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Search Results: 1 - 10 of 1467 matches for " Konstantinos Chorianopoulos "
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User-based key frame detection in social web video
Konstantinos Chorianopoulos
Computer Science , 2012,
Abstract: Video search results and suggested videos on web sites are represented with a video thumbnail, which is manually selected by the video up-loader among three randomly generated ones (e.g., YouTube). In contrast, we present a grounded user-based approach for automatically detecting interesting key-frames within a video through aggregated users' replay interactions with the video player. Previous research has focused on content-based systems that have the benefit of analyzing a video without user interactions, but they are monolithic, because the resulting video thumbnails are the same regardless of the user preferences. We constructed a user interest function, which is based on aggregate video replays, and analyzed hundreds of user interactions. We found that the local maximum of the replaying activity stands for the semantics of information rich videos, such as lecture, and how-to. The concept of user-based key-frame detection could be applied to any video on the web, in order to generate a user-based and dynamic video thumbnail in search results.
Methods and Applications in Interactive Broadcasting
Konstantinos Chorianopoulos,George Lekakos
Journal of Virtual Reality and Broadcasting , 2007,
Abstract: Interactive TV technology has been addressed in many previous works, but there is sparse research on the topic of interactive content broadcasting and how to support the production process. In this article, the interactive broadcasting process is broadly defined to include studio technology and digital TV applications at consumer set-top boxes. In particular, augmented reality studio technology employs smart-projectors as light sources and blends real scenes with interactive computer graphics that are controlled at end-user terminals. Moreover, TV producer-friendly multimedia authoring tools empower the development of novel TV formats. Finally, the support for user-contributed content raises the potential to revolutionize the hierarchical TV production process, by introducing the viewer as part of content delivery chain.
Video Pulses: User-Based Modeling of Interesting Video Segments
Markos Avlonitis,Konstantinos Chorianopoulos
Advances in Multimedia , 2014, DOI: 10.1155/2014/712589
Abstract: We present a user-based method that detects regions of interest within a video in order to provide video skims and video summaries. Previous research in video retrieval has focused on content-based techniques, such as pattern recognition algorithms that attempt to understand the low-level features of a video. We are proposing a pulse modeling method, which makes sense of a web video by analyzing users' Replay interactions with the video player. In particular, we have modeled the user information seeking behavior as a time series and the semantic regions as a discrete pulse of fixed width. Then, we have calculated the correlation coefficient between the dynamically detected pulses at the local maximums of the user activity signal and the pulse of reference. We have found that users' Replay activity significantly matches the important segments in information-rich and visually complex videos, such as lecture, how-to, and documentary. The proposed signal processing of user activity is complementary to previous work in content-based video retrieval and provides an additional user-based dimension for modeling the semantics of a social video on the web. 1. Introduction The web has become a very popular medium for sharing and watching video content [1]. Moreover, many organizations and academic institutions are making lecture videos and seminars available online. Previous work on video retrieval has investigated the content of the video and has contributed a standard set of procedures, tools, and data-sets for comparing the performance of video retrieval algorithms (e.g., TRECVID), but they have not considered the interactive behavior of the users as an integral part of the video retrieval process. In addition to watching and browsing video content on the web, people also perform other “social metadata” tasks, such as sharing, commenting videos, replying to other videos, or just expressing their preference/rating. User-based research has explored the association between commenting and microblogs, primarily tweets, or other text-based and explicitly user-generated content. Although there are various established information retrieval methods that collect and manipulate text, they could be considered burdensome for the users, in the context of video watching. In many cases, there is a lack of comment density when compared to the number of viewers of a video. There are a few research efforts to understand user-based video retrieval without the use of social metadata. In our research, we have developed a method that utilizes more so implicit user interactions for
CELL: Connecting Everyday Life in an archipeLago
Konstantinos Chorianopoulos,Vassiliki Tsaknaki
Computer Science , 2012,
Abstract: We explore the design of a seamless broadcast communication system that brings together the distributed community of remote secondary education schools. In contrast to higher education, primary and secondary education establishments should remain distributed, in order to maintain a balance of urban and rural life in the developing and the developed world. We plan to deploy an ambient and social interactive TV platform (physical installation, authoring tools, interactive content) that supports social communication in a positive way. In particular, we present the physical design and the conceptual model of the system.
Efficient Video Indexing on the Web: A System that Leverages User Interactions with a Video Player
Ioannis Leftheriotis,Chrysoula Gkonela,Konstantinos Chorianopoulos
Computer Science , 2012,
Abstract: In this paper, we propose a user-based video indexing method, that automatically generates thumbnails of the most important scenes of an online video stream, by analyzing users' interactions with a web video player. As a test bench to verify our idea we have extended the YouTube video player into the VideoSkip system. In addition, VideoSkip uses a web-database (Google Application Engine) to keep a record of some important parameters, such as the timing of basic user actions (play, pause, skip). Moreover, we implemented an algorithm that selects representative thumbnails. Finally, we populated the system with data from an experiment with nine users. We found that the VideoSkip system indexes video content by leveraging implicit users interactions, such as pause and thirty seconds skip. Our early findings point toward improvements of the web video player and its thumbnail generation technique. The VideSkip system could compliment content-based algorithms, in order to achieve efficient video-indexing in difficult videos, such as lectures or sports.
Uneven development and neo-corporatism in the Greek urban realm
Análise Social , 2010,
Abstract: this paper portrays the urbanisation and governance profile of greek cities and explores their capacity to respond to eu calls for enhanced competitiveness and synergistic policy-making. the distinctiveness of the greek urban example, it is argued, is not well adjusted to european spatial priorities and neo-corporatist modes of intervention. two case study cities illustrate the argument: keratsini-drapetsona, facing the realities of de-industrialisation, and iraklion, a city on the island of crete with dynamic development indicators. the paper concludes by discussing the mode of incorporation of cities in the current national strategic reference framework (2007-2013).
Uneven development and neo-corporatism in the Greek urban realm Desenvolvimento desigual e neo-corporativismo na esfera urbana Grega
Ioannis Chorianopoulos
Análise Social , 2010,
Abstract: This paper portrays the urbanisation and governance profile of Greek cities and explores their capacity to respond to EU calls for enhanced competitiveness and synergistic policy-making. The distinctiveness of the Greek urban example, it is argued, is not well adjusted to European spatial priorities and neo-corporatist modes of intervention. Two case study cities illustrate the argument: Keratsini-Drapetsona, facing the realities of de-industrialisation, and Iraklion, a city on the island of Crete with dynamic development indicators. The paper concludes by discussing the mode of incorporation of cities in the current National Strategic Reference Framework (2007-2013). Este artigo retrata o perfil de urbaniza o e de governan a das cidades gregas e analisa as suas reac es face às propostas da UE de desenvolvimento de políticas mais competitivas e sinergéticas. Argumenta-se que as especificidades da esfera urbana grega n o se encontram adaptadas às prioridades espaciais europeias e aos correspondentes modos neo-corporativos de interven o. Estudos de caso em duas cidades ilustram este argumento: Keratsini-Drapetsona, enfrentando a desindustrializa o; e Iraklion, uma cidade na ilha de Creta, que apresenta bons indicadores de desenvolvimento. O artigo conclui com uma discuss o sobre a incorpora o das cidades gregas no presente Quadro de Referência Estratégico Nacional (2007-2013).
Beyond the Dirac Phase Factor: Dynamical Quantum Phase-Nonlocalities in the Schrödinger Picture  [PDF]
Konstantinos Moulopoulos
Journal of Modern Physics (JMP) , 2011, DOI: 10.4236/jmp.2011.211156
Abstract: Generalized solutions of the standard gauge transformation equations are presented and discussed in physical terms. They go beyond the usual Dirac phase factors and they exhibit nonlocal quantal behavior, with the well-known Relativistic Causality of classical fields affecting directly the phases of wavefunctions in the Schrödinger Picture. These nonlocal phase behaviors, apparently overlooked in path-integral approaches, give a natural account of the dynamical nonlocality character of the various (even static) Aharonov-Bohm phenomena, while at the same time they seem to respect Causality. For particles passing through nonvanishing magnetic or electric fields they lead to cancellations of Aharonov-Bohm phases at the observation point, generalizing earlier semiclassical experimental observations (of Werner & Brill) to delocalized (spread-out) quantum states. This leads to a correction of previously unnoticed sign-errors in the literature, and to a natural explanation of the deeper reason why certain time-dependent semiclassical arguments are consistent with static results in purely quantal Aharonov-Bohm configurations. These nonlocalities also provide a remedy for misleading results propagating in the literature (concerning an uncritical use of Dirac phase factors, that persists since the time of Feynman’s work on path integrals). They are shown to conspire in such a way as to exactly cancel the instantaneous Aharonov-Bohm phase and recover Relativistic Causality in earlier “paradoxes” (such as the van Kampen thought-experiment), and to also complete Peshkin’s discussion of the electric Aharonov-Bohm effect in a causal manner. The present formulation offers a direct way to address time-dependent single- vs double-slit experiments and the associated causal issues—issues that have recently attracted attention, with respect to the inability of current theories to address them.
The Physics of an Absolute Reference System  [PDF]
Konstantinos Patrinos
Journal of Applied Mathematics and Physics (JAMP) , 2019, DOI: 10.4236/jamp.2019.73033
Abstract: The hypothesis of the absolute reference system, unlike the existing physics theories, is not based on the concept of relativity (that is, it is not based on a relativistic description like Galileo’s relativity or Einstein’s theory of relativity). The absolute reference system is the framework of material in which any activity in the universe has begun. Also, each inertial reference system is accompanied by a peculiar electromagnetic wave due to the structure of matter. The physics of the absolute system of reference is based on three basic principles. The first of these principles is that the electromagnetic field quantitative estimates are made in the inertial reference system of the source of the electromagnetic field. The second principle is that the basic constituent of matter is “bound photons, which make up the internal structure of the elementary particles. The third principle is that the framework of material of an inertial system undergoes a contraction of length which is a real physical contraction and a corresponding real change in “time flow, not due to the geometry of space-time, but is due to the internal operation of the micro-structure of matter. These principles have the effect of changing the relativistic physical magnitudes, such as velocity, momentum and kinetic energy, into physical magnitudes described as absolute. This theory is consistent with experimental data so far and provides satisfactory answers to physics problems such as dark matter, particle physics experiments to confirm the dynamics, interpretation of experimental results of measurement of neutrinos velocity that are incompatible with the relativity, and magnetic induction experiments which are not explained by the classical electromagnetic theory.
Essential Oils of Satureja Species: Insecticidal Effect on Culex pipiens Larvae (Diptera: Culicidae)
Antonios Michaelakis,Spiridon A. Theotokatos,Georgios Koliopoulos,Nikos G. Chorianopoulos
Molecules , 2007, DOI: 10.3390/12122567
Abstract: The chemical composition of the essential oils of the wild growing plants of Greek S. spinosa L., S. parnassica subsp. parnassica Heldr.& Sart ex Boiss., S. thymbra and S. montana were determined by GC and GC/MS analysis. The larvicidal activities of the essential oils were assayed against Culex pipiens biotype molestus. The analytical data indicated that various monoterpene hydrocarbons and phenolic monoterpenes constitute the major constituents of the oils, but their concentration varied greatly among the oils examined. The bioassay results indicated that the oils possess significant larvicidal activities and represent an inexpensive source of natural substances mixture that exhibit potentials for use to control the mosquito larvae.
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