Lower bound for the maximal number of facets of a 0/1 polytope

We show that there exist 0/1 polytopes in R^n with as many as (cn / (log n)^2)^(n/2) facets (or more), where c>0 is an absolute constant.Comment: 19 page

Investigation of sine-wave inputs for an FDM EIT system

Includes bibliographical references.This thesis project report describes the research done by the author under the supervision of Prof. J. Tapson. The area of research is an investigation of sine-wave drive for a frequency division multiplexing (FDM) electrical impedance tomography (EIT) system. This thesis was commissioned by Prof. J. Tapson, on the 1 st of November 200 1. The goals were as follows: 1. Investigate the research done on this project by previous researchers. 2. Investigate the current applications in which capacitance, resistance and impedance tomography are used in research level and in industry. 3. Design and develop a working 8-electrode impedance tomography system. Also, make provisions for a possible upgrade of the 8-electrode system to a 16-electrode (16 capacitance and 16 resistance electrodes) system employing FDM and using sine-wave excitation. 4. VerifY and compare the performance of the 8-electode impedance tomography system to the previous research done by Teague [53], for static configurations of multi-phase air-gravel-seawater mixtures. 5. Evaluate the ability of the system to differentiate between air and gravel mass in static situations. 6. Draw conclusions regarding the performance, effectiveness and limitations of the system. 7. Make recommendations for future project developments. 8. Submit the thesis by the 28th of March 2003

Main transport challenges in South Eastern Europe, after enlargement

This paper looks at the main challenges that are facing the Transport sector in the countries of S. E. Europe after enlargement. First, it looks at the challenge of setting a common Transport policy and points as priority areas the questions of: frontier crossings, road transport quotas, working hours (road transport), restructuring of railways, promotion of Rail Freight “Freeways”, new financing schemes through Public Private Partnerships, and other issues. Then it looks at the factors that will determine the future transport outlook of the area in both qualitative and quantitative terms and it finds that there is a web of factors and issues that will play a role, such as for example the socio-political climate and preferences, the advent of New Technologies, and the degree of development of the Trans-European Networks. The paper looks at the “challenges” facing the inter-urban and urban transport separately. As regards the first it concludes that a) higher integration of the transport provider into the whole transport and logistics chain, and b) closer co-operation and “integration” with the customer, will be the main ones, while for urban transport the main challenge will be improvement of urban traffic management systems and, inevitably, demand management measures, as well as implementation and operation of a whole new series of technologies and systems of urban ICT that will form the Integrated Urban ICT environment of the future

Destination brand equity research from 2001 to 2012

The present study delves into a review of the destination brand equity literature published since 2001, aiming to offer tourism researchers a reference guide to the general context, corresponding methods,and focus of previous works. A multisource search resulted in the identification of 64 relevant papers. Content analysis using multiple classifier variables provides further insights into specific geographical, conceptual, and methodological aspects. Conclusions pertain to the multidimensional character of the construct, the methodology, and context in which destination brand performance has been developed. Destination brand equity appears as a rapidly conceived concept, borrowed from traditional (corporate/product) branding theory, while discussion on its definition and operationalization is still in progress and has yet to mature in a multidisciplinary context. As the first attempt to review destination brand equity within the top tourism and marketing journals and relevant search engines, the study may contribute to a comprehensive overview of the field. The outcomes offer marketing scholars an in-depth view of the concept, providing an overall insight on the various ways destination brands might be evaluated

Estimation in high dimensions: a geometric perspective

This tutorial provides an exposition of a flexible geometric framework for high dimensional estimation problems with constraints. The tutorial develops geometric intuition about high dimensional sets, justifies it with some results of asymptotic convex geometry, and demonstrates connections between geometric results and estimation problems. The theory is illustrated with applications to sparse recovery, matrix completion, quantization, linear and logistic regression and generalized linear models.Comment: 56 pages, 9 figures. Multiple minor change

Coronary microvascular disease in hypertrophic and infiltrative cardiomyopathies

Pathologic hypertrophy of the cardiac muscle is a commonly encountered phenotype in clinical practice, associated with a variety of structural and non-structural diseases. Coronary microvascular disease is considered to play an important role in the natural history of this pathological phenotype. Non-invasive imaging modalities, most prominently positron emission tomography and cardiac magnetic resonance, have provided insights into the pathophysiological mechanisms of the interplay between hypertrophy and the coronary microvasculature. This article summarizes the current knowledge on coronary microvascular dysfunction in the most frequently encountered forms of pathologic hypertrophy. Keywords: CMD; CMR; Coronary microvascular disease; cardiac PET; coronary flow reserve; left ventricular hypertrophy

Expression of HLA-G in patients with B-cell chronic lymphocytic leukemia (B-CLL).

The expression of HLA-G was reported in certain malignancies and its role in escaping from immunosurveillance in cancers was proposed since HLA-G is a nonconventional HLA class I molecule that protects fetus from immunorecognition during pregnancy. Recent studies proposed HLA-G as novel prognostic marker for patients with B-CLL. HLA-G was showed to bear even better prognostic information compared to Zeta-chain associated protein of 70kDa (ZAP-70) and CD38 although some other authors did not find HLA-G expression in CLL. Therefore in this study we characterized the expression of HLA-G on both RNA and protein level. In most of 20 B-CLL patients we were able to detect signal from HLA-G using flow cytometry analysis. The expression of HLA-G was confirmed on messenger level by real-time RT-PCR experiments. No correlation between HLA-G expression and expression of well established prognostic factors such as ZAP-70 and CD38 was detected. These results confirm that HLA-G is expressed on CLL leukemic cells. Furthermore the expression of HLA-G on CLL cells suggests that this molecule might be involved in escaping of CLL cells from immunosurveillance

The residual STL volume as a metric to evaluate accuracy and reproducibility of anatomic models for 3D printing: application in the validation of 3D-printable models of maxillofacial bone from reduced radiation dose CT images.

BackgroundThe effects of reduced radiation dose CT for the generation of maxillofacial bone STL models for 3D printing is currently unknown. Images of two full-face transplantation patients scanned with non-contrast 320-detector row CT were reconstructed at fractions of the acquisition radiation dose using noise simulation software and both filtered back-projection (FBP) and Adaptive Iterative Dose Reduction 3D (AIDR3D). The maxillofacial bone STL model segmented with thresholding from AIDR3D images at 100 % dose was considered the reference. For all other dose/reconstruction method combinations, a "residual STL volume" was calculated as the topologic subtraction of the STL model derived from that dataset from the reference and correlated to radiation dose.ResultsThe residual volume decreased with increasing radiation dose and was lower for AIDR3D compared to FBP reconstructions at all doses. As a fraction of the reference STL volume, the residual volume decreased from 2.9 % (20 % dose) to 1.4 % (50 % dose) in patient 1, and from 4.1 % to 1.9 %, respectively in patient 2 for AIDR3D reconstructions. For FBP reconstructions it decreased from 3.3 % (20 % dose) to 1.0 % (100 % dose) in patient 1, and from 5.5 % to 1.6 %, respectively in patient 2. Its morphology resembled a thin shell on the osseous surface with average thickness <0.1 mm.ConclusionThe residual volume, a topological difference metric of STL models of tissue depicted in DICOM images supports that reduction of CT dose by up to 80 % of the clinical acquisition in conjunction with iterative reconstruction yields maxillofacial bone models accurate for 3D printing

3D printed ventricular septal defect patch: a primer for the 2015 Radiological Society of North America (RSNA) hands-on course in 3D printing.

Hand-held three dimensional models of the human anatomy and pathology, tailored-made protheses, and custom-designed implants can be derived from imaging modalities, most commonly Computed Tomography (CT). However, standard DICOM format images cannot be 3D printed; instead, additional image post-processing is required to transform the anatomy of interest into Standard Tessellation Language (STL) format is needed. This conversion, and the subsequent 3D printing of the STL file, requires a series of steps. Initial post-processing involves the segmentation-demarcation of the desired for 3D printing parts and creating of an initial STL file. Then, Computer Aided Design (CAD) software is used, particularly for wrapping, smoothing and trimming. Devices and implants that can also be 3D printed, can be designed using this software environment. The purpose of this article is to provide a tutorial on 3D Printing with the test case of complex congenital heart disease (CHD). While the infant was born with double outlet right ventricle (DORV), this hands-on guide to be featured at the 2015 annual meeting of the Radiological Society of North America Hands-on Course in 3D Printing focused on the additional finding of a ventricular septal defect (VSD). The process of segmenting the heart chambers and the great vessels will be followed by optimization of the model using CAD software. A virtual patch that accurately matches the patient's VSD will be designed and both models will be prepared for 3D printing