scholarly journals Predictability of geomagnetic series

2003 ◽  
Vol 21 (5) ◽  
pp. 1101-1109 ◽  
Author(s):  
E. Bellanger ◽  
V. G. Kossobokov ◽  
J.-L. Le Mouël

Abstract. The aim of this paper is to lead a practical, rational and rigorous approach concerning what can be done, based on the knowledge of magnetic series, in the field of prediction of the extreme geomagnetic events. We compare the magnetic vector differential at different locations computed with different resolutions, from an entire day to minutes. We study the classical correlations and the simplest possible prediction scheme to conclude a high level of predictability of the magnetic vector variation. The results obtained are far from a random guessing: the error diagrams are either comparable with earthquake prediction studies or out-perform them when the minute sampling is used in accounting for hourly magnetic vector variation. We demonstrate how the magnetic extreme events can be predicted from the hourly value of the magnetic variation with a lead time of several hours. We compute the 2-D empirical distribution of consecutive values of the magnetic vector variation for the estimation of conditional probabilities of different types. The achieved results encourage further development of the approach to prediction of the extreme geomagnetic events.Key words. Ionosphere (modeling and forecasting) – Magnetospheric physics (storms and substorms)

Total twenty different processed meat plant producing emulsion type sausage were histologically and chemically examined for detection of adulteration with unauthorized tissues. Results revealed that samples were adulterated with different types of animal tissues included; hyaline cartilage, tendon, spongy bone, peripheral nerve trunk, basophilic matrix, lymphatic tissue, fascia, fibrocartilage and vascular tissue. Moreover, these samples were adulterated Also, adulterated with plant tissue included; plant stem, leaves and root. Chemical analysis showed a significant difference in their chemical composition (moisture, fat, protein, ash and calcium) content. Moisture and fat content varied around the permissible limit of E.S.S. while low protein, high ash and calcium content was detected in the examined samples. Therefore, Histological and chemical examinations can be used as reliable methods to detect adultration using unauthorized addition of both animal and plant tissues in processed meat product samples which revealed a high level of falsification.


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Yizhe Wang ◽  
Cunqian Feng ◽  
Yongshun Zhang ◽  
Sisan He

Precession is a common micromotion form of space targets, introducing additional micro-Doppler (m-D) modulation into the radar echo. Effective classification of space targets is of great significance for further micromotion parameter extraction and identification. Feature extraction is a key step during the classification process, largely influencing the final classification performance. This paper presents two methods for classifying different types of space precession targets from the HRRPs. We first establish the precession model of space targets and analyze the scattering characteristics and then compute electromagnetic data of the cone target, cone-cylinder target, and cone-cylinder-flare target. Experimental results demonstrate that the support vector machine (SVM) using histograms of oriented gradient (HOG) features achieves a good result, whereas the deep convolutional neural network (DCNN) obtains a higher classification accuracy. DCNN combines the feature extractor and the classifier itself to automatically mine the high-level signatures of HRRPs through a training process. Besides, the efficiency of the two classification processes are compared using the same dataset.


2014 ◽  
Vol 112 (6) ◽  
pp. 1584-1598 ◽  
Author(s):  
Marino Pagan ◽  
Nicole C. Rust

The responses of high-level neurons tend to be mixtures of many different types of signals. While this diversity is thought to allow for flexible neural processing, it presents a challenge for understanding how neural responses relate to task performance and to neural computation. To address these challenges, we have developed a new method to parse the responses of individual neurons into weighted sums of intuitive signal components. Our method computes the weights by projecting a neuron's responses onto a predefined orthonormal basis. Once determined, these weights can be combined into measures of signal modulation; however, in their raw form these signal modulation measures are biased by noise. Here we introduce and evaluate two methods for correcting this bias, and we report that an analytically derived approach produces performance that is robust and superior to a bootstrap procedure. Using neural data recorded from inferotemporal cortex and perirhinal cortex as monkeys performed a delayed-match-to-sample target search task, we demonstrate how the method can be used to quantify the amounts of task-relevant signals in heterogeneous neural populations. We also demonstrate how these intuitive quantifications of signal modulation can be related to single-neuron measures of task performance ( d′).


Author(s):  
Oleksii Omelyanovych ◽  
◽  
Fedir Demishkan ◽  

The study considered the main approaches to the concept of diversification. It was determined that there are different types of diversification depending on the sources of its origin, but the main groups of classification are: functional (by processes), commercial and resource. In general, the economic system can have four typical situations when a process of diversification (specialization) occurs: 1) specialization is more profitable than the possible option of diversification; 2) specialization is the only possible way of further development and existence for this economic system in specific economic conditions; 3) diversification is more profitable than specialization; 4) diversification is the only possible way of further existence and development. Diversification is especially important in conditions of uncertainty in the development of the external environment. In such situations, diversification is the only way to avoid collapse and achieve sustainable development. The firm makes several bets in the hope that at least one of them will win. Offensive motives include aggressive growth policies; financial opportunities; overcoming the limits of growth; achieving synergistic effects. Here it is necessary to determine the presence of defense motives for the use of diversification: the distribution of business risk; reduction of cyclical instability; replacement of the declining activity. In accordance with the objectives of the study for the trucking company, it is possible to propose the use of such diversification strategies as industrial diversification, which is realized through changes in the production capacity of the trucking company; marketing diversification, which will promote the positioning of the relocation service in different market segments, and competitive diversification, which should be carried out using the methods of portfolio analysis of the company's positioning in the market.


Author(s):  
Konstantinos Apostoleris ◽  
Basil Psarianos ◽  
Ioannis-Alexandros Choupas ◽  
Vassilios Matragos

Skew superelevation has proven to be an efficient pavement constructional measure to address hydroplaning phenomena under specific critical superelevation runoff designs. However, this technique has raised concerns about user’s comfort when driving over the skewed edge of the pavement, especially for heavy vehicles and when the traveling speed is higher than the design speed. This paper aims to evaluate the driving comfort outcome on an improved skew superelevation design, where a rounding of the skew edge has been applied. This is achieved through the use of a simulation program which examines the vehicle and driver behavior when passing over it. The simulation program estimates many parameters including the lateral and vertical accelerations ( Gy and Gz) imposed on both elements, the vehicle and the driver. This evaluation is made for different alignment designs provided in the freeway design and for a broad range of especially high velocities ranging from 80 to 160 km/h (50–100 mph), as well as for different types of heavy vehicles. Also, the influence on the above parameters has been investigated in respect of the distance between two consecutive skew superelevations, concerning cases of entering and exiting a simple, low-length curve. The outcomes are classified in order to evaluate their variability as affected by each parameter change (speed, geometry, vehicle). Simulation results are compared with thresholds, as provided in the international literature, to ensure driver comfort and a high level of road safety.


2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
Lars-Ola Bligård ◽  
Anna-Lisa Osvalder

To avoid use errors when handling medical equipment, it is important to develop products with a high degree of usability. This can be achieved by performing usability evaluations in the product development process to detect and mitigate potential usability problems. A commonly used method is cognitive walkthrough (CW), but this method shows three weaknesses: poor high-level perspective, insufficient categorisation of detected usability problems, and difficulties in overviewing the analytical results. This paper presents a further development of CW with the aim of overcoming its weaknesses. The new method is called enhanced cognitive walkthrough (ECW). ECW is a proactive analytical method for analysis of potential usability problems. The ECW method has been employed to evaluate user interface designs of medical equipment such as home-care ventilators, infusion pumps, dialysis machines, and insulin pumps. The method has proved capable of identifying several potential use problems in designs.


2012 ◽  
Vol 116 (1183) ◽  
pp. 963-979 ◽  
Author(s):  
Yihua Cao ◽  
Guozhi Li ◽  
R. A. Hess

Abstract A method to predict the effects of rotor icing on the flight characteristics of a UH-60A helicopter is presented. By considering both natural ice shedding and different types of ice accretion due to local temperature variations on the blade surface, an improved rotor icing model was developed. Next, the effects of icing on rotor force, torque and flapping were incorporated in a nonlinear helicopter dynamic model. Based upon icing design envelopes in cumuliform clouds, trim and stability characteristics were studied. Further development of the helicopter state-space model allowed control and handling qualities characteristics to be investigated with variation of the three icing-related cloud variables (atmospheric temperature, liquid water content, and median volumetric diameter). Results indicated that this method of evaluating rotorcraft icing is both feasible and useful.


2018 ◽  
Vol 386 ◽  
pp. 315-320
Author(s):  
Vladimir S. Egorkin ◽  
Igor E. Vyaliy ◽  
Nikolay S. Sviridov ◽  
Alexander N. Minaev ◽  
Sergey L. Sinebryukhov ◽  
...  

Plasma electrolytic oxidation (PEO) of 5754 aluminum alloy in a tartrate electrolyte was carried out to form a base layer. Composite fluoropolymer coatings were obtained on the base layers in two ways allowing the formation of two different types of morphological structure: a continuous polymer film and a multimodal islet relief. The resulted coatings exhibit substantially different wettability along with high level of barrier properties.


2018 ◽  
Vol 12 (1) ◽  
pp. 1107-1112
Author(s):  
Shiva Raoufi-Danner ◽  
Sterwin Carl ◽  
Abtahi Jahan

Background: Ameloblastoma is the second most common odontogenic tumor. It shows a locally aggressive behavior, with a high level of recurrence. Wide resection of the jaw is recommended for treatment of ameloblastoma. However, radical surgery causes an abnormal mandibular movement, facial asymmetry, and masticatory dysfunction. Methods: Three cases of different types of ameloblastoma is presented, with different reconstruction techniques including Non-Vascularized Bone Graft (NVBG), Osteocutaneous Fibula Free Flap (OFFF), and Deep Circumflex Iliac Artery flap (DCIA). Results: In all three cases the tumor site was successfully reconstructed to obtain very good esthetic results as well as functional oral rehabilitation with implants and fixed prosthetics for optimal masticatory function. Conclusion: For reconstruction of the mandible, we prefer bone grafts from the iliac crest. The natural curvature and variable bone height offer a very good reconstruction of the defect.


Author(s):  
Shiva Abbasi ◽  
Neda Mohsen-Pour ◽  
Niloofar Naderi ◽  
Shahin Rahimi ◽  
Majid Maleki ◽  
...  

Introduction: Congenital heart disease (CHD) is the most common congenital abnormality and the main cause of infant mortality worldwide. Some of the mutations that occur in the GATA4 gene region may result in different types of CHD. Here, we report our in silico analysis of gene variants to determine the effects of the GATA4 gene on the development of CHD. Methods: Online 1000 Genomes Project, ExAC, gnomAD, GO-ESP, TOPMed, Iranome, GME, ClinVar, and HGMD databases were drawn upon to collect information on all the reported GATA4 variations.The functional importance of the genetic variants was assessed by using SIFT, MutationTaster, CADD,PolyPhen-2, PROVEAN, and GERP prediction tools. Thereafter, network analysis of the GATA4protein via STRING, normal/mutant protein structure prediction via HOPE and I-TASSER, and phylogenetic assessment of the GATA4 sequence alignment via ClustalW were performed. Results: The most frequent variant was c.874T>C (45.58%), which was reported in Germany.Ventricular septal defect was the most frequent type of CHD. Out of all the reported variants of GATA4,38 variants were pathogenic. A high level of pathogenicity was shown for p.Gly221Arg (CADD score=31), which was further analyzed. Conclusion: The GATA4 gene plays a significant role in CHD; we, therefore, suggest that it be accorded priority in CHD genetic screening.


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