For an end $\tau $ and a tree $T$ of a graph $G$ we denote respectively by $m(\tau )$ and $m_{T}(\tau )$ the maximum numbers of pairwise disjoint rays of $G$ and $T$ belonging to $\tau $, and we define $\mathop {\mathrm tm}(\tau ) := \min \lbrace m_{T}(\tau )\: T \text{is} \text{a} \text{spanning} \text{tree} \text{of} G \rbrace $. In this paper we give partial answers—affirmative and negative ones—to the general problem of determining if, for a function $f$ mapping every end $\tau $ of $G$ to a cardinal $f(\tau )$ such that $\mathop {\mathrm tm}(\tau ) \le f(\tau ) \le m(\tau )$, there exists a spanning tree $T$ of $G$ such that $m_{T}(\tau ) = f(\tau )$ for every end $\tau $ of $G$.
Global Navigation Satellite System (GNSS) positioning has characteristics of simple operation, high efficiency and high precision technique for landslide surface monitoring. In recent years, finalization of modern GNSS systems Galileo and BeiDou has brought a possibility of multi-GNSS positioning. The paper focuses on evaluation of possible benefits of multi-GNSS constellations in landslide monitoring. While simulating observational conditions of selected Recica landslide in the Czech Republic, one-month data from well-established permanent GNSS reference stations were processed. Besides various constellation combinations, differential and Precise Point Positioning techniques, observation data lengths and observation sampling intervals were evaluated. Based on the results, using a combination of GPS and GLONASS, or GPS, GLONASS and Galileo systems can be recommended, together with a static differential technique and observation periods for data collection exceeding eight hours. In the last step, data from GNSS repetitive campaigns realized at the Recica landslide during two years were processed with optimal setup and obtained displacement results were compared to standard geotechnical measurements.
This paper discusses n-island finite automata whose transition graphs can be expressed as n-member sequences of islands i1,i2,…,in, where there is a bridge leaving ij and entering ij+1 for each 1≤j≤n−1. It concentrates its attention on even computation defined as any sequence of moves during which these automata make the same number of moves in each of the islands. Under the assumption that these automata work only in an evenly computational way, the paper proves its main result stating that n-island finite automata and Rosebrugh-Wood n-parallel right-linear grammars are equivalent. Then, making use of this main result, it demonstrates that under this assumption, the language family defined by n-island finite automata is properly contained in that defined by (n+1)-island finite automata for all n≥1. The paper also points out that this infinite hierarchy occurs between the family of regular languages and that of context-sensitive languages. Open questions are formulated in the conclusion.
Providing information on the impacts of climate change on hydrological processes is becoming ever more critical. Modelling and evaluating the expected changes of the water resources over different spatial and time scales can be useful in several fields, e.g. agriculture, forestry and water management. Previously a Budyko-type spatially distributed long-term climate-runoff model was developed for Hungary. This research includes the validation of the model using historical precipitation and streamflow measurements for three nested sub-catchments of the Zala River Basin (Hungary), an essential runoff contributing region to Lake Balaton (the largest shallow lake in Central Europe). The differences between the calculated (from water balance) and the estimated (by the model) mean annual evapotranspiration varied between 0.4% and 3.6% in the validation periods in the sub-catchments examined. Predictions of the main components of the water balance (evapotranspiration and runoff) for the Zala Basin are also presented in this study using precipitation and temperature results of 12 regional climate model simulations (A1B scenario) as input data. According to the projections, the mean annual temperature will be higher from period to period (2011–2040, 2041–2070, 2071–2100), while the change of the annual precipitation sum is not significant. The mean annual evapotranspiration rate is expected to increase slightly during the 21st century, while for runoff a substantial decrease can be anticipated which may exceed 40% by 2071–2100 relative to the reference period (1981–2010). As a result of this predicted reduction, the runoff from the Zala Basin may not be enough to balance the increased evaporation rate of Lake Balaton, transforming it into a closed lake without outflow.
This paper describes the technical information and performance of a new multi-objective chamber system enabling the control of environmental variables (e.g., temperature, CO2, air humidity, wind speed, and UV-B radiation) for understanding plant responses to climate change. Over a whole growing season, four different climate scenarios were evenly programmed into the system’s 16 chambers as ambient environment (AMB), elevated temperature (ET), elevated CO2 concentration (EC) and elevated temperature and CO2 concentration (ETC). Simultaneously, the chamber effects were assessed regarding the physiological responses and growth of a boreal perennial grass (reed canary grass, Phalaris arundinacea L.). During the growing season, the chamber system provided a wide variety of climatic conditions for air temperature (T a), relative humidity (RH) and CO2 concentration (C a) in the AMB chambers following outside conditions. The target temperature (+3.5°C) was achieved to a good degree in the ET and ETC chambers, being on average 3.3°C and 3.7°C higher than ambient conditions, respectively. The target concentration of CO2 (700 ppm) was also well achieved in the EC and ETC chambers, being on average 704 ppm and 703 ppm, respectively. The stable airflow condition inside all of the chambers provided a homogeneous distribution of gases and temperature. The decreases in RH and increases in vapour pressure deficit (VPD) in the elevated temperature chambers were also maintained at a low level. Chamber effects were observed, with some physiological and growth parameters of plants being significantly lower in the AMB chambers, compared to outside conditions. The plant growth was negatively affected by the reduced radiation inside the chambers., X. Zhou ... [et al.]., and Obsahuje bibliografii
In this paper, a multi-layer perceptron (MLP) neural network (NN) is put forward as an efficient tool for performing two tasks: 1) optimization of multi-objective problems and 2) solving a non-linear system of equations. In both cases, mathematical functions which are continuous and partially bounded are involved. Previously, these two tasks were performed by recurrent neural networks and also strong algorithms like evolutionary ones. In this study, multi-dimensional structure in the output layer of the MLP-NN, as an innovative method, is utilized to implicitly optimize the multivariate functions under the network energy optimization mechanism. To this end, the activation functions in the output layer are replaced with the multivariate functions intended to be optimized. The effective training parameters in the global search are surveyed. Also, it is demonstrated that the MLP-NN with proper dynamic learning rate is able to find globally optimal solutions. Finally, the efficiency of the MLP-NN in both aspects of speed and power is investigated by some well-known experimental examples. In some of these examples, the proposed method gives explicitly better globally optimal solutions compared to that of the other references and also shows completely satisfactory results in other experiments.
In this paper a collection of iron objects from the Anatolian Seljuks Period, ca. 12th–13th century AD, are analysed and discussed from a metallurgical perspective. A total number of 21 iron-steel objects, small knives and flat bodied (with thin cross-section) arrowheads was examined. These objects are coming from the Seljuks’ cultural layers of Eğirdir (Isparta, Central Anatolian Caravanserai), Kubad Abad (Konya, Central Anatolian Sultan’s Palace Complex), and Samsat (Adıyaman, Eastern Anatolian Fortress). In the samples which were taken from iron tools, composite-like structures formed by different ferrous phases were revealed by metallography, SEM-EDX and micro hardness examinations. These structures are classified according to the production materials and techniques. The first group revealed signs of continuous forging and, in some cases, bloomery iron folding, which can lead to such composite-like structures. The second group consisted of tools which were produced from different starting materials which were forgewelded before or during shaping process. The crucible steel knives can be classified as another group, in which the composite-like structure exhibits totally different constituents leading to more homogeneous mechanical character. In modern times, composite materials have gained importance and become key engineering materials due to their outstanding specific properties. This study reveals that skilled Seljuks’ blacksmiths made similar materials design choices in the production of iron or steel objects, despite limited materials and metallurgical knowledge. and V příspěvku je diskutována kolekce železných předmětů z období rúmského sultanátu, ca 12.–13. stol. n. l., analyzovaná a hodnocená z metalurgického hlediska. Celkem 21 železných předmětů, menších nožů a plochých hrotů šípů (stenkým průřezem). Předměty pocházejí z kulturních vrstev rúmského sultanátu v Eğirdiru (Isparta, středoanatolský karavanseraj), Kubad Abad (Konya, středoanatolský sultanský pálácový komplex) a Samsat (Adıyaman, východoanatolská pevnost). Vzorky odebrané z železných nástrojů vykazovaly struktury podobné kompozitním, sestávající z různých strukturních fází vymezených pomocí metalografie, SEM-EDX a měřením mikrotvrdosti. Dané struktury byly kategorizovány podle užitých materiálů a techniky výroby. První skupina vykazovala známky kontinuálního kování a místy paketování svářkového kovu, které může vést k takovýmto jakoby kompozitním strukturám. Druhá skupina sestávala z nástrojů vyráběných z různých výchozích materiálů, které byly před nebo v průběhu tváření svařovány. Nože z kelímkové oceli lze klasifikovat jako další skupinu, ve které kompozitní struktura vykazuje naprosto odlišné složky, vedoucí k rovnoměrnějším mechanickým charakteristikám. V dnešní době nabyly kompozitní materiály velkého významu a díky svým výjimečným specifickým vlastnostem se staly klíčovými materiály strojírenství. Tato studie odhaluje, že zruční seldžučtí kováři volili podobnou materiálovou konstrukci při výrobě železných nebo ocelových předmětů, navzdory omezeným materiálovým a metalurgickým znalostem.
Reduction kinetics of P700+ after far-red radiation (FR)-induced oxidation in intact tobacco leaves was examined by analysing the post-irradiation relaxation of 810-830 nm absorbance difference. The reduction curve could be de-convoluted distinctively into two or three exponential decaying components, depending on the FR irradiance, the treating and measuring temperatures, and the extent of dark adaptation. The multi-phasic kinetics of P700+ re-reduction upon the turning off of FR irradiation is related to the heterogeneity of electron transport around photosystem 1 in thylakoid membranes. and Ming-Xian Jin, Zheng-Ju Yao, Hualing Mi.
This paper discusses the cluster analysis and visualisation tool, the self-organizing map (SOM). The pros and cons of different network sizes are discussed, in particular how they are suited to the purposes of direct data browsing and also the cluster analysis with U-matrices. The tree-structured SOM (TS-SOM) [4, 5] is proposed as a method of acquiring multi-resolution/multi-purpose mappings of a given input space. The TS-SOM is discussed in detail and a novel modification to the algorithm that improves its reliability as a multi-resolution visualization method is presented.
Accurate prediction of the Baltic index makes great difference to the strategic decision and risk avoidance of the enterprise. For the multi-step Baltic Supermax Index prediction, direct prediction and iterative prediction has its own advantages. Therefore, in this paper, in combination with direct and iterative prediction, based on Support Vector Machine (SVM), a hybrid multistep prediction model is put forward. In hybrid model, the output from the iterative model is a rough prediction and it need also be adjusted based on the output from the direct model. And weekly BSI data from January 2011 to November 2014 are used to test the model. The results show that the hybrid multistep prediction model based on SVM has high accuracy, and is feasible in the BSI prediction.