27-07-2012, 11:32 AM
A spatial computing approach for integrity checking of objects groups
A spatial computing approach.pdf (Size: 4.22 MB / Downloads: 31)
INTRODUCTION
Integrity checking is important in many activities, both in
the real world and in the information society. Essentially, it
consists in verifying that a set of objects, parts, components,
people remains the same along some activity or process, or
remains consistent against a given property (such as a part
count).
In the real world, it is a common step in logistic: objects
to be transported are usually checked by the sender (for their
conformance to the recipient expectation), and at arrival by the
recipient. When a school get a group of children to a museum,
people responsible for the children will regularly check that no
one is missing. Yet another common example is to check for
our personal belongings when leaving a place, to avoid lost.
While important, these verification are tedious, vulnerable to
human errors, and often forgotten.
SPATIAL COMPUTING
Computation supported by physical processes and real
world objects is not new, and various programming models
relying on this concept has been proposed in the past,
such as [1]–[3]. The general principle is to associate digital
information to physical objects, leveraging on the physical
space to support data structures (organized spatially) and
mobility to support computing process. The spatial configuration
of objects and their movements then implicitely control
an information system. A trivial example of such a system
is a shopping cart where items are tagged by their price,
using RFID tags. The volume of the shopping cart implicitely
reflects the total price of the shopping session, while adding
or removing an item updates it.
INTEGRITY CHECKING FOR GROUPS OF PHYSICAL
OBJECTS
Consider the following application scenario, which will help
identify the key issues of the problem: someone is at the airport
ready to cross the security gate. He is required to wear off his
jacket, his belt, to put in a container his mobile phone, his
music player, to remove from his bag his notebook computer,
and may be other objects... All that in hurry, with other people
in the queue doing the same. Obviously, personal objects are
vulnerable to get lost in this situation: objects can get stuck
inside the scanner, can stack up on each other at the exit of
the scanner, and it is easy to forget something while being
stressed to get a flight. Another vulnerability is to get the
object of someone else, such as a notebook computer of the
same model.
SYSTEM DESIGN
The Ubi-Check system is based on the principle of coupled
objects. Coupled objects are a group of physical objects that
are logically associated together, meaning that they carry
digital information referencing other objects from the set, or
representing their membership to the group. An important
property is that this information is physically stored on the
object. Typically, this information will be stored on RFID
memory tags embedded on the objects.
RELATED WORKS
RFID is a hot topic with many issues given its broad
application domain and emerging success in security, accountability,
tracking, etc. However, the Ubi-Check service and
its underlying coupled-objects principle differs than many
RFID systems where the concept of identification is central,
and related to database supported information systems. In
some works, the tags memory are used to store semantic
informations, such as annotation, keywords, properties [7], [8].
Ubi-Check is in the line of this idea: RFID are used to store
in a distributed way group information over a set of physical
artifacts.