ATLeS-SN

As wireless sensor network platforms become increasingly more complex to design and optimize due to the multitude of interdependent parameters that must be considered, computer simulations have emerged as the primary solution to feasibly analyze the long-term effects of design changes within a deployed system. Although several successful wireless sensor network simulators have already been developed, to our knowledge, none provide the modularity necessary to model sensor nodes and/or environmental components at differing levels of abstraction. In this paper, we present the Arizona Transaction-Level Simulator for Sensor Networks (ATLeS-SN), which by virtue of its implementation language—SystemC—allows application developers to easily specify interchangeable component models in order to achieve the desired simulation correctness, performance, and scalability. We provide an overview of our proposed simulation framework and highlight its benefits using a sound ranging application.     

Minor components in oils and their effects on frying performance

Minor components are the non‐triacylglycerol constituents of oil and constitute up to 5% of the total lipid composition. Though minor in composition, they can exert major influence on the performance of oil during frying. The effect of the minor components on frying performance depends on their chemical nature, composition and amount in the oil. Among these minor components tocopherols, phytosterols, phospholipids, γ‐oryzanol, lignans, phenolics, and carotenoids are the most important. Here, their effect on the frying performance of edible oils is discussed.     

Sex ratios: are there natural variations within the human population?

OBJECTIVE: To investigate on a population basis the suggestion that certain factors naturally alter the odds of having a boy or a girl, and that some women are predisposed towards having children of one particular gender. DESIGN: Routine data analysis. POPULATION: Routinely collected data on singleton infants born in Scotland from 1975 to 1988, linked so that births (live and still) to the same mother could be identified. The analyses relate to 549,048 first to fifth order births occurring to 330,088 women whose records were complete from the first delivery onwards. MAIN OUTCOME MEASURES: Gender of infant. RESULTS: Of 549,048 births, 51.4% were male. Apart from random variation, the sex ratio of 1.06 remained constant at all birth orders (P = 0.18). The probability of a male infant appeared unrelated to the genders of the preceding siblings (P > 0.20 in second to fifth deliveries), and there was no evidence of variation with maternal age (P = 0.31), maternal height (P = 0.69), paternal social class (P = 0.12), maternal social class (P = 0.57), year of delivery (P = 0.84) or season of birth (P = 0.41). Whilst mothers whose children were all the same gender were more likely to continue childbearing than those with children of different genders, there was no evidence that those with daughters were more likely to continue than those with sons. CONCLUSIONS: The suggestion that some women have a natural predisposition towards having children of a particular gender is not supported by these data. On a population basis there is no evidence to suggest that gender determination is anything other than a chance process.     

Polymerization of lactams, 87. Block copolymers of poly(ϵ-caprolactam) and polybutadiene prepared by anionic polymerization. Part I: Preparation and properties

The effect of the polymerization conditions on the properties of poly(?-caprolactam)-polybutadiene block copolymers prepared by polymerization casting through anionic polymerization of ?-caprolactam initiated with potassium salt of ?-caprolactam in the presence of α,ω-dihydroxy-polybutadiene and isocyanates or their blocked derivatives as functionalizing agents was investigated. The influence of the content of telechelic polybutadiene, its molecular weight, type of diisocyanate, and polymerization temperature on the fundamental mechanical properties of the prepared materials and on the polymerization rate was evaluated.     

Exergy analysis for the evaluation of a thermal storage system employing PCMS with different melting temperatures

This article presents evaluation of the performance of phase-change, thermal-energy storage units from the second-law viewpoint. The analysis is performed for a complete charging-discharging cycle of a system consisting of two storage units in series. Both units are melted and solidified by the same hot and cold working fluids. The upstream unit has the higher of the two melting temperatures. The storage capacity of each unit is sized such that both units must change phase over the same period of time. A computer program is developed to find the dependence of the best second-law efficiency on different operational and design parameters.     

Reasoning about places, times, and actions in the presence ofmobility

The current trend toward portable computing systems (e.g., cellular phones, laptop computers) brings with it the need for a new paradigm to facilitate thinking about and designing distributed applications. We use the term mobile to refer to distributed systems that include moving, autonomous agents which loosely cooperate to accomplish a task. The fluid nature of the interconnections among components of a mobile system provides new challenges and opportunities for the research community. While we do not claim to have fully grasped all the issues involved in specifying and modeling such systems, we believe that the notions of place, time, and action will play a central role in any model that is developed. We show that these concepts can be expressed and reasoned about in the UNITY logic with a minimal amount of additional notation. The formal derivation of a control system for a radio-dispatched elevator is used to show how considerations involving place, time, and actions impact the design process, be it formal or semiformal