Statistical Analysis of the Smoothing Effect for Photovoltaic Systems in a Large Area

2010 ◽  
Vol 130 (5) ◽  
pp. 491-500 ◽  
Author(s):  
Takashi Oozeki ◽  
Takumi Takashima ◽  
Kenji Otani ◽  
Yoshihiro Hishikawa ◽  
Gentaro Koshimizu ◽  
...  
Author(s):  
Takashi Oozeki ◽  
Kenji Otani ◽  
Takumi Takashima ◽  
Yoshihiro Hishikawa ◽  
Gentarou Koshimizu ◽  
...  

2018 ◽  
Vol 218 ◽  
pp. 02012 ◽  
Author(s):  
Mohammad A. AL-Adaileh ◽  
Mohammed Anbar ◽  
Yung-Wey Chong ◽  
Ahmed Al-Ani

Software-defined networkings (SDNs) have grown rapidly in recent years be-cause of SDNs are widely used in managing large area networks and securing networks from Distributed Denial of Services (DDoS) attacks. SDNs allow net-works to be monitored and managed through centralized controller. Therefore, SDN controllers are considered as the brain of networks and are considerably vulnerable to DDoS attacks. Thus, SDN controller suffer from several challenges that exhaust network resources. For SDN controller, the main target of DDoS attacks is to prevent legitimate users from using a network resource or receiving their services. Nevertheless, some approaches have been proposed to detect DDoS attacks through the examination of the traffic behavior of networks. How-ever, these approaches take too long to process all incoming packets, thereby leading to high bandwidth consumption and delays in the detection of DDoS at-tacks. In addition, most existing approaches for the detection of DDoS attacks suffer from high positive/negative false rates and low detection accuracy. This study proposes a new approach to detecting DDoS attacks. The approach is called the statistical-based approach for detecting DDoS against the controllers of software-defined networks. The proposed approach is designed to detect the presence of DDoS attacks accurately, reduce false positive/negative flow rates, and minimize the complexity of targeting SDN controllers according to a statistical analysis of packet features. The proposed approach passively captures net-work traffic, filters traffic, and selects the most significant features that contribute to DDoS attack detection. The general stages of the proposed approach are (i) da-ta preprocessing, (ii) statistical analysis, (iii) correlation identification between two vectors, and (iv) rule-based DDoS detection.


Author(s):  
Lucas Ramos Tavares ◽  
Tatiane S. Costa ◽  
Karen Barbosa de Melo ◽  
Joao Lucas de S. Silva ◽  
Marcelo G. Villalva

1951 ◽  
Vol 14 (3) ◽  
pp. 105-108 ◽  
Author(s):  
F. B. Claiborne ◽  
K. E. Cox

A survey is presented of the use of preserved milk samples shipped from a state-wide area to a central laboratory for examination. Statistical analysis of comparative results on a large number of samples proved that within 3 days there was no significant change in grade of preserved milk samples from the grade of the identical samples immediately before preservative was added. This method is suggested for uniformity of the laboratory aspects of milk grading programs throughout a large area, and for evaluation of performance of laboratories engaged in this work.


Author(s):  
Baldoino Sonildo Nóbrega ◽  
Waleria Guerreiro Lima ◽  
Raphael Henrique Falcão de Melo ◽  
Edvan Cruz Aguiar ◽  
Rute Cavalcante Pereira ◽  
...  

<p>The present work has the objective of presenting a fixed and solar tracker photovoltaic systems comparative study, through the technical and financial viability evaluation in a public education institution located in the backlands of the state of Paraíba (Brazil). Through a System Advisor Model simulation software, we estimated the electrical energy production of the systems. Then, we performed a statistical analysis to evaluate the differences between the energy production of the proposed systems. Finally, financial indicators were used to assess which system had better financial viability. The results on performance have shown that the annual production of electric energy for photovoltaic systems with tracking is 32% higher than the fixed system. Statistical analysis proved by hypothesis testing that there is evidence that the tracking system produces more electric energy in relation to the fixed system. As for financial evaluation, the fixed system was more advantageous, since its financial indicators were better in all aspects. The research contributed to a better understanding of the differences between photovoltaic systems in terms of technical, financial and statistical aspects, which may help the decision making when choosing the installation of these systems in the region which is being studied.</p>


Solar Energy ◽  
2016 ◽  
Vol 136 ◽  
pp. 401-411 ◽  
Author(s):  
Vandana Khanna ◽  
B.K. Das ◽  
Vandana ◽  
P.K. Singh ◽  
Prabha Sharma ◽  
...  

2009 ◽  
Vol 67 ◽  
pp. 1-6
Author(s):  
A.A.D.T. Adikaari ◽  
D.M.N.M. Dissanayake ◽  
N.K. Mudugamuwa ◽  
S.R.P. Silva

Organic-inorganic photovoltaic systems which attempt to integrate benefits of both material types in terms of ease of fabrication, stability and efficiency are reviewed. Three broad categories; inorganic-small molecule systems, carbon naotube incorporated organic photovoltaics and nanostructured organic surfaces-based photovoltaics have been discussed with reference to recent literature. Nanocrystal-organic systems are designed to improve broadband photon collection possibilty, nanostructred organic surfaces-based systems attempt to enhance exciton dissociation at the increased area interface. Incorporation of carbon nanotubes in donor-acceptor type photovoltaic systems have been shown as a technique to mitigate drawbacks from short carrier diffusion lengths of organic materials. The concepts present new opportunities for complex photovoltaic systems, which need to be cheap, large area and efficient in order to arrive at an economically viable level for mass uptake.


2008 ◽  
Vol 4 (S256) ◽  
pp. 30-35
Author(s):  
Igor Soszyński

AbstractThe third phase of the Optical Gravitational Lensing Experiment (OGLE-III) has been conducted since 2001 and regularly monitors the brightness of about 200 million stars. The OGLE-III fields cover both Magellanic Clouds and a large area in the Galactic bulge and disk. Here we describe the first parts of the OGLE-III Catalog of Variable Stars which is being prepared on the basis of these data. We present the principles of the catalog and methods used to select variable stars. We expect that the whole catalog will contain at least one million variable stars of all types. The catalog includes the list of variable sources along with their basic parameters, high precision multi-epoch I and V-band photometry and accurate astrometry. All objects are classified and cross-identified with previously published catalogs. We also carry out a preliminary statistical analysis of these huge samples of variable stars.


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