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See detailA utility-based dynamic demand estimation model that explicitly accounts for activity scheduling and duration
Cantelmo, Guido UL; Viti, Francesco UL; Nigro, Marialisa et al

in Transportation Research. Part A, Policy and Practice (2018)

This paper proposes a Dynamic Demand Estimation (DODE) framework that explicitly accounts for activity scheduling and duration. By assuming a Utility-Based departure time choice model, the time-dependent ... [more ▼]

This paper proposes a Dynamic Demand Estimation (DODE) framework that explicitly accounts for activity scheduling and duration. By assuming a Utility-Based departure time choice model, the time-dependent OD flow becomes a function, whose parameters are those of the utility function(s) within the departure time choice model. In this way, the DODE is solved using a parametric approach, which, on one hand, has less variables to calibrate with respect to the classical bi-level formulation while, on the other hand, it accounts for different trip purposes. Properties of the model are analytically and numerically discussed, showing that the model is more suited for estimating the systematic component of the demand with respect to the standard GLS formulation. Differently from similar approaches in literature, which rely on agent-based microsimulators and require expensive survey data, the proposed framework is applicable with all those DTA models, which are based on OD matrix, and do not necessarily need any data at user level. This has been proven by applying the proposed approach with a standard macroscopic realistic Dynamic Traffic Assignment (DTA) [less ▲]

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See detaildeveloping early number competencies through games played in school and at home
Tinnes-Vigne, Mélanie UL; Poncelet, Débora UL; de Chambrier, Anne-Françoise et al

in Bergqvist, Ewa; Österholm, Magnus; Granberg, Carina (Eds.) et al Proceedings of the 42nd Conference of the International Group for the Psychology of Mathematics Education (2018, July 07)

Most research studies show that initial number knowledge constitutes the basis for understanding several major principles of mathematics. Moreover, early number competencies are considered as strong ... [more ▼]

Most research studies show that initial number knowledge constitutes the basis for understanding several major principles of mathematics. Moreover, early number competencies are considered as strong predictors of mathematics outcomes at the end of the first grade and even later on (Jordan, Kaplan, Ramineni & Locuniak, 2009). In preschool, the development of these competencies should obviously not give rise to formal learning but is developed through significant activities. However, while everyday situations offer significant contexts, they are still not sufficient to develop the basic number competencies necessary for first grade children (Cannon & Ginsburg, 2008). Adults have to create opportunities to learn mathematical competencies. Mathematical games can meet this requirement. The MathPlay project aims to develop early number competencies through games implemented in school and/or at home. According to the literature, early number competencies consist in counting, conservation ability, magnitude comparison, and (de)composition of numbers. To develop these competencies, we decided to adapt 8 well-known family games. To evaluate the effect of this play-based approach on the development of number competencies, an instrument was created and validated. A quasi-experimental research design (pre/post-test) was implemented in four countries: Luxembourg, Belgium, France and Switzerland. Seven hundred and twenty-five children from all these countries participated in this study. They were divided into one control group and one experimental group with two treatment conditions, X1 (with games at school), and X2 (with games both at school and at home). The post-test was administrated at two moments: just after the intervention and eight weeks later. Data is currently being analysed. This communication will present the first outcomes and will answer our research question: what is the immediate and deferred effect of this play-based approach (X1-X2) on students’ number competencies? [less ▲]

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See detailRight to appeal under international criminal law: the intrinsic limitations in the ICC System
Mosna, Anna UL

in Revista Fórum de Ciências Criminais (2018), 5(9), 139158

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See detailA test to measure early number skills progress among 4 to 6 years old children
De Chambrier, Anne-Françoise; Fagnant, Annick; Giauque, Nadine et al

Scientific Conference (2018, July)

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See detailOptimal multi-line bus dispatching at terminals with electric charging scheduling constraints
Rinaldi, Marco UL; Parisi, Federico; D'Ariano, Andrea et al

Scientific Conference (2018, July)

We consider the problem of optimally determining the sequence of electric and conventional internal combustion buses departing from a multi-line bus terminal, considering both service constraints ... [more ▼]

We consider the problem of optimally determining the sequence of electric and conventional internal combustion buses departing from a multi-line bus terminal, considering both service constraints (schedule adherence) and energy constraints (electric bus charging status, bus recharging scheduling in capacitated facilities). The problem is formulated as a Mixed Integer Linear Program, with the objective of minimizing the total operational cost for the bus lines in question. System dynamics are captured by twenty sets of constraints, ranging from scheduling adherence to discharge-recharge dynamics. Individual operational costs at the bus level (cost of running an electric / non electric bus per km, cost of recharging) and at the trip level (penalty due to failed schedule adherence) are fully parametrised, allowing for extensive sensitivity analysis. We investigate a real-life case study based in the city of Luxembourg, where two charging stations have been installed in the central station’s bus terminal. Through the model we investigate: i) the minimum amount of electric buses necessary to perform a day’s schedule for two currently partially electrified lines, without resorting to conventional internal combustion alternatives; ii) the impact of electrifying two additional lines, specifically considering the trade-offs related to either adding new buses or new charging stations at the bus terminal. [less ▲]

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See detailCONSISTENT LEAST SQUARES ESTIMATOR FOR CO-ARRAY-BASED DOA ESTIMATION
Sedighi, Saeid UL; Shankar, Bhavani UL; Maleki, Sina et al

Poster (2018, July)

Sparse linear arrays (SLAs), such as nested and co-prime arrays, have the attractive capability of providing enhanced degrees of freedom by exploiting the co-array model. Accordingly, co-array-based ... [more ▼]

Sparse linear arrays (SLAs), such as nested and co-prime arrays, have the attractive capability of providing enhanced degrees of freedom by exploiting the co-array model. Accordingly, co-array-based Direction of Arrivals (DoAs) estimation has recently gained considerable interest in array processing. The literature has suggested applying MUSIC on an augmented sample covariance matrix for co-array-based DoAs estimation. In this paper, we propose a Least Squares (LS) estimator for co-array-based DoAs estimation employing the covariance fitting method as an alternative to MUSIC. We show that the proposed LS estimator provides consistent estimates of DoAs of identifiable sources for SLAs. Additionally, an analytical expression for the large sample performance of the proposed estimator is derived. Numerical results illustrate the finite sample behavior in relation to the derived analytical expression. Moreover, the performance of the proposed LS estimator is compared to the co-array-based MUSIC. [less ▲]

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See detailBioTOOL - a Readily and Flexible Biogas Rate Prediction Tool for End_users
Hien, Sebastian; Hansen, Joachim UL; Drewes, Jörg et al

in Environmental Modeling & Assessment (2018)

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See detailMicrometer-Scale Porous Buckling Shell Actuators Based on Liquid Crystal Networks
Jampani, Venkata UL; Mulder, Dirk; Reguengo de Sousa, Kevin UL et al

in Advanced Functional Materials (2018), 28(31), 1801209

Micrometer‐scale liquid crystal network (LCN) actuators have potential for application areas like biomedical systems, soft robotics, and microfluidics. To fully harness their power, a diversification in ... [more ▼]

Micrometer‐scale liquid crystal network (LCN) actuators have potential for application areas like biomedical systems, soft robotics, and microfluidics. To fully harness their power, a diversification in production methods is called for, targeting unconventional shapes and complex actuation modes. Crucial for controlling LCN actuation is the combination of macroscopic shape and molecular‐scale alignment in the ground state, the latter becoming particularly challenging when the desired shape is more complex than a flat sheet. Here, one‐step processing of an LCN precursor material in a glass capillary microfluidic set‐up to mold it into thin shells is used, which are stretched by osmosis to reach a diameter of a few hundred micrometers and thickness on the order of a micrometer, before they are UV crosslinked into an LCN. The shells exhibit radial alignment of the director field and the surface is porous, with pore size that is tunable via the osmosis time. The LCN shells actuate reversibly upon heating and cooling. The decrease in order parameter upon heating induces a reduction in thickness and expansion of surface area of the shells that triggers continuous buckling in multiple locations. Such buckling porous shells are interesting as soft cargo carriers with capacity for autonomous cargo release. [less ▲]

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See detailFreshwater pearl mussels as a stream water stable isotope recorder
Pfister, Laurent UL; Thielen, Frank; Deloule, Etienne et al

in Ecohydrology (2018), 11:e2007

For several decades, stable isotopes have been a commonly used and effective tool for flow path analysis, stream water source apportionment, and transit time analysis. The Global Network of Isotopes in ... [more ▼]

For several decades, stable isotopes have been a commonly used and effective tool for flow path analysis, stream water source apportionment, and transit time analysis. The Global Network of Isotopes in Precipitation repository now has monthly precipitation isotope time series extending over several years and even decades in some settings. However, stream water isotope composition time series remain rather short with only very few data sets spanning over more than a few years. A critical challenge in this respect is the collection of stream water isotope data sets across a wide variety of headwater streams and for long durations. We rely on a new approach for stream signal reconstruction based on freshwater mussels, specifically the freshwater pearl mussel Margaritifera margaritifera. We use secondary ion mass spectrometry (SIMS) to quantify oxygen isotope ratios in pearl mussel shell growth bands. In our study area, the observed seasonal variability in precipitation δ18O values ranges between −15‰ and −3‰. This input signal is strongly damped in stream water, where observed values of δ18O range between −10‰ and −6.5‰. These values are consistent with our measured average shell‐derived stream water δ18O of −7.19‰. Along successive growth bands, SIMS‐based stream water δ18Ow values varied within a seasonal range of −9‰ to −5‰. The proposed SIMS‐based shell analysis technique is obviously well suited for analysing isotopic signatures of O in shell material—especially from the perspective of reconstructing historical series of in‐stream isotope signatures. [less ▲]

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See detailAnalysis and Design of Privacy-Enhancing Information Sharing Systems
Symeonidis, Iraklis UL

Doctoral thesis (2018)

Recent technological advancements have enabled the collection of large amounts of personal data of individuals at an ever-increasing rate. Service providers, organisations and governments can collect or ... [more ▼]

Recent technological advancements have enabled the collection of large amounts of personal data of individuals at an ever-increasing rate. Service providers, organisations and governments can collect or otherwise acquire rich information about individuals’ everyday lives and habits from big data-silos, enabling profiling and micro-targeting such as in political elections. Therefore, it is important to analyse systems that allow the collection and information sharing between users and to design secure and privacy enhancing solutions. This thesis contains two parts. The aim of the first part is to investigate in detail the effects of the collateral information collection of third-party applications on Facebook. The aim of the second part is to analyse in detail the security and privacy issues of car sharing systems and to design a secure and privacy-preserving solution. In the first part, we present a detailed multi-faceted study on the collateral information collection privacy issues of Facebook applications; providers of third-party applications on Facebook exploit the interdependency between users and their friends. The goal is to (i) study the existence of the problem, (ii) investigate whether Facebook users are concerned about the issue, quantify its (iii) likelihood and (iv) impact of collateral information collection affecting users, (v) identify whether collateral information collection is an issue for the protection of the personal data of Facebook users under the legal framework, and (vi) we propose solutions that aim to solve the problem of collateral information collection. In order to investigate the views of the users, we designed a questionnaire and collected the responses of participants. Employing real data from the Facebook third-party applications ecosystem, we compute the likelihood of collateral information collection affecting users and quantify its significance evaluating the amount of attributes collected by such applications. To investigate whether collateral information collection is an issue in terms of users’ privacy we analysed the legal framework in light of the General Data Protection Regulation. To provide countermeasures, we propose a privacy dashboard extension that implements privacy scoring computations to enhance transparency towards collateral information collection. [less ▲]

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See detailKonstruktion von Gemeinschaft im frühpädagogischen Alltag. Praxistheoretische Rekonstruktion einer konfliktbezogenen Interventionssituation.
Göbel, Sabrina UL

in Kaul, Ina; Schmidt, Desirée; Thole, Werner (Eds.) Kinder und Kindheiten. Studien zur Empirie der Kindheit. Unsicherheiten, Herausforderungen und Zumutungen. (2018)

In dem Band werden über historische, empirisch-rekonstruktive und theoretische Bezüge differente Perspektiven auf Kinder und Kindheiten eröffnet, um sowohl deren Modulationen als auch die Bedingungen des ... [more ▼]

In dem Band werden über historische, empirisch-rekonstruktive und theoretische Bezüge differente Perspektiven auf Kinder und Kindheiten eröffnet, um sowohl deren Modulationen als auch die Bedingungen des Aufwachsens und die Gestaltung institutioneller Arrangements in den Blick zu nehmen. Thematisiert werden Fragen zu den subjektiven Konstruktionen und gesellschaftlichen Bezügen des Aufwachsens in Deutschland, Brasilien und Südkorea unter professionalisierungstheoretischen, kindheits-, sozial- sowie schulpädagogischen Perspektiven. Der Inhalt• Vorstellungen und Deutungen von Kinderarmut im frühpädagogischen Feld• Vorstellungen über Kinder und Kindheiten im Kontext der Bildungsorientierung der Kindertageseinrichtungen• Konstruktionen von Gemeinschaft im frühpädagogischen Alltag• Kinder im Leistungssport – Leben zwischen Schule, Wettkampf und Erfolg• Überlegungen zum Zweck der Schule in Brasilien unter der Perspektive der Conditio Humana • Konstruktionen des Kindes durch Fachkräfte eines Allgemeinen Sozialen Dienstes• Die Konstruktion des Kindes im Verfassungsrecht• Antizipierte Bedürfnisse von Kindern im öffentlich-medialen Diskurs um Social Freezing• Annäherungen an Bilder über Kinder und Kindheiten ohne Kinder? [less ▲]

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See detailTowards Estimating and Predicting User Perception on Software Product Variants
Martinez, Jabier; Sottet, Jean-Sebastien; Garcia-Frey, Alfonso et al

in 17th International Conference on Software Reuse (ICSR) (2018, May)

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See detailCharacterising Deprecated Android APIs
Li, Li; Gao, Jun UL; Bissyande, Tegawendé François D Assise UL et al

in 15th International Conference on Mining Software Repositories (MSR 2018) (2018, May)

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See detailThe logics and politics of circulation: exploring the urban and non-urban spaces of Amazon.com
Hesse, Markus UL

in Ward, Kevin; Jonas, Andrew E.G.; Miller, Byron (Eds.) et al The Routledge International Handbook on Spaces of Urban Politics (2018)

The digital economy is a catalyst for the circulation of people, goods and information, affecting both urban and non-urban realms. This chapter uses the empirical case of Amazon.com to discuss the digital ... [more ▼]

The digital economy is a catalyst for the circulation of people, goods and information, affecting both urban and non-urban realms. This chapter uses the empirical case of Amazon.com to discuss the digital and physical arrangement of production, labour, distribution, advertising, purchasing, and consumption as a means of creating particular spaces of politics. What started as mail order retail for books about 20 years ago can now be understood as an all-encompassing platform for performing a variety of socio-economic practices. These practices evolve from disruptive innovation and are backed by venture capital as well as an aggressive market strategy, leading to a compartmentalized organisation of value chains. The related implications on place, space and territory reveal a certain “logics of dislocation” (Barnes 1996), creating particular spaces of circulation both in urban centres and peripheries. The abstract system’s imperative not only steers the orchestration of the firm’s network but also, given its hegemony in online-markets, threatens to assume an almost totalitarian form. It thus also performs as a powerful agent of policy-making. Against this background, the chapter explores the spaces of circulation and related politics that are produced and reproduced by Amazon.com. [less ▲]

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See detailHandlungsfähigkeiten und Übergänge: Theoretische Zugänge und methodische Herausforderungen im Projekt „TransCare“
Göbel, Sabrina UL

Scientific Conference (2018, March 20)

Neben der Präsentation des Projektdesigns zur Erforschung von Übergängen junger Menschen aus der Heimerziehung und aus Pflegefamilien werden ausgehend von Fragen, die Emirbayer & Mische (Emirbayer ... [more ▼]

Neben der Präsentation des Projektdesigns zur Erforschung von Übergängen junger Menschen aus der Heimerziehung und aus Pflegefamilien werden ausgehend von Fragen, die Emirbayer & Mische (Emirbayer & Mische 1998, 1005ff.) zur empirischen Untersuchung von Agency stellen, auf der Basis von Interviews mit Care Leaver*innen Vorschläge zur methodischen wie empirischen Annäherung an „Agency“ gemacht. Es werden die Herausforderungen und Schwierigkeiten vorgestellt, die mit einem relationalem Konzept von Agency verbunden sind. Die empirische Analyse wird bei Emirbayer und Mische an einem Konzept von „agentic orientations“ (Handlungsorientierungen) ausgerichtet, die auf dreifache und in zeitlicher Weise dimensioniert werden: als iterativ (die selektive Reaktivierung vergangener Muster), projektiv (die imaginative Aktivierung möglicher Zukünfte und die damit mögliche Rekonfiguration von Beziehungen) und evaluativ (die Fähigkeit praktische und normative Entscheidungen zu treffen in der situativen Konfrontation mit Anforderungen, Ambivalenzen und Dilemmata) (vgl. ebd., 971). Gefragt wird danach, wie unterschiedliche zeitlich-relationale Kontexte zu spezifischen Handlungsbefähigungen führen bzw. die Herstellung von Handlungsfähigkeit der jungen Erwachsenen im Prozess des Leaving Care unterstützen. Quellennachweis: Emirbayer, Mustafa, & Mische, Ann (1998). What Is Agency? American Journal of Sociology 103(4), 962–1023. [less ▲]

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See detailAgency in Konstellationen des Übergangs
Peters, Ulla UL; Göbel, Sabrina UL; Lunz, Marei UL

Scientific Conference (2018, March 20)

Abstract zur Arbeitsgruppe:Übergänge markieren verdichtete Wandlungsprozesse individueller und sozialer Konstellationen, an denen sich Fragen nach der Vermitteltheit von Handeln und Strukturen ... [more ▼]

Abstract zur Arbeitsgruppe:Übergänge markieren verdichtete Wandlungsprozesse individueller und sozialer Konstellationen, an denen sich Fragen nach der Vermitteltheit von Handeln und Strukturen herauskristallisieren. Vor dem Hintergrund praxistheoretischer Konzepte und einem damit verbundenen Handlungs- und Praxisverständnis (vgl. Schäfer 2016) arbeiten wir mit einem Konzept von „Agency“, das Handlungsfähigkeit als eingebettet in Praktiken verstehbar macht. Im Kontext von Übergängen junger Menschen aus den Hilfen zur Erziehung, die sich im Spannungsfeld zwischen institutionellen Rahmenbedingungen und Strukturierungen und dem Handeln professioneller wie nicht-professioneller Akteure bewegen, stellt das Agency-Konzept einen zentralen Zugang zum Verständnis der wechselseitigen Bedingtheit sozialer Interaktionen, Situationen und individueller Handlungsfähigkeiten dar. In der Arbeitsgruppe wird das Konzept vor der Folie aktueller Forschungsergebnisse diskutiert und im Kontrast zu anderen konzeptionellen Zugänge wie Autonomie, Bewältigung, Soziale Unterstützung und Zugehörigkeit auf seine Anschlussfähigkeit und Erklärungskraft hin untersucht. [less ▲]

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