The symbolic model for algebra : functions and mechanisms

The symbolic mode of reasoning in algebra, as it emerged during the sixteenth century, can be considered as a form of model-based reasoning. In this paper we will discuss the functions and mechanisms of this model and show how the model relates to its arithmetical basis. We will argue that the symbolic model was made possible by the epistemic justification of the basic operations of algebra as practiced within the abbaco tradition. We will also show that this form of model-based reasoning facilitated the expansion of the number concept from Renaissance interpretations of number to the full notion of algebraic numbers

Испытание изоляции вакуумного выключателя на трекингостойкость

Выпускная квалификационная работа содержит 146 с., 45 рисунков, 17 таблиц, 36 источников, 7 приложений. Ключевые слова: трекингостойкость, полиэтилен, стеклотекстолит, полистирол, оргстекло, винипласт, фторопласт, фарфор Объектом исследования являются электроизоляционные материалы подверженные трекингом. Цель работы – определение трекингостойкости различных электроизоляционных материалов. В процессе работы проводились экспериментальные испытания на трекингостойкость различных электроизоляционных материалов, согласно ГОСТ 27473. В результате выполнения работы была сконструирована установка для проведения испытаний на трекингостойкость, проведены эксперименты по определению трекингостойкости, оргстекла, фторопласта-4, фарфора, твердого поливинилхлорида ПВХ, полиэтилена низкого давления.Finale qualifiziert Arbeit enthält 146 p . , 45 Abbildungen, Tabellen 17, 36 Quellen 7-Anwendungen . Stichwort: -verfolgung , Polyethylen, Glasfaser , Polystyrol, Acryl, Vinyl -Liner , Teflon, Porzellan Die Aufgabe der Studie sind Isoliermaterialien anfällig für Verfolgung. Ziel - Definieren Verfolgung verschiedenen Dämmstoffen . In dem Prozess , ein Pilottest- Tracking von verschiedenen elektrischen Isoliermaterialien nach GOST 27473. der Durchführung Als ein Ergebnis der Arbeit für die Installation der on- Tracking- Tests entwickelt wurde, durchgeführten Experimente zu bestimmen -tracking , Plexiglas, PTFE -4 , Porzellan, aus Hart-Polyvinylchlorid PVC , HDPE, eine vergleichende Analyse von Dämmstoffen -tracking

Open-Source ANSS Quake Monitoring System Software

ANSS stands for the Advanced National Seismic System of the U.S.A., and ANSS Quake Monitoring System (AQMS) is the earthquake management system (EMS) that most of its member regional seismic networks (RSNs) use. AQMS is based on Earthworm, but instead of storing files on disk, it uses a relational database with replication capability to store pick, amplitude, waveform, and event parameters. The replicated database and other features of AQMS make it a fully redundant system. A graphical user interface written in Java, Jiggle, is used to review automatically generated picks and event solutions, relocate events, and recalculate magnitudes. Add‐on mechanisms to produce various postearthquake products such as ShakeMaps and focal mechanisms are available as well. It provides a configurable automatic alarming and notification system. The Pacific Northwest Seismic Network, one of the Tier 1 ANSS RSNs, has modified AQMS to be compatible with a freely available, capable, open‐source database system, PostgreSQL, and is running this version successfully in production. The AQMS Software Working Group has moved the software from a subversion repository server hosted at the California Institute of Technology to a public repository at gitlab.com. The drawback of AQMS as a whole is that it is complex to fully configure and comprehend. Nevertheless, the fact that it is very capable, documented, and now free to use, might make it an attractive EMS choice for many seismic networks

Phase transitions and the internal noise structure of nonlinear Schr\"odi nger equation solitons

We predict phase-transitions in the quantum noise characteristics of systems described by the quantum nonlinear Schr\"odinger equation, showing them to be related to the solitonic field transition at half the fundamental soliton amplitude. These phase-transitions are robust with respect to Raman noise and scattering losses. We also describe the rich internal quantum noise structure of the solitonic fields in the vicinity of the phase-transition. For optical coherent quantum solitons, this leads to the prediction that eliminating the peak side-band noise due to the electronic nonlinearity of silica fiber by spectral filtering leads to the optimal photon-number noise reduction of a fundamental soliton.Comment: 10 pages, 5 figure

Spin of random stationary light

We develop a theoretical foundation for the spin angular momentum (SAM) of random, statistically stationary polychromatic light fields within the framework of classical optical coherence theory. The formulation is valid for fields of arbitrary frequency bandwidth and dimensionality. Both temporal and spectral representations are given, and we further elucidate the relationship between the SAM and the polarization characteristics of such fields as compared to monochromatic light. The special cases of quasimonochromatic light and planar fields are analyzed separately. Generally, our paper offers deeper insights into the SAM and polarization structures as well as their interlinked connections in random stationary light, which could be beneficial in exploiting SAM in stochastic optical near fields and tightly focused beams exhibiting complex polarization character

Descriptors of dimensionality for n × n density matrices

By using the recently introduced parametrization of an n-dimensional density matrix in terms of the indices of population asymmetry and the intrinsic coherences, we define descriptors in both integer and continuous forms of the effective dimension that take place for a complete description of a density matrix, thus providing accurate information beyond the rank of the density matrix. The concepts of dimensional folding, hidden dimensional purity, and dimensional entropy are introduced and discussed in view of the new approach presented. The results are applicable to any physical system represented by a density matrix, such as n-level quantum systems, qutrits, sets of interacting pencils of radiation, classical polarization states, and to transformations of density matrices, as occurs with quantum channels

Efficient generation of correlated photon pairs in a microstructure fiber

We report efficient generation of correlated photon pairs through degenerate four-wave mixing in microstructure fibers. With 735.7 nm pump pulses producing conjugate signal (688.5 nm) and idler (789.8 nm) photons in a 1.8 m microstructure fiber, we detect photon pairs at a rate of 37.6 kHz with a coincidence/accidental contrast of 10:1 with a full-width-at-half-maximum bandwidth of 0.7 nm. This is the highest rate reported to date in a fiber-based photon source. The nonclassicality of this source, as defined by the Zou-Wang-Mandel inequality, is violated by 1100 times the uncertainty.Comment: 11 pages, 3 figure

Influence of Feeding Regime on Growth and Body Size in the Boa (Boa Imperator)

Because snakes are gape-limited predators, much emphasis has been placed on the role of prey size in inducing plastic changes to trophic morphology. In contrast, few studies have researched the effect of feeding frequency on growth and body size, even though many snakes experience long fasting periods between meals. We conducted an experimental, multiple year study of growth in Boas, (Boa imperator) that experienced different feeding regimes. Three liters of full siblings were randomly assigned into two groups. One group received a meal equal to 5% of their body mass every 7 days and the other group received a meal equal to 25% body mass in food every 35 days. Using x-ray radiographs, we measured body size and a several skeletal morphological variables before the feeding regimes began and annually thereafter. We observed that those boas fed frequently grew larger in body mass and exhibited greater robustness, whereas boas feed infrequently had lower body mass and were laterally compressed. Our results suggest that phenotypic plasticity resulting from feeding frequency may play a role in morphological diversity. Further, the changes we observed mirrored the evolutionary changes of mainland and island populations boas from Central America