bluuebunny/crossref_metadata_2025 huggingface dataset:
Integration of multiple diffractive elements on photonic crystal surface emitting lasers for beam manipulation
Authors: Chen Lih-Ren , Hong Kuo-Bin , Chen Shuo-Ling , Huang Kuan-Chih , Lu Tien-Chang
Published: September 2020

We demonstrate the multi-sectional diffractive elements integrated vertically on photonic crystal surface emitting laser featuring the naturally formed periodic ITO cladding layer. The corresponding output beam steering mechanism is investigated in depth.
Single-Mode VCSEL with Double-Focusing High-Contrast Gratings
Authors: Jia Xiangli , Ji Yipeng , Chang-Hasnain Connie
Published: September 2020

We present designs of high-contrast gratings (HCGs) functioning as both reflection mirror and double-sided wavefront engineering plate for single-mode 940-nm VCSELs. This approach enables simultaneous engineering of VCSEL cavity and emitting properties.
Optical fibers: Challenges and Opportunities in SDM
Authors: DiGiovanni David J.
Published: September 2020

Continued growth in bandwidth demand is pushing the limits of capacity of optical fiber and cable, especially in cost-sensitive applications. This presentation reviews the current status and predictions for development of fibers specially designed to scale optical capacity to higher levels.
Hybrid master oscillator power amplifier single-frequency, nanosecond, multi-mJ, 5 kHz at 1030 nm
Authors: Hamoudi Thomas , Délen Xavier , Dherbecourt Jean-Baptiste , Godard Antoine , Melkonian Jean-Michel , Raybaut Myriam , Georges Patrick
Published: September 2020

We demonstrate that the combination of Ytterbium doped-fiber and bulk crystals amplifiers, in a Master Oscillator Power Amplifier configuration (MOPA) allows obtaining 3.6 mJ, 15 ns, single-frequency pulses and 5 kHz repetition rate.
Erbium-Doped Tellurium-Oxide-Coated Silicon Nitride Waveguide Amplifiers
Authors: Frankis Henry C. , Mbonde Hamidu M. , Bonneville Dawson B. , Zhang Chenglin , Mateman Richard , Leinse Arne , Bradley Jonathan D. B.
Published: September 2020

We demonstrate 5 dB of net gain at 1558 nm in a 6.7 cm long erbium-doped tellurium- oxide-coated silicon nitride waveguide, in a process compatible with silicon nitride photonic integrated circuits.
In Situ Temporal Periodic Poling of Lithium Niobate Thin Films
Authors: Nagy Jonathan Tyler , Prabhakar Karan , Reano Ronald M.
Published: September 2020

We repeatedly pole and unpole a lithium niobate thin film second harmonic generator while monitoring the switching of the optical output. Increasing asymmetry in the poling waveform results in increasing optical extinction ratio.
Material Deposition with Spatial Thickness Variation for Reflective Color Filter
Authors: Li Xinhao , Tan Zheng Jie , Fang Nicholas X.
Published: September 2020

A new material deposition method to pattem 2D structures with spatial thickness variation using single fixed shadow mask is demonstrated. The method is applied to fabricate multispectral reflective color filter arrays of high customizability
Post-Processing Dispersion Engineering of Frequency Combs In Microresonator Addressing Atomic Clock
Authors: Modle Gregory , Lu Xiyuan , Rao Ashutosh , Westly Daron , Srinivasan Kartik
Published: September 2020

We study S13N4 microresonator frequency comb to address atomic transition in the visible. We show that thanks to our air-clad system, post-process dispersion engineering through trimming allows precise control of the dispersive wave position.
Ultra-Low Threshold Broadband Soliton Frequency Comb Generation
Authors: Ji Xingchen , Jang Jae K. , Dave Utsav D. , Joshi Chaitanya , Corato-Zanarella Mateus , Gaeta Alexander L. , Lipson Michal
Published: September 2020

We measure a record-low threshold power of 84 pW for parametric oscillation using resonators with intrinsic Q of 31.8 ± 4.4 million and demonstrate a broadband single soliton comb spectrum spanning 1097 nm-2040 nm (126 THz). The resonator compact profile is designed to minimize higher order modes excitation.
Real-Time Monitoring of the Impact of Cascaded Wavelength-Selective Switches in Digital Coherent Receivers
Authors: Pilori Dario , Nespola Antonello , Forghieri Fabrizio , Piciaccia Stefano , Bosco Gabriella
Published: September 2020

A simple real-time monitoring algorithm for the impact of cascaded WSSs in elastic optical networks, which exploits the information available in a digital coherent receiver, is proposed and demonstrated through both numerical simulations and experiments.
Second-Harmonic Generation from WS2 Monolayers Enhanced by BIC Resonances
Authors: Bernhardt Nils , Koshelev Kirill , White Simon , Meng Kelvin Wong Choon , Froch Johannes E. , Tran Trong Toan , Kim Sejeong , Choi Duk-Yong , Kivshar Yuri , Solntsev Alexander S.
Published: September 2020

Through the utilization of resonant dielectric metasurfaces governed by bound states in the continuum, we demonstrate a strong increase in the second-harmonic generation in WS2 monolayers by a factor exceeding 700
Electronic and UV light programmable doping in graphene for memory applications
Authors: Frydendahl Christian , Indukuri S.R.K. Chaitanya , Grajower Meir , Mazurski Noa , Shappir Joseph , Levy Uriel
Published: September 2020

We demonstrate the integration of graphene with conventional flash memory technology. The structure allows for programmable memory by electrostatic doping in graphene. The device could also find applications in tunable plasmonics, chemical sensing, photodetection, etc.
AlN microresonators fabricated with standard photolithography for broadband Kerr frequency comb generation
Authors: Weng Haizhong , Liu Jia , Afridi Adnan Ali , Li Jing , Lu Qiaoyin , Donegan John F. , Guo Weihua
Published: September 2020

A near octave comb spectrum ranging from 1100 to 2150 nm is generated at 406 mW pump power for AlN microresonators fabricated with standard photolithography. This work decreases the requirement for fabrication significantly.
Observation of islands of stability in the chaotic regime of Kerr Frequency combs
Authors: Hu Futai , Vinod Abhinav Kumar , Jia Chuancheng , Gong Mali , Wong Chee Wei
Published: September 2020

We present results on the transition from chaos to dark pulse and back to chaos with uni-directional pump tuning in Kerr microresonators using an ultrafast spectrum analyzer based on a four-wave-mixing time lens.
Ultra-broadband complementary vibrational spectroscopy with cascaded intra-pulse difference frequency generation
Authors: Hashimoto Kazuki , Badarla Venkata Ramaiah , Ideguchi Takuro
Published: September 2020

We demonstrate ultra-broadband dual-modal Fourier-transform spectroscopy simultaneously measuring infrared absorption and Raman scattering spectra spanning from 800 to 2900 cm-1 by expanding infrared spectrum via cascaded intra-pulse difference frequency generation
Dual Independent Enhanced Scan Engines, Large-Field Two Photon Microscopy (DIESEL2p)
Authors: Yu Che-Hang , Stirman Jeffrey N. , Hira Riichiro , Yu Yiyi , Smith Spencer L.
Published: September 2020

We developed a large field-of-view (0>5mm) two-photon microscopy with simultaneous and independent two-region access to enable the imaging of neuronal activities widely-distributed in mice’s visual cortex, which is hardly achievable with current commercial systems.
Widefield fluorescence optical sectioning microscopy in a miniature fiber-coupled microscope with active axial scanning
Authors: Sanchez Gabriel Martinez , Supekar Omkar D. , Futia Gregory L. , Ozbay Baris N. , Welle Cristin , Bright Victor M. , Gopinath Juliet T. , Restrepo Diego , Shepherd Douglas , Gibson Emily A.
Published: September 2020

We present widefield structured illumination in a miniature, light-weight fiber-coupled microscope with electrowetting axial scanning. We demonstrate imaging of YFP-labeled neurons in mouse brain tissue showing potential for fast volumetric imaging in freely moving animals.
MoO3-x as a wideband optical saturable absorber for passively Q-switching ytterbium-, erbium-, and thulium-doped fiber lasers
Authors: Wang Meng , Huang Shaolong , Zeng Yu-Jia , Huang Ruqing , Sun Dalin , Wang Meng , Pei Jihong , Ruan Shuangchen
Published: September 2020

Wideband optical saturable absorbers (SA) are an ideal laser component for pulse laser generation in different wavelengths, which has attracted tremendous attention in recent years. Herein, a MoO3-x-based novel wideband optical SA has been demonstrated by utilizing it for ∼1/1.5/2 μm Q-switched pulses generation. After separately integrating the MoO3-x-SA into Yb-, Er- and Tm-doped fiber lasers, passively Q-switched pulses with pulse durations of ∼1.5/2.2/1.6 μs, repetition rates of several tens kilohertz at corresponding wavelengths of ∼1038/1562.9/1910 nm are obtained. Our work firstly reveals the remarkable wideband optical saturable absorption of the MoO3-x, which strongly implies the potential application in infrared photonics devices. It may also provide new opportunities for wideband optical SA based on oxygen-deficient metal oxides.
Brasil e Portugal. Ditaduras e transições para a democracia
Authors: Dockhorn Gilvan Veiga , Nunes João Paulo Avelãs , Konrad Diorge Alceno
Published: September 2020

Com a obra Brasil e Portugal: ditaduras e transições para a democracia, inicia-se a segunda etapa da Coleção “História Contemporânea”, publicada pela Imprensa da Universidade de Coimbra sob a Coordenação Científica do Centro de Estudos Interdisciplinares do Século XX da Universidade de Coimbra (CEIS20/UC). A Direção da Coleção passa a ser assegurada por António Rafael Amaro (historiador, docente da Faculdade de Economia da Universidade de Coimbra, investigador do CEIS20/UC) e por João Paulo Avelãs Nunes (historiador, docente do Departamento de História, Estudos Europeus, Arqueologia e Artes da Faculdade de Letras da Universidade de Coimbra, investigador do CEIS20/UC). À semelhança do que sucedeu na etapa anterior, durante a qual Maria Manuela Tavares Ribeiro foi responsável pela criação e pelo funcionamento da Coleção, procura-se divulgar estudos de qualidade e socialmente relevantes sobre história contemporânea portuguesa e de outros países (séculos XIX a XXI). Aceitam-se para avaliação por referees monografias e obras colectivas, abordagens mono, inter e transdisciplinares, leituras menos ou mais comparativas, textos em português e em outras línguas (inglês, francês, castelhano, italiano), trabalhos da autoria de investigadores do CEIS20/UC e de investigadores ligados a outras instituições ou organizações. Observando-se, na presente conjuntura, a intensificação dos indicadores de crise e de tensão nos planos nacional, subcontinental e internacional, a historiografia — pressupostos deontológicos e epistemológicos, conceitos e metodologias, propostas de reconstituição e interpretação — sobre a época contemporânea vê ampliada a sua relevância social global.
USING THE AUTOMATIC VECTORISATION METHOD IN GENERATING THE VECTOR ALTIMETRY OF THE HISTORICAL VLTAVA RIVER VALLEY
Authors: Kratochvílová Darina , Cajthaml Jiří
Published: September 2020

The article describes, in detail, the generation procedure of vector altimetry of an upper and middle course of the Vltava River historical valley. By the historical valley, the shape of the river valley before the construction of dams on the Vltava River in the second half of the 20th century is understood. The vector altimetry will serve as the base for creating a 3D model of this valley. The initial input data were old maps, specifically scanned first-edition prints of the State Map 1 : 5 000 - Derived (SMO-5). By combining automatic and manual vectorisation, the altimetry component of these maps (contour lines and spot elevations) will be converted to a vector format. Individual processing steps, including the description of automatic vectorisation in the ArcScan extension to the ArcGIS system, together with examples of the results, are presented in the text below.
DEFORMATION ANALYSIS OF LAYERED REINFORCED CONCRETE - FOAM CONCRETE FLOOR SLABS
Authors: Lytvyniak Oksana
Published: September 2020

This article presents a theoretical study of a stress-strain state of layered reinforced concrete - foam concrete floor slabs (hereinafter called as the LRFCS), with the use of a deformation analysis. Compressive and tensile diagrams of the foam concrete, a tensile diagram of the reinforced concrete and compressive and tensile diagrams of the reinforcement rod are used for the estimation of the stress-strain state of the calculated cross-section of the LRFCS. It should be noted that this article presents the deformation method of loading by the scheme of pure bending for the LRFCS. This deformation method of loading is determined by six shapes of the stress-strain state. These shapes of the stress-strain state are represented by the corresponding distribution diagrams of the relative deformations and the distribution diagrams of internal stresses in the calculated cross-section of the floor slab. Also, this article presents the corresponding equilibrium equations of internal efforts and moments, which act in the calculated cross-section of the floor slab for all shapes of its stress-strain state. Consequently, the mentioned recommendations and mathematical dependencies allow to evaluate the stress-strain state of the LRFCS from its initial loading to its destruction.
PILE SETTLEMENT INDUCED FROM SOIL MOVEMENT DUE TO BREAKDOWN OF RETAINING WALL
Authors: Shukla Rajesh Prasad
Published: September 2020

Very few studies measured the settlement of retaining wall supported piles foundation under a soil movement. This study explores the pile settlement induced from the sudden breakdown of a closely located retaining wall using a small-scale experimental model. Various factors affect the pile settlement, but the influence of the embedment ratio of the pile and collapsed height of the retaining wall is relatively more visible. The induced settlement decreases with pile embedment depth and increases with the collapsed height of the retaining wall. The pile settlement initially increases at a higher rate with an increase in the collapsed height to a certain extent, beyond which, becomes relatively less observable. Pile group settlement reduces with the increase in spacing and the number of piles in longer piles. However, opposite trends have been observed in piles with a smaller embedment ratio. The settlement reduces logarithmically with the increase in the distance between piles and the retaining wall. Pile groups with small embedment ratio are severely more affected by the breakdown of the retaining wall than the piles of a large embedment ratio. Pile groups placed parallel to the retaining wall are more affected than those placed orthogonally.
Degradación ambiental por procesos de cambios de uso y cubierta del suelo desde una perspectiva espacial en el estado de Guanajuato, México
Authors: Pérez-Vega Azucena , Regil García Héctor Hugo , Mas Caussel Jean François
Published: September 2020

Se analizaron los cambios de cubierta/uso del suelo en el estado de Guanajuato identificando los procesos de transformación y degradación ambiental. El análisis consideró tres periodos de tiempo 2002-2007, 2007-2011 y 2011-2014 basados en la cartografía de uso del suelo y vegetación de INEGI. Se utilizaron métodos de evaluación de tasas de cambio, intensidad de cambio y las secuencias temporales de las cubiertas del suelo. Los mayores porcentajes de intensidad de cambio los presentaron ecosistemas de ambientes áridos y caducifolios como los Mezquite (-3.6%), Selva Baja Caducifolia (-2.1%) y Bosque de encino (-1.4%). La deforestación se redujo a la mitad entre el primer y el último periodo afectando los piedemontes y lomeríos. La mayor intensidad ocurrió durante 2002-2007, seguida de una fuerte reducción en 2007-2011 y finalmente de 2011-2014 un incremento importante de la dinámica sin alcanzar la intensidad del primer periodo. Las trayectorias de cambio no fueron uniformes ni en el tiempo, ni entre categorías. Las cubiertas antrópicas de mayor tasa anual relativa de ganancia fueron los asentamientos humanos establecidos sobre suelos fértiles, así como los pastizales inducidos. Las agriculturas de temporal y riego mostraron muy bajas tasas de cambio relativo pero muy altas tasas de cambio absoluto, entre ellas mantienen secuencias circulares íntimamente ligadas a la disponibilidad de agua subterránea. Existe una estrecha relación entre el abatimiento de los acuíferos y el incremento de la superficie de agricultura de riego, la cual ocupa el 80% del agua subterránea extraída en el estado de Guanajuato.
Governança no setor sucroalcooleiro: uma análise comparada de São Paulo e do Cerrado Mineiro e Goiano
Authors: Feltre Cristiane , Benzaquen Perosa Bruno
Published: September 2020

O objetivo deste artigo foi comparar as formas de governança no abastecimento de cana-de-açúcar nos principais estados brasileiros produtores (São Paulo, Goiás e Minas Gerais). A pesquisa foi desenvolvida a partir de metodologia quantitativa e qualitativa, com base em dados secundários e revisão bibliográfica. Os resultados mostram que, ao longo do tempo, o abastecimento de cana sofreu algumas alterações nos principais estados produtores que podem ser explicadas pelas mudanças na estrutura regulatória, pelo perfil e organização dos produtores e pelo perfil gerencial das usinas. No caso das regiões do Cerrado goiano e mineiro, observou-se no início da expansão canavieira um processo de maior integração das usinas (maior proporção de cana própria) devido à falta de fornecedores nessas regiões. Contudo, esse processo vem se revertendo à medida que muitos agricultores de outras atividades inserem a cana em suas propriedades e passam a se organizar em associações para gerir a produção e comercialização com as usinas.
Minimização da disparidade de gênero na área de Ciências Exatas, Engenharias e Computação: o impacto da extensão universitária no cotidiano de alunas de escolas públicas na cidade de Santa Maria, Brasil
Authors: Da Rocha Isabela Garcia , Dos Santos Flávia Ferrari , Barden Carla De Oliveira , Collazzo Gabriela Carvalho
Published: September 2020

O objetivo principal deste trabalho foi divulgar as atividades de um projeto de extensão, chamado UniEscola, desenvolvido em parceria entre a Universidade Federal de Santa Maria, Brasil, e escolas da periferia da cidade de Santa Maria localizada no Rio Grande do Sul. O projeto traz como meta principal despertar o interesse das meninas, estudantes de escolas públicas pelas áreas de ciências exatas, engenharia e computação potencializando suas vocações científicas, oferecendo-lhes aprendizagens relacionadas à sua vida diária e capacitando-as para o mundo do trabalho e protagonismo social. Diversas atividades foram realizadas durante este período, como por exemplo, cursos, oficinas, palestras, atividades de iniciação científica, visitas. Como principais resultados podem-se se destacar a vivência das participantes no meio acadêmico, desmistificação destas áreas e incentivo a extensão universitária. E por fim o principal resultado foi a busca e aplicação de conhecimentos tanto por parte das alunas das escolas quanto pelas participantes da universidade.
Violencias en vínculos sexuales y afectivos. Proyecto de extensión con mujeres de la ciudad de Córdoba
Authors: Bonavitta Paola , Gastiazoro María Eugenia
Published: September 2020

Presentamos, a través de dos proyectos de extensión universitaria (2018–2019), un recorte de intervenciones realizadas sobre violencias en vínculos sexuales y afectivos a partir de las experiencias de mujeres en territorios urbanos populares cordobeses. Se trabajó con una metodología transformativa de Investigación Acción Participativa ampliada desde las miradas feministas. En este marco de investigación participativa feminista se incluyeron diversas técnicas: entrevistas individuales en profundidad; observación participante; grupos focales; talleres y autoetnografía. Por medio de la cartografía y círculos feministas se generó conocimiento colectivo sobre cómo se viven las violencias sexuales en los propios cuerpos. Como investigadoras y participantes encontramos que estas violencias nos atraviesan como sociedad y desvalorizan la vida, el sistema genera sometimiento a través de nuestros cuerpos colonizados por el patriarcado y el sistema sexo–género. Frente a esto, recuperamos voces colectivas sobre cómo imaginar y crear otro tipo de vínculos sexo–afectivos, más libres y placenteros.
Series2Graph
Authors: Boniol Paul , Palpanas Themis
Published: September 2020

Subsequence anomaly detection in long sequences is an important problem with applications in a wide range of domains. However, the approaches that have been proposed so far in the literature have severe limitations: they either require prior domain knowledge that is used to design the anomaly discovery algorithms, or become cumbersome and expensive to use in situations with recurrent anomalies of the same type. In this work, we address these problems, and propose an unsupervised method suitable for domain agnostic subsequence anomaly detection. Our method, Series2Graph, is based on a graph representation of a novel low-dimensionality embedding of subsequences. Series2Graph needs neither labeled instances (like supervised techniques), nor anomaly-free data (like zero-positive learning techniques), and identifies anomalies of varying lengths. The experimental results, on the largest set of synthetic and real datasets used to date, demonstrate that the proposed approach correctly identifies single and recurrent anomalies without any prior knowledge of their characteristics, outperforming by a large margin several competing approaches in accuracy, while being up to orders of magnitude faster.
Fast subtrajectory similarity search in road networks under weighted edit distance constraints
Authors: Koide Satoshi , Xiao Chuan , Ishikawa Yoshiharu
Published: September 2020

In this paper, we address a similarity search problem for spatial trajectories in road networks. In particular, we focus on the
subtrajectory similarity search
problem, which involves finding in a database the subtrajectories similar to a query trajectory. A key feature of our approach is that we do not focus on a specific similarity function; instead, we consider
weighted edit distance
(WED), a class of similarity functions which allows user-defined cost functions and hence includes several important similarity functions such as EDR and ERP. We model trajectories as strings, and propose a generic solution which is able to deal with any similarity function belonging to the class of WED. By employing the filter-and-verify strategy, we introduce
subsequence filtering
to efficiently prunes trajectories and find candidates. In order to choose a proper subsequence to optimize the candidate number, we model the choice as a discrete optimization problem (NP-hard) and compute it using a 2-approximation algorithm. To verify candidates, we design
bidirectional tries
, with which the verification starts from promising positions and leverage the shared segments of trajectories and the sparsity of road networks for speed-up. Experiments are conducted on large datasets to demonstrate the effectiveness of WED and the efficiency of our method for various similarity functions under WED.
Auto-transform
Authors: Jin Zhongjun , He Yeye , Chauduri Surajit
Published: September 2020

Data Transformation is a long-standing problem in data management. Recent work adopts a "transform-by-example" (TBE) paradigm to infer transformation programs based on user-provided input/output examples, which greatly improves usability, and brought such features into mainstream software like Microsoft Excel, Power BI, and Trifacta.

While TBE is great progress, the need for users to provide paired input/output examples still poses limits on its applicability. In this work, we study an alternative that transforms data based on input/output
data patterns
only (without paired examples). We term this new paradigm
transform-by-patterns
(TBP). Specifically, we demonstrate that there is a rich class of transformations in TBP that can be "learned" from large collections of paired table columns. We show the proposed method can harvest such transformations across diverse domains and corpora (e.g., in different languages such as English, Chinese, Spanish, etc.). TBP transformations so obtained can be used in scenarios such as suggesting data-repairs in tables, or automating transformations in ETL pipelines. Extensive experiments on real data suggest that TBP outperforms existing methods on tasks such as data repairs, and is a promising direction for future research.
FSST
Authors: Boncz Peter , Neumann Thomas , Leis Viktor
Published: September 2020

Strings are prevalent in real-world data sets. They often occupy a large fraction of the data and are slow to process. In this work, we present Fast Static Symbol Table (FSST), a
lightweight
compression scheme for strings. On text data, FSST offers decompression and compression speed similar to or better than the best speed-optimized compression methods, such as LZ4, yet offers significantly better compression factors. Moreover, its use of a static symbol table allows
random access
to individual, compressed strings, enabling lazy decompression and query processing on compressed data. We believe these features will make FSST a valuable piece in the standard compression toolbox.
Ease.ml/snoopy in action
Authors: Renggli Cedric , Rimanic Luka , Kolar Luka , Wu Wentao , Zhang Ce
Published: September 2020

We demonstrate ease.ml/snoopy, a data analytics system that performs
feasibility analysis
for machine learning (ML) applications
before
they are developed. Given a performance target of an ML application (e.g., accuracy above 0.95), ease.ml/snoopy provides a decisive answer to ML developers regarding whether the target is achievable or not. We formulate the feasibility analysis problem as an instance of Bayes error estimation. That is, for a data (distribution) on which the ML application should be performed, ease.ml/snoopy provides an estimate of the Bayes error - the
minimum error rate
that can be achieved by
any
classifier. It is well-known that estimating the Bayes error is a notoriously hard task. In ease.ml/snoopy we explore and employ estimators based on the combination of (1) nearest neighbor (NN) classifiers and (2) pre-trained feature transformations. To the best of our knowledge, this is the first work on Bayes error estimation that combines (1) and (2). In today's cost-driven business world, feasibility of an ML project is an ideal piece of information for ML application developers - ease.ml/snoopy plays the role of a reliable "
consultant.
"
RDFFrames
Authors: Mohamed Aisha , Abuoda Ghadeer , Ghanem Abdurrahman , Kaoudi Zoi , Aboulnaga Ashraf
Published: September 2020

Knowledge graphs represented in RDF are becoming increasingly popular and are essential to many machine learning applications. A rich ecosystem of RDF data management systems and tools has evolved over the years, most notably RDF database management systems that support the SPARQL query language. Surprisingly, machine learning tools for knowledge graphs typically do not use SPARQL despite the obvious advantages of using a database system. This is due to the mismatch between SPARQL and machine learning tools in terms of expected data model and interface style. Machine learning tools work on data in tabular format and process it using imperative relational API calls, while SPARQL matches graph patterns to RDF triples. To access knowledge graphs for machine learning, we observe that it is more natural to use a navigational paradigm based on graph traversal rather than the SPARQL paradigm based on triple patterns. We demonstrate RDFFrames, a framework that bridges the gap between machine learning tools and RDF database systems by offering the usability and flexibility of machine learning tools together with the performance of a database system. RDFFrames enables the user to make a sequence of Python calls to define the data to be extracted from a knowledge graph stored in an RDF database system, and it translates these calls into a compact SPARQL query, executes it on the database system, and returns the results in a standard tabular format.
Scilens news platform
Authors: Romanou Angelika , Smeros Panayiotis , Castillo Carlos , Aberer Karl
Published: September 2020

We demonstrate the SciLens News Platform, a novel system for evaluating the quality of news articles. The SciLens News Platform automatically collects contextual information about news articles in real-time and provides quality indicators about their validity and trustworthiness. These quality indicators derive from i) social media discussions regarding news articles, showcasing the reach and stance towards these articles, and ii) their content and their referenced sources, showcasing the journalistic foundations of these articles. Furthermore, the platform enables domain-experts to review articles and rate the quality of news sources. This augmented view of news articles, which combines automatically extracted indicators and domain-expert reviews, has provably helped the platform users to have a better consensus about the quality of the underlying articles. The platform is built in a distributed and robust fashion and runs operationally handling daily thousands of news articles. We evaluate the SciLens News Platform on the emerging topic of
COVID-19
where we highlight the discrepancies between low and high-quality news outlets based on three axes, namely their newsroom activity, evidence seeking and social engagement. A live demonstration of the platform can be found here:
http://scilens.epfl.ch.
Orca-SR
Authors: Augustine Jees , Shetiya Suraj , Asudeh Abolfazl , Thirumuruganathan Saravanan , Nazi Azade , Zhang Nan , Das Gautam , Srivastava Divesh
Published: September 2020

Reconstructing a high dimensional unknown signal, using lower dimensional observations is a challenging problem, known as
signal reconstruction problem
(SRP), with diverse applications including network traffic engineering, medical image reconstruction, and astronomy. Recently the database community has shown significant advancements in solving the SRP problem efficiently, effectively, and in scale by leveraging database techniques such as similarity joins. In this demo, we demonstrate Orca-SR that highlights the benefits of signal reconstruction in scale by demonstrating real-time network traffic flow analysis on large networks that were not possible before. Orca-SR is a web application that enables a user to generate network flow and load the network for interactive analysis of the impact of different traffic patterns on signal reconstruction.
PyTorch distributed
Authors: Li Shen , Zhao Yanli , Varma Rohan , Salpekar Omkar , Noordhuis Pieter , Li Teng , Paszke Adam , Smith Jeff , Vaughan Brian , Damania Pritam , Chintala Soumith
Published: September 2020

This paper presents the design, implementation, and evaluation of the PyTorch distributed data parallel module. Py-Torch is a widely-adopted scientific computing package used in deep learning research and applications. Recent advances in deep learning argue for the value of large datasets and large models, which necessitates the ability to scale out model training to more computational resources. Data parallelism has emerged as a popular solution for distributed training thanks to its straightforward principle and broad applicability. In general, the technique of distributed data parallelism replicates the model on every computational resource to generate gradients independently and then communicates those gradients at each iteration to keep model replicas consistent. Despite the conceptual simplicity of the technique, the subtle dependencies between computation and communication make it non-trivial to optimize the distributed training efficiency. As of v1.5, PyTorch natively provides several techniques to accelerate distributed data parallel, including bucketing gradients, overlapping computation with communication, and skipping gradient synchronization. Evaluations show that, when configured appropriately, the PyTorch distributed data parallel module attains near-linear scalability using 256 GPUs.
Automated generation of materialized views in Oracle
Authors: Ahmed Rafi , Bello Randall , Witkowski Andrew , Kumar Praveen
Published: September 2020

Automated generation of a right set of materialized views is a challenging task. It is a highly desirable feature for autonomous databases. The selection of materialized views must be based on cost and verifiable in the actual database environment. This paper describes an automated system that generates, selects, verifies, and maintains materialized views in the Oracle RDBMS; it presents a novel technique, called the extended covering sub-expression algorithm, for the automated generation of materialized views. An extensive set of experiments is described that demonstrates the feasibility and efficiency of this approach. This system has been fully implemented and is going to be deployed on the Oracle Autonomous Database on the Cloud.
AnalyticDB-V
Authors: Wei Chuangxian , Wu Bin , Wang Sheng , Lou Renjie , Zhan Chaoqun , Li Feifei , Cai Yuanzhe
Published: September 2020

With the explosive growth of unstructured data (such as images, videos, and audios), unstructured data analytics is widespread in a rich vein of real-world applications. Many database systems start to incorporate unstructured data analysis to meet such demands. However, queries over unstructured and structured data are often treated as disjoint tasks in most systems, where
hybrid queries
(
i.e.
, involving both data types) are not yet fully supported.

In this paper, we present a hybrid analytic engine developed at Alibaba, named
AnalyticDB-V
(ADBV), to fulfill such emerging demands. ADBV offers an interface that enables users to express
hybrid queries
using SQL semantics by converting unstructured data to high dimensional vectors. ADBV adopts the
lambda
framework and leverages the merits of approximate nearest neighbor search (ANNS) techniques to support hybrid data analytics. Moreover, a novel ANNS algorithm is proposed to improve the accuracy on large-scale vectors representing massive unstructured data. All ANNS algorithms are implemented as physical operators in ADBV, meanwhile, accuracy-aware cost-based optimization techniques are proposed to identify effective execution plans. Experimental results on both public and in-house datasets show the superior performance achieved by ADBV and its effectiveness. ADBV has been successfully deployed on Alibaba Cloud to provide hybrid query processing services for various real-world applications.
Exploiting domain knowledge to address multi-class imbalance and a heterogeneous feature space in classification tasks for manufacturing data
Authors: Hirsch Vitali , Reimann Peter , Mitschang Bernhard
Published: September 2020

Classification techniques are increasingly adopted for quality control in manufacturing, e.g., to help domain experts identify the cause of quality issues of defective products. However, real-world data often imply a set of analytical challenges, which lead to a reduced classification performance. Major challenges are a high degree of multi-class imbalance within data and a heterogeneous feature space that arises from the variety of underlying products. This paper considers such a challenging use case in the area of End-of-Line testing, i.e., the final functional test of complex products. Existing solutions to classification or data pre-processing only address individual analytical challenges in isolation. We propose a novel classification system that explicitly addresses both challenges of multi-class imbalance and a heterogeneous feature space together. As main contribution, this system exploits domain knowledge to systematically prepare the training data. Based on an experimental evaluation on real-world data, we show that our classification system outperforms any other classification technique in terms of accuracy. Furthermore, we can reduce the amount of rework required to solve a quality issue of a product.
A drop-in middleware for serializable DB clustering across geo-distributed sites
Authors: Saurez Enrique , Balasubramanian Bharath , Schlichting Richard , Tschaen Brendan , Narayanan Shankaranarayanan Puzhavakath , Huang Zhe , Ramachandran Umakishore
Published: September 2020

Many geo-distributed services at web-scale companies still rely on databases (DBs) primarily optimized for single-site performance. At AT&T this is exemplified by services in the network control plane that rely on third-party software that uses DBs like MariaDB and PostgreSQL, which do not provide strict serializability across sites without a significant performance impact. Moreover, it is often impractical for these services to re-purpose their code to use newer DBs optimized for geo-distribution. In this paper, a novel drop-in solution for DB clustering across sites called Metric is presented that can be used by services without changing a single line of code. Metric leverages the single-site performance of an existing service's DB and combines it with a cross-site clustering solution based on an entry-consistent redo log that is specifically tailored for geo-distribution. Detailed correctness arguments are presented and extensive evaluations with various benchmarks show that Metric outperforms other solutions for the access patterns in our production use-cases where service replicas access different tables on different sites. In particular, Metric achieves up to 56% less latency and 5.2x higher throughput than MariaDB and PostgreSQL clustering, and up to 90% less latency and 26x higher throughput than CockroachDB and TiDB, systems that are designed to support geo-distribution.
Table extraction and understanding for scientific and enterprise applications
Authors: Burdick Douglas , Danilevsky Marina , Evfimievski Alexandre V , Katsis Yannis , Wang Nancy
Published: September 2020

Valuable high-precision data are often published in the form of tables in both scientific and business documents. While humans can easily identify, interpret and contextualize tables, developing general-purpose automated techniques for extraction of information from tables is difficult due to the wide variety of table formats employed across corpora.

To extract useful data from tables, data cells must be correctly extracted and linked to all relevant headers, units of measure and in-text references.
Table extraction
involves identifying the border and cell structure for each document table, while
table understanding
provides context by linking cells with semantic information inside and outside the table, such as row and column headers, footnotes, titles, and references in surrounding text.

The objective of this tutorial is to provide a detailed synopsis of existing approaches for table extraction and understanding, highlight open research problems, and provide an overview of potential applications.
Recognition of multifont English electronic prescribing based on convolution neural network algorithm
Authors: Mohammed Muthana J. , Mohammed Emad A. , Jarjees Mohammed S.
Published: September 2020

The printed character recognition is an efficient and automatic method for inputting information to a computer nowadays that is used to translate the printed or handwritten images into an editable and readable text file. This paper aims to recognize a multifont and multisize of the English language printed word for a smart pharmacy purpose. The recognition system has been based on a convolution neural network (CNN) approach where line, word, and character are separately corrected, and then each of the separated characters is fed into the CNN algorithm for recognition purposes. The OpenCV open-source library has been used for preprocessing, which can segment English characters accurately and efficiently, and for recognition, the Keras library with the backend of TensorFlow has been used. The training and testing data sets have been designed to include 23 different fonts with six different sizes. The CNN algorithm achieves the highest accuracy of 96.6% comparing to the other state-of-the-art machine learning methods. The higher classification accuracy of the CNN approach shows that this type of algorithm is ideal for the English language printed word recognition. The highest error rate after testing the system using English electronic prescribing written with all proposed font-types is 0.23% in Georgia font.
A forgotten translation by Theodorus Gaza unveiled and its context
Authors: Galán Vioque Guillermo
Published: September 2020

The emigrant Byzantine humanist Theodorus Gaza (c. 1400 -1475) is well known as a teacher of Greek in various Italian cities, as a copyist of Greek manuscripts, and as a translator of Greek philosophical works into Latin. His undertakings as a translator of Latin works into Greek, among which his version of Cicero’s De senectute deserves mention, have gone relatively unnoticed. In this article we rediscover a largely forgotten translation of Cic. Fam. 1.1, despite it having been printed independently twice (Paris 1542 and 1548) and having been included as an example of translation in the oft reprinted manual of rhetorical exercises, Elementa rhetoricae (first printed in Basel in 1541), by the Lutheran Joachim Camerarius.
Die Wiederentdeckung von Byzanz: Die kretische Ikone von Göttingen und die Koimesis-Darstellung in der byzantinischen und postbyzantinischen Epoche
Authors: Giannoulis Markos
Published: September 2020

What are the similarities and the differences of icons from the same workshop depicting the same subject? An important portable icon with the representation of the Dormition of the Virgin, hitherto unknown, preserved today in the Art Collection of the University of Göttingen, helps answering this question. The studydeals with the fascinating journey of this icon from Venetian-dominated Crete in the 15th century to Germany of the 18th century. Furthermore, this paper shows that the icon of Göttingen belongs to a group of a numerous icons that they all derive from the same icon-workshop of the renowned Cretan painters Andreas and Nikolaos Ritzos in Candia. Finally, it turned out that this icon was also the inspiration for Cretan painters of the 17th CE such as Emmanuel Lambardos and Viktor.
Writing letters and chronography in parallel: the case of Michael Glykas’ letter collection and Biblos Chronike in the 12th century
Authors: Kiapidou Eirini-Sophia
Published: September 2020

This paper focuses on the 12th-century Byzantine scholar Michael Glykas and the two main pillars of his multifarious literary production, Biblos Chronike and Letters, thoroughly exploring for the first time the nature of their interconnection. In addition to the primary goal, i. e. clarifying as far as possible the conditions in which these two works were written, taking into account their intertextuality, it extends the discussion to the mixture of features in texts of different literary genre, written in parallel, by the same author, based on the same material. By presenting the evidence drawn from the case of Michael Glykas, the paper attempts to stress the need to abandon the strictly applied taxonomical logic in approaching Byzantine Literature, as it ultimately prevents us from constitute the full mark of each author in the history of Byzantine culture.
When Christology intersects with embryology: the viewpoints of Nestorian, Monophysite and Chalcedonian authors of the sixth to tenth centuries
Authors: Krausmüller Dirk
Published: September 2020

The notion that the soul comes into existence simultaneously with the body at the moment of conception was originally introduced into the Patristic discourse as an alternative to the Origenist notion of a pre-existing soul. Yet from the sixth century onwards it was itself regarded as an Origenist tenet. Now it was claimed that only those who believed the soul to be created after the body were truly orthodox. The present article examines the links between this development and the Christological conversies.
Eight unedited poems to his friends and patrons by Manuel Philes
Authors: Kubina Krystina
Published: September 2020

This article presents the critical edition of eight hitherto unpublished poems by Manuel Philes together with a translation and a commentary. The poems are verse letters addressed to various high-ranking individuals. Poem 1 is addressed to the emperor, whose power is emphasised in a request to help Philes escape from his misery. Poem 2 is a fragment likewise addressed to the emperor. Poem 3 is a consolatory poem for a father whose son has died. In poem 4, Philes addresses a patron whose wife hurried to Constantinople after she had become the object of hostility of unknown people. Poem 5 is addressed to the month of August and deals with the return of a benefactor of Philes to Constantinople. In poem 6, Philes writes on behalf of an unnamed banker and asks the megas dioiketes Kabasilas to judge the latter justly. Poems 7 and 8 are tetrasticha including a request for wine.
Four lead seals of the 11th century from Yozgat
Authors: Laflı Ergün , Seibt Werner
Published: September 2020

In the museum of Yozgat in eastern-central Anatolia four eleventh century A.D. seals of Byzantine dignitaries are stored, all of them originate probably from central Anatolia. Basileios Trichinopodes was hypatos and strategos of Anazarbus in Cilicia in the middle of the eleventh century, Katakalon was hypatos and strategos of Larissa in Cappadocia in the third quarter of the same century, a civil dignitary, probably named Pirmanes, was protospatharios and chartoularios of the Bucellarian Theme in the second half of the tenth or early eleventh century, and Samuel Alousianos, a grandson of the last Bulgarian tsar Ivan Vladislav, was proedros and dux, probably fighting the Turkish invaders in Eastern Anatolia during the difficult years in the 1070s.
Coda: Literature, language, and creativity
Authors: Kukkonen Karin
Published: September 2020

Literature is often considered the creative expression of language par excellence. This coda considers how the perspectives from Construction Grammar, as they are outlined in this special issue, can enter into dialogue with recent developments in how literary studies address creativity. Construction Grammar concerns itself with the productive generation and manipulation of language in everyday contexts, but, as this special issue goes to show, these processes can also be discussed in terms of creativity and deployed to shed light on creative processes in the arts. Convergences between Construction Grammar and (cognitive) literary studies appear to emerge in particular around the question of creative practice in literary language and (1) in how far writing gives rise to particular kinds of creativity; (2) how one can generalize between different creative media, such as literature, painting and music; and (3) how writing-based creativity can be investigated. Literary studies with its interests in media environments, social/historical context and textual analysis might provide a larger testing ground for claims about the compatibility and incompatibility of everyday and literary creativity as they are put forward in this special issue.