Consultation Cartographique à Genève

Le site du Service des agents de ville et du domaine public de la ville de Genève donne la posibilité de faire des consultations cartographiques en ligne (avec le logiciel d’Autocad Volo View Express 2). Les éléments du domaine public ne sont plus seulement catalogués, mais peuvent être consultés dans leur situation d’implantation sur des cartes et sont illustrés par des photographies, des plans ou des séquences vidéo.

Self-Mapping in 802.11 Location Systems

Self-Mapping in 802.11 Location Systems, Anthony LaMarca, Jeffrey Hightower, Ian Smith and Sunny Consolvo.

The authors propose a self-mapping algorithm that can reduce or even eliminate the overhead of mapping. With self mapping, only a small amount of initial map data (seed data) is needed to deploy the system. They present a graph-based algorithm for mapping radio beacons:

• Nodes in the graph represent radio beacons and weighted edges represent the nearness of the two beacons
• Edge weights are determined by using the radio scans to infer which beacons are near wich other beacons.
• By anchoring the beacons in the seed set at their known locations, we can treat the graph as a constraint problem and compute likely locations for the unknown beacons by minimizing constaint violations.

The results show that self-mapping works well in practice and is a viable alternative to explicit mapping.

Real-Time Awareness Maps of Cell Phone Usage

People of SENSEable City Lab have developed a continuously changing real-time maps of cell phone usage in Graz, Austria. They “track” anonymous data from thousands of mobile phones. The get the data by ‘pinging’ the cell phones, so they probably have an agreement with austrian GSM providers. The project is a means of observing, and reading the city, a tool that traces its evolution and real-time fluctuation.

Graz in Real Time

Spatial view of Graz

CatchBob! Videos

I have edited the CatchBob! video:

long version of 3:30min (15MB)
short version of 1:30min (8MB)

The sequences show:
- Instruction to the game
- Pre-game strategy planning
- Campus exploration
- Real-time map annotation
- Player refining their strategy
- Spatial coordination
- Catching bob
- Post-game replay

The video footage was taken by a student of the art school “Ecole des Arts Décoratifs de Genève” when he came to play CatchBob early this year.

A Location Representation for Generating Descriptive Walking Directions

A Location Representation for Generating Descriptive Walking Directions, Gary Look, Buddhika Kottahachchi, Robert Laddaga, Howard Shrobe

In this study, the authors argue that while many location-aware applications can reason about space at the level of coordinates and containment relationships, these applications have no way to express the semantics that define how a particular space is used. They developed LAIR that generates walking directions that are similar to those a person would give. It is based on an ontology to model both the geographical relationships between spaces as well as the functional purpose of a given space.

Their examination of the directions revealed a useful list of characteristics. As a result of this analysis, their walking guide produce walking directions with the following properties:
- Directions do no use metric distance or cardinal directions.
- Directions are more complex than a sequence of “go-to” and “turn” directives
- Use landmarks to identify places to turn
- Use landmarks to verify travel in the right direction
- Describe the physical spaces a route passes by, or passes through
- Doors are useful landmarks
- Describe hallway intersections

Control, Deception, and Communication: Evalutatin the Deployment of a Location-Enhanced Messaging Service

Control, Deception, and Communication: Evalutatin the Deployment of a Location-Enhanced Messaging Service, Giovanni Iachello, Ian Smith, Sunny Consolvo, Gregory Abowd, Jeff Hughes, James Howard, Fred Potter, James Scott, Timothy Sohn, Jeffrey Hightower and Anthony LaMarca.

This study is specifically aimed at investigating the need for and effectiveness of automatic location disclosure mechanisms, the emerging strategies to achieve plausible deniability, and at understanding how place and activity are used to communicate plans, intentions and provide awareness. The results show a lack of value of automatic messaging functions, confirm the need for supporting plausible deniability in communications, and highlight the prominent use of activity instead of place to indicate one’s location.

The authors are particularly interested in location-enhanced applications, because location plays a fundamental role in accomplishing everyday communication and coordination tasks. For example, studies agree that one of the most frequent uses of SMS is to coordinate and schedule meetings, for which location plays a significant role. They have developed Reno, a location-enhanced messaging application for Nokia Series 60 phones (GSM positioning) that allows the user to request the location of other users and tell his/her location to them. Reno uses SMS messages to communicate.

The outcomes are:
- The participants did not want automatic features. When asked about the amount of messages sent and received daily, no participants mentioned being overwhelmed by the number of requests. When ask for the reason about the reasons for not configuring automatic features, some participants mentioned that they were not confident of how the features would work in practice. There was also a lack of trust “I felt like sometimes it would be wrong”, and loss of control “it’s just like, y’know, the phone is taking over”.

- All participants viewed Reno as an enhanced messaging application, rather than strictly a location-enhanced service.

- People want to deceive, or deny replies, from time to time, for purpose that are important to them. People decide whether to disclose information about their activities and location based on the indentity of the requester more than on the situation in which this happens.

- In Reno, imprecision and ambiguity afford a space of privacy

Location-Aware Networking: We Know Where You Are

Location-Aware Networking: We Know Where You Are gives a rather technological overview for managers of the emerging technologies in location-aware computing. It covers privacy, and security issues, and the technological constrains. However it fails to mention any added-value for the usage of location-aware systems. Half of the article is focused on the E911 legislation and explain on how it “should” work.

Encontrar un Piso en Barcelona

Los mejores sitios para encontrar un piso en Barcelona:

Loquo: http://www.loquo.com/
Craigslist: http://barcelona.craigslist.org/
Idealista.com: http://www.idealista.com/
Catalunya Classified: http://www.catalunya-classified.com/

Week-end en Francilie, Vigilence et Propreté

6 dias en BCN y Asturias