Resource constrained scheduling on multiple machines

This paper is devoted to Resource Constrained Scheduling. An instance for this problem is given by a set of n jobs with lengths and weights and a set of m machines with capacities. At every time each machine can run arbitrary many jobs in parallel but the total weight of these jobs must not exceed the capacity of the machine. Furthermore the m machines work in parallel and we wish to find a schedule that minimizes the makespan or the sum of completion times. Thus load balancing on a cluster of servers is a typical application for scheduling under resource constraints. For both measures the problem is -complete even for m=1. We show that the problem is approximable within factors of 2 (makespan) and 14.85 (sum of completion times) for arbitrary m.     

Defensive secretion of Therea petiveriana: chemical identification and evidence of an alarm function

The volatile constituents of the supposed defensive secretions of the glandular pouches of the adults of both sexes of the cockroach Therea petiveriana have been shown to contain N-3-methylbutylacetamide (MBA) and N-3-methylbutylpropanamide (MBP), which represented 60% of the volatile fraction. The other 40% included acidic, aromatic, and aldehydic compounds. Behavioral experiments demonstrated that the secretion acts as an alarm pheromone for adults.     

Observed maternal strategies and children's health locus of control in low-income Mexican Americans.

This study examined the relationship among mothers' health locus of control (HLOC) beliefs, their socialization strategies, and their children's HLOC beliefs in 80 low-income Mexican American families. Maternal socialization strategies were assessed from videotaped interactions of mothers and children engaged in a structured task. Factor analysis of the coded strategies yielded 4 factors: Tell Answer, Teaching, Clarify, and Reinforce. Findings indicated that maternal-health-internally scores negatively predicted mothers' use of the Tell Answer strategies and positively predicted their use of Teaching strategies. Mothers who believed that Powerful Others (e.g., health professionals) controlled their health were more likely to use the Tell Answer strategy. In contrast, mothers who believed that health was due to chance were less likely to use Teaching. Maternal use of Teaching strategies predicted children's internal HLOC, whereas maternal Tell Answer strategies predicted children's external HLOC. Findings suggest that mothers' HLOC beliefs influence the socialization strategies they use and that these strategies are associated with children's HLOC beliefs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Artificial Neural Networks vs. Fuzzy Logic: Simple Tools to Predict and Control Complex Processes—Application to Plasma Spray Processes

The plasma-sprayed coating architecture and in-service properties are derived from an amalgamation of intrinsic and extrinsic spray parameters. These parameters are interrelated; following mostly non-linear relationships. For example, adjusting power parameters (to modify particle temperature and velocity upon impact) also implies an adjustment of the feedstock injection parameters in order to optimize geometric and kinematic parameters. Optimization of the operating parameters is a first step. Controlling these is a second step and consists of defining unique combinations of parameter sets and maintaining them as constant during the entire spray process. These unique combinations must be defined with regard to the in-service coating properties. Several groups of operating parameters control the plasma spray process; namely (i) extrinsic parameters that can be adjusted directly (e.g., the arc current intensity) and (ii) intrinsic parameters, such as the particle velocity or its temperature upon impact, that are indirectly adjusted. Artificial intelligence (AI) is a suitable approach to predict operating parameters to attain required coating characteristics. Artificial Neural Networks (ANN) and Fuzzy Logic (FL) were implemented to predict in-flight particles characteristics as a function of power process parameters. The so-predicted operating parameters resulting from both methods were compared. The spray parameters are also predicted as a function of achieving a specified hardness or a required porosity level. The predicted operating parameters were compared with the predicted in-flight particle characteristics. The specific case of the deposition of alumina-titania (Al₂O₃-TiO₂, 13% by weight) by APS is considered.     

SmartShape™ technology. Modifying the shape of the beef cuberoll and the consumer response to shaped scotch fillet steaks

SmartShape™ is a novel meat processing technology that uses air pressure to compress and elongate whole cold-boned primals and packages them to retain form. A two stage study was conducted. The first stage established the ability of the SmartShape™ treated beef cube roll (m. longissimus lumborum) to retain shape in a commercial setting. Twelve hours chilling time following treatment was found to be adequate for steaks to retain their shape for up to 24 h after slicing. Steak shape and size did not change substantially until after cooking, when the steaks looked less formed. In the second stage a survey was conducted of 421 consumers to clarify the response to the shaping of a subset of raw and cooked scotch fillet steaks. There was no difference in preference for shaped or control steaks. A secondary survey found that informed consumers were more amenable to the SmartShape™ scotch fillet steaks presented here, but would not pay a premium for them.     

Ablative degradation of cryogenic thermal protection and fuel boil-off: Improvement of using graded density insulators

A simple modeling of the heat transfer through insulating bilayers of cryogenic reservoir subjected to surrounding environment or aerothermal flux is presented. The model permits to determine the instantaneous evolution of maximum fuel temperatures and the boil-off rate as well as the possible insulation ablation. To get a realistic estimation of the maximum fuel temperature and boil-off loss, the good knowledge of the internal convection coefficient, taking into account the possible fuel ebullition, is indispensable. The aerothermal flux provokes the insulation degradation and its ablation. Because of the ablation, the reservoir becomes less and less thermally protected, which may cause an important fuel boil-off. Compared to classical insulations with uniform density, those with spatially graded densities appear as potential insulations permitting to meet both light-weight and low boil-off requirements.     

Differences in splicing of mRNA encoding LH receptor in theca cells according to breeding season in ewes

Splice variants of mRNA encoding the LH receptor (LHR) during follicular development were characterized in cyclic and non-cyclic ewes. Granulosa and theca cells were collected from individual follicles. After amplification by RT-PCR of a region situated between exon 9 and exon 11 of the LHR gene, three distinct bands, LHR1 (full length), LHR2 (deletion of exon 10), LHR3 (deletion of 262 bp in exon 11), were observed in the granulosa and theca cells of ovine antral follicles of various sizes (2.5-6.0 mm). Expression of LHR mRNA in theca cells varied with the annual cycle of reproduction (P < 0.001), and was highly expressed in all classes of follicle collected from anoestrous ewes (1.3 +/- 0.1, n = 8 in small follicles; 1.8 +/- 0.2, n = 8 in medium follicles; 1.7 +/- 0.3, n = 4 in large follicles; arbitrary units) compared with follicles collected from oestrous ewes (0.19 +/- 0.06, n = 8 in small follicles; 0.2 +/- 0.04, n = 9 in medium follicles; 0.18 +/- 0.04, n = 5 in large follicles). During the breeding season, no differences in the relative expression of the different splice variants were observed according to follicle size. In contrast, during anoestrus, LHR3 mRNA was significantly more abundant in large (6.0-6.5 mm) and medium (4.0-5.5 mm) than it was in small (2.5-3.5 mm) follicles. These results indicate that RNA alternative splicing plays a role in the seasonal and physiological control of LH receptor expression in theca cells.     

Comparison between newly developed and classical determinations of index and thickness of thin films on substrates by ellipsometry

In the well-known classical determination of the index and thickness of thin transparent films formed on known substrates from the ellipsometric data, the film thickness is computed from its index value which is found first, independently of the former. However, these parameters of very thin films well under 100 Å may not be accurately thus determined in the presence of experimental angular errors particularly that in the angle of incidence. In this paper, not only the film parameters but also the angle of incidence are found using a new method from the ellipsometric data measured on two film-absorbing substrate reflecting system formed with the same transparent film but up to different thicknesses. The parameters obtained and their uncertainties estimated from the two methods are compared and consequently the limits of application of the methods are defined. The new method shows resistance to the propagation of angular errors to the parameters sought. Furthermore, a correlation detectedn between the error in the substrate real index and the uncertainty in the angle of incidence computed allows one to correct one of these by making use of the angle of incidence measured. These results are illustrated by applying the method presented to recently published experimental data.