Steering a quantum system over a Schroedinger bridge

A new approach to the steering problem for quantum systems relying on Nelson's stochastic mechanics and on the theory of Schroedinger bridges is presented. The method is illustrated by working out a simple Gaussian example.Comment: Proc. Intern. Conf. on the Mathematical Theory of Networks and Systems, Perpignan, France, June 2000, CD-ROM, paper nr. 268, M. Fliess and A. El Jai Ed

The effect of Tricresyl-Phosphate (TCP) as an additive on wear of Iron (Fe)

The effect of tricresyl phosphate (TCP) as an antiwear additive in lubricant trimethyol propane triheptanoate (TMPTH) was investigated. The objective was to examine step loading wear by use of surface analysis, wetting, and chemical bonding changes in the lubricant. The investigation consisted of steploading wear studies by a pin or disk tribometer, the effects on wear related to wetting by contact angle and surface tension measurements of various liquid systems, the chemical bonding changes between lubricant and TCP chromatographic analysis, and by determining the reaction between the TCP and metal surfaces through wear scar analysis by Auger emission spectroscopy (AES). The steploading curve for the base fluid alone shows rapid increase of wear rate with load. The steploading curve for the base fluid in presence of 4.25 percent by volume TCP under dry air purge has shown a great reduction of wear rate with all loads studied. It has also been found that the addition of 4.25 percent by volume TCP plus 0.33 percent by volume water to the base lubricant under N2 purge also greatly reduces the wear rate with all loads studied. AES surface analysis reveals a phosphate type wear resistant film, which greatly increases load-bearing capacity, formed on the iron disk. Preliminary chromatographic studies suggest that this film forms either because of ester oxidation or TCP degradation. Wetting studies show direct correlation between the spreading coefficient and the wear rate

Decompositions of Triangle-Dense Graphs

High triangle density -- the graph property stating that a constant fraction of two-hop paths belong to a triangle -- is a common signature of social networks. This paper studies triangle-dense graphs from a structural perspective. We prove constructively that significant portions of a triangle-dense graph are contained in a disjoint union of dense, radius 2 subgraphs. This result quantifies the extent to which triangle-dense graphs resemble unions of cliques. We also show that our algorithm recovers planted clusterings in approximation-stable k-median instances.Comment: 20 pages. Version 1->2: Minor edits. 2->3: Strengthened {\S}3.5, removed appendi

The effect of residential urban greenness on allergic respiratory diseases in youth: A narrative review

Background: Environmental exposures across the life course may be a contributor to the increased worldwide prevalence of respiratory and allergic diseases occurring in the last decades. Asthma and rhinoconjunctivitis especially contribute to the global burden of disease. Greenness has been suggested to have beneficial effects in terms of reduction of occurrence of allergic respiratory diseases. However, the available evidence of a relationship between urban greenness and childhood health outcomes is not yet conclusive. The current review aimed at investigating the current state of evidence, exploring the relationship between children's exposure to residential urban greenness and development of allergic respiratory diseases, jointly considering health outcomes and study design. Methods: The search strategy was designed to identify studies linking urban greenness exposure to asthma, rhinoconjunctivitis, and lung function in children and adolescents. This was a narrative review of literature following PRISMA guidelines performed using electronic search in databases of PubMed and Embase (Ovid) from the date of inception to December 2018. Results: Our search strategy identified 2315 articles; after exclusion of duplicates (n = 701), 1614 articles were screened. Following review of titles and abstracts, 162 articles were identified as potentially eligible. Of these, 148 were excluded following full-text evaluation, and 14 were included in this review. Different methods for assessing greenness exposure were found; the most used was Normalized Difference Vegetation Index. Asthma, wheezing, bronchitis, rhinoconjunctivitis, allergic symptoms, lung function, and allergic sensitization were the outcomes assessed in the identified studies; among them, asthma was the one most frequently investigated. Conclusions: The present review showed inconsistencies in the results mainly due to differences in study design, population, exposure assessment, geographic region, and ascertainment of outcome. Overall, there is a suggestion of an association between urban greenness in early life and the occurrence of allergic respiratory diseases during childhood, although the evidence is still inconsistent. It is therefore hard to draw a conclusive interpretation, so that the understanding of the impact of greenness on allergic respiratory diseases in children and adolescents remains difficult

Variations in pulp/tooth area ratio as an indicator of age: a preliminary study

This paper details for age determination of adult from single rooted theeth. The sample consisted of 100 Italians white Caucasioan patients (46 men, 54 womwn) aged between 18 and 72 years. The single rooted maxillary right canine was utilized in this preliminary study. Pulp/root ration, tooth length ratio, pulp/root area and pulp/root width ratios at three different levels were computed. Pearson's correlation coefficients between age and these variables showed that the ratio between pulp and tooth area correlated best with age (r2 = 0,85). Stepwise multiple regression models yielded a linear relationship between pulp/root width at mid-root level and chronological age and a linear relationship when pulp/tooth area was compared to age. Statistical analysis indicated that these two variables explain 84,9% of variations in estimated chronological age. The median of the absolute value of residual errors between actual and estimated ages was less than four years

Age estimation in children by measurement of open apices in teeth

This paper concerns a method for estimating the age of children based on their teeth. The sample consisted of 455 Italian white children (213 boys, 242 girls) aged between 5 and 15 years. The purpose of the present investigation was to present a method for assessing chronological age based on the relationship between age and measurement of the open apices in teeth. Pearson\u2019s correlation coefficients between age and these variables showed that the correlations between age and the open apices in teeth were significant and negative. Furthermore, gender and the number of teeth with the apical end of the root canals completely closed (N0) showed a significant correlation with chronological age. With the aid of a stepwise multiple regression model, a linear relationship between open apices, N0, and age was shown. Statistical analysis indicated that these morphological variables explain 83.6% of the variations in estimated chronological age. The median of residual errors between the actual and estimated ages was 120.035 years [interquartile range (IQR)=1.18 years]

A new markovian model for tennis matches

In this paper we present a generalisation of previously considered Markovian models for Tennis that overcome the assumption that the points played are i.i.d. Indeed, we postulate that in any game there are two different situations: the first 6 points and the, possible, additional points after the first deuce, with different winning probabilities. We are able to compute the winning probabilities and the expected number of points played to complete a game and a set in this more general setting. We apply our results considering scores of matches between Novak Djokovic, Roger Federer and Rafael Nadal

Empathes: A general code for nudged elastic band transition states search

An easy and flexible interface, Empathes (Extensible Minimum PATH EStimator), that allows to perform Nudged Elastic Band calculation for the determination of transition states is presented. The code is designed to be easily modified, in order to be associated with the user's preferred calculation software, even with those which implement composite approaches. In particular, the interfaces to Gaussian and Siesta programs are discussed in details, being the former only used for testing purpose, while the latter can be productively employed for transition states search with that commonly used density functional theory software for periodic calculations. Program summary: Program Title: Empathes CPC Library link to program files: https://doi.org/10.17632/v525mwf3cc.1 Developer's repository link: https://github.com/marberti/empathes Code Ocean capsule: https://codeocean.com/capsule/2394233 Licensing provisions: GPLv3 Programming language: Fortran 08 Nature of problem: The search for the structure of transition states through computational methods, essentially based on Density Functional Theory, is of overwhelming importance for the determination of the elementary steps forming a reaction mechanism. Allowing to develop basic knowledge, these investigations can be used to direct experimentalists towards a more efficient realization of chemical compounds synthetic processes. In cases where it is necessary to describe the reactive system through periodic calculations, which is very common in heterogeneous catalysis, this research must be done through the use of non-analytical methods. Solution method: In case of lacking of analytical procedures, the search for the transition states associated with the elementary stages that make up chemical reactions must take place through numerical methods. The Nudged Elastic Band (NEB) approach is, together with its variants, one of the most used for this purpose. In accordance with the NEB algorithm, a chain of geometric structures, generated by interpolating between the reactant and product geometries and joined by fictitious springs, is relaxed on the minimum energy path, allowing the association of the transition state to the maximum along this path. The NEB method involves the determination of molecular energies and forces acting on the nuclei of the system, which is generally carried out through a program for electronic structure calculation. The present code is a useful general interface

How long does a tennis game last?

In this paper we present a generalisation of previously considered Markovian models for Tennis that overcome the assumption that the points played are i.i.d and includes the time into the model. Firstly we postulate that in any game there are two different situations: the first 6 points and the, possible, additional points after the first deuce, with different winning probabilities. Then we assume that the duration of any point is distributed with an exponential random time. We are able to compute the law of the (random) duration of a game in this more general setting