Abstract

Online education has witnessed a spike during the COVID-19 pandemic[1], due to which it is important to be performance efficient and serve the content in a reasonable time. In this case study of Virtual Labs, an e-learning platform we analyse and propose a set of approaches which helps in improving the website’s performance. Virtual Labs is an e-learning website for virtual experiments in topics on science and engineering. These experiments are in the form of static webpages. This paper delineates the steps we followed to improve the performance of the static e-learning website. It shares insights into some of the concepts which can help improve the website performance.

Abstract

Model checking is now a standard technology for verifying large and complex systems. While there are a range of tools and techniques to verify various properties of a system under consideration, in this work, we restrict our attention to safety checking procedures using explicit state space generation. The necessary hardware resources required in this approach depends on the model complexity and the resulting state transition graph that gets generated. This cannot be estimated apriori. For reasonably realistic models, the available main memory in even high end servers may not be sufficient. Hence, we have to use distributed safety verification approaches on a cluster of nodes. However, the problem of estimating the minimum number of nodes in the cluster for the verification procedure to complete successfully remains unsolved. In this paper, we propose a dynamically scalable model checker using an actor based architecture. Using the proposed approach, an end user can invoke a model checker hosted on a cloud platform in a push button fashion. Our safety verification procedures automatically expands the cluster by requesting more virtual machines from the cloud provider. Finally, the user gets to pay only for the hardware resources he rented for the duration of the verification procedure. We refer to this as Model Checking as Service. We approach this problem by proposing an asynchronous algorithm for safety checking in actor framework. The actor based approach allows for scaling the resources on a need basis and redistributes the work load transparently through state migration. We tested our approach by developing a distributed version of SpinJA model checker using Akka actor framework. We conducted our experiments on Google Cloud Engine (GCE) platform wherein we scale our resources automatically using the GCE API. On large models such as anderson.8 from BEEM benchmark suite, our approach reduced the model checking cost in dollars by 8.6x while reducing the wall clock time to complete the safety checking procedure 5.5x times.

Abstract

The importance of algorithms and data structures in computer science curricula has been amply recognized.For many students, however, gaining a good understanding of algorithms remains a challenge.Because of the automated nature of sequential algorithms there is an inherent tension in directly applying the ‘learning by doing’ approach. This partly explains the limitations of efforts like algorithm animationand code tracing.Algodynamics, the approach we propose and advocate, situates algorithms within the framework of transi-tion systems and their dynamics and offers an attractive approach for teaching algorithms. Algodynamics starts with the premise that the key ideas underlying an algorithm can be identified and packaged into interactive transition systems. The algorithm when ‘opened up’, reveals a transition system, shorn of most control aspects, enriched instead with interaction. The design of an algorithm can be carried out by constructing a series of interactive systems, progressively trading interactivity with automation. The setransition systems constitute a family of notional machines.We illustrate the algodynamics approach by considering Bubblesort. A sequence of five interactive tran-sition systems culminate in the classic Bubblesort algorithm. The exercise of constructing the individualsystems also pays off when coding Bubblesort: a highly modular implementation whose primitives are bor-rowed from the transition systems. The transition systems used for Bubblesort have been implemented as interactive experiments. These web based implementations are easy to build. The simplicity and flexibility afforded by the algodynamics framework makes it an attractive option to teach algorithms in an interactive way.

Abstract

With increasing computing power, capacity and internet connectivity, the ability to learn has crossed classroom boundaries in the form of online learning. The adoption rate and effectiveness of online learning continues to be an area of research. Collaborative and Cooperative (CoCo) learning involves a joint effort by students to understand and solve problems or tasks. Adoption of open source software has also increased with technology-aided collaboration and cooperation. Leveraging the practices of crowdsourced software development, we propose CoCo Learning approach for technical education using virtual labs. About 145 undergraduate engineering students from various institutes participated in our study for a period of one full semester. About 92% of the students conducted an average of 24 virtual experiments with this approach. Nearly 90% of the faculty from these institutes also confirmed that their students' understanding of courses has improved while delivering tangible software artifacts as outcomes.

Abstract

We examine the mutual exclusion problem of concurrency through the systematic application of modern feedback control theory, by revisiting the classical problem involving mutual exclusion: the Generalised Dining Philosophers problem. The result is a modular development of the solution using the notions of system and system composition in a formal setting that employs simple equational reasoning. The modular approach separates the solution architecture from the algorithmic minutiae and has the benefit of simplifying the design and correctness proofs. Two variants of the problem are considered: centralised and distributed topology with N philosophers. In each case, solving the Generalised Dining Philosophers reduces to designing an appropriate feedback controller.

Abstract

Domain Specific Modeling Languages (DSML) significantly improve productivity in designing Computer Based System (CBS), by enabling them to be modeled at higher levels of abstraction. It is common for large and complex systems with distributed teams, to use DSMLs, to express and communicate designs of such systems uniformly, using a common language. DSMLs enable domain experts, with no or minimal software development background, to model solutions, using the language and terminologies used in their respective domains. Although, there are already a number of DSMLs available for modeling CBSs, their need is felt strongly across multiple domains, which still are not well supported with DSMLs. Developing a new DSML, however, is non trivial, as it requires (a) significant knowledge about the domain for which the DSML needs to be developed, as well as (b) skills to create new languages. In the current practice, DSMLs are developed by experts, who have substantial understanding of the domain of interest and strong background in computer science. One of the many challenges in the development of DSMLs, is the collection of domain knowledge and its utilization, based on which the abstract syntax, the backbone of the DSML is defined. There is a clear gap in the current state of art and practice, with respect to overcoming this challenge. We propose a methodology, which makes it easier for people with different backgrounds such as domain experts, solution architects, to contribute towards defining the abstract syntax of the DSML. The methodology outlines a set of steps to systematically capture knowledge about the domain of interest, and use that to arrive at the abstract syntax of the DSML. The key contribution of our work is in abstracting a CBS from a domain into a Domain Specific Machine, embodied in domain specific concepts. The methodology outlines, how the Domain Specific Machine, when coupled with guidelines from current practices of developing DSMLs, results in the definition of the abstract syntax of the intended DSML. We discuss our methodology in detail, in this paper.

Abstract

The focus of the ongoing Digital and Industry 4.0 revolution is on re-engineering business operations to take advantage of various technologies, including robotics. Conceptualizing, say, a robotics solution to automate aspects of warehouse operations involves multiple activities: understanding the problem space in sufficient detail to identify the right automation opportunities; working through the space of possible solution options and developing the solution design; and building a prototype solution with sufficient functional detail to enable customer experts to assess its suitability with respect to multiple concerns, and its impact on the business processes and environment. Only after that can a project be initiated to engineer and deploy the production solution, while making the necessary changes to the business system. With current practice, conceptualization and prototyping typically takes several months and considerable manual effort. In this paper, we present an environment for rapid prototyping of robotics solutions that facilitates a knowledge-centric approach based on capability composition. The environment enables systematic capture of functional domain knowledge, modular composition of solution space capabilities, and expression of the solution concept using a constrained natural language. Detailed functional simulators are generated automatically from the resulting design. This results in high customer confidence in the solution, substantial reductions in cycle time, and productivity gains due to modular reusability of solution knowledge and components.

Abstract

This is a short report on the Tutorials and Tech Briefings session of the 12th Innovations in Software Engineering (ISEC 2019) confer- ence held on 14th February 2019 in Pune, India. The tutorials and tech briefings at ISEC have been popular with the participants because they offer a gentle and friendly introduc- tion to cutting edge topics and research at the frontiers of the discipline of software engineering. This year’s track attracted a total of 11 submissions (four tutorial and seven tech briefings). The five submissions that were selected reflect the current interests and directions of the field of software engineering

Abstract

We are interested in the problem of enabling transformation of existing, already published web pages. We call this Renarration of web content. In our earlier work, we had already established the role and importance of renarration for improving Web Accessibility. There are nearly a billion websites on the web, making transformation of pages a domain on its own. In this paper, we present the development of a Domain-Specific Language (DSL) for the purpose of web page transformation. We show how the design and implementation of our DSL is driven by our problem domain, its terminology and its unique requirements. We take up an existing online video-course delivery system, which has accessibility challenges, as a specific case to demonstrate our DSL. We end with insights and reflections for future work in both DSL and web page transformations.

Abstract

Virtual Labs allow performance of experiments without real world instrumentation needs. Most of these virtual experiments are simulation based and developed using proprietary or Open Source simulation, Adobe Flash, and other client side software. The procedural steps involved in conducting these experiments are hardwired and require software modification for enhancements or alignment to the course structure. We propose a model based approach that eases development of virtual experiments without dependency on software programmers for any changes. We demonstrate our model driven based approach on Chemical Sciences labs of Virtual Labs, a Government of India initiative. With our model driven based approach, the effort for new experiment development or FOSS conversion of existing experiments that were using outdated technologies is less than a person day as compared to more than a person …