cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Analysis of Automatic Fault Detection Methods for Commercially Operated PV Power Plants
Creators: name: Sarquis Filho, E.A.
name: Kiefer, K.
name: Holland, N.
name: Kollosch, B.
name: Müller, B.
name: Costa Branco, P.J.
Publisher: name: WIP
Year: 2021
Subjects: PV Systems – Modelling, Design, Operation and Performance
Operation, Performance and Maintenance of PV Systems

description: 38th European Photovoltaic Solar Energy Conference and Exhibition; 961-966
description: Automatic fault detection (AFD) is a key technology to optimize the Operation and Maintenance of photovoltaic (PV) systems portfolios. Although several recent studies suggest methods and procedures for automatic fault detection, they lack a common basis for testing their effectiveness under real operating conditions. In this study, we have selected and implemented a list of methods suitable for the data available in the standard monitoring of commercial systems. The performance of these methods was tested using measurements collected over 58 months on 85 rooftop-type PV systems installed in Germany. The maintenance records from these systems were used to measure the accuracy of the fault detection alerts and to analyze the sensitivity and specificity of each method. The best performing was able to identify almost one third (29.6%) of the faults observed in PV systems with an average of 15.8% false alerts. The method with the least false alerts (11.7%) could identify 19% of the faults. The AFD methods tested show different sensitivity depending on the type of fault, which suggests that a combination of methods can increase the overall sensitivity.
Neutron star radii and crusts: uncertainties and unified equations of state
Creators: name: Fortin, M.
name: Providencia, C.
name: Raduta, A. R.
name: Gulminelli, F.
name: Zdunik, J. L
name: Haensel, P.
name: Bejger, M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The uncertainties in neutron star (NS) radii and crust properties due to our limited knowledge of the equation of state (EOS) are quantitatively analysed. We first demonstrate the importance of a unified microscopic description for the different baryonic densities of the star. If the pressure functional is obtained matching a crust and a core EOS based on models with different properties at nuclear matter saturation, the uncertainties can be as large as $\sim 30\%$ for the crust thickness and $4\%$ for the radius. Necessary conditions for causal and thermodynamically consistent matchings between the core and the crust are formulated and their consequences examined. A large set of unified EOS for purely nucleonic matter is obtained based on 24 Skyrme interactions and 9 relativistic mean-field nuclear parametrizations. In addition, for relativistic models 17 EOS including a transition to hyperonic matter at high density are presented. All these EOS have in common the property of describing a $2\;M_\odot$ star and of being causal within stable NS. A span of $\sim 3$ km and $\sim 4$ km is obtained for the radius of, respectively, $1.0\;M_\odot$ and $2.0\;M_\odot$ star. Applying a set of nine further constraints from experiment and ab-initio calculations the uncertainty is reduced to $\sim 1$ km and $2$ km, respectively. These residual uncertainties reflect lack of constraints at large densities and insufficient information on the density dependence of the EOS near the nuclear matter saturation point. The most important parameter to be constrained is shown to be the symmetry energy slope $L$ which exhibits a linear correlation with the stellar radius, particularly for masses $\sim 1.0\;M_\odot$. Potential constraints on $L$, the NS radius and the EOS from observations of thermal states of NS are also discussed. [Abriged]
description: Submitted to Phys. Rev. C. Supplemental material not included
Fault Detection in Operation and Maintenance of PV Systems
Creators: name: Louwen, A.
name: Miorandi, D.
name: Torrero, C.
name: Venturini, F.
name: Moser, D.
Publisher: name: WIP
Year: 2021
Subjects: PV Systems – Modelling, Design, Operation and Performance
Operation, Performance and Maintenance of PV Systems

description: 38th European Photovoltaic Solar Energy Conference and Exhibition; 967-972
description: Concurrently with the strong decline in installed PV system prices, the margin for operation and maintenance (O&M) operators has decreased, as O&M costs are commonly budgeted as a fixed percentage of installed system costs. Hence, there is a need to improve the efficiency of O&M operations. In the PV4.0 project, we are aiming to improve O&M efficiency across the value chain, by implementing Industry 4.0 concepts. One key part of these concepts is to implement an automatic fault detection system, that is used to quickly detect faults in PV plant operation, minimizing electricity generation losses. Furthermore, this fault detection system is to be used to automatically generate maintenance tickets, so corrective maintenance can be performed as soon as possible. In this paper, we present the development of two neural network (NN) based machine learning models. Model A is a four-layer NN, trained to classify individual datapoints as either normal or faulty. Detected faults are subsequently classified as either a hard (zero power output) or soft (power output higher than zero but lower than nominal) failures. Model B is a model that attempts to predict whether the number of failures in the next days exceed a certain threshold. Our results indicate that Model A has a fault detection rate of 79% in our testing dataset, while the performance of Model B is lower, at a fault detection rate of 49% for 1-day-ahead predictions, and only 30% for 2-day-ahead predictions. Further work will focus on improving the failure detection rate for both models. For Model B, we will additionally focus on improving the input dataset, so that better predictions might become possible. Model A will be implemented in a real-time O&M environment to test its performance in real operating conditions.
Quantum Cosmology in $(1+1)$-dimensional Hořava-Lifshitz theory of gravity
Creators: name: Pitelli, J. P. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In a recent paper [Phys. Rev. D 92:084012, 2015], the author studied the classical $(1+1)$-dimensional Friedmann-Robertson-Walker (FRW) universe filled with a perfect fluid in Hořava-Lifshitz (HL) theory of gravity. This theory is dynamical due to the anisotropic scaling of space and time. It also resembles the Jackiw-Teitelboim model, in which a dilatonic degree of freedom is necessary for dynamics. In this paper, I will give one step further in the understanding of (1+1)-dimensional HL cosmology by means of the quantization of the FRW universe filled with a perfect fluid with equation of state (EoS) $p=wρ$. The fluid will be introduced in the model via Schutz formalism and Dirac's algorithm will be used for quantization. It will be shown that the Schrödinger equation for the wave function of the universe has the following properties: for $w=1$ (radiation fluid), the characteristic potential will be exponential, resembling Liouville quantum mechanics; for $w\neq 1$, a characteristic inverse square potential appears in addition to a regular polynomial which depends on the EoS. Explict solutions for a few cases of interesting will be found and the expectation value of the scale factor will be calculated. As in usual quantum cosmology, it will be shown that the quantum theory smooth out the big-bang singularity, but the classical behavior of the universe is recovered in the low-energy limit.
description: 8 pages. To appear in Phys. Rev. D
A Hybrid Solar Irradiance Nowcasting Approach: Combining All Sky Imager Systems and Persistence Irradiance Models for Increased Accuracy
Creators: name: Nouri, B.
name: Blum, N.
name: Wilbert, S.
name: Zarzalejo, L.F.
Publisher: name: WIP
Year: 2021
Subjects: PV Systems – Modelling, Design, Operation and Performance
Solar Resource and Forecasting

description: 38th European Photovoltaic Solar Energy Conference and Exhibition; 952-955
description: New technical challenges arise due to the growing share of distributed and intermittent solar power generation. Intra-minute and intra-hour variabilities, when insufficiently accounted for, could lead to grid instabilities. Shortest-term forecasts, often referred as nowcast, can anticipate such variabilities with high resolutions in space and time. Therefore, nowcasts are suited for fine-grained control applications in solar power plants and electrical grids. Highly resolve nowcasts can be obtained by all sky imager (ASI) systems. Sky conditions are analyzed and irradiance nowcasts a derived from the hemispherical sky images. In this work, ASI based nowcasts and persistence based nowcasts are combined to a hybrid nowcasts approach. This hybrid approach archived a reduction of the root mean square deviation of 12% over a 62-day lasting validation data set.
Model discrimination in pseudoscalar-meson photoproduction
Creators: name: Nys, J.
name: Ryckebusch, J.
name: Ireland, D. G.
name: Glazier, D. I.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: To learn about a physical system of interest, experimental results must be able to discriminate among models. We introduce a geometrical measure to quantify the distance between models for pseudoscalar-meson photoproduction in amplitude space. Experimental observables, with finite accuracy, map to probability distributions in amplitude space, and the characteristic width scale of such distributions needs to be smaller than the distance between models if the observable data are going to be useful. We therefore also introduce a method for evaluating probability distributions in amplitude space that arise as a result of one or more measurements, and show how one can use this to determine what further measurements are going to be necessary to be able to discriminate among models.
Cloud Segmentation and Classification to Improve the Short-Term PV Forecasting Using Sky Imager
Creators: name: Melliti, D.E.
name: Ha, D.L.
name: Marechal, P.
name: Ghalila-Sevestre, S.
name: Lehaire, J.
name: Capelle, T.
name: Tremoy, G.
Publisher: name: WIP
Year: 2021
Subjects: PV Systems – Modelling, Design, Operation and Performance
Solar Resource and Forecasting

description: 38th European Photovoltaic Solar Energy Conference and Exhibition; 956-960
description: Accurate prediction of photovoltaic energy remains a challenge, as PV production is dependent on fluctuating weather conditions, such as solar irradiance which relies on cloudy conditions. In this context, our work is based on a specific “All Sky Imager” (ASI) , integrating “fish-eye” concave lenses with a 180° field of view. This paper presents a novel approach of cloud segmentation using ASI to improve - PV production forecasting. First, we improve the identification of various components in the images (clouds, sun, noise, etc.). Then, we study the very short-term impact of clouds through a sky images segmentation and tracking processing. Finally, we correlate the skylevel segmented image to fluctuations in the actual on-site solar irradiance measurements. The results show that the segmentation is efficient in clear and overcast sky conditions. However, high precision irradiance accuracy in partially cloudy sky conditions is difficult to obtain due to the chaotic impact of the circumsolar region and different cloud opacities.
Basic tactics for a Black Bloc
Creators: name: :Unav
Publisher: name: University of Victoria Libraries
Year: 2020
Subjects: subject: Anarchists
valueUri: http://id.worldcat.org/fast/808401
subject: Civil disobedience
valueUri: http://id.worldcat.org/fast/862481
subject: Anarchism
valueUri: http://id.worldcat.org/fast/808387
subject: Social groups
valueUri: http://id.worldcat.org/fast/1122482
subject: Demonstrations
valueUri: http://id.worldcat.org/fast/890222
subject: Passive resistance
valueUri: http://id.worldcat.org/fast/1054436
subject: Protest movements
valueUri: http://id.worldcat.org/fast/1079826
subject: Anarchism--Societies, etc.
valueUri: http://id.worldcat.org/fast/808396

description: Details the strategy and tactics for a protest including wearing all black and face masks to deter law enforcement and to protect each other, to link arms and form a bloc, to only have photo i.d., to give the police limited information if arrested, among other legal advice.
Port Service and Its Effect on Humanitarian Logistics in Addis Ababa
Creators: name: Tadesse, Girma
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2016

description: The aim of this study was to assess the significance of port service provision in humanitarian aid services and the level of organizations' satisfaction in Addis Ababa. The main reason for selecting the topic was that the service the community demanded was not given significant emphasis, while the demand for humanitarian service is rising in absolute terms in recent years both from the public and donation. Hence, it is found to be a critical area for the underlined problem. The research design selected in this study is a descriptive, cross-sectional design. The data was collected all at the same time (or within a short time frame). The data showed that analysis of trend of growth of supply of goods imported for humanitarian services decreased from 2008 to 2015. The price change in 2008 was dramatically increased by 89.08 % whereas there are two years (2010 and 2013) which have decreased the importing goods in relief food and foods items by 43.25 % and 39.60 percent respectively. The result indicated that there is a very low responsiveness to customers, offering choices of non-standardized services; that lead by persuasions and incentives as a factor of port service demand. Flexible and adaptable to deliver high quality goods and services and empower citizens rather than simply serving those as institution are also the problematic issue in port service in Ethiopia. The correlation analysis illustrate the relation between the port service satisfaction and humanitarian logistics as it is highly or strongly correlated as r=0.705 and r=0.864 for correlation between humanitarian logistics and port availability and r=0.933 for humanitarian logistics with port cost. But port service demand has a weak correlation (r=0.046). It can be concluded that this study measures port efficiency or performance indicators use a diverse range of techniques for assessment and analysis, but although many analytical tools and instruments exist, a problem arises when one tries to apply them to a range of ports and terminals for humanitarian logistics. It is recommended as the need of a proper port performance measurement based on indicators: macro performance indicators quantifying aggregate port impacts on economic activity, and micro performance indicators evaluating input/output ratio measurements of port operations in the country
Spatio-Temporal Machine Learning Methods for Multi-Site PV Power Forecasting
Creators: name: Carrillo Rangel, R.E.
name: Schubnel, B.
name: Simeunovic, J.
name: Langou, R.
name: Alet, P.-J.
Publisher: name: WIP
Year: 2021
Subjects: PV Systems – Modelling, Design, Operation and Performance
Solar Resource and Forecasting

description: 38th European Photovoltaic Solar Energy Conference and Exhibition; 946-948
description: In this paper we present recent advances at CSEM in multi-site PV forecasting that rely entirely on past production data. The presented methods take a graph signal processing perspective and exploit the intuition that a dense network of PV stations provides enough information for short-term prediction horizons (up to six hours ahead) with a high temporal and spatial resolution. The proposed forecasting models are based on recent advances in graph machine learning to capture the spatio-temporal dependencies of the PV production data. The proposed methods were evaluated in two data sets for an entire year: 1) production data from 304 real PV systems, and 2) simulated production of 1000 PV systems, in both cases distributed over Switzerland. The best of the proposed methods achieves a daytime NRMSE (over all sites) of 15.5% for the real data set and 12% for the synthetic data set for 6 hours ahead prediction and 7.5% for the real data set and 3.5% for the synthetic data set for 15 minutes ahead prediction. Furthermore, the proposed nonlinear methods outperform state-of-the-art methods with NWP as inputs on time horizons between 0 h and 5 h.
Die apostolischen Kirchen des Orients und die Pluralität in der einen Kirche
Creators: name: Kéramé, Orest
Publisher: name: Concilium
Year: 1970

description: Concilium, Bd. 9 Nr. 10 (1973): Concilium: Internationale Zeitschrift für Theologie, Band 9, Heft 10
Submillimeter water masers as excellent tools to study jet-disk like structures in high-mass YSOs?
Creators: name: de Gregorio-Monsalvo, Itziar
name: Gil, Santiago
name: Santamaría-Miranda, Alejandro
name: Pérez-Sánchez, Andrés Felipe
name: Gómez, José Francisco
name: Plunkett, Adele
name: Schreiber, Matthias
Publisher: name: Zenodo
Year: 2023

description: Water is one of the few molecules capable of producing maser emission in star-forming regions and it has been detected in a wide range of masses from low to massive young stellar objects (YSO). Previous studies focused on the water maser transition at 22 GHz, which constitutes a good tracer of mass-loss activity in young stars of all masses. In low-mass protostars these are mostly present during the first stages of their evolution and they tend to be located close to the central protostar when the most powerful mass-loss phenomena are present. Recent studies suggest these masers trace also mass loss phenomena in intermediate and high mass YSOs. The water molecule shows several maser transitions at submillimeter wavelengths, which makes last generation of submillimeter telescopes like APEX and ALMA excellent facilities to follow up in the submillimeter the studies done in the past decades at 22 GHz. In this talk we present preliminary results on a survey of submillimeter water maser transitions at 321 and 325 GHz in a sample of YSOs with a wide range of masses, from high- to low-mass.
Vibro-Band: Supporting Needle Placement for Physicians with Vibrations
Creators: name: Reinschluessel, Anke Verena
name: Cebulla, Sarah Christin
name: Herrlich, Marc
name: Döring, Tanja
name: Malaka, Rainer
Publisher: name: Fachbereich 03: Mathematik/Informatik (FB 03)
Year: 2018
Subjects: subject: Vibration
subject: Tactile
subject: Task Load
subject: Needle-Based Intervention
subject: SUS
subject: Wrist-band
subject: User study
subject: 0

description: Medical images and navigation systems support physicians during needle-based interventions. As the information is primarily displayed on monitors, the physician's attention is drawn away from the patient's body. To address this issue, we explore the additional use of a vibration wristband that directs the movements for needle-based operations via different vibration patterns on the operator's arm. We conducted a first user study comparing the combination of tactile and visual guidance versus visual-only feedback with 12 participants to investigate the general feasibility. Our results show that task times, usability scores, cognitive load, and accuracy are comparable for both conditions suggesting that vibration feedback is generally suitable for medical navigation tasks and warranting further iteration and research in this direction.
Assessment of Cloud Mask Forecasts from the WRF-Solar Ensemble Prediction System
Creators: name: Yang, J.
name: Kim, J.-H.
name: Sengupta, M.
name: Jimenez, P.A.
name: Xie, Y.
Publisher: name: WIP
Year: 2021
Subjects: PV Systems – Modelling, Design, Operation and Performance
Solar Resource and Forecasting

description: 38th European Photovoltaic Solar Energy Conference and Exhibition; 949-951
description: Numerical weather prediction (NWP) models are important tools used by government agencies and the renewable energy enterprise to forecast solar radiation. Cloud prediction, a key process of NWP models, has the highest impact on the accuracy of solar forecasting. This study uses satellite observations from the National Solar Radiation Database (NSRDB) to evaluate the cloud mask forecast by the Weather Research and Forecasting-Solar Ensemble Prediction System (WRF-Solar EPS). Preliminary analysis of the data in 2018 demonstrates the need for further improvement in predicting thin and low-level clouds. The information obtained from this work will be used to enhance WRF-Solar EPS in reproducing the cloud field over the contiguous U.S. and reducing solar forecasting errors.
Letter from William Powell Frith to Henry Keyworth Raine, [September?] 24, 1895
Creators: name: Frith, William Powell, 1819-1909
Publisher: name: University of Victoria Libraries
Year: 2022
Subjects: subject: Painters
valueUri: http://id.worldcat.org/fast/1050530
subject: Artists--Family relationships
valueUri: http://id.worldcat.org/fast/817581
subject: Painters--Correspondence
valueUri: http://id.worldcat.org/fast/1050538
subject: Families
valueUri: http://id.worldcat.org/fast/1728849
subject: Artists
valueUri: http://id.worldcat.org/fast/817559
subject: Artists--Correspondence
valueUri: http://id.worldcat.org/fast/817571

description: Part of a collection of 21 letters sent by William Powell Frith to his great nephew Henry Keyworth Raine, dating from March 16, 1890 to March 29, 1908. William Powell Frith (1819-1909), painter of historical and genre works, including large canvases such as Derby Day (1858). “The Race for Wealth” comprises five paintings, all based around a fictional central character, a corrupt financier called The Spider, and all dealing with the theme of reckless financial speculation. Inspired by characters found in the novels of Charles Dickens and Anthony Trollope, The Spider persuades his victims to invest in dubious schemes. Often compared with Hogarth’s “The Rake’s Progress,” “The Race for Wealth” portrays The Spider’s initial success, his unmasking, his trial, and ends with his imprisonment.
title: Human-Robot Handshaking: A Review
Creators: name: Prasad, Vignesh
name: Stock-Homburg, Ruth
name: Peters, Jan
Publisher: name: Springer Netherlands
Year: 2024

description: For some years now, the use of social, anthropomorphic robots in various situations has been on the rise. These are robots developed to interact with humans and are equipped with corresponding extremities. They already support human users in various industries, such as retail, gastronomy, hotels, education and healthcare. During such Human-Robot Interaction (HRI) scenarios, physical touch plays a central role in the various applications of social robots as interactive non-verbal behaviour is a key factor in making the interaction more natural. Shaking hands is a simple, natural interaction used commonly in many social contexts and is seen as a symbol of greeting, farewell and congratulations. In this paper, we take a look at the existing state of Human-Robot Handshaking research, categorise the works based on their focus areas, draw out the major findings of these areas while analysing their pitfalls. We mainly see that some form of synchronisation exists during the different phases of the interaction. In addition to this, we also find that additional factors like gaze, voice facial expressions etc. can affect the perception of a robotic handshake and that internal factors like personality and mood can affect the way in which handshaking behaviours are executed by humans. Based on the findings and insights, we finally discuss possible ways forward for research on such physically interactive behaviours.
Ends of finite volume, nonpositively curved manifolds
Creators: name: Avramidi, Grigori
Publisher: name: arXiv
Year: 2015
Subjects: subject: Geometric Topology (math.GT)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics

description: We study complete, finite volume $n$-manifolds $M$ of bounded nonpositive sectional curvature. A classical theorem of Gromov says that if such $M$ has negative curvature then it is homeomorphic to the interior of a compact manifold-with-boundary, and we denote this boundary $\partial M$. If $n\geq 3$, we prove that the universal cover of the boundary $\widetilde{\partial M}$ and also the $π_1M$-cover of the boundary $\partial\widetilde M$ have vanishing $(n-2)$-dimensional homology. For $n=4$ the first of these recovers a result of Nguyen Phan saying that each component of the boundary $\partial M$ is aspherical. For any $n\geq 3$, the second of these implies the vanishing of the first group cohomology group with group ring coefficients $H^1(Bπ_1M;\mathbb Zπ_1M)=0$. A consequence is that $π_1M$ is freely indecomposable. These results extend to manifolds $M$ of bounded nonpositive curvature if we assume that $M$ is homeomorphic to the interior of a compact manifold with boundary. Our approach is a form of "homological collapse" for ends of finite volume manifolds of bounded nonpositive curvature. This paper is very much influenced by earlier, yet still unpublished work of Nguyen Phan.
description: 30 pages, 4 figures
An Interactive-Shoe For Surgeons: Hand-Free Interaction With Medical 2D Data
Creators: name: Zaman, Ambreen
name: Reisig, Lars
name: Reinschluessel, Anke Verena
name: Bektas, Huseyin
name: Weyhe, Dirk
name: Herrlich, Marc
name: Döring, Tanja
name: Malaka, Rainer
Publisher: name: Fachbereich 03: Mathematik/Informatik (FB 03)
Year: 2018
Subjects: subject: Human-computer interaction
subject: Foot mouse
subject: Usability
subject: 2D images
subject: 0

description: During interventions, surgeons often need to review medical imaging data, e.g., CT scans. Usually, surgeons need to rely on an assistant to browse the images because of sterility requirements. Communication with a substitute operator is tedious and error-prone if the operator does not have an equal level of professional experience and might interrupt the workflow. We present a sensor-integrated shoe allowing surgeons to browse and manipulate 2D medical image data by foot movement. It is portable and wearable. The shoe uses an optical sensor taken from an off-the-shelf computer mouse for tracking the foot movements and an additional micro-switch to turn it on or off. We evaluated the performance of the shoe interface against a control condition with assistant together with ten surgeons in an empirical user study. Our results provide first indications for the effectiveness of a shoe interface in this application area.
An Assessment of Corporate Social Responsibility Practice in Addis Modjo Edible Oil Company
Creators: name: Amanuel, Mahlet
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2016

description: The main objective of the study is to assess the corporate social responsibility practice of addis modjo edible oil company and suggest possible solutions that contribute to the betterment of the company's corporate social responsibility practice. To achieve this objective, the primary data was collected by questionnaire survey, interview and Secondary data was collected from the company's documentation. The collected data were analyzed by descriptive statistics method (mean and standard deviation). The population of the study was defined as the company's customers, the company's logistics and supply chain department employees; the company's logistics supply chain manager. From this population a total 0f 200 customers, 10 employees and were considered in the questionnaire and 1 manager for the interview. The findings reveal that the corporate social responsibility practice of addis modjo is weak. The results indicate that if the company increase its corporate social responsibility practices it will increase its sustainability in the business. Key words: corporate social responsibility, edible oil
Symmetry classes of alternating sign matrices in the nineteen-vertex model
Creators: name: Hagendorf, Christian
name: Morin-Duchesne, Alexi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Combinatorics (math.CO)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The nineteen-vertex model on a periodic lattice with an anti-diagonal twist is investigated. Its inhomogeneous transfer matrix is shown to have a simple eigenvalue, with the corresponding eigenstate displaying intriguing combinatorial features. Similar results were previously found for the same model with a diagonal twist. The eigenstate for the anti-diagonal twist is explicitly constructed using the quantum separation of variables technique. A number of sum rules and special components are computed and expressed in terms of Kuperberg's determinants for partition functions of the inhomogeneous six-vertex model. The computations of some components of the special eigenstate for the diagonal twist are also presented. In the homogeneous limit, the special eigenstates become eigenvectors of the Hamiltonians of the integrable spin-one XXZ chain with twisted boundary conditions. Their sum rules and special components for both twists are expressed in terms of generating functions arising in the weighted enumeration of various symmetry classes of alternating sign matrices (ASMs). These include half-turn symmetric ASMs, quarter-turn symmetric ASMs, vertically symmetric ASMs, vertically and horizontally perverse ASMs and double U-turn ASMs. As side results, new determinant and pfaffian formulas for the weighted enumeration of various symmetry classes of alternating sign matrices are obtained.
description: 61 pages, 13 figures
Uncertainty of Tilted Irradiance Measurements Using Photodiodes and Reference Cells
Creators: name: Driesse, A.
name: Wilbert, S.
name: Forstinger, A.
Publisher: name: WIP
Year: 2021
Subjects: PV Systems – Modelling, Design, Operation and Performance
Solar Resource and Forecasting

description: 38th European Photovoltaic Solar Energy Conference and Exhibition; 929-937
description: Irradiance is one of the most important parameters for the solar industry. However, it is very challenging to measure accurately, therefore it is all the more important to quantify the uncertainty of irradiance measurements. Current best practices tend to use worst-case assumptions and apply them more-or-less uniformly, possibly leading to overly pessimistic uncertainty evaluations. In this work we evaluate the uncertainty of individual tilted irradiance measurements of time series data using two different approaches: first, we compare the measurements from five different devices of each type operating in parallel for a GUM type A evaluation; and second, we calculate the uncertainty associated with several key properties of the instruments (spectral response, directional response, temperature response) and combine them in a GUM type B evaluation for comparison. Correlations seen between the A and B results in one year of data at two very different sites indicate that the second method should be suitable for uncertainty evaluations in other locations.
Non self-adjoint Hamiltonians with complex eigenvalues
Creators: name: Bagarello, Fabio
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Motivated by what one observes dealing with PT-symmetric quantum mechanics, we discuss what happens if a physical system is driven by a diagonalizable Hamiltonian with not all real eigenvalues. In particular, we consider the functional structure related to systems living in finite-dimensional Hilbert spaces, and we show that certain intertwining relations can be deduced also in this case if we introduce suitable antilinear operators. We also analyze a simple model, computing the transition probabilities in the broken and in the unbroken regime.
description: in press in Journal of Physics A
A Comparative Analysis of Forecasting Methods for Photovoltaic Power and Energy Generation with and without Exogenous Inputs
Creators: name: Starosta, A.
name: Kaushik, K.
name: Jhaveri, P.
name: Munzke, N.
name: Hiller, M.
Publisher: name: WIP
Year: 2021
Subjects: PV Systems – Modelling, Design, Operation and Performance
Solar Resource and Forecasting

description: 38th European Photovoltaic Solar Energy Conference and Exhibition; 938-945
description: With drive towards a green energy sector and significant cost reduction of photovoltaic (PV) technology, global PV capacity has increased multi folds in the last decade. PV power increases the variability of power supply due to the sun’s changing position and weather volatility. Battery systems tackle these problems. For an optimized battery charging management, accurate PV energy forecasts are vital. The present work compares five 1-day-ahead PV power prediction models for a PV array of 8.64 kWp at KIT with 30° tilt and a 15° eastward orientation. The power prediction is used for intelligent battery charging management. The models are the offline persistence forecast (PF), an online forecast based on numerical weather prediction (NWP) and the machine-learning based offline Facebook prophet (FBP), support vector regression (SVR) and multilayer perceptron (MLP). According to the needs of intelligent battery charging management, the hourly PV energy forecast for the rest of the day is evaluated and compared for the different methods. The prediction methods are configurable for arbitrary inclinations and orientations. To the knowledge of the authors, FBP is compared for the first time to other models in the context of PV prediction. The results are evaluated for one year of data between March 2020 and February 2021. When comparing the performance of the models for different times of the day, SVR and MLP outperform the other models around noon, while the PF and most of the time NWP and FBP outperform the SVR and MLP in the morning and evening. When evaluating the models over one year, SVR outperforms the other model’s power and energy prediction. At the same time, the other models have similar power prediction performance, but varying energy prediction performance. When evaluating the models over the meteorological seasons, there are striking differences of the models’ performance. The SVR performs mostly best but is outperformed by the NWP in spring. At the same time, the NWP performs worst in winter. This is associated to reasons of spatial resolution of the NWP data. With the two best models SVR and MLP, it is shown that endogenous values generally suffice, while the partial outperformance of the NWP still motivates for a further investigation into the use of exogenous input.
Put That Needle There: Customized Flexible On-Body Thin-Film Displays for Medical Navigation
Creators: name: Herrlich, Marc
name: Reinschluessel, Anke Verena
name: Willems, Markus
name: Langhorst, Nils
name: Black, David
name: Döring, Tanja
name: Rieder, Christian
name: Kikinis, Ron
name: Malaka, Rainer
Publisher: name: ACM
Year: 2020
Subjects: subject: Intra-operative information
subject: Electroluminescence
subject: Task Load
subject: Needle-Based Intervention
subject: 0

description: Informed by modern imaging techniques, current medical navigation systems support physicians during a variety of interventions, such as needle-based operations. During these, an abundance of information is often displayed on monitors placed in positions that are uncomfortable for the operator to view. In this article, we address these issues with the concept and prototype of a customized flexible display that is placed on the patient’s body to provide the essential information at just the right location. We present an empirical evaluation comparing the flexible display against a control condition using a standard interventional monitor setup and an additional condition that combines both. Our results show that the flexible display significantly reduces task load while improving overall usability. Furthermore, we found indications that the flexible display reduces task completion time while also observing a negative effect on accuracy, which needs to be balanced carefully.
Investigating the connection between Quasi Periodic Oscillations and spectral components with NuSTAR data of GRS 1915+105
Creators: name: Jassal, Anjali Rao
name: Vadawale, Santosh V.
name: S, Mithun N. P.
name: Misra, Ranjeev
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The low frequency quasi periodic oscillations (QPOs) are commonly observed during hard states of black hole binaries. Several studies have established various observational/empirical correlations between spectral parameters and QPO properties, indicating a close link between the two. However, the exact mechanism of generation of QPO is not yet well understood. In this paper, we present our attempts to comprehend the connection between the spectral components and the low frequency QPO observed in GRS 1915+105 using the data from NuSTAR. Detailed spectral modeling as well as the presence of the low frequency QPO and its energy dependence during this observation have been reported by Miller et al. (2013) and Zhang et al. (2015) respectively. We investigate the compatibility of the spectral model and energy dependence of the QPO by simulating light curves in various energy bands for small variation of the spectral parameters. The basic concept here is to establish connection, if any, between the QPO and the variation of either a spectral component or a specific parameter, which in turn can shed some light on the origin of the QPO. We begin with the best fit spectral model of Miller et al. (2013) and simulate the light curve by varying the spectral parameter at frequencies close to the observed QPO frequency in order to generate the simulated QPO. Further we simulate similar light curves in various energy bands in order to reproduce the observed energy dependence of RMS amplitude of the QPO. We find that the observed trend of increasing RMS amplitude with energy can be reproduced qualitatively if the spectral index is assumed to be varying with the phases of the QPO. Variation of any other spectral parameter does not reproduce the observed energy dependence.
description: 8 pages, 5 figures, 1 table, Accepted for publication in ApJ
Availability of parts and definition of technologies for wafer-to-wafer hybridization
Creators: name: F. Huegging
name: T. Fritzsch
Publisher: name: Zenodo
Year: 2023
Subjects: WP6

description: Within WP6 (Hybrid Pixel Sensors for 4D Tracking and Interconnection Technologies) Milestone MS25 contains the availability of parts and definition of technologies for wafer-to-wafer hybridization. This milestone has been successfully achieved and is reported in this document.
Improving the Prediction of DNI via Physics-Based Simulation of All-Sky Circumsolar Radiation
Creators: name: Xie, Y.
name: Yang, J.
name: Sengupta, M.
name: Liu, Y.
Publisher: name: WIP
Year: 2021
Subjects: PV Systems – Modelling, Design, Operation and Performance
Solar Resource and Forecasting

description: 38th European Photovoltaic Solar Energy Conference and Exhibition; 912-914
description: Direct Normal Irradiance (DNI) is one of the most used quantities to quantify the magnitude of solar energy resource. The concept of DNI is often interpreted differently for ground measurements and solar forecasting by numerical weather prediction (NWP) models, leading to substantial bias during evaluation of DNI forecasts especially under cloudysky conditions. To eliminate the bias, we use the Fast All-sky Radiation Model for Solar applications with DNI (FARMSDNI) to provide a physics-based solution of solar radiation in the circumsolar region. The FARMS-DNI is implemented in the Weather Research and Forecasting model with solar extensions (WRF-Solar) to forecast day-ahead DNI in the north America. By comparing with conventional predictions from WRF-Solar and satellite observations from the National Solar Radiation Data Base (NSRDB), we found significant improvements in our prediction of DNI.
The Effect of Internal Marketing on Job Satisfaction: The Case of Commercial Bank of Ethiopia
Creators: name: Selamawit, Asfaw
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2019

description: The objective of this study is to examine the effect of internal marketing on job satisfaction of CBE Employees. The study used quantitative research approach to collect data from front line employees of CBE. A survey was made by taking 352 samples of CBE frontline employees as respondents through systematic random sampling technique. A structured questionnaire on five Likert scale basis was used to collect data. Both descriptive and inferential (correlation and regression) statistics were utilized using SPSS version 20 to analyze the data. The results indicate that all selected dimensions of internal marketing (training, empowerment, motivation and internal communication) have significantly and positively affect job satisfaction. Thus, CBE is recommended to fully implement internal marketing program to increase employees' job satisfaction. This indicates to us that the management must consider the organization as its first market and satisfy the needs of its internal customers. Furthermore, it also establishes internal marketing program for CBE on the basis of those internal marketing dimensions which enhance job satisfaction of the employee.
Characterizing the Convergence and Robustness of the Kernel Density Mapping Method for Site-Adaptation of Global Horizontal Irradiation in Western Europe
Creators: name: Yezeguelian, L.
name: Vernay, C.
name: Carriere, T.
name: Blanc, P.
Publisher: name: WIP
Year: 2021
Subjects: PV Systems – Modelling, Design, Operation and Performance
Solar Resource and Forecasting

description: 38th European Photovoltaic Solar Energy Conference and Exhibition; 915-922
description: The estimation of the annual solar resource at a given location is a crucial part of the financing of new photovoltaic power plants. The standard practice is to use satellite-derived databases of ground irradiance estimations. Although these databases have a long-term history that properly captures the climatological variations of a given site, they are not calibrated with ground measurements and therefore may suffer from significant biases. In this paper, we focus on Western Europe and propose to use ground measurements of global horizontal irradiation (GHI) combined with a Kernel Density Mapping algorithm to calibrate several satellite databases (Solargis, HelioClim-3 and CAMS Radiation); we then show that their biases can be reduced from roughly ±3 % down to 0.5 %. More importantly, we perform a sensitivity analysis on the minimal amount of ground measurements required to perform a proper calibration and show that 12 months is the perfect duration to achieve optimal calibration performance. Additionally, we compare the calibration performance on several different satellite databases and show that a combination of several databases can lead to lower overall uncertainty.
Auditory Display for Telerobotic Transnasal Surgery Using a Continuum Robot
Creators: name: Black, David
name: Lilge, Sven
name: Fellmann, Carolin
name: Reinschluessel, Anke Verena
name: Kreuer, Lars
name: Nabavi, Arya
name: Hahn, Horst K.
name: Kikinis, Ron
name: Burgner-Kahrs, Jessica
Publisher: name: World Scientific Publishing Co Pte Ltd
Year: 2019
Subjects: subject: Continuum robot
subject: Transnasal surgery
subject: Human-computer interaction
subject: Surgical navigation
subject: Sonification
subject: Auditory display
subject: Neurosurgery
subject: User Interfaces
subject: Usability
subject: Task Load
subject: 0

description: Tubular continuum robots can follow complex curvilinear paths to reach restricted areas within the body. Using teleoperation, these robots can help minimize incisions and reduce trauma. However, drawbacks include the lack of haptic feedback and a limited view of the situs, often due to camera occlusion. This work presents novel auditory display to enhance interaction with such continuum robots to increase accuracy and path-following efficiency and reduce cognitive workload. We recreate a typical use case with a test environment that simulates a transnasal intervention through the sphenoidal sinus including a simulated continuum robot. Distance information is mapped to changes in a real-time audio synthesizer using sung voice to provide navigation cues. User studies with novice participants and clinicians were performed to evaluate the effects of auditory display on accuracy, task time, path following efficiency, subjective workload, and usability. When using auditory display, participants exhibit significant increase in accuracy, efficiency, and task time compared to visual-only display. Auditory display reduced subjective workload and raised usefulness and satisfaction ratings. The addition of auditory display for augmenting interaction with a teleoperated continuum robot has shown to benefit performance as well as usability. The method could benefit other scenarios in navigated surgery to increase accuracy and reduce workload.
Optimizing Methodology for Estimating Global Horizontal Irradiance (GHI) Using Solar Photovoltaics’ Output AC Power Measurements
Creators: name: Khan, M.A.
name: Archer, D.-E.
name: Sommerfeldt, N.
Publisher: name: WIP
Year: 2021
Subjects: PV Systems – Modelling, Design, Operation and Performance
Solar Resource and Forecasting

description: 38th European Photovoltaic Solar Energy Conference and Exhibition; 923-928
description: In this paper, optimization of a model for estimation of global horizontal irradiance (GHI) using PV’s AC power output is proposed such that errors in estimated GHI are minimized. Modification of the developed model is carried out to adopt the methodology into different programming environment and to make it consistent with the available datasets. Results show that the developed model on Python language has Mean Absolute Percentage Error (MAPE) of 5.77% compared to GHI measurements using pyranometers for estimation of one month’s data. Modifications are done in detection of clear sky periods and minimization of loss functions for estimation of orientation in contrast with other methods. During model optimization it was also found that Ineichen/Perez’s Clear Sky GHI model, Direct Insolation Simulation Code (DISC) Model for Direct Normal Irradiance (DNI) estimation and Perez Model for sky diffuse irradiance calculations had minimum MAPE. Moreover, modelling parameters in the model were also adjusted to find best estimates of GHI. It was observed that timestep of 10 mins and past data of 120 days for estimation of orientation weights and error function were suitable. Number of iterations were also reduced to 10 from a starting number of 30 for estimation of GHI considering MAPE and computation times. Therefore, the main purpose of this research is to develop an optimized model that could be commercialized aiming to convert a PV system into virtual GHI sensor providing; information of solar potential and serve as an input data for solar forecasting or performance monitoring.