873 publications from this institution
This paper presents a neural network approach to modelling interregional telephone traffic. Real world observations in Austria have been used as a benchmark in our experiments. Single hidden layer feedforward connectionist networks have been designed to model interregional (domestic) telephone traffic flows between 32 Austrian regions. Remarkable success has been achieved in training the networks to learn the telephone traffic flows between the regions and in making accurate predictions. Our results show that the neural network approach is a leading contender to the conventional statistical approach.
In the development of regional science methodology we observe an increasing series of trends from aggregate towards disaggregate, deterministic towards pro
This paper presents a continuous version of the model of distribution dynamics to analyse the transition dynamics and implied long-run behaviour of the EU-
This volume of the 'Mededelingen Rijks Geologische Dienst' is devoted to the Holocene development of the coastal plain of the Netherlands. It comprises results of geological research of the past 5 to 10 years carried out in connection with the systematic mapping program of the Geological Survey and in connection with the Dutch research project 'Coastal Genesis'. The latter project involves a co-operation of engineers, geologists, physical geographers and historians. It started in 1986 and aims at a better understanding of the behaviour of the coastal zone of the Netherlands. In this project many studies are executed, ranging in subject from the detailed mechanics of sediment transport processes to the long-term and large-scale Holocene development of the coastal plain. The contents of the present volume consists of ten papers. All authors have the Dutch nationality and most of them work at the Rijks Geologische Dienst (Geological Survey of the Netherlands). Eight articles contain detailed descriptions and interpretations of data collected in parts of the coastal area. The remaining two are of a more overall nature and discuss respectively: the general influence of the Late Weichselian morphology on the development of the Dutch coastal plain (De Gans and Van Gijssel) and the influence of storm-surges and the like along the North Sea coast (Van Malde). The latter two papers are the first in this volume. thereafter the articles are geographically arranged (Figure 1), starting in the northeastern part (Van der Spek) and ending in the southwestern area (Ebbing and Laban). Especially the paper on sea-level rise of De Groot et al., based on data form the Frisian Islands, should be mentioned here for its more than local importance. Complementary to the text a visual impression of the Dutch coast is given by three coloured aerial photographs (see for the locations Figure 1): respective on page 2 (frontspiece), 4 and 9.
ISHS Eucarpia symposium on Fruit Breeding and Genetics SEARCH FOR POLYGENIC SCAB AND MILDEW RESISTANCE IN APPLE VARIETIES CULTIVATED AT THE FRUIT GENEBANK DRESDEN-PILLNITZ
The spatial irradiance distribution of optical modified fibers with beveled tips which can be used for lateral-aiming delivery systems was calculated using 3-D ray tracing. Light refraction and reflection at the front surface and second refraction at this surface after reflection by cylindrical fiber surface were taken into account. The results were compared to measurements using CCD-camera and goniometric measurements performed for silica (n equals 1.457) 0.6 mm-fibers in air and in water. The slope angle was varied from 18 degree(s) to 60 degree(s). To prevent a forward lighting, gold coating of the front fiber face was considered. Measured damage threshold of this coating yielded 2 W in air and 30 W in water for continuous wave Nd:YAG laser. For the Ho:YAG laser (250 microsecond(s) , 2 Hz) the measured threshold was 60 mJ in water and in air. To increase the focusing effect the front side of the fiber can be modified as a beveled spherical surface.
This article views spatial analysis as a research paradigm that provides a unique set of specialized techniques and models for a wide range of research questions in which the prime variables of interest vary significantly over space. The heart of spatial analysis is concerned with the analysis and modeling of spatial data. Spatial point patterns and area referenced data represent the most appropriate perspectives for applications in the social sciences. The researcher analyzing and modeling spatial data tends to be confronted with a series of problems such as the data quality problem, the ecological fallacy problem, the modifiable areal unit problem, boundary and frame effects, and the spatial dependence problem. The problem of spatial dependence is at the core of modern spatial analysis and requires the use of specialized techniques and models in the data analysis. The discussion focuses on exploratory techniques and model-driven (confirmatory) modes of analyzing spatial point patterns and area data. In closing, prospects are given towards a new style of data-driven spatial analysis characterized by computational intelligence techniques such as evolutionary computation and neural network modeling to meet the challenges of huge quantities of spatial data characteristic in remote sensing, geodemographics, and marketing.
Der Genfonds an Malus-Arten in der DDR und seine Nutzung was published in Band 32 on page 383.
This paper uses a factor-augmented vector autoregressive model to examine the impact of monetary policy shocks on housing prices across metropolitan and micropolitan regions. To simultaneously estimate the model parameters and unobserved factors we rely on Bayesian estimation and inference. Policy shocks are identified using high-frequency suprises around policy announcements as an external instrument. Impulse reponse functions reveal differences in regional housing price responses, which in some cases are substantial. The heterogeneity in policy responses is found to be significantly related to local regulatory environments and housing supply elasticities. Moreover, housing prices responses tend to be similar within states and adjacent regions in neighboring states.
No abstract is provided for this article.
Aufgrund des histologischen Aufbaus der Nebennierenrinde unterscheidet man die 3 verschiedenen Zellschichten: die zona glomerulosa, die mittlere zona fasciculata sowie die innere, dem Nebennierenmark benachbarte zona reticularis. Entsprechend dieser Zellpopulationen...
No abstract is provided for this article.
The skeleton is a potential metastatic target of many malignant tumors. Up to 85% of prostate and breast cancer patients may develop bone metastases causing severe pain syndromes in many of them. In patients suffering from multilocular, mainly osteoblastic lesions and pain syndrome, radionuclide therapy is recommended for pain palliation. Low-energy beta-emitting radionuclides ((153)samarium-ethylenediaminetetrameth-ylenephosphonate (EDTMP) and (89)strontium) deliver high radiation doses to bone metastases and micrometastases in the bone marrow, but only negligible doses to the hematopoietic marrow. The response rate regarding pain syndrome is about 75%; about 25% of the patients may even become pain free. The therapy is repeatable, depending on cell counts. Concomitant treatment with modern bisphosphonates does not interfere with the treatment effects. Clinical trials using a new, not yet approved nuclide ((223)Radium) and/or combinations of chemotherapy and radionuclides are aiming at a more curative approach.
In this paper a systematic introduction to computational neural network models is given in order to help spatial analysts learn about this exciting new field. The power of computational neural networks viz-a-viz conventional modelling is illustrated for an application field with noisy data of limited record length: spatial interaction modelling of telecommunication data in Austria. The computational appeal of neural networks for solving some fundamental spatial analysis problems is summarized and a definition of computational neural network models in mathematical terms is given. Three definitional components of a computational neural network - properties of the processing elements, network topology and learning - are discussed and a taxonomy of computational neural networks is presented, breaking neural networks down according to the topology and type of interconnections and the learning paradigm adopted. The attractiveness of computational neural network models compared with the conventional modelling approach of the gravity type for spatial interaction modelling is illustrated before some conclusions and an outlook are given.
