Showing papers by "Vienna University of Technology published in 2005"
TL;DR: In this article, experimental conditions and mathematical fitting procedures for the collection and analysis of Raman spectra of soot and related carbonaceous materials have been investigated and optimised with a Raman microscope system operated at three different laser excitation wavelengths (514, 633, and 780 nm).
3,304 citations
TL;DR: Eight pharmaceuticals, two polycyclic musk fragrances and nine endocrine disrupting chemicals were analysed in several waste water treatment plants and the SRT is an important design parameter and its impact on achievable treatment efficiencies was evaluated.
931 citations
TL;DR: The urgent need for service composition is discussed, the required technologies to perform service composition are presented, and several different composition strategies, based on some currently existing composition platforms and frameworks are presented.
Abstract: Due to the web services' heterogeneous nature, which stems from the definition of several XML-based standards to overcome platform and language dependence, web services have become an emerging and promising technology to design and build complex inter-enterprise business applications out of single web-based software components. To establish the existence of a global component market, in order to enforce extensive software reuse, service composition experienced increasing interest in doing a lot of research effort. This paper discusses the urgent need for service composition, the required technologies to perform service composition. It also presents several different composition strategies, based on some currently existing composition platforms and frameworks, re-presenting first implementations of state-of the-art technologies, and gives an outlook to essential future research work.
920 citations
TL;DR: Investigations lead to the conclusion that low effluent concentrations can be achieved in WWTPs operating SRTs higher than 10 days, which corresponds to the requirements forWWTPs situated in sensitive areas according to the urban wastewater directive of the European Community in moderate climatic zones.
743 citations
TL;DR: In this paper, a subset of 154 biomass samples of very different origin (for instance wood, grass, rye, rape, reed, brewery waste, and poultry litter) have been selected from the database BIOBIB.
720 citations
TL;DR: There is no good reason to continue to use the [mean+/-2 sdev] rule, originally proposed as a 'filter' to identify approximately 2(1/2)% of the data at each extreme for further inspection at a time when computers to do the drudgery of numerical operations were not widely available and no other practical methods existed.
686 citations
04 Jul 2005
TL;DR: This work presents an algorithm for the automatic alignment of two 3D shapes ( data and model), without any assumptions about their initial positions, and develops a fast branch-and-bound algorithm based on distance matrix comparisons to select the optimal correspondence set and bring the two shapes into a coarse alignment.
Abstract: We present an algorithm for the automatic alignment of two 3D shapes (data and model), without any assumptions about their initial positions. The algorithm computes for each surface point a descriptor based on local geometry that is robust to noise. A small number of feature points are automatically picked from the data shape according to the uniqueness of the descriptor value at the point. For each feature point on the data, we use the descriptor values of the model to find potential corresponding points. We then develop a fast branch-and-bound algorithm based on distance matrix comparisons to select the optimal correspondence set and bring the two shapes into a coarse alignment. The result of our alignment algorithm is used as the initialization to ICP (iterative closest point) and its variants for fine registration of the data to the model. Our algorithm can be used for matching shapes that overlap only over parts of their extent, for building models from partial range scans, as well as for simple symmetry detection, and for matching shapes undergoing articulated motion.
634 citations
31 May 2005
TL;DR: The task of building automation and the systems and communications infrastructure necessary to address it is introduced and an overview of relevant standards is given, including BACnet, LonWorks and EIB/KNX as open systems of key significance in the building automation domain.
Abstract: Building automation systems (BAS) provide automatic control of the conditions of indoor environments. The historical root and still core domain of BAS is the automation of heating, ventilation and air-conditioning systems in large functional buildings. Their primary goal is to realize significant savings in energy and reduce cost. Yet the reach of BAS has extended to include information from all kinds of building systems, working toward the goal of "intelligent buildings". Since these systems are diverse by tradition, integration issues are of particular importance. When compared with the field of industrial automation, building automation exhibits specific, differing characteristics. The present paper introduces the task of building automation and the systems and communications infrastructure necessary to address it. Basic requirements are covered as well as standard application models and typical services. An overview of relevant standards is given, including BACnet, LonWorks and EIB/KNX as open systems of key significance in the building automation domain.
542 citations
TL;DR: It is concluded that oligonucleotide barcode is a powerful tool for the routine identification of Hypocrea/Trichoderma species and should be useful as a complement to traditional methods.
414 citations
TL;DR: It is demonstrated that important processes such as the input of metals from contamination sources and the contribution of sea-salts via marine aerosols to the soil can be identified and separated.
394 citations
TL;DR: In this article, the relative performance of a range of methods for transposing catchment model parameters to ungauged catchments was examined and the results indicated that two methods perform best.
Abstract: . In this study we examine the relative performance of a range of methods for transposing catchment model parameters to ungauged catchments. We calibrate 11 parameters of a semi-distributed conceptual rainfall-runoff model to daily runoff and snow cover data of 320 Austrian catchments in the period 1987-1997 and verify the model for the period 1976-1986. We evaluate the predictive accuracy of the regionalisation methods by jack-knife cross-validation against daily runoff and snow cover data. The results indicate that two methods perform best. The first is a kriging approach where the model parameters are regionalised independently from each other based on their spatial correlation. The second is a similarity approach where the complete set of model parameters is transposed from a donor catchment that is most similar in terms of its physiographic attributes (mean catchment elevation, stream network density, lake index, areal proportion of porous aquifers, land use, soils and geology). For the calibration period, the median Nash-Sutcliffe model efficiency ME of daily runoff is 0.67 for both methods as compared to ME=0.72 for the at-site simulations. For the verification period, the corresponding efficiencies are 0.62 and 0.66. All regionalisation methods perform similar in terms of simulating snow cover.
TL;DR: The investigation of the fringes makes possible interferometry on the attosecond time scale and produces a situation in which one and the same electron encounters a single and a double slit at the same time.
Abstract: A new scheme for a double-slit experiment in the time domain is presented. Phase-stabilized few-cycle laser pulses open one to two windows (slits) of attosecond duration for photoionization. Fringes in the angle-resolved energy spectrum of varying visibility depending on the degree of which-way information are measured. A situation in which one and the same electron encounters a single and a double slit at the same time is observed. The investigation of the fringes makes possible interferometry on the attosecond time scale. From the number of visible fringes, for example, one derives that the slits are extended over about 500 as.
15 Jun 2005
TL;DR: This survey discusses different state-of-the-art approaches of combining exact algorithms and metaheuristics to solve combinatorial optimization problems and divides the approaches into collaborative versus integrative combinations.
Abstract: In this survey we discuss different state-of-the-art approaches of combining exact algorithms and metaheuristics to solve combinatorial optimization problems. Some of these hybrids mainly aim at providing optimal solutions in shorter time, while others primarily focus on getting better heuristic solutions. The two main categories in which we divide the approaches are collaborative versus integrative combinations. We further classify the different techniques in a hierarchical way. Altogether, the surveyed work on combinations of exact algorithms and metaheuristics documents the usefulness and strong potential of this research direction.
TL;DR: It is proposed that the same building blocks can be found on the surfaces of bulk oxides, such as the reduced corundum (0001) surface, which is a wide-gap insulator.
Abstract: The well-ordered aluminum oxide film formed by oxidation of the NiAl(110) surface is the most intensely studied metal surface oxide, but its structure was previously unknown. We determined the structure by extensive ab initio modeling and scanning tunneling microscopy experiments. Because the topmost aluminum atoms are pyramidally and tetrahedrally coordinated, the surface is different from all Al2O3 bulk phases. The film is a wide-gap insulator, although the overall stoichiometry of the film is not Al2O3 but Al10O13. We propose that the same building blocks can be found on the surfaces of bulk oxides, such as the reduced corundum (0001) surface.
TL;DR: In this article, the authors report the first geochemical traverse to integrate U-Pb ages and Hf data on single detrital zircons with bulk-rock Sm-Nd-Rb-Sr isotopic measurements across the breadth of the Himalayan orogen, in northwest India.
TL;DR: In this paper, the structural aspects and the possibility to introduce functional organic groups are discussed, and a detailed review of the chemical modification of titanium alkoxides by alkoxy-and amino-alcohols, s-diketones and s-ketoesters is presented.
Abstract: The chemical modification of titanium alkoxides by alkoxy- and aminoalcohols, s-diketones, s-ketoesters, carboxylic and phosphonic acids, and related compounds, and the hydrolysis behavior of the organically modified precursors are reviewed Special focus is put on structural aspects and on the possibility to introduce functional organic groups Such precursors have a high potential for innovative materials syntheses because they permit control of the precursor reactivity in sol–gel processes and the preparation of titania-based inorganic–organic hybrid materials Coordination, solvation, aggregation and redistribution equilibria play an important role in the chemistry of the modified titanium alkoxides, and organic side reactions have to be taken into account
18 May 2005
TL;DR: The rational for and an outline of the design of a time-triggered (TT) Ethernet that unifies real-time and non-real-time traffic into a single coherent communication architecture are presented.
Abstract: This paper presents the rational for and an outline of the design of a time-triggered (TT) Ethernet that unifies real-time and non-real-time traffic into a single coherent communication architecture. TT Ethernet is intended to support all types of applications, from simple data acquisition systems, to multimedia systems up to the most demanding safety-critical real-time control systems which require a fault-tolerant communication service that must be certified. TT Ethernet distinguishes between two traffic categories: the standard event-triggered Ethernet traffic and the time-triggered traffic that is temporally guaranteed. The event triggered traffic in TT Ethernet is handled in conformance with the existing Ethernet standards of the IEEE. The design of TT Ethernet has been driven by the requirement of certification of safety-critical configurations and an uncompromising stand with respect to the integration of legacy applications and legacy Ethernet hardware.
08 May 2005
TL;DR: A system architecture for interactive, infrastructure-independent multi-user AR applications running on off-the-shelf handheld devices is presented and a four-user interactive game installation is implemented as an evaluation setup to encourage playful engagement of participants in a cooperative task.
Abstract: Augmented Reality (AR) can naturally complement mobile computing on wearable devices by providing an intuitive interface to a three-dimensional information space embedded within physical reality. Unfortunately, current wearable AR systems are relatively complex, expensive, fragile and heavy, rendering them unfit for large-scale deployment involving untrained users outside constrained laboratory environments. Consequently, the scale of collaborative multi-user experiments have not yet exceeded a handful of participants. In this paper, we present a system architecture for interactive, infrastructure-independent multi-user AR applications running on off-the-shelf handheld devices. We implemented a four-user interactive game installation as an evaluation setup to encourage playful engagement of participants in a cooperative task. Over the course of five weeks, more than five thousand visitors from a wide range of professional and socio-demographic backgrounds interacted with our system at four different locations.
TL;DR: This work describes the emission of highly collimated, spatially coherent X-rays, at a wavelength of about 1 nanometre and at photon energies extending to 1.3 kiloelectronvolts, from atoms that have been ionized by a 5-femtosecond laser pulse.
Abstract: Generating X-rays that have the properties of laser light has been a long-standing goal for experimental science. Here we describe the emission of highly collimated, spatially coherent X-rays, at a wavelength of about 1 nanometre and at photon energies extending to 1.3 kiloelectronvolts, from atoms that have been ionized by a 5-femtosecond laser pulse. This means that a laboratory source of laser-like, kiloelectronvolt X-rays, which will operate on timescales relevant to many chemical, biological and materials problems, is now within reach.
TL;DR: The multiconfiguration time-dependent Hartree-Fock approach for the description of correlated few-electron dynamics in the presence of strong laser fields is introduced and a comprehensive description of the method is given in this article.
Abstract: The multiconfiguration time-dependent Hartree-Fock approach for the description of correlated few-electron dynamics in the presence of strong laser fields is introduced and a comprehensive description of the method is given. Total ionization and electron spectra for the ground and first excited ionic channels are calculated for one-dimensional model systems with up to six active electrons. Strong correlation effects are found in the shape of photoelectron peaks and the dependence of ionization on molecule size.
05 Jul 2005
TL;DR: The result of the evaluation shows that the platform Moodle outperforms all other platforms and also obtained the best rating in the adaptation category.
Abstract: This paper presents an evaluation of open source e-learning platforms. The main focus is on adaptation issues. The result of the evaluation shows that the platform Moodle outperforms all other platforms and also obtained the best rating in the adaptation category.
TL;DR: The time-dependent intensity changes in certain Raman bands were compared to conventional parameters used to determine the extent of oxidation in oils, such as anisidine value and K(270), and showed good correlation.
TL;DR: An introductory overview of the basic theory of strong field ionization can be found in this paper, where the physics and the dynamics of the electron transition to the continuum and the shape of the wavepacket as it appears in the continuum are discussed.
Abstract: Strong field ionization is a starting point for a rich set of physical phenomena associated with attosecond science. This paper provides an introductory overview of the basic theory of strong field ionization and focuses on (i) the physics and the dynamics of the electron transition to the continuum, and (ii) the shape of the electron wavepacket as it appears in the continuum.
TL;DR: In this paper, the authors examined the predictive performance of various flood regionalisation methods for the ungauged catchment case, based on a jack-knifing comparison of locally estimated and regionalised flood quantiles for 575 Austrian catchments, 122 of which have a record length of 40 years or more.
Proceedings Article•
01 Jan 2005
TL;DR: From the results, both crucial and problematic parts of the algorithm for Rhythm Patterns feature extraction are identified and two new feature representations are introduced: Statistical Spectrum Descriptors and Rhythm Histogram features.
Abstract: We present a study on the importance of psycho-acoustic transformations for effective audio feature calculation. From the results, both crucial and problematic parts of the algorithm for Rhythm Patterns feature extraction are identified. We furthermore introduce two new feature representations in this context: Statistical Spectrum Descriptors and Rhythm Histogram features. Evaluation on both the individual and combined feature sets is accomplished through a music genre classification task, involving 3 reference audio collections. Results are compared to published measures on the same data sets. Experiments confirmed that in all settings the inclusion of psycho-acoustic transformations provides significant improvement of classification accuracy.
TL;DR: The local scattering function (LSF) and the channel correlation function (CCF) are introduced and shown to characterize, respectively, the mean power and the correlation of non-WSSUS scatterers.
Abstract: We propose a novel framework for the statistical characterization of fading dispersive channels that do not satisfy the assumption of wide-sense stationary uncorrelated scattering (WSSUS). The local scattering function (LSF) and the channel correlation function (CCF) are introduced and shown to characterize, respectively, the mean power and the correlation of non-WSSUS scatterers. Furthermore, the practically important class of doubly underspread (DU) channels is introduced, and it is shown that for DU channels, the LSF has numerous useful properties. The practical relevance of our approach is illustrated via application examples and numerical experiments.
18 May 2005
TL;DR: The newly introduced Global Contrast Factor (GCF) corresponds closer to the human perception of contrast and can be used in various application areas like rendering, tone mapping, volume visualization, and lighting design.
Abstract: Contrast in image processing is usually defined as a ratio between the darkest and the brightest spots of an image. In this paper we introduce a different contrast definition. The newly introduced Global Contrast Factor (GCF) corresponds closer to the human perception of contrast. GCF uses contrasts at various resolution levels in order to compute overall contrast. Experiments were conducted in order to find weight factors needed to calculate GCF. GCF measures richness of detail as perceived by a human observer, and as such can be used in various application areas like rendering, tone mapping, volume visualization, and lighting design.
TL;DR: The Simulation of Electron Spectra for Surface Analysis (SESSA) as mentioned in this paper database contains extensive sets of data for quantitative Auger-electron and X-ray photoelectron spectroscopy (AES/XPS).
Abstract: A description of a new NIST database for quantitative Auger-electron and X-ray photoelectron spectroscopy (AES/XPS) is given: Simulation of Electron Spectra for Surface Analysis (SESSA). This database contains extensive sets of data for the physical quantities relevant to AES and XPS. The internal databases are linked to a user interface via a small expert system that allows a user to automatically retrieve data needed for a specific practical application. SESSA can simulate AES and XPS spectra for a multilayered thin-film sample for measurement conditions specified by the user. Experimental information needed by SESSA is entered via an interface that matches the settings of AES/XPS instrumentation. The structure of SESSA is described together with information on special features, unique capabilities, and sources of the physical data. Examples of practical applications of SESSA for angle-resolved XPS on Al and Si samples, determination of the depth distribution function in XPS, and the use of empirical peak shapes for spectrum simulation are given. These and other applications are contained in SESSA in the form of tutorial files with command-language statements that can be loaded into SESSA and modified as necessary for similar simulations.
TL;DR: It is shown that XPath can be processed much more efficiently, and proposed main-memory algorithms for this problem with polynomial-time combined query evaluation complexity with profitably integrated into existing XPath processors.
Abstract: Our experimental analysis of several popular XPath processors reveals a striking fact: Query evaluation in each of the systems requires time exponential in the size of queries in the worst case. We show that XPath can be processed much more efficiently, and propose main-memory algorithms for this problem with polynomial-time combined query evaluation complexity. Moreover, we show how the main ideas of our algorithm can be profitably integrated into existing XPath processors. Finally, we present two fragments of XPath for which linear-time query processing algorithms exist and another fragment with linear-space/quadratic-time query processing.
21 Nov 2005
TL;DR: A novel concept for direct multi-object volume visualization which allows control of the appearance of inter-penetrating objects via two-dimensional transfer functions is introduced and a unifying approach to efficiently integrate many non-photorealistic rendering models is presented.
Abstract: Illustrations play a major role in the education process. Whether used to teach a surgical or radiologic procedure, to illustrate normal or aberrant anatomy, or to explain the functioning of a technical device, illustration significantly impacts learning. Although many specimens are readily available as volumetric data sets, particularly in medicine, illustrations are commonly produced manually as static images in a time-consuming process. Our goal is to create a fully dynamic three-dimensional illustration environment which directly operates on volume data. Single images have the aesthetic appeal of traditional illustrations, but can be interactively altered and explored. In this paper we present methods to realize such a system which combines artistic visual styles and expressive visualization techniques. We introduce a novel concept for direct multi-object volume visualization which allows control of the appearance of inter-penetrating objects via two-dimensional transfer functions. Furthermore, a unifying approach to efficiently integrate many non-photorealistic rendering models is presented. We discuss several illustrative concepts which can be realized by combining cutaways, ghosting, and selective deformation. Finally, we also propose a simple interface to specify objects of interest through three-dimensional volumetric painting. All presented methods are integrated into VolumeShop, an interactive hardware-accelerated application for direct volume illustration.