Model-Based System Development For Asynchronous Distance Learning
Journal of Distance Education Technologies, 1(4), 39-54, Oct-Dec 2003 39Model-Based System Developmentfor AsynchronousDistance LearningShu-Ching Chen, Florida International University, USASheng-Tun Li, National Kaohsiung First University of Science and Technology, TaiwanMei-Ling Shyu, University of Miami, USAABSTRACTThe innovation and diversification of development in multimedia technology and networkinfrastructures have brought a significant impact to education, especially for distance learning. This paper presents a model-based asynchronous distance learning system developmentthat consists of a presentation semantic model called the multimedia augmented transitionnetwork (MATN) model and an asynchronous distance learning system called the Java-basedIntegrated Asynchronous Distance Learning (JIADL) system. The MATN model is powerful inmodeling the synchronization and quality-of-service (QoS) for distance learning multimediapresentations. The JIADL system can support diverse asynchronous distance learning servicesby integrating RealPlayer and Java technology to augment the superiority of both models. Acourse sample is used to illustrate and validate the effectiveness of the system. How to use theMATN model to model the diversity requirements of a distance learning multimedia presentation is also discussed. Furthermore, the initial experimental results show that our system is costeffective and has a wide range of applications.Keywords: multimedia augmented transition network; distance learning; Java media frameworkINTRODUCTIONThe recent advances in multimediatechnology such as the high-speed communication networks, large-capacity storage devices, digitized media, and data compression technologies have drasticallychanged the way learners communicatewith their instructors and with each other,especially in distance education. With theinnovation of new network and Internet infrastructures and the development of mul-timedia technology, the distances perceivedby the learners have been virtually diminished and distance learning has become oneof the most interesting new directions foreducation.Multimedia information has been usedin several applications including education,computer-based training (CBT), manufacturing, medicine, entertainment, videoconferencing, etc. In particular, distancelearning has become the mainstream ofcomputer-based training and education. ForCopyright 2003, Idea Group Inc. Copying or distributing in print or electronic forms without writtenpermission of Idea Group Inc. is prohibited.
40 Journal of Distance Education Technologies, 1(4), 39-54, Oct-Dec 2003example, there are 247 articles with thedistance learning subject published on IEEE/IEE Library in 1997 and 1999(IEEELibrary), and different surveys showthat there are one million students takingdistance learning classes via the Internetand predict that the number of college students enrolled in online courses will reach2.2 million by 2002 (Syed, 2001). Moreover, the seamless integration of the overwhelming World Wide Web (WWW) andthe emerging Java technology further endorses the universal accessibility to diversedistance learning services. The former provides a cross-platform consistent visualuser interface for accessing informationwhereas the latter allows the applicationcode (applets) to be downloaded over theInternet and run on any Java-compliant Webbrowsers.In general, distance learning servicescan be delivered in three ways: synchronous (real-time), asynchronous (on-demand) and hybrid of both. Synchronous distance learning systems provide live lecturecontents as in the traditional classroom.Asynchronous distance learning systemsoffer archived lectures by using Web and/or streaming technologies and try to provide the most of the capabilities and experience that an in-class participant can haveto a remote participant. Hybrid systemssupply complementary services to thoselisted above.For the asynchronous systems, anearly development is to use television tobroadcast courses (Egan, 1993). The maindrawback of this type of television instruction is the lack of interaction between thestudents and the instructors. Later, the Webis used to support asynchronous activities.One example is to develop the online programs using Web pages to access coursematerials, announcements, and other information for a course. Another example is toprovide the online activities that includeforums, chat rooms, and emails. Also, thestudents can submit their assignmentsonline in multimedia formats and receiveonline reviews of the assignments in thesame formats from their instructors.Maly et al. (1997) proposed a synchronous distance learning system. In theirsystem, a virtual classroom is developed toallow the students to have a conventionalclassroom experience through a workstation since the students and the instructorsinteract with video conferencing. Such anenvironment incorporates an X-Windowsbased group-collaboration system calledXTV (Abdel, 1994) so that any participantcan take control of a window to multicasthis/her inputs to the distance participant.Under this environment, those tools suchas Netscape and PowerPoint can be sharedthrough a window-sharing engine. However, there are two disadvantages in suchan environment, namely speed and bandwidth. In other words, an extraordinary loadis put on the reliable multicast protocol andthe environment works only on high-speednetworks. Another system proposed inSaini (1999) studied how to immerse thestudents in a virtual environment that provides them with feedback. In their system,the student interactions are computed andthe system reacts like an educational game.However, the issue of how to share a virtual world among the students is not discussed.In this paper, we present a projectthat aims at digitizing and distributing videotapes recorded in a synchronous distancelearning classroom to improve curriculums,to provide another channel for learning, andto complement synchronous/asynchronouslearning. In order to broaden the functionsand the effectiveness of such service, anumber of interactive and cooperative services are integrated by mainly applying JavaCopyright 2003, Idea Group Inc. Copying or distributing in print or electronic forms without writtenpermission of Idea Group Inc. is prohibited.
Journal of Distance Education Technologies, 1(4), 39-54, Oct-Dec 2003 41technology, which results in the paradigmof Java-based integrated asynchronous distance learning (JIADL) system. Unlikemost related work in the literature, we integrate RealPlayer and Java technology sothat the superiority of both models can beaugmented in the JIADL system. Thisproject is supported by the Ministry of Education, R.O.C. and implemented at NationalKaohsiung First University of Science andTechnology (NKFUST).However, due to the variety of mediadata (such as video, audio, text, and imagedata) that needs to be transmitted and synchronized for multimedia presentations, adistance learning system development involving multimedia data becomes morecomplicated than the traditional system development. In addition, for a multimedia system to be useful, reliable, adaptable andeconomic, it must be based on a sound datamodel so that this model is a valuable communication tool between the system developers and the users. Hence, it will be ofgreat benefit to have a presentation modelthat can represent and model the differentrequirements for multimedia data in a distance learning system.Towards these demands, a modelbased distance learning system that consists of a presentation semantic model calledthe multimedia augmented transition network (MATN) model to model the distancelearning multimedia presentations for theJIADL system is proposed in this paper. AMATN has a finite set of nodes (states)connected by labeled directed arcs. A labeled arc represents the transition function,where an arc represents an allowable transition. The multimedia input strings that cancapture the temporal relationships of themedia streams and model the concurrentand optional displaying of the media streamsin a distance learning multimedia presentation are used as the inputs for the MATNmodel. In addition, the synchronization andquality-of-service (QoS) of each presentation are maintained by a condition/actiontable associated with a MATN. In the condition/action table, a set of conditions forthe synchronization and/or QoS is checkedfor each input symbol. Each condition hasits own set of actions. When a certain condition is satisfied, then the correspondingset of actions is activated.An example course is used to illustrate how a distance learning course canbe modeled by the MATN model in theJIADL system. The MATN model is powerful in modeling the synchronization andquality-of-service (QoS) for distance learning multimedia presentations. In addition,our initial experimental results show thatthis JIADL system that is based on theMATN semantic model is cost effectiveand has a wide range of applications.The remainder of the paper is as follows. The next section briefly describes thekernel technologies employed in developing the JIADL system.We then introducethe multimedia augmented transition network (MATN) model, the JIADL paradigmand its components, and how to use theMATNs to model distance learning multimedia presentations in the JIADL systemwith an example course. The multimediainput strings and the condition/action tablesused in the MATN model are also presented in this section. Finally, the conclusion to this paper follows.INFORMATIONTECHNOLOGIES FORJIADLJava-Centric ComputingThe Java programming language, initially designed for small consumer devices,Copyright 2003, Idea Group Inc. Copying or distributing in print or electronic forms without writtenpermission of Idea Group Inc. is prohibited.
42 Journal of Distance Education Technologies, 1(4), 39-54, Oct-Dec 2003became more prevalent when it wascoupled with the WWW for developing distribution applications including distancelearning. For example, the Virtual Laboratory at the University of Catania is developed in Java to support remote users toaccess tutorials, perform simulations, andcontrol an educational industrial system(JavaJMF). Reed and Afjeh (1998) designed and implemented a Java Gas Turbine Simulator to provide an interactiveenvironment for constructing and analyzing gas turbine systems. De Santo andChianese (Arcelli, 1998) proposed a Distributed Learning Environment SupportTool employing Java language in an intranetenvironment (Stefano, 1997). TheJavaGram application developed atClemson University allows the students toturn in their homework diagrams such asthe signal flowcharts in signal processingclasses (Patterson, 1998). The GVA system presented in Min (1998) is a Java-basedmultimedia distance education system,which provides a distance lecture environment and a study environment.Java has a number of distinct featuressuch as architecture neutrality,concurrency, distribution, user interaction,persistence, mobility, security, andinteroperability, which make it popular inmany applications. Moreover, accompaniedwith a comprehensive set of APIs, Javaoffers a potential framework for efficientlydeveloping a wide range of applications including image processing, multimedia, database management, electronic commerce,information security, telephony, embeddedsystems, to name a few. A Java industryera is expected to emerge in the near future.Streaming Archived LecturesTo transmit the archived lecture con-tents, the Java Media Framework (JMF)from SUN (JavaJMF) and RealPlayer fromReal Networks (RealPlayerJava) are twocommonly used approaches. JMF providesa platform-neutral framework for buildingmedia players and supports a variety ofmedia content types, including the high-quality MPEG-1. It specifies a unified architecture, messaging protocol and programming interface for playback, capture andconferencing of compressed streaming andstored timed-media including audio, video,and MIDI across all Java enabled platforms. On the other hand, the RealPlayerG2 supplies an efficient service for playingstreaming video (RealVideo) and audio(RealAudio) objects. Choosing MPEG orRealVideo for delivering archived lecturesis a tradeoff between network infrastructures and constraints on efficient compression. Recently, RealPlayer for Java, a wrapper around the RealSystem G2 released byReal Networks, provides a comprised solution that allows the ability to play G2 objects via the JMF API (RealPlayerJava).By utilizing RealPlayer for Java, the goalof delivering archived streaming contentsefficiently can be achieved without loss ofthe salient features of the Java computingmodel.A MULTIMEDIAPRESENTATION MODELFOR JIADLBenefits of HavingSemantic ModelsIn any software system design, it isnecessary to have a conceptual model ofthat software system provide a high-levelview of the system once the initial analysisof the user’s requirements for the softwaresystem have been identified. Such a con-Copyright 2003, Idea Group Inc. Copying or distributing in print or electronic forms without writtenpermission of Idea Group Inc. is prohibited.
Journal of Distance Education Technologies, 1(4), 39-54, Oct-Dec 2003 43ceptual model is a valuable communicationtool between the system designer, softwaredevelopers, and users since the involvingcomponents, functionalities, and relationships of the system are documented in thisconceptual model.A data model is a symbolic or abstractrepresentation of a system, which can highlight the important facts by efficiently eliminating uninteresting details. Symbols, arcsand notations are used to represent functions, objects and relationships for a system. For a trivial and small system, a conceptual model may exist only in the mindof the developer responsible for establishing the specifications since the developerunderstands the details of each function orcomponent together with the limitations,conditions, and actions. However, this doesnot work for the non-trivial systems suchas a multimedia system.A multimedia system may involve different media types such as videos, audio,images, texts, graphics, and animations. Toprovide a better multimedia system, several factors need to be considered. Forexample, the temporal relationships amongmedia streams need to be modeled. Synchronization and QoS need to be maintainedin order to have a high-quality presentation. User interactions should be providedso that the system allows two-way communications between the user and the system. User loops also need to be providedso that the users can continue watching thesame part of a presentation more thanonce.In such a non-trivial system, the system to be modeled is usually complex andmany situations need to be considered andhandled. A mental model is not suitablesince the model in the developer’s mindnormally is incomplete and imprecise.Therefore, it is necessary to establish anexplicit and precisely defined data modelat an early design stage so that the systemcan be understood.The MATN ModelThe benefits of using a semanticmodel for a software system were presented in the last subsection. Specifically,there are several factors that need to beconsidered for a multimedia presentationin a multimedia system. In order to modelthe complex multimedia presentation, weproposed to use the multimedia augmentedtransition network (MATN) model as theunderlying data model for the distancelearning multimedia presentation in theJIADL system.A MATN can be represented diagrammatically by a transition graph. TheMATN consists of a finite set of nodes(states) connected by labeled directed arcs.An arc represents allowable transition fromthe state at its tail to the state at its head,and the labeled arc represents the transition function. An input string is acceptedby the grammar if there is a path of transition that corresponds to the sequence ofsymbols in the string and leads from a specified initial state to one of a set of specifiedfinal states. Multimedia input strings areused as the inputs for the MATN model.The multimedia input strings have the capabilities to capture the temporal relationships of the media streams, and to modelthe concurrent and optional displaying ofthe media streams in a distance learningmultimedia presentation.Conditions and actions in the arcs inMATNs maintain the synchronization andquality of service (QoS) of a multimediapresentation by permitting a sequence ofconditions and actions to be specified oneach arc. The conditions are to specifyvarious situations in the multimedia presentation. A condition is a Boolean combina-Copyright 2003, Idea Group Inc. Copying or distributing in print or electronic forms without writtenpermission of Idea Group Inc. is prohibited.
44 Journal of Distance Education Technologies, 1(4), 39-54, Oct-Dec 2003tion of predicates involving the current input symbol, variable contents and the QoS.A new input symbol cannot be taken unless the condition is evaluated to true. Moreelaborate restrictions can be imposed onthe conditions if needed. For example, ifthe communication bandwidth is not enoughto transmit all the media streams on timefor the presentation, then the action is toget the compressed version of mediastreams instead of the raw data. In thisway, synchronization can be maintainedbecause all the media streams can arriveon time. In addition, QoS can be specifiedin the conditions to maintain synchronization. The actions provide a facility for explicitly building the connections among thewhole MATN. The variables are the sameas the symbolic variables in programminglanguages. They can be used in later actions, perhaps on subsequent arcs. Theactions can add or change the contents ofthe variables, go to the next state, or replace the raw media streams with the compressed ones, etc. If a condition ismatched, then the corresponding action isinvoked. Different actions can generatedifferent presentation sequences which aredifferent from the original sequence.The JIADL ParadigmThe high-level architecture of theJIADL paradigm is outlined in Figure 1.The archived lecture contents are convertedinto RealVideo files by RealEncoder in advance and are stored in the Coursewaredatabase. Mobile learners may downloadthe system applets from Web Server andretrieve the courseware of interest via theJDBC mechanism. The student databasekeeps records of students’ learning progressand personal registration information. RMIServer supports the collaborative learningin chat rooms. Currently, the platform forApplication Server, Web Server, and RMIServer is on NT4.0.There are three subsystems in theJIADL system. An example course offeredby the Center of General Education atFigure 1: The JIADL paradigmCopyright 2003, Idea Group Inc. Copying or distributing in print or electronic forms without writtenpermission of Idea Group Inc. is prohibited.
Journal of Distance Education Technologies, 1(4), 39-54, Oct-Dec 2003 45NKFUST, Science and Technology hadbeen experimented on the JIADL Paradigm. The lecture was broadcast in livevideo from NKFUST to four neighboringuniversities via three ISDN-dedicated linesat 384K. StudDBMS: Any students, including onesin the classes, can log into the JIADLsystem by registering it in advance asshown in Figure 2. The StudDBMS subsystem allows learners to query andmodify personal information besides registration. As shown in Figure 2, studentsneed to register into the system by giving personal information such as StudID, Password, Name, SSN, and so on.Three options are provided to let students register, query, or update their personal information. CourseDBMS: The CourseDBMS subsystem endows the lecturers or administrators to manage the digitizedcourseware. The control layout of theCourseDBMS subsystem is shown inFigure 3. Student ID and Password needto be specified in order for them to access the corresponding courses. CyberLearn: The CyberLearn subsystemis the kernel part of the JIADL paradigm which allows the student to browsethe static lecture notes and the corresponding video lecture. After studentsspecify their student ID, Password, andthe course information, they click on theOK button in Figure 4 to activate thenext window as shown in Figure 5. Thereare two options — Show Outline andShow Video. When the Show Outlineoption is highlighted, the lecture noteswill be displayed. The same situation applies for the Show Video option. If bothoptions are selected, both lecture notesand video (audio) lecture will be displayed synchronously. Therefore, thestudent can browse the static lecturenotes and the corresponding video lecture by simply clicking on the Play button, which results in a RealPlay windowpopped out as shown in Figure 6. As wecan see in this figure, both lecture notesFigure 2: The control layout of the JIADL StudDBMS subsystemCopyright 2003, Idea Group Inc. Copying or distributing in print or electronic forms without writtenpermission of Idea Group Inc. is prohibited.
46 Journal of Distance Education Technologies, 1(4), 39-54, Oct-Dec 2003Figure 3: The control layout of the JIADL CourseDBMS subsystemFigure 4: The control layout o the JIADL CyberLearn subsystemCopyright 2003, Idea Group Inc. Copying or distributing in print or electronic forms without writtenpermission of Idea Group Inc. is prohibited.
Journal of Distance Education Technologies, 1(4), 39-54, Oct-Dec 2003 47Figure 5: The CyberLearn subsystemand video lecture are displayed sinceboth Show Outline and Show Videobuttons are highlighted in Figure 6.Empowered by Real Player G2, thestudent is granted the capability of controlling voice and lecture progress. Furtherfunctionality like lecture clips can also beeasily implemented. One important supple-Figure 6: The archived lecture played by RealPlayer for Java.Copyright 2003, Idea Group Inc. Copying or distributing in print or electronic forms without writtenpermission of Idea Group Inc. is prohibited.
48 Journal of Distance Education Technologies, 1(4), 39-54, Oct-Dec 2003Figure 7: The whiteboard subsystem.mentary function for mobile learner is theNotes Area (the bottom area in Figure 5),in which the learner may write down thenotes and send them via the SMTP protocol. The capability of attaching MIME objects from the local learning environmentis incorporated. From the learning theory,learners of distance learning are not expected to sit still and stare at the lecturesconsistently. To improve the learning performance, an interactive multi-userchatroom and a collaborative real-timewhiteboard are offered, which are basedon the Java RMI-distributed computingmodel. Figure 7 depicts the layout of suchservices, where a number of vivid imagescan be added into the whiteboard.USING MATNS TO MODELDISTANCE LEARNINGMULTIMEDIAPRESENTATIONSA MATN consists of nodes (states)and arcs. Each state has a state name andeach arc has an arc label. Each arc labelrepresents the media streams to be displayed in a time duration. Therefore, timeintervals can be represented by transitionnetworks. In this transition network, anew state is created whenever there is anychange of media streams in the presentation. There are two situations for the changeof media streams:1) Any media stream finishes to display;2) Any new media stream joins to display.Figure 8 is a timeline to represent themultimedia presentation for Figure 6. In thisexample, part of the presentation is depictedfor simplicity. There are four time instants(t1 to t4) and three time durations (d1 tod3). There are three occurrences of mediastream combinations at each time duration:1) Duration d1: V1, A1, and T1.2) Duration d2: V2, A2, and T2.3) Duration d3: V3, A3, and T3.Figure 9 is a transition network forFigure 8. There are four states and threearcs which represent four time instants andCopyright 2003, Idea Group Inc. Copying or distributing in print or electronic forms without writtenpermission of Idea Group Inc. is prohibited.
Journal of Distance Education Technologies, 1(4), 39-54, Oct-Dec 2003 49Figure 8: Timeline for the distance learning multimedia presentation as shown in Figure 6three time durations, respectively. Statenames are in the circles to indicate presentation status. State name P/ means the beginning of the transition network (presentation) and state name P/X1 denotes thestate after X1 has been read. The reasonto use Xi (i 1, 2, 3) is for conveniencepurposes. In fact X1 can be replaced byV1*& A1*& T1*. State name P/X3 is the final state of the transition network to indicate the end of the presentation. State P/Xi represents presentation P just finishesto display Xi and the presentation can proceed without knowing the complete historyof the past.Each arc label Xi (i 1, 2, 3) in Figure 9 is created to represent the mediastream combination for each duration asabove. For example, arc label X1 representsthat media streams V1, A1, and T1 displaytogether at duration d1. A new arc is created when new media streams V1, A1, andT1 display. A multimedia input string is usedas an input for this transition network, andFigure 9: Augmented transition network for multimedia presentation as shown in Figure 8Copyright 2003, Idea Group Inc. Copying or distributing in print or electronic forms without writtenpermission of Idea Group Inc. is prohibited.
50 Journal of Distance Education Technologies, 1(4), 39-54, Oct-Dec 2003the symbol “&”‘ between media streamsindicates these two media streams are displayed concurrently. A multimedia inputstring consists of several input symbols andeach of them represents the media streamsto be displayed at a time interval.When an ATN is used for languageunderstanding, the input for the ATN is asentence which consists of a sequence ofwords with linear order. In a multimediapresentation, when user interactions suchas user selections and loops are allowed,we cannot use sentences as inputs for anATN. In our design, each arc in a MATNis a string containing one or more mediastreams displayed at the same time. Amedia stream is represented by a lettersubscripted by some digits. This single letter represents the media stream type anddigits are used to denote various mediastreams of the same media stream type.For example, T1 means a text media streamwith identification number one. A multimedia input string consists of one or moremedia streams and is used as an input for aMATN. Multimedia input strings adopt thenotations from regular expressions. Regular expressions (Kleene, 1956) are usefuldescriptors of patterns such as tokens usedin a programming language. Regular expressions provide convenient ways of specifying a certain set of strings. In our framework, multimedia input strings are used torepresent the presentation sequences of thetemporal media streams. A multimedia input string goes from the left to right, whichcan represent the time sequence of a multimedia presentation as shown in [1].Multimedia input string:(V2*&A2*&T2*)(V3*&A3*&T3*)(V 1 * &A 1 * &T 1 * )(1)In (1), the “&” between two mediastreams indicates these two media streamsare displayed concurrently. The “*” sym-bol is used to indicate the media streamwhich can be dropped in the on-line presentation. For example, V1*&A1*&T1* represents media streams V1, A1, and T1 beingdisplayed concurrently, but each of themcan be dropped if Show Outline and/orShow Video buttons are not highlighted.Table 1 shows a simple example of acondition/action table. A condition/action(transition) table in the MATN can be usedto control the synchronization and qualityof-service (QoS). The first column in thistable contains the input symbols. The second and third columns show the conditionsand the actions, respectively. When the current input symbol V1*&A1*&T1* is read, thecondition is to check whether the pre-specified presentation duration to display V1, A1,and/or T1 is reached. If it is not, the displaycontinues. The start time (stime) is definedto be the time starting the display of V1, A1,and/or T1, and the difference between thecurrent time (ctime) and the start time isthe total display time so far. The secondcondition is met when the total display timeis equal to the pre-specified duration. Inthis case, a next input symbol V2*&A2*&T2*is read. Conditions three to five are usedto check whether Show Outline and/orShow Video buttons (as shown in Figure5) are highlighted or not. The corresponding actions will be performed for each condition. Synchronization can be maintainedby specifying the detailed control in theactions. For simplicity, details are skippedin this paper. Similarly, the process continues until the final state is reached.PERFORMANCEEVALUATIONTable 2 shows the performanceevaluation of streaming archived lecturesin terms of the packet statistics of streams.Copyright 2003, Idea Group Inc. Copying or distributing in print or electronic forms without writtenpermission of Idea Group Inc. is prohibited.
Journal of Distance Education Technologies, 1(4), 39-54, Oct-Dec 2003 51Table 1: Condition/action table: D(Xi) is the pre-specified presentation duration for Xi (i 1, 2, 3). Display procedure is to display the media streams. Get Symbol is a procedure toread the next input symbol of multimedia input string. Next State is a procedure toadvance to the next state in MATN.InputSymbolsConditionIf ctime-stime(X1) D(X1)If ctime-stime(X1) D(X1)If Show Outline X1true & Show Video false(V1*&A1*&T1*) If Show Outline false & Show Video trueIf Show Outline true & Show Video trueIf ctime-stime(X2) D(X2)If ctime-stime(X2) D(X2)If Show Outline X2true & Show Video false(V2*&A2*&T2*) If Show Outline false & Show Video trueIf Show Outline true & Show Video trueIf ctime-stime(X3) D(X3)If ctime-stime(X3) D(X3)If Show Outline X3true & Show Video false(V3*&A3*&T3*) If Show Outline false & Show Video trueIf Show Outline true & Show Video trueActionContinueGet Symbol andNext StateDisplay T1Display V1 and A1Display V1, A1, and T1ContinueGet Symbol
In general, distance learning services can be delivered in three ways: synchro-nous (real-time), asynchronous (on-de-mand) and hybrid of both. Synchronous dis-tance learning systems provide live lecture contents as in the traditional classroom. Asynchronous distance learning systems offer archived lectures by using Web and/
Bruksanvisning för bilstereo . Bruksanvisning for bilstereo . Instrukcja obsługi samochodowego odtwarzacza stereo . Operating Instructions for Car Stereo . 610-104 . SV . Bruksanvisning i original
10 tips och tricks för att lyckas med ert sap-projekt 20 SAPSANYTT 2/2015 De flesta projektledare känner säkert till Cobb’s paradox. Martin Cobb verkade som CIO för sekretariatet för Treasury Board of Canada 1995 då han ställde frågan
service i Norge och Finland drivs inom ramen för ett enskilt företag (NRK. 1 och Yleisradio), fin ns det i Sverige tre: Ett för tv (Sveriges Television , SVT ), ett för radio (Sveriges Radio , SR ) och ett för utbildnings program (Sveriges Utbildningsradio, UR, vilket till följd av sin begränsade storlek inte återfinns bland de 25 största
Hotell För hotell anges de tre klasserna A/B, C och D. Det betyder att den "normala" standarden C är acceptabel men att motiven för en högre standard är starka. Ljudklass C motsvarar de tidigare normkraven för hotell, ljudklass A/B motsvarar kraven för moderna hotell med hög standard och ljudklass D kan användas vid
LÄS NOGGRANT FÖLJANDE VILLKOR FÖR APPLE DEVELOPER PROGRAM LICENCE . Apple Developer Program License Agreement Syfte Du vill använda Apple-mjukvara (enligt definitionen nedan) för att utveckla en eller flera Applikationer (enligt definitionen nedan) för Apple-märkta produkter. . Applikationer som utvecklas för iOS-produkter, Apple .
och krav. Maskinerna skriver ut upp till fyra tum breda etiketter med direkt termoteknik och termotransferteknik och är lämpliga för en lång rad användningsområden på vertikala marknader. TD-seriens professionella etikettskrivare för . skrivbordet. Brothers nya avancerade 4-tums etikettskrivare för skrivbordet är effektiva och enkla att
Den kanadensiska språkvetaren Jim Cummins har visat i sin forskning från år 1979 att det kan ta 1 till 3 år för att lära sig ett vardagsspråk och mellan 5 till 7 år för att behärska ett akademiskt språk.4 Han införde två begrepp för att beskriva elevernas språkliga kompetens: BI
**Godkänd av MAN för upp till 120 000 km och Mercedes Benz, Volvo och Renault för upp till 100 000 km i enlighet med deras specifikationer. Faktiskt oljebyte beror på motortyp, körförhållanden, servicehistorik, OBD och bränslekvalitet. Se alltid tillverkarens instruktionsbok. Art.Nr. 159CAC Art.Nr. 159CAA Art.Nr. 159CAB Art.Nr. 217B1B
