http://hdl.handle.net/20.500.12416/285 2026-10-28T16:55:27Z http://hdl.handle.net/20.500.12416/8461 Firm Survival in Times of Crisis: Do Innovation and Financing Constraints Matter? Insights from the COVID-19 Pandemic Özşuca, Ekin Ayşe Utilizing survey data collected over three rounds, this paper investigates the impact of pre-COVID innovation performance, innovation type, sources of knowledge, and the moderating role of financial constraints on survival following the outbreak of COVID-19. The findings pinpoint a strong and positive link between firm survival and innovation, especially process innovation, confirming the ability of innovators to adapt to new conditions as a determinant of survival. Moreover, relying on internal knowledge is found to increase the chance of survival and adaptability to times of crisis. The results further indicate that access to finance strengthens the positive impact of innovation on firm survival/adaptation. 2023-01-01T00:00:00Z http://hdl.handle.net/20.500.12416/8448 ECG Signal Denoising with SciLab Ahmad, Imteyaz; Özaydın, Selma This paper presents a study on de-noising electrocardiogram (ECG) signals using Scilab, an open-source software package known for its signal processing capabilities. ECG signals are often contaminated by various noise sources, which can reduce the accurate diagnosis and monitoring of heart health. In this work, digital signal processing methods such as Finite Impulse Response (FIR) and Infinite Impulse Response (IIR) filters are used to effectively suppress noise while preserving the essential features of the ECG waveform. We explore main noise sources that commonly affect ECG recordings, such as baseline wandering noise, power-line interference, and muscle artifacts, and discuss their respective challenges. The de-noising methods has been extensively evaluated and demonstrated its ability to improve signal quality and diagnostic accuracy by eliminating noise artifacts. The results highlight Scilab's potential for de-noising ECG signals and its importance in improving patient care and biomedical signal processing applications. The efficacy of the de-noising methods is thoroughly evaluated through comparative analyses with other commonly used de-noising approaches. Experimental results demonstrate its superiority in preserving the QRS complex while efficiently eliminating noise artifacts, leading to more accurate and reliable diagnostic information. In conclusion, this paper presents a comprehensive study on de-noising ECG signals using Scilab, offering a valuable contribution to the field of biomedical signal processing. Researchers and practitioners in the domain of ECG signal processing can benefit from the insights and techniques presented herein to advance their studies and further applications. 2023-09-21T00:00:00Z http://hdl.handle.net/20.500.12416/8434 Comparative Performance Analysis of Filtering Methods for Removing Baseline Wander Noise from an ECG Signal Özaydın, Selma; Ahmad, Imteyaz ECG signals play a vital role in the diagnosis of cardiovascular conditions. However, they often su®er from the e®ects of various noise sources, including baseline wandering, respiratory artifact noise, power line interference and electrode motion artifacts. To overcome these challenges, it is imperative to implement low-frequency signal noise reduction strategies. Such strategies aim to signi¯cantly improve the quality of ECG signals, thus promoting more accurate and reliable diagnosis of cardiovascular disorders. This paper conducts a comparative analysis to assess the e®ectiveness of commonly used ¯ltering and wavelet techniques in reducing Baseline Wander (BW) noise within ECG signals generated by the in°uence of breathing or electrode movements. It is common to observe the selection and evaluation of only one particular technique in the existing literature. In contrast, this study aims to provide a comprehensive comparative analysis, providing insight into the performance and relative merits of di®erent techniques. Our research uses both ¯ltering and Discrete Wavelet Transform (DWT) techniques in baseline noise removal. In this context, a reference point is established utilizing noise-free signals and a meticulous investigation of the wavelet-based approach that most e®ectively eliminates the resulting noise is provided. Subsequently, we assess the reference input and output signal via Signal-to-Noise Ratio (SNR) and Kolmogorov–Smirnov statistical test measurements. The most important contribution of this work to the scienti¯c community resides in the comprehensive examination of IIR/FIR-based and wavelet method-based ¯ltering methods capable of yielding the highest SNR levels across various ECG signals with various types of BW noise. Additionally, the e®ectiveness of the Chebychev-II ¯lter in BW noise removal is highlighted. Our study was conducted using the MATLAB platform and code command lines were shared to facilitate the reproduction of our study by other researchers. It is considered that this study will be an important reference in the selection of e®ective techniques for removing BW noise within ECG signals. 2024-01-01T00:00:00Z http://hdl.handle.net/20.500.12416/8333 Türkiye’de Banka Sermaye Tamponları, Kredi Büyümesi Ve İş Çevrimleri Özşuca, Ekin Ayşe Bu çalışmada, Türkiye’de faaliyet gösteren bankaların sermaye tamponlarının iş çevrimleri ve kredi büyümesi ile ilişkisi 2002-2017 dönemi için üç aylık veriler kullanılarak incelenmiştir. Tahminler sistem genelleştirilmiş momentler metodu kullanılarak yapılmış ve söz konusu etkilerin bankaların faaliyet türlerine göre farklılık gösterip göstermediği ayrıca test edilmiştir. Elde edile sonuçlara göre, Türkiye’de banka sermaye tamponları iş çevrimlerine karşı döngüsel hareket etmektedir.Ancak bu bulgu yatırım ve kalkınma bankaları için geçerli değildir. Diğer yandan, bankalara özgü özelliklerle ilgili panel regresyon sonuçlarına göre, büyüklük, karlılık ve risk ticari bankaların sermaye tamponlarının anlamlı belirleyicileri olarak ortayaçıkmaktadır. Aynı zamanda, bankacılık sektörünün yapısı ve 2008 küresel finansal krizinin banka sermaye tamponları üzerinde etkili olduğu gözlenmiştir. Sermaye tamponlarının bankaların kredi arzı üzerindeki etkisine dair bulgular ise ters yönlü bir ilişkiye işaret etmektedir. Çalışmanın bulguları, banka sermaye yeterliliğine ilişkin düzenlemeler ile Basel III uzlaşısı kapsamında önerilen ve yakın zamanda uygulamaya koyulan döngüsel sermaye tamponuna dair sonuçları bakımından önem taşımaktadır 2018-01-01T00:00:00Z