109 research outputs found

    New H∞ control design for polytopic systems with mixed time-varying delays in state and input

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    This paper concerns with the problem of state-feedback H∞ control design for a class of linear systems with polytopic uncertainties and mixed time-varying delays in state and input. Our approach can be described as follows. We first construct a state-feedback controller based on the idea of parameter-dependent controller design. By constructing a new parameter-dependent Lyapunov-Krasovskii functional (LKF), we then derive new delay-dependent conditions in terms of linear matrix inequalities ensuring the exponential stability of the corresponding closed-loop system with a H∞ disturbance attenuation level. The effectiveness and applicability of the obtained results are demonstrated by practical examples

    Primary Cementless Bipolar Long Stem Hemiarthroplasty for Unstable Osteoporotic Intertrochanteric Fracture in the Elderly Patients

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    BACKGROUND: Intertrochanteric fracture (ITF) is a major part of fracture in femoral head fracture. 95% of ITF are found in elderly patients. Osteosynthese is the preferred method of choice. However, elderly patients had osteoporotic, combined with many of chronic disease conditions that increase the rate of osteosynthese failure. Hemiarthroplasty bipolar long-stem is a surgical method that helps patients relieve pain, facilitate early rehabilitation, limit long-term complications, and improve quality of life for patients. AIM: The aim of our study is to evaluate the clinical of result of primary cementless bipolar long stem hemiarthroplasty in treatment for unstable ITF in the elderly patients who have severe osteoporosis. METHODS: Between 01/2016 and 12/2017, 35 patients with ITF type A2.2 and A2.3 (AO) were included in our prospective study. These patients were over 70 years old and treatment by hemiarthroplasty cementless long stem at E hospital and Saint Paul hospital by one group surgeons. RESULTS: Mean age of studied subjects was 84.29 ± 6.17, the lowest was 71, the highest was 96; ratio male/female was 1/4. Follow-up of 35 patients for at least 6 months showed 88.6% caused by a low-energy injury; Average rehabilitation time was 4.63 ± 1.7 days. The average Harris point at the end was 90.4 ± 4.72. CONCLUSION: Primary cementless bipolar long stem hemiarthroplasty is one of good choices in treatment unstable ITF in elderly patients with severe osteoporosis helped patients improve the quality of life

    Proposal of MIMO Ultra-Wide Band Antenna with Low Mutual Coupling

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    In this paper, a new ultra-wide band (UWB) MIMO antenna is proposed. A MIMO antenna set consists of two single ultra-wide band antennas. This simple and compact MIMO antenna, which is designed to work from 3.1 GHz to 10.6 GHz, has a broad bandwidth with the VSWR ≤ 2. In addition, MIMO antenna characteristics such as radiation pattern, maximal gain are thoroughly investigated

    Multifactorial Evolutionary Algorithm For Clustered Minimum Routing Cost Problem

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    Minimum Routing Cost Clustered Tree Problem (CluMRCT) is applied in various fields in both theory and application. Because the CluMRCT is NP-Hard, the approximate approaches are suitable to find the solution for this problem. Recently, Multifactorial Evolutionary Algorithm (MFEA) has emerged as one of the most efficient approximation algorithms to deal with many different kinds of problems. Therefore, this paper studies to apply MFEA for solving CluMRCT problems. In the proposed MFEA, we focus on crossover and mutation operators which create a valid solution of CluMRCT problem in two levels: first level constructs spanning trees for graphs in clusters while the second level builds a spanning tree for connecting among clusters. To reduce the consuming resources, we will also introduce a new method of calculating the cost of CluMRCT solution. The proposed algorithm is experimented on numerous types of datasets. The experimental results demonstrate the effectiveness of the proposed algorithm, partially on large instance

    Comparison of Decontamination Standards

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    The quality of materials used in nuclear-related facilities is critical, especially the ease of decontamination of different paints and coatings. Standards describe different testing methods for classification. Nevertheless, compliance with these standards cannot be carried out negligibly from a safety point of view. In this study, a withdrawn Hungarian (MSZ-05 22.7662-83), an international ISO (ISO 8690:1988), and Russian (GOST 25146- 82) decontamination standard were compared. Four different paints were tested as part of this survey. The ease of decontamination varied mainly from poor to fair levels in the case of the Hungarian standard, while the ISO standard exhibited very good level. In the case of the Russian standard, only a theoretical comparison was carried out. Based on the results, it was found that a special epoxy-based coating can be recommended for isotope laboratories due to being the best material from an ease of decontamination point of view. From comparison of the standards considered here, it was found that the application of ISO standard is significantly faster and simpler than the withdrawn Hungarian standard. However, in the case of the Hungarian standard the data described the ease of decontamination in more details. The use of water or some other cleaning agents can be effective to remove 137 Cs and 60 Co contamination right after early identification. Isotope 137 Cs and 60 Co contamination of a surface can be cleaned quickly and effectively using distilled water for the 137 Cs isotope removal from the surfaces being several times easier than that of 60 Co

    Evolution of Native Kidney Function After Pancreas Transplantation Alone

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    peer reviewedIntroduction. This study investigated changes in kidney function over time among a cohort of patients undergoing pancreas transplantation alone (PTA) from January 2002 to December 2011. Patients and Methods. Ten of eighteen PTA patients bearing functioning grafts for at least 1 year were recruited for the analysis. Primary endpoints were changes in mean serum creatinine (SCr, mg/L) and mean estimated glomerular filtration rate (eGFR) using the 4-variable Levey-MDRD equation (mL/min/1.73 m2) comparing baseline (pretransplantation) to 6-month, 1-year, 3-year, and 5-year posttransplantation values. Mean follow-up time was 75.7 20.5 months (range, 46–106.5). Results. Baseline eGFR was 89.3 27.9 (range, 58–145). eGFR decreased to 75.7 26.2, 71 20.6, 66.5 14.8, and 62.1 11.2 at 6 months, 1, 3, and 5 years representing 15.2%, 20.5%, 15.8%, and 22.6% percentage decreases respectively (P .05 for all pairwise comparisons). The Baseline SCr was 8.6 2.3 mg/L (range, 5–13). SCr progressively increased to 10.1 3, 10.5 3.1, 10.9 3.1, and 11.3 1.7 at 6 months, 1, 3, and 5 years a 17.1%, 22%, 16.6%, and 19.9% increase respectively (P .05 for all pairwise comparisons). One of ten, 2/8, and 3/7 patients displayed an eGFR 60 at transplantation versus 3 and 5 years thereafter, respectively. No patient developed a SCr 25 mg/L or eGFR 30 or needed dialysis or kidney transplantation. Five of ten patients had micro-albuminuria or proteinuria before transplantation. Tacrolimus levels were within recommended therapeutic ranges over time. Conclusion. Kidney function deteriorated significantly after PTA. Understanding of risk factors for the development of renal impairment is important to preserve kidney function and to select appropriate candidates for PTA

    Kinematic and dynamic modelling for a class of hybrid robots composed of m local closed-loop linkages appended to an n-link serial manipulator

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    Recently, more and more hybrid robots have been designed to meet the increasing demand for a wide spectrum of applications. However, development of a general and systematic method for kinematic design and dynamic analysis for hybrid robots is rare. Most publications deal with the kinematic and dynamic issues for individual hybrid robots rather than any generalization. Hence, in this paper, we present a novel method for kinematic and dynamic modelling for a class of hybrid robots. First, a generic scheme for the kinematic design of a general hybrid robot mechanism is proposed. In this manner, the kinematic equation and the constraint equations for the robot class are derived in a generalized case. Second, in order to simplify the dynamic modelling and analysis of the complex hybrid robots, a Lemma about the analytical relationship among the generalized velocities of a hybrid robot system is proven in a generalized case as well. Last, examples of the kinematic and dynamic modelling of a newly designed hybrid robot are presented to demonstrate and validate the proposed method

    Influence of Temperature And Concentration of Ethanol on Properties of Borosilicate Glass Photonic Crystal Fiber Infiltrated by Water – Ethanol Mixture

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    In this paper, we present a numerical simulation of the properties of a photonic crystal fiber (PCF) made of borosilicate glass infiltrated by the water-ethanol mixture. We examine the influence of temperature and ethanol concentration for the refractive index, dispersion properties, effective mode area and confinement loss of the fundamental mode by a Lumerical simulation method. We also calculate the fundamental mode of the fiber infiltrated with a water-ethanol mixture with the concentration range of ethanol from 0% to 100% in the temperature range from 10°C to boiling point of ethanol. The results show that all fibers infiltrated with water-ethanol mixture have flat dispersion characteristics in the infrared range above 1.32. The best flatness exists for pure ethanol. Furthermore, it is possible to shift the zero-dispersion wavelength and modify fundamental properties of PCFs by both temperature and concentration of ethanol. The results obtained are important because of that we not only use their reasonable parameters for the design and manufacture but also use them in nonlinear phenomena and nonlinear applications of fibers as supercontinuum generation

    Numerical simulation of all-normal dispersion visible to near-infrared supercontinuum generation in photonic crystal fibers with core filled chloroform

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    This study proposes a photonic crystal fiber made of fused silica glass, with the core infiltrated with chloroform as a new source of supercontinuum (SC) spectrum. We numerically study the guiding properties of the fiber structure in terms of characteristic dispersion and mode area of the fundamental mode. Based on the results, we optimized the structural geometries of the CHCl3-core photonic crystal fiber to support the broadband SC generations. The fiber structure with a lattice constant of 1 μm, a filling factor of 0.8, and the diameter of the first-ring air holes equaling 0.5 μm operates in all-normal dispersion. The SC with a broadened spectral bandwidth of 0.64 to 1.80 μm is formed by using a pump pulse with a wavelength of 850 nm, 120 fs duration, and power of 0.833 kW. That fiber would be a good candidate for all-fiber SC sources as cost-effective alternative to glass core fibers
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