Objectively-measured step cadence and walking patterns in a rural African setting: a cross-sectional analysis

Objectives To investigate free-living, accelerometry-derived step cadence and walking strategy parameters in 263 adult women (19-56 years) within a rural African setting. Participants were categorised into weight groups: Under-Normal Weight (UW/NW: <25 kg.m−2), Overweight-Obese (OW/OB: ≥25 kg.m−2). From the minute-by-minute uni-axial accelerometry data, outcomes describing physical activity intensity, step volume, step cadence and step bouts were extracted. In addition, walking pattern parameters for step bout length and step cadence were determined. Results Average step volume was 13568 steps.day−1, and >85% of participants were classified as active-to-highly-active. Overall, ≈45% of daily steps was accumulated in the low-to-moderate intensity range. Peak cadence indices were higher in the UW/NW group (p≤0.0112). For both groups, 75% of steps were accumulated in bouts >15 minutes, and 95% of bouts were accumulated at 1-39 steps.minute−1. The UW/NW group employed a more varied step cadence, and higher cadences contributed more to step accumulation than the OW/OB group (p≤0.05). There were no significant group differences in bout length strategy parameters (p≥0.0861). Despite no difference between the weight groups in step volume, there were differences in some step cadence indices which reflect higher step intensities, and in cadence strategies chosen to accumulate steps.

The risk-based strategy model technical maintenance of the unique technological structures

The article considers an approach to the development of a risk-based strategy model for the technical maintenance of a unique technological structure. It is proposed to use the minimum risk of the structure failure as a criterion for optimizing the technical maintenance of the structure. It is shown that this approach allows to decrease considerably and by limited means the risk of the elements failure especially those influencing the structure safety. The task of determining the strategy parameters of technical maintenance of the construction object under consideration is formulated as a Boolean mathematical programming task. The theoretical conclusions are confirmed by the calculation example. The solution showed the advantage concerning the risk of use of the proposed strategy in comparison with the current one.

Metrics for quantifying cognitive factors that may underlie individual variation in exoskeleton use

Individual differences in adaptation to exoskeletons have been observed, but are not well understood. Kinematic, kinetic, and physiologic factors are commonly used to assess these systems. Parameters from experimental psychology and gait literature wereadapted to probe the lower extremity perception-cognition-action loop using measures of reaction times, gait task performance, and gait strategy. Parameters were measured in 15 subjects via two tasks: (1) a modified Simon task and (2) a speed-achievement task with secondary go/no-go cues on a self-paced treadmill. Outcome metrics were assessed for significantly different intra- versus inter-subject variability. Reaction time measures from the modified Simon task, as well two speed-achievement metrics and one gait-strategy characteristic we re found to show significant differenc es in intra- versus inter-subject variability. These results suggest that select cognitive factors may differentiate between individuals and be potential predictors for individual variation during exoskeleton system operation.

Pareto Efficiency of Mixed Quantum Strategy Equilibria

The aim of the paper is to investigate Nash equilibria and correlated equilibria of classical and quantum games in the context of their Pareto optimality. We study four games: the prisoner's dilemma, battle of the sexes and two versions of the game of chicken. The correlated equilibria usually improve Nash equilibria of games but require a trusted correlation device. We analyze the quantum extension of these games in the Eisert-Wilkens-Lewenstein formalism with the full SU(2) space of players&rsquo; strategy parameters. It has been shown that the Nash equilibria of these games in quantum mixed Pauli strategies are closer to Pareto optimal results than their classical counterparts. The relationship of mixed Pauli strategies equilibria and correlated equilibria is also analyzed.

Optimizing replenishment base on order structure in crane & shuttle based storage and retrieval system

A new automatic warehouse sorting system, the crane & shuttle based storage and retrieval system (C&SBS/RS), is proposed in this paper. In C&SBS/RS, the crane-based storage and retrieval system (CBS/RS) in the pallet storage area provides the pallets picking, the shuttle-based storage and retrieval system (SBS/RS) in the tote storage area handles the cases and items picking. When the inventory in SBS/RS is lower than safety stock, SBS/RS initiates replenishment transaction. Besides, the order matrix is proposed to study order structure parameters, such as the order density, the order strength, the wave size and so on. Moreover, this paper analyzes the influence of order structure on the replenishment with four evaluation parameters, e.g., the workload of CBS/RS and SBS/RS, the number of used storage position in SBS/RS, the replenishment time. Numerical experiments are carried out to analysis the impact of the wave size and the proportion of high turnover SKU on those four evaluation parameters under multiple order structure, which is to help warehouse operation manager decide replenishment strategy parameters.

Influence of Scanning Strategy Parameters on Residual Stress in the SLM Process According to the Bridge Curvature Method for AISI 316L Stainless Steel

The present paper deals with the investigation and comparison of the influence of scanning strategy on residual stress in the selective laser melting (SLM) process. For the purpose of the experiment, bridge geometry samples were printed by a 3D metal printer, which exhibited tension after cutting from the substrate, slightly bending the samples toward the laser melting direction. Samples were produced with the variation of process parameters and with a change in scanning strategy which plays a major role in stress generation. It was evaluated using the Bridge Curvature Method (BCM) and optical microscopy. At the end, a recommendation was made.

Modelling Customer Satisfaction to Improve Receivables of a Firm in a Supply Chain

A firm in a supply chain usually defines payment strategies such as penalty rate, delivery time, customer discount, and quantity of order fulfilment regarding the invoices issued for the products ordered by the customers, whilst these payment strategies affect not only the amount paid by the customers but also customer satisfaction. The main aim of this article is to evaluate the effects of customer satisfaction on the cash inflow of a firm in a supply chain. In fact, this article develops an optimisation mathematical model to maximise the amount of cash received from customer within a time horizon through maximizing customer satisfaction and optimising the payment strategy parameters. Customer satisfaction in each period is defined as a dependent variable of three parameters such as penalty rate, demand variation and delivery time. All the firms in a supply chain can adjust these parameters to improve the amount of cash received from the customers. The penalty rate in each period is related to the amount and time of cash received from the customers in that period and the amount are supposed to be received from the customers in the next period. Consequently, customer discount can be applied to improve the firm's input.