S odeh+S Abu Shanab 2009 UBICC Journal 306 306 by tabindah


More Info

                                            Salaheddin Odeh
    Department of Computer Engineering, Faculty of Engineering, Al-Quds University, Abu Dies, Jerusalem,

                                         Shatha Abu Shanab
Electronic and Computer Engineering Master Program, Faculty of Engineering, Al-Quds University, Abu Dies,
                                          Jerusalem, Palestine

               In engineering and science education, laboratories represent an essential part of the
               study curriculum, and studies are incomplete if laboratories are not present.
               Laboratories cover the practical side of engineering studies, through which
               students can improve their theoretical knowledge as a stable basis to strengthen
               their skills required for enabling them to deal with any real problem in the future
               after graduation. This research tries to realize the idea of combining internet
               laboratories with augmented reality. This is what we can designate as an
               Augmented Reality Internet Laboratory (ARI-Lab). Definitively, augmented
               reality is to combine the interactive real world with a generated world by an
               interactive computer system in such a way that they appear as one environment. It
               shows the real world with an overlay of additional information so that the user can
               not distinguish between the real world and the virtual augmentation [1], [2]. In our
               consideration, a web-based remote experimentation using augmented reality is
               achieved through the facts that students can carry out an engineering experiment
               represented by real and virtual elements, components and equipments, through
               overlaying real kits with virtual (graphical) objects. AR technologies make
               possible the interaction between students and the graphically represented remote
               experiment to be no longer restricted in a face-to-screen fashion; rather it will be
               strived to dissolve students in a remotely located real environment laboratory. A
               number of modern laboratory instruments and equipments can only not be
               controlled and accessed interactively, but rather more through special kind of
               interfaces as well, enabling us to control and to implement the experiment via the
               internet. In this contribution, it will be shown how we can design, develop and
               implement an interactive web-based ARI-Lab.

               Keywords: Augmented Reality (AR), human-computer interaction, experimenting
               kit, remote laboratories, distributed systems, usability testing, C# and .NET.

1   INTRODUCTION                                            interaction between students and instructors.
                                                            Simulator programs serves as a supportive
     The main goal of an engineering or a science           complementary for traditional laboratories and could
laboratory is to provide students with the practical        not be replaced by face-to-face laboratory rooms.
skills through experimenting with real devices and               Nowadays, the creation of remote laboratories
instruments [3], offering them a complete learning,         that students can access at any time and from any
which consists of a mixture of theoretical and              place is possible through the facts that internet
practical sessions for enabling them to deal with and       technologies offer a new education and training
to solve any real world problem after graduation. In        system and contemporary laboratory instruments
recent time, the usage of laboratory simulator              already support remote control via the internet.
programs has been increased rapidly. Although               Conventional experimentation has several constraints
students can build their circuits and test it by these      left unsolved. For example, time restriction
programs, simulator programs are mostly based on            constraints organizing for evening part-time students,
mathematical models characterized by giving                 resource intensiveness increases teaching costs to
inaccurate real calculations, dealing with graphically      operate conventional labs requiring equipments,
or virtually represented equipments, and lacking of         space, manpower, safety etc., time limitation

                     Ubiquitous Computing and Communication Journal                                             1
complicates course organization around an               2   AUGMENTED REALITY: DEFINITION,
experiment, and last, but not least, using shared           COMPARISON AND APPLICATIONS
equipments leads to the so-called “Driver-passenger”
syndrome. By contrast, there are several advantages          Definitively, augmented reality is the
of the internet remote experimentation such as          combination of the interactive real world with an
solving most of above problems, accessing the           interactive computer-generated world in such a way
remote experimentation through a standard web           that they appear as one environment, such that the
browser anytime and anywhere, and manual                user can’t distinguish between the real world and the
procedures etc. are also available and accessible at    virtual augmentation [1], [2]. While AR augments
the same time.                                          the user's view of the real world by composing
                                                        virtual objects with their real world counterparts,
     Apart from these benefits, there are several       necessitating that the user maintains a sense of
complicating factors in the architecture of remote      presence in that world, Virtual Reality immerses a
environments such as time-, transmission- and           user inside a virtual world that completely replaces
operation delays as well as incomplete feedback.        the real world outside [1], [2]. It breaks the physical
Additionally, there are many devices originally         limitations of space and allows users to act as though
designed for direct control, and thus do not have       they were somewhere else [9]. It is to note that
adequate sensors or status information so that its      mixtures of the two approaches are possible,
integration in remote experiment requires an            depending on the application field to be manipulated.
additional efforts and costs.                           Fig 1 classifies AR on the reality virtually (RV)
     Unfortunately, most of remote laboratories         continuum dimension.
represent its instruments and equipments graphically,        In recent years, AR has been successfully
leading to decrease the reality environment of remote   applied in various fields. One of the applications of
labs [3], [4]. This research tries to compensate this   AR is to provide visualization of hidden
lack of information visualization by augmented          objects [1], [2], [8], [10]. In the following, we are
reality (AR). Rather than showing either the actual     going to mention some examples, where AR has
world or a virtual world, augmented reality shows       been successfully applied.
the real world with an overlay of additional
information so that the user can’t distinguish
between the real world and the virtual
augmentation [1], [2]. Nowadays, augmented reality
technology offers new applications in the human life
in many forms. It may range from medical and
military systems [5] to applications for
entertainments [6], manufacturing, maintenance, and         Figure 1: Reality Virtually (RV) Continuum [6]
repair [7]. Analyzing and understanding how AR has
been implemented and applied, can, therefore, be of     •   Process control [11]: Video information is used
great significance regarding contributing of newer          as sensor data to control process variables that
ideas to applying AR in internet laboratories.              are difficult to measure. Operators use real-life
     This paper shows the techniques and methods            process pictures along with an overlay of signal
necessary to apply AR to internet laboratories for          values visualized by virtual objects to control
achieving web-based remote experimentation based            the technical process. The interfering between
on augmented reality or augmented reality internet          video pictures and signal values is what makes
laboratories. That is, students can carry out an            the system AR.
engineering experiment represented by real and          •   Medical systems [12]: AR systems create 3D
virtual elements, components and equipments,                volume visualizations from CT (computerized
through overlaying real kits with virtual (graphical)       tomography) or MRI (magnetic resonance
objects. The combined objects consisting of both            imager) data for surgery. AR systems can view a
computer graphics of electronic elements and real           volumetric rendered image of the fetus overlaid
electronic elements are familiar to students. An ARI-       on the abdomen of the pregnant woman or
Lab is a system composed of hardware and software           present an overlay of an acoustic neuroma after
components that enable students to perform their            resection, showing how it had entered the
experiments via conventional web browser so that            internal auditory meatus.
students can independently learn from time and place.   •   Military systems [5]: AR systems display
                                                            information to the pilot on the windshield of the
                                                            cockpit or the visor of their flight helmet.
                                                            Solders receive information about their
                                                            environment (e.g. locations of friends and foes)

                    Ubiquitous Computing and Communication Journal                                           2
     and information that helps them to coordinate         equipments overlaid on real-time video of the
     their locations.                                      experimental kit is what makes our distance learning
 •   Entertainment [6]: AR can be applied to enhance       environment      augmented-realistic,     aiming     at
     games that people play. The image that the            providing engineering students a quasi real
     players see is not only of the game area and their    environment lab.
     real opponents but virtual players are also                The application server (Fig. 2) is responsible for
     playing along with them.                              the application processing and data management,
 •   Manufacturing, Maintenance and Repair [7]: For        where as a client runs the representation software,
     manufacturing, maintenance and repair, AR             the web-based AR user-interface. The best
     systems insert additional information into the        architectural model for describing the order of these
     field of view such as outputting labels displayed     distributed subsystems is the thin-client model [13].
     at parts of a system and along with operating         By contrast, in the fat-client model, the server
     instructions while repairing a system by a            undertakes only the data management and the client
     mechanic.                                             software implements the application logic and the
                                                           interaction with the users. The events for controlling
 3   DISTRIBUTED SYSTEM ARCHITECTURE                       the system could be either interactive commands
                                                           entered by the students or control signals given by
      Distance laboratories enable remotely located        the experimental kit on its interface. That is, our
 students to complete lab experiments unconstrained        system is categorized as an event-processing system.
 by time or geographical considerations. They have              The architecture proposes that our distributed
 the opportunity to practice their experimental            application should be made of these components (Fig.
 laboratory by obtaining live data in real time similar    2):
 to face-to-face classroom lab. In addition to the
 ability that an ARI lab offers students the possibility   3.1    Web server
 to experiment real-time labs remotely from any place          The web server is the communication
 and at any time [10], it presents the experimental kit    middleware over the internet between the clients (the
 through real videos combined with an overlay of           students) and the remote experiment, whose
 virtual objects. However, in our approach, setting up     visualization on the client side bases on the
 computer graphics of electronic elements and              augmented reality technology. A web browser serves
                                                           as mediator between the implementing student and

Figure 2: System architecture of the augmented reality environment for web-based remote experimentation

                      Ubiquitous Computing and Communication Journal                                            3
the lab server, representing the central unit of the e-   describes how the web-based AR user-interface
learning environment and functioning along with the       allows students to control the experiment kit and
web server as a coordinator between the various           instruments remotely through operating the virtual
components.                                               elements presented on the live-video frame, causing
                                                          real responses of the remote physical experiment to
3.2     Lab Server and remote experiment                  be transferred back to client; thus, students feel as
     At the server end, laboratory instrumentations       being in the real class room lab.
and the experimenting kit are connected to the server          Another functionality of the lab server is to
designated here as lab server. The lab server             mange and to schedule students' accesses into the
communicates with the web server to exchange data         system. On the lab server, every registered student
with the remote distributed clients via the internet.     has an account, in which his/her login name and
As      previously   discussed,   internet    remote      password, results and marks of the experiment
experimentation are aimed at using of real                quizzes and tests, schedule data of accessible time
instruments and equipments in laboratories instead of     are stored. When a student tries to access to the
simulations. Fortunately, most of the current             experiment, the management and the schedule
instrumentations such as oscilloscopes and                component examines whether he/she is allowed to do
multimeters are provided with control through PCI         this according to a schedule time-table. Moreover,
GPIB (General Purpose Interface Bus) card and             this component manages the registration procedures
GPIB cable [14], allowing PCs to communicate with         of the students for enabling them to execute the
over 2000 instruments made by over 200                    experiment. The entered data will be temporarily
manufacturers. This technological progress is what        stored and after its verification by the experiment
makes internet remote experimentation possible            administrator, it will be stored in the database
because of the facts that these instruments make          permanently. The system informs the students about
measured values available for other systems sharing       the failure or the success of their registration
the same GPIB. The main purpose of the general            attempts by email confirmations. Once the login
purpose-interface bus (GPIB) is to send information       name and password entered by a student are correct,
between two or more devices. An internet remote           the lab server establishes a connection between the
experiment can be any one of engineering or science       user-client and the remote experiment. Students and
labs covering topic related to electric circuits or       instructors have different web-based user interfaces
electronics consisting of resistors, capacitors,          tailored to their special needs.
inductors, electromechanical modules and so on. One
drawback the expansion of conventional experiments        3.3    User Client: a web-based AR user-interface
is time and cost intensive is because remote                   One important goal of this research project is to
experiment designers have to reform and expand            access the web-based AR lab through the internet via
conventional experiments for allowing them to be          a conventional web browser such as Microsoft
easily integrated in contemporary remote e-               Internet Explorer and Netscape, providing a suitable
laboratories.                                             mean for data exchange between the user-interface
     Before sending any data, GPIB devices must be        and the lab server. When a student activates the URL
configured to send the data in the proper order and       address of the web-based AR lab, the web browser
according to the proper protocol. The electrical          loads the start web-page of the experiment lab, which
specifications as well as the cables, connectors,         encompasses an authentication page for entering the
control protocol, and messages required to allow          system through a correct user name and password.
information transfer between devices are defined by            When designing the web-based AR interface,
the IEEE-488 standard [15]. For instance, by              various human-computer interaction rules for user-
chaining IEEE-488 cables from one device to the           interface design have to be taken into account. These
next, it is possible to connect up to 14 devices          are consistency of data display (labeling and graphic
together. IEEE-488 supports data transfer at up to 1      conventions), efficient information assimilation by
Mbytes/sec. In addition to simple data transfers, the     the user, minimal memory load on user,
IEEE-488 standard defines a number of specialized         compatibility of data display with data entry,
commands for interface programming in the form of         flexibility for user control of data display,
subroutines available as programming libraries for        presentation of information graphically where
different programming languages such as C, Pascal,        appropriate, standardized abbreviations, presentation
C# etc.                                                   of digital values only where knowledge of numerical
     Augmented reality interfaces for web-based           value is necessary and useful [16].
remote experimentation demand real-time videos                 In the section "User-Interface and Experimental
combined with virtual user-interface objects.             Kit Development" it will be shown, how students
Therefore, a high quality web-cam is necessary to         interactively implement the electronic circuit via the
send real-time video of the experiment to give            AR lab interface managed by a conventional web
realistic feedback for the students. Next section         browser. The interaction between the students and

                     Ubiquitous Computing and Communication Journal                                           4
the user-interface takes place visually and through an   5    USER-INTERFACE AND EXPERIMENTAL
interaction device such as keyboard and mouse.                KIT DEVELOPMENT
                                                              As previously discussed, on the augmented
3.4    E-Instructor                                      reality web-based user-interface, video-captured
     Students might connect sensitive circuit            images are used along with graphical objects, so that
elements such as ICs with power supply elements          users can not differ between the real world and the
falsely, causing these components to get damaged.        virtual augmentation [1], [2]. Since we deal with
As such, there is a need to provide the system with a    remote e-laboratories for teaching the practical side
further software component, which protects the           of engineering or science studies to strengthen the
system from damage in that it prevents dangerous         students' skills required after graduation, the
circuit configurations like short circuits or unwanted   techniques and the methods for developing and for
high power connections. Since this software              designing augmented reality web-based user-
component undertakes some activities of a human          interfaces discussed here can be used to present any
instructor, it could be designated as e-instructor. In   one of engineering or science labs covering topic
the future, the e-instructor can be expanded to a        related to electric circuits, electronics, mechanics etc.,
simplified rule-based system, embracing conditional      in the form of mixed virtual and real (video-
rules in the form "if-then" about the correct            captured) laboratories' elements. These can not only
experiment configuration. Johannsen [17] expanded        be simple elements such as resistors, capacitors,
the rule-based system architecture presented by          inductors, electromechanical modules, but also more
Raulefs [18] with additional components that are         complicated units such as oscilloscopes, DDMs,
what makes a rule-based system to be embeddable in       function generators as well. Fig. 3 illustrates a
a real-time system. The e-instructor evaluates the       prototype of the augmented reality web-based user-
rules cyclically to react in according to students'      interface, presenting an experiment about the series
implementations on the experimental kit.                 resonant circuit presented in Fig. 4. Additionally, the
                                                         circuit shows how several instrumentations are
4     SYSTEM REQUIREMENTS AND DESIGN                     implemented to measure the desired voltage and
                                                         current signals.
Sommerville [13] notes that, in most cases, the               One reason the circuit example selected is very
requirements and design issues of research projects      simple is that our concern is to mediate the features
are uncertain; therefore, while developing and           and functionalities of the user-interface and its
implementing the system, we have followed the            experimental kit:
prototyping approach. The system software and
hardware crystallize incrementally within an iterative   •   The circuit-board image is captured by a video
process, in which each increment includes new                camera and processed by a video server in real
system functionality. In the iterative process, the          time. On the circuit board, some of the RCL
stages: specification, design, development, and              circuit elements (resistor R and capacitor C) are
testing are not chained, but rather interleaved and          already installed.
concurrent.                                              •   The other circuit element (inductor L), which
     From Fig. 2, the augmented reality environment          does not exist on the circuit board, can be
for web-based remote experimentation is not only             graphically selected by means of a graphical
composed of pure technical software and hardware             component bar and then can be placed on the
components, but it encompasses ergonomic                     circuit board. In the bar, more than one resistor,
aspects [19] for allowing effective human-computer           capacitor, inductor, etc., are possible to be
interaction [16]. The user-interface plays a central         selected by the experimenting student,
role for obtaining a harmonic interaction with the           depending on his decisions or calculations
whole lab, necessitating to create it with an                required in the experiment. Visually, the
interactive development system like Microsoft                students must be able to distinguish between the
Visual Web Developer 2005 Express Edition along              real and virtual experimental elements. The
with these tools: Microsoft Visual C# 2005 Express           computer graphics or virtual objects are
Edition [20], Microsoft SQL Server 2005, Web                 overlapped on the circuit-board image and are
Server: IIS (Internet Information Service), as well as       displayed to the user.
Web Development. All these tools are integrated in a     •   The instrumentations such as oscilloscopes and
convenient developmental .Net environment with               multimeters visualized on the augmented reality
powerful user-interface tools and rich libraries for         user-interface can be both real and virtual
creating user-interface components to enable data to         (graphical). Real-time video-captured images
be displayed in many forms.                                  are used to visualize the remote real
                                                             instrumentations,      whereas     the     virtual
                                                             equipments are shown by computer graphics. In
                                                             case of remote real instrumentations, the

                     Ubiquitous Computing and Communication Journal                                              5
    Figure 3: Prototype of the augmented reality web-based user-interface
       measured values are visually mediated to the         •     Layered mask: On the graphical user-interface,
       students through translated video-captured                 an additional layer consisting of the virtual
       images. By contrast, the virtual instrumentations          highlighted circles positioned exactly on the
       on the user-interface receive their values from
       the lab server measured by the equivalent
       instrumentations made their measured values
       available for other systems sharing the same
•      For wiring the electronic elements together and
       connecting the circuit board with the
       instrumentations, a wiring and connecting tool
       realized as a pop-up menu can be used. The pop-
       up menu offers various types of wires and
       cables. The color and width properties are

    The connection locations on the circuit board as
well as the inputs and outputs of the instrumentations
are marked with highlighted circles. There are two
approaches to recognize these locations:                        Figure 4: A series resonant circuit.
•      HSL filter: In this image processing approach,             connection points will be placed. The layered
       an image processing filter, the HSL filter [21] is         mask is transparent unless the highlighted color-
       used. A unique color such as pink marks these              edged circles.
       locations physically. The HSL filter removes all
       pixels in the image except the pink-marked               The latter technique is superior to the first one
       color-filled circles, whose x y positions can be     because, on the one hand, the HSL filter is noise
       easily determined by the software.                   sensitive, and, on the other hand, every connection

                       Ubiquitous Computing and Communication Journal                                            6
location in the experimental kit must be physically         processing and data management is carried out on
marked with a color-filled circle. These difficulties       our application server and the representation
will not occur when using the second approach since         software interacts with the users, enabling them to
the mask layer is a pure software-technical                 perform on real (physical) experiments remotely
implementation. One drawback of the layered mask            whenever they want and anywhere they are. The
approach is the circuit board and the                       user-interface represents the remote experimental kit
instrumentations visualized as video-captured images        using a mixture of virtual and real (video-captured)
have to be fixed and are not allowed to be shifted          objects and the students can connect these objects by
because this impairs the adjusted positions of the          means of various virtual wire and cables interactively
virtual edged circles on the connection points.             (see Fig. 3). For example in Fig. 3, the experimenting
                                                            student is placing a virtual inductor L on the circuit
     If the mouse cursor moves on such circles, the         board, where two circuit elements, the capacitor C
software recognizes the corresponding connection            and the resistor R, are already configured. A
through its x y positions. If the wiring and                graphical component bar will graphically offer the
connecting mode is selected and the student moves           virtual components.
the cursor while pressing the left button of the mouse,          Virtual components on the user-interface can be
a connection between the desired locations is               placed on the circuit board to connect them with
graphically created. After proving the correctness of       other elements to achieve a certain circuit
the created connection by the e-instructor, the server      configuration. Once such an element is placed on the
connects the equivalent switches in the remote              circuit board, the connectors of the corresponding
experimental kit (see Fig. 5).                              physical element in the kit configuration will be
     As mentioned, the system architecture of the           connected. For instance, after placing the graphically
web-based augmented reality laboratory follows the          represented inductor L on the experimenting field of
thin-client model because all of the application            the user-interface, the switches S41 and S42 will be

      Figure 5: The circuit configuration of the experimental kit located on the application side

                     Ubiquitous Computing and Communication Journal                                             7
closed, making this element connectable to other          •   Sub-session 2: web-based virtual reality
circuit elements through the grid.                            interface
     It is noted that the software program can control    •   Sub-session 3: actual reality experiment (face-to
the IEEE-488 instrumentations sharing the same                face)
GPIB. The input of the oscilloscope is connected
with the resistor R to show the signal curve of the            The different realities represent the independent
voltage. The elements R, C and L are connected with       variables, whereas the evaluation criteria such as
each other in such away to achieve the series             transparency, navigation etc., serve as dependent
resonant circuit.                                         variables. It is of enormous importance to find out
     Given these facts illuminated, the experimental      the features shared between the different
kit must be in a position to receive these commands       environments to use as evaluation criteria. Some
and to response accordingly. That is, if the student      aspects to measure are to what extent the following
intends to connect two objects or to place a virtual      characteristics are realized: abstract versus concrete,
object on the user-interface, in the experimental kit,    user-centered versus techniques-oriented, transparent
the equivalent physical objects must be activated         versus unintelligible, incomplete versus complete
through connecting them or making them available          feedback etc.
for further connecting. Fig. 5 shows the circuit of the        The Student's test (t-test) or one-way ANOVA
experimental kit represented to the students by the       are suitable means for comparing mean values of two
web-based       augmented      reality   user-interface   sets of numbers to obtain an overview of the
illustrated in Fig. 3. The lab server translates the      statistical significance of means' differences. While
virtual connections implemented on the user-              carrying out a usability testing experiment, the
interface to real connections through closing the         usability engineer clarifies a subject all operations
equivalent switches in the kit. From Fig. 5, a            related to the experiment and the interfaces. The
programmable grid, consisting of horizontal and           usability engineer can handle the raw data of the
vertical lines, can connect all components of the         experiments statistically using the Student's test (t-
experimental kit with each other. Each crossing           test) [24] and then analyze the outcome by SPSS [25].
vertical and horizontal lines can be connected            The statistical result should be analyzed and
together via controllable switch. For example, to         reviewed by the usability engineers and the system
connect resistor R with the capacitor C (connectors       designers, so that the final results helped in revising
c1 and c3, the highlighted two switches (Fig. 5) must     and optimizing the design of the interactive software
be closed.                                                system on the one hand; and the system designers
                                                          could have defined new or corrected existing design
6   USABILITY TESTING                                     guidelines for future systems on the other hand.

     After implementing the web-based ARI lab, an         7   CONCLUSION
extensive evaluation to expose the strengths and
weaknesses of augmented reality user-interfaces for            It has been shown how augmented reality can be
web-based remote experimentation will be carried          applied to internet laboratories through combing the
out. In this research, the methods and techniques for     interactive real world with an overlay of virtually
evaluating of e-learning software for school students     represented information such so that they appear as
in primary stages can be adopted [22]. For                one environment. Video pictures of real kits will be
comparing our system adapting the augmented               overlaid with virtual (graphical) objects of electronic
reality with other systems implemented within the         elements       and     instrumentations.      Through
actual or virtual reality, the students must interact     conventional web browsers, students can perform
with these systems. A session represents one of the       their experimental laboratories and obtain the live
three different environments: (actual, virtual and        data in real time, resembling face-to-face classroom
augmented), in which the same scenarios will be           laboratories. For developing the software for the
offered to the students to cope with [23]. In order to    web-based remote experimentation using augmented
avoid possible learning effects caused by holding the     reality, contemporary development environments
same sequence of the scenarios, every student gets a      such as .NET are used; thus, the software can be
different order of the scenarios. This phenomenon         easily adapted to other platforms. Placing of
appears also while holding the same order of the          graphical objects such as electronic elements and
environments for all subjects. As such, the usability     modules on the experimenting field of the user-
engineer must permutate their order.                      interface causes connectors of the corresponding
     Every subject (student) carries out the              physical elements to become closed.
experiment in three different sub sessions:                    After completing building and implementing the
                                                          whole system, we expect various results to be
•   Sub-session 1: web-based augmented reality            achieved such as: putting up students in real
    interface                                             environment laboratories, preserving equipments

                     Ubiquitous Computing and Communication Journal                                            8
from getting damaged, providing safer experimental            visualization techniques for process S&C, Proc.
environments for students, saving money through               IEEE International Conference on Systems,
reducing the numbers of instructors and equipments,           Man and Cybernetics, Le Touquet, France, 367-
and last but not least increasing collaboration               372, 1993.
between students and instructors because accessing     [12]   F. P. Vidal, F. Bello, K. W. Brodlie, N. W. John,
an experiment takes place at anytime and from                 D. Gould, R. Phillips & N. J. Avis, Principles
anywhere.                                                     and applications of computer graphics in
                                                              medicine, Computer Graphics Forum, Vol. 25,
8   REFERENCES                                                Issue 1, pp. 113-137 (2006).
                                                       [13]   I. Sommerville, Software Engineering (8th
[1] J. R. Vallino: Interactive Augmented Reality,             Edition), Addison Wesley (2007).
     doctoral diss., University of Rochester, New      [14]   IEEE 488.1-2003: Standard for Higher
     York (1998).                                             Performance Protocol for the Standard Digital
[2] T. Nilsen, S. Linton, J. Looser: Motivations for          Interface for Programmable Instrumentation,
     augmented reality gaming, Proc. the New                  IEEE Instrumentation and Measurement
     Zealand Game Developers Conference, New                  Society (2003).
     Zealand, pp. 86-93 (2004).                        [15]   CEC, CEC 488 programming and reference,
[3] S. Das, L. N. Sharma, A. K. Gogoi: Remote                 Part number 370966A-01 (2003).
     Communication Engineering Experiments             [16]   B. Shneiderman, C. Plaisant, Designing the
     Through Internet, International Journal of               User Interface: Strategies for Effective Human-
     Online Engineering, Vol. 2, No. 1 (2006).                Computer Interaction (4th Edition). Addison
[4] A.      Bischoff,      C.     Rohrig:     Remote          Wesley Longman (2004).
     Experimentation in Collaborative Virtual          [17]   G. Johannsen: Mensch-Maschine-Systeme,
     Environment, rep., Department of Electrical              Berlin: Springer (1993).
     Engineering, University of Hagen, Germany         [18]   P. Raulefs: Expertensysteme, Kuenstliche
     (2001).                                                  Intelligenz, Informatik-Fachbereiche, W. Bibel,
[5] J. Juhnke, T. Mills, J. Hoppenrath: Designing             J. H. Siekmann (Ed.), Proc. 59, Berlin: Springer,
     for augmented cognition - problem solving for            pp. 61-98 (1982).
     complex environments, Foundations of              [19]   N. A. Streitz: Cognitive compatibility as a
     Augmented Cognition, Berlin: Springer-Verlag,            central issue in human-computer interaction:
     pp. 424-433 (2007).                                      Theoretical framework and empirical findings,
[6] C. E. Hughes, C. B. Stapleton, D. E. Hughes, E.           Cognitive engineering in the design of human-
     M. Smith: Mixed Reality in Education,                    computer interaction and expert systems, in G.
     Entertainment, and Training, IEEE Computer               Salvendy (Ed.), Amsterdam: Elsevier, pp. 75-
     Graphics & Applications,Vol. 25 Issue 6, pp.             82 (1987).
     24-30 (2005).                                     [20]   H. M. Deitel, P. J. Deitel: C# for programmers
[7] N. Navab: Developing killer apps for industrial           (2nd edition). Prentice Hall (2006).
     augmented reality, IEEE Computer Graphics &       [21]   Z. Li, M. S. Drew: Fundamentals of
     Applications,Vol. 24 Issue 3, pp. 16-20 (2004).          Multimedia, Prentice-Hall (2004).
[8] P. Milgram, H. Takemura, A. Utsumi, F.             [22]   S. Odeh, O. Qaraeen: Evaluation Methods and
     Kishino: Augmented Reality: A Class of                   Techniques for E-Learning Software for School
     Displays on the Reality Virtuality Continuum,            Students in Primary Stages, International
     Proc. Telemanipulator and Telepresence                   Journal of Emerging Technologies in Learning,
     Technologies (1994).                                     vol. 2, Nr. 3 (2007).
[9] B. Shneiderman, C. Plaisant: Designing the         [23]   M. B. Rosson, J. M. Carroll: Usability
     User Interface: Strategies for Effective Human-          Engineering: Scenario-Based Development of
     Computer Interaction (4th Edition). Addison              Human-Computer           Interaction,    Morgan
     Wesley Longman (2004).                                   Kaufmann Publishers (2002).
[10] H. C. Jones: E-Learning Designing Tomorrow's      [24]   R. A. Johnson, G. K. Bhattacharyya: Statistics:
     Education,     Communication         from   the          Principles and Methods, Wiley (2000).
     Commission, Commission of the European            [25]   Pallant, J.: SPSS Survival Manual, Open
     Communities, Brussels (2000).                            University Press (2004).
[11] K. Zinser: Integrated multimedia and

                    Ubiquitous Computing and Communication Journal                                           9

To top