Ensemble clustering for result diversification

This paper describes the participation of the University of Twente in the Web track of TREC 2012. Our baseline approach uses the Mirex toolkit, an open source tool that sequantially scans all the documents. For result diversification, we experimented with improving the quality of clusters through ensemble clustering. We combined clusters obtained by different clustering methods (such as LDA and K-means) and clusters obtained by using different types of data (such as document text and anchor text). Our two-layer ensemble run performed better than the LDA based diversification and also better than a non-diversification run

Systemwandel und monetäre Transformation: Eine ordnungsökonomische Perspektive

Diese Schrift behandelt ordnungs- und institutionenökonomische Aspekte des Systemwandels im allgemeinen sowie die monetäre Transformation im besonderen. Das auf dem Washington Consensus beruhende wirtschaftspolitische Standardkonzept und dessen Theoriedefizite werden hinterfragt und um ordnungspolitische Elemente erweitert. Eine Schlüsselrolle hinsichtlich der transformationspolitischen Zentralaufgaben fällt der Schaffung einer funktionsfähigen (marktwirtschaftlichen) Wettbewerbs-, Privatrechts- und Geldordnung zu.Ordnungsökonomik, (monetäre) Transformation, Washington Consensus

Toward Robots with Peripersonal Space Representation for Adaptive Behaviors

The abilities to adapt and act autonomously in an unstructured and human-oriented environment are necessarily vital for the next generation of robots, which aim to safely cooperate with humans. While this adaptability is natural and feasible for humans, it is still very complex and challenging for robots. Observations and findings from psychology and neuroscience in respect to the development of the human sensorimotor system can inform the development of novel approaches to adaptive robotics. Among these is the formation of the representation of space closely surrounding the body, the Peripersonal Space (PPS) , from multisensory sources like vision, hearing, touch and proprioception, which helps to facilitate human activities within their surroundings. Taking inspiration from the virtual safety margin formed by the PPS representation in humans, this thesis first constructs an equivalent model of the safety zone for each body part of the iCub humanoid robot. This PPS layer serves as a distributed collision predictor, which translates visually detected objects approaching a robot\u2019s body parts (e.g., arm, hand) into the probabilities of a collision between those objects and body parts. This leads to adaptive avoidance behaviors in the robot via an optimization-based reactive controller. Notably, this visual reactive control pipeline can also seamlessly incorporate tactile input to guarantee safety in both pre- and post-collision phases in physical Human-Robot Interaction (pHRI). Concurrently, the controller is also able to take into account multiple targets (of manipulation reaching tasks) generated by a multiple Cartesian point planner. All components, namely the PPS, the multi-target motion planner (for manipulation reaching tasks), the reaching-with-avoidance controller and the humancentred visual perception, are combined harmoniously to form a hybrid control framework designed to provide safety for robots\u2019 interactions in a cluttered environment shared with human partners. Later, motivated by the development of manipulation skills in infants, in which the multisensory integration is thought to play an important role, a learning framework is proposed to allow a robot to learn the processes of forming sensory representations, namely visuomotor and visuotactile, from their own motor activities in the environment. Both multisensory integration models are constructed with Deep Neural Networks (DNNs) in such a way that their outputs are represented in motor space to facilitate the robot\u2019s subsequent actions

Time-Dependent Model for Evaluating Corrosion Potential and Electrical Resistivity of Reinforced Concrete

The main work presented in this paper is to propose prediction models for estimating electrical resistivity of concrete and corrosion potential of steel in reinforced concrete. The prediction models for electrical resistivity of concrete (r) and corrosion potential of steel (Ecorr) incorporated hydration degree (αHyd (t)), pozzolanic reaction degree (αPoz (t)), porosity (PCap (t)) and chloride content ([CL-]). Predicted results were verified with results of experimental measurement. An experimental program was run for 1 year with various concrete mix proportions. According to the results, corrosion resistance of concrete increased with time as the degree of hydration increased. Further, the introduction of fly ash offered a good corrosion resistance, which also increased with time. Lastly, the existence of chloride ions in the concrete weakened passive film on steel surface, by the fact that its presence eased the movement of ions in the concrete and increased the risk of corrosion

Learning to extract folktale keywords

Manually assigned keywords provide a valuable means for accessing large document collections. They can serve as a shallow document summary and enable more efficient retrieval and aggregation of information. In this paper we investigate keywords in the context of the Dutch Folktale Database, a large collection of stories including fairy tales, jokes and urban legends. We carry out a quantitative and qualitative analysis of the keywords in the collection. Up to 80% of the assigned keywords (or a minor variation) appear in the text itself. Human annotators show moderate to substantial agreement in their judgment of keywords. Finally, we evaluate a learning to rank approach to extract and rank keyword candidates. We conclude that this is a promising approach to automate this time intensive task

Audience and the Use of Minority Languages on Twitter

On Twitter, many users tweet in more than one language. In this study, we examine the use of two Dutch minority languages. Users can engage with different audiences and by analyzing different types of tweets, we find that characteristics of the audience influence whether a minority language is used. Furthermore, while most tweets are written in Dutch, in conversations users often switch to the minority language

A new flood estimation paradigm for the design of civil infrastructure systems

Methods for quantifying flood risk of civil infrastructure systems such as road and rail networks require considerably more information compared to traditional methods that focus on flood risk at a point. These systems are characterised by multiple interconnected components, whereby a ‘failure’ of the overall system can arise because of complex combinations of failures in system subcomponents. For example, flooding of a single bridge along a railway may leave the entire railway inoperable, and the interest is often in the probability that one or more bridges along a stretch of railway will be flooded, rather than designing each bridge in isolation. Similarly, the viability of evacuation routes often requires an assessment of the probability that the route is flooded, conditional on an evacuation being necessary as a result of floods elsewhere in the system. Conventional design flood estimation processes are ill-equipped to deal with these complex problems. Whereas traditional flood estimation approaches focus on estimating flood risk at a single location, this thesis proposes a new estimation paradigm that focuses on estimating system-wide risk. The approach builds on the traditional intensity-duration-frequency (IDF) methods that are commonly used in engineering practice in Australia and internationally; however, this is implemented in such a way at to provide information on the spatial dependence of design storms. A particular innovation in this thesis is to estimate spatial rainfall dependence across multiple storm durations, allowing it to be used to estimate flood risk across multiple catchments with differing times of concentration. This enables the estimation of both conditional probabilities (e.g. probability of one part of a system being flooded conditional on another part of the system being flooded) and joint probabilities (e.g. the probability of multiple parts of a system experiencing floods simultaneously). Finally, whereas traditional IDF approaches consider conversion from point rainfall to spatial rainfall via areal reduction factors as a post-processing step, the approach proposed herein enables this conversion implicitly as part of the method. The proposed approach is based on two classes of extreme value model: max-stable process models, and inverted max-stable process models. These models differ in their assumption for how spatial dependence scales in the limit, as the rainfall events become increasingly extreme (referred to as “asymptotic dependence”). In particular, max-stable models assume asymptotic dependence (i.e. the spatial dependence converges to a non-zero limit), whereas inverted max-stable models assume asymptotic independence. This assumption has significant implications for very rare events (e.g. the 1% annual exceedance probability event), particularly when the estimates are based on relatively short observational records. Specifically, implementation focuses on the (inverted) Brown-Resnick family of models. This class of model was adjusted by accounting for spatial dependence across multiple storm burst durations. The adjustment used the theoretical pairwise extremal coefficient function as a function of both distance and duration. The integration of multiple durations into the modelling framework was tested on a 21,400 km2 spatial domain in the Greater Sydney region, with data on sub-daily rainfall from 25 stations. The updated model shows a reasonable fit between the observed pairwise extremal coefficients and the theoretical pairwise extremal coefficient function across all durations. The asymptotic dependence and comparison with empirically derived areal reduction factors was tested next, and it was shown that the observed data follow the behaviour of an asymptotically independent process, which leads to ARFs that decrease with an increasing return period. This demonstrates that inverted max-stable process models such as the inverted Brown-Resnick model are the most suitable method for simulating spatial rainfall in the study areas that were investigated. Finally, the outcomes of this research are demonstrated by implementing the spatially dependent IDF approach in a realistic case study that requires information on both conditional and joint dependence. The case study examines a highway upgrade project on the east coast of Australia, containing five bridge crossings with differing contributing catchment areas, and thus differing times of concentration. The results are used to show the differences between conditional-flood and conventional-flood estimates at each bridge, and the relationship between the overall failure of a system and the failure probability of an individual bridge. For example, if one were to design the highway section for a 1% probability of at least one bridge being flooded in any given year, it would be necessary to design each individual bridge to a % annual exceedance probability design flood. This research therefore is shown to enable a different paradigm for design flood risk estimation, which focuses attention on the risk of the entire system rather than considering individual system elements in isolation.Thesis (Ph.D.) -- University of Adelaide, School of Civil, Environmental and Mining Engineering, 201

Zur Leistungsfähigkeit der genossenschaftlichen Bankunternehmung

Dieser Aufsatz dient dem Versuch, ein konsistentes wirtschaftspolitisches Bewertungsverfahren zur Analyse der Leistungsfähigkeit der genossenschaftlichen Bankunternehmung zu entwickeln. Dafür wird das auf linearer Programmierung beruhende Schätzverfahren "Data Envelopment Analysis (DEA)" verwendet, das die Gesamteffizienz, die Skaleneffizienz und die technische (X-)Effizienz ermittelt. Die Leistungsfähigkeit genossenschaftlicher Kreditinstitute wird daran gemessen, ob und inwieweit eine effiziente Form der Leistungserstellung zur Mitgliederförderung gewährleistet wird. Die Kosteneffizienz von 227 lokalen People's Credit Funds in Vietnam wird anhand der Bilanz- und Erfolgszahlen für das Jahr 2000 bewertet. Faktoren, von denen ein Einfluss auf die X-Effizienz vermutet wird, werden anhand des Tobit- Modells und der DEA-Bootstrap-Regression (DBR) ermittelt

Understanding Organizational Citizenship Behaviour through Organizational Justice and its Consequences among Vietnamese’s Universities Employees

This paper aims to investigate the impact of organizational justice components on job satisfaction, organizational commitment, and organizational citizenship behaviours (OCB) of employees in the higher education sector of Vietnam. Although many research studies have been conducted in organizations on the topics of organizational justice, as well as organizational commitment, and organizational citizenship behaviour, there is a shortage of these topics in higher education institutions as well as in Asian context. Therefore, this article attempts to fill this literature gap. A total of 317 employees from various universities in Vietnam participated in this study, and a self-administered survey was conducted, which was modified based on suggestions from the universities' management team following interviews. The collected data were analyzed using the partial least squares structural equation modeling (PLS-SEM) technique. The results showed that procedural justice and interactional justice had a significant impact on both job satisfaction and organizational commitment, while distributive justice only affected job satisfaction. Furthermore, the study found that job satisfaction and organizational commitment significantly affected OCB. However, this study had a limitation in terms of the narrow sample size, which only included participants from universities. Future studies should broaden the sample size to include participants from vocational colleges. On paper, the study shows the effects of organizational justice on OCB through the mediating roles of individual work outputs, which received inadequate attention in previous studies. Doi: 10.28991/ESJ-2023-SIED2-08 Full Text: PD