Information Technology Reference
In-Depth Information
The first tag, resource name, is a basic item for the management server to
handle. Users can package a multimedia resource and upload it to the server
with a specified name. This name is for users to easily manage their contents.
On the server side, a unique ID will be generated automatically.
Longitude and latitude attributes are collected from the GPS module of a
user's mobile device. These two attributes are important tags in the multime-
dia resource information structure. After a user has produced a multimedia
resource, the value of longitude and latitude will be recorded automatically.
Other users can find these resources in the database of the management server
according to their locations. If users want to access multimedia contents related
to the location they are at, the travel note wizard (mentioned in the previous
section) can also present image, audio, or video to users immediately.
Longitude and latitude attributes provide an easy way to retrieve multi-
media objects in specified locations. Users can make a simple query directly
to the management server without relying on agents to collect information
from the huge network. Although the coverage of retrieval can only be lim-
ited to the management server, users can get precise query results quickly.
Before users start to make a query to find simple resources at their current
location, they need to input a parameter or radius. The meter is adopted as
the distance unit of radius. Since latitude and longitude are hard for users,
a transferring procedure is necessary to solve this problem. After users
input the value of radius, the wizard will transfer the input to management
and complete the retrieval process with longitude and latitude attributes.
The following algorithm shows a simple verification of target multimedia
resources retrieved from the management server.
• : Radius input by users
C
R
• : A set of information of users' current location
n
• : Numbers of multimedia objects in the management server
M
• : An information set of multimedia objects stored in the manage-
ment server
dist
• ( ): To get distance of two input values
e
• : A coeficient to transfer meters to value of latitude and longitude
Q
• : A list to store the query results
Selecting target resource with radius(R, C)
Loop l : i
1 ~
n
If
dist
(
M
[
i
].latitude,
C
.longitude)
<
R
*
e
and
dist
(
M
[
i
].
latitude,
C
.longitude)
<
R
*
e
Q
[
j
]
M
[
i
]
j
j
+
1
Repeat
l
Output
Q
End
