Cartographic Design and Usability of Visual Variables for Linear Features

This article addresses the measurement and assessment of response times and error rates in map-reading tasks relative to various modes of linear feature visualization. In a between-subject design study, participants completed a set of map-reading tasks generated by approaches to a traffic problem. These entailed quick and correct decoding of graphically represented quantitative and qualitative spatial information. The tasks first involved the decoding of one graphic variable, then of two variables simultaneously. While alternative representations of qualitative information included colour hue and symbol shape, the quantitative information was communicated either through symbol size or colour value. In bivariate tasks, quantitative and qualitative graphical elements were combined in a single display. Individual differences were also examined. The concept of cognitive style partially explains the variability in people’s perception and thinking, describing individual preferences in object representation and problem-solving strategies. The data obtained in the experiment suggest that alternative forms of visualization may have different impacts on performance in map-reading tasks: colour hue and size proved more efficient in communicating information than shape and colour value. Apart from this, it was shown that individual facets of cognitive style may affect task performance, depending on the type of visualization employed.     

Diurnal and seasonal variations of sporadic meteor parameters

Diurnal variations of the median echo durations of sporadic meteor echoes during August and December-January periods are discussed. It is shown that differences between seasonal distributions result from the superposition of simultaneous diurnal effects controlling the electron loss processes in the ionized meteor trail.     

Similarities of and differences between three mountain belts at the border of the pannonian basin due to the behaviour of the mohorovičić discontinuity

Summary The Dinarides, the Eastern Alps and the Western Carpathians being situated at the borders of the Pannonian basin, are of very similar origin. Therefore, the results obtained in the investigation of correlations between Earth gravity field parameters (absolute geoid undulations, gravity anomalies), the surface topography and the shape of the Mohorovičić discontinuity, were compared. It was found that these three regions have the same basic characteristics, but also their own specific features. While the similarities follow clearly from these investigations, the found differences might partly be a consequence of non-uniformity and unmatched quality of data sets used for the three regions. A short version of this paper, entitled "Kindredness of three mountain belts at the border of the Pannonian basin — deduced from the behavior of the Mohorovičić discontinuity" was presented at the 7th International Symposium "Geodesy and Physics of the Earth", Potsdam, October 5–10, 1992 and published in the Proceedings. Presently a visiting professor at the Graz University of Technology, Institute for Theoretical Geodesy, Department for Physical Geodesy, Austria. Presently at the Berlin University of Technology, Germany, as an Alexander von Humboldt Foundation Research Fellow.     

Exploratory analysis of paleoecological data using the program CanoDraw

This paper attempts to persuade the reader that methods of direct gradient analysis may serve as a basis for more detailed exploration of the data and that these exploration methods can be also used for checking the appropriateness of the assumptions of the applied ordination method. Generalized linear models and generalized loess smoothing together with several ways of data presentation are used to explore a sample data set.     

On the occurrence of blue asymmetry in chromospheric flare spectra

We present observations of optical spectra of a flare in which blue line asymmetry was seen for more than 4 min close to the flare onset. The maximum blue asymmetry coincided with the maximum of a hard X-ray and microwave burst. We discuss possible interpretations of the blue asymmetry and conclude that the most plausible one is electron-beam heating with return current. Although this process predicts downflows in the lower transition region and upper chromosphere, its ultimate effect on the line profiles can be blue asymmetry: the upper layers moving away from us absorb the radiation of the red peak thus lowering its intensity in comparison to the blue one.     

Graphic symbols and local identity: the case of use and perception of municipal emblems in the Liberec Region (Czechia)

This paper analyses the role of graphic symbols in local representation and in the process of local identity formation. The extent of graphic symbols utilization by local development actors in the region, its importance for image formation of the locality (municipality) from the point of view of the local development actors and an assessment of the degree of identification with the municipal emblems among the local population are evaluated, based on the results of a corresponding survey targeted at municipal representatives. Municipal emblems tend to (and also should) have a local representative function. These should emphasize local specificity, uniqueness. Municipal emblems have a potential to play the role of connecting, mediating and activating factors also on a higher as well as a local level. Municipal emblems are still not used enough and in the right way by actors of municipality representations. These are often misunderstood and deemed unimportant for local development.     

Climate variability impact assessment on the flood risk in Slovenia

Assessment of climate change or climate variability is a significant topic in most geophysical disciplines. In this study, the flood frequency approach was selected to analyze changes in flood series. Discharge data from 55 gaging stations in Slovenia were used. The annual maximum method was applied to define the samples. The data sets were divided into 30-year periods based on a 10-year moving window. For each part of the data-set, the flood frequency analysis was performed. Changes in the estimated design discharge values with a 10-year return period, which is commonly used in engineering design, were observed for the two selected 30-year periods, namely 1961–1990 and 1981–2010, and the results were compared with the Mann–Kendall (MK) test. The results indicate that no uniform pattern can be found in the differences between estimated design discharge values for the two selected periods. The same applies to the MK trend test results, which were positive and statistically significant with the chosen significance level of 0.05 only for approximately 5% of stations. However, our comparison of the results of the flood frequency analyses among different 30-year periods showed considerable changes in the design discharge for some stations.     

The footpoints of giant arches

We have detected chromospheric footpoints of the giant post-flare coronal arches discovered by HXIS a few years ago. H photographs obtained at Big Bear and Udaipur Solar Observatories show chromospheric signatures associated with 5 sequential giant arch events observed in the interval from 6 to 10 November, 1980. The set of footpoints at one end of the arches consists of enhancements within a plage at the northeast periphery of the active region and the set of footpoints at the other end of the arch consists of brightenings of the chromosphere south of the active region. Both sets of footpoints show very slow brightness variations correlated in time with the brightness variations of the X-ray arches. Current-free modelling of the coronal magnetic field by Kopp and Poletto (1989), based on a Kitt Peak magnetogram, confirms the identification of the two sets of footpoints by showing magnetic field lines connecting them.The brightenings appear as a succession of point-like enhancements whose individual lifetimes are of the time-scale of minutes but which continue to occur for periods of several hours. This behaviour allows us to infer a fine structure in the coronal arches, undetectable in the X-ray images. The discovery of these brightenings and their location at the periphery of the active region also alters our conception of the relationship of the giant arches to the flares that begin concurrently with them. The giant arch phenomenon appears now to be either: (1) a long-lived, semi-permanent, coronal structure which is revived and fed with plasma and energy by underlying dynamic flares, or alternatively (2) a system of high-altitude loops which open at the onset of every such flare and subsequently reconnect over intervals of many hours.