208 research outputs found
Currency substitution in high inflation countries : an empirical analysis
Ankara : The Department of Economics, Bilkent University, 2001.Thesis (Master's) -- Bilkent University, 2001.Includes bibliographical references leaves 46-48.This study explores the importance of currency substitution phenomena,
encountered mostly in high inflation countries rather than other countries. First, it
investigates the causes and consequences of currency substitution. It then employs a
measure of the currency substitution to estimate the elasticity of substitution between two
currencies; national and foreign currencies in a money-in-the-utility framework. The
utility function of representative agents includes consumption and money services
separately and is linear in consumption. Money services are produced by combining
domestic and foreign real balances in Constant Elasticity of Substitution production function. The presence of money services in the utility function is to indicate the
transaction costs reducing properties of the two currencies.
Ten high inflation countries are analyzed for the empirical measurements. Assumed as
small, open economies each of these countries is compared to the rest of the world
represented by the United States. The shares of domestic and foreign real balances, the
discount factors, the shares of money services in the utility functions and the elasticities
of substitution are directly estimated by Hansen’s Generalized Method of Moments
procedure. The fact that inflation reduces the credibility of domestic currency leads to
high elasticity of substitution between two currencies in the market of high inflation
countries. In other words, the public is vulnerable to the changes in the relative prices
while deciding their money allocations and currency substitution is of first-order
importance in these countries.Yılmaz, Çiğdem GüneyM.S
On the use of the SOS metaheuristic algorithm in hybrid image fusion methods to achieve optimum spectral fidelity
Image fusion aims to spatially enhance a low-resolution multispectral (MS) image by utilizing a high-resolution panchromatic (Pan) band. Various image fusion methodologies have been proposed with the aim to improve the spatial detail quality without deteriorating the colour content of the input MS image. Previous studies revealed the fact that there is no such thing as 'the best image fusion method' since all fusion methods cause either spectral distortion or spatial detail loss to some extent, which motivates the researchers to develop more advanced methods to keep the colour content while increasing the spatial detail quality. This study proposed to use the Symbiotic Organisms Search (SOS) metaheuristic algorithm in hybrid image fusion methods to achieve the optimum colour quality in the fused images. The SOS algorithm was used in two hybrid fusion approaches, one including the Intensity-Hue-Saturation (IHS) and Discrete Wavelet Transform (DWT) methods and the other one including the IHS and Discrete Wavelet Frame Transform (DWFT) methods. The results of the proposed methods were qualitatively and quantitatively compared in three test sites against those of eighteen widely-used image fusion methods. It was concluded that the proposed methods led to superior colour quality with both singlesensor and multisensor input images, regardless of the spatial resolution difference between the input images. The proposed methods were also found to be very successful in sharpening the images, despite the fact that their main purpose was to keep the colour content as much as possible
Product design concept evaluation by using analytical hierarchy and analytical network processes
The aim of this study is to improve the success and efficiency of the design concept evaluation and selection activity in industrial design by adapting two specialized evaluation-selection methods to the design process and comparatively demonstrating their use. The methods are called the Analytic Hierarchy Process (AHP) and the Analytic Network Process (ANP). In their application, first the main design objective is decided upon and the evaluation criteria are determined accordingly, followed by the listing of the design concept alternatives. Then the criteria's importance values as well as relations between them are investigated and evaluation of the alternatives is done according to the criteria by using the tools provided by the methods. The application presented in the article evaluates seven hand cart designs by using the two methods. First the tasks that are common in both methods, then the tasks specific to each method are explained. The general criteria to be used in the evaluation are identified and the effects of these criteria on the evaluation process are determined through interviews with designers and users participating in the study. Then the relative performance rankings of the available seven hand cart alternatives are calculated by using both methods. Numerical results are listed in a descending order to show the success levels of the design concepts, pointing to the one that received the highest overall performance. The findings obtained from two methods are comparatively interpreted
Türkiye’deki Suriyeli Göçmenlerin İstihdamına Y ve Z Kuşağının Bakışı: Bir Alan Araştırması
DergiPark: 733435trakyaiibfSon yıllarda görülen en büyük kitlesel göç hareketi 2011 yılında Suriye’de ki çatışmaların iç savaşa dönüşmesi ile birlikte yaklaşık 13 milyon Suriyelinin evini terk etmek zorunda kalmasıyla başlamıştır. 6 milyon Suriyeli ülke içinde yer değiştirirken yaklaşık 6 milyon Suriyeli de kendine komşu olan ülkelere sığınmıştır. İç savaştan Türkiye en çok etkilenen ülkelerden biri olmuştur. Savaş sonrası Türkiye’ye göç eden 3.684.835 Suriyeli geçici koruma kapsamına alınmıştır. Suriyeliler yoğun olarak sınır illerde yaşamını devam ettirmenin yanı sıra İstanbul, Ankara, İzmir başta olmak üzere Türkiye’nin 81 ilinde yaşamaktadır. Suriyelilerin Türkiye’ye gelişleri ile beraber uzayan misafirlik süreci ve yardımların yetersiz kalışı Suriyelilerin temel ihtiyaçlarını sağlamak üzere emek piyasasına girişine neden olmuştur. Türkiye’de 32.199 göçmene belirli koşullar altında çalışma izni verilmiştir. Çalışma izni alamayan ya da iznin dışındaki sektör ve illerde çalışanlar kayıt dışı olarak emek piyasasına dâhil olmuşlardır. Suriyeli göçmenler Türkiye’de ağırlıklı olarak tekstil, inşaat, tarım ve ağır sanayi sektörlerinde çalışmaktadır. Türkiye’de istihdamda yer alan bireylerin çoğunluğu Y ve Z Kuşağından oluşmaktadır. Suriyeli göçmenlerin ülkeye yerleşmesi ile birlikte istihdamda yer alması istihdamda bulunan çalışanlar açısından önem arz etmektedir. Bu çalışma, Y ve Z Kuşağının, Suriyelilerin istihdamına yönelik bakış açısını ölçmeyi amaçlamaktadır. Çalışmada seçili üniversitede çalışan 100 Y Kuşağı akademisyen ve 505 Z Kuşağı öğrenci ile anket çalışması yapılmış ve 4 anket geçersiz sayılarak toplamda 601 kişiye ulaşılmıştır. Anket cevapları ile elde edilen veriler yapılan analiz sonuçları ile değerlendirilmiştir
Heavy metal pollution in surface sediment and mussel samples in the Gulf of Gemlik
Sediment quality data provide essential information for evaluating ambient environmental quality
conditions. An evaluation is presented of heavy metal pollution, on the basis of statistical analysis of metal
concentrations from the sediments of the Gulf of Gemlik, southeastern Marmara Sea, Turkey, which has
been subject to high levels of pollution. The ranges for heavy metal concentrations (Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) at the 63 μm fractions. Not only large industrialized seaports but also resort areas throughout the Gulf are flagged as hotspots for elevated concentrations, generally higher compared to those from the other Turkish marine environment. The highest concentrations of Cr, Pb, and Ni were measured in the outer part of the Gulf, while the highest concentrations of Cu were documented offshore the main rivers. While the concentrations of Cr, Fe, Mn and Ni in some stations approach the severe effect level given in various sediment quality guidelines, the concentrations of the most human-related metals (Cd and Zn) in the mussels collected from the Port Mudanya were higher than the acceptable values for human consumption set by various health organizations.The research fund of the Istanbul University; project UDP-200
BUILDING AWARENESS OF WORLD ENGLISHES AMONG UNIVERSITY PREPARATORY STUDENTS
The increasing number of non-native English speakers in the world has led to the use of varieties of English. Today, the number of speakers of English in the expanding circle has exceeded the number of speakers in the outer and inner circles. This has given rise to the scrutiny of English as a Lingua Franca (ELF). In this regard, the research and studies in this particular area have increased over the last decades. The purpose of this action research was to build awareness of World Englishes (WEs) among preparatory students at a private university in Turkey. The study was mainly concerned with acquainting the group with the term and raising consciousness about this subject matter. The research was conducted in a private university in İstanbul, Turkey to 20 preparatory students aged 18-21 with A2 level English proficiency. Adapted EFL materials including videos, dialogues, reading and listening texts were utilized. The data were collected through questionnaires and reflective essays. With regard to the results, the students had an idea about the concept of WEs and they became aware of the varieties of English to some extent; specifically, they displayed consciousness about the status of English across the world and sympathy toward WEs.Keywords: world Englishes, ELF, expanding circle, lingua franc
Maligniteyi taklit eden pulmoner arteriyovenöz malformasyon: Olgu sunumu
Pulmonary arteriovenous malformations (AVM) are congenital lesions and are often arise in the lower lobes due to abnormal capillary development. Forty-two years old male patient presented with hemoptysis and he was referred to our clinic with the suspicion of malignancy.
Postero-anterior chest roentgenogram revealed homogenous opacity on the right perihilar zone. Computed tomography revealed a mass which was located at the right upper lobe. For the dia gnosis and staging 18F-FDG PET- CT was obtained. The mass was 6.5x5x4.5 cm and showed increased FDG uptake, 2,97. The lesion was considered as a large PAVM because of the linear density showing luminal contrast enhancement which was located between the lesion and right upper pulmonary vein. Dynamic contrast enhaced tomography revealed a solid mass with a suspicion of PAVM with thrombotic occlusion. Pulmonary angiography was free of AVM and fistulae. The patient underwent right upper lobectomy. Pathologic studies were consistent with pulmonary AVM. This case is presented because of upper lobe involvement, normal pulmonary angiography and the need of surgical operation as the only diagnostic tool
Mezial temporal lob epilepsili olgularda wada testi ve ameliyat öncesi/amaliyat sonrası bellek ilişkisi
Objectives: To study the correlation between Wada memory test and neuropsychometric tests which were applied preoperatively to mesial temporal lobe epilepsy patients associated with hippocampal sclerosis (MTLE-HS) who had undergone selective amygdalohippocampectomy and find out the effects of early onset epileptic seizures on atypical memory dominance. Methods: Drug-resistant 27 patients (16 left, 11 right MTLE-HS) had video EEG, cranial MRI and Wada test preoperatively. Weschler visual subtest and verbal memory processing tests were applied to all patients before surgery and the first year after the operation. Results: The number of left hemisphere memory dominant patients was 6 (22.2%) and the number of atypical memory dominant patients was 21 (77.8%) according to the Wada test. There was a significant difference between the two groups when compared for epileptic seizure onset age; (p=0.042), and also a significant diffference when compared for HS (right/left) side (p=0.002). When we analyzed the correlation between preoperative and postoperative verbal and nonverbal tests and left memory Wada dominance; in verbal memory processing tests ‘delayed recall’ scores between groups were significant (p=0.042), on the other hand in patients with atypical memory dominance ‘total learning’ scores between groups were significant (p<0.001). Conclusion: As a result, we found that the earlier the onset of seizures, the more atypical the memory dominance (right or bilateral). The Wada test was effective for assessing verbal memory; on the other hand, it was inadequate for assessing visual memory dominance. If the scores of ‘delayed recall’ in verbal memory were high in the patients with typical verbal dominance and ‘total learning’ scores in the patients with atypical verbal dominance, the scores also tended to rise after the operation.Amaç: Selektif amigdalohippokampektomi yapılan hipokampal sklerozla ilişkili mesial temporal lob epilepsili (HS-MTLE) hastalarda ameliyat öncesi dönemde yapılan Wada testi ile nöropsikometrik testler arasındaki ilişkiyi inceleyerek erken yaşta başlayan epilepsi nöbetlerinin belleğin atipikleşmesi üzerindeki etkilerini araştırmak. Gereç ve Yöntem: Medikal tedaviye dirençli 27 hastaya (16 sol, 11 sağ HS-MTLE) cerrahi oncesi video EEG, kranial manyetik rezonans görüntüleme, Wada testi ile ameliyat öncesi ve sonrası birinci yılda Weschler görsel subtest ve sözel bellek süreçleri testleri uygulanmıştır. Bulgular: Wada bellek testinde sol hemisfer dominant bulunanlarn sayısı 6 (%22.2), atipik yerleşimli olanların sayısı 21 (%77.8) idi. Bellek dominansı sol ve atipik olanlarda nöbet başlama yaşı (p=0.042), ve HS (sağ/sol) tarafı açısından karşılaştırıldığında da anlamlı fark saptanmıştır (p=0.002). Yine sol bellek dominant olanlar ile ameliyat öncesi ve sonrası verbal ve nonverbal testler arasındaki korelasyona bakıldığında sözel bellek süreçleri testlerinden ‘gecikmeli hatırlama’ puanları arasında anlamlı ilişki bulunurken (r=0.829; p=0.042) atipik bellek dominansı olanlarda ‘toplam öğrenme’ puanları arasında anlamlı ilişki bulunmuştur (r=0.731; p<0.001). Sonuç: Nöbet başlama yaşı ne kadar düşükse bellek dominansı o kadar atipiktir (sağ veya bilateral). Wada testi sırasında yapılan bellek değerlendirmesi verbal belleği değerlendirmede etkili ancak görsel belleği değerlendirmede yetersizdir. Tipik bellek dominansı olanlarda ‘gecikmeli hatırlama’, atipik olanlarda ‘toplam öğrenme ’ puanları başlangıçta yüksek ise, ameliyat sonrası dönemde de yükselme göstermektedir
Evaluation of canal cleanliness and tubular penetration of root canal sealers in extracted primary second molars: a SEM study
Objectives: To evaluate canal surface changes and the remaining debris/smear after canal preparation, and the subsequent penetration of root canal sealers into dentinal tubules in extracted primary second molars, using scanning electron microscopy (SEM). Materials and Methods: The widest roots of 120 recently extracted human primary second molars were used. The roots were randomly distributed into four groups, according to instrumentation techniques [conventional stainless-steel hand files / nickel-titanium (Ni-Ti) rotary files] and irrigation solutions [0.5% sodium hypochlorite (NaOCl) and 0.9% saline solution/0.4% chlorhexidine gluconate (CHX)] employed. Surface change, the debris/smear layer remaining after instrumentation/irrigation, and the tubular penetration of root canal sealers [zinc oxide and eugenol (ZOE)/Apexit Plus (AP)] were evaluated using SEM. All data were analyzed statistically using the Kruskal-Wallis and Mann-Whitney U tests. Results: No significant difference was found between the surface changes and debris/smear layer scores based on root canal preparation technique and irrigant solution (P>0.05). ZOE cement was unable to enter dentinal tubules, while AP-based calcium hydroxide was able to gain limited entry to the tubules of some roots, but not others. Conclusions: No differences in canal cleanliness were noted among the instrumentation and irrigant protocols evaluated. AP was found in this SEM study to penetrate the dentinal tubules of prepared primary molar root canals more effectively than ZOE; though, penetration with AP was not noted in every root canal
Molecular investigation of mechanisms considered to cause preterm premature membrane rupture
Purpose: The aim of this study was to investigate the mRNA expression level of p16, CDK4, CDK6, Cyclin D, RB1, and E2F genes in preterm premature rupture of membrane (PPROM) cases and their roles in etiopathogenesis of PPROM.Materials and Methods: Twenty-one pregnancies with PPROM before 34th gestational weeks (study group) were compared with twenty pregnancies with no complication, who gave birth after 37th gestational-week (control group). Both groups chorioamniotic membranes were compared for mRNA expression of p16, cyclin D, CDK4, CDK6, RB1 and E2F genes.Results: The mRNA expression levels of p16, cyclin D, CDK4, CDK6, RB1and E2F genes decreased in the PPROM group compared to control group at a statistically significant level.Conclusion: Our findings have shown that oxidative stress may not act on the p16 pathway in these cases. In order to understand the molecular mechanism of PPROM, biomarkers of oxidative stress and aging should be evaluated together with other pathways related to aging and oxidative stress in future studies.Amaç: Bu çalışmanın amacı, preterm erken membran
rüptürü (PEMR) vakalarında, p16 ile CDK4, CDK6, siklin
D, RB1, E2F genlerinin mRNA ekspresyon seviyelerini ve
bu genlerin etiyopatogenezdeki rollerini saptamaktır.
Gereç ve Yöntem: Çalışmamızda 34. gebelik haftasından
önce membran rüptürü olan 21 gebe (çalışma grubu) ile
herhangi bir durumla komplike olmamış ve 37. gebelik
haftasından sonra doğum yapmış 20 gebenin (kontrol)
doğum sonu koryoamniyotik membranları incelendi ve bu
iki grubun koryoamniyotik membran örnekleri p16, siklin
D, CDK4, CDK6, RB1 ve E2F genlerinin mRNA
ekspresyon seviyeleri açısından karşılaştırıldı.
Bulgular: Çalışmamızda, kontrol grubu ile kıyaslandığında
p16, siklin D, CDK4, CDK6, RB1 ve E2F genlerinin
ekspresyon seviyelerinin PEMR grubunda anlamlı
derecede azaldığı saptandı.
Sonuç: Bulgularımız bu vakalarda oksidatif stresin p16
yolağı üzerinden etki etmeyebileceğini göstermiştir.
PEMR’nin moleküler mekanizmasını anlamak için,
gelecekteki çalışmalarda oksidatif stres ve yaşlanma
biyobelirteçleri ile yaşlanma ve oksidatif streste görevli
diğer yolaklar birlikte değerlendirilmelidir.Cukurova Universit
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