Search

Pair trading is a market-neutral strategy which is based on the use of standard, well-known statistical tests applied to time series of price to identify suitable pairs of stock. This article studies the potential benefits of using additional qualitative information for this type of trade. Here we use an ontology to represent and structure information extracted from financial SEC reports in a way that is optimised for search. These mandatory reports are originally published as XML using a schema that has varied over the years. The XML format itself is not easy to query, e.g. projections to fields or their composition are hard to find even when using an XML store. Our ontology-based approach provides uniformity of representation, which is further enhanced by the strife to use common vocabulary wherever possible. The ontology is then used to identify links between companies, by finding common senior employees or major shareholders. This is also potentially useful information to identify suitable pairs of stock. We show that the ontology increases the probability of selecting cointegrated pairs of stock from the data, with no negative effect on the survival time of such pairs when compared to random ones.

Bu çalışmada, Snyder Testi kullanılarak çürük aktivitesi yüksek olan 60 birey tespit edilmiş tir. Bireylerin tükrük ve plak örnekleri alınarak gerek Streptokokların sayı ve dağılımları gerekse tükrük bikarbonat, pH, laktat dehidrojenaz enzim aktiviteleri ile plak pH'ları üzerine kullanılan antimikrobiyal ağız çalkalama solüsyonlarının etkinlikleri çift kör deneyi ile incelenmiştir. Bu solüsyonlar %0.12'lik Klorheksidin ve %0. 03 Sanguinarin-Zn içermektedir. Kontrol grubunda ise %0,9'luk Sodyumklorür içeren Serum fizyolojik kullanılmıştır. Klorheksidin ve Sanguinarin içeren ağız çal kalama solüsyonlarının her ikisininde bakteri plağının diş yüzeyinden uzaklaştırılmasına yardımcı olduğu ve hem tükrük hem de bakteri plağı içindeki mikro organizmaların sayı ve dağılımlarında önemli bir düşüşe neden olduğu saptanmıştır (p0,05). Sanguinarin ve Klorheksidin içeren ağız çal kalama solüsyonu ile Serum fizyolojik kullanılan grubun tükrük bikarbonat değerlerinde istatistiksel olarak anlamlı bir farklılık bulunamamıştır (p>0.05). In this study, individuals having high rate of caries activity were selected using Snyder Test. Individual saliva and dental plaque samples were obtained and then several tests were conducted. These tests included the determination of the number and distribution of Streptococcus mutans, bicarbonate and pH levels and lactat dehidrogenase enzyme activities of saliva and the effects of various antiseptic solutions contained 0.12% Chlorhexidine and 0.03% Sanguinarine-Zn on the pH levels of dental plaque. Evaluations were made by using double blind test. It was found that both solutions Chlor hexidine and Sanguinarine helped to remove the plaque from tooth surfaae and signif iaantly reduced the number and distribution of microorganisms present in saliva and dental plaque (p0.05). In terms of saliva bicarbonate values, no statistically significant difference was observed between the groups using Sanguinarine and Chlorhexidine mouthwashes and physiological saline solution (p>0.05). 91