Output Feedback Invariants

The paper is concerned with the problem of determining a complete set of invariants for output feedback. Using tools from geometric invariant theory it is shown that there exists a quasi-projective variety whose points parameterize the output feedback orbits in a unique way. If the McMillan degree $n\geq mp$, the product of number of inputs and number of outputs, then it is shown that in the closure of every feedback orbit there is exactly one nondegenerate system.Comment: 15 page

Degree of the generalized Pl\"ucker embedding of a Quot scheme and Quantum cohomology

We compute the degree of the generalized Pl\"ucker embedding $\kappa$ of a Quot scheme $X$ over \PP^1. The space $X$ can also be considered as a compactification of the space of algebraic maps of a fixed degree from \PP^1 to the Grassmanian $\rm{Grass}(m,n)$. Then the degree of the embedded variety $\kappa (X)$ can be interpreted as an intersection product of pullbacks of cohomology classes from $\rm{Grass}(m,n)$ through the map $\psi$ that evaluates a map from \PP^1 at a point x\in \PP^1. We show that our formula for the degree verifies the formula for these intersection products predicted by physicists through Quantum cohomology~\cite{va92}~\cite{in91}~\cite{wi94}. We arrive at the degree by proving a version of the classical Pieri's formula on the variety $X$, using a cell decomposition of a space that lies in between $X$ and $\kappa (X)$.Comment: 18 pages, Latex documen

International poverty projections

The authors investigate the methodology used in projections of international poverty - particularly those used in many World Bank documents. The methodology, as developed by Ahluwalia, Carter, and Chenery (1979) in an influential paper, is examined critically and subjected to sensitivity analysis. It was found that their projections of poverty are not robust to reasonable changes and improvements in the methodology; in some cases, even the projections'time trend is reversed. Thus, analysts and policymakers should treat such global forecasts of poverty with caution.Economic Theory&Research,Achieving Shared Growth,Economic Conditions and Volatility,Inequality,Environmental Economics&Policies

Identifying Unclear Questions in Community Question Answering Websites

Thousands of complex natural language questions are submitted to community question answering websites on a daily basis, rendering them as one of the most important information sources these days. However, oftentimes submitted questions are unclear and cannot be answered without further clarification questions by expert community members. This study is the first to investigate the complex task of classifying a question as clear or unclear, i.e., if it requires further clarification. We construct a novel dataset and propose a classification approach that is based on the notion of similar questions. This approach is compared to state-of-the-art text classification baselines. Our main finding is that the similar questions approach is a viable alternative that can be used as a stepping stone towards the development of supportive user interfaces for question formulation.Comment: Proceedings of the 41th European Conference on Information Retrieval (ECIR '19), 201

Clinical submission of supernumerary head of adducter brevis muscle

Adductor brevis is an important member of the adductor family occupying the medial compartment of the thigh executing the function of adduction and medial rotation. Deviations from normal anatomy are unusual and rarely reported. A survey of anatomical archives revealed occasional mention of additional bellies of adductor brevis muscle. The present study reports a double belly of adductor brevis muscle (AB) found during a cadaveric dissection class for medical students. The left sided AB displayed two bellies disposed in the same plane. This case report attempts to present the clinical applications of supernumerary bellies of this important adductor muscle of the thigh. It is feasible to categorize these muscular variations upon specialized radiological procedures such as CT and MRI scans only if the radiologist possesses satisfactory understanding of variant anatomy of this region. It is thereafter inferred that upon recognition these muscles present a fair chance of being of utilitised in reconstructions. A biomechanical overview of the present anomaly is also attempte

Unlocking the Secrets of Stem Cells in Orthodontics

Human Periodontal Ligament Stem Cells (hPDLSCs) have immense potential for use in tissue regeneration and angiogenesis. These cells are influenced by mechanical forces, particularly in orthodontic applications. Understanding how mechanical stress modulates stem cell behavior is essential for optimizing therapeutic strategies

Evaluation of functional outcome of lumbar spondylolisthesis treated with posterior lumbar interbody fusion with instrumentation

Background: Spondylolisthesis with or without spondylolysis occurs in 5% to 8% of the adult population. It is commonly believed that spondylolysis does not exist at birth. The incidence is 4.4% to 5% at the age of 6 years, increasing to 6% at the age of 18 years, which is quite similar to that observed in adulthood.To analyze the functional outcome of posterior stabilization by pedicle screws with decompression and interbody fusion by PLIF (Posterior Lumbar Interbody Fusion) technique in adult single level spondylolisthesis. In this study our aim is to analyze the correlation between the degrees of fusion with functional outcomes.Methods: This is a prospective study of 20 patients carried out in the Department of Orthopaedics, Govt. Dharmapuri Medical College Hospital, Dharmapuri from January 2016 to December 2017. All patients were evaluated with anteroposterior, lateral and oblique radiographs of the lumbosacral spine. Dynamic plain radiographs of all our patients showed instability. CT/MRI evaluation of all patients was done.Results: In our study four patients (20%) had a complete reduction of the preoperative slip, fourteen patients (70%) showed a reduction of slip by one grade, while in two patients (10%) there was no change from the preoperative slip percentage.Conclusions: Further, three dimensional multislice thin section CT scans with multiplanar reconstruction are ideal to study the incorporation of the bone graft within the disc space