Precise Modelling of Compensating Business Transactions and its Application to BPEL

We describe the StAC language which can be used to specify the orchestration of activities in long running business transactions. Long running business transactions use compensation to cope with exceptions. StAC supports sequential and parallel behaviour as well as exception and compensation handling. We also show how the B notation may be combined with StAC to specify the data aspects of transactions. The combination of StAC and B provides a rich formal notation which allows for succinct and precise specification of business transactions. BPEL is an industry standard language for specifying business transactions and includes compensation constructs. We show how a substantial subset of BPEL can be mapped to StAC thus demonstrating the expressiveness of StAC and providing a formal semantics for BPEL

O Consumo de Drogas e o Envolvimento em Actividades de Lazer na Adolescência

O presente artigo pretende contribuir para uma descrição das prevalências dos consumos de tabaco, álcool e drogas em estudantes do ensino secundário, de uma escola secundária do Norte de Portugal. Este enquadra-se na necessidade actual de aprofundar o estudo do fenómeno da droga, permitindo deste modo, um crescimento no conhecimento científi co nesta área. Utilizou-se, uma metodologia quantitativa recorrendo a um questionário de avaliação dos consumos de tabaco, álcool e drogas (Carvalho, 2001) 5 , do qual fi zeram parte 170 estudantes dos 10º, 11º e 12º anos de escolaridade, com idades compreendidas entre os 16 e os 22 anos de idade (M=17,5; DP=1,4). Os resultados apontam para a presença de consumos, particularmente, de álcool, tabaco, inalantes e marijuana ou haxixe, destacando-se também o de tranquilizantes ou sedativos (sem prescrição médica), sendo os restantes quase inexistentes. São os estudantes que frequentam mais vezes discotecas e bares os que apresentam maiores consumos de álcool, tabaco e marijuana ou haxixe. Destacam-se ainda os estudantes que afi rmam andar mais de bicicleta os que apresentam maiores consumos de marijuana ou haxixe.info:eu-repo/semantics/publishedVersio

Digital transformation of a manufacturing firm: A matter of combining resources and strategizing in business networks

Manufacturing firms are gradually undergoing digital transformation through starting to implement new digital technologies, and creating new offerings to meet customer needs. As no business is an island, the process of creating new digital offerings and selling these to customers involves collaboration with other actors. These actors need to develop and combine resources to successfully create value in the business network. Under these circumstances, manufacturing firms develop strategic actions to access and combine such resources. The purpose of this thesis is to understand resource combining and strategizing in business networks, as part of the process of digital transformation, from the perspective of a focal manufacturing firm interacting with customers and suppliers. This thesis relies on the Industrial Network Approach (INA), and more specifically literature on resources and strategizing, to study business relationships with regard to digital transformation and reveal the nuances and effects of characteristics of digital resources during resource combining and value creation. A single case study of a manufacturing firm undergoing the process of digital transformation, and its related business network, was conducted. By applying the case study method, details about different business relationships within the context of digital transformation were captured and analysed.The findings of this thesis show that a focal firm needs to take a variety of strategic actions when interacting with other actors, creating and consolidating elements of the business relationships. Focal firms also strive to access and combine key digital and non-digital resources. As a result of this resource combining, value can be created in the forms of flexibility, efficiency, novelty and functioning digital solutions. This thesis advances the understanding of the interplay between creating/consolidating elements of business relationships to access and combine digital resources during the process of digital transformation. Based on the intrinsic characteristics of digital resources, the forms of resource combining provided in this study offer a perspective on the opportunities, values and challenges that digitalisation presents in the ever-evolving digital business landscape

Muitas Palavras à Procura de Silêncio: A Caminho do Ciberespaço

Homenagem a Yvette Centeno a partir de análise do que publicou na blogosesfera

Convergence of LR algorithm for a one-point spectrum tridiagonal matrix

We proved convergence for the basic LR algorithm on a real unreduced tridiagonal matrix with a one-point spectrum - the Jordan form is one big Jordan block. First we develop properties of eigenvector matrices. We also show how to deal with the singular case

Preventing Atomicity Violations with Contracts

Software developers are expected to protect concurrent accesses to shared regions of memory with some mutual exclusion primitive that ensures atomicity properties to a sequence of program statements. This approach prevents data races but may fail to provide all necessary correctness properties.The composition of correlated atomic operations without further synchronization may cause atomicity violations. Atomic violations may be avoided by grouping the correlated atomic regions in a single larger atomic scope. Concurrent programs are particularly prone to atomicity violations when they use services provided by third party packages or modules, since the programmer may fail to identify which services are correlated. In this paper we propose to use contracts for concurrency, where the developer of a module writes a set of contract terms that specify which methods are correlated and must be executed in the same atomic scope. These contracts are then used to verify the correctness of the main program with respect to the usage of the module(s). If a contract is well defined and complete, and the main program respects it, then the program is safe from atomicity violations with respect to that module. We also propose a static analysis based methodology to verify contracts for concurrency that we applied to some real-world software packages. The bug we found in Tomcat 6.0 was immediately acknowledged and corrected by its development team

Problemas de ajustamento psicológico em crianças expostas a violência nas relações íntimas : será que o tipo de residência faz a diferença?

Orientação: Diogo Lamela ; co-orientação: Ricardo PintoA investigação sobre o ajustamento psicológico de crianças expostas a violência nas relações de intimidade (VRI) tem algumas limitações importantes que precisam ser abordadas, tais como a utilização de amostras exclusivamente comunitárias, através de projetos transversais com medidas retrospetivas de auto-relato. Uma limitação importante da literatura é que não são encontrados estudos que analisem o impacto da residência em Casa Abrigo vs. a viver em casa com a mãe e com o companheiro agressivo no desenvolvimento e ajustamento psicológico nas crianças. Tendo em conta tais limitações, o presente estudo teve como objetivo testar diferenças entre crianças que viviam em Casa Abrigo destinadas para vítimas de VRI e crianças que viviam na residência com a mãe e o companheiro agressivo. Neste estudo foi utilizada uma amostra de alto risco, de 155 mães e 155 crianças, com mães e crianças a residir em Casa Abrigo e outras a residir em casa com o companheiro agressivo. De modo a testar tais diferenças, foram recolhidos dados sobre o ajustamento da criança, tais como os níveis de sintomas de internalização (SI) e sintomas de externalização (SE), bem como variáveis do ajustamento materno e da parentalidade, que a investigação prévia indicou serem preditivas do ajustamento psicológico das crianças, nomeadamente a frequência de vitimação, psicopatologia, suporte social, práticas parentais e competência materna. Os principais resultados obtidos revelaram que as mães a viver em Casa Abrigo relatam mais problemas de internalização e externalização nos seus filhos do que mães a viverem com o companheiro. Estes resultados mantiveram-se significativos, mesmo após o controlo estatístico de outras variáveis que poderiam influenciar esta diferença, tais como a vitimação e o suporte social materno. Não foram encontradas diferenças entre os dois grupos ao nível da psicopatologia materna, práticas parentais e competência materna. As implicações dos resultados para a prática clínica são também discutidas.An investigation about children’s psychological adjustment after being exposed to intimate partner violence (IPV) has some important limitations that need to be addressed, just as the use of samples that are exclusively from communities, through some transverse projects with self-related retrospective measurements. An important limitation of the literature is that there has not been found studies that analyze the impact of living in a shelter home vs. living at home with the mom along with her abusive partner in children’s’ psychological development and adjustment. Considering these limitations, this study had as objective to test differences among children that lived at shelter homes designated to IPV victims and children that live in their homes with the mom and the abusive partner. In this study the sample used was high risk, out of 155 mothers and 155 children, with mothers and children living in a shelter home and others living at home with their abusive partner. To test these differences, there was data collection about the child’s adjustment, such as the levels of internalization symptoms (SI) and externalization symptoms (SE), as well as variances of adjustment with the mother and parenting, been that the previous investigation indicated these as been predictors of children psychological adjustment, along with the frequency of the abuse, psychopathology, social support, parental practices and mother competence. Important results developed revealed that the mothers living at the shelter home show more problems of internalization and externalization on their children than mothers living with their partner. These results were significant, even after the statistic control of other variables that could have influence this difference, such as victimization and the mother’s social support. There were no differences found between the two groups related to the mother psychopathology, parental practices and competences from the mother. Results implications to a clinical practice are discussed as well

Eigenpairs of Wilkinson Matrices

In the 1950s J. H. Wilkinson introduced two families of symmetric tridiagonal integer matrices. Most of the eigenvalues are close to diagonal entries. We develop the structure of their eigenvectors in a natural way which reveals that these eigenvectors all look the same to the naked eye. The shape of the envelopes is like twin peaks (or a badly dented bell curve). We also analyze the eigenvectors of the remaining noninteger eigenvalues.FCT -Fundação para a Ciência e a Tecnologia(UID/MAT/00013/2013