21 research outputs found

    Optimizing Boiler Efficiency by Data Mining Teciques: A Case Study

    Get PDF
    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

    Get PDF
    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 18ā€“85 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 ā€œunchanged/moreā€ physical activity (p < 0.001), or ā€œunchanged/moreā€ drinking (p < 0.001 for only anxiety), or ā€œunchanged/healthierā€ eating (p < 0.001), and high PB score (p < 0.001), as compared to those without UHC and without S-COVID-19-S, ā€œnever/stopped/lessā€ physical activity, drinking, ā€œless 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

    No full text
    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)

    No full text
    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:2ā€²,3ā€²-d]pyrrole-based hyperbranched polymers by direct arylation polymerization

    No full text
    Abstract Background Although poly(N-acyl dithieno[3,2-b:2ā€²,3ā€²-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:2ā€²,3ā€²-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 UVā€“vis and fluorescence spectroscopies. Results Hyperbranched conjugated polymers containing N-benzoyl dithieno[3,23,2-b:2ā€²,3ā€²-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:2ā€²,3ā€²-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 molāˆ’1 were obtained in 80ā€“92% 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 UVā€“vis 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

    Get PDF
    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
    corecore