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Article Citation - WoS: 6Citation - Scopus: 9Comparative Assessment of Electromagnetic Simulation Tools for Use in Microstrip Antenna Design: Experimental Demonstrations(Wiley, 2019) Bilgin, Gulsima; Yilmaz, Vadi Su; Kara, Ali; Aydin, ElifThis paper presents a better understanding of the use of finite integration techniques (FIT) and finite element method (FEM) in different types of microstrip antennas in order to determine which numerical method gives relatively more accurate results. Although the theoretical formulation based on Maxwell's equations of both FEM and FIT are approached from different aspects in the literature, there is still a lack of comparison of the same antenna type using different numerical methods employing FEM and FIT. Therefore, in this study, FEM and FIT were applied to two different types of microstrip antennas, and their simulation and experimental results was compared. For the first antenna demonstration, a multilayer structure was chosen to achieve one of the significant parameters. Then, a microstrip antenna with a compact structure was used in the second demonstration. Using these two antennas, the accuracy of FEM and FIT in different structures were compared and all simulated return loss and gain results were verified by the measured results. The experimental demonstrations show that FEM performs better for both types of microstrip antennas while FIT provides an adequate result for two-layer microstrip antennas.Article Citation - WoS: 2Citation - Scopus: 3Development of New Vehicle Safety Structures by Using Third Generation Steels(Sae int, 2022) Erzincanlioglu, Samet; Aydiner, Tamer; Aras, Firat; Celik, Hafize; Billur, Eren; Karabulut, Semih; Gumus, Iskender OnderResearch and development efforts in the automotive industry have been long focused on crashworthy, durable vehicles with the lowest mass possible as higher mass requires more energy and, thus, causes more CO2 emissions. One way of approaching these objectives is to reduce the total vehicle weight by using higher strength-to-weight ratio materials, such as Advanced High-Strength Steels (AHSS). Typically, as the steel gets stronger, its formability is reduced. The steel industry has been long developing (so-called) third-generation (Gen3) AHSS for the automotive industry. These grades offer higher formability compared to first-generation (Gent) and cost less compared to the second-generation (Gen2) AHSS. Transformation Induced Plasticity (TRIP)-aided Bainitic Ferrite (TBF) and Quenching and Partitioning (Q&P) steel families are considered to be the Gen3 AHSS. These grades can be cold-formed to more complex shapes, compared with the Geni Dual Phase (DP) and TRIP steels at equivalent strength levels. In this article, new single-piece A- and B-pillar reinforcements were designed using a Gen3 AHSS, TBF980. Spot-welding operations were eliminated due to part consolidation with the more formable steel. These parts will be the first structural automotive parts which were manufactured with cold-forming technology using TBF steels with a sstrength level close to 1 GPa or even more. Weight and cost reductions were realized by the new design while improving the crash performance.Article Citation - WoS: 2Perceptions of Turkish Nursing Students on Nursing Diagnoses(Marmara Univ, inst Health Sciences, 2022) Sonmez, Munevver; Kisacik, Oznur GurlekObjective: This study aimed to determine how Turkish nursing students' perceived nursing diagnosis. Methods: This descriptive and cross-sectional study was carried out with 655 nursing students in the Departments of Nursing in the Health Sciences Faculties of two universities, in the Aegean and western Black Sea Region, between 15 February and 5 April 2020. The Students Information Form and Perceptions of Nursing Diagnosis Scale were used for data collection. The independent samples t-test, one-way ANOVA test, and the Mann-Whitney U-test with Bonferroni-correction were used to determine the differences between the groups. Pearson correlation analysis was used to determine the effects of independent variables Results: The mean age of the nursing students was 21.12 +/- 1.39; 76.6% of them were female and 36.8% were in the second-year. 53.7% of the nursing students reported that they had difficulty in making nursing diagnoses. The overall Perceptions of Nursing Diagnosis Survey score of the nursing students was found to be 2.46 +/- 051. Statistically significant difference was found between Perceptions of Nursing Diagnosis Survey scores in terms of gender (p=0.012), the necessity of nursing diagnosis (p<0.001), and having sufficient knowledge about nursing diagnosis (p=0.019). Conclusions: The findings of this study have revealed that Turkish nursing students' perceptions of nursing diagnoses are positive. It is important that use effective teaching methods in teaching nursing diagnoses in fundamental nursing education, to give more importance to nursing diagnoses. It is recommended to plan qualitative studies to in-depth examine students' perceptions with randomized controlled studies involving innovative educational interventions in the future.Article Citation - WoS: 2The Visibility of Scholarly Knowledge: Awareness for Open Access in Hacettepe University(Turkish Librarians Assoc, 2010) Erturk, Korhan Levent; Kucuk, Mehmet EminThe scholars begin to place their works into the open repositories or open access journals as well as their personal web sites. In the international arena, the open repositories contain a total of 14,000 Turkey-based scholarly contents. The focus of this study is to determine the level of awareness for open access concept of scholars in Hacettepe University. An electronic questionnaire was conducted to scholars. The data were collected through questionnaire from full time academic staff member in Hacettepe University. It was found that 50% of scholars are aware of the open access concept and 92% of the scholars are willing to place their works into the institutional repository of their university. According to questionnaire study result, different types of works such as articles and assertions can be placed in the institutional open repositories in Turkey and their functionality can be increased in a short time.Article Citation - Scopus: 4Cost Efficient Design of Mechanically Stabilized Earth Walls Using Adaptive Dimensional Search Algorithm(Turkish Chamber of Civil Engineers, 2020) Kazemzadeh Azad,S.; Akiş,E.Mechanically stabilized earth walls are among the most commonly used soil-retaining structural systems in the construction industry. This study addresses the optimum design problem of mechanically stabilized earth walls using a recently developed metaheuristic optimization algorithm, namely adaptive dimensional search. For a cost efficient design, different types of steel reinforcement as well as reinforced backfill soil are treated as discrete design variables. The performance of the adaptive dimensional search algorithm is investigated through cost optimization instances of mechanically stabilized earth walls under realistic design criteria specified by standard design codes. The numerical results demonstrate the efficiency and robustness of the adaptive dimensional search algorithm in minimum cost design of mechanically stabilized earth walls and further highlight the usefulness of design optimization in engineering practice. © 2020 Turkish Chamber of Civil Engineers. All rights reserved.Article Citation - WoS: 1Citation - Scopus: 1Internet of Things (iot) and Artificial Neural Networks Towards Water Pollution Forecasting(Middle Pomeranian Sci Soc Env Prot, 2020) Ibrahim, Thaer; Mishra, Alok; Software EngineeringWater could be some-times a source of danger on people's lives and property. Although it is one of the most important elements of life on this planet. This article define the threat of water pollution in Tigris River in Iraq. by collecting a data that generated by sensors that installed in a water pollution sensing project in Baghdad city, also this article aimed to detect and analyze the behavior of water environment. It is an effort to predict the threat of pollution by using advanced scientific methods like the technology of Internet of Things (IoT) and Machine learning in order to avoid the threat and/or minimize the possible damages. This can be used as a proactive service provided by E-governments towards their own citizens.Article Citation - WoS: 1Citation - Scopus: 1On the Accuracy of an Emitter Localization Method Based on Multipath Exploitation in Realistic Scenarios(Taylor & Francis Ltd, 2022) Al Imran, M. A.; Ank, E.; Dalveren, Y.; Tabakcioglu, M. B.; Kara, A.; Arık, E.This study aims to evaluate the accuracy of a method proposed for passive localization of radar emitters around irregular terrains with a single receiver in Electronic Support Measures systems. Previously, the authors targeted only the theoretical development of the localization method. In fact, this could be a serious concern in practice since there is no evidence regarding its accuracy under the real data gathered from realistic scenarios. Therefore, an accurate ray-tracing algorithm is adapted to enable the implementation of the method in practice. Then, realistic scenarios are determined based on the geographic information system map generated to collect high-resolution digital terrain elevation data, as well as realistic localization problems for radar emitters. Next, simulations are performed to test the localization method. Thus, the performance of the method is verified for practical implementation in the electronic warfare context for the first time. Lastly, the performance bounds of the method are discussed.Article Citation - WoS: 7Citation - Scopus: 15Lossless Text Compression Technique Using Syllable Based Morphology(Zarka Private Univ, 2011) Akman, Ibrahim; Bayindir, Hakan; Ozleme, Serkan; Akin, Zehra; Misra, Sanjay; Computer EngineeringIn this paper, we present a new lossless text compression technique which utilizes syllable-based morphology of multi-syllabic languages. The proposed algorithm is designed to partition words into its syllables and then to produce their shorter bit representations for compression. The method has six main components namely source file, filtering unit, syllable unit, compression unit, dictionary file and target file. The number of bits in coding syllables depends on the number of entries in the dictionary file. The proposed algorithm is implemented and tested using 20 different texts of different lengths collected from different fields. The results indicated a compression of up to 43%.Article Citation - WoS: 2Citation - Scopus: 1Investigation 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: 15Citation - Scopus: 17Activation Energy of Metastable Amorphous Ge2sb2< From Room Temperature To Melt(Amer inst Physics, 2018) Muneer, Sadid; Scoggin, Jake; Dirisaglik, Faruk; Adnane, Lhacene; Cywar, Adam; Bakan, Gokhan; Gokirmak, AliResistivity of metastable amorphous Ge2Sb2Te5 (GST) measured at device level show an exponential decline with temperature matching with the steady-state thin-film resistivity measured at 858 K (melting temperature). This suggests that the free carrier activation mechanisms form a continuum in a large temperature scale (300 K - 858 K) and the metastable amorphous phase can be treated as a supercooled liquid. The effective activation energy calculated using the resistivity versus temperature data follow a parabolic behavior, with a room temperature value of 333 meV, peaking to similar to 377 meV at similar to 465 K and reaching zero at similar to 930 K, using a reference activation energy of 111 meV (3k(B)T/2) at melt. Amorphous GST is expected to behave as a p-type semiconductor at T-melt similar to 858 K and transitions from the semiconducting-liquid phase to the metallic-liquid phase at similar to 930 K at equilibrium. The simultaneous Seebeck (S) and resistivity versus temperature measurements of amorphous-fcc mixed-phase GST thin-films show linear S-T trends that meet S = 0 at 0 K, consistent with degenerate semiconductors, and the dS/dT and room temperature activation energy show a linear correlation. The single-crystal fcc is calculated to have dS/dT = 0.153 mu V/K-2 for an activation energy of zero and a Fermi level 0.16 eV below the valance band edge. (C) 2018 Author(s).
