Detecting Precipitation Climate Changes: An Approach Based on a Stochastic Daily Precipitation Model

2002 Mathematics Subject Classification: 62M10.We consider development of daily precipitation models based on [3] for some sites in Bulgaria. The precipitation process is modelled as a two-state first-order nonstationary Markov model. Both the probability of rainfall occurrance and the rainfall intensity are allowed depend on the intensity on the preceeding day. To investigate the existence of long-term trend and of changes in the pattern of seasonal variation we use a synthesis of the methodology presented in [3] and the idea behind the classical running windows technique for data smoothing. The resulting time series of model parameters are used to quantify changes in the precipitation process over the territory of Bulgaria

Wykrywanie w czasie rzeczywistym i niwelowanie masowych ataków w sieciach SDN

Distributed Denial of Service (DDoS) flooding attack threats are becoming more and more relevant due to the advances in the Software Defined Networks (SDN). This rising trend creates an emerging need for defense mechanisms against such attacks. In order to address those issues the following paper focuses primarily on the implementation of an automatic real-time DDoS defense application based on sFlow technology. Initially we start by constructing a special flow, bound to a metric in order to capture traffic of interest. As soon as the flow reaches a certain predefined metric level, it is sent to an analyzer. Next we implement a detection algorithm based on the event handling capabilities of the sFlow-RT real-time analyser. Finally, the algorithm is tested with emulation network Mininet using network traffic, resulting in quick and effective DDoS attack mitigation.Zagrożenia w wyniku rozproszonej odmowy usługi (DDos) w przypadku masowego ataku stają się coraz bardziej możliwe z uwagi na rozwój programowalnych sieci (SDN). Ten rosnący trend powoduje konieczność tworzenia mechanizmów obronnych na wypadek takich ataków. W celu odniesienia sie do takich zagadnień, artykuł ten przede wszystkim skupia się na wdrażaniu automatycznych, działających w czasie rzeczywistym aplikacji obronnych DDoS, opartych na technologii sFlow. Wstępnie rozpoczynamy od stworzenia określonego przepływu, związanego z pomiarem w celu wychwycenia jak duże jest zainteresowanie eksploracją danych. Jak tylko przepływ osiągnie pewien wcześniej określony poziom, informacja zostaje wysłana do analityka. Następnie wdrażamy algorytm wykrywania, w oparciu o zdarzenie, który posiada funkcje analityka sFlow dzialajacego w czasie rzeczywistym. Na koniec testuje się algorytm przy wykorzystaniu emulacyjnej sieci Mininet, wykorzystującej eksplorację danych, co w rezultacie szybko i w efektywny sposób niweluje masowy atak DDoS

Нordein polymorphism between spring barley cultivars by SDS-PAGE electrophoresis

Abstract. In this study reserve endosperm proteins, hordeins of seven spring barley cultivars with different origin: Zernogradskii (Russia), Bodega, Fink, Scarlett and Barke (Germany), Josefin and Astoria (France) were fractionated and characterized by SDS-PAGE electrophoresis. On the basis of the obtained spectra 19 bands (D + C + B) with different relative electrophoretic mobility and intensity were identified. The electrophoresis profiles of the groups D-, C- and B- hordein are designated as separate types (models) using the index corresponding to hordein blocks. We have established one profile type for D-hordein (D1), two- for C-hordein (C1, C2), and five – for B-hordein (B1, B2, B3, B4, B5). Based on these results hordein formulas (configurations) of accessions are constructed, which enable the expression of specific varietal characteristics and prove the existence of the inter allelic variation (hordein polymorphism) due to the presence or absence of protein components and their different electrophoretic mobility in the profiles of D-, C- and B-hordein

Yield and coefficient of ecological valence of spring barley in the regions of Sadovo and Karnobat, Bulgaria

Abstract. The study was conducted to examine the yield and the coefficient of ecological valence of spring barley in the regions of Sadovo and Karnobat. Seven spring barley cultivars were planted in the first and second ten days of March, in comparative cultivars trials on the block method in four repetitions of an area of 10 m2, with sowing rate of 450 germinating seeds per m2. They were assessed on the standard for the French cultivar Josefin used of the Executive Agency of Varietal Testing, Field Inspection and Seed Control. The statistical processing of the results was carried out by ANOVA. The coefficient of ecological valence (W) is calculated. Cultivars grown in the region of Sadovo showed better ecological plasticity, but gave lower yields, in the region of Karnobat were more productive but difficult to adapt to environmental conditions. Suitable cultivars for growing spring barley in the regions of Sadovo and Karnobat are Barke, Scarlett and Bodega. They exceed the standard variety Josefin in yield with proven differences at both test sites

Medium-density fibreboards bonded with phenol-formaldehyde resin and calcium lignosulfonate as an eco-friendly additive

The potential of addition of calcium lignosulfonate as an eco-friendly additive with a phenol-formaldehyde (PF) resin, at different ratios, to produce medium-density fibreboards (MDF) with acceptable properties, was investigated in this work. The fibreboards were fabricated in the laboratory with low PF resin percentage (3%, 4%, 5%), while the addition levels of calcium lignosulfonate varied from 5% to 15% (on the dry fibres). The physical and mechanical properties of the fibreboards were evaluated, and further statistically analysed in order to determine the optimal values of PF resin content and lignosulfonate addition for fulfilling the European standards. It was shown that at the low PF resin content (3%), addition of lignosulfonate should not exceed 10% to avoid deterioration in the mechanical properties. It was concluded that PF resin content of 3.5% can be recommended for the production of lignosulfonate-PF bonded MDF panels to comply with the EN standard requirements. © 2020 Informa UK Limited, trading as Taylor & Francis Group