89 research outputs found
Makespan Minimization in Re-entrant Permutation Flow Shops
Re-entrant permutation flow shop problems occur in practical applications such as wafer manufacturing, paint shops, mold and die processes and textile industry. A re-entrant material flow means that the production jobs need to visit at least one working station multiple times. A comprehensive review gives an overview of the literature on re-entrant scheduling. The influence of missing operations received just little attention so far and splitting the jobs into sublots was not examined in re-entrant permutation flow shops before. The computational complexity of makespan minimization in re-entrant permutation flow shop problems requires heuristic solution approaches for large problem sizes. The problem provides promising structural properties for the application of a variable neighborhood search because of the repeated processing of jobs on several machines. Furthermore the different characteristics of lot streaming and their impact on the makespan of a schedule are examined in this thesis and the heuristic solution methods are adjusted to manage the problem’s extension
Investigating the use of activity trackers to observe high-risk work environments
The New Zealand forestry industry has the country's highest rate of workplace fatalities. The reasons are not well studied or understood and no large-scale systematic physical and physiological data has been recorded to investigate this. Current research focusses on developing mechanised solutions and changing worker behaviour. We believe the first step in identifying any successful solution is to develop a fine-grained understanding of the physical context of forestry work by performing large-scale data collection of the levels of physical activity the workers engage in as well as their sleep patterns over extended periods of time. Our goal is to use lightweight, wearable technology (so-called activity trackers) to collect this data. In order to do so we need a clear understanding of the capabilities and limitations of such devices, both in general and in the proposed use environment for forestry workers. In this paper we present the results of user studies and comparisons of six activity trackers and three mobile phone applications used to track activity and sleep. We also discuss our initial pilot study with forestry workers and discuss the problems encountered using the trackers in the environment
Chaotic properties of a turbulent isotropic fluid
By tracking the divergence of two initially close trajectories in phase space
in an Eulerian approach to forced turbulence, the relation between the maximal
Lyapunov exponent , and the Reynolds number is measured using
direct numerical simulations, performed on up to collocation points.
The Lyapunov exponent is found to solely depend on the Reynolds number with
and that after a transient period the divergence of
trajectories grows at the same rate at all scales. Finally a linear divergence
is seen that is dependent on the energy forcing rate. Links are made with other
chaotic systems.Comment: 8 pages, 8 figure
Quantifying turbulence from field measurements at a mixed low tidal energy site
© 2015 Elsevier Ltd. This study explores typical characteristics of the mean and turbulent profiles at a mixed low tidal energy site (40 m mean water depth) where the waves have limited effects on the currents. The turbulence profiles were derived from secondary current data using a 5-beam ADCP which was optimised for wave measurements. The tidal currents have peak flows of ~1 m/s during spring tide. The turbulence intensity is no less than 10% at peak flows and compares well with values at other tidal channels (at ~5 m from seabed). The Reynolds stresses show symmetry at the neap tide but less so for the spring tide. Although the qualitative profiles of TKE are similar between the neap and spring tides, the values of TKE for flood flow are the largest throughout the deployment. The integral length scales are in good agreement with theory, and with estimates based on the mixing length concept. The measured turbulence parameters are sensitive to flow inhomogeneity, Doppler noise, and ADCP tilt. The findings demonstrate the practical benefits of exploiting secondary current data at a mixed low tidal energy site for estimating typical turbulence characteristics; such information can be used to define design standards and protocols for marine energy devices
Genetic Variation in ABCC4 and CFTR and Acute Pancreatitis during Treatment of Pediatric Acute Lymphoblastic Leukemia
Background: Acute pancreatitis (AP) is a serious, mechanistically not entirely resolved side effect of L-asparaginase-containing treatment for acute lymphoblastic leukemia (ALL). To find new candidate variations for AP, we conducted a genome-wide association study (GWAS). Methods: In all, 1,004,623 single-nucleotide variants (SNVs) were analyzed in 51 pediatric ALL patients with AP (cases) and 1388 patients without AP (controls). Replication used independent patients. Results: The top-ranked SNV (rs4148513) was located within the ABCC4 gene (odds ratio (OR) 84.1; p = 1.04 × 10−14). Independent replication of our 20 top SNVs was not supportive of initial results, partly because rare variants were neither present in cases nor present in controls. However, results of combined analysis (GWAS and replication cohorts) remained significant (e.g., rs4148513; OR = 47.2; p = 7.31 × 10−9). Subsequently, we sequenced the entire ABCC4 gene and its close relative, the cystic fibrosis associated CFTR gene, a strong AP candidate gene, in 48 cases and 47 controls. Six AP-associated variants in ABCC4 and one variant in CFTR were detected. Replication confirmed the six ABCC4 variants but not the CFTR variant. Conclusions: Genetic variation within the ABCC4 gene was associated with AP during the treatment of ALL. No association of AP with CFTR was observed. Larger international studies are necessary to more conclusively assess the risk of rare clinical phenotypes
Diversity analysis of cotton (Gossypium hirsutum L.) germplasm using the CottonSNP63K Array
Cotton germplasm resources contain beneficial alleles that can be exploited to develop germplasm adapted to emerging environmental and climate conditions. Accessions and lines have traditionally been characterized based on phenotypes, but phenotypic profiles are limited by the cost, time, and space required to make visual observations and measurements. With advances in molecular genetic methods, genotypic profiles are increasingly able to identify differences among accessions due to the larger number of genetic markers that can be measured. A combination of both methods would greatly enhance our ability to characterize germplasm resources. Recent efforts have culminated in the identification of sufficient SNP markers to establish high-throughput genotyping systems, such as the CottonSNP63K array, which enables a researcher to efficiently analyze large numbers of SNP markers and obtain highly repeatable results. In the current investigation, we have utilized the SNP array for analyzing genetic diversity primarily among cotton cultivars, making comparisons to SSR-based phylogenetic analyses, and identifying loci associated with seed nutritional traits. (Résumé d'auteur
Visualizing the Effects of rTMS in a Patient Sample: Small N vs. Group Level Analysis
The use of transcranial magnetic stimulation (TMS) to assess changes in cortical excitability is a tool used with increased prevalence in healthy and impaired populations. One factor of concern with this technique is how to achieve adequate statistical power given constraints of a small number of subjects and variability in responses. This paper compares a single pulse excitability measure using traditional group-level statistics vs single subject analyses in a patient population of subjects with focal hand dystonia, pre and post repetitive TMS (rTMS). Results show significant differences in cortical excitability for 4/5 subjects using a split middle line analysis on plots of individual subject data. Group level statistics (ANOVA), however, did not detect any significant findings. The consideration of single subject statistics for TMS excitability measures may assist researchers in describing the variably of rTMS outcome measures
Perancangan Peraga LED Terprogram Berbasis Mikrokontroler AT89C52
Dengan tersedianya mikrokontroler yang memiliki berbagai fasilitas serta murahnya
harga PC yang ditawarkan, maka peluang untuk merancang peralatan pengendalian LED untuk
berbagai keperluan menjadi sangat terbuka. Tujuan dari penelitian ini adalah merancang dan
menguji peraga LED terprogram berbasis mikrokontroler AT89C52. Alat penampil LED matrik
dirancang data-nya bisa dimasukan secara otomatis, sehingga LED dapat menampilkan data
dengan segera. Perancangan sistem penampil LED matrik yang dibuat meliputi dua bagian
utama yaitu bagian perangkat keras dan bagian perangkat lunak. Perangkat keras meliputi
mikrokontroler AT89C52 sebagai pusat pengontrol, penggerak kolom dan penggerak baris serta
LED matrik untuk menampilkan data. Perangkat lunak meliputi bahasa mesin mikrokontroler
dan untuk berhubungan dengan PC menggunakan Borland Delphi. Pengujian dilakukan dengan
membandingkan tampilan LED matrik dengan data masukan dari PC. Alat ini dapat
mengendalikan dan menampilkan LED sesuai data yang diberikan. LED matrik dapat
menampilkan empat baris teks yang masing-masing baris maksimal enam karakter, gambar
serta animasi running text (teks berjalan)
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