Distributed State Machine Supervision for Long-baseline Gravitational-wave Detectors

The Laser Interferometer Gravitational-wave Observatory (LIGO) consists of two identical yet independent, widely-separated, long-baseline gravitational-wave detectors. Each Advanced LIGO detector consists of complex optical-mechanical systems isolated from the ground by multiple layers of active seismic isolation, all controlled by hundreds of fast, digital, feedback control systems. This article describes a novel state machine-based automation platform developed to handle the automation and supervisory control challenges of these detectors. The platform, called \textit{Guardian}, consists of distributed, independent, state machine automaton nodes organized hierarchically for full detector control. User code is written in standard Python and the platform is designed to facilitate the fast-paced development process associated with commissioning the complicated Advanced LIGO instruments. While developed specifically for the Advanced LIGO detectors, Guardian is a generic state machine automation platform that is useful for experimental control at all levels, from simple table-top setups to large-scale multi-million dollar facilities.Comment: Version 2: 11 pages, 9 figures. Submitted to Review of Scientific Instrument

Draw like a builder, build like a writer. And the crack is in the detail

As the inevitable building by numbers ensues, London’s Thames Gateway becomes one of many playgrounds for bar charting enthusiasts. Houses measured by the thousands and little clues as to where it is, that ghost in the machine, what they are, the structures of everyday contemporary life, and who's life it is anyway. Fernand Braudel, Georges Perec, Jorge Luis Borges, amongst others, are employed to examine just how Wittgensteins radiators find their ways into Barratts South East catalogue. They supply the container for Dickensian content with Sinclairesque detail, while late Jan Turnovski's epic lunacy will help to once and for all allay widespread popular fears that Wittgenstein 1 and 2 may add up to one-and-a-half, simple as that. Never has the ideal of treating technology involved with building as an intellectual discipline been further removed from any notion of genius, loci or otherwise; housing policy housing, building policy building. Against the backdrop of mass housing and landmark buildings with little space or time for anything in between, five years of studio work with diploma students at the University of Greenwich, Vienna University of Technology and University Innsbruck, concerned themselves with the structural narrative of the Thames Gateway. This paper, as well as the projects presented through it, is a premature attempt at anchoring buildings on the words they are built on, technology on the sentence structure of its description, assembly instructions written in the most specific of dialects. It describes techniques, suggesting an architecture read backwards, sideways, horizontal and in parallel, free associative sequence, thus discussing issues of site, context, detail and conceptual adhesion. It also poses questions: concerning locality, history, ritual, conceptualisation and intellectual detachment. Above all, in view of the sheer relentlessness of commercially driven urban expansion, questions of soul and character, of design sustainability in terms of creating space to accommodate viable structures social, cultural, narrative. Allowing history to continue, creating place worth telling tales about

Education for all and for life? : An introduction into primary school education in Senegal

Generally, school participation in Senegal has achieved a lot of progress in recent years. However, several problems remain to be tackled for further improvement. Still, too many children never attend a school. An even more severe problem is the high rate of drop outs, especially when it comes to the transition from primary to secondary school. Here, the national grade six exam, higher costs of schooling and still limited availability of secondary schools are the main barriers. As a result, only a fraction of children completes the ten years of compulsory schooling which is considered necessary to have superior job perspectives. Another issue regarding absenteeism or incomplete formal schooling is the popularity of Quranic education in Senegal. Many parents prioritize religious (esp. Quranic) studies and do not want their children to attend a formal school. In many cases, those who try to combine formal and religious schooling sooner or later have to decide on whether to drop one or the other. Despite the existence of differences between rural and urban milieus no substantial gender disparity can be observed at the primary school level. At the secondary school level, however, girls’ education perspectives worsen so that completion of ten years of schooling is even less likely for girls than for boys. While the quantity of enrolled children has undoubtedly risen during the past years, the development of school quality is more ambiguous. Many school buildings are in a bad condition and pedagogical material is often lacking or hardly usable. After the summer holidays many school facilities face damages due to heavy rainfalls which lead to delayed starts and many schools cannot afford the maintenance costs. The quality of classes itself suffers from too big class sizes, multigrade classes and irregular attendance of pupils. In summary it can be stated that primary school education in Senegal has achieved some noticeable improvements. However, high drop out rates and rivalry with Quranic schooling lead to a low percentage of students with completed secondary education or higher. Since it is expected that formal schooling only pays off in economic terms after at least ten years of education, the achievement of a higher share of students with completed secondary school should be a reasonable task. The purpose of further study will thus be to shed more light on some of the reasons preventing school enrollment and completion. One task will consist in identifying the reasons why many children are never enrolled in school. The research project will proceed with a household survey in the region of Saint-Louis. This region nearly reflects average educational figures of the whole country and is very diverse regarding geographical conditions, population density and economic activity of the population. Data from this survey will allow to disentangle the role of supply and demand sides. According to our expectations and impressions gained from the qualitative field work, even in areas where public schools are available and accessible, not all children are enrolled in school. For this group, parents might not see the benefit of attending formal school or might favor rival activities such as work or attendance of a religious school. A related question is whether school enrollment then depends primarily on household characteristics. Families of a certain educational level and of specific professions could be more prone to sending their children to school. On the other hand, there seems to be heterogeneity within households. We will have to study why some children attend school while their siblings do not. Reasons for the higher drop out rates of girls will also be subject to further study

The Estimation of Flows on Regional Labour Markets By Using the ADETON Procedure

An in-depth analysis of regional labour markets requires information not only on stocks but also on flows. As a tool for detailed flow analysis the Multi Account System (MAS) has been developed at the Institute for Employment Research (IAB) which uses fine grained transition matrices as basic information. To estimate these transition matrices from possibly incomplete and inconsistent statistical data the ADETON procedure has been worked out to compute matrices which are struc-turally similar to given reference matrix and at the same time satisfy certain linear con-straints. As main advantage of ADETON in comparison to conventional methods soft constraints may be specified which allow information of inherently fuzzy character about transition flows to be taken into account. By using soft constraints of this kind it is possible to in-clude data affected by sampling errors or are distorted by some kind of “noiseâ€. To obtain structural similarity to a reference matrix two different distance measures can be used: relative entropy and the chi-square distance function. They have been proven to give approximately identical results. Up to now ADETON has shown to be an efficient computation method even for complex problems with thousands of matrix elements and constraints. ADETON has been applied to estimate matrices of the Multi Account System. The results are used for the guidance of regional labour market policy.