cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Using Accelerated Tests and Field Data to Predict Module Reliability and Lifetime
Creators: name: Wohlgemuth, J.H.
name: Cunningham, D.
name: Amin, D.
name: Shaner, J.
name: Xia, Z.
name: Miller, J.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Components for PV Systems
PV Modules

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2663-2669
description: This paper discusses how BP Solar utilizes long term module exposure data, field return data and accelerated stress tests to determine module lifetimes, expected failure rates and to identify failure mechanisms. A small number of modules have been deployed outdoors for long time periods with periodic measurements of performance in order to establish degradation rates. Field returns are reviewed for both overall return rates and to identify the failure mechanism that caused the return. Accelerated stress tests are utilized to evaluate commercial products and all new materials, processes and designs against known failure mechanisms.
In order to ensure the 25 year warranty offered on most crystalline silicon products, BP Solar has designed an extended accelerated test sequence. This paper presents results of this test sequence as applied to BP Solar modules as well as to modules from nine other PV manufacturers.
98.8% Inverter Efficiency With SiC Transistors
Creators: name: Burger, B.
name: Goeldi, B.
name: Kranzer, D.
name: Schmidt, H.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Components for PV Systems
Balance of System Components

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2688-2692
description: Modern single-phase inverter circuits such as HERIC® from Sunways or H5 from SMA already
achieve efficiencies of 98%. A further increase in the efficiency seemed difficult until recently, while the
development of Silicon (Si) power transistors showed comparatively slow progress and every new transistor line is
more specialised. There are now transistors from several manufacturers that are optimised for various switching
frequencies at the expense of conduction losses. Transistors with low switching losses have a high forward voltage
drop and vice versa. A leap in technology that promised low switching and conduction losses was not foreseeable
and so increases in efficiency of only 10ths of a percent were expected. Now first laboratory samples of silicon
carbide (SiC) MOSFETs, JFETs and bipolar transistors (BJTs) are available. They show quite good On-state and
switching behaviour, so that big increases in inverter efficiency are now possible [2], [3], [4].
Finite type modules and Bethe Ansatz for quantum toroidal gl(1)
Creators: name: Feigin, B.
name: Jimbo, M.
name: Miwa, T.
name: Mukhin, E.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Algebra (math.QA)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We study highest weight representations of the Borel subalgebra of the quantum toroidal gl(1) algebra with finite-dimensional weight spaces. In particular, we develop the q-character theory for such modules. We introduce and study the subcategory of `finite type' modules. By definition, a module over the Borel subalgebra is finite type if the Cartan like current ψ^+(z) has a finite number of eigenvalues, even though the module itself can be infinite dimensional. We use our results to diagonalize the transfer matrix T_{V,W}(u;p) analogous to those of the six vertex model. In our setting T_{V,W}(u;p) acts in a tensor product W of Fock spaces and V is a highest weight module over the Borel subalgebra of quantum toroidal gl(1) with finite-dimensional weight spaces. Namely we show that for a special choice of finite type modules $V$ the corresponding transfer matrices, Q(u;p) and T(u;p), are polynomials in u and satisfy a two-term TQ relation. We use this relation to prove the Bethe Ansatz equation for the zeroes of the eigenvalues of Q(u;p). Then we show that the eigenvalues of T_{V,W}(u;p) are given by an appropriate substitution of eigenvalues of Q(u;p) into the q-character of V.
description: Latex 42 pages
IGraph/M: graph theory and network analysis for Mathematica
Creators: name: Horvát, Szabolcs
name: Podkalicki, Jakub
name: Csárdi, Gábor
name: Nepusz, Tamás
name: Traag, Vincent
name: Zanini, Fabio
name: Noom, Daniel
Publisher: name: arXiv
Year: 2022
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Mathematical Software (cs.MS)
subject: Combinatorics (math.CO)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: IGraph/M is an efficient general purpose graph theory and network analysis package for Mathematica. IGraph/M serves as the Wolfram Language interfaces to the igraph C library, and also provides several unique pieces of functionality not yet present in igraph, but made possible by combining its capabilities with Mathematica's. The package is designed to support both graph theoretical research as well as the analysis of large-scale empirical networks.
description: submitted to Journal of Open Source Software on August 30, 2022
Wakkanai Mega-Solar Project 1-Year Result
Creators: name: Miwa, S.
name: Matsuno, N.
name: Ito, T.
name: Hara, R.
name: Kita, H.
name: Matsuoka, N.
name: Taira, K.
Publisher: name: WIP-Munich
Year: 2008
Subjects: PV Systems
Grid-connected Applications

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 3234-3235
description: The New Energy and Industrial Technology Development Organization (NEDO) selected Japanese northernmost city of Wakkanai to the verification site of “Verification of Grid Stabilization with Large-scale PV Power Generation” which is sponsored in 2006. We collected more than one-year data of 1st stage 80kW PVs. In addition, the operation of 2MW PV and 500kW NAS battery began in March 2008, and PV output fluctuation suppression technology is examined. This paper reports on current study results of Wakkanai mega-solar project.
Preliminary Results of the "Conto Energia" Monitoring Programme
Creators: name: Castello, S.
name: De Lillo, A.
name: De Lia, F.
name: Lato, C.
name: Trezza, F.
Publisher: name: WIP-Munich
Year: 2008
Subjects: PV Systems
Grid-connected Applications

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 3245-3248
description: ENEA (Italian National Agency for New Technologies, Energy and the Environment) is carrying out, in the framework of an agreement with the GSE (Manager of the Electric Services) the monitoring of the “Conto energia” Programme. The activities have been articulated in three main lines. The first one, aimed at evaluating the Programme trend, consists in the analysis of the technical and economic data of all the plants installed and put in operation. Up to now, the data of about 10,000 plants have been analysed. Detailed plant performance evaluation is the objective of the second line of the agreement. Activities are based on a standard measurement programme. Operational data of a sample of 25 plants, representing the most significant plant typology and module technology will be collected and analysed in order to evaluate the most significant index of performance such as yields, efficiencies and performance ratio. The third activity line of the agreement is aimed to check the status of the Italian photovoltaic industry and research. In particular each operator is classified according to the capacity and the real production, the characteristics of the products, the process phases and the raw materials used as well as prices and import export data.
Evolution of Residual Stress and its Relation to Microstructure in Multicrystalline Silicon Thin Film Solar Cells on Glass Prepared by Combined Laser Crystallization and Solid Phase Epitaxy
Creators: name: Sarau, G.
name: Becker, M.
name: Bochmann, A.
name: Gawlik, A.
name: Andrä, G.
name: Christiansen, S.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Thin Films Solar Cells
Thin Film Crystalline Silicon Solar Cells and Wafer Equivalents

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 2494-2499
description: Stress engineering in thin film solar cells on foreign substrates represents an important manufacturing issue to
prevent cracking or peeling off the film or even substrate warpage resulting in an increased breakage risk and processing
difficulties. Moreover, stresses relax by generating recombination active extended defects such as dislocations and grain
boundaries that first of all reduce the efficiency and secondly induce very locally stress concentrations that reduce the
mechanical stability of the solar cells. A new process based on a combination of laser crystallization of an amorphous silicon
seed layer and epitaxial thickening of the seed layer by solid phase crystallization is being explored. Indeed, we measure by
micro-Raman spectroscopy local stress concentrations including both compressive and tensile contributions inside grains and
at grain boundaries in the laser crystallized seed layer. We attribute these stresses to particular defect
configurations/structures since they do not correlate with both the misorientation inside grains and the low angle grain
boundaries determined by electron backscatter diffraction. In most cases, the local stress concentrations in the seed layer are
found to relax, presumably by structural rearrangements, during the solid phase epitaxy process. The structural evolution
with respect to extended defect formation and stress built up during processing will be discussed.
Lithium-Ion Batteries in PV Off-Grid Systems: Comparison of 3 Battery Systems and their Effects on System Efficiency
Creators: name: Perrin, M.
name: Haupt, H.
name: Bärwaldt, G.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Components for PV Systems
Engineering and System Integration

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2774-2776
description: In PV off-grid systems energy storage is a key factor for maintaining system operability. Lithium-Ion Batteries offer an alternative to commonly used Lead-Acid Batteries with promising properties such as a high energy
density, high cell efficiency and high lifetime expectation. Nevertheless their impact on the system performance of an existing off-grid system remains questionable. Ambiguous effects on the system-efficiency could occur, mainly due to a necessary additional Battery Management Systems (BMS) and a difference in voltage levels. While neglect able in larger-scaled energy supply systems, the consumption of the BMS can play a major role influencing the system efficiencyof small PV based systems. A reduced system performance could lead to a limited benefit from the promising properties. Aiming at an energy supply system for a small remote satellite telecommunications system, three Lithium-Ion and one Lead-Acid Battery System are examined in order to find the most promising system set-up of components for a prototype of the energy supply system. To achieve this they are examined regarding cell efficiency, self-consumption and BMS consumption. Based on these findings, the system performance for the different solutions is compared.
Tensor classification of structure in smoothed particle hydrodynamics density fields
Creators: name: Forgan, Duncan
name: Bonnell, Ian
name: Lucas, William
name: Rice, Ken
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: As hydrodynamic simulations increase in scale and resolution, identifying structures with non-trivial geometries or regions of general interest becomes increasingly challenging. There is a growing need for algorithms that identify a variety of different features in a simulation without requiring a "by-eye" search. We present tensor classification as such a technique for smoothed particle hydrodynamics (SPH). These methods have already been used to great effect in N-Body cosmological simulations, which require smoothing defined as an input free parameter. We show that tensor classification successfully identifies a wide range of structures in SPH density fields using its native smoothing, removing a free parameter from the analysis and preventing the need for tesselation of the density field, as required by some classification algorithms. As examples, we show that tensor classification using the tidal tensor and the velocity shear tensor successfully identifies filaments, shells and sheet structures in giant molecular cloud simulations, as well as spiral arms in discs. The relationship between structures identified using different tensors illustrates how different forces compete and co-operate to produce the observed density field. We therefore advocate the use of multiple tensors to classify structure in SPH simulations, to shed light on the interplay of multiple physical processes.
description: 14 pages, 28 figures, accepted for publication in MNRAS
A New Tool to Measure Monolithic Multi Junction Solar Cells With Up to Six Subcells
Creators: name: Schachtner, M.
name: Hoheisel, R.
name: Sabuncuoglu, F.
name: Siefer, G.
name: Bett, A.W.
name: Darou, S.
name: Spinner, D.
Publisher: name: WIP
Year: 2011
Subjects: Advanced Photovoltaics : New Concepts and Ultra-High Efficiency
Solar Cells, Modules and PV Systems for Space Applications

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 199-204
description: New monolithic multi-junction cell concepts with more than three subcells are a challenge for a precise
light IV-curve characterization. The available sun simulator tools are not suitable for the characterization of these
devices. Therefore, a new six channel sun simulator was set up to measure and characterize monolithic solar cells
with up to six subcells. This paper presents main benchmark data of the new simulator, like uniformity and spectrum.
Calibrated light IV-curves of four- and six-junction solar cells are shown.
Вестник научной мысли,Выпуск 2 2022
Creators: name: Дагестанский территориальный институт профессиональных бухгалтеров
Publisher: name: Дагестанский территориальный институт профессиональных бухгалтеров
Year: 2022

description: Вестник научной мысли,Выпуск 2 2022
Differentiable Safe Controller Design through Control Barrier Functions
Creators: name: Yang, Shuo
name: Chen, Shaoru
name: Preciado, Victor M.
name: Mangharam, Rahul
Publisher: name: arXiv
Year: 2022
Subjects: subject: Systems and Control (eess.SY)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Learning-based controllers, such as neural network (NN) controllers, can show high empirical performance but lack formal safety guarantees. To address this issue, control barrier functions (CBFs) have been applied as a safety filter to monitor and modify the outputs of learning-based controllers in order to guarantee the safety of the closed-loop system. However, such modification can be myopic with unpredictable long-term effects. In this work, we propose a safe-by-construction NN controller which employs differentiable CBF-based safety layers, and investigate the performance of safe-by-construction NN controllers in learning-based control. Specifically, two formulations of controllers are compared: one is projection-based and the other relies on our proposed set-theoretic parameterization. Both methods demonstrate improved closed-loop performance over using CBF as a separate safety filter in numerical experiments.
description: Accepted by IEEE Control Systems Letters (L-CSS)
Вестник научной мысли,Выпуск 3 2022
Creators: name: Дагестанский территориальный институт профессиональных бухгалтеров
Publisher: name: Дагестанский территориальный институт профессиональных бухгалтеров
Year: 2022

description: Вестник научной мысли,Выпуск 3 2022
Quantum embedding of multi-orbital fragments using the Block-Householder-transformation
Creators: name: Yalouz, Saad
name: Sekaran, Sajanthan
name: Fromager, Emmanuel
name: Saubanère, Matthieu
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Recently, some of the authors introduced the use of the Householder transformation as a simple and intuitive method for the embedding of local molecular fragments (see Sekaran et. al., Phys. Rev. B 104, 035121 (2021), and Sekaran et. al., Computation 10, 45 (2022)). In this work, we present an extension of this approach to the more general case of multi-orbital fragments using the block version of the Householder transformation applied to the one-body reduced density matrix, yet unlocking the applicability to general quantum chemistry/condensed-matter physics Hamiltonians. A step by step construction of the Block-Householder transformation is presented. Both physical and numerical interest of the approach are highlighted. The specific mean-field (non-interacting) case is thoroughly detailed as it is shown that the embedding of a given $N$ spin-orbitals fragment leads to the generation of two separated sub-systems: a $2N$ spin-orbitals "fragment+bath" cluster that exactly contains $N$ electrons, and a remaining cluster's "environment" which is described by so-called core electrons. We illustrate the use of this transformation in different cases of embedding {scheme} for practical applications. We particularly focus on the extension of the previously introduced Local Potential Functional Embedding Theory (LPFET) and Householder-transformed Density Matrix Functional Embedding Theory (Ht-DMFET) to the case of multi-orbital fragments. These calculations are realized on different types of systems such as model Hamiltonians (Hubbard rings) and \textit{ab initio} molecular systems (hydrogen rings).
A Review of kWh/kWp Measurements, Analysis and Modelling
Creators: name: Ransome, S.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Components for PV Systems
Engineering and System Integration

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2795-2800
description: kWh/kWp energy yield comparisons have been measured and modelled around the world for many years using individual modules or large arrays [1]-[7]. Most studies just publish one value of kWh energy yield over a year. Often tests disagree with each other as to which technology (e.g. c-Si or a Thin Film) or which manufacturer gives the highest yields. In their conclusions authors often attribute variations in yield to be technology related due to differences in intrinsic properties e.g. relative performance at low light levels, high angle of incidence, high diffuse fraction or high temperatures. However without analysing and reporting the raw data there is no way to determine which of several factors are the most critical to determine the final energy yield.
This paper analyses in detail a study performed by ISET on seven different technologies to determine how to tell which factors were the most important.
High Energy/Large Spot Excimer Laser for High Efficient Selective Emitters Solar Cells
Creators: name: Gall, S.
name: Lerat, J.F.
name: Emeraud, T.
name: Huet, K.
name: Boniface, C.
name: Manuel, S.
name: Paviet-Salomon, B.
name: Pirot, M.
name: Monna, R.
name: Heslinga, D.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Mono- and Multicrystalline Silicon Materials and Cells

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 1852-1854
description: Our work focuses on industrial laser doping process from phosphosilicate glass with a high energy, large spot,
pulsed UV (308nm) Excimer laser source to realize selective emitter structures. A highly homogenous process
enabling the accurate control of two different N-doped emitters by the simultaneous activation of low and highly
doped areas is demonstrated. At present, solar cells performances are limited actually by both Jsc and FF. Current
losses will be avoided by adapting the laser beam to irradiate on front contact regions only while optimized screen
printing process should solve contact resistance issue.
High Aspect Ratio Front Contacts by Single Step Dispensing of Metal Pastes
Creators: name: Specht, J.
name: Zengerle, K.
name: Pospischil, M.
name: Erath, D.
name: Haunschild, J.
name: Clement, F.
name: Biro, D.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Mono- and Multicrystalline Silicon Materials and Cells

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 1867-1870
description: A dispensing process was developed, allowing for a single step, contactless front side metallization of
silicon solar cells. Compared to screen printing, the dispensed fingers showed superior geometry, with line widths
down to 65μm across the whole wafer area and aspect ratios (height:width) of up to 0.5. Silicon solar cells were
produced using both multi- and monocrystalline (cz) material. The efficiency gain on industrial solar cells was 0.6%
absolute on multicrystalline material and 0.4% absolute on monocrystalline material, comparing the best dispensed
cell with the best screen-printed cell. The average efficiency gain of the two groups was 0.3% (mc) and 0.2% (cz).
Effect of c-Si Base Layer Thickness on Efficiency Limits of Thin – Film c-Si Solar Cells on Glass
Creators: name: Grancic, B.
name: Westra, J.
name: Zeman, M.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Thin Films Solar Cells
Thin Film Crystalline Silicon Solar Cells and Wafer Equivalents

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 2596-2600
description: Thin-film crystalline silicon (c-Si) on glass is a promising approach for low cost, high efficiency solar cells. Efficiency limits
of thin-film c-Si on glass solar cells in a heterojunction configuration were investigated by means of computer simulation
with the ASA program. Effect of c-Si base-layer thickness, minority charge-carrier life time ( ) and back contact surface recombination
velocity (SLn ) on the solar cell efficiency was investigated. Optimal thickness of the base layer was determined
with respect to base layer quality represented by  and back surface passivation quality represented by SLn. Light trapping is
an important tool for increasing of the absorption in thin c-Si base layer. In the ideal case of the c-Si base layer, high minority
lifetime of 10-4 s and low surface recombination velocity of 10 m/s, using light trapping, the efficiency of the heterojunction
solar cell with 1 m and 10 m thick base layer can achieve up to 16% and 21%, respectively.
Modelling of Light Trapping in Thin Silicon Solar Cells With Back-Side Dielectric Diffraction Grating
Creators: name: Gjessing, J.
name: Marstein, E.S.
name: Sudbø, A.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Thin Films Solar Cells
Thin Film Crystalline Silicon Solar Cells and Wafer Equivalents

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 2604-2607
description: We have designed and investigated in numerical simulations a light-trapping structure in the form of a
bi-periodic back-side diffraction grating. In addition to the grating, the light-trapping structure also includes an oxide
(SiO2) layer that separates the grating from the back-side aluminium (Al) mirror. This light-trapping structure is
expected to give a potential short-circuit current density Jsc of 35.0 mA/cm2 when put on the back side of a 20 μm
thick Si solar cell with a single layer anti-reflection coating (ARC), assuming that all electron-hole pairs are collected
at the contacts. This is an improvement of 15 % compared to a reference cell with the same thickness, a single layer
ARC and a planar back-side Al mirror. The improvement is almost exclusively confined to the wavelength range
from 800 nm to 1100 nm. We also investigate how the thickness of the Si substrate affects the light trapping
efficiency.
Spin wave study of magnetic perpendicular surface anisotropy in single crystalline MgO$\text{/}$Fe$\text{/}$MgO films
Creators: name: Solano, José
name: Gladii, Olga
name: Kuntz, Pierre
name: Henry, Yves
name: Halley, David
name: Bailleul, Matthieu
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Broadband ferromagnetic resonance is measured in single crystalline Fe films of varying thickness sandwiched between MgO layers. An exhaustive magnetic characterization of the films (exchange constant, cubic, uniaxial and surface anisotropies) is enabled by the study of the uniform and the first perpendicular standing spin wave modes as a function of applied magnetic field and film thickness. Additional measurements of non-reciprocal spin wave propagation allow us to separate each of the two interface contributions to the total surface anisotropy. The results are consistent with the model of a quasi-bulk film interior and two magnetically different top and bottom interfaces, a difference ascribed to different oxidation states.
The exceptional generalised geometry of supersymmetric AdS flux backgrounds
Creators: name: Ashmore, Anthony
name: Petrini, Michela
name: Waldram, Daniel
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We analyse generic AdS flux backgrounds preserving eight supercharges in $D=4$ and $D=5$ dimensions using exceptional generalised geometry. We show that they are described by a pair of globally defined, generalised structures, identical to those that appear for flat flux backgrounds but with different integrability conditions. We give a number of explicit examples of such "exceptional Sasaki-Einstein" backgrounds in type IIB supergravity and M-theory. In particular, we give the complete analysis of the generic AdS$_5$ M-theory backgrounds. We also briefly discuss the structure of the moduli space of solutions. In all cases, one structure defines a "generalised Reeb vector" that generates a Killing symmetry of the background corresponding to the R-symmetry of the dual field theory, and in addition encodes the generic contact structures that appear in the $D=4$ M-theory and $D=5$ type IIB cases. Finally, we investigate the relation between generalised structures and quantities in the dual field theory, showing that the central charge and R-charge of BPS wrapped-brane states are both encoded by the generalised Reeb vector, as well as discussing how volume minimisation (the dual of $a$- and $\mathcal{F}$-maximisation) is encoded.
description: 40 pages
Enhanced Photocurrent in Evaporated Solid-Phase-Crystallised Poly-Si Thin-Film Solar Cells Using Rear Surface Plasmons
Creators: name: Ouyang, Z.
name: Beck, F.
name: Kunz, O.
name: Campbell, P.
name: Catchpole, K.R.
name: Varlamov, S.
name: Pillai, S.
name: Green, M.A.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Thin Films Solar Cells
Thin Film Crystalline Silicon Solar Cells and Wafer Equivalents

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 2608-2610
description: We demonstrate enhancements in photocurrent and conversion efficiency for thin-film Si cells on glass
due to plasmonic light-trapping. In this work, silver nanoparticles were formed on the rear surface of evaporated
solid-phase-crystallised poly-Si thin-film solar cells coated with an intermediate dielectric layer. We find that
localised surface plasmon excited in nanoparticles can increase the light absorption of the Si films and thereby
enhance the spectral response and efficiency of the cells. Short-circuit current and efficiency under standard
illumination condition increased by 13% and 10% respectively compared to the same cell without surface plasmons.
This is a very important finding as evaporated Si thin-film solar cells have few options for effective light trapping
which are simple and do not harm the cell structure, like surface plasmons. Effects of different dielectric layers on
enhancement are also investigated.
Knowledge Distillation to Ensemble Global and Interpretable Prototype-Based Mammogram Classification Models
Creators: name: Wang, Chong
name: Chen, Yuanhong
name: Liu, Yuyuan
name: Tian, Yu
name: Liu, Fengbei
name: McCarthy, Davis J.
name: Elliott, Michael
name: Frazer, Helen
name: Carneiro, Gustavo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: State-of-the-art (SOTA) deep learning mammogram classifiers, trained with weakly-labelled images, often rely on global models that produce predictions with limited interpretability, which is a key barrier to their successful translation into clinical practice. On the other hand, prototype-based models improve interpretability by associating predictions with training image prototypes, but they are less accurate than global models and their prototypes tend to have poor diversity. We address these two issues with the proposal of BRAIxProtoPNet++, which adds interpretability to a global model by ensembling it with a prototype-based model. BRAIxProtoPNet++ distills the knowledge of the global model when training the prototype-based model with the goal of increasing the classification accuracy of the ensemble. Moreover, we propose an approach to increase prototype diversity by guaranteeing that all prototypes are associated with different training images. Experiments on weakly-labelled private and public datasets show that BRAIxProtoPNet++ has higher classification accuracy than SOTA global and prototype-based models. Using lesion localisation to assess model interpretability, we show BRAIxProtoPNet++ is more effective than other prototype-based models and post-hoc explanation of global models. Finally, we show that the diversity of the prototypes learned by BRAIxProtoPNet++ is superior to SOTA prototype-based approaches.
description: MICCAI 2022
Al Doped ALD ZnO for CIGS Buffer Layer
Creators: name: Baji, Z.
name: Labadi, Z.
name: Fried, M.
name: Vad, K.
name: Toth, J.
name: Barsony, I.
Publisher: name: WIP
Year: 2011
Subjects: Thin Film Solar Cells
CIS and Related Ternary and Quaternary Thin Film Solar Cells

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 2992-2997
description: Vacuum compatible deposition of a buffer layer onto CIGS is a key issue for CIGS solar cell
technology, and ALD ZnO is one of the most promising solutions. However the technology and mechanism of Al
doping of the ZnO and its effect on the device performance is not yet studied in detail. The purpose of this work is to
optimize the Al doping of ZnO buffer layer deposition using Atomic Layer Deposition (ALD) method. The
mechanism and efficiency of doping is investigated.
Solar Wings a New Lightweight PV Tracking System
Creators: name: Baumgartner, F.P.
name: Büchel, A.
name: Bartholet, R.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Components for PV Systems
Engineering and System Integration

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2790-2794
description: Solar tracking systems increase the electricity production by about 30% relative to fixed installations. A robust design of the mechanical system requiring less material than 100kg steel per kW nominal PV module power is essential to further improve the economics of PV tracker plants. The Solar Wings approach reaches this goal by using steel cables as a mounting system for the PV modules and benefits by the long-time experience of project partner BMF using steel cables in transportation systems such as ski-lift, funicular, aerial passenger lines. Tests with the first Solar Wings prototype in Switzerland passed successfully. The first 600 kW PV plant powered by the one axis Solar Wings tracking system will put into operation in December 2008 in Southern Germany. To maximize reliability and reduce maintenance costs only one electrical three-phase asynchronous motor is used to track 100kW PV modules. A two-axis tracking Solar Wings system will be available next year. Further development targets are low optical concentration by the use of planar mirrors mounted on a parallel axis to the PV module axis. PV modules and mirrors track individually and thus an increase of the electricity production of higher than 60% relative to fixed mounted installation is expected. First results of the measured increase of performance by individual tracking of the planar mirrors and the PV modules, performed on a small scale dish model, are reported.
Polynomials with rational generating functions and real zeros
Creators: name: Forgacs, Tamas
name: Tran, Khang
Publisher: name: arXiv
Year: 2016
Subjects: subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 30C15, 26C10, 11C08

description: This paper investigates the location of the zeros of a sequence of polynomials generated by a rational function with a binomial-type denominator. We show that every member of a two-parameter family consisting of such generating functions gives rise to a sequence of polynomials $\{P_{m}(z)\}_{m=0}^{\infty}$ that is eventually hyperbolic. Moreover, the real zeros of the polynomials $P_{m}(z)$ form a dense subset of an interval $I\subset\mathbb{R}^{+}$, whose length depends on the particular values of the parameters in the generating function.
Finite temperature quantum condensations in the space of states: General Proof
Creators: name: Ostilli, Massimo
name: Presilla, Carlo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We formalize and prove the extension to finite temperature of a class of quantum phase transitions, acting as condensations in the space of states, recently introduced and discussed at zero temperature~(Ostilli and Presilla 2021 \textit{J. Phys. A: Math. Theor.} \textbf{54} 055005). In details, we find that if, for a quantum system at canonical thermal equilibrium, one can find a partition of its Hilbert space $\mathcal{H}$ into two subspaces, $\mathcal{H}_\mathrm{cond}$ and $\mathcal{H}_\mathrm{norm}$, such that, in the thermodynamic limit, $\dim \mathcal{H}_\mathrm{cond}/ \dim \mathcal{H} \to 0$ and the free energies of the system restricted to these subspaces cross each other for some value of the Hamiltonian parameters, then, the system undergoes a first-order quantum phase transition driven by those parameters. The proof is based on an exact probabilistic representation of quantum dynamics at an imaginary time identified with the inverse temperature of the system. We also show that the critical surface has universal features at high and low temperatures.
description: 18 pages, 4 figures. arXiv admin note: substantial text overlap with arXiv:2203.05803
The history of stellar metallicity in a simulated disc galaxy
Creators: name: Snaith, O. N.
name: Bailin, J.
name: Gibson, B. K.
name: Bell, E. F.
name: Stinson, G.
name: Valluri, M.
name: Wadsley, J.
name: Couchman, H.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We explore the chemical distribution of stars in a simulated galaxy. Using simulations of the same initial conditions but with two different feedback schemes (MUGS and MaGICC), we examine the features of the age-metallicity relation (AMR), and the three-dimensional age-metallicity-[O/Fe] distribution, both for the galaxy as a whole and decomposed into disc, bulge, halo, and satellites. The MUGS simulation, which uses traditional supernova feedback, is replete with chemical substructure. This sub- structure is absent from the MaGICC simulation, which includes early feedback from stellar winds, a modified IMF and more efficient feedback. The reduced amount of substructure is due to the almost complete lack of satellites in MaGICC. We identify a significant separation between the bulge and disc AMRs, where the bulge is considerably more metal-rich with a smaller spread in metallicity at any given time than the disc. Our results suggest, however, that identifying the substructure in observations will require exquisite age resolution, on the order of 0.25 Gyr. Certain satellites show exotic features in the AMR, even forming a 'sawtooth' shape of increasing metallicity followed by sharp declines which correspond to pericentric passages. This fact, along with the large spread in stellar age at a given metallicity, compromises the use of metallicity as an age indicator, although alpha abundance provides a more robust clock at early times. This may also impact algorithms that are used to reconstruct star formation histories from resolved stellar populations, which frequently assume a monotonically-increasing AMR.
description: 25 pages, 14 Figures, 2 Tables. Accepted for publication in MNRAS
Hyperspectral and LiDAR data for the prediction via machine learning of tree species, volume and biomass: a possible contribution for updating forest management plans
Creators: name: Michelini, Daniele
name: Dalponte, Michele
name: Carriero, Angelo
name: Kutchart, Erico
name: Pappalardo, Salvatore Eugenio
name: De Marchi, Massimo
name: Pirotti, Francesco
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: This work intends to lay the foundations for identifying the prevailing forest types and the delineation of forest units within private forest inventories in the Autonomous Province of Trento (PAT), using currently available remote sensing solutions. In particular, data from LiDAR and hyperspectral surveys of 2014 made available by PAT were acquired and processed. Such studies are very important in the context of forest management scenarios. The method includes defining tree species ground-truth by outlining single tree crowns with polygons and labeling them. Successively two supervised machine learning classifiers, K-Nearest Neighborhood and Support Vector Machine (SVM) were used. The results show that, by setting specific hyperparameters, the SVM methodology gave the best results in classification of tree species. Biomass was estimated using canopy parameters and the Jucker equation for the above ground biomass (AGB) and that of Scrinzi for the tariff volume. Predicted values were compared with 11 field plots of fixed radius where volume and biomass were field-estimated in 2017. Results show significant coefficients of correlation: 0.94 for stem volume and 0.90 for total aboveground tree biomass.
Electronic States in Arbitrarily Shaped Quantum Dots
Creators: name: Puthen-Veetil, B.
name: König, D.
name: Patterson, R.
name: Kampwerth, H.
name: Green, M.A.
name: Conibeer, G.J.
Publisher: name: WIP
Year: 2011
Subjects: Advanced Photovoltaics : New Concepts and Ultra-High Efficiency
Fundamental Studies

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 89-92
description: Quantum Dots (QDs) are the working material in third generation photovoltaic cells, especially in all Si
tandem solar cells and energy selective contacts (ESC) for Hot Carrier Solar Cells (HC-SCs). Optical and electronic
properties of these QDs depend on their size and shape in dielectric matrix. Recently developed characterization
techniques have shown that self assembled QDs cannot be described by straightforward mathematical shapes, which
makes these calculations extremely difficult to carry out using conventional methods. We have developed an efficient
numerical model based on Full Multi Grid (FMG) methods for 3-dimensional (3-D) analysis of the electronic
properties of complex shaped QDs. The electronic states were calculated by self-consistently solving the
Schrödinger-Poisson system with Exchange interactions. The model was used on realistic QD morphologies and their
electronic states were compared with regular shapes.
A brief journey through collision models for multipartite open quantum dynamics
Creators: name: Cattaneo, Marco
name: Giorgi, Gian Luca
name: Zambrini, Roberta
name: Maniscalco, Sabrina
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The quantum collision models are a useful method to describe the dynamics of an open quantum system by means of repeated interactions between the system and some particles of the environment, which are usually termed "ancillas". In this paper, we review the main collision models for the dynamics of multipartite open quantum systems, which are composed of several subsystems. In particular, we are interested in models that are based on elementary collisions between the subsystems and the ancillas, and that simulate global and/or local Markovian master equations in the limit of infinitesimal timestep. After discussing the mathematical details of the derivation of a generic collision-based master equation, we provide the general ideas at the basis of the collision models for multipartite systems, we discuss their strengths and limitations, and we show how they may be simulated on a quantum computer. Moreover, we analyze some properties of a collision model based on entangled ancillas, derive the master equation it generates for small timesteps, and prove that the coefficients of this master equation are subject to a constraint that limits their generality. Finally, we present an example of this collision model with two bosonic ancillas entangled in a two-mode squeezed thermal state.
description: Accepted version in the special issue of Open Syst. Inf. Dyn. devoted to the memory of Prof. A. Kossakowski. We have added the current Appendix A, new references, and additional discussions on the cascade master equation
Daleel: Simplifying Cloud Instance Selection Using Machine Learning
Creators: name: Samreen, Faiza
name: Elkhatib, Yehia
name: Rowe, Matthew
name: Blair, Gordon S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: Machine Learning (cs.LG)
subject: Performance (cs.PF)
subject: FOS: Computer and information sciences

description: Decision making in cloud environments is quite challenging due to the diversity in service offerings and pricing models, especially considering that the cloud market is an incredibly fast moving one. In addition, there are no hard and fast rules, each customer has a specific set of constraints (e.g. budget) and application requirements (e.g. minimum computational resources). Machine learning can help address some of the complicated decisions by carrying out customer-specific analytics to determine the most suitable instance type(s) and the most opportune time for starting or migrating instances. We employ machine learning techniques to develop an adaptive deployment policy, providing an optimal match between the customer demands and the available cloud service offerings. We provide an experimental study based on extensive set of job executions over a major public cloud infrastructure.
description: In the IEEE/IFIP Network Operations and Management Symposium (NOMS), April 2016
A Theoretical Study of the Effect of Degradation Caused by Diffusion over a 30-Year Lifespan in c-Si PV Devices
Creators: name: Sætre, T.O.
name: Yordanov, G.H.
name: Midtgård, O.-M.
name: Odden, J.O.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Mono- and Multicrystalline Silicon Materials and Cells

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 1732-1736
description: An important issue for the crystalline Si wafer based PV industry is the performance of the cells over a life
span of 25 to 30 years. The present paper discusses the main sources of degradation with focus on the diffusion of
elements in a wafer over a 30- year period which may result in semiconductor device degradation. The possibility of
carrying out accelerated tests at elevated temperatures as a method of testing individual cells is discussed with the aid of
diffusion models.
Comprehensive Study of SiNx Ablation with High Energy Large Spot Excimer Laser Source
Creators: name: Gall, S.
name: Emeraud, T.
name: Huet, K.
name: Boniface, C.
name: Manuel, S.
name: Paviet-Salomon, B.
name: Muñoz, D.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Mono- and Multicrystalline Silicon Materials and Cells

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 1849-1851
description: Our work investigates an ablation process to remove a silicon nitride layer deposited onto a silicon
substrate by using a high energy/short wavelength laser source. Intermediary fluence regimes induce either chemical
and morphological modifications of the initial SiNx layer or its partial removal with local residues. The selective
ablation process window highlighted at higher fluence will facilitate the fabrication of advanced solar cell structures.
High Voc Crystalline Silicon Thin Film Solar Cells through Recrystallised Wafer Equivalent Applied to Sintered Silicon
Creators: name: Grau, M.
name: Blangis, D.
name: Lindekugel, S.
name: Janz, S.
name: Reber, S.
name: Straboni, A.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Thin Films Solar Cells
Thin Film Crystalline Silicon Solar Cells and Wafer Equivalents

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 2615-2618
description: Among Crystalline Silicon Thin-Films (CSiTF), the concept of Recrystallised Wafer Equivalents
(RexWE) established by Fraunhofer ISE has steadily shown high efficiencies on good quality substrates. But no
low-cost substrate has yet shown high enough results for an industrial launch of this technology. Meanwhile, the
recently created company S’TILE has developed a new approach in wafer manufacturing with Sintering of Silicon
Powders. It is a cheap process which presents among other advantages the avoiding of sawing kerf loss and the
possibility of high throughput of large area wafers. For this reason, sintered silicon wafers have been used as
substrates for RexWE.
Up to 9.2 % of efficiency was obtained on non-optimised 4 cm² solar cells with an excellent open circuit voltage of
580 mV. This Voc is the best obtained up to now with this technology with such low-cost substrates. As the RexWE
cell process used here has poor optical confinement, the efficiency is likely to dramatically improve with the
CSiTF-optimised texturisation and back reflector already developed at Fraunhofer ISE.
These very promising results may thereby open to a new lead in CSiTF and trigger some large scale manufacturing.