cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The B-quadrilateral lattice, its transformations and the algebro-geometric construction
Creators: name: Doliwa, Adam
Publisher: name: arXiv
Year: 2006
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: Differential Geometry (math.DG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The B-quadrilateral lattice (BQL) provides geometric interpretation of Miwa's discrete BKP equation within the quadrialteral lattice (QL) theory. After discussing the projective-geometric properties of the lattice we give the algebro-geometric construction of the BQL ephasizing the role of Prym varieties and the corresponding theta functions. We also present the reduction of the vectorial fundamental transformation of the QL to the BQL case.
description: 23 pages, 3 figures; presentation improved, some typos corrected
Efficiency and Productivity in the Spanish Food Distribution Sector
Creators: name: Palomares, Rafaela Dios
name: Palomares, Rafaela Dios
Publisher: name: Unknown
Year: 2002
Subjects: subject: Productivity Analysis
subject: Efficiency
subject: Productivity
subject: DEA method
subject: Malmquist index
subject: Food Distribution Unit

description: This study investigated the efficiency and productivity change of a sample of food distribution units (MERCAs) in Spain over the 1.997-1.999 period, applying non-parametric frontier methodology in a sales efficiency framework. We specified a mean sales model composed of two blocks of variables, the production block, and the marketing management block. Then we applied output oriented DEA methodology to perform the efficiency analysis, also taking into account the overall efficiency decomposition into pure and scale efficiency. The Malmquist index was calculated in order to analyse the components of the productivity change. The mean pure sales efficiency index was high, around 0.8, the mean scale index being 0,9. As appears from the results, six food distribution units were efficient, but some of the wholesale markets need to adapt their sales technology in order that their input bundle reaches a Most Productive Scale Size unit. We found no evidence of technical change during the period considered, but concluded that a notable scale efficiency change took place during the studied period. To summarise, we conclude that improvement in sales efficiency could be reached in the studied sector in both the pure and the scale efficiency.
Scalar and Vector Massive Fields in Lyra's Manifold
Creators: name: Casana, R.
name: de Melo, C. A. M.
name: Pimentel, B. M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The problem of coupling between spin and torsion is analysed from a Lyra's manifold background for scalar and vector massive fields using the Duffin-Kemmer-Petiau (DKP) theory. We found the propagation of the torsion is dynamical, and the minimal coupling of DKP field corresponds to a non-minimal coupling in the standard Klein-Gordon-Fock and Proca approaches. The origin of this difference in the couplings is discussed in terms of equivalence by surface terms.
description: Preprint version 7 pages. Talk presented in the Fourth International Winter Conference on Mathematical Methods in Physics, 9 to 23 August 2004, Rio de Janeiro, Brazil
Ultracold Neutrons
Creators: name: Kirch, Klaus
name: Lauss, Bernhard
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: High Energy Physics - Experiment (hep-ex)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Ultracold neutrons (UCN) are free neutrons that can be stored in experimental setups for several minutes. Some of the most important properties of the neutron, such as its tiny permanent electric dipole moment and its beta decay lifetime, are best measured with UCN. Also searches for well motivated but yet unknown, hypothetical additional interactions are being pursued with UCN. Such measurements in the field of low-energy, precision physics may have far reaching implications from particle physics to cosmology. Most experiments are statistics limited and need high-intensity UCN sources. The UCN source at PSI is at the forefront of the field and home to the international nEDM collaboration and its world-leading search for the neutron electric dipole moment. This article aims at giving an overview of the fascinating research using ultracold neutrons emphasizing on activities at PSI including various physics side-analyses which were pioneered by the nEDM collaboration.
description: 20 pages, 10 figures; invited article in 'Swiss Neutron News', the journal of the Swiss Neutron Science Society https://sgn.web.psi.ch/
Quantification of Coulomb Interactions in layered Lithium and Sodium Battery Cathode Materials
Creators: name: Kim, Bongjae
name: Kim, Kyoo
name: Kim, Sooran
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Despite the importance of the electron correlation in the first-principles description of the Li-ion cathode materials, the Coulomb interaction parameter, U is often treated as an ad hoc value. In practice, one usually relies on empirical ways of parametric treatment of U to optimally match the experimentally observed physical properties such as band gap or reaction energy. Here, using constrained random phase approximation (cRPA) method, we self-consistently evaluate the Coulomb U and Hund J values for representative layered cathode materials including not only Li compounds but also Na compounds; LiCoO2, LiNiO2, LiMnO2, NaCoO2, NaNiO2, and NaMnO2. We found that the Coulomb interaction parameters for Li and Na compounds and their polymorphs with different layer stackings do not deviate much, which shows the dominant role of local environment rather than of global structural features. We have analyzed the origin of variable Coulomb parameters, which is mainly due to the competition between the localization and screening. We provided cRPA Coulomb parameters for battery cathode materials and validate the values by observing systematic improvement in describing the experimentally observed average intercalation voltage and lattice parameters. These results can be applied for the first-principles calculations as well as model-based simulations for the theoretical investigation of cathode systems.
An Agent-Based Simulation for Water Sharing Between Different Users
Creators: name: Le Bars, M.
name: Attonaty, Jean Marie
name: Pinson, S.
name: Le Bars, M.
name: Attonaty, Jean Marie
name: Pinson, S.
Publisher: name: Unknown
Year: 2002
Subjects: subject: Resource /Energy Economics and Policy
subject: Multiagent-based simulation
subject: user and agent modelling
subject: conflict resolution and negotiation
subject: irrigation application

description: Water sharing has become a serious problem in France. One of the objectives of 1992 and 2000 directives proposed by the European Union was to reduce both the frequency and the extent of water conflicts through the establishment of multilateral negotiations, where different public and private interests can be represented in a structured institutional environment. In France, many negotiations take place at local level between farmers, water supplies, public services and environmental lists to allocate water resources between users. We suggest that Agent-Based Modelling (ABM) using a multi-agent approach could help negotiations between different players by showing the consequences of water allocation rules and taking in consideration the players' respective attitudes and their ability to change their behaviour.
The Uses of Argument in Mathematics
Creators: name: Aberdein, Andrew
Publisher: name: arXiv
Year: 2005
Subjects: subject: History and Overview (math.HO)
subject: FOS: Mathematics
subject: 00A35 (Primary); 00A30, 03A05 (Secondary)

description: Stephen Toulmin once observed that `it has never been customary for philosophers to pay much attention to the rhetoric of mathematical debate'. Might the application of Toulmin's layout of arguments to mathematics remedy this oversight? Toulmin's critics fault the layout as requiring so much abstraction as to permit incompatible reconstructions. Mathematical proofs may indeed be represented by fundamentally distinct layouts. However, cases of genuine conflict characteristically reflect an underlying disagreement about the nature of the proof in question.
description: 10 pages, 5 figures. To be presented at the Ontario Society for the Study of Argumentation Conference, McMaster University, May 2005 and LOGICA 2005, Hejnice, Czech Republic, June 2005
Analysis of the Impact of Urbanization and Enhanced Incomes on Demand for Food Quality in Hanoi
Creators: name: Ali, Mubarik
name: Quan, Nguyen The
name: Van Nam, Ngo
name: Ali, Mubarik
name: Quan, Nguyen The
name: Van Nam, Ngo
Publisher: name: Unknown
Year: 2006
Subjects: Demand and Price Analysis
Food Consumption/Nutrition/Food Safety

description: This study relates the demand for quality foods in Hanoi in terms of its nutritional composition, diversity, price, processing stage, source, and extent eaten outside home with urbanization and enhanced incomes. The vast differences in these foods quality parameters across different socioeconomic groups and regions in and around Hanoi city suggest the changing nature of the food quality with increased income and urbanization. One lesson learned from this analysis is that urbanization and increased income may not necessarily bring all positive changes in food quality. While the diet becomes more balanced in terms of micronutrient, the increased demand for fat-based calories, processed and restaurant foods, and drift away from fresh sources of farm and home-garden foods raised alarm for food quality and safety. These trends provide a space for government policies to intervene for the purpose of maintaining hygiene standards of food and public health.
The study of cavitands and carceplexes with C5 symmetry
Creators: name: Place, Samuel
Publisher: name: University of British Columbia
Year: 2009

description: This thesis presents a study of the synthesis of carceplex 65•2 DMF. [5]cavitand 58 was synthesized and the 2-methyl groups then underwent selective free radical bromination to give Br-[5]cavitand 60, which was converted to SH-[5]cavitand 61. The coupling of two molecules SH-[5]cavitand 61 proved to be successful and led to the formation of carceplex 65•2 DMF which has a C ₅ symmetry unique to carceplexes as well as hemispheres that are linked by disulfide bonds. ¹H NMR data showed carceplex 65 to have encapsulated 2 DMF molecules. MALDI MS experiments confirmed the correct mass of disulfide carceplex 65•2 DMF. Carceplex 65•2 DMF is an intriguing system for several reasons: 1) 65•2 DMF is the first ever carceplex that possesses a C ₅ symmetry 2) 65•2 DMF is the first carceplex system that has disulfide linkers and 3) 65 has the ability to encapsulate multiple guest molecules (2 DMF's) within its interior. These unique characteristics have been investigated and shall be reported within this thesis.
A Producer's Propensity to Conserve Framework: Application to a US and Australian Conservation Program
Creators: name: Eigenraam, Mark
name: Doering, Otto C.
name: Spinelli, Felix
name: Eigenraam, Mark
name: Doering, Otto C.
name: Spinelli, Felix
Publisher: name: Unknown
Year: 2006
Subjects: Resource /Energy Economics and Policy

description: Increasing recognition of the environmental impact of agriculture has led to increasing public activity around the world encouraging public conservation programs. Different countries have taken different program approaches to accomplish this. The comparison and contrast here is between Australia and the United States, examining the CREP program in the U.S. and the Eco Tender program in Australia. A different historical experience in the U.S. sets certain parameters that are expected in their conservation programs. To some extent, the Australian program could take more of a clean slate approach. The Australian program is able to take a broader landscape approach, specifically considering multiple benefits with knowledge about off-site benefits as well. This is tied into a structured auction process that does not allow gaming of the auction process. While the U.S. approach does include a bidding process, its structure is such that it has characteristics of an incentive program. The U.S. approach also gives less incentive to farmers to provide environmental amenities at the lowest possible cost. Taking off-site impacts into consideration and finding ways to induce competition among farmers to provide amenities at the lowest cost to the public are seen as important characteristics of cost effective conservation programs.
Deep-inelastic scattering and the operator product expansion in lattice QCD
Creators: name: Detmold, William
name: Lin, C. -J. David
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We discuss the determination of deep-inelastic hadron structure in lattice QCD. By using a fictitious heavy quark, direct calculations of the Compton scattering tensor can be performed in Euclidean space that allow the extraction of the moments of structure functions. This overcomes issues of operator mixing and renormalisation that have so far prohibited lattice computations of higher moments. This approach is especially suitable for the study of the twist-two contributions to isovector quark distributions, which is practical with current computing resources. While we focus on the isovector unpolarised distribution, our method is equally applicable to other quark distributions and to generalised parton distributions. By looking at matrix elements such as $$ (where $V^μ$ and $A^ν$ are vector and axial-vector heavy-light currents) within the same formalism, moments of meson distribution amplitudes can also be extracted.
description: 10 pages, 5 figures, version accepted for publication
Institutional Change in East German Water Management Systems
Creators: name: Schleyer, Christian
name: Schleyer, Christian
Publisher: name: Unknown
Year: 2006
Subjects: Institutional and Behavioral Economics
Resource /Energy Economics and Policy

description: Like in many fen land regions in East Germany, long-standing intensive arable farming -enabled by reclamation - has caused soil deterioration and high water runoff in the Schraden region. More than ten years of economic and political transformation that followed the breakdown of the socialist regime has worsened the situation and even added new problems. The visible consequences are droughts in the summer, waterlogged plots in the spring, and worn-down water management facilities that operate in an uncoo rdinated or unautho rized way. Given the local public good character of so me features of the fen land, the common-pool character of the intermittently scarce resource water within the ecosystem, and the conflicting interests of regional stakeholders, it is argued that the reallocation of property rights over reclamation systems, together with ineffective coordination mechanisms, have caused the physical and institutional failure of the water management system and thus impeded app ropriate land use. More precisely, the combination of legal insecurities accompanied by enforcement problems, fragmented land ownership structure, and a high number of short-term lease contracts have reduced the incentives for the majority of farmers to maintain the reclamation works. Due to limited statutory rights in conjunction with limited financials, the present water association appears to be an inadequate local coordination mechanism. Furthermore, the complete and timeintensive restructuring process at all levels of water administration has resulted in cumbersome or even nonexistent interrelations between various governmental layers as well as in rare transboundary contacts.
ILAT induced recruitment of domain general systems (Dreyer et al., 2020)
Creators: name: Dreyer, Felix R.
name: Doppelbauer, Lea
name: Büscher, Verena
name: Arndt, Verena
name: Stahl, Benjamin
name: Lucchese, Guglielmo
name: Hauk, Olaf
name: Mohr, Bettina
name: Pulvermüller, Friedemann
Publisher: name: ASHA journals
Year: 2020
Subjects: subject: Language
subject: 110904 Neurology and Neuromuscular Diseases
subject: FOS: Clinical medicine

description: Purpose: This study aimed to provide novel insights into the neural correlates of language improvement following intensive language-action therapy (ILAT; also known as constraint-induced aphasia therapy).Method: Sixteen people with chronic aphasia underwent clinical aphasia assessment (Aachen Aphasia Test [AAT]), as well as functional magnetic resonance imaging (fMRI), both administered before (T1) and after ILAT (T2). The fMRI task included passive reading of single written words, with hashmark strings as visual baseline.Results: Behavioral results indicated significant improvements of AAT scores across therapy, and fMRI results showed T2–T1 blood oxygenation-level-dependent (BOLD) signal change in the left precuneus to be modulated by the degree of AAT score increase. Subsequent region-of-interest analysis of this precuneus cluster confirmed a positive correlation of T2–T1 BOLD signal change and improvement on the clinical aphasia test. Similarly, the entire default mode network revealed a positive correlation between T2–T1 BOLD signal change and clinical language improvement.Conclusion: These results are consistent with a more efficient recruitment of domain-general neural networks in language processing, including those involved in attentional control, following aphasia therapy with ILAT.
Supplemental Material S1. Supplemental figures and tables.
Dreyer, F. R., Doppelbauer, L., Büscher, V., Arndt, V., Stahl, B., Lucchese, G., Hauk, O., Mohr, B., & Pulvermüller, F. (2020). Increased recruitment of domain-general neural networks in language processing following intensive language-action therapy: fMRI evidence from people with chronic aphasia. American Journal of Speech-Language Pathology. Advance online publication. https://doi.org/10.1044/2020_AJSLP-19-00150
Publisher Note: This article is part of the Special Issue: Select Papers From the 49th Clinical Aphasiology Conference.
Maize Yield Response to Fertilizer and Profitability of Fertilizer Use Among Small-Scale Maize Producers in Zambia
Creators: name: Xu, Zhiying
name: Govereh, Jones
name: Black, J. Roy
name: Jayne, Thomas S.
name: Xu, Zhiying
name: Govereh, Jones
name: Black, J. Roy
name: Jayne, Thomas S.
Publisher: name: Unknown
Year: 2006
Subjects: subject: Crop Production/Industries
subject: Maize
subject: Yield
subject: Fertilizer
subject: Profitability
subject: Survey data

description: Multi-year nationwide survey data is used to estimate maize yield response functions and determine profitability of fertilizer use by small-scale farmers in Zambia. There has been a dearth of empirical studies on economics of fertilization in the context of Sub-Saharan Africa. In this paper we identify major methodological issues arising from using survey data and estimate maize yield response functions for small-scale rural households that have various management practices and soil conditions in two major agro-climatic zones. Profitability of fertilizer use is determined for each group of households. Our findings provide the following key messages. First, households that obtained fertilizer on time and used animal draught power or mechanical power for land preparation are more likely to find fertilizer use profitable than other households with similar agro-ecological and market access conditions. Second, farmers' proximity to the provincial centers has a significant impact on the profitability of fertilizer use. Greater distances and transport costs from provincial centers erode the profitability of fertilizer use. Third, high interest rates also reduce the profitability of fertilizer use. Small farmers may find fertilizer use unprofitable until efforts are made to reduce transportation costs and interest rates as well as to ensure more timely delivery of fertilizer.
Pseudo-self-affine tilings in R^d
Creators: name: Solomyak, Boris
Publisher: name: arXiv
Year: 2005
Subjects: subject: Dynamical Systems (math.DS)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 52C22

description: It is proved that every pseudo-self-affine tiling in R^d is mutually locally derivable with a self-affine tiling. A characterization of pseudo-self-similar tilings in terms of derived Voronoi tessellations is a corollary. Previously, these results were obtained in the planar case, jointly with Priebe Frank. The new approach is based on the theory of graph-directed iterated function systems and substitution Delone sets developed by Lagarias and Wang.
description: 16 pages, submitted to a volume dedicated to A. M. Vershik
Destabilising Farmers' Revenues by Shifting to Direct Payments? The Case of EU's Common Agricultural Policy
Creators: name: Hansen, Heiko
name: Hansen, Heiko
Publisher: name: Unknown
Year: 2006
Subjects: subject: Agricultural and Food Policy
subject: Common Agricultural Policy (CAP)
subject: revenue stabilisation
subject: direct payments
subject: Producer Support Estimate (PSE)

description: This paper quantifies the effects of EU's Common Agricultural Policy (CAP) on the instability of domestic farmers' revenues during the period 1986 to 2004. Comparing explicitly the situations with and without policy shows that CAP transfers have lowered the variability of revenues for major commodities through time. The decomposition of agricultural support allows to reveal the impacts of single instruments on instability and indicates that arable area and beef headage payments, introduced in the 1990s, tend to stabilise domestic farmers' revenues. With market price support, however, farmers' revenues are more stable.
Small scale contributions to CMB: A coherent analysis
Creators: name: Douspis, Marian
name: Aghanim, Nabila
name: Langer, Mathieu
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We reanalyse Cosmic Microwave Background data from experiments probing both large and small scales. We assume that measured anisotropies are due not only to primary fluctuations but also, especially at small scales, to secondary effects (namely the Sunyaev-Zel'dovich effect) and possible point source contaminations. We first consider primary and secondary anisotropies only. For the first time in such analyses, the cosmological dependence of secondary fluctuations is fully taken into account. We show in that case that a higher value of the normalisation $σ\_8$ is preferred, as found by previous studies, but also higher values of the optical depth $τ$ and power spectrum index $n\_s$ are needed. In the second part of our analysis, we further include possible contaminations from unresolved and unremoved point sources. Under these considerations, we discuss the effects on the cosmological parameters. We further obtain the best combination of relative contributions of the three kinds of sources to the measured microwave power on small scales at each frequency. Our method allows us to simultaneously obtain cosmological parameters and explain the so-called small scale power excess in a consistent way.
description: 9 pages
A Computational Study of Exact Subgraph Based SDP Bounds for Max-Cut, Stable Set and Coloring
Creators: name: Gaar, Elisabeth
name: Rendl, Franz
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 90C22, 90C27

description: The "exact subgraph" approach was recently introduced as a hierarchical scheme to get increasingly tight semidefinite programming relaxations of several NP-hard graph optimization problems. Solving these relaxations is a computational challenge because of the potentially large number of violated subgraph constraints. We introduce a computational framework for these relaxations designed to cope with these difficulties. We suggest a partial Lagrangian dual, and exploit the fact that its evaluation decomposes into several independent subproblems. This opens the way to use the bundle method from non-smooth optimization to minimize the dual function. Finally computational experiments on the Max-Cut, stable set and coloring problem show the excellent quality of the bounds obtained with this approach.
description: arXiv admin note: substantial text overlap with arXiv:1902.05345
The state of glacier hydrology research in Canada
Creators: name: Hanly, Katherine
name: Marshall, Shawn
name: McDowell, Graham
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Ecology
subject: FOS: Biological sciences
subject: Science Policy

description: Glaciers across Canada are rapidly retreating, engendering significant implications for glacier-fed hydrological systems, ranging from aquatic ecology and groundwater recharge to downstream economic activities and traditional cultural values. Despite a well-developed body of literature regarding glacio-hydrological systems and dynamics, there has been no systematic assessment of this research to date. In response, this study adopted a systematic review methodology to examine the state of existing peer-reviewed glacio-hydrological literature in Canada (1900–2021). We found that peer-reviewed glacio-hydrological research in Canada emerged in the early 1950s and has substantially grown over the last two decades, with almost all work being done by natural scientists using field-based approaches to examine physical hydrology, water quantity and resources, and water quality in western Canada. There is a declining trend in research related to glacio-hydrological hazards and a relative lack of research related to glacier ecohydrology, human vulnerability, and adaptation. The absence of such work constrains our ability to adapt to the consequences of climatic change and other anthropogenic stressors. In highlighting these gaps, this study aims to inform research needs and contribute to evidence-based policy formation that supports regionally appropriate plans, enhancing our ability to navigate the current and future challenges facing glacio-hydrologic systems in Canada, including the human and non-human systems that depend on them.
Onasch, Konrad, Einführung in die Konfessionskunde der orthodoxen Kirchen ...
Creators: name: Schaeder, Hildegard
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 11 Nr. 3 (1962): Ökumenische Rundschau, Band 11, Heft 3
Improving Agricultural Market Access for African LDCs: Deepening, Widening, Broadening and Strengthening Trade Preferences
Creators: name: Yu, Wusheng
name: Yu, Wusheng
Publisher: name: Unknown
Year: 2006
Subjects: International Relations/Trade

description: The July Package of WTO agricultural trade negotiations and the recent Hong Kong WTO Ministerial declaration call for duty and quota-free access for imports originated from least developed countries, including the African LDCs (ALDCs). This paper discusses the merits of this proposal. The usefulness of preferences has been revealed by the high utilization rate of agricultural trade preferences and the case for improving trade preferences is supported by the possibility of preference erosions. Based on these, this paper interprets the July Package text as deepening, widening, broadening and strengthening trade preferences. A set of CGE simulations illustrates the potential impact of implementing this proposal. The first scenario confirms the ALDCs' vulnerability in multilateral liberalization. Deepening and widening trade preferences (scenario 2) would more than offset these negative effects. At the same time, harmonizing the preferences programs would help reveal true comparative advantages of the ALDCs. Adding selected advanced developing countries to the preference-granting group (i.e., broadening preferences) would further expand exports from the ALDCs. It should be noted that the added benefits from broadening preferences would be smaller than what could be achieved from the deepening and widening scenario. However, these estimated benefits would not be fully realized without strengthening the legal foundation of the preference programs and the ALDCs need to conduct domestic policies reforms aiming at creating an enabling environment for their exportoriented industry to take advantage of this opportunity.
Motors Employing Superconducting DC Field Windings and Cryogenically Cooled Conventional Conductor AC Windings for Aircraft Applications
Creators: name: Kalsi, S
name: Lumsden, Grant
name: Storey, James
name: Badcock, Rodney
Publisher: name: Open Access Te Herenga Waka-Victoria University of Wellington
Year: 2024
Subjects: classificationCode: 51
subject: Physical sciences
subject: FOS: Physical sciences
classificationCode: 40
subject: Engineering
classificationCode: 4008
subject: Electrical engineering

description: Significant effort is being applied globally to develop lightweight, highly efficient motors and generators for airplane applications. These machines employ a variety of architectures, with designers choosing between permanent or coil magnets for excitation, air-core or ironcore magnetic circuits, and copper, aluminums or superconducting windings. Air-core machines (no magnet iron) have the potential to be the most lightweight and efficient. These machines can use superconductors for both DC excitation field coils and AC armature coils, however the AC coils proposed rely on the availability of new conductors such as MgB2 and Bi2212, which are still in development. Roadmaps for large electric aircraft include cryogenic fuels, and if liquid-hydrogen (LH2) is available on a plane and can be used as a coolant, it becomes feasible to develop machines with AC armature coils made from cryogenically cooled conventional conductors such as copper, aluminum, and high-purity aluminum (hyper-Al). Aluminum and copper exhibit a very large reduction in electrical resistivity as the temperature drops below 100K and this has a significant effect on the power density and efficiency of an electric motor designed to operate with these winding temperatures. A 3 MW, 4,500 RPM motor is a useful benchmark for application in electric thrusters. We present a design employing REBCO CORC conductor for the DC field coils and investigate a selection of conventional conductors for the AC armature coils, all cooled to around 20K by LH2 available on the plane. The rotor and stator coils are contained in separate cryostats, allowing the flexibility to operate them at different temperatures. Superconducting DC excitation coils are retained on the rotor and are operated at 40 K to work successfully with a brushless flux pump exciter. In this study motor efficiency, mass and losses are compared for stator windings employing copper, aluminum, and high-conductivity aluminum (Hyper-Al). Compared with copper and aluminum machines, the machine employing Hyper-Al has the best efficiency, mass and total losses.
The radiative potential method for calculations of QED radiative corrections to energy levels and electromagnetic amplitudes in many-electron atoms
Creators: name: Flambaum, V. V.
name: Ginges, J. S. M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We derive an approximate expression for a "radiative potential" which can be used to calculate QED strong Coulomb field radiative corrections to energies and electric dipole (E1) transition amplitudes in many-electron atoms with an accuracy of a few percent. The expectation value of the radiative potential gives radiative corrections to the energies. Radiative corrections to E1 amplitudes can be expressed in terms of the radiative potential and its energy derivative (the low-energy theorem): the relative magnitude of the radiative potential contribution is ~alpha^3 Z^2 ln(1/(alpha^2 Z^2)), while the sum of other QED contributions is ~alpha^3 (Z_i+1)^2, where Z_i is the ion charge; that is, for neutral atoms (Z_i=0) the radiative potential contribution exceeds other contributions ~Z^2 times. The advantage of the radiative potential method is that it is very simple and can be easily incorporated into many-body theory approaches: relativistic Hartree-Fock, configuration interaction, many-body perturbation theory, etc. As an application we have calculated the radiative corrections to the energy levels and E1 amplitudes as well as their contributions (-0.33% and 0.42%, respectively) to the parity non-conserving (PNC) 6s-7s amplitude in neutral cesium (Z=55). Combining these results with the QED correction to the weak matrix elements (-0.41%) we obtain the total QED correction to the PNC 6s-7s amplitude, (-0.32 +/- 0.03)%. The cesium weak charge Q_W=-72.66(29)_{exp}(36)_{theor} agrees with the Standard Model value Q_W^{SM}=-73.19(13), the difference is 0.53(48).
description: 29 pages, 2 figures
Relativistic Positioning Systems
Creators: name: Coll, Bartolomé
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The theory of relativistic {\em location systems} is sketched. An interesting class of these systems is that of relativistic {\em positioning systems,} which consists in sets of four clocks broadcasting their proper time. Among them, the more important ones are the {\em auto-located positioning systems,} in which every clock broadcasts not only its proper time but the proper times that it receives from the other three. At this level, no reference to any exterior system (the Earth surface, for example) and no synchronization are needed. Some properties are presented. In the SYPOR project, such a structure is proposed, eventually anchored to a classical reference system on the Earth surface, as the best relativistic structure for Global Navigation Satellite Systems.
description: 8 pages; 1 figure; to appear in Proc. Spanish Relativity Meeting ERE-2005, Oviedo (Spain); v2: minor formal changes
Inertial Measurements for Motion Compensation in Weight-bearing Cone-beam CT of the Knee
Creators: name: Maier, Jennifer
name: Nitschke, Marlies
name: Choi, Jang-Hwan
name: Gold, Garry
name: Fahrig, Rebecca
name: Eskofier, Bjoern M.
name: Maier, Andreas
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Involuntary motion during weight-bearing cone-beam computed tomography (CT) scans of the knee causes artifacts in the reconstructed volumes making them unusable for clinical diagnosis. Currently, image-based or marker-based methods are applied to correct for this motion, but often require long execution or preparation times. We propose to attach an inertial measurement unit (IMU) containing an accelerometer and a gyroscope to the leg of the subject in order to measure the motion during the scan and correct for it. To validate this approach, we present a simulation study using real motion measured with an optical 3D tracking system. With this motion, an XCAT numerical knee phantom is non-rigidly deformed during a simulated CT scan creating motion corrupted projections. A biomechanical model is animated with the same tracked motion in order to generate measurements of an IMU placed below the knee. In our proposed multi-stage algorithm, these signals are transformed to the global coordinate system of the CT scan and applied for motion compensation during reconstruction. Our proposed approach can effectively reduce motion artifacts in the reconstructed volumes. Compared to the motion corrupted case, the average structural similarity index and root mean squared error with respect to the no-motion case improved by 13-21% and 68-70%, respectively. These results are qualitatively and quantitatively on par with a state-of-the-art marker-based method we compared our approach to. The presented study shows the feasibility of this novel approach, and yields promising results towards a purely IMU-based motion compensation in C-arm CT.
description: 10 pages, 2 figures, 2 tables, accepted at MICCAI 2020
Incommensurate Mott Insulator in One-Dimensional Electron Systems close to Quarter Filling
Creators: name: Yoshioka, Hideo
name: Seo, Hitoshi
name: Fukuyama, Hidetoshi
Publisher: name: arXiv
Year: 2005
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: A possibility of a metal-insulator transition in molecular conductors has been studied for systems composed of donor molecules and fully ionized anions with an incommensurate ratio close to 2:1 based on a one-dimensional extended Hubbard model, where the donor carriers are slightly deviated from quarter filling and under an incommensurate periodic potential from the anions. By use of the renormalization group method, interplay between commensurability energy on the donor lattice and that from the anion potential has been studied and it has been found that an "incommensurate Mott insulator" can be generated. This theoretical finding will explain the metal-insulator transition observed in (MDT-TS)(AuI$_2$)$_{0.441}$.
description: 4 pages, 4 figures, submitted to J. Phys. Soc. Jpn. at December 24 2004
Food Safety as a Global Public Good: Is There Underinvestment?
Creators: name: Unnevehr, Laurian J.
name: Unnevehr, Laurian J.
Publisher: name: Unknown
Year: 2006
Subjects: subject: Food Consumption/Nutrition/Food Safety
subject: food safety
subject: global public good
subject: trade facilitation

description: Globalization of the food system is shaped by demand trends that bring about deep integration of agricultural production and marketing. As diets and food quality become more similar around the world, risks are shared across borders, creating global public "goods" and "bads." Examples of globally shared food safety risks include acute risks such as microbial pathogens, as well as chronic risks, such as those arising from pesticide residues or mycotoxins. Food safety is addressed as a global public good through private sector efforts, institutional innovations such as the SPS agreement under the WTO, and trade capacity building efforts to improve food safety management for developing country exports. Data on food safety import violations from the U.S. and the EU show where the global food system is experiencing failures in delivering safe food. Microbial pathogens in seafood are an area of common concern; other problems reflect differences in standards between these two major high income markets. WTO's database on trade facilitation shows that most efforts focus on general capacity building and only a few address specific risks or commodities. Although meeting standards for high income consumers motivates trade facilitation, the spillovers for developing country consumers from such investments could be large.
Generalized Boltzmann formalism for oscillating neutrinos
Creators: name: Strack, P.
name: Burrows, A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics (astro-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: In the standard approaches to neutrino transport in the simulation of core-collapse supernovae, one will often start from the classical Boltzmann equation for the neutrino's spatial, temporal, and spectral evolution. For each neutrino species, and its anti-particle, the classical density in phase space, or the associated specific intensity, will be calculated as a function of time. The neutrino radiation is coupled to matter by source and sink terms on the "right-hand-side" of the transport equation and together with the equations of hydrodynamics this set of coupled partial differential equations for classical densities describes, in principle, the evolution of core collapse and explosion. However, with the possibility of neutrino oscillations between species, a purely quantum-physical effect, how to generalize this set of Boltzmann equations for classical quantities to reflect oscillation physics has not been clear. To date, the formalisms developed have retained the character of quantum operator physics involving complex quantities and have not been suitable for easy incorporation into standard supernova codes. In this paper, we derive generalized Boltzmann equations for quasi-classical, real-valued phase-space densities that retain all the standard oscillation phenomenology, including resonant flavor conversion (the MSW effect), neutrino self-interactions, and the interplay between decohering matter coupling and flavor oscillations. With this formalism, any code(s) that can now handle the solution of the classical Boltzmann or transport equation can easily be generalized to include neutrino oscillations in a quantum-physically consistent fashion.
description: 8 pages, 4 figures, accepted to Phys. Rev. D
Non-abelian vector backgrounds with restored Lorentz invariance
Creators: name: Dietrich, Dennis D.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The influence of vector backgrounds with restored Lorentz invariance on non-abelian gauge field theories is studied. Lorentz invariance is ensured by taking the average over a Lorentz invariant ensemble of background vectors. Like in the abelian case [hep-ph/0506210], the propagation of fermions is suppressed over long distances. Contrary to the fermionic sector, pure gauge configurations of the background suppress the long-distance propagation of the bosons only partially, i.e. not beyond the leading contribution for a large number of colours.
description: 6 pages, no figures
The autonomous hidden camera crew
Creators: name: Callemein, Timothy
name: Van Ranst, Wiebe
name: Goedemé, Toon
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Reality TV shows that follow people in their day-to-day lives are not a new concept. However, the traditional methods used in the industry require a lot of manual labour and need the presence of at least one physical camera man. Because of this, the subjects tend to behave differently when they are aware of being recorded. This paper will present an approach to follow people in their day-to-day lives, for long periods of time (months to years), while being as unobtrusive as possible. To do this, we use unmanned cinematographically-aware cameras hidden in people's houses. Our contribution in this paper is twofold: First, we create a system to limit the amount of recorded data by intelligently controlling a video switch matrix, in combination with a multi-channel recorder. Second, we create a virtual camera man by controlling a PTZ camera to automatically make cinematographically pleasing shots. Throughout this paper, we worked closely with a real camera crew. This enabled us to compare the results of our system to the work of trained professionals.
description: 4 pages, 6 figures
Food Safety. Commodity Science Point of View
Creators: name: Zalewski, Romuald I.
name: Skawinska, Eulalia
name: Zalewski, Romuald I.
name: Skawinska, Eulalia
Publisher: name: Unknown
Year: 2006
Subjects: subject: Food Consumption/Nutrition/Food Safety
subject: food safety
subject: food quality
subject: risk

description: The paper addresses "food safety" and 'food quality' from the position of commodity and food science rather than economy. The various descriptions of both terms in literature are reviewed in connection with customer/supplier ability to evaluate food safety and quality by examination of various characteristics. Food safety has been described as opposite to food risk. Differences in perception of food risk by customer, producer/supplier and official agencies are discussed in this paper. The objective safety (and quality) of food can be evaluated using three categories of food risk (biological, chemical and physical) measured on a seven step intensity scale by producers and official agencies but not by customers. This leads to formulating food safety policy which has been described as a set of voluntary, obligatory and supplementary systems under inspection of official bodies. The efficiency of this formulation has been examined and described for Wielkopolska region of Poland. The results indicate sufficient analytical performance of laboratories in industry and some gaps in co-operation with official food safety control institutions.
1,3-dipolar cycloadditions with porphyrins
Creators: name: Flemming, Jeffrey
Publisher: name: University of British Columbia
Year: 2009

description: The objective of this work is to use 1,3-dipolar cycloadditions to synthesize novel aromatic compounds based on meso-phenyl substituted porphyrins. These compounds are potential photosensitizers for use in photodynamic therapy. Tetraphenylporphyrins with a variety of substituents were reacted with selected 1,3-dipoles. Tetraphenylporphyrin (TPP), 5,10-diphenylporphyrin (DPP), and tetrakis(pentafluorophenyl)porphyrin (pFTPP) were used in reactions with azomethine ylides, carbonyl ylides, diazoalkanes, nitrile oxides, thiocarbonyl ylides, nitrile ylides, and ozone, with varying results. Centrally metallated porphyrins were also used. Azomethine ylides reacted with pFTPP efficiently giving cycloadducts of pFTPP. Three n-substituted azomethine ylides (R = benzyl, 3,5-dimethoxybenzyl, and propyl) were used. The different substituents on the pyrrolidine ring did not affect the ultra-violet / visible (UV-Vis) spectra of the chlorin. Carbonyl ylides form cycloadducts with both TPP and pFTPP. The electron deficient pFTPP reacts with non-stabilized carbonyl ylides, while TPP reacts with the electron deficient tetracyano-substituted carbonyl ylide. These results highlight the differences in reactivity of these two porphyrins. The cyano groups of 42 were hydrolyzed with concentrated hydrochloric acid, and then methylated giving 41. Changes were observed in the UV-Vis spectra as the substituents were modified. Diazomethane gave the cycloadduct pyrazoline with pFTPP (45). Compound 45 was then subjected to heat or light, both of which caused the loss of N₂ giving the cyclopropane 46. The UV-Vis a spectrum of the cyclopropane derivative was red-shifted as compared to the pyrazoline, possibly by distortion in the porphyrin ring system as a result of the cyclopropane ring.
Online Test Vector Insertion: A Concurrent Built-In Self-Testing (CBIST) Approach for Asynchronous Logic
Creators: name: Maier, Jürgen
name: Steininger, Andreas
Publisher: name: arXiv
Year: 2020
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences
subject: B.6.2; B.5.3

description: Complementing concurrent checking with online testing is crucial for preventing fault accumulation in fault-tolerant systems with long mission times. While implementing a non-intrusive online test is cumbersome in a synchronous environment, this task becomes even more challenging in asynchronous designs. The latter receive increasing attention, mainly due to their elastic timing behaviour; however the issues related with their testing remain a key obstacle for their wide adoption. In this paper we present a novel approach for testing of asynchronous circuits that leverages the redundancy present in the conventional 4-phase protocol for implementing a fully transparent and fully concurrent test procedure. The key idea is to use the protocol's unproductive NULL phase for processing test vectors, thus effectively interleaving the incoming 4-phase data stream with a test data stream in a 2-phase fashion. We present implementation templates for the fundamental building blocks required and give a proof-of-concept by an example application that also serves as a platform for evaluating the overheads of our solution which turn out to be moderate.
description: 7 pages, 9 figures