An important characteristic of Service-Oriented Architectures is that clients do not depend on the service implementation's internal assignment of methods to objects. It is perhaps the most important technical characteristic that differentiates them from more common object-oriented solutions. This characteristic makes clients and services malleable, allowing them to be rearranged at run-time as circumstances change. That improvement in malleability is impaired by requiring clients to direct service requests to particular services. Ideally, the clients are totally oblivious to the service structure, as they are to aspect structure in aspect-oriented software. Removing knowledge of a method implementation's location, whether in object or service, requires re-defining the boundary line between programming language and middleware, making clearer specification of dependence on protocols, and bringing the transaction-like concept of failure scopes into language semantics as well. This paper explores consequences and advantages of a transition from object-request brokering to service-request brokering, including the potential to improve our ability to write more parallel software.

Text in Afrikaans / In hierdie studie is die aard en gevolge van bendegeweld onder kinders in die vroeë adolessente jare by bendegeteisterde skole in die Wes-Kaap ondersoek ten einde terapeutiese riglyne te bepaal vir leerders wat bendegeweld by die skool ervaar. Die verskynsel van bendegeweld is in die literatuur ondersoek. Die bio-ekologiese teorie van Urie Bronfenbrenner het as teoretiese grondslag vir die navorsing gedien, welke teorie die wedersydse invloed wat persone en hul omgewing op mekaar het, beskryf. Trauma by die vroeë adolessent en drie bestaande modelle vir traumaberading word bespreek, waarna ’n stel maatstawwe vir ’n traumaberadingsmodel uit die drie modelle sowel as die literatuur gekies word. Die empiriese navorsing is deur middel van sowel kwantitatiewe- as kwalitatiewe navorsingsmetodes gedoen. ’n Fokusgroepbespreking én onderhoude met onderwysers en skoolhoofde het plaasgevind om diepgaande inligting oor behoeftes ná voorvalle van bendegeweld te verkry. Twee in-diepte onderhoude is met persone wat kenners op die gebied van bendes en bendegeweld is, gevoer. Vervolgens is twee vraelyste, een vir leerders en een vir onderwysers en skoolhoofde, opgestel om vas te stel watter hulp hulle met betrekking tot ’n trauma-intervensieprogram benodig. Die studie het bevind dat bendegeweld leerders se akademiese prestasie sowel as hul emosionele en sosiale funksionering raak, terwyl dit gevoelens van magteloosheid en frustrasie by onderwysers en skoolhoofde veroorsaak. Die studie sluit af met ’n verskeidenheid aanbevelings oor die daarstel van terapeutiese riglyne vir opvoeders om die impak van bendegeweld op leerders by skole in bendegeteisterde gebiede te hanteer. / This study investigated the nature and effects of gang violence among children in the early adolescent stage of development at gang-infested schools in the Western Cape in order to identify therapeutic guidelines for learners who experience gang violence at school. The phenomenon of gang violence was explored in the literature study. The bioecosystems theory of Urie Bronfenbrenner was employed as the theoretical basis for the study, which describes the reciprocal influence between humans and their environment. Early adolescent trauma and three existing models for trauma counselling are discussed, followed by the selection of a set of criteria for a trauma counselling model based on the three models as well as the literature studied. The empirical research was carried out through both quantitative and qualitative research methodologies. A focus group discussion as well as interviews with educators and principals were conducted in order to obtain in-depth information on their needs after incidents of gang violence. Two in-depth interviews have been conducted with professionals who are experts in the domain of gangs and gang related violence. This led to the development of two questionnaires, one for learners and one for educators and principals, to determine what type of support they need in terms of a trauma intervention programme. The study found that gang violence severely affects learners’ academic performance as well as their emotional and social functioning, while it creates feelings of frustration and powerlessness among teachers and principals. The study concludes by offering a range of recommendations for the formulation of therapeutic guidelines for educators to address the effects of gang violence on learners who attend schools in gang-infested areas. / Psychology of Education / D. Ed. (Psychology of Education)

Enforcing security policies to distributed systems is difficult, in particular, when a system contains untrusted components. We designed AspectKE*, a distributed AOP language based on a tuple space, to tackle this issue. In AspectKE*, aspects can enforce access control policies that depend on future behavior of running processes. One of the key language features is the predicates and functions that extract results of static program analysis, which are useful for defining security aspects that have to know about future behavior of a program. AspectKE* also provides a novel variable binding mechanism for pointcuts, so that pointcuts can uniformly specify join points based on both static and dynamic information about the program. Our implementation strategy performs fundamental static analysis at load-time, so as to retain runtime overheads minimal. We implemented a compiler for AspectKE*, and demonstrate usefulness of AspectKE* through a security aspect for a distributed chat system.

La investigación realizada a los sistemas de seguridad electrónica de edificios, plantea como objetivo principal el reconocimiento de tres gestos de un lenguaje corporal del personal de vigilancia, y la consecuente activación de alarma en forma automática. Inicialmente se realizó una encuesta dirigida a las administraciones y personal de edificios, para saber cuales eran las ocurrencias que vulneraban la seguridad de un edificio multifamiliar, luego se observaron y analizaron las imágenes capturadas por una cámara de vigilancia ubicada en la recepción, identificando las ocurrencias más vulnerables y gestos asociados a dichos eventos; se seleccionaron tres gestos que en forma inconsciente realizaba el personal de vigilancia ante dichas situaciones. A determinados cuadros que comprenden estas imágenes se le aplicaron técnicas de procesamiento espacial, con ayuda de una iluminación artificial que era más intensa en la parte posterior del sujeto de análisis, consiguiéndose la definición de una silueta binarizada en el entorno Matlab, técnicas como selección del plano rojo, plano de bits más significativo, invertir imagen y transformaciones morfológicas tipo cerradura, definieron una silueta que ayudó a desarrollar un algoritmo matemático para generar una señal eléctrica en el puerto serial USB del ordenador, donde se conectó físicamente una plataforma de hardware Arduino que activa la alarma. La elección de esta plataforma se debió a que Matlab cuenta con un grupo de instrucciones para Arduino, con el objetivo de lograr una comunicación sincronizada entre ordenador e interface. Las técnicas utilizadas reconocieron 62,5% de los eventos descritos en las encuestas realizadas y que no son mencionadas en temas de investigación similar. Para lograr el objetivo fue necesario analizar un cuadro por segundo. The research poses as their main objective the three gestures recognition of a body language of surveillance personnel and the consequent activation of alarm automatically. It was initially carried out a survey of the administration and the offices of the buildings to know which were the occurrences that violate the security of a multi-family building, then were observed and analyzed images captured by a surveillance camera located in the reception, identifying the most vulnerable occurrences and gestures associated with these events; were selected three gestures that unconsciously performs surveillance personnel before such situations; to certain pictures that comprise these images were applied spatial processing techniques, with the help of an artificial lighting that was more intense in the back of the subject of analysis, getting the definition of a silhouette binarized in the Matlab environment, techniques such as plane selection red, more significant bit plane, to invest an image and convolution close type, defined a silhouette that allowed to develop a mathematical algorithm that generated an electrical signal in USB serial port of the computer, where it is physically connected a hardware platform Arduino that active the alarm.This platform choice is due to the fact that Matlab has a group of instructions for Arduino, achieving an orderly communication between computer and interface. The techniques used recognized 62.5 % of the events described in the surveys carried out and which aren’t mentioned in similar research topics. To achieve the objective was necessary to analyze a picture per second.

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