Volatilitede uzun hafıza ve yapısal kırılma: Borsa Istanbul örneği

The aim of this paper is to examine validity of the efficient market hypothesis in Borsa İstanbul. Daily returns series are calculated by using daily closing price for BİST100 and BİST30 indices for periods of 1988-2014 and the presence of long memory on the volatility of the returns series is examined by means of Adaptive-FIGARCH (A-FIGARCH) model proposed by Baillie and Morana (2009). Empirical results suggest that there are multiple structural breaks on variance of returns series and A-FIGARCH model outperforms. In addition, it is found evidence in favor of long memory on the conditional variance of returns series and hence it can be said that Borsa İstanbul is not weak form efficient market

Volatilitede uzun hafıza ve yapısal kırılma: Borsa Istanbul örneği

The aim of this paper is to examine validity of the efficient market hypothesis in Borsa İstanbul. Daily returns series are calculated by using daily closing price for BİST100 and BİST30 indices for periods of 1988-2014 and the presence of long memory on the volatility of the returns series is examined by means of Adaptive-FIGARCH (A-FIGARCH) model proposed by Baillie and Morana (2009). Empirical results suggest that there are multiple structural breaks on variance of returns series and A-FIGARCH model outperforms. In addition, it is found evidence in favor of long memory on the conditional variance of returns series and hence it can be said that Borsa İstanbul is not weak form efficient market

LONG MEMORY AND STRUCTURAL BREAKS ON VOLATILITY: EVIDENCE FROM BORSA ISTANBUL

Bu çalışmanın amacı Borsa İstanbul’da etkin piyasalar hipotezinin geçerliliğini ampirik olarak araştırmaktır. Bu amaçla 1988 ile 2014 yılları arasında BİST100 ve BİST30 endeksleri için günlük kapanış verileri kullanılarak getiri serileri oluşturulmuş ve getiri serilerinin koşullu varyansında uzun hafızanın varlığı Baillie ve Morana (2009) tarafından geliştirilen Uyarlanabilir (Adaptive)-FIGARCH (A-FIGARCH) model ile araştırılmıştır. Analiz sonucunda, endeks getirilerinin varyansında çok sayıda yapısal kırılma noktası bulunmuş ve A-FIGARCH modelin getiri serilerini tahmin etmede daha üstün sonuçlar verdiği belirlenmiştir. Ayrıca, getiri serilerinin koşullu varyansının uzun hafıza özelliği gösterdiği ve buna bağlı olarak Borsa İstanbul’un zayıf formda etkin olmadığı sonucuna ulaşılmıştır.The aim of this paper is to examine validity of the efficient market hypothesis in Borsa İstanbul. Daily returns series are calculated by using daily closing price for BİST100 and BİST30 indices for periods of 1988-2014 and the presence of long memory on the volatility of the returns series is examined by means of Adaptive-FIGARCH (A-FIGARCH) model proposed by Baillie and Morana (2009). Empirical results suggest that there are multiple structural breaks on variance of returns series and A-FIGARCH model outperforms. In addition, it is found evidence in favor of long memory on the conditional variance of returns series and hence it can be said that Borsa İstanbul is not weak form efficient market

Examination of conservatory students' anxiety levels for the individual instrument baglama exam

Ülkemizde var olan eğitim sistemi içerisinde öğrencilerin daha etkin olmaları gereken, kişisel performans ve sistematik çalışma gerektiren, tüm bunlara ek olarak mesleki uzmanlık eğitimleri almalarını sağlayan eğitim dönemi yükseköğretim sürecidir. Bu dönem sonucunda öğrenciler tercih ettikleri meslek grupları ile ilgili uzmanlık ve mesleki yeterlilik kazanımı elde etmiş olurlar. Yükseköğretim sürecinin dikkat çeken önemli unsurlarından bir diğeri de ilgili kurumda yürütülen ölçme-değerlendirme faaliyetleridir. Bu durum öğrenciler üzerinde kaygıyı da beraberinde getirmiştir. Bu araştırma; yükseköğretim kurumu olan konservatuvarlarda, bağlama çalgısı eğitimi alan öğrencilerin bu çalgıya yönelik yapılan sınavlardaki kaygı düzeylerini ölçmeyi amaçlamıştır. Gerçekleştirilen bu çalışma; performans sergilemeye yönelik yapılan bağlama sınavındaki kaygı, heyecan ve yetersiz hissetme gibi unsurların tespiti açısından önem arz etmektedir. Araştırma 2021-2022 eğitim öğretim yılı içerisinde Afyon Kocatepe Üniversitesi, İzmir Ege Üniversitesi ve Kocaeli Üniversitesi Devlet Konservatuvarlarının ilgili bölümlerinde eğitim alan THM Bölümü bağlama öğrencileri üzerinde gerçekleştirilmiştir. Araştırmada bahsi geçen üniversitelerin 1. 2. 3. ve 4. sınıf öğrencilerinden oluşan 41 kişilik bir örneklem grubuna Polat D. tarafından geliştirilen “Sınav Kaygısı Ölçeği” uygulanmıştır. Araştırma kapsamında sınavlara yönelik kendi düşünceleri, başkalarının düşünceleri, hazırlanma endişeleri-sınav kaygısı ve zihinsel-bedensel tepkiler arasındaki ilişkiler tespit edilmiştir. Çalışma sonucunda ulaşılan bilgiler analiz edilmiş olup bu analizlerden elde edilen veriler yorumlanmıştır. Ayrıca sonuçlar üzerinden öneri ve sürece katkı sağlayacağı düşünülen tartışmalara yer verilmiştir.In the education system in our country, the education period is the higher education process that requires students to be more effective, requires personal performance and systematic work, and in addition to all these, enables them to receive vocational specialization training. As a result of this period, students gain expertise and professional competence related to the occupational groups they prefer. Another important element of the higher education process is the measurement-evaluation activities carried out in the relevant institution. This situation also brought anxiety on the students. This research; The aim of this study is to measure the anxiety levels of the students who receive baglama instrument training in conservatories, which are higher education institutions, in the exams for this instrument. This study carried out; It is important in terms of determining the factors such as anxiety, excitement and feeling inadequate in the baglama exam for performing. The research was carried out on the baglama students of the THM Department, who were educated at Afyon Kocatepe University, Izmir Ege University and Kocaeli University State Conservatory in the 2021-2022 academic year. The “Exam Anxiety Scale” developed by Polat D. was applied to a sample group of 41 students consisting of 1st, 2nd, 3rd and 4th grade students of the universities mentioned in the research. Within the scope of the research, the relationships between own thoughts, thoughts of others, preparation concerns-exam anxiety and mental-body reactions towards exams were determined. The information obtained as a result of the study was analyzed and the data obtained from these analyzes were interpreted. In addition, suggestions and discussions that are thought to contribute to the process are included on the results

Retrospective Evaluation of Serologic and Molecular Test Results of Toxoplasmosis Suspected Patients

Toxoplasma gondii is a compulsory intracellular protozoan parasite with a wide range of host in warm-blooded vertebrates and has importance in terms of health and economy. Toxoplasmosis is very common because it can infect people with a variety of ways; ingestion of contaminated water and nutrients; raw or undercooked meats containing tissue cysts, blood transfusions, organ transplantantation and transplacental transfer. The aim of this study was to evaluate serologic and molecular test results of toxoplasmosis pre-diagnosed patients. Anti-T.gondii-IgG, anti-T.gondii-IgM ELISA, anti-T.gondii-IgM IFAT and anti- T.gondii-IgG avidity serological tests and PCR tests were applied by using blood, cerebrospinal fluid, amniotic fluid, pericardial fluid and abscess samples from patients who have admitted to Erciyes University Faculty of Medicine Department of Parasitology routine serology and molecular diagnosis laboratories with a pre-diagnosis of toxoplasmosis. Among 6547 patients 3.3% (n= 220) were only IgM positive, 9.2% were both IgG and IgM positive (n= 598). Among male patients, the positivity rates were lower and only IgM seropositive patients were 0.6% (n= 45) while the frequency of both IgG and IgM positive patients was 0.8% (n= 47). The number of both IgG and IgM seropositive cases among new borns, constituting 6.4% (n= 425) of the total number of patients, was 20 (0.3%) and the number of IgM seropositive samples was 25 (0.4%). Only 290 patients positive for IgM antibodies were studied for IFAT and 22 of these patients were positive for anti-T.gondii-IFAT IgM. Anti- T.gondii IgG avidity test was performed in all IgG positive patients regardless of their IgM seropositivity; low avidity was found in 0.7% (n= 18) of IgM-negative patients' sera and equivocal avidity was detected in 6.5% (n= 179). Low avidity was detected in 2.6% of IgM positive patients. Nine of the patients evaluated as anti-T.gondii IgM negative and IgG positive were detected as positive by PCR and two of them were negative. One of these PCR-positive patient's amniotic fluid was sent after the serological test results and detected as positive. Twenty CSF samples were studied by PCR and 7 samples were positive. Also, 8 blood samples which were anti-T.gondii IgM negative and IgG positive were found to bepositive in 7 and negative in one sample with PCR results, subsequently. PCR tests with pericardial fluid and abscess materials were found to be negative. In the case of suspicious or risky situations such as false negatives or false positives resulting from cross-reaction that can occur in ELISA tests, unnecessary medication or interventional approaches can be avoided by applying molecular-based testing at laboratories with appropriate infrastructure. For this reason, we believe that the application of molecular tests in addition to serological tests in risky situations may give more reliable results