Unified Modeling Language Class Diagrams Research Articles

Accessible Modeling on the Web: A Case Study

With the growth of software engineering disciplines and visual languages like the UML (Unified Modeling Language) and consequently increase of modeling activities that use this visual languages, the access of the visually impaired is harmed and they need the assistance of other people both for reading and editing this models. In this paper we present a case study conducted to evaluate the effectiveness of a prototype tool developed by the authors and was designed to allow users to model using UML class diagrams using two distinct views: a traditional graphical view that sighted users are used to work with and an equivalent textual view where blind or visually impaired users can read, create models and also collaborate on models created by the graphical view. The study was conducted with one totally blind subject and counted with a previous pilot with a visually impaired subject to validate the study design. Results indicate that the AWMo approach was successful and well accepted by the users while they see potential that it could actually be used on professional environments.

Evaluation of a UML-Based Versus an IEC 61131-3-Based Software Engineering Approach for Teaching PLC Programming

A field experiment investigated the evaluation, teaching, and application of two different approaches to automatic control in programmable logic controllers, in particular comparing the Unified Modeling Language (UML) to the classic procedural paradigm (IEC 61131-3). A total of 85 apprentices from a vocational school for production engineering with a specialization in mechatronics took part in the training and the experiment. This paper details the results of the training using both approaches, and the correlations found between the modeling and/or programming performance and cognitive abilities, interest, workload, expertise, and school grades. In general, the results show that students can be trained to carry out authentic programming tasks within one and a half days, even for beginners in programming. The data distinguish the two approaches. Function Block Diagram programming (IEC 61131-3) can be best predicted by the grade in mathematics, programming experience, and cognitive demand. For performance in UML class diagram and state chart (UML/CD+SC) modeling, the grade in mathematics plays an even more prominent role; this explains the greater variance in modeling performance in the UML group than in the 61131/Function Block Diagram group. With respect to other findings, the paper concludes that special problem-solving skills and skills for abstract thinking should be taught when teaching UML-based modeling approaches.

An Information Model for Pedestrian Routing and Navigation Databases Supporting Universal Accessibility

This study focuses on the information content of the geospatial databases used to guide pedestrians as well as those with disabilities. In this paper we introduce an information model for describing this content. The model covers the physical environment faced by a person moving on foot. We have used the Unified Modeling Language class diagrams to formalize the information model on a conceptual level. The features are divided into two abstract top-level classes: one allowing pedestrian access and the other hindering it. A consistent and comprehensive pedestrian network is at the core of the model. The model also covers other geographical information to increase accessibility. The aim of the created information model is to help data providers to collect and store appropriate data using the appropriate methods.

Modeling and validation of execution of tasks on high speed network under distributed environment

During the past years, distributed computing approach has become an integral part of many of the software companies. This is because of low cost infrastructure involvement and faster execution of the tasks, sharing of resources, etc. In the year 2009, the Indian Government has established distributed network called as National Knowledge Network (NKN). The main objective of NKN is to connect all of the Indian universities, research institutions, computing labs, digital libraries, countrywide classrooms, etc. In the present paper, a well-known object-oriented Unified Modeling Language (UML) is used to construct a model for the execution of the tasks across a distributed network. Authors have designed a static step topology for the faster execution of tasks. Static and dynamic behaviors of the execution of the tasks are represented through UML class and state diagrams, respectively. For validation of the UML model, the state diagram is converted into a Finite State Machine (FSM) and different test cases are generated to validate the proposed model across distributed network environment.

Automatic code generation from unified modelling language sequence diagrams

Unified modelling language (UML) is a visual modelling language, which has gained popularity among software practitioners. In a model-driven software development environment, the existing UML tools mainly support automatic generation of structural code from UML class diagrams. However, the code generation from UML diagrams such as statechart, activity, collaboration and sequence diagrams (SDs) are not supported by most UML tools and also have scarcely been reported in the literatures. This work proposes an approach to automatic generation of code from UML 2.x SDs of use cases. From the XML metadata interchange (XMI) representation of an SD of a use case, the authors construct a graph model called sequence integration graph (SIG). The SIG encapsulates information related to messages, control flow and method scope of interactions. These information are then used to generate code. The proposed approach has been tested using a number of real-life application systems and the results substantiate the efficacy of the approach to synthesise the code for controller classes. The authors observe that approximately 48% of the total lines of code within controller class methods can be generated with the proposed approach. The proposed approach can be easily extended to other behavioural UML models such as interaction-overview diagrams, communication diagrams and activity diagrams.

Visualizing offscreen elements of node-link diagrams

Visual representations of node-link diagrams are very important for the software development process. In many situations, large diagrams have to be explored, whereby diagram elements of interest are often clipped from the viewport and are therefore not visible. Thus, in state-of-the-art modeling tools, navigation is accompanied by time-consuming panning and zooming. One solution to this problem is offscreen visualization techniques. Usually, they indicate the existence and direction of clipped elements by overlays at the border of the viewport. In this article, we contribute the application of offscreen visualization techniques to the domain of node-link diagrams in general and to Unified Modeling Language class diagrams in particular. The basic idea of our approach is to represent offscreen nodes by proxy elements located within an interactive border region around the viewport. The proxies show information of the associated offscreen nodes and can be used to quickly navigate to the respective node. In addition, we contribute techniques that preserve the routing of edges during panning and zooming and present strategies to make our approach scalable to large diagrams. We conducted a formative pilot study of our first prototype. Based on the observations made during the evaluation, we suggest how particular techniques should be combined. Finally, we ran a user evaluation to compare our technique with a traditional zoom+pan interface. The results showed that our approach is significantly faster for exploring relationships within diagrams than state-of-the-art interfaces. We also found that the offscreen visualization combined with an additional overview window did not improve the orientation within an unknown diagram. However, an overview should be offered as a cognitive support. CR categories: D.2.2 [Software Engineering]: Design Tools and Techniques— User Interface; H.5.2 [Information Interfaces and Presentation]: User Interfaces— Graphical User Interfaces General terms: Design, Human Factors

Sharing of NKN Facilities in Static Step Topology under Distributed Environment

The government of India has set up distributed network in India for sharing the knowledge among the higher learning Institutions in the year 2009 under Next Generation Services (NGN) and slowly-slowly it is expanding as the distributed computing network becomes very popular now days due to low cost involvement. This network is called as a National Knowledge Network (NKN) whose main purpose is to connect all the Indian universities, research institutions, research labs, digital libraries, countrywide classroom, etc. under one platform. In the present work, sharing of different kinds of facilities under NKN is demonstrated for the static step topology designed by the authors. The different kinds of facilities are connected through step topology and a well known modeling technique i.e. Unified Modeling Language (UML) is used for demonstrating the UML class diagram for sharing of all these facilities through step topology. Some experimental results are also demonstrated for the topology.

UML Modeling of Generic Agent Database Approach under Distributed Computing Environment

Due to presence of high speed bandwidth network called as National Knowledge Network (NKN) environment, the communication between the two computer systems by message passing and data transmission techniques have improved significantly. The existence of heterogeneous network environment has different configuration supporting network. In such type of networks, the process execution depends upon several factors related with the hardware like cpu speed, clock rate, memory size, etc. and software events like execution scenario of processes based on software programming and database approach results in a best optimum performance of the network. One of such kind of approach has been proposed by the authors and a model has been designed for the general process execution concept through distributed database agent supported in distributed computing environment to obtain optimum process execution. This approach has been designed by considering two phases; one phase based on the client node and other is based on controller system. The model has been created by the use of well known Unified Modeling Language (UML) and UML class, sequence and activity diagrams are designed. General Terms Generic System, Distributed Approach

Textual Requirement Analysis for UML Diagram Extraction by using NLP

Requirement analysis is the preliminary step in software development process. The requirements stated by the clients are analyzed and an abstraction of it, is created which is termed as requirement model. The automatic generation of UML diagram from natural language requirements is highly challenging and demanding very efficient methodology. Unified Modeling Language (UML) models are helpful for understanding the problems, communicating with application experts and preparing documentation. The static design view of the system can be modeled using a UML class diagram. System requirements stated by the user are usually in natural language form. This is an imprecise and inconsistent form which is difficult to be used by the developer for design UML model. We present a new methodology for generating UML diagrams or models from natural language problem statement or requirement specification. We have named our methodology as Requirement analysis and UML diagram extraction (RAUE). General Terms

Guidelines for using UML association classes and their effect on domain understanding in requirements engineering

The analysis and description of the application domain are important parts of the requirements engineering process. Domain descriptions are frequently represented as models in the de-facto standard unified modeling language (UML). Recent research has specified the semantics of various UML language elements for domain modeling, based on ontological considerations. In this paper, we empirically examine ontological modeling guidelines for the UML association construct, which plays a central role in UML class diagrams. Using an experimental study, we find that some, but not all, of the proposed guidelines lead to better application domain models. We use a process-tracing study to investigate in more detail the effects of ontological guidelines. The combined results indicate that ontological guidelines can improve the usefulness of UML class diagrams for describing the application domain, and thus have the potential to improve downstream system development activities and ultimately affect the successful information systems implementation.

Modeling and implementation of the vegetable supply chain traceability system

In a traceability system, a large and dynamic group of participants must be identified. The identification of information to be recorded represents the most important requirement for developing an effective traceability system. The information identified during the transport and processing of vegetables is often lost and inaccurate. In this paper, a system approach is used in order to develop a methodology for the implementation of the vegetable supply chain traceability. First of all, the main discussed issues emerge at various abstraction levels throughout the elaboration of traceability systems. Secondly, a Unified Modeling Language model is introduced for traceability along with a set of suitable patterns. A series of Unified Modeling Language class diagrams is developed in order to conceive a method for modeling the product, process, and quality information in the vegetable supply chain. Then will be discussed the adequate technological standards for setting out, registering, as well as for enabling the business collaborations. Finally, a traceability system implementation will be shown through a case study on vegetable supply chains and a comparison with European Union's General Food Law.

Transformation of UML Class Diagram to UML Sequence Diagram

For object-oriented software development, The Unified Modeling Language (UML) has become an industrial standard. There are different models which have been described under UML notation. Use case model can represent the functional view of the system, UML class model can represent static view of the system, activity or sequence diagram can represent the dynamic view of the system. If we focus on field of UML class diagram & UML activity diagrams then a lots of research still is required. In this paper we describe a transformation process which can be used to transform the UML class diagram to UML sequence diagram. Transformation process is quite helpful so that we can easy obtain the UML sequence diagram from UML class diagram. General Terms UML Class diagram, UML Sequence diagram

Students' different understandings of class diagrams

The software industry needs well-trained software designers and one important aspect of software design is the ability to model software designs visually and understand what visual models represent. However, previous research indicates that software design is a difficult task to many students. This article reports empirical findings from a phenomenographic investigation on how students understand class diagrams, Unified Modeling Language (UML) symbols, and relations to object-oriented (OO) concepts. The informants were 20 Computer Science students from four different universities in Sweden. The results show qualitatively different ways to understand and describe UML class diagrams and the “diamond symbols” representing aggregation and composition. The purpose of class diagrams was understood in a varied way, from describing it as a documentation to a more advanced view related to communication. The descriptions of class diagrams varied from seeing them as a specification of classes to a more advanced view, where they were described to show hierarchic structures of classes and relations. The diamond symbols were seen as “relations” and a more advanced way was seeing the white and the black diamonds as different symbols for aggregation and composition. As a consequence of the results, it is recommended that UML should be adopted in courses. It is briefly indicated how the phenomenographic results in combination with variation theory can be used by teachers to enhance students’ possibilities to reach advanced understanding of phenomena related to UML class diagrams. Moreover, it is recommended that teachers should put more effort in assessing skills in proper usage of the basic symbols and models and students should be provided with opportunities to practise collaborative design, e.g. using whiteboards.

Vehicle Insurance Policy System through UML

Unified Modeling Language known as UML is widely accepted around the globe as an object oriented modeling language which is used to construct the software designs. It is independent to the object-oriented programming languages and designed UML models can be easily implemented by any object-oriented programming language. In the present paper, UML model is proposed for the Vehicle Insurance Policy System (VIPS). A real case study of BAJAJ Company of India is considered and proposed model is applicable for all the types of the vehicles available in the world. UML class, sequence and activity diagrams are designed and the model has also been validated by performing several queries on the designed sample database. Unified Modeling Language (UML) is a well known recognized, powerful and leading diagrammatic modeling language which is used to model the software research problems. It is a very popular for analysis of the research problems and easily compatible to the object oriented programming language. Nowadays, UML becomes a standard modeling language for the Software Industries which is used by the various software designers. Modeling plays an important role for any system and contributes the understanding of the source inputs and outputs but from the literature it is observed that UML is not much used for the object-oriented databases. Let us first describe some of the important references related to the UML. Booch et al. (1-3) described the important diagrams of the UML which are widely used for the development of the software designs. After the development of the UML, Agrawal et al. (4) first time applied UML for the multidimensional large database and used the concept of UML aggregation. With the help of UML they described the theoretical approach of the data cubes. In 1998, Paulo and Norman (5) designed a User Interface (UI) through UML. The strength and weaknesses of the UI are also explained in the paper. OMG is an active group released various versions of UML and these are listed in (6-8). Lopez-Sanz et al. (9) explained modeling of various service-oriented architectures with UML. They study the architectural properties of the SOA paradigm and on the basis of this; developed the MDA approach for abstraction. Saxena et al. (10-12) has also applied the UML in the field of computer architecture, dataware housing; proposed a protocol for mutual exclusion for the distributed operating

Representation of Object-Oriented Database for the Development of Web Based Application Using Db4o

Impedance mismatch of data flow is the major problem in the relational database when one is using the web based application development on the computer system. It effects the development of scalable and reusable web application. Due to this, the research cost of development and maintenance increases. Therefore the present work is an attempt towards an object-oriented database system by using Db4o to overcome the impedance mismatch problem. In the current work, the development of web application for Indian Postal Services by using Db4o is demonstrated on dot NET platform. Before developing the application, the authors used a Unified Modeling Language (UML) model in the form of UML class, sequence and use-case diagrams. The Db4o is used to store the object-oriented database and the performance of Db4o is observed through several object-oriented queries and corresponding results are demonstrated.

Coupling-based transformations of Z specifications into UML diagrams

Due to their accuracy in describing systems, formal specifications can play an important role during forward as well as reverse engineering activities. However, besides dense mathematical expressions, their lack in visually appealing notations impedes their use and exchange among different stakeholders. One solution to this problem is to enrich the specification by other views, in most cases Unified Modelling Language (UML) diagrams. But the mapping is not trivial, and existing approaches have their impediments, among them the assignment of methods to classes--which has to be re-done by hand quite often. By the example of Z, this paper demonstrates that the situation can be improved. The new approach combines existing mapping strategies, but additionally lets the assignment of methods rest on quality-related measures. The basic idea is to balance the values of coupling for all methods within and between the UML classes. With that, two issues are addressed: firstly, the mapping of sets, types, and operations (to UML classes and UML methods) is based on reproducible measures that are intuitively comprehensible. Secondly, implementations based on the resulting UML class diagrams very likely also have comparable quality-related properties.

Modeling fuzzy information in UML class diagrams and object-oriented database models

Conceptual data modeling has become essential for non-traditional application areas. Some conceptual data models have been proposed as tools for database design and object-oriented database modeling. Information in real-world applications is often vague or ambiguous. Currently, a little research is underway on modeling the imprecision and uncertainty in conceptual data modeling and the conceptual design of fuzzy databases. The unified modeling language (UML) is a set of object-oriented modeling notations and a standard of the object management group (OMG) with applications to many areas of software engineering and knowledge engineering, increasingly including data modeling. This paper introduces different levels of fuzziness into the class of UML and presents the corresponding graphical representations, with the result that UML class diagrams may model fuzzy information. The fuzzy UML data model is also formally mapped into the fuzzy object-oriented database model.

Fuzzy information modeling in UML class diagram and relational database models

Computer applications in non-traditional area have put requirement on conceptual data modeling. Some conceptual data models, being the tool of design databases, have been proposed. On one hand, the Unified Modeling Language (UML) can be applied for many areas of software and knowledge engineering, and is being applied to data modeling. On the other hand, information in real world application is often vague or ambiguous. Currently, less research has been done in modeling imprecision and uncertainty in conceptual data model and design of databases with imprecision and uncertainty. In this paper, based on fuzzy set and possibility distribution theory, different levels of fuzziness are introduced into the UML class diagram model and the corresponding formal representations are given. The UML class diagram model is then extended to fuzzy UML data model. The formal mapping of the fuzzy UML data model into the fuzzy relational database schema is proposed in the paper.

Design of a Multidimensional Model Using Object Oriented Features in UML

A data warehouse is a single repository of data which includes data generated from various operational systems. Conceptual modeling is an important concept in the successful design of a data warehouse. The Unified Modeling Language (UML) has become a standard for object modeling during analysis and design steps of software system development. The paper proposes an object oriented approach to model the process of data warehouse design. The hierarchies of each data element can be explicitly defined, thus highlighting the data granularity. We propose a UML multidimensional model using various data sources based on UML schemas. We present a conceptual-level integration framework on diverse UML data sources on which OLAP operations can be performed. Our integration framework takes into account the benefits of UML (its concepts, relationships and extended features) which is more close to the real world and can model even the complex problems easily and accurately. Two steps are involved in our integration framework. The first one is to convert UML schemas into UML class diagrams. The second is to build a multidimensional model from the UML class diagrams. The white-paper focuses on the transformations used in the second step. We describe how to represent a multidimensional model using a UML star or snowflake diagram with the help of a case study. To the best of our knowledge, we are the first people to represent a UML snowflake diagram that integrates heterogeneous UML data sources.

Generating operation specifications from UML class diagrams: A model transformation approach

One of the more tedious and complex tasks during the specification of conceptual schemas (CSs) is modeling the operations that define the system behavior. This paper aims to simplify this task by providing a method that automatically generates a set of basic operations that complement the static aspects of the CS and suffice to perform all typical life-cycle create/update/delete changes on the population of the elements of the CS. Our method guarantees that the generated operations are executable, i.e. their executions produce a consistent state wrt the most typical structural constraints that can be defined in CSs (e.g. multiplicity constraints). In particular, our method takes as input a CS expressed as a Unified Modeling Language (UML) class diagram (optionally defined using a profile to enrich the specification of associations) and generates an extended version of the CS that includes all necessary operations to start operating the system. If desired, these basic operations can be later used as building blocks for creating more complex ones. We show the formalization and implementation of our method by means of model-to-model transformations. Our approach is particularly relevant in the context of Model Driven Development approaches.