Mohd Izzuddin Mohd Tamrin

Closure properties of Watson-Crick Grammars

In this paper, we define Watson-Crick context-free grammars, as an extension of Watson-Crick regular grammars and Watson-Crick linear grammars with context-free grammar rules. We show the relation of Watson-Crick (regular and linear) grammars to the sticker systems, and study some of the important closure properties of the Watson-Crick grammars. We establish that the Watson-Crick regular grammars are closed under almost all of the main closure operations, while the differences between other Watson-Crick grammars with their corresponding Chomsky grammars depend on the computational power of the Watson-Crick grammars which still need to be studied.

Weighted Watson-Crick automata

There are tremendous works in biotechnology especially in area of DNA molecules. The computer society is attempting to develop smaller computing devices through computational models which are based on the operations performed on the DNA molecules. A Watson-Crick automaton, a theoretical model for DNA based computation, has two reading heads, and works on double-stranded sequences of the input related by a complementarity relation similar with the Watson-Crick complementarity of DNA nucleotides. Over the time, several variants of Watson-Crick automata have been introduced and investigated. However, they cannot be used as suitable DNA based computational models for molecular stochastic processes and fuzzy processes that are related to important practical problems such as molecular parsing, gene disease detection, and food authentication. In this paper we define new variants of Watson-Crick automata, called weighted Watson-Crick automata, developing theoretical models for molecular stochastic and fuzzy proce...

Prediction of Changes in Visual Acuity and Contrast Sensitivity Function by Tissue Redness after Pterygium Surgery

ABSTRACT Purpose: The goal of this study was to predict visual acuity (VA) and contrast sensitivity function (CSF) with tissue redness grading after pterygium surgery. Materials and methods: A total of 67 primary pterygium participants were selected from patients who visited an ophthalmology clinic. We developed a semi-automated computer program to measure the pterygium fibrovascular redness from digital pterygium images. The final outcome of this software is a continuous scale grading of 1 (minimum redness) to 3 (maximum redness). The region of interest (ROI) was selected manually using the software. Reliability was determined by repeat grading of all 67 images, and its association with CSF and VA was examined. Results: The mean and standard deviation of redness of the pterygium fibrovascular images was 1.88 ± 0.55. Intra-grader and inter-grader reliability estimates were high with intraclass correlation ranging from 0.97 to 0.98. The new grading was positively associated with CSF (p < 0.01) and VA (p < 0.01). The redness grading was able to predict 25% and 23% of the variance in the CSF and the VA, respectively. Conclusions: The new grading of pterygium fibrovascular redness can be reliably measured from digital images and showed a good correlation with CSF and VA. The redness grading can be used in addition to the existing pterygium grading.

Generative Power and Closure Properties of Watson-Crick Grammars

We define WK linear grammars, as an extension of WK regular grammars with linear grammar rules, and WK context-free grammars, thus investigating their computational power and closure properties. We show that WK linear grammars can generate some context-sensitive languages. Moreover, we demonstrate that the family of WK regular languages is the proper subset of the family of WK linear languages, but it is not comparable with the family of linear languages. We also establish that the Watson-Crick regular grammars are closed under almost all of the main closure operations.

Fibrovascular redness grading using Gaussian process regression with radial basis function kernel

Information obtained from redness grading can assist clinician for diagnosis and in making clinical decision. This research work aims to mimic human perception of fibrovascular redness using features extracted from color entropy. Gaussian process regression with the radial basis function kernel has been employed to fuse relevant features and established the model of redness perception. In this paper, we present the results of the radial basis function kernel incorporated as the covariance function in the GPR as the scale, sigma is varied.

Using Information Management Architecture to Support Flexible Supply Chain Management

Integration between the members in complex network of the supply chain group has been an issue for flexible supply chain management. Restructuring of pre-planned activities across the group to react to known deviation may not be possible. The authors decided to introduce an Information Management Architecture (IMA) as the intermediary process which can provide semi-automated assistance for tighter integration. The IMA sits between the RFID infrastructure and the existing supply chain systems and continuously monitors the current activities and wraps services from existing systems to increase the flexibility for immediate process restructuring. A comparison was made between two types of deviations that occurred at the early and final stages of a customization process with and without IMA support. The results showed that the IMA was more stable compared to other supports and significantly performed better in completing joint tasks.

Watson–Crick Context-Free Grammars: Grammar Simplifications and a Parsing Algorithm

A Watson–Crick (WK) context-free grammar, a context-free grammar with productions whose right-hand sides contain nonterminals and double-stranded terminal strings, generates complete double-stranded strings under Watson–Crick complementarity. In this paper, we investigate the simplification processes of Watson–Crick context-free grammars, which lead to defining Chomsky like normal form for Watson–Crick context-free grammars. The main result of the paper is a modified CYK (Cocke–Younger–Kasami) algorithm for Watson–Crick context-free grammars in WK-Chomsky normal form, allowing to parse double-stranded strings in O(n^6) time.

A Comparative Performance Analysis of Modified Dӧmӧsi’s Cryptosystem and Data Encryption Standard

The performance has a central importance for all cryptosystems. This paper aims to provide a framework and platform to evaluate a performance of Modified Dӧmӧsi’s Cryptosystem, a stream cipher based on finite automata, comparing to Data Encryption Standard. The performance is evaluated in terms of encrypting time and throughput.

The computational power of Watson-Crick grammars: Revisited

A Watson-Crick finite automaton is one of DNA computational models using the Watson-Crick complementarity feature of deoxyribonucleic acid (DNA). We are interested in investigating a grammar counterpart of Watson-Crick automata. In this paper, we present results concerning the generative power of Watson-Crick (regular, linear, context-free) grammars. We show that the family of Watson-Crick context-free languages is included in the family of matrix languages.

A performance improvement of Dömösi’s cryptosystem

Domosi’s cryptosystem [2, 3] is a new stream cipher based on finite automata. The cryptosystem uses specific deterministic finite accepters as secret keys for the encryption and decryption. Though this cryptosystem has been proven to be secure against different standard attacks (see [8]), the proposed encryption algorithms in [2, 3] involve exhaustive backtracking in order to generate ciphertexts. In this research, we propose a modified encryption algorithm to improve performance of the system up to a better linear-time without effecting its security.