• Honam Mathematical Journal
• /
• v.40 no.1
• /
• pp.199-210
• /
• 2018

In this paper we obtain some formulae for several sums of generalized Fibonacci numbers $U_n$ and generalized Lucas numbers $V_n$ and their dual forms $G_n$ and $H_n$ by using extensions of an interesting identity by A. R. Amini for Fibonacci numbers to these four kinds of generalizations and their first and second derivatives.

• Communications of the Korean Mathematical Society
• /
• v.32 no.4
• /
• pp.1009-1024
• /
• 2017

In this paper, we consider the new faster iterative scheme due to Sintunavarat and Pitea ([32]) for further investigation and we prove its strong and ${\Delta}$-convergence theorems, data dependence and stability results in hyperbolic space. Our results extend, improve and generalize several recent results in CAT(0) space and uniformly convex Banach space.

• Communications of the Korean Mathematical Society
• /
• v.31 no.4
• /
• pp.713-727
• /
• 2016

In this paper, we introduce two general iteration schemes with bounded error terms and prove some theorems related to the strong and ${\Delta}$-convergence of these iteration schemes for multi-valued maps in a hyperbolic space. The results which are presented here extend and improve some well-known results in the current literature.

• The Pure and Applied Mathematics
• /
• v.25 no.4
• /
• pp.243-252
• /
• 2018

In this paper, we study the sequentially open and closed subsets of sequential topological groups determined by sequentially continuous group homomorphism. In particular, we investigate the sequentially openness (closedness) and sequentially compactness of subsets of sequential topological groups by the aid of sequentially continuity, sequentially interior or closure operators. Moreover, we explore subgroup and sequential quotient group of a sequential topological group.

• Honam Mathematical Journal
• /
• v.44 no.2
• /
• pp.195-208
• /
• 2022

In this article, the matrix representation of commutative elliptic octonions and their properties are described. Firstly, definitions and theorems are given for the commutative elliptic octonion matrices using the elliptic quaternion matrices. Then the adjoint matrix, eigenvalue and eigenvector of the commutative elliptic octonions are investigated. Finally, α = -1 for the Gershgorin Theorem is proved using eigenvalue and eigenvector of the commutative elliptic octonion matrix.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.17
• /
• pp.7263-7266
• /
• 2014

Background: Cervical cancer which is one of the most preventable cancers is an important public health problem worldwide, and especially in developing countries. The aim of this study was to determine knowledge and attitudes about the HPV vaccination of mothers with 0- to 18-year old children. Materials and Methods: Written approval was taken from the local authorities. The study subjects consisted of 799 mothers who agreed to participate. The data were collected via a "Personal Information Form" which included 30 questions that were prepared by the researchers themselves in line with the literature. The data were collected by face to face interviews with the mothers. Analyses were performed using commercial software. Results: The mean age of the mothers who participated in the study was $32.0{\pm}6.52$, and 88.1% reported no information about HPV, and 83.5% no information about HPV vaccination. Only 0.7% of the mothers had daughters who had HPV vaccination, and 44.3% of the mothers who had sons were found out to be indecisive about having HPV vaccination. There was a significant corelation between the educational status of the mothers and their knowledge about HPV vaccination (p<0.05). However, there was no significant correlation in terms of economic conditions (p>0.05). Conclusions: This study suggested that mothers had very little information on HPV and HPV vaccination. Knowledge of the disease and its vaccination is an essential factor for the success of the vaccination program. It is of great importance that mothers are trained in this subject by health professionals.

• Geomechanics and Engineering
• /
• v.23 no.4
• /
• pp.301-311
• /
• 2020

In this study, shear strength behavior of fine-grained soils was investigated under unsaturated conditions. The samples in the unsaturated state were subjected to a net normal stress (σ-u_a) of 40 kPa and different matric suctions (u_a-u_w) of 50, 100 and 150 kPa. The matric suction values applied in the triaxial tests were selected according to the bubbling pressures determined from the SWC curves. The study was carried out on prepared re-constituted cylindrical samples by uniaxial consolidation of soil slurries. First, consolidated drained (CD) triaxial compression tests were performed on the saturated samples and the cohesion and angle of internal friction were determined. After that, drained triaxial compression tests under matric suctions were performed on the unsaturated samples. In order to obtain unsaturated test results, cohesion and internal friction angle values of saturated samples were used. The nonlinear surface representing the shear strength surface was approximated consisting of two planes (double planar surface). The reason for the nonlinear behavior of some soils is that the amount of sand content contained in it is relatively high and the bubbling pressure/permanent water content value is relatively low.

• Structural Engineering and Mechanics
• /
• v.82 no.1
• /
• pp.81-92
• /
• 2022

Ultra-high performance fiber reinforced concrete (UHPFRC) is a composite building material with high ductility, fatigue resistance, fracture toughness, durability, and energy absorption capacity. The aim of this study is to develop a nonlinear finite element model that can simulate the response of the UHPFRC beam exposed to impact loads. A nonlinear finite element model was developed in ABAQUS to simulate the real response of UHPFRC beams. The numerical results showed that the model was highly successful to capture the experimental results of selected beams from the literature. A parametric study was carried out to investigate the effects of reinforcement ratio and impact velocity on the response of the UHPFRC beam in terms of midpoint displacement, impact load value, and residual load-carrying capacity. In the parametric study, the nonlinear analysis was performed in two steps for 12 different finite element models. In the first step, dynamic analysis was performed to monitor the response of the UHPFRC beam under impact loads. In the second step, static analysis was conducted to determine the residual load-carrying capacity of the beams. The parametric study has shown that the reinforcement ratio and the impact velocity affect maximum and residual displacement value substantially.

• ETRI Journal
• /
• v.44 no.1
• /
• pp.135-146
• /
• 2022

The importance of big data analytics has become apparent with the increasing volume of data on the Internet. The amount of data will increase even more with the widespread use of Internet of Things (IoT). One of the most important application areas of the IoT is healthcare. This study introduces new real-time data analytics architecture for an IoT-based smart healthcare system, which consists of a wireless sensor network and a radio-frequency identification technology in a vertical domain. The proposed platform also includes high-performance data analytics tools, such as Kafka, Spark, MongoDB, and NodeJS, in a horizontal domain. To investigate the performance of the system developed, a diagnosis of Wolff-Parkinson-White syndrome by logistic regression is discussed. The results show that the proposed IoT data analytics system can successfully process health data in real-time with an accuracy rate of 95% and it can handle large volumes of data. The developed system also communicates with a riverbed modeler using Transmission Control Protocol (TCP) to model any IoT-enabling technology. Therefore, the proposed architecture can be used as a time-saving experimental environment for any IoT-based system.

• Steel and Composite Structures
• /
• v.50 no.4
• /
• pp.475-487
• /
• 2024

The usage of fiber-reinforced polymer materials increases in the construction sector due to their advantages in terms of high mechanical strength, lightness, corrosion resistance, low density and high strength/density ratio, low maintenance and painting needs, and high workability. In this study, it is aimed to improve mechanical properties of GFRP box profiles, produced by pultrusion method, by filling the polymer concrete into them. Within the scope of study, hybrid use of polymer concrete produced with GFRP box profiles was investigated. Hybrid pressure and bending specimens were produced by filling polymer concrete (polyester resin manufactured with natural sand and stone chips) into GFRP box profiles having different cross-sections and dimensions. Behavior of the produced hybrid members was investigated under bending and compression tests. Hollow GFRP_xx profiles, polymer-filled hybrid members, and nominative polymeric concrete specimens were tested as well. The behavior of the specimens under pressure and bending tests, and their load bearing capacities, deformations and changes in toughness were observed. According to the test results; It was deduced that hybrid design has many advantages over its component materials as well as superior physical and mechanical properties.