Browsing by Author "Ünlü, Ramazan"

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Citation - Scopus: 2
Future of Clean Cooking Energy Access in Emerging Economies by 2030
(Springer International Publishing, 2025) Çakır, Mehmet Ali; Ünlü, Ramazan; Çakir, Sümeyra Çay; Xanthopoulos, Petros; 01. Abdullah Gül University; 02.02. Endüstri Mühendisliği; 02. Mühendislik Fakültesi
This study assesses the future of clean energy and technology access for cooking in emerging economic blocs—BRICS, MINT, ASEAN, and MENA—through 2030. Cooking contributes 3% of global greenhouse gas emissions, with over half of household emissions coming from cooking. Therefore, clean cooking energy is critical for sustainability and human health. The study aims to evaluate the likelihood of achieving the UN Sustainable Development Goal of universal clean cooking energy access by 2030 and the 2050 net-zero emissions target. Machine learning techniques, such as support vector regression, gradient boosting, and linear regression, alongside an ensemble approach, provide forecasts for these regions. The findings show a varied outlook. Within ASEAN, two countries are expected to reach 100% clean energy access for cooking by 2030, while two are likely to experience a decline. The MENA region shows stronger progress, with eight countries expected to meet the 2030 target. Among BRICS countries, only India is projected to reach full accessibility, while Russia faces a decline. The MINT countries face challenges, with none expected to meet the target, and Nigeria is projected to experience a decrease in clean energy access. The study concludes that the current trajectory makes achieving the 2030 Sustainable Development Goals and the 2050 net-zero emissions target unlikely for these regions. Policymakers must reassess their strategies and learn from successful countries to improve outcomes. © 2025 Elsevier B.V., All rights reserved.
Karadeniz Bölgesi’nde Kurak ve Nemli Dönemlerin SPI Yöntemi Kullanılarak Belirlenmesi
(2024) Ünlü, Ramazan; Öztürk, Yasemin Deniz; 01. Abdullah Gül University; 02.02. Endüstri Mühendisliği; 02. Mühendislik Fakültesi
Karadeniz bölgesi Türkiye’nin en çok yağış alan bölgesidir. Ancak Karadeniz Bölgesi’nde yağışlar hem yıllar arasında hem de bölge içerisinde önemli farklılıklara sahiptir. Bu durum bölgede kuraklıkların yaşanabilmesine ve kurak-nemli dönemlerin birbirini takip etmesine neden olmaktadır. Bu çalışmada yıllık ve 12 aylık SPI değerlerine göre Karadeniz bölgesinde yaşanan kurak ve nemli dönemlerin belirlenmesi amaçlanmıştır. Bölge genelinden seçilen 26 istasyonun 1960-2020 yılları arasındaki ortalama yağış verilerine göre standardize yağış indeksi (SPI) değerleri hesaplanmıştır. Tespit edilen kurak ve nemli dönemlerin eğilimleri Mann-Kendall trend analizi kullanılarak tespit edilmiştir. Ayrıca ısı haritası kullanılarak Karadeniz Bölgesi kıyı ve iç kesimleri olarak ayrılıp kurak ve nemli dönemleri saptanmıştır. Analiz sonuçlarına göre 1966, 1969, 1974-1977, 1984-1986, 1993-1994, 2006-2007 ve 2019-2020 yıllarının normalden daha az yağış aldığı ve birçok istasyonun kuraklığı şiddetli şekilde olduğu saptanmıştır. 1967, 1988, 1996-1997, 1999, 2009 ve 2016 yıllarının ise normalden fazla yağış aldığını yani nemli karakterde olduğunu göstermektedir. Mann-Kendall trend analiz sonuçlarına göre Batı Karadeniz Bölgesinin kıyı kesimlerinde azalma eğilimde olduğu saptanmamıştır. Fakat azalışta anlamlılık bulunamamıştır. Orta ve Doğu Karadeniz bölgesinde ise artış eğilimi göstermekle birlikte bu eğilim bazı istasyonlarda anlamlı bulunmuştur. Bölgenin yer şekilleri dolayısıyla genel bir kurak ve genel bir nemli dönem olmadığı, doğu-batı doğrultusu ve kıyı-iç kesimlerde kurak ve nemli dönemlerin farklılık gösterdiği saptanmıştır.
Sembolik Toplam Yaklaşım Kümelemesi Yoluyla BIST100 Yatırımlarında Yön Bulma: Yatırımcılara Yönelik Bilgiler
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2024) Nalici, Mehmet Eren; Ünlü, Ramazan; Söylemez, İsmet; 01. Abdullah Gül University; 02.02. Endüstri Mühendisliği; 02. Mühendislik Fakültesi
Market stakeholders, including traders and investors, strive to forecast stock market returns for informed decision-making. Computational finance employs various tools such as machine learning techniques to analyse extensive financial datasets to provide predictive insights for investors. Among all those techniques, clustering is one of the most well-known and used machine learning methods to reveal hidden patterns from unlabelled data. This study aims to help investors make more robust decisions by autonomously identifying companies that may exhibit similar price movements. In our study, with the model developed based on the Symbolic Aggregate Approximation (SAX) method, BIST100 companies are divided into clusters of various numbers and various scenarios are developed for investors from different perspectives such as risk minimization and strategic investment. The SAX clustering method is employed for analysing share movements. Moreover, dendrogram tree graph is used to analyse the clustering of different SAX combinations.
Symbolic Aggregate Approximation-Based Clustering of Monthly Natural Gas Consumption
(2024) Söylemez, İsmet; Ünlü, Ramazan; Nalici, Mehmet Eren; 01. Abdullah Gül University; 02.02. Endüstri Mühendisliği; 02. Mühendislik Fakültesi; 07. Fen Bilimleri Enstitüsü; 07.03. Endüstri Mühendisliği Anabilim Dalı
Natural gas is an indispensable non-renewable energy source for many countries. It is used in many different areas such as heating and kitchen appliances in homes, and heat treatment and electricity generation in industry. Natural gas is an essential component of the transportation sector, providing a cleaner alternative to traditional fuels in vehicles and fleets. Moreover, natural gas plays a vital role in boosting energy efficiency through the development of combined heat and power systems. These systems produce electricity and useful heat concurrently. As nations move towards more sustainable energy solutions, natural gas has gained prominence as a transitional fuel. This is due to its lower carbon emissions when compared to coal and oil, thus making it an essential component of the global energy framework. In this study, monthly natural gas consumption data of 28 different European countries between 2014 and 2022 are used. Symbolic Aggregate Approximation method is used to analyse the data. Analyses are made with different numbers of segments and numbers of alphabet sizes, and alphabet vectors of each country are created. These letter vectors are used in hierarchical clustering and dendrogram graphs are created. Furthermore, the elbow method is used to determine the appropriate number of clusters. Clusters of countries are created according to the determined number of clusters. In addition, it is interpreted according to the consumption trends of the countries in the determined clusters.
Citation - Scopus: 3
Türkiye’de Yapılan Kuraklık Analiz Çalışmaları Üzerine Bir Derleme
(Ankara University, 2022) Deniz Öztürk, Yasemin; Ünlü, Ramazan; 01. Abdullah Gül University; 02.02. Endüstri Mühendisliği; 02. Mühendislik Fakültesi
Drought has become one of the most studied disaster issues by scientists, especially after the 2000s, with the importance of climate change. Many scientific publications on drought have been produced, due to many different methods on drought and the study of drought by many disciplines of science. In the study, theses, national and international articles, which include drought analysis by using any statistical method over meteorological data in Turkey, were compiled. A total of 270 studies, including 73 master's and Ph.D. theses, 107 national articles, and 90 international articles, written between 1943-2021 were examined. These studies were classified according to the year of publication, the drought analysis methods used, in publication, the scientific field of the first author, and the region examined in the study, and their frequency distributions were revealed. The main conclusions of this study are as follows: Although the first published studies on drought analysis in Turkey were made in 1943, 1956, and 1965, studies on drought started to increase after 2000 and the total number of publications reached 37 in 2019, 43 in 2020, and 64 in 2021. Publications in the period of 2019-2021 correspond to 53% of all publications. This rapid increase in recent years has led to a logarithmic increase in the number of publications. Although 63 different methods are used in drought analysis in the studies, the standardized precipitation index is the dominant method with a usage rate of 56%. Most of the studies were carried out on the basins (113). In 41 studies, the whole of Turkey was examined. Other studies were carried out for geographical regions, provinces, and smaller settlements. According to the scientific fields, it is seen that the Civil Engineering (131 units) and Geography (41 units) departments are the scientific fields that carry out the most drought analysis studies. © 2025 Elsevier B.V., All rights reserved.