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    <article-meta>
      <title-group>
        <article-title>Virtual Laboratory for Distance Learning: Conceptual Design and Technology Choices</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Evgen Kozlovsky</string-name>
          <email>evgen@ksu.ks.ua</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Hennadiy Kravtsov</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Kherson State University,</institution>
          ,
          <addr-line>40 r. Zhovtnya 27, Kherson</addr-line>
          ,
          <country country="UA">Ukraine</country>
        </aff>
      </contrib-group>
      <fpage>116</fpage>
      <lpage>125</lpage>
      <abstract>
        <p>Questions of designing and a choice of technologies of creation of virtual laboratory for the distance learning system are considered. Distance learning system «Kherson Virtual University» is used as illustration.</p>
      </abstract>
      <kwd-group>
        <kwd>distance learning system</kwd>
        <kwd>virtual laboratory</kwd>
        <kwd>Rich Internet Application</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1 Introduction</title>
      <p>Objects of research are systems distance learning systems and virtual laboratories
(VL). Research objective is designing and description of technology choices of virtual
laboratory development in distance learning system for expansion of educational
possibilities of distance education.</p>
      <p>Virtualization from the point of view of education is a process and result of
communicative interaction of subjects and objects of education in the virtual
educational environment which specificity of the maintenance is defined by concrete
subjects and objects during the interaction.</p>
      <p>The wide concept of virtuality should be narrowed to area of the concepts
describing virtuality from positions of processes modeling in a concrete subject
domain. Virtuality is a set of prospective interactions of real objects representations
among themselves, and also possible consequences, i.e. conditional interactions of
concepts images and objects formally represented as real.</p>
      <p>Concept "laboratory" is a place specially organized for execution of laboratory
works, experiments and a place for search of decisions in the field of fundamental
sciences, or for the tasks solutions in a certain application area of knowledge.</p>
      <p>The concept of the virtual laboratory has not the accurate settled definition,
therefore often companies interpret it at own discretion, and they adjust it under
concrete needs of their products. We will introduce concept of virtual laboratory,
being based on the resulted definitions. So, the virtual laboratory is a virtual
environment in which the possibility of research of conducts of models of objects,
their sets and the derivatives, set with the certain stake of detailing in relation to the
real objects, in a certain field of knowledge is organized.</p>
      <p>Analysis of the Internet resources shows that the overwhelming majority of
projects of virtual laboratories are not conforming to the concept of laboratory. More
frequent it is Internet sites where the texts of laboratory works are present, supported
by media maintenance. Frequently only one process without management possibility
is displayed in accompaniment. If in the context of such "laboratories" are any objects
they are very limited in possibilities, and they are procedural programs, but not
objects, without possibility to modify or to complement the motion of going
processes.</p>
      <p>That is, there is a certain discrepancy of purpose and the name of the majority of
the Internet resources – «virtual laboratories». From this follows the research
problematic – creation of the project and development of the software of virtual
laboratory.</p>
      <p>Besides, it is necessary to notice, that modern IT possibilities allow to expand
concept of virtual laboratory – to apply it not only for fundamental sciences but also
for more wide range of fields of knowledge, for example rendering support at
studying of arts, linguistics, the rights, philology, etc.</p>
      <p>In department of multimedia and distance learning technologies KSU there are
already preconditions to creation of such virtual laboratory. In the asset of department
there is an experience of creation of declarative virtual systems of processes
modeling, in particular, the demo-project «Electrotechnics» in which the algorithms
of creation and an estimation of quality of interaction processes in electric circuit are
laid. The distance course "Cytology" is the software product the purpose of which is
support of process of execution of virtual educational laboratory works on the course
of the discipline with the same name. Besides, there is an experience of creation of
virtual educational training simulators, such as, a microscope and the electric motor,
allowing studying the details of construction and principles of its work. Also, there is
a long-term experience of teaching of discipline «Modeling of physical processes»,
students create virtual models for calculation and visualization of processes in various
sections of course of physics under the guidance of employees of department. Thus,
we have concepts of creation of virtual laboratory which can unite in itself support
training process of students on the whole spectrum of fundamental and applied
disciplines.</p>
      <p>As we understand, the virtual laboratory should function inside the system of
distance learning. Using the virtual laboratory works is capable to expand
qualitatively possibilities of distance learning, and also effectively support execution
of practical works.</p>
      <p>Interviewing of teachers and students – users of distance learning system «Kherson
virtual university» (DLS KVU) has shown, that answers for the question «What
tutorials do you prefer?» show the positive growth of requirement and interest to
nonstandard approaches in education (Fig. 1). There is already a category of people who
consider that the possibilities, which are integrated in the standards of distance
learning (DL), are not enough today. The wider toolkit for execution of virtual
laboratory works is needed for active users of DL.</p>
      <p>Progress of DLS has caused the transferring to the virtual environment the basic
forms and ways of education - the groups, courses, tests, libraries, virtual rooms of
communication, virtual boards with wide exposition facilities of information. The
following stage of development DLS is obvious - it is necessity for creation of the
universal virtual laboratory, which will have the digital analogues of laboratory
offices of university, with all necessary tools. In such laboratory the support of
scientific researches of students and the control at all stages of cognitive process are
provided.</p>
    </sec>
    <sec id="sec-2">
      <title>2 Analysis of existence of interaction between DLS and virtual laboratories</title>
      <p>There is a big variety of DLS. The systems are free-extended, brand and author's
systems. All systems are developed according to the international standards of
distance learning, which allow providing the compatibility of components and the
possibility of their repeated use in other systems, guaranteeing their invariance and
unequivocal treatment. In opinion of the authors of DLS KVU any system has
viability if it completely conforms to standards, and also it goes on a step ahead,
introducing new educational means, it expands possibilities for the users, it introduces
innovations which will not contradict the basis – standards, such as IMS and SCORM.</p>
      <p>
        In the standards of DL virtual laboratories are not regulated, there is only a
generalized description of objects of education. Requirements to such objects of
training are in two key concepts: first of all the property of isolation, as a black box
with the entrance and target strict-designated parameters, they are parameters of
initialization of object and the parameters describing results of work. The educational
resource should correspond to the standard at level of statement of an educational
task, provide execution of educational task and should give an estimation of results,
for the account in the rating estimation system. Packing of this type of a resource for
carrying over to other educational system should be provided. The system resource
will not contradict the standard at performance of these conditions [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ].
      </p>
      <p>The analysis of experience of introduction of virtual laboratories in DLS shows,
that the problem of development the virtual laboratory as a part of DLS was yet not
set by developers.</p>
      <p>More often, laboratories reflect only one field of knowledge, usually it is sections
of classical sciences, such as an electricity, analytical chemistry, optics etc. Also it is
necessary to notice, overwhelming number of laboratories are in a format of
distributive local software products which are delivered on separate computers, or on
a small local area network, school or high school.</p>
      <p>On-line Laboratories are presented in smaller volume and variety. Thus this class
of software products is actively developed, superseding off-line versions from the
market of educational.</p>
      <p>On-line Laboratories are presented in smaller volume and variety. Thus this type of
software products is actively developed, superseding from the educational market
offline resources.</p>
      <p>Both these of type of virtual laboratories are frequently used limited, not in
distance learning system, but only as additional facultative resources. In them there
are not or partially realized modules of support of educational process. Usually the
control of knowledge is realized in the form of self-checking questions, or the
elementary test, the results of modeling are simply displayed to the user, but are not
gotten to group journal of progress automatically.</p>
      <p>
        The virtual educational and engineering laboratories of the industrial enterprises
intended for automation of engineering work are the separate class. They are used in
highly specialized areas of engineering science. These laboratory cabinets model real
industrial problems of the concrete enterprise with high level of detailed elaboration.
The main attention is usually given to realization of procedures of mathematical
modeling, calculation and optimization of studied objects or processes during their
creation [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ].
      </p>
      <p>During projecting and development of virtual laboratory the most effective
approach will be focused on this class of software products, they have powerful
analytical and mathematical appliance, the detailed level of imitation of processes.</p>
      <p>
        The urgency of creation of virtual laboratory is caused not only development of
DL. There are a number of disciplines in which laboratory researches mean
considerable charges of educational institutions on machine tools, tools, preparations,
reactants, etc. Besides as practice shows, students can’t execute laboratory work
correctly, after theoretical preparation in first time. Often for a successful execute the
laboratory work it is necessary to make experiments several times, and then the
expenses can essentially increase. Besides, in educational institutions, far not always
there are means for purchase and completion of laboratory offices by all necessary.
Virtual models are used in cases when the experiment is dangerous, expensive, occurs
in inconvenient scale of space and time (too long-term, too short-term, lingered), is
impossible, unique, not visual etc. [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. In these cases the virtual laboratories become
the necessity, it gives the chance to spend educational process with smaller expenses,
or it will allow saving means, preparing students at first on special training apparatus,
for the subsequent transition for real expensive laboratory stands.
      </p>
      <p>In our opinion, the virtual laboratory is capable to expand a spectrum of given
educational services considerably. Its use will allow expanding possibilities of
interaction of all participants of educational process. The authors put the objective –
to create virtual laboratory as an educational resource in DLS «Kherson virtual
university».</p>
    </sec>
    <sec id="sec-3">
      <title>3 System architecture</title>
      <sec id="sec-3-1">
        <title>3.1 General approaches of realization and place of virtual laboratory in DLS</title>
        <p>Modern possibilities of network technologies, universal prevalence of high bandwidth
telecommunication channels, and also the width of possibilities of means of
programming, in which it is comfortably to develop the web-oriented software
products, allow saying that virtual educational means are expedient to create in the
form of web-services.</p>
        <p>Considering that fact that DLS KVU is the Internet application, the designing and
development of VL should be executed as a web-oriented application. Though, it is
not necessary to reject the possibility of creation of the software adapted under a local
network with possibility at work to contact a server for data exchange.
(a)
(b)</p>
        <p>In fig. 2 the basic approaches of work of client-server applications are presented. In
fig. 2 (a) the model of the web-oriented applications in which the client receives and
uses the freshest versions of the software is presented. In fig. 2 (b) the model of
locally network applications in which the software is installed on the computer of the
user is presented. The user should contact the developer and receive corresponding
modules of updating for reception of updating of the software.</p>
        <p>The virtual laboratory has considerable volume of the information which at the first
approach can demand much disk space and operative memory that will occupy
definitely superfluous resources at each application launch. Frequently all laboratory
modules are not necessary for user at once, in this case an optimum variant is to make
possibility for loading only the basic environment of the certain working module and
necessary section of library of objects. Then the user will save the traffic of resources
and can increase the effectiveness of work.</p>
        <p>It is necessary to notice, that in both cases there are advantages and lacks, therefore
the realization of both ways of installation of applications will be the best variant then
the concrete user can choose the way of installation more suitable for him,
considering its personal needs.</p>
        <p>In fig. 3 the place of virtual laboratory in DLS «Kherson virtual university» is
shown. The laboratory is considered by developers as one of the important resources
of system. Educational and the control facilities are an integral part of educational
process in the distance form.</p>
        <p>Developers put the task to create such mechanisms:
1. Possibility of creation of the working model or construction
2. Possibility of carrying out of various transformations and change of statuses
(editing) of model or construction
3. Possibility to carry out necessary calculations and measurements of parameters of
model or construction virtual measuring devices</p>
        <p>
          Let's consider the method of creation of the module of virtual laboratory in the
form of the client-server application in format Rich Internet Application (RIA) [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ].
The choice of this model is connected with advantages which are given by this format
to developers and users. First of all it is necessary to note the possibility of the user to
work on any computer with Internet connection in any browser with installed module
Flash Player. The interface and level of interaction of the user with RIA application
can be similar with functionality of traditional desktop applications. Developers and
designers receive freedom in realization of ideas, considering specificity of concrete
area of knowledge.
        </p>
        <p>
          Today level of use of module Flash Player of users is 96 % [
          <xref ref-type="bibr" rid="ref5">5</xref>
          ]. Universal
prevalence of Flash-technologies allows speaking about availability to users of such
approach in realization of the module of virtual laboratory.
        </p>
        <p>
          There is a wide variety of developing tools for creating RIA applications. These are
such technologies as Adobe Flash\Flex, Backbase, Google’sGWT framework, java
applications, Microsoft ActiveX controls, Microsoft Silverlight, etc. [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ] Our choose of
technology for developing client application is Adobe Flex, firstly of all because it
installed on the wide prevalence on computers of users, and also it has full multimedia
possibilities of Flash that allows to open the essence of modeling of processes VL
widely.
        </p>
      </sec>
      <sec id="sec-3-2">
        <title>3.2 Scheme of components of the module «Virtual laboratory»</title>
        <p>In fig.4 the scheme represents the architecture of the program module «Virtual
laboratory» is presented. In the server part of the application there are three basic
components – the module kernel, the connected databases and the mathematical
processor.</p>
        <p>The set of the basic classes of management are In the module kernel:
1. "Management" is responsible for the rights of accounts of users, provides
synchronization of resources of users, and connects options of the components
used by the concrete user.
2. «Event analyzer» writes down, orders and stores all actions of users for the
subsequent reproduction.
3. «Data assembly» provides creation of packages of data and files of resources for
library of the user with the subsequent sending in repository on a server at the start
of the work.
4. «Sessions manager» creates virtual rooms, connects to them users, and provides
authorization and administration of rooms. It is responsible for reception and data
transmission between users and a server.
5. The module «Data-packing» creates packages from resources which will be sent to
the client, and also for maintenance of integrity of data and creates metadata of
these packages of resources.
6. Module "Parsing" provides transformation of arriving inquiries and messages from
the client application and transfer of given data to operating modules.
7. "Data exchange" is the interface of web services of interaction with client
applications.</p>
        <p>In module VL databases of DLS «Kherson virtual university» are used. First of all,
it is base of authorization, statistics, also sending of data about progress of users in
base estimation is realized, etc. Except used DLS bases, the module has own database,
where records about job of all components of the module, the information about
objects, records of events, and also links with storehouses of resources of libraries are
stored.</p>
        <p>The mathematical processor serves for maintenance of difficult mathematical
calculations which cannot be carried out by client computers. These are calculations
of the solution of the equations of the higher orders, the calculations demanding use
of mathematical methods of correlation, specification, iterations, and calculations of
errors, an analysis, and others.</p>
        <p>The client part of the software of VL has components for creation and work with
virtual models:
1. «Objects and interactions library» contains sets of objects of a certain subject
domain, and also the ways of the interaction defined by the current field of
knowledge.
2. «Scripting manager» allows adjusting interactions between objects, setting their
parameters, imposing conditions. Also it is intended for the description of
properties and interactions of the new objects created in the editor.
3. «Work scheduler» has two operating modes. In elapsing mode of laboratory
research the user should according to offered course of work make all necessary
operations for result reception. In the mode of creation of new work this
component writes down history of events, allows to correct them, and to form the
scenario of performance of work.
4. In "editor" VL the designing of the new objects is made. Users can on the basis of
existing VL of library, preparing them, create other objects. Using in parallel the
component of scripting, users can specify and finish new parameters and methods
of interaction with other objects, finish new ways of behavior.
5. "Visualizer" is the component in which there is laboratory research, provides
display of all designs of objects. In this module the current statistical data, such as
values of parameters of system are also displayed, resultants of a direction of
movements are specified. Directly here there is a process of modeling and
management of a work scenario.
6. "Tool kit" is control facilities of user and changes of the objects which are in
components the Visualizer and the Editor.
7. «User interface» – is set of methods of display and interaction of the user and
system.</p>
      </sec>
      <sec id="sec-3-3">
        <title>3.3 Description of job of users with the interface of the program module «Virtual laboratory» in DLS KVU</title>
        <p>In DLS KVU there are two basic roles of users which work in virtual laboratory
tutor and student. Working with module VL is carried out in two modes: work of the
tutor in editor VL in a mode of creation of virtual laboratory work and work of the
student in the training mode in VL. The tutor has the rights to create new models in
the editor and to look through them, and the student can use ready model during work
in VL.</p>
        <p>Process of work of the tutor with VL begins with creation of new model of virtual
lab work (VLW) in a window of the editor. First of all, the tutor always bases the
educational activity on the working program of discipline. In the working program
training basic elements, such as lectures, practical and laboratory works are reflected.
The first step of creation of virtual laboratory work is creation of scenario. At this
stage the tutor creates scenario VLW in the form of algorithm which realizes during
laboratory work.</p>
        <p>Then, the tutor consistently fills the model of VLW with objects from library VL,
realizing the scenario of its performance. The tutor sets to objects parameters,
methods of interactions, designs from them blocks, and thus forms definitive scenario
VLW.</p>
        <p>When the new laboratory work is completely designed, it is passed to the server
which processes it and compiles ready model of laboratory work.</p>
        <p>The student at performance of VLW has the necessary set of resources of training:
tools, objects for work according to the scenario. In conformity with the requirement
of isolation of module VLW, it should provide an estimation of quality of
performance VLW. Therefore, after performance of laboratory work by the student,
the module of performance VLW passes results of work in the form of estimation to a
server.</p>
        <p>Thus, the process of work in module VL allows to model educational process in
real research laboratory, to create, to train and make control of the work.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4 Conclusions</title>
      <p>In the article the project of model is developed and technologies of designing the
program module «Virtual laboratory» for distance learning system «Kherson virtual
university» are described. The technology of designing of program module VL is
based on the client-server application in format Rich Internet Application.</p>
    </sec>
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