R&R (repeatability and reproducibility) gage study applied on gaps’ measurements of aircraft assemblies made by a laser technology device

This paper presents the competitive advantages when a type of laser instrument is applied in the aircraft production environment. This contribution reports the winnings that could be achieved when measurements made by a laser technology are done. This proposed application comprises a modern and suitable resource that contributes to a higher performance and relevant gains in competitiveness for the companies. It can provide a high level of accuracy, flexibility, productivity, quality and speed on the manufacturing floor. A case study, based on a statistics gage named repeatability and reproducibility method, is done to demonstrate the gained advantages and benefits when the laser device is used. This study aims to evaluate and compare the variability of measurements between a manual instrument of measurement and a laser instrument during aircraft production processes and its relevant quality issues for the business.     

Panoramic view and national identity: two of Santiago de Chile's public spaces in the second half of the nineteenth century

This article shows how the panorama, as a modern form of visualization and representation, became a model for the Santa Lucia Hill and the Cousiño Park, two emblematic projects of Santiago's transformation, carried out by Benjamín Vicuña Mackenna between 1872 and 1875. On the one hand, supported by the height and location of the hill and its pattern of paths and terraces, the Santa Lucia promenade became an effective mechanism for visual control of the city as a whole, as well as a reference to the new urban order that was to be imposed. On the other hand, by proposing a landscape design that served as an urban window into Santiago's geographical surroundings, the Cousiño Park project interpreted the qualities of the panorama from a strongly local sensitivity that highlighted the values of life in contact with nature. The analysis of these two cases will show how the panorama remarkably influenced Santiago's first transformation in the republican era, while representing fundamental values of the emerging national identity.     

Forest recovery trends derived from Landsat time series for North American boreal forests

A critical component of landscape dynamics is the recovery of vegetation following disturbance. The objective of this research was to characterize the forest recovery trends associated with a range of spectral indicators and report their observed performance and identified limitations. Forest disturbances were mapped for a random sample of three major bioclimate zones of North American boreal forests. The mean number of years for forest to recover, defined as time required to for a pixel to attain 80% of the mean spectral value of the 2 years prior to disturbance, was estimated for each disturbed pixel. The majority of disturbed pixels recovered within the first 5 years regardless of the index ranging from approximately 78% with normalized burn ratio (NBR) to 95% with tasselled cap greenness (TCG) and after 10 years more than 93% of disturbed pixels had recovered. Recovery rates suggest that normalized differenced vegetation index (NDVI) and TCG saturate earlier than indices that emphasize longer wavelengths. Thus, indices such as NBR and the mid-infrared spectral band offer increased capacity to characterize different levels of forest recovery. The mean length of time for spectral indices to recover to 80% of the pre-disturbance value for pixels disturbed 10 or more years ago was highest for NBR, 5.6 years, and lowest for TCG, 1.7 years. The mid-infrared spectral band had the greatest difference in recovered pixels among bioclimate zones 1 year after disturbance, ranging from approximately 42% of disturbed pixels for the cold and mesic bioclimate zone to 60% for the extremely cold and mesic bioclimate zone. The cold and mesic bioclimate zone had the longest mean years to recover ranging from 1.9 years for TCG to 4.2 years for NBR, while the cool temperate and dry bioclimate zone had the shortest mean years to recover ranging from 1.6 years for TCG to 2.9 years for NBR suggesting differences in pre-disturbance conditions or successional processes. The results highlight the need for caution when selecting and interpreting a spectral index for recovery characterization, as spectral indices, based upon the constituent wavelengths, are sensitive to different vegetation conditions and will provide a variable representation of structural conditions of forests.     

Modulation doping for iterative demapping of bit-interleaved coded modulation

In this letter, the problem of the transmitter design for bit-interleaved coded modulation (BICM) with the receiver employing iterative demapping, is addressed. Conventionally, the design is focused on the appropriate choice of the constellation mapping so that the iterative process converges to small values of bit- or block- error rates. Here, instead of a difficult design of a new mapping, we propose to use symbols modulated using two different mappings. Through numerical simulation, our simple design is shown to outperform the conventional approach without increase in the receiver's complexity.     

A technique to quantify morphological damage of the flute profile in the midplane of corrugated fibreboard

This research presents a technique to quantify morphological damage to flutes in corrugated fibreboard (CFB). The method involves laser cutting thin samples and analysing digital images of the flute profiles. The surface profiles of creased CFB before and after laser cutting were measured using fringe projection and showed that the sample preparation does not significantly affect the flute profile. After imaging the laser cut samples, skeleton analysis was used to derive a digitised profile of the flute shape. To characterise the level of damage to the flute profile, a similarity factor (SF) was introduced to quantify the relative difference between test sample and reference flute profiles. Validation of this analysis technique was done by generating known images of flute profile with variations that include distortions that could occur to CFB. These images were then fed into the skeleton analysis, and the results were compared with the original profile. This comparison showed good agreement between the initial and skeleton‐analysed flutes. A demonstration of the skeleton analysis on purposefully damaged actual CFB flute profiles shows that the SF reduces as the level of crushing increases, showing that the technique could be used to enumerate morphological damage to CFB during manufacture, conversion, and use.     

Visual Analysis of protein‐ligand interactions

The analysis of protein‐ligand interactions is complex because of the many factors at play. Most current methods for visual analysis provide this information in the form of simple 2D plots, which, besides being quite space hungry, often encode a low number of different properties. In this paper we present a system for compact 2D visualization of molecular simulations. It purposely omits most spatial information and presents physical information associated to single molecular components and their pairwise interactions through a set of 2D InfoVis tools with coordinated views, suitable interaction, and focus+context techniques to analyze large amounts of data. The system provides a wide range of motifs for elements such as protein secondary structures or hydrogen bond networks, and a set of tools for their interactive inspection, both for a single simulation and for comparing two different simulations. As a result, the analysis of protein‐ligand interactions of Molecular Simulation trajectories is greatly facilitated.     

A General Illumination Model for Molecular Visualization

Several visual representations have been developed over the years to visualize molecular structures, and to enable a better understanding of their underlying chemical processes. Today, the most frequently used atom‐based representations are the Space‐filling, the Solvent Excluded Surface, the Balls‐and‐Sticks, and the Licorice models. While each of these representations has its individual benefits, when applied to large‐scale models spatial arrangements can be difficult to interpret when employing current visualization techniques. In the past it has been shown that global illumination techniques improve the perception of molecular visualizations; unfortunately existing approaches are tailored towards a single visual representation. We propose a general illumination model for molecular visualization that is valid for different representations. With our illumination model, it becomes possible, for the first time, to achieve consistent illumination among all atom‐based molecular representations. The proposed model can be further evaluated in real‐time, as it employs an analytical solution to simulate diffuse light interactions between objects. To be able to derive such a solution for the rather complicated and diverse visual representations, we propose the use of regression analysis together with adapted parameter sampling strategies as well as shape parametrization guided sampling, which are applied to the geometric building blocks of the targeted visual representations. We will discuss the proposed sampling strategies, the derived illumination model, and demonstrate its capabilities when visualizing several dynamic molecules.     

Hydrogen storage in an activated carbon bed: Effect of energy release on storage capacity of the tank

Thermal effects during dynamic charging of a two-liter, adsorbent, packed bed, hydrogen storage tank were studied through numerical modeling. For packed-bed materials having adsorption capacities smaller than 2 wt%, the conversion to heat of the mechanical work required to feed the tank produces more than 60% of the temperature increase that occurs during the charging process. However, for materials having adsorption capacities greater than 3 wt%, 60% of the heating is due to the adsorption process. The temperature increase for a material that would fulfill the DOE recommendation of 6 wt% storage capacity is 130 K. This reduces the storage capacity by 20% relative to what would be obtained from an isothermal charging process. Simulations showed that the limitation in the storage capacity can be reduced to less than 10%, if a packed bed having an effective conductivity of a few W m^?1 K^?1 can be used.     

Fast coastal algorithm for automatic geometric correction of AVHRR images

A coastal algorithm for fully automatic geometric correction of Advanced Very High Resolution Radiometer (AVHRR) images is presented. Inputs are the AVHRR image and updated ephemeris data and outputs are the georeference image and a cloud image mask. Its principal advantage and novelty is that it requires only manual control in the first stage of the process. Particularly, the detection of Ground Control Points (GCPs), usually rather time consuming, is performed with this method in an automatic way. The procedure only requires the previous existence of a coastal reference-windows database. To find the exact location of the GCPs, the routine searches the best match of these referencewindows with the image. The complete automation of the process makes the routine very fast, then allowing its operative application on a large volume of images. The process provides accuracies to within 1-1.5 AVHRR pixels.