In the paper Borne theoretical considerations about dynamic measurement
scenarios aspects are discussed. The Dynamic Measure- ment Scenarios
are used for creating and managing job workflow in the Virtual Laboratory
system. It facilitate defining and monitoring mea- surement process
which quite often consists of many tasks connected between themselves.
Virtual laboratories (VL) are now in the scope of activities of research
groups and companies which are working on new solutions for the Grid
computational environment [1,3]. The main reason for creating such laboratories
is the remote access to the scientific equipment, the facility and acceleration
of the education process, exchanging opinions in research groups and
the management of the ex- periment results. This idea is especially
attractive for the experimental sciences and technologies, particularly
physics, chemistry, structural biology, experimen- tal medicine, radio
astronomy and also for widely taken engineering .
Virtual Laboratory is a heterogeneous, distributed environment, which
al- lows scientists all over the world to work on a common group of
projects. This . environment should allow conducting experiments with
the usage of physical devices, doing simulation using the computational
application, and communica- tion between users working on the same topic.
Similarly to typical laboratory tools and research techniques depending
on the specific field of science, virtual laboratories can benefit from
same collaboration techniques as tele-immersion, but they are not mandatory.
2 DYNAMIC MEASUREMENT SCENARIOS
The experiment process execution in many types of laboratories consists
of very similar stages. The given experimental process is often recurrent
and must be executed many times by same parameters modification. In
this situation the measurement scenarios conception seems to be very
The conception of the dynamic measurement scenarios allows defining
the process of an experiment in any way, from pre-processing, through
executing the experiment, to the post-processing and visualization tasks.
It is very important that thanks to the DMS we can connect experimental
and computational jobs together in a one workflow. Users are also allowed
to add their own module as a part of the scenario. Defining the measurement
scenario allows to spare a lat of time during computation. The user
does not have to wait for the end of a given process stage to subrnit
another one. It is made automatically.
This simple task's execution chain we call a static measurement scenario
(SMS). It allows connecting particular stages only between themselves.
Here, the execution path is specific and the user can not manipulate
To increase the possibility of the jobs scenario the dynamic measurement
scenario (DMS) was defined. In the DMS model, besides the definition
of the tasks execution sequence, we can also define same extra connections
(e.g. loops, parallel connections), conditions on the connections and
different lengths of the execution paths. In fact, DMS allows to define
many SMS models in one scenario. Thanks to the possibility of the conditions
defining on the connections paths the real path is determined during
execution and can depend on computational results.
To properly define the dynamic measurement scenario the system has to
have knowledge about connections which are enabled. In case of the laboratory
type where the processing software is well known, it seems to be easy.
The case will be more complex when we want to define the DMS model for
a wider range of virtuallaboratories.
An expertise from a particular discipline is necessary to define rules
for DMS. It can be dane by a laboratory administrator together with
a domain expert.
3 PUTTING INTO PRACTICE
The Virtual Laboratory system is developed in Pozna Supercomputing and
Net- working System  in collaboration with the Institute of Bioorganic
Chemistry  and Radioastronomy Department of Nicolaus Copernicus University
The Dynamic Measurement Scenarios will apply in two of our exemplary
implementation of virtual laboratories: the Virtual Laboratory of NMR
Spec- troscopy (devices: Bruker Avance 600, Varian Unity 300) and the
Virtual Lab- oratory of Radiotelescopy (device: radiotelescope -diameter
32m) available to the Grid users .
As we mentioned before the connection diagram has to be defined in the
initial stage of the DMS creating. In Fig. 1 we demonstrate an exemplary
diagram for the Virtual Laboratory of NMR Spectroscopy. There are presented
major processing stages in NMR experiment and applications assigned
to each stage.
On the figure below (see Fig. 2) we present an exemplarymeasurement
sce- nario diagram for the same laboratory type. This diagram can be
created using special software called Scenario Submission Application
(SSA). Thanks to the SSA the user can easily define, submit and monitor
the progress of the DMS realization.,
Basing on the DMS we would like also entirely automating the process
of defining and executing the VLBI experiment in the Virtual Laboratory
of Ra- diotelescopy. Virtual laboratory user only needs specify necessary
observation parameters. Parameters distribution to radio telescopes,
recalculation them to appropriate radio telescope values, launching
observation on time, data trans- porting and correlating and post-processing
execution can be performed auto- matically.
Virtual Laboratories are undoubtedly the technology of the future. They
are perceived as a remedy for problems connected with access or buying
costs of expensive and rare devices. Current technologies connected
with VL are in their first stadium of development. New created services
allow to fun simple experi- ments, which can be managed by changes in
a limited parameter paolo
The Dynamic Measurement Scenario is a flexible and very convenient way
to define workflow in many types of virtuallaboratories. It allows to
spare a lat of user's time and speed up of the project realization.
Thanks to the Submission Scenario Application the user can easily define,
submit and monitor the progress of the DMS realization. In a case of
an interactive task realization, it is possible to reserve a time slot
on a laboratory device or computational server and notify the user about
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