cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Joint Millimeter-Wave Fronthaul and OFDMA Resource Allocation in Ultra-Dense CRAN
Creators: name: Stephen, Reuben George
name: Zhang, Rui
Publisher: name: arXiv
Year: 2016
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: Ultra-dense (UD) wireless networks and cloud radio access networks (CRAN) are two promising network architectures for the emerging fifth-generation (5G) wireless communication systems. By jointly employing them, a new appealing network solution is proposed in this paper, termed UD-CRAN. In a UD-CRAN, millimeter-wave (mmWave) wireless fronthaul is preferred for information exchange between the central processor and the distributed remote radio heads (RRHs), due to its lower cost and higher flexibility in deployment, compared to fixed optical links. This motivates our study in this paper on the downlink transmission in a mmWave fronthaul enabled, orthogonal frequency division multiple access (OFDMA) based UD-CRAN. In particular, the fronthaul is shared among the RRHs via time division multiple access (TDMA), while the RRHs jointly transmit to the users on orthogonal frequency subchannels using OFDMA. The joint resource allocation over the TDMA-based mmWave fronthaul and OFDMA-based wireless transmission is investigated to maximize the weighted sum rate of all users. Although the problem is non-convex, we propose a Lagrange duality based solution, which can be efficiently computed with good accuracy. To further reduce the complexity, we also propose a greedy search based heuristic, which achieves close to optimal performance under practical setups. Finally, we show the significant throughput gains of the proposed joint resource allocation approach compared to other benchmark schemes by simulations.
description: Accepted for publication in IEEE Transactions on Communications
Energy Rating Based on Thermal Modelling of Five Different PV Technologies
Creators: name: Carigiet, F.
name: Baumgartner, F.P.
name: Sutterlueti, J.
name: Allet, N.
name: Pezzotti, M.
name: Haller, J.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
PV Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 3311-3315
description: Minute by minute outdoor measurements of five commercial PV modules including multi c-Si, HIT, a- Si/μc-Si, CIS, CdTe over one year were used to develop a model for predicting the individual module temperatures. The simulated module temperatures over a whole year in minute interval correspond to the outdoor measured values within a RMSE of 1.5°C. Input of the model includes irradiance measurements, which are extracted from the measured short circuit current ISC, the measured wind speed and the ambient temperature. The measured energy weighted module temperature for Zurich was found to be between 33.3°C and 38.0°C for the different module types with a maximum difference of 0.8°C relative to the simulated average module temperature. Due to the high module temperature, the annual average efficiency was reduced relative to the STC values by only 2.6% (HIT) and 5.6% (CIS). Another reduction of the STC efficiency could clearly be attributed to the efficiency at low ISC values which classify low irradiance values. The value is a decrease of the annual energy output of 4.7% and an increase of 1.1%. A further loss analysis was performed to separate spectrum related losses resulting in a relative difference of 2% for the tandem compared to the multi c-Si module.
Polynomial functors and combinatorial Dyson-Schwinger equations
Creators: name: Kock, Joachim
Publisher: name: arXiv
Year: 2015
Subjects: subject: Mathematical Physics (math-ph)
subject: Category Theory (math.CT)
subject: Quantum Algebra (math.QA)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 81T15, 16T10, 05C05, 81T16, 18D50

description: We present a general abstract framework for combinatorial Dyson-Schwinger equations, in which combinatorial identities are lifted to explicit bijections of sets, and more generally equivalences of groupoids. Key features of combinatorial Dyson-Schwinger equations are revealed to follow from general categorical constructions and universal properties. Rather than beginning with an equation inside a given Hopf algebra and referring to given Hochschild $1$-cocycles, our starting point is an abstract fixpoint equation in groupoids, shown canonically to generate all the algebraic structure. Precisely, for any finitary polynomial endofunctor $P$ defined over groupoids, the system of combinatorial Dyson-Schwinger equations $X=1+P(X)$ has a universal solution, namely the groupoid of $P$-trees. The isoclasses of $P$-trees generate naturally a Connes-Kreimer-like bialgebra, in which the abstract Dyson-Schwinger equation can be internalised in terms of canonical $B_+$-operators. The solution to this equation is a series (the Green function) which always enjoys a Faà di Bruno formula, and hence generates a sub-bialgebra isomorphic to the Faà di Bruno bialgebra. Varying $P$ yields different bialgebras, and cartesian natural transformations between various $P$ yield bialgebra homomorphisms and sub-bialgebras, corresponding for example to truncation of Dyson-Schwinger equations. Finally, all constructions can be pushed inside the classical Connes-Kreimer Hopf algebra of trees by the operation of taking core of $P$-trees. A byproduct of the theory is an interpretation of combinatorial Green functions as inductive data types in the sense of Martin-Löf Type Theory (expounded elsewhere).
description: v4: minor adjustments, 49pp, final version to appear in J. Math. Phys
Prediction Model for Potential Induced Degradation Effects on Crystalline Silicon Cells
Creators: name: Koch, S.
name: Berghold, J.
name: Abdullah, B.
name: Hinz, C.
name: Grunow, P.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
Performance and Reliability of Solar Cells

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 3327-3333
description: This paper will present a further developed PID phenomenological prediction model [1]. The potential-induced degradation (PID) progress can be manly described by three parameters (A1, t0 and p). The performance of a solar module is the fundamental characteristic. The power in turn is related to the shunt resistance, which reveals in advance the PID. The purpose of this work is the development of a simulation model for the PID prediction using climate data. For the mathematical description of the degradation process a logistic function is presented. This feature is already applied in other fields of research and is here adjusted for simulating the potential-induced degradation. The development of the shunt resistance can be described mathematically with this function. Additionally a mathematical description of the regeneration will be given as well. With the help of the latest outdoor data, which were measured by a special designed shunt detector, new findings are presented. This leads to innovative assumptions to develop a simplified model for PID prediction.
Ab initio-Untersuchung von 29 SI- und 17 O-NMR-chemischen Verschiebungen in Zeolithen und dichten SiO 2 -Modifikationen
Creators: name: Bussemer, Beate
Publisher: name: Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I
Year: 2000
Subjects: subject: Ab initio
subject: NMR
subject: Zeolith
subject: Simulation
subject: ab initio
subject: zeolite
subject: simulation
subject: 540 Chemie
subject: 30 Chemie
subject: VE 5657
subject: VE 8607
subject: VE 9607

description: In der vorliegenden Arbeit sollte untersucht werden, inwieweit man quantenchemische Methoden zur Berechnung von NMR-chemischen Verschiebungen auf Festkoerper anwenden kann. Es wurden die 29Si- und 17O-NMR-chemischen Verschiebungen von Zeolithen und dichten SiO2-Modifikationen berechnet. Dabei wurden zahlreiche Untersuchungen zur Abhaengigkeit der chemischen Verschiebung von der Festkoerperstruktur und von verschiedenen Parametern bei der Berechnung (Basissatz, Methode) durchgefuehrt. Die Qualitaet der Simulationen wurde an experimentellen Daten gemessen. Es konnte gezeigt werden, dass mit einer geeigneten Kombination von Rechenparametern eine Simulation von NMR-Spektren moeglich ist, die das Experimente sehr genau wiedergibt.
description: The following work studies, how far quantum chemical methods to compute NMR chemical shifts are applicable to solids. The 29Si and 17O NMR spectra of several zeolites and silicates were investigated. Numerous investigations were carried out to examine the dependence of the chemic al shift on the used zeolite structures and computing methods. The quality of the results was judged on experimental data. It could be shown, that a calculation of NMR spectra with a suitable combination of simulation parameters leads to results which reproduce very well the experimental results.
Ein linearer Programmierungsansatz zur Lösung von Stopp- und Steuerungsproblemen
Creators: name: Röhl, Stefan
Publisher: name: Humboldt-Universität zu Berlin, Wirtschaftswissenschaftliche Fakultät
Year: 2001
Subjects: subject: Stoppproblem
subject: Lineare Programmierung
subject: Stochastische Steuerung
subject: Hausdorffsches Momentenproblem
subject: stopping problem
subject: linear programming
subject: stochastic control
subject: Hausdorff moment problem
subject: 330 Wirtschaft
subject: 17 Wirtschaft
subject: QH 425

description: Es wird ein Ansatz und ein Algorithmus zur Lösung von stochastischen Stoppproblemen vorgestellt, der auf einer dualen Formulierung zum klassischen Lösungsansatz für Stoppprobleme mittels Variationsungleichungen basiert. Unter bestimmten Voraussetzungen kann man für diese duale Formulierung ein äquivalentes unendlichdimensionales lineares Programm aufstellen, das die Momente des Aufenthaltsmaßes des stochastischen Prozesses bis zum Stoppzeitpunkt und die Momente der Verteilung des Prozesses zum Zeitpunkt des Stoppens als Variablen enthält. Für dieses unendlichdimensionale Problem werden endlichdimensionale Approximationen formuliert und gelöst, wobei die Momente nur bis zu einer endlichen Ordnung berücksichtigt werden. Die Güte der numerischen Resultate hängt davon ab, wie genau der Träger des Maßes zum Stoppzeitpunkt identifiziert werden kann. Aus diesem Grund wird ein Verfeinerungsalgorithmus entwickelt, mit dem diese Identifizierung in einer Reihe von Fällen gelingt und sich sehr genaue Ergebnisse erzielen lassen. Der für Stoppprobleme entwickelte Algorithmus kann auch bei der Ermittlung von optimalen Steuerungen für stetige stochastische Prozesse angewandt werden. Für einzelne Beispiele wird gezeigt, welche Resultate dabei erzielt werden können.
description: We present an approach to, and an algorithm for solving optimal stopping problems. The approach is based on a dual formulation of the classical method for solving stopping problems using variational inequalities. Under suitable conditions it is possible to express the dual formulation as an infinite-dimensional linear program. This linear program uses the moments of the occupation measure and the moments of the stopping measure as variables. We formulate and solve finite-dimensional approximations to this infinite-dimensional program by restricting the number of moments. The accuracy of the numerical results depend on how well the support of the stopping measure can be identified. To this end we develop an iterative procedure which works very well in many cases. In the second part of the dissertation we show how the algorithm, developed for stopping problems, can be used for solving stochastic control problems.
Identifying Voltage Dependant Features in Photovoltaic Modules Using Electroluminescence Imaging
Creators: name: Crozier, J.L.
name: Van Dyk, E.E.
name: Vorster, F.J.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
PV Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 3288-3291
description: Electroluminescence (EL) is a useful solar cell and module characterisation technique as it is fast, nondestructive and sensitive to the effects of shunt and series resistance and recombination processes. EL is emitted by a solar cell under forward bias and can be detected by a cooled silicon CCD camera in dark conditions or with appropriate filters. There is a proportional relationship between the intensity of the emitted EL and the local junction voltage. Thus resistive losses like series and shunt resistances can be identified in the EL image. These resistive areas can be detected by comparing EL images taken at different applied biases. Other defects like micro-cracks and broken contact fingers are also easily identified in the EL images. These defects can have a significant effect of the performance and longevity of the module. This study investigates the relationship between the applied voltage and the intensity of the EL image pixels of observed features. The dark current-voltage (I-V) behaviour of the module and individual cells is considered and the relation between the EL image and the I-V curve is discussed.
Investigation on Light-Trapping Structures Using Ray Tracing
Creators: name: Reiners, N.
name: Blieske, U.
name: Kirkes, C.
name: Czyba, D.
name: Minich, W.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
PV Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 3305-3307
description: One way to improve the performance of solar modules under low and oblique light conditions is to use
textured front surfaces such as pyramidal structures in glass. The aim of this work is to develop a ray tracing model
that simulates the behavior of different textures under direct and diffuse radiation. The developed model can then be
used to test and design different structures for the front surface of solar modules on the computer.
The presented ray tracing model was evaluated with the help of solar module measurements under a solar flasher and
under outdoor conditions. The model showed a very good fit for direct radiation but delivered slightly higher results
compared to the measurements for the diffuse radiation.
Time independent quantum circuits with local interactions
Creators: name: Seifnashri, Sahand
name: Keyanvash, Farzad
name: Nobakht, Jahangir
name: Karimipour, Vahid
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Heisenberg spin chains can act as quantum wires transferring quantum states either perfectly or with high fidelity. Gaussian packets of excitations passing through dual rails can encode the two states of a logical qubit, depending on which rail is empty and which rail is carrying the packet. With extra interactions in one or between different chains, one can introduce interaction zones in arrays of such chains, where specific one or two qubit gates act on any qubit which passes through these interaction zones. Therefore universal quantum computation is made possible in a static way where no external control is needed. This scheme will then pave the way for a scalable way of quantum computation where specific hardwares can be connected to make large quantum circuits. Our scheme is an improvement of a recent scheme where we have achieved to borrow an idea from quantum electrodynamics to replace non-local interactions between spin chains with local interactions mediated by an ancillary chain.
description: 26 pages, 8 figures, accepted for publication in Physical Review A
Energy Yield Prediction Model for PV Modules Including Spatial and Temporal Effects
Creators: name: Goverde, H.
name: Herteleer, B.
name: Anagnostos, D.
name: Köse, G.
name: Goossens, D.
name: Aldalali, B.
name: Govaerts, J.
name: Baert, K.
name: Catthoor, F.
name: Driesen, J.
name: Poortmans, J.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
PV Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 3292-3296
description: An optical-thermal-electrical model of a photovoltaic (PV) module is presented, suitable for energy loss analyses and short- and long-term energy yield calculations as a function of ambient conditions (temperature, wind and irradiance). This bottom-up model consists of a thermal and electrical equivalent sub-circuit. The thermal equivalent circuit incorporates the conduction, convection and radiation of heat within and from the PV module. Finite element modelling (FEM) computational fluid dynamics (CFD) models and wind tunnel tests were used to calibrate the thermal model, both for spatial and temporal effects. Thermal capacitance and resistance values were extracted from measurement and FEM models and the full thermal model was validate by indoor and outdoor measurements. The 1- diode model was used for the electrical circuit of the cell. The parameters of the electrical model were extracted from flash and steady-state I-V measurements. The thermal sub-circuit was used to calculate the temperature of each cell in the module, and this temperature is then further used to calculate the electrical characteristics of every individual cell. A full model of a Phoenix-Solar-PHX-160 module was constructed and the model was used for energy yield simulations. The result was successfully compared to outdoor measurements.
Mobile Testing System for PV Plants (MUPA)
Creators: name: Tegtmeyer, D.
name: Maris, N.
name: Hellmuth, S.
name: Behrmann, T.
name: Dittrich, A.
name: Lemmel, M.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
PV Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 3237-3239
description: Power checks of PV modules installed may require a full disassembly from the substructure before
checking I-V curve and STC power. Within the research project “MUPA”, funded by the German ministry of
research and technology, the three partners work together for researching a service, which is able to check I-V curves
and STC power of PV modules without disassembling from the construction. A portable I-V curve analyzer contains
all, that is necessary to provide the service crew with data base (for modules as well as for the specific order),
measures I-V curves, controls simulated sunlight and stores all I-V curves measured. This device is handled by a
small tablet computer, which shows all relevant data before and after the I-V curve sweep. When a
telecommunication net is in reach, all data are synced with the central database at the headquarter of the service
provider. Therefore a central measuring unit in combination with a lightweight irradiance source is needed.
An Optimal Energy Estimator to Reduce Correlated Noise for the EXO-200 Light Readout
Creators: name: 200 Collaboration
name: Davis, C. G.
name: Hall, C.
name: Albert, J. B.
name: Barbeau, P. S.
name: Beck, D.
name: Belov, V.
name: Breidenbach, M.
name: Brunner, T.
name: Burenkov, A.
name: Cao, G. F.
name: Cen, W. R.
name: Chambers, C.
name: Cleveland, B.
name: Coon, M.
name: Craycraft, A.
name: Daniels, T.
name: Danilov, M.
name: Daugherty, S. J.
name: Davis, J.
name: Delaquis, S.
name: Der Mesrobian-Kabakian, A.
name: DeVoe, R.
name: Didberidze, T.
name: Dilling, J.
name: Dolgolenko, A.
name: Dolinski, M. J.
name: Dunford, M.
name: Fairbank, W.
name: Farine, J.
name: Feldmeier, W.
name: Feyzbakhsh, S.
name: Fierlinger, P.
name: Fudenberg, D.
name: Gornea, R.
name: Graham, K.
name: Gratta, G.
name: Hughes, M.
name: Jewell, M. J.
name: Johnson, A.
name: Johnson, T. N.
name: Johnston, S.
name: Karelin, A.
name: Kaufman, L. J.
name: Killick, R.
name: Koffas, T.
name: Kravitz, S.
name: Krücken, R.
name: Kuchenkov, A.
name: Kumar, K. S.
name: Leonard, D. S.
name: Licciardi, C.
name: Lin, Y. H.
name: Ling, J.
name: MacLellan, R.
name: Marino, M. G.
name: Mong, B.
name: Moore, D.
name: Njoya, O.
name: Nelson, R.
name: Odian, A.
name: Ostrovskiy, I.
name: Piepke, A.
name: Pocar, A.
name: Prescott, C. Y.
name: Retière, F.
name: Rowson, P. C.
name: Russell, J. J.
name: Schubert, A.
name: Sinclair, D.
name: Smith, E.
name: Stekhanov, V.
name: Tarka, M.
name: Tolba, T.
name: Tsang, R.
name: Twelker, K.
name: Vuilleumier, J. -L.
name: Waite, A.
name: Walton, J.
name: Walton, T.
name: Weber, M.
name: Wen, L. J.
name: Wichoski, U.
name: Wood, J.
name: Yang, L.
name: Yen, Y. -R.
name: Zeldovich, O. Ya.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The energy resolution of the EXO-200 detector is limited by electronics noise in the measurement of the scintillation response. Here we present a new technique to extract optimal scintillation energy measurements for signals split across multiple channels in the presence of correlated noise. The implementation of these techniques improves the energy resolution of the detector at the neutrinoless double beta decay Q-value from $\left[1.9641\pm 0.0039\right]\%$ to $\left[1.5820\pm 0.0044\right]\%$.
description: 21 pages, 8 figures, 1 table
Degradation of c-Si Photovoltaic Module Induced by Over-Stress Salt Mist Test
Creators: name: Hsu, S.-T.
name: Long, Y.-S.
name: Ma, H.-C.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
PV Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 3162-3165
description: Qualification tests for Photovoltaic (PV) modules like the damp heat test of IEC 61215 regularly cause
corrosion at cell interconnects solder joints and various metallic parts. Especially, the installation of PV modules in
coastal areas or on de-ice roads with sodium chloride may lead to additional environmental stress. Besides corrosion
of metallic parts, power loss and affected adhesives were identified in the field. Corrosion of silicone based adhesive
sealing may result in consequential loss of insulation properties as well as adhesive strength, and could cause a hazard
to human beings and animals or the infrastructure. Therefore, corroded contacts may ultimately cause DC arcing and
hence potentially forms a fire. In this study, field failures are to be analyzed and simulated in environmental test and
salt test chambers. We monitored on corrosion process of PV modules under over-stress salt corrosion test for 56
days. This paper aims to realize the influences of salt corrosion test for c-Si PV modules, address the examination on
the degradation phenomenon of PV modules in the worst test condition of IEC 61730-2 (Sev. 6), and record abnormal
electrical data (Pmax, Rs, Rsh) and EL images or visual inspection for critical components in detailed. Result also
propose a new I-V analysis method to monitor remote module in real-time, especially under the condition lacking EL
or performance data.
Fabrication of colloidal Laves phases via hard tetramers and hard spheres: bulk phase diagram and sedimentation behaviour
Creators: name: Avvisati, Guido
name: Dasgupta, Tonnishtha
name: Dijkstra, Marjolein
Publisher: name: arXiv
Year: 2016
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Colloidal photonic crystals display peculiar optical properties which make them particularly suitable for application in different fields. However, the low packing fraction of the targeted structures usually poses a real challenge in the fabrication stage. Here, we propose a novel route to colloidal photonic crystals via a binary mixture of hard tetramers and hard spheres. By combining theory and computer simulations, we calculate the phase diagram as well as the stacking diagram of the mixture, and show that a colloidal analogue of the MgCu2 Laves phase -- which can serve as a precursor of a photonic bandgap structure -- is a thermodynamically stable phase in a large region of the phase diagram. Our findings show a relatively large coexistence region between the fluid and the Laves phase, which is potentially accessible by experiments. Furthermore, we determine the sedimentation behaviour of the suggested mixture, by identifying several stacking sequences. Our work uncovers a new self-assembly path towards a photonic structure with a band gap in the visible region.
Development Process of a Biobased Envelope in the European Project BASAJAUN
Creators: name: Fuente González, Marta
Publisher: name: Zenodo
Year: 2023
Subjects: envelope, wood, construction, faÇades, wood-based materials, insulation, tests

description: The work was presented at the "The future envelope: towards zero carbon buildings" conference, which took place in Bolzano between 15 and 16 December 2022 and was organized by the European FaÇade Network (https://www.europeanfacadenetwork.eu/). The presentation contains an introduction to the Basajaun project and the presentation of the innovation in the system design of a new building faÇade, Basajaun faÇade. Basajaun project has received funding from the European Union´s Horizon 2020, research and Innovation programme under grant agreement No. 862942
Comparison of Hot Spot Investigations of Photovoltaic Modules at Laboratory and Field Conditions
Creators: name: Wendlandt, S.
name: Krause, M.
name: Berendes, S.
name: Hanusch, M.
name: Drobisch, A.
name: Berghold, J.
name: Schoppa, M.
name: Krauter, S.
name: Grunow, P.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
PV Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 3209-3213
description: In PV applications solar modules are not always fully illuminated but occasionally partly shaded. In this case the partly shaded cells potentially operate in reverse bias of the current voltage characteristic. For this reason the cells heat up and in the worst case the polymer foils can melt. For studying the thermal stability of a module the standardized hot spot test can be applied. The standardized conditions of the hot spot test allow some degrees of freedom like the module temperature of the non shadowed module area. In this work, the influence of the module temperature and of the radiation level on the maximum hot spot temperature will be analyzed indoor. Then, an outdoor hot spot tests will performed. Finally, this paper will show a worst case comparison between the in- and outdoor hot spot test conditions.
Accelerated Damp Heat Test Combining Current Stressor
Creators: name: Chen, H.
name: Hsueh, C.H.
name: Chen, C.
name: Chang, M.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
PV Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 3182-3185
description: Damp heat test is one of the crucial qualification test in IEC 61215 standard to evaluate the ability to
withstand thermal and humidity penetration. In this paper, by applying with Arrhenius model, the activation energy
extracted from extended damp heat for P-multi crystalline silicon PV module is 0.78eV. Furthermore, we
simultaneously exert short circuit current (Isc) bias as another stressor to investigate the failure modes and the
correlation with temperature and humidity. The acceleration factor is 1.48 for applying Isc loading, and it is almost
equivalent to that (1.42) of raising temperature from 85 °C to 90°C during damp heat. The module with and without
electric current bias shows similar failure modes – mainly due to corrosion. After inspecting those defects in detail
analysis, we propose to add current bias to shorten timeframe of extended damp heat test.
Isotropy of Angular Frequencies and Weak Chimeras With Broken Symmetry
Creators: name: Bick, Christian
Publisher: name: arXiv
Year: 2015
Subjects: subject: Dynamical Systems (math.DS)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Chaotic Dynamics (nlin.CD)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: The notion of a weak chimeras provides a tractable definition for chimera states in networks of finitely many phase oscillators. Here we generalize the definition of a weak chimera to a more general class of equivariant dynamical systems by characterizing solutions in terms of the isotropy of their angular frequency vector - for coupled phase oscillators the angular frequency vector is given by the average of the vector field along a trajectory. Symmetries of solutions automatically imply angular frequency synchronization. We show that the presence of such symmetries is not necessary by giving a result for the existence of weak chimeras without instantaneous or setwise symmetries for coupled phase oscillators. Moreover, we construct a coupling function that gives rise to chaotic weak chimeras without symmetry in weakly coupled populations of phase oscillators with generalized coupling.
Devant le temps. Etica della responsabilità e scrittura della storia. Recensione a: Georges Didi-Huberman, Storia dell’arte e anacronismo delle immagini
Creators: name: Cengiarotti, Giuseppe
Publisher: name: La Rivista di Engramma
Year: 2008
Subjects: Images
Anachronism
Art

description: Review of the book “Storia dell’arte e anacronismo delle immagini“ written by Georges Didi-Huberman and published by Bollati Boringhieri. The present Italian translation of the volume by Georges Didi-Huberman, together with the very recent one of “La prize de parole“ by Michel de Certeau (2007), the last stage of a new attention in publishing for the work of this scholar, leads to to insist on reflecting on the statute of the historical discipline, increasingly invested by heated debates, such as that on denial, which perhaps it would be appropriate to bring back to the more distant controversies surrounding revisionism, starting with the passionate discussions that took place in the 1960s between and Trevor-Roper on gentry ("rising" or "declining"?), to those, equally heated, on the general crisis of the seventeenth century and on the causes of the English revolution (was it "rebellion" or "revolution"?), to arrive at the controversial and the debated notion of proof, understood both in the technical sense of proof and in the current one of evidence.
Unbounded Human Learning: Optimal Scheduling for Spaced Repetition
Creators: name: Reddy, Siddharth
name: Labutov, Igor
name: Banerjee, Siddhartha
name: Joachims, Thorsten
Publisher: name: arXiv
Year: 2016
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: In the study of human learning, there is broad evidence that our ability to retain information improves with repeated exposure and decays with delay since last exposure. This plays a crucial role in the design of educational software, leading to a trade-off between teaching new material and reviewing what has already been taught. A common way to balance this trade-off is spaced repetition, which uses periodic review of content to improve long-term retention. Though spaced repetition is widely used in practice, e.g., in electronic flashcard software, there is little formal understanding of the design of these systems. Our paper addresses this gap in three ways. First, we mine log data from spaced repetition software to establish the functional dependence of retention on reinforcement and delay. Second, we use this memory model to develop a stochastic model for spaced repetition systems. We propose a queueing network model of the Leitner system for reviewing flashcards, along with a heuristic approximation that admits a tractable optimization problem for review scheduling. Finally, we empirically evaluate our queueing model through a Mechanical Turk experiment, verifying a key qualitative prediction of our model: the existence of a sharp phase transition in learning outcomes upon increasing the rate of new item introductions.
description: Accepted to the ACM SIGKDD Conference on Knowledge Discovery and Data Mining 2016
Effects of insulin sensitizing drug metformin on clinical features, endocrine and metabolic profiles in obese women with polycystic ovary syndrome
Creators: name: Steinheim, Elena
Publisher: name: Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité
Year: 2007
Subjects: subject: Adipositas
subject: Syndrom der polyzystischen Ovarien (PCOS)
subject: Metformin
subject: Hyperinsulinämie
subject: obesity
subject: polycystic ovary syndrome
subject: metformin
subject: hyperinsulinemia
subject: 610 Medizin
subject: 33 Medizin
subject: YM 4504

description: Metformineinnahme scheint reproduktive und metabolische Funktionen bei Frauen mit PCOS zu verbessern. Die zwiespältige aktuelle Studienlage kann bisher keine konkrete Aussage liefern, ob Metformin eine erfolgreiche therapeutische Möglichkeit des Syndroms darstellt. Ziel der vorliegenden randomisierten, placebo-kontrollierten Studie war es, die Auswirkung des antihyperglykämischen Medikaments Metformin in Kombination mit Ernährungsberatung und Sport auf übergewichtige Frauen mit PCOS zu ermitteln. Besondere Aufmerksamkeit galt der Wirkung des Medikaments hinsichtlich Insulin und Glukose-Stoffwechsel, endokrinologischen und biochemischen Parametern, sowie dem Menstruationszyklus. 46 adipöse Frauen mit PCOS im Alter von 22 bis 39 Jahren und mit einem mittleren BMI von 38,1 nahmen an der Studie teil. Die verabreichte Dosis von Metformin betrug 1,5 g (3x500 mg) täglich über einen Zeitraum von 16 Wochen. Gemessen wurden Veränderungen von FSH, LH, Oestradiol, Testosteron, DHEA-S, SHBG, Cholesterol, Triglyzeriden, Insulin, Glukose, HbA1c, Leptin und IGF-I im Serum. Monatlich wurde eine Ernährungsberatung angeboten. Jede Teilnehmerin erhielt darüber hinaus individuelle dietätische Beratung. Signifikante Gewichtsreduktion (P
description: Use of metformin seems to improve reproductive and metabolic abnormalities in women with PCOS. However, the disparity of results in clinical studies cannot give us a conclusive answer if metformin is a new line therapy of the syndrome. The present randomised, placebo-controlled study was designed to compare the antihyperglycemic drug metformin vs. placebo combined with lifestyle modification in the treatment of polycystic ovary syndrome in obese women. Special attention was paid to the effects of this medication on insulin and glucose metabolism, endocrine and biochemical parameters, and menstrual function. Forty six obese women with PCOS, aged between 22-39 years and mean BMI 38.1 were randomized to receive either metformin (500 mg three times a day for 16 weeks) or placebo. The metformin and placebo groups were matched for age, endocrinological and metabolic parameters. Changes in FSH, LH, estradiol, testosterone, DHEA-S and SHBG, total cholesterol, triglycerides, insulin, glucose, HbA1c, leptin and IGF-I were assessed. Group therapy with aspects in nutrition and physical activity was conducted monthly. Each woman received individual counselling by a dietician. Significant (P
Selection of direction of the ordered moments in Na$_2$IrO$_3$ and $α-$RuCl$_3$
Creators: name: Sizyuk, Yuriy
name: Woelfle, Peter
name: Perkins, Natalia B.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The magnetic orders in Na$_2$IrO$_3$ and $α-$RuCl$_3$, honeycomb systems with strong spin-orbit coupling and correlations, have been recently described by models with the dominant Kitaev interactions. In this work we discuss how the orientation of magnetic order parameter is selected in this class of models. We show that while the order-by-disorder mechanism in the models with solely Kitaev anisotropies always select cubic axes as easy axes for magnetic ordering, the additional effect of other small bond-dependent anisotropies, such as, e.g., $Γ$-terms, lead to a deviation of the order parameter from the cubic directions. We show that both the zigzag ground state and the face-diagonal orientation of magnetic moments in Na$_2$IrO$_3$ can be obtained within the $J_1-K_1-J_2-K_2-J_3$ model in the presence of perturbatively small $Γ$-terms. We also show that the zigzag phase found in the nearest neighbor Kitaev-Heisenberg model, relevant for $α-$RuCl$_3$, has some stability against the $Γ$-term.
description: 10 pages, 6 figures
Evaluation of the PV Module Output Power Change by Means of Light-Induced Degradation and Thermal Recovery due to Thermal Reliability Tests
Creators: name: Tsuno, Y.
name: Kera, S.
name: Morita, K.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
PV Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 3186-3189
description: It is generally known that crystalline silicon solar cells are stable devices. However an initial performance
drop by light-induced degradation is observed. There are some reports that light induced degradation was rapidly
recovered by thermal annealing under 200 ºC conditions. On the other hands, the temperature condition of the
IEC 61215 sequential tests such as thermal cycle and damp heat test is 85 ºC and testing time is over 1000h. When a
degraded module by light soaking is placed into an environmental test chamber, annealing effects are expected. But
the recovering of output power by thermal annealing is not considered in the current sequential test of IEC 61215. In
this paper, the output power change by light-induced degradation and thermal recovery under thermal reliability test
conditions were investigated. As a result, thermal recovery was observed under 85 ºC, 360h conditions. Additionally,
re-degradation of light soaking after thermal reliability test was also observed. This result indicates that additional
light soak test is required when the actual amount of the degradation rate is estimated.
UniSAFE: University Of Akureyri – institutional policy to address gender-based violence
Creators: name: Huck, Averil
name: Andreska, Zuzana
name: Linkova, Marcela
Publisher: name: Zenodo
Year: 2022
Subjects: Gender based-violence
policy framework
gender+
institutional policy

description: UniSAFE has mapped the policies and measures to address and combat GBV in 48 universities and research organisations in 15 European countries. For each institution, the team created Vignettes which present national context, institutional policy, training, role in knowledge production, content of the policy, institutional procedure and implementation of the policy.
Effect of observational holes in fractal analysis of galaxy survey masks
Creators: name: García-Farieta, Jorge E.
name: Casas-Miranda, Rigoberto A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Observations reveal that the Universe has a hierarchy of galaxy clustering with transition to homogeneity on large scales according to the $Λ$CDM model. On the other hand some observational estimates suggest a multifractal behavior where galactic clustering is based on generalization of the correlation dimension. We study the influence of veto areas on fractal measurements in masks of galaxy surveys. We investigate if these holes can produce fractal behaviors or modify the scale of cosmic homogeneity. From the footprint of BOSS-DR12, we build a homogeneous sample following the radial selection function for 73,412 points limited to the redshift range $0.002
description: 21 pages, 8 figures. Matches the published version
Development of a Test Method for the Investigation of the Abrasive Effect of Sand Particles on Components of Solar Energy Systems
Creators: name: Völker, C.
name: Philipp, D.
name: Masche, M.
name: Kaltenbach, T.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
PV Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 3142-3146
description: Currently, there is no appropriate, standardized, accelerated test method to investigate the abrasion
resistance of components of solar energy systems under sand storm conditions. Therefore, this paper deals with the
development of a test method for the investigation of the sand abrasion mechanism on selected solar technical
components. For this purpose, first, the mechanisms of surface damage induced by trickling sand are experimentally
investigated. The designed method based on ASTM D968-05 enables to describe the sand abrasion mechanisms on
aluminum reflectors and solar glasses. Also, differences in the abrasion resistance of the samples are revealed. In
addition to changes in their optical properties, an increased surface roughness can be determined. Depending on the
impact angle, hardness of the exposed material, sand trickling mass and sand concentration, different surface changes
are caused. The concentrated particle stream led to strong abrasive damage on the reflector surfaces, whereas glasses
show a better abrasion resistance to trickling sand because of their higher hardness. The second, horizontal test
method designed according to the sandblasting principle allows a more realistic investigation of the sand abrasion
process on samples under strong wind conditions. The low, sand-laden air flow causes less abrasive damage on the
reflector surfaces.
Pairwise Markov properties for regression graphs
Creators: name: Sadeghi, Kayvan
name: Wermuth, Nanny
Publisher: name: arXiv
Year: 2015
Subjects: subject: Statistics Theory (math.ST)
subject: Other Statistics (stat.OT)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: With a sequence of regressions, one may generate joint probability distributions. One starts with a joint, marginal distribution of context variables having possibly a concentration graph structure and continues with an ordered sequence of conditional distributions, named regressions in joint responses. The involved random variables may be discrete, continuous or of both types. Such a generating process specifies for each response a conditioning set which contains just its regressor variables and it leads to at least one valid ordering of all nodes in the corresponding regression graph which has three types of edge; one for undirected dependences among context variables, another for undirected dependences among joint responses and one for any directed dependence of a response on a regressor variable. For this regression graph, there are several definitions of pairwise Markov properties, where each interprets the conditional independence associated with a missing edge in the graph in a different way. We explain how these properties arise, prove their equivalence for compositional graphoids and point at the equivalence of each one of them to the global Markov property.
description: 11 pages, 1 figure
Accoustic and Electric Diagnostics of Degradation in PV Cells and Mini-Modules
Creators: name: Schlosser, V.
name: Serini, M.
name: Váry, M.
name: Saly, V.
name: Packa, J.
name: Perný, M.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
PV Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 3200-3203
description: The aim of this work was to find the possibility to estimate the influence of forced ageing on the
properties of photovoltaic modules. We have measured sound velocities in crystalline silicon PV modules before and
after forced ageing. The commercially available mini-modules consisted of three high efficiency c-Si cells connected
in series. Investigation of electrical properties was performed also before and after accelerated ageing under increased
temperature and PID. It was found that forced ageing strongly affects the sound velocity of the complete modules. It
was shown that impedance spectroscopy measurement and characterization is an important tool to reveal the
degradation of the solar cells due to high voltage stress and increased temperature stress.
Experimentally Feasible Quantum-Key-Distribution Scheme Using Qubit-Like Qudits And Its Comparison With Existing Qubit- and Qudit-Based Protocols
Creators: name: Chau, H. F.
name: Wang, Qinan
name: Wong, Cardythy
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Cryptography and Security (cs.CR)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Recently, Chau introduced an experimentally feasible qudit-based quantum-key-distribution (QKD) scheme. In that scheme, one bit of information is phase encoded in the prepared state in a $2^n$-dimensional Hilbert space in the form $(|i\rangle\pm|j\rangle)/\sqrt{2}$ with $n\ge 2$. For each qudit prepared and measured in the same two-dimensional Hilbert subspace, one bit of raw secret key is obtained in the absence of transmission error. Here we show that by modifying the basis announcement procedure, the same experimental setup can generate $n$ bits of raw key for each qudit prepared and measured in the same basis in the noiseless situation. The reason is that in addition to the phase information, each qudit also carries information on the Hilbert subspace used. The additional $(n-1)$ bits of raw key comes from a clever utilization of this extra piece of information. We prove the unconditional security of this modified protocol and compare its performance with other existing provably secure qubit- and qudit-based protocols on market in the one-way classical communication setting. Interestingly, we find that for the case of $n=2$, the secret key rate of this modified protocol using non-degenerate random quantum code to perform one-way entanglement distillation is equal to that of the six-state scheme.
description: extensively revised, conclusions changed, 7 pages, 2 figures and 1 table, published in PRA
Mechanical Load Test Study for Optimize PV Module Installation Method
Creators: name: Chen, C.
name: Chen, H.
name: Hsueh, C.H.
name: Chang, M.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
PV Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 3157-3161
description: This study focuses on when the PV module is performed the mechanical load test, and using the
different mounting mode to research the deformation degree of the P-mono PV module and the monitoring continuity.
The probability of PV module damaging by extend weight decreases when a best installation is chosen. The output
power and electroluminescence images are applied for investigation in this work, and the important parameters which
influence the power loss of PV module are also discussed. We provide the best mounting method for the mechanical
loading endurance for the module makers or system installers in the design and planning stage which need to take
into account.