111 research outputs found

    Performance analysis of global local mean square error criterion of stochastic linearization for nonlinear oscillator

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    The paper presents a performance analysis of global-local mean square error criterion of stochastic linearization for some nonlinear oscillators. This criterion of stochastic linearization for nonlinear oscillators bases on dual conception to the local mean square error criterion (LOMSEC). The algorithm is generally built to multi-degree of freedom (MDOF) nonlinear oscillators. Then, the performance analysis is carried out for two applications which comprise a rolling ship oscillation and two-degree of freedom one. The improvement on accuracy of the proposed criterion has been shown in comparison with the conventional Gaussian equivalent linearization (GEL)

    Patient satisfaction with health care services at a National Institute of Ophthalmology

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    Little is known about how patients in developing countries, such as Vietnam, are satisfied with eye care services. The purpose of this study was to assess the satisfaction with health services and its associated factors among patients attending a national institute of ophthalmology in Vietnam. In a cross-sectional study utilizing quantitative methods, 500 inpatients and their relatives attending a national institute of ophthalmology in Vietnam were approached for data collection. The results indicated that under 50% of the patients were satisfied with eye care services. However, when classified by level of satisfaction, only 6.8% were very satisfied with all domains of care. There was no significant difference in satisfaction by gender and income, while significant differences by department, residence, and education were found. Patients who were from rural areas, were better educated, and used the services of the glaucoma department, were more satisfied with eye care than those from urban areas, were less educated, and used the services of treatment-on-demand department. Multivariable regression detected 2 main factors, gender and location, associated with patient satisfaction. Patients who were female and came from rural and remote areas were more likely to be satisfied than patients who were male and living in urban areas. The study suggests that to continue to improve health care quality, it is important to eliminate differences in providing eye care services regardless of whether patients are male or female, and whether they come from a rural or urban area. Copyright © 2017 John Wiley & Sons, Ltd

    The roles of, activities of, and competencies for, community nursing services in rural Vietnam: Implications for policy decisions

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    Community health workforce plays a vital role in providing primary health care services as per the needs of residents; however, few studies have examined how nurses work within commune health centers (CHCs). Using qualitative methods including interviews and focus group discussions with key stakeholders, this study explores the roles, activities, and competencies required of community nursing services in rural districts within Vietnam. Two primary roles were identified: CHC nursing and family nursing. For the latter, in addition to providing people with general health care and health communication, they were expected to also deliver psychological care. CHC nursing fulfilled more roles and required four specific competencies: clinical care, communication, management, and planning/coordination activities. Despite these various roles serving people within a community, few ongoing efforts at either the local or national level are aimed at supporting these nurses. The study highlights the need for policy decisions via either developing a new job position policy or adapting the existing policy by integrating new roles into the existing positions of CHC nurses in Vietnam. © 2018 John Wiley & Sons, Ltd. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Nguyen Huy" is provided in this record*

    On the design of an optimum active mass-spring-inverted pendulum dynamic vibration absorber for the inverted pendulum type structure

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    A Dynamic Vibration Absorber (DVA) is appropriate equipment for vibration control in many kinds of engineering. In general, there are two main types of DVAs: the passive DVAs and the active DVAs. The paper presents a design of an active mass-spring-inverted pendulum DVA for the inverted pendulum type structure in case the external force is white noise process. The design is based on the optimum passive DVA as carried out in [4] and apply the optimum control force by minimizing the performance index. Numerical simulation which is done for an inverted pendulum structure in the ocean in three cases without DVA, with passive DVA, with active DVA shows that the active DVA is better than the passive one

    Một cơ chế quản lý hàng đợi tích cực cải tiến VBLUE trên môi trường truyển video

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    The rapid development of video streaming applications over the internet poses a growing challenge. The requirements for bandwidth capacity and latency of transmission package often change constantly. One of the queue management mechanisms commonly used to increase the performance and prevent the degradation of video transmission quality is the active queue management mechanism (AQM). However, though the internet is a good effort network it does not have distinctions among transmission packets on the network leading to a significant percentage of video data packet discarded by the network router upon the occurrence of lacking bandwidth on the traffic lines due to congestion. The impact of the lost video package degrading the quality of watching at the receiver may vary from negligible to unacceptable levels. This paper proposes an innovative solution using selected VBLUE to discard the package which is built in the BLUE active queue management mechanism. The simulation results on NS-2 are given to show the efficiency of VBLUE for increasing the significant quality of video streaming.Sự phát triển nhanh chóng các ứng dụng truyền video trên Internet đặt ra những thách thức ngày càng lớn. Các yêu cầu về khả năng băng thông và độ trễ truyền dẫn gói tin thường biến đổi liên tục. Một trong các cơ chế quản lý hàng đợi thường được sử dụng để tăng hiệu năng mạng và ngăn cản sự suy giảm chất lượng truyền video là cơ chế quản lý hàng đợi tích cực (AQM). Tuy nhiên, do mạng Internet là mạng mặc dù được xây dựng với nỗ lực tối đa nhưng chưa thể đảm bảo về QoS (best-effort network) và không có sự phân biệt giữa các gói tin truyền trên mạng dẫn đến tỷ lệ đáng kể các gói dữ liệu video bị loại bỏ bởi các bộ định tuyến mạng khi xảy ra tình trạng thiếu băng thông trên các đường truyền do bị tắc nghẽn. Ảnh hưởng của việc mất gói tin video làm suy giảm chất lượng xem ở phía máy nhận có thể thay đổi từ không đáng kể đến mức không thể chấp nhận được. Bài báo này đề xuất một giải pháp cải tiến VBLUE sử dụng lựa chọn loại bỏ gói tin được tích hợp ngay trong cơ chế hàng đợi tích cực BLUE. Các kết quả mô phỏng trên NS-2 đã cho thấy hiệu quả của VBLUE làm tăng chất lượng phát luồng video một cách đáng kể.  

    STUDY ON FLUORINATION AND HYDROGENATION IN TRANSPARENT CONDUCTING ZINC OXIDE THIN FILMS

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    Fluorination and hydrogenation are known as two methods for enhancing crystalline structural and electrical properties of ZnO material. The ZnO thin films normally require a low resistivity and a high transmittance for using as high-performance transparent electrodes in optoelectronic applications. In this study, we report successful preparation of fluorinated and hydrogenated ZnO thin films (FZO and HFZO) by using d.c. magnetron sputtering technique. The hydrogenation was carried out by depositing the films in hydrogen plasma atmosphere, while a highly-sintered body of ZnO and ZnF2 compound was employed as a sputtering target for the fluorination. The results show that the strong improvements in carrier concentration, mobility and resistivity of the FZO and HFZO films as compared to the pure ZnO films. The carrier concentration increases to 2x1020 cm-3 which is mainly due to the hydrogenation. The effect combination of the fluorination and the hydrogenation is responsibility for enhancing the mobility up to 43 cm2/Vs. These results give rise to two-order reduction in resistivity, from 0.06 Ohm.cm (ZnO) to 7.5x10-4 Ohm.cm (HFZO), which can be a good choice for thin-film electrode application. In addition, the crystalline structure and optical transmission of the films are also discussed

    Mechanism of an ATP-independent Protein Disaggregase - I. Structure of a Membrane Protein Aggregate Reveals a Mechanism of Recognition by its Chaperone

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    Protein aggregation is detrimental to the maintenance of proper protein homeostasis in all cells. To overcome this problem, cells have evolved a network of molecular chaperones to prevent protein aggregation and even reverse existing protein aggregates. The most extensively studied disaggregase systems are ATP-driven macromolecular machines. Recently, we reported an alternative disaggregase system in which the 38-kDa subunit of chloroplast signal recognition particle (cpSRP43) efficiently reverses the aggregation of its substrates, the light-harvesting chlorophyll a/b-binding (LHC) proteins, in the absence of external energy input. To understand the molecular mechanism of this novel activity, here we used biophysical and biochemical methods to characterize the structure and nature of LHC protein aggregates. We show that LHC proteins form micellar, disc-shaped aggregates that are kinetically stable and detergent-resistant. Despite the nonamyloidal nature, the LHC aggregates have a defined global organization, displaying the chaperone recognition motif on its solvent-accessible surface. These findings suggest an attractive mechanism for recognition of the LHC aggregate by cpSRP43 and provide important constraints to define the capability of this chaperone

    The Vietnamese Version of the Brief Illness Perception Questionnaire and the Beliefs about Medicines Questionnaire:Translation and Cross-cultural Adaptation

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    OBJECTIVE: To translate and cross-culturally adapt the Brief Illness Perception Questionnaire (BIPQ) and the Beliefs about Medicines Questionnaire (BMQ) into Vietnamese. METHODS: We followed the guideline by Beaton et al. (2000 & 2007). Stage I: two translators (informed and uninformed) translated the questionnaires. Stage II: the translations were synthesized. Stage III: back translation was performed by two translators fluent in both Vietnamese and English but naïve to the outcome measurement. Stage IV: seven experts reached consensus on the pre-final Vietnamese version (BIPQ-V and BMQ-V). Stage V: field test of the questionnaires on 16 twelve-year-old students and 31 Vietnamese patients. In addition, we determined the internal consistency and test-retest reliability of the questionnaires in 34 Vietnamese patients with acute coronary syndrome. RESULTS: All experts agreed that there was semantic, idiomatic, experiential, and conceptual equivalence between the original and pre-final Vietnamese versions of the BIPQ and BMQ. Cronbach's alpha coefficients of the internal consistency were acceptable for the BMQ-V Specific-Necessity (0.64), BMQ-V Specific-Concerns (0.62), and BMQ-V General-Harm (0.60), with the exception of BMQ-V General-Overuse (0.27). Intra-class correlation coefficients of the test-retest reliability was acceptable for the subscales of BMQ-V (range: 0.77-0.86), and BIPQ-V items (range: 0.62-0.85) with the exception of BIPQ-V 1 (0.44, 95% CI -014-0.72) and BIPQ-V 4 (0.57, 95% CI 0.22-0.81). CONCLUSIONS: The Vietnamese version of BIPQ and BMQ are reliable tools to assess illness perceptions and beliefs about medicines of patients with acute coronary syndrome. Psychometric properties of these questionnaires should be tested in different patient populations

    Composted tobacco waste increases the yield and organoleptic quality of leaf mustard

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    Tobacco (Nicotiana tabacum) waste is produced in many countries and is phytotoxic due to the alkaloid content; in Vietnam the waste is usually burned causing air pollution. We composted tobacco waste with chicken manure in different proportions—1 t of waste ± accelerant (C1 and C2); 0.8 t of waste + 0.2 t of chicken manure ± accelerant (C3 and C4); and 0.7 t of waste + 0.3 t of chicken manure ± accelerant (C5 and C6)—for 30 d in covered heaps. Three mixtures containing the accelerant (C2, C4, and C6) reached temperatures of ∼55 °C, that 5s, hot enough to suppress disease and weeds. Composting decreased the alkaloid content from ∼6,000 to ∼200 mg kg−1, and C4 with a C/N ratio of 19:1, was used in a field trial. The compost treatments (0, 10, 15, and 20 t ha−1) were combined fertilizer with phosphorus (40 kg ha−1), nitrogen (60 kg ha−1) and potassium (90 kg ha−1) for leaf mustard (Brassica integrifolia). The yield increased from ∼17 to ∼29 t ha−1 with the amount of compost applied, and the nitrate concentration decreased concomitantly from ∼67 to ∼42 mg NO3–N kg−1 fresh weight, presumably due to ongoing composting (nitrogen drawdown). Organoleptic evaluation showed a preference for the crops grown with the compost amendments. Whether remains to be seen whether one-off compost applications >20 t ha−1 and repeated, large applications provide additional, long-term production benefits, or if the benefits may be outweighed by the accumulation of persistent, phytotoxic alkaloids

    Red light emission of Mn doped beta-tricalcium phosphate -Ca3(PO4)2

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    This paper is the first report on the red light emission of manganese (Mn) doped beta-tricalcium phosphate (b-Ca3(PO4)2, TCP) synthesis by co-precipitation method followed by thermal annealing. The annealed Mn doped TCP phosphor showed dominant spheres with a diameter of about 500 nm. The influences of the Mn concentration, annealing temperature, and atmospheres on the photoluminescence intensities of the phosphors were investigated and the results indicate that the annealing temperatures and Mn concentrations are the main factors. The phosphor showed visible emission peaks appeared at about 660 nm and 580 nm results in from the 4T1-6A1 transitions within Mn2+ ion. The Mn-TCP phosphor may serve as a candidate for light-emitting diode application in agriculture lighting. Keywords. Hydroxyapatite; manganese; luminescence; tricalcium phosphate
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