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Now showing 1 - 10 of 69
  • Article
    Citation - WoS: 11
    Citation - Scopus: 20
    The Taylor Series Method and Trapezoidal Rule on Time Scales
    (Elsevier Science inc, 2020) Georgiev, Svetlin G.; Erhan, Inci M.
    The Taylor series method for initial value problems associated with dynamic equations of first order on time scales with delta differentiable graininess function is introduced. The trapezoidal rule for the same types of problems is derived and applied to specific examples. Numerical results are presented and discussed. (c) 2020 Elsevier Inc. All rights reserved.
  • Article
    Citation - WoS: 27
    Citation - Scopus: 28
    Generalized Meir-Keeler Type Contractions on g-metric Spaces
    (Elsevier Science inc, 2013) Mustafa, Zead; Aydi, Hassen; Karapinar, Erdal
    In this manuscript, we introduce generalized Meir-Keeler type contractions over G-metric spaces. Moreover, we show that every orbitally continuous generalized Meir-Keeler type contraction has a unique fixed point on complete G-metric spaces. We illustrate our results by some given examples. (C) 2013 Elsevier Inc. All rights reserved.
  • Review
    Citation - WoS: 91
    Citation - Scopus: 105
    Recommendations for Head and Neck Surgical Oncology Practice in a Setting of Acute Severe Resource Constraint During the Covid-19 Pandemic: an International Consensus
    (Elsevier Science inc, 2020) Mehanna, Hisham; Hardman, John C.; Shenson, Jared A.; Abou-Foul, Ahmad K.; Topf, Michael C.; AlFalasi, Mohammad; Holsinger, F. Christopher
    The speed and scale of the global COVID-19 pandemic has resulted in unprecedented pressures on health services worldwide, requiring new methods of service delivery during the health crisis. In the setting of severe resource constraint and high risk of infection to patients and clinicians, there is an urgent need to identify consensus statements on head and neck surgical oncology practice. We completed a modified Delphi consensus process of three rounds with 40 international experts in head and neck cancer surgical, radiation, and medical oncology, representing 35 international professional societies and national clinical trial groups. Endorsed by 39 societies and professional bodies, these consensus practice recommendations aim to decrease inconsistency of practice, reduce uncertainty in care, and provide reassurance for clinicians worldwide for head and neck surgical oncology in the context of the COVID-19 pandemic and in the setting of acute severe resource constraint and high risk of infection to patients and staff.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Asymptotic Representation of Solutions for Second-Order Impulsive Differential Equations
    (Elsevier Science inc, 2018) Akgol, S. Dogru; Zafer, A.
    We obtain sufficient conditions which guarantee the existence of a solution of a class of second order nonlinear impulsive differential equations with fixed moments of impulses possessing a prescribed asymptotic behavior at infinity in terms of principal and nonprincipal solutions. An example is given to illustrate the relevance of the results. (C) 2018 Elsevier Inc. All rights reserved.
  • Article
    Citation - WoS: 22
    Citation - Scopus: 37
    Performing and Analyzing Non-Formal Inspections of Entity Relationship Diagram (erd)
    (Elsevier Science inc, 2013) Cagiltay, Nergiz Ercil; Tokdemir, Gul; Kilic, Ozkan; Topalli, Damla
    Designing and understanding of diagrammatic representations is a critical issue for the success of software projects because diagrams in this field provide a collection of related information with various perceptual signs and they help software engineers to understand operational systems at different levels of information system development process. Entity relationship diagram (ERD) is one of the main diagrammatic representations of a conceptual data model that reflects users' data requirements in a database system. In today's business environment, the business model is in a constant change which creates highly dynamic data requirements which also requires additional processes like modifications of ERD. However, in the literature there are not many measures to better understand the behaviors of software engineers during designing and understanding these representations. Hence, the main motivation of this study is to develop measures to better understand performance of software engineers during their understanding process of ERD. Accordingly, this study proposes two measures for ERD defect detection process. The defect detection difficulty level (DF) measures how difficult a defect to be detected according to the other defects for a group of software engineers. Defect detection performance (PP) measure is also proposed to understand the performance of a software engineer during the defect detection process. The results of this study are validated through the eye tracker data collected during the defect detection process of participants. Additionally, a relationship between the defect detection performance (PP) of a software engineer and his/her search patterns within an ERD is analyzed. Second experiment with five participants is also conducted to show the correlation between the proposed metric results and eye tracker data. The results of experiment-2 also found to be similar for DF and PP values. The results of this study are expected to provide insights to the researchers, software companies, and to the educators to improve ERD reasoning process. Through these measures several design guidelines can be developed for better graphical representations and modeling of the information which would improve quality of these diagrams. Moreover, some reviewing instructions can be developed for the software engineers to improve their reviewing process in ERD. These guidelines in turn will provide some tools for the educators to improve design and review skills of future software engineers. (c) 2013 Elsevier Inc. All rights reserved.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 8
    Preterm Birth and Maternal Sensitivity: Findings From a Non-Western Country
    (Elsevier Science inc, 2020) Akkus, P. Zengin; Saygan, B. Bahtiyar; Bahadur, E. Ilter; Ozdemir, G.; Ozmert, E. N.
    Introduction: Although there are several studies on maternal sensitivity of preterm-born children conducted in Western countries, the factors affecting the sensitivity of mothers of preterm infants have not been investigated outside the Western context. Objectives: This study aimed to compare maternal sensitivity of preterm children at 18 months of corrected age with their healthy term-born peers and explore the factors associated with maternal sensitivity in a middle-income non-Western country. Moreover, the associations of maternal sensitivity with socio-demographic factors, maternal depression, and social-emotional competency and behavior problems of infants were investigated. Methods: In total, 70 (40 preterm-born and 30 term-born) mother-child dyads participated in this study. An observation-based measurement tool, Maternal Sensitivity Scale, was used to assess maternal sensitivity. Social-emotional competency and behavior problems of infants were evaluated via The Turkish version of the Brief Infant-Toddler Social Emotional Assessment. Maternal depressive symptoms were assessed via the Beck Depression Inventory. In addition, a demographic information form was filled out by the mothers. Results: Maternal sensitivity scores of preterm infants were significantly lower compared to term infants. Depressive symptoms scores and employment status of mothers, socio-economic status (SES), gestational age, breastfeeding duration, and behavior problems of children were the factors related to maternal sensitivity scores. In hierarchical regression analysis, SES and gestational age were the strongest predictors of maternal sensitivity. After controlling SES and gestational age, maternal depressive symptoms scores negatively predicted maternal sensitivity scores. Conclusion: This study pointed out the factors associated with the maternal sensitivity of preterm infants outside the Western context. Interventions to improve sensitive parenting behaviors of preterm infants are needed, especially in socio-economically disadvantaged groups.
  • Article
    Citation - WoS: 25
    Citation - Scopus: 32
    High-Dimensional Optimization of Large-Scale Steel Truss Structures Using Guided Stochastic Search
    (Elsevier Science inc, 2021) Azad, Saeid Kazemzadeh; Aminbakhsh, Saman
    Despite a plethora of truss optimization algorithms devised in the recent literature of structural optimization, still high-dimensional large-scale truss optimization problems have not been properly tackled basically due to the excessive computational effort required to handle the foregoing instances. In this study, application of a recently developed design-driven heuristic, namely guided stochastic search (GSS), is extended to a more challenging class of truss optimization problems having thousands of design variables. Two variants of the algorithm, namely GSSA and GSSB, have been employed for sizing optimization of four high-dimensional examples of steel trusses, i.e., a 2075-member single-layer onion dome, a 2688-member double-layer open dome, a 6000-member doublelayer scallop dome, and a 15048-member double-layer grid as per AISC-LRFD specification. The numerical results obtained indicate the efficiency of GSSA and GSSB in handling high-dimensional instances of large-scale steel trusses with up to 15048 discrete design variables.
  • Article
    Citation - WoS: 27
    Citation - Scopus: 28
    Polycrystalline Diamond End Mill Cutting Edge Design To Improve Ductile-Mode Machining of Silicon
    (Elsevier Science inc, 2018) Oliaei, S. N. B.; Karpat, Y.
    Silicon is a commonly used material in optoelectronics and micro fluidics devices. Micro mechanical milling of silicon with polycrystalline diamond (PCD) tools has the potential to produce three-dimensional surfaces with good surface finish and an increased material removal rate. PCD micro end mill geometry is known to influence process outputs yet its effect has not been studied in detail. In this study, a PCD end mill with a hexagonal geometry has been considered, and its micro cutting geometry has been modified to have a parallelogram shape featuring a large negative rake angle on the bottom of the tool. The proposed micro geometry also reduces the contact area between the tool and the work material. The proposed geometry was fabricated using wire electric discharge machining (WEDM). Ductile-to-brittle transition conditions and areal surface roughness have been investigated as a function of tool geometry and feed during micro milling of silicon. A significant improvement in material removal rate and surface roughness has been obtained compared to a commercially available PCD end mill having hexagonal geometry with flat bottom. The results show that PCD micro end mill geometry significantly affects the process outputs.
  • Article
    Citation - WoS: 18
    Citation - Scopus: 21
    Musculoskeletal Pain, Related Factors, and Posture Profiles Among Adolescents: a Cross-Sectional Study From Turkey
    (Elsevier Science inc, 2021) Ozdemir, Serpil; Gencbas, Dercan; Tosun, Betul; Bebis, Hatice; Sinan, Ozlem
    Purpose: The aim of the study was to evaluate musculoskeletal pain due to mechanical reasons and related risk factors in adolescents and to define posture profiles of adolescents. Design: A cross-sectional study. Methods: The study was conducted with 2221 adolescents between February 2015 and May 2015. The questionnaire used to collect data consisted of three parts: (1) descriptive characteristics of the participants, (2) pain assessment of 14 parts of the body, and (3) Back Pain and Body Posture Evaluation Instrument (BackPEI). Results: The prevalence of low back pain among the participants was 73.3% (n = 1,343), while the prevalence of back pain was 68.4% (n = 1,254). The participants attributed their pain to their poor sitting postures at school (38.1%, n = 847) and carrying school backpacks (84.1%, n = 1,713). There was a statistically significant difference in the physical activities of adolescents and the BackPEI score (z = 4.40; p = .001). Posture factors of the BackPEI score increased while school desk comfort score increased (Spearman's rho = 0.148; p = .001), but it decreased while the school grades of the adolescents increased (Spearman's rho [rho] = -0.161; p = .001). Conclusions: According to this study, body posture was related to musculoskeletal pain and was correlated with physical activities, school desk comfort, and school grades of the adolescents. It is suggested that correct posture and ergonomic positions should be taught to adolescents when using computers, carrying school backpacks, and sitting in school chairs to prevent musculoskeletal pain. (C) 2020 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.
  • Article
    Citation - WoS: 59
    Citation - Scopus: 70
    Effects of Reflexology and Progressive Muscle Relaxation on Pain, Fatigue, and Quality of Life During Chemotherapy in Gynecologic Cancer Patients
    (Elsevier Science inc, 2019) Dikmen, Hacer Alan; Terzioglu, Fusun
    Purpose: Our aim was to investigate the effect of reflexology and progressive muscle relaxation (PMR) exercises on pain, fatigue, and quality of life (QoL) of gynecologic cancer patients during chemotherapy. Methods: Eighty participants were randomly assigned to one of four groups: reflexology, progressive muscle relaxation (PMR) exercises, both (reflexology + PMR), or a control group. Data were collected with a general data collection form, Brief Pain and Fatigue inventories, and Multidimensional Quality-of-Life Scale-Cancer. Results: In reflexology and reflexology + PMR groups, a significant decrease in pain severity and fatigue and an increase in QoL were found (p < .05). In the PMR alone group, pain severity and fatigue decreased significantly (p < .05), but there was no significant change identified in QOL (p > .05). Conclusions: Reflexology and PMR exercises given to gynecologic cancer patients during chemotherapy were found to decrease pain and fatigue and increase QoL. (C) 2019 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.