Remote learning of design patterns

Since the early 1990's, the software community focuses on the significant benefits of software reuse. Nowadays, the design pattems in object-oriented systerns have been considered one of the best strategies in order to improve software design, based on the idea of reusable solutions to design problerns. A pattem addresses a recurring design problem that arises in specific design situations and presents an abstract solution to it. Although its application is not simple (since they have a complexity cost), it describes the problem, the solution (when it applies the solution) and its consequences. So, it is necessary to let important learning period to help the software designers in the learning process of using correctly design pattems. Our research team is actually designing and developing a flexible platform model aimed to computer-based distance learning, which is going to support plug-in of intelligent learning systerns. In this paper we describe a tutoring system to support presence and distance learning of design pattems in object-oriented systerns -LeSOOP (Learning System of Object-Oriented Pattems). This system uses uniform and contextual diagnosis processes ín order to help the software designers in the correct application of design pattems. We also discuss about the plug-in and integration features of our system in a distance-learning platform

An Exploration of parametric software cost estimating models for Jackson Systems Development

Most parametric software cost estimation models used today evolved in the late 70's and early 80's. At that time, the dominant software development techniques being used were the early 'structured methods'. Since then, several new systems development paradigms and methods have emerged, one being Jackson Systems Development (JSD). As current cost estimating methods do not take account of these developments, their non-universality means they cannot provide adequate estimates of effort and hence cost. In order to address these shortcomings two new estimation methods have been developed for JSD projects. One of these methods JSD-FPA, is a top-down estimating method, based on the existing MKII function point method. The other method, JSD-COCOMO, is a sizing technique which sizes a project, in terms of lines of code, from the process structure diagrams and thus provides an input to the traditional COCOMO method.The JSD-FPA method allows JSD projects in both the real-time and scientific application areas to be costed, as well as the commercial information systems applications to which FPA is usually applied. The method is based upon a three-dimensional view of a system specification as opposed to the largely data-oriented view traditionally used by FPA. The method uses counts of various attributes of a JSD specification to develop a metric which provides an indication of the size of the system to be developed. This size metric is then transformed into an estimate of effort by calculating past project productivity and utilising this figure to predict the effort and hence cost of a future project. The effort estimates produced were validated by comparing them against the effort figures for six actual projects.The JSD-COCOMO method uses counts of the levels in a process structure chart as the input to an empirically derived model which transforms them into an estimate of delivered source code instructions

FROM REALITY-BASED MODEL TO GIS PLATFORM. MULTI-SCALAR MODELING FOR IRRIGATED LANDSCAPE MANAGEMENT IN THE PAVIA PLAIN

This research aims to define a low-cost replicable methodology for obtaining fast multiscale information models. The experiments carried out were conducted by researchers from Dada LAB and PLAY experimental Laboratories of the University of Pavia, Department of Civil Engineering and Architecture, on the case study of the irrigated landscape of the Pavia plain. The entire work process was developed according to a low-cost purpose, starting from fast acquisition activities with UAV instruments, to the processing of photogrammetric data, urban and detailed scale modelling with open-source software, to the census, filing, and computerisation of the model. The resulting product is configured as a multiscale reality-based information system. A census card is associated with each constituent element of the model (crops, canals, valuable hydraulic artefacts). Connection to the GIS platform allows the user to query the model. The result is a digital system oriented to facilitate the management of the agricultural and irrigation landscape, and to digitally document and preserve the heritage of historical hydraulic existing artefacts. Two different GIS platforms for structuring the information system were tested. The first involved a high-budget solution using ESRI ArcGIS Pro/ArcSCENE software, and the second involved using QGIS software, an Open-Source Geographic Information System, to develop an accessible information system without license fees, to evaluate the advantages and disadvantages of low-cost processes

Experiences with formal engineering: model-based specification, implementation and testing of a software bus at Neopost

We report on the actual industrial use of formal methods during the development of a software bus. During an internship at Neopost Inc., of 14 weeks, we developed the server component of a software bus, called the XBus, using formal methods during the design, validation and testing phase: we modeled our design of the XBus in the process algebra mCRL2, validated the design using the mCRL2-simulator, and fully automatically tested our implementation with the model-based test tool JTorX. This resulted in a well- tested software bus with a maintainable architecture. Writing the model (mdev), simulating it, and testing the implementation with JTorX only took 17% of the total development time. Moreover, the errors found with model-based testing would have been hard to find with conventional test methods. Thus, we show that formal engineering can be feasible, beneficial and cost-effective.\ud The findings above, reported earlier by us in (Sijtema et al., 2011) [1], were well- received, also in industrially oriented conferences (Ferreira and Romanenko, 2010) [2] and [3]. In this paper, we look back on the case study, and carefully analyze its merits and shortcomings. We reflect on (1) the added benefits of model checking, (2) model completeness and (3) the quality and performance of the test process.\ud Thus, in a second phase, after the internship, we model checked the XBus protocol—this was not done in [1] since the Neopost business process required a working implementation after 14 weeks. We used the CADP tool evaluator4 to check the behavioral requirements obtained during the development. Model checking did not uncover errors in model mdev, but revealed that model mdev was neither complete nor optimized: in particular, requirements to the so-called bad weather behavior (exceptions, unexpected inputs, etc.) were missing. Therefore, we created several improved models, checked that we could validate them, and used them to analyze quality and performance of the test process. Model checking was expensive: it took us approx. 4 weeks in total, compared to 3 weeks for the entire model-based testing approach during the internship.\ud In the second phase, we analyzed the quality and performance of the test process, where we looked at both code and model coverage. We found that high code coverage (almost 100%) is in most cases obtained within 1000 test steps and 2 minutes, which matches the fact that the faults in the XBus were discovered within a few minutes.\ud Summarizing, we firmly believe that the formal engineering approach is cost-effective, and produces high quality software products. Model checking does yield significantly better models, but is also costly. Thus, system developers should trade off higher model quality against higher costs

Contribution to Quality-driven Evolutionary Software Development process for Service-Oriented Architectures

The quality of software is a key element for the successful of a system. Currently, with the advance of the technology, consumers demand more and better services. Models for the development process have also to be adapted to new requirements. This is particular true in the case of service oriented systems (domain of this thesis), where an unpredictable number of users can access to one or several services. This work proposes an improvement in the models for the software development process based on the theory of the evolutionary software development. The main objective is to maintain and improve the quality of software as long as possible and with the minimum effort and cost. Usually, this process is supported on methods known in the literature as agile software development methods. Other key element in this thesis is the service oriented software architecture. Software architecture plays an important role in the quality of any software system. The Service oriented architecture adds the service flexibility, the services are autonomous and compact assets, and they can be improved and integrated with better facility. The proposed model in this thesis for evolutionary software development makes emphasis in the quality of services. Therefore, some principles of evolutionary development are redefined and new processes are introduced, such as: architecture assessment, architecture recovery and architecture conformance. Every new process will be evaluated with case studies considering quality aspects. They have been selected according to the market demand, they are: the performance, security and evolutionability. Other aspects could be considered of the same way than the three previous, but we believe that these quality attributes are enough to demonstrate the viability of our proposal

Aspect-Oriented Modeling for Representing and Integrating Security Aspects in UML Models

Security is a challenging task in software engineering. Traditionally, addressing security concerns are considered as an afterthought to the development process and security mechanisms are fitted into pre-existing software without considering the consequences on the main functionality of the software. Enforcing security policies should be taken care of during early phases of the software development life cycle; this benefits the development costs and reduces the maintenance time. In addition to cost saving, this encourages development of reliable software. Since security related concepts will be considered in each step of the design, the implications of inserting such concepts into the existing system requirements will help mitigate the defects and vulnerabilities present in the system. Although integrating security solutions into every stage of the software development cycle, results in scattering and tangling of security features across the entire design. The traditional security hardening approaches are tedious and prone to many errors as they involve manual modifications. In this context, the need for a systematic way to integrate security aspects/mechanisms into the design phase of the development cycle should be considered. In this work, an aspect-oriented modeling approach for specifying and integrating security aspects in to Unified Modeling Language (UML) design model is presented. This approach allows the security experts to specify generic security aspects and weave them into target software base model early in the software development phase. In contrast to traditional approaches, model-to-model transformation mechanisms discussed in this approach are designed to have an efficient and a fully automatic weaving process. This work further discusses additional components that are introduced into the weaving process. These newly introduced components allow the security experts to provide more appropriate security hardening concepts. Furthermore, the additional components are designed based on object-oriented principles and allow the security experts to exercise these principles in the model-to-model transformation. The additions to the weaver application are tested using the Session Initiation Protocol (SIP) communicator as a base model. The description of the additional components and the results of testing of the weaving process are discussed further in this thesis

Simulator Arsitektural Dari Sirkuit Elektronis Guna Tujuan Pembelajaran

The electronic circuit engineering learning processes generally requires specific infrastructures which sometimes constrained to cost factors in the procurement. Circuit simulator could be an alternative as electronic circuit engineering learning tool. Architectural simulation provides designers the ability to quickly examine a wide variety of design choices. The recent trend in system design toward architectures that react to circuit-level phenomena has outstripped the capabilities of traditional cycle-based architectural simulators. In this paper, a simulator that incorporates a circuit modeling capability, permitting architectural-level simulations that react to circuit characteristics (such as latency, energy, power brightness, or current draw) on a cycle-by-cycle basis is presented. As for learning purpose, circuit template and pre-built circuits for many categories are provided. The environment enables process visualization and simulation of analog and digital circuits. The system enables the creation of many laboratory exercises, which offer students opportunities to follow visually characteristic processes in analog and digital circuits. At this research, Rational Unified Process (RUP) software process model and Object Oriented Programming (OOP) are implemented.Keywords: architectural simulation, circuit simulation, learning, RUP, OO

MDA-driven development of standard-compliant OSS components: the OSS/J inventory case-study.

The telecommunications-oriented Operational Support Systems (OSS) industry have recognised the value of technology independent modelling of OSS solutions as a way to reduce cost, add agility, validate and verify solution designs against architectural guidelines of an enterprise and most importantly provide traceability in the design methodology process. The challenges faced by the OSS community is how MDA tools can deliver the promise of advanced meta-modelling, model definition and validation and model transformation for both OSS software components and integration logic in the larger OSS landscape. This paper describes how an advanced extensible meta-modelling tool is used to build an OSS component following best practice industry guidelines. Extended MOF, extended executable OCL and a powerful transformation language are used to capture the constraints in the meta-models as well as models followed by complete, 100% code generation from models. Furthermore, meta-models are also developed to capture graphical user interface elements in conjunction with the inventory data models, which are then automatically translated into code. This work is the precursor for defining extensive meta-models for a component-based OSS infrastructure based on industry best practice, for adding high degree of formality to model specifications and for enabling the verification of domain requirements by executing the models through model snapshot creation, way before system implementation takes place

Development of a platform for simulating and optimizing thermoelectric energy systems

Thermoelectrics are solid state devices that can convert thermal energy directly into electrical energy. They have historically been used only in niche applications because of their relatively low efficiencies. With the advent of nanotechnology and improved manufacturing processes thermoelectric materials have become less costly and more efficient As next generation thermoelectric materials become available there is a need for industries to quickly and cost effectively seek out feasible applications for thermoelectric heat recovery platforms. Determining the technical and economic feasibility of such systems requires a model that predicts performance at the system level. Current models focus on specific system applications or neglect the rest of the system altogether, focusing on only module design and not an entire energy system. To assist in screening and optimizing entire energy systems using thermoelectrics, a novel software tool, Thermoelectric Power System Simulator (TEPSS), is developed for system level simulation and optimization of heat recovery systems. The platform is designed for use with a generic energy system so that most types of thermoelectric heat recovery applications can be modeled. TEPSS is based on object-oriented programming in MATLAB®. A modular, shell based architecture is developed to carry out concept generation, system simulation and optimization. Systems are defined according to the components and interconnectivity specified by the user. An iterative solution process based on Newton\u27s Method is employed to determine the system\u27s steady state so that an objective function representing the cost of the system can be evaluated at the operating point. An optimization algorithm from MATLAB\u27s Optimization Toolbox uses sequential quadratic programming to minimize this objective function with respect to a set of user specified design variables and constraints. During this iterative process many independent system simulations are executed and the optimal operating condition of the system is determined. A comprehensive guide to using the software platform is included. TEPSS is intended to be expandable so that users can add new types of components and implement component models with an adequate degree of complexity for a required application. Special steps are taken to ensure that the system of nonlinear algebraic equations presented in the system engineering model is square and that all equations are independent. In addition, the third party program FluidProp is leveraged to allow for simulations of systems with a range of fluids. Sequential unconstrained minimization techniques are used to prevent physical variables like pressure and temperature from trending to infinity during optimization. Two case studies are performed to verify and demonstrate the simulation and optimization routines employed by TEPSS. The first is of a simple combined cycle in which the size of the heat exchanger and fuel rate are optimized. The second case study is the optimization of geometric parameters of a thermoelectric heat recovery platform in a regenerative Brayton Cycle. A basic package of components and interconnections are verified and provided as well