A Grid-Based E-Learning Model for Open Universities

8/11/2019 A Grid-Based E-Learning Model for Open Universities

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A Grid-Based E-Learning Model for Open Universities

Oy O y Department of computer and information sciences, Covenant Universi, Nigeria

emebo.onyeka,dwande{@gmail.com},[email protected]

E-leaing has grown to become a widelyaccepted method of leaing al over the worl As aresult, many e-leaing plaorms which have beendeveloped based on vaing technologies were facedwith some limitations ranging from storagecapabili, computing power, to availabili oraccess to the leaing support iastructures. This

has brought about the need to develop ws toeectively manage and share the limited resourcesavailable in the e-leaing plaorm. Grid computingtechnolo has the capabili to enhance the qualiof pedago on the e-leaing plaorm.

In this paper we propose a Grid-based e-leaingmodel for Open Universities. An atribute of suchuniversities is the seting up of multiple remotelylocated campuses within a count. The grid-basede-leaing model presented in this work possessesthe atributes of an elegant architectural ameworkthat wil facilitate ecient use of available elearning resources and cost reduction, leading to

general improvement of the overal quali of theoperations of open universities.

E-Leaing is overtaking conventional classroomteaching methods. Via this approach, knowledge cabe more exibly propagated and absorbediespective of the teaching personel d leers.Many universities in the world ae adopting eleaing as their principal teaching method.

Distance Education is a vital lnk in theapplication of e-leing. The advantage of Distanceeducation is that it ca solve the problem ofgeographical location with Accessibility fo thoseliving fa away om the educational center.Furermore, it can conserve money, time and energyconsumed in commuting between classes, improvedexibility to study in any convenient location withan Inteet connection, Just-in-time leing; moreopportunities to study the most current materialavailable, exibility for those with iegula workschedules, accessibility for those with restricted

mobility (e.g., handicapped, iured, elderly), daccessibility for those with family responsibilities(e.g., parents with young children at home). This has

been the focus of Open Universities.

Distace Education delive mode for e-leingcan roughly be classied into the four described

below [8].Voice: Instrctional audio tools include the

interactive technologies of telephone, audioconferencing, and short-wave radio. Passive (i.e.,one-way) audio tools include tapes ad radio.

Video: Instructional video tools include stillimages such as slides, pre-produced moving images

(e.g., lm, videotape), ad real-time moving imagescombined with audio conferencing (one-way or twoway video with two-way audio).

Data Computers send ad receive infoationelectronically. For this reason, the te "data" is

used to describe this broad category of instructionaltools. Computer applications for distance educationare varied d include:

Computer-assisted instruction (CA) - usesthe computer as a self-contained teachingmachine to present individual lessons.

Computer-managed instruction (CMI) - usesthe computer to orgaize instrction d

track student records ad progress. einstrction itself need not be delivered via acomputer, although CA is oen combined

with CM!. Computer-mediated education (C)

describes computer applications that facilitatethe delive of instruction. Exaples includeElectronic mail, fax, real-time computerconferencing, ad World-Wide Webapplications.

Print is is a foundational element of distanceeducation progras ad the basis om which allother delive systems have evolved. Vious print

formats ae available including: textbooks, studyguides, workbooks, corse syllabi, d case studies.

Although Distance Education has mayadvtages, its principal drawback is the costly andcomplex technology associated with using ELeaing platform. In order to help OpenUniversities apply Distance Education, this paperpropose adopting Grid Computing technologies suchas Access and Data Grid that features expadability,

resorce-shaing ad virtual collaboration capabilityto enhance quality of pedagogy on the e-leaingplatform.


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There are a number of approaches to Grid-basedE-leing that have been repored in literature.

According to Chao-Tng Yang et al. [7], GridComputing ad Pallel Virual File Server (PVFS)

Tecnologies for Constrction of e-LeingEnvironment was used to integrate the idle computerstorage spaces in academies so as to save cost and

mae the best use of available resources.Chao-Tung Yang et al. [6], employed a kind of

Grid Computing technology called Data Grid tointegrate idle computer resources in enterprises intoe-leaing platfos, thus eliminating the need to

purchase costly high-level servers d otherequipment.

Akinyemi et al. [3], proposed a grid enabled ELeaing ework for Nigeria EducationalInstitution. The solution proposed leverages a

intergrid inastructe that has the capability toenable virtual collaboration ad resource shingamong remotely located panering Universities.

Jianxin et al. [12], gave a novel E-Leaingarchitecte along with an implementation approach

to build ecient E-Leing applications. In thearchitecture, E-Leaing inastrcture used the Grid

technology to choose the best available resoces forE-Leaing objects execution.

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The grid computing paradigm [5] essentiallyaggregates the view on existing hardwae adsowae resources. The term id alludes to anelectric power id and emphasizes the perceptionthat access to computational resources should beeasy as the common access to power grid. Inaddition, a grid user should not have to care where

the computational power he or she is crently usingcomes om.

Grid computing is a form of distributedcomputing that involves coordinating d shaingcomputing capability, application, storage device, or

network resources across dynaic andgeographically dispersed institutions. When we tuon the PCs or facilities on the grid, other computersamong the grid will search amongst themselves tobegin processing d computing the relative work.This work not only uses the resoces of the localcomputer, but also obtains the powerl virtual

resources om other remote computers, includingthe computing ad storage capabilities, applicationprogras, database d 0 devices spread over thewhole grid. This is then called Grid Computing. Inother words, Grid Computing ca be considered asa virtual super computer [4].

A

Access Grid is the tecnology developed by U.S.Argonne National Laborato. It enables maypeople to process ieractions ad opinion exchagesthrough video and audio. At present, it has been used

in many sites that need video such as training,teaching, conference d semina, etc. Theapplication sowae of Access Grid is called AccessGrid Toolkit. This is a eeware that ca be eelydownloaded om the Access Grid web site. The website also provides complete technical archives atgive the needed assistace to its users. The latestversion of Access Grid Toolkit is Version 3.1. is

release includes new nctionality, including thelatest VIC (video) d RAT (audio) tools om theSmover project, suppor for hierarchical venue datastorage, improved bridging support, d certicate

based Venue access controls [2].

Aer Version 2.0, Access Grid has alreadytightly combined with Grid technology, therefore theGrid Middleware Globus Toolkit needs to beinstalled before the installation of Access GridToolkit 2.0.

The middlewe Globus will check thoroughlyall the available resources in the Grid when making acomputing task, such as which hosts are available,

how much processing capability is le, what theavailable data is in the database. Then, the tasks

required by the users will allocate its resources adcontrol its action by the system.

As Access Grid 3.1 has already tightly combined

with Grid so that all the nctions of Grid technologysuch as authentication, resource allocation, ad

remote data access ad fault detection are thestandd nction of Access Grid; at the sae time,X Web service is also the data trasmittingmethod of Access Grid.

Tk

The Globus Toolkit (GT) has been developedsince the late 1990s to support the development ofservice-oriented distributed computing applicationsand inastructures.

The vital task in realizing a Grid is establishinga common open stadad. Its core is based on anopen set of standads d protocols - e.g., the OpenGrid Services Architecture (OGSA) - that enablecommnication across heterogeneous,geographically dispersed environments. With GridComputing, institutions c optimize computing anddata resources, pool them for large-capacity

workloads, share them across networks, d enablecollaboration [9]. Some protocols ad applications

have been proposed and implemented in actualworks, such as the GT [1].

The GT is an open-achitecture, open-sourcesuite of services d sowae libraries that support


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Grids and Grid applications. It provides soaretools that enable coupling with computers, databases,ad instrments. With Globus, jobs ca be on

two or more high-performace machines at the saetime, even though these machines might be locatedfa apart ad owned by different institutions. The

toolkit includes sowae for security, informationinastructre, resorce management, data

maagement, communication, fault detection, dportability .

The GT components most relevant to OGSA arethe Grid Resorce Allocation d Management(GRAM) protocol, the Meta Directory Service(S-2), ad the Grid Security Inastructure (GSI).These components provide the following essentialelements of a service-oriented architecture:1. GRAM protocol: this component provides forsecure, reliable, service creation d maagement ofabitra computations.

2. S-2: this component provides a unifoamework for information discovery through sostate registration, data modeling, d a local registry.3. GSI protocol: this component supports single signon, authentication, communication protection, adcertication mapping.

GT5.0 being the latest release contains anupgrade to the web services specications used bythe toolkit as well as new features in all services[11].

D

Scientic studies such as high energy physics andcomputational genomics require access to largeaounts of data, that will require managementservices such as data le magement, replicatedles magement ad trsfer, ad distributed dataaccess maagement. The data grid inastrctureintegrates the data storage devices d data

management service into the grid environment. DataGrid consists of scattered computing d storage

resources, which, though located in differentcountries, remain accessible to users [13].

The proposed Grid-based E-leing ameworkwill adopt the GT as the Data Grid inastrcture.

May research projects, such as EU DataGrid [17]ad Paticle Physics Data Grid PPDG [15], a basedon the GT. The Globus Data Grid comes in twolayers. On the Low Level are Data Grid CoreServices, and on the upper layer are High LevelComponents [18].

The storage system is a basic data gridcomponent. It dees d covers all storage

technologies capable of adding, deleting, reading,writing ad operating le instances [10], such asSS, ad DPSS (Distributed Parallel StorageSystem). Data access services ae set up to access,

manage, d transfer data in the storage system [14].

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The Grid-based E-Leaing Model Architecture foropen Universities being proposed in this paperemulates the grid-cluster model that wasimplemented in [6]. With implementation for the

ont end that consist of the Grid Portal and the backend to contain the Data Grid contents. Here weintroduced the Access Grid layer as shown in Figure

Midlwar Gobu

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Access

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At the ont end, a portal web site is set up in eGrid system to provide services to Grid members andacts as a teaching platfo for other remotely locatedcampuses via the Inteet. Campuses that have not

joined the Grid will be restricted in their access tosome resources. The Education Grid set up will me

use of the NMI's OGCE (Open Grid Computing

Environment) Portal [16] as the network Grid PortalSite. The OGCE Portal includes the followingnctions:1. Posting on e Discussions board adcommnicating with iends in Chat rooms, and

providing users with the latest grid-relatedtechnological updates in the News section;2. Monitoring Grid resorces, such as node operatingconditions;3. Submitting tasks for Grid operations;4. Trasmitting data within the Grid via GridFTP;and5. Maging the Grid CA via the Proxy Maager.


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The OGCE Poral amework provides a generalporal achitecte that supports virtual orgizationscomposed of scientists and project developers, which

provides the API for the development of reusable,modular components that c be used to access theservices being developed within the Grid

orgization.The middleware Globus is responsible for

checking systematically all the available resources inthe Grid when making a computing task.

The Access grid enables virual collaborationbetween lecturers, students, researchers, etc toprocess interactions ad opinion exchages throughvideo and audio. It also enables the campusesintegrate teaching coses and materials within thegrid for enhced teaching exibility.

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The back end comprises of the Data id,Computational grid d y other grid inastructureas depicted in Figure I above.

The Data grid technology will comprise of idleteaching or administrative storage computerresoces within the capus. This will be used as asubstitute for the demand of a lage storage serverknowing that as the size of teachingmaterial(multimedia, text etc) and the nber ofstudents who use this e-eaing platform (for real

time courses or watch if absent) increase, there willalso be a need for a high level storage server. With

the Data grid, it is possible that the storage space

obtained will not be less tha that of a expensivestorage device, such as a Disk Array or NAS, inserving as e-eaing platform storage device. TheComputational grid will comprise of resources that

will improve the processing capability of users onthe Grid.

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The implementation of the grid-based e-eaingmodel presented in this work will facilitate ecientuse of available e-eaing resoces and costcutback, virtual collaboration between remotelylocated capuses leading to general improvement of

the overall quality of the operations of openuniversities.

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As immediate next step, we intend toimplement the concepts presented in is paper using

the National Open University of Nigeria (NO)d its study centers located in various states in thecontry.

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[1] About the Globus Toolkit.http://www.globus.org/toolkitabout.html, Access date:June 20,2010.

[2] Access Grid. http://www.accessgrid.org/, Access date:June 22,2010

[3] Akinyemi, I. 0, Daamola, 1. O. and Adebiyi A. A."Grid-Enabled e-Leing Fraework for NigerianEducational Institutions, Proceedings of the InteationalConference of the Nigeria Computer Socie (NCS).Volume 18,2007,pp. 91-97.

[4] Alexander Reinefeld ad Florian Schintke, "Concepts

ad Technologies for a Worldwide Grid Infrastructure,Euro-Par 22 Parallel Processing volume 24 ofLecture Notes in Computer Science, 2002,pp. 62-71.

[5] Berman, F., Fox, G., Hey, T., eds. Grid Computing:Maing the Global Infrastructure a Reality, John Wileyad Sons,Inc.,New York,2003.

[6] Chao-Tung Yag ad Hsin-Chua. " e-LeingPlatform Based on Grid Architecture Joual ofInformation Science ad Engineering Vol 21, 2005, pp.911-928.

[7] Chao-Tung Yang, Hsin-Chuan Ho, ad Chien-TungPan, "Using Grid Computing ad PVFS2 Technologies for

Construction of a e-Leing Environment, Proceedingof the Fih IEEE Inteational Conference on AdvacedLeing Technologies (CALT'05) 2005.

[8] Distance Education: Overview.http://www.uidaho.edeo/dist1.html, Access date: May13,2010.

[9] Fox, G., "Grid computing environments, Computingin Science and Engineering, Vol. 5,2003,pp. 68-72.

[10] Getting Stted with the Globus Replica Catalog.www.globus.org/toolkitdocs/2.4/datagrid/deliverables/replicaGettingStared.pdf Access date: June 20,2010.

[11] News about the globus toolkithttp://www.globus.org/toolkit Access date: June 20,2010.

[12] Jianxin C., Zenggag X. ad Xuemin Z., "Resechon a novel E-Leing architecture integrated GridTechnology, Future Information Technology andMagement Engineering,FIT 08,2008,pp. 94-97.

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A Grid-Based E-Learning Model for Open Universities