Scheduling Sensors for Guaranteed Sparse Coverage

Sensor networks are particularly applicable to the tracking of objects in motion. For such applications, it may not necessary that the whole region be covered by sensors as long as the uncovered region is not too large. This notion has been formalized by Balasubramanian et.al. as the problem of $\kappa$-weak coverage. This model of coverage provides guarantees about the regions in which the objects may move undetected. In this paper, we analyse the theoretical aspects of the problem and provide guarantees about the lifetime achievable. We introduce a number of practical algorithms and analyse their significance. The main contribution is a novel linear programming based algorithm which provides near-optimal lifetime. Through extensive experimentation, we analyse the performance of these algorithms based on several parameters defined

Landslide Stabilization Along The Ohio River Using Cantilevered Stub Piers

Landslide activity along U.S. 50 in Cincinnati, Ohio has caused roadway damage for decades. After a necessary closure of 3 lanes due to slope movements, emergency stabilization measures were undertaken to protect the roadway by providing a “pseudo” short-term solution (target 3 to 5 years) necessitated by ODOT budget constraints. The landslide shear plane was near the top of a sloping bedrock surface as much as 50 feet below grade. “Stub Piers” were installed 40 feet downslope of the roadway shoulder. The shafts were heavily reinforced across the deep shear plane but steel reinforcing did not extend the full length of the shafts and was stopped well short of the ground surface. The goal was to provide shear resistance across the failure plane, forcing the theoretical failure surface higher into the overburden soil profile, resulting in a comparatively higher safety factor against slope failure. These “Stub Piers” were installed and found to meet all of the project goals. The stub piers and surrounding ground were instrumented and analyses of collected data to date showed earth pressures and horizontal deflections were over-predicted in the original design. Instrumentation by means of inclinometers, vibrating wire earth pressure cells, and strain gages has been monitored over a period of several years since construction of the Stub Piers and results indicate this option offers an attractive alternative to conventional drilled piers or tiedback drilled pier solutions

Numerical Modeling and Use of Settlement Reducing Auger Cast-In-Place Piles Below a Mat Foundation

The 45-story Great American Tower, the tallest building in Cincinnati, is not only changing the downtown skyline, but is an excellent case study of innovation in geotechnical engineering. This project is an excellent example of the use of technological advances in site characterization and soil-structure methods. When an opportunity arises to combine state-of-the-art concepts with advanced modeling tools, engineers need to combine knowledge and forward thinking to geotechnical solutions to promote the state-of-practice. The Great American Tower at Queen City Square in Cincinnati, Ohio combines a mat foundation with a limited number of auger cast-inplace (ACIP) piles, with the piles primarily acting as settlement reducers. Promoting the unique soil-structure interaction based foundation system required the use of sophisticated numerical modeling tools and seamless communication with the designers, contractor, and owner. Traditional standard penetration test boring data (SPT) was initially used to develop a numerical analysis of the soil-structure interaction using FLAC 3D software. The model was further modified with cone penetration (CPT) and pressuremeter testing (PMT), load test results on several ACIP pile elements of varying lengths, but all tipping above bedrock, and ongoing monitoring. Integrating industry knowledge, with sophisticated modeling techniques, has provided a successful real-world case study

(2S,5S,6R)-5-(4-Methyl­phen­yl)-3-phenyl-4,8-dioxa-3-aza­tricyclo­[7.4.0.02,6]trideca-1(13),9,11-triene-6-carbonitrile

In the title compound, C24H20N2O2, the six-membered pyran ring adopts a half-chair conformation with one C atom deviating from the mean plane of the remaining ring atoms by 0.654 (6) Å. The five-membered isoxazole ring adopts an N-envelope conformation with the N atom displaced by 0.742 (5) Å from the mean plane formed by the remaining ring atoms. The carbonitrile side chain is almost linear, with a C—C—N angle of 178.6 (5)°. The crystal packing is stabilized by inter­molecular C—H⋯N inter­actions, through bifurcated acceptor hydrogen bonds formed between the carbonitrile N atom and two alternate C atoms in the unsubstituted benzene ring. The mol­ecular structure and crystal packing are further stabilized by intra­molecular and inter­molecular C—H⋯π inter­actions

X-ray intensity statistics of approximately centrosymmetric structures

The joint probability distribution of X-ray structure factors of a non-centrosymmetric structure (true structure) and that of a centrosymmetric structure (assumed model) from which it deviates slightly, are given. These are characterised by a parameter D=<cos2πH.Δrj> where Δrj are the deviations of the N atoms from the centrosymmetric arrangements. The limiting forms of the distribution for D=0, and D=1 are respectively the acentric and centric distributions of Wilson. Intermediate values of D characterise different degrees of centrosymmetry of the structure. The parallelism of the results to another "approximately centrosymmetric" situation (Srinivasan, Indian J. Pure Appl. Phys., 1965, 3, 187), is pointed out

Degree of centrosymmetry of a crystal structure and the statistical distribution of X-ray intensities

This article does not have an abstract

Treatment of W. bancrofti (Wb) in HIV/Wb Coinfections in South India

Background: The disease course of human immunodeficiency virus (HIV) is often altered by existing or newly acquired coincident infections. Methodology/Principal Findings: To assess the influence of pre-existing Wuchereria bancrofti infection on HIV progression, we performed a case-controlled treatment study of HIV positive individuals with (FIL+) or without (FIL-) W. bancrofti infection. Twenty-eight HIV+/FIL+ and 51 matched HIV+/FIL- subjects were treated with a single dose of diethylcarbamazine and albendazole (DEC/Alb) and followed for a year at regular intervals. Sixteen of the HIV+/FIL+ subjects (54%) and 28 of the HIV+/FIL- controls (57%) were on antiretroviral therapy (ART) during the study. Following treatment, no differences were noted in clinical outcomes between the 2 groups. There also was no significant difference between the groups in the HIV viral load at 12 months as a percentage of baseline viral load (HIV+/FIL+ group had on average 0.97 times the response of the HIV+/FIL- group, 95% CI 0.88, 1.07) between the groups. Furthermore, there were no significant differences found in either the change in viral load at 1, 3, or 6 months or in the change in CD4 count at 3, 6, or 12 months between the 2 groups. Conclusions/Significance: We were unable to find a significant effect of W. bancrofti infection or its treatment on HIV clinical course or surrogate markers of HIV disease progression though we recognized that our study was limited by the smaller than predicted sample size and by the use of ART in half of the patients. Treatment of W. bancrofti coinfection in HIV positive subjects (as is usual in mass drug administration campaigns) did not represent an increased risk to the subjects, and should therefore be considered for PLWHA living in W. bancrofti endemic areas

Supersymmetric dS/CFT

We put forward new explicit realisations of dS/CFT that relate ${\cal N}=2$ supersymmetric Euclidean vector models with reversed spin-statistics in three dimensions to specific supersymmetric Vasiliev theories in four-dimensional de Sitter space. The partition function of the free supersymmetric vector model deformed by a range of low spin deformations that preserve supersymmetry appears to specify a well-defined wave function with asymptotic de Sitter boundary conditions in the bulk. In particular we find the wave function is globally peaked at undeformed de Sitter space, with a low amplitude for strong deformations. This suggests that supersymmetric de Sitter space is stable in higher-spin gravity and in particular free from ghosts. We speculate this is a limiting case of the de Sitter realizations in exotic string theories.Comment: V2: references and comments added, typos corrected, version published in JHEP; 27 pages, 3 figures, 1 tabl