Pekka Toivanen

Lossless Compression of Hyperspectral Images Using a Quantized Index to Lookup Tables

We propose an enhancement to the algorithm for lossless compression of hyperspectral images using lookup tables (LUTs). The original LUT method searched the previous band for a pixel of equal value to the pixel colocalized with the one to be predicted. The pixel in the same position as the obtained pixel in the current band is used as a predictor. LUTs were used to speed up the search. The LUT method has also been extended into a method called Locally Averaged Interband Scaling (LAIS)-LUT that uses two LUTs per band. One of the two LUT predictors that is the closest one to the LAIS estimate is chosen as the predictor for the current pixel. We propose the uniform quantization of the colocated pixels before using them for indexing the LUTs. The use of quantization reduces the size of the LUTs by an order of magnitude. The results show that the proposed method outperforms previous methods; a 3% increase in compression efficiency was observed compared to the current state-of-the-art method, LAIS-LUT.

Two practical man-in-the-middle attacks on Bluetooth secure simple pairing and countermeasures

We propose two new Man-In-The-Middle (MITM) attacks on Bluetooth Secure Simple Pairing (SSP). The attacks are based on the falsification of information sent during the input/output capabilities exchange and also the fact that the security of the protocol is likely to be limited by the capabilities of the least powerful or the least secure device type. In addition, we devise countermeasures that render the attacks impractical, as well as improvements to the existing Bluetooth SSP in order to make it more secure. Moreover, we provide a comparative analysis of the existing MITM attacks on Bluetooth.

Edge detection in multispectral images using the self-organizing map

In this paper, two new methods for edge detection in multispectral images are presented. They are based on the use of the self-organizing map (SOM) and a grayscale edge detector. With the 2-dimensional SOM the ordering of pixel vectors is obtained by applying the Peano scan, whereas this can be omitted using the 1-dimensional SOM. It is shown that using the R-ordering based methods some parts of the edges may be missed. However, they can be found using the proposed methods. Using them it is also possible to find edges in images which consist of metameric colors. Finally, it is shown that the proposed methods find the edges properly from real multispectral airplane images The size of the SOM determines the amount of found edges. If the SOM is taught using a large color vector database, the same SOM can be utilized for numerous images.

Security Threats in ZigBee-Enabled Systems: Vulnerability Evaluation, Practical Experiments, Countermeasures, and Lessons Learned

In this paper, two practical attacks against ZigBee security are proposed and the latter one is also carried out in our laboratory environment. The attack scenarios are based on utilizing several vulnerabilities found from the main security components of ZigBee technology. The first attack is based on sabotaging the ZigBee End-Device by sending a special signal that makes it wake-up constantly until the battery runs out. The second attack is based on exploiting the key exchange process in ZigBee when using the Standard Security level defined by the ZigBee specification: we also demonstrate with experimental figures that attacks against ZigBee-enabled devices become practical by using our attack scenario. In addition, countermeasures that render the proposed attacks impractical, although not totally eliminating their potential danger, are devised. Moreover, some new ideas that will be used in our future research work are proposed.

Constant coefficients linear prediction for lossless compression of ultraspectral sounder data using a graphics processing unit

The amount of data generated by ultraspectral sounders is so large that considerable savings in data storage and transmission bandwidth can be achieved using data compression. Due to this large amount of data, the data compression time is of utmost importance. Increasing the programmability of the commodity Graphics Processing Units (GPUs) offer potential for considerable increases in computation speeds in applications that are data parallel. In our experiments, we implemented a spectral image data compression method called Linear Prediction with Constant Coefficients (LP-CC) using NVIDIAs CUDA parallel computing architecture. LP-CC compression method represents a current state-of-the-art technique in lossless compression of ultraspectral sounder data. The method showed an average compression ratio of 3.39 when applied to publicly available NASA AIRS data. We achieved a speed-up of 86 compared to a single threaded CPU version. Thus, the commodity GPU was able to significantly decrease the computational time of a compression algorithm based on a constant coefficient linear prediction.

Three practical attacks against ZigBee security: Attack scenario definitions, practical experiments, countermeasures, and lessons learned

In this paper, three practical attacks against ZigBee security are carried out in our laboratory environment. The attack scenarios are based on utilizing several vulnerabilities found from the main security components of ZigBee technology. The first attack is based on discovering all ZigBee-enabled networks within range as well as the configurations of the corresponding ZigBee-enabled devices: This vital and fundamental basic information can be used for performing further and more severe attacks against the discovered ZigBee-enabled devices/networks. The second attack can be seen as an extension to the first attack and thus the prerequisite for it is the successful completion of the first attack. In the second attack, an attacker eavesdrops on the unencrypted or encrypted traffic of a ZigBee-enabled network in order to obtain and utilize any sensitive/useful information. The third attack is based on replaying (re-transmitting) the captured data as if the original sender is sending the data again. To keep this attack extremely simple, straightforward, and practical, we decided to devise and implement it without having a Man-In-The-Middle (MITM) between the victim devices, since the presence of the MITM would have made the attack very difficult to implement in practice, thus giving it only a theoretical relevance. Indeed, we demonstrate with experimental figures that attacks against ZigBee-enabled devices become practical by using our three attack scenarios. In addition, countermeasures that render the attacks impractical, although not totally eliminating their potential danger, are devised. Moreover, some new ideas that will be used in our future research work are proposed.

Fractal dimension analysis and statistical processing of paper surface images towards surface roughness measurement

In this paper we present a method for optical paper surface roughness measurement, which overcomes the disadvantages of the traditional methods. Airflow-based roughness measurement methods and profilometer require expensive special equipment, essential laboratory conditions, are contact-based and slow and unsuitable for on-line control purposes methods. We employed an optical microscope with a built-in CCD-camera to take images of paper surface. The obtained image is considered as a texture. We applied statistical brightness measures and fractal dimension analysis for texture analysis. We have found a strong correlation between the roughness and a fractal dimension. Our method is non-contact–based, fast and is suitable for on-line control measurements in the paper industry.

Designing and Simulating a Sensor Network of a Virtual Intelligent Home Using TOSSIM Simulator

In this paper, we evaluate the features and limitations of Tiny OS mote Simulator (TOSSIM), the sensor network simulator in TinyOS systems. The focus is on the applicability of TOSSIM for intelligent home research. As a part of the research work, we designed and implemented a simple sensor network that can be used in a virtual intelligent home. Our conclusions are based on the tests performed with the simulator as well as articles already published on TOSSIM.

Designing and implementing an intelligent Zigbee and WLAN enabled robot car

In this paper, a designing process and implementation details of an intelligent ZigBee and wireless local area network (WLAN) enabled robot car are described. ZigBee was used for the delivery of the robot car controlling commands, while WLAN was used for in-car image transmission to the controlling computer. In addition, intelligent solutions currently used in the robot car are explained. In order to test the operational capabilities of the robot car, a simple controlling scheme was implemented using a green laser dot. Moreover, intelligent methods and some new ideas that will be used in our future research work are proposed.

Emotions in Robots

This article gives a general overview of emotions in robotics. It sheds light on the composition of emotions in human beings and how this information can be used as blue print for creation of emotional robots. It discusses different factors involved in creation and detection of emotion. The article briefly explains the social aspects of having emotional robots in society. A system architecture to build emotional system of robot is presented, along with information about working of its modules.