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Design of the dual constellation GPS/GALILEO mobile device for improving navigation of the visually impaired in an urban area

Drypczewski K., Moszyński M., Demkowicz J., Bikonis K., Stepnowski A.

Polish Maritime Research

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2015

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nr 4

15--20

EN

The article discusses damages of essential tribological associations in crankshaft and piston systems of large power two-stroke engines used as main engines, which take place during transport tasks performed by those ships. Difficulties are named which make preventing those damages impossible, despite the fact that the technical state of engines of this type is identified with the aid of complex diagnostic systems making use of advanced computer technology. It is demonstrated that one of causes of the damages is the lack of research activities oriented on recognising random properties of the loads leading to those damages. A proposal is made for the loads acting at a given time t on tribological associations in crankshaft and piston systems of internal combustion engines used as main engines to be considered as random variables Qt. At the same time the loads examined within a given time interval tr ≤ t ≤ tz would be considered stochastic processes {Q(t): t ≥ 0}. Essential properties of the loads of the abovementioned tribological associations are named and explained by formulating hypotheses which need empirical verification. Interval estimation is proposed for estimating the expected value E(Qt) of the load Qt acting at time t. A relation is indicated between the mechanical load and the thermal load acting on tribological associations in the ship main engine crankshaft and piston system. A suggestion is formulated that a stochastic form of the relation between these types of load is to be searched for, rather than statistic relation, and a proposal is made to measure the intensity (strength) of the stochastic relation using the Czuprow’s convergence coefficient.

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Client-server Approach in the Navigation System for the Blind

Markiewicz Ł., Drypczewski K., Wiśniewski B., Kamiński Ł.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2013

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Vol. 7, no. 3

395--400

EN

The article presents the client-server approach in the navigation system for the blind - “Voice Maps”. The authors were among the main creators of the prototype and currently the commercialization phase is being finished. In the implemented prototype only exemplary, limited spatial data were used, therefore they could be stored and analyzed (for pathfinding process) in the mobile device’s memory without any difficulties. The resulting increase of spatial data scale and complexity required a modification of the data storage and operation. Consequently, the decision was made to maintain a central spatial database, which is accessed remotely. After that modification, the mobile application fetches the required batch of spatial data (with the pathfinding and search results) from the central server through the mobile internet connection, which has also become necessary for other purposes (e.g. voice recognition). The authors present the advantages and disadvantages of this new approach along with the results of the server operational tests.

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"Voice Maps" - Portable, Dedicated GIS for Supporting Street Navigation and Self-dependent Movement of Blind

Kamiński Ł., Łubniewski R., Kowalik R., Stepnowski A.

Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne

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2010

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T. 18

281-286

EN

A concept and a prototype application of a system supporting street navigation and independent, outdoor movement of the blind is presented. The system utilises GIS database of geometric network of pedestrian paths in a city and is capable of finding a route from an indicated source to a destination. Subsequently, the system supports movement of the blind along the found route. Information on user's position and his movement direction is obtained utilising a GPS receiver, a magnetic compass and a gyrocompass. The system communicates with the blind by a simple keyboard and by voice messages generated by a voice synthesizer. First tests of the system operation and performance were carried out by the blind users in two districts of Gdańsk city. The preliminary results of the tests proved the usefulness of the system and justified the necessity of further work on the system development.

PL

W artykule zaprezentowana została idea systemu wspierającego samodzielne poruszanie się po terenie miejskim osób niewidomych oraz prototyp aplikacji realizującej tę ideę. Przedstawiony system wykorzystuje bazę danych przestrzennych zawierającą miejską sieć tras dostępnych dla osób pieszych, co umożliwia mu znalezienie optymalnej trasy z punktu początkowego do wybranego celu. Ponadto, system wspiera niewidomego użytkownika poruszającego się wzdłuż znalezionej ścieżki. Informacje na temat położenia i ruchu użytkownika uzyskiwane są przy pomocy odbiornika GPS, kompasu elektronicznego oraz żyrokompasu. System komunikuje się z użytkownikiem poprzez prostą klawiaturę bezprzewodową oraz komunikaty głosowe generowane przez syntezator mowy. Testy systemu były przeprowadzone z udziałem osób niewidomych w dwóch dzielnicach Gdańska. Wyniki tych testów udowodniły użyteczność systemu i potwierdzają konieczność dalszych prac nad jego rozwojem.