TY - JOUR A1 - Völske, Michael A1 - Gollub, Tim A1 - Hagen, Matthias A1 - Stein, Benno T1 - A keyquery-based classification system for CORE JF - D-Lib Magazine N2 - We apply keyquery-based taxonomy composition to compute a classification system for the CORE dataset, a shared crawl of about 850,000 scientific papers. Keyquery-based taxonomy composition can be understood as a two-phase hierarchical document clustering technique that utilizes search queries as cluster labels: In a first phase, the document collection is indexed by a reference search engine, and the documents are tagged with the search queries they are relevant—for their so-called keyqueries. In a second phase, a hierarchical clustering is formed from the keyqueries within an iterative process. We use the explicit topic model ESA as document retrieval model in order to index the CORE dataset in the reference search engine. Under the ESA retrieval model, documents are represented as vectors of similarities to Wikipedia articles; a methodology proven to be advantageous for text categorization tasks. Our paper presents the generated taxonomy and reports on quantitative properties such as document coverage and processing requirements. KW - Massendaten KW - Taxonomie KW - Dynamic Taxonomy Composition, Keyquery, Classification Systems, Reverted Index, Big Data Problem Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170426-31662 ER - TY - JOUR A1 - Ataollahi Oshkour, Azim A1 - Talebi, Hossein A1 - Seyed Shirazi, Seyed Farid A1 - Bayat, Mehdi A1 - Yau, Yat Huang A1 - Tarlochan, Faris A1 - Abu Osman, Noor Azuan T1 - Comparison of various functionally graded femoral prostheses by finite element analysis JF - Scientific World Journal N2 - This study is focused on finite element analysis of a model comprising femur into which a femoral component of a total hip replacement was implanted. The considered prosthesis is fabricated from a functionally graded material (FGM) comprising a layer of a titanium alloy bonded to a layer of hydroxyapatite. The elastic modulus of the FGM was adjusted in the radial, longitudinal, and longitudinal-radial directions by altering the volume fraction gradient exponent. Four cases were studied, involving two different methods of anchoring the prosthesis to the spongy bone and two cases of applied loading. The results revealed that the FG prostheses provoked more SED to the bone. The FG prostheses carried less stress, while more stress was induced to the bone and cement. Meanwhile, less shear interface stress was stimulated to the prosthesis-bone interface in the noncemented FG prostheses. The cement-bone interface carried more stress compared to the prosthesis-cement interface. Stair climbing induced more harmful effects to the implanted femur components compared to the normal walking by causing more stress. Therefore, stress shielding, developed stresses, and interface stresses in the THR components could be adjusted through the controlling stiffness of the FG prosthesis by managing volume fraction gradient exponent. KW - Finite-Elemente-Methode KW - Hüftgelenk KW - Funktioneller Gradientenwerkstoff Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170413-31194 ER -