Pregovaranje u Internetu stvari

Internet of things as a market, and the number of connected devices in particular is growing very rapidly. Currently, application owners deploy new devices for each application that needs the data. As the number of sensors increases, it will become much more practical to reuse existing sensors for new applications than to deploy new ones. But the problem is that the application owner needs to agree with device owners on conditions under which will the data be made available to applications. Doing this manually is very expensive both in terms of money and time. We implemented a system that does this automatically using negotiating agents. The system was tested on simulated environments and showed that it can mediate between devices and applications with reasonable performance.Internet stvari kao tržište, a posebno broj spojenih uređaja, raste vrlo brzo. Danas vlasnici aplikacija postavljaju nove uređaje za svaku aplikaciju kojoj su potrebni podatci. Kako se povećava broj senzora u upotrebi, postaje sve praktičnije koristiti postojeće senzore nego postavljati nove. Problem predstavlja činjenica da se vlasnik aplikacije mora dogovoriti s vlasnicima uređaja o uvjetima pod kojima će aplikacijama biti dozvoljeno dohvaćanje izmjerenih vrijednosti. Pojedinačno je dogovaranje između vlasnika za svaki uređaj skupo i sporo. Izgradili smo sustav koji automatizira ovaj proces pomoću programskih agenata koji pregovaraju. Sustav je ispitan na simuliranom okruženju i pokazuje da može posredovati između uređaja i aplikacija s razumnim performansama

Heuristički postupci izdvajanja značajki u obradi signala

Extraction of relevant features is essential stage in a pattern recognition and classification system. Goal of the feature extraction algorithm is to find feature subset where relevant information for recognition is contained in minimal number of features. Proposed algorithms are based on the assumption that features with better individual discrimination ability will also be better in combination with other features. Features are first extracted from the initial set, then sorted according to their individual fitness. Sorted set is used to form the search tree. Two heuristic algorithms are proposed: the first one performs the depth first search, bounded with required increase of fitness function and the second one is based on genetic algorithm. Their performances are compared with complete search and sequential search (FSS, BSS) algorithms.Izdvajanje relevantnih značajki je ključan korak u sustavu za raspoznavanje uzoraka i klasifikaciju. Cilj postupka izdvajanja značajki je pronalaženje najmanjeg skupa značajki koji sadrži informacije potrebne za raspoznavanje uzorka. Predloženi postupak temeljen je na pretpostavci da će značajke koje pojedinačno bolje razlikuju uzorke iz različitih klasa to svojstvo imati i u kombinaciji s drugim značajkama. Nakon izdvajanja iz početnog skupa, značajke se sortiraju po padajućoj vrijednosti kriterijske funkcije. Iz sortiranog skupa značajki formira se stablo pretraživanja, tako da će skupovi koji sadrže pojedinačno bolje značajke biti pretraženi prije. Predložena su dva postupka izdvajanja značajki: prvi provodi pretraživanje stabla po dubini ograničeno zadanim porastom vrijednosti kriterijske funkcije, a drugi je temeljen na genetskom algoritmu. Postupci su prema kvaliteti izdvojenih skupova značajki i efikasnosti uspoređeni s postupkom potpunog pretraživanja i slijednim postupcima (FSS, BSS)

Roboti za razminiranje – zahtjevi i ograničenja

One of the most urgently needed applications for mobile robots is demining. Using robots in a minefield is accomplished with severe demands for mobility in an environment covered with dense vegetation and containing various obstacles. Furthermore, it is required that robot should cover the whole area with the detector, avoiding previously detected mines. Different configurations of demining robots are analyzed regarding control and navigation, size and locomotion.Razminiranje je jedno od najvažnijih potencijalnih područja primjene mobilnih robota. Korištenje robota u minskom polju povezano je sa strogim zahtjevima na pokretljivost u okolišu prekrivenom gustom vegetacijom koji sadrži različite prepreke. Povrh toga, robot mora omogućiti pregled cijelog područja detektorom, izbjegavajući prethodno otkrivene mine. U radu su analizirane različite strukture robota za razminiranje s obzirom na upravljanje, navigaciju, veličinu i način kretanja

Framework for 4D medical data compression

U ovom radu predložen je novi programski okvir za kompresiju četvero-dimenzionalnih (4D) medicinskih podataka. Arhitektura ovog programskog okvira temelji se na različitim procedurama i algoritmima koji detektiraju vremenske i prostorne zalihosti u ulaznim 4D medicinskim podacima. Pokret kroz vrijeme analizira se pomoću vektora pomaka koji predstavljaju ulazne parametre za neuronske mreže koje se koriste za procjenu pokreta. Kombinacijom segmentacije, pronalaženja odgovarajućih blokova i predikcijom vektora pomaka, zajedno s ekspertnim znanjem moguće je optimirati performanse sustava. Frekvencijska svojstva se analiziraju proširenjem wavelet transformacije na tri dimenzije. Za mirne volumetrijske objekte, moguće je konstruirati različite wavelet pakete s različitim filtrima koji omogućavaju širok raspon analiza frekvencijskih zalihosti. Kombinacijom uklanjanja vremenskih i prostornih zalihosti moguće je postići vrlo visoke omjere kompresije.This work presents a novel framework for four-dimensional (4D) medical data compression architecture. This framework is based on different procedures and algorithms that detect time and spatial (frequency) redundancy in recorded 4D medical data. Motion in time is analyzed through the motion fields that produce input parameters for the neural network used for motion estimation. Combination of segmentation, block matching and motion field prediction along with expert knowledge are incorporated to achieve better performance. Frequency analysis is done through an extension of one dimensional wavelet transformation to three dimensions. For still volume objects different wavelet packets with different filter banks can be constructed, providing a wide range of frequency analysis. With combination of removing temporal and spatial redundancies, very high compression ratio is achieved

Numerical simulation of debris flows triggered from the Strug rock fall source area, W Slovenia

The Strug landslide was triggered in December 2001 as a rockslide, followed by a rock fall. In 2002, about 20 debris flows were registered in the Kosec village; they were initiated in the Strug rock fall source area. They all flowed through the aligned Brusnik channel, which had been finished just before the first debris flow reached the village in April 2002. Debris flow events were rainfall-induced but also governed by the availability of rock fall debris in its zone of accumulation. After 2002 there was not enough material available for further debris flows to reach the village. Nevertheless, a decision was reached to use mathematical modeling to prepare a hazard map for the village for possible new debris flows. Using the hydrological data of the Brusnik watershed and the theological characteristics of the debris material, 5 different scenarios were defined with the debris flow volumes from 1000 m(3) to a maximum of 25 000 m(3). Two mathematical models were used, a one-dimensional model DEBRIF-1D, and a two-dimensional commercially available model FLO-2D. Due to the lack of other field data, data extracted from available professional films of debris flows in 2002 in the Kosec village were used for model calibration. The computational reach was put together from an 800-m long upstream reach and 380-m long regulated reach of the Brusnik channel through the village of Kosec. Both mathematical models have proved that the aligned Brusnik channel can convey debris flows of the volume up to 15 000 m(3). Under the most extreme scenario a debris flow with 25 000 m3 would locally spill over the existing levees along the regulated Brusnik channel. For this reason, additional river engineering measures have been proposed, such as the raising of the levees and the construction of a right-hand side sedimentation area for debris flows at the downstream end of the regulated reach

ATLAS - Advanced Tools and Languages for Microprocessor Architecture Simulation

In this paper the digital system simulation program package ATLAS (Advanced Tools and Languages for microprocessor Architecture Simulation) is described. Different software modules, parts of ATLAS are developed: COMPAS - COnfigurable MicroProcessor Architecture Simulator, CONAS - CONfigurable ASsembler, ADEL - Assembler DEscription Language, COMDEL- COMponent DEscription Language and SYSDEL - SYStem DEscription Language. The simulator COMPAS and its implementation are explained in more details. The digital component description language features are given

Evaluation of objective video quality assessment methods on video sequences with different spatial and temporal activity encoded at different spatial resolutions

With the development of Video on Demand applications due to the availability of high-speed internet access, adaptive streaming algorithms have been developing and improving. The focus is on improving user’s Quality of Experience (QoE) and taking it into account as one of the parameters for the adaptation algorithm. Users often experience changing network conditions, so the goal is to ensure stable video playback with satisfying QoE level. Although subjective Video Quality Assessment (VQA) methods provide more accurate results regarding user’s QoE, objective VQA methods cost less and are less time-consuming. In this article, nine different objective VQA methods are compared on a large set of video sequences with various spatial and temporal activities. VQA methods used in this analysis are: Peak Signal-to-Noise Ratio (PSNR), Structural Similarity Index (SSIM), MultiScale Structural Similarity Index (MS-SSIM), Video Quality Metric (VQM), Mean Sum of Differences (DELTA), Mean Sum of Absolute Differences (MSAD), Mean Squared Error (MSE), Netflix Video Multimethod Assessment Fusion (Netflix VMAF) and Visual Signal-to-Noise Ratio (VSNR). The video sequences used for testing purposes were encoded according to H.264/AVC with twelve different target coding bitrates, at three different spatial resolutions (resulting in a total of 190 sequences). In addition to objective quality assessment, subjective quality assessment was performed for these sequences. All results acquired by objective VQA methods have been compared with subjective Mean Opinion Score (MOS) results using Pearson Linear Correlation Coefficient (PLCC). Measurement results obtained on a large set of video sequences with different spatial resolutions show that VQA methods like SSIM and VQM correlate better with MOS results compared to PSNR, SSIM, VSNR, DELTA, MSE, VMAF and MSAD. However, the PLCC results for SSIM and VQM are too low (0.7799 and 0.7734, respectively), for the usage of these methods in streaming services instead of subjective testing. These results suggest that more efficient VQA methods should be developed to be used in streaming testing procedures as well as to support the video segmentation process. Furthermore, when comparing results obtained for different spatial resolutions, it can be concluded that the quality of video sequences encoded at lower spatial resolutions in cases of lower target coding bitrate is higher compared to the quality of video sequences encoded at higher spatial resolutions at the same target coding bitrate, particularly when video sequences with higher spatial and temporal information are used

Autonomous Mobile Mailbox Model for Communication Cost Reduction

This paper presents a cost-reductive communication schema for distributed multi-agent environments containing mobile agents. Communication cost reduction is achieved by employing autonomous mobile mailbox as a message-relay system component. Beneficial modes of mobile mailbox behavior are identified under various operational conditions. A mobile mailbox model is proposed and simulation conducted in order to verify its usability

WEATHER FORECAST PRESENTATION BASED ON LEADING EDGE MOBILE PHONES AND JAVA TECHNOLOGIES

The paper presents a new method of weather forecast presentation, which was developed as a project during the course of postgraduate study. So far, the use of mobile phones in the presentation of weather forecasts was limited and non-interactive. This application provides an interactive access to meteorological products in Croatia. It has been developed in the MicroJava programming language and successfully tested in an emulator and on real mobile devices. The rapid development of mobile technologies will allow for intensive application of such products