Dynamic Pairs Trading Strategy For The Companies Listed In The Istanbul Stock Exchange

In this research we performed pairs trading strategy based on a comparative mean reversion of asset prices with daily data over the period 2002 through 2008 in Istanbul Stock Exchange. We did not categorize stock pairs by sectors and therefore it is possible to observe mean reversion characteristics of different stocks that are selected from ISE-30 index. The initial formation period is 125 days (approx. 6 months) while we measure the performance results daily. Then both formation process and trading strategies have been structured as dynamic (rolling windows) market trading model through 2008. The results indicate that pairs produced average returns of % 3.36 daily comparing with the naïve buy and hold strategy. However ISE30 daily average return performance % 0.038 between 2002-2008 period. Our trading constraints and trading commissions take away the excess return on pairs mostly. Furthermore, the performance analysis reveals that the pairs trading strategy yields excess returns with less volatility than the market portfolio.mean reversion, pairs trading, distance method, market neutral portfolio, Istanbul Stock Exchange, trading strategies

Developing A Modular Web based System for Special Education: Advantages and Challenges

AbstractThe increasing complexity of regulations governing and tracking the special education process made it ever more difficult for all parties which may be special education centers (SECs), individuals, educators, parents, government and healthcare centers. Since there are many difficulties in the management of special education, SECs cannot easily process their essence aim. In this manner, information technologies help these parties to participate equally for managing special education. Modular web based systems are one of the information technology solutions to overcome these problems. In this paper, the goal is to show the fundamental advantages and also discuss the challenges in developing such a modular web based system for special education. If the advantages of the system can be understood and the challenges of the system can be properly addressed, the development of a modular web based system for special education, in our opinion, can be promoted significantly.Selection and peer review under responsibility of Prof. Dr. Hafize Keser

The costs of hospitalization in patients with acute exacerbation of chronic obstructive pulmonary disease

Sevket Ozkaya1, Serhat Findik2, Atilla Guven Atici21Rize University, Department of Pulmonary Medicine, Rize, Turkey; 2Ondokuz Mayis University, Department of Pulmonary Medicine, Atakum, Samsun, TurkeyIntroduction: Chronic obstructive pulmonary disease (COPD) is a major public health problem. It imparts a substantial economic burden on individuals and society. Acute exacerbations are the main cause of hospital admissions and hospitalizations in patients with COPD in Turkey.Objectives: We aimed to determine the costs of hospitalization in patients with acute exacerbations of COPD (AECOPD).Results: A total of 7832 (1556 women, 6276 men) patients were hospitalized due to acute exacerbations of COPD between 2005–2009 in the Samsun Chest Diseases and Thoracic Surgery Hospital, northern Turkey. The mean age was 64.6 ± 19.8 years old and median length of hospital stay was 14.8 ± 9.5 days. The mean cost per admission was US$718 ± 364. Drug costs accounted for the largest portion (53.5%) of the mean cost, followed by bed cost (19.6%). One hundred seventy-four (2.2%) of the total hospitalized patients with AECOPD died in hospital.Conclusion: AECOPD continues to have both significant economic burden and high mortality rate.Keywords: COPD, acute exacerbation, hospitalization, cost

Dynamic Pairs Trading Strategy For The Companies Listed In The Istanbul Stock Exchange

In this research we performed pairs trading strategy based on a comparative mean reversion of asset prices with daily data over the period 2002 through 2008 in Istanbul Stock Exchange. We did not categorize stock pairs by sectors and therefore it is possible to observe mean reversion characteristics of different stocks that are selected from ISE-30 index. The initial formation period is 125 days (approx. 6 months) while we measure the performance results daily. Then both formation process and trading strategies have been structured as dynamic (rolling windows) market trading model through 2008. The results indicate that pairs produced average returns of % 3.36 daily comparing with the naïve buy and hold strategy. However ISE30 daily average return performance % 0.038 between 2002-2008 period. Our trading constraints and trading commissions take away the excess return on pairs mostly. Furthermore, the performance analysis reveals that the pairs trading strategy yields excess returns with less volatility than the market portfolio

Comparison of Vinorelbine-Cisplatin with Gemcitabine-Cisplatin in Patients with Advanced Non-Small Cell Lung Cancer

Purpose The objective of this trial was to compare cisplatin-plus-vinorelbine regimen with cisplatin-plus-gemcitabine regimen in patients with stage IIIB-IV non-small cell lung cancer (NSCLC). Patients and Methods Chemonaive patients with stage IIIB-IV NSCLC received either vinoelbine 30 mg/m 2 (days 1 and 8) plus cisplatin 80 mg/m 2 (day 1) every 21 days (VC arm) or gemcitabine 1250 mg/m 2 (days 1 and 8) plus cisplatin 80 mg/m 2 (day 1) every 21 days (GC arm). Results One hundred thirtyfour patients (67 VC and 67 GC) were included to the study. Overall response rates for the VC arm (31.2%) were not significantly different from that of the GC arm (34.3%). There were no differences in overall survival and one-year survival rates. Median survival and one-year survival rates for the VC and GC groups were 10.6 and 11.5 months, 45% and 46.8%, respectively. Grade 3-4 thrombocytopenia was significantly higher on the GC arm (VC 1.4% v GC 8.9%, p < 0.05), as was febrile neutropenia on the VC arm (VC 8.9% v GC 1.4%, p < 0.05). Conclusion VC and GC demonstrated similar efficacy but there were differences in toxicity profiles

Asymptomatic double aortic arch

Muzaffer Sariaydin1, Serhat Findik1, Atilla Guven Atici1, Sevket Ozkaya2, Aziz Uluisik11Department of Pulmonary Medicine, Faculty of Medicine, Ondokuz Mayis University, Samsun, Turkey; 2Department of Pulmonary Medicine, Faculty of Medicine, Rize University, Rize, TurkeyAbstract: A 51-year-old male patient with a past history of lung tuberculosis was referred to our clinic for routine control. The patient reported no complaints and chest X-ray was normal. Three-dimensional thoracic computed tomography revealed a balanced-type double aortic arch with no compression of trachea or esophagus.Keywords: double aortic arch, asymptomatic, adult, three dimensional computed tomograph

The Role of Sports Participation in Hemispheric Dominance: Assessment by Electrodermal Activity Signals

This study aims at evaluating hemispheric differences between active sportsmen (n=17) and sedentary control subjects (n=21) using Electrodermal Activity (EDA), which is a physiologic measure of emotional sweating. Following the denoising of the acquired EDA records, feature extraction functions were utilized for each record to generate a feature vector, containing 14 parameters per record. Statistical significances of the differences and similarities between feature vectors were determined by unpaired t-test (p0.95). Findings from this study show that the agreement of hemispheric dominance test with hand preference is significantly lower for active sportsmen in comparison to control group. This implies that participation in sport activity may play a facilitative role in a more equally weighted development of both hemispheres by somewhat decreasing the hemispheric lateralization