cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Roots of Sparse Polynomials over a Finite Field
Creators: name: Kelley, Zander
Publisher: name: arXiv
Year: 2016
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: For a $t$-nomial $f(x) = \sum_{i = 1}^t c_i x^{a_i} \in \mathbb{F}_q[x]$, we show that the number of distinct, nonzero roots of $f$ is bounded above by $2 (q-1)^{1-\varepsilon} C^\varepsilon$, where $\varepsilon = 1/(t-1)$ and $C$ is the size of the largest coset in $\mathbb{F}_q^*$ on which $f$ vanishes completely. Additionally, we describe a number-theoretic parameter depending only on $q$ and the exponents $a_i$ which provides a general and easily-computable upper bound for $C$. We thus obtain a strict improvement over an earlier bound of Canetti et al.\ which is related to the uniformity of the Diffie-Hellman distribution. Finally, we conjecture that $t$-nomials over prime fields have only $O(t \log p)$ roots in $\mathbb{F}_p^*$ when $C = 1$.
Degradation Analysis of Photovoltaic Systems in a Tropical Environment
Creators: name: Nobre, A.
name: Malhotra, R.
name: Tang, C.H.
name: Reise, C.
name: Kiefer, K.
name: Rüther, R.
name: Reindl, T.
Publisher: name: WIP
Year: 2013
Subjects: PV SYSTEMS
PV System Reliability and Availability

description: 28th European Photovoltaic Solar Energy Conference and Exhibition; 3673-3677
description: Less than 10% of photovoltaic (PV) systems worldwide are located in tropical regions. With favorable
irradiance conditions and present (or fast approaching) grid parity, installations in these areas of the world are
expected to grow substantially in the near future. In this investigation for the location of Singapore with constant hot
and humid climate conditions throughout the year, 25 solar PV systems (17 of silicon wafer-based and 8 of silicon
thin-film technologies) with a combined installed capacity of ~670 kWp were analytically monitored for 1.5 to 3
years (depending on the installation of the monitoring system). Annual median degradation rates of PV systems were
found to be 0.7% p.a. for the DC-side and 1.5% p.a. for the AC-side of silicon wafer-based systems and 1.2% p.a.
(DC) and 1.6% p.a. (AC) for silicon thin-film based systems. These values are above those in present literature
reviews, which indicate that tropical climate conditions potentially lead to higher degradation rates. Detailed root
cause analyses are underway.
Distortion of embeddings of binary trees into diamond graphs
Creators: name: Leung, Siu Lam
name: Nelson, Sarah
name: Ostrovska, Sofiya
name: Ostrovskii, Mikhail
Publisher: name: arXiv
Year: 2015
Subjects: subject: Metric Geometry (math.MG)
subject: Combinatorics (math.CO)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 05C12, 30L05, 46B85

description: Diamond graphs and binary trees are important examples in the theory of metric embeddings and also in the theory of metric characterizations of Banach spaces. Some results for these families of graphs are parallel to each other, for example superreflexivity of Banach spaces can be characterized both in terms of binary trees (Bourgain, 1986) and diamond graphs (Johnson-Schechtman, 2009). In this connection, it is natural to ask whether one of these families admits uniformly bilipschitz embeddings into the other. This question was answered in the negative by Ostrovskii (2014), who left it open to determine the order of growth of the distortions. The main purpose of this paper is to get a sharp-up-to-a-logarithmic-factor estimate for the distortions of embeddings of binary trees into diamond graphs, and, more generally, into diamond graphs of any finite branching $k\ge 2$. Estimates for distortions of embeddings of diamonds into infinitely branching diamonds are also obtained.
description: Improved presentation and corrected references
PV Power Ramp Rates, Sampling Frequency and Effect on Grid Voltage
Creators: name: Aghatehrani, R.
name: Golnas, A.
name: Voss, S.
Publisher: name: WIP
Year: 2013
Subjects: PV SYSTEMS
PV System and Grid Integration Aspects

description: 28th European Photovoltaic Solar Energy Conference and Exhibition; 3627-3630
description: The movement of compact, opaque clouds between the point source of the sun and an irradiance sensor
can result in dramatic and nearly instantaneous increases and decreases in measured irradiance. The spatial extent of a
photovoltaic (PV) power plant helps dampen the rate of the fluctuation of real power produced by the plant. The location
and size of the PV plant further influence the impact of this variability on a given section of the grid.
In this work we examine the ramp rates exhibited by a PV plant in the time-frequency domain at an island location on a
day with high variability of the solar resource. The impact of this variability on the grid is further modeled as a function
of distance from the circuit substation. A wavelet based power fluctuation index is employed as a metric for assessing
the relative impact of fluctuations of various durations (persistence) and distances from the substation.
Characterization of threshold functions: state of the art, some new contributions and open problems
Creators: name: Freixas, Josep
name: Freixas, Marc
name: Kurz, Sascha
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computer Science and Game Theory (cs.GT)
subject: FOS: Computer and information sciences
subject: 91A12, 06E30, 94C10, 68T27, 92B20

description: This paper has a twofold scope. The first one is to clarify and put in evidence the isomorphic character of two theories developed in quite different fields: on one side, threshold logic, on the other side, simple games. One of the main purposes in both theories is to determine when a simple game is representable as a weighted game, which allows a very compact and easily comprehensible representation. Deep results were found in threshold logic in the sixties and seventies for this problem. However, game theory has taken the lead and some new results have been obtained for the problem in the last two decades. The second and main goal of this paper is to provide some new results on this problem and propose several open questions and conjectures for future research. The results we obtain depend on two significant parameters of the game: the number of types of equivalent players and the number of types of shift-minimal winning coalitions.
description: 26 pages, 5 tables
Funktionsstörungen des Musculus trapezius, des Plexus cervicalis und der Schulter nach Neck dissection
Creators: name: Agha-Mir-Salim, Parwis
Publisher: name: Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité
Year: 2002
Subjects: subject: Trapezius
subject: Oberflächenelektromyografhie
subject: Schulterfunktionsstörungen
subject: Neck dissection
subject: surface electromyography
subject: shoulder function
subject: 610 Medizin
subject: 33 Medizin
subject: XH 1800

description: Einleitung Funktionsstörungen der Schulter treten mit unterschiedlicher Häufigkeit nach Neck dissection auf. Die durchgeführten Studien untersuchten den Einfluss einer Trapeziusparese und einer Schädigung des Plexus cervicalis auf die Entstehung einer Schulterfunktionsstörung. Hierzu sollten neue Methoden zur Bewertung der Aktivität des Musculus trapezius entwickelt werden. Die genauen Auswirkungen auf die Lebenssituation des Patienten waren bisher unklar. Methode Zur Bewertung der Trapeziusfunktion wurde eine simultane Oberflächenlelektromyographie und Schulterhebekraftmessung durchgeführt. In Vorversuchen erfolgte die Entwicklung des Versuchsaufbaus. Wir verwendeten eine bipolare Ableitung des oberen und unteren Trapeziusanteils und eine isometrische Schulterhebekraftmessung bei 90° Abduktion. Es wurden frequenz- und amplitudenabhängige Merkmale bei rampenförmig ansteigender Schulterhebekraft berechnet (Root Mean Square, Mean Frequency, Mean Power Frequency, Frequenzverhältnis und Turnanalyse nach Willison). Die Datenanalyse erfolgte unter LabVIEW(r). Die Funktion des Plexus cervicalis wurde anhand einer semiquantitativen Erfassung der Oberflächensensibilität festgestellt. Die Auswirkung der Schulterfunktionsstörung auf die Lebenssituation des Patienten wurde mittels des Constant Murley Scores eingeschätzt. Ergebnisse Die erste Studie beinhaltete 90 Probanden und zeigte einen statistisch signifikanten Anstieg (p
description: Introduction Functional shoulder disorders after neck dissection have different incidences. The following studies investigated the influence of a trapezius muscle palsy and a damage of the cervical plexus on the frequency of painful shoulder complaints. The consequences for shoulder function and for daily life activities were not yet clear. Methods For assessment of the trapezius function a simultaneous surface electromyography and force measurement were performed. We used a bipolar electrode configuration and an increasing isometric contraction in 90° arm abduction. Frequency and amplitude based parameters (Root Mean Square, Mean Frequency, Mean Power Frequency, Frequency Ratio, Turn Analysis of Willison) were computed and analysed in LabVIEW(r). The cervical plexus function was determined by semiquantitative measurement of the cutaneous sensibility. Shoulder function and restriction in daily life activities were assessed by the Constant Murley Score. Results The first group included 90 probands and showed a statistical significant (p
hi_class: Horndeski in the Cosmic Linear Anisotropy Solving System
Creators: name: Zumalacarregui, Miguel
name: Bellini, Emilio
name: Sawicki, Ignacy
name: Lesgourgues, Julien
name: Ferreira, Pedro G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We present the public version of hi_class (www.hiclass-code.net), an extension of the Boltzmann code CLASS to a broad ensemble of modifications to general relativity. In particular, hi_class can calculate predictions for models based on Horndeski's theory, which is the most general scalar-tensor theory described by second-order equations of motion and encompasses any perfect-fluid dark energy, quintessence, Brans-Dicke, $f(R)$ and covariant Galileon models. hi_class has been thoroughly tested and can be readily used to understand the impact of alternative theories of gravity on linear structure formation as well as for cosmological parameter extraction.
description: 17 pages + appendices, 4 figures, code available on https://github.com/miguelzuma/hi_class_public
3D-SIM (3D-Solar Irradiance Modelling): The Optimization of An Irradiance-Interpolation-Method and its Application for Central Europe
Creators: name: Luger, S.
name: Mock, J.
name: Zehner, M.
name: Lorenz, E.
name: Kühnert, J.
name: Weigl, T.
name: Nagl, L.
name: Rauscher, T.
name: Becker, G.
name: Betts, T.R.
name: Gottschalg, R.
Publisher: name: WIP
Year: 2013
Subjects: PV SYSTEMS
PV System Reliability and Availability

description: 28th European Photovoltaic Solar Energy Conference and Exhibition; 3656-3659
description: During an analysis of high temporal resolution measurement data of several locations in Europe
irradiation peaks above 1000 W/m² were recognized. These Irradiance Enhancements (IE) effect all types of PV systems,
as parts of the system can operate under IE whereas other parts are at the same time clouded. These effects are especially
interesting for larger PV plants and for studies on grid integration with several PV systems. The spatial aspects of IE can
be modelled with a three-dimensional irradiance-interpolation-method: 3D-Solar Irradiance Modelling (3D-SIM). For its
implementation a temporally and spatially high resolved measurement grid of irradiance sensors is necessary, as it
generates an irradiation map from these sensors. 3D-SIM is a modification of a former method named the Cloud-
Velocity-Vector (CVV) Analysis which determined the cloud movement by following the irradiation minima across the
sensor plane. This paper focuses on the optimization of this method by substituting the CVV through the more accurate
satellite-derived Cloud-Motion-Vector (CMV). Consequently, the computation time of the three-dimensional irradiance
field is much lower. Furthermore, the method has been simplified and is now easier to automate. As a result of the 3DSIM
application for a representative location in Central Europe a 3D-irradiance-grid for a whole year is accessible.
Minimizing PV Electricity Curtailment due to Grid Management
Creators: name: Giesler, B.
name: Burger, B.
name: Mayer, J.N.
name: Spring, A.
name: Wirth, G.
name: Zehner, M.
Publisher: name: WIP
Year: 2013
Subjects: PV SYSTEMS
PV System and Grid Integration Aspects

description: 28th European Photovoltaic Solar Energy Conference and Exhibition; 3583-3588
description: In 2013, photovoltaic (PV) systems with a total capacity of 35 GW are installed in Germany. They
produce 6 % of the annual electricity consumption and supply up to 60 % of the total load on sunny weekends. In
Germany household grid parity was reached in 2011. At this point, producing PV power for self-consumption is
cheaper than buying power from the utility. That is one reason why people build PV Systems for self-consumption
and feed only the surplus energy to the grid which is not used directly. Since 2012 all new installed PV systems as
well as existing systems with a power of more than 100 kW can be power-reduced by the grid operators. This study
shows the maximum possible PV capacity for Germany without reducing their power output. New PV plants should
be built close to the centres of consumption. The distribution grid is optimized when PV is higher than 130 % of local
consumption [1]. For Germany it can be estimated that up to 100 % of the load can theoretically be covered by PV for
some hours of the year. Therefore additional power export during the day and power import during the night is
unavoidable as long as there are no large scale storage systems available. This assumption was used to calculate at
which point PV systems must be power limited at the latest.
Quantum Properties of the radiation emitted by a conductor in the Coulomb Blockade Regime
Creators: name: Mora, Christophe
name: Altimiras, Carles
name: Joyez, Philippe
name: Portier, Fabien
Publisher: name: arXiv
Year: 2015
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present an input-output formalism describing a tunnel junction strongly coupled to its electromagnetic environment. We exploit it in order to investigate the dynamics of the radiation being emitted and scattered by the junction. We find that the non-linearity imprinted in the electronic transport by a properly designed environment generates strongly squeezed radiation. Our results show that the interaction between a quantum conductor and electromagnetic fields can be exploited as a resource to design simple sources of non-classical radiation.
description: 14 pages, 4 figures, includes Supplementary
From PV Systems to Energy Solutions
Creators: name: Nordmann, T.
Publisher: name: WIP
Year: 2013
Subjects: PV SYSTEMS
PV System and Grid Integration Aspects

description: 28th European Photovoltaic Solar Energy Conference and Exhibition; 3589-3593
description: With the recent economical and technical improvements of PV technology and system design
European markets, such as Germany and Italy, have reached penetration rates of PV production of 5…10% of the
overall electricity production. The development of these markets has up to date mainly been driven by Feed-in Tariffs
(FiT) and the strive for price reductions. With higher penetration rates, the PV community has to contribute to grid
integration of renewables by developing and proposing potentially successful ways to integrate PV with high
penetration rates into the existing power grid. The existing European building stock is a key-player in such an
approach. We propose the four dimensional concept “E P G M” of maximizing self-consumption exploiting different
aspects of energy and electricity use in buildings for an ecological, technical and economical post FiT concept. This
helps secure sustainable market growth and chances for future PV projects. A lot of effort is already being put in
thermal improvement of existing buildings by means of better insulation and development of components (windows,
etc). The question of electrical power use is often an issue, which is not being addressed in these existing thermal
processes. The proposed concept with four energy dimensions combines the electrical with the thermal process,
which is key to providing energy solutions.
Flow towards diagonalization for Many-Body-Localization models : adaptation of the Toda matrix differential flow to random quantum spin chains
Creators: name: Monthus, Cecile
Publisher: name: arXiv
Year: 2016
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The iterative methods to diagonalize matrices and many-body Hamiltonians can be reformulated as flows of Hamiltonians towards diagonalization driven by unitary transformations that preserve the spectrum. After a comparative overview of the various types of discrete flows (Jacobi, QR-algorithm) and differential flows (Toda, Wegner, White) that have been introduced in the past, we focus on the random XXZ chain with random fields in order to determine the best closed flow within a given subspace of running Hamiltonians. For the special case of the free-fermion random XX chain with random fields, the flow coincides with the Toda differential flow for tridiagonal matrices which is related to the classical integrable Toda chain and which can be seen as the continuous analog of the discrete QR-algorithm. For the random XXZ chain with random fields that displays a Many-Body-Localization transition, the present differential flow should be an interesting alternative to compare with the discrete flow that has been proposed recently to study the Many-Body-Localization properties in a model of interacting fermions (L. Rademaker and M. Ortuno, Phys. Rev. Lett. 116, 010404 (2016)).
description: 24 pages
A review of new and existing non-extractive techniques for monitoring marine protected areas
Creators: name: McGeady, Ryan
name: Runya, Robert M.
name: Dooley, James S.G
name: Fox, Clive J.
name: Wheeler, Andrew J.
name: Summers, Gerard
name: Callaway, Alexander
name: Beck, Suzanne
name: Brown, Louise S.
name: DOOLY, GERARD
name: McGonigle, Chris
Publisher: name: University of Limerick
Year: 2023
Subjects: classificationCode: 410305
subject: Environmental marine biotechnology

description: Ocean biodiversity loss is being driven by several anthropogenic threats and significant efforts are required to halt losses and promote healthy marine ecosystems. The establishment of a network of Marine Protected Areas (MPAs) can help restrict damaging activities and have been recognised as a potential solution to aid marine conservation. When managed correctly they can deliver both ecological and socio-economic benefits. In recent times, MPA designations have increased rapidly while many countries have set future MPA targets for the decades ahead. An integral element of MPA management is adequate monitoring that collects data to assess if conservation objectives are being achieved. Data acquired by monitoring can vary widely as can the techniques employed to collect such data. Ideally, non-destructive and non-invasive methods are preferred to prevent damage to habitats and species, though this may rule out a number of traditional extractive sampling approaches such as dredges and trawls. Moreover, advances in ocean observation technologies enable the collection of large amounts of data at high resolutions, while automated data processing is beginning to make analyses more logistically feasible and less time-consuming. Therefore, developments to existing marine monitoring techniques and new emerging technologies have led to a diverse array of options when choosing to implement an MPA monitoring programme. Here, we present a review of new and existing non-extractive techniques which can be applied to MPA monitoring. We summarise their capabilities, applications, advantages, limitations and possible future developments. The review is intended to aid MPA managers and researchers in determining the suitability of available monitoring techniques based on data requirements and site conditions
On the shape of dark matter halos from MultiDark Planck simulations
Creators: name: Vega-Ferrero, Jesús
name: Yepes, Gustavo
name: Gottlöber, Stefan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The halo shape plays a central role in determining important observational properties of the haloes such as mass, concentration and lensing cross-sections. The triaxiality of lensing galaxy clusters has a substantial impact on the distribution of the largest Einstein radii, while weak lensing techniques are sensitive to the intrinsic halo ellipticity. In this work, we provide scaling relations for the shapes of dark matter haloes as a function of mass (peak height) and redshift over more than four orders of magnitude in halo masses, namely from $10^{11.5}$ to $10^{15.8}~h^{-1}~$M$_\odot$. We have analysed four dark matter only simulations from the MultiDark cosmological simulation suite with more than 56 billion particles within boxes of 4.0, 2.5, 1.0 and 0.4 $h^{-1}$Gpc size assuming \textit{Planck} cosmology. The dark matter haloes have been identified in the simulations using the {\sc rockstar} halo finder, which also determines the axis ratios in terms of the diagonalization of the inertia tensor. In order to infer the shape for a hypothetical halo of a given mass at a given redshift, we provide fitting functions to the minor-to-major and intermediate-to-major axis ratios as a function of the peak height.
description: Accepted for publication in MNRAS (14 pages, 13 figures). The ROCKSTAR outputs used in this paper are available at https://www.cosmosim.org/cms/simulations/data/
Unitarity Constraints on non-minimal Universal Extra Dimensional Model
Creators: name: Jha, Tapoja
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We examine the unitarity constraints in gauge and scalar sectors of non-minimal Universal Extra Dimensional model. We show that some of the tree-level two-body scattering amplitudes in gauge and scalar sectors do not respect partial wave unitarity. Unitarity analysis of this model leads to an upper bound on corresponding boundary-localized (BLT) parameter which depends on the maximum number of Kaluza-Klein (KK) mode considered in the analysis. This upper bound of the relevant BLT parameter decreases with the increasing KK-modes. The results are, in effect, independent of the inverse of compactifiaction radius. The upper bound on BLT parameter also results in a lower bound on gauge and scalar KK-masses.
description: 40 pages, 11 figures and 3 tables; added new discussions and figures; typos fixed; references added; matches published version
A Comprehensive Study of Photovoltaic Power Generation Forecasts in Multiple Locations in Japan
Creators: name: Fonseca Jr., J.G.S.
name: Oozeki, T.
name: Ohtake, H.
name: Shimose, K.-I.
name: Takashima, T.
name: Ogimoto, K.
Publisher: name: WIP
Year: 2013
Subjects: PV SYSTEMS
PV System and Grid Integration Aspects

description: 28th European Photovoltaic Solar Energy Conference and Exhibition; 3601-3606
description: The objective of this study is to characterize one-day-ahead forecasts of power generated by nonresidential
PV systems in Japan. One year of forecasts of PV power generation were done for 756 systems installed in
all main regions of Japan. Furthermore, different examples of PV systems regarding cell types, conversion
efficiencies, and installation conditions were included in the set to make the analysis as general as possible. A support
vector regression algorithm, weather forecast data and past measured PV power generation were used to make the
forecasts. The annual results show that for the non-residential PV systems studied, the average error RMSEa,
expressed as the RMSE normalized by the systems’ annual average power generation, was 0.505 kWh/kWhavg, and
92.5% of the PV systems had an RMSEa lower than 0.6 kWh/kWhavg. On the other hand, the location of the PV
systems affected the forecast performance, as systems installed in Hokkaido or in Tohoku regions, usually had an
RMSEa 26% and 12% higher than the national average. Finally, some factors that caused forecasts with high errors
were identified and they show some limitations of the forecast method. Among these factors are PV systems with
modules installed in tilt angles higher than 40 degrees, and low accuracy of the weather forecast data used as input of
the forecasts.
The Integration of VRE in the Italian Power System: The Over Generation Phenomena and Market-Coupling Effects
Creators: name: Sommantico, G.
name: Elia, E.
name: Portoghese, P.
name: Venturini, A.
Publisher: name: WIP
Year: 2013
Subjects: PV SYSTEMS
PV System and Grid Integration Aspects

description: 28th European Photovoltaic Solar Energy Conference and Exhibition; 3576-3582
description: During the last years Italy has experienced a strong increase in distributed generation from Variable Renewable
Energy (VRE). The recent wide penetration of wind and photovoltaic power plants may produce a surplus in
generation which is not balanceable compared to the local or national electricity demand. The Over Generation (OG)
phenomena characterizes several bottom-load situations and it is expected to be even more frequent in the next future.
This paper has the aim to investigate the OG issue within the Italian power system with reference to a mid-term
horizon. According to this purpose, the studies performed – through the market simulator PROMED – demonstrate
how both the achievement of market-coupling frameworks – following the approval of the Third Energy Package –
and the optimization of Pumped-Storage Hydroelectric (PSH) management, are going to significantly affect the
power system reducing the overall OG. As a consequence, a more-efficient and sustainable integration of VRE
generation – in particular wind and photovoltaic – could be achieved in the next future.
Spectral Sensitivity Analyses of Tandem Modules Using Standard Flasher and Dynamic LED Backlight
Creators: name: Schär, D.
name: Baumgartner, F.P.
Publisher: name: WIP
Year: 2013
Subjects: COMPONENTS FOR PV SYSTEMS
Standardisation as Tool for Innovation and Cost Reduction

description: 28th European Photovoltaic Solar Energy Conference and Exhibition; 3532-3535
description: As the solar spectra are changing during the day, seasons and weather conditions, the accurate annual
energy rating has to be based not only on the nominal power at Standard Test Conditions STC but also on the
sensitivity of power versus spectrum. The aim of the work is to measure the spectral sensitivity of tandem modules
within the current/voltage scan. A standard industrial flasher was used to measure amorphous / microcrystalline (a-
Si/uc-Si) tandem modules. This system was equipped with a special developed dynamic LED backlight at ZHAW.
Test samples were analyzed using different shapes of dynamic backlight superposing the standard flasher STC
spectra. The change of the LED backlight in the millisecond regime according to triangular, rectangular and
sinusoidal shapes were applied. The analyzes were manly performed on a-Si/uc-Si tandem modules (1.1m x 1.3m). A
triangle backlight characteristic was applied, increasing the IR LED light from 0% to 7% of ISC of the crystalline
Silicon reference cell. Immediately after that period of 1.25ms, the IR LEDs are turned off and the blue LED decay
from again 7% of ISC to 0% remaining on top of the STC spectra. This analysis shows significantly different spectral
sensitivity at this specific time of changing from IR to blue. On the one hand the current of the module at maximum
power point (MPP) changes proportionally with the IR intensity increase. On the other hand the tandem module’s
short circuit current shows no significant changes at the same IR intensity variation. The same method of analyzes are
applied to a-Si/uc-Si tandem modules operating during 4 months and 34 months respectively, under real outdoor
conditions. It is evident that this outdoor degraded modules show only marginal changes of the module current at
MPP for the same increase of this dynamic IR LED backlight. Thus, a method together with the setup is presented
and confirmed to measure the state of degradation of this kind of tandem module during the flasher period of a few
milliseconds. The use of the presented dynamic LED backlight has the potential, in the industrial module production
process, to improve the output of a standard STC flash during several milliseconds by providing information about
the current matching of top and bottom tandem cells on a module scale.
Determining of Reflection and Glare Caused by Reflected Sunlight on PV Modules Surfaces at PV Systems
Creators: name: Herz, M.
name: Sepanski, A.
name: Nixdorf, I.
name: Reuter, M.
name: Reil, F.
name: Herrmann, W.
Publisher: name: WIP
Year: 2013
Subjects: PV SYSTEMS
PV System and Grid Integration Aspects

description: 28th European Photovoltaic Solar Energy Conference and Exhibition; 3607-3609
description: The specially developed software calculates for a specific location the reflections of photovoltaic
systems with a particular fix mounted orientation and displays them graphically for all directions and for all days
during a whole year. The sun's position and the reflected rays of the sun can be presented both in Polar and Cartesian
coordinates to detect intersections with the position of objects in the neighborhood. Another graph shows the duration
of the reflected radiation within a year. So it can be determined how long in a certain range, reflections of a
photovoltaic system occur and if given limits are exceeded. For these calculations the height profile of the hazard area
can be imported to facilitate the detection of precise glare times.
Towards a Fully LED-Based Solar Simulator - Spectral Mismatch Considerations
Creators: name: Plyta, F.
name: Betts, T.R.
name: Gottschalg, R.
Publisher: name: WIP
Year: 2013
Subjects: COMPONENTS FOR PV SYSTEMS
Standardisation as Tool for Innovation and Cost Reduction

description: 28th European Photovoltaic Solar Energy Conference and Exhibition; 3496-3499
description: LED solar simulators have a high potential for high quality characterisation of solar cells. One of the
main challenges is to achieve a close spectral match to the AM1.5 solar spectrum from 350nm to 1300nm. The main
sources of measurement uncertainty are the spectral mismatch, the non-uniformity of light and the reference cell. The
spectral mismatch can increase the measurement uncertainty significantly. In order to minimize a major uncertainty
factor a close spectral match needs to be acquired. It will be shown that the usage of LEDs, which are narrow
wavelength emitting light sources, can improve the measurement accuracy of the solar simulator by accurately
matching the solar spectrum. The process of choosing the best combination of wavelengths and the LED population
per wavelength is a complex, dual optimization problem. This paper evaluates the optimisation algorithms chosen and
examines the influence of different fitness functions in acquiring a Class A+ spectral match.
Generalized Wick theorems in conformal field theory and the Borcherds identity
Creators: name: Takagi, Taichiro
name: Yoshikawa, Takuma
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: As a counterpart of the well-known generalized Wick theorem by Bais et. al. in 1988 for interacting fields in two dimensional conformal field theory, we present a new contour integral formula for the operator product expansion of a normally ordered operator and a single operator on its right hand. Quite similar to the original Wick theorem for the opposite order operator product, it expresses the contraction i.e.the singular part of the operator product expansion as a contour integral of only two terms, each of which is a product of a contraction and a single operator. We discuss the relation between these formulas and the Borcherds identity satisfied by the quantum fields associated with the theory of vertex algebras.
description: 28 pages
Symmetries of second order differential equations on Lie algebroids
Creators: name: Popescu, Liviu
Publisher: name: arXiv
Year: 2016
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 17B66, 34A26, 53C05, 70S10

description: In this paper we investigate the relations between semispray, nonlinear connection, dynamical covariant derivative and Jacobi endomorphism on Lie algebroids. Using these geometric structures, we study the symmetries of second order differential equations in the general framework of Lie algebroids.
description: Section 4 revised, Journal of Geometry and Physics, 2017. arXiv admin note: text overlap with arXiv:1302.5212
Area-width scaling in generalised Motzkin paths
Creators: name: Haug, Nils
name: Prellberg, Thomas
name: Siudem, Grzegorz
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Combinatorics (math.CO)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We consider a generalised version of Motzkin paths, where horizontal steps have length $\ell$, with $\ell$ being a fixed positive integer. We first give the general functional equation for the area-length generating function of this model. Using a heuristic ansatz, we derive the area-length scaling behaviour in terms of a scaling function in one variable for the special cases of Dyck, (standard) Motzkin and Schröder paths, before generalising our approach to arbitrary $\ell$. We then derive an expression for the generating function of Schröder paths and analyse the scaling behaviour of this function rigorously in the vicinity of the tri-critical point of the model by applying the method of steepest descents for the case of two coalescing saddle points. Our results show that for Dyck and Schröder paths, the heuristic scaling ansatz reproduces the rigorous results.
description: 20 pages, 3 figures
Interactive Software for Parameters Identification of Forward/Reverse Bias I-V Characteristics of PV Modules
Creators: name: Saigaa, D.
name: Drif, M.
name: Bouchelaghem, A.
name: Pérez-Higueras, P.J.
name: Aguilera Tejero, J.
Publisher: name: WIP
Year: 2013
Subjects: COMPONENTS FOR PV SYSTEMS
Standardisation as Tool for Innovation and Cost Reduction

description: 28th European Photovoltaic Solar Energy Conference and Exhibition; 3549-3551
description: Designers of photovoltaic (PV) systems, in particularly those operating under partially shaded insolation
conditions such as: grid-connected building integrated photovoltaic systems (GC-BIPV) need a reliable tool to estimate
energy production from PV modules before and after their installation. In this paper, interactive software under Labview
for extracting the electrical parameters of photovoltaic modules has been developed.
A general implicit model has been used in order to identify the usual five parameters (Iph, Io, Rs, Rsh, and m) from the
forward measured I-V curve, however, an expression describing PV cells operation in reverse bias by using Bishop
model has been used in order to identify the three parameters (a, n and Vbr) of measured I-V curve on a cell under
darkness. In addition, a technique for behavior simulation of PV modules partially shaded was introduced.
Development of Test Procedures for Flexible PV Modules
Creators: name: Geyer, D.
name: Hummel, S.
name: Lechner, P.
name: Mohring, H.-D.
Publisher: name: WIP
Year: 2013
Subjects: COMPONENTS FOR PV SYSTEMS
Standardisation as Tool for Innovation and Cost Reduction

description: 28th European Photovoltaic Solar Energy Conference and Exhibition; 3519-3522
description: Flexible photovoltaic (PV) modules based on both thin film technologies and membrane modules with crystalline cells do
not contain glass panes in contrast to conventional PV modules. Their main application is building integration. Especially
during installation and maintenance mechanical stresses can occur due to stretching, bending or impacting of the flexible PV
modules. These kinds of loads cannot arise to stiff PV modules with glass panes. The possible resulting defects can affect
electrical safety or power rating although they withstand the tests as demanded in the existing PV standard IEC 61215 and
IEC 61646 as well as the safety standard IEC 61730. The special properties of flexible modules are not yet taken into
account by the existing standards.
Mandatory test standards regarding the mechanical load of flexible PV modules can ensure high quality and safety of these
products in this market segment. Furthermore imperative tests help to avoid a bad reputation due to unreliable products.
For the load cases described above which can only occur at flexible modules, relevant stress tests regarding intrusion and
bending could be developed including parameters and analytical methods.
The project results can serve as base for an amendment of the above mentioned standards.
Charges in nonlinear higher-spin theory
Creators: name: Didenko, V. E.
name: Misuna, N. G.
name: Vasiliev, M. A.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Nonlinear higher-spin equations in four dimensions admit a closed two-form that defines a gauge-invariant global charge as an integral over a two-dimensional cycle. In this paper we argue that this charge gives rise to partitions depending on various lower- and higher-spin chemical potentials identified with modules of topological fields in the theory. The vacuum contribution to the partition is calculated to the first nontrivial order for a solution to higher-spin equations that generalizes AdS4 Kerr black hole of General Relativity. The resulting partition is non-zero being in parametric agreement with the ADM-like behavior of a rotating source. The linear response of chemical potentials to the partition function is also extracted. The explicit unfolded form of 4d GR black holes is given. An explicit formula relating asymptotic higher-spin charges expressed in terms of the generalized higher-spin Weyl tensor with those expressed in terms of Fronsdal fields is obtained.
description: 23 pages; V3: typos corrected; references and acknowledgement added; example of the topological contribution to spin-4 charge added; new Section 3.1 added establishing relation of our construction for asymptotic charges with the canonical one. Version published in JHEP
New realizations of modular forms in Calabi-Yau threefolds arising from $ϕ^4$ theory
Creators: name: Logan, Adam
Publisher: name: arXiv
Year: 2016
Subjects: subject: Number Theory (math.NT)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14J32, 11F11, 11F23, 14E15, 81Q30

description: It has been found experimentally by Brown and Schnetz that the number of points over ${\mathbb F}_p$ of a graph hypersurface is often related to the coefficients of a modular form. In this paper I prove this relation for one example of a modular form of weight $4$ and two of weight $3$, refine the statement and suggest a method of proving it for four more of weight $4$, and use the one proved example to construct two new rigid Calabi-Yau threefolds that realize Hecke eigenforms of weight $4$ (one provably and one conjecturally).
description: Brief note added in separate file, indicating that a condition on which one of the results depends can now be removed, also, journal reference and DOI added. Main file unchanged
Topological quantum phase transitions in a Majorana chain with spatial modulation
Creators: name: Ohta, Takumi
name: Totsuka, Keisuke
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We numerically study the quantum phase transitions and the stability of Majorana zero modes in a generalized Kitaev model in one dimension when the chemical potential is periodically modulating in space. By using the exact diagonalization method for open boundary condition, we investigate the ground-state phases in terms of the non-local properties such as the entanglement spectrum (ES) and the string correlation functions. When we vary the phase of the modulation, the number of the Majorana zero modes changes, which manifests itself in the degeneracy of the lowest level of the ES. Next, we study the quantum phase transitions driven by the change in the amplitude of the modulation. In particular, for certain values of the wave number and the phase of the modulation, we observe a quantum phase transition from one topological phase into another where the string correlation function oscillates in space. We also show a case where the degeneracy of the ES does not change even for large enough amplitude of the modulation. Finally, we characterize the phases of the system with periodic boundary condition by the topological invariant, which reflects the number of the zero-energy excitations.
description: 8 pages, 8 figures
A New Algorithm for Determining I-V Characteristics of Partially Shaded Photovoltaic Modules
Creators: name: Drif, M.
name: Saigaa, D.
name: Pérez-Higueras, P.J.
name: Aguilera Tejero, J.
Publisher: name: WIP
Year: 2013
Subjects: COMPONENTS FOR PV SYSTEMS
Standardisation as Tool for Innovation and Cost Reduction

description: 28th European Photovoltaic Solar Energy Conference and Exhibition; 3523-3526
description: Partial shading of solar cell modules can cause two principal effects: extrinsically, it leads to reduction of
incident solar irradiance and consequently a reduction in power production; and intrinsically, the inhomogeneous
irradiance on the PV surface may cause electrical mismatch and even hot spots particularly for no bypassed modules.
Knowledge of I-V characteristics of PV modules under shadow condition enables accurate calculations of the energy
production.
In this paper, a new method for determining I-V characteristics of partially shaded PV modules is proposed. This method
is based on the well-known three quadrant model developed by J. Bishop. The authors have developed a new algorithm
for calculating the actual electrical parameters from a few standard conditions parameters which given by the
manufacturer. Also, we have proposed a general solar cells interconnection making-up commercial PV modules.
The aim of this paper is to present the principles of the proposed method and the algorithm used for determining the I-V
curve for on a shaded PV module incorporating bypass diodes. In addition, the results of the comparison between the
simulated and real values of this method are presented.
Solar Tracker in Tomsk
Creators: name: Okhorzina, A.
name: Yurchenko, A.V.
name: Kitaeva, M.
Publisher: name: WIP
Year: 2013
Subjects: COMPONENTS FOR PV SYSTEMS
Balance of System Components

description: 28th European Photovoltaic Solar Energy Conference and Exhibition; 3452-3454
description: In the paper, closed-loop and open-loop types of solar tracking have been compared. Estimation of
efficiency of single-axis and two-axis tracking has been presented. Closed-loop tracking system has been created. This
tracker is powered with PV module oriented with the same tracker. Required accuracy of orientation has been determined
experimentally.
The results of the system in Tomsk (Western Siberia) have been performed. The power gain by using tracking systems
during the year has been analyzed. The calculated results for the tracking systems effectiveness in some Russian cites
have been presented.
Agreement dynamics on directed random graphs
Creators: name: Lipowski, Adam
name: Lipowska, Dorota
name: Ferreira, Antonio L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We examine some agreement-dynamics models that are placed on directed random graphs. In such systems a fraction of sites $\exp(-z)$, where $z$ is the average degree, becomes permanently fixed or flickering. In the Voter model, which has no surface tension, such zealots or flickers freely spread their opinions and that makes the system disordered. For models with a surface tension, like the Ising model or the Naming Game model, their role is limited and such systems are ordered at large~$z$. However, when $z$ decreases, the density of zealots or flickers increases, and below a certain threshold ($z\sim 1.9-2.0$) the system becomes disordered. On undirected random graphs agreement dynamics is much different and ordering appears as soon the graph is above the percolation threshold at $z=1$.
description: 7 pages, J. Stat. Mech. (in press)
Sphericons and D-forms: a crocheted connection
Creators: name: Seaton, Katherine A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: History and Overview (math.HO)
subject: FOS: Mathematics
subject: 97M80

description: Sphericons and D-forms are 3D objects created and described by artists, which have separately received attention in the mathematical literature in the last 15 or so years. The attempt to classify a seamed, crocheted form geometrically led to the observation, which appears not to have been previously made explicit, that these objects are related. General results concerning $(N,k)$-icons and seam-, D- and pita-forms are given. Instructions to crochet D-forms are given in the Appendix.
description: 11 pages, 12 figures; submitted to Journal of Mathematics and the Arts; Revised version uploaded June 15, 2016 Revised version of Jan 6, 2017 contains 17 figures and 14 pages; Further revision (as accepted by Journal) uploaded March 2017
Taming the Noise in Reinforcement Learning via Soft Updates
Creators: name: Fox, Roy
name: Pakman, Ari
name: Tishby, Naftali
Publisher: name: arXiv
Year: 2015
Subjects: subject: Machine Learning (cs.LG)
subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: Model-free reinforcement learning algorithms, such as Q-learning, perform poorly in the early stages of learning in noisy environments, because much effort is spent unlearning biased estimates of the state-action value function. The bias results from selecting, among several noisy estimates, the apparent optimum, which may actually be suboptimal. We propose G-learning, a new off-policy learning algorithm that regularizes the value estimates by penalizing deterministic policies in the beginning of the learning process. We show that this method reduces the bias of the value-function estimation, leading to faster convergence to the optimal value and the optimal policy. Moreover, G-learning enables the natural incorporation of prior domain knowledge, when available. The stochastic nature of G-learning also makes it avoid some exploration costs, a property usually attributed only to on-policy algorithms. We illustrate these ideas in several examples, where G-learning results in significant improvements of the convergence rate and the cost of the learning process.