Empirical Analysis of Pre-Paid and Post-Paid Mobile Subscription in Turkey

Bu çalışmada, Türkiye’de mobil telefon aboneliğinde faturalı ve faturasız hat tercihinin belirleyicileri incelenmektedir. Abone karakteristikleri ile abonelik türü (faturasız – faturalı hat) tercihi arasındaki ilişki ikili lojistik regresyon kullanılarak analiz edilmektedir. Analizlerde kullanılan veriler 2009 üçüncü çeyrekte yapılan anket sonucunda elde edilmiştir. Sonuçlar abonelik tercihi ile kullanılan bağımsız değişkenler arasında anlamlı bir ilişki olduğunu göstermektedir. Analizler neticesinde ankete katılan bireylerin tercihleri üzerinde bu bireylerle aynı hanedeki diğer bireylerin tercihlerinin önemli etkileri olduğu bulunmuştur. Ayrıca, bulunan sonuçlar, mobil telefonlarını genellikle konuşma ve internete girmek için kullanan abonelerin faturalı hat tercih etme olasılığının yüksek olduğunu gösterirken, faturasız hat tercih eden abonelerin ise mobil telefonlarını çoğunlukla kısa mesaj gönderme ve mobil telefon oyunları oynamak için kullanmaktadırlar.This paper investigates the determinants of pre-paid and post-paid mobile phone subscriptions in Turkey. The binary logit analysis is employed to explore the relationship between the subscribers’ characteristics and their subscription type i.e. pre-paid or post-paid. The data used in the analysis relies on a survey carried out during 2009-Q3. The results indicate that there is a statistically significant relationship between the subscription type choice and the dependent variables. It is found that the choices of the other members living in the respondents’ household have significant effect on the decisions of the subscribers. The results also show that the subscribers who use their phones mainly for mobile calls and for surfing on internet are more likely to have a post-paid subscription while the pre-paid users usually use their phones for short messages and for playing games on their mobile phones

Empirical Analysis of Pre-Paid and Post-Paid Mobile Subscription in Turkey

Bu çalışmada, Türkiye’de mobil telefon aboneliğinde faturalı ve faturasız hat tercihinin belirleyicileri incelenmektedir. Abone karakteristikleri ile abonelik türü (faturasız – faturalı hat) tercihi arasındaki ilişki ikili lojistik regresyon kullanılarak analiz edilmektedir. Analizlerde kullanılan veriler 2009 üçüncü çeyrekte yapılan anket sonucunda elde edilmiştir. Sonuçlar abonelik tercihi ile kullanılan bağımsız değişkenler arasında anlamlı bir ilişki olduğunu göstermektedir. Analizler neticesinde ankete katılan bireylerin tercihleri üzerinde bu bireylerle aynı hanedeki diğer bireylerin tercihlerinin önemli etkileri olduğu bulunmuştur. Ayrıca, bulunan sonuçlar, mobil telefonlarını genellikle konuşma ve internete girmek için kullanan abonelerin faturalı hat tercih etme olasılığının yüksek olduğunu gösterirken, faturasız hat tercih eden abonelerin ise mobil telefonlarını çoğunlukla kısa mesaj gönderme ve mobil telefon oyunları oynamak için kullanmaktadırlar.This paper investigates the determinants of pre-paid and post-paid mobile phone subscriptions in Turkey. The binary logit analysis is employed to explore the relationship between the subscribers’ characteristics and their subscription type i.e. pre-paid or post-paid. The data used in the analysis relies on a survey carried out during 2009-Q3. The results indicate that there is a statistically significant relationship between the subscription type choice and the dependent variables. It is found that the choices of the other members living in the respondents’ household have significant effect on the decisions of the subscribers. The results also show that the subscribers who use their phones mainly for mobile calls and for surfing on internet are more likely to have a post-paid subscription while the pre-paid users usually use their phones for short messages and for playing games on their mobile phones

Determination of heavy metal content in commercial marine fish hunted from southeast Aegean Sea (Turkey) and their potential risk for public health

In this study, heavy metals such as Al, Cr, Cu, Zn, Cd, Hg, Pb etc. content in liver, muscle and gill of three economical marine species [striped seabream (Lithognathus mormyrus Linneaus, 1758), two-band bream (Diplodus vulgaris Geoffroy Saint-Hilaire, 1817) and Common pandora (Pagellus erythrinus Linneaus, 1758)] obtained from 4 stations (Fethiye, Bodrum, Datça, Marmaris) in South Aegean coast were analyzed. After tissues were mineralized with wet-ashing, their heavy metal concentrations were measured with inductively coupled plasma mass spectrometry (ICP-MS). According to the findings, sediment samples had more heavy metals than water samples and none of heavy metal concentrations in the water samples exceeded national legal limits. Furthermore it was reported that the accumulation of heavy metal in liver and gill was the highest whereas in muscle the proportion was the lowest. Results showed that the mean concentration of the studied heavy metals in muscle tissues did not pose a risk in terms of public health in comparison with the international standards

Determining the effective constitutive parameters of finite periodic structures: photonic crystals and metamaterials

Cataloged from PDF version of article.A novel approach to find the effective electric and A novel approach to find the effective electric and magnetic parameters of finite periodic structures is proposed. The method uses the reflection coefficients at the interface between a homogenous half-space and the periodic structure of different thicknesses. The reflection data are then approximated by complex exponentials, from which one can deduce the wavenumber, and the effective electric and magnetic properties of the equivalent structure by a simple comparison to the geometrical series representation of the generalized reflection from a homogenous slab. Since the effective parameters are for the homogenous equivalent of the periodic structure, the results obtained are expected to be independent of the number of unit cells used in the longitudinal direction. Although the proposed method is quite versatile and applicable to any finite periodic structure, photonic crystals and metamaterials with metallic inclusions have been used to demonstrate the application of the method in this paper. © 2008 IEEE

Symptomatic Giant Cavernous Haemangioma of the Liver: Is Enucleation a Safe Method?

Twenty-three patients with symptomatic giant hemangioma of the liver were treated by surgery between 1979 and 1996 at the department of General Surgery, Faculty of Medicine, University of Çukurova. Twenty-three enucleations were performed in 21 patients, left lateral segmentectomy in one patient and enucleation plus left lobectomy in one patient. The tumors were enucleated along the interface between the hemangioma and normal liver tissue. The diameters of the tumors ranged from 5×5 to 25×15 cm. The mean blood loss for enucleations was 525 ml (range 500–1000 ml). There was no mortality and no postoperative bleeding. Three patients had postoperative complications. Enucleation is the best surgical technique for symptomatic giant hemangioma of the liver. It may be performed with no mortality, low morbidity and the preservation of all normal liver parenchyma

Optimal interval and duration of CAM-ICU assessments for delirium detection after cardiac surgery

STUDY OBJECTIVE: Our goal was to determine when postoperative delirium first occurs, and to assess evaluation strategies that reliably detect delirium with lowest frequency of testing. DESIGN: This was a retrospective study that used a database from a five-center randomized trial. SETTING: Postoperative cardiothoracic ICU and surgical wards. PARTICIPANT: Adults scheduled for elective coronary artery bypass and/or valve surgery. INTERVENTION AND MEASUREMENTS: Postoperative delirium was assessed using CAM-ICU questionnaires twice daily for 5 days or until hospital discharge. Data were analyzed using frequency tables and Kaplan-Meier time-to-event estimators, the latter being used to summarize time to first positive CAM-ICU over POD1-5 for all patients for various evaluation strategies, including all assessments, only morning assessment, and only afternoon assessments. Sensitivity for various strategies were compared using McNemar\u27s test for paired proportions. MAIN RESULTS: A total of 95 of 788 patients (12% [95% CI, 10% to 15%]) had at least 1 episode of delirium within the first 5 postoperative days. Among all patients with delirium, 65% were identified by the end of the first postoperative day. Delirium was detected more often in the mornings (10% of patients) than evenings (7% of patients). Compared to delirium assessments twice daily for five days, we found that twice daily assessments for 4 days detected an estimated 97% (95% CI 91%, 99%) of delirium. Measurements twice daily for three days detected 90% (82%, 95%) of delirium. CONCLUSIONS: Postoperative delirium is common, and CAM-ICU assessments twice daily for 4 days, versus 5 days, detects nearly all delirium with 20% fewer assessments. Four days of assessment may usually be sufficient for clinical and research purposes

Distance laboratory applications ERRL: A study on radio communication in electronic field

In the last decade, the effect of internet usage in education is gradually increased. When we look from academic perspective, the new technologies provided alternatives for students learning. As distance education becomes important everyday, the indispensable elements of teaching and education, laboratories must be reachable via remote connection. Consequently, the education that is going to be given to the students will be more flexible with respect to place and time constraints and students can reach laboratory facilities at any time and anywhere not only in lectures and practical hours. In this study, European Remote Radio Laboratory (ERRL) which is a distance remote Radio Frequency (RF) laboratory designed for electrical-electronics students, is described generally. The software architecture, infrastructure and experiment that can be done with a remote connection have been described

MR imaging of osteochondral grafts and autologous chondrocyte implantation

Surgical articular cartilage repair therapies for cartilage defects such as osteochondral autograft transfer, autologous chondrocyte implantation (ACI) or matrix associated autologous chondrocyte transplantation (MACT) are becoming more common. MRI has become the method of choice for non-invasive follow-up of patients after cartilage repair surgery. It should be performed with cartilage sensitive sequences, including fat-suppressed proton density-weighted T2 fast spin-echo (PD/T2-FSE) and three-dimensional gradient-echo (3D GRE) sequences, which provide good signal-to-noise and contrast-to-noise ratios. A thorough magnetic resonance (MR)-based assessment of cartilage repair tissue includes evaluations of defect filling, the surface and structure of repair tissue, the signal intensity of repair tissue and the subchondral bone status. Furthermore, in osteochondral autografts surface congruity, osseous incorporation and the donor site should be assessed. High spatial resolution is mandatory and can be achieved either by using a surface coil with a 1.5-T scanner or with a knee coil at 3 T; it is particularly important for assessing graft morphology and integration. Moreover, MR imaging facilitates assessment of complications including periosteal hypertrophy, delamination, adhesions, surface incongruence and reactive changes such as effusions and synovitis. Ongoing developments include isotropic 3D sequences, for improved morphological analysis, and in vivo biochemical imaging such as dGEMRIC, T2 mapping and diffusion-weighted imaging, which make functional analysis of cartilage possible

Development and Validation of a Risk Quantification Index for 30-Day Postoperative Mortality and Morbidity in Noncardiac Surgical Patients

ABSTRACT Background: Optimal risk adjustment is a requisite precondition for monitoring quality of care and interpreting public reports of hospital outcomes. Current risk-adjustment measures have been criticized for including baseline variables that are difficult to obtain and inadequately adjusting for highrisk patients. The authors sought to develop highly predictive risk-adjustment models for 30-day mortality and morbidity based only on a small number of preoperative baseline characteristics. They included the Current Procedural Terminology code corresponding to the patient'