APPLYING THE REAL TIME SHADOWING METHOD FOR CREATING SOFT SHADOWS IN OPENGL

This paper presents a technique for rapidly generating and rendering of soft shadows on the scene. The method has the advantage of real-time creating of shadows which look more realistic than hard shadows and have high quality, also it has not high demands in resources. The main idea is to replace a complex light source with a collection of multiple point sources of light in order to decrease rendering time. The mathematic model, experiments, and comparison with similar techniques are given and described

A SURVEY ON TOPOLOGY-BASED MESSAGE BROADCAST SCHEMES IN VEHICULAR NETWORKS

Vehicular ad-hoc networks (VANETs) are subclass of mobile ad-hoc networks (MANETs). They have been the most promising research field and development for the last few years. VANETs use vehicles as mobile nodes to provide communication among nearby vehicles and between vehicles and nearby roadside equipment. VANETs come with several challenging characteristics, such as dynamic and potentially large scale network topology, high mobility and intermittent connectivity of vehicular nodes, and broadcasting as the predominant communication to disseminate the safety messages. When a traffic accident happens, the safety message should be broadcasted to all vehicles in the area exposed to potential hazard. Recently, there have been a significant number of broadcasting protocols for VANETs reported in the literature. In this survey paper we provide an overview of topology-based broadcasting protocols and associated requirements, along with challenges and their proposed current and past major solutions. In addition, classification and comparison of topology-based broadcasting protocols are described from their pros and cons. Featured solutions in this domain are categorized and discussed

A RUNLENGTH CODED ADAPTIVE QIM FOR THE CULTURAL HERITAGE 3D MODELS AUTHENTICATION

We describe a simple and effective quantization scheme for a digital 3D cultural heritage models authentication and watermarking. It is based on runlength coding which converts a class of deletion channels that have infinite memory into memoryless channels. We consider a novel application of this technique in multimedia watermarking and authentication using quantization index modulation operating on the three dimensional mesh vertices, which are invariant to geometric and topological transformation. Vector of the vertex indices is extracted from a huge digital 3D model using our powerful vertex extraction tool. The coding recovers the data hidden in the vertices removed by the process of mesh simplification

Improvement of the Accuracy of Prediction Using Unsupervised Discretization Method: Educational Data Set Case Study

This paper presents a comparison of the efficacy of unsupervised and supervised discretization methods for educational data from blended learning environment. Naïve Bayes classifier was trained for each discretized data set and comparative analysis of prediction models was conducted. The research goal was to transform numeric features into maximum independent discrete values with minimum loss of information and reduction of classification error. Proposed unsupervised discretization method was based on the histogram distribution and implementation of oversampling technique. The main contribution of this research is improvement of accuracy prediction using the unsupervised discretization method which reduces the effect of ignoring class feature for educational data set

INVESTIGATING THE IMPACT OF TREE-BASED NETWORK TOPOLOGY ON THE SDN CONTROLLER PERFORMANCE

Software Defined Networking (SDN) is an important technology that enables a new approach to how we develop and manage networks. SDN divides the data plane and control plane and promotes logical centralization of network control so that the controller can schedule the data in the network effectively through the OpenFlow protocol. The performance and capabilities of the controller itself are important. The impact of network topology type on controller performance can be very significant. In order to have better communication in SDN, it is essential to have an analysis of the performance of specific network topologies. In this paper, we simulate ONOS and RYU controllers and compare their different network parameters under the proposed complex custom Tree-based topology. A network topology has been designed using a Mininet emulator, and the code for topology is executed in Python. From the throughput, packet transmission rate, and latency analysis, the ONOS controller displayed better results than RYU, showing that it can respond to requests more efficiently under complex SDN topologies and traffic loads. On the contrary, the RYU controller provides better results for the less complex SDN networks

THE APPROACH TO MEASUREMENT OF REQUIREMENT QUALITY BY APPLICATION OF GENERALIZED PRIORITIZED FUZZY CONSTRAINT SATISFACTION PROBLEM

The requirement quality affects product development at all lifecycle stages, as well as the end product. Poorly defined requirements bring to extended deadlines, increased financial costs, even to project disruption. Current researches related to the good quality of requirements include characteristics of good requirements and the development of new elicitation techniques. Requirement quality evaluation should be tailored both to the professionals and users who defined requirements according to their needs. Therefore, the model is designed for requirement quality measurement based on the characteristics of good requirements by application of the Generalized Prioritized Fuzzy Constraint Satisfaction Problem. The model enables the participation of selected characteristics of good requirements in quality evaluation, according to priorities. The evaluator obtains information if the requirement satisfies the given quality satisfaction threshold based on the degree of fulfillment of selected characteristics of a good requirement. The model is applied to all types of requirements, as well as to the evaluation of requirements at all software development lifecycle stages

COMPARISON OF DATA MINING ALGORITHMS, INVERTED INDEX SEARCH AND SUFFIX TREE CLUSTERING SEARCH

New documents are created every day and the number of digital documents in the world is exponentially growing. Search engines do a great job by making these documents easily available to the world population. Data mining works with large amount of data sets and offers data to the end user; it consists of many different techniques and algorithms. These techniques allow faster and better search for large amounts of data. Clustering is one of the techniques used in a data mining process; it is based on data grouping according to the features, or any property they have in common, thus, a search process is faster, and a user gets better search results. On the other hand, an inverted index is a structure that provides fast search too, but this structure does not create clusters or groups of similar data. Instead, it processes all data in a document and measures appearance of specific terms in a document. The goal of this paper is to compare these two algorithms. The authors created applications that use these two algorithms and tested them on the same corpus of documents. For both algorithms, the authors are presenting improvements that provide faster search and better search results

TRANSFORMING SMARTPHONE INTO GEOSPATIAL VIDEO PROVIDER

Modern handheld devices, i.e. smartphones, have gone beyond their basic purpose for some time now. Beside powerful screens, which usually surpass those we use on our desktops, powerful cameras, and internet connectivity, these devices usually integrate many sensors. In this paper, we discuss how we can combine smart phone’s camera, connectivity, GPS receiver, accelerometer, and magnetometer in order to transform this kind of a device into geospatial video source. To validate and test suggested solution, we implemented a simple mobile app that fetches frames and sensors’ data, calculates georeference and streams geospatial video. In the paper, we also discussed limitations that are caused by the limited precision of used sensors

COMPARISON OF SPHERICAL CUBE MAP PROJECTIONS USED IN PLANET-SIZED TERRAIN RENDERING

A wide variety of projections from a planet surface to a two-dimensional map are known, and the correct choice of a particular projection for a given application area depends on many factors. In the computer graphics domain, in particular in the field of planet rendering systems, the importance of that choice has been neglected so far, and inadequate criteria have been used to select a projection. In this paper, we derive evaluation criteria, based on texture distortion, suitable for this application domain, and apply them to a comprehensive list of spherical cube map projections to demonstrate their properties

Contribution of Agro-Physiological and Morpho-Anatomical Traits to Grain Yield of Wheat Genotypes under Post-Anthesis Stress Induced by Defoliation

Post-anthesis drought affects wheat production worldwide, primarily through the limitation of grain filling. The enhanced remobilization of stem reserves induced by drought can provide considerable carbon sources for grain filling. The aim of this study, which was part of an ongoing wheat-breeding program targeting drought tolerance, was to assess the ability of 20 contrasting common wheat genotypes (2 cultivars, 8 F6:7 families (FAM), and 10 parent genotypes (PAR) used to make the families) to remobilize stem dry matter under water-stressed conditions simulated via defoliation 10 days after anthesis, and to estimate the contribution of stem dry matter remobilization to grain weight. In two-year field trials, the genotypes were scored for agro-physiological and peduncle morpho-anatomical traits. Stem reserve contribution to grain weight per spike was significantly enhanced in defoliated plants but did not differ amongst the groups of genotypes. F6:7 families had higher grain-filling rate and 1000-grain weight but without improvement in grain weight per spike under defoliation compared with parental groups. The total area of chlorenchyma, phloem-area-related traits, and stem reserve contribution to grain weight were positively associated with grain weight per spike under defoliation, whilst in both treatments, the grain-filling rate was determined by stem height. These results imply that the grain-filling rate is a trait desirable for drought tolerance that can be improved during the breeding process. © 2023 by the authors