293 research outputs found
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
Yedinci Sınıf Öğrencilerinin Yerel Sosyobilimsel Konulardaki Argümanlarında Kullandıkları Veri Bileşeninin İncelenmesi
The purpose of this study is to examine the quantity and quality of the data component used by seventh-grade students in their arguments related to issues unique to the city of Bolu: Seben Lake, chicken coops, leather tanneries, base stations, and Hydroelectric Power Plants (HPP). Three different study groups, with 12 participants in each group (in total 36 participants), were the subject of this research, which was conducted over a total of 10 weeks. Each study group interacted with a different data source: the outdoor group collected data on field trips, the newspaper group read and examined related articles in the press, and the presentation group listened to visual presentations. The groups reflected the data obtained from their data sources to the argumentation implementations. The resulting of content analyses, based on the items in Toulmin’s (1958) argument model showed that, of the total of 847 data components generated in the participants’ argumentations, the newspaper group used the most data in their arguments, while the presentation group employed the least data. The outdoor and presentation groups generally utilized data based on the data cited in their data source, while the newspaper group used more data based on their daily life experiences. The highest amount of data was employed in relation to the issue of leather tanneries based on data acquired during field trips in the outdoor group, in relation to HPP based on visual presentations in the presentation group, and in relation to Seben Lake based on daily life experiences in the newspaper group. In conclusion, the quantity and the quality of the data component used in students’ arguments with regard to local socioscientific issues changed according to the data source with which they interacted and the content of the socioscientific issue. In light of this, a few suggestions are made in this paper’s conclusion.Bu araştırmanın amacı, yedinci sınıf öğrencilerinin Bolu şehrine özgü Seben Göleti, tavuk kümesleri, deri tabakhaneleri, baz istasyonları ve Hidroelektrik Santrali (HES) konularıyla ilgili argümanlarında kullandıkları veri bileşeninin niceliğini ve niteliğini ortaya çıkarmaktır. Üç farklı çalışma grubunun (her grupta 12 katılımcı) yer aldığı bu araştırmaya toplamda 36 katılımcı katılmış ve 10 haftalık bir uygulama yapılmıştır. Gezi grubunda alan gezileri, gazete grubunda gazete haberleri ve sunum grubunda görsel sunumlar olmak üzere üç farklı veri kaynağı ile etkileşen katılımcı grupları, topladıkları verileri küçük grup ve toplu sınıf tartışmalarındaki argümantasyonlarına yansıtmıştır. Toulmin’in (1958) argüman modelinde yer alan ögelere göre yapılan içerik analizi, argümantasyonlarda üretilen toplamda 847 adet veri bileşeninden en çoğunun gazete grubunda en azının ise sunum grubunda kullanıldığını göstermiştir. Gezi ve sunum grubu çoğunlukla etkileşimde bulunduğu veri kaynağına dayalı veri kullanırken, gazete grubu günlük yaşam deneyimlerine dayalı verileri daha çok kullanmıştır. Gezi grubu en fazla veriyi alan gezilerine dayalı deri tabakhaneleri içeriğinde, sunum grubu en fazla veriyi görsel sunumlara dayalı HES içeriğinde, gazete grubu ise en fazla veriyi günlük yaşam deneyimlerine dayalı Seben Göleti içeriğinde kullanmıştır. Bu bulgulara dayanarak yerel sosyobilimsel konularda oluşturulan argümanlarda kullanılan veri bileşeni niceliği ve niteliğinin etkileşimde bulunulan veri kaynağı ve konu içeriğine göre değiştiği sonucuna varılmıştır. Bu bağlamda, çalışmanın son kısmında birkaç öneride bulunulmuştur
Perceived Physical Literacy Scale for Adolescents (PPLSA): Validity and Reliability Study
The aim of this study is to adapt the “Perceived Physical Literacy Scale for Adolescents” into Turkish version. The research was designed with the descriptive survey model. Research data were obtained from a total of 585 participants aged between 12 and 19 years. The research was carried out with data obtained from four different study groups in 2019. In the study, language validity was performed with 20, Explanatory Factor Analysis (EFA) 218, Confirmatory Factor Analysis (CFA) 300, and reliability (test-retest) analysis with data from 47 participants. AFA and CFA were made to test the construct validity. Pearson Correlation Analysis was used to determine the relationship between factors. For item discrimination, item test correlation and 27% lower-upper group comparison were determined. Convergent and divergent validity analysis were made. Cronbach’s Alpha and test-retest analysis were used within the scope of reliability analysis. As a result of EFA, a structure with 3 factors and 9 items was determined. This structure has been verified by CFA. One-dimensional and three-dimensional models were tested for the scale structure, and it was determined that the fit indices of the 3-dimensional pattern were more significant. A positive significant relationship was found between physical literacy, which is a measured feature in the scale, and its sub-dimensions. Reliability analysis results showed that the measuring tool can measure reliably. Descriptive analysis (mean, standard deviation) showed that the perceived physical literacy scale for adolescents is high in general and in its sub-dimensions. Analyzes conducted within the context of the construct validity of the measuring tool show that the perceived physical literacy scale for adolescents is a valid and reliable instrument that can measure. Measurement tool is important in determining the physical literacy of adolescents. Specialists working in the field of physical education and sports can provide the necessary support with appropriate intervention programs in line with the determinants of the physical literacy of adolescents
A Visionary Approach Study about the Member Construction Firms of Turkish Contractors Association (TCA)
In this study Turkish Contractors Association (TCA) members construction fims’ visionary approaches were investigated. A questionnaire has applicated to technical and administrative elements who works in 56 construction firms for evaluation of visionary approach of these firms. In this wise general profile of these firms’ evaluation of visionary approach has been understand and which firms emphasize which characteristics in determine vision investigated. Acquired by findings; these firms emphasizes their quality, trust and technologies in first three; their tangibility, being polyhedral and sensuality followed them. These fims’ emphasis to quality ratios were 64.3%, emphasis on job security were 32.1% and environmental stres ratio were 35.7% in their visions. Turkish construction firms have to create and applicate the most appropriate strategies for being successfull in global competitive race and to carry that success into long term. Our companies’ competitive advantage by providing with a strategic advantage are associeted with their visions
The effect of biceps tenotomy on superior humeral migration in arthroscopic repaired full-thickness supraspinatus tears
Lesions of the long head of the biceps (LHB) tendon are a prevalent injury that frequently coexists with rotator cuff injuries. This study aimed to assess the effect of supraspinatus (SST) repair with concurrent LHB tenotomy on superior migration of the humeral head. The acromiohumeral distance (AHD) was determined via ultrasound to evaluate the superior migration of the humeral head. Methods: The study population was retrospectively recruited from patients who underwent unilateral arthroscopic repair of isolated degenerative full-thickness SST tears between January 2017 and December 2019. Patients were divided into 2 subgroups based on whether they underwent LHB tenotomies during arthroscopy. While 37 patients underwent arthroscopic single-row SST repair, the other 33 patients underwent arthroscopic single-row SST repair with LHB tenotomy. The subject group consisted of people who had undergone arthroscopic shoulder surgery. Contralateral shoulders without rotator cuff injuries were included in the control group. The AHD and SST thicknesses of patients were examined via the ultrasound in both groups and subgroups. Results: The mean age in the SST repair group was 55.52 ± 4.58 years (range, 46-63 years), whereas it was 58.24 ± 3.98 (range, 52-73 years) in the SST repair + LHB tenotomy group. In the SST repair group, 57.6% of patients were female and 42.4% were male, whereas 56.8% and 43.2% were in the SST repair + LHB tenotomy group, respectively. The mean body mass index was 28.06 ± 1.31 kg/m2 (range, 25.7-31.2 kg/m2) in the SST repair group and 28.95 ± 1.79 kg/m2 in the SST repair + LHB tenotomy group. Groups were not different for sex, surgery side, dominant side, tear size, and follow-up time; however, the SST repair + LHB tenotomy group had significantly higher mean age and body mass index than the SST repaired group. The mean AHD value and SST thickness were significantly less in both the rotator cuff repair group and the rotator cuff repair + LHB tenotomy group compared to the healthy shoulder. The mean AHD value was significantly lower in the SST repaired + LHB tenotomy group than in the SST repair group (P = .02). Conclusion: The AHD was narrowed in patients who underwent LHB tenotomy and radiologically demonstrated the depressor effect of the LHB tendon on the humeral head. As a secondary outcome, we demonstrated that regardless of tenotomy, AHD could not be restored in patients who underwent arthroscopic single-row SST repair
Evaluation of the effect of comorbid bronchiectasis on quality of life in patients with chronic obstructive pulmonary disease
Objective: The objective of this study was to evaluate the effect of comorbid bronchiectasis on quality-of-life in patients with Chronic Obstructive Pulmonary Disease (COPD). Method: 103 patients were diagnosed with COPD were included in our study. Spirometric measurements were made. The following measurement tools were used to collect data: 6-Minute Walk Test (6MWT), Modified Medical Research Council (mMRC) dyspnea scale, COPD Assessment Test (CAT), St. George Respiratory Questionnaire (SGRQ), and Short Form 36 (SF-36) quality-of-life questionnaire. Furthermore, all the patients' high Resolution Computed Tomography (HRCT) images for the last three years were included in the study. Result: 93.2% of the patients were male, with a mean age of 64.79 +/- 9.35 years. It was found that SGRQ and SF-36 quality-of-life scores decreased by half in all the patients compared to normal ones. The volume/forced vital capacity (FEV1/FVC) values in the first second of forced expiration were significantly lower in the group with bronchiectasis. A significant correlation was found to exist between the patients' mMRC dyspnea scale and CAT scores, 6MWT distances, and all subscales of SGRQ and SF-36. In addition, a significant correlation was also found to exist between FEV1 values and all subscales of SGRQ, and between subscales of SF-36. Conclusion: In our study, when we compared the quality-of-life scores of the patients with COPD and bronchiectasis with those with COPD alone, we found that the quality-of-life of both groups was impaired, but there was no significant difference between them
N-Cyano-7α-methoxycarbonyl-6,14-endo-ethenotetrahydronorthebaine
In the title compound (systematic name: methyl 17-cyano-3,6-dimethoxy-4,5α-epoxy-6,14-endo-ethenomorphinan-7-carboxylate), C23H24N2O5, the dihydrofuran ring adopts a twist conformation, while the piperidine ring is in a chair conformation. The benzene-fused cyclohexene ring adopts an envelope conformation. An intramolecular C—H⋯O hydrogen bond is observed. Intermolecular C—H⋯N and C—H⋯O hydrogen bonds form C(5) chains along the a and b axes, respectively, and together they form a three-dimensional network
Argümantasyon ve Otantik Öğrenme Tabanlı STEM Uygulamalarının Akademik Başarıya Etkisi
Araştırmada argümantasyon ve otantik öğrenme tabanlı STEM uygulamalarının akademik başarıya etkisi incelenmiştir. Uygulama öncesinde iki fen bilimleri öğretmeni ile dokuz gün boyunca her gün 120 dakikalık bir öğretmen eğitimi gerçekleştirilmiştir. Çalışma 17 hafta boyunca iki farklı devlet okulunda 120 beşinci sınıf öğrencisi ile yürütülmüştür. Amaçlı örnekleme yönteminin kullanıldığı çalışmada, karma yöntem araştırmalarından yakınsayan paralel desenden yararlanılmıştır. Araştırmanın nicel boyutunda ön test-son test kontrol gruplu yarı deneysel desen kullanılmıştır. Her iki okulda da bir kontrol ve iki deney grubu (argümantasyon ve otantik) belirlenmiştir. Nitel boyutta ise durum çalışması deseni kullanılmıştır. Nicel veri toplama araçları ışığın yayılması, insan ve çevre ile elektrik devre elemanları akademik başarı testleri; nitel veri toplama araçları ise video ve ses kayıtları, yarı yapılandırılmış görüşmeler, öğretmen ve araştırmacı gözlem formları ve öğrenci günlükleridir. Araştırma sonucunda, üç akademik başarı testinin ön test-son test puanları arasında özellikle otantik grup lehine anlamlı farklılıklar bulunmuştur. Nitel bulgularda da öğrencilerin ünitelere yönelik yaklaşımdan kaynaklı etkilerinin görüldüğü ifadeler tespit edilmiştir. Çalışmanın son bölümünde bulgulara ilişkin çeşitli önerilere yer verilmiştir
1-Methoxy-3-o-tolylbicyclo[2.2.2]oct-5-ene-2,2-dicarbonitrile
In the title compound, C18H18N2O, the cyclohexene and cyclohexane rings of the bicyclo[2.2.2]oct-5-ene unit adopt distorted boat conformations. In the crystal, molecules exist as C—H⋯N hydrogen-bonded centrosymmetric R
2
2(14) dimers, which are further linked by C—H⋯π interactions
Fen Bilimlerinde Eğitsel Oyun ve Bilimsel Öykü Kullanımı: 2010-2020 Yılları Arası Yüksek Lisans Tezleri
Bu çalışmada 2010-2020 yılları arasında fen bilimleri dersinde bilimsel öykü ve eğitsel oyunların kullanımına yönelik yüksek lisans tezleri bazı değişkenler açısından incelenmiştir. Çalışmada incelenen yüksek lisans tezleri Ulusal Tez Merkezi veri tabanından elde edilmiştir. Ulaşılan 43 yüksek lisans tezi arasından ortaokul fen bilimleri dersine yönelik olarak 33’ü incelemeye alınmıştır. Doküman analizi yöntemi kullanılarak yüksek lisans tezleri incelenmiştir. Elde edilen verilerin analizinde betimsel analiz yöntemi kullanılmıştır. Yıllara göre bakıldığında eğitsel oyunlara ilişkin en fazla çalışma 2019 yılında yapıldığı tespit edilmiştir. Ortaokul seviyelerinde en çok 6. sınıf düzeyine yönelik çalışmalar yapıldığı, konu alanı olarak en çok çalışmanın “Canlılar ve Yaşam” konu alanında yapıldığı görülmüştür. Yöntem olarak daha çok nicel araştırma yöntemlerinden yararlanıldığı, oyun çeşidi olarak kartlı oyunlara ve karma oyunlara ağırlık verildiği belirlenmiştir. Fen bilimleri, akademik başarı, başarı, eğitsel oyun gibi anahtar kelimelerin daha sık kullanıldığı ve rekabete yer verilen oyunların daha çok sayıda olduğu ortaya koyulmuştur. Araştırma sonuçlarının fen öğretiminde eğitsel oyuna ve bilimsel hikâyelere dayalı öğrenmeyi kullanacak araştırmacılara bu tekniği farklı fen konularına uygulayıp farklı sonuçlara ulaşmaları açısından yol göstereceği düşünülmektedir
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