191,323 research outputs found
Ovarian Clear Cell Adenofibroma of Low Malignant Potential developing into Clear Cell Adenocarcinoma
No full textOvarian clear cell adenofibroma is uncommon, and borderline clear cell adenofibroma (low malignant potential) is extremely rare. Borderline clear cell adenofibromas may represent the precursor lesion of clear cell adenocarcinoma of the ovary, but this has not been established. We present a case of a woman in her mid-fifties with a clear cell adenofibroma ranging from benign to borderline to frankly invasive. While some clear cell adenocarcinomas are thought to arise from endometriosis, this range of findings supports the theory that some ovarian clear cell adenocarcinomas originate from borderline tumors.Peer reviewe
Sweetners perception of polyols
No full textThis Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page
Microcellular processing of fluoropolymers and the design of a microcellular foam extrusion system for wire coating
No full textThesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1995.Includes bibliographical references (leaves 114-117).by Ravi R. Patil.M.S
Reconstructing edge-disjoint paths
No full textFor an undirected graph G=(V,E), the edge connectivity values between every pair of nodes of G can be succinctly recorded in a flow-equivalent tree that contains the edge connectivity value for a linear number of pairs of nodes. We generalize this result to show how we can efficiently recover a maximum set of disjoint paths between any pair of nodes of G by storing such sets for a linear number of pairs of nodes. At the heart of our result is an observation that combining two flow solutions of the same value, one between nodes s and r and the second between nodes r and t, into a feasible flow solution of value f between nodes s and t, is equivalent to solving a stable matching problem on a bipartite multigraph.
Our observation, combined with an observation of Chazelle, leads to a data structure, which takes O(n3.5) time to generate, that can construct the maximum number λ(u,v) of edge-disjoint paths between any pair (u,v) of nodes in time O(α(n,n)λ(u,v)n) time
Single-Sink Fractionally Subadditive Network Design
No full textWe study a generalization of the Steiner tree problem, where we are given a weighted network G together with a collection of k subsets of its vertices and a root r. We wish to construct a minimum cost network such that the network supports one unit of flow to the root from every node in a subset simultaneously. The network constructed does not need to support flows from all the subsets simultaneously.
We settle an open question regarding the complexity of this problem for k=2, and give a 3/2-approximation algorithm that improves over a (trivial) known 2-approximation. Furthermore, we prove some structural results that prevent many well-known techniques from doing better than the known O(log n)-approximation. Despite these obstacles, we conjecture that this problem should have an O(1)-approximation. We also give an approximation result for a variant of the problem where the solution is required to be a path
Iterative Methods in Combinatorial Optimization
No full textWe describe a simple iterative method for proving a variety of results in combinatorial optimization. It is inspired by Jain's iterative rounding method (FOCS 1998) for designing approximation algorithms for survivable network design problems, and augmented with a relaxation idea in the work of Lau, Naor, Salvatipour and Singh (STOC 2007) on designing an approximation algorithm for its degree bounded version. At the heart of the method is a counting argument that redistributes tokens from the columns to the rows of an LP extreme point. This token argument was further refined to
fractional assignment and redistribution in work of Bansal, Khandekar and Nagarajan on degree-bounded directed network design (STOC 2008). In this presentation, we introduce the method using the assignment problem, describe its application to showing the integrality of Edmond's characterization (1971) of the spanning tree polyhedron, and then extend the argument to show a simple proof of the Singh and Lau's approximation
algorithm (STOC 2007) for its degree constrained version, due to Bansal, Khandekar and Nagarajan. We conclude by showing how Jain's original proof can also be simplified by using a fractional token argument (joint work with
Nagarajan and Singh).
This presentation is extracted from an upcoming monograph on this topic
co-authored with Lau and Singh
Iterative Methods in Combinatorial Optimization (Invited Talk)
No full textIn these lectures, I will describe a simple iterative method that supplies new proofs of integrality of linear characterizations of various basic problems in combinatorial optimization, and also allows adaptations to design approximation algorithms for NP-hard variants of these problems involving extra "degree-like" budget constraints. It is inspired by Jain's iterative rounding method for designing approximation algorithms for survivable network design problems, and augmented with a relaxation idea in the work of Lau, Naor, Salvatipour and Singh in their work on designing the approximation algorithm for its degree bounded version. Its application was further refined in recent work of Bansal, Khandekar and Nagarajan on degree-bounded directed network design.
I will begin by reviewing the background material on LP relaxations and their solvability and properties of extreme point or vertex solutions to such problems. I will then introduce the basic framework of the method using the assignment problem, and show its application by re-deriving the approximation results of Shmoys and Tardos for the generalized assignment problem.
I will then discuss linear characterizations for the spanning tree polyhedron in undirected graphs and give a new proof of integrality using an iterative method. I will then illustrate an application to approximating the degree-bounded version of the undirected problem, by proving the results of Goemans and Lau & Singh.
I will continue with showing how these methods for spanning trees simplify and generalize to showing linear descriptions of maximum weight matroid bases and also maximum weight sets that are independent in two different matroids. This also leads to good additive approximation algorithms for a bounded degree version of the matroid basis problem.
I will close with applications of the iterative method by revisiting Jain's original proof for the SNDP and giving a new proof that unifies its treatment with that for the Symmetric TSP polyhedron (describing joint work with Nagarajan and Singh). I will also outline the versatility of the method by pointing out the other problems for which the method has been applied, summarizing the discussion in a recent monograph I have co-authored on this topic with Lap Chi Lau and Mohit Singh (published by Cambridge University Press, 2011)
SIMULINK MODEL OF AN AC MOTOR ACTUATED CONTROL VALVE FOR THERMAL COOLING CIRCUIT IN WIND TURBINES
No full textMaster'sMASTER OF SCIENCE IN COMPUTATIONAL ENGINEERING1. Mr. Ravi Kandasamy, Principal Engineer, Vestas Technology R&D Singapore Pte. Ltd. 2. Prof. Murali Damodaran, Assoc. Prof. , SMA Fellow, NT
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Ravi sihtmärgi saavutamise tõenäosus vankomütsiini korduval manustamisel enneaegsetel vastsündinutel
No full textRavimiga organismis toimuvaid protsesse uurib farmakokineetika. Ravimi mõju uurimisega organismi funktsioonidele tegeleb aga farmakodünaamika. Arvutusintensiivsete meetodite abil saab farmakokineetika ja farmakodünaamika tulemusi kombineerides ravi mõju ning kasutatavaid doose efektiivsemalt ja personaalsemalt hinnata. Vankomütsiin on antibiootikum, mis töötati välja üle 50 aasta tagasi, kuid seoses resistentsuse kasvuga tavapärastele ravimitele on selle kasutusvaldkond tugevatoimelise antibiootikumina viimasel ajal laienenud.
Käesolev bakalaureusetöö annab ülevaate farmakokineetilisest taustsüsteemist ning seni teostatud selle alastest uuringutest vankomütsiiniga. Monte-Carlo simulatsioonidel Andersoni mudelist (Anderson et al., 2006) genereeritud farmakokineetilisi parameetrite väärtuseid kasutatakse enneaegsete vastsündinute ravi 90% sihtmärgi saavutamise tõenäosuste jaoks vaja minevate dooside hindamisel.
Töö eesmärgiks on TÜ mikrobioloogia instituudis kogutud minimaalsete inhibeerivate kontsentratsioonide põhjal hinnata 90% ravi sihtmärgi saavutamiseks vajaminevaid doose erinevate farmakokineetilis-farmakodünaamiliste parameetrite piirväärtuste korral. Leitud dooside põhjal hinnatakse saavutatavate terapeutiliste kontsentratsioonide sobivust. Töös sisalduvad mitmed lisad. Erinevate lühendite loend on toodud lisas 1. Ravi sihtmärgi saavutamise tõenäosuse hindamise graafikud ning leitud dooside juures esinevad
kontsentratsioonide muutused konkreetsetel valitud juhtudel on toodud vastavalt lisades 2 ja 3. Töös esitatud jooniste ning simulatsioonide teostamiseks tarkvarale R (R Core Team, 2013) kirjutatud kood on lisas 4
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