nils-herrmann/clean_scirepeval huggingface dataset:
Searching for materials with high refractive index and wide band gap: A first principles high throughput study
Venue: Physical Review Materials
Year: 2019

Materials combining both a high refractive index and a wide band gap are of great interest for optoelectronic and sensor applications. However, these two properties are typically described by an inverse correlation with high refractive index appearing in small gap materials and vice versa. Here, we conduct a first principles high throughput study on more than 4000 semiconductors (with a special focus on oxides) Our data confirm the general inverse trend between refractive index and band gap but interesting outliers are also identified. The data are then analyzed through a simple model involving two main descriptors: the average optical gap and the effective frequency. The former can be determined directly from the electronic structure of the compounds, but the latter cannot. This calls for further analysis in order to obtain a predictive model. Nonetheless, it turns out that the negative effect of a large band gap on the refractive index can counterbalanced in two ways: (i) by limiting the difference between the direct band gap and the average optical gap which can be realized by a narrow distribution in energy of the optical transitions and (ii) by increasing the effective frequency which can be achieved through either a high number of transitions from the top of the valence band to the bottom of the conduction or a high average probability for these transitions. Focusing on oxides, we use our data to investigate how the chemistry influences this inverse relationship and rationalize why certain classes of materials would perform better. Our findings can be used to search for new compounds in many optical applications both in the linear and non linear regime (waveguides, optical modulators, laser, frequency converter, etc.
Spectral Image Visualization Using Generative Adversarial Networks
Venue: PRICAI
Year: 2018

Spectral images captured by satellites and radio telescopes are analyzed to obtain information about geological compositions distributions, distant asters as well as undersea terrain. Spectral images usually contain tens to hundreds of continuous narrow spectral bands and are widely used in various fields. But the vast majority of those image signals are beyond the visible range, which calls for special visualization technique. The visualizations of spectral images shall convey as much information as possible from the original signal and facilitate image interpretation. However, most of the existing visualizatio methods display spectral images in false colors, which contradict with human's experience and expectation. In this paper, we present a novel visualization generative adversarial network (GAN) to display spectral images in natural colors. To achieve our goal, we propose a loss function which consists of an adversarial loss and a structure loss. The adversarial loss pushes our solution to the natural image distribution using a discriminator network that is trained to differentiate between false color images and natural color images. We also use a cycle loss as the structure constraint to guarantee structure consistency. Experimental results show that our method is able to generate structure preserved and natural looking visualizations.
In Situ Polysulfide Detection in Lithium Sulfur Cells.
Venue: The journal of physical chemistry letters
Year: 2018

Lithium sulfur batteries promise significant improvements in specific energy compared to Li ion, but are limited by capacity fade upon cycling. Efforts to improve durability have focused on suppressing the solubility of intermediate polysulfides in the electrolyte. Here we describe an in situ electrochemical polysulfide detection method based on the cyclic volatmmetric response. The voltammetric peaks correlate with increased discharge, consistent with increased polysulfide species in the electrolyte as demonstrated by prior literature measurements using spectroscopic methods. We verified that adding metal sulfide species to the sulfur cathode and ceramic coatings on the polyolefin separator result in reduced polysulfide concentration, consistent with improved cycle life reported earlier. Further, the use of highly concentrated electrolytes produces no detectable dissolved polysulfide species. Future advances in Li/S technology could utilize this method to determine the polysulfide contents in the electrolyte, and thus quantify the efficacy of the sulfur sequestering strategies.
PRODUCAO DE TEXTO NA ALFABETIZACAO
Year: 2020

A aprendizagem da lingua escrita e um processo de construcao e interacao do sujeito com o meio em que vive, pensado nisso, nao podemos separar a lingua e a sociedade. A aquisicao da escrita nao se efetua da mesma maneira para todas as criancas, cada uma possui um ritmo de assimilacao e o processo pode variar dentro de uma mesma faixa etaria. Este trabalho teve por objetivo relatar as experiencias de praticas de escrita em uma turma do ciclo de alfabetizacao, com base nos direitos de aprendizagem e aprofundar o conhecimento sobre o processo de aquisicao de linguagem. Tudo isso filiado a uma perspectiva interacionista, em que a lingua e posta a servico das interacoes sociais. Para fundamentarmos teoricamente, nos baseamos em (BAKHTIN, 1995) (VYGOTSKY,1998) (ROJO,2009) (MARCUSCHI ,2008) (SCHNEUWLY,2004) e nos Documentos desenvolvidos pelo Ministerio de Educacao e Cultura (MEC) para a Alfabetizacao. Metodologicamente, partiremos de uma apresentacao sobre a nossa perspectiva de escrita e de concepcao de lingua, enquanto pratica social. Em seguida, descreveremos e analisaremos a aplicacao da sequencia didatica escolhida, trabalhando com o genero autobiografia, visando a consolidacao do direito a producao de textos escritos na alfabetizacao e o impacto dessa atividade nas criancas e para nossa formacao docente. As analises mostram a eficacia do processo evolutivo da escrita das criancas, com enfoque principal no trabalho de escrita e reescrita das atividades desenvolvidas e nos revelam tambem que o processo de escrita e o mesmo para todos nos diferentes niveis de ensino.
L'economie mondiale de l'huile d'olive
Year: 2014

Bien qu'elle ne contribue qu'a environ 3 du marche mondial des huiles vegetales alimentaires, l'huile d'olive fait l'objet d'un interet croissant de la part de nouveaux pays, notamment grace aux resultats des recherches scientifiques qui confirment les caracteristiques positives de cet <or liquide> et sa place fondamentale dans la diete mediterraneenne. Cet interet se traduit par une transformation de la structure de la production et une concurrence plus forte entre les pays producteurs derriere le geant espagnol et les producteurs traditionnels se trouvent desormais de nouveaux pays, producteurs de derniere generation qui recherchent une rentabilite maximum. L'evolution parallele des circuits commerciaux d'approvisionnement reflete egalement un changement profond de la structure du marche mondial. L'offre encore trop atomisee et la pression de la demande extremement concentree de la grande distribution donnent lieu a un niveau de prix particulierement bas et preoccupant, de nature a remettre en question la rentabilite de cette production agricole dans les zones rurales les moins competitives ou elle joue un role si important.
Recent developments in the aeroelasticity of morphing aircraft
Year: 2021

This paper presents an extensive review of the developments in the aeroelasticity of morphing aircraft that occurred in the last decade (from 2009 to 2020) It focuses mainly on fixed wing aircraft and highlights some representative examples from rotary wing aircraft. Morphing wings are usually associated with significant changes in the aerodynamic loads, structural/elastic properties, and inertial properties and hence the aeroelastic behavior. Changes in aeroelastic behavior can also affect the flight dynamics, stability, and control of air vehicles. The main motivation for this paper is the fact that it is not fully possible to assess and quantify the benefits of morphing technologies without accounting for aeroelastic effects. The literature on the aeroelasticity of morphing aircraft can be split into two main themes: Aeroelastic Stability and Aeroelastic Control. The first theme (Aeroelastic Stability) includes studies conducted on morphing concepts to ensure that they satisfy certain aeroelastic requirements/constraints and that such requirements/constraints do not limit the potential benefits of morphing. The second theme (Aeroelastic Control) includes studies that utilized morphing technologies to improve aeroelastic characteristics and/or control flight loads. It is evident that in both themes, the aeroelasticity of morphing aircraft has been analyzed using analytical, numerical, and/or computational tools with a very limited number of wind tunnel and/or flight tests. In this paper, research activities and studies are categorized according to the morphing degree of freedom they address. For each degree of freedom, research activities are arranged according to the theme they fit under. Aeroelastic frameworks developed for generic morphing applications are also reviewed. In addition, the aeroelastic models used are highlighted and discussed. Finally, trends and research gaps are identified and discussed and main conclusions are drawn.
Secondary metabolites isolated from Iris germanica.
Year: 2009

Phytochemical investigations of methanol extract of rhizome of Iris germanica L. resulted in the isolation of one new compound, 6,6 ditetradecyl 6,7 dihydrooxepin 2(3H) one (1) and five known compounds, 1 (2 (6 hydroxy 2 methylcyclohex 1 enyloxy) 5 methoxyphenyl)ethanone (2) 4 hydroxy 3 methoxyacetophenone (3) irisolone (4) irisolidone (5) and 2 acetoxy 3,6 dimethoxy 1,4 benzoquinone (6) The structures of the compounds were determined on the basis of spectroscopic techniques. The antifungal activity of different soluble portions was measured. The hexane soluble portion of the methanol extract showed significant antifungal activity where as the ethyl acetate and chloroform soluble portions showed moderate activity. The methanol extract showed no antifungal activity.
IT Leadership In A Global Environment: An Analysis Of Critical Success Factors And Software Engineering Best Practices In Context Of India
Year: 2011

Over the past few years, the IT landscape has changed dramatically to facilitate new entrants from emerging economies in the global market. Some nations such as India and China are poised to emerge as IT superpowers in the years to come. In this paper, we attempt analyze some of the critical success factors (CSF) that facilitate the development of IT leaders. Taking India as an example, we explore CSFs like educational system, governmental policies, infrastructure and entrepreneurial activities that are necessary for creating and fostering IT leaders. We conclude by describing the best practices for implementing software engineering projects in an offshore environment.
Threatened medicinal plants in China: Distributions and conservation priorities
Year: 2017

Medicinal plants are more vulnerable to threats than non medicinal plants. In China, a large number of medicinal plants are threatened by human activities and climate change, which greatly affect the conservation of species diversity, genetic resources and sustainable development of the traditional Chinese medicine industry. In this study, we established the first database for the distributions of 535 threatened medicinal plant species in China at the county level. Using this database, we explored geographic patterns, identified biodiversity hotspots and determined the conservation gaps for these threatened medicinal plants. Threatened medicinal plants were widely distributed in 1709 counties across the whole country. The species richness was higher in southern than in northern China. Using the "top 5% richness algorithm" and the "complementary algorithm" we identified 213 counties as biodiversity hotspots for threatened medicinal plants in China. However, based on further conservation gap analysis, we found that 30 hotspot counties were not covered by any type of nature reserve (complete conservation gaps) and 27 more hotspot counties were not covered by national or provincial nature reserves in mainland China. We suggest that new nature reserves should be established for the 30 complete conservation gaps, while range, level or management strategies for the current nature reserves should be improved for the remaining 27 conservation gaps to promote the conservation of threatened medicinal plants in China.
Equivalency Between Circuit and Field Theories for Describing Pulse Propagation in a Coaxial Cable
Venue: 2019 International Conference on Electromagnetics in Advanced Applications (ICEAA)
Year: 2019

A detailed analysis is conducted to describe the propagation of a step pulse along a coaxial cable of circular cross section. The geometry is chosen for two reasons: its obvious practical importance, and the fact that it can be analyzed in a simple and exact manner. The propagation of electromagnetic energy along a transmission line (of which the coaxial cable is a particular example) has led to controversy which has its roots in a misunderstanding of the physical phenomenon, namely in the confusion between the velocity of propagation of a signal and the speed of conduction electrons along the line, resulting in the absurd statement that electric charges cannot exist. This erroneous conclusion has been debunked by several researchers, see e.g.   Nevertheless, it is instructive to revisit the issue utilizing the simple geometry considered herein, which is done in the first part of this work by examining in detain the physical phenomenon of propagation of a step pulse along the cable.
Brominated flame retardants in the European chemicals policy of REACH Regulation and determination in materials.
Venue: Journal of chromatography. A
Year: 2009

The EU REACH legislation will require the registration of 30,000 currently marketed chemicals, including the main commercial BFRs in use (Deca BDE, HBCD and TBBP A) Much of the data needed for registration are already available, thanks to risk assessments of continued production and use already undertaken in the EU. Within the authorisation, substitution by less hazardous chemicals is encouraged. Both qualitative and quantitative methods for the analysis of flame retarded polymers are needed in order that the identity and concentration of the BFRs can be established and compliance with regulations including the RoHS Directive demonstrated. These are reviewed.
Robotic technologies for solar powered UAVs: Fully autonomous updraft aware aerial sensing for multiday search and rescue missions
Venue: J. Field Robotics
Year: 2018

Large scale aerial sensing missions can greatly benefit from the perpetual endurance capability provided by high performance low altitude solar powered UAVs. However, today these UAVs suffer from small payload capacity, low energetic margins and high operational complexity. To tackle these problems, this paper presents four individual technical contributions and integrates them into an existing solar powered UAV system: First, a lightweight and power efficient day/night capable sensing system is discussed. Second, means to optimize the UAV platform to the specific payload and to thereby achieve sufficient energetic margins for day/night flight with payload are presented. Third, existing autonomous launch and landing functionality is extended for solar powered UAVs. Fourth, as a main contribution an extended Kalman filter based autonomous thermal updraft tracking framework is developed. Its novelty is that it allows the end to end integration of the thermal induced roll moment into the estimation process. It is assessed against unscented Kalman filter and particle filter methods in simulation and implemented on the aircraft's low power autopilot. The complete system is verified during a 26 hour search and rescue aerial sensing mockup mission that represents the first ever fully autonomous perpetual endurance flight of a small solar powered UAV with a day/night capable sensing payload. It also represents the first time that solar electric propulsion and autonomous thermal updraft tracking are combined in flight. In contrast to previous work that has focused on the energetic feasibility of perpetual flight, the individual technical contributions of this paper are considered core functionality to guarantee ease of use, effectivity and reliability in future multi day aerial sensing operations with small solar powered UAVs.
An algorithm for calculating web video download rate based on data acquisition system
Venue: 2017 3rd IEEE International Conference on Computer and Communications (ICCC)
Year: 2017

In the era of information explosion, a monotonically increasing amount of video data is produced every day. Calculating the web video download rate to simulate user perception quickly and accurately has become a valuable issue. The web video traffic was captured from broadband network users and analyzed by our own data acquiring system. In this paper, we described the data acquiring system and proposed four algorithms to calculate the video download rate based on the text log data, and then analyzed the accuracy of the algorithms to select the most reasonable one through the comparisons with conventional method. In addition, this paper also proposed a scheme that can quickly distinguish video data from other types of web traffic with a few log information instead of parsing the HTTP content. Through our experiments, the selected algorithm was proved to be reasonable, convenient and efficient.
An Efficient Methodology for On Chip SEU Injection in Flip Flops for Xilinx FPGAs
Venue: IEEE Transactions on Nuclear Science
Year: 2018

Field programmable gate array (FPGA) based single event upset (SEU) emulation in user flip flops is essential for reliability evaluation of mapped designs. Previous approaches to inject SEUs in user flip flops utilized the configuration memory bits that control the set and reset settings of the flip flops. In contrast, this paper presents a novel approach for SEU emulation in user flip flops contents through single frame on chip partial reconfiguration (PR) The presented methodology exploits the inherent architectural features of the latest Xilinx FPGAs to support state initialization of flip flops during PR. The proposed approach does not require instrumentation overhead for flip flops and reduces the fault injection times by orders of magnitude.
Improving Transfer Learning and Squeeze and Excitation Networks for Small Scale Fine Grained Fish Image Classification
Venue: IEEE Access
Year: 2018

Scientific studies on species composition and abundance distribution of fishes have considerable importance to the fishery industry, biodiversity protection, and marine ecosystem. In these studies, fish images are typically collected with the help of scuba divers or autonomous underwater vehicles. These images are then annotated manually by marine biologists. Such a process is certainly a tremendous waste of manpower and material resources. In recent years, the introduction of deep learning has helped making remarkable progress in this area. However, fish image classification can be considered as fine grained problem, which is more challenging than common image classification, especially with low quality and small scale data. Meanwhile, well known effective convolutional neural networks (CNNs) consistently require a large quantity of high quality data. This paper presents a new method by improving transfer learning and squeeze and excitation networks for fine grained fish image classification on low quality and small scale datasets. Our method enhances data augmentation through super resolution reconstruction to enlarge the dataset with high quality images, pre pretrains, and pretrains to learn common and domain knowledge simultaneously while fine tuning with professional skill. In addition, refined squeeze and excitation blocks are designed to improve bilinear CNNs for a fine grained classification. Unlike well known CNNs for image classification, our method can classify images with insufficient low quality training data. Moreover, we compare the performance of our method with commonly used CNNs on small scale fine grained datasets, namely, Croatian and QUT fish datasets. The experimental results show that our method outperforms popular CNNs with higher fish classification accuracy, which indicates its potential applications in combination with other newly updated CNNs.
Photothermal structural fluid behaviors of PV ETFE cushion roof in summer: Numerical analysis using three dimensional multiphysics model
Year: 2020

ETFE cushion roof combines transparent ETFE films and flexible photovoltaics, making it possible to harvest both electricity and heat from solar energy simultaneously. However, high temperature caused by solar radiation remarkably affects the mechanical behaviors of ETFE foils and converting efficiency of PV due to their thermal sensitivity. To tackle this issue, it is critical to understand the photothermal structural fluid performance of PV ETFE cushion. Due to the difficulty to measure by experiment, this paper presents a three dimensional mathematical model considering heat structure fluid couplings to conduct numerical analysis. Time dependent analysis and dynamic boundary conditions are applied to study the behaviors which are difficult to observe in experiment. Results explain how photothermal structural fluid properties vary in a typical summer day from 9:00 to 17:00. Incident solar radiation and PV modules are two main factors that affect the temperature distribution of the cushion roof and the circulation of internal air. Eight groups of air circulation are found inside cushion chambers during simulating period. Air pressure is mainly determined by average temperature rather than local air flow and uneven heat distribution. It is also found that the worst structural case occurs on the upper layer at noon in terms of structural safety factor. Structural safety of PV ETFE cushion roof in typical summer days can be guaranteed. These results can be applied further to improve and optimize the design of PV ETFE cushion roof.
Bandwidth, Gain, dan Pola Radiasi Antena Dipole dan Yagi pada Frekuensi 400 MHz
Year: 2019

Untuk mengetahui parameter suatu antenna diperlukan sebuah analisa dan perbandingan yang didasarkan pada berbagai macam asumsi dalam sebuah perancangan antenna yagi dan dipole yang diinginkan. Pada perangkat yang dibuat tersebut menggunakan sebuah formulasi perbandingan yang berbeda yang sekaligus sebagai kelebihan dan kekurangan masing masing antena. Dalam penelitian ini akan dianalisa sebuah besaran bandwith,nilai gain, dan pola radiasi pada frekuensi yang sudah ditentukan yaitu pada frekuensi 400 MHz. Untuk membuat sebuah desain dan menganalisa antena yagi dan difole dibutuhkan sebuah software Computer Simulation Technology (CST) Microwave Studio dengan menggunakan frekuensi 400 MHz.