In an open channel with a mobile bed, intense transport of bed load is associated with high-concentrated sediment-laden flow over a plane surface of the eroded bed due to high bed shear. Typically, the flow exhibits a layered internal structure in which virtually all sediment grains are transported through a collisional layer above the bed. Our investigation focuses on steady uniform turbulent open-channel flow with a developed collisional transport layer and combines modelling and experiment to relate integral quantities, as the discharge of solids, discharge of mixture, and flow depth with the longitudinal slope of the bed and the internal structure of the flow above the bed. A transport model is presented which considers flow with the internal structure described by linear vertical distributions of granular velocity and concentration across the collisional layer. The model employs constitutive relations based on the classical kinetic theory of granular flows selected by our previous experimental testing as appropriate for the flow and transport conditions under consideration. For given slope and depth of the flow, the model predicts the total discharge and the discharge of sediment. The model also predicts the layered structure of the flow, giving the thickness of the dense layer, collisional layer, and water layer. Model predictions are compared with results of intense bed-load experiment carried out for lightweight sediment in our laboratory tilting flume.
Focusing on the idea that multivalent cations affect SOM matrix and surface, we treated peat and soil samples by solutions of NaCl, CaCl2 or AlCl3. Water binding was characterized with low field 1 H-NMR-relaxometry (20 MHz) and 1 H wideline NMR spectroscopy (400 MHz) and compared to contact angles. From 1 H wideline, we distinguished mobile water and water involved in water molecule bridges (WaMB). Large part of cation bridges (CaB) between SOM functional groups are associated with WaMB. Unexpectedly, 1 H NMRrelaxometry relaxation rates suggest that cross-linking in the Al-containing peat is not stronger than that by Ca. The relation between percentage of mobile water and WaMB water in the context of wettability and 1 H NMR relaxation times confirms that wettability controls the water film surrounding soil particles. Wettability is controlled by WaMB-CaB associations fixing hydrophilic functional groups in the SOM interior. This can lead to severe water repellency. Wettability decreases with increasing involvement of functional groups in CaB-WaMB associations. The results demonstrate the relevance of CaB and WaMB for the dynamics of biogeochemical and hydrological processes under field conditions, as only a few percent of organic matter can affect the physical, chemical, and biological functioning of the entire 3-phase ecosystem.
People partaking in a conversation can add to the common ground of said conversation by performing different speech acts. That is, they can influence which propositions are presumed to be shared among them. In this paper, I am going to apply the common ground framework to the phenomenon of epistemic injustice. In doing so, I am going to focus on two kinds of speech acts: making assertions and asking certain kinds of questions. And I am going to look at three varieties of epistemic injustice: testimonial injustice, inquiring injus- tice and interpretative injustice. I am going to argue that what all these varieties of epistemic injustice have in common is that they unfairly inhibit the speaker’s ability to add to the common ground in the way intended by her. This in turn negatively affects which conversational roles a speaker can play in a given conversation. Based on these results, I am going to end by looking at some of the harms that epistemic injustice inflicts upon its victims.
The paper deals with the paradoxes of inference and analysis. It attempts to show what is specific about these paradoxes. They have got a lot in common. Often, they are not considered paradoxes in the strict sense at all. Moreover, they both raise the same problem: How can the requirements of correctness and informativeness be both met for inference and for conceptual analysis? The strategies developed to address the problem are similar for both cases. In the paper, I claim that the paradoxes have common origins. This claim is supported by comparing different strategies adopted to resolve the problem. Regarding their origins, both paradoxes share the epistemological framework that is grounded in Aristotle’s theory of science. This is related to the problem of implicit knowledge, which is a variation on a dilemma formulated by Plato in his Meno. Aristotle’s solution to the dilemma of Meno is discussed and considered as another plausible strategy for dealing with the paradoxes of inference and analysis., Příspěvek se zabývá paradoxy odvození a analýzy. Snaží se ukázat, co je na těchto paradoxech specifické. Mají spoustu společného. Často nejsou vůbec považovány za paradoxy. Oba tyto otázky navíc vyvolávají stejný problém: Jak mohou být splněny požadavky na správnost a informativnost pro závěry a pro koncepční analýzu? Strategie vyvinuté pro řešení tohoto problému jsou podobné v obou případech. V příspěvku tvrdím, že paradoxy mají společný původ. Toto tvrzení je podpořeno porovnáním různých strategií přijatých k vyřešení problému. Pokud jde o jejich původ, oba paradoxy sdílejí epistemologický rámec, který je založen na Aristotelově teorii vědy. To souvisí s problémem implicitní znalosti, což je variace na dilema formulované Platónem v jehoMeno . Aristotelovo řešení dilematu Meno je diskutováno a považováno za další přijatelnou strategii pro řešení paradoxů odvození a analýzy., and Karel Šebela
The goal of this paper is to demonstrate that procedurally structured con- cepts are central to human communication in all cultures and throughout history. This thesis is supported by an analytical survey of three very different means of communication, namely Egyptian hieroglyphs, pictures, and Inca knot writing known as khipu. My thesis is that we learn, communicate and think by means of concepts; and regardless of the way in which the meaning of an expression is encoded, the meaning is a concept. Yet we do not define concepts within the classical set-theoretical framework. Instead, within the logical framework of Transparent Intensional Logic, we explicate concepts as logical procedures that can be assigned to expressions as their context-invariant meaning. In particular, complex meanings, which structurally match complex expressions, are complex procedures whose parts are sub-procedures. The moral suggested by the paper is this. Concepts are not flat sets; rather, they are algorithmically structured abstract procedures. Unlike sets, concepts have constituent sub-procedures that can be executed in order to arrive at the product of the procedure (if any). Not only particular parts matter, but also the way of combining these parts into one whole ''instruction'' that can be followed, understood, executed, learnt, etc., matters., Cílem příspěvku je ukázat, že procesně strukturované koncepty jsou ústředním bodem lidské komunikace ve všech kulturách a v průběhu dějin. Tato práce je podpořena analytickým průzkumem tří velmi odlišných komunikačních prostředků, konkrétně egyptských hieroglyfů, obrázků a psaní uzlů Inků známých jako khipu. Má diplomová práce je, že se učíme, komunikujeme a myslíme pomocí konceptů; a bez ohledu na způsob, jakým je význam výrazu zakódován, významem je pojem. Nedefinujeme však koncepty v rámci klasického teoretického rámce. Místo toho, v logickém rámci Transparentní Intenzionální Logiky, vysvětlujeme pojmy jako logické procedury, které mohou být přiřazeny výrazům jako jejich kontextově invariantní význam. Zejména složité významy, které strukturně odpovídají komplexním výrazům, jsou složité postupy, jejichž součástí jsou dílčí postupy. Morální návrh, který tento článek navrhl, je toto. Pojmy nejsou ploché soupravy; jsou to spíše algoritmicky strukturované abstraktní postupy. Na rozdíl od sad, koncepty mají dílčí dílčí postupy, které mohou být provedeny, aby se dospělo k produktu postupu (pokud existuje). Nezáleží jen na jednotlivých částech, ale také na způsobu spojování těchto částí do jedné ,,instrukce'', kterou lze sledovat, chápat, realizovat, učit se atd., Záleží na tom., and Marie Duží
Long-term water uptake of Douglas-fir and Norway spruce trees, growing in condition of Moravian upland, was studied with aim of comparing sap flow in small roots with flow in stems. Sap flow was measured by the heat field deformation method using multi-point sensors for stems and single-point sensors for roots. Differences between species were found in relationships between sap flow in tree stems and water uptake by roots, suggesting that Douglas-fir is able to take water from deeper soil more efficiently than spruce. This allows Douglas-fir to transpire more water especially during drought and grow faster than spruce. These biological features should be taken into account for future forest species compositions because they may have impact on both, forestry and hydrology.
Groundwater and surface water interaction play an important role for groundwater recharge, drought management and water quality issues. Based on a case study in Lower Austria different techniques for estimation of riverbed infiltration were applied. The aim was to assess the impact of upstream release flow directions for the downstream sections. Due to the fact of large streambed conductivities, infiltration losses considerably contribute to the water balance of the system. The applied methods dealt with empirical infiltration formulas based on sediment particle size distribution, soil physical analysis, difference discharge measurements along river branches and point measurements of infiltration by means of double ring infiltrometer and riverbed lysimeter. Awaring the fact that the infiltration processes vary in space and time the gained results formed a basis for definition of potential values of infiltration. It could be concluded, that for the investigated environment the different methods exhibited comparable results with the exception of the empirical formulas, which tend to significantly overestimate the average values. and Vzájemná interakce povrchové a podzemní vody je velmi důležitá pro hodnocení zdrojů podzemních vod, hospodaření s vodou a její kvalitu. Na základě zkušeností s řešením projektu v Dolním Rakousku byly použity pro odhad infiltrace říčním korytem dále uvedené metody. Cílem řešení bylo mimo jiné stanovit vliv průtoku a směru pohybu vody v horní části toku na profily v spodní části toku. Vzhledem k vysoké hydraulické vodivosti dna toku se ztráty infiltrací výrazně podílejí na vodní bilanci systému. Pro odhad infiltrace byly použity jednak empirické rovnice (na základě granulometrického složení), fyzikální rozbory půdních vzorků, terénní lysimetrická měření ve dně toku a ''bodová'' měření dvouválcovou metodou. Uvážíme-li, že infiltrace je časově a prostorově proměnná, dosažené výsledky jsou základem pro určení potenciální hodnoty infiltrace. Závěrem je možno konstatovat, že v daných podmínkách použité metody poskytly srovnatelné výsledky, s výjimkou empirických rovnic, jejichž výsledky byly systematicky řádově vyšší.
In this study Active Learning Method (ALM) as a novel fuzzy modeling approach is compared with optimized Support Vector Machine (SVM) using simple Genetic Algorithm (GA), as a well known datadriven model for long term simulation of daily streamflow in Karoon River. The daily discharge data from 1991 to 1996 and from 1996 to 1999 were utilized for training and testing of the models, respectively. Values of the Nash-Sutcliffe, Bias, R2 , MPAE and PTVE of ALM model with 16 fuzzy rules were 0.81, 5.5 m3 s -1, 0.81, 12.9%, and 1.9%, respectively. Following the same order of parameters, these criteria for optimized SVM model were 0.8, -10.7 m3 s-1, 0.81, 7.3%, and -3.6%, respectively. The results show appropriate and acceptable simulation by ALM and optimized SVM. Optimized SVM is a well-known method for runoff simulation and its capabilities have been demonstrated. Therefore, the similarity between ALM and optimized SVM results imply the ability of ALM for runoff modeling. In addition, ALM training is easier and more straightforward than the training of many other data driven models such as optimized SVM and it is able to identify and rank the effective input variables for the runoff modeling. According to the results of ALM simulation and its abilities and properties, it has merit to be introduced as a new modeling method for the runoff modeling. and Cieľom štúdie bolo porovnať možnosti dlhodobej simulácie denných prietokov v rieke Karoon pomocou novovyvinutej fuzzy metódy aktívneho učenia (Active Learning Method - ALM) a známej metódy vektormi podporených strojov (Support Vector Machine - SVM), optimalizovanej genetickým algoritmom (GA). Na tréning a testovanie modelov boli použité časové rady denných prietokov za obdobie rokov 1991 až 1996 a 1996 až 1999. Hodnoty parametrov Nash-Sutcliffe, Bias, R2 , MPAE a PTVE pre model ALM boli 0,81; 5,5 m3 s-1; 0,81; 12,9% a 1,9%. Parametre v tom istom poradí pre model SVM boli 0,8 -10,7 m3 s-1, 0,81; 7,3%; a -3,6%. Z výsledkov simulácií vyplýva, že aplikáciou metód ALM a SVM možno získať porovnateľné a akceptovateľné výsledky. Podobnosť výsledkov medzi ALM a SVM implikuje vhodnosť novovyvinutej metódy ALM pre simuláciu odtoku. Tréning ALM je ľahší a jednoduchší ako je tréning ďalších dátami riadených modelov podobného typu. Navyše algoritmus ALM je schopný identifikovať a zoradiť efektívne vstupné premenné pre modelovanie odtoku. Na základe dosiahnutých výsledkov možno metódu ALM zaradiť medzi nové, alternatívne metódy modelovania odtoku.
Complete descriptions of the particle-size distribution (PSD) curve should provide more information about various soil properties as opposed to only the textural composition (sand, silt and clay (SSC) fractions). We evaluated the performance of 19 models describing PSD data of soils using a range of efficiency criteria. While different criteria produced different rankings of the models, six of the 19 models consistently performed the best. Mean errors of the six models were found to depend on the particle diameter, with larger error percentages occurring in the smaller size range. Neither SSC nor the geometric mean diameter and its standard deviation correlated significantly with the saturated hydraulic conductivity (Kfs); however, the parameters of several PSD models showed significant correlation with Kfs. Porosity, mean weight diameter of the aggregates, and bulk density also showed significant correlations with PSD model parameters. Results of this study are promising for developing more accurate pedotransfer functions.