It is internationally recognized that structural control was introduced in civil engineering through a pioneering article by Yao and through the implementations promoted by Kobori. The concepts of ...active and semi-active structural control in civil and infrastructure engineering date back 40 years and much progress has been recorded during these four decades. Periodically, state-of-the-art manuscripts have been published and technical books were also printed to testify the maturation of the topic. This article only covers the period from the second semester of 2009 to the first semester of 2011, emphasizing the developments in terms of theoretical, numerical and experimental studies, as well as the use of control algorithms and devices in actual implementations. It is observed that there are still several operational limitations to prevent from the expected growth of the applications in standard design. Nevertheless, some innovative concepts help to foresee future developments within special sectors of applications.
A shortage of empty containers has become a global crisis with more devastating effects than during previous periods when combined with various problems arising from the COVID-19, such as an increase ...in an imbalance of global trade between supply and demand, a decrease in the workforce, and restrictions by countries or regional quarantine practices. The absence of empty containers in regions where they are needed slows down industrial activities and locks the global supply networks, necessitating the use of alternative methods that are inefficient. Although this shortage causes many disruptions in global trade, solutions to the issue have not been studied in detail. Therefore, the aim of this study was to determine the issues caused by the shortage of empty containers and to rank the appropriate solutions. Four main criteria and sixteen subcategories used to define the issues, as well as a multi criteria decision model comprising five criteria for the solutions, were proposed based on information from the literature, sectorial publications, and expert opinions. The issues’ weighted order of importance in our proposed model was calculated using the SWARA (Step-wise Weight Assessment Ratio Analysis) method; solutions were ranked using the ARAS (Additive Ratio Assessment) method. The results of the study revealed that the issues were ranked in importance as cost increases, uncertainty in the supply chain, volume loss, and increases in blank sailing announcements. Appropriate solutions were ranked as booking guarantee applications and information communication technologies, using shipper-owned containers, inducement calls, and E2E (end to end) delivery services.
Nowadays, intensive investigations on the potential of rubberized concrete as a structural material are available in the literature due to its promising characteristic in terms of sustainability, ...ductility, high absorption of energy, and enhanced vibration behavior. These works have initiated the introduction of multiple estimation methods to rapidly evaluate its properties. Over the last few decades, hundreds of researches have been conducted to assess different mathematical approaches for modeling concrete’s properties. Among them, multivariable regression analysis is considered one of the simplest multipurpose options. However, its adaptation is sometimes inefficient, and its results are not highly accurate. This study proposes an enhancement to the estimation technique for rubberized concrete’s mechanical characteristics by conducting a data reconstruction using kernel principal component analysis and then utilizing multivariable regression to develop the prediction models. The importance of the kernel principal component analysis comes from its capability to transform the input parameters to visualize the dataset’s information described by multiple inter-correlated quantitative variables so that it discovers underlying patterns. In general, the research results have shown that the performance of the proposed method can significantly overcome that of the conventional regression techniques with as high as 80% reduction in the root-mean-square error in the case of compressive strength.
Over the last few years, many studies were performed to investigate rubberized concrete’s behavior as a sustainable alternative for conventional concrete by replacing natural aggregates with ...recycling old rubber tires. These studies have shown that the concrete's mechanical and durability properties are significantly reduced, while its ductility and damping ratio improved. Accordingly, using this material in RC structures could be a promising solution for improving their energy dissipation capabilities. Currently, the literature lacks a numerical study that can highlight the effectiveness of using high-strength rubberized concrete for retrofitting RC structures subject to earthquake loadings . Therefore, this research investigates the seismic performance of reinforced concrete buildings strengthened using different high-strength rubberized concrete mixtures under various ground motion excitations. As a part of the study, finite element models of reinforced concrete structure retrofitted with these concrete mixes will be analyzed using nonlinear response history analysis and compared against two different control models composed of a bare structure and a jacketed RC structure using the control concrete mixture. In general, using rubberized concrete jacketing improved the seismic performance of the bare structure significantly. Furthermore, utilizing high-strength rubberized concrete rather than the control one resulted in increasing the damping energy and slightly reducing the base shear forces of the structure.
Yeni Dünya Düzeninde Türk Dış Politikası YILDIRIM, Umut Turgut
Turkish Journal of Middle Eastern Studies,
12/2021, Letnik:
8, Številka:
2
Journal Article, Book Review
Recenzirano
Odprti dostop
Devletlerin dış politikalarını bölgesel ve küresel çapta cereyan eden ilişkiler ağından bağımsız düşünmek günümüz konjonktürünün gereklilikleri doğrultusunda gittikçe zorlaşan bir hal almıştır. ...Özellikle güçler dengesi sistemine adapte olmuş Soğuk Savaş döneminin sona ermesi ve liberal demokrasinin piyasa ekonomisiyle entegrasyonu üzerine konumlanan yeni dünya düzeni düşüncesinin oluşması da bu süreci hızlandıran gelişmeler olarak okunabilmektedir. Bu eser yeni dünya düzeni bağlamında Türk dış politikasının (TDP) tarihsel perspektifle inceleyen; Soğuk Savaş öncesi ve sonrası gelişmeleri TDP analizi temelinde örneklerle analiz ederek Türk dış politikasının yaşadığı değişim ve dönüşümler üzerine tespit ve tahlillerde bulunan bir eser niteliğindedir.
Based on ethnographic fieldwork (2005 to February 2007, and March and August 2008) in Diyarbakır, southeastern Turkey, this article explores the conceptual intersection of recent anthropological ...literature on space, neoliberalism and resistance to study the affective life of politics in the context of the war between the Partiye Karkêren Kurdistan and the Turkish State in the 1990s. Offering a contribution to regional studies on the neoliberal restructuring of the urban space and to the anthropology of resistance, this article seeks to make ‘the political’ into a conceptual thread. The article deploys this approach to think through dissonant affects at a site where uncountable deaths are woven into the neoliberal restructuring of space, yet denied through the form that such governance takes.
The design and analysis of base-isolated structures are critical for ensuring seismic performance and safety. Nevertheless, to effectively design and analyze base-isolated structures, it is essential ...to consider the structure's response under various ground motions that may occur during an earthquake. The nonlinear response history analysis (NRHA) is a common method for evaluating structures' seismic response under a specific set of ground motions. However, conducting this analysis for many earthquakes can be computationally expensive and time-consuming. Therefore, it is desirable to have a method for selecting a subset of earthquake records representative of the earthquake population. Accordingly, this study introduces a novel block-based framework based on the K-means unsupervised clustering techniques for efficient earthquake records' selection NRHA of base-isolated structures. The proposed approach aims to reduce the number of records required for investigations by identifying clusters of similar seismic signals and selecting representative records from each cluster for the NRHA. Additionally, the proposed framework serves a vital role in identifying the earthquake records that can be used as a training dataset for developing artificial neural network (ANN) models, enabling rapid response estimation of base-isolated structures. This dual functionality of the proposed method provides significant value for researchers and engineers working in earthquake-prone countries. This article presents two case studies to demonstrate the applicability and effectiveness of the proposed framework. The first case study focuses on selecting a subset of earthquake records from a suit that meets the ASCE 7–22 requirements for NRHA on base-isolated structures, aiming to achieve the close mean responses between the full suit and the subset of records. The second case study highlights the development of an ANN model for response estimation of such structures using the proposed framework to select suitable earthquakes as the training dataset, hence providing an adequate database to achieve high estimation results. In general, the study results highlight the capabilities of the proposed frameworks and the benefits of the K-means unsupervised clustering approach in addressing the gap in the literature and providing a robust method for earthquake record selection in various analysis scenarios.
•Introducing a novel K-means clustering-based framework for efficiently selecting earthquake records.•The framework enhances earthquake record selection for NRHA and helps train ANN models.•An average error of 6 % was observed in the ASCE 7-22 case while reducing the required number of records by 55 %.•A 2.9 % average error was achieved in the second case indicating applicability for building a robust database in ANN models.•The proposed method can extend to other structural systems beyond base-isolated structures after adequate validations.
Bu çalışma ile amaç, ilgili her türlü yapıya uyarlanabilir Yapısal Sağlığı İzleme yönteminin, yapıdaki eskimeyi veya anlık değişiklikleri tespit ederek gerekli hallerde yapının bakım ve onarımını ...ivedilikle sağlayıp ömrünü uzatmasını sağlayan bir süreç yönetimi geliştirmektir. Bunun için Avrupa Birliği Marie Curie Araştırma Programı tarafından desteklenen SmartEN projesi kapsamında, Yaşam Döngüsü Yönetiminin ve Yapı Sağlığı İzleme yöntemlerinin güçlü yönlerini birleştirmek ve faydalarını göstermek için genel bir çerçeve ve süreç geliştirmek amaçlanmıştır. Yapısal sistem tanımlama araçları, gerçek modları ve yapısal tepkileri yakalama yeteneği sağlar. Ancak bu parametreler, Yaşam Döngüsü Yönetiminin için anlamlı değildir, bu parameterelerin eyleme geçirilebilir verilere dönüştürülmesi için güvenilirlik endeksine çevrilmesi gerekmektedir. Bu nedenle, yapısal elemanların veya yapının kendisinin güvenilirlik endeksini veya mevcut yapısal özelliklerinde değişiklik veya değişim nedeniyle yetersizlik olasılığını bulmak için mevcut hizmet verilebilirlik veya sınır limit durum fonksiyonu için bir tür parametre veya eğilimin tanımlanması gerekir. Bu araştırmada, Avusturya'nın Reibersdorf kentinde bulunan S101 ardgerilmeli betonarme köprü kirişinin güvenilirlik değerlendirmesi incelenmiştir. Aşamalı-hasarlı test senaryosunda; ardgerilmiş donatı miktarındaki kaybın, çekme kuvvetlerinin kesit alanında da bir azalmaya yol açacağı varsayılmaktadır. Mesnet ve açıklık hali için iki ayrı güvenilirlik analizi durumu göz önünde bulundurulmuştur. Uygulanan yöntem, doğrusal olmayan bir sonlu eleman yapısal modeli, trafik yükü için olasılık modeli ve hasarlı kirişin özellikleri, boyutları ve donatı yerleşimi ile ilgili dayanım modelini içermektedir. Güvenilirlik, birinci dereceden güvenilirlik yöntemi kullanılarak güvenilirlik endeksi cinsinden tahmin edilmiştir. Köprü güvenilirlikleri, nihai sınır durumları için hesaplanmıştır.
This study aims to develop a process management that enables the Structural Health Monitoring method, which can be adapted to any relevant structure, to detect aging or instantaneous changes in the structure, to provide immediate maintenance and repair of the structure when necessary and to extend its life. To this end, within the scope of the SmartEN project supported by the European Union Marie Curie Research Program, it is aimed to develop a general framework and process to combine the strengths of Life Cycle Management and Structural Health Monitoring methods and demonstrate their benefits. Structural system identification tools provide the ability to capture real modes and structural responses. However, these parameters are not meaningful for Lifecycle Management, these parameters need to be translated into reliability index to be converted into actionable data. Therefore, to find the reliability index or failure probability of the structural elements or the structure itself, it is necessary to define some kind of parameter or trend for the current serviceability limit or ultimate limit state function. In this research, the structural reliability evaluation of S101 post-tensioned reinforced concrete bridge girder located in Reibersdorf, Austria was investigated. In the pogressive-damaged test scenario; it is assumed that the loss in the amount of post-tensioned reinforcement will also lead to a reduction in the cross-sectional area of the tensile forces. Two separate reliability analysis cases were considered for the support and span of the S101 Bridge. The applied method included a nonlinear finite element structural model, a probability model for traffic load, and a resistance model related to the properties, dimensions and reinforcement placement of the damaged girder. Structural reliability was estimated in terms of reliability index using the first order reliability method. Bridge reliability was calculated for ultimate limit states.
Yachts emit harmful gases to human health and the environment into the atmosphere and marinas and surrounding vicinity are the most affected regions by these pollutants. This study applied a ...bottom‐up approach involving emission factors to make an anthropogenic emissions inventory of yachts and to offer solutions for reducing emissions by investigating the NMVOC, NOx, NH3, CO, and PM emissions from 2002 yacht movements between June 1 and August 31, 2019 at Turgutreis D‐Marin in Bodrum Turkey. These emissions are categorized based on yacht operation modes and types. Quarterly yachting emissions are estimated as 3099 tons for NMVOC, 0.003 tons for NH3, 14,526 tons for NOx, 1896 tons for PM, and 15,576 tons for CO.
Over the last few decades, the field of base isolation systems has made significant strides forward by developing new systems to improve the behavior of isolated structures under moderate and severe ...seismic excitations. One of the most efficient systems is the multi-stage friction pendulum that can provide a wide range of effective pendula with various regimes to reach high energy dissipation capability. The difficulty in designing such bearing at the preliminary stage comes from the relatively long process of trials to select the parameters of each sliding surface in order to ensure that the required effective period, effective damping, and displacement capacities are met. Thus, the following study proposes a direct design approach relying on a physics-informed and physics-penalized neural network model to overcome this issue. Within the context of the analysis, a large dataset composed of over 35000 isolators that covers a wide range of properties of the recently developed generation of friction pendulum “Quintuple Friction Pendulum” was generated following the mechanics-driven approach and then utilized as the case study to test the reliability of suggested design strategy and capability of the proposed multi-output neural network method. Thereafter, the performance of the physics-informed and physics-penalized model was compared to a purely data-driven approach and a physics-informed one. Generally, the results have shown that the proposed model has considerable accuracy with a maximum MAPE of 4.89% for achieving the required QFP properties. Additionally, they showed that the presented method provides an effective way for rapidly designing a quintuple friction pendulum isolator.
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