Mühendislik ve Doğa Bilimleri Fakültesi Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.13091/1624

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Citation - Scopus: 5
Achieving Shojinka by Integrated Balancing of Multiple Straight Lines With Resource Dependent Task Times
(Springer New York LLC, 2019) Atasagun, Y.; Kara, Y.; Can Atasagun, Gözde
The concept of Shojinka, which is an important element of Just in Time production system, is attaining flexibility on the number of workers in a workshop due to demand variations. Even though Just in Time production system adopts U-shaped line layout, traditional straight lines can be combined and balanced in an integrated manner to obtain the advantages of Shojinka. In this case, the problem, which is called Integrated Balancing of Multiple Straight Lines, arises. On the other hand, the basic assumption of assembly line balancing is that every task’s time is fixed. However, in practice, different resource alternatives such as equipment or assistant worker may be available to process a task with different times. The problem in this case is to assign tasks and resources to stations that minimise total cost. In this study, a binary integer mathematical model is presented for integrated balancing of multiple straight lines, assuming that task times are resource dependent. The proposed model is illustrated and validated using several examples. An experimental analysis is also conducted to emphasize the advantages of the integrated balancing concept, compared to the situation in which the lines are balanced independent from each other. The experimental results show that, when multiple straight assembly lines are balanced in an integrated manner with resource dependent task times, an average total cost improvement of 23.105% can be obtained compared to the independent balances of the lines. This is a significant improvement that emphasizes the importance of balancing multiple straight lines in an integrated manner, to take the advantages of shojinka and to adhere to the main philosophy of Just in Time. © Springer Nature Switzerland AG 2019.
Air Quality of Karaman City, Turkey
(Hysen MANKOLLI, 2020) Mankolli, H.; Toros, H.; Dursun, S.
Karaman is a new and developing city in Turkey's economy is developing and the industry. Geographically, the location of Karaman is located in the south of the Central Anatolia region, in the north of the Taurus Mountains. With its fertile lands, the economy and industry based on Karaman agriculture are developing. Karaman city center has modern industrial facilities open for employment. It is known to have an important industrial potential in recent years. The total surface area of 887 thousand ha of Karaman province; 229 thousand hectares (26%) are flat areas and 654 thousand hectares (74%) are mountainous. The population size is around 250 thousand. Turkey is ahead in the production of bakery products, 35% and 20% of total wheat production is produced by Karaman biscuit manufacturing industry. Turkey, as in general in Karaman in fossil fuel consumption for heating in the cold winter air pollution as it is used in many developed cities is also observed. Traffic vehicles vehicle exhausts and fossil fuels used in industry are other important sources of pollution in the city center. In Turkey, the year 2020 at the beginning of March with the gorilla-19 Covidien epidemic, there has been a significant improvement in air quality. The field dust event that occurred after pandemic virus measures, especially PM pollution increase was observed. © 2020, Hysen MANKOLLI. All rights reserved.
Air Quality of O3 and No2 Timeline Changes in Konya City Center
(2021) Toros Hüseyin; Mankolli Hysen; Dursun, Şükrü
In cases that air quality will change the living health or environmental quality, the composition of the air should not change or the substances that are dangerous to be in the air that not be present in the atmosphere. Air pollution, which is a result of urbanization and fuel use brought about by different life styles, can cause a dangerous impact area on a global scale as well as in Turkey. Air pollution has a significant impact on human health, so the issue of air quality is of great importance all over the world. The management of the parameters related to the outdoor air quality is carried out in accordance with the Air Quality Assessment and Management Regulation. A country's orregion's success in improving and protecting the air quality, local and national air pollution problems, and the support of citizens who are well informed and informed about the developments in pollution reduction are needed. For the investigation of air pollution in Konya, NO2 and O3 parameters have been evaluated. The stations are statistically analysed according to the measurement results made in the required periods. As a result of this, it is aimed to study on the continuously measured parameters and their effects, what the necessary measures should be in order to reduce the effect and what the applications could be by evaluating and graphing the data. In this study, the effect of temporal NO2 and O3 changes on air quality was evaluated.
Almanya Münih Bölgesinde Qdaedalus Sistemi ile Gözlemlenen Astrojeodezik Çekül Sapma Verilerinin Ggmplus ve Egm2008 ile Kestirilen Değerlerle Karşılaştırılması
(2020) Albayrak, Müge; Zeray Öztürk, Emel; Bildirici, İbrahim Öztuğ; Hirt, Christian; Guillaume, Sebastien; Shum, C.
Astrojeodezik sistemlerle gözlemlenen astrojeodezik çekül sapma verisi, yeryuvarının gravite alanı ile ilgili önemli bilgiler sağlaması nedeniyle, yerbilimleri alanında, özellikle jeodezi ve jeofizik gibi bilimsel disiplinlerde, yersel, hava ve uydu gravite verilerinin kontrolü ve validasyonunda sıklıkla kullanılmaktadır. Bu çalışmada, Münih bölgesinde yer alan 10 nirengi noktasında astrojeodezik çekül sapma verisi gözlemleyebilmek için total station temelli QDaedalus sisteminden yararlanılmıştır. Gözlemlenen verilerin doğruluğunun ~0.2 yaysaniyesi (?) olduğu saptanmıştır. Yüksek doğruluklu bu veri seti, iki global gravite alan modelinin—Global Gravite Modeli plus (GGMplus) ve Yer Gravite Modeli 2008 (Earth Gravitational Model 2008–EGM2008)—kalitesini değerlendirebilmek için kullanılmıştır. QDaedalus sistemi ile gözlemlenen ve GGMplus modeli ile kestirilen çekül sapma bileşenleri arasındaki farklar, hem Kuzey-Güney (KG) hem de Doğu-Batı (D-B) bileşenlerinde yaklaşık 0.2? olmakla beraber, maksimum farklar K-G ve D-B bileşenlerinde sırasıyla ~0.3? ve ~0.4? olarak tespit edilmiştir. Sonuçlar EGM2008 modeli için analiz edildiğinde ise, gözlemlenen ve EGM2008 ile kestirilen çekül sapma bileşenleri arasındaki maksimum farkların K-G bileşeninde 0.9?; D-B bileşeninde ise 1.8? olduğu saptanmıştır. Dolayısıyla, EGM2008 ile kestirilen değerlerin, GGMplus ile kestirilen değerlere göre doğruluğunun daha düşük olduğu görülmüştür. Bu çalışmadan elde edilen sonuçlar, daha önce İstanbul’da QDaedalus gözlemleri ile EGM2008 ve GGMplus modellerinin kıyaslandığı uygulama sonuçlarıyla da karşılaştırılmıştır. Bu makale kapsamında, İstanbul ve Münih’te aynı sistem ve global gravite alan modelleri kullanılarak elde edilen çekül sapma verileri arasındaki farkların sebepleri tartışılarak, GGMplus ile kestirilen çekül sapma veri setinin, hem Münih hem de İstanbul’da daha yüksek doğruluğa sahip olmasının nedenleri açıklanmıştır.
Citation - WoS: 1
Ambient Particle Matter Pollution of Bosnia District of Konya City, Turkey
(HEALTH & ENVIRONMENT ASSOC, 2019) Dursun, Şükrü
Population growth, urbanization, industrialization and migration have been effected in city in the recent century since the beginning of the world is the most important problems. Konya city Turkey during last 2-3-decade, important province pile pollution has increased a median. Air pollution, which started to be effective after 1975 in Konya, is the most important question of the city today. Konya Metropolitan Municipality Environmental Protection and Control Department's regulation on the subject continues air pollution follows: It is important to board of directors with air pollution. The air quality measuring devices of Konya city are monitored on the regularly and are also shared online for the public to follow. In addition, the appearance of polluting sources influences the causes of a pollutant (Industry, Traffic and Domestic Business) in the city. For this purpose, the project of Modelling Air Quality and Creating Clean Air Action Plans was launched in 2017. Air Pollution monitoring project results, which were prepared and completed in 2009, are aimed to be prepared and already underway. It focusses on reducing airborne levels towards this goal; we evaluate it in every dimension and implement the explanation. Bosnia district of the Konya is the most fast-growing part with parallel to increasing university student in the region. In this study atmospheric particle matter levels were investigated and modelled. Evaluation and evaluation of the measurement results were made by Surfer v8 program and modelling maps were created. Form the results of this study; source of air pollution will be investigated. As a result of the evaluation of the measurement results made at 22 different points, it was observed that when the assessment was made according to the WHO and EPA, values were higher than the limit values at some measurement points.
Amonyum Floroborat Üretimi ve Üretim Parametrelerinin Belirlenmesi
(2020) Ceyhan, Ayhan Abdullah; Bağcı, Safiye; Baytar, Orhan; Şahin, Ömer
Bu çalışmada, borik asit ve amonyum hidrojen florürün reaksiyonu ile amonyum floroborat (NH4 BF4 ) üretimine ait üretim parametreleri incelenmiştir. Bu amaçla, reaktif besleme oranı, reaksiyon sıcaklığı, karıştırma hızı, karıştırıcı cinsi, ikinci çözücü etkisi parametrelerinin etkileri ayrı ayrı belirlenmiştir. Reaksiyon sonucu elde edilen kristallerin yapısal analizleri ve yüzey morfolojileri ise sırasıyla XRD, FT-IR ve SEM analizleri yapılarak aydınlatılmaya çalışılmıştır. Amonyum floroborat üretimi için en uygun reaksiyon şartları; reaktif besleme oranı, 1:2; reaksiyon sıcaklığı, 90 o C; karıştırıcı cinsi, sıcak hava şeklinde tespit edilmiştir. Limit oksijen indeksi analizleri, amonyum floroboratın mükemmel alev geciktirici olduğunu göstermiştir.
Citation - Scopus: 4
An Analysis and Countermeasures of Fatal Accidents Caused by Firedamp Explosions in Underground Coal Mines in Turkey
(2019) Dursun, Arif Emre
Fatal accidents in underground coal mines in Turkey are common and experienced frequently. The major accident categories for underground coal mining in Turkey are gas related accidents (firedamp and outbursts), roof falls, flooding, fire and transport. In recent years, coal mine gas related accidents in Turkey, which are usually caused by firedamp and outbursts, are still threatening miners’ lives. Firedamp explosions are majorly serious mine accidents that can occur quickly and cause great deal damage. In this study, work-related accidents caused by firedamp and another gas accidents in Turkey between the years 2010-2016 were analyzed. As a result of these analyses, the number of deaths in underground coal mines in the past 7 years is 550 and the fatality rate is found to be 96.86%. The percentage of gases as the cause of the deaths is 70.18%. In this study, countermeasures are proposed that can prevent and control firedamp explosions and other gas related accidents.
Application of an Artificial Neural Network for Predicting Compressive and Flexural Strength of Basalt Fiber Added Lightweight
(Tulpar Academic Publishing, 2021) Calis, G.; Yıldızel, S.A.; Keskin, U. S.
Concrete is known as one of the fundamental materials in construction with its high amount of use. Lightweight concrete (LWC) can be a good alternative in reducing the environmental effect of concrete by decreasing the self-weight and dimensions of the structure. In order to reduce self-weight of concrete artificial aggregates, some of which are produced from waste materials, are utilized, and it also contributes to de-velop a sustainable material Artificial neural networks have been the focus of many scholars for long time with the purpose of analyzing and predicting the lightweight concrete compressive and flexural strengths. The artificial neural network is more powerful method in terms of providing explanation and prediction in engineering studies. It is proved that the error rate of ANN is smaller than regression method. Furthermore, ANN has superior performance over nonlinear regression model. In this paper, an ANN based system is proposed in order to provide a better understand-ing of basalt fiber reinforced lightweight concrete. In the regression analysis pre-dicted vs. experimental flexural strength, R-sqr is determined to be 86%. The most important strength contributing factors were analyzed within the scope of this study. © 2021, Tulpar Academic Publishing. All rights reserved.
Citation - Scopus: 4
An Application of Fuzzy Ahp, Edas and Waspas for the Selection of Process Method in Software Projects
(Springer Science and Business Media Deutschland GmbH, 2022) Yel, İ.; Sarucan, Ahmet; Baysal, M.E.
In software development projects, the complexity of the tasks to be completed and the fact that the resources are real people, unlike in the manufacturing sector, are important factors that pose challenges to project management. In addition, operational reasons such as time-dependent changes in software requirements also complicate the management of projects. During the execution of the projects, in addition to the internal dynamics of the project, the organizational characteristics of the participants and the competencies of the team also influence the success of the project. In this context, various software development process methodologies are used for change management, including “Agile and Waterfall Methods”. The aim is to select projects based on technical and managerial criteria by considering the skills of the development teams that actively participate in the project. In the study, the weights of the criteria are determined using fuzzy AHP. Then, Fuzzy EDAS and WASPAS methods are used for ranking the projects and the information technology teams. The statistical information about the errors after software development was obtained as a result of the process management decision made. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.
Assessment of Work Accidents in Highway, Street and Bridge Construction
(International Multidisciplinary Scientific Geoconference, 2018) Bilim, Atiye; Çelik, Osman Nuri
Occupational health and safety is an important work discipline that must be included in the working life. Especially, developed countries have been able to place this discipline in working life, while developing countries have still problems. These problems take place both in terms of legislation and practice. The situation is similar to that of developing countries, in Turkey. The construction sector is in line with the development status of a country. The construction sector contributes both directly and indirectly to the country's economy. It has become indispensable for the economy of a country with its share in employment and it stimulates production of goods and services related to the sector. The construction sector is not just about building constructions. We also need bridges, metros and high-speed train lines. Transports have a major contributor to the development of a country. In parallel with technological developments, large investments related with transports become increase. Due to the revival in this sub-sector, the number of work accidents has also tended to increase. Therefore, the work accidents in the highway, street and bridge constructions, which are the sub-activities of the construction sector, must be examined. In this study, work accidents in the sector were analyzed for Turkey and U.S. Also, the share of the sector in total work accidents and construction accidents were determined for Turkey and U.S. The causes of fatal work accidents in highway, street and bridge constructions were mentioned. © 2018, International Multidisciplinary Scientific Geoconference. All rights reserved.
Autogenous Self-Healing Assessment of 1-Year Cementitious Composites
(Springer Science and Business Media B.V., 2021) Yildirim, Gurkan; Ulugol, Huseyin; Ozturk, Oguzhan; Sahmaran, Mustafa
Traditional concrete materials are prone to cracking and as cracks form, durability issues arise which reduce the expected service life of the materials followed by structures incorporating them. This, in many occasions, may lead to repetitive repair and maintenance or even re-construction of certain structural/non-structural sections and structures. Thus, it is highly desirable to reduce the chance and/or further development of cracking. Engineered Cementitious Composites (ECC) are feasible materials to suppress cracking formation and progression through their strain-hardening response under uniaxial tensile loading conditions. Even at the stage of failure, these materials exhibit micron-size cracks which significantly improve the capability to resist against detrimental durability issues. Moreover, these microcracks are constantly reported to be closed through autogenous healing mechanisms with no external interference from outside which significantly improve the mechanical and durability performance and service life of these materials and structures incorporating them. However, the performance of autogenous self-healing in ECC is called into question, especially for late-age specimens since reactions which produce products to plug the micro-size cracks stabilize as the specimens get more and more mature. To clarify this subject, in this study, 1-year-old specimens produced from ECC mixtures incorporated with different mineral admixtures (i.e. Class-F fly ash and ground granulated blast furnace slag) were tested for their self-healing performance. For self-healing evaluation, specimens which were severely preloaded for creating microcracks, were subjected to four different curing conditions which included "Water", "Air", "CO2-water" and "CO2-air" for 90 additional days beyond initial 1 year. Tests used for self-healing assessments were electrical impedance (EI) and rapid chloride permeability (RCP). Results indicate that water is a must-have component for enhanced autogenous self-healing efficiency. "CO2-Water" curing results in the most effective self-healing performance regardless of the composition of ECC mixtures. By properly adjusting mixture proportions and curing conditions, microcracks as large as nearly half a millimeter (458 mu m) can be healed in only 30 days of further curing. Overall, results clearly suggest that late-age autogenous self-healing capability of ECC can be made as effective as the early-age with proper further environmental conditioning and mixture design.
Betonarme Dairesel Kolonların Kesme Dayanımı ile Deformasyon Kapasite Modellerinin Araştırılması
(2022) Yüksel, Süleyman Bahadır; Foroughi, Saeid
Göçme öncesi sismik performans seviyesinde, kesmeye maruz betonarme kolonların yatay yük ve eksenel yük taşıma kapasitelerindeki azalmayı ve bu davranışların tüm yapıya etkilerini modellemeye ve tahmin etmeye ihtiyaç vardır. Kesme dayanımı ile deformasyon kapasite davranışlarının incelenmesi için farklı beton basınç dayanımı, eksenel yük seviyesi ve spiral donatı oranlarında betonarme dairesel kolon modelleri tasarlanmıştır. Tasarlanan betonarme kolonların kesme davranışı ile deformasyon kapasiteleri, ASCE/SEI 41 (2017) ve araştırmacılar tarafından önerilen modellere göre araştırılmıştır. Betonarme kolonların moment-eğrilik ilişkilerinden elde edilen karakteristik değerlere göre elastik, plastik ve toplam yer değiştirme değerleri hesaplanarak yer değiştirme süneklik ilişkileri incelenmiştir. Betonarme kolonlar için analizlerden elde edilen kesme dayanımlarının eksenel yük seviyesi, beton basınç dayanımı, spiral donatı oranı ve yer değiştirme süneklik değerlerinden etkilendiği görülmektedir.
Borularda Zamanla Peri̇yodi̇k Olarak Deği̇şen Sinir Şarti İle Geçi̇ci̇ Reji̇m Isi Transferi̇
(2018) Altun, Aziz Hakan; Ateş, Ali; Atmaca, Şükrü Ulaş; Koçak, Saim; Bilir, Şefik
Borularda ısıl gelişme bölgesi geçici rejim ısı transferi, zamanla periyodik olarak değişen cidar dış yüzey sıcaklığı sınır şartında incelenmiştir. Problem, iki bölgeli bir boruda, hidrodinamik olarak gelişmiş laminer akış için, eksenel akışkan iletimi dikkate alınarak ele alınmış ve sonlu farklar yöntemi ile sayısal olarak çözülmüştür. Peclet sayısı ve açısal frekansın ısı transferi karakteristikleri üzerindeki etkilerini belirleyebilmek için parametrik bir çalışma yapılmıştır. Elde edilen sonuçlardan akışkan eksenel iletimi nedeniyle borunun üst akış bölgesine, akışa ters yönde önemli ölçüde ısı transfer edildiği ve bunun akışkanın borunun ısıtılan alt akış bölgesine gelmeden önce ön ısıtılmasına neden olduğu görülmüştür. Ayrıca alt akış bölgesi dış yüzey sıcaklığındaki periyodik değişime uygun olarak, tüm ısı transferi karakteristiklerinin de, ön ısıtma ve tam gelişmiş bölge de dahil olmak üzere, tüm eksenel konumlarda zamanla periyodik olarak değiştiği görülmüştür.
Breast Cancer Diagnosis by Different Machine Learning Methods Using Blood Analysis Data
(2018) Aslan, Muhammet Fatih; Çelik, Yunus; Sabancı, Kadir; Durdu, Akif
Today, one of the most common types of cancer is breast cancer. It is crucial to prevent the propagation of malign cells to reduce the rate of cancer induced mortality. Cancer detection must be done as early as possible for this purpose. Machine Learning techniques are used to diagnose or predict the success of treatment in medicine. In this study, four different machine learning algorithms were used to early detection of breast cancer. The aim of this study is to process the results of routine blood analysis with different ML methods and to understand how effective these methods are for detection. Methods used can be listed as Artificial Neural Network (ANN), standard Extreme Learning Machine (ELM), Support Vector Machine (SVM) and K-Nearest Neighbor (k-NN). Dataset used were taken from UCI library. In this dataset age, body mass index (BMI), glucose, insulin, homeostasis model assessment (HOMA), leptin, adiponectin, resistin and chemokine monocyte chemoattractant protein 1 (MCP1) attributes were used. Parameters that have the best accuracy values were found by using four different Machine Learning techniques. For this purpose, hyperparameter optimization method was used. In the end, the results were compared and discussed.
The Carbon Cost of the Buildings Destroyed in Yalova in the 1999 Marmara Earthquake
(2023) Türk, Furkan; Nayan, Hayriye Nur; Doğan, Selim; Keskin, Ülkü Sultan
Natural disasters have some environmental impacts as well as economic impacts. For example, when disasters such as earthquakes are not prevented, efforts must be made to minimize the economic and environmental costs that may arise. Although the interest of society and governments in the economic consequences of the earthquake is more intense, environmental effects should also be calculated, and the significance of the situation should be shown. Herein, it estimated the CO2 emissions caused by debris transport from the 1999 Marmara earthquake in Turkey in Yalova, a province of Turkey, and the reconstruction of the destroyed structures. As a result of the calculations, it has been found that 2031 x 103 tons of CO2 were released during the transport of debris and reconstruction of 9462 building that was destroyed before the end of their life in Yalova. Moreover, 42% of these emissions are caused by concrete alone. In addition, this value corresponds to 0.73% of the CO2 emitted in Turkey in 1999
Citation - WoS: 5
Cfd Modelling of Industrial Air Curtains With Heating Unit
(E D P SCIENCES, 2019) Aksoy, Muharrem Hilmi; Yağmur, Sercan; Doğan, Sercan
Industrial air curtains are used to prevent air from moving from one space to another space or to environment. The most common used type is downward-facing blower fan mounted over the entrance of a building, or an opening door between two spaces conditioned at different temperatures. In many factories and industrial buildings, heating or cooling applications are difficult due to the huge doors. These huge doors cause heat loses with convection phenomena of the inside air. In this study an air curtain having heater unit is analyzed numerically by CFD. The height of the air curtain from the bottom side is vary between 2.5 m, 3 m, 4m, 5m and 6 m mounted over the entrance door of the conditioned volume. For CFD studies proper mesh structure is created on the flow domain and Shear Stress Transport (SST) k-omega models were used in Unsteady Reynolds Averaged Navier-Stokes (URANS) computations. The blowing temperature of the air curtain has adjusted to 60 degrees C with the inside temperature was aimed to kept at +7 degrees C while the outside temperature was-5 degrees C. It is found that there is less flow occurred to the environment from conditioned volume at 2.5 3, 4 and 5 meter height cases. In these cases, the air curtain also contributes the heating of the conditioned room. But some ratio of the air flows through the atmosphere and the room cannot kept at the +7 degrees C initial temperature at 6 m case. It is also found that the heating ratio at different blowing heights differs between 0,89-1,98 comparing the case without an air curtain.
Citation - Scopus: 7
Classification of 3b alzheimer's mr images using voxel values in volumetric loss regions
(TUBITAK, 2020) Öziç, Muhammet Üsame; Özşen, Seral
Alzheimer's Disease is a deadly neurological disease that begins with cognitive disorders and forgetfulness. Volumetric changes caused by the disease in the brain can be monitored with high resolution magnetic resonance images. In this study, volumetric losses occurring in gray matter and white matter regions were mapped by voxel-based morphometry method using 3D T1-weighted magnetic resonance images taken form OASIS database, and a decision support system was designed that classifies alzheimer's and normal magnetic resonance images with significant voxel values in these regions. SPM8, MRIcro programs and VBM8 library were used for inter-group voxel-based morphometry on magnetic resonance images. Gray matter and white matter regions were masked with binary masks obtained from volumetric loss maps. Significant data sets were created with voxel values corresponding to the same coordinate points from the areas under the mask in each gray matter and white matter image. With feature ranking methods, the data were ranked from the most meaningful feature to the most meaningless feature. The ranked features were given as input to the support vector machine using linear and rbf kernel with 10 fold cross validation. As a result of the experiments, the highest accuracy rates were found as 92.857% in gray matter classification and 79.286% in white matter classification with linear support vector machines based on t-test feature ranking. © 2020, TUBITAK. All rights reserved.
Citation - WoS: 2
Citation - Scopus: 3
A Comparison of Improved Nature-Inspired Algorithms for Optimal Power System Operation
(ROMANIAN SOC CONTROL TECH INFORMATICS, 2018) Shehu, Gaddafi S.; Çetinkaya, Nurettin
The influencing factors associated with the efficient operation of power systems are minimum fuel cost and losses in the transmission line. Optimal Power Dispatch (OPD) problem is treated to minimize instantaneous operating cost, incremental cost, and transmission line losses considering various network operating constraint. Newly developed Nature-inspired optimization algorithms approach are proposed in this analysis with robust parameter selections. The results of most popular Genetic Algorithm (GA) and based on swarm behavior Particle Swarm Optimization (PSO) are compared with four Nature-inspired metaheuristic algorithms of Cuckoo Search (CS), Bat Algorithm (BA), Flower Pollination Algorithm (FPA), and Firefly Algorithm (FA). The quadratic cost function of power generation and penalty function to account for inequality constraints on dependent variables are added for solving OPD problem. A common algorithms evaluation parameters such as population size and generation limit are designated on an equal scale. Explicit parameters for each algorithm are tuned properly for optimal operations. The algorithms are tested on IEEE-26 and IEEE-30 system. Analysis Outcomes obtained showcase the efficiency of each algorithms parametric turning improvement.
Citation - Scopus: 2
Comparison of Performance Analysis of a Moment Resisting Framed Structure According To Tbdy 2018 and Asce 41-17
(TUBITAK, 2021) Jamal, Rohullah; Yüksel, Süleyman Bahadır
Due to its simplicity, nonlinear static procedure (NSP) or pushover analysis has been using for the determination of the nonlinear performance of structural and non-structural members. While modeling the determination of the nonlinear properties and deformation capacities for each component of the structure should be determined. Pushover analysis is carried out for either user-defined nonlinear hinge properties or defaulthinge properties, available in some programs based on the TBDY 2018 and ASCE 41-17 standards. Assigning the incorrect default-hinge properties may lead to unreasonable displacement capacities for existing structures. In this study the performance analysis of a single span structure was performed according to TBDY 2018 and ASCE 41-17 codes and the results were compared. Number of stories of the structures were changed for the parametric study. Capacity curves have been obtained as a result of the analysis performed on the building systems. The peak displacement amount calculated according to ASCE 41-17 was obtained more than the peak displacement amount calculated according to TBDY 2018. The amount of base shear force and story shear forces calculated according to TBDY 2018 has been obtained more than ASCE 41-17. The most effective parameters for the plastic hinge properties are plastic hinge length and transverse reinforcement spacing. The results of analyses obtained from the TBDY 2018 and ASCE 41-17 codes show that the structural performance depends on the number of vertical loads, effective stiffness of the structural members and plastic hinge properties. © 2021, TUBITAK. All rights reserved.
Citation - WoS: 1
Citation - Scopus: 1
Comparison of Time-Frequency Analyzes for a Sleep Staging Application With Cnn
(Trans Tech Publications Ltd, 2022) Efe, Enes; Özşen, Seral
Sleep staging is the process of acquiring biological signals during sleep and marking them according to the stages of sleep. The procedure is performed by an experienced physician and takes more time. When this process is automated, the processing load will be reduced and the time required to identify disease will also be reduced. In this paper, 8 different transform methods for automatic sleep-staging based on convolutional neural networks (CNNs) were compared to classify sleep stages using single-channel electroencephalogram (EEG) signals. Five different labels were used to stage the sleep. These are Wake (W), NonREM-1 (N1), NonREM-2 (N2), NonREM-3 (N3), and REM (R). The classifications were done end-to-end without any hand-crafted features, ie without requiring any feature engineering. Time-Frequency components obtained by Short Time Fourier Transform, Discrete Wavelet Transform, Discrete Cosine Transform, Hilbert-Huang Transform, Discrete Gabor Transform, Fast Walsh-Hadamard Transform, Choi-Williams Distribution, and Wigner-Willie Distribution were classified with a supervised deep convolutional neural network to perform sleep staging. The discrete Cosine Transform-CNN method (DCT-CNN) showed the highest performance among the methods suggested in this paper with an F1 score of 89% and a value of 0.86 kappa. The findings of this study revealed that the transformation techniques utilized for the most accurate representation of input data are far superior to traditional approaches based on manual feature extraction, which acquires time, frequency, or nonlinear characteristics. The results of this article are expected to be useful to researchers in the development of low-cost, and easily portable devices.

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