A rigorous analysis of the cavity equations for the minimum spanning tree

We analyze a new general representation for the Minimum Weight Steiner Tree (MST) problem which translates the topological connectivity constraint into a set of local conditions which can be analyzed by the so called cavity equations techniques. For the limit case of the Spanning tree we prove that the fixed point of the algorithm arising from the cavity equations leads to the global optimum.Comment: 5 pages, 1 figur

Density functional theory study of the {\alpha} --> {\omega} martensitic transformation in titanium induced by hydrostatic pressure

The martensitic {\alpha} --> {\omega} transition was investigated in Ti under hydrostatic pressure. The calculations were carried out using the density functional theory (DFT) framework in combination with the Birch-Murnaghan equation of state. The calculated ground-state properties of {\alpha} and {\omega} phases of Ti, their bulk moduli and pressure derivatives are in agreement with the previous experimental data. The lattice constants of {\alpha} and {\omega}-phase at 0 K were modeled as a function of pressure from 0 to 74 GPa and 0 to 119 GPa, respectively. It is shown that the lattice constants vary in a nonlinear manner upon compression. The calculated lattice parameters were used to describe the {\alpha} --> {\omega} transition and show that the phase transition can be obtained at 0 GPa and 0 K.Comment: 6 pages, 5 figure

Belief-Propagation for Weighted b-Matchings on Arbitrary Graphs and its Relation to Linear Programs with Integer Solutions

We consider the general problem of finding the minimum weight \bm-matching on arbitrary graphs. We prove that, whenever the linear programming (LP) relaxation of the problem has no fractional solutions, then the belief propagation (BP) algorithm converges to the correct solution. We also show that when the LP relaxation has a fractional solution then the BP algorithm can be used to solve the LP relaxation. Our proof is based on the notion of graph covers and extends the analysis of (Bayati-Shah-Sharma 2005 and Huang-Jebara 2007}. These results are notable in the following regards: (1) It is one of a very small number of proofs showing correctness of BP without any constraint on the graph structure. (2) Variants of the proof work for both synchronous and asynchronous BP; it is the first proof of convergence and correctness of an asynchronous BP algorithm for a combinatorial optimization problem.Comment: 28 pages, 2 figures. Submitted to SIAM journal on Discrete Mathematics on March 19, 2009; accepted for publication (in revised form) August 30, 2010; published electronically July 1, 201

Study the Role of Congenital Toxoplasmosis with Preterm Labor, and Low Birth Weight

The study included 100 samples of blood from women who suffer from premature birth and low fetal weight, and a hundred samples from women who do not suffer from any injury. This study extends from February 1, 2019 to November 1, 2019, where the study included collecting blood samples from all women who entered the study, in addition to collecting information regarding age, weight, height, and history of infection with parasites, if any, to investigate the parasite’s DNA in blood samples collected from patients. These samples were examined using the standard methods provided by the company in which the tests were conducted.  The study included the molecular detection by PCR of toxoplasma genes, where EDTA blood samples were collected from all preterm and term pregnant women in the study. Using laboratory kit for Toxoplasma DNA extraction, samples were extracted and kept in separate sterile tubes using DAN extraction kit (Zymogene, Japan), then the DNA was detected by real-time PCR which was done according to the protocols designed by the manufacturer of the diagnostic kit. The study showed no significant relationship between the two groups regarding mean of ages. But regular contractions, reduced length of cervix and decreased weight of babies was highly related with women presented with preterm birth. The study showed that 87.5% of preterm delivery women with +ve DNA detection of T. gondii have  regular contraction comparing with 12.5% of cases with negative T. gondii infection (P<0.001). The study showed the lowest mean of baby weight at birth was recorded in pregnant women with preterm labor women who infected with T. gondii as compared with cases who were negative to T. gondii infection (P<0.001). The study demonstrated that majority of women with +ve T gondii infection were had positive history of abortion

What are the factors underlying the high educational performance – ‘overachievement’ – of Bangladeshi-heritage primary-school pupils?

This thesis examines the ‘over-achievement’1 of UK Bangladeshi-heritage pupils in the National Curriculum Standard Assessment Tests (SATS) at Key Stage (KS) 2 (year 6; ages 10- 11) in schools in an inner-city borough. The research involved four schools in one of the poorest urban areas of the country.2 The initial attraction for choosing these schools was due to my experience working as a teacher in one and noticing that it consistently attained results above the national average in KS2 SATS while nationally pupils of Bangladeshi-heritage attained below the average. This over-achievement had been noted by Ofsted and generated media attention.3 The aims of this research were to identify and investigate the factors underlying this relative over-achievement of primary-school pupils from a Bangladeshi ethnic background and heritage. My experience as a teacher provided me with insight into the value that education held within Bangladeshi-heritage communities. It was unsurprising, therefore, to find this overachievement. I approached the phenomenon from a different perspective: why weren’t Bangladeshi-heritage communities in other areas doing as well, given their sub-cultural emphasis on education – an asset of their ethnic capital. Using qualitative methodology – thematic analysis – I interviewed pupils, parents and many other significant actors involved in the education of primary pupils in the four over-achieving schools. I had no preconceived thesis. My theoretical conclusions emerged from the data. While gender, ethnicity and social class all influence educational outcomes, it was the schools’ inclusive ethos that seemed to exert the greatest positive influence. 1 ‘Overachievement’ refers to the above the national average results in Key Stage 2 Standard Assessment Tests received by Bangladeshi-heritage pupils in the four schools studied (see Appendix 1 for the Key Stage 2 SAT results). 2 Yet the borough values education. In 2010-11, the guaranteed funding per pupil was £6,792 compared to the national average which was at least £2,500 lower (see Appendix 2 for the Index of Multiple of Deprivation 2010). 3 See BBC Race UK survey 2005, Mike Baker ‘Educational Achievement’

Study of the Effect of Water Depth on Potential Flow Solution of the OC4 Semisubmersible Floating Offshore Wind Turbine

AbstractThis work aims at assessing the influence of water depth on the potential flow solution for a semisubersible floating offshore wind turbine. More specifically, the system developed for the Offshore Code Comparison Collaboration Continuation (OC4) of the Inter- national Energy Agency IEA was considered for this paper. This work has been inspired by previous studies concerning the effect of shallow water on Liquified Natural Gas Carriers (LNGC). The influence of water depth on the hydrodynamics of such systems is evident from measurements as well as from simulations, specifically when secondary effects in the wave and flow modelling are addressed. This scenario has motivated the comparative study for the Floating Wind Turbine herein reported, also taking into account second order hydrodynamics (Quadratic Transfer Functions, QTF) as well as low frequency contribution in the incoming wave, due to shallow water (Setdown effect). The simulations were conducted relying on the codes DIFFRAC and aNySIM, de- veloped at Maritime Research Institute of Netherlands (MARIN) and the results are presented for a range of water depth between the nominal value of 200 m and the extreme shallow water of 30 m

PERIODONTAL STATUS AND TREATMENT NEEDS AMONG THE PALESTINIAN REFUGEES LIVING IN THE UNITED NATIONS CAMPS IN JORDAN

A periodontal health survey, using the WHO criteria 1997, was conducted among 585 Palestinian refugees living in the United Nations Camps in Jordan. The sample consists of 363 females and 222 males aged 5-54 years. The purposes of this study were to determine the prevalence and the severity of periodontal disease and treatment needs among this population and to correlate the periodontal status with age and gender. By using WHO periodontal probes, the community periodontal index (CPI), the treatment needs (TN) and loss of attachment (LA) were measured for each subject. The number of permanent loss was also recorded. Females were found to have worse periodontal conditions than males. Also, a significant age difference was present. All subjects of the present population had experienced periodontal disease, where 34$ and 43% had a shallow pocket of 4-5 mm and deep pocket of 6 mm or more respectively. The results of this study have shown that 5.48 of sextant per subject in this population were with bleeding or higher, 4.8 with calculus or higher, 2.48 with shallow pockets or higher and 0.88 with deep pocket. This study demonstrated that the loss of attachment increased significantly with increasing age and 2% of this population had normal level of periodontal attachment, with the rest of them (58%) had different amounts of attachment loss. Almost all subjects of this population needed oral hygiene instructions, scaling and/or removal of overhangs and 43% of them needed complex periodontal treatment. The mean number of loss of permanent teeth was among this population with significant age and gender differences. Our data indicated that high prevalence and severity of periodontal disease were observed in this population require programs both for prevention and treatment

Statistical Mechanics of the Hyper Vertex Cover Problem

We introduce and study a new optimization problem called Hyper Vertex Cover. This problem is a generalization of the standard vertex cover to hypergraphs: one seeks a configuration of particles with minimal density such that every hyperedge of the hypergraph contains at least one particle. It can also be used in important practical tasks, such as the Group Testing procedures where one wants to detect defective items in a large group by pool testing. Using a Statistical Mechanics approach based on the cavity method, we study the phase diagram of the HVC problem, in the case of random regualr hypergraphs. Depending on the values of the variables and tests degrees different situations can occur: The HVC problem can be either in a replica symmetric phase, or in a one-step replica symmetry breaking one. In these two cases, we give explicit results on the minimal density of particles, and the structure of the phase space. These problems are thus in some sense simpler than the original vertex cover problem, where the need for a full replica symmetry breaking has prevented the derivation of exact results so far. Finally, we show that decimation procedures based on the belief propagation and the survey propagation algorithms provide very efficient strategies to solve large individual instances of the hyper vertex cover problem.Comment: Submitted to PR

Full scale monitoring of the twin chimneys of the rovinari power plant

The presented paper deals with the structural identification and monitoring of two twin chimneys in very close arrangement. Due to twin arrangement, important interference effects are expected to modify the chimney response to wind action, causing vortex shedding and state-dependent excitation associated to the oscillatory motion of the leeward chimney, in and out of the windward chimney wake. The complexity of the physics of this problem is increased by the dependency of the aerodynamics of circular cylinders on Reynolds number; however, there is a weakness of literature about cylinders behaviour at critical and super-critical range of Reynolds number, due to experimental limitations. Also the International Committee on Industrial Chimneys (CICIND) does not provide, at present, any specific technical guideline about twin chimneys whose interaxis distance is less or equal two times the diameter, as in this case. For this reason a Tuned Mass Damper (TMD) has been installed in order to increase the damping of the chimney, as merely suggested. This work aims at assessing the effectiveness of the installed TMD and characterizing the tower dynamic behaviour itself due to the wind excitation, as well as providing full scale measurements for twin cylinders configuration at high Reynolds numbers