Hüseyin Ergin

Operational semantics of UML activity diagram: An application in project management

With its recent adoption by the International Organization for Standardization, we foresee that UML will be systematically used for object-oriented modeling in industry. UML activity diagrams have been typically used to model software and business processes. Due to its semi-formal semantics and high complexity, its advanced constructs such as expansion regions, interruptible regions, object nodes, time events, and compound activities are rarely used in practice. There has been significant work on formalizing UML activity diagrams in terms of its semantic domain: Petri net. However, none address the recent advanced constructs it offers. In this paper, we define the semantics of UML activity diagram using a rule-based model transformation. Verification and validation of the UML activity diagram model is then achieved by simulating and analyzing the Petri net model. We illustrate our technique by using an extension of UML activity diagram to facilitate project management tasks such as scheduling, cost estimation, and resource allocation.

Design pattern oriented development of model transformations

Model-driven engineering (MDE) is considered a well-established software development approach that uses abstraction to bridge the gap between the problem space and the software implementation. In MDE, many problems are solved using model transformation, which is a paradigm that manipulates high-level models to translate, evolve, or simulate them. However, the development of a model transformation for a specific problem is still a hard task. The main reason is the lack of a development process where transformations must be designed before implemented. Design patterns provide experiential reuse to software engineers when faced with recurring problems. Given their various contexts of application, model transformations may also benefit from design patterns. Although several studies have proposed design patterns for model transformation, there is still no accepted common language to express transformation patterns. Therefore, we propose a semi-formal way to describe model transformation design patterns that is independent from a specific transformation language and described in a practical way that is directly implementable by model engineers. This paper presents a catalog of 15 model transformation design patterns. We also demonstrate how it is possible to automatically generate excerpts of a model transformation in various languages given a design pattern. We conducted an initial survey to motivate the need for model transformation design patterns and a user study to validate the methodology we propose to solve problems as model transformations based on design patterns. HighlightsFourteen unique model transformation design patterns are mined from existing literature and an additional one is proposed.A unified formalism to describe model transformation design patterns is a need in the model transformation community. Therefore, DelTa is proposed thoroughly in this paper to satisfy this need.According to our survey, model transformation engineers are willing to use provided environments to instantiate some part of the transformation they are implementing.According to the user study we have done to validate the methodology, initial results looks promising.

Towards a Language for Graph-Based Model Transformation Design Patterns

In model-driven engineering, most problems are solved using model transformation. However, the development of a model transformation for a specific problem is still a hard task. The main reason for that is the lack of a development process where transformations must be designed before implemented. As in object-oriented design, we believe that “good design” of model transformation can benefit tremendously from model transformation design patterns. Hence, in this paper, we present DelTa, a language for expressing design patterns for model transformations. DelTa is more abstract than and independent from any existing model transformation language, yet it is expressive enough to define design patterns as guidelines transformation developers can follow. To validate the language, we have redefined four known model transformation design patterns in DelTa and demonstrated how such abstract transformation guidelines can be implemented in five different model transformation languages.

Evaluating the cloud architecture of AToMPM

In model-driven engineering, stakeholders work on models in order to design, transform, simulate, and analyze systems. Complex systems typically involve many stakeholder groups working in a coordinated manner on different aspects of a system. Therefore, there is a need for collaborative platforms to allow modelers to work together. Previously, we introduced the cloud-based multi-user tool AToMPM, designed to address the challenges for building a collaborative platform for modeling. This paper presents on the multi-user, multi-view architecture of AToMPM and an initial evaluation of its performance and scalability.

Comment on An Enhanced and Secured RSA Key Generation Scheme (ESRKGS)

In this article, we do the cryptanalysis of the Enhanced and Secured RSA Key Generation Scheme (ESRKGS) given in Thangavel etźal. (2015). The authors claimed that ESRKGS is a highly secure and not easily breakable scheme compared to the traditional RSA scheme. In their scheme, the public key n is a product of two large prime numbers, but the values of Encryption E and Decryption D keys are based on the product of four large prime numbers, N, which is a multiple of n. They claimed that even if someone factorizes n, in order to obtain the private key D, brute force must be used to obtain the other two primes.We prove that we can use an alternative private key D1 to break the system. Someone does not need to employ brute force to break the system when n is factored. Hence, ESRKGS has the same security level as the traditional RSA.