by: John Applin
This is a tiny bluetooth GPS receiver which I bought from Mobile Fun Ltd, I bought this to connect to my O2 XDA 2i PDA and it cost around £40. I was intially looking on google for cheap GPS receivers and this came up as the cheapest. I thought at that price they'll be a catch, and the catch usually being poor performance, but I was pleasantly surprised! This thing really does work, and works well!
After searching for initial reviews on this device I came up with very little other than the reviews from Mobile Fun Ltd, which I was reluctant to trust for fear of them being somewhat biased. I thought for £40 I'll take a chance and so bought it, all credit to Mobile Fun the receiver arrived the very next morning. Upon opening the box I was a little disappointed, all the there was by means of instructions was a small sheet of paper that had been loosely translated from Japanese to English by a dyslexic toddler. You can download the user manual from here and the Tomtom pairing manual from here. After following these instructions you will have it set up in no time. Another thing I noticed was that there is no manufaturer's name or marks anywhere on the device or the packaging, which makes searching for support quite difficult.
A nice touch with this little device is that it is supplied with a battery that is common to a lot of Nokia phones (3.7V 850mAh Li-polymer battery, BL-5C), a quick search on ebay means that you can get replacement batteries for these receivers for about £4 which is good to know should you need one.
What's In The Box?
Bluetooth GPS Receiver x1
12v In Car Adapter (USB) x1
Basic Instructions x1
Battery x1
USB Charging Cable x1
Friday 26 September 2008
Bluetooth GPS Receiver Review
INTEGRATION OF CELLULAR AUTOMATA AND GIS FOR SIMULATING LAND USE CHANGES
by : Nagaratna P Hegde, * Dr I V MuraliKrishna, **Dr K V ChalapatiRao
Cellular automata have been used as a simulation technique in the study of an impressively wide range of urban phenomena, including regional growth, urban sprawl, gentrification, residential growth, population dynamics, economic activity and employment, historical urbanization, land use evolution, and polycentricity to name but a few.
A spatial model consists of a collection of processes performed on spatial data that will produce information, usually in the form of a map. These models can often be represented as process flow diagrams, like showing how the output from one process can be the input to a subsequent process. C A are ideal for simulating static entities in spatial models and processes that operate by diffusion. They are ideal for encoding spatial structures into simulation models.
The application of CA in land use/land cover/ urban modeling can give insights into a wide variety of urban phenomena. Urban CA
models have better performance in simulating urban growth than conventional urban models because they are much simpler than
complex mathematical equations, but produce results that are more meaningful and useful. Temporal and spatial complexities of
urban systems can be well modeled by properly defining transition rules in CA models. CA simulation provides important
information for understanding urban theories, such as the evolution of forms and structures. GIS is a technology that is used to view
and analyze data from a geographic perspective. The spatial representation of an object and its related non-spatial attribute are
merged into a unified data file. In practice the area under study is covered by a fine mesh or matrix of grid cells and particular
ground surface attribute value of interest occurring at the center of each cell point is recorded as the value for that cell. It should be
noted that while some raster models support the assignment of values to multiple attribute per discrete cell, others strictly to a single
attribute per cell structure
STUDY OF CELLULAR AUTOMATA MODELS FOR URBAN GROWTH
by: Nagaratna P Hegde, *Dr I V MuraliKrishna, **Dr K V ChalapatiRao
Abstract :
Differential equations, partial differential equations and in some instances,
empirical equations have been the underlying mathematical tools behind spatial
simulation models. Approaches based on cellular automata models are proposed
herein to replace the conventional tools. Issues such as the definition of transition rules, computer implementation with raster geographical information systems and model verification are discussed.
Cellular automata (CA) models consist of a simulation environment represented
by a grid of space (raster), in which a set of transition rules determine the
attribute of each given cell taking into account the attributes of cells in its
vicinities. These models have been very successful in view of their operationality,
simplicity and ability to embody both logics- and mathematics-based transition
rules. It is thus evident that even in the simplest CA, complex global patterns can
emerge directly from the application of local rules, and it is precisely this property
of emergent complexity that makes CA so fascinating and their usage so
appealing.
Keywords Geographic Information Systems; Simulation ,CellularAutomata
INTRODUCTION
Cellular Automata (CA) models were originally conceived by Ulam and Von
Neumann in the 1940s to provide a formal framework for investigating the
behavior of complex, extended systems. CA are dynamic, discrete space and
time systems. A cellular automaton system consists of a regular grid of cells,
each of which can be in one of a finite number of k possible states, updated
synchronously in discrete time steps according to a local, identical interaction
VECTOR CELLULAR AUTOMATA BASED GEOGRAPHICAL ENTITY
by : 1 Hu Shiyuan and 2. Li Deren
1. School of Resource and Environmental Science , Wuhan University, 129 Luoyu Road, Wuhan, China, 430079
2. School of Remote Sensing Information Engineering, Wuhan University, 129 Luoyu Road, Wuhan, China, 430079
Cellular automata (CA) are mathematical models for systems in which many simple
components act together to produce complicated patterns of behavior (Wolfram, 1985).CA have close associations with complexity theory and have been employed in the exploration of a diverse range of urban phenomena. Urban applications of CA range from traffic simulation and regional-scale urbanization to land-use dynamics, historical urbanization, and urban development. The integration of GIS and CA will accelerate GIS’s ability of simulating geographical process greatly especially (Zhou et al., 2001).
CA models are usually based on fine regular tessellations such as a grid, in which every cell is identical, has identical relations with each of its neighbors, and has a standard neighborhood of cells in which these relations operate. These neighborhoods are strictly local in that they are based on physically adjacent cells. In geographic and urban models, this may be over-simplistic (O'Sullivan, 2000), and it has some restrictions in cellular shape, neighborhood and neighbor rules,which restrict the CA’s ability to simulate real world.The standard CA exists some problems mainly as follows: (1) Space partition, namely determination of space pixel. Each kind of graphical object has itself space scale in the system which plenty of graphical entities exist together. In addition, graphical entity
represents different behavior in different space scale. It is a problem how to determinate a uniform spatial resolution. (2) Precision & Quantity. CA models are usually based on fine regular tessellations, cell is similar to the grid of grid data in GIS, it exists some problems such as imprecise locating and tremendous quantity. (3) Cell space is divided into regular tessellations on abstract space in standard CA. Every cell is identical, has identical relations with each of its neighbors. This kind of CA can expose local reciprocity among cells. But geographical system is a typical complex system, which is a compound system consisted of physical, social and economic subsystems. The complexity is an essential characteristic of Geo-Spatial System for its complexity properties such as non-equilibrium, multi-scale, indeterminacy, hierarchy, self-organizing, self-similarity, randomicity, iterativeness, and so
forth. So regular space system exists hardly in real world.
This paper will explore the relation between geographical space and cellular automata,and
build a extended CA model based on geographical entity in irregular geographical spaces.
In addition, this paper will explore the integrated pattern of GIS and CA.
Flash/SWF for GIS
By Chris Goad , The Map Bureau
The advent of programmable vector graphics in web browsers has major implications for GIS on the web.Vector-based web maps can include many forms of interactivity that are handled at the web browser with minimal need for refreshes from the server.
These range from simple zooming and panning, through interactive selection of the data to displayed, up to animated display of temporal processes.Indeed, the online map of the future will present a much richer weave of data and interaction than is currently found even in the user interfaces of GIS systems, let alone in the typical online map experience of the present day - an experience which is typically characterized by a frustrating back-and-forth between viewing of a static map and waiting for the server to download an update.
The event calendar which appears weekly in the DirectionsMag newsletter illustrates the use of this technology for a simple but novel application:
More examples are referenced at the bottom of the article.
Vector capability has been available in principle in the form of Java applets for many years, but for whatever reason, has not been widely used in online GIS applications.The more recent vector graphics technologies for web browsing are Macromedia Flash and SVG.Whether knowgingly or not, nearly every user of the web has been exposed to Flash in the form of the animated illustrations and banner ads.SVG (Scalable Vector Graphics) is a standard recently developed by the World Wide Web consortium (W3C).A recent article in this publication described GIS applications of SVG in some detail.The current article concentrates on Flash, and its advantages and disadvantages as a vector technology for GIS.More precisely, the comparison is between SWF - the file format used in Flash, and SVG, and between the available technologies for rendering and authoring the two formats.
SWF and SVG are in many respects similar technologies, and both satisfy the basic technical requirements needed to support a rich GIS experience on the web.These requirements are: (1) vector (rather than raster) representation of 2D geometrical objects (2) availability of event handling primitives that allow flexible design of interactivity (3) full access from a programming or scripting environment to the geometric and event models, so that arbitrary kinds of animation and interaction can be programmed, and (4) the ability to query the server as needed for incremental updates to the map.SWF and SVG are similar not only in the fact that they both meet these requirements, but in how they represent geometrical data: their primitives for modeling and manipulating the geometrical world correspond closely, though not exactly.
In areas other than geometrical representation, there are significant differences between SWF and SVG.In SVG's favor is its status as an XML language developed under the auspices of the W3C. SVG draws heavily on a variety of XML-related technologies, such as DOM, XLINK, and SMIL, for much of its functionality.A number of practical advantages flow from this, including excellent integration with other web technology, applicability of standard XML tools, familiarity to the large XML community, assurance of long-term stability, and the probability if not certainty of wide-spread adoption.On the downside, the aggregation of all of the standards and technology involved in full SVG functionality is dauntingly complex.
SWF was designed by Macromedia as a lightweight technology with priority given to the requirements for wide-spread adoption.Chief among these was a small plugin for swift downloading, and extensive support for authors and developers to speed the creation of compelling content.The Macromedia SWF authoring tools are particularly effective in three areas: support for creating animation and interaction without programming, integration of sound and video, and integration with server-side applications and development tools, both those of Macromedia and others.
Macromedia has been successful in its efforts: the Flash plugin for Internet Explorer on Windows is 383KB versus 2.3MB for the Windows version of the widely used SVG plugin from Adobe.There are more than one million Flash developers.The Flash player is present in more than 400 million web browsers, recently estimated at more than 96% of the online population.SVG, on the other hand, is a new standard which has not yet achieved ubiquity.
Although SWF is proprietary in the sense that its design is under the control of one company, specification of the format itself is publically available on the web, and tools for generating SWF are available from several sources.A free C++ SDK for writing SWF files is available for download from Macromedia.No royalties are involved in generating or distributing SWF content.The Flash player supports calls to and from scripts running in the browser, making integration with other kinds of web content easy to accomplish.
Where does all of this leave the GIS community? The standards-based approach of SVG makes it highly attractive as a sharable representation of interactive maps for use within the industry, and SVG is already being rapidly adopted for this role.However, there is another purpose for interactive maps: communicating geographical information to the web-browsing public at large.Several applications of this kind are well established, such as route finding services and weather maps. These established applications can be improved in performance and usability with vector-based technology, and there are exiting new possibilities as well.
It is in this role that SWF is an attractive alternative.SWF has the compelling advantage of needing no download of a plugin for most viewers.Requiring a 2.3MB download of an SVG player to view a map is not a realistic way to reach the web masses. If and when the standard installations of popular browsers include support for SVG, and these new browsers have propagated out to the public, this advantage will be reduced.However, the Flash authoring tools and Flash development community will continue to weigh in the balance, and Flash is likely to continue its rapid evolution.
In conclusion, the advent of programmable vector graphics in web browsers will lead to a revolution in the way geographic information is presented online over the next few years.More people on the web can be reached right now with Flash/SWF than with SVG.SVG, on the other hand, fits fully into the W3C world of standards, which will be a decisive advantage for many applications.In any case, we are lucky to have two technologies to support the revolution.
Examples of SWF in mapping applications
Weather maps
http://www.theweathernetwork.com/
City maps
http://www.urhere.com/
Temporal maps from Map Bureau
http://www.mapbureau.com/mapgallery/
Map of a cross-country trip with photographs every mile, developed by Second Story Interactive for Kodak
http://www.kodak.com/US/en/corp/features/onTheRoad/home/index.shtml
Maps of ski resorts
http://www.ifyouski.com/pics/flashmaps/
Map gallery from FreshMaps, including interactive trade show and real estate maps
http://www.freshmaps.com/FreshMaps/gallery/gallery.asp
Layered interactive map of the Middle East
http://www.equatorgraphics.com/temp/Mideast/MiddleEast.html
Educational map building tool from Maps.com
http://www.maps.com/learn/mapkit/
Animation of the build-out of the University of Oregon campus from the U of O InfoGraphics Laboratory
http://geography.uoregon.edu/infographics/CampusBuildout/uobuildout.html
About Flash/SWF technology
The Flash home site
http://www.macromedia.com/software/flash/
The SWF file format
http://www.openswf.org/
A detailed technical comparison between SWF and SVG.
http://www.carto.net/papers/svg/comparison_flash_svg.html
Enhancing a GIS Cellular Automata Model of Land Use Change: Bayesian Networks, Influence Diagrams and Causality
Authors: Kocabas, Verda1; Dragicevic, Suzana2
Cellular Automata (CA) models at present do not adequately take into account the relationship and interactions between variables. However, land use change is influenced by multiple variables and their relationships.
The objective of this study is to develop a novel CA model within a geographic information system (GIS) that consists of Bayesian Network (BN) and Influence Diagram (ID) sub-models. Further, the proposed model is intended to simplify the definition of parameter values, transition rules and model structure. Multiple GIS layers provide inputs and the CA defines the transition rules by running the two sub-models. In the BN sub-model, land use drivers are encoded with conditional probabilities extracted from historical data to represent inter-dependencies between the drivers. Using the ID sub-model, the decision of changing from one land use state to another is made based on utility theory. The model was applied to simulate future land use changes in the Greater Vancouver Regional District (GVRD), Canada from 2001 to 2031. The results indicate that the model is able to detect spatio-temporal drivers and generate various scenarios of land use change making it a useful tool for exploring complex planning scenarios.