SERBEST ORTAMDA LAZER İLE OPTİKSEL İLETİŞİM SİSTEMLERİ İÇİN BİLGİSAYAR SİMÜLASYONU

Free-Space Optical Communication (FSOC) systems are practical and effective wireless communication tools, because of their unique advantages: extremely high bandwidth, rapid deployment, low power consumption, weight, and size. However, adverse weather conditions, such as fog and haze degrade the system performance. In this study, a computer simulation model has been developed including semiconductor laser, photodetector and communication channel to evaluate the performance of a FSOC system for the horizontal paths shorter than 1 km.Çok yüksek band genişliği, düşük güç tüketimi, hızlı kurulum, ağırlık ve boyut gibi önemli avantajlar sağlayan Serbest Ortamda Optiksel İletişim (SOOİ) sistemleri, pratik ve etkin bir kablosuz iletişim türüdür. Bununla birlikte sisli ve puslu hava gibi hava koşulları sistemin performansını olumsuz etkiler. Bu çalışmada 1 km’den kısa yatay linkler için bir SOOİ sisteminin performansını değerlendirmek üzere yarıiletken lazer, fotodedektör ve iletişim kanalını içeren bir bilgisayar simülasyon modeli geliştirildi

Comparative evaluation of cotton and polyester woven fabrics finished with nanoparticles water repellent materials

Akademik ve endüstriyel olarak, nanometre ölçeğinde üretim miktarında bir artış görülmektedir. Ayrıca günlük hayatta ve malzeme teknolojilerindeki ileri uygulamaların kullanım taleplerinde de büyüme söz konusu olmaktadır. Moleküler seviyedeki nano teknoloji, yüksek kopma mukavemeti, sağlamlık, yumuşak tutum, su iticilik, güç tutuşurluk, anti mikrobiyal özellikler gibi istenen tekstil karakteristiklerin geliştirilmesinde kullanılabilmektedir. Nano teknolojideki son gelişmeler, tekstil endüstrisinde büyük fırsatlar yaratmaktadır. Tekstil materyallerine hidrofobik karakter kazandırmak için yapılan işlemler birçok çalışmanın konusunu oluşturmaktadır. Diğer taraftan, nano partiküllü su itici materyallerle işlem görmüş kumaşların performanslarının değerlendirilmesi yeni bir konu olarak görülmektedir. Bu çalışmanın amacı, su itici nano teknolojik bitim işlemlerinin araştırılması ve değerlendirilmesidir. Bu araştırmada ticari olarak kullanılan nano partiküllü su itici materyaller ile konvansiyonel su itici materyaller karşılaştırılmaktadır. Pamuk, polyester ve pamuk/polyester karışım kumaşlar kullanılmıştır. Numuneler iki farklı nano partiküllü kimyasal ile emdirildikten sonra termofiksaj işlemi yapılmıştır. Her tipte su iticilik maddesi ile işlem görmüş kumaşların yüzey özellikleri incelenmiştir. Kumaşların performanslarını ölçmek için sprey test cihazı ve hidrostatik test cihazı kullanılmış, ayrıca deneysel sonuçlar istatistiksel olarak değerlendirilmiştir. Deney sonuçları, nano partiküllü su iticilik maddeleriyle yapılan bitim işlemlerinin kumaşların su iticilik özelliklerini arttırdığını göstermektedir.There is an increasing amount of academic and industrial activity to produce multifunctional nanometre -scale containers and a growing demand for their use in sophisticated applications in the life and materials sciences. Nanotechnology at the molecular level can also be used to develop desired textile characteristics, such as high tensile strength, durability, soft hand, water repellent, fire retardant, antimicrobial properties and more alike. Recent advances in Nanotechnology have, indeed, created enormous opportunities and challenges for the textile industry, including the cotton industry. Treatment of textile materials in order to attain hydrophobic character has been the subject of many researches. On the other hand, finishing of fabrics with. Nano particles Water Repellent Materials and evaluation of quality performances of the resultant fabrics appear to be a receptive issue. The focus of this paper is, therefore, to investigate and evaluate applications of Nanotechnology finishing concerning water repellence

MODELLING OF AIR CONDITIONING SYSTEM BY FUZZY LOGIC APPROACH

One of the main problems in control systems is the difficulty to form the mathematical model associated with the control mechanism. Even though this model can be formed, to realize the application with conventional logic may cause very complex problems. The fuzzy logic without using mathematical model of control system can create control mechanism only with the help of linguistic variables. In this article the modeling has been realized by fuzzy logic

TRAFFIC SIGNALS MODELLING WITH LONG DISTANCE COMMUNICATIONS USING PIC MICROCONTROLLER

Today, microcontrollers are widely used in control and automation systems. For the automation of traffic signalization, the crossroads need to be controlled by microcontrollers and for the automation of more than one crossroad the communication of more than one microcontroller is required. In some special cases, the intercommunication of microcontrollers is required to change crossroad status and obtain continuous flow (green weave) synchronization. In this study, a method is proposed to control the traffic flow on a hospital road with two crossroads located several km. apart from each other. For the purpose of changing the crossroads status to have a continuous flow of the traffic, the series of PIC16F877 microcontroller is used

PIC MİKRODENETLEYİCİ İLE UZAK MESAFE HABERLEŞMESİ KULLANILARAK TRAFİK SİNYALİZASYON MODELLEMESİ

Günümüzde mikro denetleyiciler kontrol ve otomasyon sistemlerinde yoğun olarak kullanılmaktadır. Trafik sinyalizasyon otomasyonu için kavşak kontrol sisteminin bir denetleyici tarafından kontrolü ve birden çok kavşağın birlikte otomasyonu için ise birbirleri ile haberleşmesi gerekmektedir. Özel durumlarda kavşaklar normal çalışma modlarını değiştirmek ve yeşil dalga senkronizasyonunu sağlamak amacı ile birbirleri ile haberleşme ihtiyacı duymaktadır. Bu çalışmada bir hastane yolu üzerinde birbirinden uzak mesafelerde bulunan iki kavşak üzerinde bir ambulans yolunun açılabilmesi için kavşak çalışma modlarının değiştirilmesi ve kavşakların PIC 16F877 mikrodenetleyici ile kontrolünün gerçekleştirilmesi için bir model proje gerçekleştirilmiştir

Does transient hypothyroxinemia influence metabolic bone disease of prematurity?

Objective: To investigate the relationship between Metabolic Bone Disease (MBD) and Transient Hypothyroxinemia of Prematurity (THOP). Method: One hundred twenty-four infants, born in Marmara University Hospital with a gestational age 900 IU/l. THOP was defined as a serum free and/or total thyroxine level lower than -1 SD for gestational age at the 7th postnatal day. Result: THOP was diagnosed in nineteen (15.3%) patients. MBD was diagnosed in 52 (41.9%) at the 3rd month. Low birth weight, low gestational age and prolonged parenteral nutrition were associated with MBD. Multivariate analysis documented a significant relationship solely between MBD and gestational age. Conclusion: The risk of MBD does not increase significantly in babies with THOP

Warehouse Drone: Indoor Positioning and Product Counter with Virtual Fiducial Markers

The use of robotic systems in logistics has increased the importance of precise positioning, especially in warehouses. The paper presents a system that uses virtual fiducial markers to accurately predict the position of a drone in a warehouse and count items on the rack. A warehouse scenario is created in the simulation environment to determine the success rate of positioning. A total of 27 racks are lined up in the warehouse and in the center of the space, and a 6 × 6 ArUco type fiducial marker is used on each rack. The position of the vehicle is predicted by supervised learning. The inputs are the virtual fiducial marker features from the drone. The output data are the cartesian position and yaw angle. All input and output data required for supervised learning in the simulation environment were collected along different random routes. An image processing algorithm was prepared by making use of fiducial markers to perform rack counting after the positioning process. Among the regression algorithms used, the AdaBoost algorithm showed the highest performance. The R2 values obtained in the position prediction were 0.991 for the x-axis, 0.976 for the y-axis, 0.979 for the z-axis, and 0.816 for the γ-angle rotation

Comparison of three neonatal pain scales during minor painful procedures

Objective. There is no single or widely accepted method to define pain in neonates. The aim of this study was to compare three different neonatal pain scales in the estimation of the pain response to minor painful stimuli in healthy term neonates. Method. Thirty healthy neonates were included in the study. Video recordings of infants during heel prick blood sampling were evaluated by two observers according to the Neonatal Infant Pain Scale (NIPS), the Neonatal Facial Coding System (NFCS), and the Douleur Aigu du Nouveau-n (DAN). Crying times of infants were recorded, and the correlation between the three pain scales and crying time was calculated. The pain scores and inter-observer variability were analyzed. Results. The highest correlation between the crying time and each of the three different neonatal pain scales was found for NIPS (r=0.74, p < 0.001), while similar results were found for the DAN scale (r=0.67, p < 0.001) and the NFCS (r=0.67, p < 0.001). Inter-observer variability was similar for the three scales (NFCS r=0.95; DAN r=0.97; NIPS r=0.96). NFCS had a coefficient of variation (CV) of 59.8 +/- 32.2%. The DAN scale and NIPS had similar CV values (41.5 +/- 26.1% and 43.2 +/- 31.6%, respectively), but these values were significantly lower than that of NFCS. Conclusion. All three scales provided comparable results, with a slight difference favoring NIPS. Therefore, NIPS can be used to evaluate pain during minor painful procedures in neonates