Suppression of threading defects formation during Sb-assisted metamorphic buffer growth in InAs/InGaAs/InP structure

A virtual substrate for high quality InAs epitaxial layer has been attained via metalorganic vapor-phase epitaxy growth of Sb-assisted InxGa1-xAs metamorphic buffers, following a convex compositional continuous gradient of the In content from x = 53 % to 100 %. The use of trimethylantimony (or its decomposition products) as a surfactant has been found to crucially enable the control over the defect formation during the relaxation process. Moreover, an investigation of the wafer offcut-dependence of the defect formation and surface morphology has enabled the achievement of a reliably uniform growth on crystals with offcut towards the [111]B direction

Callimaco, il «Fedone» e la scuola filosofica cirenaica nell’epigramma per Cleombroto (Call. 23 Wil.)

Muovendo dall\u2019epigramma per Cleombroto (AP 7,471 = 23 Wil. = 53 G.-P.), l\u2019articolo si propone di rivalutare la posizione di Callimaco rispetto a un autentico interesse per la filosofia. Contro le interpretazioni pi\uf9 recenti, che hanno letto l\u2019epigramma alla luce di una polemica innanzitutto \u201cmetacomunicativa\u201d, si cerca di mostrare come l\u2019intento ironico dei versi possa essere compreso pienamente solo ammettendo una simpatia di Callimaco per la scuola cirenaica. L\u2019epigramma sembra dunque presupporre una critica alle tesi sostenute nel Fedone, in effetti incompatibili con le dottrine dei Cirenaici, che non dovevano condividere la lettura platonica dell\u2019insegnamento di Socrate, almeno per come questa emerge nel dialogo. \uc8 cos\uec possibile riconoscere la pointe dell\u2019epigramma nell\u2019intenzione di mostrare le tensioni interne al Fedone, specificamente in merito alla questione del suicidio

Luttinger liquid behavior in weakly disordered quantum wires

We have measured the temperature dependence of the conductance in long V-groove quantum wires (QWRs) fabricated in GaAs/AlGaAs heterostructures. Our data is consistent with recent theories developed within the framework of the Luttinger liquid model, in the limit of weakly disordered wires. We show that for the relatively small amount of disorder in our QWRs, the value of the interaction parameter g is g=0.66, which is the expected value for GaAs. However, samples with a higher level of disorder show conductance with stronger temperature dependence, which does not allow their treatment in the framework of perturbation theory. Trying to fit such data with perturbation-theory models leads inevitably to wrong (lower) values of g.Comment: 4 pages, 4 figure

Unusual nanostructures of "lattice matched" InP on AlInAs

We show that the morphology of the initial monolayers of InP on Al0.48In0.52As grown by metalorganic vapor-phase epitaxy does not follow the expected layer-by-layer growth mode of lattice-matched systems, but instead develops a number of low-dimensional structures, e.g., quantum dots and wires. We discuss how the macroscopically strain-free heteroepitaxy might be strongly affected by local phase separation/alloying-induced strain and that the preferred aggregation of adatom species on the substrate surface and reduced wettability of InP on AlInAs surfaces might be the cause of the unusual (step) organization and morpholog

OntoJob: Automated Ontology Learning from Labor Market Data

Due to the rapidly changing labor market and the consequently widening information gap between the labor market and education, there is a need for methods that can tackle, or at least ease, the construction of labor market ontologies. The current study set out to examine the viability of Ontology Learning (OL) methods for the (semi-)automated construction of labor market ontologies and / or taxonomies. The purpose of this paper is to propose an unsupervised framework, OntoJob, that can identify and extract from raw vacancy text instances, attributes, and relations, such as job titles, worker qualities, and the non-Taxonomic 'is-A' relations between those concepts, and convert those to an expressive descriptive logic. Evaluation of the extracted worker qualities from OntoJob, using a small sample of 5621 job postings representing 1048 occupations, showed an overall lexical precision of 0.36 and recall of 0.22. </p

ANALISIS FAKTOR-FAKTOR YANG MEMPENGARUHI PRODUKSI IKAN BANDENG DI KOTA BANDA ACEH

ABSTRAKPenelitian ini bertujuan untuk mengetahui faktor-faktor yang mempengaruhi produksi ikan bandeng di Kota Banda Aceh. Penelitian ini dilakukan menggunakan metode survey dan pengambilan sampelnya dengan teknik sampel acak sederhana Simple Random Sampling.Lokasi penelitian dilakukan di Kota Banda Aceh, yaitu Kecamatan Syiah Kuala, Meuraxa, Kuta Alam, dan Kuta Raja. Waktu Penelitian dilaksanakan pada bulan Oktober 2013 sampai dengan Juli 2014. Model yang digunakan dalam penelitian ini adalah menggunakan model analisis kuantitatif untuk mengetahui Faktor-faktor yang mempengaruhi produksi ikan bandeng di Kota Banda Aceh yaitu tenaga kerja, luas tambak, jumlah nener, dan penggunaan pupuk..Untuk menguji hubungan antara variabel faktor-faktor yang mempengaruhi produksi ikan bandeng di Kota Banda Aceh, digunakan uji statistik dengan menggunakan uji T, F, dan R2.Hasil penelitian ini dapat disimpulkan bahwa secara serempak faktor , tenaga kerja, luas tambak, jumlah nener, dan jumlah pupuk berpengaruh nyata terhadap produksi ikan bandeng di Kota Banda Aceh. Secara parsial faktor jumlah nener berpengaruh nyata terhadap produksi ikan bandeng di Kota Banda Aceh. Sedangkan faktor tenaga kerja, luas tambak dan jumlah pupuk tidak berpengaruh nyata terhadap produksi ikan bandeng di Kota Banda Aceh.Kata Kunci: Ikan bandeng, analisis produksiABSTRACTThis research aims to determine the factors that affect fish production in the city of Banda Aceh. This research was conducted using a survey method and sampling with simple random sampling techniques.Location of the research conducted in the city of Banda Aceh , the District Syiah KuaLa, Meuraxa, Kuta Alam, and Kuta Raja. Time research conducted in October 2013 to July 2014 model used in this research was to use quantitative analysis model to determine the factors that affect milkfish production in Banda Aceh, namely labor, large farms, the amount of milkfish, and use of fertilizers.For Examine the relationship between the variable factors that affect milkfish production in Banda Aceh, used statistical tests using T test, F, and R2.The results of this research it can be concluded that the factors simultaneously, labor, large ponds, milkfish amount, and the amount of fertilizer significantly affect milkfish production in the city of Banda Aceh. Partially factors significantly affect the amount of milkfish fry production of milkfish in Banda Aceh. While the labor factor, vast farms and the amount of fertilizer had no significant effect on the production of milkfish in Banda Aceh .Keywords: Milkfish, production analysisBanda Ace

The Challenge of using Map-reduce to Query Open Data

For transparency and democracy reasons, a few years ago Public Administrations started publishing data sets concerning public services and territories. These data sets are called open, because they are publicly available through many web sites. Due to the rapid growth of open data corpora, both in terms of number of corpora and in terms of open data sets available in each single corpus, the need for a centralized query engine arises, able to select single data items from within a mess of heterogeneous open data sets. We gave a first answer to this need in (Pelucchi et al., 2017), where we defined a technique for blindly querying a corpus of open data. In this paper, we face the challenge of implementing this technique on top of the Map-Reduce approach, the most famous solution to parallelize computational tasks in the Big Data world

Statistical study of stacked/coupled site-controlled pyramidal quantum dots and their excitonic properties

We report on stacked multiple quantum dots (QDs) formed inside inverted pyramidal recesses, which allow for the precise positioning of the QDs themselves. Specifically, we fabricated double QDs with varying inter-dot distances and ensembles with more than two nominally highly symmetric QDs. For each, the effect of the interaction between QDs is studied by characterizing a large number of QDs through photoluminescence spectroscopy. A clear red-shift of the emission energy is observed together with a change in the orientation of its polarization, suggesting an increasing interaction between the QDs. Finally, we show how stacked QDs can help influencing the charging of the excitonic complexes