stc annual report 2008

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STC@MIUN - annual report 2008

Table of contents 1. Introduction ..................................................................................................................... 1 2. The STC reference system ............................................................................................... 1 3. Research objectives ......................................................................................................... 2 4. Summary of research results ............................................................................................ 4

4.1. STC Systems and applications ................................................................................. 4 4.2. STC Network solutions ............................................................................................ 5 4.3. STC Wireless solutions ............................................................................................ 5 4.4. STC Sensor solutions ................................................................................................ 6 4.5. STC – MediaSense ................................................................................................... 6 4.6. Common demonstrator systems ................................................................................ 7

4.6.1 High Accuracy Wireless Instrument (SENTIO-HA) .......................................... 8 4.6.2 Wireless sensor platform for environmental monitoring (SENTIO-e2) ............. 8 4.6.3 Urban sensing (SENTIO-BT) ............................................................................. 9 4.6.4 High performance ZigBee platform (SENTIO32) ............................................ 10

5. PhD examinations during 2008 ..................................................................................... 11 6. New staff and promotions .............................................................................................. 16

6.1 New PhD students within STC and supporting projects ......................................... 16 7. Publications 2008 .......................................................................................................... 19 8. STC@MIUN research projects ...................................................................................... 21

The STC@MIUN research program 20 April 2009 Electronic systems for Sensible Things that Communicate

Mid Sweden University 1 Department of Information Technology and Media

1. Introduction The evolution of the 3G mobile telephone systems, from the first point-to-point commu-

nication 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 pos-sible 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 Com-municate include technology for data communication, data processing, and sensing. The re-search field covers a large area, which can be described by the access network presented in the Fig. 1.1.

2. The STC reference system

Access network node

Communication access point

Surveillance node

Telemedicine node

Visualization node Multimedia terminal

Dispensable communication terminal

Arbitrary STC

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 five different technology platforms with tech-nologies 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 aggrega-tion and system security

3. Wireless hardware platform (STC Wireless Solution)

- Low power wireless sensor node design and energy harvesting


2 Mid Sweden University Department of Information Technology and Media

4. Sensor hardware platform (STC Sensor Solution) - Development of innovative sensor structures for industrial surveillance

From 2008, STC also includes a fifth technology platform targeting personal sensor based services.

5. Wireless services platform (STC MediaSense) - Sensor based mobile services and urban measurements

3. Research objectives The objective of STC@MIUN is to develop knowledge and technology to support-

distributed sensing in industrial and personal applications. Distributed sensing technology will enable advanced digital services such as, for example, remote presence or high precision visi-bility in industrial supply chains, as illustrated in Fig 1.2 below. The distributed sensing de-mands stable intelligent sensor network solutions operating at low power levels, utilizing en-ergy 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. 1.2 Illustration of the evolution of telecommunication towards true remote presence services. Our main focus is on key technology areas such as:

- real-time video processing - power efficient routing and networking - low-power collaborative sensing - energy harvesting - low-cost radiation sensor solutions - printed electronics - mobile services based on sensor data

Initially, our resources were concentrated on the development of key technologies of rele-

vance 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. 1.3.



Fig. 1.3 Time evolution of objectives for the STC@MIUN research program

Example of such concept and service demonstrators that have started during 2008: - Early warning system for surveillance of industrial machines, which includes research

within: o Computational platforms for wireless visual sensor nodes o Platforms for wireless sensor nodes o Communication strategies and methods for visual sensor nodes o Building industrial services targeting to create new markets for traditional

industry. - Urban measurement systems, which includes research within:

o Wireless sensor nodes o Wireless sensor networks o Mobile services

Development of technology plattforms

Development of con-cept demonstrators Further development of technology plattforms Demonstration of servi-ce concepts

Start End



4. Summary of research results During 2008 there has been significant development in STC@MIUN’s technology plat-

forms. 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 be-

ing 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’s work includes a number of ac-tivities on embedded machine vision applications. Design experience from these performance demanding applications has contributed with knowledge into our FPGA technology develop-ment. The results for 2008 can be summarized as follows: Automatic design methods for optimized implementation of real-time video processing systems: We have developed a memory synthesis design flow for FPGA implementation of real-time video processing. This synthesis is based on methods to optimize the memory archi-tecture for area and power and for a selected FPGA architecture. This year’s work includes power optimizations based on the constraining of the placement and routing process. In addi-tion, the searched design space is now extended with both distributed memory as well as block-Rams. A doctoral thesis was presented in this area and cooperation with Mälardalens Högskola and Prof. Lars Asplund was initiated.

Investigation of specific challenges in real-time video processing systems: An FPGA based multi-channel analogue video-display computer was demonstrated during previous years. During 2008, the extension with digital Ethernet-based video streams was partly added to the previous video graphics processor. This year’s work indicates that it will be possible to reach real-time performance for the demultiplexing of up to four input Ethernet video streams. Our work will be continued during 2009 with MJPEG decoding for all four video streams, downscaling and displaying. Up until now, we have all reasons to believe that the whole graphics processor can be implemented on a single FPGA and thus enable a low cost solution for the consumer market. Analysis and development of embedded machine vision applications: A project in coop-eration with STC Sensor Solutions is aimed at the detection and characterization of magnetic particles in hydraulic fluid. This is an industrial application of video processing at low sam-pling rates in the temporal domain. Reaching low energy for a battery powered wireless solu-tion is a clear research challenge. A work has been initiated during this year to study energy costs for such image processing operations on an FPGA platform in comparison with a gen-eral purpose processor. We have in addition two externally funded projects in embedded machine vision. These pro-jects investigate real-time measurements of surface topology on paper and optical positioning. An experimental topology measurement system for laboratory environments was set up to work with good results during 2008. The front-end image processing of a position- and orien-tation measurement system was modelled and also partly implemented on an FPGA platform.



4.2. STC Network solutions The overall goals for the network solution part of the profile are to discover efficient (low-

er power) and secure sensor data collection for applications such as environment monitoring, surveillance and network traffic monitoring. Our results for 2008 can be summarized as:

Traffic Load Distribution in Large-Scale and Dense Wireless Sensor Networks: Traffic load is not evenly distributed over the nodes in a multi-hop wireless sensor network (WSN). Understanding the traffic load distribution can guide the network-wide energy allocation, di-rect the design of routing algorithms, and optimize the node deployment in WSNs. We have analysed the traffic load in wireless sensor network. We found the traffic load distribution over the deployed nodes as a function of their distances from the sink in the even-distributed large-scale and dense sensor networks. The results are useful for proposing efficient energy allocation scheme thus the energy allocation is balanced according to the traffic load. Policy-Based Security Management for Sensor Networks: we propose a sensor network security management framework called Sec-SNMP, which organizes and manages security related behaviors in sensor networks based on security policies. There are three main compo-nents in Sec-SNMP: Sec-SNMP manager, Sec-SNMP agent and a policy control and deploy-ment protocol. Sec-SNMP manager provides the interface between human administrator and the managed mesh network. Sec-SNMP agent represents Sec-SNMP manager to enforce secu-rity policies within the managed mesh network. The policy control and deployment protocol allows the communication between Sec-SNMP manager and Sec-SNMP agents.

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. Two new fields of applications for wireless sensor networks have been started up in 2008; WSN for environ-mental monitoring and urban sensing. Distributed angular sensor: We have presented a joint angular sensor consisting of four dis-crete 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 ob-tained we are able to demonstrate an accuracy level which is higher by a factor of 10. More-over 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. The accumulated knowledge in joint-angular sensing has been summarized in a survey paper that has been accepted for publication in IEEE Transactions on Instrumentation and Meas-urements (“Joint-angle Measurement Using Accelerometers and Gyroscopes - A Survey”). Analysis of the communication requirements for closed-loop control system: By analys-ing the proposed standard for wireless sensor networks (IEEE802.15.4) for applications hav-ing hard real-time requirements, we have concluded that only a very few applications are ful-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, portable instrument for spectroscopic

identification alpha emitters, X-ray imaging microscope for material resolving and develop-ment of X-ray imaging sensors are in development and have been investigated during 2008. Development of low-cost thermal detector for detection of CO2 using NDIR method: Spreading the thermopiles in a thermopile structure more evenly and running developed de-sign optimization software. The sensitivity could be increased and the response time de-creased. This optimisation method together with new thermopile materials gives a respon-sivety of 60 V/W at a wavelength of 1.56 um. Portable instrument for detection of Polonium and other alpha emitters: Due to the in-creased threat of terrorism and other incidents where radioactive materials are dispersed there is an increasing need to detect the presence of such materials. Alpha is much more difficult to detect than beta or gamma radiation because of the attenuation in air, However alpha particles is very dangerous to humans if inhaled or ingested due to the high kinetic energy of alpha particles. Therefore it is needed a portable instrument which can by an electrostatic field col-lect airborne dust particles with radioactive contaminations. The instrument should be able to determine which type of radioactive material it is and gives therefore more information than for example a Geiger-Muller counter. Material resolving X-ray imaging microscope: An X-ray microscopy setup for energy re-solved imaging have been built. The microscopy consists of a micro focus source, a slit and a pixel detector. Small object can then be investigated and the possibility of energy resolution makes it possible to discriminate different materials Development of X-ray imaging sensors: Different types of X-ray imaging detectors have been developed at Mid Sweden University. A detector with 220x220 um pixel detectors have been developed where spectral performance is more important than spatial resolution. The size of the detector is 15x15 mm. Next project is to increase the size of the detector into a quad-detector. The detector needs now four readout electronic circuit, bump bonded to detec-tor. The size increase therefore to 30x30 mm, which increase the number of applications

4.5. STC – MediaSense The MediaSense project has made good progress in initializing activities as well as produc-

ing early results, since the project kickoff in June 2008. The initial activities this fall have been focused on creating means for aggregating and distri-buting user information from sensor information. This is pivotal to the project since the new service behavior which the platform should enable requires access to such information. Our initial approach is to, via Bluetooth, connect Wireless Sensor Networks (WSN) gateways to mobile phones or other devices and we have developed a low-power platform for commu-nicating with a multitude of sensors. Demonstration of research: At the Ericsson Research Mobile Java Communication Frame-work (MJFC) Developers Day on December 15, 2008 in Kista we successfully demonstrated a mobile group service with real-time sensor information (GPS, humidity, and temperature). This service is based on Presence in 3GPP IP Multimedia System (IMS). The service visua-



lizes groups of users along with sensor information in Google Maps for both mobile phones and PCs connected to the Internet. At the STC Expo co-located with the Sundsvall42 Conference in October 2008, we success-fully demonstrated a Mobile Awareness service which visualizes groups of users along with sensor information in Google Maps. Equally importantly, we demonstrate how this enables a Mobile Awareness service to alert users to proximity of members with common interests. We have created a first version of scalable support which is required to share and provide sensor data in large communities on the Internet in real-time. This support has interworking with IMS. Therefore, during 2009 we will be in the position to leverage access to distributed sensor in-formation in other application areas, in particular IPTV which also leverages progress made in supporting seamless services.

4.6. Common demonstrator systems An early effort of the STC program was to develop a prototyping platform for wireless

sensor networks. The purpose is to work as an integrating vehicle for the different technology platforms. Hereafter follows a description of the SENTIO prototyping platform.

The SENTIO platform for the rapid development of wireless sensor networks with short-

range communication has been developed and the first version has been available for all part-ners in STC since 2005. SENTIO has been used extensively in various applications involving very different characteristics. During 2007, for example, it was 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 net-works 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. The sensor platforms developed within STC enable rapid prototyping and evaluation of full-scale wireless sensor networks based on different technologies. It makes it possible for new sensor technologies to go wireless, new embedded systems and applications to be transferred to wireless network solutions.



4.6.1 High Accuracy Wireless Instrument (SENTIO-HA) The initial step in developing wireless sensors in systems or processes where no measure-ments have previously been made is to characterize the process. Therefore a high precision wireless instrument has been developed to tryout different solutions before going for an opti-mized custom/application-specific solution. This is a general-purpose unit that allows integra-tion of various types of sensors.

This provides a platform for evaluating new sensors in different applications where the re-quirements on a specific wireless sensor solution for a specific application can be evaluated. 4.6.2 Wireless sensor platform for environmental monitoring (SENTIO-e2) This unit is designed based on the requirements from wireless sensor networks for environ-mental monitoring. It is configurable and can be configured to handle all types of nodes (A-E) depicted in the figure below.

The local area WSN communication uses the 433MHz ISM band, and for global communica-tion GSM/GPRS can be used. It can also be configured for bridges between wireless networks and Internet.

Key features: ZigBee ready (2.4GHz, 250kbit/s) 24bit ADC, 128kS/s, 4 channels 32bit MCU with DSP instr. set Low energy consumption



A low-energy MAC protocol has been developed for local area WSN. Server support (Linux-based) with sensor database and presentation of sensor data in graphs and on Google Maps has been developed. This platform enables rapid development of large area sensor networks for various applications.

4.6.3 Urban sensing (SENTIO-BT) A new concept, developed together with the MediaSense project, where the mobile phones acts like gateways to the global communication infrastructure is used to pass on data from sensors. The basic idea is that when a sensor, with (Bluetooth communication capability) has new data to post, it tries to connect to a mobile phone via Bluetooth and then send the sensor information to it. The mobile phone simply passes on the data to a globally accessible data-base that can be used for all kinds of services. The SENTIO-BT is a sensor platform to which different kinds of sensors can be attached.

Key Features Dynamic power management for low power with low standby currents (down to 6 μA)

Sensor interface supporting digital (SPI) and analog sen‐sors

On‐board temperature sensor Auto‐detection of USB power Unregulated power input 2.2V to 5.6V DC 433MHz Local communication (up to 1km) Operation temperature range ‐40 to +85˚C Supports GSM/GPRS module with GPS USB interface 1 Mb/s Current monitoring on sub‐blocks enabled Size: 98 × 70 mm

Key features:

Range: up to 197m to a mobile phone Battery lifetime: up to 5 years Memory: 2GByte on microSD card Low power: 32μA in sleep mode Fast connect: Connects to mobile phone located inside a car passing by at 70km/h.



4.6.4 High performance ZigBee platform (SENTIO32) This platform has been developed to meet the requirements on sensor nodes with high local processing capability, reliable wireless communication and large local storage capability.

Key features: Communication

ZigBee ready (2.4GHz, 250kbit/s) 150m with on‐board printed antenna

Senor node processing capability 32bit RISC MCU (AVR32) 75DMIPS at 60MHz with DSP instruction set.

General Low sleep current : 60µA with 32KHz clock running Support microSD card with size up to 16GB Small size: 50 × 31×8 [mm]

Flexible sensor add‐on interface



5. PhD examinations during 2008 Dr. Henrik Andersson, Position Sensitive Detectors - Device Technology and Applica-

tions in Spectroscopy Henrik’s thesis deals with the development, processing and cha-

racterization of position sensitive detectors and, in addition, to the development of compact and cost effective spectrometers. Position sensitive detectors are used to measure, with great accuracy and speed, the position of a light spot incident on the surface. Their main use is for triangulation, displacement and vibration measurements.

A type of position sensitive detector based on the MOS prin-ciple and using optically transparent indium tin oxide as a gate con-tact has been developed. This type of detector utilizes the MOS principle where an induced channel forms beneath the gate oxide in

the surface of the Silicon substrate. One and two dimensional detectors have both been fabricated and characterized. The first

measurements showed that the linearity did not fulfill expectations and it was suspected that stress induced by the gate contact could be the reason for the seemingly high nonlinearity.

Further investigations into both the p-n junction and the MOS type position sensitive de-tectors lead to the conclusion that the indium tin oxide gate is responsible for inducing a sub-stantial stress in the surface of the detector, thus giving rise to increased position nonlinearity. The heat treatment step which was conducted was determined to be critical as either a too short or too long heat treatment resulted in stress in the gate and channel leading to position nonlinearity. If a correctly timed heat treatment is performed then the detector’s linearity is in parity with the best commercial position sensitive detectors.

In addition, the development of very small, compact and cost effective spectrometers has been performed with the aim of constructing devices for use in the process industry. The de-velopment of a wedge shaped array of Fabry-Perot interferometers that can be mounted di-rectly on top of a detector makes it possible to construct a very compact spectrometer using the minimum amount of optics. This wedge interferometer has been evaluated by means of array pixel detectors and position sensitive detectors for both the infrared and the visible wa-velength ranges.

When used with a position sensitive detector it is necessary to use a slit to record the in-tensity of the interferogram for many points over the detector, equivalent to pixels on an array detector. Usually the use of moving parts in a spectrometer will impose the use of high preci-sion scanning mechanisms and calibration. By using a position sensitive detector for the inter-ferogram readout both the position and the intensity are known for every measurement point and thus the demands placed on the scanning system are minimized.

Dr. Magnus Engholm, Materials Optimization for Optical Fiber Amplifiers and Fiber

Lasers Optical fibers doped with rare-earth ions such as erbium, ytter-

bium or thulium are frequently used as fiber amplifiers and fiber lasers. Erbium is a commonly used dopant in optical fibers for am-plification of optical signals in e.g. point to point transmission links or metro networks. The Er

3+ ion has broad absorption and emission

bands at the low loss transmission window in silica glass (near 1.5um) and are thus suitable as an active rare-earth ion for use in optical fiber amplifiers and fiber lasers.



The interest for fiber lasers has increased dramatically during the last decade. In particu-lar, there is a large interest for high power fiber lasers for use in different industrial applica-tions. Fiber lasers have a high efficiency and show several advantages compared with conven-tional lasers in terms of better beam quality, lower cost and a compact design. Materials processing such as cutting, welding and marking are the major application areas today. The ytterbium ion is the active ion of choice because it has a simple energy level structure and high optical conversion efficiency.

There is, nevertheless, still room for improvements of both the erbium and ytterbium doped silica glass matrix for use as fiber amplifiers and fiber lasers. The objective of the work presented in Magnus’s thesis is to improve the performance of the erbium doped fiber am-plifier and fiber laser by optimization of the silica glass material. The applied route is to pre-pare the glass material by doping with special precursor molecules to increase the separation between the Er

3+ ions and thereby reduce loss mechanisms related to the Er

3+ interatomic dis-

tance. Two different Er-precursors have been investigated. Induced optical losses, also known as photo darkening, is a loss mechanism in ytterbium

doped high power fiber lasers. It is found that the Yb3+ valence state is unstable in the silica glass and a fraction of the Yb-ions can be transferred to Yb2+, depending on the preparation conditions. Furthermore, it is found that this change in valence state (Yb2+ → Yb3+) can also be induced by a so called charge-transfer process. A model based on this valence instability is used to explain the photo darkening phenomenon in ytterbium doped fiber lasers. By using this model different paths to reduce, or even prevent, the extent of photo darkening are pre-sented in the thesis.

Dr. Jon Alfredsson, Limitations of Subthreshold Digital Floating-Gate Circuits in

Present and Future Nanoscale CMOS Technologies The people working within the electronic industry and who are

involved in electronic design are aware that one of the most critical future issues in electronics involves power consumption. The ITRS (International Technology Roadmap for Semiconductors), a branch organization, has even named the reduction of power consumption as one of the five major “grand challenges” defined for the future in integrated electronics. In order to reduce power consumption, one approach has involved reduction in the power supply, but the draw-back with this method is that there is also a reduction in speed per-formance and noise margins. Floating-gate circuit technique (FGMOS) has been suggested as a technique for improving perfor-mance when power supply is reduced. This is particularly desirable

for those events when the supply voltage is reduced to subthreshold for the transistors. In Jon’s thesis, the focus has been to investigate the behavior of certain floating-gate cir-

cuits working under subthreshold conditions and to compare their performance to convention-al static CMOS when they are designed for present nanoscale technologies. The performance parameters investigated in this case are based mainly on switching speed and power consump-tion. They can for example be used for trade-offs and combined into Power-Delay Product (PDP) and Energy-Delay Product (EDP).

Another of the grand challenges for the future, as is defined by ITRS, is Design for Manu-facturability (DFM). This is an important knowledge for electronic designers and also covered in his thesis. It involves the type of DFM that is required from the viewpoint of a FGMOS subthreshold designer in order to succeed.

In addition to the investigations into the performance of the parameters stated above, the work also includes guidelines on how to select floating-gate capacitances, how a large fan-in



the FGMOS circuit is able to handle in subthreshold and also how the performance will be limited by the use of different types of refresh circuits.

According to the Monte Carlo simulations and estimations, problems will probably arise in the manufacture of the FGMOS circuits with 100% yield and these will mainly be due to charge leakages and reduced noise margins. The conclusion from this research will show that at present, FGMOS in subthreshold is not a good alternative to CMOS and this will continue to be the case until new types of low-leakage processes are been developed.

Dr. Aron Larsson, Essays on Theories and Applications of Decision Analysis in Impre-

cise Domains Aron’s thesis consists of a collection of papers contributing to

the field of decision analysis. The main concern is the development of a framework for computer based decision modeling and evalua-tion, supporting the use of imprecise assessments and input parame-ters for the decision model. The papers are categorized into four research categories, 1) extensions, 2) evaluation methods, 3) appli-cations, and 4) interfaces.

The focus with respect to the first category has been on extend-ing a computational framework for decision analysis in imprecise domains, to support analysis of decisions with multiple objectives as well as under risk in a common model. This has been achieved

by developing procedures for allowing the use and coexistence of well founded models such as criteria hierarchies and influence diagrams in the framework.

Work falling within the second category is concerned with the investigation of decision evaluation procedures when allowing for probabilities of the second order to model epistemic uncertainty. The second order probability distribution on sets of probabilities and utilities is utilized in order to improve the power of expression in both input statements and evaluation results.

The third category studies and describes applications of the proposed decision analysis methods, presented as case studies. These case studies investigate one specific decision prob-lem at a time or classes of similar problems, and propose analytical models to assist in the formal analysis of these problems. Applications of the suggested methodology of this kind can partly be viewed upon as a validation of the suggested methods, and partly as a source of lessons to be learned for future development.

The final category is concerned with the interface between the decision analysis model, supposed to improve the decision maker’s capabilities, and the decision maker. It is important to mention that the interfaces are not limited to graphical user interfaces of software tools, but also with the means by which to elicit values and beliefs from stakeholders. The major con-cern associated with this category in Aron’s thesis has been the study of elicitation of risk attitudes.



Dr. Roger Olsson, Synthesis, Coding, and Evaluation of 3D Images Based on Integral Imaging

In recent years camera prototypes based on Integral Imaging (II) have emerged that are capable of capturing three-dimensional (3D) images. When being viewed on a 3D display, these II-pictures con-vey depth and content that realistically change perspective as the viewer changes the viewing position. Roger’s dissertation concen-trates on three restraining factors concerning II-picture progress. Firstly, there is a lack of digital II-pictures available for inter alia comparative research and coding scheme development. Secondly, there is an absence of objective quality metrics that explicitly meas-ure distortion with respect to the II-picture properties: depth and view-angle dependency. Thirdly, low coding efficiencies are

achieved when present image coding standards are applied to II-pictures. A computer synthesis method has been developed, which enables the production of dif-

ferent II-picture types. An II-camera model forms a basis and is combined with a scene de-scription language that allows for the describing of arbitrary complex virtual scenes. The light transport within the scene and into the II-camera is simulated using ray-tracing and geometri-cal optics. A number of II-camera models, scene descriptions, and II-pictures are produced using the presented method.

Two quality evaluation metrics have been constructed to objectively quantify the distor-tion contained in an II-picture with respect to its specific properties. The first metric models how the distortion is perceived by a viewer watching an II-display from different viewing-angles. The second metric estimates the depth distribution of the distortion. New aspects of coding-induced artefacts within the II-picture are revealed using the proposed metrics. Fi-nally, a coding scheme for II-pictures has been developed that inter alia utilizes the video cod-ing standard H.264/AVC by firstly transforming the II-picture into a pseudo video sequence. The properties of the coding scheme have been studied in detail and compared with other cod-ing schemes using the proposed evaluation metrics. The proposed coding scheme achieves the same quality as JPEG2000 at approximately 1/60th of the storage- or distribution require-ments.

Ulf Jennehag, Bandwidth Efficient IPTV Distribution- On Error Resilience and Fast

Channel Change Television is now changing its traditional distribution forms to

being distributed digitally over broadband networks. The recent de-velopment of broadband Internet connectivity has made the transition to Internet Protocol Television (IPTV) possible. When changing dis-tribution technique of an existing service, it is important that the new technique does not make the service worse from the user's point of view. Although a broadband network offers high capacity and has excellent performance there will be occasional packet losses and de-lays which could negatively influence the user experience of the de-livered broadband service. Since bandwidth is a key constraint for

video distribution there is a strong incentive for finding schemes to increase bandwidth utili-zation, especially when distributing high bandwidth IPTV services. In digital video coding it is common to use predictive coding to remove temporal redundancy in video sequences. This technique greatly increases the coding efficiency but makes the sequence more sensitive to information loss or delay. In addition, the use of predictive coding also introduce a inter frame dependency which could make the channel change significantly slower.



Ulf’s thesis addresses two important areas related to bandwidth efficient IPTV distribu-

tion, namely error resilience and fast channel change. A method to numerically estimate the decoded objective video quality of scalable coded video is presented and evaluated. The method can be used to estimate objective video quality for a scalable video transmission sys-tem subject to packet-loss. The quality gain of temporally scalable video in a priority packet dropping environment is also investigated and quantified. Synchronization Frames for Chan-nel Switching (SFCS) is proposed as a method to code and distribute video with IP-multicast, which can be used to efficiently combat packet-loss, increase bandwidth utilization, and offer a channel change speed up. The performance of SFCS is analyzed and bandwidth estimation expressions are formulated, analytical results are complemented with computer simulations. The results show that SFCS deployed in an IPTV delivery system can significantly lower the bandwidth consumption and speed up the channel change



6. New staff and promotions Christine Grafström, Communication and PR, Bachelor of information and PR from Mid Sweden University

Christine is our most recent contribution of employees related to STC@MIUN. Working with communication and PR, Christine will be re-sponsible for things like newsletters, the STC homepage, advertising and public materials.

Tingting Zhang, Professor, Computer Engineering

Docent Tingting Zhang has been promoted to Professor in Computer Engi-neering from 1 October 2008. Her current research works are in the areas of increasing the reliability of communication systems, protecting system from malicious attacks and guarantee user’s privacy, especially in reliable multi-media communication, secure and efficient sensor network and privacy pro-tection for network based applications.

Mårten Sjöström, Docent, Signal processing

Dr. Mårten Sjöström has been promoted to Docent in Signal Processing. He presented an overview of the field on a docent lecture on March 16, 2008. His current research is focused on 3D-TV and has recently obtained research fund-ing for two projects in this area. He is coordinating these projects under the name Realistic 3D.

6.1 New PhD students within STC and supporting projects

Sebastian Bader, Dipl.Ing. (FH) from the University of Applied Sciences in Wilhelmshaven (Germany), Source of funding: STC@MIUN

Sebastian is doing research in wireless sensor networks as a measurement system for environmental monitoring applications. He focuses mainly in communication protocols, system design and RF behavior of networked em-bedded systems.



Xiaozhou Meng, MSc from Royal Institute of Technology (KTH), Source of funding: STC@MIUN.

Xiaozhou is doing his PhD on System On Chip (SoC) architectures for real-time processing of video on Field Programmable Gate Arrays (FPGA). His current activities are focused on the decoding, processing and displaying of multiply video streams. Aspects such as product- maintenance and lifetimes related to the use of soft IP-based designs will also be part of his research.

Xin Huang, MSc from Royal Institute of Technology (KTH), Source of funding: STC@MIUN

Xin Huang received his MSc from Information and Communication Systems Security, Royal Institute of Technology, Stockholm, Sweden. He has been a PhD student at Mid Sweden University since September 2008. There are now more and more applications utilizing sensors in wearable com-puting and thus the influence of information diffusion to privacy issues has become more and more important. His tentative research field is in location based mobile sensor application and privacy protection for these applications.

Omeime Esebamen, MSc from Mid Sweden University, Source of funding: STC@MIUN

Omeime is doing his PhD on development of position sensitive silicon detector for UV and electron irradiation. Special attention is put on the long term stability of sensitivity as well as aspects on the nonlinearity.

Xin Cheng, MSc from Electronic and Communication Engineering, Southeast University in China, Source of funding: KKS – project OptiPos

Xin Cheng is doing his PhD on optical real-time measurement systems for position and orientation in at most six dimensions of freedom. These are machine vision systems which are suitable for aggressive parallelization and implementation on Field Programmable Gate Arrays (FPGA). He will work on the improvement of algorithms and measurement methods and he will develop suitable hardware architectures for mapping onto FPGAs.

Jinlan Gao, MSc from Beijing University of Technology, Source of funding: Vinnova NordIte.

Jinlan works within the area of printed RFID sensor solutions. Current focus is on development and implementation of printed memory solutions of the type Write Once Read Many (WORM). The technology is used in conjunc-tion with RFID technology to produce cost effective wireless sensors who for example can tell if a sensor label has been exposed to excessive temperature, humidity or wetness.



Krister Hammarling, MSc from Mid Sweden University, Source of funding: Acreo Fiber Op-tic Centre

Krister works with fibre optic sensors, specifically research in fibre optic sen-sors for PH and temperature measurement. By developing and testing new types of hollow optic fibre, the project will investigate if it is possible make a sensor that can read the PH-level and temperature at the same time.

Hari Babu Kotte, MSc from Mid Sweden University, Source of funding: Vinnova and Ener-gimyndigheten

Hari Babu Kotte is doing his PhD in the area of high frequency switch mode power supplies. The research aims to develop the new generation high fre-quency switch mode power supplies (SMPS) by using silicon carbide tran-sistors together with recently, at Mid-Sweden University developed trans-formers. An increased switching frequency enables more compact and cheaper design as expensive passive and bulky components can be replaced

with smaller and cheaper counterparts Radhika Ambatipudi, MSc from Mid Sweden University, Source of funding: Vinnova and Energimyndigheten

Radhika Ambatipudi is doing her PhD in the high frequency transformers for switch mode power supplies (SMPS). Power Supply Unit (PSU) plays a vital role in all the Electronic equipments. It is required to design a compact power supply to make it compatible with the most modern Electronic equipments. The transformer is one of the crucial parts in modern SMPS. As the switching frequency is increased, the size of the passive components such as transformers and capacitors gets reduced.



7. Publications 2008 This is a list of publications produced during 2008 and connected to STC:

1. Fredrik Linnarsson, Cheng Peng, Bengt Oelmann, "A Power Aware MAC protocol for

Wireless Closed Loop Control System in Loader Cranes," IEEE International Sympo-sium on Industrial Electronics, Cambridge, UK, 2008

2. S. Aunet, B. Oelmann, P.A. Norseng, Y. Berg, "Real-time Reconfigurable Subthresh-old CMOS Perceptron," IEEE Transactions on Neural Networks, vol. 19, Issue 4, 2008.

3. Jon Alfredsson and Snorre Aunet, "Trade-offs for High Yield in 90 nm Subthreshold Floating-gate Circuits by Monte Carlo Simulations", Proceedings of VLSI-SOC, 2008.

4. Jon Alfredsson and Snorre Aunet, "Pseudo Floating-Gate Design Limitations in Nano-CMOS with Low Power Supply", Proceedings of VLSI-SOC, 2008.

5. Mattias O’Nils, Jan Thim, Börje Norlin, Bengt Oelmann, “Threshold Modulation for Continuous Energy Resolution with Two Channels per Pixel in a Photon Counting X-ray Image Detector”, Int. Workshop on Radiation Imaging Detectors, 2008.

6. Jan Thim, Börje Norlin, “CMOS for Color X-Rays - Where do we go from here?” In-vited paper at Emerging CMOS Technologies, Vancouver, Canada, August 2008.

7. Jan Thim, Mattias O’Nils, Anatoliy Manuilskiy, Benny Thörnberg “Simulating the Impact of Topographical Microstructures on Triangulation Measurement Setups using Matlab”, Nordic MATLAB User Conference, November 2008, Stockholm,

8. Lisa Nordin, Mattias O’Nils, Per Engstrand and Öjvind Sundvall, “Towards relevant dewatering measurement techniques - Characterisation and classification of dewater-ing measurement techniques for mechanical pulps”, FMPRS, May 2008.

9. Börje Norlin, Christer Fröjdh, “Characterisation of spectral performance of pixelated X-ray imaging detectors”, Int. Workshop on Radiation Imaging Detectors, 2008.

10. J. Sidén, B. Lee, B. Ganjei, “On the Efficiency of RFID Tag Antennas Produced by Copper Plating Catalytic Ink Traces”, Proc. of ECWC 11, Electronic Circuits World Convention, 2008

11. J. Sidén, M. Fein, A. Koptioug, H-E. Nilsson, “Logos as RFID Tag Antennas”, Inter-national journal on wireless and optical communications, Vol 5, Issue, 1 pp.87-98 September 2008, Special Issue on Antennas for Emerging Radio Frequency Identifica-tion (RFID) Applications", 2008

12. C. Mattsson, G. Thungström, K. Bertilsson, H. Nilsson, H. Martin, Design of a Mi-cromachined Thermopile Infrared Sensor with a Self-Supported SiO2/SU-8 Mem-brane, IEEE Sensors Journal, v8, n12, 2008

13. L. Herrnsdorf, M. Björk, B. Cederquist. C.G. Mattsson, G. Thungström, C. Fröjdh, ”Aspect of point dose profile measurement using solid state detector in characteristics of computed tomography”, Int. Workshop on Radiation Imaging Detectors, 2008.

14. Wang, Q.; Zhang, T., “Source traffic modelling in wireless sensor networks for target tracking”, The Fifth ACM International Workshop on Performance Evaluation of Wireless Ad Hoc, Sensor, and Ubiquitous Networks, 2008.

15. Wang, Q.; Zhang, T., “Sec-SNMP: policy-based security management for sensor net-works”, The 2008 International Conference on Security and Cryptography, 2008.

16. Wang, Q.; Zhang, T., “Security in Wireless Sensor Networks”, Security in RFID and Sensor Networks, Auerbach Publications, Taylor&Francis Group – USA, 2008.

17. Wang, Q.; Zhang T.; Pettersson, S., “An Effort to Understand the Optimal Routing Performance in Wireless Sensor Network”, The IEEE 22nd International Conference



on Advanced Information Networking and Applications, Ginowan City, Okinawa, Ja-pan. p. 279 – 286, 2008.

18. Patrik Österberg and Tingting Zhang, “Fair Allocation of Multicast Transmission Costs”, International Journal On Advances in Telecommunications, issn 1942-2601, vol. 1, no. 1, year 2008,1:13

19. Ulf Jennehag and Stefan Pettersson, “On synchronization frames for channel switch-ing in a GOP-based IPTV environment,” in IEEE Consumer Communications and Networking Conf. (CCNC), Las Vegas, USA, 2008.

20. B. Marx, J. Kollecker, B. Lammen, J. Nordin, T. Zhang, M. Sjöström, Distributed Ve-hicle Simulation - A Student Project in Mechatronics and Distributed Systems, In the proceedings of 9th International Workshop on Research and Education in Mechatron-ics, Bergamo, Italy, 18-19 September 2008.

21. H. Andersson, K. Bertilsson, G. Thungström, H. Nilsson, Processing and Characteri-zation of a MOS Type Tetra Lateral Position Sensitive Detector with Indium Tin Ox-ide Gate Contact, IEEE Sensors Journal, v 8, n 10, Oct. 2008, p 1704-9

22. T. Unander, H.-E. Nilsson, U. Lindefelt, “Characterization of a printed nano-particle based relative humidity sensor”, 2008

23. Andersson, H.A.; Bylund, N.; Thungstrom, G.; Nilsson, H.-E., “Analysis and im-provement of the position nonlinearity caused by a residual stress in MOS-type posi-tion-sensitive detectors with indium tin oxide gate contact”, Semiconductor Science and Technology, v 23, n 7, Jul 1, 2008, p 075012

24. C. Mattsson, G. Thungström, K. Bertilsson, H. Nilsson, H. Martin, Fabrication and evaluation of a thermal sensor formed on a thin photosensitive epoxy membrane with low thermal conductivity, Journal of Physics: Conference Series, v 100, pt.8, 1 March 2008, p 082048 (5 pp.)

25. H. Andersson, A. Manuilskiy, G. Thungström, A. Lundgren, H. Nilsson, Principle of FT Spectrometer based on a Lateral Effect Position Sensitive Detector and Multi Channel Fabry-Perot Interferometer, Measurement, 2008

26. Andersson, H.A.; Manuilskiy, A.; Thungstrom, G.; Nilsson, H.-E., “Evaluation of an integrated Fourier-transform spectrometer utilizing a lateral effect position sensitive detector with a multi-channel Fabry-Perot interferometer”, Measurement Science & Technology, v 19, n 4, April 2008, p 045306-1-10

27. Andersson, H.; Thungstrom, G.; Nilsson, H-E, “Electroless deposition and silicidation of Ni contacts into p-type Porous Silicon”, Journal of Porous Materials, v 15, n 3, June, 2008, p 335-341

28. B. Norlin, C. Fröjdh, G. Thungström, D. Greiffenberg, Spectroscopic Imaging with an X-ray Microscopy Setup Using a Pixelated Detector with Single Photon Processing, IEEE Nuclear Science Symposium Conference Record 2008

29. C. Nilsson, J. Pallon, G. Thungström, N. Marrero, M. Elfman, P. Kristiansson, C. Nilsson, M. Wegden, Characterisation of a pre-cell hit detector to be used in single cell irradiation experiments at the Lund Nuclear Microprobe, Nuclear Instruments and Methods in Physics Research B, v266, n21, 2008

30. H. Andersson, A. Manuilskiy, G. Thungström, H. Nilsson, Broadband Parameters of Compact FT Spectrometer based on Fabry-Perot Interferometer Integrated with de-tector, Presented at smart systems integration conference, Barcelona, 2008



8. 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 2009.

PROJECT INFORMATION – February, 2009STC – Sensible Things that Communicate

Mid Sweden University Phone: 0771-975 000 STC – Sensible Things that Communicates Fax: 060-14 84 56 851 70 Sundsvall Internet: www.miun.se/stc

www.kks.se

CAD TOOL FOR REAL-TIME VIDEO PROCESSING SYSTEMS

BackgroundFPGA based implementations of videoprocessing systems are efficient but have acomplex programming model. The synthesis toolpresented here reduces the design complexityand still produces effective implementations.

Objectives IMEM (Interface and MEmory Model), anextension of SystemC modelling library,captures video processing systems as coarsegrained synchronous dataflow graphs (Fig 1),where each node represents an abstract videointerface, the memory model and the descriptionof the functional behaviour of the task, whereaseach edge in the graph represents the data widthof each pixel in the video frame.

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Figure 1: IMEM model of a video processing system.

Memory requirements of a video processingsystem are separated from its behavioural C++description. A memory model, which may beneighbourhood oriented is implemented asFIFOs in block RAMs, distributed memory andregisters. We have developed our own methodsand tool for this memory synthesis. Heuristicmethods are used to minimize block RAMallocation while power dissipation is reduced.This power reduction is achieved throughconstraining of the routing process based on thehigh level memory model.

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Functional behaviour is implemented usingavailable high level synthesis tools or manualHDL coding.

ResultsAllocating small data dependencies todistributed RAM can save block RAMs whilelow power dissipation is maintained. Memorystorage in block RAMs or distributed RAM hasdifferent power costs in terms of fixed powerand scaling with storage size. Fig 2 shows blockRAM savings for a neighbourhood orientedvideo system configured for 6 to 10 bit pixels.

Dr. B. Thörnberg Dr. N. Lawal Prof. M. O’[email protected] [email protected]

For further information contact:



www.kks.se

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

BackgroundSystems that can measure their own locationsare becoming more frequently used in differentapplications. A helmet for Virtual Reality (VR)presentation must measures its position andorientation in order to track the movement of itsuser’s head. It is also necessary to measureposition and orientation for a handheld printerthat operates as a computer mouse, printing textand graphics while it is moved over a largesurface.

Objectives Optical position measurement methods and itsrelated algorithms and implementations will beinvestigated in this project. Methods based onprepared environments already exist that canmeasure an objects position and orientationwithin a room for 6 Dimensions Of Freedom(6DOF) or in 3DOF over a surface. We intend toinvestigate if these methods can be enhanced towork in general unprepared environments, if itis possible to optimize these algorithms in orderto reduce implementation costs and also if it ispossible to automate the estimation ofimplementation costs for such algorithms.

ResultsFigure 1A show a prototype for 3DOFmeasurements. This system exemplifies anavigation system with a controllable xy table.This table was programmed for a sine wavemovement. The navigation system was able todetermine and predict future positions with 1%accuracy.

Ongoing activities Currently, the 6DOF system in Figure 1B candetect reference points in its surrounding and

A)

B)

Figure 1. Prototype for A) 3DOF and B) 6DOF

wirelessly report number of detected referencesto a host computer. An ongoing student projectaims at including calculation of spatial positionsof reference points using Centre Of Gravity.Current research is aimed on how to improveprecision of calculated positions.

Dr. B. Thörnberg Dr. N. Lawal Xin [email protected] [email protected]


PROJECT INFORMATION – February, 2009 STC – Sensible Things that Communicate

Mid Sweden University Phone: 0771-975 000 STC – Sensible Things that Communicates Fax: 060-14 84 56 851 70 Sundsvall Internet: www.miun.se/stc www.kks.se

OPTICAL ONLINE CHARACTERIZATION OF LARGE SURFACE

TOPOGRAPHY IN PAPER MACHINES

Background The paper manufacturing industry is currently exploring the possibility of measuring micro structural topography online in a paper manufacturing machine, which is intended to lead to a more precise measure of the paper quality, reel to reel, and a more efficient use of raw material. A need has also been expressed to use topography measurements when controlling the paper machine systems, in order to improve the quality online. In order to realize this, an online characterisation of paper topography in the production chain is required. 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, producing 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. Results A MATLAB based simulation environment has been developed for elaboration of physical limitations settings of the paper topography measurement setup. The simulated

measurement setup is based on the targeted light beam triangulation technique. The settings that can be elaborated in the simulation model is light beam and camera angels, light beam width, level of noise and finally how occlusion caused by small structures can affect the accuracy of the measurement. The resulting wavelength spectra translated from the paper topography is used as a parameter of quality in the evaluations.

Sample 3D simulation and wavelength spectra.

For further information contact:Ph. D. Jan Thim [email protected]

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www.kks.se

FPGA BASED COMPUTER SYSTEMS

BackgroundThe ever growing integration of functionality inindustrial and automotive embedded systemshas introduced the requirement for real timevideo processing capabilities in many systems.An FPGA based implementation of embeddedsystems provides many attractive characteristicssuch as high flexibility, low cost and a high levelof integration. These characteristics make FPGAsespecially suitable for video related applications.FPGAs provide the possibility for System OnChip (SoC) designs where most of the systemcomponents, such as CPUs, video andcommunication controllers are all implementedon the FPGA. In addition to the variousadvantages of a SoC design, IntellectualProperty (IP) based FPGA designs also avoid theproblems caused by the end of life for standardcomponents.

Objectives The goal of this project is to develop FPGAbased architectures that allow the design of costefficient FPGA based SoC with real time videoprocessing capabilities. A frequently occurringrequirement for embedded computer systems isthe capability of displaying multiple real timevideo sources combined with computergenerated graphics. Real time video processingis a very data intensive task which is oftenbeyond the capabilities of the general purposeCPUs used in typical industrial and automotiveapplications. With an FPGA based SoC thatprovides real time video data directly to thedisplay memory, any computer system can bemade capable of displaying real time video.

ResultsWe have developed a SoC design for the channelsplitting of multiple Ethernet based videostreams. A MicroBlaze softcore processor is

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implemented on an FPGA. This processor isprogrammed to handle the Ethernet protocoland to split the MJPEG video streams originatingfrom two independent Ethernet basedsurveillance cameras. The aim of this experimentis to find out the maximum capacity and the bestprocessor configuration for splitting compressedvideo. Fig1 shows the CPU load for variouscombinations of frame and compressions ratesfor two 480 by 360 pixel video streams. From thiswe can conclude that the MicroBlaze has thecapacity to handle four cameras at acompression rate of 30 times and a frame rate of10 frames per second.

Liu Fang Xiaozhou MengSupervisors:Dr. Najeem Lawal, [email protected]. Benny Thörnberg and Prof. Mattias O’Nils




PRIVACY PROTECTION IN WIRELESS SENSOR NETWORK APPLICATIONS

Background With more and more applications utilizing sensor in wearable computing, wide diffusion become much easier than before. However, traditional privacy protection always ignores the existence of diffusion. Even with all other privacy protected mechanisms being carefully designed, if the system does not pay attention to proper diffusion scaling, there is a chance that more exist messages and wider diffusion scale of these messages increase the probability of under attack. In this situation, it is hard to say whether this system becomes more secure or not. Objectives In this project, the goal is to analyze the system privacy in consideration of information diffusion. Ongoing activities There are numerous studies which prove that, a real world network has both the small world phenomenon and scale free characteristics. Social networks, the connectivity of the Internet and gene networks all exhibit small world network characteristics. Scale‐free networks are noteworthy because many empirically observed networks appear to be scale free, including the World Wide Web, protein networks, citation networks, and some social networks. Currently we are analyze system privacy in propose using information diffusion in both scale‐free networks and small world networks.

Results We propose using diffusion to analyze privacy and divide system into different categories to get optimized diffusion function. Based on user’s requirements of the diffusion scale, we categorize all systems into public, protected and private system.

For further information contact:Xin Huang [email protected] Supervisor: Prof. Tingting Zhang



Traffic Load Distribution in Large-Scale and Dense Wireless Sensor

Networks

Background In large‐scale wireless sensor networks (WSNs), the dominating communication pattern is a large number of sensor nodes deliver their sensed information to one or a few data sinks through multi‐hop transmission. This kind of communication pattern drastically imbalance the traffic load distribution across the network where the nodes close to a sink experience heavy traffic loads. The understanding of the traffic load distribution in WSNs is important. For example, the knowledge of the traffic load distribution can guide the energy allocation over the nodes to extend the network lifetime. The knowledge of the traffic load distribution can also be used to direct the design of efficient routing algorithms, and optimize the node distribution over the area.

Objectives In this project, the goal is to understanding of the traffic load distribution in large‐Scale and dense wireless sensor networks. Ongoing activities Currently we study the traffic load distribution in large scale and dense planar WSNs. We consider a WSN of n sensor nodes evenly deployed in a disk area of radius R. There is a sink node located in the center of the deployed disk area. All the deployed sensor nodes regularly sense the physical phenomenon around and forward that information to the sink directly or by multi‐hop transmission. We assume the considered network is large‐scale and dense. The large‐scale assumption means that the distance of routing hop is negligible

compared to the diameter of the network. The denseness assumption means the forwarding node can always find the next relay node along the line segment determined by the forwarding node and the sink node, which is also the final destination for all data messages. A weak routing assumption is also imposed: the number of relay times during the transmission of a packet is linearly proportional to the distance between the source and the destination. Results We find that an analytic traffic load function is proposed based on a planar sensor network. Further, the effects of network scale and routing strategy on traffic load are also researched. The traffic loads on individual nodes are found to be in direct proportion to the radius of the network and in inverse proportion to the routing hop distance, while independent of network density.

For further information contact: Qinghua Wang [email protected]: Prof. Tingting Zhang


Mid Sweden University Phone: 0771-975 000 STC – Sensible Things that Communicate Fax: 060-14 84 56 851 70 Sundsvall Internet: www.miun.se/stc www.kks.se

JOINT ANGULAR SENSORS FOR CONTACT-LESS MEASUREMENTS

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.

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

different sensor configurations based on accelerometers. 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 [email protected] Supervisor: Prof. Bengt Oelmann


Mid Sweden University Phone: 0771-975 000 STC – Sensible Things that Communicate Fax: 060-14 84 56 851 70 Sundsvall Internet: www.miun.se/stc www.kks.se

WIRELESS SENSOR NETWORKS FOR ENVIRONMENTAL MONITORING

Background Wireless sensor network technology evolves into a novel way of constructing autonomous measurement systems. Using a large amount of small and inexpensive smart sensors, capable of communicating with each other or a central network intelligence, allows monitoring large and remote sites. Environmental monitoring is one, maybe the most typical application for these large scale sensing networks. Measurements can be obtained over large spatial deployment, high density and without direct human interaction, making these solutions superior over conventional systems. These systems however require long lifetime in which the system powers itself by for example using battery supply. Mechanisms and solutions need to be investigated to enlarge lifetime and reduce power consumption.

Objectives The goal of this project is to develop a wireless sensor network based monitoring system, which can obtain measurement data autonomously after deployment and has reasonable lifetime to

avoid battery replacement. Initial investigations face power consumption reduction methods in data gathering network communication protocols. Ongoing activities Recent activities include the recently finished hardware platform for the before mentioned wireless sensor network system, which allows real‐world deployment and measurement tests. Main design considerations for the platform cover low power usage and flexibility to different application tasks. Furthermore we investigate possibilities of power savings in the communication protocol of the system. A synchronous protocol based on TDMA has been developed and is currently under test. Using these methods we expect to decrease the average power consumption of our system to reach quiescent current levels. Results First obtained results include the verification of hardware functionality. The designed platform works with very low power consumption, while it stays scalable to different tasks and application requirements. Furthermore modelling and tests on the communication protocol show that average power consumption can be decreased in the order of magnitude by keeping sensor nodes synchronized, allowing devices to attend a communication schedule.

For further information contact:Dipl.Ing.(FH) Sebastian Bader [email protected] Supervisor: Prof. Bengt Oelmann



INNOVATIVE RFID SOLUTIONS AND PRINTED ELECTRONICS

Dr. Johan Sidén and Doctoral Student Jinlan Gao work within the area of RFID and printed electronics. Research is currently focused on the combination of printed sensor technology and commercially available low‐cost RFID chips. Background With a long academic experience on innovative antenna solutions for RFID tags we have now taken tag antenna design one step further by letting the antenna work also as sensor element. This allows for cost effective wireless sensors with more or less infinite life time since no battery needs to be changed.

Example of humidity measurement system for hidden locations, where a “sensitive tag” is embedded in moisture absorbing material. Objectives and Ongoing activities Key concept is based upon pairs of RFID tags where one tag is “normal” and the other tag has its antenna degraded in proportion to a condition of interest to measure, for example the level of relative humidity (%RH). The degradable antenna can for example be embedded in moisture absorbing material for retrieving the value at the time of reading, or it can be a printed sensor that remembers the highest value it’s been exposed to. As measurements take more than 10 seconds to

perform, focus is now also put on development of a more suitable handheld reader together with industrial partners.

(a) (b)

(a) Close-up of printed moisture sensor with memory function (WORM) and (b) RFID Tag antenna with the sensor element in (a) “short-circuiting” the RFID chip upon sensor activation, making it harder to read. Results The graph below show results for humidity level measurements with an embedded tag. The tag antenna with WORM similarly has a 20 dB power difference after being exposed to 75% RH for a few hours and remain in that mode if the humidity drops to dryer values.

Difference in minimum output power required from an RFID reader in order to read two passive tags in a label where one is covered or embedded in a moisture absorbing material.

For further information contact:Dr. Johan Sidén [email protected] Tel. +46 70 671 71 71



www.kks.se

Portable instrument for detection of polonium and other alpha emitters H. Andersson, G. Thungström and S. Petersson

Background Due to the increased threat of terrorism and other incidents where radioactive materials are dispersedthere is an increasing need to be able to detect the presence of such materials. Alpha is much moredifficult to detect than beta or gamma radiation because it travels only a few cm in air, nevertheless alpharadiating material is very dangerous to humans if inhaled or ingested due to the high energy.

Introduction

The goal of this project is to build a personal detector to detect alpha emitting radioactive materials. Such an instrument can be used at airports, subway stations or be carried by personnel in environments where they run the risk of being exposed to radiation. By analyzing the energies of the emitted particles, the radio active material can be identified such as 210Polonium, Radon, depleted Uranium and others. The instrument is meant to be used in air, and therefore the technique is based on collection of dust particles containing the radioactive material on the detector surface.

Fig. 1. Photo of manufactured alpha detector showing the dimensions.

This is done by means of a high electric field. The emitted particles from the radioactive material that hit the detector surface are energy analyzed and from that the material can be determined. Fig.1 shows two of the manufactured detectors. In Fig.2 is shown a measurement done on 232U.

In Fig.3 is shown the layout of the proposed instrument.

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Fig. 3. Layout of the instrument, where charged dust particles containing radioactive material is attracted to the detector surface by an electric field. For further information contact: Göran Thungströ[email protected]+46 60 14 88 05 Fax +46 60 14 84 56



www.kks.se

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

BackgroundThermal sensors for IR detection, such asbolometer and thermopiles are used in a numberof applications. These applications includeremote temperature control and gas detection.One step in the direction towards a low costsystem is the use of a low cost infrared detector.

Objectives The goal of this research project has been toproduce a low cost thermal detector usingstandard processing techniques and newmaterials.

In many existing thermal detectors the thermallink is formed by constructing a thin membraneof either Si or Si3N4. In a low cost detector, apolymer such as SU 8 could be an alternative toregular Si and Si3N4 membranes. SU 8 has lowthermal conductivity and requires only standardsilicon lithography processing.

Ongoing activities The work has been concentrated on developing anew design layout for the SU 8 membrane basedthermopile detector in order to increasesensitivity. A thermal simulation and designoptimization tool implemented in MATLAB wasdeveloped and the new designed thermopilewas fabricated and evaluated.

ResultsIn the thermopile structure presented earlier, theseries connected thermocouples were positionedalong the membrane rim. By spreading thethermocouples more evenly over the membraneand running the developed design optimizationtool, the sensitivity could be increased and theresponse time decreased. Figure 1 shows the

fabricated Al/Bi thermopile. The responsivityachieved using a infrared laser with wavelengthof 1.56 m, a sensitivity of 60 V/W and a timeconstant of 70 ms was measured. This should becompared to 7.5 V/W and 385 ms of the previouspresented Ni/Ti thermopile, see figure 2.

Figure 1 Fabricated Al/Bi thermopile. Centrepart is magnified.

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For Further informationcontact:Lic. Eng. Claes [email protected]: Prof. Hans ErikNilsson



www.kks.se

Development of X-ray imaging sensors Göran Thungström, Börje Norlin, Christer Fröjdh

Background The Medipix system is at present the most advanced single photon processing X ray readout available.The imaging detector is bump bonded to the readout. Different types of X ray imaging detectors to bebonded to the Medipix chip are being developed at Mid Sweden University.

220x220 µm pixel detectors

Photo of a fabricated detector on a readout chip and circuit board from the Medipix collaboration. On the present chip a guard-ring is surrounding the detector perimeter.

This detector is developed for applicationswhere spectral performance is more importantthan spatial resolution. The detectors arefabricated in the clean room facilities at MidSweden University. The 300 m thick wafer isdoped using solid phosphorus and borondiffusion sources.

The backside deposition is an aluminium layerwith thickness 300 nm. The contacts opening inthe detector windows are deposited with 20 nmtitanium followed by 300 nm nickel. The

deposition is done using an electron beamevaporator.

55x55 µm pixel detectors with distributed contacts

For large object X ray imaging applications, it isnessecary to tile several chips together. Thepresent technique is to use detectors with largepixels at the boundaries. The new type ofdetectors being developed have pixels equallydistributed over the sensor area, instead thecontacs for bump bonding are shifted to fit thereadout chip as illustrated below.

Illustration of mounting (left) to overcome the tiling problem in the border between the readout chips (right).

For further information contact: Göran Thungströ[email protected]+46 60 14 88 05+46 730 61 26 19Fax +46 60 14 84 56

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Al

210 m 10 m20 m



www.kks.se

Material resolving X-ray imaging microscope Börje Norlin, Christer Fröjdh, Göran Thungström, Omieme Esebamen, Jan Thim, Mattias O’Nils, Suliman Abdalla

Background An X ray microscopy setup for energy resolved imaging is built. The principle for X ray microscopy issimple geometrical magnification as sketched below.

Sketch of the X-ray microscopy setup

Photo of the X-ray Microscopy setup ,

Example of geometrical magnification, a transistor with magnification 1.04 and 2.83 respectively.

Energy resolving X-ray imaging The detector system is developed in the Medipixcollaboration directed from CERN in Geneva.The readout chip is pixelated and each pixelcontains single photon processing readout.

Hence each pixel in the image containsspectroscopic X ray energy information. Sincethe absorption coefficient for X rays is stronglydependent of the atom number of the material inthe object, material resolving X ray imaging canbe achieved.

Transmission image of a test object containing Tin (top), Gadolinium (middle) and Iodine (bottom). RGB representation of the transmission energy variation where cyan represents 10 – 30 keV, magenta represents 30 – 43 keV and yellow represents 43 – 60 keV.

Examples of applications were material resolved X-ray imaging is interesting

Wood-chip characterisation, online Paper characterisation, online Paper coating characterisation, online Welding quality surveillance General online manufacturing quality surveillance Contrast agents identification in medical imaging Dose reduction in medical imaging Security surveillance

For further information contact: Börje [email protected]+46 60 14 85 94+46 70 525 63 63Fax +46 60 14 84 56

Tin

Gadolinium

Iodine

Detector Object Slits Microfocus source

Led shield box

Börje Norlin, Suliman Abdalla och Jan Thim

PROJECT INFORMATION – February, 2009

Mid Sweden University Internet:www.miun.se/itm/smps Phone: 0771-975 000 www.kks.se Fax: 060-14 84 56 www.energimyndigheten.se 851 70 Sundsvall www.vinnova.se

Mega Hertz coreless PCB transformers for high speed SMPS

Introduction

Power Supply Unit (PSU) plays a vital role in all the Electronic equipments. It is required to design a compact Switch Mode Power Supplies (SMPS) to make it compatible with the most modern Electronic equipments. The transformer is one of the crucial parts in modern SMPS. The miniaturized SMPS is possible only with the increased switching frequency which in turn results smaller passive elements, reduced cost and high speed voltage regulation. Introduction

The goal of the project is to design the compact, highly energy efficient and cost‐effective switch mode power supply (SMPS) by designing the efficient transformers operating at higher frequencies (MHz) and also with the help of SiC technology transistors. Ongoing Activities

At Mid Sweden University, high frequency coreless PCB transformers for power transfer applications were designed. These transformers were characterized by using network analyzer and also placing them in the converter circuit and tested for low power levels of about 30‐40watts. The research has been focused to achieve the high energy efficiency of the converter at high power levels by reducing the switching losses in the transistor and the copper losses in the transformers.

Results

The maximum available efficiency of the designed transformers obtained using network analyzer is in the range of 90‐98%.

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The experimental results of the flyback converter using the 4 layer transformer with the switching frequency range of 3‐3.4MHz shows the converter efficiency of about 80‐90% with the power levels of about 20W, input supply voltage range of 30‐100V.

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Converter Efficiency

Fig. 2. Input voltage vs. Efficiency of the flyback converter For further information contact: Hari Babu Kotte ([email protected]) Ambatipudi Radhika ([email protected]) Supervisor: Dr.Kent Bertilsson



STC MediaSense

Background Mobile telecommunications is changing rapidly. People not only communicate regardless of time and place, but also share information that is important for the tasks they will perform. Increased bandwidth in mobile networks, packet‐oriented access and coding techniques enable us to use multi‐modal communication related to what we are engaged in each moment. TV will be reshaped to include ad hoc self‐published media, regardless of access form as our communication increasingly takes place in digital communities on the Internet. Objectives MediaSense aims to enable innovative digital services by creating a technology platform that brings together several technologies in new ways: sensors, interactive media, and context‐sensitive communication. Media Sense combines these areas in order to create new technology components and digital services are expected to be commercialized in new and existing businesses in the region. Ongoing activities MediaSense is conducted in cooperation with public sector and industry, in particular: Ericsson Research, Acreo, Fiber‐Optic Valley, ITV Arena, ServaNet, Kramfors Mediateknik, Swedish Connection, and Telia Sonera.

The initial activities this fall have been focused on creating means for aggregating and distributing user information from sensor information. Our initial approach is to connect Wireless Sensor Networks (WSN) gateways to mobile phones or other devices via Bluetooth. Results We developed a low‐power platform for communicating with a multitude of sensors and a first version of scalable support to share and provide sensor data in large communities on the Internet in real‐time. This support has interworking with the IP Multimedia Subsystem (IMS) in 3G networks. We created a mobile awareness service (demonstrated at STC Expo’08) for sharing of sensor information from wireless sensor networks attached to a 3G mobile phones via a Bluetooth sensor network gateway. At the Ericsson Research Mobile Java Communication Framework (MJFC) Developers Day on December 15, 2008 in Kista we successfully demonstrated a mobile group service with real‐time sensor information (GPS, humidity, and temperature). For further information contact: Theo G. Kanter, Prof. of Computer Science; Distributed Systems

Mail: [email protected]

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

Adal AB

www.miun.se/stc

stc annual report 2008

Documents

stc systems

stc wireless solutions

stc mediasense

stc sensor solutions

stc network solutions

stc annual report

stc reference system

electronic systems