Complexity Issues within Eigenvalue-Based Multi-Antenna Spectrum Sensing

This chapter provides a deep insight into multiple antenna eigenvalue-based spectrum sensing algorithms from a complexity perspective. A review of eigenvalue-based spectrum-sensing algorithms is provided. The chapter presents a finite computational complexity analysis in terms of Floating Point Operations (flop) and a comparison of the Maximum-to-Minimum Eigenvalue (MME) detector and a simplified variant of the Multiple Beam forming detector as well as the Approximated MME method. Constant False Alarm Performances (CFAR) are presented to emphasize the complexity-reliability tradeoff within the spectrum-sensing problem, given the strong requirements on the sensing duration and the detection performance.

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A Reliable Spectrum Sensing Strategy Based on Multiple-Antenna Technique

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.765-767.2305 ◽

2013 ◽

Vol 765-767 ◽

pp. 2305-2308

Author(s):

Shou Tao Lv ◽

Ze Yang Dai ◽

Jian Liu

Keyword(s):

Performance Analysis ◽

False Alarm ◽

Closed Form ◽

Spectrum Sensing ◽

Detection Probability ◽

False Alarm Probability ◽

Multiple Antenna ◽

Single Antenna ◽

Simulation Results ◽

Present Simulation

In this paper, we propose a reliable spectrum sensing strategy based on multiple-antenna technique, called RSS-MAT, to combat the channel uncertainties. We derive the closed-form expressions of the false alarm probability and detection probability for RSS-MAT. Finally, we present simulation results to validate our performance analysis. As expected, the simulation results show that RSS-MAT outperforms the spectrum sensing strategy with single antenna.

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Effective Usage of Available Spectrum Using Dispersion Detection Technique

Intelligent Systems and Computer Technology - Advances in Parallel Computing ◽

10.3233/apc200172 ◽

2020 ◽

Author(s):

Durga R ◽

Selvaraj D

Keyword(s):

Cognitive Radio ◽

False Alarm ◽

Frequency Spectrum ◽

Spectrum Sensing ◽

False Alarm Probability ◽

Detection Technique ◽

Decision Threshold ◽

Multiple Antenna ◽

Test Statistic ◽

A New Technique

Spectrum sensing techniques are used for aquising the frequency spectrum in cognitive radio. From research, the efficiency of the spectrum sensing technique increases only if its complexity is increased and if its complexity is decreased then its efficiency decreases. so, a new technique is proposed in this paper based on Dispersion Detection (DD) to balance both complexity and efficiency. Using this detection technique, the false alarm probability is derived for multiple antenna using test statistic distribution. The decision threshold is derived to provide the accurate results. The derived values are verified with Monto Carlo simulation.

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Thousands of human sequences provide deep insight into single genomes

Nature ◽

10.1038/d41586-020-01485-4 ◽

2020 ◽

Vol 581 (7809) ◽

pp. 385-386

Author(s):

Deanna M. Church

Keyword(s):

Deep Insight ◽

Insight Into

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Mobile-Friendly Dashboards to Display Associations Between Cited-by and Similar Journals on Mobile Health Research: A Bibliometric Study (Preprint)

10.2196/preprints.11771 ◽

2018 ◽

Author(s):

Tsair-Wei Chien ◽

Hsien-Yi Wang ◽

Yang Shao ◽

Willy Chou

Keyword(s):

Social Network ◽

Mobile Health ◽

Health Research ◽

Similarity Criteria ◽

Network Density ◽

Deep Insight ◽

Density Indices ◽

The Subject ◽

The Given ◽

Insight Into

BACKGROUND Researchers often spend a great deal of time and effort retrieving related journals for their studies and submissions. Authors often designate one article and then retrieve other articles that are related to the given one using PubMed’s service for finding cited-by or similar articles. However, to date, none present the association between cited-by and similar journals related to a given journal. Authors need one effective and efficient way to find related journals on the topic of mobile health research. OBJECTIVE This study aims (1) to show the related journals for a given journal by both cited-by and similarity criteria; (2) to present the association between cited-by and similarity journals related to a given journal; (3) to inspect the patterns of network density indices among clusters classified by social network analysis (SNA); (4) to investigate the feature of Kendall's coefficient(W) of concordance. METHODS We obtained 676 abstracts since 2013 from Medline based on the keywords of ("JMIR mHealth and uHealth"[Journal]) on June 30, 2018, and plotted the clusters of related journals on Google Maps by using MS Excel modules. The features of network density indices were examined. The Kendall coefficient (W) was used to assess the concordance of clusters across indices. RESULTS This study found that (1) the journals related to JMIR mHealth and uHealth are easily presented on dashboards; (2) a mild association(=0.14) exists between cited-by and similar journals related to JMIR mHealth and uHealth; (3) the median Impact Factor were 3.37 and 2.183 based on the representatives of top ten clusters grouped by the cited-by and similar journals, respectively; (4) all Kendall’s coefficients(i.e., 0.82, 0.89, 0.92, and 0.75) for the four sets of density centrality have a statistically significant concordance (p < 0.05). CONCLUSIONS SNA provides deep insight into the relationships of related journals to a given journal. The results of this research can provide readers with a knowledge and concept diagram to use with future submissions to a given journal in the subject category of Mobile Health Research. CLINICALTRIAL Not available

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Deep insight into the charge transfer interactions in 1,2,4,5-tetracyanobenzene-phenazine cocrystal

Chinese Chemical Letters ◽

10.1016/j.cclet.2021.03.045 ◽

2021 ◽

Author(s):

Hongnan Wu ◽

Yajing Sun ◽

Lingjie Sun ◽

Liwei Wang ◽

Xiaotao Zhang ◽

...

Keyword(s):

Charge Transfer ◽

Deep Insight ◽

Insight Into

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Surface contact behavior of functionally graded thermoelectric materials indented by a conducting punch

Applied Mathematics and Mechanics ◽

10.1007/s10483-021-2732-8 ◽

2021 ◽

Author(s):

Xiaojuan Tian ◽

Yueting Zhou ◽

Lihua Wang ◽

Shenghu Ding

Keyword(s):

Thermoelectric Materials ◽

Singular Integral Equations ◽

Damage Mechanism ◽

Functionally Graded ◽

Deep Insight ◽

Displacement Fields ◽

Thermoelectric Effects ◽

Homogeneous Solutions ◽

The Fourier Transform ◽

Insight Into

AbstractThe contact problem for thermoelectric materials with functionally graded properties is considered. The material properties, such as the electric conductivity, the thermal conductivity, the shear modulus, and the thermal expansion coefficient, vary in an exponential function. Using the Fourier transform technique, the electro-thermo-elastic problems are transformed into three sets of singular integral equations which are solved numerically in terms of the unknown normal electric current density, the normal energy flux, and the contact pressure. Meanwhile, the complex homogeneous solutions of the displacement fields caused by the gradient parameters are simplified with the help of Euler’s formula. After addressing the non-linearity excited by thermoelectric effects, the particular solutions of the displacement fields can be assessed. The effects of various combinations of material gradient parameters and thermoelectric loads on the contact behaviors of thermoelectric materials are presented. The results give a deep insight into the contact damage mechanism of functionally graded thermoelectric materials (FGTEMs).

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Efficient Approximations for Optimization of N-Out-of-K Rule for Heterogeneous Cognitive Radio Networks

Applied Sciences ◽

10.3390/app11073083 ◽

2021 ◽

Vol 11 (7) ◽

pp. 3083

Author(s):

Youheng Tan ◽

Xiaojun Jing

Keyword(s):

Cognitive Radio ◽

Computational Complexity ◽

Spectrum Sensing ◽

Cognitive Radio Networks ◽

Radio Networks ◽

Closed Form Expression ◽

Sampling Point ◽

Mutual Cooperation ◽

Communication Time ◽

Sensing Time

Spectrum sensing (SS) has attracted much attention due to its important role in the improvement of spectrum efficiency. However, the limited sensing time leads to an insufficient sampling point due to the tradeoff between sensing time and communication time. Although the sensing performance of cooperative spectrum sensing (CSS) is greatly improved by mutual cooperation between cognitive nodes, it is at the expense of computational complexity. In this paper, efficient approximations of the N-out-of-K rule-based CSS scheme under heterogeneous cognitive radio networks are provided to obtain the closed-form expression of the sensing threshold at the fusion center (FC), where the false alarm probability and its corresponding detection probability are approximated by the Poisson distribution. The computational complexity required to obtain the optimal sensing threshold at the FC has greatly decreased and theoretical derivations state that the approximation error is negligible. The simulations validate the effectiveness of the proposed scheme.

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Mechanistic insights into the allylic oxidation of aliphatic compounds by tetraamido iron(v) species: A C–H vs. O–H bond activation

New Journal of Chemistry ◽

10.1039/d0nj03095c ◽

2020 ◽

Vol 44 (44) ◽

pp. 19103-19112

Author(s):

Monika ◽

Azaj Ansari

Keyword(s):

Comparative Study ◽

Bond Activation ◽

Iron Complex ◽

Catalytic Reactions ◽

Allylic Oxidation ◽

Deep Insight ◽

Aliphatic Compounds ◽

High Valent ◽

Insight Into

This work is based on a deep insight into a comparative study of C–H vs. O–H bond activation of allylic compound by the high valent iron complex. Our theoretical findings can help to design catalysts with better efficiency for catalytic reactions.

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Conceptualizing Small and Medium-Sized Smart Cities in the Mediterranean Region

International Journal of E-Planning Research ◽

10.4018/ijepr.2019100102 ◽

2019 ◽

Vol 8 (4) ◽

pp. 17-41

Author(s):

Maria Panagiotopoulou ◽

Margarita Kokla ◽

Anastasia Stratigea

Keyword(s):

Empirical Evidence ◽

Smart City ◽

Mediterranean Region ◽

Smart Cities ◽

Semantic Interoperability ◽

Spatial Context ◽

Deep Insight ◽

Key Drivers ◽

The Mediterranean ◽

Insight Into

Despite the remarkable interest in smart cities, noticed during the last decade, a consistent comprehension of the concept is not yet fully realized. Various definitions, ranging from exclusively technology-oriented perceptions to broader views, have been introduced, establishing a definitional polyphony and causing lack of semantic interoperability. Empirical evidence witnesses the prevalence of technology-pushed smart city initiatives as well as their failure to meet expectations in several urban domains. When planning “smart,” the relevance of ICT and their applications should be in alignment with spatial and other urban peculiarities and sub-systems' interactions, implying the need for getting deep insight into the city's ontology. The paper focuses on the extension/enrichment of an existing smart city ontology, with concepts and relationships stemming from Mediterranean small and medium-sized cities, in an attempt to outline their main key drivers and their interrelationships and fully grasp the smart city concept in the particular spatial context.

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