1,720,973 research outputs found
Cutting of 316L stainless steel by plasma arc method and improvement of cutting quality
No full text16.03.2026 tarihine kadar kullanımı yazar tarafından kısıtlanmıştır.Bu çalışmada, 316L paslanmaz çeliklerin plazma ark yöntemiyle kesiminde akım, gerilim ve kesme hızı gibi parametrelerin kesim kalitesine etkisi detaylı şekilde incelenmiştir. Kesim kalitesi; yüzey pürüzlülüğü, kerf genişlikleri, kerf açısı, ısı tesiri altındaki bölge ve malzeme kaldırma oranı gibi kriterlerle değerlendirilmiştir. SWARA yöntemiyle belirlenen kriter ağırlıkları, CoCoSo, MABAC ve GİA gibi Çok Kriterli Karar Verme (ÇKKV) yöntemleriyle entegre edilerek hibrit yaklaşımlar oluşturulmuş ve kesim kalitesini iyileştirmek amacıyla karşılaştırılmıştır. Deney sonuçlarına göre, akım, gerilim ve kesme hızı arttıkça yüzey kalitesi azalmıştır. Kesme hızı arttıkça, akım ve gerilim azaldıkça kerf genişliği ve ısı tesiri altında kalan bölge azalmıştır. En düşük kerf açısı en yüksek kesme hızı ve akım ile en düşük gerilimde elde edilmiştir. En yüksek malzeme kaldırma oranı ise kesme parametrelerinin en yüksek seviyelerinde elde edilmiştir. Hibrit SWARA-CoCoSo, SWARA-MABAC ve SWARA-GİA yöntemlerinin tümünde en iyi deney koşulunu 3 numaralı deneyin (Akım: 130 A, Gerilim: 141 V ve Kesme Hızı: 1900 mm/dk) sağladığı hesaplanmıştır. Son olarak, Spearman'ın sıra korelasyon katsayı analizi ile üç farklı hibrit ÇKKV yaklaşımının arasındaki sıralama ilişkileri incelenmiş olup birbirleri ile uyumu %95'in üzerinde olduğu belirlenmiştir.In this study, the effects of cutting parameters such as current, voltage, and cutting speed on the cutting quality of 316L stainless steel using the plasma arc method were thoroughly investigated. Cutting quality was evaluated based on criteria such as surface roughness, kerf widths (top and bottom), kerf angle, heat-affected zone, and material removal rate. The criterion weights were determined using the SWARA method and integrated with CoCoSo, MABAC, and GRA multi-criteria decision-making (MCDM) methods to form hybrid approaches, which were compared to improve cutting quality. According to the experimental results, as current, voltage, and cutting speed increased, surface quality deteriorated. Higher cutting speeds and lower current and arc voltage led to reductions in kerf width and the heat-affected zone. The lowest kerf angle was achieved at the highest cutting speed and current, with the lowest voltage. The highest material removal rate was obtained at the maximum levels of cutting parameters. All three hybrid methods (i.e., SWARA-CoCoSo, SWARA-MABAC, and SWARA-GRA) identified the third experiment (130 A current, 141 V voltage, and 1900 mm/min cutting speed) as the optimal condition. Finally, Spearman's rank correlation coefficient analysis showed over 95% agreement among the ranking results of the three hybrid MCDM approaches
Thermoplastic material selection for high temperature applications: a comparative multi-criteria decision making approach
Full text linkBu çalışma, otomotiv endüstrisinde hibrit araç akü paketleri için optimum termoplastik malzeme seçiminde yüksek sıcaklık ortamlarının neden olduğu zorlukları ele almakta ve karşılaştırmalı çok kriterli karar verme yaklaşımını kullanmaktadır. Çalışma, kritik faktörler temelinde malzemeleri titizlikle değerlendirerek, pil verimliliğini, uzun ömürlülüğünü ve araç performansını artıracak malzemeleri belirlemeyi amaçlamaktadır. SWARA-ARAS, SWARA-EDAS ve SWARA-TOPSİS gibi ileri düzey karar verme yöntemlerinden yararlanarak, çeşitli polimerler sistematik bir şekilde sıralanmakta ve güvenlik, performans ve sürdürülebilirliği ön planda tutan stratejik öneriler sunulmaktadır. Bulgular, üreticilerin veri odaklı malzeme seçim kararları almasına olanak tanıyarak, sürdürülebilir otomotiv teknolojilerinin gelişimine katkı sağlamaktadır.This study investigates the difficulties presented by high-temperature environments in the automotive industry, specifically focusing on the choice of optimal thermoplastic materials for hybrid vehicle battery packs. By applying a comparative multi-criteria decision-making framework, the research rigorously evaluates materials based on critical factors. The study aims for determining materials that not only enhance battery efficiency and longevity but also improve overall vehicle performance. Leveraging advanced decision-making techniques, including SWARA-ARAS, SWARA-EDAS, and SWARA-TOPSIS, the analysis ranks and evaluates different polymer options, offering strategic suggestions prioritizing safety, performance, and sustainability. The results provide actionable insights for manufacturers, empowering them to make data-driven material selection decisions that drive the development of next-generation sustainable automotive technologies
Cutting of 316L stainless steel by plasma arc method and improvement of cutting quality
No full text16.03.2026 tarihine kadar kullanımı yazar tarafından kısıtlanmıştır.Bu çalışmada, 316L paslanmaz çeliklerin plazma ark yöntemiyle kesiminde akım, gerilim ve kesme hızı gibi parametrelerin kesim kalitesine etkisi detaylı şekilde incelenmiştir. Kesim kalitesi; yüzey pürüzlülüğü, kerf genişlikleri, kerf açısı, ısı tesiri altındaki bölge ve malzeme kaldırma oranı gibi kriterlerle değerlendirilmiştir. SWARA yöntemiyle belirlenen kriter ağırlıkları, CoCoSo, MABAC ve GİA gibi Çok Kriterli Karar Verme (ÇKKV) yöntemleriyle entegre edilerek hibrit yaklaşımlar oluşturulmuş ve kesim kalitesini iyileştirmek amacıyla karşılaştırılmıştır. Deney sonuçlarına göre, akım, gerilim ve kesme hızı arttıkça yüzey kalitesi azalmıştır. Kesme hızı arttıkça, akım ve gerilim azaldıkça kerf genişliği ve ısı tesiri altında kalan bölge azalmıştır. En düşük kerf açısı en yüksek kesme hızı ve akım ile en düşük gerilimde elde edilmiştir. En yüksek malzeme kaldırma oranı ise kesme parametrelerinin en yüksek seviyelerinde elde edilmiştir. Hibrit SWARA-CoCoSo, SWARA-MABAC ve SWARA-GİA yöntemlerinin tümünde en iyi deney koşulunu 3 numaralı deneyin (Akım: 130 A, Gerilim: 141 V ve Kesme Hızı: 1900 mm/dk) sağladığı hesaplanmıştır. Son olarak, Spearman'ın sıra korelasyon katsayı analizi ile üç farklı hibrit ÇKKV yaklaşımının arasındaki sıralama ilişkileri incelenmiş olup birbirleri ile uyumu %95'in üzerinde olduğu belirlenmiştir.In this study, the effects of cutting parameters such as current, voltage, and cutting speed on the cutting quality of 316L stainless steel using the plasma arc method were thoroughly investigated. Cutting quality was evaluated based on criteria such as surface roughness, kerf widths (top and bottom), kerf angle, heat-affected zone, and material removal rate. The criterion weights were determined using the SWARA method and integrated with CoCoSo, MABAC, and GRA multi-criteria decision-making (MCDM) methods to form hybrid approaches, which were compared to improve cutting quality. According to the experimental results, as current, voltage, and cutting speed increased, surface quality deteriorated. Higher cutting speeds and lower current and arc voltage led to reductions in kerf width and the heat-affected zone. The lowest kerf angle was achieved at the highest cutting speed and current, with the lowest voltage. The highest material removal rate was obtained at the maximum levels of cutting parameters. All three hybrid methods (i.e., SWARA-CoCoSo, SWARA-MABAC, and SWARA-GRA) identified the third experiment (130 A current, 141 V voltage, and 1900 mm/min cutting speed) as the optimal condition. Finally, Spearman's rank correlation coefficient analysis showed over 95% agreement among the ranking results of the three hybrid MCDM approaches
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Demand and Capacity Modelling of Acute Services Using Simulation and Optimization Techniques
Full text linkThe level of difficulty that hospital management have been experiencing over the past decade in terms of balancing demand and capacity needs has been at an unprecedented level in the UK. Due to shortage of capacity, hospitals are unable to treat patients, and in some cases, patients are transferred to other hospitals, outpatient referrals are delayed, and accident and emergency (A&E) waiting times are prolonged. So, it’s time to do things differently, because the current status quo is not an option. A whole hospital level decision support system (DSS) was developed to assess and respond to the needs of local populations. The model integrates every component of a hospital (including A&E, all outpatient and inpatient specialties) to aid with efficient and effective use of scarce resources. An individual service or a specialty cannot be assumed to be independent, they are all interconnected. It is clear from the literature that this level of generic hospital simulation model has never been developed before (so this is an innovative DSS). Using the Hospital Episode Statistics and local datasets, 768 forecasting models for the 28 outpatient and inpatient specialties are developed (to capture demand). Within this context, a variety of forecasting models (i.e. ARIMA, exponential smoothing, stepwise linear regression and STLF) for each specialty of outpatient and inpatient including the A&E department were developed. The best forecasting methods and periods were selected by comparing 4 forecasting methods and 3 periods (i.e. daily, weekly and monthly) according to forecast accuracy values calculated by the mean absolute scaled error (MASE). Demand forecasts were then used as an input into the simulation model for the entire hospital (all specialties). The generic hospital simulation model was developed by taking into account all specialties and interactions amongst the A&E, outpatient and inpatient specialties. Six hundred observed frequency distributions were established for the simulation model. All distributions used in the model were based on age groups. Using other inputs (i.e. financial inputs, number of follow ups, etc.), the hospital was therefore modelled to measure key output metrics in strategic planning. This decision support system eliminates the deficiencies of the current and past studies around modelling hospitals within a single framework. A new output metric which is called ‘demand coverage ratio’ was developed to measure the percentage of patients who are admitted and discharged with available resources of the associated specialty. In addition, a full factorial experimental design with 4 factors (A&E, elective and non-elective admissions and outpatient attendance) at 2 levels (possible 5% and 10% demand increases) was carried out in order to investigate the effects of demand increases on the key outputs (i.e. demand coverage ratio, bed occupancy rate and total revenue). As a result, each factor is found to affect total revenue, as well as the interaction between elective and non-elective admissions. The demand coverage ratio is affected by the changes in outpatient demands as well as A&E arrivals and non-elective admissions. In addition, the A&E arrivals, non-elective admissions and elective admissions are most important for bed occupancy rates, respectively. After an exhaustive review of the literature we notice that an entire hospital model has never been developed that combines forecasting, simulation and optimization techniques. A linear optimization model was developed to estimate the required bed capacity and staff needs of a mid-size hospital in England (using essential outputs from forecasting and forecasting-simulation) for each inpatient elective and non-elective specialty. In conclusion, these results will bring a different perspective to key decision makers with a decision support tool for short and long term strategic planning to make rational and realistic plans. This hospital decision support system can become a crucial instrument for decision makers for efficient service in hospitals in England and other parts of the world
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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