Authors:Doğuş Özuyar Abstract: Inthis study, high-precision photometric data of V960 Tau are presented in orderto reveal the pulsation characteristics of the star. The data are taken fromthe HI-1A instrument of the STEREOsatellite between 2007 and 2011. The results of the photometric analysis arecompared with findings derived from spectroscopic line measurements (equivalentwidth and line intensity) to have a better understanding of the relationbetween light curve variabilities and circumstellar disk structure. As a resultof the photometric and spectroscopic analyses, it is seen that frequencydistribution and amplitude intensities of the star are the same with those of atypical Be star. The star has at least 14 independent frequencies and most ofthese are accumulated around the peaks at 1.01 and 1.95 c/d. With thisconfiguration, the star exhibits 2:1 frequency distribution. Even though thefrequency distribution is quite similar to a Slowly Pulsating B type star, V960Tau may be considered as a β Cepheitype variable based on its temperature and luminosity values. Additionally, theequivalent width and line intensity values of the emission lines appear to be correlatedwith the light curve variations. This may be an indication that the photometricvariations may be related to the environmental disc structure. PubDate: Wed, 01 Aug 2018 00:00:00 +030
Authors:Ozge Mercanoglu Sincan; Hacer Yalim Keles, Suleyman Tosun Abstract: In this paper, wepresent a novel method to detect and classify moving objects from surveillancevideos that are obtained from a moving camera. In our method, we first estimatethe camera motion by interpreting the movement of interest points in the scene.Then, we eliminate the camera motion and find candidate regions that belong tothe moving objects. Considering these regions as priors, we apply an efficientsegmentation algorithm to obtain accurate object boundaries for the movingobjects. Finally, we classify the detected objects as people, vehicle, orothers using some morphological features and the velocity vectors of movingobjects. The evaluation of the proposed approach on our surveillance datasetshows that our approach is very effective for determining the classes of movingobjects in a moving camera setting. PubDate: Wed, 01 Aug 2018 00:00:00 +030
Authors:Esmat Bekir Abstract: Observation of binary star orbits reveals only the apparent orbit of these two celestialbodies which differs from the true orbit. Due to the inclination of the plane of the true orbit onecan only observe its projection onto the plane of sky. Computing the true orbit from the apparentorbit is based on constructing the auxiliary ellipse. This process is well known (Kallrath 2009) butrequires arduous numerical computations. In this paper a simpler approach to obtain the auxiliaryellipse is presented and its derivation is provided. This approach finds out that the coefficients ofthe auxiliary ellipse are very simple functions of those of the apparent ellipse. PubDate: Wed, 01 Aug 2018 00:00:00 +030
Authors:Abdullah Bülbül; Salah Haj Ismail Abstract: Thepopulation of refugees in Turkey is significantly growing since 2014 and it hasalready exceeded three millions. This situation urges to study their conditionsand issues as well as their opinions. In this study, we propose a method toanalyze the dataset collected from social media accounts of refugees in Turkeyin a textual and visual manner. Firstly, we acquire social media activities ofrefugees, and then we make textual analysis for which the results are presentedusing word clouds. Finally, for the most significant words obtained from thetextual analysis, we perform a visual analysis to find out the mostrepresentative image or a group of images shared in social networks. Theassociation between textual and visual results enhances their perceptibilityand help decreasing the ambiguity of inferences over analysis results. Weexperimented with different scenarios and suggested several methods to enhancecomputational and qualitative results. PubDate: Wed, 01 Aug 2018 00:00:00 +030
Authors:Dogan Mansuroglu Abstract: Theiodine doped plasma-polymerized biphenyl thin film is investigated in thisstudy. Iodine atoms lead to increase the charge transfer complexes and changethe electronic equilibrium in the polymer structure due to their highelectronegativity. Therefore, the iodine doped films show significantimprovements in the electrical characteristics as compared to the undoped ones.The results of Raman spectroscopy verify the presence of the iodined groups inthe structure of deposited thin films. The number density of the iodined groupsincreases with increasing the radio frequency input power. The ID/IG ratiochanges in a range from 0.40 to 072 for the undoped thin films while itdecreases from 0.74 to 0.58 for the iodine doped thin films which can be due tothe rearrangement in the structure. Photoluminescence spectra show a broad redemission band at about 630 nm as well as unclear bands placed like smallshoulders at 580 nm and 731 nm. These bands become to seem clearly after theiodine doping process. The conjugation length of the polymer thin filmsincreases with iodine doping as well as increasing the power values. Alldepositions are produced using a capacitively coupled plasma system with 13.56MHz radio frequency source. During the doping process, the vaporized iodinematerial is directly exposed to the plasma discharge and mixed with thebiphenyl polymer material. All results are characterized in detail. PubDate: Wed, 01 Aug 2018 00:00:00 +030
Authors:Derya OZKAYA; Ilhan KOSALAY Abstract: Powergeneration systems with multiple input-multiple output have a wide operatingrange and may not be fully defined by a fixed model due to high-order nonlineardynamics. As the parameters of the conventional excitation and speed governorcontrollers are determined by the system model which is linearized around oneoperating point, the performances of the controllers at different operatingpoints can be reduced. Large disturbances encountered in the system can causethe controllers to operate outside the linear region. In addition, when theplant's operating structure changes with time or with changing environmentalconditions, it is necessary to readjust the controller parameters. Thisreadjustment is needed because the controller parameters that are set toprovide the best performance at one operating point may not provide the sameperformance when the operating points change. In order to avoid the degradationin controller performance, system identification can be performed so that thecontroller parameters will have an adaptive structure. At the same time, itwill be possible to make predictive maintenance, determine optimum operatingpoints, diagnose faults and estimate performance by means of the power plantmodel built on the basis of system identification. In order to meet theserequirements, system identification methods used in power generation systemshave been examined throughout this review study and the performances obtainedas a result of the changes made in the controllers have been compared. PubDate: Wed, 01 Aug 2018 00:00:00 +030
Authors:Oğuzhan Timur; Kasım Zor, Özgür Çelik, Ahmet Teke Abstract: Ascending energydemand and vanishing nonrenewable energy resources have increased the prominenceof energy efficiency nowadays. In order to accomplish an energy efficient future for the forthcominggenerations of humanity, traditional devices possessing low efficiency shouldbe altered with intelligent devices having high efficiency. Thanks to internetof things (IoT), conventional devices have been turned into intelligent deviceswhich can be remotely accessed, monitored and controlled by utilizingubiquitous sensor mechanisms. In this study, enhancement of a low-costintelligent device (iDev) is targeted to develop in order to compute and storeelectrical energy consumption into a database by an embedded card named asArduino which has the capability of measuring voltage, current, frequency andpower factor for improving energy efficiency in buildings. When a classicdevice is connected to the enhanced iDev, the device is converted to anintelligent device that is remotely controllable. As a consequence, if a wholebuilding is equipped with the proposed iDev, it is considered that a largeamount of electrical energy will be saved for a better and livable Earth. PubDate: Wed, 01 Aug 2018 00:00:00 +030
Authors:ZINAH ABBAS AL-MASHHADANI; ISA NAVRUZ Abstract: Therefractive index sensors based on tapered optical fiber are attractive for manyindustries due to sensing capability in a variety of application. In thispaper, we proposed a refractive index sensor based on multicore fiber (MCF)sandwiched between two standard single mode fibers (SMF). The sensor consistingof three sections, SMF- MCF-SMF is structurally simple and can be easilyproduced by joining these parts. The MFC contains seven cores and these coresare surrounded by a single cladding. The sensing region is obtained by taperingthe MCF section where the evanescent field is generated. The single modepropagating along the SMF is stimulated at the first joint and is coupled tothe cladding modes. These modes interfere with the core mode after passing thesecond joint. The transmission spectrum of the output light at the end of thethird section is sensitive to the refractive index (RI) of the environmentsurrounding the cladding. In this study, the RI sensitivity of the proposedsensor was analyzed numerically and the RI sensing characteristic wasinvestigated for different measurement ranges and different structuralconfigurations. The results show that the refractive index sensitivity isextremely high in the range of about 1.44 to 1.45 RIU. In addition, the developed sensor has manyadvantages such as compact construction, low cost, small size and easyfabrication. It also has the potential to perform high precision measurementsin fields such as biochemistry, health care and biological applications. PubDate: Wed, 01 Aug 2018 00:00:00 +030
Authors:YILMAZ AR Abstract: The accuracy ofpredictions is better if the combinations of the different approaches are used.Currently in collaborative filtering research, the linear blending of variousmethods is used. More accurate classifiers can be obtained by combining lessaccurate ones. This approach is called ensembles of classifiers. Differentcollaborative filtering methods uncover the different aspects of the dataset.Some of them are good at finding out local relationships; the others work forthe global characterization of the data. Ensembles of different collaborativefiltering algorithms can be created to provide more accurate recommendersystems. PubDate: Wed, 01 Aug 2018 00:00:00 +030
Authors:Şifa ÖZSARI; Harun UĞUZ, Tayfun ÇAY Abstract: It is called farming, which is made on land to produce useful and essential products for life. Agriculture has ever been the main source of human life. However, as the human population are growing day by day, the earth presence in the world remains the same, even decreasing. In Turkey, due to various reasons agricultural land is small, fragmented and scattered. This situation affects the agricultural productivity in negative direction. In order to increase productivity legal measures, which prevent further fragmentation of agricultural land, should be taken first and then the existing fragmented structure should be reassembled and regulated according to the principles of modern agricultural management, i.e. land consolidation (LC) must be done. LC process consists of various time consuming and complex stages. In this study, it has been emphasized that the interview stage of the land consolidation process, which is currently carried out manually, is carried out automatically. In order to solve problem genetic algorithm (GA) has been applied on the problem and the results obtained have been evaluated. PubDate: Wed, 01 Aug 2018 00:00:00 +030
Open Access journal
