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Brinzila et al. /Environmental Engineering and Management Journal 6 (<strong>2007</strong>), 6, 517-520<br />

available and the results are distributed/<br />

communicated. Many different options are occurring<br />

as regards reports publishing, data sharing, and<br />

remotely controlling the applications (Girao, 2003).<br />

2. The presentation of the system architecture<br />

An adaptive architecture based on web server<br />

application is proposed, in order to increase the<br />

performance of the server that hosts a dedicated<br />

(environmental monitoring) Web site, and customize<br />

the respective site in a manner that emphasizes the<br />

interests of the clients. The most virtual laboratories<br />

normally provide access either to one remote<br />

application, or accept only one user at a time. The<br />

system presented below provides a multitask<br />

connection, by accessing different detectors, working<br />

with different clients, and offering different variants<br />

for dedicated remote jobs, including technical tests of<br />

terminals, direct measurements of environment<br />

parameters, remote expertises, technical<br />

demonstrations or vocational training and education<br />

(Fig. 1).<br />

soil etc. and web-E-nose pollution monitor). The<br />

following procedures are implemented on laboratory<br />

server: dynamically allocation, web interfaces and<br />

Slab-SL interface. The communications between<br />

Centre server and each measurement workstation are<br />

performed by bi-directional interfaces SL-Slab and<br />

Slab-SL. On the front panel of application, the setup<br />

parameters are prescribed, and the data are transferred<br />

to the e-multitask interface. From the main web page<br />

of the centre server, the operator has the possibility to<br />

directly and selectively supervise the measurements<br />

protocols and select the parameters display, the<br />

publishing procedure, warning degree etc. On the<br />

other hand, due to the multitask facility, the number<br />

of users (clients) connected in the same time - to<br />

exploit the results - may become unlimited.<br />

We propose an Internet Based Environmental<br />

Monitoring Center with an increasing data exchange<br />

speed of information between the small<br />

meteorological distributed centers and the other hand<br />

all the world can see the evolution of meteorological<br />

parameters using World Wide Web. In this case we<br />

can warn the people in utile time about bad weather.<br />

Electronic mail messages are automatically generated<br />

to notify researchers about any identified anomalies.<br />

The data are then stored in secure electronic databases<br />

and made available for retrieval and analysis via<br />

standard web browsers. Authorized users may select<br />

any portion of the data and conduct a variety of<br />

predefined, automated analysis procedures or import<br />

the data into local spreadsheets, databases, or other<br />

local analysis software.<br />

Fig. 1. System architecture for remote and distributed<br />

environmental measurement center<br />

The instrumentation control and<br />

communication software has been designed under<br />

LabView graphical programming language. In<br />

particular, the PC-server – via TCP/IP protocol and<br />

the client-server - via CGI (Common Gateway<br />

Interface) technology, have the important role of<br />

developing the PC-instruments communication. CGI<br />

simply defines an interface protocol by which the<br />

server communicates with the applications. A<br />

dedicated software package supports the CGI<br />

applications in form of virtual instruments, used to<br />

develop interactive applications for Web-enabled<br />

experimental set-ups (that may be geographically<br />

distributed stations or expensive instruments,<br />

distributed areas of specialized sensors for water, air,<br />

Fig. 2. The main page of the virtual environmental<br />

measurement center and Virtual Laboratory for on-line<br />

measurements<br />

The authors propose in the same time an<br />

educational measurement remote system. Today,<br />

many academic institutions offer a variety of webbased<br />

experimentation environments so called remote<br />

laboratories that support remotely operated physical<br />

experiments. Such remote experiments entail remote<br />

operation of “distant” physical equipment offering<br />

students more time for laboratory work. This is one<br />

518

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