A NEW PHYSICAL EFFECT MODELED BY AN IKEDA MAP DEPENDING ON A MONOTONICALLY TIME-VARYING PARAMETER

1999 ◽  
Vol 09 (06) ◽  
pp. 1111-1120 ◽  
Author(s):  
JOHN ARGYRIS ◽  
CORNELIU CIUBOTARIU

In this paper we study the dynamics of a charged particle in a constant external magnetic field and the field due to a polarized electromagnetic wave. We observe a new phenomenon, the chaotic gun effect, which appears in the case of a sufficiently large amplitude of the wave. We show that the longitudinal component of the momentum undergoes oscillations with a chaotic modulation of the amplitude which increases suddenly to a value which remains constant between two consecutive phase Larmor circles. The novel effect may be modeled by a time-regressive system associated with an Ikeda map depending on a monotonically time-varying parameter.

2016 ◽  
Vol 5 (3) ◽  
pp. 117
Author(s):  
I PUTU GEDE DIAN GERRY SUWEDAYANA ◽  
I WAYAN SUMARJAYA ◽  
NI LUH PUTU SUCIPTAWATI

The purpose of this research is to forecast the number of Australian tourists arrival to Bali using Time Varying Parameter (TVP) model based on inflation of Indonesia and exchange rate AUD to IDR from January 2010 – December 2015 as explanatory variables. TVP model is specified in a state space model and estimated by Kalman filter algorithm. The result shows that the TVP model can be used to forecast the number of Australian tourists arrival to Bali because it satisfied the assumption that the residuals are distributed normally and the residuals in the measurement and transition equations are not correlated. The estimated TVP model is . This model has a value of mean absolute percentage error (MAPE) is equal to dan root mean square percentage error (RMSPE) is equal to . The number of Australian tourists arrival to Bali for the next five periods is predicted: ; ; ; ; and (January - May 2016).


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sandang Guo ◽  
Yaqian Jing

PurposeIn order to accurately predict the uncertain and nonlinear characteristics of China's three clean energy generation, this paper presents a novel time-varying grey Riccati model (TGRM(1,1)) based on interval grey number sequences.Design/methodology/approachBy combining grey Verhulst model and a special kind of Riccati equation and introducing a time-varying parameter and random disturbance term the authors advance a TGRM(1,1) based on interval grey number sequences. Additionally, interval grey number sequences are converted into middle value sequences and trapezoid area sequences by using geometric characteristics. Then the predicted formula is obtained by using differential equation principle. Finally, the proposed model's predictive effect is evaluated by three numerical examples of China's clean energy generation.FindingsBased on the interval grey number sequences, the TGRM(1,1) is applied to predict the development trend of China's wind power generation, China's hydropower generation and China's nuclear power generation, respectively, to verify the effectiveness of the novel model. The results show that the proposed model has better simulated and predicted performance than compared models.Practical implicationsDue to the uncertain information and continuous changing of clean energy generation in the past decade, interval grey number sequences are introduced to characterize full information of the annual clean energy generation data. And the novel TGRM(1,1) is applied to predict upper and lower bound values of China's clean energy generation, which is significant to give directions for energy policy improvements and modifications.Originality/valueThe main contribution of this paper is to propose a novel TGRM(1,1) based on interval grey number sequences, which considers the changes of parameters over time by introducing a time-varying parameter and random disturbance term. In addition, the model introduces the Riccati equation into classic Verhulst, which has higher practicability and prediction accuracy.


1967 ◽  
Vol 31 ◽  
pp. 385-389 ◽  
Author(s):  
G. L. Verschuur

The interpretation of Zeeman-effect measurements in terms of interstellar magnetic fields is strongly involved with the problems of the nature of interstellar clouds, and of their relationship to the structure of the field. The best measurements furnish, for the mean longitudinal component of the spectrum of Tau A, a value of + 1·1 ± 3·0 μG (micro-gauss), and for that in the Orion-Arm feature in Cas A, - 0·8 ± 3·5 μG. These values are consistent with an upper limit of 7 μG to a uniform magnetic field, pervading the absorbing clouds and directed parallel to the local spiral arm.


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