Weak form efficiency tests in Istanbul Stock Exchange by using moving averages

Ankara : The Graduate School of Business Administration of Bilkent Univ., 1996.Thesis (Master's) -- Bilkent University, 1996.Includes bibliographical references.This study tests the weak-foim efficiency in Istanbul Stock Exchange by forming portfolios of randomly selected stocks and applying moving averages methodology on these portfolios. Differing moving average rules are applied on random portfolios for the time period 1/1/1988-30/9/1995. Finally, returns of the selected strategies are compared with naive buy hold policy by computing excess returns and t ratios. This study shows that Istanbul Stock Exchange is not weak-form efficient. The returns of certain strategies brought returns significantly higher than the naive buy-hold policy.Yılmaz, HSerkanM.S

Stoma Prolapse

The incidence of prolapse which is a late complication of stoma ranges between 0–25%. In this study the records of the patients who had been treated and followed up with the diagnosis of stoma prolapse between 1995 -2005 in the General Surgery Department of Dicle University Hospital were examined, retrospectively. There were 12 patients (5 men, 7 women) with a mean age of 51,6±15.01 years. The causes of stoma construction were malign diseases in 9 patients and benign diseases in 3 of them. The average time between construction of stoma and formation of prolapse was 10,9±6.84 month. The type of stoma was loop in 7 patient, end stoma in 4 patient and double bowel enterostomy in 1 patient. Of nine patients with stoma prolapse had been subjected chemotherapy. The overall rate of stomal prolapsus was 3,1% in this series. It was 10,8% in patients who had received chemoradiotherapy. Since stomal prolasus is a serious complication and its reconstruction needs general anesthesia great care should be shown when creatig a stoma

Outcomes of the chondral lesions of knee treated by microfracture technique and effective factors on the results

Objectives: The aim of this study was to evaluate the results of the microfracture technique in the treatment of chondral lesions.Materials and methods: A retrospective study was performed in 26 patients who had treated by arthroscopic microfracture technique for chondral lesions in the femoral condils between January 2003 and 2007september in our department. There were 11 females and 15 males with mean age of 37.2 years (range from 23 to 56 years). The average time between beginning of complaints and operation were 9.7 months (range from 3 to 35 months). The average of chondral lesions size were 1,6 cm2 (range from 0.7 to 2.4 mm2). The average follow-up period was 24.3 months (ranged from 10 to 44 months). Patients assessed according to subjective patient satisfaction and Lisholm scale at preoperative and postoperative time.Results: The mean Lysholm score increased from a preoperative 56.9 (range from 43 to 72) to a postoperative 77.9 (range from 62 to 100) (p<0.05). The rating was excellent in 9 patients (34.6%), good in 7 (27%) and fair in 10 (38.4%) according to Lysholm scale. All patients were satisfied with their knee function. The results of MRI taken at postoperative sixth month were proportional with patient’s satisfaction and Lysholm scores.Conclusion: Patients with excellent or good results had short symptom period, small chondral lesion and young age. Applied early microfracture technique in treatment of chondral lesions was a low cost, effective and successful treatment modalit

Rüzgar hızı dağılımının tahmin edilmesi için istatistiksel bir yaklaşım: Gelibolu bölgesi örneği

Wind energy is renewable and environment friendly. It is an alternative clear energy source compared to the fossil fuels that pollute the lower layer of atmosphere. The most important parameter of the wind energy is the wind speed. Statistical methods are useful for estimating wind speed because it is a random phenomena. For this reason, wind speed probabilities can be estimated by using probability distributions. An accurate determination of probability distribution for wind speed values is very important in evaluating wind speed energy potential of a region. In this study, first, we tried to determine appropriate theoretical pdf (probability density function) by comparing 10 pdf for the wind speed data measured for Gelibolu region. In determining proper pdf , an approach consisting of 3 goodness of fit tests and fitted graphics have been used.Rüzgar enerjisi yenilenebilir ve çevre dostu bir enerjidir. Rüzgar enerjisi atmosferi kirleten fosil yakıtlarıyla kıyaslandığında, temiz enerji kaynağı için bir alternatiftir. Rüzgar enerjisinin potansiyelinin en önemli parametresi rüzgar hızıdır. Rüzgar hızı rassal olay olarak tanımlandığı için rüzgar hız tahminlerinde istatistiksel yöntemleri kullanmak yararlıdır. Bu nedenle rüzgar hızı, olasılık dağılımları kullanılarak tahmin edilebilir. Bir bölgenin rüzgar hızı enerji potansiyelinin değerlendirilmesi ve tahmini için geçerli bir olasılık dağılımının belirlenmesi çok önemlidir. Bu çalışmada Gelibolu bölgesinde ölçülen rüzgar hızı verilerini temsil edebilecek uygun bir olasılık dağılımı 10 dağılım karşılaştırılarak belirlenmeye çalışılmıştır. Bu amaçla üç uyum iyiliği testi ve grafik yöntemi kullanılmıştır

Türk sürücülerinin kendi bildirimlerine dayanan trafik ihlalleri ve riskli sürüş tutumlari: Eskişehir örneği

Risky driving attitude terminology is used to explain behaviors, which directly increase accident risk, such as over speeding or violation to traffic rules while driving and attitudes related to traffic safety. This study is focused on driver factors in traffic accidents and was carried out in order to show risky drivers' attitudes tendency, especially. In this study, in order to develop a risky driver attitude model, factors explaining obedience to speed rules, caring about traffic accidents, risk taking tendency in traffic and violations of basic traffic rules were studied. For this reason with the assistance of structural equation models LISREL 8.54 was used to try to develop a model, and fitness of the model has been discussed considering various fitness criteria. On the other hand, analysis of variance was performed for factors measuring sex, education level, age and driving experience, in order to portrait risky drivers.Riskli sürücü tutumu terminolojide, trafik güvenliğiyle ilgili sürüş, tutumlar, trafik kural ihlalleri veya hızlı sürüş gibi kaza riskini doğrudan arttıran davranışları açıklamak için kullanılmaktadır. Bu çalışma trafik kazalarındaki sürücüden kaynaklanan faktörleri ve özellikle riskli sürücü tutum eğilimini açıklamaya odaklanmıştır. Çalışmada hız kurallarına uyma, trafik kazalarına karşı ilgi, trafikte risk alma eğilimi ve temel trafik kural ihlalleri faktörleriyle açıklanan “Riskli Sürücü Tutum Modeli” geliştirilmeye çalışılmıştır. Bu amaçla LISREL 8.54 kullanılarak Yapısal Eşitlik Modelleri yardımıyla bir model geliştirilmeye çalışılmış ve geliştirilen model çeşitli uyum kriterleri dikkate alınarak uygunluğu tartışılmıştır. Diğer yandan riskli sürücüleri betimlemek için cinsiyet, eğitim durumu, yaş ve sürüş deneyimi faktörleri yardımıyla varyans analizi yapılmıştır

Chemoradiotherapy for elderly patients with rectal cancer: A single‑institution study

Introduction: The incidence of cancer, particularly rectal cancer (RC), in older adults is gradually increasing. The aim of the present study was to evaluate radiotherapy (RT) and chemoradiotherapy (CRT) results, clinicopathological features, and survival factors in older patients with RC. Methods: We evaluated patients aged ≥65 years with RC treated at a radiation oncology clinic. The demographic, clinical, and histopathological data of the patients were obtained by reviewing their medical records. The toxicity criteria of the Radiation Therapy Oncology Group were applied. Results: Among 401 patients with RC, 183 (45.6%) were older adults (65–92 years). Furthermore, 122 (66.7%) patients had clinically stage 3 and above RC, and 183 and 91 patients received RT and neoadjuvant CRT, respectively. Surgical treatment was performed for 116 (63.4%) patients, 41 (34.4%) and 76 (65.6%) of whom underwent postoperative CRT and preoperative RT, respectively. Grade 3 or higher toxicity was observed in 22 (18.9%) patients during CRT. RT was performed in 64 patients(35%) at a 1–15‑day interval. The mean follow‑up duration was 34.7 (range, 1.4–149.0) months. The 2‑ and 5‑year overall survival (OS) rates were 71.4 and 37.4%, respectively, and the 2‑ and 5‑year disease‑free survival (DFS) rates were 65.7 and 35.3%, respectively. OS was 49.4 and 34.9 months for patients aged 65–74 and ≥75 years, respectively. Survival was shorter in patients with the advanced geriatric disease (p = 0.013). In the multivariate analysis, factors affecting overall and DFS were age, distance from the tumor to the anal canal, and metastasis (p < 0.05). Conclusion: The results of this study suggested that the selection of treatment modalities for older patients with RC should be based on performance status and not age. RT and CRT were safe treatment modalities for older patients with RC, particularly for those who could not undergo surger

Integrated Lax Formalism for PCM

By solving the first-order algebraic field equations which arise in the dual formulation of the D=2 principal chiral model (PCM) we construct an integrated Lax formalism built explicitly on the dual fields of the model rather than the currents. The Lagrangian of the dual scalar field theory is also constructed. Furthermore we present the first-order PDE system for an exponential parametrization of the solutions and discuss the Frobenious integrability of this system.Comment: 24 page

Performance of Some Forages Species (\u3cem\u3eFestuca arundinacea\u3c/em\u3e L., \u3cem\u3eChloris gayana\u3c/em\u3e var. Katambora, \u3cem\u3eLotus corniculatus\u3c/em\u3e L. and \u3cem\u3eMedicago sativa\u3c/em\u3e L.) in Saline Soil

Salinity is a soil degradation process which reduces plant diversity and agricultural productivity, decreases fertility and devalues the land in regions with arid and semi-arid climate. This process inhibits water and nutrient intake of plants from soil due to changeable nitrogen percentage and/or the intensity of soluble salt concentration. When the fact that agricultural lands are limited around the world and that the need for nutrition increases incrementally is taken into consideration, it is obvious that available lands should be used more effectively. Hence, it is quite crucial to reclaim saline soil and utilize it more economically (Woods 1996)