Eliminating small cells from census counts tables: empirical vs. design transition probabilities

The software SAFE has been developed at the State Statistical Institute Berlin-Brandenburg and has been in regular use there for several years now. It involves an algorithm that yields a controlled cell frequency perturbation. When a microdata set has been protected by this method, any table which can be computed on the basis of this microdata set will not contain any small cells, e.g. cells with frequency counts 1 or 2. We compare empirically observed transition probabilities resulting from this pre-tabular method to transition matrices in the context of variants of microdata key based post-tabular random perturbation methods suggested in the literature, e.g. Shlomo, N., Young, C. (2008) and Fraser, B.,Wooton, J. (2006)Peer Reviewe

Eliminating small cells from census counts tables: empirical vs. design transition probabilities

The software SAFE has been developed at the State Statistical Institute Berlin-Brandenburg and has been in regular use there for several years now. It involves an algorithm that yields a controlled cell frequency perturbation. When a microdata set has been protected by this method, any table which can be computed on the basis of this microdata set will not contain any small cells, e.g. cells with frequency counts 1 or 2. We compare empirically observed transition probabilities resulting from this pre-tabular method to transition matrices in the context of variants of microdata key based post-tabular random perturbation methods suggested in the literature, e.g. Shlomo, N., Young, C. (2008) and Fraser, B.,Wooton, J. (2006)

Morpheus - Remote access to micro data with a quality measure

Morpheus is a novel approach in providing remote access to micro data of official statistics. Researchers work on anonymous micro data files with common statistical software packages and get their results back in real time. Additionally, a measure of goodness of fit will be provided for every single result. Therefore researchers can work with the anonymous results as they can have confidence that they would have obtained the same or very similar results with the original data. All statistical analyses and all commands are allowed. Furthermore, users can browse through the anonymous data which is very helpful when developing program syntax and not possible in most other systems of remote access. Research data centres would greatly benefit from such a system as well, as the cumbersome manual disclosure control would be eliminated. All results would be safe and automatically returned to the researcher. This system would respect the special requirements to micro data access even in Germany where laws are especially strict.Morpheus ist ein neuartiger Ansatz, einen echten Fernzugriff auf Mikrodaten der amtlichen Statistik zu gewähren. Wissenschaftler werten mit den üblichen Statistik-Softwarepaketen einen anonymen Datensatz aus und erhalten ihre Ergebnisse in Echtzeit zurück. Zusätzlich erhalten sie zu jedem einzelnen Ergebnis ein Gütemaß. Obwohl die Wissenschaftler mit den anonymen Ergebnissen arbeiten, können sie dadurch sicher sein, dass sie das gleiche oder ein sehr ähnliches Ergebnis mit den Originaldaten erhalten hätten. Alle statistischen Analysen sind erlaubt. Darüber hinaus können sich die Wissenschaftler d ie anonymen Daten anschauen. Dies ist sehr hilfreich, wenn man Programme entwickelt und es ist in den meisten anderen Remote-Access-Systemen bisher nicht möglich. Forschungsdatenzentren würden von solch einem System ebenfalls in großem Maße profitieren, da die mühsame manuelle Geheimhaltungsprüfung entfallen würde. Alle Ergebnisse wären sicher und werden automatisch dem Wissenschaftler zugesandt. Dieses System würde die strengen gesetzlichen Datenschutzvorgaben für den Zugang zu Mikrodaten in Deutschland erfüllen

Das Verfahren Morpheus – Auf dem Weg zu Remote Access

"Morpheus ist ein neuartiger Ansatz, einen echten Fernzugriff auf Mikrodaten der amtlichen Statistik zu gewähren. Wissenschaftler werten mit den üblichen Statistik-Softwarepaketen einen anonymen Datensatz aus und erhalten ihre Ergebnisse in Echtzeit zurück. Zusätzlich erhalten sie zu jedem einzelnen Ergebnis ein Gütemaß. Obwohl die Wissenschaftler mit den anonymen Ergebnissen arbeiten, können sie dadurch sicher sein, dass sie das gleiche oder ein sehr ähnliches Ergebnis mit den Originaldaten erhalten hätten. Alle statistischen Analysen sind erlaubt. Darüber hinaus können sich die Wissenschaftler d ie anonymen Daten anschauen. Dies ist sehr hilfreich, wenn man Programme entwickelt und es ist in den meisten anderen Remote-Access-Systemen bisher nicht möglich. Forschungsdatenzentren würden von solch einem System ebenfalls in großem Maße profitieren, da die mühsame manuelle Geheimhaltungsprüfung entfallen würde. Alle Ergebnisse wären sicher und werden automatisch dem Wissenschaftler zugesandt. Dieses System würde die strengen gesetzlichen Datenschutzvorgaben für den Zugang zu Mikrodaten in Deutschland erfüllen." [Autorenreferat

Seasonal Differences in the Attenuation of Polar Trace Organics in the Hyporheic Zone of an Urban Stream

Attenuation of trace organic compounds (TrOCs) in a river occurs to a large extent in its hyporheic zone. A major part of the attenuation of polar TrOCs is of microbial origin. As microbial activity depends on temperature and redox conditions, seasonal differences in TrOC attenuation are likely. We investigated TrOC attenuation at a river influenced by treated wastewater during two sampling campaigns, one in summer and one in winter. In addition to redox conditions and temperature, we also determined residence times of porewater in sediment using three methods: (a) non‐parametric deconvolution of electrical conductivity time series, (b) the model VFLUX 2.0 based on temperature time series (only summer), and (c) applying Darcy's law to differences in hydraulic heads (only summer). Contrary to our expectations, we found higher attenuation for 12 out of 18 TrOCs in winter, while three TrOCs were better attenuated in summer. Sediment conditions varied between seasons as more of the top sandy layer with a higher hydraulic permeability accumulated on the river bed in summer. As a result, residence times in the sediment were shorter in summer. In winter, longer residence times, lower temperatures, and a steeper oxygen gradient in sediment coincided with higher TrOC attenuation. Further research is needed to understand our unexpected findings and underlying mechanisms.Key Points The attenuation of 12 out of 18 trace organic compounds (TrOCs) in the hyporheic zone was higher in winter while three TrOCs were attenuated better in summer Residence times in sediment were longer and more diverse in winter The extent of the oxic sediment was similar between seasons but the gradient from the oxic to anoxic zone was steeper in winterDeutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659EC | H2020 | H2020 Priority Excellent Science | H2020 Marie Skłodowska‐Curie Actions (MSCA) http://dx.doi.org/10.13039/100010665University of Western Australia ‐ University Postgraduate AwardAustralian Government Research Training Program ScholarshipBundesministerium für Bildung und Forschung (BMBF) http://dx.doi.org/10.13039/501100002347Peer Reviewe

Is the Hyporheic Zone Relevant beyond the Scientific Community?

Rivers are important ecosystems under continuous anthropogenic stresses. The hyporheic zone is a ubiquitous, reactive interface between the main channel and its surrounding sediments along the river network. We elaborate on the main physical, biological, and biogeochemical drivers and processes within the hyporheic zone that have been studied by multiple scientific disciplines for almost half a century. These previous efforts have shown that the hyporheic zone is a modulator for most metabolic stream processes and serves as a refuge and habitat for a diverse range of aquatic organisms. It also exerts a major control on river water quality by increasing the contact time with reactive environments, which in turn results in retention and transformation of nutrients, trace organic compounds, fine suspended particles, and microplastics, among others. The paper showcases the critical importance of hyporheic zones, both from a scientific and an applied perspective, and their role in ecosystem services to answer the question of the manuscript title. It identifies major research gaps in our understanding of hyporheic processes. In conclusion, we highlight the potential of hyporheic restoration to efficiently manage and reactivate ecosystem functions and services in river corridors

A state-inherent object and programming model for the simulation of natural emergent processes: The potential in using multi-agent technology for school education

Natural systems, that are systems from nature, represent a potential source for new algorithms and/or applications in the technology; however, an investigation of these systems is necessary, in order to measure the consequences of interferences. For the investigation of natural systems, multi-agent technology based simulation tools are used to lower the entrance threshold, and to thus reach an extended group of users. The simulation model of available tools can be improved to promote system thinking in the context of school application. In the context of this thesis, firstly a state-based object model is developed, which allows a simpler transformation of existing biological models into simulation models. Further, the state-based object model permits the user a simpler change of the object behavior by super-ordinate structuring, as well as the reduction of the administration efforts. Object programming takes place by means of an object-orientated-flow programming language, similar to a data flow programming. The implementation of control structures, difficult to represent in data flow oriented programming languages, is realized in a simple manner using the developed state-based object model. The programming model was implemented prototypically in form of a visual programming language and environment, using special visualization techniques

Simulation of the model organism Dosidicus gigas - analysis of the implications of an energy driven life history

This thesis investigates the potential of computer modeling techniques to elucidate the life history and population-level features of Dosidicus giga

Ein zustandsinhärentes Objekt- und Programmiermodell zur Simulation natürlicher emergenter Prozesse: Nutzungsmöglichkeiten von Multiagententechnik für die schulische Bildung

Natural systems, that are systems from nature, represent a potential source for new algorithms and/or applications in the technology; however, an investigation of these systems is necessary, in order to measure the consequences of interferences. For the investigation of natural systems, multi-agent technology based simulation tools are used to lower the entrance threshold, and to thus reach an extended group of users. The simulation model of available tools can be improved to promote system thinking in the context of school application. In the context of this thesis, firstly a state-based object model is developed, which allows a simpler transformation of existing biological models into simulation models. Further, the state-based object model permits the user a simpler change of the object behavior by super-ordinate structuring, as well as the reduction of the administration efforts. Object programming takes place by means of an object-orientated-flow programming language, similar to a data flow programming. The implementation of control structures, difficult to represent in data flow oriented programming languages, is realized in a simple manner using the developed state-based object model. The programming model was implemented prototypically in form of a visual programming language and environment, using special visualization techniques