The optimal linear regulator with state-dependent sampling

The optimal linear regulator with state-dependent sampling is formulated and the existence of an optimal solution is proved. A search algorithm is developed which uses both the necessary conditions obtained from nonlinear programming theory and a sequential unconstrained minimization technique to compute the optimal control. An application is presented.     

Active demand management for substitute products through price optimisation

This paper presents a systematic mathematical programming approach for active demand management in process industries. The proposed methodology aims to determine optimal pricing policies as well as output levels for substitute products, while taking into consideration manufacturing costs, resource availability, customer demand elasticity, outsourcing and market competition. First, profit maximisation analytical formulae are derived for determining Nash equilibrium in prices for a duopolistic market environment where each company produces only one product. An iterative algorithm is then proposed so as to determine the decision-making process by solving a series of non-linear mathematical programming (NLP) models before determining the Nash equilibrium in prices for the competing companies. The proposed algorithm is extended in order to accommodate the case of multi-product companies, each one selling a set of substitute products at different prices. The applicability of the proposed methodology is demonstrated by a number of illustrative examples.     

Towards a low‐cost high‐quality carbon‐nanotube field‐emission display

Abstract— We have developed field‐emission‐display technology driven by chemical‐vapor‐deposition‐grown carbon‐nanotube emitters incorporated in a simple, low‐cost device structure. Here, we report on frit‐sealed test displays with a brightness of 3000 cd/m² at 3 kV and a lifetime of 9000 hours with only 45% degradation. We also demonstrate the scalability of the technology with a uniform high‐brightness 6‐in. QVGA that displays video images with a switching voltage of 40 V.     

Physically-based models of low-power wireless links using signal power simulation

We propose deriving wireless simulation models from experimental traces of radio signal strength. Because experimental traces have holes due to packet losses, we explore two algorithms for filling the gaps in lossy experimental traces. Using completed traces, we apply the closest-fit pattern matching (CPM) algorithm, originally designed for modeling external interference, to model signal strength.We compare the observed link behavior using our models with that of the experimental packet trace. Our approach results in more accurate packet reception ratios (PRR) than current simulation methods, reducing the absolute error in PRR by up to about 0.3 in the experiments we present. We also find that using CPM for signal strength improves simulation of packet burstiness, reducing the Kantorovich–Wasserstein (KW) distance of conditional packet delivery functions (CPDFs) by a factor of about three for intermediate links. Our model reduces the factor of error in the number of parent changes in the standard TinyOS collection protocol (CTP) by an order of magnitude or more as compared to a real signal power trace in two simple test scenarios. We show that our methods are robust to the sampling frequency of the learning deployment and are thus generally applicable for simulating arbitrary applications without a pre-determined packet transmission frequency.These improvements give low-power wireless network simulators a better capability to capture real-world dynamics and edge conditions that protocol designers typically must wait until deployment to detect.     

Dry-Aging Effects on Palatability of Beef Longissimus Muscle

ABSTRACT: Beef strip loins and short loins were vacuum aged for 7 or 14 d, then these cuts were dry aged for 7, 14, or 21 d. At 2, 9, and 16 d of post-dry-aging vacuum storage, strip steaks were analyzed for sensory, physical, and microbial differences. Controls were vacuum aged for 14 d. Dry aging for 14 and 21 d produced steaks with greater (P < 0.05) dry-aged flavor, tenderness, and juiciness than controls or steaks dry aged for 7 d. Shear forces were lower (P < 0.05) for steaks dry aged for 21 d. Time of vacuum storage before and after dry aging had minimal effects on development of dry-aged flavor attributes.     

Flipper, a mobile Fot1-like transposable element in Botrytis cinerea

A transposable element, Flipper, was isolated from the phytopathogenic fungus Botrytis cinerea. The element was identified as an insertion sequence within the coding region of the nitrate reductase gene. The Flipper sequence is 1842 bp long with perfect inverted terminal repeats (ITRs) of 48 bp and an open reading frame (ORF) of 533 amino acids, potentially encoding for a transposase; the element is flanked by the dinucleotide TA. The encoded protein is very similar to the putative transposases of three elements from other phytopathogenic fungi, Fot1 from Fusarium oxysporum, and Pot2 and MGR586 from Magnaporthe grisea. The number of Flipper elements in strains of B. cinerea varied from 0 to 20 copies per genome. Analysis of the descendants of one cross showed that the segregation ratio of Flipper elements was 2:2 and that the copies were not linked.     

Scaling Virtual Worlds with a Physical Metaphor

Online virtual worlds have long been an anticipated medium for digital communications. They provide a compelling substrate for shared, networked environments where people can communicate, shop, socialize, collaborate, and learn. However, today's systems fall short of their imagined potential. The Meru project is designing and implementing an architecture for virtual worlds of the future. Our key insight is that a virtual model of the real world is a comfortable metaphor which addresses a wide range of issues including security, scalability, and federation. This symmetry between real and virtual worlds also permits a natural interaction between the two.     

The seated bus passenger--a review

The paper describes the inter-relationship of anthropometry, rig studies and dynamic testing of aspects related to problems of the seated bus passenger. It seeks to draw together sub-sections of a very large study sponsored by the government through the Transport and Road Research Laboratory and undertaken by the Human Factors Group of Leyland Truck and Bus. It is relevant to all those designing passenger carrying transport systems.     

Mesh Networking Research and Technology for Multihop Wireless Networks

Mesh networking encompasses a broad class of wireless networks in which nodes collaboratively route packets. All mesh networks' benefits, such as lower costs, scalability, and easy installation, introduce new challenges that we must address.