139,800 research outputs found
Long Memory in the Turkish Stock Market Return and Volatility
No full textThis paper examines the dual long memory property of the Turkish stock market. The data set consists of daily returns, and long memory tests are carried out both for the returns and volatility. The results indicate that long memory dynamics in the returns and volatility might be modeled by using the ARFIMA-FIGARCH model. The results of the ARFIMAFIGARCH model show strong evidence of long memory in both returns and volatility. The long memory in returns implies that stock prices follow a predictable behavior, which is inconsistent with the efficient market hypothesis. The evidence of long memory in volatility, however, shows that uncertainty or risk is an important determinant of the behavior of daily stock data in the Turkish stock market.ARFIMA, FIGARCH, Long memory, Turkish stock market
Opportunities and challenges facing female managers: A qualitative study
No full textDünya genelinde kadınlar işgücüne katılım ve yönetici pozisyonunda temsil açısından erkeklerden daha dezavantajlı konumdadır.
Nüfusunun yarısına ekonomik, sosyal ve siyasal hakları tam anlamıyla sunamayan toplumların nasıl gelişeceği şüphelidir. Pek çok
ülkede olduğu gibi, Türkiye’de de kadın yöneticilerin sayısı erkeklere oranla daha azdır. Bu nedenle, kadınların yönetici olmalarını
engelleyen unsurların tespit edilmesi ve bu engelleri ortadan kaldıracak politikaların oluşturulması önem taşımaktadır. Böylece
yönetim kademesinde cinsiyet eşitliği sağlanabilir. Bu araştırmada, kolayda örneklem ile ulaşılan 22 kadın yöneticiye kariyer
hikâyeleri ve yöneticiliğe giden süreçteki deneyimleri yarı yapılandırılmış mülakatlar aracılığıyla sorulmuştur. Bulgular betimsel analiz
yöntemi ile yorumlanmıştır. Yönetici olmaya giden yolda katılımcıların özveriyle çalışmak ve kendini geliştirmeye önem vermek gibi
benzer özellikleri vurguladığı görülmüştür. Ayrıca, üstlerden destek almak, kurumun sağladığı imkânlar gibi yönetici olmayı
kolaylaştıran unsurlar olduğu ortaya çıkmıştır. Bununla birlikte, iş-aile çatışması, erkeklerden kaynaklanan baskılar gibi kadınlar için
yönetici olmayı zorlaştırıcı çeşitli unsurlar da tespit edilmiştir. Katılımcıların işyerinde cinsiyet eşitliğine ilişkin farklı görüşlere sahip
oldukları anlaşılmıştır. Bulgular, toplumsal cinsiyet çerçevesinde tartışılmıştır. Kadınların yönetici olma sürecini analiz eden nitel
araştırmaların, yönetici olma yolunda karşılaşılan zorlukları ve kolaylıkları belirlemek açısından zengin bir veri kaynağı oluşturacağı
düşünülmektedir. Bu tip araştırmaların kariyer hedefi olan genç kadınlara bir yol haritası sunması ve toplumsal cinsiyet eşitliği
politikalarına katkıda bulunması umulmaktadır.Women are more disadvantaged than men in terms of representation in managerial positions worldwide. It is questionable how
societies that cannot fully offer economic, social, and political rights to half of their population will develop. As seen in many
countries, in Turkey, the number of female managers is less than men. Therefore, identifying the factors that prevent women from
becoming managers and developing policies to eliminate these obstacles is essential. Thus, achieving gender equality at the
management level might be possible. In this study, semi-structured interviews were implemented among 22 female managers who
were reached with convenience sampling to learn about their career narratives and experiences during the process leading to
management. Findings were interpreted with the descriptive analysis method. On the way to managerial ranks, it was observed that
the participants emphasized similar characteristics, such as working devotedly. Several factors making it easy or difficult to become
a manager have been revealed. Findings were discussed in the context of gender. It is believed that qualitative research will generate
a rich data source for identifying the difficulties and conveniences encountered in this way. The expectation is that such research
can provide a roadmap for young women with career goals and contribute to creating gender equality policies
Position estimates for existing trenchless installations
No full textThe position and alignment of existing cables and ducts, previously installed by trenchless technologies, has not always been recorded with sufficient accuracy for new works to be safely conducted close to existing installations. Inaccurate or missing registration in the past, manual data entry, previous activities in the same areas, can all lead to deviations between recorded and actual location. Location detection is often hampered by the depth of installations, especially in the case of HDD. The Netherlands Society for Trenchless Technologies (NSTT) has conducted a survey of the accuracy of trenchless installation techniques over the past decades, and of external factors influencing the position of existing cables and ducts, to get an estimate of the positional accuracy of older TT installations. This paper gives an overview of estimated accuracies for cables and ducts installed by HDD, micro-tunnelling, impact moling/ramming, auger boring and other TT installation techniques, taking soil conditions and the state of technology at the time of installation into account. The paper also gives an overview of which TT came to the Dutch market in which period.Geo-engineerin
A fully integrated biosensing platform combining acoustofluidics and electromagnetic metamaterials
No full textA key challenge in biosensing technology is to develop integrated approaches with the multiple capabilities of bio-sampling, fluid manipulation, high-precision detection and wireless operation. In this work, we present a new concept of integrated biosensing technology using the functionalities of electromagnetic metamaterials and acoustofluidic technology onto a single platform. The new concept of using a single structure to perform microfluidic functions at acoustic frequencies and to detect the characteristics of liquid at microwave frequencies will enable the development of improved lab-on-a-chip devices. As a case study, we demonstrated efficient acoustofluidic functions of mixing and pumping using the designed surface acoustic wave (SAW) device on a LiNbO3 substrate in an experimental setup that also allows the measurement of the electromagnetic characteristics of the interdigitated transducer (IDT) pattern of the same device. We demonstrated microfluidic functions at 10-25 MHz. The device also exhibits electromagnetic resonance at 4.4 GHz with a quality factor value of 294. We showed the device can be used for glucose detection with a good sensitivity of 28 MHz/(mg/ml)
Carta de Tadeusz Czežowski a Alain Guy. Torun, 12 de Febrero de 1980
No full textCarta de Tadeusz Czeżowski a Alain Guy donde le pide que escriba un artículo sobre la enseñanza francesa para la revista Ruch Filozoficzny. -Observaciones: Se conserva el sobre. Tadeusz Czeżowski profesor de las Universidades Stefan Batory y Nicolás Copérnico, así como editor de la Revista Ruch Filozoficzny. – Bibliografía que aparece en la carta: Ruch Filozoficzny. Torun: Universidad Nicolás Copérnico, Sociedad filosófica polaca, 1911
Desarrollo y validación de ecuaciones antropométricas para estimar la composición corporal en mujeres adultas
No full textABSTRACT: To develop anthropometric equations to predict body fat percentage (BF%). Methods: In 151 women (aged 18-59) body weight, height, eight-skinfold thickness (STs), six- circumferences (CIs), and BF% by hydrodensitometry were measured. Subjects data were randomly divided in two groups, equation-building group (n= 106) and validation group (n= 45). The equation-building group was used to run linear regression models using anthropometric measurements as predictors to find the best prediction equations of the BF%. The validation group was used to compare the performance of the new equations with those of Durnin-Womersley, Jackson-Pollock and Ramirez-Torun. Results: There were two preferred equations: Equation 1= 11.76 + (0.324 x tricipital ST) + (0.133 x calf ST) + (0.347 x abdomen CI) + (0.068 x age) - (0.135 x height) and Equation 2= 11.37 + (0.404 x tricipital ST) + (0.153 x axilar ST) + (0.264 x abdomen CI) + (0.069 x age) - (0.099 x height). There were no significant differences in BF% obtained by hydrodensitometry (31.5 ±5.3) and Equation 1 (31.0 ±4.0) and Equation 2 (31.2 ±4.0). The BF% estimated by Durning-Womersley (35.8 ±4.0), Jackson-Pollock (26.5 ±5.4) and Ramirez-Torun (32.6 ±4.8) differed from hydrodensitometry (p <0.05). The interclass correlation coefficient (ICC) was high between hydrodensitometry and Equation 1 (ICC= 0.77), Equation 2 (ICC= 0.76), and Ramirez-Torun equation (ICC= 0.75). The ICC was low between hydrodensitometry and Durnin-Womersley (ICC= 0.51) and Jackson-Pollock (ICC= 0.53) equations. Conclusion: The new Equations-1 and 2, performed better than the commonly used anthropometric equations to predict BF% in adult women.RESUMEN: Desarrollar ecuaciones antropométricas para predecir el porcentaje de grasa corporal (% GC). Métodos: En 151 mujeres (18-59 años) se midieron peso corporal, estatura, ocho pliegues cutáneos (PCs), seis perímetros (PEs) y el %GC por hidrodensitometría. Se formaron dos grupos al azar, desarrollo de ecuaciones (n= 106) y validación (n= 45). En el grupo desarrollo ecuaciones se calcularon modelos de regresión lineal, con las medidas antropométricas como predictores, para encontrar la mejor ecuación de predicción del %GC. El grupo validación se utilizó para comparar el desempeño de las nuevas ecuaciones con las de Durnin-Womersley, Jackson-Pollock y Ramírez-Torun. Resultados: Se seleccionaron dos ecuaciones: Ecuación-1= 11.76 + (0.324 x tríceps PC) + (0.133 x pantorrilla-medial PC) + (0.347 x abdomen PE) + (0.068 x edad-años) - (0.135 x estatura) y Ecuación-2= 11.37 + (0.404 x tríceps PC) + (0.153 x axilar PC) + (0.264 x abdomen PE) + (0.069 x edad-años) - (0.099 x estatura). No hubo diferencias significativas en el %GC obtenido por hidrodensitometría (31.5 ±5.3) y Ecuación-1 (31.0 ±4.0) o Ecuación-2 (31.2 ±4.0). Los %GC estimados por Durning-Womersley (35.8 ±4.0), Jackson-Pollock (26.5 ±5.4) y Ramírez-Torun (32.6 ±4.8) fueron diferentes del obtenido por hidrodensitometría (p <0.05). El coeficiente de correlación intraclase (ICC) fue alto entre hidrodensitometría y las Ecuaciones 1 (ICC= 0.77), 2 (ICC= 0.76), y Ramírez-Torun (ICC= 0.75). El ICC fue bajo entre hidrodensitometría y Durnin-Womersley (ICC= 0.51) y Jackson-Pollock (ICC= 0.53). Conclusión: Las nuevas ecuaciones 1 y 2 presentaron mejor rendimiento que las ecuaciones tradicionales para predecir el %GC en mujeres adultas.COL0003249COL000732
Spatially-localized time dependent solutions including turbulence and their interactions in 2D Kolmogorov flow
No full textIn 2D Kolmogorov flow in small aspect ratio domains, spatially-localized solutions such as kink, traveling or time-dependent kink-antikink pars coexist. However, the conservation of the flow rate in the y direction strongly restrict combination of localized solutions and their positioning. We find that by adding a homogeneous flow U y their positioning is controlled and each of localized solutions including a spatially-localized chaos is isolated. Numerical results suggest that these isolated solutions can be elements constructing a whole flow
Investigating femtosecond laser interaction with tellurite glass family
No full textFocusing ultrafast laser pulses induce localized permanent structural modifications on the surface or in transparent materials, that are of particular interest for photonic applications. Among the materials of interest, the tellurite glass family is attractive for near-infrared and photonics applications due to its broad-transparency window and high optical nonlinearity. Here, we systematically investigate structural changes occurring in various TeO2-based glasses exposed to femtosecond laser with various laser parameters. Remarkably, in a regime where heat accumulated after successive pulses, we observed the formation of polarization-controlled self-organized patterns expanding well beyond the focal volume, suggesting the presence of an evanescent coupling mechanism enhancing the self-organization. In addition, our results, obtained with compositional elemental analysis coupled with Raman spectra suggest different ion migration mechanisms in the laser affected zone at the surface and inside the glass. The formation of crystalline tellurium (t-Te) from glass structural units due to photo-induced elemental dissociation was observed only at the surface. The formation of ultrathin layer of crystalline tellurium offers the possibility to explore structural transitions in two-dimensional (2D) glasses by observing changes in the short- and medium- range structural orders, induced by spatial confinement
Characteristics of overlap region in high-Reynolds number turbulent channel flow
No full textDirect numerical simulation of the fully developed turbulent channel flows have been carried out at the Reynolds number based on the friction velocity and the channel half width, 2000, 4000 and 8000. A hybrid 10th order accurate finite difference scheme in the stream and spanwise directions, and a second-order scheme in the wall-normal direction is adapted as the spatial discretization method. We observed the plateau profiles in the indicator function corresponded to the von Karman constant. Furthermore, second peak of streamwise pre-multiplied spectra were appeared in the same wall normal height, 300 < y+ < 600, in case of Re = 4000. Nevertheless, the effects of the lager than the channel half height scale on the streamwise turbulent intensity are fixed contributions without dependence on Reynolds number. These results suggested that the new streamwise vortexes are formed between buffer layer and outer layer with increasing of Reynolds number
La 'circunstancia' de 'Herederos y Pretendientes
No full textIn June 2010, the Ortega y Gasset Foundation hosted a Conference about the “Spanish Philosophical Transition” in order to debate the book of Francisco Vázquez, La filosofía española. Herederos y Pretendientes. Una lectura sociológica (1963-1990), recently published. This paper is the author’s response to criticism raised in the Conference and to published reviews received by this book. First, the author summarized the argument of Herederos y pretendientes. Secondly he responds and takes into account the most important objections against the book’s hypothesis and methodology. Finally the author evaluates the favorable judgments received by the book and suggests the limits of the historian’s task.Fundación Ortega y Gasset-Marañó
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