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Articles 1891 - 1920 of 10319
Full-Text Articles in Physical Sciences and Mathematics
On The Autocentralizer Subgroups Of Finite $P$--Groups, Parisa Seifizadeh, Ali Gholamian, Amirali Farokhniaee, Mohammad Mehdi Nasrabadi
On The Autocentralizer Subgroups Of Finite $P$--Groups, Parisa Seifizadeh, Ali Gholamian, Amirali Farokhniaee, Mohammad Mehdi Nasrabadi
Turkish Journal of Mathematics
Let $G$ be a finite group and ${\rm Aut}(G)$ be the group of automorphisms of $G.$ Then, the autocentralizer of an automorphism $\alpha\in {\rm Aut}(G)$ in $G$ is defined as $C_{G}(\alpha)= \lbrace g \in G\vert \alpha(g)=g\rbrace.$ Let $Acent(G)=\lbrace C_{G}(\alpha)\vert \alpha \in {\rm Aut}(G) \rbrace.$ If $\vert Acent(G)\vert= n,$ then $G$ is an $n$--autocentralizer group. In this paper, we classify all $n$--autocentralizer abelian groups for $n=$ 6, 7 and 8. We also obtain a lower bound on the number of autocentralizer subgroups for $p$--groups, where $p$ is a prime number. We show that if $p\neq 2,$ there is no $n$--autocentralizer $p$--group …
Some Results On A System Of Multiterm Fractional Integro-Differential Equations, Shahram Rezapour, Fethi̇ye Müge Sakar, Seher Meli̇ke Aydoğan, Elahe Ravash
Some Results On A System Of Multiterm Fractional Integro-Differential Equations, Shahram Rezapour, Fethi̇ye Müge Sakar, Seher Meli̇ke Aydoğan, Elahe Ravash
Turkish Journal of Mathematics
In present study, we investigate the existence of solution for a multiterm fractional integro-differential system with special boundary conditions under some different conditions. In this way, we provide different results for the existence of solutions for the system and also for obtaining unique solution for the system under different conditions. We also present three numerical examplesin which by using the Legendre multiwavelet method, we approximate solutions of the system. These examples illustrate our main results.
Lerch Matrix Collocation Method For 2d And 3d Volterra Type Integral And Second Order Partial Integro Differential Equations Together With An Alternative Error Analysis And Convergence Criterion Based On Residual Functions, Seda Çayan, Mehmet Sezer
Lerch Matrix Collocation Method For 2d And 3d Volterra Type Integral And Second Order Partial Integro Differential Equations Together With An Alternative Error Analysis And Convergence Criterion Based On Residual Functions, Seda Çayan, Mehmet Sezer
Turkish Journal of Mathematics
In this study, second order linear Volterra partial integro-differential equation with two- and three-dimensional are solved by collocation method based on Lerch polynomials. This method is composed of the operational matrix and collocation methods, which are based upon the matrix forms of the Lerch polynomials with the parameter $\lambda$ and Taylor polynomials, and their derivatives and integrals. The approximate solutions of the mentioned equations are investigated in terms of the Lerch polynomials the different values of $\lambda$. Also, to verify the accuracy and efficiency of the present method, an alternative convergence criterion along with error analysis depending on residual function …
Fluvio-Karstic Evolution Of The Taşeli Plateau (Central Taurus, Turkey), Muhammed Zeynel Öztürk
Fluvio-Karstic Evolution Of The Taşeli Plateau (Central Taurus, Turkey), Muhammed Zeynel Öztürk
Turkish Journal of Earth Sciences
Uplift history is an important factor in the structural patterns and karstification of the Taşeli Plateau. The morphological development of the study area consists of five stages according to its sedimentation, rotation, uplift, and climatic properties. (1) Shallow carbonates accumulated during the Early Miocene. (2) An emersion and drainage network developed as a result of the compressional neotectonic regime in the Late Miocene. (3) Dense joint systems were formed due to the ~40° clockwise rotation of the eastern limb of the Isparta Angle. (4) The climate of the study area changed as a result of rapid uplift from Late Pliocene …
The Ypresian To Lutetian Marine Record In Nw Turkey: A Revised Biostratigraphy Andchronostratigraphy And Implications For Eocene Paleogeography, Ercan Özcan, Zahi̇de Özcan, Aral I. Okay, Kenan Akbayram, Aynur Hakyemez
The Ypresian To Lutetian Marine Record In Nw Turkey: A Revised Biostratigraphy Andchronostratigraphy And Implications For Eocene Paleogeography, Ercan Özcan, Zahi̇de Özcan, Aral I. Okay, Kenan Akbayram, Aynur Hakyemez
Turkish Journal of Earth Sciences
The Eocene sedimentary units in the Kocaeli and Armutlu peninsulas and İznik-Geyve region (northwest Turkey) consist of marine siliciclastic and carbonate deposits, locally intercalated with volcaniclastic rocks and tuffs (Middle Eocene Magmatic Rocks-MEMR). The record of larger benthic fauna (LBF) and pelagic microfossils, such as planktonic foraminifera and calcareous nannoplankton, combined with lithological description, indicate a wide spectrum of depositional environments ranging from shallowto deep-marine. These deposits contain in situ and/or allochthonous assemblages of orthophragminids, nummulitids, subordinate rotaliids, and sparse alveolinids. The in situ assemblages (mainly orthophragminids) point to several episodes of shallow marine depositional conditions during a) early Ypresian …
Optimal Design Of A Flux Reversal Permanent Magnet Machine As A Wind Turbinegenerator, Majid Ghasemian, Farzad Tahami, Zahra Nasiri-Gheidari
Optimal Design Of A Flux Reversal Permanent Magnet Machine As A Wind Turbinegenerator, Majid Ghasemian, Farzad Tahami, Zahra Nasiri-Gheidari
Turkish Journal of Electrical Engineering and Computer Sciences
Flux reversal permanent magnet generators are well suited for use as wind turbine generators owing to their high torque generation ability and magnetic gear. However, they suffer from poor voltage regulation due to their high winding inductance. In this paper, a design optimization method is proposed for flux reversal generators in wind turbine applications. The proposed method includes a new multiobjective function. Cost, volume of the generator, and mass of the permanent magnet are considered in it independently and simultaneously. Besides the new objective function, the main superiority of this paper compared with published papers is considering winding inductance in …
Effect Of Mg Doping On Morphology, Photocatalytic Activity And Related Biological Properties Of Zn$_{\Mathbf{1-X}}$ Mg$_{X}$ O Nanoparticles, Bestenur Yalçin, Doğan Akcan, İbrahi̇m Ertuğrul Yalçin, Mehmet Can Alphan, Kenan Şentürk, İbrahi̇m İlker Özyi̇ği̇t, Lütfi̇ Arda
Effect Of Mg Doping On Morphology, Photocatalytic Activity And Related Biological Properties Of Zn$_{\Mathbf{1-X}}$ Mg$_{X}$ O Nanoparticles, Bestenur Yalçin, Doğan Akcan, İbrahi̇m Ertuğrul Yalçin, Mehmet Can Alphan, Kenan Şentürk, İbrahi̇m İlker Özyi̇ği̇t, Lütfi̇ Arda
Turkish Journal of Chemistry
The objective of this study is to synthesize ZnO and Mg doped ZnO (Zn$_{1-x}$Mg$_{x}$O) nanoparticles via the sol-gel method, and characterize their structures and to investigate their biological properties such as antibacterial activity and hemolytic potential.Nanoparticles (NPs) were synthesized by the sol-gel method using zinc acetate dihydrate (Zn(CH$_{3}$COO)$_{2}$.2H$_{2}$O) and magnesium acetate tetrahydrate (Mg(CH$_{3}$COO)$_{2}$.4H$_{2}$O) as precursors. Methanol and monoethanolamine were used as solvent and sol stabilizer, respectively. Structural and morphological characterizations of Zn$_{1-x}$Mg$_{x}$O nanoparticles were studied by using XRD and SEM-EDX, respectively. Photocatalytic activities of ZnO and selected Mg-doped ZnO (Zn$_{1-x}$Mg$_{x}$O) nanoparticles were investigated by degradation of methylene blue (MeB). Results …
Nonlocal Means Estimation Of Intrinsic Mode Functions For Speech Enhancement, Sagar Reddy Vumanthala, Bikshalu K
Nonlocal Means Estimation Of Intrinsic Mode Functions For Speech Enhancement, Sagar Reddy Vumanthala, Bikshalu K
Turkish Journal of Electrical Engineering and Computer Sciences
The main aim of this paper is to introduce a new approach to enhance speech signals by exploring the advantages of nonlocal means (NLM) estimation and empirical mode decomposition. NLM, a patch-based denoising method, is extensively used for two-dimensional signals like images. However, its use for one-dimensional signals has been attracting more attention recently. The NLM-based approach is quite useful for removing low-frequency noises based on nonlocal similarities present among samples of the signal. However, there is an issue of under averaging in the high-frequency regions. The temporal and spectral characteristics of the speech signal are changing markedly over time. …
Multiplicative-Additive Despeckling In Sar Images, Gülay Aksoy, Fati̇h Nar
Multiplicative-Additive Despeckling In Sar Images, Gülay Aksoy, Fati̇h Nar
Turkish Journal of Electrical Engineering and Computer Sciences
Visual and automatic analyses using synthetic aperture radar (SAR) images are challenging because of inherently formed speckle noise. Thus, reducing speckle noise in SAR images is an important research area for SAR image analysis. During speckle noise reduction, homogeneous regions should be smoothed while details such as edges and point scatterers need to be preserved. General speckle noise model contains gamma distributed multiplicative part which is dominant and Gaussian distributed additive part which is in low amount and mostly neglected in literature. In this study, a novel sparsity-driven speckle reduction method is proposed that takes both multiplicative noise model and …
Detection Of Bga Solder Defects From X-Ray Images Using Deep Neural Network, Ceren Türer Akdeni̇z, Zümray Ölmez, Tamer Ölmez
Detection Of Bga Solder Defects From X-Ray Images Using Deep Neural Network, Ceren Türer Akdeni̇z, Zümray Ölmez, Tamer Ölmez
Turkish Journal of Electrical Engineering and Computer Sciences
In the literature it is observed that complex image processing operations are used in the classification of Ball Grid Array (BGA) X-ray images, however high classification results were not achieved. In recent years, it has been shown that deep learning methods are very successful especially in classification problems. In this study, a new deep neural network (DNN) model is proposed to classify the BGA X-ray images. The proposed DNN model contains feature extractor layers and a minimum distance classifier. Since the proposed network consists of less number of layers (4 convolution layers and 1 fully connected layer), determination of the …
Connectivity Considerations For Mission Planning Of A Search And Rescue Drone Team, Evşen Yanmaz Adam
Connectivity Considerations For Mission Planning Of A Search And Rescue Drone Team, Evşen Yanmaz Adam
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, we analyze the mission success performance and mission times of centralized, distributed, and hybrid path-planning methods for a drone team whose mission is to find a target and inform the ground control. We propose two methods that integrate connectivity into the search mission path decisions. We observe that even though the coverage path-planning leads to lower search times, when target connectivity is also required, schemes that incorporate end--end connectivity into path planning result in at least 50 % better mission times for small communication ranges and lower number of drones. Our results also indicate that methods to …
Fuzzy Genetic Based Dynamic Spectrum Allocation (Fgdsa) Approach For Cognitive Radio Sensor Networks, Ganesan Rajesh, Xavier Mercilin Raajini, Kulandairaj Martin Sagayam, Bharat Bhushan, Utku Kose
Fuzzy Genetic Based Dynamic Spectrum Allocation (Fgdsa) Approach For Cognitive Radio Sensor Networks, Ganesan Rajesh, Xavier Mercilin Raajini, Kulandairaj Martin Sagayam, Bharat Bhushan, Utku Kose
Turkish Journal of Electrical Engineering and Computer Sciences
Cognitive Radio Sensor Network (CRSN) is known as a distributed network of wireless cognitive radio sensor nodes. Such system senses an event signal and ensures collaborative dynamic communication processes over the spectrum bands. Here, the concept of Dynamic Spectrum Access (DSA) denes the method of reaching progressively to the unused range of spectrum band. As among the essential CRSN user types, the Primary User (PU) has the license to access the spectrum band. On the other hand, the Secondary User (SU) tries to access the unused spectrum eciently, by not disturbing the PU. Considering that issue, this study introduces a …
Wavelength Sensitivity Of Indium Tin Oxide On Surface Plasmon Resonance Angles, Antonio Ruiz, Carlos Villa Angulo, Ivan Olaf Hernandez-Fuentes
Wavelength Sensitivity Of Indium Tin Oxide On Surface Plasmon Resonance Angles, Antonio Ruiz, Carlos Villa Angulo, Ivan Olaf Hernandez-Fuentes
Turkish Journal of Electrical Engineering and Computer Sciences
Surface plasmon resonance (SPR) is a charge-density oscillation that occurs when a beam of p-polarized monochromatic light impinges with a greater angle than the critical angle in a dielectric-metal interface. Because of the high losses related to metals, the generated surface plasmon waves propagate with high attenuation in the visible and near-infrared spectral regions in most of the dielectric-metal interfaces. An alternative to reduce such losses is to use a transparent indium tin oxide (ITO) film. In this paper, we compared theoretical calculations and experimental measurements of the SPR angle $\theta_{SPR}$ on the interfaces of a borosilicate prism (Bp) and …
Mlcocoa: A Machine Learning-Based Congestion Control For Coap, Alper Kami̇l Demi̇r, Fati̇h Abut
Mlcocoa: A Machine Learning-Based Congestion Control For Coap, Alper Kami̇l Demi̇r, Fati̇h Abut
Turkish Journal of Electrical Engineering and Computer Sciences
Internet of Things (IoT) is a technological invention that has the potential to impact on how we live and how we work by connecting any device to the Internet. Consequently, a vast amount of novel applications will enhance our lives. Internet Engineering Task Force (IETF) standardized the Constrained Application Protocol (CoAP) to accommodate the application layer and network congestion needs of such IoT networks. CoAP is designed to be very simple where it employs a genuine congestion control (CC) mechanism, named as default CoAP CC leveraging basic binary exponential backoff. Yet efficient, default CoAP CC does not always utilize the …
Optimization Of Real-Time Wireless Sensor Based Big Data With Deep Autoencoder Network: A Tourism Sector Application With Distributed Computing, Beki̇r Aksoy, Utku Kose
Optimization Of Real-Time Wireless Sensor Based Big Data With Deep Autoencoder Network: A Tourism Sector Application With Distributed Computing, Beki̇r Aksoy, Utku Kose
Turkish Journal of Electrical Engineering and Computer Sciences
Internet usage has increased rapidly with the development of information communication technologies. The increase in internet usage led to the growth of data volumes on the internet and the emergence of the big data concept. Therefore, it has become even more important to analyze the data and make it meaningful. In this study, 690 million queries and approximately 5.9 quadrillion data collected daily from different servers were recorded on the Redis servers by using real-time big data analysis method and load balance structure for a company operating in the tourism sector. Here, wireless networks were used as a triggering factor …
Hyracoidea From The Middle Miocene Hominoid Locality Of Paşalar (Nw Turkey), Martin Pickford, Serdar Mayda, Berna Alpagut, Fatma Arzu Demi̇rel, Ayşegül Şarbak, Tümel Tanju Kaya
Hyracoidea From The Middle Miocene Hominoid Locality Of Paşalar (Nw Turkey), Martin Pickford, Serdar Mayda, Berna Alpagut, Fatma Arzu Demi̇rel, Ayşegül Şarbak, Tümel Tanju Kaya
Turkish Journal of Earth Sciences
Previously available samples of Hyracoidea from Paşalar (MN 6, Middle Miocene), Turkey, have indicated the presence of Pliohyracidae at the site, but the material was too scanty for confident identification. The single upper molar, an upper molar ectoloph fragment and an ascending ramal fragment were too uninformative for determining the taxonomic identity of the fossils, although several names have been proposed in the literature. Additional fossils collected from Paşalar include upper and lower premolars, which help to tie down the affinities of this hyracoid. They are attributed to the genus Prohyrax, but were not named specifically, even though they are …
When Did The Drainage System Of The Kızılırmak River Form In Cappadocia (Anatolia,Turkey)? A Revised Geological And Geomorphological Stratigraphy, Uğur Doğan, Çeti̇n Şenkul
When Did The Drainage System Of The Kızılırmak River Form In Cappadocia (Anatolia,Turkey)? A Revised Geological And Geomorphological Stratigraphy, Uğur Doğan, Çeti̇n Şenkul
Turkish Journal of Earth Sciences
The Kızılırmak is the longest river in Turkey, extending from the western part of eastern Anatolia to the Black Sea, and crossing the orogenic Central Anatolian Plateau (CAP) and Black Sea Mountains. This study focuses on the formation period of the drainage system of the Kızılırmak River in the Cappadocia region, which is situated in the middle of the CAP. The Upper Pliocene-Quaternary geological and geomorphological stratigraphy of the Cappadocia region was revised with new findings and those of previous studies. In this study, the oldest terrace (Sünnetli Tepe Terrace, T0) of the Kızılırmak River was identified 214 m above …
Source Rock Potential And Depositional Environment Of The Lower Oligocene İhsaniyeformation In Nw Turkey (Thrace, Karaburun), Emilia Tulan, Reinhard F. Sachsenhofer, Gabor Tari, Rachel Flecker, Vanessa Fairbank, Magdalena Pupp, Ryan B. Ickert
Source Rock Potential And Depositional Environment Of The Lower Oligocene İhsaniyeformation In Nw Turkey (Thrace, Karaburun), Emilia Tulan, Reinhard F. Sachsenhofer, Gabor Tari, Rachel Flecker, Vanessa Fairbank, Magdalena Pupp, Ryan B. Ickert
Turkish Journal of Earth Sciences
The Lower Oligocene succession of the İhsaniye Formation, exposed at Karaburun on the Turkish (Thrace) coast of the Black Sea, provides insights into potential hydrocarbon source rock extent in the southwestern part of the Black Sea Basin. Presently, no detailed study of the İhsaniye Formation exists with regards to organic matter content and type. We analyzed 78 fine-grained samples from a c. 70-m-thick section near Karaburun. Relatively high total organic carbon (TOC) contents (average 1.45 wt.%) are present in the lower part of the İhsaniye Formation; the hydrogen index values reach a maximum of 252 mg HC/g TOC, indicating the …
The Stratigraphy Of The Oligocene-Lower Miocene Deposits Of Southern Ukraine, Yuliia V. Vernyhorova, Tamara S. Ryabokon
The Stratigraphy Of The Oligocene-Lower Miocene Deposits Of Southern Ukraine, Yuliia V. Vernyhorova, Tamara S. Ryabokon
Turkish Journal of Earth Sciences
Lithostratigraphic units (formation, strata, and beds) and regional stages of the Oligocene-lower Miocene succession of southern Ukraine are described based on the results of comprehensive lithological and paleontological data analysis. The historical perspective on the stratigraphical investigations of the Maikop Group in the Crimean and Kerch Peninsulas and their equivalents in the broader Peri-Black Sea Region were also integrated in this overview. Moreover, a correlation was established between the locally defined regional stages and specific stratigraphic horizons of southern Ukraine, the global Oligocene and Miocene stages (defined by the International Stratigraphic Chart), and the stages of the Eastern Paratethys. The …
The Generalized Inverses Of The Products Of Two Elements In A Ring, Kai Yan, Qingping Zeng
The Generalized Inverses Of The Products Of Two Elements In A Ring, Kai Yan, Qingping Zeng
Turkish Journal of Mathematics
In this paper, new extensions of Jacobson's lemma and Cline's formula for Drazin inverses, generalized Drazin inverses, and ($m,n$)-pseudo-inverses are given. As applications, we provide a formula for the powers of the products of two elements and establish connections between two B-Fredholm elements through the canonical map.
4-Generated Pseudo Symmetric Monomial Curves With Not Cohen-Macaulay Tangent Cones, Ni̇l Şahi̇n
4-Generated Pseudo Symmetric Monomial Curves With Not Cohen-Macaulay Tangent Cones, Ni̇l Şahi̇n
Turkish Journal of Mathematics
In this article, standard bases of some toric ideals associated to 4-generated pseudo symmetric semigroups with not Cohen-Macaulay tangent cones at the origin are computed. As the tangent cones are not Cohen-Macaulay, nondecreasingness of the Hilbert function of the local ring was not guaranteed. Therefore, using these standard bases, Hilbert functions are explicitly computed as a step towards the characterization of Hilbert function. In addition, when the smallest integer satisfying $k(\alpha_2+1)
Network Dynamics Reconstruction From Data, Deni̇z Eroğlu
Network Dynamics Reconstruction From Data, Deni̇z Eroğlu
Turkish Journal of Physics
We consider the problem of recovering the model of a complex network of interacting dynamical units from time series of observations. We focus on typical networks which exhibit heterogeneous degrees, i.e. where the number of connections varies widely across the network, and the coupling strength for a single interaction is small. In these networks, the behavior of each unit varies according to their connectivity. Under these mild assumptions, our method provides an effective network reconstruction of the network dynamics. The method is robust to a certain size of noise and only requires relatively short time series on the state variable …
Transfer Matrix In Scattering Theory: A Survey Of Basic Properties And Recent Developments, Ali̇ Mostafazadeh
Transfer Matrix In Scattering Theory: A Survey Of Basic Properties And Recent Developments, Ali̇ Mostafazadeh
Turkish Journal of Physics
We give a pedagogical introduction to time-independent scattering theory in one dimension focusing on the basic properties and recent applications of transfer matrices. In particular, we begin surveying some basic notions of potential scattering such as transfer matrix and its analyticity, multidelta-function and locally periodic potentials, Jost solutions, spectral singularities and their time-reversal, and unidirectional reflectionlessness and invisibility. We then offer a simple derivation of the Lippmann-Schwinger equation and the Born series, and discuss the Born approximation. Next, we outline a recently developed dynamical formulation of time-independent scattering theory in one dimension. This formulation relates the transfer matrix and therefore …
Quantum Gravity Correction To The Thermodynamic Quantities Of The Charged Drgt Black Hole, Gani̇m Geçi̇m
Quantum Gravity Correction To The Thermodynamic Quantities Of The Charged Drgt Black Hole, Gani̇m Geçi̇m
Turkish Journal of Physics
In this study, in the framework of the Hamilton approach, the quantum gravity effect on Hawking temperature, on the specific heat capacity, and on the stability conditions of the charged de Rham, Gabadadze, and Tolley (dRGT) black hole are investigated by using the tunneling processes of both charged massive scalar and Dirac particles. It is shown that quantum corrected Hawking temperature depends not only on the black hole properties but also on the properties of the tunnelling particles. It is also observed that quantum corrected Hawking temperature is lower than that of the standard Hawking temperature. Also, the specific heat …
Analysis Of Chaotic And Regular Behavior Of Matinyan-Yang-Mills-Higgshamiltonian System, Engi̇n Kandiran, Avadi̇s Si̇mon Hacinliyan
Analysis Of Chaotic And Regular Behavior Of Matinyan-Yang-Mills-Higgshamiltonian System, Engi̇n Kandiran, Avadi̇s Si̇mon Hacinliyan
Turkish Journal of Physics
In this study we analyze the Matinyan-Yang-Mills-Higgs (MYMH) system, based on semiclassical solutions to a Yang-Mills model, using Poincaré surfaces of section and the method of averaging. To investigate the possible chaotic behavior for the system, we simulate the trajectories of the system and calculate the Lyapunov exponents. We observe that the system displays weakly chaotic behavior. We search for the existence of approximately conserved quantities for the system using the method of averaging. In this way, we show the existence of four fixed points where period orbits exist.
Hypergeometric Distribution Of The Number Of Draws From An Urn With Two Types Of Items Before One Of The Counts Reaches A Threshold, J. L. Gonzalez-Santander
Hypergeometric Distribution Of The Number Of Draws From An Urn With Two Types Of Items Before One Of The Counts Reaches A Threshold, J. L. Gonzalez-Santander
Turkish Journal of Mathematics
We consider an urn with $R$ elements of one type and $B$ elements of other type. We calculate the probability distribution $P_{n_{R},n_{B}}^{R,B}\left( s\right) $ wherein the random variable $s$ is the number of draws from the urn until we reach $n_{R}$ elements of type $R$ or $n_{B}$ elements of type $B$. We calculate the mean value $\left\langle s\right\rangle $ and the standard deviation $\sigma $ of $P_{n_{R},n_{B}}^{R,B}\left( s\right) $ in terms of hypergeometric functions. For $n_{R}=n_{B}$ and $B=R$ , we reduce $\left\langle s\right\rangle $ and $\sigma $ in terms of elementary functions. Also, the normalization condition leads to a new …
Stable Carbon And Oxygen Isotopes As Environmental Indicators Of The Late Pleistocene Inel Arenoso, Sonora, Northwest Mexico, Victor Adrian Perez Crespo, Tamara Cruz Y Cruz, Alejandro Terrazas Mata, Pedro Morales Puente, Martha Benavente, Edith Cienfuegos-Alvrado, Francisco J. Otero
Stable Carbon And Oxygen Isotopes As Environmental Indicators Of The Late Pleistocene Inel Arenoso, Sonora, Northwest Mexico, Victor Adrian Perez Crespo, Tamara Cruz Y Cruz, Alejandro Terrazas Mata, Pedro Morales Puente, Martha Benavente, Edith Cienfuegos-Alvrado, Francisco J. Otero
Turkish Journal of Earth Sciences
The paleoenvironment conditions that existed in the Late Pleistocene at the archaeological-paleontological site of El Arenoso, Sonora, NW Mexico, were inferred using the carbon and oxygen stable isotopes from one bison, one mammoth, and thirteen horses as well as the pedological characteristics and the carbon isotopes of calcium carbonates from paleosoil. The values δ13C of the bison (-1.4‰), the horses (-2.8‰), and the mammoth (-4.3‰) show that these animals fed mainly on C4 plants and carbon isotopic values from profile horizons of locality 4Bgk (-3.4‰), 3Ck (-3.4‰), and 2Bgk2 (-5.7‰) indicated the presence of C3/C4 vegetation mixed in El Arenoso. …
Sedimentology And Hydrocarbon Potential Of The Late Ordovician Glacial Deposits On Thearabian Platform And Southeastern Turkey, Muhi̇tti̇n Şenalp, Sema Teti̇ker
Sedimentology And Hydrocarbon Potential Of The Late Ordovician Glacial Deposits On Thearabian Platform And Southeastern Turkey, Muhi̇tti̇n Şenalp, Sema Teti̇ker
Turkish Journal of Earth Sciences
The Late Ordovician glacial deposits are widespread and constitute a significant portion of the Early Paleozoic stratigraphic sequence of the cover rocks of the Arabian and African platforms. The glaciation lasted less than one million years between the Late Ashgillian (445 Ma) and Early Silurian (444 Ma) but it had a strong impact on the whole area. It has been proven that the glaciofluvial sandstones form important oil and gas reservoirs in Saudi Arabia and in North African and other Middle Eastern countries, including SE Turkey, but their heterogeneity and internal lithofacies characteristics have not been fully understood yet. In …
Joint Modeling Of Rayleigh Wave Dispersion And H/V Spectral Ratio Using Pareto-Basedmultiobjective Particle Swarm Optimization, Ersi̇n Büyük, Ekrem Zor, Abdullah Karaman
Joint Modeling Of Rayleigh Wave Dispersion And H/V Spectral Ratio Using Pareto-Basedmultiobjective Particle Swarm Optimization, Ersi̇n Büyük, Ekrem Zor, Abdullah Karaman
Turkish Journal of Earth Sciences
Estimating the shear wave velocity and thickness of geologic units in a sedimentary structure is important for quantifying the local site effect caused by an earthquake. Inversion of the Rayleigh wave dispersion alone is sensitive to the absolute average shear wave velocity, while the H/V spectral ratio is sensitive to velocity contrasts. The solution of these models in a joint system using conventional inversion techniques suffers from difficulties while evaluating partial derivatives, dependencies to the initial model that is sometimes difficult to estimate, and trapping at a local minimum. Herein, a joint model using the Pareto optimality technique with multiobjective …
A Spreadsheet-Based Decision Support System For Examination Timetabling, Mehmet Güray Güler, Ebru Geçi̇ci̇
A Spreadsheet-Based Decision Support System For Examination Timetabling, Mehmet Güray Güler, Ebru Geçi̇ci̇
Turkish Journal of Electrical Engineering and Computer Sciences
Examination timetabling is an inevitable problem of educational institutions. Each institution has its own particular limitations; however, the main structure is the same: assigning exams to time slots and classrooms. Several institutions solve the problem manually, but it becomes more difficult every year with increasing numbers of students and limited resources. There are many studies in the literature addressing the examination timetabling problem (ETP) and providing high quality solutions within reasonable amounts of time. Nevertheless, almost none of them can be used in practice since they are not converted into a decision support system (DSS). Commercial DSSs, on the other …