The Formal Semantics of an UML Activity Diagram

Due to lack of strictly defined formal semantics, an UML activity diagram is unsuitable for the tasks of formal analysis, verification and assertion on the system it describes. In this paper, Petri net is used to define the formal semantics of an UML activity diagram containing object flow states, laying a foundation for the precise description and analysis of a workflow system.

Activity Diagram Synthesis Using Labelled Graphs and the Genetic Algorithm

Many applications need to meet diverse requirements of a large-scale distributed user group.That challenges the current requirements engineering techniques.Crowd-based requirements engineering was proposed as an umbrella term for dealing with the requirements development in the context of the large-scale user group.However,there are still many issues.Among others,a key issue is how to merge these requirements to produce the synthesized requirements description when a set of requirements descriptions from different participants are received.Appropriate techniques are needed for supporting the requirements synthesis.Diagrams are widely used in industry to represent requirements.This paper chooses the activity diagrams and proposes a novel approach for the activity diagram synthesis which adopts the genetic algorithm to repeatedly modify a population of individual solutions toward an optimal solution.As a result,it can automatically generate a resulting diagram which combines the commonalities as many as possible while leveraging the variabilities of a set of input diagrams.The approach is featured by:1)the labelled graph proposed as the representation of the candidate solutions during the iterative evolution;2)the generalized entropy proposed and defined as the measurement of the solutions;3)the genetic algorithm designed for sorting out the high-quality solution.Four cases of different scales are used to evaluate the effectiveness of the approach.The experimental results show that not only the approach gets high precision and recall but also the resulting diagram satisfies the properties of minimization and information preservation and can support the requirements traceability.

Test Case Generation from UML-Diagrams Using Genetic Algorithm

Software testing has been attracting a lot of attention for effective software development.In model driven approach,Unified Modelling Language(UML)is a conceptual modelling approach for obligations and other features of the system in a model-driven methodology.Specialized tools interpret these models into other software artifacts such as code,test data and documentation.The generation of test cases permits the appropriate test data to be determined that have the aptitude to ascertain the requirements.This paper focuses on optimizing the test data obtained from UML activity and state chart diagrams by using Basic Genetic Algorithm(BGA).For generating the test cases,both diagrams were converted into their corresponding intermediate graphical forms namely,Activity Diagram Graph(ADG)and State Chart Diagram Graph(SCDG).Then both graphs will be combined to form a single graph called,Activity State Chart Diagram Graph(ASCDG).Both graphs were then joined to create a single graph known as the Activity State Chart Diagram Graph(ASCDG).Next,the ASCDG will be optimized using BGA to generate the test data.A case study involving a withdrawal from the automated teller machine(ATM)of a bank was employed to demonstrate the approach.The approach successfully identified defects in various ATM functions such as messaging and operation.

Application and comparison of coaxial correlation diagram and hydrological model for reconstructing flood series under human disturbance

Intense human activities have greatly changed the flood generation conditions in most areas of the world, and have destroyed the consistency in the annual flood peak and volume series. For design flood estimation, coaxial correlation diagram and conceptual hydrological model are two frequently used tools to adjust and reconstruct the flood series under human disturbance. This study took a typical mountain catchment of the Haihe River Basin as an example to investigate the effects of human activities on flood regime and to compare and assess the two adjustment methods. The main purpose is to construct a conceptual hydrological model which can incorporate the effects of human activities. The results show that the coaxial correlation diagram is simple and widely-used, but can only adjust the time series of total flood volumes. Therefore, it is only applicable under certain conditions(e.g. There is a strong link between the flood peaks and volumes and the link is not significantly affected by human activities). The conceptual model is a powerful tool to adjust the time series of both flood peak flows and flood volumes over different durations provided that it is closely related to the catchment hydrological characteristics, specifically accounting for the effects of human activities, and incorporating expert knowledge when estimating or calibrating parameters. It is suggested that the two methods should be used together to cross check each other.

Formalization and Verification of Business Process Modeling Based on UML and Petri Nets

In order to provide a quantitative analysis and verification method for activity diagrams based business process modeling, a formal definition of activity diagrams is introduced. And the basic requirements for activity diagrams based business process models are proposed. Furthermore, the standardized transformation technique between business process models and basic Petri nets is presented and the analysis method for the soundness and well-structured properties of business processes is introduced.

Activity Model of Fe-Si-B Ternary Metallic Melts

According to the ion and molecule coexistence theory, the activity model of Fe-Si-B ternary system was es- tablished, and the influence of ratio ：Csi/XZe, boron content and temperature, etc. on the activity of the melt com- pound was investigated. The results show that the FeB activity is high in the liquid iron, when Xsl/XFo is 0. 5 ; the ac- tivity of boron increases with increasing the boron content for different contents of xe and xs, and the activity of boron at the ratio xFo = 0.4 is about one order of magnitude higher than that for the XFo = 0. 8; The activities of the melt compound were also affected by temperature, but the influencing extent was little. The equal activity diagrams of silicon and boron were drawn for the first time according to the model results.

DEVS and MBSE:A review

We review Discrete-Event system Specification(DEVS)in the context of Model-based Systems Engineering(MBSE)and discuss an application of DEVS methodology to MBSE.We outline support for an envisioned MBSE development cycle of DEVS top-to-bottom MBSE capability and offer an example of mapping UML activity diagrams into executable activity-based DEVS models.We close with conclusions and future research directions.

A Powerful Simulation Language for Large and Complex Models

To tackle large and complex problems, a modern simulation modeling system must posses six characteristics: simplicity, user extensibility, object orientation, flexibility, capability, and initialization. Simplicity allows those users who are nonprofessionals in simulation modeling to use the system to build their models. User extensibility is a self perfection mechanism by which the user is able to extend the abilities of the system for large and complex problems. Object oriented methodology is a natural way of simulation modeling. Flexibility can increase the range to which the system can be applied. Powerful systems satisfy demand for ever growing complicated problems. Efficient facilities for the initialization of a model reduces the pain of initializing complicated models. The GPMS language owns each of these features. It is an English like user extensible simulation language, providing simplicity for less experienced users and allowing new data types to be defined to increase its ability. It gives the user a choice between object oriented and function oriented modeling style. Its flexibility in building models prevents the user from obeying strict rules. Its powerful constructs allow the user to describe arbitrarily complicated models. Intelligent model initialization reduces the user’s effort greatly.