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The STC@MIUN research program Electronic systems for Sensible Things that Communicates

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STC@MIUN - annual report 2007 1. Introduction The evolution of the 3G mobile telephone systems, from the first point-to-point communication used in the telephone prototype patented by Graham Bell in 1875, has been driven by man’s underlying dream of increasing the range of senses. The telephone extends the range of our voice and hearing. Wireless solutions provide additional flexibilities, which makes it possible to extend our senses in our daily activities. The same technology can be utilized in all kinds of service applications. We define the technology that allows this as technology for Sensible Things that Communicate (STC). Electronic systems for Sensible Things that Communicate include technology for data communication, data processing, and sensing. The research field covers a large area, which can be described by the access network presented in the Fig. 1.1.

2. The STC reference system Dispensable communication terminal Visualization node

Multimedia terminal

Communication access point Arbitrary STC Telemedicine node

Access network node

Surveillance node

Fig. 1.1. Distributed electronic system used as the reference system for the research in the profile.

The reference system in Fig. 1.1 contains areas of global interest and lies within the fields of research interest for both the academic and industrial partners. Within STC@MIUN we are developing four different technology platforms with technologies that can be combined together to form an STC system. The technology platforms are 1. Computational platform (STC System and application) Optimization of computational routines in measurement systems utilizing FPGA hardware platforms 2. Network platform (STC Network Solutions) Optimization and design of network algorithms for efficient data aggregation and system security Mid Sweden University Department of Information Technology

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3. Wireless hardware platform (STC Wireless Solution) Low power wireless sensor node design and energy harvesting 4. Sensor hardware platform (STC Sensor Solution) Development of innovative sensor structures for industrial surveillance Within STC@MIUN, we have designed a wireless demonstrator platform called SENTIO in which each technology platform can evaluate its research results in a full STC system solution. A sensor node from the SENTIO demonstrator is presented in Fig. 1.2.

Fig. 1.2. SENTIO sensor nodes Left: first version, Right: second version

3. Research objectives The objective of STC@MIUN is to develop knowledge and technology to supportdistributed sensing in industrial applications. Distributed sensing technology will enable advanced digital services such as, for example, remote presence or high precision visibility in industrial supply chains, as illustrated in Fig 1.3 below. The distributed sensing demands stable intelligent sensor network solutions operating at low power levels, utilizing energy harvesting or other smart power solutions. The focus of STC@MIUN is on particular sensor network technologies of relevance for our industrial partners and utilizing advantages associated with both the research environment and competence at Mid Sweden University. The targeted research field is large and STC@MIUN will not be able to cover all aspects of the field.

Fig. 1.3. Illustration of the evolution of telecommunication towards true remote presence services.

Our main focus is on key technology areas such as: Mid Sweden University Department of Information Technology

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real time video processing power efficient routing and networking low power collaborative sensing energy harvesting low cost radiation sensor solutions

Initially, our resources were concentrated on the development of key technologies of relevance for different industrial partners. The next step in the project is to target the development of more system oriented demonstrators where the developed technologies will be utilized to show new functionalities and service solutions. Our ambition is to demonstrate both new technological solutions and new service concepts of general industrial interest. The evolution of the research objectives within STC@MIUN are presented in Fig. 1.4.

Development of concept demonstrators Development of technology plattforms

Further development of technology plattforms Demonstration of service concepts

Start

End

Fig. 1.4. Time evolution of objectives for the STC@MIUN research program

4. Summary or research results During 2007 there has been significant development in STC@MIUN’s technology platforms. In the following section we will summarize the progress made so far. 4.1. STC Systems and applications The mission statement for the STC Systems and Applications was initially defined as being to discover when, where and how system integration on FPGA is a good implementation alternative for industrial and automotive embedded systems. Points of investigation were with regards to developing applications for the technology, investigating cost issues and optimizing low power consumption in FPGA based systems. This year has seen the start of a number of activities on embedded machine vision applications and these are perceived as being able to contribute application knowledge into the technology development during the project. The results for 2007 can be summarized as follows: Automatic design methods for optimized implementation of real-time video processing systems: We have extended our work into developing a behavioural memory synthesis design flow for FPGA implementation of real-time video processing, with methods to optimize the synthesis towards the selected FPGA architecture. The results so far have proved to be very promising and we will continue to investigate further use of this technology. Mid Sweden University Department of Information Technology

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Investigation of specific challenges in real-time video processing systems: The results of the optimization work of a multi channel analogue video display computer were demonstrated. These results show that a multi channel video display (more than 4 sources) can be implemented using a small and inexpensive FPGA circuit thus, enabling compact and lowcost implementations. We are now investigating how to extend this work to digital IP-based video streams. In addition, a macro scale positioning system has been analyzed and implemented in order to demonstrate the developed CAD methods and also to identify new research challenges. The results from this work also indicate that the whole system can be implemented on a small FPGA and thus enable usage for the consumer market. Analysis and development embedded machine vision applications: During the year, two externally funded projects in embedded machine vision were started. These investigate realtime measurements of surface topology on paper and optical positioning. Additionally, in cooperation with Sensor Solutions, a joint project to detect and characterize magnetic particles in hydraulic fluid has been initiated. 4.2. STC Network solutions The overall goals for the network solution part of the profile are to discover efficient (lower power) and secure sensor data collection for applications such as environment monitoring, surveillance and network traffic monitoring. Our results for 2007 can be summarized as: Performance analysis of information collection of wireless sensor network routing: We have achieved a formal routing analysis using our proposed analytical model and the new information based network lifetime definition. Experiments have shown that our model can generate tight upper bounds for different situations, and can be used to evaluate existing algorithms. Detecting Anomaly Node Behaviour in Wireless Sensor Networks: We present a method which builds accurate node profiles based on traffic modelling of each interested node. For the first time, the traffic patterns are learned in a way which is based on the arrival order of different packet events in wireless sensor networks. 4.3. STC Wireless solutions The objective for the work in Wireless solutions is to develop distributed measurement systems based on wireless sensor technology. The focus has been on wireless sensor networks in industrial applications. The work has consisted of solving the implementation problems for an entirely contact-less positioning system for mobile heavy-duty cranes. Distributed angular sensor: We have presented a joint angular sensor consisting of four discrete wireless two-axis MEMS accelerometers spatially distributed on adjacent arm links. We have proved that the method is theoretically error-free and from the experimental results obtained we are able to demonstrate an accuracy level which is higher by a factor of 10. Moreover the distributed sensor enables a gradual degradation of the accuracy in the event of the failure of one of the sensor devices, which is an important property for robustness operation. Analysis of the communication requirements for closed-loop control system: By analysing the proposed standard for wireless sensor networks (IEEE802.15.4) for applications having hard real-time requirements, we have concluded that only a very few applications are fulMid Sweden University Department of Information Technology

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filled by it. Our proposal is a MAC protocol which fulfils the requirements associated with low energy consumption for the communication rather better. 4.4. STC Sensor solutions Low-cost sensor solutions in NIR radiation area and an integrated compact optical spectroscopical solution have been developed and investigated during 2007. Development of low-cost thermal detector for detection of CO2 NDIR method: A metal film resistance bolometer and a thermopile have been fabricated. Both types of detector consist of a 4 um thin SU-8 membrane, into which the temperature sensitive elements were encapsulated. The thermopile displays a sensitivity of approximately 5.6V/W and the bolometer solution a sensitivity of 9.3V/W (bias 2.5V@10 Hz). The measurements were performed using a diode laser with a power of 4.5 mW and a wavelength of 1.56 um. Integrated compact FT spectrometer based on a position sensitive detector and FabryPerot interferometer wedge: The spectrometer is based on a multi channel Fabry-Perot interferometer manufactured as a glass wedge. A Lateral Position Sensitive Detector (PSD) is used as the detector. The advantage using a PSD is the necessity for a simple readout circuit with only two analogue-inputs, compared to an array solution in which several hundred analogue-inputs are required. However the present solution requires a movable slit and the intensity must not change during measurements (during moving the slit). Nevertheless the movement of slit does not require any synchronisation with readout electronics, since the information of position is to be found in the two signals from the PSD. 4.5. The SENTIO demonstrator system The SENTIO platform for the rapid development of wireless sensor networks with shortrange communication has been developed and the first version has been available for all partners in STC since 2005. SENTIO has been used extensively in various applications involving very different characteristics. During 2007, for example, it has been used to set up a fully working positioning system on HIAB’s cranes, in a pre-study of testing rims on armoured vehicles at BAE Systems, on horses for the detection of lameness, and for sensor-activated surveillance cameras. Course material and lab equipment for our students on our courses in wireless sensor networks have been developed and in addition, it has also been used in thesis projects, in which, for example, a wireless ECG and a wireless gamma detector have been developed. 4.6. Publications 2007 •

J. Sidén, M. Fein, A. Koptioug, H-E. Nilsson, “Printed Antennas with Variable Conductive Ink Layer Thickness”, IET Microwaves, Antennas & Propagation Magazine, Vol. 1, Iss. 2 April 2007 H-E. Nilsson, J. Siden, A. Koptioug, S. Hussain, T. Olsson and P. Jonsson, “Evaluation of a printed patch antenna for robust microwave RFID tags”, IET Microwaves, Antennas & Propagation, Vol. 1, Iss. 3, June 2007. J. Sidén, M. Fein, A. Koptioug, H-E. Nilsson, “Logos as RFID Tag Antennas”, submitted to International journal on wireless and optical communications, Special Issue on "Antennas for Emerging Radio Frequency Identification (RFID) Applications", 2007 T. Olsson, J. Sidén, H-E Nilsson, “Comparative robustness study of planar antennas”, IET Microwaves, Antennas & Propagation Vol. 1, Iss. 3, June 2007 pp:674 - 680

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H.-E. Nilsson, C. Mattsson, J. Sidén, U. Geyer, “Printing of UHF modulators on embedded silicon in semi-passive RFID tags”, submitted to Smart Systems Integration 2008 J. Sidén, X. Zeng, T. Unander, H.-E. Nilsson, “Remote Moisture Sensing utilizing Ordinary RFID Tags”, Proc of IEEE Sensors 2007 Int. Conf. on., 2007 D. Timpe, L. Olsson, J. Sidén, “Cost analysis of introducing a log identification system using RFID in the wood supply chain: A case study at a Swedish forest company”, submitted to The Journal of Forest Economics, 2007 T. Olsson, J. Sidén, M. Hjelm, H.-E. Nilsson, “Robustness of Printed Patch Antenna”, Accepted for publication in IEEE Transactions on Antennas and Propagation, 2007 X. Zeng, J. Sidén, G. Wang and H-E. Nilsson, “Slots in Metallic Label as RFID Tag Antenna”, Proceedings of IEEE AP-S 2007 J. Sidén and H.-E. Nilsson, “Line Width Limitations of Flexographic- Screen- and Inkjet printed RFID Antennas”, Proceedings of IEEE AP-S 2007 X. Zeng, J. Sidén, G. Wang and H.-E. Nilsson, “Silver Ink Patch Antenna for RFID”, Int. Symp. on Ant. and Prop, ISAP’07 J. Sidén, M. Fein, A. Koptioug, H-E. Nilsson, “Printed Antennas with Variable Conductive Ink Layer Thickness”, IET Microwaves, Antennas & Propagation Magazine, Vol. 1, Iss. 2 April 2007 C. Fröjdh, S. Pettersson, G. Thungström, ” Characterization of 3D thermal neutron semiconductor detectors”, IWORID 8 2007-10-02 H. Andersson , H.-E. Nilsson, G. Thungström, ” Evaluation of FT Spectrometer utilizing a Lateral Effect Position Sensitive Detector with a scanning slit and Multi Channel Fabry-Perot Interferometer”, 2007 H. Andersson, H.-E. Nilsson, G. Thungström, ” Principle of FT Spectrometer based on a Lateral Effect Position Sensitive Detector and Multi Channel Fabry-Perot Interferometer”, Measurement 2007, Elsevier Claes Mattsson, Göran Thungström, Kent Bertilsson, Hans-Erik Nilsson and Hans Martin, "Fabrication and evaluation of a thermoelectric infrared sensor formed on a thin photosensitive epoxy membrane with low thermal conductivity", Paper accepted for publication in Journal of Physics: Conference Series. Claes Mattsson, Göran Thungström, Kent Bertilsson, Hans-Erik Nilsson and Hans Martin, "Development of an infrared thermopile detector with a thin self-supporting SU-8 membrane", Paper accepted for publication in IEEE Sensors Conference Proceeding 2007. H. Norell, N. Lawal, M. O'Nils, Automatic Generation of Spatial and Temporal Memory Architectures for Embedded Video Processing Systems, EURASIP Journal on Embedded Systems, Volume 2007, 2007. N. Lawal, M. O'Nils, B. Thörnberg, "C++ based System Synthesis of Real-Time Video Processing Systems targeting FPGA Implementation", Proceeding of the Reconfigurable Architectures Workshop, 2007. N. Lawal, M. O'Nils, B. Thörnberg, "Power-aware Automatic Constraint Generation for FPGA Based Real-Time Video Processing Systems”, Proceedings of the IEEE Norchip Conference, 2007 P. Österberg, T. Zhang, “Bid-based cost sharing among multicast receivers”, in Proceedings of 4th ACM International Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness (QShine), Vancouver, Canada, August 2007 J. Alfredsson and S. Aunet, "D-latch for Subthreshold Floating-Gate Circuits Exploiting Threshold Elements", IEEE Norchip Conference 2007

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S. Aunet, B. Oelmann, P.A. Norseng, Y. Berg, "Real-time Reconfigurable Subthreshold CMOS Perceptron," IEEE Trans. on Neural Networks. P. Österberg and T. Zhang, "Fair Cost Sharing Among Multicast Receivers", In Proceedings of 2nd IEEE International Conference on Digital Telecommunications, ICDT, Silicon Valley, CA, USA, July 2007. (Best Paper Award) P. Österberg, T. Zhang and M. Gidlund, "Bandwidth Allocation in Broadband Access Networks", In Proceedings of 12th European Conference on Networks & Optical Communications, NOC, Kista, Sweden, June 2007. Qinghua Wang, Tingting Zhang , "Detecting Anomaly Node Behavior in Wireless Sensor Networks", Proc. the 3rd IEEE International Symposium on Security in Networks and Distributed Systems (SSNDS-07), Niagara Falls, Canada, May 21-23, 2007. Qinghua Wang, Tingting Zhang and Stefan Pettersson, "Bounding the Information Collection Performance of Wireless Sensor Network Routing", Proc. The 5th Annual communication networks and services research conference (CNSR2007), Fredericton, New Brunswick, Canada May 14 - 17, 2007. (Best Paper Award). U. Jennehag, T. Zhang, and S. Pettersson, "Improving Transmission Efficiency in H.264 Based IPTV Systems", the IEEE Trans. on Broadcasting, March 2007. Henrik A. Andersson, Göran Thungström, Hans-Erik Nilsson, "Electroless deposition and silicidation of Ni contacts into p-type Porous Silicon", Journal of Porous Materials, 2007 J. Uher, C. Fröjdh, J. Jakůbek, C. Kenney, Z. Kohout, V. Linhart, S. Parker, S. Petersson, S. Pospíšil and G. Thungström "Characterization of 3D thermal neutron semiconductor detectors", Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, In Press, Corrected Proof, 2007, Göran Thungström, C.G. Mattsson and Camilla Rönnqvist "Fabrication and characterization of silicon detectors for use in radiotherapy dosimetry, pre-irradiated by highenergy electrons", Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, In Press, Corrected Proof, 2007, Cao Cao and Bengt Oelmann, "The Analysis of Power-Related Characteristics of FSM Benchmarks", the 50th IEEE Int'l Midwest Symposium on Circuits & Systems/5th IEEE Int'l Northeast Workshop on Circuits & Systems, Montreol, Canada, 2007. Mattias O'Nils, Benny Thörnberg, Najeem Lawal, "C++ based System Synthesis of Real-Time Video Processing Systems targeting FPGA Implementation", Proceedings of the FPGA World Conference, 2007. B. Thörnberg, M. Palkovic, Q. Hu, L. Olsson, P. Gunnar Kjeldsberg, M. O’Nils, F. Catthoor, "Bit-Width Constrained Memory Hierarchy Optimization for Real-Time Video Systems", IEEE Transactions on Computer Aided Design of Integrated Circuits and Systems, 2007. Jan Lundgren, Mattias O’Nils, Bengt Oelmann, Börje Norlin, Suliman Abdalla, "An Area Efficient Readout Architecture for Photon Counting Color Imaging", Nuclear Instruments and Methods in Physics Research Section A, 2007. Jan Lundgren, Mattias O’Nils, Bengt Oelmann, Suliman Abdalla, " Power Distribution and Substrate Noise Coupling Investigations on the Behavioral Level for Photon Counting Imaging Readout Circuits ", Nuclear Instruments and Methods in Physics Research Section A, 2007.

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Bengt Oelmann and Cao Cao, ”A Mixed Synchronous/Asynchronous Design Approach for Fine-Grained Dynamic,” Book Chapter (Chapt. 13), Brain Inspired Nano Architectures 2007, World Science. Fredrik Linnarsson, Peng Cheng, and Bengt Oelmann, ” IEEE Second International Symposium on Industrial Embedded Systems - SIES'2007 2007 Suliman Abdalla, Bengt Oelmann, Mattias O'Nils, Jan Lundgren, ” Architecture and Circuit Design for Color X-Ray Pixal Array Detector Read-Out Electornics,” IEEE Norchip Conference 2007, pp. 271 – 276. Peng Cheng, Fredrik Linnarsson, and Bengt Oelmann, ” Distributed Joint Angular Sensor Based on Biaxial MEMS Accelerometers,” IEEE IECON08, Taipei, Taiwan. Cao Cao and Bengt Oelmann, ” Low-Power State-Encoding for FSMs with Mixed Synchronous/Asynchronous State Memory,” VLSI Integration 2007, Elsevier Publ. Unander, T., Nilsson, H.-E., Oelmann B., ” Printed touch sensor for interactive packaging and display,” Polytronic 2007, the 6th International IEEE Conference on Polymers and Adhesives in Microelectronics and Photonics 2007. Jon Alfredsson, Snorre Aunet and Bengt Oelmann, ” Small Fan-in Floating-gate Circuits with Application to an Improved Adder Structure,” Proceedings of 20th International Conference on VLSI Design 2007 Jon Alfredsson, Snorre Aunet, ”Performance of CMOS and Floating-Gate Full-Adder Circuits at Subthreshold Power Supply," accepted for publication at PATMOS'07, Gothenburg.

5. PhD examinations during 2007 The STC@MIUN program involves both PhD students and post doc projects. During 2007 we had 8 PhD thesis examinations related to STC@MIUN. Dr. Håkan Norell, Development, Analysis and Implementation of Pre-Processing Video Filters The usage of video systems in households and industry has increased rapidly over the past few years. The benefits of visual processing, control and inspection have offered great opportunities for real-time video processing systems (RTVPS) for the general public as well as for heavy industries. The high volume market media systems can absorb a great deal of the cost related to the development of standard components, such as Field Programmable Gate Arrays (FPGAs). The development of industrial systems can benefit from this new technology by utilizing these cheap components. In this thesis, examples of video processing algorithms suitable for the pre-processing of digital video, applicable for both industrial and media usage is shown. In addition a methodology supporting the designer in implementing memory architectures suitable for such algorithms is presented. In this thesis two video processing algorithms are presented and described in detail. The common denominator is their utilization of data from temporally adjacent frames in order to be effective, in terms of compression efficiency, and to produce an attractive result for the viewer. However, from the aspect of quality improvement, considerations have to be taken into account in order to enable an actual hardware implementation. Utilizing data from temporally adjacent frames in a real-time data stream is a non-trivial task. From the algorithm designer’s view the data dependencies and memory requirements are not in focus, but for the hardware designer they are. Having the right data available at the right time is the only consideration in order to have a functional system. Present day algorithm and hardware development methods and architectures do not converge into a common design flow, even though this has been attempted. The gap between the algorithm designer and his/her hardware counterpart has to be bridged in order to obtain an efficient and rapid implementation. Methodologies that ab-

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stract and reduce the amount of time spent on implementing memory architectures for video processing applications are required. The buffering requirements are often too complex to analyze manually in order to efficiently utilize the resources available in FPGAs. In this thesis a method for the synthesis and implementation of memory architectures for real-time video processing systems, IMapper, is presented. The architecture supports the implementation of spatio- and temporal video processing algorithms and utilizes methodologies for global optimization of on-fabric available memory resources for FPGAs. This methodology provides an efficient and flexible implementation environment and also offers the benefits of the global optimizations it utilizes. Håkan Norell is currently working with research and development at Navaero AB in Sundsvall.

Dr. Johan Sidén, On the Design, Characterization and Optimization of RFID Tag Antennas Remotely read electronic identification tags are being established as the standard method of identifying objects in transport logistics. They are referred to as RFID tags and with successful research and development they are likely to one day replace all of the present day barcodes, which are found on a wide variety of items and objects. As RFID systems consist of many different parts spanning over just as many academic subjects, this thesis investigates some of the main issues regarding RFID tag antennas. The main focus is placed on the performance and cost optimization of relatively simple onelayer antennas, suitable for mass production in commercial printing presses using electrically conductive ink. Examples of specially designed antennas include those able to operate upon metallic objects and antennas that can be physical bent. It is also shown how RFID tag antennas that will be widely exposed to the human eye can include a commercial value by allowing their geometric design to originate from group insignias and company logos. The thesis also presents a solution with regards to how pairs of ordinary low cost RFID tags can be used as remotely read moisture sensors. Johan Sidén continues his research in a joint program between the spin-of company Sensible Solutions and Mid Sweden University. He will also take a more active role in the supervision of PhD students within the area of printed electronics.

Dr. Börje Norlin, Characterization and application of photon counting X-ray detector systems This thesis concerns the development and characterization of X-ray imaging systems based on single photon processing. “Color” X-ray imaging opens up new perspectives within the fields of medical X-ray diagnosis and also in industrial X-ray quality control. The difference in absorption for different “colors” can be used to discern materials in the object. For instance, this information might be used to identify diseases such as brittle-bone disease. The “color” of the X-rays can be identified if the detector system can process each X-ray photon individually. Such a detector system is called a “single photon processing” system or, less precisely, a “photon counting system”. With modern technology it is possible to construct photon counting detector systems that can resolve details to a level of approximately 50 µm. However with such small pixels a problem will occur. In a semiconductor detector each absorbed X-ray photon creates a cloud of charge which contributes to the image. For high photon energies the size of the charge cloud is comparable to 50 µm and might be distributed between several pixels in the image. Charge sharing is a key problem since, not only is the resolution degenerated, but it also destroys the “color” information in the image.

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This thesis presents characterization and simulations to provide a detailed understanding of the physical processes concerning charge sharing in detectors from the MEDIPIX collaboration. Charge summing schemes utilizing pixel to pixel communications are proposed. Charge sharing can also be suppressed by introducing 3Ddetector structures. In the next generation of the MEDIPIX system, Medipix3, charge summing will be implemented. This system, equipped with a 3D-silicon detector, or a thin planar high-Z detector of good quality, has the potential to become a commercial product for medical imaging. This would be beneficial to the public health within the entire European Union. BĂśrje Norlin continues his research at Mid Sweden University within the sensor technology group. He is also actively involved in the education programs at the University.

Dr. Patrik Ă–sterberg, Fair Treatment of Multicast Sessions and Their Receivers: Incentives for more efficient bandwidth utilization Media-streaming services are rapidly gaining in popularity, and new ones are knocking on the door. Standard-definition Internet protocol television (IPTV) has already entered many living rooms, and high-definition IPTV will become common property in the not too distant future. Then even more advanced and resource-demanding services, such as three-dimensional and free-view TV, are next in line. Video streaming is by nature extremely bandwidth intensive, and this development will place significant stresses upon the existing network infrastructure. In scenarios where many receivers are simultaneously interested in the same data, which is the case with popular live content, multicast transmission is more bandwidth efficient than unicast. The reason is that the receivers of a multicast session share the resources through a common transmission tree where data are only transmitted once along any branch. The use of multicast transmission can therefore yield huge bandwidth savings. There are however no really strong incentives for the Internet service providers (ISPs) to support multicast transmission, and the deployment has consequently been slow. We propose that more bandwidth is allocated to multicast flows in the case of network congestion. The ratio is based upon the number of receivers and the bit rate that they are able to obtain, since this is what determines the degree of resource sharing. We believe that it is fair to take this into account, and accordingly call the proposed allocation multicast-favorable max-min fair. Further, we present two bandwidth-allocation policies that utilize different amounts of feedback to perform allocations that are reasonably close to being multicast-favorable maxmin fair. We also propose two cost-allocation mechanisms that build upon the assumption that the cost for data transmission should be covered by the receivers. The mechanisms charge the receivers based on their share of the resources usage, which in general is favorable to multicast receivers. The two cost-allocation mechanisms differ in that one strives for optimum fair cost allocations, whereas the other might give discounts to some receivers. The discounts facilitate larger groups of receivers, which are also able to provide cheaper services for the nondiscounted receivers. The proposals make multicast transmission more attractive to the users of media-streaming services. If the proposals were implemented in multicast-enabled networks, the rest of the ISPs would be forced to support multicast, in order to remain competitive. Patrik Ă–sterberg is currently involved in post doc research at Mid Sweden University within the area of computer science and development of IPTV services.

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Dr. Torbjรถrn Olsson, Antenna Robustness Modelling Antennas run an increasing risk of being physically damaged as transceivers become implemented in applications and environments where they have not been previously used. Military applications with extensive networking, even incorporating artillery shells as communication nodes, civilian applications of electronic marking of goods at the item level where the electronic components are constructed from conductive ink and polymers, are rapidly growing areas where antennas are likely to be damage. However, the systems must maintain functionality even when they are damaged. With an ever increasing number of antennas for various applications and environments the necessity for design rules to improve robustness of antennas is essential. In this thesis the need for special measures in order to achieve robustness against physical damage for planar antennas has been studied. Furthermore, a Monte Carlo based methodology for antenna robustness monitoring when exposing the antennas to randomly oriented damage of different types has been developed. Finally the methodology has been used to describe the robustness of some commonly used antennas. The result is a significant step forward when it comes to antenna design where the antenna is adapted to its environment based on aspects other than electromagnetic considerations . The thesis also gives support to the design of robust antennas with smaller, and thus with a reduced cost, conductor area. Torbjรถrn Olsson is currently working for BAE Systems Bofors in Karlskoga where he is actively taking part in the coordination of research collaboration with academia.

Dr. Cao Cao, Automatic Synthesis of Partitioned FSMs Based on Mixed Synchronous/Asynchronous State Memory The rapid development of digital circuits with high density and frequency means that power, in addition to area and speed, has become an important parameter in design constraints. Nowadays, the electronic design industry is confronted by increasingly costly package and cooling systems due to power dissipation. Battery-powered portable devices, such as laptops, mobile phones etc., which provide higher computational capacity and support multi-media information transformation, add greatly to the original slim power budget. Although synchronous digital design has, over the past few decades, become the industry standard, this new challenge suggests that asynchronous design techniques should now be reconsidered, as they possess the potential for a reduction in power dissipation. Finite state machine (FSM) partitioning has proved to be effective for power optimization. In this thesis, a mixed synchronous/asynchronous state memory structure in the decomposed FSM is proposed, which results in implementations with low power dissipation and low area overhead. The state memory is composed of the synchronous local state memory and an asynchronous global state memory, where the former is used to distinguish the states inside a sub-FSM, and the latter is responsible for controlling sub-FSM communication. Although asynchronous communication mechanism is introduced between sub-FSMs, the input/output behaviour of the decomposed FSM is still, cycle by cycle, equal to that of a complete synchronous FSM. The power consumption can be further reduced by using the clock gating technique and low power state assignment. Based on this mixed synchronous/asynchronous structure, an automatic synthesis tool was developed, which accepts a state transition graph (STG) as the input and synthesizable VHDL code as the output. The output can be directly used for synthesis at the gate level by the standard tool. The FSM partitioning algorithm, power and area estimation and trade-off and state encoding optimization aimed at this specific structure were integrated into the tool. In addition, the input to the tool was also analyzed and a variation coefficient was proposed as an important measure for the quantitative analysis of power-related characteristics of standard benchmark circuits. The effectiveness of the whole procedure was verified through optimization of standard benchmarks where a power reduction of up to 70% has been demonstrated. Moreover, the proposed asynchronous modules implemented in

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the tool provide a direction with reference as to how the asynchronous design can be effectively combined into a largely synchronous environment. Cao Cao is currently working on research and development at Aditus Science AB in Lund.

Dr. Jan Lundgren-Thim, Simulating Behavioral Level On-Chip Noise Coupling In this thesis, noise coupling simulation is introduced into the behavioural level. Methods and models for simulating on-chip noise coupling at the behavioural level in a design flow are presented and verified for accuracy and validity. Today, designs of electronic systems are becoming denser and more and more mixedsignal systems such as System-on-Chip (SoC) are being devised. This raises problems when the electronics components start to interfere with each other. Often, digital components disturb analogue components, introducing noise into the system causing degradation of the performance or even introducing errors into the functionality of the system. Today, these effects can only be simulated at a very late stage in the design process, causing large design iterations and increased costs if the designers are required to return and make alterations, which may have occurred at a very early stage in the process. This is why the focus of this work is centred on extracting noise coupling simulation models that can be used at a very early design stage, such as at the behavioural level and then follow the design through the various design stages. To achieve this, SystemC is selected as a platform and implementation example for the behavioural level models. SystemC supports design refinement, which means that when designs are being refined and are crossing the design levels, the noise coupling models can also be refined to suit the current design. This new method of thinking in primarily mixed-signal designs is called Behavioural level Noise Coupling (BeNoC) simulation and shows great promise in enabling a reduction in the costs of design iterations due to component cross-talk and simplifies the work for mixed-signal system designers. Jan Lundgren-Thim remains with Mid Sweden University as a co-supervisor for a new generation of PhD students working within STC@MIUN.

Dr. Xavier Liopart Cudié, Design and Characterization of 64K Pixels Chips Working in Single Photon Processning Mode Progress in CMOS technology and in fine pitch bump bonding has made possible the development of high granularity single photon counting detectors for X-ray imaging. This thesis studies the design and characterization of three pulse processing chips with 65536 square pixels of 55 μm x 55 μm designed in a commercial 0.25 μm 6-metal CMOS technology. The 3 chips share the same architecture and dimensions and are named Medipix2, Mpix2MXR20 and Timepix. The Medipix2 chip is a pixel detector readout chip consisting of 256 x 256 identical elements, each working in single photon counting mode for positive or negative input charge signals. The preamplifier feedback provides compensation for detector leakage current on a pixel by pixel basis. Two identical pulse height discriminators are used to define an energy window. Every event falling inside the energy window is counted with a 13-bit pseudo-random counter. The counter logic, based in a shift register, also behaves as the input/output register for the pixel. Each cell also has an 8-bit configuration register which allows masking, test-enabling and 3-bit individual threshold adjust for each discriminator. The chip can be configured in serial mode and readout either serially or in parallel. Measurements show an electronic noise ~160 e- rms with a gain of ~9 mV/ke-. The threshold spread after equalization of ~120 e- rms brings the full chip minimum detectable charge to ~1100 e-. The analog static power consumption is ~8 μW per pixel with Vdda=2.2 V.

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The Mpix2MXR20 is an upgraded version of the Medipix2. The main changes in the pixel consist of: an improved tolerance to radiation, improved pixel to pixel threshold uniformity, and a 14-bit counter with overflow control. The chip periphery includes new threshold DACs with smaller step size, improved linearity, and better temperature dependence. Timepix is an evolution of the Mpix2MXR20 which provides, independently in each pixel, information concerning arrival time, time-over-threshold or event counting. Timepix uses, as a time reference, an external clock (Ref_Clk) up to 100 MHz which is distributed all over the pixel matrix during acquisition mode. The preamplifier is improved and there is a single discriminator with 4-bit threshold adjustment in order to reduce the minimum detectable charge limit. Measurements show an electrical noise ~100 e- rms and a gain of ~16.5 mV/ke-. The threshold spread after equalization of ~35 e- rms brings the full chip minimum detectable charge either to ~650 e- with a naked chip (i.e. gas detectors) or ~750 e- when bump-bonded to a detector. The pixel static power consumption is ~13.5 ÎźW per pixel with Vdda=2.2 V and Ref_Clk=80 MHz. This family of chips has been used for a wide variety of applications. During these studies a number of limitations have come to light. Among those are limited energy resolution and surface area. Future developments, such as Medipix3, will aim to address those limitations by carefully exploiting developments in microelectronics. Xavier Llopart CudiĂŠ started his PhD study as collaboration between CERN and the University of Barcelona. The main part of his research has been conducted at CERN in collaboration with Mid Sweden University and STC@MIUN. At the end of his study he transferred his PhD studies to Mid Sweden University and completed his PhD in June 2007. He currently holds a post doc position at CERN in a collaboration sponsored by Mid Sweden University.

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6. STC@MIUN research projects In the following section we present the ongoing STC@MIUN PhD student projects. In addition we also present some areas where new PhD students will be allocated during 2008.

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PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

OPTIPOS - OPTICAL POSITION MEASUREMENT IN REAL-TIME FOR CONSUMER PRODUCTS

Background

implementation costs, and also if it is possible to  automate the estimation of implementation costs  for such algorithms.  The automation of cost estimation is aimed to be  implemented  in  a  CAD‐tool.  The  cost  efficiency  of  an  optical  position  measurement  system  will  be demonstrated in a prototype. Optical position  measurement can be done using a single camera  or  using  a  dual  camera  stereo‐vision  based  approach.  We  will  study  methods  and  algorithms  based  on  a  single  camera  approach,  aiming  for  lower  system  complexity  and  implementation  costs.  One  of  the  more  important  challenges  is  to  exploit  image  structures  of  objects  in  the  environment  with  known  positions.  The  view  of  several  objects  at  known positions enables the system so calculate  its own position and orientation.   

Systems that  can  measure  their  own  locations  are  becoming  more  frequently  used  in  different  applications.  The  figure  below  shows  two  examples  of  applications  that  measure  the  position  in  a  3‐  or  2‐dimensional  space:  a)  is  a  helmet  for  Virtual  Reality  (VR)  presentation,  which also measures its position and orientation  in  order  to  track  the  movement  of  the  user’s  head  and  b)  is  a  handheld  printer.  The  printer  operates as a computer mouse, printing text and  graphics  while  it  is  moved  over  a  large  surface.  Typically,  these  applications  have  two  major  things in common. High precision is required for  the  position  measurement  and  they  are  both  price sensitive. 

a)

b)

Planned project start The project is planned to start in April 2008 and  will continue for three years.   

Budget The total budget is 1.835 MSEK and will cover 20  percentage of a senior researcher together with a  new PhD student to be hired.     

Objectives Optical position  measurement  methods  and  its  related  algorithms  and  implementations  will  be  investigated  in  this  project.  Methods  based  on  prepared  environments  already  exist  that  can  measure an objects position and orientation in a  3‐dimensional  space  or  over  a  2‐dimensional  surface.  We  intend  to  investigate  if  these  methods  can  be  enhanced  to  work  in  general  unprepared  environments,  if  it  is  possible  to  optimize  these  algorithms  in  order  to  reduce 

  Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

For further information contact: Dr. Benny Thörnberg  benny.thornberg@miun.se 

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

OPTICAL ONLINE CHARACTERIZATION OF LARGE SURFACE TOPOGRAPHY IN PAPER MACHINES Background

Results

The industry  of  paper  manufacturing  is  today  looking  for  ways  to  set  a  quality  value  on  their  paper  while  it  is  produced.  The  quality  for  graphical  paper  products  is  highly  correlated  with  the  topography  of  the  paper.  With  smoother  surfaces  comes  higher  quality.  Additionally,  it  could  be  used  to  control  the  paper  machine.  In  order  to  realize  this,  an  on‐ line  characterisation  of  paper  topography  in  the  production chain is required.    

A model  has  been  developed  to,  in  the  image  sensor  system,  convert  the  incoming  light  position  data  to  topographic  height.  A  study  to  analyse  the  sub‐pixel  precision  has  been  done.  This  analysis  shows  that  methods  like  using  adaptive thresholds in the camera readout yields  large  gains  in  signal‐to‐noise  ratio,  and  solves  the same problems as anamorphic optics do.   A  comparison  of  light  source  setups  using  laser  vs.  LED  has  been  done,  showing  that  a  LED  array yields lower noise than a laser source due  to lower speckle noise. 

Objectives In this  project,  the  goal  is  to  investigate  the  possibilities  and  limitations  of  online  topography measurement in a paper production  machine,  to  develop  an  optical  system  that  has  sufficient  performance,  and  to  construct  a  prototype  for  installation  on  an  existing  paper  machine.  This  work  will  include  analysing  the  topography  measurement  setup  characteristics  to  clearly  define  limitations  and  possibilities  in  these  kinds  of  measurement  on  paper.  Experimental  tests  are  needed  in  the  development of lighting source, which produces  a  line  on  the  paper  surface  that  is  used  in  triangulation  method  that  yields  paper  topography at specific positions. The production  of  the  actual  prototype  will  incorporate  results  from  all  previous  experiments  and  model  analysis from the project.   

Sample of a paper topography profile.   

Ongoing activities

For further information contact: Prof. Mattias O’Nils  Mattias.Onils@miun.se  Dr. Jan Thim  Jan.Thim@miun.se 

Currently, a  system  setup  to  produce  the  illuminate  line  is  being  developed.  Also,  model  simulations  on  parameter  limitations  and  error  estimations are being done.     

  Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

CAD TOOL FOR REAL-TIME VIDEO PROCESSING SYSTEMS Background

implemented using  high  level  synthesis  tool  or  manual HDL coding. 

FPGA based  implementations  of  video  processing  systems  are  effective  but  have  a  complex programming model. The synthesis tool  presented  here  reduces  the  design  complexity  and still produces effective implementations.   

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Figure 3: CAD tool system synthesis workflow 

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We are  currently  optimising  the  CAD  tool  such  that  the  generated  hardware  is  optimized  for  low power. This optimisation can be achieved at  all  levels  of  the  system  synthesis  workflow  (Figure 1). Hence we are investigating how each  stage of the workflow can independently, and in  conjunction  with  other  levels,  lead  to  lower  power consumption in the final hardware. 

IMEM model B) Task C++ function

Figure 1: IMEM model of a video processing system.  Neighbourhood a11 a12 a13 data a21 a22 a23

Results

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SLWC

The tool  manages  memory  requirements  of  video  processing  systems  and  provides  the  designers  with  a  user‐friendly  FPGA  programming  model  while  generating  efficient  hardware of the memory sub‐systems.   

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IMEM Projector High-level Synthesis 3

IMEM (Interface  and  MEmory  Model),  an  extension  of  SystemC  modelling  library,  captures  video  processing  systems  as  coarse‐ grained  synchronous  dataflow  graph  (Fig  1),  where  each  node  represents  an  abstract  video  interface, the memory model and the description  of the functional behaviour of the task, whereas  each edge in the graph represents the data width  of each pixel in the video frame.  

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IMEM Conceptual Modelling

Simulation Input Stimuli

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Figure 2: Boundary conditions implementation  architecture. 

For further information contact: Najeem Lawal  Najeem.lawal@miun.se  Supervisor: Prof. Mattias O’Nils  Dr. Benny Thörnberg 

Memory requirements of a video processing are  separated  from  its  behavioural  C++  description  (Fig.  3).  A  memory  model,  which  may  be  neighbourhood  oriented  (Fig  2)  is  implement  in  different  phases,  whereas  systems  behaviour  is 

  Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

DEMONSTRATION OF HIGH-PERFORMANCE FPGA IMPLEMENTATION OF AN OPTICAL NAVIGATION SYSTEM Background

Ongoing activities

Performance of video processing systems can be  increased  through  parallel  operation  of  the  system  blocks.  It  can  be  further  increased  by  implementing  the  video  processing  system  in  hardware.  FPGA  provides  the  benefits  of  high  hardware  performance  and  reconfigurability.   This  project  targets  to  demonstrate  the  effectiveness of  the  FPGA implementation  of an  imaging system.   

We are  currently  implementing  the  hardware  system  after  verifying  the  simulation  models  of  all  the  parts  in  the  navigation  system  interfaced  to the mechanical setup. 

Results Figure 2  shows  a  simulation  the  hardware  prototype  shown  in  Figure  1  was  programmed  to  follow  a  sine‐wave.  The  navigation  system  was  able  to  determine  and  predict  the  future  position  with  1%  accuracy.  Figure  2  shows  the  discrepancy  between  mechanical  path,  optical  sensor ROI position, and predictions. 

Objectives To prepare the demonstration we have modelled  the  system  using  Matlab/Simulink  and  constructed  optical,  mechanical  and  hardware  systems,  see  Figure  1.  The  optical  system  captures  image  data,  which  are  used  in  the  hardware  system  implementing  a  navigation  algorithm  to  define  the  location  of  the  mechanical system.     The core of this project is correlation‐based real‐ time  image  processing  and  is  implemented  in  the  hardware  system.  At  the  beginning  the  image  of  a  reference  location  is  captured  and  stored  in  memory.  Image  correlation  between  the reference image and successive image data is  used  to  determine  the  current  position  of  the  mechanical system.  

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Figure 2: Boundary conditions implementation  architecture. 

For further information contact: Najeem Lawal  Najeem.lawal@miun.se  Supervisor: Prof. Mattias O’Nils 

Figure 1: Experimental setup. 

  Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

FPGA BASED COMPUTER SYSTEMS Background The ever‐growing integration of functionality in  industrial  and  automotive  embedded  systems  has  introduced  the  requirement  for  real‐time  video  processing  capabilities  in  many  systems.  An  FPGA‐based  implementation  of  embedded  systems provides many attractive characteristics  such as high flexibility, low cost, and a high level  of  integration.  These  characteristics  make  FPGA:s  especially  suitable  for  video  related  applications.  FPGA:s  provide  the  possibility  for  System‐on‐Chip (SoC) designs where most of the  system  components,  such  as  CPU:s  video‐,  and  communication  controllers,  are  all  implemented  on  the  FPGA.  In  addition  to  the  various  advantages  of  a  SoC  design,  FPGAs  also  avoid  the  problems  caused  by  the  end‐of‐life  for  standard components.    

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Results A set  of  FPGA‐based  architectures  that  perform  cropping, scaling and de‐interlacing of real‐time  video  streams  has  been  designed.  These  architectures are suitable for use in FPGA‐based  video enabled computer systems and allow these  systems to be implemented using low cost FPGA  devices.  An  FPGA‐based  video  enabled  computer  system  that  supports  the  display  of  four separate video sources can be implemented  using a Xilinx Spartan 3E FPGA with 500 Kgates.  The work has been reported in a licentiate thesis.   

Objectives The goal  of  this  project  is  to  develop  FPGA‐ based architectures that allow the design of cost‐ effective  FPGA‐based  computer  systems  with  real‐time  video  processing  capabilities.  A  frequently  occurring  requirement  for  embedded  computer systems is the capability of displaying  multiple  real‐time  video sources  combined  with  computer  generated  graphics.  Real‐time  video  processing is a very data intensive task which is  often  beyond  the  processing  capabilities  of  the  CPU:s used in typical industrial and automotive   applications.  With  an  FPGA  based  video  pre‐ processor  that  provides  real‐time  video  data  directly  to  the  display  memory,  any  computer  system  can  be  made  capable  of  displaying  real‐ time video. 

Ongoing activities Currently a  prototype  system  is  being  designed  for  further  evaluation  of  the  designed  video  processing architectures. For further information contact: Professor Mattias O’Nils  mattias.onils@miun.se 

Niklas Lepistö  niklas.lepisto@miun.se 

  Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

SIMULATING BEHAVIORAL LEVEL ON-CHIP NOISE COUPLING Background

developed, resulting  in  BeNoC  that  is  a  behavioural  level  noise  coupling  simulation  method consisting of several models for physical  properties  and  noise  injection.  Adaptations  of  existing  models  have  been  made  for  physical  properties  and  noise  injection  for  use  in  higher  design  levels  such  as  the  behavioural  level.  The  adoption includes an increase of accuracy for an  interpolation  method  used  in  substrate  resistance  extraction.  A  simplification  of  gate  level  noise  injection  models  for  capacitive  coupling  and  impact  ionization  noise  has  also  been  developed.  Finally,  a  test  has  been  conducted using BeNoC in a real system design  example  of  a  photon  counting  pixel  detector  readout system.     

The integration  of  analog  and  digital  systems  onto  a  single  chip  causes  significant  problems  related  to  noise  coupling,  which  appears  as  switching currents that couple from digital logic  to sensitive analog nodes. In order for designers  of mixed‐signal systems to be able to locate noise  coupling  problems  and  to  insert  counter‐ measures,  means  of  simulating  the  source  of  noise  coupling  problems  are  required.  Since  the  only  simulation  tools  available  for  noise  coupling    are  intended  for  layout  level,  the  problem  at  hand  is  to  define  how  to  simulate  noise coupling throughout an entire design flow,  where  the  starting  point  occurs  at  an  early  design level.    

Objectives The contribution of this project and this thesis is  the  introduction  of  the  simulation  methods  and  models  called  BeNoC  (Behavioral  level  Noise  Coupling),  which  can  be  used  to  quantify  noise  coupling  problems  in  behavioral  level  designs.  In  an  application  test  case,  noise  coupling  in  photon  counting  pixel  detector  readout  systems  will be investigated.   

Noise models Capacitive coupling

Impact ionization

Noise injection

Noise coupling simulation models

Physical properties Substrate model

Power distribution model

Final noise spread

Ongoing activities

Schematic image of the different models needed in an  on‐chip noise coupling simulation method.       

The work has resulted in a doctoral thesis (ISBN:  978‐91‐85317‐54‐7) that has attracted attention by  a  Norwegian  company,  resulting  in  an  idea  to  apply for project funding for the development of  applicable  simulation  models  in  a  design  environment.   

For further information contact: Ph. D. Jan Thim  Jan.Thim@miun.se 

Results A low‐level  motivational  study  of  the  on‐chip  noise  coupling  problems,  which  can  occur  in  photon counting pixel detector readout systems,  has  been  done.  Simulation  models  have  been 

  Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

PERFORMANCE OF INFORMATION COLLECTION OF WIRELESS SENSOR NETWORK ROUTING Background

lifetime definition  increases  the  difficulty  in  building  formal  mathematical  models,  ,  since  there  is  no  fixed  reference  for  the    application  power  requirement.  We  have,  however,  achieved a formal routing analysis method using  this information metric and the new information  based  network  lifetime  definition.  Experiments  have  shown  that  our  model  can  generate  tight  upper bounds for different situations, and that it  can be used to evaluate existing algorithms, such  as  minimum  hop  (MH),  minimum  energy  consuming  path  (MTE)  and  flow  augmentation  (FA), as well as future routing algorithms.  

Handling routing problems is considered to be  the  core  of  a  wireless  sensor  network  design.  This  is  particularly  true  for  those  ubiquitous  information‐collecting purpose sensor networks,  where  communication  dominates  the  critical  sensor  energy  usage  and  the  efficiency  of  the  underlying  routing  algorithm  determines  the  efficiency  of  the  whole  network.  However,  the  fundamental  performance  bounds  or  reference  to  the  “optimal”  solution  for  maximizing  the  information  during  the  “lifetime”  of  a  wireless  sensor network still remain unclear.    

4000 Information collected throughout network lifetime

Objectives    In  this  project,  the  goal  is  to  find  a  formal  routing  analysis  model  that  can  provide  a  tight  upper  bound  of  the  information  collection.   Accordingly  thus  the  model  can  be  used  to  evaluate  existing  and  upcoming  routing  algorithms. 

Ongoing activities Currently our  optimization  model  is  under  evaluation.  The  result  shows  that  the  proposed  model  can  be  used  as  a  benchmark  for  performance  evaluation  of  sensor  network  routing algorithms.   However,  the  model  does  not  take  the  link  quality  routing  overhead  into  consideration.  This can be the future work.    

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  For further information, contact:  Qinghua Wang  qinghua.wang@miun.se  Supervisor: Doc. Tingting Zhang 

We propose  an  analytical  model  where  the  lifetime  of  an  information‐collecting  sensor  network  was  determined  by  the  condition  that  the  residual  network  power  should  not  fail  to  supply the power requirement of the underlying  application. This new and more realistic network 

Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

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Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

SECURITY IN WIRELESS SENSOR NETWORK Background

node. Correspondingly,  the  traffic  transmitted  between different nodes is classified. Obviously,  such  a  classification  limits  the  size  of  the  set  of  translated  packet  events  and  the  set  of  traffic  patterns  recorded  based  on  these  events.  As  a  consequence  the  node  profiles  recorded  are  appropriate  for  anomaly  detection  on  sensor  nodes  with  limited  resources.  The  analysis  of  detection  of  example  attacks  shows  that  node  profiles  built  like  this  has  the  ability  to  differentiate  between  normal  behavior  and  an  attack.   

The security  threats  to  wireless  sensor  network  are  quite  different  from  those  in  Internet  and  mobile  ad  hoc  networks.  The  wireless  communication, large scale and possible human  unattended  deployment  make  attacks  on  wireless  sensor  networks  relatively  easier  to  perform.  Furthermore,  all  features  that  make  sensor  nodes  cheap  and  affordable,  such  as  limited energy resource, limited bandwidth and  limited  memory,  also  make  many  established  security  mechanisms  inappropriate  in  sensor  networks.   

Objectives In this  project,  the  goal  is  to  develop  sensor  network  security  mechanisms,  both  technical  and at management level, that are power aware.  

Local Local Local Neighbor ...

Ongoing activities

Results 1. A  study  of  secure  and  energy‐efficient  group  communication  for  sensor  networks  has  been  performed.  2.  We  have  presented  a  method,  which  builds  accurate node profiles based on traffic modeling  of  each  interested  node.  For  the  first  time,  the  traffic  patterns  are  recorded  according  to  the  packet  arrival  event  order  in  the  network.  To  make  the  traffic‐based  recording  strategy  scalable in networks of different sizes, the nodes  are  classified  in  categories  such  as  local  nodes,  non‐local nodes etc., centering on each interested 

Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

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RREQ RREP DATA HELLO …

A B C D …

Node Address: 00—Sink, 10—“me”

Currently our profile‐based anomaly detection  model is evaluated. We are building sensor node  profiles in a simulated wireless sensor network  and check its performance in detecting different  kinds of attacks. An automatic emergency  response system is on the way to be investigated.   

 

Event … A B D C C

Translation Table

Src

Dest

... 15 00 12 15 15

… 00 15 10 00 00

Packet Type … RREQ RREP HELLO DATA DATA

Src

Dest

… Local Sink Neighbor Local Local

… Sink Local Me Sink Sink

Packet Type … RREQ RREP HELLO DATA DATA

(a) Extract selected features (b) Packet Classification from arriving packets For further information, contact:  Qinghua Wang  qinghua.wang@miun.se  Supervisor: Doc. Tingting Zhang 

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

PERFORMANCE OF DIGITAL FLOATING-GATE CIRCUITS OPERATING AT SUBTHRESHOLD POWER SUPPLY VOLTAGES Background

CMOS at 150 mV power supply. Other aspects of  FGMOS design have been to look at how refresh  circuits  will  affect  performance  (semi‐floating‐ gate circuits) and how a larger fan‐in will change  noise margin and EDP. When it comes to fan‐in  the simulations shows that a maximum fan‐in of  5 is possible at 250 mV supply and it decrease to  3 when supply voltage is reduced to 150 mV.   

All who are involved in electronic design knows  that one of the critical issues in todays electronic  is the power consumption. Designers are always  looking  for  new  approaches  in  order  to  reduce  currents  while  still  retaining  the  performance.  Floating‐gate  (FGMOS)  circuits  have  previously  been  shown  to  be  a  promising  technique  to  improve  speed  and  still  keep  the  power  consumption  low,  when  the  power  supply  voltage  is  reduced  below  subthreshold  voltage  for the transistors.   

Objectives In this project, the goal is to determine how good  floating‐gate  circuits  can  be  compared  to  conventional  static  CMOS  when  the  circuits  are  working  in  subthreshold.  The  investigation  also  includes  trade‐offs  between  speed  and  power  consumption  for  better  performance,  how  to  select  floating‐gate  capacitances,  how  a  large  circuit  fan‐in  will  affect  performance  and  also  the  influence  of  different  kinds  of  refresh  circuits.       

Ongoing activities Currently the  yield  issue  for  FGMOS  circuits  is  investigated for low‐voltage operation.   

For further information contact: Lic. Eng. Jon Alfredsson  Jon.Alfredsson@miun.se  Supervisor: Prof. Bengt Oelmann

Results The first simulations of the FGMOS circuits in a  0.13 μm process have several interesting results.  First  of  all,  in  the  best  case  it  is  shown  that  FGMOS has potential to achieve up to 260 times  in  better  EDP‐performance  compared  with  

  Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

POWER AWARE WIRELESS CLOSED LOOP CONTROL SYSTEM FOR LOADER CRANES the wireless sensor network on a loader crane for  a local positioning system?   

Background Advances  in  microelectronics  and  wireless  communication  technology  provide  opportunities  for  many  different  application  fields.  A  vast  number  of  systems  that  traditionally  have  been  wired  and  inhibited  by  cost and feasibility of wiring, can today often be  replaced  by  wireless  solutions.  However,  when  going  wireless,  several  new  challenges  must  be  overcomed.  One  challenge  is  the  power  supply  for  all  sensor  devices.  To  expand  the  lifetime  of  the  network  it  is  therefore  a  key  design  parameter  to  minimize  the  power  consumption  in the sensor devices.   

 

Ongoing activities  Currently a framework for describing the design  of a wireless sensor network for local positioning  system  taking  real‐time,  low‐power,  and  reliability aspects into account is developed.    

Results

 

Objectives One  goal  is  to  build  a  technology  platform  for  exploring  different  sensor  configurations  to  verify  the  theoretical  models  experimentally  in  field  tests  (resulting  in  the  SENTIO  platform).  The  project  should  also  answer  the  questions:  What  are  the  limitations  of  currently  proposed  standards  for  wireless  sensor  networks  in  closed‐loop control systems? How to organise    

  Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

A hardware/software platform for short‐range  wireless sensor networks has been developed  and used in various applications. Also, the  limitations of the proposed standard  IEEE802.15.4 has been identified and described.  An alternative protocol has been proposed for  wireless closed‐loop control systems with hard  real‐time requirements. 

For further information contact: MSc. Fredrik Linnarsson  Fredrik.Linnarsson@miun.se  Supervisor: Prof. Bengt Oelmann

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

JOINT ANGULAR SENSORS FOR CONTACT-LESS MEASUREMENTS different sensor  configurations  based  on  accelerometers.    

Background Joint  angular  sensors  are  widely  used  in  the  industry, from highly effective robots in product  line  and  heavy  construction  machines  in  building  sites  to  small  knobs  on  home  appliances.  There  are  contact‐less  joint  angular  sensing  methods  available,  such  as  inertial  measurement  by  Micro‐Electro‐Mechanical  System (MEMS) gyroscopes and accelerometers.  The big advantage of these contacts‐less sensing  methods  over  their  conventional  counterparts is  that  they  do  not  have  relative  mechanical  movements, which can make them more reliable,  cost less as well as last longer. 

Ongoing activities  Currently,  hardware  for  accurate  sensor  electronics  is  developed.  These  devices  will  be  used  for  several  purposes.  The  results  obtained  for the DCMR method that is theoretically error‐ free  contains  small  errors  that  we  so  far  cannot  explained.   Here  the  more  accurate  sensor  electronics  will  hopefully guide us to the sources of these errors.  It  will  also  be  used  for  field  tests  on  HIABs  cranes  to  explore  performances  of  the  distributed  wireless  sensor  network  as  well  as  redundancy schemes.   

Results On  the  basis  of  the  error  model  of  the  CMR  method,  we  give  an  analysis  outlining  the  advantage  of  the  theoretically  error‐free  DCMR  method. The sensor calibration and alignment is  described  and  both  methods  are  characterized  on  a  rigid  body  robot  arm  model.  The  experiment shows the angular error up to 0.4 rad  from  the  CMR  method  whereas  just  0.03  rad  from the DCMR method. 

For further information contact: MSc. Peng Cheng  Peng.Cheng@miun.se  Supervisor: Prof. Bengt Oelmann

Objectives The goal of this project is to develop methods for  contacts‐less  measurements  that  can  withstand  harsh  environments  often  found  in  industrial  and automotive applications. The initial problem  addressed  is  the  development  error‐models  for 

  Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

INNOVATIVE RFID SOLUTIONS AND PRINTED ELECTRONICS Johan Sidén works within the area of RFID as well as  printed  electronics  and  graduated  from  his  PhD  studies  in  May  2007.  He  now  divides  his  time  between a continued academic career and at the spin‐ off company Sensible Solutions Sweden AB. 

Background Radio Frequency  IDentification  (RFID)  is  a  collection  of  technologies  for  wireless  identification  and/or  to  retrieve  information  about  an  object.  The  academic  focus  is  put  on  innovative antenna solutions that allow effective  implementation of RFID, where it earlier was not  technically or economically possible. 

Moisture measurement  system  based  upon  pairs  of ordinary RFID tags 

 

Results The group  has for  example  shown  how  pairs  of  ordinary  RFID  tags  can  be  configured  and  applied  similar  to  a  sticker  to  be  used  as  remotely read as moisture sensors, placed within  floors and walls.  In  collaboration  with  industry,  the  group  has  also  developed  an  extremely  small  RFID  tag  (relative to the wavelength) which can be placed  within  metallic  cavities  and  survive  under  very  hard  conditions.  Similar  examples  involve  integration of RFID tags in a metallic label used  by the local industry without changing the outer  dimensions.  The  printed  electronics  has  also  demonstrated  a  printed magneto static speaker. 

Typical RFID Tag   

Objectives and Ongoing activities In this  project,  one  of  the  goals  is  to  develop  RFID  tag  antennas  for  applications,  where  commercially  available  products  do  not  live  up  to  the  requirements.  Another  technical  objective  is  to  combine  available  low‐cost  RFID  technology  with  sensors.  A  third  objective  is  to  together  with  local  industries  form  an  interest  organisation within the general area of RFID.   

For further information contact: Dr. Johan Sidén   Johan.Siden@miun.se  Tel. +46 70 671 71 71 

Left: Printed Magneto static speaker  Middle:  An  UHF  RFID  tag  measuring  only  0.05  wavelengths in diameter to be put in metallic cavities.  Right: A metallic label with integrated RFID antenna. 

  Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

ARCHITECTURE AND CIRCUIT DESIGN OF PHOTON-COUNTING READOUT FOR X-RAY IMAGING SENSORS Background

Hybrid pixel  array  detectors  for  X‐ray  imaging  are  based  on  different  technologies  for  sensor  and  readout  electronics.  The  readout  electronics  are  based  on  standard  CMOS  technologies  that  are  experiencing  continuously  rapid  improvements  by  means  of  down‐scaling  the  feature  sizes,  which  in  turn  leads  to  higher  transistor  densities,  lower  power  consumption,  and faster circuits.   The  advantages  of  down‐scaling  the  CMOS  technology can be utilized to increase the spatial  resolution  by  reducing  the  pixel  sizes.  Recent  research indicates however that the bottleneck in  reaching  further  spatial  resolution  in  X‐ray  imaging  sensors  may  not  be  limited  by  the  circuit  area  occupied  by  the  functions  necessary  in  the  pixels,  but  is  instead  related  to  problems  associated  with  charge‐sharing  of  charges  generated  by  the  sensor  which  are  distributed  over a neighbourhood of pixels and will limit the  spatial resolution and lead to a distortion of the  energy spectrum.   

Ongoing activities Currently an  experimental  platform  is  developed  to  support  elaboration  of  different  readout architectures through experiments.   

Results The method  is  based  on  colour  sub‐sampling  with  intensity  biasing.  For  three‐level  energy  discrimination,  that  corresponds  to  colour  imaging systems for visible light with R, G, and  B  colour  components,  the  increase  in  circuit  complexity will be only 20% higher than that for  the  Bayer  method  but  it  results  in  significantly  better image quality.   The  proposed  architecture  and  its  circuit  implementation  are  evaluated  with  respect  to  circuit  complexity  (area)  and  power  consumption.  For  a  photon‐counting  pixel  it  is  demonstrated  that  the  complete  pixel,  with  charge‐sharing  suppression  mechanism,  can  be  implemented  using  300  transistors  with  an  idle  power consumption of 2.7μW in a 120nm CMOS  technology operating with a 1.2V power supply.     

Objectives The improvements in CMOS technology can also  be used to extend the range of applications for X‐ ray imaging sensors. In this project, the objective  is  to  explore  different  readout  architectures  that  can  take  advantage  of  the  down‐scaled  CMOS  technology  to  advance  the  readout  electronics’  capability  to  increase  spatial  resolution  and  multiple  energy  discrimination  to  be  used  in  future colour X‐ray imagers. 

  Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

For further information  contact:  Lic. Eng. Suliman Abdalla  Suliman.Abdalla@miun.se  Supervisor:   Prof. Bengt Oelmann 

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

INTEGRATED COMPACT FT SPECTROMETER BASED ON A POSITION SENSITIVE DETECTOR AND FABRY-PEROT INTERFEROMETER WEDGE Background

number of measurement points, equivalent to pixels on a CCD, and thereby a large spatial resolution. In the figure is shown a spectra of a green Diode Pumped Solid State laser (DPSS) displaying the primary green frequency-doubled wavelength at 532 nm from the KTP crystal as well as the 1064 nm primary lasing wavelength and the IR pump laser diode at 808 nm.The resolution is approximately 5 nm for the constructed device but can potentially be higher. The advantage of using a PSD for readout is the simplicity of the electronics and that the position of each measurement is accurately known without the need for a high precision scanning mechanism or calibration source.

For many  applications  there  is  an  interest  in  developing  compact  and  cost‐effective  spectrometers  for  handheld  and  compact  stationary instruments.    

Objectives To construct  and  evaluate  these  compact  and  cost‐effective  spectrometers  based  on  Fabry‐ Perot wedge interferometers. 

Ongoing activities An FT  spectrometer  based  on  a  multi  channel  wedge  Fabry‐Perot  interferometer  using  a  scanning  slit  and  a  lateral  effect  position  sensitive  detector  (PSD)  has  been  manufactured  and evaluated.     

Results The spectrometer is based on a multi channel Fabry-Perot interferometer manufactured as a glass wedge, where the transmission function for each wavelength and thickness of the wedge is given by the equation

T (λ ) =

(1 − R )2 (1 − R )2 + 4 R sin 2 (2πnd cosθ / λ )

The resulting interferogram is detected using a PSD by scanning a slit in front of the interferometer wedge and PSD, thereby obtaining both the intensity and position for each measurement.

    For further information contact: Lic. Eng. Henrik Andersson  Henrik.Andersson@miun.se  Supervisor:   Dr. Göran Thungström

The position of the slit is accurately known for each measurement thereby eliminating the need for a high-precision scanning mechanism or calibration source. The spectral resolution can potentially be very high because of the high resolution of PSDs. Using a long detector combined with a narrow slit gives a large

 

Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

DEVELOPMENT OF LOW-COST THERMAL DETECTOR FOR DETECTION OF CO2 USING NDIR METHOD Background

V/W. Biasing the bolometer with 2.5 V @ 10Hz  resulted in a sensitivity of 9.3 V/W.   

Thermal sensors  for  IR  detection,  such  as  bolometers  and  thermopiles  are  used  in  a  number  of  applications.  These  applications  include  remote  temperature  control  and  gas  detection.  One  step  in  the  direction  towards  a  low‐cost  system  is  the  usage  of  a  low‐cost  infrared  detector.   

Objectives

The goal  of  this  research  project  has  been  to  produce  a  low‐cost  thermal  detector  using  standard  processing  techniques  and  new  materials.    In many existing thermal detectors the thermal  link is formed by a thin membrane of either Si or  Si3N4. In a low‐cost detector, a polymer such as  SU‐8 could be an alternative to regular Si and  Si3N4 membranes. SU‐8 has low thermal  conductivity and requires only standard silicon  lithography processing.   

   

Ongoing activities

   

Thermopile IR response

The current  work  is  concentrated  on  increasing  the yield of the process and the sensitivity of the  detectors.   

For Further information  contact:  Lic. Eng. Claes Mattsson  Claes.Mattsson@miun.se  Supervisor:  Dr. Göran Thungström 

Results A metal film resistance bolometer and a  thermopile detector were fabricated. Both types  of detectors consisted of a 4 μm thin SU‐8  membrane, into which the temperature sensitive  elements where encapsulated. The IR sensitivity  was evaluated using an infrared diode laser with  a power of 4.5 mW and a wavelength of 1.56 μm.  The thermopile show a sensitivity of about 5.6 

 

Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


PROJECT INFORMATION – February, 2008 STC – Sensible Things that Communicate

INTEGRATION OF RADIATION DETECTORS IN WIRELESS SENSOR NETWORKS Background

There is  an  increasing  demand  for  security  solutions  in  order  to  ensure  sustainable  and  responsible  usage  of  radioactive  resources.  This  is especially true as nuclear energy production is  considered  in  regions  with  significant  political  instability.  Global  sensor  networks  based  on  global mobile telephone platforms maybe a very  interesting  way  to  create  a  world  wide  nuclear  watch dog service.    

Ongoing activities  The  project  is  a  new  identity  within  the  STC@MIUN  but  is  based  on  the  knowledge  platform  for  integrated  radiation  detectors  developed  since  1996  at  the  Mid‐Sweden  University.  Together  with  researchers  in  computer  science  and  informatics  the  more  general  society  oriented  questions  can  be  addressed.    

Objectives  

Results

The aim of the project is to promote world wide  integration of sensor functions in mobile phones  that  may  be  used  to  monitor  the  nuclear  radiation  world  wide.  The  project  restricts  itself  to  technology  issues.  However,  we  also  would  like  to  initiate  a  discussion  regarding  using  the  mobile  phone  systems  for  surveillance  of  environmental  parameters  of  interest  for  humanity  world  wide.  We  hope  to  do  this  by  showing sensor  functionalities  related  to  mobile  phone  that  can  provide  the  desired  functionalities.  In  addition  we  would  like  to  investigate  optimal  sensor  functions  for  such  surveillance  application  by  answering  questions  like    ‐ Is  the  total  radioactive  dose  the  main  issue or do we need energy resolution in  the detector?  ‐ How  should  the  communication  protocol be organized?  ‐ What kind of intelligence do we need to  threshold the communication?  ‐ Can  such  detector  system  be  developed  utilizing  a  Wikinomics  type  of  business  model  or  is  it  entirely  an  issue  for  national security organisations? 

This is  a  new  research  project  based  on  earlier  research  results  obtained  in  the  area  of  medical  imaging  and  direct  photon  counting  colour  X‐ .ray imaging. The new application area demands  technologies  that  offers  extremely  low  noise  readout  of  sensor  data.  The  photon  counting  readout  technique  can  deliver  such  low  noise  operation.     To  get  a  small  size,  a  semiconductor  detector  is  preferred. Heavy compounds like CdTe or GaAs  have  much  better  absorption  than  Si  for  high  energies,  but  the  internal  fluorescence  in  the  material  distorts  the  energy  signature.  The  influence  of  fluorescence  in  CdTe  has  been  studied in several recent publications.        

  Mid Sweden University STC – Sensible Things that Communicates 851 70 Sundsvall

For further information contact Dr. Börje Norlin   Borje.Norlin@miun.se  Mid‐Sweden University 

Phone: 0771-975 000 Fax: 060-14 84 56 Internet: www.miun.se/stc www.kks.se


A research program at Mid Sweden University, sponsored by The Knowledge Foundation, in partnership with:

Adal AB

STC Annual Report 2007  

2007 års årsrapport för Mittuniversitetets forskningsprojekt Sensible Things that Communicate.

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