Cooperative IDED in a medium-traffic primary network over Rayleigh-faded sensing channels

2015 ◽  
Author(s):  
Ramtin Rabiee ◽  
Kwok Hung Li
Keyword(s):  
Primary Network

Effect of CSI Imperfection on Cognitive Underlay Transmission over Nakagami-m Fading Channel

2015 ◽  
Vol 1 ◽  
pp. 59
Author(s):  
Nguyen Hong Giang ◽  
Vo Nguyen Quoc Bao ◽  
Hung Nguyen-Le
Keyword(s):  
Fading Channels ◽  
System Performance ◽  
Performance Metrics ◽  
Maximal Ratio Combining ◽  
Relay Nodes ◽  
Channel State ◽  
Primary Network ◽  
Secondary Network ◽  
System Designs ◽  
Approximate Expressions

This paper analyzes the performance of a cognitive underlay system over Nakagami-m fading channels, where maximal ratio combining (MRC) is employed at secondary destination and relay nodes. Under the condition of imperfect channel state information (CSI) of interfering channels, system performance metrics for the primary network and for the secondary network are formulated into exact and approximate expressions, which can be served as theoretical guidelines for system designs. To verify the performance analysis, several analytical and simulated results of the system performance are provided under various system and channel settings.

Radial versus primary network distribution

1934 ◽  
Vol 53 (3) ◽  
pp. 489-489
Author(s):  
H. E. Wulfing
Keyword(s):  
Primary Network

Rainfall estimates from opportunistic sensors in Germany across spatio-temporal scales – Geostatistical interpolation framework

2021 ◽  
Author(s):  
Micha Eisele ◽  
Maximilian Graf ◽  
Abbas El Hachem ◽  
Jochen Seidel ◽  
Christian Chwala ◽  
...  
Keyword(s):  
Meteorological Data ◽  
Pearson Correlation ◽  
Urban Catchment ◽  
Space And Time ◽  
Geostatistical Interpolation ◽  
Primary Network ◽  
Ground Measurement ◽  
Catchment Areas ◽  
Important Input ◽  
Spatio Temporal

<p>Precipitation - highly variable in space and time - is the most important input for many hydrological models. As these models become more and more detailed in space and time, high-resolution input data are required. Especially for modeling and prediction in fast reacting catchments, such as urban catchment areas, a higher space-time resolution is needed than the current ground measurement networks operated by national weather services usually provide. With the increasing number and availability of opportunistic sensors such as commercial microwave links (CMLs) and personal weather stations (PWS) in recent years, new opportunities for measuring meteorological data are emerging.</p><p>We developed a geostatistical interpolation framework which allows a combination of different opportunistic sensors and their specific features and geometric properties, e.g. point and line information. In this framework, a combined kriging approach is introduced, taking into account not only the point information of a reliable primary network, e.g., from national weather services, but also the higher uncertainty of the PWS- and CML-based precipitation. The path-averaged information of the CMLs is included through a block kriging-type approach.</p><p>The methodology was applied for two 7-months periods in Germany using an hourly temporal and a 1x1 km spatial resolution. By incorporating CMLs and PWS, the Pearson correlation could be increased from 0.56 to 0.73 compared to using only primary network for interpolation. The resulting precipitation maps also provided good agreement compared to gauge adjusted radar products.</p>

scholarly journals The use of social network methodological framework in nursing care to breastfeeding women

2009 ◽  
Vol 17 (3) ◽  
pp. 354-360 ◽  
Author(s):  
Maria Helena do Nascimento Souza ◽  
Ivis Emília de Oliveira Souza ◽  
Florence Romijn Tocantins
Keyword(s):  
Social Network ◽  
Social Context ◽  
Network Analysis ◽  
Nursing Care ◽  
Nursing Practice ◽  
Methodological Framework ◽  
Strong Bond ◽  
The People ◽  
Primary Network ◽  
The Social

This study aimed to discuss the contribution of the social network methodological framework in nursing care delivered to women who breastfeed their children up to six months of age. This qualitative study aimed to elaborate the social network map of 20 women through tape-recorded interview. Social network analysis evidenced a "strong" bond between these women and members from their primary network, especially friends, neighbors, mothers or with the child's father, who were reported as the people most involved in the breastfeeding period. The contribution of this framework to nursing practice is discussed, especially in care and research processes. We believe that nurses' appropriation of this framework can be an important support for efficacious actions, as well as to favor a broader perspective on the social context people experience.

scholarly journals Dual-Path Attention Compensation U-Net for Stroke Lesion Segmentation

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Haisheng Hui ◽  
Xueying Zhang ◽  
Zelin Wu ◽  
Fenlian Li
Keyword(s):  
Input Image ◽  
Core Network ◽  
Lesion Segmentation ◽  
Coverage Area ◽  
Primary Path ◽  
Primary Network ◽  
Segmentation Methods ◽  
Mri Scans ◽  
Stroke Lesion ◽  
Segmentation Task

For the segmentation task of stroke lesions, using the attention U-Net model based on the self-attention mechanism can suppress irrelevant regions in an input image while highlighting salient features useful for specific tasks. However, when the lesion is small and the lesion contour is blurred, attention U-Net may generate wrong attention coefficient maps, leading to incorrect segmentation results. To cope with this issue, we propose a dual-path attention compensation U-Net (DPAC-UNet) network, which consists of a primary network and auxiliary path network. Both networks are attention U-Net models and identical in structure. The primary path network is the core network that performs accurate lesion segmentation and outputting of the final segmentation result. The auxiliary path network generates auxiliary attention compensation coefficients and sends them to the primary path network to compensate for and correct possible attention coefficient errors. To realize the compensation mechanism of DPAC-UNet, we propose a weighted binary cross-entropy Tversky (WBCE-Tversky) loss to train the primary path network to achieve accurate segmentation and propose another compound loss function called tolerance loss to train the auxiliary path network to generate auxiliary compensation attention coefficient maps with expanded coverage area to perform compensate operations. We conducted segmentation experiments using the 239 MRI scans of the anatomical tracings of lesions after stroke (ATLAS) dataset to evaluate the performance and effectiveness of our method. The experimental results show that the DSC score of the proposed DPAC-UNet network is 6% higher than the single-path attention U-Net. It is also higher than the existing segmentation methods of the related literature. Therefore, our method demonstrates powerful abilities in the application of stroke lesion segmentation.

scholarly journals Performance Enhancement for Multihop Cognitive DF and AF Relaying Protocols under Joint Impact of Interference and Hardware Noises: NOMA for Primary Network and Best-Path Selection for Secondary Network

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Tran Trung Duy ◽  
Pham Thi Dan Ngoc ◽  
Phuong T. Tran
Keyword(s):  
Spectrum Sharing ◽  
Performance Enhancement ◽  
Path Selection ◽  
Secondary Source ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Transmit Power ◽  
Primary Network ◽  
Secondary Network ◽  
Relaying Protocols

In this paper, we propose and evaluate performance of multihop multipath underlay cognitive radio networks. In a primary network, an uplink nonorthogonal multiple access method is employed to allow primary transmitters to simultaneously transmit their data to a primary receiver. Using an underlay spectrum-sharing method, secondary source and secondary relays must adjust their transmit power to guarantee quality of service of the primary network. Under the limited transmit power, cochannel interference from the primary transmitters, and hardware noises caused by impairments, we propose best-path selection methods to improve the end-to-end performance for the secondary network. Moreover, both multihop decode-and-forward and amplify-and-forward relaying protocols are considered in this paper. We derive expressions of outage probability for the primary and secondary networks and propose an efficient method to calculate the transmit power of the secondary transmitters. Then, computer simulations employing the Monte-Carlo approach are realized to validate the derivations.

Transient temperature variations in the primary network of a solar power plant

1978 ◽  
Vol 1 (2) ◽  
pp. 185-195 ◽  
Author(s):  
O. Barra ◽  
M. Conti ◽  
L. Correra ◽  
R. Visentin ◽  
V. Marinelli
Keyword(s):  
Power Plant ◽  
Solar Power ◽  
Transient Temperature ◽  
Solar Power Plant ◽  
Temperature Variations ◽  
Primary Network

Controlling a Direct Matrix Frequency Converter of Secondary Power Supply Sources for Autonomous Objects

2021 ◽  
Vol 7 (7) ◽  
pp. 41-50
Author(s):  
Maxim A. KISLYAKOV ◽  
◽  
Kirill K. KRUTIKOV ◽  
Vyacheslav V. ROZHKOV ◽  
◽  
...  
Keyword(s):  
Frequency Converter ◽  
Favorable Effect ◽  
Time Interval ◽  
Sliding Modes ◽  
Phase Voltage ◽  
Average Deviation ◽  
Discontinuous Control ◽  
Frequency Converters ◽  
Primary Network ◽  
Autonomous Objects

A version of using "sliding modes" in performing discontinuous control of dynamic objects for matrix frequency converters (MFC) as part of an on-board aircraft network is proposed. Unlike the way used in the existing MFC control algorithms, the sinusoidal voltages available in the primary network are processed according to the proposed modernized technology of "sliding modes". The level of discontinuous voltages is selected from the condition of minimum deviations from the target, which has a favorable effect on the spectrum of output voltages. On the selected time interval, the input primary network phase voltages and the specified output network phase voltages are sampled. A positive minimum difference between the primary network phase voltage closest to its desired value and the specified secondary network phase voltage is produced. This difference acts as a positive discontinuous control. A negative difference acts as a negative discontinuous control. Over the calculated interval, the average deviation from the specified phase voltage is zero. Owing to this feature, the smallest distortions in the MFC output voltage spectrum are obtained at arbitrary loads and evolutions of the primary network voltage frequency and amplitude. Versions of three-phase and six-phase primary sources are considered. The effectiveness of the proposed version of using "sliding modes" has been confirmed by simulation.

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