730 research outputs found

    Designing Volumetric Truss Structures

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    We present the first algorithm for designing volumetric Michell Trusses. Our method uses a parametrization approach to generate trusses made of structural elements aligned with the primary direction of an object's stress field. Such trusses exhibit high strength-to-weight ratios. We demonstrate the structural robustness of our designs via a posteriori physical simulation. We believe our algorithm serves as an important complement to existing structural optimization tools and as a novel standalone design tool itself

    Roulette-Wheel Selection-Based PSO Algorithm for Solving the Vehicle Routing Problem with Time Windows

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    The well-known Vehicle Routing Problem with Time Windows (VRPTW) aims to reduce the cost of moving goods between several destinations while accommodating constraints like set time windows for certain locations and vehicle capacity. Applications of the VRPTW problem in the real world include Supply Chain Management (SCM) and logistic dispatching, both of which are crucial to the economy and are expanding quickly as work habits change. Therefore, to solve the VRPTW problem, metaheuristic algorithms i.e. Particle Swarm Optimization (PSO) have been found to work effectively, however, they can experience premature convergence. To lower the risk of PSO's premature convergence, the authors have solved VRPTW in this paper utilising a novel form of the PSO methodology that uses the Roulette Wheel Method (RWPSO). Computing experiments using the Solomon VRPTW benchmark datasets on the RWPSO demonstrate that RWPSO is competitive with other state-of-the-art algorithms from the literature. Also, comparisons with two cutting-edge algorithms from the literature show how competitive the suggested algorithm is

    Some parameters of dried pork produced with lower salt content

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    Production of meat products with lower salt/sodium content is the goal of today's meat industry because of bad influence of exceed sodium intake by food. In this paper are presented some physico-chemical parameters during processing of dried pork produced with lower salt content. Pork (m. longissimus dorsi) was cured with nitrite curing salt in amount of 3 kg/100 kg of meat. In meat were measured the weight loss during curing and drying; moisture content by standard method SRPS ISO 1442:1998, water activity using awmeter (Wert-Messer, Durotherm) at temperature of 25°C; and pH value by pH-meter (MA-5730; PAT N° 35398, Iskra) according to SRPS ISO 29 17:2004. Average moisture content in dried meat at the end of production was 40.10%. Average weight loss was 2.39% after 7 days of production (after curing) and it is increased up to the end of production, average 34.57%. Acidity of meat during curing, smoking and drying was similar; pH value was around 6.00. Water activity was gradually decreased from average 0.985 after curing (7th day) up to 0.899 at the end of production. During the storage of dried meat under vacuum conditions, pH value decreased from 5.43 in the final product up to 5.11 at the end of storage (120th day). These values are characteristic for curing, drying and fermentation of meat. Dried meat was shelf stable for 120 day under vacuum conditions, without signs of rancidity and without changes in other sensory attributes

    Temporal Network Analysis of Email Communication Patterns in a Long Standing Hierarchy

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    An important concept in organisational behaviour is how hierarchy affects the voice of individuals, whereby members of a given organisation exhibit differing power relations based on their hierarchical position. Although there have been prior studies of the relationship between hierarchy and voice, they tend to focus on more qualitative small-scale methods and do not account for structural aspects of the organisation. This paper develops large-scale computational techniques utilising temporal network analysis to measure the effect that organisational hierarchy has on communication patterns within an organisation, focusing on the structure of pairwise interactions between individuals. We focus on one major organisation as a case study - the Internet Engineering Task Force (IETF) - a major technical standards development organisation for the Internet. A particularly useful feature of the IETF is a transparent hierarchy, where participants take on explicit roles (e.g. Area Directors, Working Group Chairs). Its processes are also open, so we have visibility into the communication of people at different hierarchy levels over a long time period. We utilise a temporal network dataset of 989,911 email interactions among 23,741 participants to study how hierarchy impacts communication patterns. We show that the middle levels of the IETF are growing in terms of their dominance in communications. Higher levels consistently experience a higher proportion of incoming communication than lower levels, with higher levels initiating more communications too. We find that communication tends to flow "up" the hierarchy more than "down". Finally, we find that communication with higher-levels is associated with future communication more than for lower-levels, which we interpret as "facilitation". We conclude by discussing the implications this has on patterns within the wider IETF and for other organisations

    Spin Manipulation by Creation of Single-Molecule Radical Cations

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    All-trans-retinoic acid (ReA), a closed-shell organic molecule comprising only C, H, and O atoms, is investigated on a Au(111) substrate using scanning tunneling microscopy and spectroscopy. In dense arrays single ReA molecules are switched to a number of states, three of which carry a localized spin as evidenced by conductance spectroscopy in high magnetic fields. The spin of a single molecule may be reversibly switched on and off without affecting its neighbors. We suggest that ReA on Au is readily converted to a radical by the abstraction of an electron.Comment: 5 pages, 3 figures, accepted for publication in Phys. Rev. Let

    Toward Fairness in Speech Recognition: Discovery and mitigation of performance disparities

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    As for other forms of AI, speech recognition has recently been examined with respect to performance disparities across different user cohorts. One approach to achieve fairness in speech recognition is to (1) identify speaker cohorts that suffer from subpar performance and (2) apply fairness mitigation measures targeting the cohorts discovered. In this paper, we report on initial findings with both discovery and mitigation of performance disparities using data from a product-scale AI assistant speech recognition system. We compare cohort discovery based on geographic and demographic information to a more scalable method that groups speakers without human labels, using speaker embedding technology. For fairness mitigation, we find that oversampling of underrepresented cohorts, as well as modeling speaker cohort membership by additional input variables, reduces the gap between top- and bottom-performing cohorts, without deteriorating overall recognition accuracy.Comment: Proc. Interspeech 202

    Individual, household and national factors associated with iron, vitamin A and zinc deficiencies among children aged 6-59 months in Nepal

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    Iron, vitamin A and zinc deficiencies are the top three micronutrients contributing to disability‐adjusted life years globally. The study assessed the factors associated with iron, vitamin A, and Zinc deficiencies among Nepalese children (n = 1709) aged 6–59 months using data from the 2016 Nepal National Micronutrient Status Survey. The following cut‐off points were applied: iron deficiency [ferritin 8.3 mg/L], vitamin A deficiency (retinol‐binding protein < 0.69 μmol/L) and zinc deficiency (serum zinc < 65 μg/dl for morning sample and <57µg/dl for afternoon sample). We used multiple logistic regression adjusted for sampling weights and clustering to examine the predictors of micronutrient deficiencies. The prevalence of iron depletion (ferritin), tissue iron (sTfR), vitamin A and zinc deficiencies were 36.7%, 27.6%, 8.5% and 20.4%, respectively. Children were more likely to be iron deficient (ferritin) if aged 6–23 months, stunted, and in a middle‐wealth quintile household. Vitamin A deficiency was associated with development region and was higher among children living in severe food‐insecure households and those who did not consume fruits. Zinc deficiency was higher among children in rural areas and the poorest wealth quintile. The Government of Nepal should focus on addressing micronutrient deficiencies in the early years, with emphasis on improving food systems, promote healthy diets, among younger and stunted children and provide social cash transfer targeting high‐risk development regions, poorest and food insecure households
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