163 research outputs found

    A field study on the change in airline companies and operations created by global airline alliances

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    Günümüzde en hızlı gelişim gösteren sektörlerden birisi olan hava taşımacılığı sektörü de çok boyutlu bir kavram olan küreselleşme sürecinden payını almış, zaman içinde büyük değişimler göstermiştir. Havayolu sektöründe faaliyet gösteren işletmeler de sektörün geçirdiği değişimi yaşamışlar artan rekabet unsurları, artan dışa açılma ve küresel bir havayolu olma baskıları ile karşı karşıya gelmekte ve bu etkenlere karşı yeni çözümler geliştirip, yeni yönetim teknikleri ile bu çözümleri hayata geçirmeye çalışmışlardır. Bu bağlamda, söz konusu sürecin havayolu taşımacılığında ve havayolu işletmelerinde yarattığı en önemli değişimler ise, maliyet politikalarının değişimi, işletmelerin toplam kalite yönetimi felsefesini benimsemeleri, işletmelerin iş birliklerine gitmeleri ve işletmelerin düşük maliyetli havayolu kimliğine bürünmek istemeleri olarak karşımıza çıkmıştır. Havayolu işletmelerinde bilhassa Uçak Filo Sigorta Primleri işletme maliyetinin önemli bir unsuru olmaktadır. Çalışmanın uygulama bölümünde ise, görev tanımına göre belirlenen 500 konu ile ilgili havayolu çalışanından amaçsal örnekleme yolu ile seçilen en az 50 kişiye önceden yapılandırılarak anket uygulanmıştır. Elde edilen verilerle yapılan analizler, küresel havayolu ittifaklarının havayolu işletmeleri üzerinde yarattığı önemli değişimleri, yönetim yapılarını, stratejilerini, kurumsal itibarlarını, pazar paylarını, ürün ve/veya hizmetlere olan bakışlarını nasıl etkilediğini açıklamaktadır.The air transportation as one of the fastest growing sectors today, has taken its share from the globalization process which is a multi-dimensional concept, and has shown major changes in the time. Enterprises operating in the airline industry have also experienced those changes in the sector, faced with pressures from increasing competition, from demand to be more active abroad and becoming a global airline and they have tried to develop and implement new solutions for such problems with new management techniques. In this context, the most important effects of this globalization process on airline transportation and airline companies are; the change in costing/pricing policies, the adaptation of the total quality management philosophy in operations, the cooperation and marriages of the companies and the desire of the companies to become alow-cost airline. Aircraft Fleet Insurance Premiums is particularly an important element of the operational cost of the airline companies. In the application part of the study, a pre-structured questionnaire was applied to at least 50 people selected by purposive sampling among 500 airline employees related to the subject determined according to the job description. Analyzes made with the data obtained explain how the important changes created by global airline alliances on airline businesses affect their management structures, strategies, corporate reputation, market shares, and their view of products and / or services

    First-principles calculations to investigate the structural, electronic, elastic, vibrational and thermodynamic properties of the full-Heusler alloys X2ScGa (X = Ir and Rh)

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    This study has investigated ab initio pseudopotential calculations on the structural, electronic, elastic, vibrational and thermodynamic properties of the full-Heusler X2ScGa (X = Ir and Rh) alloys. The calculations have taken place under consideration of the generalized gradient approximation (GGA) of the density functional theory (DFT) with using the plane-wave ab initio pseudopotential method. According to the calculations, the major contribution to electronic states at the Fermi energy has been achieved by d orbitals, revealing a more active role for transition metals Ir (Rh) and Sc atoms. The reckonings point out that the Ir2ScGa and Rh2ScGa have metallic behavior at the equilibrium lattice constant with the density of states (DOS) at the Fermi level (N (EF)) of 1.412 states/eV and 1.821 states/eV, respectively. The results of the elastic constants showed that these compounds met the criteria for Born mechanical stability. It was also observed that they have a ductile structure and exhibit anisotropic behavior according to Pugh criteria. Besides, the full phonon spectra and their projected partial density of states of the alloys have been analyzed with the first-principle linear-response approach of the density-functional perturbation theory. All the alloys behaved dynamically stable in the L21 phase. Furthermore, internal free energy, entropy, specific heat capacity at constant volume and vibrational free energy changes of Ir2ScGa and Rh2ScGa alloys were analyzed and discussed between the temperature range of 0–800 K using the quasi harmonic approximation. According to the results, these alloys are potential candidate for industrial use. © 2020 Elsevier Lt

    Ağ Değişimlerinde Optimal Yolun Bulunması

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    DergiPark: 245966trakyafbdBu çalışmada, yeni bir akıllı karınca tipi kullanılmaktadır ve onlar ağ değişimlerinde yeni optimal yolu bulmaya çalışmaktadırlar. Kendini klonlayan karınca kolonisi yaklaşımı optimal yolu bulmak için kullanılır. Bu yaklaşım, arama ve yönlendirme algoritmalarına odaklanarak tasarlanmıştır. Kendini klonlayan karıncalar kendilerini klonlayabilir ya da yok edebilirler. Bu karıncalar kaynak ve hedef düğüm arasındaki optimal yolu bulurlar. Bu çalışmada, gerçek bir ağ içerisinde, iki farklı ağ ortamı oluşturulmuştur ve bu farklı ağ ortamlarındaki iki yönlendirme tablosu bu yaklaşım kullanılarak güncellenmiştir.In this study, a new intelligent agent type which tries to find the new optimal path when the network changes is used. Self Cloning Ant Colony Approach is used to find the optimal path. The approach focusing on the search and routing algorithm has been developed. Self Cloning Ants can clone or destroy themselves. These ants find the optimal path between the source and destination node. In this study, in a real network, two different network environments have been created and two routing tables in these different network environments have been updated by using this approach

    Zgodność badania kolposkopowego wykonanego przy wykorzystaniu skali Reida z histopatologią

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    Objectives: The aim of the study was to evaluate the diagnostic efficacy of colposcopy and to determine the strength of correlation between colposcopic impression using the Reid Colposcopic Index (RCI) and histopathology. Material and methods: This was a prospective cross-sectional study carried out at the colposcopy clinic of Bakırköy Dr Sadi Konuk Education and Research Hospital, Department of Obstetrics and Gynecology, between June 2011 and September 2011. A total of 105 women who met the selection criteria were included in the study. All women underwent colposcopy and the final diagnosis was made using RCI. Colposcopy-guided biopsy was obtained from the abnormal areas. In cases when colposcopy did not reveal any lesion, a four-quadrant biopsy from the squamocolumnar junction was taken, which served as the gold standard. Results: According to the Reid scoring system, there were 60% of benign cases, whereas 27.6%, 5.7%, and 6.7% of the women were diagnosed with CIN 1, CIN 2, CIN 3, respectively. As far as histologic results were concerned, 62.9% of the subjects were benign, whereas 25.7%, 3.8%, and 7.6% of the patients were diagnosed with CIN 1, CIN 2, CIN 3, respectively. The correlation between the Reid scoring system and histologic results was statistically significant (p>0.05). Conclusions: The correlation between colposcopic lesions graded with RCI and histology was strong, particularly in women who had HGSIL on a Pap smear. Good correlation between colposcopic imaging using RCI and histopathology makes it a reproducible technique, easy to implement in colposcopy clinics.Cel pracy: Celem tej pracy jest ocena skuteczności diagnostycznej badania kolposkopowego i zbadanie zgodności obrazów kolposkopowych, uzyskanych przy użyciu skali Reida (RCI) z histopatologią. Materiał i metody: Badanie prospektywne, przekrojowe przeprowadzono w okresie od czerwca 2011 do września 2011 w Szpitalu Naukowo - Badawczym Bakırköy Dr Sadi Konuk w Pracowni Kolposkopii Kliniki Ginekologiczno- Położniczej. Do badania włączono 105 kobiet odpowiadających kryteriom. Wszystkie pacjentki miały wykonane badanie kolposkopowe i przy użyciu skali RCI postawiono diagnozę. Wykonano biopsję obszarów nieprawidłowych pod kontrolą kolposkopu. U kobiet, u których nie wykryto kolposkopowo patologii, wykonano biopsję na granicy nabłonków w czterech kwadrantach, które uznano jako złoty standard. Wyniki: Według skali Reida wykryto 60% zmian niezłośliwych, podczas gdy u 27,6% zdiagnozowano CIN 1, u 5,7% CIN 2, i u 6,7% CIN 3. Na podstawie badania histopatologicznego znaleziono 62,9% pacjentek ze zmianami niezłośliwymi, 25,7% CIN 1, 3,8% CIN 2, i 7,6% CIN 3. Związek indeksu RCI z histopatologią jest statystycznie znaczący (p>0.05). Dyskusja: Istnieje wysoki stopień zgodności pomiędzy prognozą dysplazji wykonaną przy pomocy RCI, a dysplazją w wynikach ostatecznych histologii. Zgodność jest jeszcze wyraźniejsza zwłaszcza u pacjentów z nieprawidłowym wynikiem wymazu HGSIL. Wysoka zgodność obrazów uzyskanych przy użyciu RCI z histopatologią zapewnia możliwość łatwej integracji tego narzędzia w pracowniach kolposkopowych, a także pozwala na stosowanie go przez innych lekarzy ginekologów

    A Case of Brucellosis with a Rare Complication: Pericarditis

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    Objectives: To describe brucellosis and its possible complications according to clinical, laboratory and radiological findings. Methods: We describe a case of Brucella pericarditis visualized at transthoracic echocardiography with clinical manifestations. Results: Clinical manifestations, imaging and laboratory findings provided the correct diagnosis of Brucella pericarditis. The patient recovered fully following doxycycline and rifampin therapy. Conclusion: Brucellosis should be considered in the differential diagnosis of disorders that affect the pericardium in endemic areas

    An interactive 3D virtual environment to reduce the public speaking anxiety levels of novice software engineers

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    Software engineering is a set of activities that relies no only on technical tasks but also requires abilities focused on social duties such as daily meetings and product introduction presentations. However, engineers may experience elevated levels of anxiety when required to present their work in an unfamiliar environment. More specifically, they may suffer from public speaking anxiety even though they are supposed to be effective in those social tasks as well as in their engineering activities. Fortunately, previous studies suggest that virtual exposure therapy is an effective strategy to reduce public speaking anxiety. In this study, an interactive 3D virtual environment similar to real classrooms and auditoriums was developed to examine if this might decrease the anxiety levels of novice software engineers. To compare traditional and virtual exposure therapy, the sample set (N = 14) was divided equally into 2 groups including one experimental group and one control group. For 4 weeks, the virtual exposure therapy was conducted in the experimental group whereas psychoeducation was used in the control group. The findings from our study illustrate that virtual exposure therapy may be represent an alternative solution to the traditional therapeutic intervention for software engineers seeking to overcome public presentation anxiet

    COVID-19 during pregnancy and its impacts on perinatal health

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    n this review, we reviewed current literature on COVID-19 infection during pregnancy and provided up-to-date information and community/society recommendations. Although it has previous examples such as SARS and MERS and the infection findings appeared at an earlier period and have become known in China, the infection could not be limited and spread worldwide. Until June 8, 2020, a total of 6.8 million cases were reported and 397,000 cases died. As of the same date, the total case number in Turkey is 171,000 and total number of death is 4711. COVID-19 virus spread by droplets and its incubation period varies between 2 and 14 days. The rate of asymptomatic cases is 42% in non-pregnant patients while it is 44–89% in pregnant women. The disease progresses with mild-medium severity in about 80% of the patients, and it recovers by itself. A total of 17 maternal death cases has been reported. Although vertical transmission risk is very low according to a study investigating 265 pregnant women, there are cases showing fetal vertical transmission and we reviewed such cases in detail in this review

    Biosorption Behaviour of an Arid Land Plant, Euphorbia Rigida, Towards to Heavy Metals: Equilibrium, Kinetic and Thermodynamic Studies

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    T he potential of an arid-land plant, Euphorbia rigida E. rigida , for the removal of heavy metals [Pb II , Zn II , Cu II , Cd II , Ni II ] from aqueous solutions was studied in the current work. Batch sorption experiments were conducted to investigate the effects of pH, particle size, initial metal ion concentration, contact time and temperature. Besides, biosorption data was analysed by different isotherm and kinetic models. Equilibrium studies showed that the biosorption closely follows the Langmuir and Freundlich isotherms. From the kinetic point of view, pseudo-second order model gave the best fitting with the experimental results. The evaluated thermodynamic parameters showed that biosorption onto E. rigida was a feasible, spontaneous and endothermic process. The affinities of metal ions onto E. rigida decreased as Pb II > Zn II > Cd II > Cu II > Ni II in single metal biosorption. Besides, binary and ternary metal sorption studies were conducted to investigate the co-ion effect. Experimental results showed that E. rigida can be used as an alternative and effective low cost biosorbent for the removal of heavy metals from aqueous solution

    Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Imaging of a Patient with Squamous Cell Carcinoma of Prostate

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    Primary squamous cell carcinoma is an uncommon tumor of the prostate gland. We report a 77-year-old male patient with urinary frequency and constipation. Fine needle biopsy from prostate was suspicious of squamous cell carcinoma of the prostate. Whole body positron emission tomography/computed tomography scan revealed high fluorodeoxyglucose uptake in prostate gland. Transurethral resection confirmed the diagnosis. In contrast to prostatic adenocarcinoma, high fluorodeoxyglucose accumulation was observed in the primary tumor of the prostate gland

    An observational, multicenter, registry-based cohort study of Turkish Neonatal Society in neonates with Hypoxic ischemic encephalopathy

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    BACKGROUND: Hypoxic ischemic encephalopathy (HIE) is a significant cause of mortality and short- and long-term morbidities. Therapeutic hypothermia (TH) has been shown to be the standard care for HIE of infants ≥36 weeks gestational age (GA), as it has been demonstrated to reduce the rates of mortality, and adverse neurodevelopmental outcomes. This study aims to determine the incidence of HIE in our country, to assess the TH management in infants with HIE, and present short-term outcomes of these infants. METHODS: The Turkish Hypoxic Ischemic Encephalopathy Online Registry database was established for this multicenter, prospective, observational, nationally-based cohort study to evaluate the data of infants born at ≥34 weeks GA who displayed evidence of neonatal encephalopathy (NE) between March, 2020 and April 2022. RESULTS: The incidence of HIE among infants born at ≥36 weeks GA (n = 965) was 2.13 per 1000 live births (517:242440), and accounting for 1.55% (965:62062) of all neonatal intensive care unit admissions. The rates of mild, moderate and severe HİE were 25.5% (n = 246), 58.9% (n = 568), and 15.6% (n = 151), respectively. Infants with severe HIE had higher rates of abnormal magnetic resonance imaging (MRI) findings, and mortality (p0.05). TH was administered to 85 (34.5%) infants with mild HIE, and of those born of 34-35 weeks of GA, 67.4% (n = 31) received TH. A total of 58 (6%) deaths were reported with a higher mortality rate in infants born at 34-35 weeks of GA (OR 3.941, 95% Cl 1.446-10.7422, p = 0.007). CONCLUSION: The incidence of HIE remained similar over time with a reduction in mortality rate. The timing of TH initiation, whether [removed
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