Artificial neural network approach for modeling of the short range precipitation

Yağış kaynaklı doğal afetlerin önlenebilmesi ile su kaynakları ve havza yönetimi için yağışların ölçümü, modellenmesi ve tahminleri çok önemlidir. Kurulu olan yağış ölçer ağlarının hem zaman hem de uzay değişkenliklerinin yüksek olması sebebiyle, küçük ölçeklerdeki şiddetli yağışların belirlenmesinde çeşitli zorluklar vardır. Mevcut hava tahminlerinin son yıllardaki güvenilir sonuçlarına rağmen, konvektif yağışların zaman ve alan yağış desenleri tam olarak yakalanamamaktadır. Bu sebeple uydulardan elde edilen bilgiler hava tahmin modellerine girdi olarak kullanılmaktadır. Yağış tür ve miktarının uzaktan algılama ile belirlenmesi meteoroloji alanındaki önemli konulardan biridir. Bu amaçla kullanılan cihazlar radar ve uydulardır. Bunlar arasında zaman ve uzay çözünürlüğü en yüksek olan uydu sistemleridir ve bu da onlara önemli bir avantaj sağlamaktadır. Konvektif yapılar için bulut tepe sıcaklığı yağış ile ilişkilendirilebilen anahtar bir parametredir. Buradaki yaklaşım, soğuk tepeli bulutların sıcak tepelilerden daha fazla yağış ürettiklerine dayanmaktadır. Buradan hareketle Arkin, GOES yağış indeksi, ayarlanmış GOES yağış indeksi, Griffith-Woodley, Negri-Adler-Woodley, konvektif-stratiform, güçlendirilmiş konvektif-stratiform, otomatik tahmin edici ve geliştirilmiş otomatik tahmin edici teknikleri gibi ekvator yörüngeli uydu verisini kullanan yöntemler geliştirilmiştir. Tüm bunlar yapılarında doğrusal amprik denklemler içermektedir ve bu denklemlerdeki katsayıların ülkemiz için belirlenmesi zorunluluğu vardır. Buradan hareketle, bu çalışmada 2000 yılı içerisindeki 5-7 Eylül dönemine ait bir konvektif yağışlı olay incelenerek, bir Yapay Sinir Ağı modeli kurulmuştur. Bu model Eylül ayı yağışını gayet iyi tahmin etmiştir. Anahtar Kelimeler: Marmara, yağış, kısa vadeli tahmin, yapay sinir ağları, uzaktan algılama.  In order to mitigate with the natural hazards (surface water, floods, etc.) of precipitation origin it is necessary to measure, model and predict the precipitation for water resources and basin management. Due to high spatial and temporal variability of precipitation measurement networks, there are difficulties in determining small scale intensive rainfall events. Currently available weather prediction models yield reliable results, but they cannot catch the spatio-temporal patterns of convective rainfall events. For this reason, the satellite based meteorological information is used as input in weather prediction models. One of the most significant subjects in meteorology domain is the determination of precipitation pattern types and quantities through remote sensing. The instruments used for this purpose are radars and satellites. Satellite systems have the most refined resolution among all these instruments, which provide them significant superiority. For convective structures the cloud top temperature is a key parameter that can be related to precipitation. The basic idea herein is that the cold cloud top temperatures generate more precipitation than hot or warm cloud top temperatures. Keeping this point in mind, first currently available techniques in the literature are explained in detail including Arkin, GOES precipitation index, adjusted GOES precipitation index, Griffith-Woodley, Negri-Adler-Wooley, convective-stratiform, enhanced convective-stratiform, automatic estimator, and advanced automatic estimator techniques. They include empirical equations in their structure and the parameters of these equations must be determined for our country. On the other hand, these methods include linear relationships. In this paper, one convective precipitation event in 2000 is examined each within time period as 5-7 September. These are explained by considering Meteosat 7 infrared channel data for 6-hour total rainfall amounts in such a manner that the data at the upper troposphere vertical levels are transferred to grid points from NCEP/NCAR. The application of the methodology is presented for 26 Marmara region raingauge stations. On the other hand, as effective methodology Artificial Neural Network (ANN) is used and, it has the analogy such that the inputs are taken from the environment through the neurons and transmitted to the brain. ANNs can be thought as a black box model, which processes inputs and produces convenient outputs for inputs. As a first stage this black box is trained and after training system reaches level of decision for inputs. ANNs have ability of learning, due to their training stages. This is feature that there is not available in any classical method. The ANN model can learn by training similar to a human and it has a non-linear structure. Such a non-linearity provides a distinctive possibility in the domain of artificial intelligence. For the model ANN and its analysis, various statistical criteria are used as detection probability (POD), bias, wrong alarm ratio (FAR), critical success index (CSI), target ratio (HR), and transferring of grid points to station points by using a method called inverse distance square. These statistical criteria are explained in this paper. By following the methodology explained above, as a result of ANN properties, convenient architecture for total precipitation amount prediction is proposed that constitutes single input, hidden and output layers with 37, 19 and 1 neurons, respectively. Furthermore, this model is used for precipitation prediction by considering each within time period as 5-7 September. The correlation value of ANN model is 0.89 in testing. Moreover, statistical values are calculated as POD = 0.61, FAR = 0.30, CSI = 0.49, BIAS = 0.86 and HR = 0.77. For this period, rainy events are predicted with success. As it is seen from the descriptions and application results, the cloud top temperature is more related to precipitation by considering low level data of troposphere. Under the light of the proposed prediction model this is the result of key parameter, which reflects the cloud top temperature significant relationship to precipitation. Although other parameters have also significance to lesser degrees the final prediction model take into consideration few of the input variables. In the mean time different combinations of the prediction are investigated throughout the study. Keywords: Marmara, precipitation, short range, prediction, artificial neural network, remote sensing. 

The validation service of the hydrological SAF geostationary and polar satellite precipitation products

Abstract. The development phase (DP) of the EUMETSAT Satellite Application Facility for Support to Operational Hydrology and Water Management (H-SAF) led to the design and implementation of several precipitation products, after 5 yr (2005–2010) of activity. Presently, five precipitation estimation algorithms based on data from passive microwave and infrared sensors, on board geostationary and sun-synchronous platforms, function in operational mode at the H-SAF hosting institute to provide near real-time precipitation products at different spatial and temporal resolutions. In order to evaluate the precipitation product accuracy, a validation activity has been established since the beginning of the project. A Precipitation Product Validation Group (PPVG) works in parallel with the development of the estimation algorithms with two aims: to provide the algorithm developers with indications to refine algorithms and products, and to evaluate the error structure to be associated with the operational products. In this paper, the framework of the PPVG is presented: (a) the characteristics of the ground reference data available to H-SAF (i.e. radar and rain gauge networks), (b) the agreed upon validation strategy settled among the eight European countries participating in the PPVG, and (c) the steps of the validation procedures. The quality of the reference data is discussed, and the efforts for its improvement are outlined, with special emphasis on the definition of a ground radar quality map and on the implementation of a suitable rain gauge interpolation algorithm. The work done during the H-SAF development phase has led the PPVG to converge into a common validation procedure among the members, taking advantage of the experience acquired by each one of them in the validation of H-SAF products. The methodology is presented here, indicating the main steps of the validation procedure (ground data quality control, spatial interpolation, up-scaling of radar data vs. satellite grid, statistical score evaluation, case study analysis). Finally, an overview of the results is presented, focusing on the monthly statistical indicators, referred to the satellite product performances over different seasons and areas

Konveksiyonel takım tezgahlarının modernizasyonunda dijital koordinat ölçme sistemlerinin analizi

Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır.ÖZET Anahtar KelimelenElektronik ölçüm, Fotoelektriksel tarama, Tezgah verimliliği, Üretim maliyeti. Bu tezde, literatürde var olan bazı elektronik yer değişim ölçüm sistemlerinin prensipleri araştırıldı, bu sistemlerin dayandığı bilimsel temeller saptandı. Endüstri uygulamalarında karşılaşılan problemler ve çözüm yöntemleri vurgulandı. Klasik ölçme yöntemleriyle karşılaştırılarak verim ve maliyete olan etkisi saptandı. Birinci bölümde, elektronik ölçüm sistemlerinin genel özellikleri, takım tezgahlarına getirdikleri üstünlükler ele alındı. İkinci bölümde, yer değişimin elektronik verilere çevrilme prensiplerinden bazıları araştırıldı. Konu iki ana kısımda incelendi. Birinci kısımda elektriksel veri elde etme yöntemleri (direnç değişimi, kapasitans değişimi, manyetik endüktif işlemler) ele alındı. İkinci kısımda ise direk dijital (lojik) çıkış elde etme yöntemleri (fırçalı ve elektro-optik sistemler) incelendi. Üçüncü bölümde, elektro-optik sistemlerin (foto-elektriksel tarama) endüstri uygulamaları incelendi. Karşılaşılan problemler (montaj, ısıl davranış) değerlendirildi. Dördüncü bölümde ise, geometrileri birbirinden farklı olan iki makina elemanı, hem dijital ölçme sistemi kullanılarak hem de klasik ölçme sistemi kullanılarak imal edildi. Bu uygulama ile, imalatta dijital ölçme sistemi kullanmanın maliyete olan etkisi araştırılmıştır. Ayrıca geometri farklılığının elde edilen sonuçları değiştirip değiştirmediği belirlenmiştir. Sonuçlar bölümünde ise, mekanik ölçme ile dijital ölçme kıyaslanarak elde edilen sonuçlar tartışıldı.THE ANALYSIS OF DIGITAL READOUTS IN MODERNISATION OF CONVENTIONAL TOOLING Keywords: Electronic measurement, Photoelectrical scaning, Productivity of tooling, The cost of production. In this thesis, the prenciples of some electronic system of displacement measurements that are in literature were searched and the scientific bases that based upon these system were fixed. The problems encountered at the industrial aplications and soluation methods were emphasizsed. Comparing with the classical methods of measurements and its effect on cost and productivity was fixed. In the first chapter, general features of electronic displacement system and superiorities that gained by tooling were discussed. In the second chapter, some of the transduction prenciples of displacement to electronic outputs were searched. This was searched in two parts. At the first part, the methods of getting electrical output (resistance change, capacitance change, magnetic inductive processes) were discussed. At the second part, the methods of getting direct digital (logic) output were look up (with brushes system or electro- optic system). In the third chapter, the industrial applications of electro-optic system (photo electrical scaning) were discussed. Encountered problems (mounting, thermal behaviour) were evaluated. In the four chapter, two workpiece these are different each other of geometry were produced using both digital measuring system and classical measuring system. In this working, the effect of use of digital measuring system in production to cost price was searched. In the addition the effect of different of geometry to outcomes were studied. At the conclusion, comparing mechanical measurement with electronic measurement and outcomes were discussed. X

The Reactions Of The Leading International Organizations To The Illegal Annexation Of Crimea

21 Kasım 2013’te Yanukoviç hükümetinin, Avrupa Birliği ile Ukrayna arasında imzalanması planlanan Ortaklık Anlaşmasını askıya aldığını açıklamasından sonra başlayan protestolar, kısa sürede genişleyerek iktidar karşıtı protestolara dönüşmeye başlamış ve büyük bir iç siyasi mesele haline gelmiştir. Ukrayna bu sorunun çözümü için uğraş verirken, Rusya Federasyonu 2014 Mart ayı başlarında Kırım’a asker göndermiş ve 16 Mart 2014’te yasadışı bir referandum sonucu Kırım ile Akyar’ı (Sivastapol), kendi federal bölgesi olarak ilan etmiştir. Bu işgal ve yasadışı ilhaka birçok devlet ve uluslararası örgütten tepki gelmiştir. Bu çalışma, Kırım’ın yasadışı ilhak sürecini irdelemekte ve bu yasadışı ilhaka Birleşmiş Milletler, Avrupa Birliği, NATO, Avrupa Güvenlik ve İşbirliği Teşkilatı, Şanghay İşbirliği Örgütü, Kolektif Güvenlik Anlaşması Örgütü ve İslam İşbirliği Teşkilatı gibi önde gelen uluslararası örgütlerin tepkilerini incelemektedirThe protest, which started on 21 November 2013 after Yanukovych government’s announcement about the suspension of the Association Agreement, which was planned to be signed between the European Union and Ukraine, soon evolved into anti-government protests and turned into a major domestic political issue. While Ukraine was struggling to solve this problem, Russian Federation sent its troops to Crimea in early March 2014 and annexed Crimea and Akyar (Sevastapol) following an illegal referendum held on 16 March 2014. Many states and international organizations react to this occupation and illegal annexation. This study reviews the process of the illegal annexation process of Crimea and examines the reactions of the leading international organizations, namely, United Nations, European Union, North Atlantic Treaty Organization, Organization for Security and Cooperation in Europe, Shanghai Cooperation Organization, Collective Security Treaty Organization and Organization of Islamic Cooperation