Representation, editing and real-time visualization of complex 3D terrains

Ankara : The Department of Computer Engineering and the Graduate School of Engineering and Science of Bilkent University, 2012.Thesis (Master's) -- Bilkent University, 2012.Includes bibliographical references leaves 154-158.Terrain rendering is a crucial part of many real-time computer graphics applications such as video games and visual simulations. It provides the main frame-ofreference for the observer and constitutes the basis of an imaginary or simulated world that encases the observer. Storing and rendering terrain models in real-time applications usually require a specialized approach due to the sheer magnitude of data available and the level of detail demanded. The easiest way to process and visualize such large amounts of data in real-time is to constrain the terrain model in several ways. This process of regularization decreases the amount of data to be processed and also the amount of processing power needed at the cost of expressivity and the ability to create interesting terrains. The most popular terrain representation, by far, used by modern real-time graphics applications is a regular 2D grid where the vertices are displaced in a third dimension by a displacement map, conventionally called a height map. It is the simplest and fastest possible terrain representation, but it is not possible to represent complex terrain models that include interesting terrain features such as caves, overhangs, cliffs and arches using a simple 2D grid and a height map. We propose a novel terrain representation combining the voxel and height map approaches that is expressive enough to allow creating complex terrains with caves, overhangs, cliffs and arches, and efficient enough to allow terrain editing, deformations and rendering in real-time. We also explore how to apply lighting, texturing, shadowing and level-of-detail to the proposed terrain representation.Koca, ÇetinM.S

A New Method for The Optimization of Insulation Thickness for Radiant Wall Heating Systems

In this study we proposed a new modified New Degree-Day Method (NDDM) for the optimization of insulation thickness of the wall where the radiant panels are mounted (WMRP) in which heat generation inside the wall is considered. The existing Standard Degree-Day Method (SDDM) is not applicable to estimate the optimum insulation thickness for the buildings where the WMRP is mounted. Because SDDM method uses indoor air temperature as a base temperature, hence heat generation through the WMRP cannot be taken into account. In the new method, important parameters were obtained from the series of the CFD analysis for different thermal transmittance coefficient (U) and outdoor air temperature (To) values are used to create an empirical equation for the estimation of Tp (new base temperature) with the multiple polynomial regression method. Then the numerical results were validated with experimental results which were obtained from the real-size test chamber. Using the new method optimum insulation thickness, net energy saving and payback periods for radiant wall heating systems were calculated (for Istanbul climate) and compared with the results which were obtained using the standard degree-day method (SDDM). The results showed that, the SDDM significantly lower (85-95%) estimates the optimum insulation thickness and can’t be used for the buildings where the WMRP is used. The new method can be used for radiant wall heating systems where the performance of radiant heating systems is significantly affected by the insulation capabilities and has a great importance in the sizing process of the radiant systems.Bu çalışmada ışınım ısıtma panellerin kullandığı duvarlardaki yalıtım kalınlığının optimizasyonu için, duvarlardaki ısı üretimini dikkate alan, yeni bir derece-gün yöntemi (NDDM) geliştirilmiştir. Standard Derece-Gün Yöntemi (SDDM) temel sıcaklık olarak mahal hava sıcaklığını dikkate almakta ve duvara monte edilmiş ışınım panellerindeki ısı üretimini dikkate alamamaktadır. Bu yüzden standart yöntem ile ışınım panellerin bulundugu duvarlar için yalıtım kalınlığı optimizasyonu yapmak imkansızdır. Önerilen yeni metotta kullanılan yeni temel sıcaklık değerinin (Tp) elde edilmesinde kullanılan ampirik ifade (3. dereceden polinom) farklı yapı ısı geçirgenlik katsayısı (U) ve farklı dış hava sıcaklıkları (To) parametreleri için sayısal analizlerden elde edilmiştir. Daha sonra sayısal çalısmaların sonuçları aynı şartlarda yürütülen gerçek ölçekli deney sisteminde doğrulanmıştır. İstanbul iklim şartları için yeni yöntem ve eski yontem kullanılarak ideal yalıtım kalınlıkları, enerji tasarrufları ve geri dönüş süreleri hesaplanmış, iki yöntemden elde edilen sonuçlar kıyaslanmiştir. Sonuçlara göre eski yöntemle hesaplanan ideal yalıtım kalınlığı yeni yöntemden elde edilen değerin çok altında (%85-95) kalmaktadır. Bu yüzden standart yöntemin ısı üretimi olan duvarlarda kullanılmasının mümkün olmadığı görulmüştür. Önerilen yeni yöntem ise, ışınımla ısıtma sistemlerinin projelendirilmesinde önemli bir kriter olan ısı kayıplarının hesaplanması ve ideal yalıtım kalınlığının belirlenmesinde kullanılabilecektir

A hybrid representation for modeling, interactive editing, and real-time visualization of terrains with volumetric features

<div><p>Terrain rendering is a crucial part of many real-time applications. The easiest way to process and visualize terrain data in real time is to constrain the terrain model in several ways. This decreases the amount of data to be processed and the amount of processing power needed, but at the cost of expressivity and the ability to create complex terrains. The most popular terrain representation is a regular 2D grid, where the vertices are displaced in a third dimension by a displacement map, called a heightmap. This is the simplest way to represent terrain, and although it allows fast processing, it cannot model terrains with volumetric features. Volumetric approaches sample the 3D space by subdividing it into a 3D grid and represent the terrain as occupied voxels. They can represent volumetric features but they require computationally intensive algorithms for rendering, and their memory requirements are high. We propose a novel representation that combines the voxel and heightmap approaches, and is expressive enough to allow creating terrains with caves, overhangs, cliffs, and arches, and efficient enough to allow terrain editing, deformations, and rendering in real time.</p></div

Prevalence of urınary ıncontınence ın women who applıed to a famıly health center ın the Van Provınce

Our aim of this study was to determine the incidence of urinary incontinence in women living in a family health center district in the province of Van, the effect of birth rate and type of delivery on urinary incontinence, the awareness level of women in this subject. This is a descriptive-cross-sectional study. The study was conducted by face to face survey method in women gave birth who applied to Family Health Center no.1 in Ipekyolu District. 227 women who agreed to participate in the study were included in the study. The mean number of pregnancies was 4.13 ± 0.71, 83 of the women (36.6%) stated that they had incontinent. 31 (37.3%) reported compression type, 25 (30.1%) stress type and 27 (32.6%) mixed type incontinence, 170 (74.9%) of the women see urinary incontinence as a health problem. The high number of children significantly increases urinary incontinence. Urinary incontinence is significantly higher in patients with diabetes mellitus. Women who have had their birth at home have higher urinary incontinence incidence than the women who have had all their births at hospital. Receiving education for 8 years and below increases to see urinary incontinence as a health problem. It is important in terms of women's health to educate women on reproductive health, to make full use of family planning services and to take all necessary measures to make all deliveries in hospital

Güneydoğu Anadolu Bölgesi Hububat Alanlarında Bulunan Cercopis sanguinolenta (Scopoli, 1763) (Hem.: Cercopidae)’nın Yayılışı ve Yoğunluğu Üzerine Notlar

Bu çalışma; 2014-2015 yıllarında Güneydoğu Anadolu Bölgesi’nde Cercopidae familyasına ait Cercopis sanguinolenta (Scopoli 1763) (Hemiptera: Auchenorrhyncha)  türünün yayılış ve yoğunluklarının belirlenmesi amacıyla yapılmıştır. Adıyaman, Diyarbakır, Mardin ve Şanlıurfa illeri buğday ve arpa ekiliş alanlarından, Nisan ve Mayıs aylarında örneklemeler yapılarak bu türe ait bireyler toplanmıştır. Cercopis sanguinolenta’nın toplam birey sayısı ve ortalama yoğunluğu en fazla Mardin ilinde (toplam 3.050 ergin, 105.2 ergin tarla), en az ise Diyarbakır ilinde (toplam 252 ergin, 7.0 ergin tarla) elde edilmiştir. Arpa alanlarında C. sanguinolenta’nın buğday alanlarına göre daha fazla bulunduğu ve bu oranın sırasıyla ortalama 94.9 ergin tarla, 22.8 ergin tarla olduğu belirlenmiştir. Sonuç olarak arpa ve buğday alanlarında yoğun olarak bulunan; C. sanguinolenta’nın zarar durumuna ait çalışmaların yapılmasının gerekli olduğu düşünülmektedir

Evaluation Of Family Physicians' Concerns About Working Conditions, Transmission Of The Disease And Transmission To Family Members İn The COVID-19 Pandemic

Introduction: Family Physicians (FPs) who are experiencing high levels of stress and psychological distress as a result of the recent COVID-19 outbreak are also faced with the dilemma of "keep them alive or survive" due to the difficulty of managing the pandemic. The purpose of this study was to look into the working conditions of FPs during the COVID-19 pandemic, as well as their concerns about the disease spreading to them and their families. Method: A total of 255 FPs participated in this cross-sectional study. A 26-question Descriptive Data Form was used as data collection tool. Results: While the average working year of FPs was 13.7±10.2, the average weekly working hour was 42.1±7.6 during the pandemic. 39.2% of FPs work in the family health center, 38.0% in university hospitals, 16.5% in state hospitals. 51.4% of FPs stated that they hadn't experienced an epidemic before, and 54.9% stated that their expenses increased during the pandemic period. 92.9 % said they vaccinated the COVID-19 vaccine. 22.7 % of FPs were forced to stay somewhere other than their homes to avoid transmission, 51.4 % of physicians' working orders have changed. 54.1 % worked in a pandemic hospital, while 78.8% looked after a suspected COVID-19 patient. The level of anxiety increases as the number of patients treated rises (p&lt;0.05). It was found that as the difficulty of coping increased while doing this in the daily routine, the anxiety of infecting the disease and infecting the family increased as well (p&lt;0.05) Conclusions: Family physicians were more concerned about transmitting the COVID-19 disease to their family members than themselves. There was a link between the difficulty of coping while performing services for COVID-19 patients and the anxiety of transmission of the disease. Family physicians should be supported not only at their workplace but also for the ones that they are as caregivers.</p