Combination of SRTM3 and repeat ASTER data for deriving alpine glacier flow velocities in the Bhutan Himalaya

The present study evaluates the fusion of DEMs from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument and the Shuttle Radar Topography Mission (SRTM). The study area consists of high elevation glaciers draining through the rough topography of the Bhutan Himalayas. It turns out that the ASTER-derived and SRTM3 DEMs have similar accuracy over the study area, but the SRTM3 DEM contains less gross errors. However, for rough topography large sections of the SRTM3 DEM contain no data. We therefore compile a combined SRTM3-ASTER DEM. From this final composite-master DEM, we produce repeat ASTER orthoimages from which we evaluate the DEM quality and derive glacier surface velocities through image matching. The glacier tongues north of the Himalayan main ridge, which enter the Tibet plateau, show maximum surface velocities in the order of 100-200 m year⁻¹. In contrast, the ice within the glacier tongues south of the main ridge flows with a few tens of meters per year. These findings have a number of implications, among others for glacier dynamics, glacier response to climate change, glacier lake development, or glacial erosion. The study indicates that space-based remote sensing can provide new insights into the magnitude of selected surface processes and feedback mechanisms that govern mountain geodynamics.     

Mega capture of the Rio Negro and formation of the Anavilhanas Archipelago, Central Amazônia, Brazil: Evidences in an SRTM digital elevation model

In the Central Amazônia (Brazil), the Solimões River and the Negro River (“Rio Negro”) merge to form the Amazonas, the largest river in the world. Analysis of a digital elevation model produced by the Shuttle Radar Topographic Mission (SRTM) in that region reveals the relicts of a large ancient drainage system hidden by the tropical rain forest. Interpretation of this unreported terrain feature in the context of the regional geological framework indicates that the present lower course of the Rio Negro results from a mega fluvial capture driven by an active tectonic regime prevailing in the Amazonian basin. The diversion of the Rio Negro was controlled by pre-existing NW-SE structural features, in which the arrangement of fault blocks compelled the river to funnel down into a strait. Partially blocked by this natural barrier, the Rio Negro widens upstream, assuming a lake-like appearance (up to 20 km-wide). Free space availability and low energy favored the deposition of sediments to form the Anavilhanas Archipelago, the largest group of freshwater islands on the world, refuge of a diversified fauna and flora.     

Forwarders vs. centralized server: an evaluation of two approaches for locating mobile agents

This paper evaluates and compares the performance of two approaches for locating an agent in a mobile agent environment. The first approach dynamically creates a chain of forwarders to locate a moving agent, whereas the second one relies on a centralized server to perform this task. Based on a Markov chain analysis, we compute the performance of each scheme (time to reach an agent, number of forwarders) and compare them first with simulations and second with experimental results obtained by using ProActive, a Java library. Depending on the system parameters we identify the best scheme and observe that over a LAN the server yields the best performance, whereas the forwarders yield the best performance over a MAN.     

Patient-number-based computerized medical records in Crete. A tool for planning and assessment of primary health care.

Primary Health Care (PHC) in Crete is in a state of rapid development. The strategy for introducing PHC involves an orientation towards the population and the creation of possibilities for evaluation. A case records system, "Egino", was installed in the University of Heraklion and at the Health Centre in Spili in 1988, and was further developed according to local needs during 1989, when also a Greek version of the statistical system, "DoIt", was installed. The main reasons for establishing a computerized medical information system were (i) to assess the health needs in Crete, (ii) to monitor activities of the primary health care organizations, and (iii) to introduce epidemiological research into primary health care in Greece. The information system was based on specially assigned patient numbers containing several pieces of information about the individual; the system was developed at the Dalby Health Sciences Centre in Sweden. Each month, data were extracted in Spili Health Centre, and these data were regularly used to present incidence and prevalence indices. Some of the data extracted were reported to the health authorities in Greece. "EginO" and "DoIt" gave possibilities to evaluate health services by following the morbidity, while also making it possible to describe and analyse health needs in the population of Spili and other primary health care catchment areas in Greece.     

Monitoring yield and fruit quality parameters in open-canopy tree crops under water stress. Implications for ASTER

Work on water stress detection at tree and orchard levels using a high-spatial airborne thermal sensor is presented, showing its connection with yield and some fruit quality indicators in olive and peach commercial orchards under different irrigation regimes. Two airborne campaigns were conducted with the Airborne Hyperspectral Scanner (AHS) over olive and peach orchards located in Córdoba, southern Spain. The AHS sensor was flown at three different times on 25 July 2004 and 16 July 2005, collecting 2 m spatial resolution imagery in 80 spectral bands in the 0.43-12.5 μm spectral range. Thermal bands were assessed for the retrieval of land surface temperature using the split-window algorithm and TES (Temperature-Emissivity-Separation) method, separating pure crowns from shadows and sunlit soil pixels using the reflectance bands. Stem water potential and stomatal conductance were measured on selected trees at the time of airborne flights over the orchards. Tree fruit yield and quality parameters such as oil, weight and water content (for the olive trees), and fruit volume and weight (for the peach trees) were obtained at harvest and through laboratory analysis. Relationships between airborne-estimated crown temperature minus air temperature and stem water potential yielded r² = 0.5 (12:30 GMT) at the olive tree level, and r² = 0.81 (9:00 GMT) at the treatment level in peach trees. These results demonstrate that water stress can be detected at the crown level even under the usual water management conditions of commercial orchards. Regressions of yield and fruit quality against remote sensing estimates of crown temperature as an indicator of water stress, yielded r² = 0.95 (olive fruit water content) and r² = 0.94 (peach fruit mean diameter). These results suggest that high-spatial remote sensing thermal imagery has potential as an indicator of some fruit quality parameters for crop field segmentation and irrigation management purposes. A simulation study using ASTER spectral bands and aggregated pixels for stress detection as a function of irrigation level was conducted in order to study the applicability of medium resolution thermal sensors for the global monitoring of open-canopy tree crops. The determination coefficients obtained between the ASTER-simulated canopy temperature minus air temperature and stem water potential yielded r² = 0.58 (12:30 GMT) for olive trees, suggesting the potential for extrapolating these methods to ASTER satellite for global monitoring of open tree canopies.     

A numerical model for the winter circulation in Lake Trichonis, Greece

Progress in the understanding and eventual management of lakes depends upon iterative interactions between model-guided measurements and measurement-tested model development. A research example of this progress can be demonstrated by the measurement campaigns that were mounted in Lake Trichonis, in central Greece. Numerical simulations and analytical theories have been tested against currents, surface seiche and temperatures. Simultaneous water gauges, current meters, anemometric stations, thermometers, sediment and water samplers were used for the verification of the model. The agreement between the theoretically predicted and experimentally determined data was satisfactory for most of the verifications. The most significant error was due to atmospheric pressure. The computed surface seiche showed excellent agreement with the observations, even in spectral analysis. The computed currents showed circulation patterns very similar to those measured in the field. The computed temperature distributions throughout the lake were not in good agreement because of incoming water from the bottom.     

Wind characteristics and mapping for power production in the Island of Lesvos, Greece

This study investigated the wind characteristics of the island of Lesvos, Greece, with the objective of providing the necessary data for identifying the wind power production capabilities of the island. Weather patterns were examined using weather data from four Remote Automatic Weather Stations. Specific tools were used to produce the necessary windroses, Weibull curves and charts that helped to understand the prevailing wind characteristics. By using the tools of Geographic Information Systems (GIS) and the Wind Atlas Analysis and Application Program (WAsP) as the basic calculation platform, a wind map was produced portraying the wind speeds that prevail at a height of 10 m above ground level. The results of the analysis were tested and evaluated with measurements from 15 wind turbine sites by creating six alternative scenarios. The optimum scenario was used to investigate the installation of a small wind farm with five wind turbines, of 3 MW total capacity.     

Forest mapping by geoinformatics for landscape fire behaviour modelling in coastal forests,Greece

This study aims at quantifying and mapping fire-related characteristics of forest structure through field inventories, statistics, remote sensing, and geographical information systems in the island of Lesvos, northeast Aegean Sea, Greece. Simulation of fire behaviour requires forest biomass inputs that describe surface fuel types/models along with canopy fuel properties, such as canopy cover, stand height, crown base height, and crown bulk density, to accurately predict surface and crown fire spread and spotting potential. Forest canopy characteristics and other vegetation attributes were sampled and derived in over 100 field plots, the majority of which were located in coastal pine forest stands. Regression models involving four dependent forest stand variables (stand height, canopy cover, crown base height, and crown bulk density) were developed using generalized additive models. The values of adjusted R ² were 0.72 for stand height, 0.68 for canopy cover, 0.51 for crown base height, and 0.33 for crown bulk density. These regression models were used to create forest fuel characteristics layers, which can be used as inputs to fire management applications and state-of-the-art landscape-scale fire behaviour models.     

A method for delineating structurally homogeneous regions in protein sequences.

A homogeneous region in a protein sequence is a set of contiguous residues that share common features, concerning physico-chemical, structural and mutational information. This paper presents a method for identifying such homogeneous regions. From a profile describing a given type of biological information along the sequence, the algorithm allows the segmentation of the sequence by optimizing a criterion characterized by two user-defined control parameters: the 'homogenizing degree' of the regions and the 'site neighbourhood' size. We apply the method to the envelope proteins of the human immunodeficiency virus HIV-1, for the identification of homogeneous regions in a hydrophobicity profile and the delineation of variable and conserved regions in a variability profile.     

Numerical simulations for the evaluation of the free surface history in porous media. Comparison between two different approaches

This paper shown an empirical comparison of two different models for the theoretical analysis of the zero pressure surface position during the imbition of a partially saturated porous medium: the model based on the unsaturated-saturated approach, and the model which describes the zero pressure surface as a free external boundary for the fully saturated zone. A domain FD technique is applied for solving the governing equations of the first model, whereas a BEM formulation has been chosen for the equations of the second one. The comparison is based on numerical experiments which deal with the imbition of an academic system. The results obtained highlight the tendency of the fully saturated approximation to provide solutions where the rise of the free surface is much more localized near the injection zone than in the case of the unsaturated-saturated approach. In addition, owing to the capability of describing the capillary fringe, these latter solutions affect thicker layers of porous matrix. So, the users have to consider the system of interest with the greatest care before they choose the mathematical model which is the most suitable for the aims of the planned simulation.     

MODBUS与CANBUS总线在环保物联网的现场应用研究

就目前环境监测现场中总线技术的采用,分析了在应用中使用MODBUS总线的状况。从环境监测的体系架构出发,通过分析CAN总线的高层和底层通信协议,描述其在现场替代MODBUS的优势,提出了污染源在线实时监测系统现场的总线实施方案,给出了适于环境监测现场应用的CAN总线接入系统拓扑并详述原因。     

Combined use of ASTER and ALI data for hydrothermal alteration mapping in the northwestern part of the Kerman magmatic arc,Iran

The study area is located in the Kerman magmatic arc in southern Iran, which is known for its world-class porphyry-type deposits. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Advanced Land Imager (ALI) visible–near-infrared to shortwave-infrared bands were used to investigate the spectral discrimination of hydrothermally altered rocks based on their mineral assemblages. Band ratioing, directed principal component analysis (DPCA), and the Spectral Angle Mapper (SAM) were applied on ASTER and ALI data for separating ferric iron-poor from ferric iron-rich phyllic alteration zones. The individual principal component images through DPCA could detect specific alteration zones dominated by minerals such as iron oxides, sericite, kaolinite, chlorite, and epidote. The phyllic zone associated with copper mineralization is generally rich in iron oxide minerals at the surface, which can be especially detected by ALI. The altered areas were sampled and studied using X-ray diffraction analysis, spectral measurements, chemical analysis, and thin-section studies. The results of this analysis have shown that more than 90% of the known copper mineralization falls within the ASTER/ALI-mapped alteration areas. These data can be useful for mapping alteration minerals related to porphyry deposits in other regions with similar geological settings.     

Corporate-internal vs. national standard – A comparison study of two ergonomics evaluation procedures used in automotive manufacturing

Manufacturing corporations sometimes use corporate-internal procedures to evaluate and monitor the ergonomic status of the workplace. This article describes an industrial case study in the Swedish automotive sector, where an internally developed evaluation procedure was compared with a procedure based on a Swedish national standard provision.It was found that the national standard procedure tended to give more severe ratings and statistical support shows that the two evaluation procedures are not equivalent. The ability of the methods to identify body segments at risk was also compared.The quantitative comparison was followed up with interviews, where the influence of professional tasks and objectives became evident, as well as the fact that evaluation criteria are quantified differently by the two procedures. The main finding is that unforeseen differences in analysis procedure, criteria of acceptability and levels of detail can cause use-related difficulties for different professional groups when methods are used interchangeably.

Relevance to industry

Industrial corporations wishing to monitor ergonomics consistently are advised by the authors to ensure that ratings from internal evaluations are interpreted the same way by all involved personnel, and that they at least have criteria levels equivalent to those of a national standard.     

Artificial neural network vs. nonlinear regression for gold content estimation in pyrometallurgy

Pyrometallurgy is often used in the industrial process for treating gold-bearing slime. Slag compositions have remarkable influences on gold recovery and gold content in slag. In this paper, the relationships between the slag compositions in the soda–borax–silica glass-salt system and the gold content in the slag are investigated by using nonlinear regression and artificial neural network. A neural network model for estimating the gold contents of different slag compositions is presented, including the neural network type, structure and its learning algorithms. The study indicates that the three-layer back propagation neural network model can be applied to estimate gold content in the slag. Compared with the traditional regression methods, the neural network has many advantages.     

Cueing for transfer in multimedia programmes: process worksheets vs. worked-out examples

Abstract We investigate the effects of cueing, in a multimedia programme for the individualized training of the ‘whole task’ to prepare a plea, on the learning outcomes of 43 sophomore law students. The cueing formats of worked‐out examples (WOEs), process worksheets (PWs), and both WOE and PW are compared to a no‐cueing control condition. Our hypotheses that WOE enhance near transfer, by stimulating imitation processes to similar tasks, and that PW foster far transfer, by stimulating mindful abstraction processes to different tasks were partly confirmed by learning outcomes on the training task and two transfer tasks.     

Accuracy vs. Lifetime: Linear Sketches for Aggregate Queries in Sensor Networks

The in–network aggregation paradigm in sensor networks provides a versatile approach for evaluating aggregate queries. Traditional approaches need a separate aggregate to be computed and communicated for each query and hence do not scale well with the number of queries. Since approximate query results are sufficient for many applications, we use an alternate approach based on summary data–structures. We consider two kinds of aggregate queries: location range queries that compute the sum of values reported by sensors in a given location range, and value range queries that compute the number of sensors that report values in a given range. We construct summary data–structures called linear sketches, over the sensor data using in–network aggregation and use them to answer aggregate queries in an approximate manner at the base–station. There is a trade–off between accuracy of the query results and lifetime of the sensor network that can be exploited to achieve increased lifetimes for a small loss in accuracy. Most commonly occurring sets of range queries are highly correlated and display rich algebraic structure. Our approach takes full advantage of this by constructing linear sketches that depend on queries. Experimental results show that linear sketching achieves significant improvements in lifetime of sensor networks for only a small loss in accuracy of the queries. Further, our approach achieves more accurate query results than the other classical techniques using Discrete Fourier Transform and Discrete Wavelet Transform. This work was supported in part by NASA under Cooperative Agreement NCC5–315.     

MOMENT: software for analysis and display of amphiphilic regions in proteins.

MOMENT is a 53 kbyte program written in Borland TurboPascal with Borland Turbo Graphics, which will run on IBM PC-compatible machines. The program reads protein sequence files and calculates the hydrophobic moment of user-defined segments. The values produced can be displayed in the form of a scan through the sequence, as vector diagrams and helical wheels, as plots of hydrophobic moment versus hydrophobicity, or as hydrophobic moment as a function of angle.     

Extremal optimization vs. learning automata: Strategies for spin selection in portfolio selection problems

Nowadays, various imitations of natural processes are used to solve challenging optimization problems faster and more accurately. Spin glass based optimization, specifically, has shown strong local search capability and parallel processing. But, spin glasses have a low rate of convergence since they use Monte Carlo simulation techniques such as simulated annealing (SA). Here, we propose two algorithms that combine the long range effect in spin glasses with extremal optimization (EO-SA) and learning automata (LA-SA). Instead of arbitrarily flipping spins at each step, these two strategies aim to choose the next spin and selectively exploiting the optimization landscape. As shown in this paper, this selection strategy can lead to faster rate of convergence and improved performance. The resulting two algorithms are then used to solve portfolio selection problem that is a non-polynomial (NP) complete problem. Comparison of test results indicates that the two algorithms, while being very different in strategy, provide similar performance and reach comparable probability distributions for spin selection. Furthermore, experiments show there is no difference in speed of LA-SA or EO-SA for glasses with fewer spins, but EO-SA responds much better than LA-SA for large glasses. This is confirmed by tests results of five of the world's major stock markets. In the last, the convergence speed is compared to other heuristic methods such as Neural Network (NN), Tabu Search (TS), and Genetic Algorithm (GA) to approve the truthfulness of proposed methods.     

Seed Selection for Spread of Influence in Social Networks: Temporal vs. Static Approach

The problem of finding optimal set of users for influencing others in the social network has been widely studied. Because it is NP-hard, some heuristics were proposed to find sub-optimal solutions. Still, one of the commonly used assumption is the one that seeds are chosen on the static network, not the dynamic one. This static approach is in fact far from the real-world networks, where new nodes may appear and old ones dynamically disappear in course of time. The main purpose of this paper is to analyse how the results of one of the typical models for spread of influence - linear threshold - differ depending on the strategy of building the social network used later for choosing seeds. To show the impact of network creation strategy on the final number of influenced nodes - outcome of spread of influence, the results for three approaches were studied: one static and two temporal with different granularities, i.e. various number of time windows. Social networks for each time window encapsulated dynamic changes in the network structure. Calculation of various node structural measures like degree or betweenness respected these changes by means of forgetting mechanism - more recent data had greater influence on node measure values. These measures were, in turn, used for node ranking and their selection for seeding. All concepts were applied to experimental verification on five real datasets. The results revealed that temporal approach is always better than static and the higher granularity in the temporal social network while seeding, the more finally influenced nodes. Additionally, outdegree measure with exponential forgetting typically outperformed other time-dependent structural measures, if used for seed candidate ranking.