Journal articles on the topic 'Channel reliability metrics'
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Forsting, Johannes, Marlena Rohm, Martijn Froeling, Anne-Katrin Güttsches, Matthias Vorgerd, Lara Schlaffke, and Robert Rehmann. "High Inter-Rater Reliability of Manual Segmentation and Volume-Based Tractography in Healthy and Dystrophic Human Calf Muscle." Diagnostics 11, no. 9 (August 24, 2021): 1521. http://dx.doi.org/10.3390/diagnostics11091521.
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Background: Muscle diffusion tensor imaging (mDTI) is a promising surrogate biomarker in the evaluation of muscular injuries and neuromuscular diseases. Since mDTI metrics are known to vary between different muscles, separation of different muscles is essential to achieve muscle-specific diffusion parameters. The commonly used technique to assess DTI metrics is parameter maps based on manual segmentation (MSB). Other techniques comprise tract-based approaches, which can be performed in a previously defined volume. This so-called volume-based tractography (VBT) may offer a more robust assessment of diffusion metrics and additional information about muscle architecture through tract properties. The purpose of this study was to assess DTI metrics of human calf muscles calculated with two segmentation techniques—MSB and VBT—regarding their inter-rater reliability in healthy and dystrophic calf muscles. Methods: 20 healthy controls and 18 individuals with different neuromuscular diseases underwent an MRI examination in a 3T scanner using a 16-channel Torso XL coil. DTI metrics were assessed in seven calf muscles using MSB and VBT. Coefficients of variation (CV) were calculated for both techniques. MSB and VBT were performed by two independent raters to assess inter-rater reliability by ICC analysis and Bland-Altman plots. Next to analysis of DTI metrics, the same assessments were also performed for tract properties extracted with VBT. Results: For both techniques, low CV were found for healthy controls (≤13%) and neuromuscular diseases (≤17%). Significant differences between methods were found for all diffusion metrics except for λ1. High inter-rater reliability was found for both MSB and VBT (ICC ≥ 0.972). Assessment of tract properties revealed high inter-rater reliability (ICC ≥ 0.974). Conclusions: Both segmentation techniques can be used in the evaluation of DTI metrics in healthy controls and different NMD with low rater dependency and high precision but differ significantly from each other. Our findings underline that the same segmentation protocol must be used to ensure comparability of mDTI data.
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Amezcua Valdovinos, Ismael, Patricia Elizabeth Figueroa Millán, Jesús Arturo Pérez-Díaz, and Cesar Vargas-Rosales. "Distributed Channel Ranking Scheduling Function for Dense Industrial 6TiSCH Networks." Sensors 21, no. 5 (February 25, 2021): 1593. http://dx.doi.org/10.3390/s21051593.
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The Industrial Internet of Things (IIoT) is considered a key enabler for Industry 4.0. Modern wireless industrial protocols such as the IEEE 802.15.4e Time-Slotted Channel Hopping (TSCH) deliver high reliability to fulfill the requirements in IIoT by following strict schedules computed in a Scheduling Function (SF) to avoid collisions and to provide determinism. The standard does not define how such schedules are built. The SF plays an essential role in 6TiSCH networks since it dictates when and where the nodes are communicating according to the application requirements, thus directly influencing the reliability of the network. Moreover, typical industrial environments consist of heavy machinery and complementary wireless communication systems that can create interference. Hence, we propose a distributed SF, namely the Channel Ranking Scheduling Function (CRSF), for IIoT networks supporting IPv6 over the IEEE 802.15.4e TSCH mode. CRSF computes the number of cells required for each node using a buffer-based bandwidth allocation mechanism with a Kalman filtering technique to avoid sudden allocation/deallocation of cells. CRSF also ranks channel quality using Exponential Weighted Moving Averages (EWMAs) based on the Received Signal Strength Indicator (RSSI), Background Noise (BN) level measurements, and the Packet Delivery Rate (PDR) metrics to select the best available channel to communicate. We compare the performance of CRSF with Orchestra and the Minimal Scheduling Function (MSF), in scenarios resembling industrial environmental characteristics. Performance is evaluated in terms of PDR, end-to-end latency, Radio Duty Cycle (RDC), and the elapsed time of first packet arrival. Results show that CRSF achieves high PDR and low RDC across all scenarios with periodic and burst traffic patterns at the cost of increased end-to-end latency. Moreover, CRSF delivers the first packet earlier than Orchestra and MSF in all scenarios. We conclude that CRSF is a viable option for IIoT networks with a large number of nodes and interference. The main contributions of our paper are threefold: (i) a bandwidth allocation mechanism that uses Kalman filtering techniques to effectively calculate the number of cells required for a given time, (ii) a channel ranking mechanism that combines metrics such as the PDR, RSSI, and BN to select channels with the best performance, and (iii) a new Key Performance Indicator (KPI) that measures the elapsed time from network formation until the first packet reception at the root.
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Jin, Yong, and Guangwei Bai. "Energy-Aware Adaptive Cooperative FEC Protocol in MIMO Channel for Wireless Sensor Networks." Journal of Electrical and Computer Engineering 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/891429.
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We propose an adaptive cooperative forward error correction (ACFEC) based on energy efficiency combining Reed-Solomon (RS) coder algorithm and multiple input multiple output (MIMO) channel technology with monitoring signal-to-noise ratio (SNR) in wireless sensor networks. First, we propose a new Markov chain model for FEC based on RS codes and derive the expressions for QoS on the basis of this model, which comprise four metrics: throughput, packet error rate, delay, and energy efficiency. Then, we apply RS codes with the MIMO channel technology to the cross-layer design. Numerical and simulation results show that the joint design of MIMO and adaptive cooperative FEC based on RS codes can achieve considerable spectral efficiency gain, real-time performance, reliability, and energy utility.
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Bokharaie, V. Samadi, and A. Jahanian. "Side-channel leakage assessment metrics and methodologies at design cycle: A case study for a cryptosystem." Journal of Information Security and Applications 54 (October 2020): 102561. http://dx.doi.org/10.1016/j.jisa.2020.102561.
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Chiariotti, Federico, Israel Leyva-Mayorga, Čedomir Stefanović, Anders E. Kalør, and Petar Popovski. "Spectrum Slicing for Multiple Access Channels with Heterogeneous Services." Entropy 23, no. 6 (May 28, 2021): 686. http://dx.doi.org/10.3390/e23060686.
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Wireless mobile networks from the fifth generation (5G) and beyond serve as platforms for flexible support of heterogeneous traffic types with diverse performance requirements. In particular, the broadband services aim for the traditional rate optimization, while the time-sensitive services aim for the optimization of latency and reliability, and some novel metrics such as Age of Information (AoI). In such settings, the key question is the one of spectrum slicing: how these services share the same chunk of available spectrum while meeting the heterogeneous requirements. In this work we investigated the two canonical frameworks for spectrum sharing, Orthogonal Multiple Access (OMA) and Non-Orthogonal Multiple Access (NOMA), in a simple, but insightful setup with a single time-slotted shared frequency channel, involving one broadband user, aiming to maximize throughput and using packet-level coding to protect its transmissions from noise and interference, and several intermittent users, aiming to either to improve their latency-reliability performance or to minimize their AoI. We analytically assessed the performances of Time Division Multiple Access (TDMA) and ALOHA-based schemes in both OMA and NOMA frameworks by deriving their Pareto regions and the corresponding optimal values of their parameters. Our results show that NOMA can outperform traditional OMA in latency-reliability oriented systems in most conditions, but OMA performs slightly better in age-oriented systems.
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Kulow, Alexander, Thomas Schamberger, Lars Tebelmann, and Georg Sigl. "Finding the Needle in the Haystack: Metrics for Best Trace Selection in Unsupervised Side-Channel Attacks on Blinded RSA." IEEE Transactions on Information Forensics and Security 16 (2021): 3254–68. http://dx.doi.org/10.1109/tifs.2021.3074884.
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Ateeq, Muhammad, Muhammad Khalil Afzal, Muhammad Naeem, Muhammad Shafiq, and Jin-Ghoo Choi. "Deep Learning-Based Multiparametric Predictions for IoT." Sustainability 12, no. 18 (September 19, 2020): 7752. http://dx.doi.org/10.3390/su12187752.
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Wireless Sensor Networks (WSNs) and Internet of Things (IoT) often suffer from error-prone links when deployed in resource-constrained industrial environments. Reliability is a critical performance requirement of loss-sensitive applications, and Signal-to-Noise Ratio (SNR) is a key indicator of successful communications. In addition to the improvement of the physical layer through modulation and channel coding, machine learning offers adaptive solutions by configuring various communication parameters dynamically. In this paper, we apply a Deep Neural Network (DNN) to predict SNR and Packet Delivery Ratio (PDR). Analysis results based on a real dataset show that the DNN can predict SNR and PDR at the accuracy of up to 96% and 98%, respectively, even when trained with very small fraction (≤10%) of data. Moreover, a common subset of features turns out to be useful in predicting both SNR and PDR so as to encourage considering both metrics jointly. We may control the transmission power in the dynamic and adaptive manner when we have predictable SNR and PDR, and thus fulfill the reliability requirements with energy conservation. This can help in achieving sustainable design for the communication system.
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Asuti, Manjunath G., and Prabhugoud I. Basarkod. "Efficiency enhancement using optimized static scheduling technique in TSCH networks." International Journal of Electrical and Computer Engineering (IJECE) 10, no. 2 (April 1, 2020): 1952. http://dx.doi.org/10.11591/ijece.v10i2.pp1952-1962.
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In recent times, the reliable and real-time data transmission becomes a mandatory requirement for various industries and organizations due to the large utilization of Internet of Things (IoT) devices. However, the IoT devices need high reliability, precise data exchange and low power utilization which cannot be achieved by the conventional Medium Access Control (MAC) protocols due to link failures and high interferences in the network. Therefore, the Time-Slotted Channel Hopping (TSCH) networks can be used for link scheduling under the IEEE 802.15.4e standard. In this paper, we propose an Optimized Static Scheduling Technique (OSST) for the link scheduling in IEEE 802.15.4e based TSCH networks. In OSST the link schedule is optimized by considering the packet latency information during transmission by checking the status of the transmitted packets as well as keeping track of the lost data packets from source to destination nodes. We evaluate the proposed OSST model using 6TiSCH Simulator and compare the different performance metrics with Simple distributed TSCH Scheduling.
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Gibbs, Matthew S., David McInerney, Greer Humphrey, Mark A. Thyer, Holger R. Maier, Graeme C. Dandy, and Dmitri Kavetski. "State updating and calibration period selection to improve dynamic monthly streamflow forecasts for an environmental flow management application." Hydrology and Earth System Sciences 22, no. 1 (February 1, 2018): 871–87. http://dx.doi.org/10.5194/hess-22-871-2018.
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Abstract. Monthly to seasonal streamflow forecasts provide useful information for a range of water resource management and planning applications. This work focuses on improving such forecasts by considering the following two aspects: (1) state updating to force the models to match observations from the start of the forecast period, and (2) selection of a shorter calibration period that is more representative of the forecast period, compared to a longer calibration period traditionally used. The analysis is undertaken in the context of using streamflow forecasts for environmental flow water management of an open channel drainage network in southern Australia. Forecasts of monthly streamflow are obtained using a conceptual rainfall–runoff model combined with a post-processor error model for uncertainty analysis. This model set-up is applied to two catchments, one with stronger evidence of non-stationarity than the other. A range of metrics are used to assess different aspects of predictive performance, including reliability, sharpness, bias and accuracy. The results indicate that, for most scenarios and metrics, state updating improves predictive performance for both observed rainfall and forecast rainfall sources. Using the shorter calibration period also improves predictive performance, particularly for the catchment with stronger evidence of non-stationarity. The results highlight that a traditional approach of using a long calibration period can degrade predictive performance when there is evidence of non-stationarity. The techniques presented can form the basis for operational monthly streamflow forecasting systems and provide support for environmental decision-making.
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Yamashkin, Stanislav, Milan Radovanovic, Anatoliy Yamashkin, and Darko Vukovic. "Using ensemble systems to study natural processes." Journal of Hydroinformatics 20, no. 4 (March 5, 2018): 753–65. http://dx.doi.org/10.2166/hydro.2018.076.
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Abstract Increasing accuracy of the data analysis of remote sensing of the Earth significantly affects the quality of decisions taken in the field of environmental management. The article describes the methodology for decoding multispectral space images based on the ensemble learning concept, which can effectively solve important problems of geosystems mapping, including diagnostics of the structure and condition of catchment basins, inventory of water bodies and assessment of their ecological state, study of channel processes; monitoring and forecasting of functioning, dynamics and development of geotechnical systems. The developed methodology is based on an algorithm for analyzing the structure of geosystems using ensemble systems based on a fundamentally new organization of the metaclassifier that allows for a weighted decision based on the efficiency matrix, which is characterized by an increase in accuracy of the decoding of space images and resistance to errors. The metaclassification training algorithm based on the method of weighted voting of monoclassifiers is proposed, in which the weights are calculated on the basis of error matrix metrics. The methodology was tested at the test site ‘Inerka’. The performed experiments confirmed that the use of ensemble systems increases the final accuracy, objectivity, and reliability of the analysis.
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Hao, Sheng, and Huyin Zhang. "MAC Performance Analysis for Reliable Power-Line Communication Networks with ARQ Scheme." Sensors 21, no. 1 (December 30, 2020): 196. http://dx.doi.org/10.3390/s21010196.
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Power-line communication (PLC) networks have been increasingly used for constructing industrial IoT (internet of things) and home networking systems due to their low-cost installation and broad coverage feature. To guarantee the transmission reliability, ARQ (automatic repeat request) scheme is introduced into the link layer of reliable PLC networks, which allows the retransmission of a data frame several times so that it has a higher probability to be correctly received. However, current studies of performance analysis for PLC MAC (medium access control) protocol (i.e., IEEE 1901) do not take into account of the impact of ARQ scheme. To resolve this problem, we propose an analytical model to investigate the MAC performance of IEEE 1901 protocol for reliable PLC networks with ARQ scheme. In the modeling process, we first establish a PLC channel model to reflect the impacts of PLC channel types (containing Rayleigh fading and Log-normal fading), additive non-Gaussian noise feature and ARQ scheme on data transmission at link layer. Next, we employ Renewal theory and Queueing dynamics to capture the transmission attempt behavior of executing IEEE 1901 protocol in the unsaturated environment with finite transit buffer size. On the basis of combining these two models, we derive the closed-form expressions of 1901 MAC metrics considering the influence of the ARQ scheme. Furthermore, we prove that the proposed analytical model has the convergence property. Finally, we evaluate the MAC performance of 1901 protocol for reliable PLC networks with ARQ scheme and verify the proposed analytical model.
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Yankovskii, Nikita, and Igor Pastushok. "On multiplexing data streams using trellis-coded modulation in centralized wireless networks." Information and Control Systems, no. 2 (April 29, 2021): 52–59. http://dx.doi.org/10.31799/1684-8853-2021-2-52-59.
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Problem statement: The proliferation of services and applications requiring ultra-low latency and high reliability of data transmission in communication networks leads to creating new approaches and architectures in order to ensure the simultaneous transmission of Enhanced Mobile Broadband (eMBB) and Ultra-Reliable and Low Latency Communication (URLLC) traffic. Providing efficient eMBB and URLLC multiplexing schemes with preset key performance indicators for each stream is the most challenging problem in wireless network development. Purpose: To provide a simultaneous transmission of eMBB and URLLC streams without reducing the user experience of eMBB services by developing a multiplexing scheme and the coherent architecture of physical (PHY) and media access control (MAC) layers in the downlink channel. Results: An eMBB and URLLC multiplexing scheme has been proposed, along with a coherent architecture for PHY and MAC layers, ensuring the given wireless network key performance indicators. The proposed solution performance has been estimated by simulation. The multiplexing scheme outperforms the baseline solution in Bit Error Rate and Frame Error Rate metrics. The coherent PHY and MAC layers architecture provides transmission with an arrival rate of 400 messages per millisecond and 99% message delivery probability in one millisecond. Practical relevance: The obtained results allow communication system developers to deploy centralized wireless networks at industrial objects.
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Monowar, Muhammad Mostafa, and Madini O. Alassafi. "On the Design of Thermal-Aware Duty-Cycle MAC Protocol for IoT Healthcare." Sensors 20, no. 5 (February 25, 2020): 1243. http://dx.doi.org/10.3390/s20051243.
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Wireless Body Area Networks (WBANs) are designed to provide connectivity among diverse miniature body sensors that support different Internet of Things (IoT) healthcare applications. Among diverse body sensors, WBANs exploit in-vivo sensor nodes that detect and collect the required biometric data of certain physiological change inside the human body, and transmits the sensed data utilizing wireless communication. However, sensing and wireless communication activities of in-vivo sensors produce heat and could result thermal damage to the human tissue if the sensing and communication continues for a long period. Furthermore, Quality of Service (QoS) provisioning for diverse traffic types is another striking requirement for WBANs. These pressing yet conflicting concerns trigger the design of ThMAC—a Thermal aware duty cycle MAC protocol for IoT healthcare. The protocol regulates the communication operation of a body sensor based on estimated temperature surrounding a tissue to maintain moderate temperature level in a body, also avoiding hotspot. Exploiting both contention-based and contention free channel access mechanisms, ThMAC introduces a superframe structure, where disjoint periods are allocated for diverse traffic types to achieve QoS provisioning. Moreover, ThMAC ensures a reliable and timely delivery of sporadically generated emergency data through an emergency data management mechanism. ThMAC performance is evaluated through computer simulations in terms of thermal rise, energy consumption as well as QoS metrics such as delay and reliability. The results show superior performance of ThMAC compared to that of IEEE 802.15.6.
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Akhtar, Zain Ul Abiden, and Hongyu Wang. "WiFi-Based Driver’s Activity Monitoring with Efficient Computation of Radio-Image Features." Sensors 20, no. 5 (March 3, 2020): 1381. http://dx.doi.org/10.3390/s20051381.
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Driver distraction and fatigue are among the leading contributing factors in various fatal accidents. Driver activity monitoring can effectively reduce the number of roadway accidents. Besides the traditional methods that rely on camera or wearable devices, wireless technology for driver’s activity monitoring has emerged with remarkable attention. With substantial progress in WiFi-based device-free localization and activity recognition, radio-image features have achieved better recognition performance using the proficiency of image descriptors. The major drawback of image features is computational complexity, which increases exponentially, with the growth of irrelevant information in an image. It is still unresolved how to choose appropriate radio-image features to alleviate the expensive computational burden. This paper explores a computational efficient wireless technique that could recognize the attentive and inattentive status of a driver leveraging Channel State Information (CSI) of WiFi signals. In this novel research work, we demonstrate an efficient scheme to extract the representative features from the discriminant components of radio-images to reduce the computational cost with significant improvement in recognition accuracy. Specifically, we addressed the problem of the computational burden by efficacious use of Gabor filters with gray level statistical features. The presented low-cost solution requires neither sophisticated camera support to capture images nor any special hardware to carry with the user. This novel framework is evaluated in terms of activity recognition accuracy. To ensure the reliability of the suggested scheme, we analyzed the results by adopting different evaluation metrics. Experimental results show that the presented prototype outperforms the traditional methods with an average recognition accuracy of 93.1 % in promising application scenarios. This ubiquitous model leads to improve the system performance significantly for the diverse scale of applications. In the realm of intelligent vehicles and assisted driving systems, the proposed wireless solution can effectively characterize the driving maneuvers, primary tasks, driver distraction, and fatigue by exploiting radio-image descriptors.
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Pan, Yuangang, Ivor W. Tsang, Avinash K. Singh, Chin-Teng Lin, and Masashi Sugiyama. "Stochastic Multichannel Ranking with Brain Dynamics Preferences." Neural Computation 32, no. 8 (August 2020): 1499–530. http://dx.doi.org/10.1162/neco_a_01293.
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A driver's cognitive state of mental fatigue significantly affects his or her driving performance and more important, public safety. Previous studies have leveraged reaction time (RT) as the metric for mental fatigue and aim at estimating the exact value of RT using electroencephalogram (EEG) signals within a regression model. However, due to the easily corrupted and also nonsmooth properties of RTs during data collection, methods focusing on predicting the exact value of a noisy measurement, RT generally suffer from poor generalization performance. Considering that human RT is the reflection of brain dynamics preference (BDP) rather than a single regression output of EEG signals, we propose a novel channel-reliability-aware ranking (CArank) model for the multichannel ranking problem. CArank learns from BDPs using EEG data robustly and aims at preserving the ordering corresponding to RTs. In particular, we introduce a transition matrix to characterize the reliability of each channel used in the EEG data, which helps in learning with BDPs only from informative EEG channels. To handle large-scale EEG signals, we propose a stochastic-generalized expectation maximum (SGEM) algorithm to update CArank in an online fashion. Comprehensive empirical analysis on EEG signals from 40 participants shows that our CArank achieves substantial improvements in reliability while simultaneously detecting noisy or less informative EEG channels.
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He, Xin, and Frank Y. Li. "Metric-Based Cooperative Routing in Multihop Ad Hoc Networks." Journal of Computer Networks and Communications 2012 (2012): 1–12. http://dx.doi.org/10.1155/2012/893867.
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Cooperative communication fully leverages the broadcast nature of wireless channels and exploits time/spatial diversity in a distributed manner, thereby achieving significant improvements in system capacity and transmission reliability. Cooperative diversity has been well studied from the physical layer perspective. Thereafter, cooperative MAC design has also drawn much attention recently. However, very little work has addressed cooperation at the routing layer. In this paper, we propose a simple yet efficient scheme for cooperative routing by using cooperative metrics including packet delivery ratio, throughput, and energy consumption efficiency. To make a routing decision based on our scheme, a node needs to first determine whether cooperation on each link is necessary or not, and if necessary, select the optimal cooperative scheme as well as the optimal relay. To do so, we calculate and compare cooperative routing metric values for each potential relay for each different cooperative MAC scheme (C-ARQ and CoopMAC in this study), and further choose the best value and compare it with the noncooperative link metric. Using the final optimal metric value instead of the traditional metric value at the routing layer, new optimal paths are set up in multihop ad hoc networks, by taking into account the cooperative benefits from the MAC layer. The network performance of the cooperative routing solution is demonstrated using a simple network topology.
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Arun, Henridass, and Gulam Nabi Alsath M. "CPW fed circularly polarized wideband pie-shaped monopole antenna for multi-antenna techniques." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 37, no. 6 (November 5, 2018): 2109–21. http://dx.doi.org/10.1108/compel-12-2017-0515.
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Purpose This paper aims to present the design and implementation of a circularly polarized co-planar waveguide (CPW) fed wideband pie-shaped monopole antenna for multi-antenna techniques. Multi-antenna techniques are promising solutions for higher data rate and enhanced reliability of wireless applications. They find numerous applications in 4G/5G networks and in most wireless standards such as wireless local area networks (WLAN), wireless fidelity and worldwide interoperability for microwave access systems to enhance the channel capacity without additional spectrum by means of multi-path propagation techniques. Design/methodology/approach The antenna is designed to operate at three WLAN frequency bands of 4.8, 5.2 and 5.8 GHz. The measured 10 dB impedance bandwidth of the proposed antenna element is 1.2 GHz (24.23 per cent). The proposed CPW fed, pie-shaped monopole antenna has a gain of 5.4 dB and an efficiency of 72.8 per cent at 4.8 GHz. Findings To use the proposed antenna in a multi-antenna environment, the antennas have to be placed in a close proximity to each other. The close proximity introduces strong mutual coupling between the antennas, which in turn degrades the performance of multi-antenna systems. A multi-antenna system with two antenna elements has been constructed with an edge to edge spacing of 0.24 λ0 (15 mm), and the mutual coupling level is −17 dB. To enhance the isolation between the antenna elements, a shorting pin-based interconnected semicircles enclosed decoupling structure is proposed, which improves the isolation by a factor of 12.67 dB at 4.8 GHz. Originality/value To validate the performance of the proposed multi-antenna in working environment, the performance metrics such as envelope correlation coefficient (ECC), diversity gain (DG) and total active reflection coefficient (TARC) are computed for the proposed multiple-input multiple-output (MIMO) antenna. The ECC value is 0.000366 at center frequency and below 0.09 for the entire operating bandwidth, which is well below the acceptable level of 0.5 as per 3GPP standard. The DG value lies above 9.5 dB for the entire operating bandwidths and it is well above the minimum value of 3 dB. The TARC values are calculated based on S parameters, and it proves that the proposed antenna a good candidate for the multi-antenna systems.
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Raees, Muhammad. "Study of Software Quality Improvement through Reliability Metrics Models and Root Cause Analysis Program." International Journal of Computer Engineering and Information Technology 12, no. 6 (June 30, 2020): 42–47. http://dx.doi.org/10.47277/ijceit/12(6)1.
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Software quality is the most crucial requirement of any organization to survive in the current market scenario. The improvement of quality in software products depends on number of factors such as its architecture, quality metrics, reliability models and root cause analysis for defect handling. This paper focuses on the use of different reliability metrics to improve the reliability in software systems. Paper also emphasizes that removing defects for once is not beneficial for quality improvement, rather using a quality improvement program such as root cause analysis to get to base of defects and decrease the chances of occurrence of same defects again and again. Paper shows that effective root cause analysis program improves the learning process in any organization and helps in development of standards. This article provides an overview of software reliability metrics and root cause analysis program for the improvement of total software quality
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Ogundile, O. O., M. O. Oloyede, O. A. Osanaiye, and F. A. Aina. "Improved distance metric technique for deriving soft reliability information over Rayleigh Fading Channel." Nigerian Journal of Technology 37, no. 4 (November 15, 2018): 1110. http://dx.doi.org/10.4314/njt.v37i4.34.
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Loeliger, H. A. "A practical reliability metric for block codes used on binary-input channels." IEEE Transactions on Communications 38, no. 4 (April 1990): 405–8. http://dx.doi.org/10.1109/26.52649.
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Ma, Lai, and Michael Ladisch. "Evaluation complacency or evaluation inertia? A study of evaluative metrics and research practices in Irish universities." Research Evaluation 28, no. 3 (April 16, 2019): 209–17. http://dx.doi.org/10.1093/reseval/rvz008.
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Abstract Evaluative metrics have been used for research assessment in most universities and funding agencies with the assumption that more publications and higher citation counts imply increased productivity and better quality of research. This study investigates the understanding and perceptions of metrics, as well as the influences and implications of the use of evaluative metrics on research practices, including choice of research topics and publication channels, citation behavior, and scholarly communication in Irish universities. Semi-structured, in-depth interviews were conducted with researchers from the humanities, the social sciences, and the sciences in various career stages. Our findings show that there are conflicting attitudes toward evaluative metrics in principle and in practice. The phenomenon is explained by two concepts: evaluation complacency and evaluation inertia. We conclude that evaluative metrics should not be standardized and institutionalized without a thorough examination of their validity and reliability and without having their influences on academic life, research practices, and knowledge production investigated. We also suggest that an open and public discourse should be supported for the discussion of evaluative metrics in the academic community.
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Shim, Yong-Geol. "An Efficient Decoding Algorithm for Block Codes Based on the Communication Channel Reliability Information." Emerging Science Journal 4, no. 5 (October 1, 2020): 336–44. http://dx.doi.org/10.28991/esj-2020-01235.
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For channel codes in communication systems, an efficient algorithm that controls error is proposed. It is an algorithm for soft decision decoding of block codes. The sufficient conditions to obtain the optimum decoding are deduced so that the efficient method which explores candidate code words can be presented. The information vector of signal space codes has isomorphic coherence. The path metric in the coded demodulator is the selected components of scaled regions. The carrier decision is derived by the normalized metric of synchronized space. An efficient algorithm is proposed based on the method. The algorithm finds out a group of candidate code words, in which the most likely one is chosen as a decoding result. The algorithm reduces the complexity, which is the number of candidate code words. It also increases the probability that the correct code word is included in the candidate code words. It is shown that both the error probability and the complexity are reduced. The positions of the first hard-decision decoded errors and the positions of the unreliable bits are carefully examined. From this examination, the candidate codewords are efficiently searched for. The aim of this paper is to reduce the required number of hard-decision decoding and to lower the block error probability.
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Havedanloo, Saeed, and Hamid Reza Karimi. "Improving the Performance Metric of Wireless Sensor Networks with Clustering Markov Chain Model and Multilevel Fusion." Mathematical Problems in Engineering 2013 (2013): 1–11. http://dx.doi.org/10.1155/2013/783543.
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The paper proposes a performance metric evaluation for a distributed detection wireless sensor network with respect to IEEE 802.15.4 standard. A distributed detection scheme is considered with presence of the fusion node and organized sensors into the clustering and non-clustering networks. Sensors are distributed in clusters uniformly and nonuniformly and network has multilevel fusion centers. Fusion centers act as heads of clusters for decision making based on majority-like received signal strength (RSS) with comparison the optimized value of the common threshold. IEEE 802.15.4 Markov chain model derived the performance metric of proposed network architecture with MAC, PHY cross-layer parameters, and Channel State Information (CSI) specifications while it is including Path-loss, Modulation, Channel coding and Rayleigh fading. Simulation results represent significant enhancement on performance of network in terms of reliability, packet failure, average delay, power consumption, and throughput.
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Ammari, Mohamed Lassaad. "Performance of Blind Turbo Equalizer in Indoor Channels." Journal of Communications Software and Systems 7, no. 2 (June 22, 2011): 52. http://dx.doi.org/10.24138/jcomss.v7i2.178.
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In this paper, we consider the transmission of turbo coded symbols in the indoor radio environment. The system isaffected by the intersymbol interference (ISI) caused by the multipath time-delay spread of the transmission medium. To reduce the channel effect, we propose to use a blind turbo equalizer combining channel estimation, equalization and turbo decoding. The equalizer consists of an interference canceller (IC) and a MAP-BCJR decoder. To improve system performances, we redefine the channel reliability factor used by the MAP-BCJR decoding algorithm. We propose a new metric that takes into account the statistics of the signal at the equalizer output. The channel coefficient estimation is performed using a recursive least squares (RLS) algorithm. A blind receiver initializationtechnique is proposed. This technique is based on a soft decisiondirected least mean square algorithm (soft DD-LMS). For the proposed turbo detector, the ISI cancellation, channel estimation and decoding are jointly performed through an iterative process where modules exchange a soft information.
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Mikryukov, A. A., and A. V. Kuular. "Development of the Incident Management Model in an Enterprise Information System Based on a Three-Tier Architecture Using Key (Relevant) Metrics." Open Education 24, no. 3 (June 27, 2020): 78–86. http://dx.doi.org/10.21686/1818-4243-2020-3-78-86.
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The aim of the study is to increase the efficiency of the incident management process in an enterprise information system. The article analyzes the work on improving the incident management process. The expediency of applying a number of key metrics is substantiated, which makes it possible to assess the degree to which the process indicators achieved their target values, that is, assess the quality of the incident management: the speed of solving the incident, the degree of satisfaction of service users and the availability of channels for processing user requests. A comparative analysis of the existing model of the incidents’ management process and the proposed model is performed. The proposed model, which includes an additional support line, can significantly improve key indicators of incident handling and resolution process. The scientific novelty of the developed proposals lies in the integrated use of a combination of process, technological and service metrics, which provides the construction of a more effective model of incident management.Materials and methods. The theoretical basis of the study is the analysis of recommendations for the use of metrics in accordance with: the management methodology of the COBIT information technology, recommendations for building an incident management process based on the ITIL library of information technology infrastructure, as well as the results of scientific research by Russian and foreign scientists and publications of leading organizations in the field of management incidents in enterprise information systems. The analysis of incident management process metrics is carried out. The mathematical methods of quantitative measurement of key metrics are used. The analysis of statistical data received by the technical support service for incident management processes was carried out.Results. The use of key metrics is justified, with the help of which the task of promptly responding to incidents, their subsequent processing and resolution is solved in conditions of ensuring guaranteed access to channels for processing calls. A three-tier incidents’ management model was developed, which made it possible to more effectively solve the problem of managing their processing based on the integrated use of key metrics.Conclusion. The study revealed the shortcomings of the existing model of the incident management process. The analysis of metrics used in existing models of the incident management process is carried out. The choice of a set of relevant metrics is substantiated, the complex application of which allowed us to develop a more effective incident management model that meets both the requirements of service consumers and the requirements for the operation of an information system. The developed model provides improved quality of incident processing (speed, completeness, reliability).A distinctive feature of the developed model is the use of objective quantitative characteristics obtained on the basis of relevant metrics of the incident management process, which made it possible to substantiate proposals for improving the existing incident management model in the enterprise information system.
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Shafique, Muhammad Akmal, Naveed Khan Baloch, Muhammad Iram Baig, Fawad Hussain, Yousaf Bin Zikria, and Sung Won Kim. "NoCGuard: A Reliable Network-on-Chip Router Architecture." Electronics 9, no. 2 (February 17, 2020): 342. http://dx.doi.org/10.3390/electronics9020342.
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Aggressive scaling in deep nanometer technology enables chip multiprocessor design facilitated by the communication-centric architecture provided by Network-on-Chip (NoC). At the same time, it brings considerable challenges in reliability because a fault in the network architecture severely impacts the performance of a system. To deal with these reliability challenges, this research proposed NoCGuard, a reconfigurable architecture designed to tolerate multiple permanent faults in each pipeline stage of the generic router. NoCGuard router architecture uses four highly reliable and low-cost fault-tolerant strategies. We exploited resource borrowing and double routing strategy for the routing computation stage, default winner strategy for the virtual channel allocation stage, runtime arbiter selection and default winner strategy for the switch allocation stage and multiple secondary bypass paths strategy for the crossbar stage. Unlike existing reliable router architectures, our architecture features less redundancy, more fault tolerance, and high reliability. Reliability comparison using Mean Time to Failure (MTTF) metric shows 5.53-time improvement in a lifetime and using Silicon Protection Factor (SPF), 22-time improvement, which is better than state-of-the-art reliable router architectures. Synthesis results using 15 nm and 45 nm technology library show that additional circuitry incurs an area overhead of 28.7% and 28% respectively. Latency analysis using synthetic, PARSEC and SPLASH-2 traffic shows minor increase in performance by 3.41%, 12% and 15% respectively while providing high reliability.
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Suneela, Dr B. "HUGE MIMO TECHNOLOGY ROLE RECOGNITION FOR ITS EFFECTIVE 5G AND SATELLITE CONNECTIVITY IMPLEMENTATION." INFORMATION TECHNOLOGY IN INDUSTRY 9, no. 2 (April 10, 2021): 929–35. http://dx.doi.org/10.17762/itii.v9i2.429.
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Wireless networking provides major problems due to the large number of users (QoS). This level of demand is supposed to be satisfied by 5G technology. And with respect to satellite communication, there is also a broad data requirement. Because of the LOS requirements, as well as an increased number of cells, today's mobile phone technology can no longer meet this bandwidth an obvious solution to this problem would be using milli-metric wave communication (MIMO). It is important to use multiple antennas (MIMO) and space multiplex when using the MIM approach to improve the spectrum efficiency and data reliability. With MIM support beam-forming and channel information, the device is able to boost energy efficiency. Similar ideas can be applied to other technologies such as satellite communication. These researchers have successfully completed the tasks related to MIM, and have now proposed a prototype for the assessment.
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Rashid, Muhammad, Naveed Khan Baloch, Muhammad Akmal Shafique, Fawad Hussain, Shahroon Saleem, Yousaf Bin Zikria, and Heejung Yu. "Fault-Tolerant Network-On-Chip Router Architecture Design for Heterogeneous Computing Systems in the Context of Internet of Things." Sensors 20, no. 18 (September 18, 2020): 5355. http://dx.doi.org/10.3390/s20185355.
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Network-on-chip (NoC) architectures have become a popular communication platform for heterogeneous computing systems owing to their scalability and high performance. Aggressive technology scaling makes these architectures prone to both permanent and transient faults. This study focuses on the tolerance of a NoC router to permanent faults. A permanent fault in a NoC router severely impacts the performance of the entire network. Thus, it is necessary to incorporate component-level protection techniques in a router. In the proposed scheme, the input port utilizes a bypass path, virtual channel (VC) queuing, and VC closing strategies. Moreover, the routing computation stage utilizes spatial redundancy and double routing strategies, and the VC allocation stage utilizes spatial redundancy. The switch allocation stage utilizes run-time arbiter selection. The crossbar stage utilizes a triple bypass bus. The proposed router is highly fault-tolerant compared with the existing state-of-the-art fault-tolerant routers. The reliability of the proposed router is 7.98 times higher than that of the unprotected baseline router in terms of the mean-time-to-failure metric. The silicon protection factor metric is used to calculate the protection ability of the proposed router. Consequently, it is confirmed that the proposed router has a greater protection ability than the conventional fault-tolerant routers.
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Maričić, Srđan, Nenad Milošević, Dejan Drajić, Dejan Milić, and Jelena Anastasov. "Physical Layer Intercept Probability in Wireless Sensor Networks over Fisher–Snedecor ? Fading Channels." Electronics 10, no. 12 (June 8, 2021): 1368. http://dx.doi.org/10.3390/electronics10121368.
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In this paper, we analyze the physical layer security (PLS) of an arbitrarily dimensioned wireless sensor network (WSN) in the presence of an unauthorized attacker. Various scheduling schemes have been exploited in order to enhance the secure transmission of reliable links impaired by Fisher–Snedecor F fading. The path loss among active nodes is also considered. The exact intercept probability expressions are derived recalling an optimal scheduling scheme (OS), a scheduling policy based on a specific cumulative distribution function (CS), and round-robin scheduling as a baseline. The asymptotic behavior of the intercept metric is also presented in a simpler form with acceptable accuracy. The secrecy diversity orders are defined and the security–reliability tradeoff of WSN is specified. Numerical results are provided to demonstrate the interplay of various main/wiretap channel conditions, the distances among nodes, the number of active sensors, and the average main-to-eavesdropper’s signal ratio in order to upgrade the quality of the WSN secrecy performance. Additionally, the impact of the outage probability on the intercept probability is defined for a variety of scenarios under which either the CS or OS scheme could be selected as suitable for PLS enhancement. The obtained results are verified by independent Monte Carlo simulations.
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De Keersmaecker, Wanda, Stef Lhermitte, Olivier Honnay, Jamshid Farifteh, Ben Somers, and Pol Coppin. "How to measure ecosystem stability? An evaluation of the reliability of stability metrics based on remote sensing time series across the major global ecosystems." Global Change Biology 20, no. 7 (April 26, 2014): 2149–61. http://dx.doi.org/10.1111/gcb.12495.
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Ali, Tariq, Muhammad Irfan, Ahmad Shaf, Abdullah Saeed Alwadie, Ahthasham Sajid, Muhammad Awais, and Muhammad Aamir. "A Secure Communication in IoT Enabled Underwater and Wireless Sensor Network for Smart Cities." Sensors 20, no. 15 (August 2, 2020): 4309. http://dx.doi.org/10.3390/s20154309.
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Nowadays, there is a growing trend in smart cities. Therefore, the Internet of Things (IoT) enabled Underwater and Wireless Sensor Networks (I-UWSN) are mostly used for monitoring and exploring the environment with the help of smart technology, such as smart cities. The acoustic medium is used in underwater communication and radio frequency is mostly used for wireless sensor networks to make communication more reliable. Therefore, some challenging tasks still exist in I-UWSN, i.e., selection of multiple nodes’ reliable paths towards the sink nodes; and efficient topology of the network. In this research, the novel routing protocol, namely Time Based Reliable Link (TBRL), for dynamic topology is proposed to support smart city. TBRL works in three phases. In the first phase, it discovers the topology of each node in network area using a topology discovery algorithm. In the second phase, the reliability of each established link has been determined while using two nodes reliable model for a smart environment. This reliability model reduces the chances of horizontal and higher depth level communication between nodes and selects next reliable forwarders. In the third phase, all paths are examined and the most reliable path is selected to send data packets. TBRL is simulated with the help of a network simulator tool (NS-2 AquaSim). The TBRL is compared with other well known routing protocols, i.e., Depth Based Routing (DBR) and Reliable Energy-efficient Routing Protocol (R-ERP2R), to check the performance in terms of end to end delay, packet delivery ratio, and energy consumption of a network. Furthermore, the reliability of TBRL is compared with 2H-ACK and 3H-RM. The simulation results proved that TBRL performs approximately 15% better as compared to DBR and 10% better as compared to R-ERP2R in terms of aforementioned performance metrics.
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Reznicek, J., T. Luhmann, and C. Jepping. "INFLUENCE OF RAW IMAGE PREPROCESSING AND OTHER SELECTED PROCESSES ON ACCURACY OF CLOSE-RANGE PHOTOGRAMMETRIC SYSTEMS ACCORDING TO VDI 2634." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B5 (June 15, 2016): 107–13. http://dx.doi.org/10.5194/isprsarchives-xli-b5-107-2016.
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This paper examines the influence of raw image preprocessing and other selected processes on the accuracy of close-range photogrammetric measurement. The examined processes and features includes: raw image preprocessing, sensor unflatness, distance-dependent lens distortion, extending the input observations (image measurements) by incorporating all RGB colour channels, ellipse centre eccentricity and target detecting. The examination of each effect is carried out experimentally by performing the validation procedure proposed in the German VDI guideline 2634/1. The validation procedure is based on performing standard photogrammetric measurements of high-accurate calibrated measuring lines (multi-scale bars) with known lengths (typical uncertainty = 5 μm at 2 sigma). The comparison of the measured lengths with the known values gives the maximum length measurement error LME, which characterize the accuracy of the validated photogrammetric system. For higher reliability the VDI test field was photographed ten times independently with the same configuration and camera settings. The images were acquired with the metric ALPA 12WA camera. The tests are performed on all ten measurements which gives the possibility to measure the repeatability of the estimated parameters as well. The influences are examined by comparing the quality characteristics of the reference and tested settings.
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Reznicek, J., T. Luhmann, and C. Jepping. "INFLUENCE OF RAW IMAGE PREPROCESSING AND OTHER SELECTED PROCESSES ON ACCURACY OF CLOSE-RANGE PHOTOGRAMMETRIC SYSTEMS ACCORDING TO VDI 2634." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B5 (June 15, 2016): 107–13. http://dx.doi.org/10.5194/isprs-archives-xli-b5-107-2016.
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This paper examines the influence of raw image preprocessing and other selected processes on the accuracy of close-range photogrammetric measurement. The examined processes and features includes: raw image preprocessing, sensor unflatness, distance-dependent lens distortion, extending the input observations (image measurements) by incorporating all RGB colour channels, ellipse centre eccentricity and target detecting. The examination of each effect is carried out experimentally by performing the validation procedure proposed in the German VDI guideline 2634/1. The validation procedure is based on performing standard photogrammetric measurements of high-accurate calibrated measuring lines (multi-scale bars) with known lengths (typical uncertainty = 5 μm at 2 sigma). The comparison of the measured lengths with the known values gives the maximum length measurement error LME, which characterize the accuracy of the validated photogrammetric system. For higher reliability the VDI test field was photographed ten times independently with the same configuration and camera settings. The images were acquired with the metric ALPA 12WA camera. The tests are performed on all ten measurements which gives the possibility to measure the repeatability of the estimated parameters as well. The influences are examined by comparing the quality characteristics of the reference and tested settings.
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Hussain, Ayaz, Muhammad Irfan, Naveed Khan Baloch, Umar Draz, Tariq Ali, Adam Glowacz, Larisa Dunai, and Jose Antonino-Daviu. "Savior: A Reliable Fault Resilient Router Architecture for Network-on-Chip." Electronics 9, no. 11 (October 27, 2020): 1783. http://dx.doi.org/10.3390/electronics9111783.
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The router plays an important role in communication among different processing cores in on-chip networks. Technology scaling on one hand has enabled the designers to integrate multiple processing components on a single chip; on the other hand, it becomes the reason for faults. A generic router consists of the buffers and pipeline stages. A single fault may result in an undesirable situation of degraded performance or a whole chip may stop working. Therefore, it is necessary to provide permanent fault tolerance to all the components of the router. In this paper, we propose a mechanism that can tolerate permanent faults that occur in the router. We exploit the fault-tolerant techniques of resource sharing and paring between components for the input port unit and routing computation (RC) unit, the resource borrowing for virtual channel allocator (VA) and multiple paths for switch allocator (SA) and crossbar (XB). The experimental results and analysis show that the proposed mechanism enhances the reliability of the router architecture towards permanent faults at the cost of 29% area overhead. The proposed router architecture achieves the highest Silicon Protection Factor (SPF) metric, which is 24.8 as compared to the state-of-the-art fault-tolerant architectures. It incurs an increase in latency for SPLASH2 and PARSEC benchmark traffics, which is minimal as compared to the baseline router.
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Lee, Young-Seok, Ki-Hun Lee, and Bang Chul Jung. "Beamforming Techniques for Over-the-Air Computation in MIMO IoT Networks." Sensors 20, no. 22 (November 12, 2020): 6464. http://dx.doi.org/10.3390/s20226464.
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In this paper, a novel beamforming technique is proposed as the over-the-air computation (AirComp) framework in a multiple-input multiple-output (MIMO) Internet-of-things (IoT) network consisting of multiple IoT sensors (STAs) and a single access point (AP). We assume that each IoT device has the channel state information (CSI) from itself to the AP and the AP has the global CSI of all IoT devices. We consider the mean squared error (MSE), which represents the reliability of function computation, as a performance metric. In short, each IoT device exploits maximum-ratio transmission (MRT) as a transmit beamforming technique to improve MSE performance by taking full advantage of multiple transmit antennae. Moreover, for the receive beamforming, we first consider a receive antenna selection (RAS) technique as the simplest beamforming method at the AP. Then, a semi-definite relaxation (SDR) method and a successive convex approximation (SCA) algorithm are considered and compared with each other in terms of MSE. Finally, we propose a novel two-step beamforming algorithm to further improve the MSE performance of the aforementioned techniques. We have numerically verified through computer simulations that the proposed framework has an improved MSE performance of about 6dB compared to the conventional single-input multiple-output (SIMO) AirComp, even with only two transmit antennae, and the modified MRT outperforms the other transmit beamforming techniques. Furthermore, the proposed receive beamforming technique, a two-step algorithm, shows the best performance in terms of MSE compared to prior studies.
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Oh, Hayoung. "Mobility-Aware Video Streaming in MIMO-Capable Heterogeneous Wireless Networks." Mathematical Problems in Engineering 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/8293582.
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Multiple input and multiple output (MIMO) is a well-known technique for the exploitation of the spatial multiplexing (MUX) and spatial diversity (DIV) gains that improve transmission quality and reliability. In this paper, we propose a quality-adaptive scheme for handover and forwarding that supports mobile-video-streaming services in MIMO-capable, heterogeneous wireless-access networks such as those for Wi-Fi and LTE. Unlike previous handover schemes, we propose an appropriate metric for the selection of the wireless technology and the MIMO mode, whereby a new address availability and the wireless-channel quality, both of which are in a new wireless-access network so that the handover and video-playing delays are reduced, are considered. While an MN maintains its original care-of address (oCoA), the video packets destined for the MN are forwarded with the MIMO technique (MUX mode or DIV mode) on top of a specific wireless technology from the previous Access Router (pAR) to the new Access Router (nAR) until they finally reach the MN; however, to guarantee a high video-streaming quality and to limit the video-packet-forwarding hops between the pAR and the nAR, the MN creates a new CoA (nCOA) within the delay threshold of the QoS/quality of experience (QoE) satisfaction result, and then, as much as possible, the video packet is forwarded with the MUX. Through extensive simulations, we show that the proposed scheme is a significant improvement upon the other schemes.
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Mua, Lilian Ndinda, and Abel Anyieni. "Merchandizing Practices and Sales Performance of Supermarkets in Nakuru County, Kenya." International Journal of Current Aspects 3, no. VI (November 4, 2019): 16–32. http://dx.doi.org/10.35942/ijcab.v3ivi.76.
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In Kenya, the challenges of sales performance are prevalent amongst the supermarkets. A declining sales performance was noted for Uchumi supermarket in its 2016 financial year leading to its poor financial performance. Nakumatt supermarket has also had poor sales performance in the recent years leading to its struggling financial position. Merchandizing is one of the aspects that can be utilized for the purposes of improving on sales performance. The purpose of the study is to determine the effect of merchandizing practices and sales performance of Supermarkets in Nakuru County, Kenya. The study seeks to examine the diverse aspects of merchandizing on sales performance and try to establish why the supermarkets are making losses and not profits on sales. The study specifically seek to determine the effect of customer attraction, product differentiation, product access and staff attributes on sales performance of Supermarkets in Nakuru town. This study used The Product Marketing Mix Theory, Customer Behaviour Theory and Impulse Buying Behaviour Theory. This study utilized descriptive research design to guide the study on data collection, analysis and presentation of findings. To obtain its data, the study will target the eight main supermarkets in Nakuru Town. The target population for the study was 590 staff comprising of management and supermarket line attendants. Nassiuma formula was used to determine the desired sample size for the study. A sample size of 86 respondents was selected. The study then use stratified sampling to select the supermarket line attendants into the study sample. This study used structured questionnaires to obtain its data from supermarket line attendants. Validity and reliability of research questionnaire was tested by conducting a pilot study. This study used Content validity to ascertain the validity of the research questionnaires. The study used Cronbach’s Alpha test of internal consistency to test the reliability of the study questionnaires. Statistical Package for Social Sciences (SPSS) version 22. This study used both descriptive and inferential statistics. The entire study used tables to present the findings. The study further concluded that there was a positive relationship between product differentiation aspects and sales performance of fast moving consumer goods in Nakuru town supermarkets. The item that had the highest mean score was that supermarket stocks products based on customer specification. It was also concluded that there was a positive relationship between product access and sales performance of fast moving consumer goods in Nakuru town supermarkets. The metric that had the highest mean score was that supermarket has presence of reliable product distribution channels throughout the year. In the context of staff attributes, the study concluded that there was a positive relationship between staff attributes and sales performance fast moving consumer goods in Nakuru town supermarkets. The statement that supermarket sales staff had sufficient knowledge on product specifications had the highest mean score. The study further concluded that merchandizing strategies, namely, customer attraction, product access, product differentiation and staff attributes significantly predicted the level of sales performance of fast moving consumer goods in Nakuru town supermarkets. Staff attributes had the highest influence on sales performance of fast moving consumer goods in Nakuru town supermarkets. The study will enable the top management of supermarkets in making decisions of merchandising. This study will also help academicians in this subject area as well future researcher for the study will add to the limited literature on merchandizing strategies and sales performance.
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Murali, K., and S. Siva Perumal. "Error rate performance analysis of power domain NOMA over AWGN and fading channels with generalized space shift keying in wireless 5G." Journal of Intelligent & Fuzzy Systems, October 26, 2020, 1–6. http://dx.doi.org/10.3233/jifs-189416.
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The Non-Orthogonal Multiple Access (NOMA) emerged as a latest solution to demand of high data rated with excellent reliability and robustness. In this paper, the performance analysis of the NOMA under fading channel is presented with emphasis on error rate calculations. In addition, the focus is on exploring the impact of various modulation techniques like binary phase shift keying (BPSK), Quadrature Phase Shift Keying (QPSK) and Generalized Space Shift Keying (GSSK). The simulation study has been performed on MATLAB tool and results are analyzed efficiently in the metrics of NOMA.
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Sharma, Vijay Kumar. "CNTFET Circuit-Based Wide Fan-In Domino Logic for Low Power Applications." Journal of Circuits, Systems and Computers, August 28, 2021, 2250036. http://dx.doi.org/10.1142/s0218126622500360.
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Carbon nanotube field effect transistors (CNTFETs) are the best alternative option for the metal oxide semiconductor field effect transistor (MOSFET) in the ultra-deep submicron (ultra-DSM) regime. CNTFET has numerous benefits such as lower off-state current, high current density, low bias potential and better transport property as compared to MOSFET. A rolled graphene sheet-based cylindrical tube is constructed in the channel region of the CNTFET structure. In this paper, an improved domino logic (IDL) configuration is proposed for domino logic circuits to improve the different performance metrics. An extensive comparative simulation analysis is provided for the different performance metrics for different circuits to verify the novelty of the proposed IDL approach. The IDL approach saves the leakage power dissipation by 95.61% and enhances the speed by 87.10% for the 4-bit full adder circuit as compared to the best reported available domino method. The effects of the number of carbon nanotubes (CNTs), temperature, and power supply voltage variations are estimated for leakage power dissipation for the 16-input OR (OR16) gate. The reliability of different performance metrics for different circuit is calculated in terms of uncertainty by running the Monte Carlo simulations for 500 samples. Stanford University’s 32[Formula: see text]nm CNTFET model is applied for circuit simulations.
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Kumar, Suresh, and Payal Arora. "Reach Enhancement of Designed Free Space Optical Communication System Using Hybrid Optical Amplifier." Journal of Optical Communications, April 5, 2019. http://dx.doi.org/10.1515/joc-2019-0022.
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AbstractFree space optical (FSO) communication is coming up as an attractive alternative to solve the connectivity hindrances. It is an efficient optical technology having several advantages such as narrow beam size, unlicensed spectrum, high reliability, huge modulation bandwidth, low power and higher grade of security. In this paper, we have proposed an FSO communication system model using EDFA-EDFA hybrid optical amplifier (HOA) configuration which provides enhanced reach and higher data rate. For transmitting channel, weak turbulence approximation which exhibits log-normal statistics is considered. Q-factor, bit error rate (BER) and Eye diagram have been taken as performance metrics. From simulative results, it has been observed that the designed FSO communication system efficiently enhances the transmission reach from 1,000 to 5,000 m along with a substantial improvement in Q-factor and BER.
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B, Nithya, Naveen Ranjan, and Justin Gopinath A. "Performance Analysis of Prioritization and Contention Control Algorithm in Wireless Body Area Networks." Computer Journal, December 14, 2020. http://dx.doi.org/10.1093/comjnl/bxaa147.
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Abstract A Wireless Body Area Network (WBAN) is the composition of a group of energy-efficient, miniature, invasive/non-invasive, light-weighted sensors that monitor human body health conditions for early detection and treatment for life-threatening diseases. Due to the stringent demands of WBAN, such as energy efficiency, reliability and low delay, the development of an efficient contention control algorithm is exceptionally crucial that aims to maximize throughput by reducing collisions. In this context, this paper proposes an adaptive algorithm, namely, Prioritization and Contention Control (PCC) algorithm, to minimize collisions, latency and energy consumption. The first phase of the proposed algorithm prioritizes sensors using run-time metrics to grant channel access only for the potential nodes to send their data. It leads to a lesser number of collisions among sensors, thereby reducing retransmission attempts. In the second phase, the Contention Window (CW) size is predicted using queue length and collision rate that accurately mimic the current channel status. The dynamic estimation of CW aids in minimizing channel access delay, collisions and energy consumption, thereby enhancing overall network performance. The performance of the proposed PCC algorithm is validated with the 2D Markov model and NS2 simulation in terms of throughput, packet delivery ratio, delay and remaining energy.
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"Performance Analysis of Bit Loading Algorithms for fault tolerant Submarine Communication." International Journal of Engineering and Advanced Technology 8, no. 6 (August 30, 2019): 4087–93. http://dx.doi.org/10.35940/ijeat.f8660.088619.
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In this paper, performance metrics of rate adaptive and margin adaptive bit loading algorithms is simulated and analyzed to improve the data rate in undersea communication channel. In fault tolerant undersea communication, achieving higher data rate is a challenge. Bit loading algorithms have proven efficient with limited power budget. An optimal bit loading algorithm with low complexity and fast convergence for rate adaptive and margin adaptive problems with bit error rate (BER) constraints will increase the data rate and reliability of the system significantly. The simulation has been carried for submarine audio channel with a bandwidth of 0- 20kHz considering ambient noise and thorps attenuation model for 16 subcarriers. Three different approaches such as Chow, Campello and Ant Colony Optimization are simulated for margin adaptive and rate adaptive criteria. Simulation results show that, for margin adaptive conditions Campello and ACO algorithms reduce energy by a factor of 71.50% and 13.05% with respect to Chow’s algorithm with an input of 90 bits. It was also observed that for rate adaptive conditions, Chow and ACO algorithms gave marginally increased bit rate compared to Campello algorithm with energy fixed at 8.35J. Campello and ACO algorithm execution time were reduced by a factor of 67% and 87.10% respectively as compared to Chow’s algorithm.
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JAIN, MANJHARI, AKHILESH A. WAOO, P. S. Patheja, and SANJAY SHARMA. "OPTIMAL ROUTE SELECTION STRATEGY FOR QOS IMPROVEMENT." International Journal of Smart Sensor and Adhoc Network., October 2012, 136–43. http://dx.doi.org/10.47893/ijssan.2012.1152.
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An ad-hoc mobile network is a collection of mobile nodes that are dynamically and arbitrarily located in such a manner that the interconnections between nodes are capable of changing on a continual basis. Ad hoc nodes operating in a single path, single channel model might experience packet loss and high latency due to the congestion caused. Nodes along the heavy traffic path could reach the maximum bandwidth limit and experience undesirable amounts of packet drop. In Ad hoc networks the nodes are mobile and contain no infrastructure. Certain emergency messages have to be delivered with very low latency and high reliability. An efficient routing protocol should ensure reliable packet delivery in a timely manner. Our Proposed solution is to setup multiple optimal paths based on bandwidth and delay. It allows storing multiple optimal paths based on Bandwidth and delay. At time of link failure, it will switch to next available path. To set up multiple paths, we have used the information that we get in the RREQ packet and also send RREP packet to more than one path It reduces overhead of local route discovery at the time of link failure. We investigated the performance metrics namely Retransmission Attempt, Media Access Delay, Network Load by through OPNET simulation.
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Junior, Edson Duarte da Silva, Jacques Wainer, and Alexandre Ferreira. "Handling classification errors by learning to reject classifications." Revista dos Trabalhos de Iniciação Científica da UNICAMP, no. 26 (December 17, 2018). http://dx.doi.org/10.20396/revpibic262018369.
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This work investigates how to improve classification metrics by learning when a classifier has higher chances of misclassification. The rejection technique increases the classification reliability and reduces the costs associated with misclassifications on cost-sensitive scenarios. A scenario of bug triaging classification shows the approach effectiveness where classification accuracy is increased from 67% up to 76%.
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"Improvising Reliability and Security in Multiple Relay Network using Optimal Scheduling." International Journal of Recent Technology and Engineering 8, no. 2 (July 30, 2019): 1243–48. http://dx.doi.org/10.35940/ijrte.b1786.078219.
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In the real-time scenario involving wireless sensor networks, the data forwarding and data gathering procedures are taking place from the remote environment. With the involvement of heterogeneous architecture and multi-hop data transmission paths, there lies a serious threat for secured data communication. There may be chances of data attacks either from the inside intruder or from the external intruder. The problem of data flow attack by adding malicious information, viz. Data injection attack and outside arbitrary attack, viz. Byzantine attacks are found to be more dangerous and cause vulnerability for the wireless sensor network. So improving the reliability and security in multi-relay networks is very much essential. In this work, the practical approach of detecting data injection and Byzantine attacks using the proposed method of random network coding is performed. Then, as improvisation measure, the priority scheduling algorithm is implemented to effectively schedule the data transfer. Real-time packets with highest priority in the distribution queue are placed first in the processing mechanism. The remaining packets are arranged based on the position of the sensor nodes and are placed in separate queues. Least priority packets can obstruct the dispensation of their direct higher precedence packets after waitlisted for a certain number of time frames. Simulation results using the NS2 environment show that using the priority scheduling algorithm has good performance values in terms of the packet delivery ratio, throughput and delay. Also, the attack detection metrics such as false positive ratio and detection ratio are also improved when using the priority scheduling algorithm. Thus an improvised priority algorithm for an uplink scheduler in WSN is implemented to increase the performance and detection metrics.
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Persad, Geeta G., Daniel L. Swain, Claire Kouba, and J. Pablo Ortiz-Partida. "Inter-model agreement on projected shifts in California hydroclimate characteristics critical to water management." Climatic Change, October 3, 2020. http://dx.doi.org/10.1007/s10584-020-02882-4.
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Abstract Shifts away from the historical hydroclimate in populated regions can have dire consequences for water management. Regions like the state of California—where highly engineered, geographically interconnected, and inflexible water management systems are predicated on particular spatiotemporal patterns of water availability—are particularly vulnerable to hydroclimate shifts. However, much of the analysis of hydroclimate sensitivity to anthropogenic climate change has focused on gross metrics like annual mean precipitation, which is highly uncertain at the regional scale. This perceived uncertainty has deterred adaptation investments and quantitative integration of climate projection data into regional water management. Here, we assess projected future shifts in the state of California in a range of hydroclimate metrics critical to water management, using data from 10 statistically downscaled global climate model and two emissions scenarios currently used by the state. We find substantial inter-model agreement under both emissions scenarios—and > 80% inter-model agreement under the more severe climate change scenario—across metrics that collectively point toward an increasingly volatile, temporally concentrated, and extreme precipitation future for the state. We show, via hydrologic and operations modeling, that accounting for shifts in these more nuanced metrics reduces the projected reliability and sustainability of current water management practices to a greater degree than would be inferred from changes in total annual precipitation alone. These results highlight both the viability and critical importance of incorporating climate change projections quantitatively into water management decisions in California and other regions vulnerable to hydroclimate shifts, and underscore the need to develop integrated climate-hydrologic-operations models and decision-making protocols capable of accounting for all projected hydroclimate shifts.
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Traßl, Andreas, Eva Schmitt, Tom Hößler, Lucas Scheuvens, Norman Franchi, Nick Schwarzenberg, and Gerhard Fettweis. "Outage prediction for ultra-reliable low-latency communications in fast fading channels." EURASIP Journal on Wireless Communications and Networking 2021, no. 1 (April 13, 2021). http://dx.doi.org/10.1186/s13638-021-01964-w.
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AbstractThe addition of redundancy is a promising solution to achieve a certain quality of service (QoS) for ultra-reliable low-latency communications (URLLC) in challenging fast fading scenarios. However, adding more and more redundancy to the transmission results in severely increased radio resource consumption. Monitoring and prediction of fast fading channels can serve as the foundation of advanced scheduling. By choosing suitable resources for transmission, the resource consumption is reduced while maintaining the QoS. In this article, we present outage prediction approaches for Rayleigh and Rician fading channels. Appropriate performance metrics are introduced to show the suitability for URLLC radio resource scheduling. Outage prediction in the Rayleigh fading case can be achieved by adding a threshold comparison to state-of-the-art fading prediction approaches. A line-of-sight (LOS) component estimator is introduced that enables outage prediction in LOS scenarios. Extensive simulations have shown that under realistic conditions, effective outage probabilities of$$10^{-5}$$10-5can be achieved while reaching up-state prediction probabilities of more than$${90}{\%}$$90%. We show that the predictor can be tuned to satisfy the desired trade-off between prediction reliability and utilizability of the link. This enables our predictor to be used in future scheduling strategies, which achieve the challenging QoS of URLLC with fewer required redundancy.
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Kumar, Nagesh, and Yashwant Singh. "An Energy Efficient and Reliable Opportunistic Routing for Wireless Sensor Networks." International Journal of Sensors, Wireless Communications and Control 10 (May 3, 2020). http://dx.doi.org/10.2174/2210327910999200503033802.
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Introduction: Routing protocols in wireless sensor networks (WSN) are of major concern because of the important factors like energy efficiency and reliability. Opportunistic routing (OR) is the simplest and reliable routing technique for ad-hoc networks and WSN. The OR protocol guarantee data delivery in the network. As WSN need energy efficient routing, therefore, energy efficient OR protocols gained popularity in the last three years. Objectives: Opportunistic routing improves the performance of the network by utilizing the broadcasting abilities of wireless channels. In this paper, new energy efficient and reliable routing protocol has been proposed that is based on the opportunistic routing technique. Methods/Statistical analysis: The proposed protocol is based on the energy efficient routing metric. The proposed OR protocol prioritize among the candidate forwarders on the basis of energy efficient routing metric and this will lead to the achievement of improved network lifetime. Findings: The end-to-end delay is reduced because of the selection of candidate forwarders is selected from the neighbor list of each node. The proposed protocol uses selective acknowledgments mechanism. The simulation results of the proposed protocol depict the improved performance as compared to other recent OR protocols. Application/Improvements: Proposed protocol can directly be used with existing WSN applications. Further improvements can be made by utilizing more parameters like distance and the quality of transmission.
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Hladkykh, Valery, and Oleg Toroshanko. "THE RESEARCH OF PRODUCTIVITY OF SENSOR NETWORK: THE KEY AND AUXILIARY PERFORMANCE INDICATORS." Visnyk Universytetu “Ukraina”, 2019. http://dx.doi.org/10.36994/2707-4110-2019-1-22-11.
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Ad Hoc sensor network with mobile network nodes is considered. The basic parameters of the bandwidth and quality of the data exchange channel constructed on the sensor network are analyzed. Statistical analysis of network service quality uses a parameter based on Mean Opinion Score (MOS). This parameter takes into account characteristics such as jitter, delay time, and packet loss rate, and allows you to quantify call quality for calls in the range of 1.0 to 5.0. At the stage of designing the sensor network and in the process of its development, the task of choosing a routing algorithm is very important. To solve the problem of optimal routing in the sensor network a partial mathematical model of the network, consisting of N switching nodes and M lines of wireless communication, has been developed. The average time for messages to remain in the line between two network nodes is determined. To improve methods and algorithms for routing in sensory networks, a generalized mathematical model of the routing process in complex networks and methodology has been developed to select the best route or a set of best routes by a set of criteria.For the most complete comparative evaluation of the effectiveness of a route, it is advisable to consider the route metric ‒ the generalized distance selected for the selected service class and the administrative distance ‒ the route parameter by which the degree of confidence in information received from neighboring devices is determined. It is shown that for optimal organization of data flows in a heterogeneous network it is advisable to use routing algorithms with many quality criteria. To do this, you must conduct an ongoing analysis of the characteristics of the network segments and automatically modify the routing tables. The basis of quality functionality is the route metric. In order to increase the reliability of the data on the state of the route, a quantitative (functional) measure of the administrative distance was introduced into the mathematical model. As a tool for evaluating and managing criteria by their relative importance, it is proposed to use the method of analysis of the Saati hierarchy.
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Tomita, Hiroyuki, Kunio Kutsuwada, Masahisa Kubota, and Tsutomu Hihara. "Advances in the Estimation of Global Surface Net Heat Flux Based on Satellite Observation: J-OFURO3 V1.1." Frontiers in Marine Science 8 (February 5, 2021). http://dx.doi.org/10.3389/fmars.2021.612361.
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The reliability of surface net heat flux data obtained from the latest satellite-based estimation [the third-generation Japanese Ocean Flux Data Sets with Use of Remote Sensing Observations (J-OFURO3, V1.1)] was investigated. Three metrics were utilized: (1) the global long-term (30 years) mean for 1988–2017, (2) the local accuracy evaluation based on comparison with observations recorded at buoys located at 11 global oceanic points with varying climatological characteristics, and (3) the physical consistency with the freshwater balance related to the global water cycle. The globally averaged value of the surface net heat flux of J-OFURO3 was −22.2 W m−2, which is largely imbalanced to heat the ocean surface. This imbalance was due to the turbulent heat flux being smaller than the net downward surface radiation. On the other hand, compared with the local buoy observations, the average difference was −5.8 W m−2, indicating good agreement. These results indicate a paradox of the global surface net heat flux. In relation to the global water cycle, the balance between surface latent heat flux (ocean evaporation) and precipitation was estimated to be almost 0 when river runoff from the land was taken into consideration. The reliability of the estimation of the latent heat flux was reconciled by two different methods. Systematic ocean-heating biases by surface sensible heat flux (SHF) and long wave radiation were identified. The bias in the SHF was globally persistent and especially large in the mid- and high latitudes. The correction of the bias has an impact on improving the global mean net heat flux by +5.5 W m−2. Furthermore, since J-OFURO3 SHF has low data coverage in high-latitudes areas containing sea ice, its impact on global net heat flux was assessed using the latest atmospheric reanalysis product. When including the sea ice region, the globally averaged value of SHF was approximately 1.4 times larger. In addition to the bias correction mentioned above, when assuming that the global ocean average of J3 SHF is 1.4 times larger, the net heat flux value changes to the improved value (−11.3 W m−2), which is approximately half the original value (−22.2 W m−2).