1,720,962 research outputs found
Monthly Flow Duration Curve Model for Ungauged River Basins
No full textFlow duration curve (FDC) is widely used in hydrology to assess streamflow in a river basin. In this study, a simple FDC model is developed for monthly streamflow data. The model consists of several steps including the nondimensionalization and then normalization in case the monthly streamflow data do not fit the normal probability distribution function. The normalized quantiles are calculated after which a back transformation is applied to the normalized quantiles to return back to the original dimensional streamflow data. In order to calculate annual streamflow of the river basin, an empirical regression equation is proposed using the drainage area and the annual total precipitation only as the input. As the final step of the model, dimensional quantiles of FDC are calculated. Ceyhan River basin in southern Turkey is chosen for the case study. Forty-two streamflow gauging stations are considered; two thirds of the gauging stations are used for the model calibration, and one third for validation. The modeled FDCs are compared to the observation and assessed with a number of performance metrics. They are found similar to the observed ones with a relatively good performance; they are good in the mid and high flow parts particularly while the low flow part of FDCs might require further detailed analysis
Annual flow duration curve model for ungauged basins
No full textAbstractA flow duration curve (FDC) plots the percentage of time that flow in a stream is equal to or exceeding a given value. In a gauged basin, it is obtained by sorting the observed flow from the largest to the smallest, and plotting against the corresponding exceedance probability. At ungauged basins where no data exist, the need for developing empirical methods emerges. This study aims at developing an FDC model for ungauged basins. The model is based on the normalized nondimensional annual mean flow quantiles. The annual mean flow is empirically calculated by a regression equation that takes drainage area and annual precipitation as input. Slope of the channel is additionally considered in the regression, however no better performance is achieved. Seyhan and Ceyhan basins in the Mediterranean region in southern Turkey are chosen as the study area. Data from 109 gauging stations are used for the calibration and validation of the model. Gauging stations on the tributaries are studied with a view to limiting anthropogenic activities on the rivers. Results of the application are found so promising that the model can be considered a good foundation for the development of FDCs at ungauged basins.</jats:p
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
Flood Analysis Using Adaptive Hydraulics (ADH) Model in Akarcay Basin
No full textEvery year, thousands of people are loosing their lives and significant financial losses occur because of flood disasters. Floods stem from basin characteristics. Floods can occur due to effects of snow melts and erratic rainfall because of shallow rivers even in summer months in the Akarcay Basin. In this study, Adaptive Hydraulics (AdH) model and The Finite Element Surface Water Modeling System (FESWMS) were used to generate a hydraulic model. Consequently, many settled areas would not face flood risk, but especially agricultural lands in some regions near the banks of streams can experience damages after floods.Afyon Kocatepe University [11, FEN.BIL.26]This study is a part of MS thesis of the first author and the study is supported with Scientific Research Project Flood modelling of Akarcay Basin (No: 11.FEN.BIL.26) funded by Afyon Kocatepe University
Numerical Modeling of Structural Irregularities on Unsymmetrical Buildings
Get PDFSince the formation of the world, it is known that the earthquakes in seismic-active regions are occurring in sequences and from their results there are losses to millions of people and buildings. As Turkey is located in one of the worldꞌs most active seismic zones there are many studies for minimizing the damages especially at buildings during earthquakes. In this study, the seismic analyses were handled for a 10-storey unsymmetrical (L-shaped) building according to the Turkish Earthquake Code (TEC). These analyses contain the controls of A1-torsional irregularity, B2-weak-storey irregularity, relative storey displacements and second order effects. Furthermore, due to the lack of symmetry of the building, model was analysed for both +X and +Y directions. In order to correct irregularities which would occur in building models, the shear walls will be placed in different +X and +Y axles and positions and the analyses were repeated. According to the results for the case of an earthquake the safest and the most economical building model was suggested. Loads in all analyses in the study were calculated using "Equivalent Earthquake Loading Method" stated in TEC. The results will reveal a new look especially in the earthquake engineering
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
- …
