J.Kaukėnas, G.Navickas, L.Telksnys. Human-Computer Audiovisual Interface. Information Technology And Control, Kaunas, Technologija, 2006, Vol. 35, No. 2, 87 - 93.
J.Kaukėnas, G.Navickas, L.Telksnys. Human-Computer Audiovisual Interface. Information Technology And Control, Kaunas, Technologija, 2006, Vol. 35, No. 2, 87 - 93.
The concept of audiovisual interface between human and stochastic process modeling and analysis software is investigated. Examples revealing the advantages of audiovisual interface over audio-only interface are given.
V.Kontrimas, A.Verikas. Tracking of Doubtful Real Estate Transactions by Outlier Detection Methods: a Comparative Study. Information Technology And Control, Kaunas, Technologija, 2006, Vol. 35, No. 2, 94 - 105.
Doubtful real estate transactions, with the prices far away from the market prices, appear because of non-commercial transactions or efforts in order to hide the taxes. To estimate the right values of parameters, such data must be removed from a data set or robust methods of parameters estimation are to be used, while developing a mass appraisal model. Such transactions are outlying observations, which can be detected and removed by outlier detection methods. The purpose of the work is: to review outlier detection methods and to test the possibility of using them to solve the task. An overview of of real estate market value, valuation methods and process of mass appraisal is made to introduce to real estate mass valuation. Overview of outlier detection method contains scaling and such methods: resampling by half means, the smallest half volume, the closest distance to the center, ellipsoidal multivariate trimming, minimum volume ellipsoid, minimum scatter determinant, analysis of projection matrix, principal components and residuals, also influence measures, robust regression, and classification methods. The reviewed methods were categorized; commonly used methods were selected and tested experimentally aiming to compare the effectiveness. Best results were achieved using the multilayer perceptron and the principal component analysis based technique.
G.Kazakevičiūtė, E.Januškevičius, R.Rosenbaum, H.Schumann. Self Annotated Raster Image. Information Technology And Control, Kaunas, Technologija, 2006, Vol. 35, No. 2, 106 - 116.
The new embedding method of annotations into raster images is presented in the article. The method combines the principles of watermarking and steganography. Using the method proposed it is possible to attach the information to the raster image and bind it to a specified object or region of the image. The JPEG2000 raster images coding standard is used as base to realize the embedding and extracting scheme of image data. The proposed scheme targeted to mobile environments and evaluate their limits. The article reviewes the existing methods of embedding for metadata and annotations; the principles of information embedding and extracting for JPEG2000 images. The main requirements for annotation scheme are defined. Embedding principles and logical structures are analyzed. These requirements are practically adopted for the new method of annotations embedding into the raster image, evaluating the JPEG2000 requirements. The scheme is tested practically and the results of these experiments are presented.
R.Damaševičius. Estimation of Design Characteristics at RTL Modeling Level Using SystemC. Information Technology And Control, Kaunas, Technologija, 2006, Vol. 35, No. 2, 117 - 123.
A successful SoC and embedded system design requires the thorough domain analysis and design space exploration. The early evaluation of design characteristics allows to take advantage of many architectural options available and to modify the system architecture, if needed. Currently, SystemC is used to model hardware and software parts of the system at the high-level. However, the characteristics of the modeled systems are obtained only at the late stages of the design. In this paper, we present a framework for the estimation of design characteristics at the modeling level of a design. The SystemC class library is extended with new classes describing the computation of area, delay and power characteristics of the SystemC models. The achieved results are illustrated with a case study.
J.Čeponis, E.Kazanavičius, A.Mikuckas. Fault Tolerant Process Networks. Information Technology And Control, Kaunas, Technologija, 2006, Vol. 35, No. 2, 124 - 130.
Kahn process network is a kind of data flow process networks. It is a computation model in which many concurrent processes communicate through unbounded FIFO buffer and can be executed simultaneously. In real time digital signal processing applications execution time is infinite. However, failures of implementation hardware can occur. In our work, dynamic run-time reconfiguration is introduced into process network, which ensures error handling, avoiding deadlocks, continuous and on-time result delivery. After dynamic reconfiguration, network execution results may become non deterministic, but this helps avoiding critical termination of network execution. In this paper, we present a description of possible failures of network execution and discuss the means for avoiding these failures.
Z.N.Milivojevic, M.Dj.Mirkovic, S.M.Milivojevic. An Estimate of Fundamental Frequency Using PCC Interpolation - Comparative Analysis. Information Technology And Control, Kaunas, Technologija, 2006, Vol. 35, No. 2, 131 - 136.
This paper deals with the algorithm for an estimate of fundamental frequency, which is based on signal processing by window functions in time domain and parametric Cubic interpolation in frequential domain. In the second part of the paper, the results of the simulation of the algorithm for Catmull-Rom's, Greville's and Greville's two-parametric kernel are presented. Taking MSE as a measure of the algorithm quality, optimal parameters of the selected kernel, selected kernel and a suitable window function are defined.
K.S.Cheung. Refinement of Petri-Net-Based System Specification. Information Technology And Control, Kaunas, Technologija, 2006, Vol. 35, No. 2, 137 - 143.
For a discrete-event system specified as a labelled Petri net, locations of conditions are denoted as places with condition labels while locations of events are denoted as transitions with event labels. Very often, the same condition label or event label may appear in multiple locations in the system specification. Since every condition is finally implemented as a unique state and every event as a unique operation, in order for the system specification to become useful for implementation, all duplicate condition labels and event labels must be eliminated. In this paper, we propose an algorithm for this refinement through the fusion of common subnets. Our algorithm has three distinctive features. First, the units of fusing are subnets instead of individual places and transitions. Second, the groups of common subnets identified for fusing are maximal and disjoint so that the fusion needs to be done once. Third, the fusion preserves firing sequences so that the system behaviours will not be altered.
T.Danikauskas, R.Butleris. Approach for IS Workspace Design Based on Output Driven Requirements Specification. Information Technology And Control, Kaunas, Technologija, 2006, Vol. 35, No. 2, 144 - 156.
The problem of information system (IS) workspace design is analysed. Different conceptions for IS workspace structure design are overviewed. Conceptions are based on Oracle CASE method, IDEF and UML application approach. The structure of the output driven requirements specification method is described. An approach to IS workspace design based on information flows specification is proposed. Some suggestions for capturing non-functional requirements for IS workspace are outlined. A case study of information system workspace design is presented.
D.Rudokaitė-Margelevičienė, H.Pranevičius, M.Margelevičius. Data Classification Using Dirichlet Mixtures. Information Technology And Control, Kaunas, Technologija, 2006, Vol. 35, No. 2, 157 - 166.
In the article, we present a method for data classification that is based on the Dirichlet mixture statistics. An important property of the method is its ability to classify data of any type. To test performance of the method, we implemented it as a stand-alone program and tested it on the three different databases of real data. Receiver operating characteristics of the classification was used to compare the method of Dirichlet mixtures to the other classification methods. The classification results and its performance are discussed in the article. The practical value of this study is that the method based on the complex statistics is implemented as a tool and compiled as a library for further development of machine learning environments.