Optimization of Spatial Joins Using Filters

When viewing present-day technical applications that rely on the use of database systems, one notices that new techniques must be integrated in database management systems to be able to support these applications efficiently. This paper discusses one of these techniques in the context of supporting a Geographic Information System. It is known that the use of filters on geometric objects has a significant impact on the processing of 2-way spatial join queries. For this purpose, filters require approximations of objects. Queries can be optimized by filtering data not with just one but with several filters. Existing join methods are based on a combination of filters and a spatial index. The index is used to reduce the cost of the filter step and to minimize the cost of retrieving geometric objects from disk. In this paper we examine n-way spatial joins. Complex n-way spatial join queries require solving several 2-way joins of intermediate results. In this case, not only the profit gained from using both filters and spatial indices but also the additional cost due to using these techniques are examined. For 2-way joins of base relations these costs are considered part of physical database design. We focus on the criteria for mutually comparing filters and not on those for spatial indices. Important aspects of a multi-step filter-based n-way spatial join method are described together with performance experiments. The winning join method uses several filters with approximations that are constructed by rotating two parallel lines around the object

Nature and Grace in Bavinck

This paper is Dr. Al Wolters’ “translation of twenty pages from Dr. Jan Veenhof’s dissertation on Bavinck, titled Revelatie en Inspiratie.” Dr. Veenhof succeeded G. C. Berkouwer in the chair for dogmatic theology at the Free University in Amsterdam, then went on to teach at the universities of Basel and Bern and for one semester at Calvin Theological Seminary. As emeritus, he is still involved in theological and pastoral work

Implementing Dried Blood Spot sampling in transplant patient care

Dosing of immunossuppressive drugs used for transplant patients’ allograft rejection prevention is based on blood drug levels. This requires transplant patient to frequently provide a venous blood sample in the hospital. The Dried Blood Spot (DBS) method enables patient home sampling by means of collecting drops of fingerprick blood on a sampling card. This card can be sent to the laboratory by mail. From this DBS sample, blood drug levels can be measured. The purpose of the DBS method is to reduce patient burden and societal costs. In this thesis entitled ‘Implementing Dried Blood Spot sampling in transplant patient care’, a description is given how to successfully implement the DBS method. The analytical method should be fast, robust and meet all criteria of relevant guidelines. In addition, DBS-specific parameters should be validated. The DBS method should be tested in a clinical validation study where DBS results are compared to results from paired venous samples. In practice, providing a DBS sample is not easy. A checklist was developed which enables objective judgment of DBS sample quality. In addition, an app was developed enabling patients to determine the quality of a DBS by means of taking a photo of the sample. We found that the logistics concerning the sending and analysis of DBS samples are very critical to achieve a successful implementation. We also found that a novel home sampling technique involving fingerprick blood sampling on a volumetric tip was inferior to the DBS method regarding both sample quality and interchangeability with venous blood results

A Comparative Numerical Study on GEM, MHSP and MSGC

In this work, we have tried to develop a detailed understanding of the physical processes occurring in those variants of Micro Pattern Gas Detectors (MPGDs) that share micro hole and micro strip geometry, like GEM, MHSP and MSGC etc. Some of the important and fundamental characteristics of these detectors such as gain, transparency, efficiency and their operational dependence on different device parameters have been estimated following detailed numerical simulation of the detector dynamics. We have used a relatively new simulation framework developed especially for the MPGDs that combines packages such as GARFIELD, neBEM, MAGBOLTZ and HEED. The results compare closely with the available experimental data. This suggests the efficacy of the framework to model the intricacies of these micro-structured detectors in addition to providing insight into their inherent complex dynamical processes

The Textiles traded by the Assyrians in Anatolia (19th-18th Centuries BC)

International audienceThe cuneiform private archives from Kaniš, dated to the beginning of the 2nd millennium B.C., belonged to Assyrian merchants who traded many textiles between their home city Aššur and central Anatolia. The numerous terms linked to textiles cited by these tablets have been extensively studied by K. Veenhof in 1972. Since then, thousands of texts have been published and deciphered, which have supplied so many new data that a new analysis is desirable. Of those exported to Anatolia, many were imported in Aššur, others were produced in Aššur or somewhere in northern Mesopotamia. In addition the Assyrian traded textiles which were produced in Anatolia. This implies that the textiles had different origins and that their names come from different languages. Most of them occur only in the Old Assyrian dialect and the overlap with the Old Babylonian vocabulary is limited.Archaeology has not produced any remains of textiles, which means that we have to try to identify them on the basis of the designations, their combinations and the context in which they occur, which most of the time is not helpful (enumerations, lists…). This means that the researcher is faced with at least three main tasks:1. Establish the origin of the textiles (Southern Mesopotamia, Aššur, Northern Mesopotamia, Anatolia) and their material2. Make a distinction between untailored textiles or ready-to-wear garments and understand their categorisation3. Analyse their nature and functions on the basis of the various qualifications (quality, price, size, weight, colour, finishing…

The first law and Wald entropy formula of heterotic stringy black holes at first order in α

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física Teórica. Fecha de Lectura: 29-09-2022The project that gave rise to these results received the support of a fellowship from ”la Caixa” Foundation (ID 100010434). The fellowship code is LCF/BQ/DI18/11660042. This project has received funding from the European Union´s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 71367