Impact of the population density on quality of life

The aim of this study was to compare life quality of people living in İstanbul, Ankara and İzmir having higher population density to those living in cities having lower population density. 2060 people from İstanbul, Ankara and İzmir, 5892 people from other cities, totally 7952 people, were participated in the study. Turkish version of WHOQOL-BREF scale consisting 27 items, developed by World Health Organization with the participation of 15 collaboration centers was used to determine life quality of participants. WHOQOL-BREF scale includes four dimensions; physical, psychological, social relations, and environment SPSS 16.0 was used to analyzed collected data. Descriptive analyze was used to determine characteristics of participants, Independent t test was used to compare cities having different populations densities, crosstab and chi square tests were used to analyze items not included in scoring. Significant differences were found between people from cities having different population density in terms of physical and environmental field (p<0.05), and psychological field (p<0.01). No significant difference was found in terms of social field (p>0.05). Consequently, according to higher level of life quality scores of people living in high population density than those living low population densities in terms of physical, psychological, social and environmental field, it can be said that it is a positive reflection of life to life quality in cities having higher population density.

A Novel Design of Low-Voltage VDIBA and Filter Application

In this study, a low-voltage low-power design of previously introduced analog signal processing element called as Voltage Differencing Inverting Buffered Amplifier (VDIBA) is presented. Level shifter current mirrors are used in the circuit design in order to accomplish the low-voltage low-power operation. The configuration operates only with ±0.4 V supply voltages and consumes power 569 μW at the bias current 50 μA. Also, low-voltage transconductor which has highly linear gm is executed with the use of bulk-driven quasi-floating gate (BD-QFG) and source degeneration techniques. The simulations of the introduced circuit have been performed with 0.18 μm TSMC CMOS technology by SPICE. The theoretical approaches have been confirmed by the simulation results

The Analysis of Patients Operated for Frontal Sinus Osteomas

Objective:Paranasal sinus osteomas are benign tumors that are smooth-walled, slow-growing, and induced by bone tissue. Although their most common localization is the frontal sinus, some osteomas are seen in the ethmoid, maxillary, and sphenoid sinuses. Frontal sinus osteomas are often asymptomatic; however, when they become symptomatic, headache is the most common complaint. In this study, we aimed to analyze the postoperative results of patients who were diagnosed with frontal sinus osteoma and were operated with appropriate surgical techniques.Methods:We retrospectively evaluated 14 patients who were diagnosed with frontal sinus osteoma and were operated in our department between March 2009 and July 2014. The following parameters were analyzed: patients’ age and gender, complaints at the time of admission to our clinic, pathological findings from physically examination, tumor features observed in preoperative paranasal sinus computed tomography (size and localization), surgical methods applied, intra- and postoperative complications, and recurrence rates. All patients preoperatively provided informed consent.Results:Of the 14 patients, 7 were males and 7 were females, with a mean age of 40.57 years. A total of 11 (79%) osteomas were located within the frontal sinus and 3 (21%) within the frontal recess. External surgical approach was performed to 11 patients, endoscopic approach was performed to 2 patients and external and endoscopic approach was performed to 1 patient together.Conclusion:Although the preferred surgical method in frontal sinus osteoma depends depended on size and localization of tumors, experience of surgeon is also important. Although the external surgical approach is appropriate for large and laterally localized osteomas, the endoscopic approach is appropriate for small and inferomedially localized osteomas. In both surgical approaches the site of origin should be drilled

Volume CXIV, Number 4, November 7, 1996

Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population.Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014.Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosis) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto's thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%.Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespa

The impacts of the wind on GPS of quadrotors

Purpose: The Global Positioning System (GPS) is crucial for determining the positions of quadrotors, enabling safe flight and maintaining stability against environmental conditions. This study aims to investigate the effect of wind on the GPS of quadrotors experimentally. Design/methodology/approach: This experimental study was conducted using an F450 frame, 980 kV motors and a Pixhawk flight controller to manage the quadrotor’s flight. To investigate the effects of wind on the quadrotor’s GPS during flight, a Pixhawk 4 Holybro flight controller was used. The experimental tests were performed on a predetermined route at different wind speeds. Findings: Analysis of the data obtained from the flight tests showed that GPS signals were more affected as the wind speed increased. The percentage of GPS jamming levels reached 18% at high wind speeds. Practical implications: Positioning services will be even more critical for quadrotors, which are expected to be used more frequently in public areas. This study is expected to be a reference for GPS-related research. Originality/value: Winds pose a significant threat to the safe flight of quadrotors in many ways. This study experimentally investigates the effects of wind on the GPSs of quadrotors and to what extent it affects them at different wind speeds under real weather conditions. The obtained data shows that wind has a significant impact on GPS jamming

A linear current-controlled floating negative resistor

In this article, a low voltage CMOS current controlled floating negative resistor which is convenient for integrated circuit implementation is designed by using a self-cascode composite transistor. The proposed circuit only required +/- 0.75 V as a power supply has a simple circuit structure and a low power consumption of which value is only 65 mu W. The basic advantages of this circuit are a wide tuning range of the resistance value, an acceptable frequency performance and a wide dynamic range. The performances of the proposed circuit are simulated with SPICE to confirm the presented theory

Driving stepper motors

Bu tezde adımlı motorların sürülmesi ile ilgili çeşitli devreler incelenmiştir. İncelenen bu devreler bugüne kadar kullanılmış olup, bazı sakıncaları gözlenmiştir. Çalışmalarımızı daha ileri götürerek şimdiye kadar hiç kullanılmamış bir sürme devresi gerçeklenmiş olup, diğer devre­lerle karşılaştırıldığında hiçbir sakıncası görülmemiştir. Ay­rıca akım-zaman eğrisi de diğerlerine nazaran oldukça iyileştirilmiştir.In this work circuits which drive the stepper motora have been examined. Circuits which have been examined were used until today and it was seen that they have some defects. When the work has been continued, a driving Circuit which was not used until today has been verified. When it has been compared with the other circuits it is seen that it is defectiveness Finally also current-time curve has been improved with regard t o the others

Investigation of wind effect on different quadrotors

Purpose Although windy weather conditions have a significant effect on the flight safety and stability of any aircraft, the fact that quadrotors are lighter than other aircraft makes them more sensitive to the wind. This study aims to examine the extent to which quadrotors and their sensors, which are used in many fields and whose use is expected to increase significantly in the future, are affected by wind. Design/methodology/approach Flight experiments were carried out on different routes assigned by using Pixhawk Holybro 4 and Radiolink flight controllers. In these flight experiments, quadrotors were exposed to winds at different speeds and directions. Findings In the flight experiments, the deviation amounts in the quadrotor's route at which wind speed was determined, and it was seen that these deviations were very serious and affected the safe flight at high wind speeds. According to the sensor information obtained from both different quadrotors' flight experiments at different wind speeds, it was determined that the wind decreased the sensors' accuracy. Practical implications It is foreseen that the data obtained in this study will be a source to be used in the design of quadrotors to be used in public areas in the future and to take the wind into account for safe flight. Originality/value In this study, numerous flight tests were carried out experimentally at various speeds from low speeds to high speeds on different routes using different flight controllers. The deviation data on the obtained routes and the effect of the wind on the sensors are experienced in real atmospheric conditions

Performance analysis of electrical flight control actuation system in a commercial transport aircraft

Purpose In more than 100 years of aviation, significant progress has been made in flight control systems. The aircrafts that have entered service for the past ten years tend towards power-by-wire flight control with electrical actuators. The purpose of this study is to analyse the effects of electrical actuation on power consumption, weight and fuel consumption on a commercial transport aircraft. Design/methodology/approach The Airbus A321-200 aircraft was chosen as a case study for analysing the effects of electrical actuation on the flight control actuation system (FCAS) architecture, and Pacelab SysArc software was used for design, modelling and analysis. As alternatives to the existing system, hybrid and all-electric models are built to a set of design guidelines with certain limitations. Findings Compared to the existing FCAS architecture model, 80 kg weight savings in the hybrid FCAS architecture model and 171 kg weight savings in the all-electric FCAS architecture model were observed. In terms of fuel consumption, it has been observed that there is 0.25% fuel savings in the hybrid FCAS architecture model, and 0.48% fuel savings in the all-electric FCAS architecture model compared to the existing FCAS architecture model at 3200 NM. Practical implications In line with the data obtained from this study, it is predicted that electrical actuation is more preferable in aircraft, considering its positive effects on weight and fuel consumption. Originality/value In this study, three different models were created: the existing FCAS architecture of a commercial transport aircraft, the hybrid FCAS architecture and the all-electric FCAS architecture. Hybrid and all-electric models are built according to a set of design guidelines, with certain limitations. Then, similar flight missions consisting of the same flight conditions are defined to analyse the effects of power consumption, weight, and fuel consumption comparatively