Bridging structured and unstructured data via hybrid semantic search and interactive ontology-enhanced query formulation

In this paper, we identify the problems of current semantic and hybrid search systems, which seek to bridge structure and unstructured data, and propose solutions. We introduce a novel input mechanism for hybrid semantic search that combines the clean and concise input mechanisms of keyword-based search engines with the expressiveness of the input mechanisms provided by semantic search engines. This interactive input mechanism can be used to formulate ontology-aware search queries without prior knowledge of the ontology. Furthermore, we propose a system architecture for automatically fetching relevant unstructured data, complementing structured data stored in a Knowledge Base, to create a combined index. This combined index can be used to conduct hybrid semantic searches which leverage information from structured and unstructured sources. We present the reference implementation Hybrid Semantic Search System ( \(HS^3\) ), which uses the combined index to put hybrid semantic search into practice and implements the interactive ontology-enhanced keyword-based input mechanism. For demonstration purpose, we apply \(HS^3\) to the tourism domain. We present performance test results and the results of a user evaluation. Finally, we provide instructions on how to apply \(HS^3\) to arbitrary domains.     

Procedural Representation of CIC Proof Terms

We propose an effective procedure, the first one to our knowledge, for translating a proof term of the Calculus of Inductive Constructions (CIC), into a tactical expression of the high-level specification language of a CIC-based proof assistant like coq (Coq development team 2008) or matita (Asperti et al., J Autom Reason 39:109–139, 2007). This procedure, which should not be considered definitive at its present stage, is intended for translating the logical representation of a proof coming from any source, i.e. from a digital library or from another proof development system, into an equivalent proof presented in the proof assistant’s editable high-level format. To testify to effectiveness of our procedure, we report on its implementation in matita and on the translation of a significant set of proofs (Guidi, ACM Trans Comput Log 2009) from their logical representation as coq 7.3.1 (Coq development team 2002) CIC proof terms to their high-level representation as tactical expressions of matita’s user interface language.     

Reversible Execution and Visualization of Programs with LEONARDO

In this paper we present LEONARDO, an integrated environment for software visualization that allows the user to edit, compile, execute, and animate general-purpose C programs. LEONARDO relies on a logic-based approach to visualization: a mapping between concrete and abstract data structures can be declared through a logic visualization language and animations are conceived as reflecting formal properties of algorithms. LEONARDO is able to automatically detect visual events during the execution of programs and simplifies the creation of visualizations according to an incremental approach. Moreover, it guarantees the complete reversibility of computations, bounded only by the potentiality of the working machine, and appears simple to be used. The latest version of LEONARDO is currently available over the Internet at the URLhttp: //www.dis.uniroma1.it/~demetres/Leonardo/.     

Toward practical encrypted email that supports private,regular-expression searches

In this paper, we develop a protocol to enable private regular-expression searches on encrypted data stored at a \(\mathsf {server}\). A novelty of the protocol lies in allowing a user to securely delegate an encrypted search query to a \(\mathsf {proxy}\), which interacts with the \(\mathsf {server}\) where the user’s data are stored encrypted to produce the search result for the user. The privacy of the query and the data are both provably protected against an arbitrarily malicious \(\mathsf {server}\) and an honest-but-curious \(\mathsf {proxy}\) under rigorous security definitions. We then detail a series of optimizations to our initial design that achieve an order-of-magnitude performance improvement over the original protocol. We demonstrate the practicality of the resulting protocol through measurements of private regular-expression searches on a real-world email dataset.     

Personalized multimedia content delivery on an interactive table by passive observation of museum visitors

The amount of multimedia data collected in museum databases is growing fast, while the capacity of museums to display information to visitors is acutely limited by physical space. Museums must seek the perfect balance of information given on individual pieces in order to provide sufficient information to aid visitor understanding while maintaining sparse usage of the walls and guaranteeing high appreciation of the exhibit. Moreover, museums often target the interests of average visitors instead of the entire spectrum of different interests each individual visitor might have. Finally, visiting a museum should not be an experience contained in the physical space of the museum but a door opened onto a broader context of related artworks, authors, artistic trends, etc. In this paper we describe the MNEMOSYNE system that attempts to address these issues through a new multimedia museum experience. Based on passive observation, the system builds a profile of the artworks of interest for each visitor. These profiles of interest are then used to drive an interactive table that personalizes multimedia content delivery. The natural user interface on the interactive table uses the visitor’s profile, an ontology of museum content and a recommendation system to personalize exploration of multimedia content. At the end of their visit, the visitor can take home a personalized summary of their visit on a custom mobile application. In this article we describe in detail each component of our approach as well as the first field trials of our prototype system built and deployed at our permanent exhibition space at LeMurate (http://www.lemurate.comune.fi.it/lemurate/) in Florence together with the first results of the evaluation process during the official installation in the National Museum of Bargello (http://www.uffizi.firenze.it/musei/?m=bargello).     

Real-time 3D fluid simulation digital art using BCI

We present a methodology about real-time 3D fluid simulation system using BCI (brain–computer interface). Spectators appreciate our work with their emotion. The advance of technology has exerted huge impacts on arts and as result a new genre called digital art has emerged. In digital art, interaction is an important element. Various types of interaction are being implemented in digital art using touch, hand gesture, sound, movement, etc., even brain wave. Usually, digital artists pursue interactions in their art work; the reason is that they want spectators’ deep appreciation and involvement. However, many of interactive digital art works fail to induce interaction as much as the artists expected. If visible interaction is weak, or interaction result is weak, spectators are not immersed much in the work. Nowadays, there are many interactive digital arts. In digital art, new type of interaction is needed to captivate spectators. So, we tried to implement BCI interaction digital art prototype (tentative title: Soul flow). Electroencephalography (EEG) is the recording of brain electrical activity along the scalp. We measured user’s EEG signal using MindSet (the MindSet senses EEG brainwave data to power the innovation of laboratory researchers and application developers like no other EEG device in the world. It delivers RAW signal, power frequency bands and NeuroSky eSense meters:attention, meditation. http://www.neurosky.com/products/mindset.aspx) to take user’s emotional state on appreciating digital art. We can get user’s emotional state in four categories (attention/inattention, meditation/uneasiness) and these emotional states interact with 3D fluid simulation system in real-time. In this art work prototype, each spectator experiences each different fluid (scale, speed and visual) because each spectator has different emotional state. Our art work prototype expressed the flow through water flow simulation. Flow means the mental state of operation in which a person performing an activity is fully immersed in a feeling of energized focus, full involvement, and enjoyment in the process of the activity. In essence, flow is characterized by complete absorption in what one does (The psychology of optimal experience 1990). In addition, it means stream in water flow. We pursued these concepts and expressed to 3D fluid simulation digital art using BCI. We used Unity3D and MindSet to implement our art work prototype. This study will expand the participation of the spectator in digital art. In addition, it will expand the possibilities of BCI in digital art interaction.     

Ecosystem on the Web: non-linear mining and forecasting of co-evolving online activities

Given a large collection of co-evolving online activities, such as searches for the keywords “Xbox”, “PlayStation” and “Wii”, how can we find patterns and rules? Are these keywords related? If so, are they competing against each other? Can we forecast the volume of user activity for the coming month? We conjecture that online activities compete for user attention in the same way that species in an ecosystem compete for food. We present EcoWeb, (i.e., Ecosystem on the Web), which is an intuitive model designed as a non-linear dynamical system for mining large-scale co-evolving online activities. Our second contribution is a novel, parameter-free, and scalable fitting algorithm, EcoWeb-Fit, that estimates the parameters of EcoWeb. Extensive experiments on real data show that EcoWeb is effective, in that it can capture long-range dynamics and meaningful patterns such as seasonalities, and practical, in that it can provide accurate long-range forecasts. EcoWeb consistently outperforms existing methods in terms of both accuracy and execution speed.     

The PSurface library

We describe PSurface, a C $++$ library that allows to store and access piecewise linear maps between simplicial surfaces in $\mathbb{R }^2$ and $\mathbb{R }^3$ . Piecewise linear maps can be used, e.g., to construct boundary approximations for finite element grids, and grid intersections for domain decomposition methods. In computer graphics the maps allow to build level-of-detail representations as well as texture- and bump maps. The PSurface library can be used as the basis for the implementation of a wide range of algorithms that use piecewise linear maps between triangulated surfaces. A few simple examples are given in this work. We document the data structures and algorithms and show how PSurface is used in the numerical analysis framework Dune and the visualization software Amira.     

Data quality,sensitive data and joint controllership as examples of grey areas in the existing data protection framework for the Internet of Things

‘The technology used to provide connectivity from anytime, any place and for anyone. Now anything can be added to the list.’¹¹ITU Internet reports 2005: ‘The Internet of Things’ <http://www.itu.int/dms_pub/itus/opb/pol/S-POL-IR.IT-2005-SUM-PDF-E.pdf> 2, accessed 27 April 2015.View all notes In the Internet of Things (‘IoT’), the amount of individuals’ data collected and processed is increasing substantially as data are being collected from various sources. Most communications between smart devices occur automatically, potentially without the user being aware of it. Many questions arise around the vulnerability of the devices in the IoT, often deployed outside a traditional IT structure and lacking sufficient built-in security. The IoT demands consideration and research into how to best balance the opportunities that the IoT affords against legal risks it imposes on data protection. Considerable questions about how our currently existing EU framework for protection of personal data applies in IoT are being raised. The data protection legislation needs to move from theory to practice and in order to achieve this; the legal framework may need additional mechanisms.     

Robust sparsity-preserved learning with application to image visualization

Linear subspace learning is of great importance for the purpose of visualization of high-dimensional observations. Sparsity-preserved learning (SPL) is a recently developed technique for linear subspace learning. Its objective function is formulated by using the $\ell _2$ -norm, which implies that the obtained projection vectors are likely to be distorted by outliers. In this paper, we develop a new SPL algorithm called SPL-L1 based on the $\ell _1$ -norm instead of the $\ell _2$ -norm. The proposed approach seeks projection vectors by minimizing a reconstruction error subject to a constraint of samples dispersion, both of which are defined using the $\ell _1$ -norm. As a robust alternative, SPL-L1 works well in the presence of atypical samples. We design an iterative algorithm under the framework of bound optimization to solve the projection vectors of SPL-L1. The experiments on image visualization demonstrate the superiority of the proposed method.     

A Solution to the PoplMark Challenge Based on de Bruijn Indices

The PoplMark challenge proposes a set of benchmarks intended to assess the usability of proof assistants in the context of research on programming languages. It is based on the metatheory of System F $_{\mathtt{<:}}$ . We present a solution to the challenge using de Bruijn indices, developed with the Coq proof assistant.     

BSP-Why: A Tool for Deductive Verification of BSP Algorithms with Subgroup Synchronisation

We present bsp-why, a tool for deductive verification of bsp  algorithms with subgroup synchronisation. From bsp  programs, bsp-why generates sequential codes for the back-end condition generator why and thus benefits from its large range of existing provers. By enabling subgroups, the user can prove the correctness of programs that run on hierarchical machines—e.g. clusters of multi-cores. In general, bsp-why is able to generate proof obligations of mpi programs that only use collective operations. Our case studies are distributed state-space construction algorithms, the basis of model-checking.     

Challenges in online collaboration: effects of scripting shared task perceptions

Difficulties with planning, such as negotiating task understandings and goals, can have a profound effect on regulation and task performance when students work collaboratively (Miller and Hadwin, Computers in Human Behaviour, 52, 573-588, 2015a). Despite planning being a common challenge, teams often fail to identify strategies for addressing those challenges successfully. The purpose of this study was to examine the effect of team planning support in the form of awareness visualizations (quantified, nominal, and no visualization of individual planning perceptions summarized across group members) on the challenges students face during collaboration, and the ways they report regulating in the face of those challenges. Findings revealed differences across conditions. Individuals in the no visualization condition (a) rated planning as more problematic, and (b) were likely to encounter doing the task, checking progress, and group work challenges when they encounter planning challenges, (c) reported more time and planning main challenges compared to doing the task and group work challenges, and (d) reported that planning strategies (adopted as a team) were most effective for addressing planning challenges, followed by teamwork strategies which were less effective. In contrast, individuals belonging to groups who received one of the two visualizations (a) reported that both planning and teamwork strategies to be equally effective for addressing planning challenges, and (b) reported higher levels of success with their strategies than groups without a visualization support. Findings attest to the importance of supporting group planning with planning visualizations.     

Optimal noise functions for location privacy on continuous regions

Users of location-based services are highly vulnerable to privacy risks since they need to disclose, at least partially, their locations to benefit from these services. One possibility to limit these risks is to obfuscate the location of a user by adding random noise drawn from a noise function. In this paper, we require the noise functions to satisfy a generic location privacy notion called \(\ell \)-privacy, which makes the position of the user in a given region \(\mathcal {X}\) relatively indistinguishable from other points in \(\mathcal {X}\). We also aim at minimizing the loss in the service utility due to such obfuscation. While existing optimization frameworks regard the region \(\mathcal {X}\) restrictively as a finite set of points, we consider the more realistic case in which the region is rather continuous with a nonzero area. In this situation, we demonstrate that circular noise functions are enough to satisfy \(\ell \)-privacy on \(\mathcal {X}\) and equivalently on the entire space without any penalty in the utility. Afterward, we describe a large parametric space of noise functions that satisfy \(\ell \)-privacy on \(\mathcal {X}\), and show that this space has always an optimal member, regardless of \(\ell \) and \(\mathcal {X}\). We also investigate the recent notion of \(\epsilon \)-geo-indistinguishability as an instance of \(\ell \)-privacy and prove in this case that with respect to any increasing loss function, the planar Laplace noise function is optimal for any region having a nonzero area.     

The influence of the search complexity and the familiarity with the website on the subjective appraisal of aesthetics,mental effort and usability

The user experience is defined as ‘a person's perceptions and responses that result from the use and/or anticipated use of a product, system or service’ (ISO FDIS 9241-210, 2009 ISO FDIS 9241-210, 2009. Ergonomics of human system interaction Ergonomics of human system interaction – Part 210: human-centered design for interactive systems (formerly known as 13407). Switzerland: International Organization for Standardization. [Google Scholar]) [Ergonomics of human system interaction Ergonomics of human system interaction – Part 210: human-centered design for interactive systems (formerly known as 13407). Switzerland: International Organization for Standardization]. Accordingly, some authors have argued that an interactive system has to be evaluated not only with regard to its usability and utility levels, but also with regard to emotional, attractiveness, and aesthetic levels. These last aspects play a substantial role on the general assessment of such systems and on the satisfaction of users. Some studies focused on the immediate aesthetic subjective perception of systems, on their subjective usability and preference perceptions. However, few studies, at least to our knowledge, have been focused on the reverse, that is, on the effect of difficulties experienced by individuals in using systems on the aesthetic appraisal. The present study aimed at determining the role of familiarity level with the website and the search complexity on the search performance and post-experiment appraisals of aesthetics, usability, and mental effort. The main results revealed that the search complexity affected negatively search performance, whereas the familiarity level affected only the re-reading of the search questions. The post-use assessments of aesthetics, mental effort, and usability satisfaction were affected by search performance. In addition, these variables were correlated except the expressive aesthetics, which seemed to be independent from the search performance and other subjective appraisals. Then, we discuss these findings in line with prior studies and present future ways of research.     

ν-twin support vector machine with Universum data for classification

A novel ν-twin support vector machine with Universum data (\(\mathfrak {U}_{\nu }\)-TSVM) is proposed in this paper. \(\mathfrak {U}_{\nu }\)-TSVM allows to incorporate the prior knowledge embedded in the unlabeled samples into the supervised learning. It aims to utilize these prior knowledge to improve the generalization performance. Different from the conventional \(\mathfrak {U}\)-SVM, \(\mathfrak {U}_{\nu }\)-TSVM employs two Hinge loss functions to make the Universum data lie in a nonparallel insensitive loss tube, which makes it exploit these prior knowledge more flexibly. In addition, the newly introduced parameters ν₁, ν₂ in the \(\mathfrak {U}_{\nu }\)-TSVM have better theoretical interpretation than the penalty factor c in the \(\mathfrak {U}\)-TSVM. Numerical experiments on seventeen benchmark datasets, handwritten digit recognition, and gender classification indicate that the Universum indeed contributes to improving the prediction accuracy. Moreover, our \(\mathfrak {U}_{\nu }\)-TSVM is far superior to the other three algorithms (\(\mathfrak {U}\)-SVM, ν-TSVM and \(\mathfrak {U}\)-TSVM) from the prediction accuracy.     

3D interactive topology optimization on hand-held devices

This educational paper describes the implementation aspects, user interface design considerations and workflow potential of the recently published TopOpt 3D App. The app solves the standard minimum compliance problem in 3D and allows the user to change design settings interactively at any point in time during the optimization. Apart from its educational nature, the app may point towards future ways of performing industrial design. Instead of the usual geometrize, then model and optimize approach, the geometry now automatically adapts to the varying boundary and loading conditions. The app is freely available for iOS at Apple’s App Store and at http://www.topopt.dtu.dk/TopOpt3D for Windows and OSX.     

Better and Simpler Approximation Algorithms for?the?Stable Marriage Problem

We first consider the problem of finding a maximum size stable matching if incomplete lists and ties are both allowed, but ties are on one side only. For this problem we give a simple, linear time 3/2-approximation algorithm, improving on the best known approximation factor 5/3 of Irving and Manlove (J. Comb. Optim., doi:10.1007/s10878-007-9133-x, 2007). Next, we show how this extends to the Hospitals/Residents problem with the same ratio if the residents have strict orders. We also give a simple linear time algorithm for the general problem with approximation factor 5/3, improving the best known 15/8-approximation algorithm of Iwama, Miyazaki and Yamauchi (SODA ??07: Proceedings of the Eighteenth Annual ACM-SIAM Symposium on Discrete Algorithms, pp.?288?C297, 2007). For the cases considered in this paper it is NP-hard to approximate within a factor of 21/19 by the result of Halldórsson et?al. (ACM Transactions on Algorithms 3(3):30, 2007). Our algorithms not only give better approximation ratios than the cited ones, but are much simpler and run significantly faster. Also we may drop a restriction used in (J. Comb. Optim., doi:10.1007/s10878-007-9133-x, 2007) and the analysis is substantially more moderate. Preliminary versions of this paper appeared in (Király, Egres Technical Report TR-2008-04, www.cs.elte.hu/egres/, 2008; Király in Proceedings of MATCH-UP 2008: Matching Under Preferences??Algorithms and Complexity, Satellite Workshop of ICALP, July 6, 2008, Reykjavík, Iceland, pp.?36?C45, 2008; Király in ESA 2008, Lecture Notes in Computer Science, vol.?5193, pp.?623?C634, 2008). For the related results obtained thenceforth see Sect.?5.     

Modulo Based Data Placement Algorithm for Energy Consumption Optimization of MapReduce System

With the explosion of data production, the efficiency of data management and analysis has been concerned by both industry and academia. Meanwhile, more and more energy is consumed by the IT infrastructure especially the larger scale distributed systems. In this paper, a novel idea for optimizing the Energy Consumption (EC for short) of MapReduce system is proposed. We argue that a fair data placement is helpful to save energy, and then we propose three goals of data placement, and a modulo based Data Placement Algorithm (DPA for short) which achieves these goals. Afterwards, the correctness of the proposed DPA is proved from both theoretical and experimental perspectives. Three different systems which implement MapReduce model with different DPAs are compared in our experiments. Our algorithm is proved to optimize EC effectively, without introducing the additional costs and delaying data loading. With the help of our DPA, the EC for the WordCount (https://src/examples/org/apache/hadoop/examples/), Sort (https://src/examples/org/apache/hadoop/examples/sort) and MRBench (https://src/examples/org/apache/hadoop/mapred/) can be reduced by 10.9 %, 8.3 % and 17 % respectively, and time consumption is reduced by 7 %, 6.3 % and 7 % respectively.     

Ensuring location diversity in privacy-preserving spatio-temporal data publishing

The rise of mobile technologies in the last decade has led to vast amounts of location information generated by individuals. From the knowledge discovery point of view, these data are quite valuable, but the inherent personal information in the data raises privacy concerns. There exists many algorithms in the literature to satisfy the privacy requirements of individuals, by generalizing, perturbing, and suppressing their data. Current techniques that try to ensure a level of indistinguishability between trajectories in a dataset are direct applications of \(k\) -anonymity, thus suffer from the shortcomings of \(k\) -anonymity such as the lack of diversity in sensitive regions. Moreover, these techniques fail to incorporate some common background knowledge, an adversary might have such as the underlying map, the traffic density, and the anonymization algorithm itself. We propose a new privacy metric \(p\) -confidentiality that ensures location diversity by bounding the probability of a user visiting a sensitive location with the \(p\) input parameter. We perform our probabilistic analysis based on the background knowledge of the adversary. Instead of grouping the trajectories, we anonymize the underlying map, that is, we group nodes (points of interest) to create obfuscation areas around sensitive locations. The groups are formed in such a way that the parts of trajectories entering the groups, coupled with the adversary background, do not increase the adversary’s belief in violating the \(p\) -confidentiality. We then use the map anonymization as a model to anonymize the trajectories. We prove that our algorithm is resistant to reverse-engineering attacks when the statistics required for map anonymization is publicly available. We empirically evaluate the performance of our algorithm and show that location diversity can be satisfied effectively.