Secant-type iteration for nonlinear ill-posed equations in Banach space

In this paper, we study secant-type iteration for nonlinear ill-posed equations involving 𝑚-accretive mappings in Banach spaces. We prove that the proposed iterative scheme has a convergence order at least 2.20557 using assumptions only on the first Fréchet derivative of the operator. Further, using a general Hölder-type source condition, we obtain an optimal error estimate. We also use the adaptive parameter choice strategy proposed by Pereverzev and Schock (2005) for choosing the regularization parameter.

Portfolio Choices with Many Big Models

This paper proposes a Bayesian-averaging heterogeneous vector autoregressive portfolio choice strategy with many big models that outperforms existing methods out-of-sample on numerous daily, weekly, and monthly datasets. The strategy assumes that excess returns are approximately determined by a time-varying regression with a large number of explanatory variables that are the sample means of past returns. Investors consider the possibility that every period there is a regime change by keeping track of many models, but doubt that any specification is able to perfectly predict the distribution of future returns, and compute portfolio choices that are robust to model misspecification. This paper was accepted by Tyler Shumway, finance.

Communication Strategies and Information Choice Strategy of the Arab Tourists

The main purpose of this study is to examine the mediating role of situational characteristics on the relationship between communication strategies and information choice strategy of the Arab tourists in Malaysia. The study adopted a cross-sectional design with a quantitative survey approach. Overall, the study finds that situational characteristics significantly mediate the influence of information source on the information choice strategy of the Arab tourists but not on the relationship between information source and information choice. The study therefore concludes among others that situational characteristic can only explain the influence of information channels on the information choice strategy but not on the influence of information source on the information choice strategy.

CRISIS AND DISASTER MANAGEMENT CHOICE STRATEGY

Predicting the occurrence of a crisis is indeed difficult, where insensitivity picks up signals from existingsymptoms, causing it to only realize when the crisis situation. If you are not able to handle it will have badconsequences, and even the impact can not be predicted when it ends. Therefore, optimal efforts to reduce risksand uncertainties are carried out during a crisis, so that crisis management is needed to quickly return to normal.Risk conditions are conditions that have an impact on a situation such that it can cause a crisis or even a disaster.Crisis is a situation of very high potential towards disaster in a short span of time. While disasters are events thatthreaten and disrupt life and livelihoods caused by natural factors and / or factors not natural or human factors,causing casualties, environmental damage, property losses, and psychological impacts. So, crises and disastersrequire proper management. Accordingly, comparative advantage as a strategy can be a choice for crisis anddisaster management.

On the Parameter Choice in the Multilevel Augmentation Method

In this paper, we apply the multilevel augmentation method for solving ill-posed Fredholm integral equations of the first kind via iterated Tikhonov regularization method. The method leads to fast solutions of the discrete regularization methods for the equations. The convergence rates of iterated Tikhonov regularization are achieved by using a modified parameter choice strategy. Finally, numerical experiments are given to illustrate the efficiency of the method.