1,720,988 research outputs found
Soil and foundation stability improvement by stone column: A case study in Adapazari city, Turkey
No full textAdapazari city is located on a very deep alluvial deposit and in a seismically active region. Due to the catastrophic earthquakes, the region had painful experiences in the past. The latest severe earthquake, called Marmara earthquake, hit the region on August 17, 1999. It resulted in nearly 4.000 deaths, over 5,000 injuries and totally destroyed more than 29,000 buildings. The region has liquefaction potential due to its geological set up. Most of the structures built on the liquefiable soil severely settled or tilted besides the structural damages. To re-accommodate these structures, it is necessary to strengthen them besides improve their ground conditions. Then, it may be possible to avoid probable damages caused by liquefaction and use them again safely. In this study, application of modified dry bottom feed stone column as one of the dominant ground improvement methods in the region was introduced. Also, a numerical analysis is carried out to check its performance with respect to displacements. According to numerical results, significant improvements were obtained in terms of displacements
Tünel inşa edilmiş sıvılaşabilir zeminlerdeki yer değiştirmelerin sayısal analizlerle incelenmesi
Get PDFThe rise in industrialization and population has led to an increase in the economic significance of existing urban areas, and thus the utilization of underground space has become quite remarkable It is an undeniable fact that in seismically active regions, the underground areas are also exposed to the risk of earthquakes. The devastating 1995 Kobe-Japan, 1999 Chi-Chi-Taiwan and 1999 Kocaeli-Turkey earthquakes are known to have caused major damage to existing underground structures. In this study, numerical models based on finite differences in FLAC 2D were established to evaluate the displacements of the ground around the tunnels located in liquefiable soils. In order to represent the liquefaction condition in the models, soils in the Adapazarı region, which have alluvial characteristics, were used. Soil deformations were examined in models with varying tunnel depths and diameters, for both liquefiable and non-liquefiable soils within the same layers. As a result of this study, it is stated that more stability losses are observed in analyzes where liquefaction can be defined - that is, changes in pore water pressures can be modeled - compared to analyzes without liquefaction. The layout of the ground layers is important for the positioning of the tunnel. The placement of the tunnel towards the solid layers caused the deformations to decrease.Sanayileşme ve nüfustaki artış, mevcut kentsel alanların ekonomik öneminin artmasına yol açmış ve böylece yeraltı alanlarının kullanımı oldukça dikkat çekici hale gelmiştir. Sismik açıdan aktif bölgelerde yeraltı alanlarının da deprem riskine maruz kaldığı yadsınamaz bir gerçektir. Yıkıcı 1995 Kobe-Japonya, 1999 Chi-Chi-Tayvan ve 1999 Kocaeli-Türkiye depremlerinin mevcut yeraltı yapılarında büyük hasara neden olduğu bilinmektedir. Bu çalışmada, sıvılaşabilir zeminlerde bulunan tünellerin etrafındaki zeminin yer değiştirmelerini değerlendirmek için FLAC 2D'de sonlu farklara dayalı sayısal modeller kurulmuştur. Modellerde sıvılaşma durumunu temsil etmek için Adapazarı bölgesindeki alüvyon karakterli zeminler kullanılmıştır. Zemin deformasyonları, aynı katmanlardaki hem sıvılaşan hem de sıvılaşmayan zeminler için değişen tünel derinlikleri ve çaplarına sahip modellerde incelenmiştir. Bu çalışma sonucunda, sıvılaşmanın tanımlanabildiği, yani boşluk suyu basınçlarındaki değişimlerin modellenebildiği analizlerde, sıvılaşma olmayan analizlere göre daha fazla stabilite kaybı gözlendiği belirtilmektedir. Zemin katmanlarının yerleşimi, tünelin konumlandırılması için önemlidir. Tünelin sağlam katmanlara doğru yerleşmesi deformasyonların azalmasına neden olmuştur
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Parametric Investigation of Corner Effect on Soil Nailed Walls and Prediction Using Machine Learning Methods
Get PDFThe performance of soil nailed walls is evaluated based on lateral displacements, especially in high walls. In this study, the displacement behavior of nailed walls, which are frequently preferred in retaining wall systems in hard clayey soils, was examined by taking into account the corner effect. The nailed wall model was created using Plaxis 2D v.23, and the performance of the model was verified with the results of inclinometer measurements taken on-site. To assess the influence of excavation pit dimensions on the corner effect, 25 three-dimensional and 25 plane–strain slice models were created using Plaxis 3D v.23, and the effect of excavation pit dimensions on the plane–strain ratio (PSR) was determined. Then, analysis studies were carried out by creating 336 3D and 336 plane–strain slice models with variable parameters, such as slope angle (β), wall angle (α), nail length (L/H), excavation depth (H), and distance from the corner (xH). Its effects on PSR were determined. The interactions of the parameters with each other and PSR estimation were evaluated using machine learning (ML) methods: artificial neural networks (ANN), classifical and regression tree (CART), support vector regression (SVR), extreme gradient boosting (XGBoost). The proposed ML prediction methods and PSR results were compared with performance metrics and reliable results were obtained
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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