scholarly journals PG 1605+072 in Wet XCov22: Support for the Multi Site Spectroscopic Telescope

2003 ◽  
Vol 12 (1) ◽  
Author(s):  
S. L. Schuh ◽  
U. Heber ◽  
S. Dreizler ◽  
S. O’Toole ◽  
C. S. Jeffery ◽  
...  
Keyword(s):  
Time Series ◽  
Virtual Instrument ◽  
Significant Contribution ◽  
Frequency Resolution ◽  
Paper Briefly ◽  
Mode Identification ◽  
Photometric Monitoring ◽  
Observational Effort ◽  
Whole Earth

AbstractThe Multi-site spectroscopic telescope is a virtual instrument and the name of a collaboration that opens up a new observational window by combining continuous observations of spectroscopic variations and simultaneous photometric monitoring. This constitutes an enormous observational effort, but in return promises to finally provide access to a mode identification for and an asteroseismological analysis of the pulsating sdB star PG 1605+072. Multi-Site Spectroscopic Telescope observations for this object have been secured during a large coordinated campaign in May and June of the year 2002. The frequency resolution and coverage of the photometric time series has been noticeably enhanced by a significant contribution from the Whole Earth Telescope, which was used to observe PG 1605+072 as an alternate target during the WET XCov22 campaign, also conducted in May 2002. This paper briefly outlines the motivation for the MSST project and tries to give a first assessment of the overall quality of the data obtained, with a focus on the Whole Earth Telescope observations.

Progress with the Whole Earth Telescope

1993 ◽  
Vol 136 ◽  
pp. 250-256
Author(s):  
D. O’Donoghue ◽  
J. Provencal
Keyword(s):  
Time Series ◽  
Power Spectra ◽  
Intrinsic Variability ◽  
Scientific Results ◽  
Whole Earth

AbstractA summary of the results from seven global runs using the Whole Earth Telescope is presented, together with an evaluation of the scientific results obtained to date. Factors such as the distance of the target star from the equator, the nature and timescales of its intrinsic variability, etc. are shown to affect the value and quality of the results, as well as the traditional factors such as brightness and long-term coherent behaviour. Experience with the network shows that, taken as a whole, it enjoys far better weather than any one of its sites, and provides unprecedented ‘uncluttered’ resolution of time-series power spectra.

A Survey on Internet of Things : Applications and Layered Wise Security Issues

2019 ◽  
pp. 171-180
Author(s):  
Uppuluri Sirisha ◽  
G. Lakshme Eswari
Keyword(s):  
Quality Of Life ◽  
Internet Of Things ◽  
Security And Privacy ◽  
Global Network ◽  
Business Growth ◽  
Paper Briefly ◽  
Smart Meters ◽  
Security Issues ◽  
Data Points

This paper briefly introduces Internet of Things(IOT) as a intellectual connectivity among the physical objects or devices which are gaining massive increase in the fields like efficiency, quality of life and business growth. IOT is a global network which is interconnecting around 46 million smart meters in U.S. alone with 1.1 billion data points per day[1]. The total installation base of IOT connecting devices would increase to 75.44 billion globally by 2025 with a increase in growth in business, productivity, government efficiency, lifestyle, etc., This paper familiarizes the serious concern such as effective security and privacy to ensure exact and accurate confidentiality, integrity, authentication access control among the devices.

scholarly journals Improving Web QoE Monitoring for Encrypted Network Traffic through Time Series Modeling

2021 ◽  
Vol 48 (4) ◽  
pp. 37-40
Author(s):  
Nikolas Wehner ◽  
Michael Seufert ◽  
Joshua Schuler ◽  
Sarah Wassermann ◽  
Pedro Casas ◽  
...  
Keyword(s):  
Neural Networks ◽  
Time Series ◽  
Recurrent Neural Networks ◽  
Quality Of Experience ◽  
Unique Feature ◽  
Time Series Modeling ◽  
Web Browsing ◽  
Large Dataset ◽  
Efficient Approximation

This paper addresses the problem of Quality of Experience (QoE) monitoring for web browsing. In particular, the inference of common Web QoE metrics such as Speed Index (SI) is investigated. Based on a large dataset collected with open web-measurement platforms on different device-types, a unique feature set is designed and used to estimate the RUMSI - an efficient approximation to SI, with machinelearning based regression and classification approaches. Results indicate that it is possible to estimate the RUMSI accurately, and that in particular, recurrent neural networks are highly suitable for the task, as they capture the network dynamics more precisely.

scholarly journals Measurements of Local Sources of Particulates with a Portable Monitor along the Coast of an Insular City

2020 ◽  
Vol 13 (1) ◽  
pp. 261
Author(s):  
Christos Petsas ◽  
Marinos Stylianou ◽  
Antonis Zorpas ◽  
Agapios Agapiou
Keyword(s):  
Air Quality ◽  
Significant Contribution ◽  
Anthropogenic Activities ◽  
Portable Monitor ◽  
Traffic Jam ◽  
Modern Cities ◽  
Anthropogenic Processes ◽  
The City ◽  
Coastal Front

The air quality of modern cities is considered an important factor for the quality of life of humans and therefore is being safeguarded by various international organizations, concentrating on the mass concentration of particulate matter (PM) with an aerodynamic diameter less than 10, 2.5 and 1 μm. However, the different physical and anthropogenic processes and activities within the city contribute to the rise of fine (<1 μm) and coarse (>1 μm) particles, directly impacting human health and the environment. In order to monitor certain natural and anthropogenic events, suspecting their significant contribution to PM concentrations, seven different events taking place on the coastal front of the city of Limassol (Cyprus) were on-site monitored using a portable PM instrument; these included both natural (e.g., dust event) and anthropogenic (e.g., cement factory, meat festival, tall building construction, tire factory, traffic jam, dust road) emissions taking place in spring and summer periods. The violations of the limits that were noticed were attributed mainly to the various anthropogenic activities taking place on-site, revealing once more the need for further research and continuous monitoring of air quality.

DYNAMICS UNDERLYING PATIENT-VENTILATOR INTERACTIONS DURING NOCTURNAL NONINVASIVE VENTILATION

2012 ◽  
Vol 22 (02) ◽  
pp. 1250030 ◽  
Author(s):  
R. NAECK ◽  
D. BOUNOIARE ◽  
U. S. FREITAS ◽  
H. RABARIMANANTSOA ◽  
A. PORTMANN ◽  
...  
Keyword(s):  
Time Series ◽  
Respiratory Failure ◽  
Shannon Entropy ◽  
Noninvasive Ventilation ◽  
Spontaneous Breathing ◽  
Sleep Stages ◽  
Common Procedure ◽  
Pressure Time ◽  
Ventilatory Assistance

Noninvasive ventilation is a common procedure for managing patients having chronic respiratory failure. The success of this ventilatory assistance is often linked with patient's tolerance that is known to be related to the quality of the synchronization between patient's spontaneous breathing cycles and ventilatory cycles delivered by the ventilator. Thirty-four sleep sessions (more than 5000 ventilatory cycles each) were automatically investigated using a specific algorithm processing airflow and pressure time series. Four groups of patients were defined according to the interplay between asynchrony events and leaks. Different mechanisms that depend on sleep stages were thus evidenced. A Shannon entropy was also proposed as a new sleep fragmentation quantification methodology.

Value-at-Risk and Expected Shortfall approaches for option premiums and the probability of default estimation based on ARMA models

2021 ◽  
Vol 57 (3) ◽  
pp. 126
Author(s):  
Nikolai Berzon
Keyword(s):  
Time Series ◽  
Option Pricing ◽  
Discrete Time ◽  
Value At Risk ◽  
Probability Of Default ◽  
Pricing Models ◽  
Arma Process ◽  
Underlying Asset ◽  
Black Scholes

The need to address the issue of risk management has given rise to a number of models for estimation the probability of default, as well as a special tool that allows to sell credit risk – a credit default swap (CDS). From the moment it appeared in 1994 until the crisis of 2008, that the CDS market was actively growing, and then sharply contracted. Currently, there is practically no CDS market in emerging economies (including Russia). This article is to improve the existing CDS valuation models by using discrete-time models that allow for more accurate assessment and forecasting of the selected asset dynamics, as well as new option pricing models that take into account the degree of risk acceptance by the option seller. This article is devoted to parametric discrete-time option pricing models that provide more accurate results than the traditional Black-Scholes continuous-time model. Improvement in the quality of assessment is achieved due to three factors: a more detailed consideration of the properties of the time series of the underlying asset (in particular, autocorrelation and heavy tails), the choice of the optimal number of parameters and the use of Value-at-Risk approach. As a result of the study, expressions were obtained for the premiums of European put and call options for a given level of risk under the assumption that the return on the underlying asset follows a stationary ARMA process with normal or Student&apos;s errors, as well as an expression for the credit spread under similar assumptions. The simplicity of the ARMA process underlying the model is a compromise between the complexity of model calibration and the quality of describing the dynamics of assets in the stock market. This approach allows to take into account both discreteness in asset pricing and take into account the current structure and the presence of interconnections for the time series of the asset under consideration (as opposed to the Black–Scholes model), which potentially allows better portfolio management in the stock market.

Modeling Time Series for Prediction of Thalassemia in Nineveh Governorate

2021 ◽  
Vol 2 (3) ◽  
pp. 120-131
Author(s):  
Shaymaa Riyadh Thanoon
Keyword(s):  
Time Series ◽  
Moving Average ◽  
Monthly Data ◽  
Number Of Patients ◽  
Auto Regressive

The aim of this research is to analyze the time series of Thalassemia cancer cases by making assumptions on the number of cases to formulate the problem to find the best model for predicting the number of patients in Nineveh governorate using (Box and Jenkins) method of analysis based on the monthly data provided by Al Salam Hospital in Nineveh for the period (2014-2018). The results of the analysis showed that the appropriate model of analysis is the Auto-Regressive Integrated Moving Average (ARIMA) (2,1,0) and based on this model the number of people with this disease was predicted for the next two years where the results showed values ​​consistent with the original values which indicates the good quality of the model.

scholarly journals Mode identification based on time-series spectrophotometry for the bright rapid sdB pulsator EC 01541−1409

2014 ◽  
Vol 563 ◽  
pp. A79 ◽  
Author(s):  
S. K. Randall ◽  
G. Fontaine ◽  
S. Geier ◽  
V. Van Grootel ◽  
P. Brassard
Keyword(s):  
Time Series ◽  
Mode Identification

scholarly journals Development of Testing Platform and Comparison Studies for Wood Nondestructive Testing

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Jian Li ◽  
Yiming Fang ◽  
Jiyong Tang ◽  
Hailin Feng ◽  
Xiongwei Lou
Keyword(s):  
Nondestructive Testing ◽  
Stress Wave ◽  
Virtual Instrument ◽  
Wood Properties ◽  
Time Interval ◽  
Peak Time ◽  
Testing Platform ◽  
Time Interval Measurement ◽  
Nondestructive Testing Methods

Stress wave based techniques have been developed for evaluating the quality of the wooden materials nondestructively. However the existing techniques have some shortcomings due to the significant variation of the wood properties and are now in need of updating. There are also stress wave based instruments which have been widely used for nondestructive testing of wood. But most of them are inflexible and unsuitable for the tentative studies. This paper proposed and implemented a wood nondestructive testing platform based on NI virtual instrument. Three wood nondestructive testing methods, including peak time interval measurement, cross-correlation, and spectrum analysis, were also tested on this platform with serious decay sample, early decay sample, and defect-free sample. The results show that new methods can be verified easily and the researches of wood nondestructive testing will be accelerated with the designed platform.

scholarly journals Development of a method for estimating the effect of transformation of the normalized frequency mismatch function of a coherent bundle of radio pulses on the quality of radar frequency resolution

2021 ◽  
Vol 4 (4(112)) ◽  
pp. 13-22
Author(s):  
Serhii Yevseiev ◽  
Oksana Biesova ◽  
Dmytro Kyrychenko ◽  
Olena Lukashuk ◽  
Stanislav Milevskyi ◽  
...  
Keyword(s):  
High Speed ◽  
Practical Importance ◽  
Frequency Resolution ◽  
Phase Fluctuations ◽  
Twofold Increase ◽  
Normalized Frequency ◽  
Frequency Mismatch ◽  
Multiplicative Effect ◽  
Radar Frequency

The necessity of studying the influence of the transformation of the frequency mismatch function of a coherent bundle of radio pulses on the quality of solving the radar frequency resolution problem is substantiated. This solution determines the effectiveness of radar observation of high-speed and maneuvering individual and group aerodynamic objects. The method is based on explicit expressions for calculating the normalized frequency mismatch function of a coherent bundle of radio pulses, taking into account its transformation due to the radial motion of high-speed and maneuvering individual and group aerodynamic objects. The estimation of the potential frequency resolution of bundles with different numbers of radio pulses with typical parameters for a coherent pulse radar is carried out. Possible values of frequency resolution under the additive effect of uncorrelated internal noise of the radar receiver and the multiplicative effect of correlated phase fluctuations of the radar signal are estimated. With an insignificant multiplicative effect of correlated phase fluctuations, a twofold increase in the number of radio pulses in a bundle provides an improvement in the frequency resolution (reduction of the width of the normalized frequency mismatch function) by 100 %. With the predominant multiplicative effect of these fluctuations, a twofold increase in the number of radio pulses results in an improvement in the frequency resolution by about 40 %. The developed method is of great theoretical and practical importance for the further development of the radar theory of high-speed and maneuvering individual and group aerodynamic objects.

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