52 research outputs found
Unknown 1612 edition of the 1561 map of Silesia by Martin Helwig
No full textWydana po raz pierwszy w 1561 roku w Nysie słynna mapa Śląska Martina Helwiga stanowiła przez wiele lat podstawę i główne źródło informacji przy przedstawianiu Śląska na mapach najwybitniejszych ówczesnych kartografów i wydawców. W wiekach XVII i XVIII ikazało się wiele wydań tej mapy - ostatnie w 1778 roku. Nieznane do tej pory wydanie mapy Śląska Helwiga pochodzi z 1612 roku.The year 1561 is the turning point in the history of the Silesian cartography. This year the first map of Silesia was published. It was based on the surveys and data collected from local residents. The author of this map was Martin Helwig, born 5 November 1516 in Nysa. He studied in Wittenberg, and later at the Akadamia Krakowska in Cracow. From 1544 Helwig worked in Świdnica, and from 1552 in Wrocław in the school of the church of Holy Mary Magdalene. He died on 26 January 1574. Helwig produced a woodcut map in the scale of ca. 1:550 000, which was cut by H. Kron. The whole sheet was printed from 12 wood blocks, but the map itself from only four wood blocks. Wide border (ca. 3 cm) around the map, which includes 28 coats of arms of Silesian duchies and their capitals was printed from eight additional wood blocks.The map measures 57,5x73 cm or, including the border, 67x81,5 cm. In the upper part of the map, there is a cartouche (9,5x19 cm) with a dedication. In the lower part, there is a cartouche with an imprint. On the right, a linear scale, surmounted by the coat of arms of the sponsor of this map. The map is south facing, extending to Cracow in the east, to Bischofswerda in the west , to Ołomuniec in the south and to Poznań in the north. On the map Helwig included more than 370 geographical names, of which the vast majority are the names of places situated mostly on the map based on the 1554 map of Europe by Gerard Mercator. Among them were towns, monasteries, castles and villages, designated by one of the four symbols shown in the key under the dedication cartouche. In addition, each location is accompanied with a fictitious silhouette, often an extended miniature of the town. The number and size of these symbols as well as the large lettering had the effect of condensing and overloading the map, but together with the decorative border around it and the coats of arms of Poland and the Czech lands, enhanced its ornamental value. The Helwig map can therefore be regarded as one of the most beautiful woodcut maps ever made. This map of Silesia was published in many editions, always printed from the same woodblocks in the years 1605, 1627, 1642, 1685, 1738, 1745, 1746, 1765, 1776 (twice) and 1778. Characteristic for these editions were changes in the text in the upper cartouche (with dedication) or in the lower cartouche (with an imprint) or in both at the same time. Unknown, and not hitherto described in the literature, is the edition from 1612. A copy of this edition turned up at auction in 2003 and was purchased for his own collection by well-known collector of maps and Polonica Dr Tomasz Niewodniczański (from Bitburg, Germany). Unfortunately this copy is damaged and the preserved part (57,5xca. 50 cm or, including the border, 67xca. 54 cm) constitutes about two thirds of the whole map. This edition with the dedication only half preserved, as on the second edition from 1605, has a completely different imprint (preserved together with the whole cartouche): Mit Roem. Kay. May. Befreyung. In verlegung HanB Eyrings vnd Johann. Perrfects bey-der Buchhaendler in Bresslaw. Zu Bress[l]aw Bey Georg Bawman. ANNO 1612. In 1889 in Wrocław Heinrich Lesser published a facsimile edition of the Helwig map, based on the 1738 edition, but with the text of the title as on the 1765 edition. Published for the first time in 1561 in Nysa, the map of Silesia by Martin Helwig constituted (until the middle of XVIIIth century) the main model and source of information for the cartographical presentation of this part of Europe on the maps of leading cartographers and publishers of those times
Integrated navigation system eurofix: Vision, concept, design, implementation & test
No full textElectrical Engineering, Mathematics and Computer Scienc
Optimal Design of a Passively-Controlled Gyro for Balance Assistance
No full textFalling is a significant problem for older adults. It can cause severe injury and even death. Furthermore, the fear of falling has a significant influence on the life of the elderly, and therefore they reduce their physical activity. Two new balance assistive devices are being developed to reduce the risk of falling. Both devices use a control moment gyroscope (CMG) to generate a moment to counter the falling motion. One device consists of a single CMG. The other device consists of two CMGs that are coupled such that the gimbals rotate in opposite direction. This is called a scissored pair CMG (SPCMG). The purpose of this study was to examine whether it is possible to design an (SP)CMG with a passive mechanism that exploits gyroscopic precession of gimbal(s) to emulate different types of impedances for balance assistance. To examine this, first, the equations of motion of a CMG and an SPCMG were derived. Next, the equations of motion were used to derive the impedance of the system. The impedance was optimized such that it would simulate the behaviour of a spring, a damper, a mass, a mass-spring-damper system, and a rotational PD controller which is proportional to the XCoM (PDXCoM), a measure of stability. The optimization used a gradient-based algorithm to find the minimum. Multiple optimizations with different random initial guesses were performed to increase the chance to find the global minimum. Two sets of optimizations were performed.One optimization with and one optimization without bounds on the optimization. The sets parameters that led to the best fit were used in a walking simulation to calculate the moments the device would generate during normal walking. It is shown that it is possible to simulate the dynamics of a spring, a damper, a mass, and a mass-springdamper system with a CMG and an SPCMG. However, it was not possible to replicate the dynamics of the PDXCoM with a CMG and an SPCMG. A walking simulation showed that the generated moments of the (SP)CMG were in the opposite direction of the angular velocity of the human. Therefore, using a passive mechanism to control an (SP)CMG could be used as balance assistance
Software radio receiver for the Cityfix system
No full textSatellite-based navigation systems may suffer from a reduced availability in the urban environment due to reflections or shading of the RF signals by man-made obstacles. To bridge these periods of unavailability, a landbased back-up system is necessary. Cityfix is a DGNSS (e.g. EUROFIX) system augmented with a terrestrial positioning and navigation system proposed by Delft University of Technology. The back-up system uses the transmissions of AM-radio broadcasts in the medium wave band, to determine the displacements of a mobile receiver relative to a calibrated starting position obtained with EUROFIX. In this paper a software radio receiver is discussed, which measures the incremental phase of the carriers of a number of transmitters, with a high degree of accuracy and integrity...Applied SciencesElectrical EngineeringTelecommunications and Traffic Control Systems Grou
Eurofix: phase stability of Loran-C on a microscopic level
No full textEuro fix is an integrated navigation system proposed by Delft University of Technology. It is based on the combination of two radionavigation systems: A satellite-oriented navigation system (GNSS, for example the Global Positioning System -GPS- or Glonass) and the Loran-C system. The Loran- C system can be used both as a backup navigation system and as a datalink to broadcast DGNSS and integrity information. In areas where the GNSS satellite signals are lost, for example in an urban environment, the Eurofix user can still calculate the position with Loran-C. This paper describes the phase stability of Loran-C, focusing on the influences of clutter. It further concentrates on the difference in phase development between the electric and magnetic field and on the stability of the time difference of the Loran-C signals. On a microscopic level measurement runs have been taken at various scenarios to investigate the influence of urban conditions. By correcting the phase of the signal for the displacements, the results then give the phase differences of the signals over the runs. It is shown that the phase of the Loran-C signal can be disturbed by several tens of meters when the signals are received in urban environments. Also the disturbance of the phase is less for a magnetic field antenna than for an electric field antenna. The measurements further show that the phases of two transmitters seem to be influenced in the same manner when the user is on the base-line of those two transmitters. Finally, the paper shows that the time differences of the Loran-C signals vary in such a magnitude that the accuracy of Loran-C positioning degrades significantly under urban conditions.Electrical Engineering, Mathematics and Computer ScienceTelecommunicatie- en Verkeersbegeleidingssysteme
Positioning & Control of the Cityfix System
No full textPosition determination systems based on differential satellite systems can achieve a very high accuracy. The Eurofix system for example, can determine positions with an accuracy of 5 metres for 95 percent of the time. A problem that arises when using these differential satellite systems, is the bad reception quality of the satellite signals in areas where ‘shadowing’ occurs. These shadowing effects are caused by large obstacles, like the buildings in cities, blocking the propagation paths of the satellite signals. During the time these effects occur, satellite signals cannot be used for a reliable position determination. A solution to this problem is to combine differential satellite systems with some kind of backup system, which is able to give accurate position determinations during the time shadowing effects occur.Electrical Engineering, Mathematics and Computer ScienceTelecommunicatie- en Verkeersbegeleidingssysteme
Division 6 DR Reports
No full textIncludes: no., author, title and IBM no., and cls.List of DR Reports published as of 25 March 1955
Improving the DGNSS performance of Eurofix Using WLS algorithms, focusing on Temporal decorrelation effects
No full textEurofix is an integrated navigation system, which combines Differential GNSS and Loran-C. The Loran-C system is used to transmit messages which contain differential corrections for GNSS by additional modulation of the transmitted signals. It has been shown that reliable data transmission using Loran-C stations up to 1000 km distance is feasible. The differential corrections are generated by a DGNSS reference station located at the Loran-C transmitter site, providing DGNSS service to all users within the datalink range. Unfortunately, different time varying conditions at the DGNSS reference station and GNSS user position, introduce positioning errors. This paper mainly focuses on the temporal aspects of the errors. In the current implementation of Eurofix the calculation ofposition is solved by means of an ordinary least squares algorithm using at least 5 measured satellite range measurements. When using Weighted Least Squares (WLS), extra available information about the error-sources of GNSS and DGNSS can be taken into account. This way higher positioning accuracies can be obtained. The weight factors of WLS are related to the measurements-error-properties caused by the earth 's atmosphere and the data latency of the Eurofix communication link. Another option for positioning could be to use a Kalman filter. However it will be shown that the conditions for this filter are currently not met by the Eurofix measurements. Finally the theory is put into practice and some interesting real-life test results are presented, showing that the already high accuracy can still be improved.Electrical Engineering, Mathematics and Computer ScienceTelecommunicatie- en Verkeersbegeleidingssysteme
New Methods of Technological Cooperation in Europe
No full text This article is founded on the basic assumption that Europe taken as a whole possesses all the necessary resources to combat successfully any non-European competitor in the fields of technology, provided that it solves the management problem of organizing the coordination of those resources. At present, the author argues, they are dispersed and so underexploited. To contribute to the solution of this core problem, he sets out a new approach to research collaboration, using the example of the German–French Institute for Automation and Robotics to show ways in which HEIs can cooperate internationally to provide industry with what it needs to be truly competitive. </jats:p
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