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Now showing 1 - 10 of 20
  • Article
    Citation - WoS: 7
    Citation - Scopus: 10
    A FUZZY CONCEPTUAL MODEL FOR MULTIMEDIA DATA WITH A TEXT-BASED AUTOMATIC ANNOTATION SCHEME
    (World Scientific Publ Co Pte Ltd, 2009) Kucuk, Dilek; Burcuozgur, N.; Yazici, Adnan; Koyuncu, Murat
    The size of multimedia data is increasing fast due to the abundance of multimedia applications. Modeling the semantics of the data effectively is crucial for proper management of it. In this paper, we present a fuzzy conceptual data model for multimedia data which is also generic in the sense that it can be adapted to all multimedia domains. The model takes an object-oriented approach and it handles fuzziness at different representation levels where fuzziness is inherent in multimedia applications and should be properly modeled. The proposed model also has the nice feature of representing the structural hierarchy of multimedia data as well as the spatial and temporal relations of the data. The model is applied to the news video domain and implemented as a fuzzy multimedia database system where it turns out to be effective in representing the domain and thereby provides an evidence for the general applicability of the model. The model is accompanied by an automatic multimedia annotation scheme which makes use of information extraction techniques on the corresponding multimedia texts.
  • Article
    Citation - WoS: 20
    Citation - Scopus: 24
    A Bibliometric/Geographic Assessment of 40 Years of Software Engineering Research (1969-2009)
    (World Scientific Publ Co Pte Ltd, 2013) Garousi, Vahid; Ruhe, Guenther
    Bibliometric rankings are quite common in the field of software engineering. For example, there are a series of ranking repeated every year which identify the top researchers and institutions at the international level in the field. There are also other studies to determine the most cited articles in software engineering journals, the most popular research topics in this area, or identify the top researchers and institutions in regional levels. However, there exists no existing bibliometric quantitative analysis of publications in the area of software engineering (SE), including relative and absolute growth in the number of all SE publications as well as an analysis among countries. This is the main goal and motivation of this article. Besides, this study intends to provide an overall quantitative trend of the software engineering papers, and compare that trend to research output in other areas of science. The bibliometric study reported in this paper is motivated by the fact that understanding the amount of geographical research contributions to the field of software engineering can help identify different countries' level of commitment to support research activities in this area over years. We analyze how the contribution levels of top-ranked countries have changed over the years and how SE compares to other disciplines of engineering and science. Among the most interesting findings of this study are: (1) Over 40 years, in total about 60% of the SE literature has been contributed by only 7% of all countries, (2) the SE research output of different countries does not necessarily correlate with their GDPs, (3) the share of contributions to the SE discipline by the American researchers has declined from 71.43% ( in 1980) to 14.90% ( in 2008), and ( 4) China is the country with the biggest share growth in the number of publications ( from 0.82% of the entire SE publications in 1991 to 13.82% in 2009).
  • Article
    Citation - WoS: 20
    Citation - Scopus: 28
    Bug Severity Assessment in Cross Project Context and Identifying Training Candidates
    (World Scientific Publ Co Pte Ltd, 2017) Singh, V. B.; Misra, Sanjay; Sharma, Meera
    The automatic bug severity prediction will be useful in prioritising the development efforts, allocating resources and bug fixer. It needs historical data on which classifiers can be trained. In the absence of such historical data cross project prediction provides a good solution. In this paper, our objective is to automate the bug severity prediction by using a bug metric summary and to identify best training candidates in cross project context. The text mining technique has been used to extract the summary terms and trained the classifiers using these terms. About 63 training candidates have been designed by combining seven datasets of Eclipse projects to develop the severity prediction models. To deal with the imbalance bug data problem, we employed two approaches of ensemble by using two operators available in RapidMiner: Vote and Bagging. Results show that k-Nearest Neighbour (k-NN) performance is better than the Support Vector Machine (SVM) performance. Naive Bayes f-measure performance is poor, i.e. below 34.25%. In case of k-NN, developing training candidates by combining more than one training datasets helps in improving the performances (f-measure and accuracy). The two ensemble approaches have improved the f-measure performance up to 5% and 10% respectively for the severity levels having less number of bug reports in comparison of major severity level. We have further motivated the paper with a cross project bug severity prediction between Eclipse and Mozilla products. Results show that Mozilla products can be used to build reliable prediction models for Eclipse products and vice versa in case of SVM and k-NN classifiers.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 5
    Electrical Characterization of Bi1.50-x< Varactors
    (World Scientific Publ Co Pte Ltd, 2014) Qasrawi, A. F.; Abu Muis, Khalil O.; Abu Al Rob, Osama H.; Mergen, A.
    The electrical properties of yttrium doped bismuth zinc niobium oxide (BZN) pyrochlore ceramics are explored by means of temperature dependent electrical conductivity dielectric constant and capacitance spectra in the frequency range of 0-3 GHz. It is observed that the doped BZN exhibit a conductivity type conversion from intrinsic to extrinsic as the doping content increased from 0.04 to 0.06. The thermal energy bandgap of the intrinsic type is 3.45 eV. The pyrochlore is observed to exhibit a dielectric breakdown at 395 K. In addition, a negative capacitance (NC) spectrum with main resonance peak position of 23.2 MHz is detected. The NC effect is ascribed to the increased polarization and the availability of more free carriers in the device. When the NC signal amplitude is attenuated in the range of 0-20 dBm at 50 MHz and 150 MHz, wide tunability is monitored. Such characteristics of the Y-doped BZN are attractive for using them to cancel the positive parasitic capacitance of electronic circuits. The canceling of parasitic capacitance improves the high frequency performance of filter inductors and reduces the common mode noise of the resonance signal.
  • Article
    Citation - WoS: 2
    Infinite Cogalois Theory, Clifford Extensions, and Hopf Algebras
    (World Scientific Publ Co Pte Ltd, 2003) Albu, Toma
    The aim of this paper is to present some connections of infinite Cogalois Theory with Clifford extensions and Hopf algebras.
  • Article
    Citation - WoS: 2
    On Radical Field Extensions of Prime Exponent
    (World Scientific Publ Co Pte Ltd, 2002) Albu, Toma
    In this paper we investigate finite separable radical extensions K subset of L of prime exponent via the concept of G-Cogalois extension. As particular cases we retrieve some older results in I. Kaplansky [9] and A. Baker and H. M. Stark [7] concerning such radical extensions.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Outer Automorphisms of Mapping Class Groups of Nonorientable Surfaces
    (World Scientific Publ Co Pte Ltd, 2010) Atalan, Ferihe
    Let N(g) be the connected closed nonorientable surface of genus g >= 5 and Mod(Ng) denote the mapping class group of N(g). We prove that the outer automorphism group of Mod(N(g)) is cyclic.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 1
    Investigation of Conductivity Characteristics of Zn-In Thin Films
    (World Scientific Publ Co Pte Ltd, 2020) Gullu, H. H.; Parlak, M.
    Zn-In-Se thin films were fabricated on the ultrasonically cleaned glass substrates masked with clover-shaped geometry by thermal evaporation of its elemental sources. Temperature-dependent conductivity characteristics of the films were investigated under dark and illuminated conditions. The semiconductor type of the films was found as n-type by thermal probe test. According to the van der Pauw technique, the dark electrical conductivity analyses showed that the variations of conductivity of unannealed and annealed at 300 degrees C samples are in exponential dependence of temperature. These conductivity profiles were found to be dominated by the thermionic emission at high temperature region whereas their behaviors at low temperatures were modeled by hopping theory. On the contrary, as a result of the further annealing temperatures, the surface of the samples showed semi-metallic characteristics with deviating from expected Arrhenius behavior. In addition, the temperature-dependent photoconductivity of the films was analyzed under different illumination intensities and the results were explained by the supra-linear characteristic based on the two-center recombination model.
  • Article
    Citation - WoS: 6
    Some Examples in Cogalois Theory With Applications To Elementary Fleld Arithmetic
    (World Scientific Publ Co Pte Ltd, 2002) Albu, Toma
    The aim of this paper is to provide some examples in Cogalois Theory showing that the property of a field extension to be radical (resp. Kneser, or Cogalois) is not transitive and is not inherited by subextensions. Our examples refer especially to extensions of type Q(root r + root d)/Q. We also effectively calculate the Cogalois groups of these extensions. A series of applications to elementary arithmetic of fields, like: for what n, d is an element of N* is root n + root d a sum of radicals of positive rational numbers when is (n0)root a(0) a finite sum of monomials of form c center dot(n1)root a(1)(j1) ... (nr)root a(r)(jr), where r, j(1), ... , j(r) is an element of N*, c is an element of Q*, and a(0), ... , a(r) is an element of Q(+)(*) are also presented.
  • Article
    Citation - WoS: 10
    Citation - Scopus: 7
    Fabrication and Characterization of Tio2 Thin Film for Device Applications
    (World Scientific Publ Co Pte Ltd, 2019) Hosseini, A.; Gullu, H. H.; Coskun, E.; Parlak, M.; Ercelebi, C.
    Titanium oxide (TiO2) film was deposited by rectification factor (RF) magnetron sputtering technique on glass substrates and p-Si (111) wafers to fabricate n-TiO2/p-Si heterojunction devices for the investigation of material and device properties, respectively. The structural, surface morphology, optical and electrical properties of TiO(2 )film were characterized by means of scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), UV-visual (UV-Vis) spectral and dark current-voltage (I-V) measurement analyses. The deposited film layer was found to be homogeneous structure with crack-free surface. The bandgap value of TiO2 film was determined as 3.6 eV and transmission was around 65-85% in the spectral range of 320-1100 nm. The conductivity type of the deposited film was determined as n-type by hot probe method. These values make TiO2 film a suitable candidate as the n-type window layer in possible diode applications. TiO2 film was also deposited on p-Si (111) wafer to obtain Al/n-TiO2/p-Si/Al heterojunction device structure. The dark I-V characteristic was studied to determine the possible conduction mechanisms and diode parameters.