51. Biomechanical characteristics of skeletal muscles and associations between running speed and contraction time in 8- to 13-year-old childrenJernej Završnik, Rado Pišot, Boštjan Šimunič, Peter Kokol, Helena Blažun, 2017, izvirni znanstveni članek Opis: Objective: To investigate associations between running speeds and contraction times in 8- to 13-year-old children.
Method: This longitudinal study analyzed tensiomyographic measurements of vastus lateralis and biceps femoris muscles’ contraction times and maximum running speeds in 107 children (53 boys, 54 girls). Data were evaluated using multiple correspondence analysis.
Results: A gender difference existed between the vastus lateralis contraction times and running speeds. The running speed was less dependent on vastus lateralis contraction times in boys than in girls. Analysis of biceps femoris contraction times and running speeds revealed that running speeds of boys were much more structurally associated with contraction times than those of girls, for whom the association seemed chaotic.
Conclusion: Joint category plots showed that contraction times of biceps femoris were associated much more closely with running speed than those of the vastus lateralis muscle. These results provide insight into a new dimension of children’s development. Ključne besede: children, tensiomyography, running speed, contraction time, skelet muscle, motor development Objavljeno: 13.07.2017; Ogledov: 105; Prenosov: 9 Celotno besedilo (454,48 KB) |
52. Lossless geometry compression through changing 3D coordinates into 1DYongkui Liu, Lijun He, Peng-jie Wang, Linghua Li, Borut Žalik, 2013, izvirni znanstveni članek Opis: A method of lossless geometry compression on the coordinates of the vertexes for grid model is presented. First, the 3D coordinates are pre-processed to be transformed into a specific form. Then these 3D coordinates are changed into 1D data by making the three coordinates of a vertex represented by only a position number, which is made of a large integer. To minimize the integers, they are sorted and the differences between two adjacent vertexes are stored in a vertex table. In addition to the technique of geometry compression on coordinates, an improved method for storing the compressed topological data in a facet table is proposed to make the method more complete and efficient. The experimental results show that the proposed method has a better compression rate than the latest method of lossless geometry compression, the Isenburg-Lindstrom-Snoeyink method. The theoretical analysis and the experiment results also show that the important decompression time of the new method is short. Though the new method is explained in the case of a triangular grid, it can also be used in other forms of grid model. Ključne besede: triangular mesh, model, lossless, compression Objavljeno: 12.07.2017; Ogledov: 182; Prenosov: 7 Celotno besedilo (332,44 KB) |
53. Dynamic arc fitting path follower for skid-steered mobile robotsPeter Lepej, Johannes Maurer, Suzana Uran, Gerald Steinbauer, 2015, izvirni znanstveni članek Opis: Many applications, such as surveillance, inspection or search and rescue operations, can be performed with autonomous robots. Our aim is a control of modular autonomous systems in rescue robotics. One of the basic problems with autonomous robotics is the execution part where the control commands (translation and rotational velocities) are produced for mobile bases. Therefore we have focused on this area because there is only a small amount of available path following software for skid-steered mobile robots. Our goal was to develop a velocity controller that could be used for multiple skid-steered mobile bases. We considered differential drive mobile bases such as tracked skid-steering mobile bases. Our approach is based on an arc fitting algorithm, which takes into account the robot constraints and kinematical model. It produces a continuous trajectory where fitting to the given path is adapted based on given parameters. Moreover, we have included orientation angle compensation while the mobile robot is moving and ground inclination compensation. Our rescue robot is described, together with the simulation setup and algorithm implementation. We compared our algorithm to the Hector-based software and curvature velocity approach. The results for the proposed algorithm are shown for the simulation results and the experiment. Ključne besede: mobile robot, arc fitting, path following, velocity control, rescue robot Objavljeno: 12.07.2017; Ogledov: 139; Prenosov: 4 Celotno besedilo (1,43 MB) |
54. Hybrid societies: challenges and perspectives in the design of collective behavior in self-organizing systemsHeiko Hamann, Yara Khaluf, Jean Botev, Mohammad Divband Soorati, Eliseo Ferrante, Oliver Kosak, Jean-Marc Montanier, Sanaz Mostaghim, Richard Redpath, Jon Timmis, Frank Veenstra, Mostafa Wahby, Aleš Zamuda, 2016, izvirni znanstveni članek Opis: Hybrid societies are self-organizing, collective systems, which are composed of different components, for example, natural and artificial parts (bio-hybrid) or human beings interacting with and through technical systems (socio-technical). Many different disciplines investigate methods and systems closely related to the design of hybrid societies. A stronger collaboration between these disciplines could allow for re-use of methods and create significant synergies. We identify three main areas of challenges in the design of self-organizing hybrid societies. First, we identify the formalization challenge. There is an urgent need for a generic model that allows a description and comparison of collective hybrid societies. Second, we identify the system design challenge. Starting from the formal specification of the system, we need to develop an integrated design process. Third, we identify the challenge of interdisciplinarity. Current research on self-organizing hybrid societies stretches over many different fields and hence requires the re-use and synthesis of methods at intersections between disciplines. We then conclude by presenting our perspective for future approaches with high potential in this area. Ključne besede: hybrid society, bio-hybrid, distributed, self-organization, design, intedisciplinary Objavljeno: 10.07.2017; Ogledov: 103; Prenosov: 29 Celotno besedilo (603,11 KB) |
55. Toward the discovery of citation cartels in citation networksIztok Fister, Iztok Fister, Matjaž Perc, 2016, izvirni znanstveni članek Opis: In this perspective, our goal is to present and elucidate a thus far largely overlooked problem that is arising in scientific publishing, namely the identification and discovery of citation cartels in citation networks. Taking from the well-known definition of a community in the realm of network science, namely that people within a community share significantly more links with each other as they do outside of this community, we propose that citation cartels are defined as groups of authors that cite each other disproportionately more than they do other groups of authors that work on the same subject. Evidently, the identification of citation cartels is somewhat different, although similar to the identification of communities in networks. We systematically expose the problem, provide theoretical examples, and outline an algorithmic guide on how to approach the subject. Ključne besede: citation network, citation cartel, network science, community detection, cooperation Objavljeno: 10.07.2017; Ogledov: 142; Prenosov: 4 Celotno besedilo (855,89 KB) |
56. Open $k$-monopolies in graphs: complexity and related conceptsDorota Kuziak, Iztok Peterin, Ismael G. Yero, 2016, izvirni znanstveni članek Opis: Closed monopolies in graphs have a quite long range of applications in several problems related to overcoming failures, since they frequently have some common approaches around the notion of majorities, for instance to consensus problems, diagnosis problems or voting systems. We introduce here open ▫$k$▫-monopolies in graphs which are closely related to different parameters in graphs. Given a graph ▫$G=(V,E)$▫ and ▫$X \subseteq V$▫, if ▫$\delta_X(v)$▫ is the number of neighbors ▫$v$▫ has in ▫$X$▫, ▫$k$▫ is an integer and ▫$t$▫ is a positive integer, then we establish in this article a connection between the following three concepts: (1) Given a nonempty set ▫$M\subseteq V$▫ a vertex ▫$v$▫ of ▫$G$▫ is said to be ▫$k$▫-controlled by ▫$M$▫ if ▫$\delta_M(v)\ge \frac{\delta_V(v)}{2}+k$▫. The set ▫$M$▫ is called an open ▫$k$▫-monopoly for ▫$G$▫ if it ▫$k$▫-controls every vertex ▫$v$▫ of ▫$G$▫. (2) A function ▫$f: V\rightarrow \{-1,1\}$▫ is called a signed total ▫$t$▫-dominating function for ▫$G$▫ if ▫$f(N(v))=\sum_{v\in N(v)}f(v)\geq t$▫ for all ▫$v\in V$▫. (3) A nonempty set ▫$S\subseteq V$▫ is a global (defensive and offensive) ▫$k$▫-alliance in ▫$G$▫ if ▫$\delta_S(v)\ge \delta_{V-S}(v)+k$▫ holds for every ▫$v\in V$▫. In this article we prove that the problem of computing the minimum cardinality of an open ▫$0$▫-monopoly in a graph is NP-complete even restricted to bipartite or chordal graphs. In addition we present some general bounds for the minimum cardinality of open ▫$k$▫-monopolies and we derive some exact values. Ključne besede: open k-monopolies, k-signed total domination, global defensive k-alliance, global offensive k-alliance Objavljeno: 10.07.2017; Ogledov: 72; Prenosov: 4 Celotno besedilo (181,59 KB) |
57. Efficient open domination in graph productsDorota Kuziak, Iztok Peterin, Ismael G. Yero, 2014, izvirni znanstveni članek Opis: A graph ▫$G$▫ is an efficient open domination graph if there exists a subset ▫$D$▫ of ▫$V(G)$▫ for which the open neighborhoods centered in vertices of ▫$D$▫ form a partition of ▫$V(G)$▫. We completely describe efficient open domination graphs among lexicographic, strong, and disjunctive products of graphs. For the Cartesian product we give a characterization when one factor is ▫$K_2$▫. Ključne besede: graph theory, efficient open domination, graph products, total domination Objavljeno: 10.07.2017; Ogledov: 77; Prenosov: 4 Celotno besedilo (804,78 KB) |
58. XML Schema metrics for quality evaluationMaja Pušnik, Marjan Heričko, Zoran Budimac, Boštjan Šumak, 2014, izvirni znanstveni članek Opis: In XML Schema development, the quality of XML Schemas is a crucial issue for further steps in the life cycle of an application, closely correlated with the structure of XML Schemas and different building blocks. Current research focuses on measuring complexity of XML Schemas and mainly do not consider other quality aspects. This paper proposes a novel quality measuring approach, based on existing software engineering metrics, additionally defining the quality aspects of XML Schemas using the following steps: (1) definition of six schema quality aspects, (2) adoption of 25 directly measurable XML Schema variables, (3) proposition of six composite metrics, applying 25 measured variables and (4) composite metrics validation. An experiment was conducted using 250 standard XML Schemas collected from available e-business information systems. The results illustrate the influence of XML Schemaʼs characteristics on its quality and evaluate the applicability of metrics in the measurement process, a useful tool for software developers while building or adopting XML Schemas. Ključne besede: XML, metrics, quality variables, quality index, evaluation, validation Objavljeno: 06.07.2017; Ogledov: 123; Prenosov: 6 Celotno besedilo (765,37 KB) |
59. Towards building a forensics aware language for secure loggingShams Zawoad, Marjan Mernik, Ragib Hasan, 2014, izvirni znanstveni članek Opis: Trustworthy system logs and application logs are crucial for digital forensics. Researchers have proposed different security mechanisms to ensure the integrity and confidentiality of logs. However, applying current secure logging schemes on heterogeneous formats of logs is tedious. Here, we propose Forensics Aware Language (FAL), a domain-specific language (DSL) through which we can apply a secure logging mechanism on any format of logs. Using FAL, we can define log structure, which represents the format of logs and ensures the security properties of a chosen secure logging scheme. This log structure can later be used by FAL to serve two purposes: it can be used to store system logs securely and it will help application developers for secure application logging by generating the required source code. Ključne besede: domain-specific language, DSL, secure logging, audit trail, digital forensics Objavljeno: 06.07.2017; Ogledov: 86; Prenosov: 5 Celotno besedilo (526,42 KB) |
60. SimpleConcepts: a lightweight extension to C++ to support constraints on generic typesReed Milewicz, Marjan Mernik, Peter Pirkelbauer, 2014, izvirni znanstveni članek Opis: Generic programming plays an essential role in C++ software through the use of templates. However, both the creation and use of template libraries is hindered by the fact that the language does not allow programmers to specify constraints on generic types. To date, no proposal to update the language to provide concepts has survived the committee process. Until that time comes, as a form of early support, this paper introduces SimpleConcepts, an extension to C++11 that provides support for concepts, sets of constraints on generic types. SimpleConcepts features are parsed according to an island grammar and source-to-source translation is used to lower concepts to pure C++11 code. Ključne besede: generic programming, C++ templates, C++ concepts Objavljeno: 06.07.2017; Ogledov: 106; Prenosov: 3 Celotno besedilo (299,20 KB) |