21 research outputs found
Optimizing Boiler Efficiency by Data Mining Teciques: A Case Study
In a fertilizer plant, the steam boiler is the most important component. In order to keep the plant operating in the effective mode, the boiler efficiency must be observed continuously by several operators. When the trend of the boiler efficiency is going down, they may adjust the controlling parameters of the boiler to increase its efficiency. Since manual operation usually leads to unex-pectedly mistakes and hurts the efficiency of the system, we build an information system that plays the role of the operators in observing the boiler and adjusting the controlling parameters to stabilize the boiler efficiency. In this paper, we first introduce the architecture of the information system. We then present how to apply K-means and Fuzzy C-means algorithms to derive a knowledge base from the historical operational data of the boiler. Next, recurrent fuzzy neural network is employed to build a boiler simulator for evaluating which tuple of input values is the best optimal and then automatically adjusting controlling inputs of the boiler by the optimal val-ues. In order to prove the effectiveness of our system, we deployed it at Phu My Fertilizer Plant equipped with MARCHI boiler having capacity of 76-84 ton/h. We found that our system have improved the boiler efficiency about 0.28-1.12% in average and brought benefit about 57.000 USD/year to the Phu My Fertilizer Plant
Associations of Underlying Health Conditions With Anxiety and Depression Among Outpatients: Modification Effects of Suspected COVID-19 Symptoms, Health-Related and Preventive Behaviors
Objectives: We explored the association of underlying health conditions (UHC) with depression and anxiety, and examined the modification effects of suspected COVID-19 symptoms (S-COVID-19-S), health-related behaviors (HB), and preventive behaviors (PB).Methods: A cross-sectional study was conducted on 8,291 outpatients aged 18ā85 years, in 18 hospitals and health centers across Vietnam from 14th February to May 31, 2020. We collected the data regarding participant's characteristics, UHC, HB, PB, depression, and anxiety.Results: People with UHC had higher odds of depression (OR = 2.11; p < 0.001) and anxiety (OR = 2.86; p < 0.001) than those without UHC. The odds of depression and anxiety were significantly higher for those with UHC and S-COVID-19-S (p < 0.001); and were significantly lower for those had UHC and interacted with āunchanged/moreā physical activity (p < 0.001), or āunchanged/moreā drinking (p < 0.001 for only anxiety), or āunchanged/healthierā eating (p < 0.001), and high PB score (p < 0.001), as compared to those without UHC and without S-COVID-19-S, ānever/stopped/lessā physical activity, drinking, āless healthyā eating, and low PB score, respectively.Conclusion: S-COVID-19-S worsen psychological health in patients with UHC. Physical activity, drinking, healthier eating, and high PB score were protective factors
Power Splitting for MIMO Energy Harvesting in Multi-User Networks
Ā© 2017 IEEE. We consider a multicell multi-user multiple-input-multiple-output (MU-MIMO) network and propose the efficient design of precoding matrices for the sum throughput maximization under throughput QoS constraints and energy harvesting (EH) constraints for energy-constrained devices in both downlink (DL) and uplink (UL) transmissions. We employ power splitting (PS) approach at the receiver to ensure practical EH and information decoding (ID). The considered practical problem is quite complex due to highly non-convex objective and constraints. Towards this end, we develop a new path-following algorithm for its solution, which just requires a convex quadratic program at each iteration and promises quick convergence
Synthesis and characterization of the photoswitchable poly(methyl methacrylate- random-methacrylate spirooxazine)
Abstract The photoswitchable poly(methyl methacrylate-random-methacrylate spirooxazine) was synthesized via atom transfer radical polymerization with the feed mole ratio of MMA/MSp comonomer of about 5.5/1. Well-defined poly(methyl methacrylate- random-methacrylate spirooxazine) have been obtained with the average molecular weight (Mn) of 6500 g/mol and polydispersity of 1.21. The structure and properties of the resulting copolymers were characterized by proton nuclear magnetic resonance (1H NMR), gel permeation chromatography, Fourier Transform infrared, UV-visible spectroscopy, and differential scanning calorimetry. Moreover, the copolymer exhibited the erasable and rewritable photoimaging on the solid state film which could to be as potential candidate for optical data storage materials
N-Benzoyl dithieno[3,2-b:2ā²,3ā²-d]pyrrole-based hyperbranched polymers by direct arylation polymerization
Abstract Background Although poly(N-acyl dithieno[3,2-b:2ā²,3ā²-d]pyrrole)s have attracted great attention as a new class of conducting polymers with highly stabilized energy levels, hyperbranched polymers based on this monomer type have not yet been studied. Thus, this work aims at the synthesis of novel hyperbranched polymers containing N-benzoyl dithieno[3,23,2-b:2ā²,3ā²-d]pyrrole acceptor unit and 3-hexylthiophene donor moiety via the direct arylation polymerization method. Their structures, molecular weights and thermal properties were characterized via 1H NMR and FTIR spectroscopies, GPC, TGA, DSC and XRD measurements, and the optical properties were investigated by UVāvis and fluorescence spectroscopies. Results Hyperbranched conjugated polymers containing N-benzoyl dithieno[3,23,2-b:2ā²,3ā²-d]pyrrole acceptor unit and 3-hexylthiophene donor moiety, linked with either triphenylamine or triphenylbenzene as branching unit, were obtained via direct arylation polymerization of the N-benzoyl dithieno[3,23,2-b:2ā²,3ā²-d]pyrrole, 2,5-dibromo 3-hexylthiophene and tris(4-bromophenyl)amine (or 1,3,5-tris(4-bromophenyl)benzene) monomers. Organic solvent-soluble polymers with number-average molecular weights of around 18,000Ā gĀ molā1 were obtained in 80ā92% yields. The DSC and XRD results suggested that the branching structure hindered the stacking of polymer chains, leading to crystalline domains with less ordered packing in comparison with the linear analogous polymers. The results revealed that the hyperbranched polymer with triphenylbenzene as the branching unit exhibited a strong red-shift of the maximum absorption wavelength, attributed to a higher polymer stacking order as a result of the planar structure of triphenylbenzene. Conclusion Both hyperbranched polymers with triphenylamine/triphenylbenzene as branching moieties exhibited high structural order in thin films, which can be promising for organic solar cell applications. The UVāvis absorption of the hyperbranched polymer containing triphenylbenzene as branching unit was red-shifted as compared with the triphenylamine-containing polymer, as a result of a higher chain packing degree
The Asian project for collaborative derivation of reference intervals: (1) strategy and major results of standardized analytes
Background : A multicenter study conducted in Southeast
Asia to derive reference intervals (RIs) for 72 commonly
measured analytes (general chemistry, inflammatory
markers, hormones, etc.) featured centralized measurement
to clearly detect regionality in test results. The
results of 31 standardized analytes are reported, with the
remaining analytes presented in the next report.
Method : The study included 63 clinical laboratories from
South Korea, China, Vietnam, Malaysia, Indonesia, and
seven areas in Japan. A total of 3541 healthy individuals
aged 20 \u2013 65 years (Japan 2082, others 1459) were recruited
mostly from hospital workers using a well-defined common
protocol. All serum specimens were transported to Tokyo
at 12 80 \ub0 C and collectively measured using reagents from
four manufacturers. Three-level nested ANOVA was used
to quantitate variation (SD) of test results due to region,
sex, and age. A ratio of SD for a given factor over residual
SD (representing net between-individual variations) (SDR)
exceeding 0.3 was considered significant. Traceability of
RIs was ensured by recalibration using value-assigned reference
materials. RIs were derived parametrically.
Results : SDRs for sex and age were significant for 19 and
16 analytes, respectively. Regional difference was significant
for 11 analytes, including high density lipoprotein
(HDL)-cholesterol and inflammatory markers. However,
when the data were limited to those from Japan, regionality
was not observed in any of the analytes. Accordingly,
RIs were derived with or without partition by sex and
region.
Conclusions : RIs applicable to a wide area in Asia were
established for the majority of analytes with traceability to
reference measuring systems, whereas regional partitioning
was required for RIs of the other analytes
Isogeometric size optimization of bi-directional functionally graded beams under static loads
Oligosaccharides and Peptide Displayed on an Amphiphilic Polymer Enable Solid Phase Assay of Hapten Specific Antibodies
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Phylodynamics of Enterovirus A71-Associated Hand, Foot, and Mouth Disease in Viet Nam
Enterovirus A71 (EV-A71) is a major cause of hand, foot, and mouth disease (HFMD) and is particularly prevalent in parts of
Southeast Asia, affecting thousands of children and infants each year. Revealing the evolutionary and epidemiological dynamics
of EV-A71 through time and space is central to understanding its outbreak potential. We generated the full genome sequences of
200 EV-A71 strains sampled from various locations in Viet Nam between 2011 and 2013 and used these sequence data to determine
the evolutionary history and phylodynamics of EV-A71 in Viet Nam, providing estimates of the effective reproduction
number (Re) of the infection through time. In addition, we described the phylogeography of EV-A71 throughout Southeast Asia,
documenting patterns of viral gene flow. Accordingly, our analysis reveals that a rapid genogroup switch from C4 to B5 likely
took place during 2012 in Viet Nam. We show that the Re of subgenogroup C4 decreased during the time frame of sampling,
whereas that of B5 increased and remained >1 at the end of 2013, corresponding to a rise in B5 prevalence. Our study reveals
that the subgenogroup B5 virus that emerged into Viet Nam is closely related to variants that were responsible for large epidemics
in Malaysia and Taiwan and therefore extends our knowledge regarding its associated area of endemicity. Subgenogroup B5
evidently has the potential to cause more widespread outbreaks across Southeast Asia