Open Access Short Research Article

Asymptotic Properties of Estimators in Stochastic Differential Equations with Additive Random Effects

Alkreemawi Walaa Khazal, Alsukaini Mohammed Sari, Wang Xiang Jun

Journal of Advances in Mathematics and Computer Science, Page 1-9
DOI: 10.9734/BJMCS/2016/26140

A stochastic differential equation (SDE) defined N independent stochastic processes (Xi (t), t ∈ [0,Ti]),i = 1, ..., N, the drift term depends on the random variable ɸi . The distribution of the random effect ɸ depends on unknown parameters. When the drift term is defined linearly on the random effect ɸi  (additive random effect) and  ɸi  has Gaussian Distribution, we propose an alternative route to prove asymptotic properties of Maximum Likelihood Estimator (MLE) by verifying the regularity conditions required through existing relevant theorems. We consider the Bayesian approach to learn the hyper parameters and proving asymptotic properties of the posterior distribution of the hyper parameters in the SDE’s model.

Open Access Short Research Article

Factor Structure, Reliability and Validity of Attitudes of Biostatistics Scale

Muhammad Shafiq Harun, Sabri Ahmad

Journal of Advances in Mathematics and Computer Science, Page 1-9
DOI: 10.9734/BJMCS/2016/25707

Confirmatory Factor Analysis (CFA) has been used for most of researchers nowadays to evaluate the goodness of fit of measurement model using structural equation modeling. The aim of this study to evaluate the factors used to validate the best model of four latent construct by using pooled confirmatory factor analysis (PCFA) technique on variable student’s attitude toward Biostatistics and to assess dimensions of students’ attitudes regarding Biostatistics courses. A survey adapted from Survey of the Attitudes toward Statistics (SATS) was employed to observe student’s attitude toward a Biostatistics course. The data be collected through questionnaires distributed to first year students at a higher education institution. The data were analysed through four model which is model specification, model estimation, model evaluation, and model modification by using Analysis Moment of Structural (AMOS) in order to improve the validity of each latent construct. The result showed that the validity and reliability of all latent variables is achieved and the pooled CFA technique is more efficient.

Open Access Original Research Article

Symmetric Key Encryption with Conjunctive Field Free Keyword Search Scheme

Sher Ali Fairouz, Song Feng Lu

Journal of Advances in Mathematics and Computer Science, Page 1-11
DOI: 10.9734/BJMCS/2016/25804

Searchable symmetric encryption (SSE) enables a sender to outsource the encrypted files to a cloud server, while maintaining the ability to conditionally search over it without knowing the sensitive data contents. Prior work in this area has focused on single keyword search. Conjunctive Keyword Searches (CKS) schemes improve system usability by retrieving the matched files, but in this type of search the receiver has to provide the server with a trapdoor for every individual keyword in the conjunction and rely on an intersection protocol to retrieve the correct set of files, in other words the receiver has to repeatedly perform the search protocol for many times based on the number of keywords in the conjunction. Most of the existing (CKS) schemes use conjunctive keyword searches with fixed position keyword fields, this type of search is not applicable for many real applications, such as the database text and the body of e-mail. In this paper, we propose a new trapdoor-indistinguishable symmetric key encryption with conjunctive keyword search, which does not need to specify the positions of the keywords. Instead of giving the server one trapdoor for each keyword in the conjunction set, the recipient give it a trapdoor for multiple keywords in the conjunction set to search on encrypted files. Furthermore, the search process could not reveal any information about the number of keywords in the query expression. Our proposed scheme is proven secure against chosen-keyword attacks under the Decisional Diffie-Hellman(DDH) assumption in the random oracle model.

Open Access Original Research Article

On Some Integral Inequalities for Twice Diferentiable φ - Convex and Quasi - Convex Functions via k - Fractional Integrals

M. Esra Yildirim, Abdullah Akkurt, Hüseyin Yildirim

Journal of Advances in Mathematics and Computer Science, Page 1-11
DOI: 10.9734/BJMCS/2016/26309

In this paper, by using the integral equality which is given in this work, we aim at establishing some new inequalities of the Simpson-like and the Hadamard-like type for functions whose second derivatives are φ-convex and quasi-convex.

Open Access Original Research Article

Statistical Arbitrage Opportunities Using Bellman Equation

Reza Habibi, Hamed Habibi

Journal of Advances in Mathematics and Computer Science, Page 1-6
DOI: 10.9734/BJMCS/2016/25967

This paper uses the dynamic programming to detect the optimal statistical arbitrage opportunities in a market including a bond and a stock. First, it is assumed that the growth rates of stock are independent random variables and Bellman equation is derived for probability of gain of a portfolio containing a long position in stock and short position in bond. The Bellman equation is derived and its approximations are studied. Then, using the simulation, the performance of method in correlated growth rates cases is proposed. Conclusions are also given.

Open Access Original Research Article

Development of an Optimized Mobile Agent Migration Pattern for Pull-All Data Strategy

M. O. Oyediran, T. M. Fagbola, S. O. Olabiyisi, E. O. Omidiora

Journal of Advances in Mathematics and Computer Science, Page 1-8
DOI: 10.9734/BJMCS/2016/26024

A mobile agent is a software entity that migrates from one host to another, performing data collection and software configuration tasks on behalf of users in distributed networks. However, studies have shown that the existing pull – all data strategy of mobile agent migration pattern moves data from one host to the next host along with the mobile agent, thereby resulting in data accumulation which lowers the performance of the mobile agent in terms of transmission time and network load. This research developed an optimized mobile agent migration pattern for the pull-all data strategy in distributed networks using path strategy of Ant Colony Optimization (ACO) technique.

The obtained results shows that the optimized pull-all data migration pattern developed produced lower network load and transmission time than the existing pull-all data migration pattern.

Open Access Review Article

Integrating a Secured Access Control Policy on Wireless Sensor Networks

S. O. Olatunji, B. K. Alese, O. S. Egwuche, K. M. Adesiji

Journal of Advances in Mathematics and Computer Science, Page 1-12
DOI: 10.9734/BJMCS/2016/25839

A new generation of high-scale sensor networks suitable for a range of enterprise application is thriving by current advancements in electronics. In this work, we proposed a mechanism for securing data generation in a wireless sensor network. Wireless sensor networks (WSNs) are networks that provide a virtual layer where the information about the physical world can be accessed by any computational system. WSNs are made up of nodes from a few to several hundreds or even thousands where each node is connected to one or several sensors. The data generated can be easily compromised by an attacker if adequate security measures are not taken. Access and Authorization to the sensory data should be given to authorized users with the right attributes if data integrity and authentication (in a fine-grained manner) should be maintained. The increased security of the proposed system is achieved by the increased in the key size above the existing system. Achieving secure fine-grained access control policy over security challenges like sensor node compromise, accessibility of users to sensor nodes, data privacy, and protection of components on WSNs need a secure system that can precisely specify what the users can access, where and when to access any data at a particular time in the network.