BSP -Style Computation: A Semantic Investigation

A BSP (Bulk Synchronous Parallelism) computation is characterized by the generation of asynchronous messages in packages during independent execution of a number of processes and their subsequent delivery at synchronization points. Bundling messages together represents a significant departure from the traditional ‘one communication at a time’ approach. In this paper the semantic consequences of communication packaging are explored. In particular, the BSP communication structure is identified with a general form of substitution—predicate substitution. Predicate substitution provides a means of reasoning about the synchronized delivery of asynchronous communications when the immediate programming context does not explicitly refer to the variables that are to be updated (unlike traditional operations, such as the assignment $x := e$, where the names of the updated variables can be extracted from the context). Proofs of implementations of Newton's root finding method and prefix sum are used to illustrate the practical application of the proposed approach.

Attachment Style in Adults who Failed to Thrive as Children: Outcomes of a 20 Year Follow-up Study of Factors Influencing Maintenance or Change in Attachment Style

A group of children identified as non-organic failure-to-thrive between 1977 and 1980 were investigated, assessed and provided with social work intervention and treatment. Those children and their families have been followed up for the last 20 years. The current paper examines the stability of an internal working model in a sample of individuals who had failed to thrive as children, by comparing each individual's adult attachment style with their childhood attachment to their mother. In this sample, several cases showed changes from insecure to secure attachment styles. Possible reasons are discussed for positive and negative changes, as well as cases when there was no change in attachment style. These include the effectiveness of intervention in addition to changes in life circumstances. The findings suggest that when appropriate support and intervention is provided, or when different circumstances or relationships are experienced, internal working models can change.

Prevalence of childhood abuse in mothers taking part in a study of parenting their own children.

This paper describes the incidence of maltreatment histories in a community sample of mothers of one-year old infants in Northern Ireland. The occurrence of five subsets of childhood maltreatment is examined: emotional abuse, emotional neglect, physical abuse, physical neglect and sexual abuse. Of the 201 women who completed the Childhood Trauma Questionnaire (CTQ), 70 mothers (35%) reported experiencing one or more types of maltreatment during childhood. Forty-eight mothers (24%) gave a history of being emotionally abused, 43 (21%) of emotional neglect, 27 (13%) of physical abuse, 20 (10%) of sexual abuse, and 19 (10%) of physical neglect. Physical abuse was the only type of maltreatment which showed an association with maternal socio-economic status, with higher incidence reported amongst Occupational Classes 4 and 5 (lower supervisory and technical occupations and semi-routine and routine groups). More than half of those with a history of abuse experienced more than one type of maltreatment (42 mothers or 60% of those reporting maltreatment). Differences in rates of incidence to more recent studies on younger adults are discussed, as well as implications for prevention and intervention.

Managing Software Requirements Changes Based On Negotiation-Style Revision

For any proposed software project, when the software requirements specification has been established, requirements changes may result in not only a modification of the requirements specification but also a series of modifications of all existing artifacts during the development. Then it is necessary to provide effective and flexible requirements changes management. In this paper, we present an approach to managing requirements changes based on Booth’s negotiation-style framework for belief revision. Informally, we consider the current requirements specification as a belief set about the system-to-be. The request of requirements change is viewed as new information about the same system-to-be. Then the process of executing the requirements change is a process of revising beliefs about the system-to-be. We design a family of belief negotiation models appropriate for different processes of requirements revision, including the setting of the request of requirements change being fully accepted, the setting of the current requirements specification being fully preserved, and that of the current specification and the request of requirements change reaching a compromise. In particular, the prioritization of requirements plays an important role in reaching an agreement in each belief negotiation model designed in this paper.