António Rito Silva

Using roles and business objects to model and understand business processes

Business process modeling focus on describing how activities interact with other business objects while sustaining the organizations strategy. Business objects are object-oriented representations of organizational concepts, such as resources and actors, which collaborate with one another in order to achieve business goals. These objects exhibit different behavior according to each specific collaboration context. This means the perception of a business object depends on its collaborations with other objects. Business process modeling techniques do not clearly separate the multiple collaborative aspects of a business object from its internal aspects, making it difficult to understand objects which are used in different contexts, thus hindering reuse. To cope with such issues, this paper proposes using role modeling as a separation of concerns mechanism to increase the understandability and reusability of business process models. The approach divides a business process model into a business object model and a role model. The business object models deals with specifying the structure and intrinsic behavior of business objects while the role model specifies its collaborative aspects.

AGILIPO: Embedding Social Software Features into Business Process Tools

In today’s changing environments, organizational design must take into account the fact that business processes are incomplete by nature and that they should be managed in such a way that they do not restrain human intervention. In this paper we propose the embedding of social software features, such as collaboration and wiki-like features, in the modeling and execution tools of business processes. These features will foster people empowerment in the bottom-up design and execution of business processes. We conclude this paper by identifying some research issues about the implementation of the tool and its methodological impact on Business Process Management.

A Role-Based Framework for Business Process Modeling

Business objects are object-oriented representations of the concepts of interest in an organization, such as activities, resources and actors. Business objects collaborate with one another in order to achieve business goals, showing different behavior and properties according to each specific collaboration context. This means the same business object may be perceived differently depending on the business objects it is collaborating with. However, most approaches to business process modeling do not separate the collaborative aspects of a business object from its internal aspects. To cope with such issues, this paper makes use of role modeling to separate these concerns while increasing the understandability and reusability of business process models. This approach makes use of object-oriented concepts to separate a business process model into a business object model and a role model. The business object models deals with specifying the structure and intrinsic behavior of business objects, while the role model specifies its collaborative aspects.

Versioned transactional shared memory for the FénixEDU web application

The FénixEDU system uses a novel infrastructure for web applications based on the Versioned Software Transactional Memory (VSTM) abstraction. The FénixEDU system has been deployed and is currently in operation in different facilities, including the Instituto Superior Técnico where it serves the entire academic community, processing between 1,000,000 and 4,500,000 transactions per day. This paper describes the ongoing work on the infrastructure support, in order to increase its scalability and fault-tolerance. For that purpose we are developing a distributed version of the VSTM, such that multiple application servers can concurrently serve different request and still coordinate in an efficient manner to provide strong consistency guarantees to the applications.

A role-based enterprise architecture framework

Organizations deal with contrasting domains such as people, strategy, business processes, and information systems as well as with their representation, alignment and governance. In this setting, different approaches to enterprise architecture have been introduced to address these concerns. This paper focuses on describing an enterprise architecture framework centered in three core concepts (role, entity and activity) from which domain-specific concepts are derived from. The framework abstracts the organizations domains as five architectural views (organization, business, information, application and technology) and captures the concept dependencies and relationships across the different domains.

Development of distributed applications with separation of concerns

We propose an object-oriented approach to the development of distributed applications emphasizing separation of concerns. Our approach combines the needs of transparency, encapsulation of distribution issues, and support for non-traditional models, where cooperation and sharing are desired. The development process is constructive, thus allowing partial verification of results. We recognize seven concerns: fragmentation, replication, naming, concurrency, failure, configuration, and communication. Each concern as perceived in three levels of abstraction: model, policy and mechanism. We also propose an integration process centered on development stages. Both concerns and stage perspectives are part of an integrated and flexible development process.

Density profile measurements by AM reflectometry in TJ-II

An amplitude modulation reflectometry system is in operation at the stellarator TJ-II. Recently, the first electron density profiles were obtained, showing good agreement with profiles measured by Thomson scattering and lithium beam diagnostics. In order to measure density profiles from the plasma edge, the extraordinary mode of polarization is used. A hyper-abrupt varactor-tuned oscillator used in combination with active multipliers generate two frequency segments: 25-36 and 36-50 etc GHz sharing a unique common wave-guide system (Ka band). The signal is amplitude modulated at 200 MHz and the phase demodulation is done at lower intermediate frequency. The time evolution of the electron density profile was measured under different experimental conditions. In this paper, we present the temporal evolution of the profiles obtained during a transition to an enhanced confinement mode and during cold pulse propagation experiments. We also report the modification in the shape of the density profile measured during a magnetic configuration scan in which a low-order rational surface is moved from the scrape-off layer into the plasma confinement region.

Making ICRF power compatible with a high-Z wall in ASDEX Upgrade

A comparison of the ASDEX Upgrade 3-strap ICRF antenna data with the linear electro-magnetic TOPICA calculations is presented. The comparison substantiates a reduction of the local electric field at the radially protruding plasma-facing elements of the antenna as a relevant approach for minimizing tungsten (W) sputtering in conditions when the slow wave is strongly evanescent. The measured reaction of the time-averaged RF current at the antenna limiters to the antenna feeding variations is less sensitive than predicted by the calculations. This is likely to have been caused by temporal and spatial fluctuations in the 3D plasma density distribution affected by local non-linear interactions. The 3-strap antenna with the W-coated limiters produces drastically less W sputtering compared to the W-coated 2-strap antennas. This is consistent with the non-linear asymptotic SSWICH-SW calculations for RF sheaths.

A hybrid approach to portfolio composition based on fundamental and technical indicators

This work proposes a multi-objective GA to efficiently manage a stock portfolio.Two objectives the return and the risk (variance of returns) are used to optimize the models.To select the best companies the algorithm uses fundamental financial ratios.To find the best entry point the algorithm uses technical indicators.The results found outperform the main indexes with lower volatility. This paper describes a new approach to portfolio management using stocks. The investment models tested incorporate a fundamental and technical approach using financial ratios and technical indicators. A Multi-Objective Evolutionary Algorithms (MOEA) with two objectives, the return and the risk, are used to optimize the models. Three different chromosomes are used for representing different investment models with real constraints equivalent to the ones faced by portfolio managers. To validate the present solution three case studies are presented for the S&P 500 for the period June 2010 until 2014. Simulations demonstrate that the stock selection based on financial ratios can be used to choose the best companies in operational terms, obtaining returns above the market average with low variances in their returns. The increase of fundamental indicators enhances the quality of the chromosomes found by the MOEA, and the results of real simulations become more precise. Some of the best chromosomes found by the algorithms invest in stocks with high return on equity (ROE), in conjunction with high rate of growth of the net income and a high profit margin. To obtain stocks with high valuation potential, it is necessary to choose companies with a lower or average market capitalization, low PER, high rates of revenue growth and high operating leverage.

Functionality and partitioning configuration: design patterns and framework

Configuration is often strongly coupled with distribution. In most of the approaches the configurable components are intrinsically deployed on distributed nodes. However, this does not need to be so, functionality configuration can be decoupled from partitioning configuration. In this paper two design patterns which support such decoupling are presented as well as their composition. An object-oriented framework which implements the patterns is also described. The proposed solution simplifies a software development process where traceability, incremental development and application maintenance are key issues. In particular the design patterns provide static and dynamic configuration of component, structure and geometry.