Tamim Ahmed Khan

On model-based regression testing of web-services using dependency analysis of visual contracts

Regression testing verifies if systems under evolution retain their existing functionality. Based on large test sets accumulated over time, this is a costly process, especially if testing is manual or the system to be tested is remote or only available for testing during a limited period. Often, changes made to a system are local, arising from fixing bugs or specific additions or changes to the functionality. Rerunning the entire test set in such cases is wasteful. Instead, we would like to be able to identify the parts of the system that were affected by the changes and select only those test cases for rerun which test functionality that could have been affected. This paper proposes a model-based approach to this problem, where service interfaces are described by visual contracts, i.e., pre and post conditions expressed as graph transformation rules. The analysis of conflicts and dependencies between these rules allows us to assess the impact of a change of the signature, contract, or implementation of an operation on other operations, and thus to decide which of the test cases is required for re-execution. Apart from discussing the conceptual foundations and justifications of the approach, we illustrate and evaluate it on a case study of a bug tracking service in several versions.

Learning Minimal and Maximal Rules from Observations of Graph Transformations

Graph transformations have been used to model services and systems where rules describe pre and post conditions of operations changing a complex state. However, despite their intuitive nature, creating such models is a time-consuming and error-prone process. In this paper we investigate the possibility of extracting rules from observations of transformations, i.e., pairs of input and output graphs resulting from successful transformations and individual input graphs were they have failed. From such positive and negative examples, minimal rules are extracted, to be extended by context that is present in all positive examples and missing in at least one negative example. The result is are a maximal and a required rule, jointly with the minimal rule defining the range of possible rules that could have created the observed transformations. We report on an implementation of the approach, evaluate its accuracy, scalability and limitations, and discuss applications to reverse engineering visual constructs from observations of object states of components under test.

Test Case Generation Using Visual Contracts

Visual contracts provide a diagrammatic notation for pre- and postconditionsas alternative to the Object-Constraint Language (OCL) or code-levelcontract languages. Using visual contracts for testing, we benefit from their executabilityand formal background in graph transformation to provide model-basedtest oracles and coverage criteria. Based on a static analysis of their dependenciesand conflicts, in this paper we use visual contracts to generate test cases accordingto these coverage criteria.Together with previous work, this adds up to a comprehensive approach aiming toautomate the three major challenges of testing through the use of models.

Towards Test Coverage Criteria for Visual Contracts

When testing component-based or service-oriented applications we cannot always rely on coverage criteria based on source code. Instead, we have to express our requirements for testing at the interface level. Specifying interfaces by graph transformation rules, so-called visual contracts, we define model-based coverage criteria exploiting the well-known relations of causal dependency and conflict on transformation rules. To this end we establish an observational semantics for graph transformation systems with rule signatures formalising a notion of test execution, and define dependency graphs to provide a structure on which coverage can be analysed.

A Comparative Analysis on Home Automation Techniques

Smart homes have emerged as an area of research interest in recent years. Home automation offers us independence and complete control over your home along with a fine designed intelligent architecture which could control your home in your absence in an efficient manner. In the recent years all the implemented techniques have not realized the Intelligent Home design in all quality aspects since every technique has its own pros and cons whether we talk in terms of technology adapted, efficiency or cost. This paper presents a brief comparative analysis on implemented techniques and provides a viable solution to realize home automation system which constitutes Bluetooth control via Android app development for in-house control and GSM (Global System for Mobile Communication) technology for mobile control using Arduino Development Board as brain of our system. To implement Intelligent Home, the need is to adapt simple, efficient and cost effective technologies and the solution presented in this paper constitutes the said features.

Comparison of Characteristics -- Lead Acid, Nickel Based, Lead Crystal and Lithium Based Batteries

Rapid growth and improvement has been witnessed in the field of batteries usage in recent years. Batteries are vital part of our everyday life. Batteries are energy storage devices that have applications in everything from small portable electronics, covering solar energy usage up to aircraft and space vehicles. Various types of batteries are available in market however all the types are application specific and they have their own characteristics in terms of technology implemented or reliability or cost. We present in this paper a comparison of various batteries types, characteristics and charging methods. We finally arrive at a proposal highlighting their suitability with respect to usage domains, especially for renewable energy solutions.

Non-technical issues in software designing phase

Software designing phase is an important phase in the software development lifecycle. There could be a number technical and non-technical issues e.g., communication issues and understand-ability issues which may hinder desired progress in this phase affecting the software project output. We study how these issues affect software project by conducting interviews and surveys within software houses and IT concerns. We report how communication issues and understand-ability issues contribute statistically significantly towards failure in software projects within organizations.

Evaluation of optical character recognition algorithms and feature extraction techniques

Optical character recognition or OCR becomes necessary first step for all applications that consider typewritten or handwritten manuscripts as input. We need to train our classifier in case we are considering to use data mining techniques for such purposes. There are several established generic classification techniques that can be used together with feature extraction mechanisms but it is important to know which of them do better under which circumstances. We evaluate three approaches for OCR from handwritten manuscripts and we study their results. We consider a case study where we need to identify cases with probability of dyslexia.

Emotion Recognition from Speech using Prosodic and Linguistic Features

Speech signal can be used to extract emotions. However, it is pertinent to note that variability in speech signal can make emotion extraction a challenging task. There are a number of factors that indicate presence of emotions. Prosodic and temporal features have been used previously for the purpose of identifying emotions. Separately, prosodic/temporal and linguistic features of speech do not provide results with adequate accuracy. We can also find out emotions from linguistic features if we can identify contents. Therefore, We consider prosodic as well as temporal or linguistic features which help increasing accuracy of emotion recognition, which is our first contribution reported in this paper. We propose a two-step model for emotion recognition; we extract emotions based on prosodic features in the first step. We extract emotions from word segmentation combined with linguistic features in the second step. While performing our experiments, we prove that the classification mechanisms, if trained without considering age factor, do not help improving accuracy. We argue that the classifier should be based on the age group on which the actual emotion extraction be required, and this becomes our second contribution submitted in this paper.

Development of online RAW achievement battery test for primary level

Abstract Achievement test is a mechanism to measure student’s knowledge and abilities. Numerous categories of achievement tests have been developed by different scholars and psychologists. Since they do not directly consider curriculum adopted during the course of study of students, they do not reflect truly upon the achievements of students. We propose an achievement test which is computerized and is based on assessment of RAW (reading, arithmetic and writing) capabilities considering curriculum used for imparting education. We set compositions and contents according to age group and educational standards. We then conduct a series of experiments to show how an achievement test linked with a curriculum is reflective, in a better manner, of the student’s achievement index then a general one. We call Online RAW Achievement Battery test and we also develop an application which use for conducting our experiment and formulation of results. Finally, we analyze our results with students’ historical records and WRAT-4 which is a well-known standardized test and report our findings.