When is it Possible to Identify 3D Objects From Single Images Using Class Constraints?

One approach to recognizing objects seen from arbitrary viewpoint is by extracting invariant properties of the objects from single images. Such properties are found in images of 3D objects only when the objects are constrained to belong to certain classes (e.g., bilaterally symmetric objects). Existing studies that follow this approach propose how to compute invariant representations for a handful of classes of objects. A fundamental question regarding the invariance approach is whether it can be applied to a wide range of classes. To answer this question it is essential to study the set of classes for which invariance exists. This paper introduces a new method for determining the existence of invariant functions for classes of objects together with the set of images from which these invariants can be computed. We develop algebraic tests that determine whether the objects in a given class can be identified from single images. These tests apply to classes of objects undergoing affine projection. In addition, these tests allow us to determine the set of views of the objects which are degenerate. We apply these tests to several classes of objects and determine which of them is identifiable and which of their views are degenerate.     

Analysis and enhancement of human–machine interfaces using a joystick controller

This article deals with performance evaluation of human operations in point‐to‐point displacement tasks using a joystick. Analysis of operator outputs during an experimental task revealed a pattern of partially overlapping submovements with predictable velocity characteristics and forms. A velocity‐dependent gain control added to the joystick–cursor interface improved performance when compared to a conventional linear transformation. This control algorithm can be recommended for many similar human–machine interfaces. A specific performance evaluation was applied to estimate the characteristics of different remote control designs. This approach can be used for evaluating human–machine systems. © 2000 John Wiley & Sons, Inc.     

Economic design of offline inspections for a batch production process

We consider a batch production process that can be either stable or unstable, in which inspection is performed offline after production of the batch is completed. The quality of a batch can be estimated with a desired level of certainty by inspecting only a sample of its units. In order to minimise the expected total cost per batch, which includes the costs of inspection, of false acceptance and of false rejection, we propose an economic inspection plan in which only a fraction of the batches, rather than each batch, is inspected. We prove that the expected total cost is a strictly quasiconvex function of the inspection interval. We establish necessary and sufficient conditions for the optimal inspection interval to be finite and propose an efficient algorithm to obtain its value. We demonstrate for the case of a single-sampling plan where the proposed economic approach outperforms the common procedure of inspecting every batch, and the proposed algorithm is very efficient.     

Organic Ag–Hg amalgam composite materials

Amalgams doped with organic molecules represent a new type of triple composite, organics@Ag–Hg. Synthetic procedures involving the dissolution of doped silver in Hg were developed. A detailed study of structure evolution and its dynamics was carried out following the intermediate phases γ-Ag–Hg and ζ-Ag–Hg, and the Ag–Hg solid solution. Three dopants – the dye Congo red (CR), the polymer Nafion and the antibacterial agent chlorhexidine (CH) – were used, indicating the generality of the approach. Detailed release studies of CR served as an additional analytical tool for inspecting the structure dynamics in the forming doped amalgams. Applications, such as for the CH@Ag–Hg amalgam, are pointed out.     

The effect of risk aversion on product family design under uncertain consumer segments

A product family refers to a group of products that have been derived from a common product platform and which are specifically designed to satisfy a variety of market segments. In this paper, we consider a firm utilising product family design in order to respond to the requirements of two consumer segments, each characterised by different quality valuations. Although the total number of consumers in the market is known, the proportions each segment share are random, with known mean and variance. We show how the uncertainty of the market segmentation affects the firm's decision whether to use common rather than unique components. Motivated by a problem faced by a major automotive manufacturer, we study the consequence of low and high uncertainty, various product quality levels and the difference of marginal valuation on the best configuration.     

Hemolymph amino acid analysis of individual Drosophila larvae

One of the most widely used transgenic animal models in biology is Drosophila melanogaster, the fruit fly. Chemical information from this exceedingly small organism is usually accomplished by studying populations to attain sample volumes suitable for standard analysis methods. This paper describes a direct sampling technique capable of obtaining 50-300 nL of hemolymph from individual Drosophila larvae. Hemolymph sampling performed under mineral oil and in air at 30 s intervals up to 120 s after piercing larvae revealed that the effect of evaporation on amino acid concentrations is insignificant when the sample was collected within 60 s. Qualitative and quantitative amino acid analyses of obtained hemolymph were carried out in two optimized buffer conditions by capillary electrophoresis with laser-induced fluorescence detection after derivatizing with fluorescamine. Thirteen amino acids were identified from individual hemolymph samples of both wild-type (WT) control and the genderblind (gb) mutant larvae. The levels of glutamine, glutamate, and taurine in the gb hemolymph were significantly lower at 35%, 38%, and 57% of WT levels, respectively. The developed technique that samples only the hemolymph fluid is efficient and enables accurate organism-level chemical information while minimizing errors associated with possible sample contaminations, estimations, and effects of evaporation compared to the traditional hemolymph-sampling techniques.     

Climatic considerations in school building design in the hot–humid climate for reducing energy consumption

Energy-conscious design of school buildings can contribute to significant energy savings and improve the students’ learning environment. The purpose of this research is to formulate design recommendations for school buildings in the hot–humid climatic zone and assess the influence of different design variables on their energy consumption. A base-case classroom was constructed by taking commonly used values for each design variable. Using computer simulation techniques, these variables were modified one by one to find the value that minimized energy consumption, while keeping thermal and visual comfort in the room. Based on these tests, the recommended value for each design variable to achieve a high performance classroom, was determined. Comparative tests were done to determine which variables have greatest impact on the energy consumption and thermal comfort in the classroom, and how their absolute influence depends on the order of implementation of each improvement. A complex interdependence among the design variables was found, but strong conclusions for energy savings could still be reached.     

Ceramide Synthase 2 Null Mice Are Protected from Ovalbumin-Induced Asthma with Higher T Cell Receptor Signal Strength in CD4+ T Cells

(1) Background: six mammalian ceramide synthases (CerS1–6) determine the acyl chain length of sphingolipids (SLs). Although ceramide levels are increased in murine allergic asthma models and in asthmatic patients, the precise role of SLs with specific chain lengths is still unclear. The role of CerS2, which mainly synthesizes C22–C24 ceramides, was investigated in immune responses elicited by airway inflammation using CerS2 null mice. (2) Methods: asthma was induced in wild type (WT) and CerS2 null mice with ovalbumin (OVA), and inflammatory cytokines and CD4 (cluster of differentiation 4)+ T helper (Th) cell profiles were analyzed. We also compared the functional capacity of CD4+ T cells isolated from WT and CerS2 null mice. (3) Results: CerS2 null mice exhibited milder symptoms and lower Th2 responses than WT mice after OVA exposure. CerS2 null CD4+ T cells showed impaired Th2 and increased Th17 responses with concomitant higher T cell receptor (TCR) signal strength after TCR stimulation. Notably, increased Th17 responses of CerS2 null CD4+ T cells appeared only in TCR-mediated, but not in TCR-independent, treatment. (4) Conclusions: altered Th2/Th17 immune response with higher TCR signal strength was observed in CerS2 null CD4+ T cells upon TCR stimulation. CerS2 and very-long chain SLs may be therapeutic targets for Th2-related diseases such as asthma.