WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14517/18

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Now showing 1 - 20 of 394

Citation Count: 5
4/3 problem, Poynting theorem, and electromagnetic energy-momentum tensor
(Canadian Science Publishing, 2015) Kholmetskii, Alexander L.; Missevitch, Oleg V.; Yarman, Tolga; Enerji Sistemleri Mühendisliği / Energy Systems Engineering
We show that the familiar 4/3 problem originates from the incorrect determination of the momentum of the electromagnetic field generated by an isolated charged particle, which results from an incorrect application of the Poynting theorem to the field. To demonstrate this, we consider a macroscopic problem: splitting a charged oil droplet into two identical smaller droplets in the rest frame K of the original droplet, and in another inertial frame K' moving with respect to K with some constant velocity, and arrive at a physically senseless solution in the framework of the standard approach. To solve this problem in a correct way, we suggest a modified Poynting theorem for an isolated charge and recalculate the momentum of the electromagnetic field of this charge, which yields the usual relativistic relationship between the field energy and momentum. Our approach is not at odds with the idea about "Poincare stresses"; however, in contrast to the standard method, it provides a usual relationship between the "Poincare stress-energy" and the associated momentum stress component. Finally, the continuity equation in four-dimensional form for the case of isolated moving charge is also proposed, which completely resolves the 4/3 problem.
Citation Count: 1
ABSTRACT CAPACITY OF REGIONS AND COMPACT EMBEDDING WITH APPLICATIONS
(Springer, 2011) Shakhmurov, Veli
The weighted Sobolev-Lions type spaces W-p,gamma(l) (Omega; E) boolean AND L-p,L-gamma (Omega; E-0) are studied, where E-0, E are two Banach spaces and E-0 is continuously and densely embedded on E. A new concept of capacity of region Omega is an element of R-n in Wp,gamma(l)(Omega; E-0, E) is introduced. Several conditions in terms of capacity of region Omega and interpolations of E-0 and E are found such that ensure the continuity and compactness of embedding operators. In, particular, the most regular class of interpolation spaces E-alpha between E-0 and E, depending of alpha and l, are found such that mixed differential operators D-alpha are bounded and compact from W-p,gamma(l)(Omega; E-0, E) to E-alpha-valued L-p,L-gamma spaces. In applications, the maximal regularity for differential-operator equations with parameters are studied.
Citation Count: 0
Acute spinal epidural hematoma: A case report and review of the literature
(Turkish Assoc Trauma Emergency Surgery, 2020) Akar, Ezgi; Ogrenci, Ahmet; Koban, Orkun; Yilmaz, Mesut; Dalbayrak, Sedat
Spinal epidural hematoma (SEH) is a rare but a significant cause of spinal cord compression and neurologic deficits. Its etiology is usually unknown and requires emergency intervention. The present study aims to review the clinical significance, treatment strategies and clinical outcomes of traumatic SEH with a rare case presentation. Our patient was a 42-year-old female who presented with back pain and loss of sensation and strength in the legs. The patient did not have any disease and did not use anticoagulant drugs. The patient developed numbness in her legs half an hour after having a traditional back walking massage due to occasional back pain. She was paraplegic and anesthetic when seen in our clinic. Thoracic computed tomography (CT) and magnetic resonance imaging (MRI) revealed posterior epidural hemorrhage at Th3-Th4 levels. In the 12th hour, the hematoma was evacuated by an emergency decompressive hemilaminectomy. At the postoperative 24th hour, the patient had symptomatic improvement, and in the sixth month, the patient was mobilized with support. SEH is a rare condition that should be considered in patients with sudden onset of back pain and extremity weakness. Although the gold standard diagnostic tool is MRI, CT is often sufficient to avoid delayed surgery. Immediate surgical decompression (laminectomy/hemilaminectomy) should be performed in cases diagnosed with SEH with neurological deficits.
Citation Count: 101
Adaptation, validity, and reliability of the metacognition questionnaire-30 for the Turkish population, and its relationship to anxiety and obsessive-compulsive symptoms
(Turkiye Sinir ve Ruh Sagligi dernegi, 2008) Tosun, Ahmet; Irak, Metehan
Objective: The present study aimed to evaluate the psychometric properties of the short form of the Metacognition Questionnaire (MCQ-30) in a population of Turkish university students. The metacognitions questionnaire (MCQ) measures individual differences in a selection of metacognitive beliefs, judgments, and monitoring tendencies considered important in the metacognitive model of psychological disorders. Method: The study included 850 university students from 15 Turkish universities. Mean age age of the participants was 21.22 years, 282 (33.17%) were female, and 558 (66.82%) were male. Results: Construct validity was evaluated by exploratory and confirmatory factor analysis (CIA). Exploratory factor analysis revealed that the Turkish version of MCQ-30 has 5 components, which is some factor structure as the original form. In addition, the fit indices of CIA suggested an acceptable fit to a 5-factor model consistent with the original MCQ-30. The Turkish MCQ-30 showed acceptable to good test-retest reliability, internal consistency, and convergent validity. Significant positive relationships between the subscales of MCQ-30 and measures of anxiety and obsessive-compulsive symptoms provided further support for the convergent validity of the Turkish version. Moreover significant negative correlations were observed between age and the MCQ-30 subscales, and the effect of gender was significant on some of the subscales. Conclusion: The psychometric properties of the Turkish version of MCQ-30 showed that the instrument is a valuable additional tool for the assessment of metacognition in Turkey.
Citation Count: 0
Addendum to Spinal Schwannomatosis: Case Report of a Rare Condition
(Turkish Neurosurgical Soc, 2017) Hakan, Tayfun; Celikoglu, Erhan; Aker, Fugen; Barisik, Nagehan
[No Abstract Available]
Citation Count: 9
Adherence to guideline-directed medical and device Therapy in outpAtients with heart failure with reduced ejection fraction: The ATA study
(Turkish Soc Cardiology, 2020) Kocabas, Umut; Kivrak, Tarik; Oztekin, Gulsum Meral Yilmaz; Tanik, Veysel Ozan; Ozdemir, Ibrahim Halil; Kaya, Ersin; Pehlivanoglu, Seckin
Objective: Despite recommendations from heart failure guidelines on the use of pharmacologic and device therapy in patients with heart failure with reduced ejection fraction (HFrEF), important inconsistencies in guideline adherence persist in practice. The aim of this study was to assess adherence to guideline-directed medical and device therapy for the treatment of patients with chronic HFrEF (left ventricular ejection fraction <= 40%). Methods: The Adherence to guideline-directed medical and device Therapy in outpAtients with HFrEF (ATA) study is a prospective, multicenter, observational study conducted in 24 centers from January 2019 to June 2019. Results: The study included 1462 outpatients (male: 70.1%, mean age: 67 +/- 11 years, mean LVEF: 30%+/- 6%) with chronic HFrEF. Renin-angiotensin system (RAS) inhibitors, beta-blockers, mineralocorticoid receptor antagonists (MRAs), and ivabradin were used in 78.2%, 90.2%, 55.4%, and 12.1% of patients, respectively. The proportion of patients receiving target doses of medical treatments was 24.6% for RAS inhibitors, 9.9% for beta-blockers, and 10.5% for MRAs. Among patients who met the criteria for implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy (CRT), only 16.9% of patients received an ICD (167 of 983) and 34% (95 of 279) of patients underwent CRT (95 of 279). Conclusion: The ATA study shows that most HFrEF outpatients receive RAS inhibitors and beta-blockers but not MRAs or ivabradin when the medical reasons for nonuse, such as drug intolerance or contraindications, are taken into account. In addition, most eligible patients with HFrEF do not receive target doses of pharmacological treatments or guideline-recommended device therapy.
Citation Count: 0
Advanced Data Mining Techniques
(informs, 2009) Ozgen, Arzum Eser
[No Abstract Available]
Citation Count: 8
Airborne pathogen projection during ophthalmic examination
(Springer, 2020) Bostanci Ceran, Basak; Karakoc, Alp; Taciroglu, Ertugrul
Purpose Microscale droplets act as coronaviruses (CoV) carriers in the air when released from an infected person and may infect others during close contact such as ophthalmic examination. The main objective of the present work is to demonstrate how CoV deposited droplets are projected during biomicroscopy and to discuss what kind of precautions should be taken in ophthalmic practice. Methods A coupled fluid-structure system comprising smoothed particle hydrodynamics and the finite element method has been built to assess the projection of droplets spreading from an infected person. Different conditions based on the maximum exit flow velocity from the infector's mouth during the ophthalmic examination were modeled. Results During exhalation, for which the exit flow is similar to 1000 mm/s, the average horizontal distance of the flow front was similar to 200 mm while individual particles can reach up to similar to 500 mm. In case of coughing or sneezing (corresponding to an exit flow of similar to 12,000 mm/s), the average horizontal distance of the flow front was similar to 1300 mm. Conclusion During the ophthalmic examination, the proximity to the patient's nose and mouth was observed to be less than the horizontal distance of flow front particles. Even though mounted breath shields are used, particles flew beyond the shield and contaminate the ophthalmologist. Compared with the current protective breath shields, the use of a larger shield with a minimum radius of 18 cm is needed to decrease viral transmission.
Citation Count: 4
Alpha Head on Collision with a Fixed Gold Nucleus, Taking into Account the Relativistic Rest Mass Variation as Implied by Mass-Energy Equivalence
(Polish Acad Sciences inst Physics, 2014) Yarman, T.; Arik, M.; Kholmetskii, A.; Altintas, A. A.; Ozaydin, F.; Enerji Sistemleri Mühendisliği / Energy Systems Engineering
We reformulate the Rutherford scattering of alpha particle for a head on collision, taking into account the rest mass variation of the particle, as implied by the energy conservation law. Our relativistic reformulation (which includes the energy conservation) constitutes a new example for the breakdown of the Lorentz invariance. Briefly speaking, even at rest or during the whole scattering process, the distance between the alpha particle and the gold nucleus is not invariant but depends on the frame of the observer attached to either object. According to our relativistic reformulation, we also provide a new set of Lorentz transformations.
Citation Count: 14
Analysis of complications following posterior vertebral column resection for the treatment of severe angular kyphosis greater than 100°
(Turkish Assoc Orthopaedics Traumatology, 2017) Atici, Yunus; Balioglu, Mehmet Bulent; Kargin, Deniz; Mert, Muhammed; Albayrak, Akif; Kaygusuz, Mehmet Akif
Objective: The aim of this study was to evaluate the complications, efficacy and safety of posterior vertebral column resection (PVCR) in severe angular kyphosis (SAK) greater than 100 degrees. Methods: The medical records of 17 patients (mean age 17.9 (range, 9-27) years) with SAK who underwent PVCR, were reviewed. Mean follow-up period was 32.2 (range, 24-64) months. Diagnosis of the patients included congenital kyphosis in 11 patients, post-tuberculosis kyphosis in 3 patients and neurofibromatosis in 3 patients. The sagittal plane parameters (local kyphosis angle, lumbar lordosis, sagittal vertical axis, pelvic tilt, sacral slope and pelvic incidence) were measured in the preoperative and the early postoperative periods and during the last follow-up on the lateral radiographs. Results: The mean preoperative localized kyphosis angle was 121.8 degrees (range, 101 degrees-149 degrees). The mean local kyphosis angle (LKA) was 71.5 degrees at postoperatively evaluation (p < 0.05). Complications were detected in 12 patients (70.6%) with spinal shock in 4 patients, hemothorax in 3 patients, postoperative infection in 2 patients, dural laceration in 2 patients, neurological deficit in 2 patients (1 paraplegia and 1 root injury), the shifted cage in 2 patients and rod fracture in 2 patients. Neurological events occurred in six patients (35%) with temporary neurological deficit in 5 patients and permanent neurological deficit in 1 patient. Conclusion: PVCR is an efficient and a successful technique for the correction of SAK. However, it can lead to a large number of major complications in SAK greater than 100 degrees. Level of evidence: Level IV, therapeutic study. (C) 2017 Turkish Association of Orthopaedics and Traumatology. Publishing services by Elsevier B.V.
Citation Count: 0
Analysis of settlement parameters of architecture faculties on university campus
(Enpress Publ Llc, 2024) Doraj, Parisa; Ozyilmaz, Havva; Akar, Umit
The selection of a suitable place for an activity is an important decision made for a project, which requires assessing it from different points of view. Educational use is one of the most complicated and substantial uses in urban space that requires precise and logical attention to its location and neighborhood with similar and consistent uses. Faculties of universities are educational spaces that should be protected against physical and moral damage to create a healthy educational environment. To do this, it is necessary to find and assess the factors affecting the location of educational spaces. The extant study aimed at finding and assessing the factors affecting the location of educational spaces to locate art and architecture schools or faculties in 4 important universities. The present study is applied developmental research in terms of nature and descriptive-analytical in terms of method. This study used the AHP (Analytical Hierarchy Process) weighing and controlled the prioritization through the TOPSIS (Technique for Order Preference by Similarity) technique in the methodology phase. Since there was no criterion and metric for these centers, six were chosen as the primary metrics after reviewing the relevant theoretical foundations, early investigations, and collecting effective data. Finally, the results indicated the most important factors of vehicular or roadway access, pedestrian access, slope, parking, adjacency, neighborhood, and area. Among the mentioned factors, pedestrian access (w: 0.4231) had the highest weight and was the priority in the location of architecture faculty in studied campuses and areas inside the universities.
Citation Count: 0
Anisotropic Differential Operators with Parameters and Applications
(Springer, 2014) Shakhmurov, V. B.
In the paper, we study the boundary-value problems for parameter-dependent anisotropic differential-operator equations with variable coefficients. Several conditions for the uniform separability and Fredholmness in Banach-valued L (p) -spaces are given. Sharp uniform estimates for the resolvent are established. It follows from these estimates that the indicated operator is uniformly positive. Moreover, it is also the generator of an analytic semigroup. As an application, the maximal regularity properties of the parameter-dependent abstract parabolic problem and infinite systems of parabolic equations are established in mixed L (p) -spaces.
Citation Count: 0
ANTHROPOMETRIC PROFILES OF YOUNG RHYTMIC GYMNASTIC ATHLESTES ACCORDING TO THEIR PARENTAL NUTRITIONAL BEHAVIOR
(Univ Ljubljana, 2022) Uslu, Burcu; Okudan, Begum; Bozdemir, Ezgi; Alphan, Mueveddet Emel
Rhythmic gymnastics is a sport that is supported by strength, speed and endurance with an emphasis on flexibility and coordination. It is assumed that low fat percentage, normal height, low body weight, and elegant and thin structure influence the performance of the athletes because it provides an aesthetically advantage in this sports branch. The aim of the study was to reveal the anthropometric properties in rhythmic gymnastics athletes, and to examine the changes and relationships of these parameters according to their parents' diet. A questionnaire with socio-demographic information, Parental Feeding Style Questionnaire, was used to gather data. The data on children's BMI, waist circumference and upper middle arm circumference were also included; these measurements were all taken by the same researcher. It was determined that the scores obtained from the parent feeding style scale differed according to the waist circumference of the child (p <0.05). It can be concluded that the scores obtained from the parent feeding style scale and its sub-dimensions of promoting to eat /encouraging feeding and instrumental feeding differ according to the child's upper middle arm circumference (p <0.05). As a result of the research, some sociodemographic and anthropometric features seem to affect the parents' feeding style of their children. The results obtained from this study can be used as a guide when creating forward-looking nutrition models for children engaged in rhythmic gymnastics, and planning the nutritional education for their parents.
Citation Count: 2
Apparent paradoxes in classical electrodynamics: a fluid medium in an electromagnetic field
(Iop Publishing Ltd, 2008) Kholmetskii, A. L.; Yarman, T.; Enerji Sistemleri Mühendisliği / Energy Systems Engineering
In this paper we analyse a number of teaching paradoxes of classical electrodynamics, dealing with the relativistic transformation of energy and momentum for a fluid medium in an external electromagnetic field. In particular, we consider a moving parallel plate charged capacitor, where the electric attraction of its plates is balanced by the pressure of gas convicted between the plates.
Citation Count: 6
Apparent paradoxes in classical electrodynamics: relativistic transformation of force
(Iop Publishing Ltd, 2007) Kholmetskii, A. L.; Yarman, T.; Enerji Sistemleri Mühendisliği / Energy Systems Engineering
In this paper, we analyse a number of paradoxical teaching problems of classical electrodynamics, dealing with the relativistic transformation of force for complex macro systems, consisting of a number of subsystems with nonzero relative velocities such as electric circuits that change their shape in the course of time.
Citation Count: 2
Application of Interval Valued Intuitionistic Fuzzy Uncertain MCDM Methodology for Ph.D Supervisor Selection Problem
(Elsevier, 2024) Mandal, Shubhendu; Gazi, Kamal Hossain; Salahshour, Soheil; Mondal, Sankar Prasad; Bhattacharya, Paritosh; Saha, Apu Kumar
The selection of Ph.D (Doctor of Philosophy) supervisor is always a vital and interesting problem in academia and especially for students who want to carry out Ph.D. Nowadays, selecting a supervisor for Ph.D in a scientific manner becomes a challenge for any student because of the variety of options available to the scholar. In this context, the present study aims to formulate a model for Ph.D. supervisor selection from the offered alternatives in an academic institute. A hybrid multi-criteria decision making (MCDM) framework has been applied to select the suitable supervisor of the student's preferred criteria under interval-valued intuitionistic fuzzy (IVIF) scenario. The IVIF Analytic Hierarchy Process (AHP) has been employed to prioritize the criteria, whereas IVIF Technique for order preference by similarity to ideal solution (TOPSIS) technique is engaged to rank the available supervisors based on criteria weight. A set of eight criteria and five alternatives have been considered for modeling the problem. Moreover, the potential criteria are weighted and ranked by the multiple decision makers in the present study. To examine the consistency and robustness of the proposed integrated approach, sensitivity analysis and comparative analysis have been carried out. From all the analyses, it can be conferred that the suggested approach is quite useful to apply in different decision-making scenarios.
Citation Count: 2
Approach of the Clinicians Practicing in Intensive Care Units to Brain Death Diagnosis and Training Expectations in Turkey: A Web-Based Survey
(Elsevier Science inc, 2020) Ferhatoglu, Sibel Yilmaz; Ferhatoglu, Murat Ferhat; Gurkan, Alp; Genel Cerrahi / General Surgery
Background. For health professionals, recognizing and diagnosing brain death is vital for the development of organ transplantation. However, cadaveric organ donation rates remain insufficient, and this problem has become one of the most serious obstacles in the treatment of end-organ failure. Objectives. This study examines the attitude and knowledge level of clinicians who practice in intensive care units (ICUs) concerning the determination of brain death and describes the hindrances in diagnosing brain death. Materials and Methods. A survey study was designed with 26 questions, including questions regarding the determination of characteristics of respondents' trainings, prac-ticing preferences, and their knowledge and approach toward brain death diagnosis. Clinicians practicing in ICUs in Turkey were invited to the survey. Results. A total of 244 surveys were fully completed. Physicians working at the university hospitals or university-affiliated hospitals answered the basic knowledge questions about brain death more accurately (P < .001). Also, physicians employed in university or university-affiliated hospitals feel more capable in diagnosing brain death (P 1/4 .002) and are more willing to receive education on the brain death issue (P < .001). Conclusion. There is a gap separating the practices suggested in guidelines and the daily practice of ICU clinicians working in state hospitals or private institutions. Academic organizations producing and leading the education curricula may assist in informing ICU clinicians who should be trained.
Citation Count: 1
An approach to improve the performance of cooperative unmanned vehicle team
(Tubitak Scientific & Technological Research Council Turkey, 2019) Kivanc, Omer Cihan
In this paper, a method based on optimal energy management is proposed in order to improve the operational and tactical abilities of collaborative unmanned vehicle teams. Collaborative unmanned systems are used in surveillance, tracking, and military operations. The optimal assignment of these tasks requires cooperation among the vehicles in order to generate a strategy that is efficient with respect to overall mission duration and satisfies all problem constraints. The key motivation behind this paper is to design an unmanned vehicle team that mitigates the disadvantages caused by the structures and characteristics of unmanned ground vehicles (UGVs) and unmanned aerial vehicles (UAVs), which are used in these systems. The design steps of the developed system are explained in three sections in a multidisciplinary fashion. In the first section, the optimal energy consumption profile is estimated by simulating the UAV's flight on a Nvidia Jetson TX2 embedded system, located on the UGV. In the second section, a UAV charger design and implementation is done via development of a TMS320F28335 DSP controlled 65 W inductive wireless power transfer circuit, and in the third section an algorithm that calculates the optimal range and route for the user-selected way points using the state of charge of the UAV's LiPo batteries and a preflight simulation using the simulated annealing method are developed. The experiments are performed in real time with an example scenario and the proposed strategy's suitability and effectiveness are verified for cooperative unmanned vehicle teams.
Citation Count: 3
ARE OBSESSIVE BELIEFS AND INTERPRETATIVE BIAS OF INTRUSIONS PREDICTORS OF OBSESSIVE COMPULSIVE SYMPTOMATOLOGY? A STUDY WITH A TURKISH SAMPLE
(Soc Personality Res inc, 2009) Cagin, Ozlem; Dag, Ihsan
The aims of the present study were to investigate the cross-cultural utility of the Obsessive Beliefs Questionnaire (OBQ) and the Interpretation of Intrusions Inventory (III) (both developed by the Obsessive Compulsive Cognitions Working Group, 1997, 2001, 2003, 2005) with college students. Following factor analysis of the OBQ - unlike the original structure found by the Obsessive Compulsive Cognitions Working Groups - threat perception and responsibility emerged as separate factors. Analysis of the III resulted in a 3-factor solution showing that theoretically derived subscales also differed empirically. Moderate to high intercorrelations were found between the subscales of both the OBQ and III and with the total score. Predictors of obsessive compulsive symptomatology and its subtypes were found to differ and results of the study provided support for the heterogeneity hypothesis of OCD.
Citation Count: 11
An Artificial Neural Network-Based Estimation of Bremsstarahlung Photon Flux Calculated by MCNPX
(Polish Acad Sciences inst Physics, 2017) Tekin, H. O.; Manici, T.; Altunsoy, E. E.; Yilancioglu, K.; Yilmaz, B.
Bremsstrahlung has an important place in the field of experimental physics, especially for description of photon-matter interaction and for characterization and analysis of materials. Bremsstrahlung photon is created by a high-energy electron, deflected in the electric field of atomic nucleus. Bremsstrahlung is also important for experimental studies, not only in the field of nuclear physics and particle physics but also in the fields of solid state physics, applied physics and astrophysics. In recent years, Monte Carlo simulation has become a widely used method for calculations related to bremsstrahlung. On the other hand, predictions by using artificial neural network can be performed with high accuracy. This study aims at observing variation in the photon flux as unction of target thickness and at processing output data by using an artificial neural network. We achieved a high degree of compatibility between two different methods. This study suggests that artificial neural network is a powerful tool for prediction of Bremsstrahlung and for other scientific problems.

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