements have led to a reduction in the wiring pitch and an increase in the number of wiring levels to fulfill demands for density and performance improvements. As device dimensions shrink to less than 0.25 μm, the propagation delay, crosstalk noise, and power dissipation due to resistance-capacitance (RC) coupling become significant. Accordingly the interconnect delay now constitutes a major fraction of the total delay limiting the overall chip performance. Equally important is the processing complexity due to an increase in the number of wiring levels. This inevitably drives cost up by lowering the manufacturing yield due to an increase in defects and processing complexity.To address these problems, new materials for use as metal lines and interlayer dielectrics (ILDs) and alternative architectures have surfaced to replace the current Al(Cu)/SiO2 interconnect technology. These alternative architectures will require the introduction of low-dielectric-constant k materials as the interlayer dielectrics and/or low-resistivity conductors such as copper. The electrical and thermomechanical properties of SiO2 are ideal for ILD applications, and a change to material with different properties has important process-integration implications. To facilitate the choice of an alternative ILD, it is necessary to establish general criterion for evaluating thin-film properties of candidate low-k materials, which can be later correlated with process-integration problems.

Low-Dielectric-Constant Materials for ULSI Interlayer-Dielectric Applications

MRS Bulletin ◽  
1997 ◽  
Vol 22 (10) ◽  
pp. 19-27 ◽  
Author(s):  
Wei William Lee ◽  
Paul S. Ho
Keyword(s):  
Packing Density ◽  
Propagation Delay ◽  
Single Chip ◽  
Crosstalk Noise ◽  
Metal Line ◽  
Total Delay ◽  
Interlayer Dielectric ◽  
Low Dielectric ◽  
Interconnect Delay ◽  
Interconnect Technology

Continuing improvement of microprocessor performance historically involves a decrease in the device size. This allows greater device speed, an increase in device packing density, and an increase in the number of functions that can reside on a single chip. However higher packing density requires a much larger increase in the number of interconnects. This has led to an increase in the number of wiring levels and a reduction in the wiring pitch (sum of the metal line width and the spacing between the metal lines) to increase the wiring density. The problem with this approach is that—as device dimensions shrink to less than 0.25 μm (transistor gate length)—propagation delay, crosstalk noise, and power dissipation due to resistance-capacitance (RC) coupling become significant due to increased wiring capacitance, especially interline capacitance between the metal lines on the same metal level. The smaller line dimensions increase the resistivity (R) of the metal lines, and the narrower interline spacing increases the capacitance (C) between the lines. Thus although the speed of the device will increase as the feature size decreases, the interconnect delay becomes the major fraction of the total delay and limits improvement in device performance.To address these problems, new materials for use as metal lines and interlayer dielectrics (ILD) as well as alternative architectures have been proposed to replace the current Al(Cu) and SiO2 interconnect technology.

Updated Efficient Area -Carry Select Adder for Low Complexity D LATCH Configuration by disease identification in brain tumor hyper spectral image

2019 ◽  
Vol 14 ◽  
Author(s):  
Teresa V.V ◽  
Anand. B
Keyword(s):  
Research Work ◽  
Low Complexity ◽  
Propagation Delay ◽  
Maximum Speed ◽  
Hyper Spectral ◽  
Ripple Carry Adder ◽  
Minimum Power Consumption ◽  
Carry Select Adder ◽  
The Look ◽  
Propagation Result

Objective: In this research work presents an efficient way Carry Select Adder (CSLA) performance and estimation. The CSLA is utilized in several system to mitigate the issue of carry propagation delay that is happens by severally generating various carries and to get the sum, select a carry because of the uses of various pairs of RCA to provide the sum of the partial section also carry by consisting carry input but the CSLA isn't time economical, then by the multiplexers extreme total and carry is chosen in the selected section. Methodology: The fundamental plan of this work is to attain maximum speed and minimum power consumption by using Binary to Excess-1. Convertor rather than RCA within the regular CSLA. Here RCA denotes the Ripple Carry Adder section. At the span to more cut back the facility consumption, a method of CSLA with D LATCH is implemented during this research work. The look of Updated Efficient Area -Carry Select Adder (UEA-CSLA) is evaluated and intended in XILINX ISE design suite 14. 5 tools. This VLSI arrangement is utilized in picture preparing application by concluding the cerebrum tumor discovery. Conclusion: In this study, medicinal pictures estimation, investigation districts in the multi phantom picture isn't that much proficient to defeat this disadvantage here utilized hyper spectral picture method is presented a sifting procedure in VLSI innovation restriction of cerebrum tumor is performed Updated Efficient Area - Carry Select Adder propagation result dependent on Matrix Laboratory in the adaptation of R2018b.

scholarly journals Investigating Master–Slave Architecture for Underwater Wireless Sensor Network

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3000
Author(s):  
Sadeeq Jan ◽  
Eiad Yafi ◽  
Abdul Hafeez ◽  
Hamza Waheed Khatana ◽  
Sajid Hussain ◽  
...  
Keyword(s):  
Wireless Sensor Network ◽  
Sensor Network ◽  
Propagation Delay ◽  
Data Packet ◽  
Wireless Sensor ◽  
Delivery Ratio ◽  
Term Survival ◽  
Limited Bandwidth ◽  
Delay Tolerant

A significant increase has been observed in the use of Underwater Wireless Sensor Networks (UWSNs) over the last few decades. However, there exist several associated challenges with UWSNs, mainly due to the nodes’ mobility, increased propagation delay, limited bandwidth, packet duplication, void holes, and Doppler/multi-path effects. To address these challenges, we propose a protocol named “An Efficient Routing Protocol based on Master–Slave Architecture for Underwater Wireless Sensor Network (ERPMSA-UWSN)” that significantly contributes to optimizing energy consumption and data packet’s long-term survival. We adopt an innovative approach based on the master–slave architecture, which results in limiting the forwarders of the data packet by restricting the transmission through master nodes only. In this protocol, we suppress nodes from data packet reception except the master nodes. We perform extensive simulation and demonstrate that our proposed protocol is delay-tolerant and energy-efficient. We achieve an improvement of 13% on energy tax and 4.8% on Packet Delivery Ratio (PDR), over the state-of-the-art protocol.

scholarly journals Indoor Airflow Distribution in Repository Design: Experimental and Numerical Microclimate Analysis of an Archive

Buildings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 152
Author(s):  
Karin Kompatscher ◽  
Rick P. Kramer ◽  
Bart Ankersmit ◽  
Henk L. Schellen
Keyword(s):  
Vertical Gradient ◽  
Building Envelope ◽  
Cfd Modeling ◽  
Indoor Climate ◽  
Ambient Conditions ◽  
Climate Control ◽  
Climate Conditions ◽  
Airflow Distribution ◽  
Air Mixing ◽  
Delay Variations

The majority of cultural heritage is stored in archives, libraries and museum storage spaces. To reduce degradation risks, many archives adopt the use of archival boxes, among other means, to provide the necessary climate control and comply with strict legislation requirements regarding temperature and relative air humidity. A strict ambient indoor climate is assumed to provide adequate environmental conditions near objects. Guidelines and legislation provide requirements for ambient indoor climate parameters, but often do not consider other factors that influence the near-object environment, such as the use of archival boxes, airflow distribution and archival rack placement. This study aimed to provide more insight into the relation between the ambient indoor conditions in repositories and the hygrothermal conditions surrounding the collection. Comprehensive measurements were performed in a case study archive to collect ambient, local and near-object conditions. Both measurements and computational fluid dynamics (CFD) modeling were used to research temperature/relative humidity gradients and airflow distribution with a changing rack orientation, climate control strategy and supply as well as exhaust set-up in a repository. The following conclusions are presented: (i) supplying air from one air handling unit to multiple repositories on different floors leads to small temperature differences between them. Differences in ambient and local climates are noticed; (ii) archival boxes mute and delay variations in ambient conditions as expected—however, thermal radiation from the building envelope may have a large influence on the climate conditions in a box; (iii) adopting night reduction for energy conservation results in an increased influence of the external climate, with adequate insulation, this effect should be mitigated; and (iv) the specific locations of the supply air and extraction of air resulted in a vertical gradient of temperature and insufficient mixing of air, and adequate ventilation strategies should enhance sufficient air mixing in combination with the insulation of external walls, and gradient forming should be reduced.

Sign in / Sign up

Export Citation Format

Share Document