NIK Norsk informatikkonferanse. Universitetet i Nordland november NIK-styret og redaksjonskomité. Høgskolen i Oslo og Akershus

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1 NIK 2012 Norsk informatikkonferanse Norsk informatikkonferanse NIK 2012 Universitetet i Nordland november 2012 NIK-styret og redaksjonskomité Lars Ailo Bongo Siri Fagernes Dag Haugland Erik Hjelmås Hein Meling Birger Møller-Pedersen Andreas Prinz Trond Aalberg ISSN ISBN Universitetet i Tromsø Høgskolen i Oslo og Akershus Universitetet i Bergen Høgskolen i Gjøvik (styreleder) Universitetet i Stavanger Universitetet i Oslo Universitetet i Agder NTNU (redaktør)

2 Norsk informatikkonferanse NIK 2012 Universitetet i Nordland november 2012 NIK-styre og redaksjonskomité Lars Ailo Bongo Siri Fagernes Dag Haugland Erik Hjelmås Hein Meling Birger Møller-Pedersen Andreas Prinz Trond Aalberg Universitetet i Tromsø Høgskolen i Oslo og Akershus Universitetet i Bergen Høgskolen i Gjøvik (styreleder) Universitetet i Stavanger Universitetet i Oslo Universitetet i Agder NTNU (redaktør)

3 NIK-stiftelsen og Akademika forlag, Trondheim 2012 ISSN ISSN (online) ISBN Det må ikke kopieres fra denne boka ut over det som er tillatt etter bestemmelser i lov om opphavsrett til åndsverk, og avtaler om kopiering inngått med Kopinor. Dette gjelder også filer, kode eller annen gjengivelse tilknyttet e- bok. Redaktør: Trond Aalberg, NTNU Digital trykk og innbinding: AIT Oslo AS Vi bruker miljøsertifiserte trykkerier Akademika forlag Postboks 2461 Sluppen 7005 Trondheim Tlf.: E- post: forlag@akademika.no Forlagsredaktør: Lasse Postmyr (lasse.postmyr@akademika.no)

4 Forord Norsk informatikkonferanse har vært arrangert hvert år siden 1988 ved de forskjellige universitetene og høyskolene i Norge. I år er turen igjen kommet til Bodø. Formålet har hele tiden vært det samme: å være et møtested for datafaglig ansatte og studenter i høyere undervisningsinstitusjoner, forskningsinstitutter og næringsliv, å gi et representativt bilde av hva som foregår av forsknings- og avansert utviklingsarbeid i hele det norske fagmiljøet, dvs forsøke å vise bredden i forskningsmiljøet, både faglig, organisatorisk og geografisk, samt å holde et høyt faglig nivå og åpne for debatt om emner som opptar det datafaglige miljøet. Årets innsendte bidrag holder et normalt nivå. 21 av 43 innsendte bidrag ble akseptert som ordinære bidrag, mens ytterligere 7 bidrag ble akseptert til en egen short paper session. Det er flere studentarbeider blant de aksepterte bidragene og disse får økonomisk støtte fra NIK for å komme til konferansen og presentere sine bidrag. I vurderingsarbeidet har programkomiteen også fått uvurderlig hjelp av frivillige faglige konsulenter, nemlig Anders Andersen, Ivar Austvoll, Abdulrahman Azab, Anya Helene Bagge, Joanna Bauer, John Markus Bjørndalen, Reggie Davidrajuh, Ingvar Eidhammer, Pål Evensen, Bård Fjukstad, Ivar Farup, Phuong Ha, Geir Hasle, Jo Herstad, Magnus Lie Hetland, Rune Hjelsvold, Kjell Jørgen Hole, Anders Kofod-Petersen, Stein Krogdahl, Hanno Langweg, Mass Soldal Lund, Fredrik Manne, Arne Maus, Ellen Munthe-Kaas, Georg Muntingh, Morten Mossige, Khalid Mughal, Tor Anders Nygaard, Erlend Tøssebro, Julius Parulek, Jonathan Read, Tom Ryen, Gerhard Skagestein, Karl Skretting, Daniel Stødle, Ragnar Stølsmark, Nils Kalstad Svendsen, Gunnar Syrrist, Lars Tiede, Yngve Villanger, Sule Yildirim, Weihai Yu, Anne-Siri Øyen og Brit Helle Aarskog. På vegne av redaksjonskomiteen vil jeg gjerne få takke disse. I likhet med tidligere år har ikke NIK opphavsrett til artiklene i denne samlingen. Den enkelte forfatter må kontaktes om rettighetene til eventuell videre gjengivelse av artiklene. I år inviterer vi Bran Selic fra Malina Software Corp. som keynote til å fortelle oss om model-based engineering. Artiklene finnes også på nettet på NIKs adresse der man også finner annen informasjon om NIK. Programkomiteen for NIK Erik Hjelmås Gjøvik, oktober 2012.

5 Innhold An Empirical Evaluation of a Metric Index for Approximate String Matching... 1 Bilegsaikhan Naidan, Magnus Lie Hetland Image Metadata as a Means to Gather Image Relevant Information Randi Karlsen, Roger Bruun Asp Hansen Efficient Rule-Matching for Automated Coherent Logic Bjarne Holen, Dag Hovland, Martin Giese Mining of Association Relations in Text Gleb Sizov, Pinar Öztürk Bruk av PC-sal under eksamen i videregående programmering Erlend Tøssebro Vurderingsform og karakterbruk Christian F. Heide, Monica Kristiansen, Tom Heine Nätt Course Improvement the TQM way Tor Stålhane, Svein Erik Bratsberg, Roger Midtstraum Language and Metamorphosis Supervising Computer Science Students diagnosed with Asperger Syndrome Kirsten Ribu Computing the Optimal Layout of a Wind Farm Jan Kristian Haugland, Dag Haugland Optimization of Wood Fuel Chip Production in Denmark Assimizele Brice, Arne Løkketangen Optimization and Parallelization of Ptychography Reconstruction Code Thomas L. Falch, Jostein B. Fløystad, Anne C. Elster, Dag W. Breiby GPU-Based Airway Segmentation and Centerline Extraction for Image Guided Bronchoscopy Erik Smistad, Anne C. Elster, Frank Lindseth Real-Time Surface Extraction and Visualization of Medical Images using OpenCL and GPUs Erik Smistad, Anne C. Elster, Frank Lindseth Towards Efficient Simulation of Task Based Parallel Applications Alexandru C. Iordan, Magnus Jahre, Lasse Natvig A Child s Voice Miriam E. N. Begnum, Synnøve Flatebø Hoelseth, Britt Johnsen, Frank Hansen Making Touch-Based Mobile Phones Accessible for the Visually Impaired Alexander Dreyer Johnsen, Tor-Morten Grønli, Bendik Bygstad

6 Mobile IT Support for Multisport Competitions Steinar Kristoffersen, Manish Shrestha Public Review of E-voting Source Code: Lessons Learnt from E-vote Bjarte M. Østvold, Edvard K. Karlsen Konstruksjon av databaser for aktuelle og historiske addresser Kjell Bratbergsengen On the Truthfulness of Petal Graphs for Visualisation of Data Frode Eika Sandnes Tekstur og dekkval i biletsteganografi Hans Georg Schaathun NFC Experiments in the NFC City Project Anders Andersen, Randi Karlsen GeStore Incremental Computation for Metagenomic Pipelines Edvard Pedersen, Nils Peder Willassen, Lars Ailo Bongo BSV Window Visualization System Lars Ailo Bongo Towards Cross-Lingual Information Retrieval using Random Indexing Hans Moen, Erwin Marsi Eye Contact in Leisure Video Conferencing Annick Van der Hoest, Simon McCallum A Personal Assistant A Push System to Offer Relevant Information with a Minimum of Input Kai A. Olsen, Alessio Malizia, Teresa Onorati A Memory Aid for Reduced Cognitive Load in Manually Entered Online Bank Transactions Frode Eika Sandnes

7 NFC experiments in the NFC city project Anders Andersen and Randi Karlsen Department of Computer Science University of Tromsø 9037 Tromsø, Norway 1 Introduction In the NFC city project 1 some initial experiments with context sensitive social networking applications have been performed. These experiments explore how Near Field Communication (NFC) technology can contribute to improve the overall functionality and user experience of such applications. The outcome of these experiments is a set of tools, libraries, and new applications that demonstrates the usefulness of NFC technology. NFC (Near Field Communication) tries to harmonize today s diverse contact-less technologies, enabling current and future solutions like access control, ticketing, payment, loyalty programs, discount coupons, and information collection and exchange. By utilizing existing technologies to provide NFC services within ticketing, payment and physical access, the project will create an arena where services from different providers can run independently and with good usability on the same mobile handsets. In this context these initial NFC experiments with context sensitive social networking applications have been performed [4]. The applications are implemented for the Android mobile platform communicating with servers running on traditional computers. 2 NFC NFC-Forum [6] describes the technology as follows: Near Field Communication (NFC) technology makes life easier and more convenient for consumers around the world by making it simpler to make transactions, exchange digital content, and connect electronic devices with a touch. In short, NFC is a set of short-range wireless technologies. Where Bluetooth works within a range of 10 meters with a maximum bandwidth of 2.1 Mbit/s, NFC is limited to distances as short as 4 cm, and with a bandwidth ranging from 106 kbit/s to 424 kbit/s. NFC can be implemented in all types of devices, including your smart phone, tablet, computer and car. NFC always involves an initiator and a target; the initiator actively generates an RF field that can power a passive target. This enables NFC targets to take very simple form Supported by the Norwegian research council, VERDIKT project number This paper was presented at the NIK-2012 conference; see

8 factors such as tags, stickers, key fobs, or cards that do not require batteries. NFC peerto-peer communication, where both devices are powered, is also possible. However, the limited bandwidth makes it inferior to Bluetooth for big data transfers. NFC tags contain data, and may be configured to be read-only or rewritable. The payload is described by a type, a length, and an optional identifier. The type identifiers may be URIs, MIME media types, or NFC-specific types. The tags can securely store personal data [3] such as debit and credit card information, loyalty program data, PINs and networking contacts, among other information. 3 The Experiments To enable a simpler development process of NFC applications on the Android platform, we have developed an Eclipse library. The library contains extendible Activity classes for reading and writing to tags, P2P, and Bluetooth pairing of Android devices. It reduces the code required when creating NFC applications by hiding much of the boiler plate code from the application developer. NfcPresenter NfcPresenter is an Android application that simplifies the user-computer interaction by creating a more intuitive way to present slide-show presentations. Traditionally, starting a presentation is a cumbersome process. The person doing the presentation usually has two alternatives; either connecting his own laptop to the projector, or transfer the presentation with a USB memory stick to a local computer which is already connected. Both routines are unnecessary tedious. With NfcPresenter we aim to create a smooth and painless presentation experience by utilizing NFC technology. Starting a presentation can be done by selecting the appropriate presentation file on the mobile device, and touching it to an NFC tag present at the presentation location. Simple as that. When the presentation has started, the Android device serves as a remote control. With a swipe you can show the next or previous slide. In addition each slide is shown on the screen of the mobile device for better control. NfcPresenter also lets a spectator download the currently active presentation to his own mobile device by scanning a tag. This is a useful feature for distributing presentation material. NfcPresenter utilizes NFC to collect the URL from a tag present at the presentation location. The URL directs to a server running on the local presentation computer, which is already connected to the projector. The application uses the recently acquired URL to upload the presentation file to the server. The server starts the presentation, and can now answer to other commands to control it remotely. NfcSafari NfcSafari is a tour guide application that aims to help people discover, experience and remember interesting locations and spots. The general application area is giving tourists visiting cities and locations for the first time a helping hand by guiding them to interesting sightseeing spots. The overall goal of creating the application is to explore how NFC can be utilized in pervasive applications. The application initiates the tour by using the current location of the user to find nearby spots. The user is given a choice between the three closest spots, and the user will start 248

9 the Safari by choosing one of them. The next screen shows a map, guiding the user from his current location to the spot he chose. When the user finds a spot, he needs to touch the nearby NFC tag to register his presence. By reading the ID of the spot, the application knows what web service to contact to download a description of the spot. If the user is logged in, he can share information about the spot through Facebook. It is also possible to give the spot a rating from 1 to 5 stars. When the user is happy with the experience he can continue the tour. PartyShare The goal of PartyShare is to bring multimedia from handheld devices to stationary devices in a seamless manner. It consists of a client running on an NFC enabled Android device, and a server running on a computer. The application lets you choose to share music or images from the android device to the computer in real-time. The transfer is done simply by touching the android device to the stationary device. As a result, the images are viewed and the music is played immediately. PartyShare uses the HTTP protocol to transfer the multimedia from the Android device to the computer. The relevant URL is stored in the NFC tag. The ImageViewer, which displays the latest image, is created using Pygame, and the music sharing is implemented using a self made libspotify-wrapper (spotipy). On the client side we use internal Android activities to handle the camera and the gallery to choose image, and the Spotify meta data API to choose music. The music sharing works by transferring a Spotify URI which is then used by spotipy to play the song. NFC quiz NFC quiz is a simple quiz application where a phone is used to touch an NFC tag to provide an answer in a quiz game. The user sees a large screen (projector screen) that presents the quiz game. The phone is used as an input device for the game. Buttons or selection areas are touched with the phone to interact with the quiz. Each such area have an NFC tag representing the selection. The NFC tag is attached to the back of the screen and is not visible for the user. Depending on the context, touching such an area has different meanings. During the quiz three of these areas represent suggested answers where the user is supposed to select one. If the user succeeds with more than a given threshold level of correct answers, the quiz application is used to write a gift code to an NFC card. The user can then bring this with him to pick up a price. In our experiments this was a free coffee or drink at a nearby café. Are You The One? Are You The One? is a quirky love tester that calculates the compatibility between two persons. The goal of the application is to illustrate how NFC can be used in social scenarios. The application works by having the user enters his or her name, and then touch another handset with the same application. As a result their love match, or compatibility, is visualized on screen as a percentage. The compatibility is calculated deterministically using their names, and obviously has no basis in reality. Nevertheless, it is a fun example of a small application which delivers something new by incorporating NFC as a vital component. 249

10 BluetoothChat This application is mostly an example application to shows how NFC can be used to do setup and configuration. It is a simple chat client which enables users to set up a connection by touching each others phone and chat via Bluetooth. The application can easily be extended to a secure generic (not limited to Bluetooth) chat application. When two phones are touched we can exchange public encryption keys, and later use these key to encrypt messages and authenticate the other participant. 4 Conclusion NFC is useful in many areas, such as payment, information sharing [7, 5], security [3], configuration, and social interaction [2]. It acts as a link between the physical and virtual world, giving us a simpler and more intuitive way of sharing information [1]. One of the properties of NFC is that context is implicit defined. This stems from the very short range of the tags. This can simplify many aspects of development, including security and configuration. Apart from payment, we feel that NFC for mobile devices are most useful where it can simplify the user-interactions of services or applications. The best example is setting up connections for WI-FI or Bluetooth, as exemplified in BluetoothChat. A task that can be tedious is replaced by an intuitive gesture that connects touching devices. 5 Acknowledgments Thanks to our excellent implementation team Øyvind Holmstad, Tor Kreutzer, and Jan- Ove Karlberg. Also thanks to our project partners, especially Sigmund Akselsen, Peter Dahle, Kjell Myksvoll, and Arne Munch-Ellingsen (all at Telenor), and the technical staff at the Department of Computer Science at University of Tromsø. References [1] G. Broll, W. Reithmeier, P. Holleis, and M. Wagner. Design and evaluation of techniques for mobile interaction with dynamic NFC-displays. In TEI 11 Proceedings, pages , Funchal, Portugal, Jan ACM. [2] A. Fressancourt, C. Hérault, and E. Ptak. NFCSocial: social networking in mobility through IMS and NFC. In First International Workshop on Near Field Communication, pages 24 29, Feb [3] E. Haselsteiner and K. Breitfuß. Security in near field communication (NFC). In Workshop on RFID Security, Malaga, Spain, July [4] Ø. Holmstad and T. Kreutzer. NFC prototype bonanza. Technical report, Department of Computer Science, Faculty of Science and Technology, University of Tromsø, Norway, July [5] M. Isomursu, P. Isomursu, and M. Komulainen-Horneman. Touch to access the mobile internet. In OZCHI 2008 Proceedings, Cairns, Australia, Dec [6] The near field communication forum [7] S. B. Paul Holleis, Gregor Broll. Advertising with NFC. In Workshop on Pervasive Advertising and Shopping, in conjunction with the 8th International Conference on Pervasive Computing (Pervasive 2010), Helsinki, Finland, May