Random point sets and their diffraction

The diffraction of various random subsets of the integer lattice $\mathbb{Z}^{d}$, such as the coin tossing and related systems, are well understood. Here, we go one important step beyond and consider random point sets in $\mathbb{R}^{d}$. We present several systems with an effective stochastic interaction that still allow for explicit calculations of the autocorrelation and the diffraction measure. We concentrate on one-dimensional examples for illustrative purposes, and briefly indicate possible generalisations to higher dimensions. In particular, we discuss the stationary Poisson process in $\mathbb{R}^{d}$ and the renewal process on the line. The latter permits a unified approach to a rather large class of one-dimensional structures, including random tilings. Moreover, we present some stationary point processes that are derived from the classical random matrix ensembles as introduced in the pioneering work of Dyson and Ginibre. Their re-consideration from the diffraction point of view improves the intuition on systems with randomness and mixed spectra.Comment: 9 pages, 2 figures; talk presented at ICQ 11 (Sapporo

Investigating life-history polymorphism: modelling mites

The thesis presents research on the life-history polymorphism in the mite Sancassania berlesei. Males of this species are andropolymorphic: there are two distinct male phenotypes. One, the fighter, develops a third thickened leg pair, with which it kills off other fighters and males which do not exhibit a third thickened leg pair, the non-fighters. A review of the life-history of S. berlesei is given, focussing on its general biology, diet, dispersal and mating behaviour. This is followed by a review of the andropolymorphism, and the current understanding of the mechanisms underlying it. The major conclusions from the experimental work presented in this thesis are that fighters primarily develop at low population densities; though the proportion of males becoming fighters at any given density may change over time. This change is likely to be due to condition-dependence. Data is presented to illuminate these matters and a model is developed linking fighter development to the costs of being a fighter (in terms of survival) and the benefits of being a fighter (in terms of fecundity). The sex ratio in S. berlesei is 1:1, and there is no evidence of density or frequency-dependent deviations from this. A delay in food supply at maturation delays the time of maximum fecundity of females for about seven days and lowers their overall egg output. Density-dependent effects reduce the overall daily fecundity of females in higher densities. Female survival is affected by density, food present and rearing conditions. Nearly all eggs laid by S. berlesei hatch regardless of the conditions. Eggs laid in very poor conditions hatched even earlier than the average time of between day three and four. At density two, animals do synchronise their frequency, when isolated together from egg stage. Poor conditions reverse female density-dependence from convex to concave with the lowest life expectancy at intermediate densities. The trade-off between survival and fecundity is the likely cause. Amalgamating the results from the previous experiments, the influence of stochastic population dynamics on male strategy was then modelled. The results indicate that the fighter morph development rule is sensitive to the probability of low population densities arising. When low densities occur, there is a selective advantage to being a fighter. With increasing probability of lower densities, becoming a fighter is more feasible. The ESS rule changes, while in a stable high density environment a density-dependent fighter rule is never selected for. This indicates an influence of stochastic population dynamics on life-history evolution. Modelling demographic stochasticity in the fighter rule shows some buffering effect of this form of stochasticity. The fighter morph determination rule is less sensitive to environmental stochasticity with a high frequency of low densities. Using an agent based model with diploid genetics, I show that under high densities a fighter male is less successful at passing on his genes than a non-fighter. At a density of one male, the fighter gains no advantage to developing the fighter phenotype (as he is not competing with other males). In this case, the advantage may arise through future increases in density (such as through immigration or maturation of offspring). The density-dependent fighter development rule is then switched within the model from density-dependent to frequency-dependent, and the model indicates, that even under the frequency-dependent rule a possible ratio of fighters to non-fighters could exist. The system does not reach this state due to condition-dependence in reality. Following on from the findings discussed above, that morph determination has a condition-dependent component, I develop an argument that relates the observed forms of morph determination (density-dependent and frequency-dependent) in three closely related species of mites via an underlying condition-dependence. It is shown that condition-dependence is likely the linking factor between frequency and density-dependence. This is shown to be possibly a rule for all species displaying polymorphism which includes physical alterations of their bodies

Einzelsprachliche und kontrastive Aspekte der Funktion von Numeralien in deutschen und italienischen Phraseologismen

The article deals with numerals as parts of German and Italian phraseologisms. On the basis of a comprehensive corpus of about 500 formations, first the equivalence relations between the phraseologisms in both languages ​​(full, partial, zero equivalency), then the semantic functions in terms of degree of idiomaticity (non-idiomatized, partially idiomized, fully idiomatized) are researched.Die Verfasserin befasst sich mit Numeralien als Teilen von deutschen und italienischen Phraseologismen. Auf der Grundlage eines ca. 500 Bildungen umfassenden Korpus werden zunächst die Äquivalenzbeziehungen zwischen den Phraseologismen in beiden Sprachen erforscht (Voll-, Teil-, Nulläquivalenz), dann die semantischen Funktionen in Hinblick auf den Idiomatizitätsgrad (nicht-idiomatisiert, teilidiomatisiert, vollidiomatisiert)

Calvino fra italiano e tedesco: sintassi e ritmo nel "Sentiero dei nidi di ragno" (1947) e nella traduzione di Th. Kolberger (1992)

In questo saggio viene presa in esame la traduzione tedesca del 1992 del primo romanzo dello scrittore italiano Italo Calvino, Il sentiero dei nidi di ragno (1947). Collocandosi al crocevia di interessi sia linguistici sia traduttologici, si studia in che modo aspetti sintattici e ritmici tipici dello stile calviniano sono stati resi nella traduzione: in particolare vengono indagati fenomeni quali la paratassi, le dislocazioni a destra o a sinistra oppure la connessione delle frasi mediante il connettore generico che. Complessivamente, la traduzione risulta soggetto a un processo di "normalizzazione" solo in parte ascrivibile a ragioni strutturali della lingua target

Re-Engineering the Acquisition Process of Manufactured On-Demand Only Spares

The purpose of this study is to explore potential alternatives to the current Department of Defense (DoD) acquisition process for low demand, high dollar value, not commercially stocked, spare parts in order to better utilize diminishing resources, reduce cycle costs, and sustain the defense industrial base. Demand for these items is insufficient to justify maintaining inventory, while the buy on-demand alternative results in long lead- times and increased costs due to the labor intensiveness of the current process, lack of willing manufacturing sources, and higher prices paid for small quantities of material. An exploratory case study method was used to study the Defense General Supply Center\u27s (DGSC\u27) acquisition process. Data gathered from secondary data review and from interviews with contracting and technical personnel was used to define the current process, hypothesize a better process, and to evaluate the costs and benefits of both processes. This evaluation lead to the conclusion that electronic commerce, agile manufacturing, and specialized contracting initiatives all have significant potential for improving the acquisition process. Recommendations were made for DGSC to continue research into using electronic commerce, agile manufacturing, and specialized contracting methods to improve the acquisition process

Macroscopic coherence effects in a mesoscopic system: Weak localization of thin silver films in an undergraduate lab

We present an undergraduate lab that investigates weak localization in thin silver films. The films prepared in our lab have thickness, $a$, between 60-200 \AA, a mesoscopic length scale. At low temperatures, the inelastic dephasing length for electrons, $L_{\phi}$, exceeds the thickness of the film ($L_{\phi} \gg a$), and the films are then quasi-2D in nature. In this situation, theory predicts specific corrections to the Drude conductivity due to coherent interference between conducting electrons' wavefunctions, a macroscopically observable effect known as weak localization. This correction can be destroyed with the application of a magnetic field, and the resulting magnetoresistance curve provides information about electron transport in the film. This lab is suitable for Junior or Senior level students in an advanced undergraduate lab course.Comment: 16 pages, 9 figures. Replaces earlier version of paper rejected by Am. J. Phys. because of too much content on vacuum systems. New version deals with the undergraduate experiment on weak localization onl

Deafness: Predicting the future for Scotland

Replaced with updated version 2020-08-11. JRThe exact numbers of deaf people in Scotland varies depending upon which source is consulted. This lack of clarity is problematic when it comes to planning for delivery of future services and it is widely recognised that there is a need to establish better reporting procedures in order to capture relevant statistics. To this end, this research has sought to investigate the source with which the Scottish Government makes policy decisions; the source that is used to ‘allocate resources and plan services’ in Scotland: The 2011 Census for Scotland (Office for National Statistics 2011). As the next Census will be taken in 2021, it would seem timely to look at what information this source currently offers on the prevalence of hearing loss in Scotland and how far it relates to the wider picture. How far does the above definition of the aims and objectives of the Census fit to enable precise data to be captured and recorded and as a result ensure optimum service planning and provision for those with hearing loss in Scotland?https://deafscotland.org/deafscotland-publications/pubpu

Testing and evaluation of nickel-cadmium spacecraft-type cells Final technical report, 6 May 1966 - 6 May 1967

Cycle life testing and evaluation of nickel- cadmium spacecraft batteries - voltage characteristic