朝鐵重油動車の成績

AB生 朝鮮鐵道協會會誌 1932 朝鮮鐵道協會會誌 Vol.11 No.9

Control system modeling of stock management for civil infrastructure

Masato Abé 국제구조공학회 2015 Smart Structures and Systems, An International Jou Vol.15 No.3

Management of infrastructure stock is essential in sustainability of society, and its analysis andoptimization are studied in the light of control system modeling in this paper. At the first part of the paper,cost of stock management is analyzed based on macroscopic statistics on infrastructure stock andeconomical growth. Stock management burden relative to economy is observed to become larger at loweconomic growth periods in developed economies. Then, control system modeling of stock management isintroduced and by augmenting maintenance actions as control input, dynamic behavior of stock is simulatedand compared with existing time history statistics. Assuming steady state conditions, applicability of themodel to cross sectional data is also demonstrated. The proposed model is enhanced so that both preventiveand corrective maintenance can be included as system inputs, i.e., feedforward and feedback control inputs. Optimal management strategy to achieve specified deteriorated stock level with minimal cost, expressed interms of preventive and corrective maintenance actions, is derived based on estimated parameter values forcorrosion of steel bridges. Relative cost effectiveness of preventive maintenance is shown when targetdeteriorated stock level is lower.

Fast response time of micropixels with in-plane switching of positive liquid crystals using crossed patterned electrodes

Clément Abélard,Aurélien Suhm,Benoit Racine,Umberto Rossini,François Templier 한국정보디스플레이학회 2019 Journal of information display Vol.20 No.3

Demonstrated herein is a fast in-plane switching (IPS) cell with positive dielectric anisotropy liquid crystals using crossed patterned electrodes in three different conditions. The ineffectiveness of one of these three structures due to the ‘Faraday cage’ effect was shown. With another structure, a fast response time was also shown to be impossible to achieve due to several contrast issues. In the third structure, a fast response time was achieved due to a combination of high-driving and crossed patterned electrodes allowing fast turn-off. Two of the three structures was manufactured. With the first one, an experiment confirmed the ‘Faraday cage’ effect. In the second structure, a response time four to eight times faster than the conventional IPS mode was experimentally demonstrated using two different kinds of liquid crystal.

A probabilistic analysis of Miner’s law for different loading conditions

Sergio Blasón,José A.F.O. Correia,Abílio M.P. De Jesus,Rui A.B. Calçada,Alfonso Fernández-Canteli 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.60 No.1

In this paper, the normalized variable V=(log N-B)(log Δσ-C), as derived from the probabilistic S-N field of Castillo and Canteli, is taken as a reference for calculation of damage accumulation and probability of failure using the Miner number in scenarios of variable amplitude loading. Alternative damage measures, such as the classical Miner and logarithmic Miner, are also considered for comparison between theoretical lifetime prediction and experimental data. The suitability of this approach is confirmed for it provides safe lifetime prediction when applied to fatigue data obtained for riveted joints made of a puddle iron original from the Fão bridge, as well as for data from experimental programs published elsewhere carried out for different materials (aluminium and concrete specimens) under distinct variable loading histories.

Strain energy-based fatigue life prediction under variable amplitude loadings

Shun-Peng Zhu,Peng Yue,José Correia,Sergio Blasón,Abílio De Jesus,Qingyuan Wang 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.66 No.2

With the aim to evaluate the fatigue damage accumulation and predict the residual life of engineering components under variable amplitude loadings, this paper proposed a new strain energy-based damage accumulation model by considering both effects of mean stress and load interaction on fatigue life in a low cycle fatigue (LCF) regime. Moreover, an integrated procedure is elaborated for facilitating its application based on S-N curve and loading conditions. Eight experimental datasets of aluminum alloys and steels are utilized for model validation and comparison. Through comparing experimental results with model predictions by the proposed, Miner’s rule, damaged stress model (DSM) and damaged energy model (DEM), results show that the proposed one provides more accurate predictions than others, which can be extended for further application under multi-level stress loadings.

Discrete-time Analysis of a Robust Model Reference Adaptive Sliding Mode Control

Deise Maria Cirolini Milbradt,Guilherme Vieira Hollweg,Hilton Abílio Gründling,Paulo Jefferson Dias de Oliveira Evald 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.5

In real-world applications, plants with parametric variations and unmodelled dynamics are very common, and, in most cases, fixed-gain controllers can not ensure global stability and hardly have high performance for large system variations. To overcome this challenge, this paper presents a Robust Model Reference Adaptive Sliding Mode Control, whose structure combines a Robust Model Reference Adaptive controller (RMRAC) and an adaptive first-order Sliding Mode controller (SMC). Its discrete-time robustness analysis and stability proofs by means of Lyapunov theory are provided. The mathematical analyses show that this hybrid adaptive controller is robust to parametric variations and unmodelled plant dynamics. Besides, it ensures that tracking error tends to a residual set in steady state, maintaining global stability. Simulation results are presented to show the controller effectiveness applied in a non-minimum phase unstable plant with unmodelled dynamics. Furthermore, a comparison with a Proportional-Resonant controller is also provided.

Systolic blood pressure variability within 120 hours of admission predicts the functional outcomes at discharge of patients with acute ischemic stroke

Pedro Tiago,Pereira Pedro,Costa Ana Sofia,Almeida Fábio,Loureiro Maria Luísa,Alfaiate Teresa,Gonçalves Abílio 대한신경집중치료학회 2022 대한신경집중치료학회지 Vol.15 No.1

Background: Blood pressure variability (BPV) is a predictor of short- and long-term disability in patients with acute ischemic stroke (AIS). Its effect on more immediate functional outcomes has been seldom studied, and the results are inconsistent. We aimed to determine the role of BPV during the first 5 days of hospitalization in functional status at the time of discharge of patients with AIS.Methods: We enrolled 134 patients diagnosed with AIS and BPV using standard deviation and coefficient of variation (CV %). These were associated with the dichotomized modified Rankin Scale at discharge using logistic regression. Results: Patients with unfavorable outcomes were significantly older (P=0.014), had a lower body mass index (P=0.001), were less likely to present with dyslipidemia (P=0.001), had lower serum triglyceride levels (P=0.012), had a longer hospitalization period (P<0.001), and had a higher mean National Institutes of Health Stroke Scale score at admission (P<0.001). After adjusting for multiple confounders, the CV % of systolic blood pressure (SBP) in the first 120 hours after admission had a significant effect on functional disability at discharge. Conclusion: Variability in SBP in the first 5 days of hospitalization had a deleterious effect on the functional outcomes at discharge of patients with AIS. The role of diabolic blood pressure variability seems to be significant only in the first 24 hours of admission; however, further research is required.

A Modified Robust Adaptive Super-twisting Sliding Mode Controller for Grid-connected Converters

Guilherme Vieira Hollweg,Wencong Su,Paulo Jefferson Dias de Oliveira Evald,Rodrigo Varella Tambara,Hilton Abílio Gründling 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.10

This work introduces the application of a new adaptive control structure, which is a modification of the robust model reference adaptive controller (RMRAC) and adaptive super-twisting sliding mode (ASTSM). This controller was previously proposed in the literature and applied to the current control of a grid-connected converter under uncertain grid environments. However, its STSM structure used the tracking error signal function as a sliding surface, which tends to impose considerable chattering in the system. The proposed controller maintains the characteristics of the known structure but replaces the signal function in the STSM equations with a sigmoid function, reducing the current tracking error and improving the system regulation since it is smoother. As the control structure lies in RMRAC theory and some core equations change, stability analysis of the adaptation algorithm is also carried out. Experimental results in a 7.5 kW converter are presented in which the known RMRAC-ASTSM controller presents 2.45% total harmonic distortion while the modified adaptive structure obtains 2.22% total harmonic distortion and better regulation performance.

Major Chemical Constituents of Supercritical Carbon Dioxide Extract of Pandanus odorus Leaves

N. N. Ab Rahman,M. N. Hassan,A. Omar,M. O. Ab Kadir 한국생약학회 1999 Natural Product Sciences Vol.5 No.2

Supercritical carbon dioxide was used as a solvent in the extraction of freeze-dried Pandanus odorus leaves. Analysis of the extract with GC-MS showed that Pandanus odorus leaves contain nutritional constituents such as α-tocopherol (Vitamin E) and squalene. The contents of α-tocopherol and squalene extracted from freeze-dried ground Pandanus odorus leaves at pressures ranging from 80 to 200 ㎏·㎝^(-2) and temperatures between 40 to 80℃ were 134∼300 ppm and 750-1,200 ppm respectively. The highest yield was obtained at 200 ㎏·㎝^(-2) and 40℃. Other major components identified were hexadecanoic acid, 9,12,15-octadecatrien-1-ol, campesterol, stigmasterol and β-sitosterol.

Omega-3 fatty acids and the treatment of depression: a review of scientific evidence

Ab Latif Wani,Sajad Ahmad Bhat,Anjum Ara 한국한의학연구원 2015 Integrative Medicine Research Vol.4 No.3

Depression is a condition in which an individual feels lethargic, irritable, and guilty, has difficulty and trouble, no enjoyment in life, mood swings, sometimes suicidal ideation and thoughts, and loss of pleasure in activities. There are hundreds of millions of individuals suffering from major depression disorder all over the world. This leads to a considerable portion of the economy going for treatment as large amounts of money are spent on drugs every year. Pharmaceutical drugs are not very effective and they also have side effects that compound the problem. There are number of studies which shows that omega-3 fatty acids are proving to be very effective against the treatment of major depression disorder and other psychiatric disorders. However, the data regarding the efficacy of omega-3 fatty acids in depression treatment are conflicted. This article reviews the recent research showing the relation between omega-3 fatty acids and depression. The roles of the omega-3 fatty acids in the treatment of depression are being studied with increased pace in the last decade due to heightened prevalence of depression. It is emphasized that omega-3 fatty acids have no record of associated side effects, which deserves greater attention for further research.