Personalized content retrieval in context using ontological knowledge

Personalized content retrieval aims at improving the retrieval process by taking into account the particular interests of individual users. However, not all user preferences are relevant in all situations. It is well known that human preferences are complex, multiple, heterogeneous, changing, even contradictory, and should be understood in context with the user goals and tasks at hand. In this paper, we propose a method to build a dynamic representation of the semantic context of ongoing retrieval tasks, which is used to activate different subsets of user interests at runtime, in a way that out-of-context preferences are discarded. Our approach is based on an ontology-driven representation of the domain of discourse, providing enriched descriptions of the semantics involved in retrieval actions and preferences, and enabling the definition of effective means to relate preferences and context

Generalization of the Darboux transformation and generalized harmonic oscillators

The Darbroux transformation is generalized for time-dependent Hamiltonian systems which include a term linear in momentum and a time-dependent mass. The formalism for the $N$-fold application of the transformation is also established, and these formalisms are applied for a general quadratic system (a generalized harmonic oscillator) and a quadratic system with an inverse-square interaction up to N=2. Among the new features found, it is shown, for the general quadratic system, that the shape of potential difference between the original system and the transformed system could oscillate according to a classical solution, which is related to the existence of coherent states in the system

Evolution of spin-wave excitations in ferromagnetic metallic manganites

Neutron scattering results are presented for spin-wave excitations of three ferromagnetic metallic $A_{1-x}A^{\prime}_{x}$MnO$_3$ manganites (where $A$ and $A^\prime$ are rare- and alkaline-earth ions), which when combined with previous work elucidate systematics of the interactions as a function of carrier concentration $x$, on-site disorder, and strength of the lattice distortion. The long wavelength spin dynamics show only a very weak dependence across the series. The ratio of fourth to first neighbor exchange ($J_4/J_1$) that controls the zone boundary magnon softening changes systematically with $x$, but does not depend on the other parameters. None of the prevailing models can account for these behaviors.Comment: Submitted to Phys. Rev. Let

The user support programme and the training infrastructure of the EGI Federated Cloud

The EGI Federated Cloud is a standards-based, open cloud system as well as its enabling technologies that federates institutional clouds to offer a scalable computing platform for data and/or compute driven applications and services. The EGI Federated Cloud is based on open standards and open source Cloud Management Frameworks and offers to its users IaaS, PaaS and SaaS capabilities and interfaces tuned towards the needs of users in research and education. The federation enables scientific data, workloads, simulations and services to span across multiple administrative locations, allowing researchers and educators to access and exploit the distributed resources as an integrated system. The EGI Federated Cloud collaboration established a user support model and a training infrastructure to raise visibility of this service within European scientific communities with the overarching goal to increase adoption and, ultimately increase the usage of e-infrastructures for the benefit of the whole European Research Area. The paper describes this scalable user support and training infrastructure models. The training infrastructure is built on top of the production sites to reduce costs and increase its sustainability. Appropriate design solutions were implemented to reduce the security risks due to the cohabitation of production and training resources on the same sites. The EGI Federated Cloud educational program foresees different kind of training events from basic tutorials to spread the knowledge of this new infrastructure to events devoted to specific scientific disciplines teaching how to use tools already integrated in the infrastructure with the assistance of experts identified in the EGI community. The main success metric of this educational program is the number of researchers willing to try the Federated Cloud, which are steered into the EGI world by the EGI Federated Cloud Support Team through a formal process that brings them from the initial tests to fully exploit the production resources. © 2015 IEEE

Appearance of Gauge Fields and Forces beyond the adiabatic approximation

We investigate the origin of quantum geometric phases, gauge fields and forces beyond the adiabatic regime. In particular, we extend the notions of geometric magnetic and electric forces discovered in studies of the Born-Oppenheimer approximation to arbitrary quantum systems described by matrix valued quantum Hamiltonians. The results are illustrated by several physical relevant examples

Komposisi Pakan Tikus Ekor Putih (Maxomys Hellwandii) Di Kandang

Tikus ekor putih (Maxomys hellwandii) adalah hewan endemik Sulawesi dengan status konsevasinya yaitu least concern yang keberadaannya masih kurang diperhatikan. Ancaman utama tikus ekor putih adalah perburuan untuk dijual penelitian ini bertujuan untuk menginventarisasi jenis-jenis pakan tikus ekor putih dan porsinya. Penelitian ini dilakukan untuk memberikan informasi tentang komposisi pakan tikus ekor putih sehingga dapat dimanfaatkan dalam upaya konservasi terutama dalam kegiatan penangkaran dengan upaya domestikasi. Metode yang digunakan dalam penelitian ini ialah ad libitum sampling dengan menghitung berat pakan yang dikonsumsi. Hasil penelitian menunjukkan bahwa komposisi jenis pakan tikus ekor putih terdiri dari: pepaya (51,3%), umbi singkong (15,7%), buah kelapa (15,6%), serangga (belalang) (13,9%), daun sirih (2,9%), kulit buah ketapang (0,4%), buah sirih (0,2%), buah beringin (0,1%). Dari hasil penelitian tersebut dapat disimpulkan bahwa tikus ekor putih mengonsumsi buah pepaya lebih dari 50% dari total pakan dan tikus ekor putih bukan spesies herbivora sejati, tetapi cenderung omnivora

Komposisi Pakan Tikus Ekor Putih (Maxomys Hellwandii) Di Kandang

Tikus ekor putih (Maxomys hellwandii) adalah hewan endemik Sulawesi dengan status konsevasinya yaitu least concern yang keberadaannya masih kurang diperhatikan. Ancaman utama tikus ekor putih adalah perburuan untuk dijual penelitian ini bertujuan untuk menginventarisasi jenis-jenis pakan tikus ekor putih dan porsinya. Penelitian ini dilakukan untuk memberikan informasi tentang komposisi pakan tikus ekor putih sehingga dapat dimanfaatkan dalam upaya konservasi terutama dalam kegiatan penangkaran dengan upaya domestikasi. Metode yang digunakan dalam penelitian ini ialah ad libitum sampling dengan menghitung berat pakan yang dikonsumsi. Hasil penelitian menunjukkan bahwa komposisi jenis pakan tikus ekor putih terdiri dari: pepaya (51,3%), umbi singkong (15,7%), buah kelapa (15,6%), serangga (belalang) (13,9%), daun sirih (2,9%), kulit buah ketapang (0,4%), buah sirih (0,2%), buah beringin (0,1%). Dari hasil penelitian tersebut dapat disimpulkan bahwa tikus ekor putih mengonsumsi buah pepaya lebih dari 50% dari total pakan dan tikus ekor putih bukan spesies herbivora sejati, tetapi cenderung omnivora