Spectral features associated with nitrogen,phosphorus, and potassium deficiencies in Eucalyptus saligna seedling leaves

Nitrogen (N), phosphorous (P) and potassium (K) deficiency symptoms were induced in Eucalyptus saligna seedlings. Leaves of these seedlings were measured radiometricaly in order to characterize spectrally the symptoms. It was used the SPECTRON SE-590, linked to a LICOR integrating sphere, running at 0.4 to 0.09 mu m spectral range. The results indicated that only the symptoms related with K deficiency could be spectrally detected in the visible region. The time lag from the beginning of the experiment was fundamental to characterize the symptoms, due to the synergism of the symptoms related with mineral deficiencies. The SPECTRON SE-590 fine spectral resolution proved unnecessary to spectrally characterize the symptoms.     

Multicomponent Cascade Reactions: A Novel and Expedient Approach to Functionalized Indoles by an Unprecedented Nucleophilic Addition‐Heterocyclization‐Oxidative Alkoxycarbonylation Sequence

A novel multicomponent cascade process is reported, based on the sequential combination between an initial nucleophilic attack step to an imine moiety and a palladium‐catalyzed oxidative heterocyclization‐alkoxycarbonylation process. By this new process, five simple molecules [2‐alkynylaniline imines, alcohol (ROH), carbon monoxide (CO), alcohol (ROH), and oxygen (O₂)] are sequentially activated, selectively leading to high value‐added functionalized indole derivatives in a single operation.     

Spectral reflectance characterization of shallow lakes from the Brazilian Pantanal wetlands with field and airborne hyperspectral data

The relationships between field water reflectance spectra and physico-chemical data of seven freshwater and five saltwater lakes from the Brazilian Pantanal wetlands were characterized. Selection of the lakes was based on previous inspection of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) images. Principal component analysis (PCA) was used to identify homogeneous groups of lakes, in which the regression relationships were evaluated. The continuum removal method was applied to characterize minor spectral variations in the depth of the absorption bands present in field and image spectra. The results showed lakes with very distinct spectral characteristics. The transition from the freshwater to the saltwater lakes was characterized by lower values of depth and Secchi depth, larger concentrations of dissolved organic carbon (DOC), total suspended sediments (TSS), calcium (Ca), magnesium (Mg), sodium (Na) and potassium (K), and higher values of pH and electrical conductivity. The saline lakes presented a higher overall reflectance in the 400–900?nm range than the freshwater lakes, as indicated by the first principal component. From the optically active constituents analysed, DOC better explained variations in water reflectance. The discrimination of the saltwater lakes along the second principal component was due to the decrease in the chlorophyll (Chl) and to the increase in the DOC concentrations from the greenish to the bluish saline lakes. The AVIRIS instrument was able to detect the narrow 630?nm absorption band present in field water reflectance spectra.     

Application of neutron radiography to study material processes during hypothetical severe accidents in nuclear reactors

Neutron radiography was applied for investigations of nuclear fuel cladding and control rod behaviour during steam oxidation at temperatures between 1123 and 1673?K under severe nuclear accident conditions. This article gives an overview of these investigations. At KIT, loss of coolant and severe nuclear accidents were experimentally simulated. Post-test examinations of damaged control rods were performed. In order to separate the effect of the neutron absorber and control rod structure materials, radiographs taken with different neutron spectra were combined. It could be seen clearly from these data that local melting resulting from the eutectic reaction between the stainless steel control rod cladding and the Zircaloy-4 guide tube. The uptake of hydrogen during steam oxidation and its diffusion in Zircaloy-4 was investigated in ex situ and in situ radiography experiments at temperatures of 1123 to 1673?K. The kinetics of hydrogen uptake and diffusion was determined. The oxide layer morphology strongly influences the hydrogen concentration in steam oxidized zirconium alloys. Differences of nearly one order of magnitude were found in samples withdrawn from large scale QUENCH experiments. The hydrogen diffusion coefficients were determined for various temperatures. Whereas the diffusion coefficients at 1123 and 1173?K agree well with values expected from literature values for pure Zr, at higher temperatures a faster diffusion was found. The determined activation energy of the hydrogen diffusion is about 10?% higher than published values in the literature.     

Interdependence and predictability of human mobility and social interactions

Previous studies have shown that human movement is predictable to a certain extent at different geographic scales. The existing prediction techniques exploit only the past history of the person taken into consideration as input of the predictors.In this paper, we show that by means of multivariate nonlinear time series prediction techniques it is possible to increase the forecasting accuracy by considering movements of friends, people, or more in general entities, with correlated mobility patterns (i.e., characterised by high mutual information) as inputs. Finally, we evaluate the proposed techniques on the Nokia Mobile Data Challenge and Cabspotting datasets.     

SID-GA: An evolutionary approach for improving observability and redundancy analysis in structural instrumentation design

In this paper the core of a genetic algorithm designed to define a sensor network for instrumentation design (ID) is presented. The tool has been incorporated into a decision support system (DSS) that assists the engineer during the ID process. The algorithm satisfactorily deals with non-linear mathematical models, and considers four design objectives, namely observability, cost, reliability and redundancy, exhibiting properties that were either never addressed by existing techniques or partially dealt with in the literature. Its performance was tested by carrying out the ID of an ammonia synthesis industrial plant. Results were statistically analysed. A face validity study on the fitness function’s soundness was also assessed by a chemical engineer with insight and expertise in this problem. The technique performed satisfactorily from the point of view of the expert in ID, and therefore it constitutes a significant upgrading for the DSS.     

Elicitation strategies for soft constraint problems with missing preferences: Properties,algorithms and experimental studies

We consider soft constraint problems where some of the preferences may be unspecified. This models, for example, settings where agents are distributed and have privacy issues, or where there is an ongoing preference elicitation process. In this context, we study how to find an optimal solution without having to wait for all the preferences. In particular, we define algorithms, that interleave search and preference elicitation, to find a solution which is necessarily optimal, that is, optimal no matter what the missing data will be, with the aim to ask the user to reveal as few preferences as possible. We define a combined solving and preference elicitation scheme with a large number of different instantiations, each corresponding to a concrete algorithm, which we compare experimentally. We compute both the number of elicited preferences and the user effort, which may be larger, as it contains all the preference values the user has to compute to be able to respond to the elicitation requests. While the number of elicited preferences is important when the concern is to communicate as little information as possible, the user effort measures also the hidden work the user has to do to be able to communicate the elicited preferences. Our experimental results on classical, fuzzy, weighted and temporal incomplete CSPs show that some of our algorithms are very good at finding a necessarily optimal solution while asking the user for only a very small fraction of the missing preferences. The user effort is also very small for the best algorithms.     

EMMA: Epidemic Messaging Middleware for Ad hoc networks

The characteristics of mobile environments, with the possibility of frequent disconnections and fluctuating bandwidth, have forced a rethink of traditional middleware. In particular, the synchronous communication paradigms often employed in standard middleware do not appear to be particularly suited to ad hoc environments, in which not even the intermittent availability of a backbone network can be assumed. Instead, asynchronous communication seems to be a generally more suitable paradigm for such environments. Message oriented middleware for traditional systems has been developed and used to provide an asynchronous paradigm of communication for distributed systems, and, also for some specific mobile computing systems recently. In this paper, we present our experience in designing, implementing, and evaluating Epidemic Messaging Middleware for Ad hoc networks (EMMA), an adaptation of Java Message Service (JMS) for mobile ad hoc environments, discussing in detail the design challenges and the solutions that have been adopted.

Foundations of distributed interaction systems

There are numerous applications where a variety of human and software participants interactively pursue a given task (play a game, engage in a simulation, etc.). In this paper, we define a basic architecture for a distributed, interactive system (DIS for short). We then formally define a mathematical construct called a DIS abstraction that provides a theoretical basis for a software platform for building distributed interactive systems. Our framework provides a language for building multiagent applications where each agent has its own behaviors and where the behavior of the multiagent application as a whole is governed by one or more “master” agents. Agents in such a multiagent application may compete for resources, may attempt to take actions based on incorrect beliefs, may attempt to take actions that conflict with actions being concurrently attempted by other agents, and so on. Master agents mediate such conflicts. Our language for building agents (ordinary and master) depends critically on a notion called a “generalized constraint” that we define. All agents attempt to optimize an objective function while satisfying such generalized constraints that the agent is bound to preserve. We develop several algorithms to determine how an agent satisfies its generalized constraints in response to events in the multiagent application. We experimentally evaluate these algorithms in an attempt to understand their advantages and disadvantages. This revised version was published online in June 2006 with corrections to the Cover Date.