Approximate symmetries and conservation laws for Itô and Stratonovich dynamical systems

AbstractA new definition for the approximate symmetries of Itô dynamical system is given. Determining systems of approximate symmetries for Itô and Stratonovich dynamical systems have been obtained. It has been shown that approximate conservation laws can be found from the approximate symmetries of stochastic dynamical systems which do not arise from a Hamiltonian. The results have been applied to an example

European Union Candidate Country and Some Countries Comparative Analysis With Factor Analysis and Data Envelopment Analysis

DergiPark: 326286trakyasobedIn this conducted study, socio-economical developmental index of European Union Candidate country and some selected countries is calculated with factor analysis and data envelopment analysis (DEA). For calculating this index 2008 year macro economical indicators are used. Data envelopment analysis is an approach of measuring efficiency of homogeneous units. In the analysis, the efficiency scores which are calculated with DEA are accepted development index of countries. DEA?s decomposion power of efficient and nonefficient countries are decreased if the variable number is too much. For this reason all the variables in factor analysis couldn't use in the analysis. On the other hand, countries are ranked with factor analysis according to factor loadings and compared with DEA ranking and are determined dissimilarities.Çalışmada, Avrupa Birliği?ne (AB) üye ve seçilmiş bazı ülkelerin gelişmişlik düzeylerinin faktör analizi ve veri zarflama analizi (VZA) ile belirlenmesi amaçlanmıştır. Bu amaca yönelik olarak analizde 2008 yılı makro ekonomik göstergeleri kullanılmıştır. Veri zarflama analizi homojen birimlerin performans göstergelerinden birisi olan etkinliklerin ölçülmesinde kullanılan bir yöntemdir. Analizde VZA ile elde edilen etkinlik skorları ülkelerin gelişmişlik düzeyleri olarak kabul edilmiş ve bu ülkeler sıralanmıştır. VZA? da değişken sayısının çok olması etkin ve etkin olmayan ülkelerin ayrıştırma gücünü azaltmaktadır. Bu nedenle, faktör analizinde kullanılan değişkenlerin tamamı kullanılamamıştır. Diğer taraftan bu çalışmada, Faktör analizi ile ülkelerin faktör skorlarına göre sıralaması yapılmış ve VZA ile yapılan sıralama ile karşılaştırılarak elde edilen farklılıklar belirlenmişti

Topsis Method With the European Union Member States of the Candidate and Mapping of Economic Indicators

DergiPark: 326263trakyasobedIn the study, levels of development of the EU member and candidate countries by using economic indicators, which is one of multi-criteria decisionmaking techniques with TOPSIS method is to ranking.TOPSIS method, Electre developed as an alternative method to solve problems, and multi-criteria decisionmaking is one of the most widely used methods. With this method, the best solution alternatives (positive ideal solution), taking into account the relative order of proximity to decision makers and provides a proposed solution is presented.EU member and candidate countries to study the economic development (performance) to be sorted according to the Maastricht criteria by taking into account (Public Debt / GDP), (Unemployment Rate%), (Budget Deficit / GDP), (Export / Import), GDP / Population) and (inflation), such as economic indicators (criteria) used 2009 data. Maastricht criteria for the economic indicators used in this study (criteria), the relative importance (weights) has been set equal. As a result, the analysis and ranked according to the criteria of the EU member and candidate countries,in this ranking Turkey's place were determinedÇalışmada, AB’ye üye ve aday ülkelerin gelişmişlik düzeyleri ekonomik göstergeler kullanılarak çok kriterli karar verme tekniklerinden birisi olan TOPSIS yöntemi ile sıralanması amaçlanmıştır. TOPSIS yöntemi, ELECTRE yöntemine alternatif olarak geliştirilmiş ve çok kriterli karar verme problemlerinin çözümünde en çok kullanılan yöntemlerden biridir. Bu yöntem ile alternatiflerin en iyi çözüme (pozitif ideal çözüme) görece yakınlıklarını dikkate alarak sıralanmasını sağlamakta ve karar vericilere bir çözüm önerisi sunulmaktadır. Çalışmada AB’ye üye ve aday ülkelerin ekonomik gelişmişliklerine (performanslarına) göre sıralanması için Maastricht Kriterleri de dikkate alınarak (Kamu Borçları/GSYİH), (İşsizlik Oranı%), (Bütçe Açığı/GSYİH), (İhracat/İthalat), GSYİH/Nüfus) ve (Enflasyon) gibi ekonomik göstergelerin (kriterler) 2009 yılı verileri kullanılmıştır. Çalışmada Maastricht Kriterleri kullanıldığı için ekonomik göstergelerin (kriterlerin) görece önemleri (ağırlıkları)eşit olarak belirlenmiştir. Sonuç olarak analizde AB’ye üye ve aday ülkeler ilgili kriterler doğrultusunda sıralanmış ve Türkiye’nin bu sıralama içerisindeki yeri belirlenmişti

ENHANCED WINTER HARDINESS IN COMMON VETCH (VICIA SATIVA L.) FOR AUTUMN-SOWING IN THE CENTRAL HIGHLANDS OF TURKEY

In central Turkey, common vetch is planted in spring, but frequent droughts cause crop failures. Autumn-sown vetch has more yield potential; but then winter killing is a major problem. Therefore, winter hardiness is a central requirement for successful vetch production. This study comprised two phases. First, eighteen lines out of 164 accessions were selected for their superiority, primarily for winter hardiness and earliness in 1999/00. Second, the selected lines along two local checks (var. SarıElçi and cv. KaraElçi) were evaluated for yield performances in multi-year trials established in autumn and spring from 2000 to 2003. Autumn-sown vetch displayed 14.9% greater yield potential than spring vetch. As winter mortality decreased, seed yield increased in two cold environments (r2=0.41 and r2=0.54). The two genotypes (L-1430 and L-1548) showed the greatest stability across six environments, while L-581 and L-1544 were the best lines for autumn sowing. In conclusion, the level of variation found in the base populations did clearly show potential for further development, and multi-environment trials singled out the V. sativa genotypes with enhanced winter hardiness

Temperature-dependent growth shapes of Ni nanoclusters on NiAl(110)

Scanning tunneling microscopy studies reveal that two-dimensional nanoscale Ni islands formed by deposition of Ni on NiAl(110) between 200–400 K exhibit far-from-equilibrium growth shapes which change systematically with temperature. Island structure reflects the two types of adsorption sites available for Ni adatoms, and island shapes are controlled by the details of adatom diffusion along island edges accounting for numerous local configurations. The temperature dependence of the island shapes is captured and elucidated by kinetic Monte Carlo simulation of a realistic atomistic-level multisite lattice-gas model incorporating precise diffusion barriers. These barriers are obtained by utilizing density functional theory to probe energetics not just at adsorption sites but also at transition states for diffusion. This success demonstrates a capability for predictive atomistic-level modeling of nanocluster formation and shape selection in systems that have a high level of energetic and kinetic complexity

The influence of artificial saliva on NiTi orthodontic wires: a study on surface characterization

Ni and Ti based alloys are prospective materials for dental orthodontic wires because of their superior mechanical properties and corrosion resistance. The studies on the corrosion resistance of these materials according to their surface characterization in artificial saliva are limited. In this study, the changes on the surface of NiTi alloy based orthodontic wires in F– and PO³₄– added or not added artificial saliva after a period of time were investigated by SEM and EDS studies.Сплави на основі Ni та Ті – перспективні для виготовлення ортодонтичних дротів завдяки своїм високим механічним характеристикам та корозійній тривкості, яка у синтетичній слині методами поверхневого аналізу досліджена недостатньо. Вивчено зміни властивостей поверхні ортодонтичних дротів із нікельтитанового сплаву під час витримки в синтетичній слині з додаванням F– та PO³₄– та без них за допомогою сканівної електронної мікроскопії (SEM) та енергодисперсійного мікроаналізу (EDS).Сплавы на основе Ni и Ті – перспективные для изготовления ортодонтичных проводов благодаря своим высоким механическим характеристикам и коррозионной стойкости, которая в синтетической слюне методами поверхностного анализа исследована недостаточно. Изучены изменения свойств поверхности ортодонтичных проводов из никельтитанового сплава во время выдержки в синтетической слюне с добавлением F– и PO³₄– и без них с помощью сканирующей электронной микроскопии (SEM) и энергодисперсионного микроанализа (EDS)

Three-dimensional nanoplasmonic surfaces with strong out-of-plane electric field enhancement

Conventional 2D plasmonic structures, with surface coverage ~50%, provide field enhancement in the plane. The proposed 3D nanoplasmonic surfaces, with unity coverage, achieve 7.2-fold stronger out-of-plane enhancement compared to the 2D counterparts. © OSA 2013

About curvature, conformal metrics and warped products

We consider the curvature of a family of warped products of two pseduo-Riemannian manifolds $(B,g_B)$ and $(F,g_F)$ furnished with metrics of the form $c^{2}g_B \oplus w^2 g_F$ and, in particular, of the type $w^{2 \mu}g_B \oplus w^2 g_F$, where $c, w \colon B \to (0,\infty)$ are smooth functions and $\mu$ is a real parameter. We obtain suitable expressions for the Ricci tensor and scalar curvature of such products that allow us to establish results about the existence of Einstein or constant scalar curvature structures in these categories. If $(B,g_B)$ is Riemannian, the latter question involves nonlinear elliptic partial differential equations with concave-convex nonlinearities and singular partial differential equations of the Lichnerowicz-York type among others.Comment: 32 pages, 3 figure

Modeling impacts of climate change scenario over Turkey

Bu çalışmada izlenen yöntem, Türkiye ve çevresi üzerinde, günümüz ve gelecek için NASA-Sonlu Hacim Genel Dolaşım Modeli (fvGCM) tarafından üretilen projeksiyonların, ICTP-Bölgesel İklim Modeli (RegCM3) kullanılarak dinamik olarak ölçek küçültülmesidir. Günümüz (1961-1990, RF) ve gelecek (2071-2100, A2) simülasyonları için, Hükümetlerarası İklim Değşikliği Paneli (IPCC) tarafından belirlenmiş sera gazları emisyon senaryoları dikkate alınmıştır. A2 ve RF simülasyonlarının sıcaklık ve yağış için yapılan mevsimsel analizleri Türkiye’nin iklimsel bölgeleri üzerinde alansal ortalama alınarak ayrı ayrı incelenmiştir. A2 simülasyonuna göre, Türkiye üzerinde sıcaklıklardaki en dramatik değişim yaz mevsiminde Ege Bölgesi üzerindeki 5 ila 6 °C’ler arasındaki artıştır. Kış ayları dışındaki mevsimlerde artış, 3-4 °C arasında değişmektedir. Gelecek simülasyonundaki minimum artış, kış mevsiminden 2-3 °C olarak hesaplanmıştır. Yine A2 simülasyonunda, Doğu Karadeniz dağları boyunca uzanan bölgede kış yağışlarıdaki artış, rüzgar paterninin değişmesiyle orografik etkinin güçlenmesine bağlıdır. Türkiye’nin güneyi üzerinde de rüzgar paterninin güneyli değişimine bağlı olarak kış yağışlarında çok ciddi azalmalar (% 34) model sonuçlarında ortaya çıkmıştır. Sonbahar meviminde ise Güneydoğu Anadolu Bölgesinde yağışlarda % 50’lere varan artışlar görülmüştür. Bu artışların ana nedeni değişen rüzgar akımlarının taşıdığı nem olabilir. Gelecek iklim senaryosunda Fırat ve Dicle su havzalarını kapsayan alandaki kış yağışlarında yaşanan azalmalarla, küresel ısınmaya paralel sıcaklık artışının buharlaşmaya etkisiyle birlikte değerlendirildiğinde, model sonuçlarının hidrolojik analizlerinin önemi daha çok ortaya çıkmaktadır. Anahtar Kelimeler: İklim değişimi, bölgesel iklim modellemesi, ölçek küçültme.The Earth's climate has changed many times and fluctuated between the glacial and the interglacial periods since its formed. These changes related to natural forcings like volcanic eruptions, intense tectonic activity, solar activity and variation of Earth's orbital parameters, were sometimes very dramatic. Today, the global change we face to is different than the natural changes occurred in the past. Human-induced climate change has been taken into consideration extensively within the last decade more than ever. Recent advances in both climate observing systems and methodologies to detect the climate change, as well as broader global coverage of observations help scientists to better understand the climate system. Scientific studies which are led by IPCC (Intergovernmental Panel on Climate Change) showed that dominance of anthropogenic effect on global warming is indisputable (IPCC, 2007). Regional climate change modeling has been applied to many different areas such as agriculture, seasonal forecasting, hydrology applications, paleoclimate and climate projections. Because of its ability to resolve sharp gradients and contrasts in the surface conditions, the regional climate modeling approach yields more accurate and spatially detailed information. In this study,  the ICTP-Regional Climate Model version 3 (RegCM3) has been used to downscale present and future scenario simulations generated by the NASA-Finite Volume General Circulation Model (fvGCM) over Turkey and its surroundings. The present-day (1961-1990, RF) and the future climate change simulations (2071-2100, A2) are based on the IPCC Greenhouse Gases emissions, which are CO2, CH4, N2O, and CFC11- CFC12. Emission scenarios for these gases have been implemented into the radiation scheme for the simulations and, relatively high resolution of 30 km is adopted to resolve the complex topography of the domain. The role of the domain characteristics such as complex land-sea distribution determines the sub-regional climatic features and spatial climate variability. This diverse climatic structure of the region brings great challenge for regional climate modeling. Levantine Sea, Aegean Sea and Black Sea are main moisture sources of the Turkey and its surrounding regions. A2 simulation results which correspond future climate indicate that warming over Turkey's climatic zones is in the range of 2-5 °C. Summer temperature changes are more dominant in the A2 scenario. This pattern has also been observed for neighboring countries. Summer heat wave conditions over Aegean region (5 °C increase) are more obvious in the area averages than in the spatial pattern based model results. The difference between the summer and winter change is about 3 °C and it could play an important role in contributing to temporal shifts of the transition seasons. In addition, warming in winter over eastern and southeastern of Turkey which have higher altitudes are nearly 1 °C higher than for Marmara and Aegean regions which have lower altitudes. Autumn temperature changes for all regions are affected by the extension of the summer season extension due to the global warming. Most significant precipitation changes in A2 scenario have been occurred over the Mediterranean region of Turkey in winter and over the Southeastern of Turkey in autumn. Our analyses show a 34% decrease over Mediterranean region and it is related to the change in the atmospheric circulation which in turn causes reduced orographic forcing. The same circulation change also enhanced orographic forcing especially over the east of the Black Sea region and results in significant precipitation increase. Decreases over the Aegean and Southeastern regions are around 20% in winter. Autumn precipitation over Southeastern region increased as high as 48%. Flow pattern changes which also affected Iraq and Syria are consistent with enhanced moisture availability over this region which may account for the major precipitation increase. All precipitation changes in winter and autumn are also statistically significant. The amount of precipitation over Turkey in summer season is very little except eastern Black Sea region. Therefore, percent changes for summer precipitation over all of regions could not be meaningful to discuss. Analyses of A2 simulation show that combined effect of precipitation decrease and evapotranspiration increase related to temperature increase could play major role to reduce water resources over Turkey. Especially, there could be significant problems over Euphrates-Tigris basin because of the decreasing water availability in future scenario. Keywords: Climate change, regional climate modeling, downscaling scenarios